ubsan.c (ubsan_expand_null_ifn): Use _v1 suffixed type mismatch builtins...

	* ubsan.c (ubsan_expand_null_ifn): Use _v1 suffixed type mismatch
	builtins, store max (log2 (align), 0) into uchar field instead of
	align into uptr field.
	(ubsan_expand_objsize_ifn): Use _v1 suffixed type mismatch builtins,
	store uchar 0 field instead of uptr 0 field.
	(instrument_nonnull_return): Use _v1 suffixed nonnull return builtin,
	instead of passing one address of struct with 2 locations pass
	two addresses of structs with 1 location each.
	* sanitizer.def (BUILT_IN_UBSAN_HANDLE_TYPE_MISMATCH,
	BUILT_IN_UBSAN_HANDLE_TYPE_MISMATCH_ABORT,
	BUILT_IN_UBSAN_HANDLE_NONNULL_RETURN,
	BUILT_IN_UBSAN_HANDLE_NONNULL_RETURN_ABORT): Removed.
	(BUILT_IN_UBSAN_HANDLE_TYPE_MISMATCH_V1,
	BUILT_IN_UBSAN_HANDLE_TYPE_MISMATCH_V1_ABORT,
	BUILT_IN_UBSAN_HANDLE_NONNULL_RETURN_V1,
	BUILT_IN_UBSAN_HANDLE_NONNULL_RETURN_V1_ABORT): New builtins.

	* c-c++-common/ubsan/float-cast-overflow-1.c: Drop value keyword
	from expected output regexps.
	* c-c++-common/ubsan/float-cast-overflow-2.c: Likewise.
	* c-c++-common/ubsan/float-cast-overflow-3.c: Likewise.
	* c-c++-common/ubsan/float-cast-overflow-4.c: Likewise.
	* c-c++-common/ubsan/float-cast-overflow-5.c: Likewise.
	* c-c++-common/ubsan/float-cast-overflow-6.c: Likewise.
	* c-c++-common/ubsan/float-cast-overflow-8.c: Likewise.
	* c-c++-common/ubsan/float-cast-overflow-9.c: Likewise.
	* c-c++-common/ubsan/float-cast-overflow-10.c: Likewise.
	* g++.dg/ubsan/float-cast-overflow-bf.C: Likewise.
	* gcc.dg/ubsan/float-cast-overflow-bf.c: Likewise.
	* g++.dg/asan/default-options-1.C (__asan_default_options): Add
	used attribute.
	* g++.dg/asan/asan_test.C: Run with ASAN_OPTIONS=handle_segv=2
	in the environment.

	* All source files: Merge from upstream 315899.
        * asan/Makefile.am (nodist_saninclude_HEADERS): Add
	include/sanitizer/tsan_interface.h.
        * asan/libtool-version: Bump the libasan SONAME.
	* lsan/Makefile.am (sanitizer_lsan_files): Add lsan_common_mac.cc.
	(lsan_files): Add lsan_linux.cc, lsan_mac.cc and lsan_malloc_mac.cc.
        * sanitizer_common/Makefile.am (sanitizer_common_files): Add
	sancov_flags.cc, sanitizer_allocator_checks.cc,
	sanitizer_coverage_libcdep_new.cc, sanitizer_errno.cc,
	sanitizer_file.cc, sanitizer_mac_libcdep.cc and
	sanitizer_stoptheworld_mac.cc.  Remove sanitizer_coverage_libcdep.cc
	and sanitizer_coverage_mapping_libcdep.cc.
        * tsan/Makefile.am (tsan_files): Add tsan_external.cc.
	* ubsan/Makefile.am (DEFS): Add -DUBSAN_CAN_USE_CXXABI=1.
	(ubsan_files): Add ubsan_init_standalone.cc and
	ubsan_signals_standalone.cc.
	* ubsan/libtool-version: Bump the libubsan SONAME.
        * asan/Makefile.in: Regenerate.
        * lsan/Makefile.in: Regenerate.
        * sanitizer_common/Makefile.in: Regenerate.
        * tsan/Makefile.in: Regenerate.
	* ubsan/Makefile.in: Regenerate.

From-SVN: r253887

261 files changed, 14251 insertions, 5763 deletions

diff --git a/libsanitizer/ChangeLog b/libsanitizer/ChangeLog
index b893e852e90..1cd9a1bf320 100644
--- a/libsanitizer/ChangeLog
+++ b/libsanitizer/ChangeLog
@@ -1,3 +1,28 @@
+2017-10-19  Jakub Jelinek  <jakub@redhat.com>
+
+	* All source files: Merge from upstream 315899.
+        * asan/Makefile.am (nodist_saninclude_HEADERS): Add
+	include/sanitizer/tsan_interface.h.
+        * asan/libtool-version: Bump the libasan SONAME.
+	* lsan/Makefile.am (sanitizer_lsan_files): Add lsan_common_mac.cc.
+	(lsan_files): Add lsan_linux.cc, lsan_mac.cc and lsan_malloc_mac.cc.
+        * sanitizer_common/Makefile.am (sanitizer_common_files): Add
+	sancov_flags.cc, sanitizer_allocator_checks.cc,
+	sanitizer_coverage_libcdep_new.cc, sanitizer_errno.cc,
+	sanitizer_file.cc, sanitizer_mac_libcdep.cc and
+	sanitizer_stoptheworld_mac.cc.  Remove sanitizer_coverage_libcdep.cc
+	and sanitizer_coverage_mapping_libcdep.cc.
+        * tsan/Makefile.am (tsan_files): Add tsan_external.cc.
+	* ubsan/Makefile.am (DEFS): Add -DUBSAN_CAN_USE_CXXABI=1.
+	(ubsan_files): Add ubsan_init_standalone.cc and
+	ubsan_signals_standalone.cc.
+	* ubsan/libtool-version: Bump the libubsan SONAME.
+        * asan/Makefile.in: Regenerate.
+        * lsan/Makefile.in: Regenerate.
+        * sanitizer_common/Makefile.in: Regenerate.
+        * tsan/Makefile.in: Regenerate.
+	* ubsan/Makefile.in: Regenerate.
+
 2017-10-05  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR sanitizer/82379
diff --git a/libsanitizer/MERGE b/libsanitizer/MERGE
index 21c2f390e97..c92f826445e 100644
--- a/libsanitizer/MERGE
+++ b/libsanitizer/MERGE
@@ -1,4 +1,4 @@
-285547
+315899
 
 The first line of this file holds the svn revision number of the
 last merge done from the master library sources.
diff --git a/libsanitizer/Makefile.am b/libsanitizer/Makefile.am
index 6afb2b0e048..018f0b06823 100644
--- a/libsanitizer/Makefile.am
+++ b/libsanitizer/Makefile.am
@@ -17,7 +17,8 @@ endif
 SUBDIRS += lsan asan ubsan
 nodist_saninclude_HEADERS += \
   include/sanitizer/lsan_interface.h \
-  include/sanitizer/asan_interface.h
+  include/sanitizer/asan_interface.h \
+  include/sanitizer/tsan_interface.h
 if TSAN_SUPPORTED
 SUBDIRS += tsan
 endif
diff --git a/libsanitizer/Makefile.in b/libsanitizer/Makefile.in
index 1f4bb8cd6bb..fd0f7fd78f9 100644
--- a/libsanitizer/Makefile.in
+++ b/libsanitizer/Makefile.in
@@ -54,7 +54,8 @@ host_triplet = @host@
 target_triplet = @target@
 @SANITIZER_SUPPORTED_TRUE@am__append_1 = include/sanitizer/common_interface_defs.h \
 @SANITIZER_SUPPORTED_TRUE@	include/sanitizer/lsan_interface.h \
-@SANITIZER_SUPPORTED_TRUE@	include/sanitizer/asan_interface.h
+@SANITIZER_SUPPORTED_TRUE@	include/sanitizer/asan_interface.h \
+@SANITIZER_SUPPORTED_TRUE@	include/sanitizer/tsan_interface.h
 @SANITIZER_SUPPORTED_TRUE@@USING_MAC_INTERPOSE_FALSE@am__append_2 = interception
 @LIBBACKTRACE_SUPPORTED_TRUE@@SANITIZER_SUPPORTED_TRUE@am__append_3 = libbacktrace
 @SANITIZER_SUPPORTED_TRUE@@TSAN_SUPPORTED_TRUE@am__append_4 = tsan
diff --git a/libsanitizer/asan/Makefile.am b/libsanitizer/asan/Makefile.am
index 43377a95622..709b6c8d75b 100644
--- a/libsanitizer/asan/Makefile.am
+++ b/libsanitizer/asan/Makefile.am
@@ -25,6 +25,7 @@ asan_files = \
 	asan_flags.cc \
 	asan_globals.cc \
 	asan_interceptors.cc \
+	asan_interceptors_memintrinsics.cc \
 	asan_linux.cc \
 	asan_mac.cc \
 	asan_malloc_linux.cc \
@@ -36,6 +37,7 @@ asan_files = \
 	asan_posix.cc \
 	asan_report.cc \
 	asan_rtl.cc \
+	asan_shadow_setup.cc \
 	asan_stack.cc \
 	asan_stats.cc \
 	asan_suppressions.cc \
diff --git a/libsanitizer/asan/Makefile.in b/libsanitizer/asan/Makefile.in
index 4dad60ba1ae..db3c3ced8b9 100644
--- a/libsanitizer/asan/Makefile.in
+++ b/libsanitizer/asan/Makefile.in
@@ -114,12 +114,13 @@ libasan_la_DEPENDENCIES =  \
 am__objects_1 = asan_activation.lo asan_allocator.lo asan_debugging.lo \
 	asan_descriptions.lo asan_errors.lo asan_fake_stack.lo \
 	asan_flags.lo asan_globals.lo asan_interceptors.lo \
-	asan_linux.lo asan_mac.lo asan_malloc_linux.lo \
-	asan_malloc_mac.lo asan_malloc_win.lo asan_memory_profile.lo \
-	asan_new_delete.lo asan_poisoning.lo asan_posix.lo \
-	asan_report.lo asan_rtl.lo asan_stack.lo asan_stats.lo \
-	asan_suppressions.lo asan_thread.lo asan_win.lo \
-	asan_win_dll_thunk.lo asan_win_dynamic_runtime_thunk.lo
+	asan_interceptors_memintrinsics.lo asan_linux.lo asan_mac.lo \
+	asan_malloc_linux.lo asan_malloc_mac.lo asan_malloc_win.lo \
+	asan_memory_profile.lo asan_new_delete.lo asan_poisoning.lo \
+	asan_posix.lo asan_report.lo asan_rtl.lo asan_shadow_setup.lo \
+	asan_stack.lo asan_stats.lo asan_suppressions.lo \
+	asan_thread.lo asan_win.lo asan_win_dll_thunk.lo \
+	asan_win_dynamic_runtime_thunk.lo
 am_libasan_la_OBJECTS = $(am__objects_1)
 libasan_la_OBJECTS = $(am_libasan_la_OBJECTS)
 libasan_la_LINK = $(LIBTOOL) --tag=CXX $(AM_LIBTOOLFLAGS) \
@@ -317,6 +318,7 @@ asan_files = \
 	asan_flags.cc \
 	asan_globals.cc \
 	asan_interceptors.cc \
+	asan_interceptors_memintrinsics.cc \
 	asan_linux.cc \
 	asan_mac.cc \
 	asan_malloc_linux.cc \
@@ -328,6 +330,7 @@ asan_files = \
 	asan_posix.cc \
 	asan_report.cc \
 	asan_rtl.cc \
+	asan_shadow_setup.cc \
 	asan_stack.cc \
 	asan_stats.cc \
 	asan_suppressions.cc \
@@ -466,6 +469,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/asan_flags.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/asan_globals.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/asan_interceptors.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/asan_interceptors_memintrinsics.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/asan_linux.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/asan_mac.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/asan_malloc_linux.Plo@am__quote@
@@ -477,6 +481,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/asan_posix.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/asan_report.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/asan_rtl.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/asan_shadow_setup.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/asan_stack.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/asan_stats.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/asan_suppressions.Plo@am__quote@
diff --git a/libsanitizer/asan/asan_activation.cc b/libsanitizer/asan/asan_activation.cc
index ecd767c5985..599e56b9e3f 100644
--- a/libsanitizer/asan/asan_activation.cc
+++ b/libsanitizer/asan/asan_activation.cc
@@ -75,13 +75,16 @@ static struct AsanDeactivatedFlags {
 
   void Print() {
     Report(
-        "quarantine_size_mb %d, max_redzone %d, poison_heap %d, "
-        "malloc_context_size %d, alloc_dealloc_mismatch %d, "
-        "allocator_may_return_null %d, coverage %d, coverage_dir %s\n",
-        allocator_options.quarantine_size_mb, allocator_options.max_redzone,
-        poison_heap, malloc_context_size,
+        "quarantine_size_mb %d, thread_local_quarantine_size_kb %d, "
+        "max_redzone %d, poison_heap %d, malloc_context_size %d, "
+        "alloc_dealloc_mismatch %d, allocator_may_return_null %d, coverage %d, "
+        "coverage_dir %s, allocator_release_to_os_interval_ms %d\n",
+        allocator_options.quarantine_size_mb,
+        allocator_options.thread_local_quarantine_size_kb,
+        allocator_options.max_redzone, poison_heap, malloc_context_size,
         allocator_options.alloc_dealloc_mismatch,
-        allocator_options.may_return_null, coverage, coverage_dir);
+        allocator_options.may_return_null, coverage, coverage_dir,
+        allocator_options.release_to_os_interval_ms);
   }
 } asan_deactivated_flags;
 
@@ -101,10 +104,10 @@ void AsanDeactivate() {
   // Deactivate the runtime.
   SetCanPoisonMemory(false);
   SetMallocContextSize(1);
-  ReInitializeCoverage(false, nullptr);
 
   AllocatorOptions disabled = asan_deactivated_flags.allocator_options;
   disabled.quarantine_size_mb = 0;
+  disabled.thread_local_quarantine_size_kb = 0;
   disabled.min_redzone = 16;  // Redzone must be at least 16 bytes long.
   disabled.max_redzone = 16;
   disabled.alloc_dealloc_mismatch = false;
@@ -124,8 +127,6 @@ void AsanActivate() {
 
   SetCanPoisonMemory(asan_deactivated_flags.poison_heap);
   SetMallocContextSize(asan_deactivated_flags.malloc_context_size);
-  ReInitializeCoverage(asan_deactivated_flags.coverage,
-                       asan_deactivated_flags.coverage_dir);
   ReInitializeAllocator(asan_deactivated_flags.allocator_options);
 
   asan_is_deactivated = false;
diff --git a/libsanitizer/asan/asan_activation_flags.inc b/libsanitizer/asan/asan_activation_flags.inc
index 4bab38213c1..e71abb96e5b 100644
--- a/libsanitizer/asan/asan_activation_flags.inc
+++ b/libsanitizer/asan/asan_activation_flags.inc
@@ -22,6 +22,7 @@
 ASAN_ACTIVATION_FLAG(int, redzone)
 ASAN_ACTIVATION_FLAG(int, max_redzone)
 ASAN_ACTIVATION_FLAG(int, quarantine_size_mb)
+ASAN_ACTIVATION_FLAG(int, thread_local_quarantine_size_kb)
 ASAN_ACTIVATION_FLAG(bool, alloc_dealloc_mismatch)
 ASAN_ACTIVATION_FLAG(bool, poison_heap)
 
@@ -31,3 +32,4 @@ COMMON_ACTIVATION_FLAG(bool, coverage)
 COMMON_ACTIVATION_FLAG(const char *, coverage_dir)
 COMMON_ACTIVATION_FLAG(int, verbosity)
 COMMON_ACTIVATION_FLAG(bool, help)
+COMMON_ACTIVATION_FLAG(s32, allocator_release_to_os_interval_ms)
diff --git a/libsanitizer/asan/asan_allocator.cc b/libsanitizer/asan/asan_allocator.cc
index d3ddb904d58..1b465469c75 100644
--- a/libsanitizer/asan/asan_allocator.cc
+++ b/libsanitizer/asan/asan_allocator.cc
@@ -19,7 +19,9 @@
 #include "asan_report.h"
 #include "asan_stack.h"
 #include "asan_thread.h"
+#include "sanitizer_common/sanitizer_allocator_checks.h"
 #include "sanitizer_common/sanitizer_allocator_interface.h"
+#include "sanitizer_common/sanitizer_errno.h"
 #include "sanitizer_common/sanitizer_flags.h"
 #include "sanitizer_common/sanitizer_internal_defs.h"
 #include "sanitizer_common/sanitizer_list.h"
@@ -158,7 +160,11 @@ struct QuarantineCallback {
   }
 
   void *Allocate(uptr size) {
-    return get_allocator().Allocate(cache_, size, 1, false);
+    void *res = get_allocator().Allocate(cache_, size, 1);
+    // TODO(alekseys): Consider making quarantine OOM-friendly.
+    if (UNLIKELY(!res))
+      return DieOnFailure::OnOOM();
+    return res;
   }
 
   void Deallocate(void *p) {
@@ -205,25 +211,27 @@ QuarantineCache *GetQuarantineCache(AsanThreadLocalMallocStorage *ms) {
 
 void AllocatorOptions::SetFrom(const Flags *f, const CommonFlags *cf) {
   quarantine_size_mb = f->quarantine_size_mb;
+  thread_local_quarantine_size_kb = f->thread_local_quarantine_size_kb;
   min_redzone = f->redzone;
   max_redzone = f->max_redzone;
   may_return_null = cf->allocator_may_return_null;
   alloc_dealloc_mismatch = f->alloc_dealloc_mismatch;
+  release_to_os_interval_ms = cf->allocator_release_to_os_interval_ms;
 }
 
 void AllocatorOptions::CopyTo(Flags *f, CommonFlags *cf) {
   f->quarantine_size_mb = quarantine_size_mb;
+  f->thread_local_quarantine_size_kb = thread_local_quarantine_size_kb;
   f->redzone = min_redzone;
   f->max_redzone = max_redzone;
   cf->allocator_may_return_null = may_return_null;
   f->alloc_dealloc_mismatch = alloc_dealloc_mismatch;
+  cf->allocator_release_to_os_interval_ms = release_to_os_interval_ms;
 }
 
 struct Allocator {
   static const uptr kMaxAllowedMallocSize =
       FIRST_32_SECOND_64(3UL << 30, 1ULL << 40);
-  static const uptr kMaxThreadLocalQuarantine =
-      FIRST_32_SECOND_64(1 << 18, 1 << 20);
 
   AsanAllocator allocator;
   AsanQuarantine quarantine;
@@ -231,6 +239,8 @@ struct Allocator {
   AllocatorCache fallback_allocator_cache;
   QuarantineCache fallback_quarantine_cache;
 
+  atomic_uint8_t rss_limit_exceeded;
+
   // ------------------- Options --------------------------
   atomic_uint16_t min_redzone;
   atomic_uint16_t max_redzone;
@@ -252,7 +262,7 @@ struct Allocator {
   void SharedInitCode(const AllocatorOptions &options) {
     CheckOptions(options);
     quarantine.Init((uptr)options.quarantine_size_mb << 20,
-                    kMaxThreadLocalQuarantine);
+                    (uptr)options.thread_local_quarantine_size_kb << 10);
     atomic_store(&alloc_dealloc_mismatch, options.alloc_dealloc_mismatch,
                  memory_order_release);
     atomic_store(&min_redzone, options.min_redzone, memory_order_release);
@@ -260,35 +270,45 @@ struct Allocator {
   }
 
   void Initialize(const AllocatorOptions &options) {
-    allocator.Init(options.may_return_null);
+    SetAllocatorMayReturnNull(options.may_return_null);
+    allocator.Init(options.release_to_os_interval_ms);
     SharedInitCode(options);
   }
 
+  bool RssLimitExceeded() {
+    return atomic_load(&rss_limit_exceeded, memory_order_relaxed);
+  }
+
+  void SetRssLimitExceeded(bool limit_exceeded) {
+    atomic_store(&rss_limit_exceeded, limit_exceeded, memory_order_relaxed);
+  }
+
   void RePoisonChunk(uptr chunk) {
-    // This could a user-facing chunk (with redzones), or some internal
+    // This could be a user-facing chunk (with redzones), or some internal
     // housekeeping chunk, like TransferBatch. Start by assuming the former.
     AsanChunk *ac = GetAsanChunk((void *)chunk);
     uptr allocated_size = allocator.GetActuallyAllocatedSize((void *)ac);
     uptr beg = ac->Beg();
     uptr end = ac->Beg() + ac->UsedSize(true);
     uptr chunk_end = chunk + allocated_size;
-    if (chunk < beg && beg < end && end <= chunk_end) {
-      // Looks like a valid AsanChunk. Or maybe not. Be conservative and only
-      // poison the redzones.
+    if (chunk < beg && beg < end && end <= chunk_end &&
+        ac->chunk_state == CHUNK_ALLOCATED) {
+      // Looks like a valid AsanChunk in use, poison redzones only.
       PoisonShadow(chunk, beg - chunk, kAsanHeapLeftRedzoneMagic);
       uptr end_aligned_down = RoundDownTo(end, SHADOW_GRANULARITY);
       FastPoisonShadowPartialRightRedzone(
           end_aligned_down, end - end_aligned_down,
           chunk_end - end_aligned_down, kAsanHeapLeftRedzoneMagic);
     } else {
-      // This can not be an AsanChunk. Poison everything. It may be reused as
-      // AsanChunk later.
+      // This is either not an AsanChunk or freed or quarantined AsanChunk.
+      // In either case, poison everything.
       PoisonShadow(chunk, allocated_size, kAsanHeapLeftRedzoneMagic);
     }
   }
 
   void ReInitialize(const AllocatorOptions &options) {
-    allocator.SetMayReturnNull(options.may_return_null);
+    SetAllocatorMayReturnNull(options.may_return_null);
+    allocator.SetReleaseToOSIntervalMs(options.release_to_os_interval_ms);
     SharedInitCode(options);
 
     // Poison all existing allocation's redzones.
@@ -305,11 +325,13 @@ struct Allocator {
 
   void GetOptions(AllocatorOptions *options) const {
     options->quarantine_size_mb = quarantine.GetSize() >> 20;
+    options->thread_local_quarantine_size_kb = quarantine.GetCacheSize() >> 10;
     options->min_redzone = atomic_load(&min_redzone, memory_order_acquire);
     options->max_redzone = atomic_load(&max_redzone, memory_order_acquire);
-    options->may_return_null = allocator.MayReturnNull();
+    options->may_return_null = AllocatorMayReturnNull();
     options->alloc_dealloc_mismatch =
         atomic_load(&alloc_dealloc_mismatch, memory_order_acquire);
+    options->release_to_os_interval_ms = allocator.ReleaseToOSIntervalMs();
   }
 
   // -------------------- Helper methods. -------------------------
@@ -356,6 +378,8 @@ struct Allocator {
                  AllocType alloc_type, bool can_fill) {
     if (UNLIKELY(!asan_inited))
       AsanInitFromRtl();
+    if (RssLimitExceeded())
+      return AsanAllocator::FailureHandler::OnOOM();
     Flags &fl = *flags();
     CHECK(stack);
     const uptr min_alignment = SHADOW_GRANULARITY;
@@ -388,24 +412,21 @@ struct Allocator {
     if (size > kMaxAllowedMallocSize || needed_size > kMaxAllowedMallocSize) {
       Report("WARNING: AddressSanitizer failed to allocate 0x%zx bytes\n",
              (void*)size);
-      return allocator.ReturnNullOrDieOnBadRequest();
+      return AsanAllocator::FailureHandler::OnBadRequest();
     }
 
     AsanThread *t = GetCurrentThread();
     void *allocated;
-    bool check_rss_limit = true;
     if (t) {
       AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
-      allocated =
-          allocator.Allocate(cache, needed_size, 8, false, check_rss_limit);
+      allocated = allocator.Allocate(cache, needed_size, 8);
     } else {
       SpinMutexLock l(&fallback_mutex);
       AllocatorCache *cache = &fallback_allocator_cache;
-      allocated =
-          allocator.Allocate(cache, needed_size, 8, false, check_rss_limit);
+      allocated = allocator.Allocate(cache, needed_size, 8);
     }
-
-    if (!allocated) return allocator.ReturnNullOrDieOnOOM();
+    if (!allocated)
+      return nullptr;
 
     if (*(u8 *)MEM_TO_SHADOW((uptr)allocated) == 0 && CanPoisonMemory()) {
       // Heap poisoning is enabled, but the allocator provides an unpoisoned
@@ -507,8 +528,7 @@ struct Allocator {
 
   // Expects the chunk to already be marked as quarantined by using
   // AtomicallySetQuarantineFlagIfAllocated.
-  void QuarantineChunk(AsanChunk *m, void *ptr, BufferedStackTrace *stack,
-                       AllocType alloc_type) {
+  void QuarantineChunk(AsanChunk *m, void *ptr, BufferedStackTrace *stack) {
     CHECK_EQ(m->chunk_state, CHUNK_QUARANTINE);
     CHECK_GE(m->alloc_tid, 0);
     if (SANITIZER_WORDSIZE == 64)  // On 32-bits this resides in user area.
@@ -516,6 +536,18 @@ struct Allocator {
     AsanThread *t = GetCurrentThread();
     m->free_tid = t ? t->tid() : 0;
     m->free_context_id = StackDepotPut(*stack);
+
+    Flags &fl = *flags();
+    if (fl.max_free_fill_size > 0) {
+      // We have to skip the chunk header, it contains free_context_id.
+      uptr scribble_start = (uptr)m + kChunkHeaderSize + kChunkHeader2Size;
+      if (m->UsedSize() >= kChunkHeader2Size) {  // Skip Header2 in user area.
+        uptr size_to_fill = m->UsedSize() - kChunkHeader2Size;
+        size_to_fill = Min(size_to_fill, (uptr)fl.max_free_fill_size);
+        REAL(memset)((void *)scribble_start, fl.free_fill_byte, size_to_fill);
+      }
+    }
+
     // Poison the region.
     PoisonShadow(m->Beg(),
                  RoundUpTo(m->UsedSize(), SHADOW_GRANULARITY),
@@ -547,7 +579,17 @@ struct Allocator {
     uptr chunk_beg = p - kChunkHeaderSize;
     AsanChunk *m = reinterpret_cast<AsanChunk *>(chunk_beg);
 
+    // On Windows, uninstrumented DLLs may allocate memory before ASan hooks
+    // malloc. Don't report an invalid free in this case.
+    if (SANITIZER_WINDOWS &&
+        !get_allocator().PointerIsMine(ptr)) {
+      if (!IsSystemHeapAddress(p))
+        ReportFreeNotMalloced(p, stack);
+      return;
+    }
+
     ASAN_FREE_HOOK(ptr);
+
     // Must mark the chunk as quarantined before any changes to its metadata.
     // Do not quarantine given chunk if we failed to set CHUNK_QUARANTINE flag.
     if (!AtomicallySetQuarantineFlagIfAllocated(m, ptr, stack)) return;
@@ -564,7 +606,7 @@ struct Allocator {
       ReportNewDeleteSizeMismatch(p, delete_size, stack);
     }
 
-    QuarantineChunk(m, ptr, stack, alloc_type);
+    QuarantineChunk(m, ptr, stack);
   }
 
   void *Reallocate(void *old_ptr, uptr new_size, BufferedStackTrace *stack) {
@@ -593,8 +635,8 @@ struct Allocator {
   }
 
   void *Calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
-    if (CallocShouldReturnNullDueToOverflow(size, nmemb))
-      return allocator.ReturnNullOrDieOnBadRequest();
+    if (CheckForCallocOverflow(size, nmemb))
+      return AsanAllocator::FailureHandler::OnBadRequest();
     void *ptr = Allocate(nmemb * size, 8, stack, FROM_MALLOC, false);
     // If the memory comes from the secondary allocator no need to clear it
     // as it comes directly from mmap.
@@ -674,6 +716,7 @@ struct Allocator {
 
   void PrintStats() {
     allocator.PrintStats();
+    quarantine.PrintStats();
   }
 
   void ForceLock() {
@@ -685,8 +728,6 @@ struct Allocator {
     fallback_mutex.Unlock();
     allocator.ForceUnlock();
   }
-
-  void ReleaseToOS() { allocator.ReleaseToOS(); }
 };
 
 static Allocator instance(LINKER_INITIALIZED);
@@ -695,18 +736,21 @@ static AsanAllocator &get_allocator() {
   return instance.allocator;
 }
 
-bool AsanChunkView::IsValid() {
+bool AsanChunkView::IsValid() const {
   return chunk_ && chunk_->chunk_state != CHUNK_AVAILABLE;
 }
-bool AsanChunkView::IsAllocated() {
+bool AsanChunkView::IsAllocated() const {
   return chunk_ && chunk_->chunk_state == CHUNK_ALLOCATED;
 }
-uptr AsanChunkView::Beg() { return chunk_->Beg(); }
-uptr AsanChunkView::End() { return Beg() + UsedSize(); }
-uptr AsanChunkView::UsedSize() { return chunk_->UsedSize(); }
-uptr AsanChunkView::AllocTid() { return chunk_->alloc_tid; }
-uptr AsanChunkView::FreeTid() { return chunk_->free_tid; }
-AllocType AsanChunkView::GetAllocType() {
+bool AsanChunkView::IsQuarantined() const {
+  return chunk_ && chunk_->chunk_state == CHUNK_QUARANTINE;
+}
+uptr AsanChunkView::Beg() const { return chunk_->Beg(); }
+uptr AsanChunkView::End() const { return Beg() + UsedSize(); }
+uptr AsanChunkView::UsedSize() const { return chunk_->UsedSize(); }
+uptr AsanChunkView::AllocTid() const { return chunk_->alloc_tid; }
+uptr AsanChunkView::FreeTid() const { return chunk_->free_tid; }
+AllocType AsanChunkView::GetAllocType() const {
   return (AllocType)chunk_->alloc_type;
 }
 
@@ -717,22 +761,19 @@ static StackTrace GetStackTraceFromId(u32 id) {
   return res;
 }
 
-u32 AsanChunkView::GetAllocStackId() { return chunk_->alloc_context_id; }
-u32 AsanChunkView::GetFreeStackId() { return chunk_->free_context_id; }
+u32 AsanChunkView::GetAllocStackId() const { return chunk_->alloc_context_id; }
+u32 AsanChunkView::GetFreeStackId() const { return chunk_->free_context_id; }
 
-StackTrace AsanChunkView::GetAllocStack() {
+StackTrace AsanChunkView::GetAllocStack() const {
   return GetStackTraceFromId(GetAllocStackId());
 }
 
-StackTrace AsanChunkView::GetFreeStack() {
+StackTrace AsanChunkView::GetFreeStack() const {
   return GetStackTraceFromId(GetFreeStackId());
 }
 
-void ReleaseToOS() { instance.ReleaseToOS(); }
-
 void InitializeAllocator(const AllocatorOptions &options) {
   instance.Initialize(options);
-  SetAllocatorReleaseToOSCallback(ReleaseToOS);
 }
 
 void ReInitializeAllocator(const AllocatorOptions &options) {
@@ -758,11 +799,6 @@ void PrintInternalAllocatorStats() {
   instance.PrintStats();
 }
 
-void *asan_memalign(uptr alignment, uptr size, BufferedStackTrace *stack,
-                    AllocType alloc_type) {
-  return instance.Allocate(size, alignment, stack, alloc_type, true);
-}
-
 void asan_free(void *ptr, BufferedStackTrace *stack, AllocType alloc_type) {
   instance.Deallocate(ptr, 0, stack, alloc_type);
 }
@@ -773,40 +809,63 @@ void asan_sized_free(void *ptr, uptr size, BufferedStackTrace *stack,
 }
 
 void *asan_malloc(uptr size, BufferedStackTrace *stack) {
-  return instance.Allocate(size, 8, stack, FROM_MALLOC, true);
+  return SetErrnoOnNull(instance.Allocate(size, 8, stack, FROM_MALLOC, true));
 }
 
 void *asan_calloc(uptr nmemb, uptr size, BufferedStackTrace *stack) {
-  return instance.Calloc(nmemb, size, stack);
+  return SetErrnoOnNull(instance.Calloc(nmemb, size, stack));
 }
 
 void *asan_realloc(void *p, uptr size, BufferedStackTrace *stack) {
   if (!p)
-    return instance.Allocate(size, 8, stack, FROM_MALLOC, true);
+    return SetErrnoOnNull(instance.Allocate(size, 8, stack, FROM_MALLOC, true));
   if (size == 0) {
-    instance.Deallocate(p, 0, stack, FROM_MALLOC);
-    return nullptr;
+    if (flags()->allocator_frees_and_returns_null_on_realloc_zero) {
+      instance.Deallocate(p, 0, stack, FROM_MALLOC);
+      return nullptr;
+    }
+    // Allocate a size of 1 if we shouldn't free() on Realloc to 0
+    size = 1;
   }
-  return instance.Reallocate(p, size, stack);
+  return SetErrnoOnNull(instance.Reallocate(p, size, stack));
 }
 
 void *asan_valloc(uptr size, BufferedStackTrace *stack) {
-  return instance.Allocate(size, GetPageSizeCached(), stack, FROM_MALLOC, true);
+  return SetErrnoOnNull(
+      instance.Allocate(size, GetPageSizeCached(), stack, FROM_MALLOC, true));
 }
 
 void *asan_pvalloc(uptr size, BufferedStackTrace *stack) {
   uptr PageSize = GetPageSizeCached();
-  size = RoundUpTo(size, PageSize);
-  if (size == 0) {
-    // pvalloc(0) should allocate one page.
-    size = PageSize;
+  if (UNLIKELY(CheckForPvallocOverflow(size, PageSize))) {
+    errno = errno_ENOMEM;
+    return AsanAllocator::FailureHandler::OnBadRequest();
   }
-  return instance.Allocate(size, PageSize, stack, FROM_MALLOC, true);
+  // pvalloc(0) should allocate one page.
+  size = size ? RoundUpTo(size, PageSize) : PageSize;
+  return SetErrnoOnNull(
+      instance.Allocate(size, PageSize, stack, FROM_MALLOC, true));
+}
+
+void *asan_memalign(uptr alignment, uptr size, BufferedStackTrace *stack,
+                    AllocType alloc_type) {
+  if (UNLIKELY(!IsPowerOfTwo(alignment))) {
+    errno = errno_EINVAL;
+    return AsanAllocator::FailureHandler::OnBadRequest();
+  }
+  return SetErrnoOnNull(
+      instance.Allocate(size, alignment, stack, alloc_type, true));
 }
 
 int asan_posix_memalign(void **memptr, uptr alignment, uptr size,
                         BufferedStackTrace *stack) {
+  if (UNLIKELY(!CheckPosixMemalignAlignment(alignment))) {
+    AsanAllocator::FailureHandler::OnBadRequest();
+    return errno_EINVAL;
+  }
   void *ptr = instance.Allocate(size, alignment, stack, FROM_MALLOC, true);
+  if (UNLIKELY(!ptr))
+    return errno_ENOMEM;
   CHECK(IsAligned((uptr)ptr, alignment));
   *memptr = ptr;
   return 0;
@@ -834,8 +893,8 @@ void asan_mz_force_unlock() {
   instance.ForceUnlock();
 }
 
-void AsanSoftRssLimitExceededCallback(bool exceeded) {
-  instance.allocator.SetRssLimitIsExceeded(exceeded);
+void AsanSoftRssLimitExceededCallback(bool limit_exceeded) {
+  instance.SetRssLimitExceeded(limit_exceeded);
 }
 
 } // namespace __asan
@@ -952,15 +1011,13 @@ uptr __sanitizer_get_allocated_size(const void *p) {
 
 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
 // Provide default (no-op) implementation of malloc hooks.
-extern "C" {
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void __sanitizer_malloc_hook(void *ptr, uptr size) {
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_malloc_hook,
+                             void *ptr, uptr size) {
   (void)ptr;
   (void)size;
 }
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void __sanitizer_free_hook(void *ptr) {
+
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_free_hook, void *ptr) {
   (void)ptr;
 }
-} // extern "C"
 #endif
diff --git a/libsanitizer/asan/asan_allocator.h b/libsanitizer/asan/asan_allocator.h
index 7eeddadd547..63260ff9895 100644
--- a/libsanitizer/asan/asan_allocator.h
+++ b/libsanitizer/asan/asan_allocator.h
@@ -31,10 +31,12 @@ struct AsanChunk;
 
 struct AllocatorOptions {
   u32 quarantine_size_mb;
+  u32 thread_local_quarantine_size_kb;
   u16 min_redzone;
   u16 max_redzone;
   u8 may_return_null;
   u8 alloc_dealloc_mismatch;
+  s32 release_to_os_interval_ms;
 
   void SetFrom(const Flags *f, const CommonFlags *cf);
   void CopyTo(Flags *f, CommonFlags *cf);
@@ -47,28 +49,29 @@ void GetAllocatorOptions(AllocatorOptions *options);
 class AsanChunkView {
  public:
   explicit AsanChunkView(AsanChunk *chunk) : chunk_(chunk) {}
-  bool IsValid();        // Checks if AsanChunkView points to a valid allocated
-                         // or quarantined chunk.
-  bool IsAllocated();    // Checks if the memory is currently allocated.
-  uptr Beg();            // First byte of user memory.
-  uptr End();            // Last byte of user memory.
-  uptr UsedSize();       // Size requested by the user.
-  uptr AllocTid();
-  uptr FreeTid();
+  bool IsValid() const;        // Checks if AsanChunkView points to a valid
+                               // allocated or quarantined chunk.
+  bool IsAllocated() const;    // Checks if the memory is currently allocated.
+  bool IsQuarantined() const;  // Checks if the memory is currently quarantined.
+  uptr Beg() const;            // First byte of user memory.
+  uptr End() const;            // Last byte of user memory.
+  uptr UsedSize() const;       // Size requested by the user.
+  uptr AllocTid() const;
+  uptr FreeTid() const;
   bool Eq(const AsanChunkView &c) const { return chunk_ == c.chunk_; }
-  u32 GetAllocStackId();
-  u32 GetFreeStackId();
-  StackTrace GetAllocStack();
-  StackTrace GetFreeStack();
-  AllocType GetAllocType();
-  bool AddrIsInside(uptr addr, uptr access_size, sptr *offset) {
+  u32 GetAllocStackId() const;
+  u32 GetFreeStackId() const;
+  StackTrace GetAllocStack() const;
+  StackTrace GetFreeStack() const;
+  AllocType GetAllocType() const;
+  bool AddrIsInside(uptr addr, uptr access_size, sptr *offset) const {
     if (addr >= Beg() && (addr + access_size) <= End()) {
       *offset = addr - Beg();
       return true;
     }
     return false;
   }
-  bool AddrIsAtLeft(uptr addr, uptr access_size, sptr *offset) {
+  bool AddrIsAtLeft(uptr addr, uptr access_size, sptr *offset) const {
     (void)access_size;
     if (addr < Beg()) {
       *offset = Beg() - addr;
@@ -76,7 +79,7 @@ class AsanChunkView {
     }
     return false;
   }
-  bool AddrIsAtRight(uptr addr, uptr access_size, sptr *offset) {
+  bool AddrIsAtRight(uptr addr, uptr access_size, sptr *offset) const {
     if (addr + access_size > End()) {
       *offset = addr - End();
       return true;
@@ -114,7 +117,11 @@ struct AsanMapUnmapCallback {
 };
 
 #if SANITIZER_CAN_USE_ALLOCATOR64
-# if defined(__powerpc64__)
+# if SANITIZER_FUCHSIA
+const uptr kAllocatorSpace = ~(uptr)0;
+const uptr kAllocatorSize  =  0x40000000000ULL;  // 4T.
+typedef DefaultSizeClassMap SizeClassMap;
+# elif defined(__powerpc64__)
 const uptr kAllocatorSpace =  0xa0000000000ULL;
 const uptr kAllocatorSize  =  0x20000000000ULL;  // 2T.
 typedef DefaultSizeClassMap SizeClassMap;
@@ -156,10 +163,17 @@ typedef FlatByteMap<kNumRegions> ByteMap;
 typedef TwoLevelByteMap<(kNumRegions >> 12), 1 << 12> ByteMap;
 # endif
 typedef CompactSizeClassMap SizeClassMap;
-typedef SizeClassAllocator32<0, SANITIZER_MMAP_RANGE_SIZE, 16,
-  SizeClassMap, kRegionSizeLog,
-  ByteMap,
-  AsanMapUnmapCallback> PrimaryAllocator;
+struct AP32 {
+  static const uptr kSpaceBeg = 0;
+  static const u64 kSpaceSize = SANITIZER_MMAP_RANGE_SIZE;
+  static const uptr kMetadataSize = 16;
+  typedef __asan::SizeClassMap SizeClassMap;
+  static const uptr kRegionSizeLog = __asan::kRegionSizeLog;
+  typedef __asan::ByteMap ByteMap;
+  typedef AsanMapUnmapCallback MapUnmapCallback;
+  static const uptr kFlags = 0;
+};
+typedef SizeClassAllocator32<AP32> PrimaryAllocator;
 #endif  // SANITIZER_CAN_USE_ALLOCATOR64
 
 static const uptr kNumberOfSizeClasses = SizeClassMap::kNumClasses;
diff --git a/libsanitizer/asan/asan_descriptions.cc b/libsanitizer/asan/asan_descriptions.cc
index 35d1619f2d9..d46962adf27 100644
--- a/libsanitizer/asan/asan_descriptions.cc
+++ b/libsanitizer/asan/asan_descriptions.cc
@@ -148,7 +148,7 @@ static void PrintHeapChunkAccess(uptr addr, const ChunkAccess &descr) {
   str.append(" %zu-byte region [%p,%p)\n", descr.chunk_size,
              (void *)descr.chunk_begin,
              (void *)(descr.chunk_begin + descr.chunk_size));
-  str.append("%s", d.EndLocation());
+  str.append("%s", d.Default());
   Printf("%s", str.data());
 }
 
@@ -250,12 +250,15 @@ static void PrintAccessAndVarIntersection(const StackVarDescr &var, uptr addr,
     str.append("%c", var.name_pos[i]);
   }
   str.append("'");
+  if (var.line > 0) {
+    str.append(" (line %d)", var.line);
+  }
   if (pos_descr) {
     Decorator d;
     // FIXME: we may want to also print the size of the access here,
     // but in case of accesses generated by memset it may be confusing.
     str.append("%s <== Memory access at offset %zd %s this variable%s\n",
-               d.Location(), addr, pos_descr, d.EndLocation());
+               d.Location(), addr, pos_descr, d.Default());
   } else {
     str.append("\n");
   }
@@ -290,7 +293,7 @@ static void DescribeAddressRelativeToGlobal(uptr addr, uptr access_size,
              MaybeDemangleGlobalName(g.name));
   PrintGlobalLocation(&str, g);
   str.append("' (0x%zx) of size %zu\n", g.beg, g.size);
-  str.append("%s", d.EndLocation());
+  str.append("%s", d.Default());
   PrintGlobalNameIfASCII(&str, g);
   Printf("%s", str.data());
 }
@@ -338,10 +341,10 @@ void StackAddressDescription::Print() const {
          ThreadNameWithParenthesis(tid, tname, sizeof(tname)));
 
   if (!frame_descr) {
-    Printf("%s\n", d.EndLocation());
+    Printf("%s\n", d.Default());
     return;
   }
-  Printf(" at offset %zu in frame%s\n", offset, d.EndLocation());
+  Printf(" at offset %zu in frame%s\n", offset, d.Default());
 
   // Now we print the frame where the alloca has happened.
   // We print this frame as a stack trace with one element.
@@ -350,7 +353,7 @@ void StackAddressDescription::Print() const {
   // previously. That's unfortunate, but I have no better solution,
   // especially given that the alloca may be from entirely different place
   // (e.g. use-after-scope, or different thread's stack).
-  Printf("%s", d.EndLocation());
+  Printf("%s", d.Default());
   StackTrace alloca_stack(&frame_pc, 1);
   alloca_stack.Print();
 
@@ -400,18 +403,18 @@ void HeapAddressDescription::Print() const {
     Printf("%sfreed by thread T%d%s here:%s\n", d.Allocation(),
            free_thread->tid,
            ThreadNameWithParenthesis(free_thread, tname, sizeof(tname)),
-           d.EndAllocation());
+           d.Default());
     StackTrace free_stack = GetStackTraceFromId(free_stack_id);
     free_stack.Print();
     Printf("%spreviously allocated by thread T%d%s here:%s\n", d.Allocation(),
            alloc_thread->tid,
            ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
-           d.EndAllocation());
+           d.Default());
   } else {
     Printf("%sallocated by thread T%d%s here:%s\n", d.Allocation(),
            alloc_thread->tid,
            ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
-           d.EndAllocation());
+           d.Default());
   }
   alloc_stack.Print();
   DescribeThread(GetCurrentThread());
diff --git a/libsanitizer/asan/asan_descriptions.h b/libsanitizer/asan/asan_descriptions.h
index 584b9ba6491..0fbb531492a 100644
--- a/libsanitizer/asan/asan_descriptions.h
+++ b/libsanitizer/asan/asan_descriptions.h
@@ -32,11 +32,8 @@ class Decorator : public __sanitizer::SanitizerCommonDecorator {
  public:
   Decorator() : SanitizerCommonDecorator() {}
   const char *Access() { return Blue(); }
-  const char *EndAccess() { return Default(); }
   const char *Location() { return Green(); }
-  const char *EndLocation() { return Default(); }
   const char *Allocation() { return Magenta(); }
-  const char *EndAllocation() { return Default(); }
 
   const char *ShadowByte(u8 byte) {
     switch (byte) {
@@ -70,9 +67,6 @@ class Decorator : public __sanitizer::SanitizerCommonDecorator {
         return Default();
     }
   }
-  const char *EndShadowByte() { return Default(); }
-  const char *MemoryByte() { return Magenta(); }
-  const char *EndMemoryByte() { return Default(); }
 };
 
 enum ShadowKind : u8 {
diff --git a/libsanitizer/asan/asan_errors.cc b/libsanitizer/asan/asan_errors.cc
index 73c4cca843b..b469b16f004 100644
--- a/libsanitizer/asan/asan_errors.cc
+++ b/libsanitizer/asan/asan_errors.cc
@@ -20,64 +20,27 @@
 
 namespace __asan {
 
-void ErrorStackOverflow::Print() {
-  Decorator d;
-  Printf("%s", d.Warning());
-  Report(
-      "ERROR: AddressSanitizer: stack-overflow on address %p"
-      " (pc %p bp %p sp %p T%d)\n",
-      (void *)addr, (void *)pc, (void *)bp, (void *)sp, tid);
-  Printf("%s", d.EndWarning());
-  scariness.Print();
-  BufferedStackTrace stack;
-  GetStackTraceWithPcBpAndContext(&stack, kStackTraceMax, pc, bp, context,
-                                  common_flags()->fast_unwind_on_fatal);
-  stack.Print();
-  ReportErrorSummary("stack-overflow", &stack);
-}
-
-static void MaybeDumpInstructionBytes(uptr pc) {
-  if (!flags()->dump_instruction_bytes || (pc < GetPageSizeCached())) return;
-  InternalScopedString str(1024);
-  str.append("First 16 instruction bytes at pc: ");
-  if (IsAccessibleMemoryRange(pc, 16)) {
-    for (int i = 0; i < 16; ++i) {
-      PrintMemoryByte(&str, "", ((u8 *)pc)[i], /*in_shadow*/ false, " ");
-    }
-    str.append("\n");
-  } else {
-    str.append("unaccessible\n");
-  }
-  Report("%s", str.data());
+static void OnStackUnwind(const SignalContext &sig,
+                          const void *callback_context,
+                          BufferedStackTrace *stack) {
+  bool fast = common_flags()->fast_unwind_on_fatal;
+#if SANITIZER_FREEBSD || SANITIZER_NETBSD
+  // On FreeBSD the slow unwinding that leverages _Unwind_Backtrace()
+  // yields the call stack of the signal's handler and not of the code
+  // that raised the signal (as it does on Linux).
+  fast = true;
+#endif
+  // Tests and maybe some users expect that scariness is going to be printed
+  // just before the stack. As only asan has scariness score we have no
+  // corresponding code in the sanitizer_common and we use this callback to
+  // print it.
+  static_cast<const ScarinessScoreBase *>(callback_context)->Print();
+  GetStackTraceWithPcBpAndContext(stack, kStackTraceMax, sig.pc, sig.bp,
+                                  sig.context, fast);
 }
 
 void ErrorDeadlySignal::Print() {
-  Decorator d;
-  Printf("%s", d.Warning());
-  const char *description = DescribeSignalOrException(signo);
-  Report(
-      "ERROR: AddressSanitizer: %s on unknown address %p (pc %p bp %p sp %p "
-      "T%d)\n",
-      description, (void *)addr, (void *)pc, (void *)bp, (void *)sp, tid);
-  Printf("%s", d.EndWarning());
-  if (pc < GetPageSizeCached()) Report("Hint: pc points to the zero page.\n");
-  if (is_memory_access) {
-    const char *access_type =
-        write_flag == SignalContext::WRITE
-            ? "WRITE"
-            : (write_flag == SignalContext::READ ? "READ" : "UNKNOWN");
-    Report("The signal is caused by a %s memory access.\n", access_type);
-    if (addr < GetPageSizeCached())
-      Report("Hint: address points to the zero page.\n");
-  }
-  scariness.Print();
-  BufferedStackTrace stack;
-  GetStackTraceWithPcBpAndContext(&stack, kStackTraceMax, pc, bp, context,
-                                  common_flags()->fast_unwind_on_fatal);
-  stack.Print();
-  MaybeDumpInstructionBytes(pc);
-  Printf("AddressSanitizer can not provide additional info.\n");
-  ReportErrorSummary(description, &stack);
+  ReportDeadlySignal(signal, tid, &OnStackUnwind, &scariness);
 }
 
 void ErrorDoubleFree::Print() {
@@ -85,17 +48,17 @@ void ErrorDoubleFree::Print() {
   Printf("%s", d.Warning());
   char tname[128];
   Report(
-      "ERROR: AddressSanitizer: attempting double-free on %p in "
+      "ERROR: AddressSanitizer: attempting %s on %p in "
       "thread T%d%s:\n",
-      addr_description.addr, tid,
+      scariness.GetDescription(), addr_description.addr, tid,
       ThreadNameWithParenthesis(tid, tname, sizeof(tname)));
-  Printf("%s", d.EndWarning());
+  Printf("%s", d.Default());
   scariness.Print();
   GET_STACK_TRACE_FATAL(second_free_stack->trace[0],
                         second_free_stack->top_frame_bp);
   stack.Print();
   addr_description.Print();
-  ReportErrorSummary("double-free", &stack);
+  ReportErrorSummary(scariness.GetDescription(), &stack);
 }
 
 void ErrorNewDeleteSizeMismatch::Print() {
@@ -103,11 +66,11 @@ void ErrorNewDeleteSizeMismatch::Print() {
   Printf("%s", d.Warning());
   char tname[128];
   Report(
-      "ERROR: AddressSanitizer: new-delete-type-mismatch on %p in thread "
+      "ERROR: AddressSanitizer: %s on %p in thread "
       "T%d%s:\n",
-      addr_description.addr, tid,
+      scariness.GetDescription(), addr_description.addr, tid,
       ThreadNameWithParenthesis(tid, tname, sizeof(tname)));
-  Printf("%s  object passed to delete has wrong type:\n", d.EndWarning());
+  Printf("%s  object passed to delete has wrong type:\n", d.Default());
   Printf(
       "  size of the allocated type:   %zd bytes;\n"
       "  size of the deallocated type: %zd bytes.\n",
@@ -117,7 +80,7 @@ void ErrorNewDeleteSizeMismatch::Print() {
   GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
   stack.Print();
   addr_description.Print();
-  ReportErrorSummary("new-delete-type-mismatch", &stack);
+  ReportErrorSummary(scariness.GetDescription(), &stack);
   Report(
       "HINT: if you don't care about these errors you may set "
       "ASAN_OPTIONS=new_delete_type_mismatch=0\n");
@@ -132,13 +95,13 @@ void ErrorFreeNotMalloced::Print() {
       "which was not malloc()-ed: %p in thread T%d%s\n",
       addr_description.Address(), tid,
       ThreadNameWithParenthesis(tid, tname, sizeof(tname)));
-  Printf("%s", d.EndWarning());
+  Printf("%s", d.Default());
   CHECK_GT(free_stack->size, 0);
   scariness.Print();
   GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
   stack.Print();
   addr_description.Print();
-  ReportErrorSummary("bad-free", &stack);
+  ReportErrorSummary(scariness.GetDescription(), &stack);
 }
 
 void ErrorAllocTypeMismatch::Print() {
@@ -149,16 +112,17 @@ void ErrorAllocTypeMismatch::Print() {
   CHECK_NE(alloc_type, dealloc_type);
   Decorator d;
   Printf("%s", d.Warning());
-  Report("ERROR: AddressSanitizer: alloc-dealloc-mismatch (%s vs %s) on %p\n",
+  Report("ERROR: AddressSanitizer: %s (%s vs %s) on %p\n",
+         scariness.GetDescription(),
          alloc_names[alloc_type], dealloc_names[dealloc_type],
          addr_description.addr);
-  Printf("%s", d.EndWarning());
+  Printf("%s", d.Default());
   CHECK_GT(dealloc_stack->size, 0);
   scariness.Print();
   GET_STACK_TRACE_FATAL(dealloc_stack->trace[0], dealloc_stack->top_frame_bp);
   stack.Print();
   addr_description.Print();
-  ReportErrorSummary("alloc-dealloc-mismatch", &stack);
+  ReportErrorSummary(scariness.GetDescription(), &stack);
   Report(
       "HINT: if you don't care about these errors you may set "
       "ASAN_OPTIONS=alloc_dealloc_mismatch=0\n");
@@ -171,10 +135,10 @@ void ErrorMallocUsableSizeNotOwned::Print() {
       "ERROR: AddressSanitizer: attempting to call malloc_usable_size() for "
       "pointer which is not owned: %p\n",
       addr_description.Address());
-  Printf("%s", d.EndWarning());
+  Printf("%s", d.Default());
   stack->Print();
   addr_description.Print();
-  ReportErrorSummary("bad-malloc_usable_size", stack);
+  ReportErrorSummary(scariness.GetDescription(), stack);
 }
 
 void ErrorSanitizerGetAllocatedSizeNotOwned::Print() {
@@ -184,10 +148,10 @@ void ErrorSanitizerGetAllocatedSizeNotOwned::Print() {
       "ERROR: AddressSanitizer: attempting to call "
       "__sanitizer_get_allocated_size() for pointer which is not owned: %p\n",
       addr_description.Address());
-  Printf("%s", d.EndWarning());
+  Printf("%s", d.Default());
   stack->Print();
   addr_description.Print();
-  ReportErrorSummary("bad-__sanitizer_get_allocated_size", stack);
+  ReportErrorSummary(scariness.GetDescription(), stack);
 }
 
 void ErrorStringFunctionMemoryRangesOverlap::Print() {
@@ -201,7 +165,7 @@ void ErrorStringFunctionMemoryRangesOverlap::Print() {
       bug_type, addr1_description.Address(),
       addr1_description.Address() + length1, addr2_description.Address(),
       addr2_description.Address() + length2);
-  Printf("%s", d.EndWarning());
+  Printf("%s", d.Default());
   scariness.Print();
   stack->Print();
   addr1_description.Print();
@@ -212,13 +176,13 @@ void ErrorStringFunctionMemoryRangesOverlap::Print() {
 void ErrorStringFunctionSizeOverflow::Print() {
   Decorator d;
   Printf("%s", d.Warning());
-  const char *bug_type = "negative-size-param";
-  Report("ERROR: AddressSanitizer: %s: (size=%zd)\n", bug_type, size);
-  Printf("%s", d.EndWarning());
+  Report("ERROR: AddressSanitizer: %s: (size=%zd)\n",
+         scariness.GetDescription(), size);
+  Printf("%s", d.Default());
   scariness.Print();
   stack->Print();
   addr_description.Print();
-  ReportErrorSummary(bug_type, stack);
+  ReportErrorSummary(scariness.GetDescription(), stack);
 }
 
 void ErrorBadParamsToAnnotateContiguousContainer::Print() {
@@ -234,14 +198,15 @@ void ErrorBadParamsToAnnotateContiguousContainer::Print() {
   if (!IsAligned(beg, granularity))
     Report("ERROR: beg is not aligned by %d\n", granularity);
   stack->Print();
-  ReportErrorSummary("bad-__sanitizer_annotate_contiguous_container", stack);
+  ReportErrorSummary(scariness.GetDescription(), stack);
 }
 
 void ErrorODRViolation::Print() {
   Decorator d;
   Printf("%s", d.Warning());
-  Report("ERROR: AddressSanitizer: odr-violation (%p):\n", global1.beg);
-  Printf("%s", d.EndWarning());
+  Report("ERROR: AddressSanitizer: %s (%p):\n", scariness.GetDescription(),
+         global1.beg);
+  Printf("%s", d.Default());
   InternalScopedString g1_loc(256), g2_loc(256);
   PrintGlobalLocation(&g1_loc, global1);
   PrintGlobalLocation(&g2_loc, global2);
@@ -260,23 +225,22 @@ void ErrorODRViolation::Print() {
       "HINT: if you don't care about these errors you may set "
       "ASAN_OPTIONS=detect_odr_violation=0\n");
   InternalScopedString error_msg(256);
-  error_msg.append("odr-violation: global '%s' at %s",
+  error_msg.append("%s: global '%s' at %s", scariness.GetDescription(),
                    MaybeDemangleGlobalName(global1.name), g1_loc.data());
   ReportErrorSummary(error_msg.data());
 }
 
 void ErrorInvalidPointerPair::Print() {
-  const char *bug_type = "invalid-pointer-pair";
   Decorator d;
   Printf("%s", d.Warning());
-  Report("ERROR: AddressSanitizer: invalid-pointer-pair: %p %p\n",
+  Report("ERROR: AddressSanitizer: %s: %p %p\n", scariness.GetDescription(),
          addr1_description.Address(), addr2_description.Address());
-  Printf("%s", d.EndWarning());
+  Printf("%s", d.Default());
   GET_STACK_TRACE_FATAL(pc, bp);
   stack.Print();
   addr1_description.Print();
   addr2_description.Print();
-  ReportErrorSummary(bug_type, &stack);
+  ReportErrorSummary(scariness.GetDescription(), &stack);
 }
 
 static bool AdjacentShadowValuesAreFullyPoisoned(u8 *s) {
@@ -470,13 +434,13 @@ void ErrorGeneric::Print() {
   uptr addr = addr_description.Address();
   Report("ERROR: AddressSanitizer: %s on address %p at pc %p bp %p sp %p\n",
          bug_descr, (void *)addr, pc, bp, sp);
-  Printf("%s", d.EndWarning());
+  Printf("%s", d.Default());
 
   char tname[128];
   Printf("%s%s of size %zu at %p thread T%d%s%s\n", d.Access(),
          access_size ? (is_write ? "WRITE" : "READ") : "ACCESS", access_size,
          (void *)addr, tid,
-         ThreadNameWithParenthesis(tid, tname, sizeof(tname)), d.EndAccess());
+         ThreadNameWithParenthesis(tid, tname, sizeof(tname)), d.Default());
 
   scariness.Print();
   GET_STACK_TRACE_FATAL(pc, bp);
diff --git a/libsanitizer/asan/asan_errors.h b/libsanitizer/asan/asan_errors.h
index 6262dcf3506..ea8fd01e287 100644
--- a/libsanitizer/asan/asan_errors.h
+++ b/libsanitizer/asan/asan_errors.h
@@ -25,61 +25,28 @@ struct ErrorBase {
   u32 tid;
 };
 
-struct ErrorStackOverflow : ErrorBase {
-  uptr addr, pc, bp, sp;
-  // ErrorStackOverflow never owns the context.
-  void *context;
-  // VS2013 doesn't implement unrestricted unions, so we need a trivial default
-  // constructor
-  ErrorStackOverflow() = default;
-  ErrorStackOverflow(u32 tid, const SignalContext &sig)
-      : ErrorBase(tid),
-        addr(sig.addr),
-        pc(sig.pc),
-        bp(sig.bp),
-        sp(sig.sp),
-        context(sig.context) {
-    scariness.Clear();
-    scariness.Scare(10, "stack-overflow");
-  }
-  void Print();
-};
-
 struct ErrorDeadlySignal : ErrorBase {
-  uptr addr, pc, bp, sp;
-  // ErrorDeadlySignal never owns the context.
-  void *context;
-  int signo;
-  SignalContext::WriteFlag write_flag;
-  bool is_memory_access;
+  SignalContext signal;
   // VS2013 doesn't implement unrestricted unions, so we need a trivial default
   // constructor
   ErrorDeadlySignal() = default;
-  ErrorDeadlySignal(u32 tid, const SignalContext &sig, int signo_)
-      : ErrorBase(tid),
-        addr(sig.addr),
-        pc(sig.pc),
-        bp(sig.bp),
-        sp(sig.sp),
-        context(sig.context),
-        signo(signo_),
-        write_flag(sig.write_flag),
-        is_memory_access(sig.is_memory_access) {
+  ErrorDeadlySignal(u32 tid, const SignalContext &sig)
+      : ErrorBase(tid), signal(sig) {
     scariness.Clear();
-    if (is_memory_access) {
-      if (addr < GetPageSizeCached()) {
-        scariness.Scare(10, "null-deref");
-      } else if (addr == pc) {
-        scariness.Scare(60, "wild-jump");
-      } else if (write_flag == SignalContext::WRITE) {
-        scariness.Scare(30, "wild-addr-write");
-      } else if (write_flag == SignalContext::READ) {
-        scariness.Scare(20, "wild-addr-read");
-      } else {
-        scariness.Scare(25, "wild-addr");
-      }
-    } else {
+    if (signal.IsStackOverflow()) {
+      scariness.Scare(10, "stack-overflow");
+    } else if (!signal.is_memory_access) {
       scariness.Scare(10, "signal");
+    } else if (signal.addr < GetPageSizeCached()) {
+      scariness.Scare(10, "null-deref");
+    } else if (signal.addr == signal.pc) {
+      scariness.Scare(60, "wild-jump");
+    } else if (signal.write_flag == SignalContext::WRITE) {
+      scariness.Scare(30, "wild-addr-write");
+    } else if (signal.write_flag == SignalContext::READ) {
+      scariness.Scare(20, "wild-addr-read");
+    } else {
+      scariness.Scare(25, "wild-addr");
     }
   }
   void Print();
@@ -170,6 +137,7 @@ struct ErrorMallocUsableSizeNotOwned : ErrorBase {
         stack(stack_),
         addr_description(addr, /*shouldLockThreadRegistry=*/false) {
     scariness.Clear();
+    scariness.Scare(10, "bad-malloc_usable_size");
   }
   void Print();
 };
@@ -187,6 +155,7 @@ struct ErrorSanitizerGetAllocatedSizeNotOwned : ErrorBase {
         stack(stack_),
         addr_description(addr, /*shouldLockThreadRegistry=*/false) {
     scariness.Clear();
+    scariness.Scare(10, "bad-__sanitizer_get_allocated_size");
   }
   void Print();
 };
@@ -256,7 +225,10 @@ struct ErrorBadParamsToAnnotateContiguousContainer : ErrorBase {
         beg(beg_),
         end(end_),
         old_mid(old_mid_),
-        new_mid(new_mid_) {}
+        new_mid(new_mid_) {
+    scariness.Clear();
+    scariness.Scare(10, "bad-__sanitizer_annotate_contiguous_container");
+  }
   void Print();
 };
 
@@ -272,7 +244,10 @@ struct ErrorODRViolation : ErrorBase {
         global1(*g1),
         global2(*g2),
         stack_id1(stack_id1_),
-        stack_id2(stack_id2_) {}
+        stack_id2(stack_id2_) {
+    scariness.Clear();
+    scariness.Scare(10, "odr-violation");
+  }
   void Print();
 };
 
@@ -290,7 +265,10 @@ struct ErrorInvalidPointerPair : ErrorBase {
         bp(bp_),
         sp(sp_),
         addr1_description(p1, 1, /*shouldLockThreadRegistry=*/false),
-        addr2_description(p2, 1, /*shouldLockThreadRegistry=*/false) {}
+        addr2_description(p2, 1, /*shouldLockThreadRegistry=*/false)  {
+    scariness.Clear();
+    scariness.Scare(10, "invalid-pointer-pair");
+  }
   void Print();
 };
 
@@ -311,7 +289,6 @@ struct ErrorGeneric : ErrorBase {
 
 // clang-format off
 #define ASAN_FOR_EACH_ERROR_KIND(macro)         \
-  macro(StackOverflow)                          \
   macro(DeadlySignal)                           \
   macro(DoubleFree)                             \
   macro(NewDeleteSizeMismatch)                  \
@@ -348,6 +325,7 @@ struct ErrorDescription {
   // We can add a wrapper around it to make it "more c++-like", but that would
   // add a lot of code and the benefit wouldn't be that big.
   union {
+    ErrorBase Base;
     ASAN_FOR_EACH_ERROR_KIND(ASAN_ERROR_DESCRIPTION_MEMBER)
   };
 
diff --git a/libsanitizer/asan/asan_fake_stack.cc b/libsanitizer/asan/asan_fake_stack.cc
index bf7566a334e..3140f9a2aeb 100644
--- a/libsanitizer/asan/asan_fake_stack.cc
+++ b/libsanitizer/asan/asan_fake_stack.cc
@@ -169,7 +169,7 @@ void FakeStack::ForEachFakeFrame(RangeIteratorCallback callback, void *arg) {
   }
 }
 
-#if SANITIZER_LINUX && !SANITIZER_ANDROID
+#if (SANITIZER_LINUX && !SANITIZER_ANDROID) || SANITIZER_FUCHSIA
 static THREADLOCAL FakeStack *fake_stack_tls;
 
 FakeStack *GetTLSFakeStack() {
@@ -181,7 +181,7 @@ void SetTLSFakeStack(FakeStack *fs) {
 #else
 FakeStack *GetTLSFakeStack() { return 0; }
 void SetTLSFakeStack(FakeStack *fs) { }
-#endif  // SANITIZER_LINUX && !SANITIZER_ANDROID
+#endif  // (SANITIZER_LINUX && !SANITIZER_ANDROID) || SANITIZER_FUCHSIA
 
 static FakeStack *GetFakeStack() {
   AsanThread *t = GetCurrentThread();
diff --git a/libsanitizer/asan/asan_flags.cc b/libsanitizer/asan/asan_flags.cc
index c18174beed0..0c83dac6747 100644
--- a/libsanitizer/asan/asan_flags.cc
+++ b/libsanitizer/asan/asan_flags.cc
@@ -59,7 +59,7 @@ void InitializeFlags() {
   {
     CommonFlags cf;
     cf.CopyFrom(*common_flags());
-    cf.detect_leaks = CAN_SANITIZE_LEAKS;
+    cf.detect_leaks = cf.detect_leaks && CAN_SANITIZE_LEAKS;
     cf.external_symbolizer_path = GetEnv("ASAN_SYMBOLIZER_PATH");
     cf.malloc_context_size = kDefaultMallocContextSize;
     cf.intercept_tls_get_addr = true;
@@ -93,6 +93,18 @@ void InitializeFlags() {
   RegisterCommonFlags(&ubsan_parser);
 #endif
 
+  if (SANITIZER_MAC) {
+    // Support macOS MallocScribble and MallocPreScribble:
+    // <https://developer.apple.com/library/content/documentation/Performance/
+    // Conceptual/ManagingMemory/Articles/MallocDebug.html>
+    if (GetEnv("MallocScribble")) {
+      f->max_free_fill_size = 0x1000;
+    }
+    if (GetEnv("MallocPreScribble")) {
+      f->malloc_fill_byte = 0xaa;
+    }
+  }
+
   // Override from ASan compile definition.
   const char *asan_compile_def = MaybeUseAsanDefaultOptionsCompileDefinition();
   asan_parser.ParseString(asan_compile_def);
@@ -104,6 +116,10 @@ void InitializeFlags() {
   const char *ubsan_default_options = __ubsan::MaybeCallUbsanDefaultOptions();
   ubsan_parser.ParseString(ubsan_default_options);
 #endif
+#if CAN_SANITIZE_LEAKS
+  const char *lsan_default_options = __lsan::MaybeCallLsanDefaultOptions();
+  lsan_parser.ParseString(lsan_default_options);
+#endif
 
   // Override from command line.
   asan_parser.ParseString(GetEnv("ASAN_OPTIONS"));
@@ -154,9 +170,24 @@ void InitializeFlags() {
     f->quarantine_size_mb = f->quarantine_size >> 20;
   if (f->quarantine_size_mb < 0) {
     const int kDefaultQuarantineSizeMb =
-        (ASAN_LOW_MEMORY) ? 1UL << 6 : 1UL << 8;
+        (ASAN_LOW_MEMORY) ? 1UL << 4 : 1UL << 8;
     f->quarantine_size_mb = kDefaultQuarantineSizeMb;
   }
+  if (f->thread_local_quarantine_size_kb < 0) {
+    const u32 kDefaultThreadLocalQuarantineSizeKb =
+        // It is not advised to go lower than 64Kb, otherwise quarantine batches
+        // pushed from thread local quarantine to global one will create too
+        // much overhead. One quarantine batch size is 8Kb and it  holds up to
+        // 1021 chunk, which amounts to 1/8 memory overhead per batch when
+        // thread local quarantine is set to 64Kb.
+        (ASAN_LOW_MEMORY) ? 1 << 6 : FIRST_32_SECOND_64(1 << 8, 1 << 10);
+    f->thread_local_quarantine_size_kb = kDefaultThreadLocalQuarantineSizeKb;
+  }
+  if (f->thread_local_quarantine_size_kb == 0 && f->quarantine_size_mb > 0) {
+    Report("%s: thread_local_quarantine_size_kb can be set to 0 only when "
+           "quarantine_size_mb is set to 0\n", SanitizerToolName);
+    Die();
+  }
   if (!f->replace_str && common_flags()->intercept_strlen) {
     Report("WARNING: strlen interceptor is enabled even though replace_str=0. "
            "Use intercept_strlen=0 to disable it.");
@@ -165,13 +196,14 @@ void InitializeFlags() {
     Report("WARNING: strchr* interceptors are enabled even though "
            "replace_str=0. Use intercept_strchr=0 to disable them.");
   }
+  if (!f->replace_str && common_flags()->intercept_strndup) {
+    Report("WARNING: strndup* interceptors are enabled even though "
+           "replace_str=0. Use intercept_strndup=0 to disable them.");
+  }
 }
 
 }  // namespace __asan
 
-#if !SANITIZER_SUPPORTS_WEAK_HOOKS
-extern "C" {
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-const char* __asan_default_options() { return ""; }
-}  // extern "C"
-#endif
+SANITIZER_INTERFACE_WEAK_DEF(const char*, __asan_default_options, void) {
+  return "";
+}
diff --git a/libsanitizer/asan/asan_flags.inc b/libsanitizer/asan/asan_flags.inc
index 34493eededf..3784f065be6 100644
--- a/libsanitizer/asan/asan_flags.inc
+++ b/libsanitizer/asan/asan_flags.inc
@@ -21,6 +21,12 @@ ASAN_FLAG(int, quarantine_size_mb, -1,
           "Size (in Mb) of quarantine used to detect use-after-free "
           "errors. Lower value may reduce memory usage but increase the "
           "chance of false negatives.")
+ASAN_FLAG(int, thread_local_quarantine_size_kb, -1,
+          "Size (in Kb) of thread local quarantine used to detect "
+          "use-after-free errors. Lower value may reduce memory usage but "
+          "increase the chance of false negatives. It is not advised to go "
+          "lower than 64Kb, otherwise frequent transfers to global quarantine "
+          "might affect performance.")
 ASAN_FLAG(int, redzone, 16,
           "Minimal size (in bytes) of redzones around heap objects. "
           "Requirement: redzone >= 16, is a power of two.")
@@ -55,8 +61,14 @@ ASAN_FLAG(
     int, max_malloc_fill_size, 0x1000,  // By default, fill only the first 4K.
     "ASan allocator flag. max_malloc_fill_size is the maximal amount of "
     "bytes that will be filled with malloc_fill_byte on malloc.")
+ASAN_FLAG(
+    int, max_free_fill_size, 0,
+    "ASan allocator flag. max_free_fill_size is the maximal amount of "
+    "bytes that will be filled with free_fill_byte during free.")
 ASAN_FLAG(int, malloc_fill_byte, 0xbe,
           "Value used to fill the newly allocated memory.")
+ASAN_FLAG(int, free_fill_byte, 0x55,
+          "Value used to fill deallocated memory.")
 ASAN_FLAG(bool, allow_user_poisoning, true,
           "If set, user may manually mark memory regions as poisoned or "
           "unpoisoned.")
@@ -65,6 +77,10 @@ ASAN_FLAG(
     "Number of seconds to sleep between printing an error report and "
     "terminating the program. Useful for debugging purposes (e.g. when one "
     "needs to attach gdb).")
+ASAN_FLAG(
+    int, sleep_after_init, 0,
+    "Number of seconds to sleep after AddressSanitizer is initialized. "
+    "Useful for debugging purposes (e.g. when one needs to attach gdb).")
 ASAN_FLAG(bool, check_malloc_usable_size, true,
           "Allows the users to work around the bug in Nvidia drivers prior to "
           "295.*.")
@@ -129,11 +145,16 @@ ASAN_FLAG(int, detect_odr_violation, 2,
           "If >=2, detect violation of One-Definition-Rule (ODR); "
           "If ==1, detect ODR-violation only if the two variables "
           "have different sizes")
-ASAN_FLAG(bool, dump_instruction_bytes, false,
-          "If true, dump 16 bytes starting at the instruction that caused SEGV")
 ASAN_FLAG(const char *, suppressions, "", "Suppressions file name.")
 ASAN_FLAG(bool, halt_on_error, true,
           "Crash the program after printing the first error report "
           "(WARNING: USE AT YOUR OWN RISK!)")
 ASAN_FLAG(bool, use_odr_indicator, false,
           "Use special ODR indicator symbol for ODR violation detection")
+ASAN_FLAG(bool, allocator_frees_and_returns_null_on_realloc_zero, true,
+          "realloc(p, 0) is equivalent to free(p) by default (Same as the "
+          "POSIX standard). If set to false, realloc(p, 0) will return a "
+          "pointer to an allocated space which can not be used.")
+ASAN_FLAG(bool, verify_asan_link_order, true,
+          "Check position of ASan runtime in library list (needs to be disabled"
+          " when other library has to be preloaded system-wide)")
diff --git a/libsanitizer/asan/asan_fuchsia.cc b/libsanitizer/asan/asan_fuchsia.cc
new file mode 100644
index 00000000000..6b1b48921ef
--- /dev/null
+++ b/libsanitizer/asan/asan_fuchsia.cc
@@ -0,0 +1,216 @@
+//===-- asan_fuchsia.cc --------------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===---------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+//
+// Fuchsia-specific details.
+//===---------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_fuchsia.h"
+#if SANITIZER_FUCHSIA
+
+#include "asan_interceptors.h"
+#include "asan_internal.h"
+#include "asan_stack.h"
+#include "asan_thread.h"
+
+#include <limits.h>
+#include <zircon/sanitizer.h>
+#include <zircon/syscalls.h>
+#include <zircon/threads.h>
+
+namespace __asan {
+
+// The system already set up the shadow memory for us.
+// __sanitizer::GetMaxVirtualAddress has already been called by
+// AsanInitInternal->InitializeHighMemEnd (asan_rtl.cc).
+// Just do some additional sanity checks here.
+void InitializeShadowMemory() {
+  if (Verbosity()) PrintAddressSpaceLayout();
+
+  // Make sure SHADOW_OFFSET doesn't use __asan_shadow_memory_dynamic_address.
+  __asan_shadow_memory_dynamic_address = kDefaultShadowSentinel;
+  DCHECK(kLowShadowBeg != kDefaultShadowSentinel);
+  __asan_shadow_memory_dynamic_address = kLowShadowBeg;
+
+  CHECK_EQ(kShadowGapEnd, kHighShadowBeg - 1);
+  CHECK_EQ(kHighMemEnd, __sanitizer::ShadowBounds.memory_limit - 1);
+  CHECK_EQ(kHighMemBeg, __sanitizer::ShadowBounds.shadow_limit);
+  CHECK_EQ(kHighShadowBeg, __sanitizer::ShadowBounds.shadow_base);
+  CHECK_EQ(kShadowGapEnd, __sanitizer::ShadowBounds.shadow_base - 1);
+  CHECK_EQ(kLowShadowEnd, 0);
+  CHECK_EQ(kLowShadowBeg, 0);
+}
+
+void AsanApplyToGlobals(globals_op_fptr op, const void *needle) {
+  UNIMPLEMENTED();
+}
+
+void AsanCheckDynamicRTPrereqs() {}
+void AsanCheckIncompatibleRT() {}
+void InitializeAsanInterceptors() {}
+
+void *AsanDoesNotSupportStaticLinkage() { return nullptr; }
+
+void InitializePlatformExceptionHandlers() {}
+void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
+  UNIMPLEMENTED();
+}
+
+// We can use a plain thread_local variable for TSD.
+static thread_local void *per_thread;
+
+void *AsanTSDGet() { return per_thread; }
+
+void AsanTSDSet(void *tsd) { per_thread = tsd; }
+
+// There's no initialization needed, and the passed-in destructor
+// will never be called.  Instead, our own thread destruction hook
+// (below) will call AsanThread::TSDDtor directly.
+void AsanTSDInit(void (*destructor)(void *tsd)) {
+  DCHECK(destructor == &PlatformTSDDtor);
+}
+
+void PlatformTSDDtor(void *tsd) { UNREACHABLE(__func__); }
+
+static inline size_t AsanThreadMmapSize() {
+  return RoundUpTo(sizeof(AsanThread), PAGE_SIZE);
+}
+
+struct AsanThread::InitOptions {
+  uptr stack_bottom, stack_size;
+};
+
+// Shared setup between thread creation and startup for the initial thread.
+static AsanThread *CreateAsanThread(StackTrace *stack, u32 parent_tid,
+                                    uptr user_id, bool detached,
+                                    const char *name, uptr stack_bottom,
+                                    uptr stack_size) {
+  // In lieu of AsanThread::Create.
+  AsanThread *thread = (AsanThread *)MmapOrDie(AsanThreadMmapSize(), __func__);
+
+  AsanThreadContext::CreateThreadContextArgs args = {thread, stack};
+  u32 tid =
+      asanThreadRegistry().CreateThread(user_id, detached, parent_tid, &args);
+  asanThreadRegistry().SetThreadName(tid, name);
+
+  // On other systems, AsanThread::Init() is called from the new
+  // thread itself.  But on Fuchsia we already know the stack address
+  // range beforehand, so we can do most of the setup right now.
+  const AsanThread::InitOptions options = {stack_bottom, stack_size};
+  thread->Init(&options);
+
+  return thread;
+}
+
+// This gets the same arguments passed to Init by CreateAsanThread, above.
+// We're in the creator thread before the new thread is actually started,
+// but its stack address range is already known.  We don't bother tracking
+// the static TLS address range because the system itself already uses an
+// ASan-aware allocator for that.
+void AsanThread::SetThreadStackAndTls(const AsanThread::InitOptions *options) {
+  DCHECK_NE(GetCurrentThread(), this);
+  DCHECK_NE(GetCurrentThread(), nullptr);
+  CHECK_NE(options->stack_bottom, 0);
+  CHECK_NE(options->stack_size, 0);
+  stack_bottom_ = options->stack_bottom;
+  stack_top_ = options->stack_bottom + options->stack_size;
+}
+
+// Called by __asan::AsanInitInternal (asan_rtl.c).
+AsanThread *CreateMainThread() {
+  thrd_t self = thrd_current();
+  char name[ZX_MAX_NAME_LEN];
+  CHECK_NE(__sanitizer::MainThreadStackBase, 0);
+  CHECK_GT(__sanitizer::MainThreadStackSize, 0);
+  AsanThread *t = CreateAsanThread(
+      nullptr, 0, reinterpret_cast<uptr>(self), true,
+      _zx_object_get_property(thrd_get_zx_handle(self), ZX_PROP_NAME, name,
+                              sizeof(name)) == ZX_OK
+          ? name
+          : nullptr,
+      __sanitizer::MainThreadStackBase, __sanitizer::MainThreadStackSize);
+  SetCurrentThread(t);
+  return t;
+}
+
+// This is called before each thread creation is attempted.  So, in
+// its first call, the calling thread is the initial and sole thread.
+static void *BeforeThreadCreateHook(uptr user_id, bool detached,
+                                    const char *name, uptr stack_bottom,
+                                    uptr stack_size) {
+  EnsureMainThreadIDIsCorrect();
+  // Strict init-order checking is thread-hostile.
+  if (flags()->strict_init_order) StopInitOrderChecking();
+
+  GET_STACK_TRACE_THREAD;
+  u32 parent_tid = GetCurrentTidOrInvalid();
+
+  return CreateAsanThread(&stack, parent_tid, user_id, detached, name,
+                          stack_bottom, stack_size);
+}
+
+// This is called after creating a new thread (in the creating thread),
+// with the pointer returned by BeforeThreadCreateHook (above).
+static void ThreadCreateHook(void *hook, bool aborted) {
+  AsanThread *thread = static_cast<AsanThread *>(hook);
+  if (!aborted) {
+    // The thread was created successfully.
+    // ThreadStartHook is already running in the new thread.
+  } else {
+    // The thread wasn't created after all.
+    // Clean up everything we set up in BeforeThreadCreateHook.
+    asanThreadRegistry().FinishThread(thread->tid());
+    UnmapOrDie(thread, AsanThreadMmapSize());
+  }
+}
+
+// This is called in the newly-created thread before it runs anything else,
+// with the pointer returned by BeforeThreadCreateHook (above).
+// cf. asan_interceptors.cc:asan_thread_start
+static void ThreadStartHook(void *hook, uptr os_id) {
+  AsanThread *thread = static_cast<AsanThread *>(hook);
+  SetCurrentThread(thread);
+
+  // In lieu of AsanThread::ThreadStart.
+  asanThreadRegistry().StartThread(thread->tid(), os_id, /*workerthread*/ false,
+                                   nullptr);
+}
+
+// Each thread runs this just before it exits,
+// with the pointer returned by BeforeThreadCreateHook (above).
+// All per-thread destructors have already been called.
+static void ThreadExitHook(void *hook, uptr os_id) {
+  AsanThread::TSDDtor(per_thread);
+}
+
+}  // namespace __asan
+
+// These are declared (in extern "C") by <zircon/sanitizer.h>.
+// The system runtime will call our definitions directly.
+
+void *__sanitizer_before_thread_create_hook(thrd_t thread, bool detached,
+                                            const char *name, void *stack_base,
+                                            size_t stack_size) {
+  return __asan::BeforeThreadCreateHook(
+      reinterpret_cast<uptr>(thread), detached, name,
+      reinterpret_cast<uptr>(stack_base), stack_size);
+}
+
+void __sanitizer_thread_create_hook(void *hook, thrd_t thread, int error) {
+  __asan::ThreadCreateHook(hook, error != thrd_success);
+}
+
+void __sanitizer_thread_start_hook(void *hook, thrd_t self) {
+  __asan::ThreadStartHook(hook, reinterpret_cast<uptr>(self));
+}
+
+void __sanitizer_thread_exit_hook(void *hook, thrd_t self) {
+  __asan::ThreadExitHook(hook, reinterpret_cast<uptr>(self));
+}
+
+#endif  // SANITIZER_FUCHSIA
diff --git a/libsanitizer/asan/asan_globals.cc b/libsanitizer/asan/asan_globals.cc
index f2292926e6a..c33b0ac7561 100644
--- a/libsanitizer/asan/asan_globals.cc
+++ b/libsanitizer/asan/asan_globals.cc
@@ -311,6 +311,26 @@ void __asan_unregister_image_globals(uptr *flag) {
   *flag = 0;
 }
 
+void __asan_register_elf_globals(uptr *flag, void *start, void *stop) {
+  if (*flag) return;
+  if (!start) return;
+  CHECK_EQ(0, ((uptr)stop - (uptr)start) % sizeof(__asan_global));
+  __asan_global *globals_start = (__asan_global*)start;
+  __asan_global *globals_stop = (__asan_global*)stop;
+  __asan_register_globals(globals_start, globals_stop - globals_start);
+  *flag = 1;
+}
+
+void __asan_unregister_elf_globals(uptr *flag, void *start, void *stop) {
+  if (!*flag) return;
+  if (!start) return;
+  CHECK_EQ(0, ((uptr)stop - (uptr)start) % sizeof(__asan_global));
+  __asan_global *globals_start = (__asan_global*)start;
+  __asan_global *globals_stop = (__asan_global*)stop;
+  __asan_unregister_globals(globals_start, globals_stop - globals_start);
+  *flag = 0;
+}
+
 // Register an array of globals.
 void __asan_register_globals(__asan_global *globals, uptr n) {
   if (!flags()->report_globals) return;
@@ -327,8 +347,26 @@ void __asan_register_globals(__asan_global *globals, uptr n) {
     Printf("=== ID %d; %p %p\n", stack_id, &globals[0], &globals[n - 1]);
   }
   for (uptr i = 0; i < n; i++) {
+    if (SANITIZER_WINDOWS && globals[i].beg == 0) {
+      // The MSVC incremental linker may pad globals out to 256 bytes. As long
+      // as __asan_global is less than 256 bytes large and its size is a power
+      // of two, we can skip over the padding.
+      static_assert(
+          sizeof(__asan_global) < 256 &&
+              (sizeof(__asan_global) & (sizeof(__asan_global) - 1)) == 0,
+          "sizeof(__asan_global) incompatible with incremental linker padding");
+      // If these are padding bytes, the rest of the global should be zero.
+      CHECK(globals[i].size == 0 && globals[i].size_with_redzone == 0 &&
+            globals[i].name == nullptr && globals[i].module_name == nullptr &&
+            globals[i].odr_indicator == 0);
+      continue;
+    }
     RegisterGlobal(&globals[i]);
   }
+
+  // Poison the metadata. It should not be accessible to user code.
+  PoisonShadow(reinterpret_cast<uptr>(globals), n * sizeof(__asan_global),
+               kAsanGlobalRedzoneMagic);
 }
 
 // Unregister an array of globals.
@@ -337,8 +375,16 @@ void __asan_unregister_globals(__asan_global *globals, uptr n) {
   if (!flags()->report_globals) return;
   BlockingMutexLock lock(&mu_for_globals);
   for (uptr i = 0; i < n; i++) {
+    if (SANITIZER_WINDOWS && globals[i].beg == 0) {
+      // Skip globals that look like padding from the MSVC incremental linker.
+      // See comment in __asan_register_globals.
+      continue;
+    }
     UnregisterGlobal(&globals[i]);
   }
+
+  // Unpoison the metadata.
+  PoisonShadow(reinterpret_cast<uptr>(globals), n * sizeof(__asan_global), 0);
 }
 
 // This method runs immediately prior to dynamic initialization in each TU,
diff --git a/libsanitizer/asan/asan_globals_win.cc b/libsanitizer/asan/asan_globals_win.cc
new file mode 100644
index 00000000000..118c0ac991c
--- /dev/null
+++ b/libsanitizer/asan/asan_globals_win.cc
@@ -0,0 +1,60 @@
+//===-- asan_globals_win.cc -----------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Global registration code that is linked into every Windows DLL and EXE.
+//
+//===----------------------------------------------------------------------===//
+
+#include "asan_interface_internal.h"
+#if SANITIZER_WINDOWS
+
+namespace __asan {
+
+#pragma section(".ASAN$GA", read, write)  // NOLINT
+#pragma section(".ASAN$GZ", read, write)  // NOLINT
+extern "C" __declspec(allocate(".ASAN$GA"))
+__asan_global __asan_globals_start = {};
+extern "C" __declspec(allocate(".ASAN$GZ"))
+__asan_global __asan_globals_end = {};
+#pragma comment(linker, "/merge:.ASAN=.data")
+
+static void call_on_globals(void (*hook)(__asan_global *, uptr)) {
+  __asan_global *start = &__asan_globals_start + 1;
+  __asan_global *end = &__asan_globals_end;
+  uptr bytediff = (uptr)end - (uptr)start;
+  if (bytediff % sizeof(__asan_global) != 0) {
+#ifdef SANITIZER_DLL_THUNK
+    __debugbreak();
+#else
+    CHECK("corrupt asan global array");
+#endif
+  }
+  // We know end >= start because the linker sorts the portion after the dollar
+  // sign alphabetically.
+  uptr n = end - start;
+  hook(start, n);
+}
+
+static void register_dso_globals() {
+  call_on_globals(&__asan_register_globals);
+}
+
+static void unregister_dso_globals() {
+  call_on_globals(&__asan_unregister_globals);
+}
+
+// Register globals
+#pragma section(".CRT$XCU", long, read)  // NOLINT
+#pragma section(".CRT$XTX", long, read)  // NOLINT
+extern "C" __declspec(allocate(".CRT$XCU"))
+void (*const __asan_dso_reg_hook)() = &register_dso_globals;
+extern "C" __declspec(allocate(".CRT$XTX"))
+void (*const __asan_dso_unreg_hook)() = &unregister_dso_globals;
+
+} // namespace __asan
+
+#endif  // SANITIZER_WINDOWS
diff --git a/libsanitizer/asan/asan_interceptors.cc b/libsanitizer/asan/asan_interceptors.cc
index 743abe51481..a8f4b72723f 100644
--- a/libsanitizer/asan/asan_interceptors.cc
+++ b/libsanitizer/asan/asan_interceptors.cc
@@ -22,6 +22,11 @@
 #include "lsan/lsan_common.h"
 #include "sanitizer_common/sanitizer_libc.h"
 
+// There is no general interception at all on Fuchsia.
+// Only the functions in asan_interceptors_memintrinsics.cc are
+// really defined to replace libc functions.
+#if !SANITIZER_FUCHSIA
+
 #if SANITIZER_POSIX
 #include "sanitizer_common/sanitizer_posix.h"
 #endif
@@ -34,56 +39,6 @@
 
 namespace __asan {
 
-// Return true if we can quickly decide that the region is unpoisoned.
-static inline bool QuickCheckForUnpoisonedRegion(uptr beg, uptr size) {
-  if (size == 0) return true;
-  if (size <= 32)
-    return !AddressIsPoisoned(beg) &&
-           !AddressIsPoisoned(beg + size - 1) &&
-           !AddressIsPoisoned(beg + size / 2);
-  return false;
-}
-
-struct AsanInterceptorContext {
-  const char *interceptor_name;
-};
-
-// We implement ACCESS_MEMORY_RANGE, ASAN_READ_RANGE,
-// and ASAN_WRITE_RANGE as macro instead of function so
-// that no extra frames are created, and stack trace contains
-// relevant information only.
-// We check all shadow bytes.
-#define ACCESS_MEMORY_RANGE(ctx, offset, size, isWrite) do {            \
-    uptr __offset = (uptr)(offset);                                     \
-    uptr __size = (uptr)(size);                                         \
-    uptr __bad = 0;                                                     \
-    if (__offset > __offset + __size) {                                 \
-      GET_STACK_TRACE_FATAL_HERE;                                       \
-      ReportStringFunctionSizeOverflow(__offset, __size, &stack);       \
-    }                                                                   \
-    if (!QuickCheckForUnpoisonedRegion(__offset, __size) &&             \
-        (__bad = __asan_region_is_poisoned(__offset, __size))) {        \
-      AsanInterceptorContext *_ctx = (AsanInterceptorContext *)ctx;     \
-      bool suppressed = false;                                          \
-      if (_ctx) {                                                       \
-        suppressed = IsInterceptorSuppressed(_ctx->interceptor_name);   \
-        if (!suppressed && HaveStackTraceBasedSuppressions()) {         \
-          GET_STACK_TRACE_FATAL_HERE;                                   \
-          suppressed = IsStackTraceSuppressed(&stack);                  \
-        }                                                               \
-      }                                                                 \
-      if (!suppressed) {                                                \
-        GET_CURRENT_PC_BP_SP;                                           \
-        ReportGenericError(pc, bp, sp, __bad, isWrite, __size, 0, false);\
-      }                                                                 \
-    }                                                                   \
-  } while (0)
-
-#define ASAN_READ_RANGE(ctx, offset, size) \
-  ACCESS_MEMORY_RANGE(ctx, offset, size, false)
-#define ASAN_WRITE_RANGE(ctx, offset, size) \
-  ACCESS_MEMORY_RANGE(ctx, offset, size, true)
-
 #define ASAN_READ_STRING_OF_LEN(ctx, s, len, n)                 \
   ASAN_READ_RANGE((ctx), (s),                                   \
     common_flags()->strict_string_checks ? (len) + 1 : (n))
@@ -91,23 +46,6 @@ struct AsanInterceptorContext {
 #define ASAN_READ_STRING(ctx, s, n)                             \
   ASAN_READ_STRING_OF_LEN((ctx), (s), REAL(strlen)(s), (n))
 
-// Behavior of functions like "memcpy" or "strcpy" is undefined
-// if memory intervals overlap. We report error in this case.
-// Macro is used to avoid creation of new frames.
-static inline bool RangesOverlap(const char *offset1, uptr length1,
-                                 const char *offset2, uptr length2) {
-  return !((offset1 + length1 <= offset2) || (offset2 + length2 <= offset1));
-}
-#define CHECK_RANGES_OVERLAP(name, _offset1, length1, _offset2, length2) do { \
-  const char *offset1 = (const char*)_offset1; \
-  const char *offset2 = (const char*)_offset2; \
-  if (RangesOverlap(offset1, length1, offset2, length2)) { \
-    GET_STACK_TRACE_FATAL_HERE; \
-    ReportStringFunctionMemoryRangesOverlap(name, offset1, length1, \
-                                            offset2, length2, &stack); \
-  } \
-} while (0)
-
 static inline uptr MaybeRealStrnlen(const char *s, uptr maxlen) {
 #if SANITIZER_INTERCEPT_STRNLEN
   if (REAL(strnlen)) {
@@ -124,6 +62,10 @@ void SetThreadName(const char *name) {
 }
 
 int OnExit() {
+  if (CAN_SANITIZE_LEAKS && common_flags()->detect_leaks &&
+      __lsan::HasReportedLeaks()) {
+    return common_flags()->exitcode;
+  }
   // FIXME: ask frontend whether we need to return failure.
   return 0;
 }
@@ -181,13 +123,14 @@ DECLARE_REAL_AND_INTERCEPTOR(void, free, void *)
 // Strict init-order checking is dlopen-hostile:
 // https://github.com/google/sanitizers/issues/178
 #define COMMON_INTERCEPTOR_ON_DLOPEN(filename, flag)                           \
-  if (flags()->strict_init_order) {                                            \
-    StopInitOrderChecking();                                                   \
-  }
+  do {                                                                         \
+    if (flags()->strict_init_order)                                            \
+      StopInitOrderChecking();                                                 \
+    CheckNoDeepBind(filename, flag);                                           \
+  } while (false)
 #define COMMON_INTERCEPTOR_ON_EXIT(ctx) OnExit()
-#define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle) \
-  CoverageUpdateMapping()
-#define COMMON_INTERCEPTOR_LIBRARY_UNLOADED() CoverageUpdateMapping()
+#define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle)
+#define COMMON_INTERCEPTOR_LIBRARY_UNLOADED()
 #define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED (!asan_inited)
 #define COMMON_INTERCEPTOR_GET_TLS_RANGE(begin, end)                           \
   if (AsanThread *t = GetCurrentThread()) {                                    \
@@ -196,11 +139,27 @@ DECLARE_REAL_AND_INTERCEPTOR(void, free, void *)
   } else {                                                                     \
     *begin = *end = 0;                                                         \
   }
-// Asan needs custom handling of these:
-#undef SANITIZER_INTERCEPT_MEMSET
-#undef SANITIZER_INTERCEPT_MEMMOVE
-#undef SANITIZER_INTERCEPT_MEMCPY
+
+#define COMMON_INTERCEPTOR_MEMMOVE_IMPL(ctx, to, from, size) \
+  do {                                                       \
+    ASAN_INTERCEPTOR_ENTER(ctx, memmove);                    \
+    ASAN_MEMMOVE_IMPL(ctx, to, from, size);                  \
+  } while (false)
+
+#define COMMON_INTERCEPTOR_MEMCPY_IMPL(ctx, to, from, size) \
+  do {                                                      \
+    ASAN_INTERCEPTOR_ENTER(ctx, memcpy);                    \
+    ASAN_MEMCPY_IMPL(ctx, to, from, size);                  \
+  } while (false)
+
+#define COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, c, size) \
+  do {                                                      \
+    ASAN_INTERCEPTOR_ENTER(ctx, memset);                    \
+    ASAN_MEMSET_IMPL(ctx, block, c, size);                  \
+  } while (false)
+
 #include "sanitizer_common/sanitizer_common_interceptors.inc"
+#include "sanitizer_common/sanitizer_signal_interceptors.inc"
 
 // Syscall interceptors don't have contexts, we don't support suppressions
 // for them.
@@ -282,48 +241,6 @@ INTERCEPTOR(int, pthread_join, void *t, void **arg) {
 DEFINE_REAL_PTHREAD_FUNCTIONS
 #endif  // ASAN_INTERCEPT_PTHREAD_CREATE
 
-#if ASAN_INTERCEPT_SIGNAL_AND_SIGACTION
-
-#if SANITIZER_ANDROID
-INTERCEPTOR(void*, bsd_signal, int signum, void *handler) {
-  if (!IsHandledDeadlySignal(signum) ||
-      common_flags()->allow_user_segv_handler) {
-    return REAL(bsd_signal)(signum, handler);
-  }
-  return 0;
-}
-#endif
-
-INTERCEPTOR(void*, signal, int signum, void *handler) {
-  if (!IsHandledDeadlySignal(signum) ||
-      common_flags()->allow_user_segv_handler) {
-    return REAL(signal)(signum, handler);
-  }
-  return nullptr;
-}
-
-INTERCEPTOR(int, sigaction, int signum, const struct sigaction *act,
-                            struct sigaction *oldact) {
-  if (!IsHandledDeadlySignal(signum) ||
-      common_flags()->allow_user_segv_handler) {
-    return REAL(sigaction)(signum, act, oldact);
-  }
-  return 0;
-}
-
-namespace __sanitizer {
-int real_sigaction(int signum, const void *act, void *oldact) {
-  return REAL(sigaction)(signum, (const struct sigaction *)act,
-                         (struct sigaction *)oldact);
-}
-} // namespace __sanitizer
-
-#elif SANITIZER_POSIX
-// We need to have defined REAL(sigaction) on posix systems.
-DEFINE_REAL(int, sigaction, int signum, const struct sigaction *act,
-    struct sigaction *oldact)
-#endif  // ASAN_INTERCEPT_SIGNAL_AND_SIGACTION
-
 #if ASAN_INTERCEPT_SWAPCONTEXT
 static void ClearShadowMemoryForContextStack(uptr stack, uptr ssize) {
   // Align to page size.
@@ -360,6 +277,11 @@ INTERCEPTOR(int, swapcontext, struct ucontext_t *oucp,
 }
 #endif  // ASAN_INTERCEPT_SWAPCONTEXT
 
+#if SANITIZER_NETBSD
+#define longjmp __longjmp14
+#define siglongjmp __siglongjmp14
+#endif
+
 INTERCEPTOR(void, longjmp, void *env, int val) {
   __asan_handle_no_return();
   REAL(longjmp)(env, val);
@@ -372,6 +294,13 @@ INTERCEPTOR(void, _longjmp, void *env, int val) {
 }
 #endif
 
+#if ASAN_INTERCEPT___LONGJMP_CHK
+INTERCEPTOR(void, __longjmp_chk, void *env, int val) {
+  __asan_handle_no_return();
+  REAL(__longjmp_chk)(env, val);
+}
+#endif
+
 #if ASAN_INTERCEPT_SIGLONGJMP
 INTERCEPTOR(void, siglongjmp, void *env, int val) {
   __asan_handle_no_return();
@@ -387,90 +316,6 @@ INTERCEPTOR(void, __cxa_throw, void *a, void *b, void *c) {
 }
 #endif
 
-// memcpy is called during __asan_init() from the internals of printf(...).
-// We do not treat memcpy with to==from as a bug.
-// See http://llvm.org/bugs/show_bug.cgi?id=11763.
-#define ASAN_MEMCPY_IMPL(ctx, to, from, size) do {                             \
-    if (UNLIKELY(!asan_inited)) return internal_memcpy(to, from, size);        \
-    if (asan_init_is_running) {                                                \
-      return REAL(memcpy)(to, from, size);                                     \
-    }                                                                          \
-    ENSURE_ASAN_INITED();                                                      \
-    if (flags()->replace_intrin) {                                             \
-      if (to != from) {                                                        \
-        CHECK_RANGES_OVERLAP("memcpy", to, size, from, size);                  \
-      }                                                                        \
-      ASAN_READ_RANGE(ctx, from, size);                                        \
-      ASAN_WRITE_RANGE(ctx, to, size);                                         \
-    }                                                                          \
-    return REAL(memcpy)(to, from, size);                                       \
-  } while (0)
-
-
-void *__asan_memcpy(void *to, const void *from, uptr size) {
-  ASAN_MEMCPY_IMPL(nullptr, to, from, size);
-}
-
-// memset is called inside Printf.
-#define ASAN_MEMSET_IMPL(ctx, block, c, size) do {                             \
-    if (UNLIKELY(!asan_inited)) return internal_memset(block, c, size);        \
-    if (asan_init_is_running) {                                                \
-      return REAL(memset)(block, c, size);                                     \
-    }                                                                          \
-    ENSURE_ASAN_INITED();                                                      \
-    if (flags()->replace_intrin) {                                             \
-      ASAN_WRITE_RANGE(ctx, block, size);                                      \
-    }                                                                          \
-    return REAL(memset)(block, c, size);                                       \
-  } while (0)
-
-void *__asan_memset(void *block, int c, uptr size) {
-  ASAN_MEMSET_IMPL(nullptr, block, c, size);
-}
-
-#define ASAN_MEMMOVE_IMPL(ctx, to, from, size) do {                            \
-    if (UNLIKELY(!asan_inited))                                                \
-      return internal_memmove(to, from, size);                                 \
-    ENSURE_ASAN_INITED();                                                      \
-    if (flags()->replace_intrin) {                                             \
-      ASAN_READ_RANGE(ctx, from, size);                                        \
-      ASAN_WRITE_RANGE(ctx, to, size);                                         \
-    }                                                                          \
-    return internal_memmove(to, from, size);                                   \
-  } while (0)
-
-void *__asan_memmove(void *to, const void *from, uptr size) {
-  ASAN_MEMMOVE_IMPL(nullptr, to, from, size);
-}
-
-INTERCEPTOR(void*, memmove, void *to, const void *from, uptr size) {
-  void *ctx;
-  ASAN_INTERCEPTOR_ENTER(ctx, memmove);
-  ASAN_MEMMOVE_IMPL(ctx, to, from, size);
-}
-
-INTERCEPTOR(void*, memcpy, void *to, const void *from, uptr size) {
-  void *ctx;
-  ASAN_INTERCEPTOR_ENTER(ctx, memcpy);
-#if !SANITIZER_MAC
-  ASAN_MEMCPY_IMPL(ctx, to, from, size);
-#else
-  // At least on 10.7 and 10.8 both memcpy() and memmove() are being replaced
-  // with WRAP(memcpy). As a result, false positives are reported for memmove()
-  // calls. If we just disable error reporting with
-  // ASAN_OPTIONS=replace_intrin=0, memmove() is still replaced with
-  // internal_memcpy(), which may lead to crashes, see
-  // http://llvm.org/bugs/show_bug.cgi?id=16362.
-  ASAN_MEMMOVE_IMPL(ctx, to, from, size);
-#endif  // !SANITIZER_MAC
-}
-
-INTERCEPTOR(void*, memset, void *block, int c, uptr size) {
-  void *ctx;
-  ASAN_INTERCEPTOR_ENTER(ctx, memset);
-  ASAN_MEMSET_IMPL(ctx, block, c, size);
-}
-
 #if ASAN_INTERCEPT_INDEX
 # if ASAN_USE_ALIAS_ATTRIBUTE_FOR_INDEX
 INTERCEPTOR(char*, index, const char *string, int c)
@@ -580,17 +425,6 @@ INTERCEPTOR(char*, __strdup, const char *s) {
 }
 #endif // ASAN_INTERCEPT___STRDUP
 
-INTERCEPTOR(SIZE_T, wcslen, const wchar_t *s) {
-  void *ctx;
-  ASAN_INTERCEPTOR_ENTER(ctx, wcslen);
-  SIZE_T length = internal_wcslen(s);
-  if (!asan_init_is_running) {
-    ENSURE_ASAN_INITED();
-    ASAN_READ_RANGE(ctx, s, (length + 1) * sizeof(wchar_t));
-  }
-  return length;
-}
-
 INTERCEPTOR(char*, strncpy, char *to, const char *from, uptr size) {
   void *ctx;
   ASAN_INTERCEPTOR_ENTER(ctx, strncpy);
@@ -707,9 +541,7 @@ INTERCEPTOR(int, __cxa_atexit, void (*func)(void *), void *arg,
 #if ASAN_INTERCEPT_FORK
 INTERCEPTOR(int, fork, void) {
   ENSURE_ASAN_INITED();
-  if (common_flags()->coverage) CovBeforeFork();
   int pid = REAL(fork)();
-  if (common_flags()->coverage) CovAfterFork(pid);
   return pid;
 }
 #endif  // ASAN_INTERCEPT_FORK
@@ -721,22 +553,11 @@ void InitializeAsanInterceptors() {
   CHECK(!was_called_once);
   was_called_once = true;
   InitializeCommonInterceptors();
-
-  // Intercept mem* functions.
-  ASAN_INTERCEPT_FUNC(memmove);
-  ASAN_INTERCEPT_FUNC(memset);
-  if (PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE) {
-    // In asan, REAL(memmove) is not used, but it is used in msan.
-    ASAN_INTERCEPT_FUNC(memcpy);
-  } else {
-    ASSIGN_REAL(memcpy, memmove);
-  }
-  CHECK(REAL(memcpy));
+  InitializeSignalInterceptors();
 
   // Intercept str* functions.
   ASAN_INTERCEPT_FUNC(strcat);  // NOLINT
   ASAN_INTERCEPT_FUNC(strcpy);  // NOLINT
-  ASAN_INTERCEPT_FUNC(wcslen);
   ASAN_INTERCEPT_FUNC(strncat);
   ASAN_INTERCEPT_FUNC(strncpy);
   ASAN_INTERCEPT_FUNC(strdup);
@@ -755,21 +576,18 @@ void InitializeAsanInterceptors() {
   ASAN_INTERCEPT_FUNC(strtoll);
 #endif
 
-  // Intecept signal- and jump-related functions.
+  // Intecept jump-related functions.
   ASAN_INTERCEPT_FUNC(longjmp);
-#if ASAN_INTERCEPT_SIGNAL_AND_SIGACTION
-  ASAN_INTERCEPT_FUNC(sigaction);
-#if SANITIZER_ANDROID
-  ASAN_INTERCEPT_FUNC(bsd_signal);
-#endif
-  ASAN_INTERCEPT_FUNC(signal);
-#endif
+
 #if ASAN_INTERCEPT_SWAPCONTEXT
   ASAN_INTERCEPT_FUNC(swapcontext);
 #endif
 #if ASAN_INTERCEPT__LONGJMP
   ASAN_INTERCEPT_FUNC(_longjmp);
 #endif
+#if ASAN_INTERCEPT___LONGJMP_CHK
+  ASAN_INTERCEPT_FUNC(__longjmp_chk);
+#endif
 #if ASAN_INTERCEPT_SIGLONGJMP
   ASAN_INTERCEPT_FUNC(siglongjmp);
 #endif
@@ -804,3 +622,5 @@ void InitializeAsanInterceptors() {
 }
 
 } // namespace __asan
+
+#endif  // !SANITIZER_FUCHSIA
diff --git a/libsanitizer/asan/asan_interceptors.h b/libsanitizer/asan/asan_interceptors.h
index 7053bb7faf5..e20d1af15a6 100644
--- a/libsanitizer/asan/asan_interceptors.h
+++ b/libsanitizer/asan/asan_interceptors.h
@@ -13,9 +13,30 @@
 #define ASAN_INTERCEPTORS_H
 
 #include "asan_internal.h"
+#include "asan_interceptors_memintrinsics.h"
 #include "interception/interception.h"
 #include "sanitizer_common/sanitizer_platform_interceptors.h"
 
+namespace __asan {
+
+void InitializeAsanInterceptors();
+void InitializePlatformInterceptors();
+
+#define ENSURE_ASAN_INITED()      \
+  do {                            \
+    CHECK(!asan_init_is_running); \
+    if (UNLIKELY(!asan_inited)) { \
+      AsanInitFromRtl();          \
+    }                             \
+  } while (0)
+
+}  // namespace __asan
+
+// There is no general interception at all on Fuchsia.
+// Only the functions in asan_interceptors_memintrinsics.h are
+// really defined to replace libc functions.
+#if !SANITIZER_FUCHSIA
+
 // Use macro to describe if specific function should be
 // intercepted on a given platform.
 #if !SANITIZER_WINDOWS
@@ -32,7 +53,7 @@
 # define ASAN_INTERCEPT_FORK 0
 #endif
 
-#if SANITIZER_FREEBSD || SANITIZER_LINUX
+#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
 # define ASAN_USE_ALIAS_ATTRIBUTE_FOR_INDEX 1
 #else
 # define ASAN_USE_ALIAS_ATTRIBUTE_FOR_INDEX 0
@@ -45,15 +66,15 @@
 #endif
 
 #if !SANITIZER_WINDOWS
-# define ASAN_INTERCEPT_SIGNAL_AND_SIGACTION 1
+# define ASAN_INTERCEPT_SIGLONGJMP 1
 #else
-# define ASAN_INTERCEPT_SIGNAL_AND_SIGACTION 0
+# define ASAN_INTERCEPT_SIGLONGJMP 0
 #endif
 
-#if !SANITIZER_WINDOWS
-# define ASAN_INTERCEPT_SIGLONGJMP 1
+#if SANITIZER_LINUX && !SANITIZER_ANDROID
+# define ASAN_INTERCEPT___LONGJMP_CHK 1
 #else
-# define ASAN_INTERCEPT_SIGLONGJMP 0
+# define ASAN_INTERCEPT___LONGJMP_CHK 0
 #endif
 
 // Android bug: https://code.google.com/p/android/issues/detail?id=61799
@@ -77,8 +98,6 @@
 #endif
 
 DECLARE_REAL(int, memcmp, const void *a1, const void *a2, uptr size)
-DECLARE_REAL(void*, memcpy, void *to, const void *from, uptr size)
-DECLARE_REAL(void*, memset, void *block, int c, uptr size)
 DECLARE_REAL(char*, strchr, const char *str, int c)
 DECLARE_REAL(SIZE_T, strlen, const char *s)
 DECLARE_REAL(char*, strncpy, char *to, const char *from, uptr size)
@@ -105,18 +124,6 @@ DECLARE_REAL(int, sigaction, int signum, const struct sigaction *act,
 #define ASAN_INTERCEPT_FUNC(name)
 #endif  // SANITIZER_MAC
 
-namespace __asan {
-
-void InitializeAsanInterceptors();
-void InitializePlatformInterceptors();
-
-#define ENSURE_ASAN_INITED() do { \
-  CHECK(!asan_init_is_running); \
-  if (UNLIKELY(!asan_inited)) { \
-    AsanInitFromRtl(); \
-  } \
-} while (0)
-
-}  // namespace __asan
+#endif  // !SANITIZER_FUCHSIA
 
 #endif  // ASAN_INTERCEPTORS_H
diff --git a/libsanitizer/asan/asan_interceptors_memintrinsics.cc b/libsanitizer/asan/asan_interceptors_memintrinsics.cc
new file mode 100644
index 00000000000..16de54cfeef
--- /dev/null
+++ b/libsanitizer/asan/asan_interceptors_memintrinsics.cc
@@ -0,0 +1,42 @@
+//===-- asan_interceptors_memintrinsics.cc --------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===---------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+//
+// ASan versions of memcpy, memmove, and memset.
+//===---------------------------------------------------------------------===//
+
+#include "asan_interceptors_memintrinsics.h"
+#include "asan_report.h"
+#include "asan_stack.h"
+#include "asan_suppressions.h"
+
+using namespace __asan;  // NOLINT
+
+void *__asan_memcpy(void *to, const void *from, uptr size) {
+  ASAN_MEMCPY_IMPL(nullptr, to, from, size);
+}
+
+void *__asan_memset(void *block, int c, uptr size) {
+  ASAN_MEMSET_IMPL(nullptr, block, c, size);
+}
+
+void *__asan_memmove(void *to, const void *from, uptr size) {
+  ASAN_MEMMOVE_IMPL(nullptr, to, from, size);
+}
+
+#if SANITIZER_FUCHSIA
+
+// Fuchsia doesn't use sanitizer_common_interceptors.inc, but the only
+// things there it wants are these three.  Just define them as aliases
+// here rather than repeating the contents.
+
+decltype(memcpy) memcpy[[gnu::alias("__asan_memcpy")]];
+decltype(memmove) memmove[[gnu::alias("__asan_memmove")]];
+decltype(memset) memset[[gnu::alias("__asan_memset")]];
+
+#endif  // SANITIZER_FUCHSIA
diff --git a/libsanitizer/asan/asan_interceptors_memintrinsics.h b/libsanitizer/asan/asan_interceptors_memintrinsics.h
new file mode 100644
index 00000000000..1dc4d64c7fa
--- /dev/null
+++ b/libsanitizer/asan/asan_interceptors_memintrinsics.h
@@ -0,0 +1,146 @@
+//===-- asan_interceptors_memintrinsics.h -----------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===---------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+//
+// ASan-private header for asan_memintrin.cc
+//===---------------------------------------------------------------------===//
+#ifndef ASAN_MEMINTRIN_H
+#define ASAN_MEMINTRIN_H
+
+#include "asan_interface_internal.h"
+#include "asan_internal.h"
+#include "asan_mapping.h"
+#include "interception/interception.h"
+
+DECLARE_REAL(void*, memcpy, void *to, const void *from, uptr size)
+DECLARE_REAL(void*, memset, void *block, int c, uptr size)
+
+namespace __asan {
+
+// Return true if we can quickly decide that the region is unpoisoned.
+// We assume that a redzone is at least 16 bytes.
+static inline bool QuickCheckForUnpoisonedRegion(uptr beg, uptr size) {
+  if (size == 0) return true;
+  if (size <= 32)
+    return !AddressIsPoisoned(beg) &&
+           !AddressIsPoisoned(beg + size - 1) &&
+           !AddressIsPoisoned(beg + size / 2);
+  if (size <= 64)
+    return !AddressIsPoisoned(beg) &&
+           !AddressIsPoisoned(beg + size / 4) &&
+           !AddressIsPoisoned(beg + size - 1) &&
+           !AddressIsPoisoned(beg + 3 * size / 4) &&
+           !AddressIsPoisoned(beg + size / 2);
+  return false;
+}
+
+struct AsanInterceptorContext {
+  const char *interceptor_name;
+};
+
+// We implement ACCESS_MEMORY_RANGE, ASAN_READ_RANGE,
+// and ASAN_WRITE_RANGE as macro instead of function so
+// that no extra frames are created, and stack trace contains
+// relevant information only.
+// We check all shadow bytes.
+#define ACCESS_MEMORY_RANGE(ctx, offset, size, isWrite) do {            \
+    uptr __offset = (uptr)(offset);                                     \
+    uptr __size = (uptr)(size);                                         \
+    uptr __bad = 0;                                                     \
+    if (__offset > __offset + __size) {                                 \
+      GET_STACK_TRACE_FATAL_HERE;                                       \
+      ReportStringFunctionSizeOverflow(__offset, __size, &stack);       \
+    }                                                                   \
+    if (!QuickCheckForUnpoisonedRegion(__offset, __size) &&             \
+        (__bad = __asan_region_is_poisoned(__offset, __size))) {        \
+      AsanInterceptorContext *_ctx = (AsanInterceptorContext *)ctx;     \
+      bool suppressed = false;                                          \
+      if (_ctx) {                                                       \
+        suppressed = IsInterceptorSuppressed(_ctx->interceptor_name);   \
+        if (!suppressed && HaveStackTraceBasedSuppressions()) {         \
+          GET_STACK_TRACE_FATAL_HERE;                                   \
+          suppressed = IsStackTraceSuppressed(&stack);                  \
+        }                                                               \
+      }                                                                 \
+      if (!suppressed) {                                                \
+        GET_CURRENT_PC_BP_SP;                                           \
+        ReportGenericError(pc, bp, sp, __bad, isWrite, __size, 0, false);\
+      }                                                                 \
+    }                                                                   \
+  } while (0)
+
+// memcpy is called during __asan_init() from the internals of printf(...).
+// We do not treat memcpy with to==from as a bug.
+// See http://llvm.org/bugs/show_bug.cgi?id=11763.
+#define ASAN_MEMCPY_IMPL(ctx, to, from, size)                           \
+  do {                                                                  \
+    if (UNLIKELY(!asan_inited)) return internal_memcpy(to, from, size); \
+    if (asan_init_is_running) {                                         \
+      return REAL(memcpy)(to, from, size);                              \
+    }                                                                   \
+    ENSURE_ASAN_INITED();                                               \
+    if (flags()->replace_intrin) {                                      \
+      if (to != from) {                                                 \
+        CHECK_RANGES_OVERLAP("memcpy", to, size, from, size);           \
+      }                                                                 \
+      ASAN_READ_RANGE(ctx, from, size);                                 \
+      ASAN_WRITE_RANGE(ctx, to, size);                                  \
+    }                                                                   \
+    return REAL(memcpy)(to, from, size);                                \
+  } while (0)
+
+// memset is called inside Printf.
+#define ASAN_MEMSET_IMPL(ctx, block, c, size)                           \
+  do {                                                                  \
+    if (UNLIKELY(!asan_inited)) return internal_memset(block, c, size); \
+    if (asan_init_is_running) {                                         \
+      return REAL(memset)(block, c, size);                              \
+    }                                                                   \
+    ENSURE_ASAN_INITED();                                               \
+    if (flags()->replace_intrin) {                                      \
+      ASAN_WRITE_RANGE(ctx, block, size);                               \
+    }                                                                   \
+    return REAL(memset)(block, c, size);                                \
+  } while (0)
+
+#define ASAN_MEMMOVE_IMPL(ctx, to, from, size)                           \
+  do {                                                                   \
+    if (UNLIKELY(!asan_inited)) return internal_memmove(to, from, size); \
+    ENSURE_ASAN_INITED();                                                \
+    if (flags()->replace_intrin) {                                       \
+      ASAN_READ_RANGE(ctx, from, size);                                  \
+      ASAN_WRITE_RANGE(ctx, to, size);                                   \
+    }                                                                    \
+    return internal_memmove(to, from, size);                             \
+  } while (0)
+
+#define ASAN_READ_RANGE(ctx, offset, size) \
+  ACCESS_MEMORY_RANGE(ctx, offset, size, false)
+#define ASAN_WRITE_RANGE(ctx, offset, size) \
+  ACCESS_MEMORY_RANGE(ctx, offset, size, true)
+
+// Behavior of functions like "memcpy" or "strcpy" is undefined
+// if memory intervals overlap. We report error in this case.
+// Macro is used to avoid creation of new frames.
+static inline bool RangesOverlap(const char *offset1, uptr length1,
+                                 const char *offset2, uptr length2) {
+  return !((offset1 + length1 <= offset2) || (offset2 + length2 <= offset1));
+}
+#define CHECK_RANGES_OVERLAP(name, _offset1, length1, _offset2, length2) do { \
+  const char *offset1 = (const char*)_offset1; \
+  const char *offset2 = (const char*)_offset2; \
+  if (RangesOverlap(offset1, length1, offset2, length2)) { \
+    GET_STACK_TRACE_FATAL_HERE; \
+    ReportStringFunctionMemoryRangesOverlap(name, offset1, length1, \
+                                            offset2, length2, &stack); \
+  } \
+} while (0)
+
+}  // namespace __asan
+
+#endif  // ASAN_MEMINTRIN_H
diff --git a/libsanitizer/asan/asan_interface.inc b/libsanitizer/asan/asan_interface.inc
new file mode 100644
index 00000000000..b2fcde1c770
--- /dev/null
+++ b/libsanitizer/asan/asan_interface.inc
@@ -0,0 +1,167 @@
+//===-- asan_interface.inc ------------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// Asan interface list.
+//===----------------------------------------------------------------------===//
+INTERFACE_FUNCTION(__asan_addr_is_in_fake_stack)
+INTERFACE_FUNCTION(__asan_address_is_poisoned)
+INTERFACE_FUNCTION(__asan_after_dynamic_init)
+INTERFACE_FUNCTION(__asan_alloca_poison)
+INTERFACE_FUNCTION(__asan_allocas_unpoison)
+INTERFACE_FUNCTION(__asan_before_dynamic_init)
+INTERFACE_FUNCTION(__asan_describe_address)
+INTERFACE_FUNCTION(__asan_exp_load1)
+INTERFACE_FUNCTION(__asan_exp_load2)
+INTERFACE_FUNCTION(__asan_exp_load4)
+INTERFACE_FUNCTION(__asan_exp_load8)
+INTERFACE_FUNCTION(__asan_exp_load16)
+INTERFACE_FUNCTION(__asan_exp_loadN)
+INTERFACE_FUNCTION(__asan_exp_store1)
+INTERFACE_FUNCTION(__asan_exp_store2)
+INTERFACE_FUNCTION(__asan_exp_store4)
+INTERFACE_FUNCTION(__asan_exp_store8)
+INTERFACE_FUNCTION(__asan_exp_store16)
+INTERFACE_FUNCTION(__asan_exp_storeN)
+INTERFACE_FUNCTION(__asan_get_alloc_stack)
+INTERFACE_FUNCTION(__asan_get_current_fake_stack)
+INTERFACE_FUNCTION(__asan_get_free_stack)
+INTERFACE_FUNCTION(__asan_get_report_access_size)
+INTERFACE_FUNCTION(__asan_get_report_access_type)
+INTERFACE_FUNCTION(__asan_get_report_address)
+INTERFACE_FUNCTION(__asan_get_report_bp)
+INTERFACE_FUNCTION(__asan_get_report_description)
+INTERFACE_FUNCTION(__asan_get_report_pc)
+INTERFACE_FUNCTION(__asan_get_report_sp)
+INTERFACE_FUNCTION(__asan_get_shadow_mapping)
+INTERFACE_FUNCTION(__asan_handle_no_return)
+INTERFACE_FUNCTION(__asan_init)
+INTERFACE_FUNCTION(__asan_load_cxx_array_cookie)
+INTERFACE_FUNCTION(__asan_load1)
+INTERFACE_FUNCTION(__asan_load2)
+INTERFACE_FUNCTION(__asan_load4)
+INTERFACE_FUNCTION(__asan_load8)
+INTERFACE_FUNCTION(__asan_load16)
+INTERFACE_FUNCTION(__asan_loadN)
+INTERFACE_FUNCTION(__asan_load1_noabort)
+INTERFACE_FUNCTION(__asan_load2_noabort)
+INTERFACE_FUNCTION(__asan_load4_noabort)
+INTERFACE_FUNCTION(__asan_load8_noabort)
+INTERFACE_FUNCTION(__asan_load16_noabort)
+INTERFACE_FUNCTION(__asan_loadN_noabort)
+INTERFACE_FUNCTION(__asan_locate_address)
+INTERFACE_FUNCTION(__asan_memcpy)
+INTERFACE_FUNCTION(__asan_memmove)
+INTERFACE_FUNCTION(__asan_memset)
+INTERFACE_FUNCTION(__asan_poison_cxx_array_cookie)
+INTERFACE_FUNCTION(__asan_poison_intra_object_redzone)
+INTERFACE_FUNCTION(__asan_poison_memory_region)
+INTERFACE_FUNCTION(__asan_poison_stack_memory)
+INTERFACE_FUNCTION(__asan_print_accumulated_stats)
+INTERFACE_FUNCTION(__asan_region_is_poisoned)
+INTERFACE_FUNCTION(__asan_register_globals)
+INTERFACE_FUNCTION(__asan_register_elf_globals)
+INTERFACE_FUNCTION(__asan_register_image_globals)
+INTERFACE_FUNCTION(__asan_report_error)
+INTERFACE_FUNCTION(__asan_report_exp_load1)
+INTERFACE_FUNCTION(__asan_report_exp_load2)
+INTERFACE_FUNCTION(__asan_report_exp_load4)
+INTERFACE_FUNCTION(__asan_report_exp_load8)
+INTERFACE_FUNCTION(__asan_report_exp_load16)
+INTERFACE_FUNCTION(__asan_report_exp_load_n)
+INTERFACE_FUNCTION(__asan_report_exp_store1)
+INTERFACE_FUNCTION(__asan_report_exp_store2)
+INTERFACE_FUNCTION(__asan_report_exp_store4)
+INTERFACE_FUNCTION(__asan_report_exp_store8)
+INTERFACE_FUNCTION(__asan_report_exp_store16)
+INTERFACE_FUNCTION(__asan_report_exp_store_n)
+INTERFACE_FUNCTION(__asan_report_load1)
+INTERFACE_FUNCTION(__asan_report_load2)
+INTERFACE_FUNCTION(__asan_report_load4)
+INTERFACE_FUNCTION(__asan_report_load8)
+INTERFACE_FUNCTION(__asan_report_load16)
+INTERFACE_FUNCTION(__asan_report_load_n)
+INTERFACE_FUNCTION(__asan_report_load1_noabort)
+INTERFACE_FUNCTION(__asan_report_load2_noabort)
+INTERFACE_FUNCTION(__asan_report_load4_noabort)
+INTERFACE_FUNCTION(__asan_report_load8_noabort)
+INTERFACE_FUNCTION(__asan_report_load16_noabort)
+INTERFACE_FUNCTION(__asan_report_load_n_noabort)
+INTERFACE_FUNCTION(__asan_report_present)
+INTERFACE_FUNCTION(__asan_report_store1)
+INTERFACE_FUNCTION(__asan_report_store2)
+INTERFACE_FUNCTION(__asan_report_store4)
+INTERFACE_FUNCTION(__asan_report_store8)
+INTERFACE_FUNCTION(__asan_report_store16)
+INTERFACE_FUNCTION(__asan_report_store_n)
+INTERFACE_FUNCTION(__asan_report_store1_noabort)
+INTERFACE_FUNCTION(__asan_report_store2_noabort)
+INTERFACE_FUNCTION(__asan_report_store4_noabort)
+INTERFACE_FUNCTION(__asan_report_store8_noabort)
+INTERFACE_FUNCTION(__asan_report_store16_noabort)
+INTERFACE_FUNCTION(__asan_report_store_n_noabort)
+INTERFACE_FUNCTION(__asan_set_death_callback)
+INTERFACE_FUNCTION(__asan_set_error_report_callback)
+INTERFACE_FUNCTION(__asan_set_shadow_00)
+INTERFACE_FUNCTION(__asan_set_shadow_f1)
+INTERFACE_FUNCTION(__asan_set_shadow_f2)
+INTERFACE_FUNCTION(__asan_set_shadow_f3)
+INTERFACE_FUNCTION(__asan_set_shadow_f5)
+INTERFACE_FUNCTION(__asan_set_shadow_f8)
+INTERFACE_FUNCTION(__asan_stack_free_0)
+INTERFACE_FUNCTION(__asan_stack_free_1)
+INTERFACE_FUNCTION(__asan_stack_free_2)
+INTERFACE_FUNCTION(__asan_stack_free_3)
+INTERFACE_FUNCTION(__asan_stack_free_4)
+INTERFACE_FUNCTION(__asan_stack_free_5)
+INTERFACE_FUNCTION(__asan_stack_free_6)
+INTERFACE_FUNCTION(__asan_stack_free_7)
+INTERFACE_FUNCTION(__asan_stack_free_8)
+INTERFACE_FUNCTION(__asan_stack_free_9)
+INTERFACE_FUNCTION(__asan_stack_free_10)
+INTERFACE_FUNCTION(__asan_stack_malloc_0)
+INTERFACE_FUNCTION(__asan_stack_malloc_1)
+INTERFACE_FUNCTION(__asan_stack_malloc_2)
+INTERFACE_FUNCTION(__asan_stack_malloc_3)
+INTERFACE_FUNCTION(__asan_stack_malloc_4)
+INTERFACE_FUNCTION(__asan_stack_malloc_5)
+INTERFACE_FUNCTION(__asan_stack_malloc_6)
+INTERFACE_FUNCTION(__asan_stack_malloc_7)
+INTERFACE_FUNCTION(__asan_stack_malloc_8)
+INTERFACE_FUNCTION(__asan_stack_malloc_9)
+INTERFACE_FUNCTION(__asan_stack_malloc_10)
+INTERFACE_FUNCTION(__asan_store1)
+INTERFACE_FUNCTION(__asan_store2)
+INTERFACE_FUNCTION(__asan_store4)
+INTERFACE_FUNCTION(__asan_store8)
+INTERFACE_FUNCTION(__asan_store16)
+INTERFACE_FUNCTION(__asan_storeN)
+INTERFACE_FUNCTION(__asan_store1_noabort)
+INTERFACE_FUNCTION(__asan_store2_noabort)
+INTERFACE_FUNCTION(__asan_store4_noabort)
+INTERFACE_FUNCTION(__asan_store8_noabort)
+INTERFACE_FUNCTION(__asan_store16_noabort)
+INTERFACE_FUNCTION(__asan_storeN_noabort)
+INTERFACE_FUNCTION(__asan_unpoison_intra_object_redzone)
+INTERFACE_FUNCTION(__asan_unpoison_memory_region)
+INTERFACE_FUNCTION(__asan_unpoison_stack_memory)
+INTERFACE_FUNCTION(__asan_unregister_globals)
+INTERFACE_FUNCTION(__asan_unregister_elf_globals)
+INTERFACE_FUNCTION(__asan_unregister_image_globals)
+INTERFACE_FUNCTION(__asan_version_mismatch_check_v8)
+INTERFACE_FUNCTION(__sanitizer_finish_switch_fiber)
+INTERFACE_FUNCTION(__sanitizer_print_stack_trace)
+INTERFACE_FUNCTION(__sanitizer_ptr_cmp)
+INTERFACE_FUNCTION(__sanitizer_ptr_sub)
+INTERFACE_FUNCTION(__sanitizer_start_switch_fiber)
+INTERFACE_FUNCTION(__sanitizer_unaligned_load16)
+INTERFACE_FUNCTION(__sanitizer_unaligned_load32)
+INTERFACE_FUNCTION(__sanitizer_unaligned_load64)
+INTERFACE_FUNCTION(__sanitizer_unaligned_store16)
+INTERFACE_FUNCTION(__sanitizer_unaligned_store32)
+INTERFACE_FUNCTION(__sanitizer_unaligned_store64)
+INTERFACE_WEAK_FUNCTION(__asan_default_options)
+INTERFACE_WEAK_FUNCTION(__asan_default_suppressions)
+INTERFACE_WEAK_FUNCTION(__asan_on_error)
diff --git a/libsanitizer/asan/asan_interface_internal.h b/libsanitizer/asan/asan_interface_internal.h
index 05605a8065f..be9605d9e6e 100644
--- a/libsanitizer/asan/asan_interface_internal.h
+++ b/libsanitizer/asan/asan_interface_internal.h
@@ -65,6 +65,11 @@ extern "C" {
   SANITIZER_INTERFACE_ATTRIBUTE
   void __asan_unregister_image_globals(uptr *flag);
 
+  SANITIZER_INTERFACE_ATTRIBUTE
+  void __asan_register_elf_globals(uptr *flag, void *start, void *stop);
+  SANITIZER_INTERFACE_ATTRIBUTE
+  void __asan_unregister_elf_globals(uptr *flag, void *start, void *stop);
+
   // These two functions should be called by the instrumented code.
   // 'globals' is an array of structures describing 'n' globals.
   SANITIZER_INTERFACE_ATTRIBUTE
@@ -163,12 +168,12 @@ extern "C" {
   void __asan_set_error_report_callback(void (*callback)(const char*));
 
   SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-  /* OPTIONAL */ void __asan_on_error();
+  void __asan_on_error();
 
   SANITIZER_INTERFACE_ATTRIBUTE void __asan_print_accumulated_stats();
 
   SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-  /* OPTIONAL */ const char* __asan_default_options();
+  const char* __asan_default_options();
 
   SANITIZER_INTERFACE_ATTRIBUTE
   extern uptr __asan_shadow_memory_dynamic_address;
@@ -240,6 +245,9 @@ extern "C" {
   void __asan_alloca_poison(uptr addr, uptr size);
   SANITIZER_INTERFACE_ATTRIBUTE
   void __asan_allocas_unpoison(uptr top, uptr bottom);
+
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  const char* __asan_default_suppressions();
 }  // extern "C"
 
 #endif  // ASAN_INTERFACE_INTERNAL_H
diff --git a/libsanitizer/asan/asan_internal.h b/libsanitizer/asan/asan_internal.h
index 15a28ff777b..a3fe755f523 100644
--- a/libsanitizer/asan/asan_internal.h
+++ b/libsanitizer/asan/asan_internal.h
@@ -34,7 +34,7 @@
 // If set, values like allocator chunk size, as well as defaults for some flags
 // will be changed towards less memory overhead.
 #ifndef ASAN_LOW_MEMORY
-# if SANITIZER_IOS || (SANITIZER_WORDSIZE == 32)
+# if SANITIZER_IOS || SANITIZER_ANDROID
 #  define ASAN_LOW_MEMORY 1
 # else
 #  define ASAN_LOW_MEMORY 0
@@ -62,21 +62,29 @@ void AsanInitFromRtl();
 
 // asan_win.cc
 void InitializePlatformExceptionHandlers();
-
-// asan_win.cc / asan_posix.cc
-const char *DescribeSignalOrException(int signo);
+// Returns whether an address is a valid allocated system heap block.
+// 'addr' must point to the beginning of the block.
+bool IsSystemHeapAddress(uptr addr);
 
 // asan_rtl.cc
+void PrintAddressSpaceLayout();
 void NORETURN ShowStatsAndAbort();
 
+// asan_shadow_setup.cc
+void InitializeShadowMemory();
+
 // asan_malloc_linux.cc / asan_malloc_mac.cc
 void ReplaceSystemMalloc();
 
 // asan_linux.cc / asan_mac.cc / asan_win.cc
+uptr FindDynamicShadowStart();
 void *AsanDoesNotSupportStaticLinkage();
 void AsanCheckDynamicRTPrereqs();
 void AsanCheckIncompatibleRT();
 
+// asan_thread.cc
+AsanThread *CreateMainThread();
+
 // Support function for __asan_(un)register_image_globals. Searches for the
 // loaded image containing `needle' and then enumerates all global metadata
 // structures declared in that image, applying `op' (e.g.,
@@ -101,17 +109,6 @@ void *AsanDlSymNext(const char *sym);
 
 void ReserveShadowMemoryRange(uptr beg, uptr end, const char *name);
 
-// Platform-specific options.
-#if SANITIZER_MAC
-bool PlatformHasDifferentMemcpyAndMemmove();
-# define PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE \
-    (PlatformHasDifferentMemcpyAndMemmove())
-#elif SANITIZER_WINDOWS64
-# define PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE false
-#else
-# define PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE true
-#endif  // SANITIZER_MAC
-
 // Add convenient macro for interface functions that may be represented as
 // weak hooks.
 #define ASAN_MALLOC_HOOK(ptr, size)                                   \
diff --git a/libsanitizer/asan/asan_linux.cc b/libsanitizer/asan/asan_linux.cc
index 9f058df71a5..a43243e3b43 100644
--- a/libsanitizer/asan/asan_linux.cc
+++ b/libsanitizer/asan/asan_linux.cc
@@ -11,7 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "sanitizer_common/sanitizer_platform.h"
-#if SANITIZER_FREEBSD || SANITIZER_LINUX
+#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
 
 #include "asan_interceptors.h"
 #include "asan_internal.h"
@@ -40,6 +40,10 @@
 #if SANITIZER_ANDROID || SANITIZER_FREEBSD
 #include <ucontext.h>
 extern "C" void* _DYNAMIC;
+#elif SANITIZER_NETBSD
+#include <link_elf.h>
+#include <ucontext.h>
+extern Elf_Dyn _DYNAMIC;
 #else
 #include <sys/ucontext.h>
 #include <link.h>
@@ -68,12 +72,18 @@ namespace __asan {
 
 void InitializePlatformInterceptors() {}
 void InitializePlatformExceptionHandlers() {}
+bool IsSystemHeapAddress (uptr addr) { return false; }
 
 void *AsanDoesNotSupportStaticLinkage() {
   // This will fail to link with -static.
   return &_DYNAMIC;  // defined in link.h
 }
 
+uptr FindDynamicShadowStart() {
+  UNREACHABLE("FindDynamicShadowStart is not available");
+  return 0;
+}
+
 void AsanApplyToGlobals(globals_op_fptr op, const void *needle) {
   UNIMPLEMENTED();
 }
@@ -93,6 +103,15 @@ static int FindFirstDSOCallback(struct dl_phdr_info *info, size_t size,
   if (internal_strncmp(info->dlpi_name, "linux-", sizeof("linux-") - 1) == 0)
     return 0;
 
+#if SANITIZER_NETBSD
+  // Ignore first entry (the main program)
+  char **p = (char **)data;
+  if (!(*p)) {
+    *p = (char *)-1;
+    return 0;
+  }
+#endif
+
   *(const char **)data = info->dlpi_name;
   return 1;
 }
@@ -108,7 +127,7 @@ static void ReportIncompatibleRT() {
 }
 
 void AsanCheckDynamicRTPrereqs() {
-  if (!ASAN_DYNAMIC)
+  if (!ASAN_DYNAMIC || !flags()->verify_asan_link_order)
     return;
 
   // Ensure that dynamic RT is the first DSO in the list
@@ -137,9 +156,9 @@ void AsanCheckIncompatibleRT() {
       // system libraries, causing crashes later in ASan initialization.
       MemoryMappingLayout proc_maps(/*cache_enabled*/true);
       char filename[128];
-      while (proc_maps.Next(nullptr, nullptr, nullptr, filename,
-                            sizeof(filename), nullptr)) {
-        if (IsDynamicRTName(filename)) {
+      MemoryMappedSegment segment(filename, sizeof(filename));
+      while (proc_maps.Next(&segment)) {
+        if (IsDynamicRTName(segment.filename)) {
           Report("Your application is linked against "
                  "incompatible ASan runtimes.\n");
           Die();
@@ -171,4 +190,4 @@ void *AsanDlSymNext(const char *sym) {
 
 } // namespace __asan
 
-#endif // SANITIZER_FREEBSD || SANITIZER_LINUX
+#endif  // SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
diff --git a/libsanitizer/asan/asan_mac.cc b/libsanitizer/asan/asan_mac.cc
index 4bf79be1728..45c66d8645c 100644
--- a/libsanitizer/asan/asan_mac.cc
+++ b/libsanitizer/asan/asan_mac.cc
@@ -46,21 +46,36 @@ namespace __asan {
 
 void InitializePlatformInterceptors() {}
 void InitializePlatformExceptionHandlers() {}
-
-bool PlatformHasDifferentMemcpyAndMemmove() {
-  // On OS X 10.7 memcpy() and memmove() are both resolved
-  // into memmove$VARIANT$sse42.
-  // See also https://github.com/google/sanitizers/issues/34.
-  // TODO(glider): need to check dynamically that memcpy() and memmove() are
-  // actually the same function.
-  return GetMacosVersion() == MACOS_VERSION_SNOW_LEOPARD;
-}
+bool IsSystemHeapAddress (uptr addr) { return false; }
 
 // No-op. Mac does not support static linkage anyway.
 void *AsanDoesNotSupportStaticLinkage() {
   return 0;
 }
 
+uptr FindDynamicShadowStart() {
+  uptr granularity = GetMmapGranularity();
+  uptr alignment = 8 * granularity;
+  uptr left_padding = granularity;
+  uptr space_size = kHighShadowEnd + left_padding;
+
+  uptr largest_gap_found = 0;
+  uptr shadow_start = FindAvailableMemoryRange(space_size, alignment,
+                                               granularity, &largest_gap_found);
+  // If the shadow doesn't fit, restrict the address space to make it fit.
+  if (shadow_start == 0) {
+    uptr new_max_vm = RoundDownTo(largest_gap_found << SHADOW_SCALE, alignment);
+    RestrictMemoryToMaxAddress(new_max_vm);
+    kHighMemEnd = new_max_vm - 1;
+    space_size = kHighShadowEnd + left_padding;
+    shadow_start =
+        FindAvailableMemoryRange(space_size, alignment, granularity, nullptr);
+  }
+  CHECK_NE((uptr)0, shadow_start);
+  CHECK(IsAligned(shadow_start, alignment));
+  return shadow_start;
+}
+
 // No-op. Mac does not support static linkage anyway.
 void AsanCheckDynamicRTPrereqs() {}
 
@@ -145,7 +160,8 @@ void asan_register_worker_thread(int parent_tid, StackTrace *stack) {
     t = AsanThread::Create(/* start_routine */ nullptr, /* arg */ nullptr,
                            parent_tid, stack, /* detached */ true);
     t->Init();
-    asanThreadRegistry().StartThread(t->tid(), 0, 0);
+    asanThreadRegistry().StartThread(t->tid(), GetTid(),
+                                     /* workerthread */ true, 0);
     SetCurrentThread(t);
   }
 }
diff --git a/libsanitizer/asan/asan_malloc_linux.cc b/libsanitizer/asan/asan_malloc_linux.cc
index cc50a388495..19f45fc3cee 100644
--- a/libsanitizer/asan/asan_malloc_linux.cc
+++ b/libsanitizer/asan/asan_malloc_linux.cc
@@ -13,7 +13,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "sanitizer_common/sanitizer_platform.h"
-#if SANITIZER_FREEBSD || SANITIZER_LINUX
+#if SANITIZER_FREEBSD || SANITIZER_FUCHSIA || SANITIZER_LINUX || \
+    SANITIZER_NETBSD
 
 #include "sanitizer_common/sanitizer_tls_get_addr.h"
 #include "asan_allocator.h"
@@ -28,9 +29,9 @@ static uptr allocated_for_dlsym;
 static const uptr kDlsymAllocPoolSize = 1024;
 static uptr alloc_memory_for_dlsym[kDlsymAllocPoolSize];
 
-static bool IsInDlsymAllocPool(const void *ptr) {
+static INLINE bool IsInDlsymAllocPool(const void *ptr) {
   uptr off = (uptr)ptr - (uptr)alloc_memory_for_dlsym;
-  return off < sizeof(alloc_memory_for_dlsym);
+  return off < allocated_for_dlsym * sizeof(alloc_memory_for_dlsym[0]);
 }
 
 static void *AllocateFromLocalPool(uptr size_in_bytes) {
@@ -41,6 +42,26 @@ static void *AllocateFromLocalPool(uptr size_in_bytes) {
   return mem;
 }
 
+static INLINE bool MaybeInDlsym() {
+  // Fuchsia doesn't use dlsym-based interceptors.
+  return !SANITIZER_FUCHSIA && asan_init_is_running;
+}
+
+static void *ReallocFromLocalPool(void *ptr, uptr size) {
+  const uptr offset = (uptr)ptr - (uptr)alloc_memory_for_dlsym;
+  const uptr copy_size = Min(size, kDlsymAllocPoolSize - offset);
+  void *new_ptr;
+  if (UNLIKELY(MaybeInDlsym())) {
+    new_ptr = AllocateFromLocalPool(size);
+  } else {
+    ENSURE_ASAN_INITED();
+    GET_STACK_TRACE_MALLOC;
+    new_ptr = asan_malloc(size, &stack);
+  }
+  internal_memcpy(new_ptr, ptr, copy_size);
+  return new_ptr;
+}
+
 INTERCEPTOR(void, free, void *ptr) {
   GET_STACK_TRACE_FREE;
   if (UNLIKELY(IsInDlsymAllocPool(ptr)))
@@ -48,63 +69,61 @@ INTERCEPTOR(void, free, void *ptr) {
   asan_free(ptr, &stack, FROM_MALLOC);
 }
 
+#if SANITIZER_INTERCEPT_CFREE
 INTERCEPTOR(void, cfree, void *ptr) {
   GET_STACK_TRACE_FREE;
   if (UNLIKELY(IsInDlsymAllocPool(ptr)))
     return;
   asan_free(ptr, &stack, FROM_MALLOC);
 }
+#endif // SANITIZER_INTERCEPT_CFREE
 
 INTERCEPTOR(void*, malloc, uptr size) {
-  if (UNLIKELY(!asan_inited))
+  if (UNLIKELY(MaybeInDlsym()))
     // Hack: dlsym calls malloc before REAL(malloc) is retrieved from dlsym.
     return AllocateFromLocalPool(size);
+  ENSURE_ASAN_INITED();
   GET_STACK_TRACE_MALLOC;
   return asan_malloc(size, &stack);
 }
 
 INTERCEPTOR(void*, calloc, uptr nmemb, uptr size) {
-  if (UNLIKELY(!asan_inited))
+  if (UNLIKELY(MaybeInDlsym()))
     // Hack: dlsym calls calloc before REAL(calloc) is retrieved from dlsym.
     return AllocateFromLocalPool(nmemb * size);
+  ENSURE_ASAN_INITED();
   GET_STACK_TRACE_MALLOC;
   return asan_calloc(nmemb, size, &stack);
 }
 
 INTERCEPTOR(void*, realloc, void *ptr, uptr size) {
+  if (UNLIKELY(IsInDlsymAllocPool(ptr)))
+    return ReallocFromLocalPool(ptr, size);
+  if (UNLIKELY(MaybeInDlsym()))
+    return AllocateFromLocalPool(size);
+  ENSURE_ASAN_INITED();
   GET_STACK_TRACE_MALLOC;
-  if (UNLIKELY(IsInDlsymAllocPool(ptr))) {
-    uptr offset = (uptr)ptr - (uptr)alloc_memory_for_dlsym;
-    uptr copy_size = Min(size, kDlsymAllocPoolSize - offset);
-    void *new_ptr;
-    if (UNLIKELY(!asan_inited)) {
-      new_ptr = AllocateFromLocalPool(size);
-    } else {
-      copy_size = size;
-      new_ptr = asan_malloc(copy_size, &stack);
-    }
-    internal_memcpy(new_ptr, ptr, copy_size);
-    return new_ptr;
-  }
   return asan_realloc(ptr, size, &stack);
 }
 
+#if SANITIZER_INTERCEPT_MEMALIGN
 INTERCEPTOR(void*, memalign, uptr boundary, uptr size) {
   GET_STACK_TRACE_MALLOC;
   return asan_memalign(boundary, size, &stack, FROM_MALLOC);
 }
 
-INTERCEPTOR(void*, aligned_alloc, uptr boundary, uptr size) {
-  GET_STACK_TRACE_MALLOC;
-  return asan_memalign(boundary, size, &stack, FROM_MALLOC);
-}
-
 INTERCEPTOR(void*, __libc_memalign, uptr boundary, uptr size) {
   GET_STACK_TRACE_MALLOC;
   void *res = asan_memalign(boundary, size, &stack, FROM_MALLOC);
   DTLS_on_libc_memalign(res, size);
   return res;
 }
+#endif // SANITIZER_INTERCEPT_MEMALIGN
+
+INTERCEPTOR(void*, aligned_alloc, uptr boundary, uptr size) {
+  GET_STACK_TRACE_MALLOC;
+  return asan_memalign(boundary, size, &stack, FROM_MALLOC);
+}
 
 INTERCEPTOR(uptr, malloc_usable_size, void *ptr) {
   GET_CURRENT_PC_BP_SP;
@@ -112,6 +131,7 @@ INTERCEPTOR(uptr, malloc_usable_size, void *ptr) {
   return asan_malloc_usable_size(ptr, pc, bp);
 }
 
+#if SANITIZER_INTERCEPT_MALLOPT_AND_MALLINFO
 // We avoid including malloc.h for portability reasons.
 // man mallinfo says the fields are "long", but the implementation uses int.
 // It doesn't matter much -- we just need to make sure that the libc's mallinfo
@@ -129,6 +149,7 @@ INTERCEPTOR(struct fake_mallinfo, mallinfo, void) {
 INTERCEPTOR(int, mallopt, int cmd, int value) {
   return -1;
 }
+#endif // SANITIZER_INTERCEPT_MALLOPT_AND_MALLINFO
 
 INTERCEPTOR(int, posix_memalign, void **memptr, uptr alignment, uptr size) {
   GET_STACK_TRACE_MALLOC;
@@ -141,10 +162,12 @@ INTERCEPTOR(void*, valloc, uptr size) {
   return asan_valloc(size, &stack);
 }
 
+#if SANITIZER_INTERCEPT_PVALLOC
 INTERCEPTOR(void*, pvalloc, uptr size) {
   GET_STACK_TRACE_MALLOC;
   return asan_pvalloc(size, &stack);
 }
+#endif // SANITIZER_INTERCEPT_PVALLOC
 
 INTERCEPTOR(void, malloc_stats, void) {
   __asan_print_accumulated_stats();
@@ -210,4 +233,5 @@ void ReplaceSystemMalloc() {
 }  // namespace __asan
 #endif  // SANITIZER_ANDROID
 
-#endif  // SANITIZER_FREEBSD || SANITIZER_LINUX
+#endif  // SANITIZER_FREEBSD || SANITIZER_FUCHSIA || SANITIZER_LINUX ||
+        // SANITIZER_NETBSD
diff --git a/libsanitizer/asan/asan_malloc_win.cc b/libsanitizer/asan/asan_malloc_win.cc
index f38cd054bb0..017481d0b81 100644
--- a/libsanitizer/asan/asan_malloc_win.cc
+++ b/libsanitizer/asan/asan_malloc_win.cc
@@ -54,11 +54,6 @@ void _free_base(void *ptr) {
 }
 
 ALLOCATION_FUNCTION_ATTRIBUTE
-void cfree(void *ptr) {
-  CHECK(!"cfree() should not be used on Windows");
-}
-
-ALLOCATION_FUNCTION_ATTRIBUTE
 void *malloc(size_t size) {
   GET_STACK_TRACE_MALLOC;
   return asan_malloc(size, &stack);
@@ -103,7 +98,7 @@ void *realloc(void *ptr, size_t size) {
 
 ALLOCATION_FUNCTION_ATTRIBUTE
 void *_realloc_dbg(void *ptr, size_t size, int) {
-  CHECK(!"_realloc_dbg should not exist!");
+  UNREACHABLE("_realloc_dbg should not exist!");
   return 0;
 }
 
diff --git a/libsanitizer/asan/asan_mapping.h b/libsanitizer/asan/asan_mapping.h
index b9fa5f79481..5496df66deb 100644
--- a/libsanitizer/asan/asan_mapping.h
+++ b/libsanitizer/asan/asan_mapping.h
@@ -113,6 +113,13 @@
 // || `[0x40000000, 0x47ffffff]` || LowShadow  ||
 // || `[0x00000000, 0x3fffffff]` || LowMem     ||
 //
+// Shadow mapping on NetBSD/x86-64 with SHADOW_OFFSET == 0x400000000000:
+// || `[0x4feffffffe01, 0x7f7ffffff000]` || HighMem    ||
+// || `[0x49fdffffffc0, 0x4feffffffe00]` || HighShadow ||
+// || `[0x480000000000, 0x49fdffffffbf]` || ShadowGap  ||
+// || `[0x400000000000, 0x47ffffffffff]` || LowShadow  ||
+// || `[0x000000000000, 0x3fffffffffff]` || LowMem     ||
+//
 // Default Windows/i386 mapping:
 // (the exact location of HighShadow/HighMem may vary depending
 //  on WoW64, /LARGEADDRESSAWARE, etc).
@@ -138,12 +145,14 @@ static const u64 kPPC64_ShadowOffset64 = 1ULL << 41;
 static const u64 kSystemZ_ShadowOffset64 = 1ULL << 52;
 static const u64 kFreeBSD_ShadowOffset32 = 1ULL << 30;  // 0x40000000
 static const u64 kFreeBSD_ShadowOffset64 = 1ULL << 46;  // 0x400000000000
+static const u64 kNetBSD_ShadowOffset64 = 1ULL << 46;  // 0x400000000000
 static const u64 kWindowsShadowOffset32 = 3ULL << 28;  // 0x30000000
 
 #define SHADOW_SCALE kDefaultShadowScale
 
-
-#if SANITIZER_WORDSIZE == 32
+#if SANITIZER_FUCHSIA
+#  define SHADOW_OFFSET (0)
+#elif SANITIZER_WORDSIZE == 32
 #  if SANITIZER_ANDROID
 #    define SHADOW_OFFSET (0)
 #  elif defined(__mips__)
@@ -176,6 +185,8 @@ static const u64 kWindowsShadowOffset32 = 3ULL << 28;  // 0x30000000
 #    define SHADOW_OFFSET kSystemZ_ShadowOffset64
 #  elif SANITIZER_FREEBSD
 #    define SHADOW_OFFSET kFreeBSD_ShadowOffset64
+#  elif SANITIZER_NETBSD
+#    define SHADOW_OFFSET kNetBSD_ShadowOffset64
 #  elif SANITIZER_MAC
 #   define SHADOW_OFFSET kDefaultShadowOffset64
 #  elif defined(__mips64)
@@ -189,7 +200,6 @@ static const u64 kWindowsShadowOffset32 = 3ULL << 28;  // 0x30000000
 
 #define SHADOW_GRANULARITY (1ULL << SHADOW_SCALE)
 #define MEM_TO_SHADOW(mem) (((mem) >> SHADOW_SCALE) + (SHADOW_OFFSET))
-#define SHADOW_TO_MEM(shadow) (((shadow) - SHADOW_OFFSET) << SHADOW_SCALE)
 
 #define kLowMemBeg      0
 #define kLowMemEnd      (SHADOW_OFFSET ? SHADOW_OFFSET - 1 : 0)
diff --git a/libsanitizer/asan/asan_memory_profile.cc b/libsanitizer/asan/asan_memory_profile.cc
index 5a2578596ad..42d07c705f1 100644
--- a/libsanitizer/asan/asan_memory_profile.cc
+++ b/libsanitizer/asan/asan_memory_profile.cc
@@ -30,69 +30,99 @@ struct AllocationSite {
 class HeapProfile {
  public:
   HeapProfile() : allocations_(1024) {}
-  void Insert(u32 id, uptr size) {
-    total_allocated_ += size;
-    total_count_++;
-    // Linear lookup will be good enough for most cases (although not all).
-    for (uptr i = 0; i < allocations_.size(); i++) {
-      if (allocations_[i].id == id) {
-        allocations_[i].total_size += size;
-        allocations_[i].count++;
-        return;
-      }
+
+  void ProcessChunk(const AsanChunkView& cv) {
+    if (cv.IsAllocated()) {
+      total_allocated_user_size_ += cv.UsedSize();
+      total_allocated_count_++;
+      u32 id = cv.GetAllocStackId();
+      if (id)
+        Insert(id, cv.UsedSize());
+    } else if (cv.IsQuarantined()) {
+      total_quarantined_user_size_ += cv.UsedSize();
+      total_quarantined_count_++;
+    } else {
+      total_other_count_++;
     }
-    allocations_.push_back({id, size, 1});
   }
 
-  void Print(uptr top_percent) {
+  void Print(uptr top_percent, uptr max_number_of_contexts) {
     InternalSort(&allocations_, allocations_.size(),
                  [](const AllocationSite &a, const AllocationSite &b) {
                    return a.total_size > b.total_size;
                  });
-    CHECK(total_allocated_);
+    CHECK(total_allocated_user_size_);
     uptr total_shown = 0;
-    Printf("Live Heap Allocations: %zd bytes from %zd allocations; "
-           "showing top %zd%%\n", total_allocated_, total_count_, top_percent);
-    for (uptr i = 0; i < allocations_.size(); i++) {
+    Printf("Live Heap Allocations: %zd bytes in %zd chunks; quarantined: "
+           "%zd bytes in %zd chunks; %zd other chunks; total chunks: %zd; "
+           "showing top %zd%% (at most %zd unique contexts)\n",
+           total_allocated_user_size_, total_allocated_count_,
+           total_quarantined_user_size_, total_quarantined_count_,
+           total_other_count_, total_allocated_count_ +
+           total_quarantined_count_ + total_other_count_, top_percent,
+           max_number_of_contexts);
+    for (uptr i = 0; i < Min(allocations_.size(), max_number_of_contexts);
+         i++) {
       auto &a = allocations_[i];
       Printf("%zd byte(s) (%zd%%) in %zd allocation(s)\n", a.total_size,
-             a.total_size * 100 / total_allocated_, a.count);
+             a.total_size * 100 / total_allocated_user_size_, a.count);
       StackDepotGet(a.id).Print();
       total_shown += a.total_size;
-      if (total_shown * 100 / total_allocated_ > top_percent)
+      if (total_shown * 100 / total_allocated_user_size_ > top_percent)
         break;
     }
   }
 
  private:
-  uptr total_allocated_ = 0;
-  uptr total_count_ = 0;
+  uptr total_allocated_user_size_ = 0;
+  uptr total_allocated_count_ = 0;
+  uptr total_quarantined_user_size_ = 0;
+  uptr total_quarantined_count_ = 0;
+  uptr total_other_count_ = 0;
   InternalMmapVector<AllocationSite> allocations_;
+
+  void Insert(u32 id, uptr size) {
+    // Linear lookup will be good enough for most cases (although not all).
+    for (uptr i = 0; i < allocations_.size(); i++) {
+      if (allocations_[i].id == id) {
+        allocations_[i].total_size += size;
+        allocations_[i].count++;
+        return;
+      }
+    }
+    allocations_.push_back({id, size, 1});
+  }
 };
 
 static void ChunkCallback(uptr chunk, void *arg) {
-  HeapProfile *hp = reinterpret_cast<HeapProfile*>(arg);
-  AsanChunkView cv = FindHeapChunkByAllocBeg(chunk);
-  if (!cv.IsAllocated()) return;
-  u32 id = cv.GetAllocStackId();
-  if (!id) return;
-  hp->Insert(id, cv.UsedSize());
+  reinterpret_cast<HeapProfile*>(arg)->ProcessChunk(
+      FindHeapChunkByAllocBeg(chunk));
 }
 
 static void MemoryProfileCB(const SuspendedThreadsList &suspended_threads_list,
                             void *argument) {
   HeapProfile hp;
   __lsan::ForEachChunk(ChunkCallback, &hp);
-  hp.Print(reinterpret_cast<uptr>(argument));
+  uptr *Arg = reinterpret_cast<uptr*>(argument);
+  hp.Print(Arg[0], Arg[1]);
+
+  if (Verbosity())
+    __asan_print_accumulated_stats();
 }
 
 }  // namespace __asan
 
+#endif  // CAN_SANITIZE_LEAKS
+
 extern "C" {
 SANITIZER_INTERFACE_ATTRIBUTE
-void __sanitizer_print_memory_profile(uptr top_percent) {
-  __sanitizer::StopTheWorld(__asan::MemoryProfileCB, (void*)top_percent);
+void __sanitizer_print_memory_profile(uptr top_percent,
+                                      uptr max_number_of_contexts) {
+#if CAN_SANITIZE_LEAKS
+  uptr Arg[2];
+  Arg[0] = top_percent;
+  Arg[1] = max_number_of_contexts;
+  __sanitizer::StopTheWorld(__asan::MemoryProfileCB, Arg);
+#endif  // CAN_SANITIZE_LEAKS
 }
 }  // extern "C"
-
-#endif  // CAN_SANITIZE_LEAKS
diff --git a/libsanitizer/asan/asan_new_delete.cc b/libsanitizer/asan/asan_new_delete.cc
index 2c4642cb27e..e95b5287191 100644
--- a/libsanitizer/asan/asan_new_delete.cc
+++ b/libsanitizer/asan/asan_new_delete.cc
@@ -23,22 +23,26 @@
 // dllexport would normally do. We need to export them in order to make the
 // VS2015 dynamic CRT (MD) work.
 #if SANITIZER_WINDOWS
-# define CXX_OPERATOR_ATTRIBUTE
-# ifdef _WIN64
-#  pragma comment(linker, "/export:??2@YAPEAX_K@Z")   // operator new
-#  pragma comment(linker, "/export:??3@YAXPEAX@Z")    // operator delete
-#  pragma comment(linker, "/export:??3@YAXPEAX_K@Z")  // sized operator delete
-#  pragma comment(linker, "/export:??_U@YAPEAX_K@Z")  // operator new[]
-#  pragma comment(linker, "/export:??_V@YAXPEAX@Z")   // operator delete[]
-# else
-#  pragma comment(linker, "/export:??2@YAPAXI@Z")   // operator new
-#  pragma comment(linker, "/export:??3@YAXPAX@Z")   // operator delete
-#  pragma comment(linker, "/export:??3@YAXPAXI@Z")  // sized operator delete
-#  pragma comment(linker, "/export:??_U@YAPAXI@Z")  // operator new[]
-#  pragma comment(linker, "/export:??_V@YAXPAX@Z")  // operator delete[]
-# endif
+#define CXX_OPERATOR_ATTRIBUTE
+#define COMMENT_EXPORT(sym) __pragma(comment(linker, "/export:" sym))
+#ifdef _WIN64
+COMMENT_EXPORT("??2@YAPEAX_K@Z")                     // operator new
+COMMENT_EXPORT("??2@YAPEAX_KAEBUnothrow_t@std@@@Z")  // operator new nothrow
+COMMENT_EXPORT("??3@YAXPEAX@Z")                      // operator delete
+COMMENT_EXPORT("??3@YAXPEAX_K@Z")                    // sized operator delete
+COMMENT_EXPORT("??_U@YAPEAX_K@Z")                    // operator new[]
+COMMENT_EXPORT("??_V@YAXPEAX@Z")                     // operator delete[]
 #else
-# define CXX_OPERATOR_ATTRIBUTE INTERCEPTOR_ATTRIBUTE
+COMMENT_EXPORT("??2@YAPAXI@Z")                    // operator new
+COMMENT_EXPORT("??2@YAPAXIABUnothrow_t@std@@@Z")  // operator new nothrow
+COMMENT_EXPORT("??3@YAXPAX@Z")                    // operator delete
+COMMENT_EXPORT("??3@YAXPAXI@Z")                   // sized operator delete
+COMMENT_EXPORT("??_U@YAPAXI@Z")                   // operator new[]
+COMMENT_EXPORT("??_V@YAXPAX@Z")                   // operator delete[]
+#endif
+#undef COMMENT_EXPORT
+#else
+#define CXX_OPERATOR_ATTRIBUTE INTERCEPTOR_ATTRIBUTE
 #endif
 
 using namespace __asan;  // NOLINT
@@ -61,12 +65,17 @@ struct nothrow_t {};
 enum class align_val_t: size_t {};
 }  // namespace std
 
-#define OPERATOR_NEW_BODY(type) \
+// TODO(alekseys): throw std::bad_alloc instead of dying on OOM.
+#define OPERATOR_NEW_BODY(type, nothrow) \
   GET_STACK_TRACE_MALLOC;\
-  return asan_memalign(0, size, &stack, type);
-#define OPERATOR_NEW_BODY_ALIGN(type) \
+  void *res = asan_memalign(0, size, &stack, type);\
+  if (!nothrow && UNLIKELY(!res)) DieOnFailure::OnOOM();\
+  return res;
+#define OPERATOR_NEW_BODY_ALIGN(type, nothrow) \
   GET_STACK_TRACE_MALLOC;\
-  return asan_memalign((uptr)align, size, &stack, type);
+  void *res = asan_memalign((uptr)align, size, &stack, type);\
+  if (!nothrow && UNLIKELY(!res)) DieOnFailure::OnOOM();\
+  return res;
 
 // On OS X it's not enough to just provide our own 'operator new' and
 // 'operator delete' implementations, because they're going to be in the
@@ -77,40 +86,42 @@ enum class align_val_t: size_t {};
 // OS X we need to intercept them using their mangled names.
 #if !SANITIZER_MAC
 CXX_OPERATOR_ATTRIBUTE
-void *operator new(size_t size) { OPERATOR_NEW_BODY(FROM_NEW); }
+void *operator new(size_t size)
+{ OPERATOR_NEW_BODY(FROM_NEW, false /*nothrow*/); }
 CXX_OPERATOR_ATTRIBUTE
-void *operator new[](size_t size) { OPERATOR_NEW_BODY(FROM_NEW_BR); }
+void *operator new[](size_t size)
+{ OPERATOR_NEW_BODY(FROM_NEW_BR, false /*nothrow*/); }
 CXX_OPERATOR_ATTRIBUTE
 void *operator new(size_t size, std::nothrow_t const&)
-{ OPERATOR_NEW_BODY(FROM_NEW); }
+{ OPERATOR_NEW_BODY(FROM_NEW, true /*nothrow*/); }
 CXX_OPERATOR_ATTRIBUTE
 void *operator new[](size_t size, std::nothrow_t const&)
-{ OPERATOR_NEW_BODY(FROM_NEW_BR); }
+{ OPERATOR_NEW_BODY(FROM_NEW_BR, true /*nothrow*/); }
 CXX_OPERATOR_ATTRIBUTE
 void *operator new(size_t size, std::align_val_t align)
-{ OPERATOR_NEW_BODY_ALIGN(FROM_NEW); }
+{ OPERATOR_NEW_BODY_ALIGN(FROM_NEW, false /*nothrow*/); }
 CXX_OPERATOR_ATTRIBUTE
 void *operator new[](size_t size, std::align_val_t align)
-{ OPERATOR_NEW_BODY_ALIGN(FROM_NEW_BR); }
+{ OPERATOR_NEW_BODY_ALIGN(FROM_NEW_BR, false /*nothrow*/); }
 CXX_OPERATOR_ATTRIBUTE
 void *operator new(size_t size, std::align_val_t align, std::nothrow_t const&)
-{ OPERATOR_NEW_BODY_ALIGN(FROM_NEW); }
+{ OPERATOR_NEW_BODY_ALIGN(FROM_NEW, true /*nothrow*/); }
 CXX_OPERATOR_ATTRIBUTE
 void *operator new[](size_t size, std::align_val_t align, std::nothrow_t const&)
-{ OPERATOR_NEW_BODY_ALIGN(FROM_NEW_BR); }
+{ OPERATOR_NEW_BODY_ALIGN(FROM_NEW_BR, true /*nothrow*/); }
 
 #else  // SANITIZER_MAC
 INTERCEPTOR(void *, _Znwm, size_t size) {
-  OPERATOR_NEW_BODY(FROM_NEW);
+  OPERATOR_NEW_BODY(FROM_NEW, false /*nothrow*/);
 }
 INTERCEPTOR(void *, _Znam, size_t size) {
-  OPERATOR_NEW_BODY(FROM_NEW_BR);
+  OPERATOR_NEW_BODY(FROM_NEW_BR, false /*nothrow*/);
 }
 INTERCEPTOR(void *, _ZnwmRKSt9nothrow_t, size_t size, std::nothrow_t const&) {
-  OPERATOR_NEW_BODY(FROM_NEW);
+  OPERATOR_NEW_BODY(FROM_NEW, true /*nothrow*/);
 }
 INTERCEPTOR(void *, _ZnamRKSt9nothrow_t, size_t size, std::nothrow_t const&) {
-  OPERATOR_NEW_BODY(FROM_NEW_BR);
+  OPERATOR_NEW_BODY(FROM_NEW_BR, true /*nothrow*/);
 }
 #endif
 
diff --git a/libsanitizer/asan/asan_poisoning.cc b/libsanitizer/asan/asan_poisoning.cc
index 8fe2bd42bdb..15cd8eaac3e 100644
--- a/libsanitizer/asan/asan_poisoning.cc
+++ b/libsanitizer/asan/asan_poisoning.cc
@@ -62,12 +62,9 @@ struct ShadowSegmentEndpoint {
 };
 
 void FlushUnneededASanShadowMemory(uptr p, uptr size) {
-    // Since asan's mapping is compacting, the shadow chunk may be
-    // not page-aligned, so we only flush the page-aligned portion.
-    uptr page_size = GetPageSizeCached();
-    uptr shadow_beg = RoundUpTo(MemToShadow(p), page_size);
-    uptr shadow_end = RoundDownTo(MemToShadow(p + size), page_size);
-    ReleaseMemoryToOS(shadow_beg, shadow_end - shadow_beg);
+  // Since asan's mapping is compacting, the shadow chunk may be
+  // not page-aligned, so we only flush the page-aligned portion.
+  ReleaseMemoryPagesToOS(MemToShadow(p), MemToShadow(p + size));
 }
 
 void AsanPoisonOrUnpoisonIntraObjectRedzone(uptr ptr, uptr size, bool poison) {
@@ -410,7 +407,7 @@ const void *__sanitizer_contiguous_container_find_bad_address(
   // ending with end.
   uptr kMaxRangeToCheck = 32;
   uptr r1_beg = beg;
-  uptr r1_end = Min(end + kMaxRangeToCheck, mid);
+  uptr r1_end = Min(beg + kMaxRangeToCheck, mid);
   uptr r2_beg = Max(beg, mid - kMaxRangeToCheck);
   uptr r2_end = Min(end, mid + kMaxRangeToCheck);
   uptr r3_beg = Max(end - kMaxRangeToCheck, mid);
diff --git a/libsanitizer/asan/asan_poisoning.h b/libsanitizer/asan/asan_poisoning.h
index 4ddcbc314d4..942e74174c2 100644
--- a/libsanitizer/asan/asan_poisoning.h
+++ b/libsanitizer/asan/asan_poisoning.h
@@ -44,8 +44,11 @@ ALWAYS_INLINE void FastPoisonShadow(uptr aligned_beg, uptr aligned_size,
   // for mapping shadow and zeroing out pages doesn't "just work", so we should
   // probably provide higher-level interface for these operations.
   // For now, just memset on Windows.
-  if (value ||
-      SANITIZER_WINDOWS == 1 ||
+  if (value || SANITIZER_WINDOWS == 1 ||
+      // TODO(mcgrathr): Fuchsia doesn't allow the shadow mapping to be
+      // changed at all.  It doesn't currently have an efficient means
+      // to zero a bunch of pages, but maybe we should add one.
+      SANITIZER_FUCHSIA == 1 ||
       shadow_end - shadow_beg < common_flags()->clear_shadow_mmap_threshold) {
     REAL(memset)((void*)shadow_beg, value, shadow_end - shadow_beg);
   } else {
@@ -84,8 +87,8 @@ ALWAYS_INLINE void FastPoisonShadowPartialRightRedzone(
   }
 }
 
-// Calls __sanitizer::ReleaseMemoryToOS() on
-// [MemToShadow(p), MemToShadow(p+size)] with proper rounding.
+// Calls __sanitizer::ReleaseMemoryPagesToOS() on
+// [MemToShadow(p), MemToShadow(p+size)].
 void FlushUnneededASanShadowMemory(uptr p, uptr size);
 
 }  // namespace __asan
diff --git a/libsanitizer/asan/asan_posix.cc b/libsanitizer/asan/asan_posix.cc
index 532afb37f1a..e113c02a8cc 100644
--- a/libsanitizer/asan/asan_posix.cc
+++ b/libsanitizer/asan/asan_posix.cc
@@ -31,72 +31,10 @@
 
 namespace __asan {
 
-const char *DescribeSignalOrException(int signo) {
-  switch (signo) {
-    case SIGFPE:
-      return "FPE";
-    case SIGILL:
-      return "ILL";
-    case SIGABRT:
-      return "ABRT";
-    default:
-      return "SEGV";
-  }
-}
-
 void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
-  ScopedDeadlySignal signal_scope(GetCurrentThread());
-  int code = (int)((siginfo_t*)siginfo)->si_code;
-  // Write the first message using fd=2, just in case.
-  // It may actually fail to write in case stderr is closed.
-  internal_write(2, "ASAN:DEADLYSIGNAL\n", 18);
-  SignalContext sig = SignalContext::Create(siginfo, context);
-
-  // Access at a reasonable offset above SP, or slightly below it (to account
-  // for x86_64 or PowerPC redzone, ARM push of multiple registers, etc) is
-  // probably a stack overflow.
-#ifdef __s390__
-  // On s390, the fault address in siginfo points to start of the page, not
-  // to the precise word that was accessed.  Mask off the low bits of sp to
-  // take it into account.
-  bool IsStackAccess = sig.addr >= (sig.sp & ~0xFFF) &&
-                       sig.addr < sig.sp + 0xFFFF;
-#else
-  bool IsStackAccess = sig.addr + 512 > sig.sp && sig.addr < sig.sp + 0xFFFF;
-#endif
-
-#if __powerpc__
-  // Large stack frames can be allocated with e.g.
-  //   lis r0,-10000
-  //   stdux r1,r1,r0 # store sp to [sp-10000] and update sp by -10000
-  // If the store faults then sp will not have been updated, so test above
-  // will not work, becase the fault address will be more than just "slightly"
-  // below sp.
-  if (!IsStackAccess && IsAccessibleMemoryRange(sig.pc, 4)) {
-    u32 inst = *(unsigned *)sig.pc;
-    u32 ra = (inst >> 16) & 0x1F;
-    u32 opcd = inst >> 26;
-    u32 xo = (inst >> 1) & 0x3FF;
-    // Check for store-with-update to sp. The instructions we accept are:
-    //   stbu rs,d(ra)          stbux rs,ra,rb
-    //   sthu rs,d(ra)          sthux rs,ra,rb
-    //   stwu rs,d(ra)          stwux rs,ra,rb
-    //   stdu rs,ds(ra)         stdux rs,ra,rb
-    // where ra is r1 (the stack pointer).
-    if (ra == 1 &&
-        (opcd == 39 || opcd == 45 || opcd == 37 || opcd == 62 ||
-         (opcd == 31 && (xo == 247 || xo == 439 || xo == 183 || xo == 181))))
-      IsStackAccess = true;
-  }
-#endif // __powerpc__
-
-  // We also check si_code to filter out SEGV caused by something else other
-  // then hitting the guard page or unmapped memory, like, for example,
-  // unaligned memory access.
-  if (IsStackAccess && (code == si_SEGV_MAPERR || code == si_SEGV_ACCERR))
-    ReportStackOverflow(sig);
-  else
-    ReportDeadlySignal(signo, sig);
+  StartReportDeadlySignal();
+  SignalContext sig(siginfo, context);
+  ReportDeadlySignal(sig);
 }
 
 // ---------------------- TSD ---------------- {{{1
diff --git a/libsanitizer/asan/asan_report.cc b/libsanitizer/asan/asan_report.cc
index 84d67646b40..51bad6e45e3 100644
--- a/libsanitizer/asan/asan_report.cc
+++ b/libsanitizer/asan/asan_report.cc
@@ -58,9 +58,8 @@ void PrintMemoryByte(InternalScopedString *str, const char *before, u8 byte,
                      bool in_shadow, const char *after) {
   Decorator d;
   str->append("%s%s%x%x%s%s", before,
-              in_shadow ? d.ShadowByte(byte) : d.MemoryByte(),
-              byte >> 4, byte & 15,
-              in_shadow ? d.EndShadowByte() : d.EndMemoryByte(), after);
+              in_shadow ? d.ShadowByte(byte) : d.MemoryByte(), byte >> 4,
+              byte & 15, d.Default(), after);
 }
 
 static void PrintZoneForPointer(uptr ptr, uptr zone_ptr,
@@ -86,7 +85,8 @@ bool ParseFrameDescription(const char *frame_descr,
   char *p;
   // This string is created by the compiler and has the following form:
   // "n alloc_1 alloc_2 ... alloc_n"
-  // where alloc_i looks like "offset size len ObjectName".
+  // where alloc_i looks like "offset size len ObjectName"
+  // or                       "offset size len ObjectName:line".
   uptr n_objects = (uptr)internal_simple_strtoll(frame_descr, &p, 10);
   if (n_objects == 0)
     return false;
@@ -99,7 +99,14 @@ bool ParseFrameDescription(const char *frame_descr,
       return false;
     }
     p++;
-    StackVarDescr var = {beg, size, p, len};
+    char *colon_pos = internal_strchr(p, ':');
+    uptr line = 0;
+    uptr name_len = len;
+    if (colon_pos != nullptr && colon_pos < p + len) {
+      name_len = colon_pos - p;
+      line = (uptr)internal_simple_strtoll(colon_pos + 1, nullptr, 10);
+    }
+    StackVarDescr var = {beg, size, p, name_len, line};
     vars->push_back(var);
     p += len;
   }
@@ -113,53 +120,15 @@ bool ParseFrameDescription(const char *frame_descr,
 // immediately after printing error report.
 class ScopedInErrorReport {
  public:
-  explicit ScopedInErrorReport(bool fatal = false) {
-    halt_on_error_ = fatal || flags()->halt_on_error;
-
-    if (lock_.TryLock()) {
-      StartReporting();
-      return;
-    }
-
-    // ASan found two bugs in different threads simultaneously.
-
-    u32 current_tid = GetCurrentTidOrInvalid();
-    if (reporting_thread_tid_ == current_tid ||
-        reporting_thread_tid_ == kInvalidTid) {
-      // This is either asynch signal or nested error during error reporting.
-      // Fail simple to avoid deadlocks in Report().
-
-      // Can't use Report() here because of potential deadlocks
-      // in nested signal handlers.
-      const char msg[] = "AddressSanitizer: nested bug in the same thread, "
-                         "aborting.\n";
-      WriteToFile(kStderrFd, msg, sizeof(msg));
-
-      internal__exit(common_flags()->exitcode);
-    }
-
-    if (halt_on_error_) {
-      // Do not print more than one report, otherwise they will mix up.
-      // Error reporting functions shouldn't return at this situation, as
-      // they are effectively no-returns.
-
-      Report("AddressSanitizer: while reporting a bug found another one. "
-             "Ignoring.\n");
-
-      // Sleep long enough to make sure that the thread which started
-      // to print an error report will finish doing it.
-      SleepForSeconds(Max(100, flags()->sleep_before_dying + 1));
-
-      // If we're still not dead for some reason, use raw _exit() instead of
-      // Die() to bypass any additional checks.
-      internal__exit(common_flags()->exitcode);
-    } else {
-      // The other thread will eventually finish reporting
-      // so it's safe to wait
-      lock_.Lock();
-    }
-
-    StartReporting();
+  explicit ScopedInErrorReport(bool fatal = false)
+      : halt_on_error_(fatal || flags()->halt_on_error) {
+    // Make sure the registry and sanitizer report mutexes are locked while
+    // we're printing an error report.
+    // We can lock them only here to avoid self-deadlock in case of
+    // recursive reports.
+    asanThreadRegistry().Lock();
+    Printf(
+        "=================================================================\n");
   }
 
   ~ScopedInErrorReport() {
@@ -177,6 +146,8 @@ class ScopedInErrorReport {
     if (common_flags()->print_cmdline)
       PrintCmdline();
 
+    if (common_flags()->print_module_map == 2) PrintModuleMap();
+
     // Copy the message buffer so that we could start logging without holding a
     // lock that gets aquired during printing.
     InternalScopedBuffer<char> buffer_copy(kErrorMessageBufferSize);
@@ -192,14 +163,19 @@ class ScopedInErrorReport {
       error_report_callback(buffer_copy.data());
     }
 
+    if (halt_on_error_ && common_flags()->abort_on_error) {
+      // On Android the message is truncated to 512 characters.
+      // FIXME: implement "compact" error format, possibly without, or with
+      // highly compressed stack traces?
+      // FIXME: or just use the summary line as abort message?
+      SetAbortMessage(buffer_copy.data());
+    }
+
     // In halt_on_error = false mode, reset the current error object (before
     // unlocking).
     if (!halt_on_error_)
       internal_memset(&current_error_, 0, sizeof(current_error_));
 
-    CommonSanitizerReportMutex.Unlock();
-    reporting_thread_tid_ = kInvalidTid;
-    lock_.Unlock();
     if (halt_on_error_) {
       Report("ABORTING\n");
       Die();
@@ -217,39 +193,18 @@ class ScopedInErrorReport {
   }
 
  private:
-  void StartReporting() {
-    // Make sure the registry and sanitizer report mutexes are locked while
-    // we're printing an error report.
-    // We can lock them only here to avoid self-deadlock in case of
-    // recursive reports.
-    asanThreadRegistry().Lock();
-    CommonSanitizerReportMutex.Lock();
-    reporting_thread_tid_ = GetCurrentTidOrInvalid();
-    Printf("===================================================="
-           "=============\n");
-  }
-
-  static StaticSpinMutex lock_;
-  static u32 reporting_thread_tid_;
+  ScopedErrorReportLock error_report_lock_;
   // Error currently being reported. This enables the destructor to interact
   // with the debugger and point it to an error description.
   static ErrorDescription current_error_;
   bool halt_on_error_;
 };
 
-StaticSpinMutex ScopedInErrorReport::lock_;
-u32 ScopedInErrorReport::reporting_thread_tid_ = kInvalidTid;
 ErrorDescription ScopedInErrorReport::current_error_;
 
-void ReportStackOverflow(const SignalContext &sig) {
+void ReportDeadlySignal(const SignalContext &sig) {
   ScopedInErrorReport in_report(/*fatal*/ true);
-  ErrorStackOverflow error(GetCurrentTidOrInvalid(), sig);
-  in_report.ReportError(error);
-}
-
-void ReportDeadlySignal(int signo, const SignalContext &sig) {
-  ScopedInErrorReport in_report(/*fatal*/ true);
-  ErrorDeadlySignal error(GetCurrentTidOrInvalid(), sig, signo);
+  ErrorDeadlySignal error(GetCurrentTidOrInvalid(), sig);
   in_report.ReportError(error);
 }
 
@@ -425,7 +380,7 @@ void __asan_describe_address(uptr addr) {
 }
 
 int __asan_report_present() {
-  return ScopedInErrorReport::CurrentError().kind == kErrorKindGeneric;
+  return ScopedInErrorReport::CurrentError().kind != kErrorKindInvalid;
 }
 
 uptr __asan_get_report_pc() {
@@ -447,9 +402,11 @@ uptr __asan_get_report_sp() {
 }
 
 uptr __asan_get_report_address() {
-  if (ScopedInErrorReport::CurrentError().kind == kErrorKindGeneric)
-    return ScopedInErrorReport::CurrentError()
-        .Generic.addr_description.Address();
+  ErrorDescription &err = ScopedInErrorReport::CurrentError();
+  if (err.kind == kErrorKindGeneric)
+    return err.Generic.addr_description.Address();
+  else if (err.kind == kErrorKindDoubleFree)
+    return err.DoubleFree.addr_description.addr;
   return 0;
 }
 
@@ -468,7 +425,7 @@ uptr __asan_get_report_access_size() {
 const char *__asan_get_report_description() {
   if (ScopedInErrorReport::CurrentError().kind == kErrorKindGeneric)
     return ScopedInErrorReport::CurrentError().Generic.bug_descr;
-  return nullptr;
+  return ScopedInErrorReport::CurrentError().Base.scariness.GetDescription();
 }
 
 extern "C" {
@@ -482,9 +439,6 @@ void __sanitizer_ptr_cmp(void *a, void *b) {
 }
 } // extern "C"
 
-#if !SANITIZER_SUPPORTS_WEAK_HOOKS
 // Provide default implementation of __asan_on_error that does nothing
 // and may be overriden by user.
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE NOINLINE
-void __asan_on_error() {}
-#endif
+SANITIZER_INTERFACE_WEAK_DEF(void, __asan_on_error, void) {}
diff --git a/libsanitizer/asan/asan_report.h b/libsanitizer/asan/asan_report.h
index 111b8400153..5d47712bd2d 100644
--- a/libsanitizer/asan/asan_report.h
+++ b/libsanitizer/asan/asan_report.h
@@ -21,6 +21,7 @@ struct StackVarDescr {
   uptr size;
   const char *name_pos;
   uptr name_len;
+  uptr line;
 };
 
 // Returns the number of globals close to the provided address and copies
@@ -43,8 +44,7 @@ bool ParseFrameDescription(const char *frame_descr,
 // Different kinds of error reports.
 void ReportGenericError(uptr pc, uptr bp, uptr sp, uptr addr, bool is_write,
                         uptr access_size, u32 exp, bool fatal);
-void ReportStackOverflow(const SignalContext &sig);
-void ReportDeadlySignal(int signo, const SignalContext &sig);
+void ReportDeadlySignal(const SignalContext &sig);
 void ReportNewDeleteSizeMismatch(uptr addr, uptr delete_size,
                                  BufferedStackTrace *free_stack);
 void ReportDoubleFree(uptr addr, BufferedStackTrace *free_stack);
diff --git a/libsanitizer/asan/asan_rtl.cc b/libsanitizer/asan/asan_rtl.cc
index 38009d2905f..3905658a494 100644
--- a/libsanitizer/asan/asan_rtl.cc
+++ b/libsanitizer/asan/asan_rtl.cc
@@ -44,6 +44,7 @@ static void AsanDie() {
     // Don't die twice - run a busy loop.
     while (1) { }
   }
+  if (common_flags()->print_module_map >= 1) PrintModuleMap();
   if (flags()->sleep_before_dying) {
     Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying);
     SleepForSeconds(flags()->sleep_before_dying);
@@ -81,26 +82,6 @@ void ShowStatsAndAbort() {
   Die();
 }
 
-// ---------------------- mmap -------------------- {{{1
-// Reserve memory range [beg, end].
-// We need to use inclusive range because end+1 may not be representable.
-void ReserveShadowMemoryRange(uptr beg, uptr end, const char *name) {
-  CHECK_EQ((beg % GetMmapGranularity()), 0);
-  CHECK_EQ(((end + 1) % GetMmapGranularity()), 0);
-  uptr size = end - beg + 1;
-  DecreaseTotalMmap(size);  // Don't count the shadow against mmap_limit_mb.
-  void *res = MmapFixedNoReserve(beg, size, name);
-  if (res != (void*)beg) {
-    Report("ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. "
-           "Perhaps you're using ulimit -v\n", size);
-    Abort();
-  }
-  if (common_flags()->no_huge_pages_for_shadow)
-    NoHugePagesInRegion(beg, size);
-  if (common_flags()->use_madv_dontdump)
-    DontDumpShadowMemory(beg, size);
-}
-
 // --------------- LowLevelAllocateCallbac ---------- {{{1
 static void OnLowLevelAllocate(uptr ptr, uptr size) {
   PoisonShadow(ptr, size, kAsanInternalHeapMagic);
@@ -332,46 +313,7 @@ static void InitializeHighMemEnd() {
   CHECK_EQ((kHighMemBeg % GetMmapGranularity()), 0);
 }
 
-static void ProtectGap(uptr addr, uptr size) {
-  if (!flags()->protect_shadow_gap) {
-    // The shadow gap is unprotected, so there is a chance that someone
-    // is actually using this memory. Which means it needs a shadow...
-    uptr GapShadowBeg = RoundDownTo(MEM_TO_SHADOW(addr), GetPageSizeCached());
-    uptr GapShadowEnd =
-        RoundUpTo(MEM_TO_SHADOW(addr + size), GetPageSizeCached()) - 1;
-    if (Verbosity())
-      Printf("protect_shadow_gap=0:"
-             " not protecting shadow gap, allocating gap's shadow\n"
-             "|| `[%p, %p]` || ShadowGap's shadow ||\n", GapShadowBeg,
-             GapShadowEnd);
-    ReserveShadowMemoryRange(GapShadowBeg, GapShadowEnd,
-                             "unprotected gap shadow");
-    return;
-  }
-  void *res = MmapFixedNoAccess(addr, size, "shadow gap");
-  if (addr == (uptr)res)
-    return;
-  // A few pages at the start of the address space can not be protected.
-  // But we really want to protect as much as possible, to prevent this memory
-  // being returned as a result of a non-FIXED mmap().
-  if (addr == kZeroBaseShadowStart) {
-    uptr step = GetMmapGranularity();
-    while (size > step && addr < kZeroBaseMaxShadowStart) {
-      addr += step;
-      size -= step;
-      void *res = MmapFixedNoAccess(addr, size, "shadow gap");
-      if (addr == (uptr)res)
-        return;
-    }
-  }
-
-  Report("ERROR: Failed to protect the shadow gap. "
-         "ASan cannot proceed correctly. ABORTING.\n");
-  DumpProcessMap();
-  Die();
-}
-
-static void PrintAddressSpaceLayout() {
+void PrintAddressSpaceLayout() {
   Printf("|| `[%p, %p]` || HighMem    ||\n",
          (void*)kHighMemBeg, (void*)kHighMemEnd);
   Printf("|| `[%p, %p]` || HighShadow ||\n",
@@ -408,6 +350,8 @@ static void PrintAddressSpaceLayout() {
   Printf("redzone=%zu\n", (uptr)flags()->redzone);
   Printf("max_redzone=%zu\n", (uptr)flags()->max_redzone);
   Printf("quarantine_size_mb=%zuM\n", (uptr)flags()->quarantine_size_mb);
+  Printf("thread_local_quarantine_size_kb=%zuK\n",
+         (uptr)flags()->thread_local_quarantine_size_kb);
   Printf("malloc_context_size=%zu\n",
          (uptr)common_flags()->malloc_context_size);
 
@@ -472,78 +416,9 @@ static void AsanInitInternal() {
 
   ReplaceSystemMalloc();
 
-  // Set the shadow memory address to uninitialized.
-  __asan_shadow_memory_dynamic_address = kDefaultShadowSentinel;
-
-  uptr shadow_start = kLowShadowBeg;
-  // Detect if a dynamic shadow address must used and find a available location
-  // when necessary. When dynamic address is used, the macro |kLowShadowBeg|
-  // expands to |__asan_shadow_memory_dynamic_address| which is
-  // |kDefaultShadowSentinel|.
-  if (shadow_start == kDefaultShadowSentinel) {
-    __asan_shadow_memory_dynamic_address = 0;
-    CHECK_EQ(0, kLowShadowBeg);
-
-    uptr granularity = GetMmapGranularity();
-    uptr alignment = 8 * granularity;
-    uptr left_padding = granularity;
-    uptr space_size = kHighShadowEnd + left_padding;
-
-    shadow_start = FindAvailableMemoryRange(space_size, alignment, granularity);
-    CHECK_NE((uptr)0, shadow_start);
-    CHECK(IsAligned(shadow_start, alignment));
-  }
-  // Update the shadow memory address (potentially) used by instrumentation.
-  __asan_shadow_memory_dynamic_address = shadow_start;
-
-  if (kLowShadowBeg)
-    shadow_start -= GetMmapGranularity();
-  bool full_shadow_is_available =
-      MemoryRangeIsAvailable(shadow_start, kHighShadowEnd);
-
-#if SANITIZER_LINUX && defined(__x86_64__) && defined(_LP64) &&                \
-    !ASAN_FIXED_MAPPING
-  if (!full_shadow_is_available) {
-    kMidMemBeg = kLowMemEnd < 0x3000000000ULL ? 0x3000000000ULL : 0;
-    kMidMemEnd = kLowMemEnd < 0x3000000000ULL ? 0x4fffffffffULL : 0;
-  }
-#endif
-
-  if (Verbosity()) PrintAddressSpaceLayout();
-
   DisableCoreDumperIfNecessary();
 
-  if (full_shadow_is_available) {
-    // mmap the low shadow plus at least one page at the left.
-    if (kLowShadowBeg)
-      ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");
-    // mmap the high shadow.
-    ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");
-    // protect the gap.
-    ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
-    CHECK_EQ(kShadowGapEnd, kHighShadowBeg - 1);
-  } else if (kMidMemBeg &&
-      MemoryRangeIsAvailable(shadow_start, kMidMemBeg - 1) &&
-      MemoryRangeIsAvailable(kMidMemEnd + 1, kHighShadowEnd)) {
-    CHECK(kLowShadowBeg != kLowShadowEnd);
-    // mmap the low shadow plus at least one page at the left.
-    ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");
-    // mmap the mid shadow.
-    ReserveShadowMemoryRange(kMidShadowBeg, kMidShadowEnd, "mid shadow");
-    // mmap the high shadow.
-    ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");
-    // protect the gaps.
-    ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
-    ProtectGap(kShadowGap2Beg, kShadowGap2End - kShadowGap2Beg + 1);
-    ProtectGap(kShadowGap3Beg, kShadowGap3End - kShadowGap3Beg + 1);
-  } else {
-    Report("Shadow memory range interleaves with an existing memory mapping. "
-           "ASan cannot proceed correctly. ABORTING.\n");
-    Report("ASan shadow was supposed to be located in the [%p-%p] range.\n",
-           shadow_start, kHighShadowEnd);
-    DumpProcessMap();
-    Die();
-  }
+  InitializeShadowMemory();
 
   AsanTSDInit(PlatformTSDDtor);
   InstallDeadlySignalHandlers(AsanOnDeadlySignal);
@@ -574,20 +449,18 @@ static void AsanInitInternal() {
   InitTlsSize();
 
   // Create main thread.
-  AsanThread *main_thread = AsanThread::Create(
-      /* start_routine */ nullptr, /* arg */ nullptr, /* parent_tid */ 0,
-      /* stack */ nullptr, /* detached */ true);
+  AsanThread *main_thread = CreateMainThread();
   CHECK_EQ(0, main_thread->tid());
-  SetCurrentThread(main_thread);
-  main_thread->ThreadStart(internal_getpid(),
-                           /* signal_thread_is_registered */ nullptr);
   force_interface_symbols();  // no-op.
   SanitizerInitializeUnwinder();
 
   if (CAN_SANITIZE_LEAKS) {
     __lsan::InitCommonLsan();
     if (common_flags()->detect_leaks && common_flags()->leak_check_at_exit) {
-      Atexit(__lsan::DoLeakCheck);
+      if (flags()->halt_on_error)
+        Atexit(__lsan::DoLeakCheck);
+      else
+        Atexit(__lsan::DoRecoverableLeakCheckVoid);
     }
   }
 
@@ -607,6 +480,11 @@ static void AsanInitInternal() {
   }
 
   VReport(1, "AddressSanitizer Init done\n");
+
+  if (flags()->sleep_after_init) {
+    Report("Sleeping for %d second(s)\n", flags()->sleep_after_init);
+    SleepForSeconds(flags()->sleep_after_init);
+  }
 }
 
 // Initialize as requested from some part of ASan runtime library (interceptors,
@@ -646,6 +524,7 @@ void NOINLINE __asan_handle_no_return() {
     top = curr_thread->stack_top();
     bottom = ((uptr)&local_stack - PageSize) & ~(PageSize - 1);
   } else {
+    CHECK(!SANITIZER_FUCHSIA);
     // If we haven't seen this thread, try asking the OS for stack bounds.
     uptr tls_addr, tls_size, stack_size;
     GetThreadStackAndTls(/*main=*/false, &bottom, &stack_size, &tls_addr,
diff --git a/libsanitizer/asan/asan_scariness_score.h b/libsanitizer/asan/asan_scariness_score.h
index d72fce69d64..aa947ed2732 100644
--- a/libsanitizer/asan/asan_scariness_score.h
+++ b/libsanitizer/asan/asan_scariness_score.h
@@ -45,7 +45,7 @@ struct ScarinessScoreBase {
   };
   int GetScore() const { return score; }
   const char *GetDescription() const { return descr; }
-  void Print() {
+  void Print() const {
     if (score && flags()->print_scariness)
       Printf("SCARINESS: %d (%s)\n", score, descr);
   }
diff --git a/libsanitizer/asan/asan_shadow_setup.cc b/libsanitizer/asan/asan_shadow_setup.cc
new file mode 100644
index 00000000000..9629b36798f
--- /dev/null
+++ b/libsanitizer/asan/asan_shadow_setup.cc
@@ -0,0 +1,159 @@
+//===-- asan_shadow_setup.cc ----------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+//
+// Set up the shadow memory.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_platform.h"
+
+// asan_fuchsia.cc has its own InitializeShadowMemory implementation.
+#if !SANITIZER_FUCHSIA
+
+#include "asan_internal.h"
+#include "asan_mapping.h"
+
+namespace __asan {
+
+// ---------------------- mmap -------------------- {{{1
+// Reserve memory range [beg, end].
+// We need to use inclusive range because end+1 may not be representable.
+void ReserveShadowMemoryRange(uptr beg, uptr end, const char *name) {
+  CHECK_EQ((beg % GetMmapGranularity()), 0);
+  CHECK_EQ(((end + 1) % GetMmapGranularity()), 0);
+  uptr size = end - beg + 1;
+  DecreaseTotalMmap(size);  // Don't count the shadow against mmap_limit_mb.
+  void *res = MmapFixedNoReserve(beg, size, name);
+  if (res != (void *)beg) {
+    Report(
+        "ReserveShadowMemoryRange failed while trying to map 0x%zx bytes. "
+        "Perhaps you're using ulimit -v\n",
+        size);
+    Abort();
+  }
+  if (common_flags()->no_huge_pages_for_shadow) NoHugePagesInRegion(beg, size);
+  if (common_flags()->use_madv_dontdump) DontDumpShadowMemory(beg, size);
+}
+
+static void ProtectGap(uptr addr, uptr size) {
+  if (!flags()->protect_shadow_gap) {
+    // The shadow gap is unprotected, so there is a chance that someone
+    // is actually using this memory. Which means it needs a shadow...
+    uptr GapShadowBeg = RoundDownTo(MEM_TO_SHADOW(addr), GetPageSizeCached());
+    uptr GapShadowEnd =
+        RoundUpTo(MEM_TO_SHADOW(addr + size), GetPageSizeCached()) - 1;
+    if (Verbosity())
+      Printf(
+          "protect_shadow_gap=0:"
+          " not protecting shadow gap, allocating gap's shadow\n"
+          "|| `[%p, %p]` || ShadowGap's shadow ||\n",
+          GapShadowBeg, GapShadowEnd);
+    ReserveShadowMemoryRange(GapShadowBeg, GapShadowEnd,
+                             "unprotected gap shadow");
+    return;
+  }
+  void *res = MmapFixedNoAccess(addr, size, "shadow gap");
+  if (addr == (uptr)res) return;
+  // A few pages at the start of the address space can not be protected.
+  // But we really want to protect as much as possible, to prevent this memory
+  // being returned as a result of a non-FIXED mmap().
+  if (addr == kZeroBaseShadowStart) {
+    uptr step = GetMmapGranularity();
+    while (size > step && addr < kZeroBaseMaxShadowStart) {
+      addr += step;
+      size -= step;
+      void *res = MmapFixedNoAccess(addr, size, "shadow gap");
+      if (addr == (uptr)res) return;
+    }
+  }
+
+  Report(
+      "ERROR: Failed to protect the shadow gap. "
+      "ASan cannot proceed correctly. ABORTING.\n");
+  DumpProcessMap();
+  Die();
+}
+
+static void MaybeReportLinuxPIEBug() {
+#if SANITIZER_LINUX && (defined(__x86_64__) || defined(__aarch64__))
+  Report("This might be related to ELF_ET_DYN_BASE change in Linux 4.12.\n");
+  Report(
+      "See https://github.com/google/sanitizers/issues/856 for possible "
+      "workarounds.\n");
+#endif
+}
+
+void InitializeShadowMemory() {
+  // Set the shadow memory address to uninitialized.
+  __asan_shadow_memory_dynamic_address = kDefaultShadowSentinel;
+
+  uptr shadow_start = kLowShadowBeg;
+  // Detect if a dynamic shadow address must used and find a available location
+  // when necessary. When dynamic address is used, the macro |kLowShadowBeg|
+  // expands to |__asan_shadow_memory_dynamic_address| which is
+  // |kDefaultShadowSentinel|.
+  if (shadow_start == kDefaultShadowSentinel) {
+    __asan_shadow_memory_dynamic_address = 0;
+    CHECK_EQ(0, kLowShadowBeg);
+    shadow_start = FindDynamicShadowStart();
+  }
+  // Update the shadow memory address (potentially) used by instrumentation.
+  __asan_shadow_memory_dynamic_address = shadow_start;
+
+  if (kLowShadowBeg) shadow_start -= GetMmapGranularity();
+  bool full_shadow_is_available =
+      MemoryRangeIsAvailable(shadow_start, kHighShadowEnd);
+
+#if SANITIZER_LINUX && defined(__x86_64__) && defined(_LP64) && \
+    !ASAN_FIXED_MAPPING
+  if (!full_shadow_is_available) {
+    kMidMemBeg = kLowMemEnd < 0x3000000000ULL ? 0x3000000000ULL : 0;
+    kMidMemEnd = kLowMemEnd < 0x3000000000ULL ? 0x4fffffffffULL : 0;
+  }
+#endif
+
+  if (Verbosity()) PrintAddressSpaceLayout();
+
+  if (full_shadow_is_available) {
+    // mmap the low shadow plus at least one page at the left.
+    if (kLowShadowBeg)
+      ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");
+    // mmap the high shadow.
+    ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");
+    // protect the gap.
+    ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
+    CHECK_EQ(kShadowGapEnd, kHighShadowBeg - 1);
+  } else if (kMidMemBeg &&
+             MemoryRangeIsAvailable(shadow_start, kMidMemBeg - 1) &&
+             MemoryRangeIsAvailable(kMidMemEnd + 1, kHighShadowEnd)) {
+    CHECK(kLowShadowBeg != kLowShadowEnd);
+    // mmap the low shadow plus at least one page at the left.
+    ReserveShadowMemoryRange(shadow_start, kLowShadowEnd, "low shadow");
+    // mmap the mid shadow.
+    ReserveShadowMemoryRange(kMidShadowBeg, kMidShadowEnd, "mid shadow");
+    // mmap the high shadow.
+    ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd, "high shadow");
+    // protect the gaps.
+    ProtectGap(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
+    ProtectGap(kShadowGap2Beg, kShadowGap2End - kShadowGap2Beg + 1);
+    ProtectGap(kShadowGap3Beg, kShadowGap3End - kShadowGap3Beg + 1);
+  } else {
+    Report(
+        "Shadow memory range interleaves with an existing memory mapping. "
+        "ASan cannot proceed correctly. ABORTING.\n");
+    Report("ASan shadow was supposed to be located in the [%p-%p] range.\n",
+           shadow_start, kHighShadowEnd);
+    MaybeReportLinuxPIEBug();
+    DumpProcessMap();
+    Die();
+  }
+}
+
+}  // namespace __asan
+
+#endif  // !SANITIZER_FUCHSIA
diff --git a/libsanitizer/asan/asan_stack.h b/libsanitizer/asan/asan_stack.h
index 2b8738156ea..aa8c4cdc2f2 100644
--- a/libsanitizer/asan/asan_stack.h
+++ b/libsanitizer/asan/asan_stack.h
@@ -39,10 +39,6 @@ void GetStackTraceWithPcBpAndContext(BufferedStackTrace *stack, uptr max_depth,
   stack->size = 0;
   if (LIKELY(asan_inited)) {
     if ((t = GetCurrentThread()) && !t->isUnwinding()) {
-      // On FreeBSD the slow unwinding that leverages _Unwind_Backtrace()
-      // yields the call stack of the signal's handler and not of the code
-      // that raised the signal (as it does on Linux).
-      if (SANITIZER_FREEBSD && t->isInDeadlySignal()) fast = true;
       uptr stack_top = t->stack_top();
       uptr stack_bottom = t->stack_bottom();
       ScopedUnwinding unwind_scope(t);
diff --git a/libsanitizer/asan/asan_suppressions.cc b/libsanitizer/asan/asan_suppressions.cc
index 1dc9d474240..00406020054 100644
--- a/libsanitizer/asan/asan_suppressions.cc
+++ b/libsanitizer/asan/asan_suppressions.cc
@@ -29,15 +29,9 @@ static const char *kSuppressionTypes[] = {
     kInterceptorName, kInterceptorViaFunction, kInterceptorViaLibrary,
     kODRViolation};
 
-extern "C" {
-#if SANITIZER_SUPPORTS_WEAK_HOOKS
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-const char *__asan_default_suppressions();
-#else
-// No week hooks, provide empty implementation.
-const char *__asan_default_suppressions() { return ""; }
-#endif  // SANITIZER_SUPPORTS_WEAK_HOOKS
-}  // extern "C"
+SANITIZER_INTERFACE_WEAK_DEF(const char *, __asan_default_suppressions, void) {
+  return "";
+}
 
 void InitializeSuppressions() {
   CHECK_EQ(nullptr, suppression_ctx);
diff --git a/libsanitizer/asan/asan_thread.cc b/libsanitizer/asan/asan_thread.cc
index 818e1261400..d0fdf6e9847 100644
--- a/libsanitizer/asan/asan_thread.cc
+++ b/libsanitizer/asan/asan_thread.cc
@@ -25,11 +25,6 @@ namespace __asan {
 
 // AsanThreadContext implementation.
 
-struct CreateThreadContextArgs {
-  AsanThread *thread;
-  StackTrace *stack;
-};
-
 void AsanThreadContext::OnCreated(void *arg) {
   CreateThreadContextArgs *args = static_cast<CreateThreadContextArgs*>(arg);
   if (args->stack)
@@ -86,7 +81,7 @@ AsanThread *AsanThread::Create(thread_callback_t start_routine, void *arg,
   AsanThread *thread = (AsanThread*)MmapOrDie(size, __func__);
   thread->start_routine_ = start_routine;
   thread->arg_ = arg;
-  CreateThreadContextArgs args = { thread, stack };
+  AsanThreadContext::CreateThreadContextArgs args = {thread, stack};
   asanThreadRegistry().CreateThread(*reinterpret_cast<uptr *>(thread), detached,
                                     parent_tid, &args);
 
@@ -164,16 +159,19 @@ void AsanThread::FinishSwitchFiber(FakeStack *fake_stack_save,
 }
 
 inline AsanThread::StackBounds AsanThread::GetStackBounds() const {
-  if (!atomic_load(&stack_switching_, memory_order_acquire))
-    return StackBounds{stack_bottom_, stack_top_};  // NOLINT
+  if (!atomic_load(&stack_switching_, memory_order_acquire)) {
+    // Make sure the stack bounds are fully initialized.
+    if (stack_bottom_ >= stack_top_) return {0, 0};
+    return {stack_bottom_, stack_top_};
+  }
   char local;
   const uptr cur_stack = (uptr)&local;
   // Note: need to check next stack first, because FinishSwitchFiber
   // may be in process of overwriting stack_top_/bottom_. But in such case
   // we are already on the next stack.
   if (cur_stack >= next_stack_bottom_ && cur_stack < next_stack_top_)
-    return StackBounds{next_stack_bottom_, next_stack_top_};  // NOLINT
-  return StackBounds{stack_bottom_, stack_top_};              // NOLINT
+    return {next_stack_bottom_, next_stack_top_};
+  return {stack_bottom_, stack_top_};
 }
 
 uptr AsanThread::stack_top() {
@@ -218,12 +216,12 @@ FakeStack *AsanThread::AsyncSignalSafeLazyInitFakeStack() {
   return nullptr;
 }
 
-void AsanThread::Init() {
+void AsanThread::Init(const InitOptions *options) {
   next_stack_top_ = next_stack_bottom_ = 0;
   atomic_store(&stack_switching_, false, memory_order_release);
   fake_stack_ = nullptr;  // Will be initialized lazily if needed.
   CHECK_EQ(this->stack_size(), 0U);
-  SetThreadStackAndTls();
+  SetThreadStackAndTls(options);
   CHECK_GT(this->stack_size(), 0U);
   CHECK(AddrIsInMem(stack_bottom_));
   CHECK(AddrIsInMem(stack_top_ - 1));
@@ -234,10 +232,15 @@ void AsanThread::Init() {
           &local);
 }
 
+// Fuchsia doesn't use ThreadStart.
+// asan_fuchsia.c defines CreateMainThread and SetThreadStackAndTls.
+#if !SANITIZER_FUCHSIA
+
 thread_return_t AsanThread::ThreadStart(
-    uptr os_id, atomic_uintptr_t *signal_thread_is_registered) {
+    tid_t os_id, atomic_uintptr_t *signal_thread_is_registered) {
   Init();
-  asanThreadRegistry().StartThread(tid(), os_id, nullptr);
+  asanThreadRegistry().StartThread(tid(), os_id, /*workerthread*/ false,
+                                   nullptr);
   if (signal_thread_is_registered)
     atomic_store(signal_thread_is_registered, 1, memory_order_release);
 
@@ -264,7 +267,21 @@ thread_return_t AsanThread::ThreadStart(
   return res;
 }
 
-void AsanThread::SetThreadStackAndTls() {
+AsanThread *CreateMainThread() {
+  AsanThread *main_thread = AsanThread::Create(
+      /* start_routine */ nullptr, /* arg */ nullptr, /* parent_tid */ 0,
+      /* stack */ nullptr, /* detached */ true);
+  SetCurrentThread(main_thread);
+  main_thread->ThreadStart(internal_getpid(),
+                           /* signal_thread_is_registered */ nullptr);
+  return main_thread;
+}
+
+// This implementation doesn't use the argument, which is just passed down
+// from the caller of Init (which see, above).  It's only there to support
+// OS-specific implementations that need more information passed through.
+void AsanThread::SetThreadStackAndTls(const InitOptions *options) {
+  DCHECK_EQ(options, nullptr);
   uptr tls_size = 0;
   uptr stack_size = 0;
   GetThreadStackAndTls(tid() == 0, const_cast<uptr *>(&stack_bottom_),
@@ -277,6 +294,8 @@ void AsanThread::SetThreadStackAndTls() {
   CHECK(AddrIsInStack((uptr)&local));
 }
 
+#endif  // !SANITIZER_FUCHSIA
+
 void AsanThread::ClearShadowForThreadStackAndTLS() {
   PoisonShadow(stack_bottom_, stack_top_ - stack_bottom_, 0);
   if (tls_begin_ != tls_end_)
@@ -297,24 +316,27 @@ bool AsanThread::GetStackFrameAccessByAddr(uptr addr,
     return true;
   }
   uptr aligned_addr = addr & ~(SANITIZER_WORDSIZE/8 - 1);  // align addr.
+  uptr mem_ptr = RoundDownTo(aligned_addr, SHADOW_GRANULARITY);
   u8 *shadow_ptr = (u8*)MemToShadow(aligned_addr);
   u8 *shadow_bottom = (u8*)MemToShadow(bottom);
 
   while (shadow_ptr >= shadow_bottom &&
          *shadow_ptr != kAsanStackLeftRedzoneMagic) {
     shadow_ptr--;
+    mem_ptr -= SHADOW_GRANULARITY;
   }
 
   while (shadow_ptr >= shadow_bottom &&
          *shadow_ptr == kAsanStackLeftRedzoneMagic) {
     shadow_ptr--;
+    mem_ptr -= SHADOW_GRANULARITY;
   }
 
   if (shadow_ptr < shadow_bottom) {
     return false;
   }
 
-  uptr* ptr = (uptr*)SHADOW_TO_MEM((uptr)(shadow_ptr + 1));
+  uptr* ptr = (uptr*)(mem_ptr + SHADOW_GRANULARITY);
   CHECK(ptr[0] == kCurrentStackFrameMagic);
   access->offset = addr - (uptr)ptr;
   access->frame_pc = ptr[2];
@@ -389,7 +411,7 @@ void EnsureMainThreadIDIsCorrect() {
     context->os_id = GetTid();
 }
 
-__asan::AsanThread *GetAsanThreadByOsIDLocked(uptr os_id) {
+__asan::AsanThread *GetAsanThreadByOsIDLocked(tid_t os_id) {
   __asan::AsanThreadContext *context = static_cast<__asan::AsanThreadContext *>(
       __asan::asanThreadRegistry().FindThreadContextByOsIDLocked(os_id));
   if (!context) return nullptr;
@@ -399,7 +421,7 @@ __asan::AsanThread *GetAsanThreadByOsIDLocked(uptr os_id) {
 
 // --- Implementation of LSan-specific functions --- {{{1
 namespace __lsan {
-bool GetThreadRangesLocked(uptr os_id, uptr *stack_begin, uptr *stack_end,
+bool GetThreadRangesLocked(tid_t os_id, uptr *stack_begin, uptr *stack_end,
                            uptr *tls_begin, uptr *tls_end, uptr *cache_begin,
                            uptr *cache_end, DTLS **dtls) {
   __asan::AsanThread *t = __asan::GetAsanThreadByOsIDLocked(os_id);
@@ -415,7 +437,7 @@ bool GetThreadRangesLocked(uptr os_id, uptr *stack_begin, uptr *stack_end,
   return true;
 }
 
-void ForEachExtraStackRange(uptr os_id, RangeIteratorCallback callback,
+void ForEachExtraStackRange(tid_t os_id, RangeIteratorCallback callback,
                             void *arg) {
   __asan::AsanThread *t = __asan::GetAsanThreadByOsIDLocked(os_id);
   if (t && t->has_fake_stack())
diff --git a/libsanitizer/asan/asan_thread.h b/libsanitizer/asan/asan_thread.h
index c51a58ad0bb..f7a91f3e73b 100644
--- a/libsanitizer/asan/asan_thread.h
+++ b/libsanitizer/asan/asan_thread.h
@@ -47,6 +47,11 @@ class AsanThreadContext : public ThreadContextBase {
 
   void OnCreated(void *arg) override;
   void OnFinished() override;
+
+  struct CreateThreadContextArgs {
+    AsanThread *thread;
+    StackTrace *stack;
+  };
 };
 
 // AsanThreadContext objects are never freed, so we need many of them.
@@ -60,8 +65,10 @@ class AsanThread {
   static void TSDDtor(void *tsd);
   void Destroy();
 
-  void Init();  // Should be called from the thread itself.
-  thread_return_t ThreadStart(uptr os_id,
+  struct InitOptions;
+  void Init(const InitOptions *options = nullptr);
+
+  thread_return_t ThreadStart(tid_t os_id,
                               atomic_uintptr_t *signal_thread_is_registered);
 
   uptr stack_top();
@@ -116,17 +123,15 @@ class AsanThread {
   bool isUnwinding() const { return unwinding_; }
   void setUnwinding(bool b) { unwinding_ = b; }
 
-  // True if we are in a deadly signal handler.
-  bool isInDeadlySignal() const { return in_deadly_signal_; }
-  void setInDeadlySignal(bool b) { in_deadly_signal_ = b; }
-
   AsanThreadLocalMallocStorage &malloc_storage() { return malloc_storage_; }
   AsanStats &stats() { return stats_; }
 
  private:
   // NOTE: There is no AsanThread constructor. It is allocated
   // via mmap() and *must* be valid in zero-initialized state.
-  void SetThreadStackAndTls();
+
+  void SetThreadStackAndTls(const InitOptions *options);
+
   void ClearShadowForThreadStackAndTLS();
   FakeStack *AsyncSignalSafeLazyInitFakeStack();
 
@@ -156,7 +161,6 @@ class AsanThread {
   AsanThreadLocalMallocStorage malloc_storage_;
   AsanStats stats_;
   bool unwinding_;
-  bool in_deadly_signal_;
 };
 
 // ScopedUnwinding is a scope for stacktracing member of a context
@@ -171,20 +175,6 @@ class ScopedUnwinding {
   AsanThread *thread;
 };
 
-// ScopedDeadlySignal is a scope for handling deadly signals.
-class ScopedDeadlySignal {
- public:
-  explicit ScopedDeadlySignal(AsanThread *t) : thread(t) {
-    if (thread) thread->setInDeadlySignal(true);
-  }
-  ~ScopedDeadlySignal() {
-    if (thread) thread->setInDeadlySignal(false);
-  }
-
- private:
-  AsanThread *thread;
-};
-
 // Returns a single instance of registry.
 ThreadRegistry &asanThreadRegistry();
 
diff --git a/libsanitizer/asan/asan_win.cc b/libsanitizer/asan/asan_win.cc
index efd82bfc3b0..02c7ed11628 100644
--- a/libsanitizer/asan/asan_win.cc
+++ b/libsanitizer/asan/asan_win.cc
@@ -25,6 +25,8 @@
 #include "asan_mapping.h"
 #include "sanitizer_common/sanitizer_libc.h"
 #include "sanitizer_common/sanitizer_mutex.h"
+#include "sanitizer_common/sanitizer_win.h"
+#include "sanitizer_common/sanitizer_win_defs.h"
 
 using namespace __asan;  // NOLINT
 
@@ -40,35 +42,50 @@ uptr __asan_get_shadow_memory_dynamic_address() {
   __asan_init();
   return __asan_shadow_memory_dynamic_address;
 }
-
-// -------------------- A workaround for the absence of weak symbols ----- {{{
-// We don't have a direct equivalent of weak symbols when using MSVC, but we can
-// use the /alternatename directive to tell the linker to default a specific
-// symbol to a specific value, which works nicely for allocator hooks and
-// __asan_default_options().
-void __sanitizer_default_malloc_hook(void *ptr, uptr size) { }
-void __sanitizer_default_free_hook(void *ptr) { }
-const char* __asan_default_default_options() { return ""; }
-const char* __asan_default_default_suppressions() { return ""; }
-void __asan_default_on_error() {}
-// 64-bit msvc will not prepend an underscore for symbols.
-#ifdef _WIN64
-#pragma comment(linker, "/alternatename:__sanitizer_malloc_hook=__sanitizer_default_malloc_hook")  // NOLINT
-#pragma comment(linker, "/alternatename:__sanitizer_free_hook=__sanitizer_default_free_hook")      // NOLINT
-#pragma comment(linker, "/alternatename:__asan_default_options=__asan_default_default_options")    // NOLINT
-#pragma comment(linker, "/alternatename:__asan_default_suppressions=__asan_default_default_suppressions")    // NOLINT
-#pragma comment(linker, "/alternatename:__asan_on_error=__asan_default_on_error")                  // NOLINT
-#else
-#pragma comment(linker, "/alternatename:___sanitizer_malloc_hook=___sanitizer_default_malloc_hook")  // NOLINT
-#pragma comment(linker, "/alternatename:___sanitizer_free_hook=___sanitizer_default_free_hook")      // NOLINT
-#pragma comment(linker, "/alternatename:___asan_default_options=___asan_default_default_options")    // NOLINT
-#pragma comment(linker, "/alternatename:___asan_default_suppressions=___asan_default_default_suppressions")    // NOLINT
-#pragma comment(linker, "/alternatename:___asan_on_error=___asan_default_on_error")                  // NOLINT
-#endif
-// }}}
 }  // extern "C"
 
 // ---------------------- Windows-specific interceptors ---------------- {{{
+static LPTOP_LEVEL_EXCEPTION_FILTER default_seh_handler;
+static LPTOP_LEVEL_EXCEPTION_FILTER user_seh_handler;
+
+extern "C" SANITIZER_INTERFACE_ATTRIBUTE
+long __asan_unhandled_exception_filter(EXCEPTION_POINTERS *info) {
+  EXCEPTION_RECORD *exception_record = info->ExceptionRecord;
+  CONTEXT *context = info->ContextRecord;
+
+  // FIXME: Handle EXCEPTION_STACK_OVERFLOW here.
+
+  SignalContext sig(exception_record, context);
+  ReportDeadlySignal(sig);
+  UNREACHABLE("returned from reporting deadly signal");
+}
+
+// Wrapper SEH Handler. If the exception should be handled by asan, we call
+// __asan_unhandled_exception_filter, otherwise, we execute the user provided
+// exception handler or the default.
+static long WINAPI SEHHandler(EXCEPTION_POINTERS *info) {
+  DWORD exception_code = info->ExceptionRecord->ExceptionCode;
+  if (__sanitizer::IsHandledDeadlyException(exception_code))
+    return __asan_unhandled_exception_filter(info);
+  if (user_seh_handler)
+    return user_seh_handler(info);
+  // Bubble out to the default exception filter.
+  if (default_seh_handler)
+    return default_seh_handler(info);
+  return EXCEPTION_CONTINUE_SEARCH;
+}
+
+INTERCEPTOR_WINAPI(LPTOP_LEVEL_EXCEPTION_FILTER, SetUnhandledExceptionFilter,
+    LPTOP_LEVEL_EXCEPTION_FILTER ExceptionFilter) {
+  CHECK(REAL(SetUnhandledExceptionFilter));
+  if (ExceptionFilter == &SEHHandler)
+    return REAL(SetUnhandledExceptionFilter)(ExceptionFilter);
+  // We record the user provided exception handler to be called for all the
+  // exceptions unhandled by asan.
+  Swap(ExceptionFilter, user_seh_handler);
+  return ExceptionFilter;
+}
+
 INTERCEPTOR_WINAPI(void, RtlRaiseException, EXCEPTION_RECORD *ExceptionRecord) {
   CHECK(REAL(RtlRaiseException));
   // This is a noreturn function, unless it's one of the exceptions raised to
@@ -141,6 +158,7 @@ namespace __asan {
 
 void InitializePlatformInterceptors() {
   ASAN_INTERCEPT_FUNC(CreateThread);
+  ASAN_INTERCEPT_FUNC(SetUnhandledExceptionFilter);
 
 #ifdef _WIN64
   ASAN_INTERCEPT_FUNC(__C_specific_handler);
@@ -197,6 +215,18 @@ void *AsanDoesNotSupportStaticLinkage() {
   return 0;
 }
 
+uptr FindDynamicShadowStart() {
+  uptr granularity = GetMmapGranularity();
+  uptr alignment = 8 * granularity;
+  uptr left_padding = granularity;
+  uptr space_size = kHighShadowEnd + left_padding;
+  uptr shadow_start =
+      FindAvailableMemoryRange(space_size, alignment, granularity, nullptr);
+  CHECK_NE((uptr)0, shadow_start);
+  CHECK(IsAligned(shadow_start, alignment));
+  return shadow_start;
+}
+
 void AsanCheckDynamicRTPrereqs() {}
 
 void AsanCheckIncompatibleRT() {}
@@ -257,52 +287,8 @@ void InitializePlatformExceptionHandlers() {
 #endif
 }
 
-static LPTOP_LEVEL_EXCEPTION_FILTER default_seh_handler;
-
-// Check based on flags if we should report this exception.
-static bool ShouldReportDeadlyException(unsigned code) {
-  switch (code) {
-    case EXCEPTION_ACCESS_VIOLATION:
-    case EXCEPTION_IN_PAGE_ERROR:
-      return common_flags()->handle_segv;
-    case EXCEPTION_BREAKPOINT:
-    case EXCEPTION_ILLEGAL_INSTRUCTION: {
-      return common_flags()->handle_sigill;
-    }
-  }
-  return false;
-}
-
-// Return the textual name for this exception.
-const char *DescribeSignalOrException(int signo) {
-  unsigned code = signo;
-  // Get the string description of the exception if this is a known deadly
-  // exception.
-  switch (code) {
-    case EXCEPTION_ACCESS_VIOLATION:
-      return "access-violation";
-    case EXCEPTION_IN_PAGE_ERROR:
-      return "in-page-error";
-    case EXCEPTION_BREAKPOINT:
-      return "breakpoint";
-    case EXCEPTION_ILLEGAL_INSTRUCTION:
-      return "illegal-instruction";
-  }
-  return nullptr;
-}
-
-static long WINAPI SEHHandler(EXCEPTION_POINTERS *info) {
-  EXCEPTION_RECORD *exception_record = info->ExceptionRecord;
-  CONTEXT *context = info->ContextRecord;
-
-  if (ShouldReportDeadlyException(exception_record->ExceptionCode)) {
-    SignalContext sig = SignalContext::Create(exception_record, context);
-    ReportDeadlySignal(exception_record->ExceptionCode, sig);
-  }
-
-  // FIXME: Handle EXCEPTION_STACK_OVERFLOW here.
-
-  return default_seh_handler(info);
+bool IsSystemHeapAddress(uptr addr) {
+  return ::HeapValidate(GetProcessHeap(), 0, (void*)addr) != FALSE;
 }
 
 // We want to install our own exception handler (EH) to print helpful reports
@@ -341,10 +327,25 @@ int __asan_set_seh_filter() {
 // immediately after the CRT runs. This way, our exception filter is called
 // first and we can delegate to their filter if appropriate.
 #pragma section(".CRT$XCAB", long, read)  // NOLINT
-__declspec(allocate(".CRT$XCAB"))
-    int (*__intercept_seh)() = __asan_set_seh_filter;
+__declspec(allocate(".CRT$XCAB")) int (*__intercept_seh)() =
+    __asan_set_seh_filter;
+
+// Piggyback on the TLS initialization callback directory to initialize asan as
+// early as possible. Initializers in .CRT$XL* are called directly by ntdll,
+// which run before the CRT. Users also add code to .CRT$XLC, so it's important
+// to run our initializers first.
+static void NTAPI asan_thread_init(void *module, DWORD reason, void *reserved) {
+  if (reason == DLL_PROCESS_ATTACH) __asan_init();
+}
+
+#pragma section(".CRT$XLAB", long, read)  // NOLINT
+__declspec(allocate(".CRT$XLAB")) void (NTAPI *__asan_tls_init)(void *,
+    unsigned long, void *) = asan_thread_init;
 #endif
+
+WIN_FORCE_LINK(__asan_dso_reg_hook)
+
 // }}}
 }  // namespace __asan
 
-#endif  // _WIN32
+#endif  // SANITIZER_WINDOWS
diff --git a/libsanitizer/asan/asan_win_dll_thunk.cc b/libsanitizer/asan/asan_win_dll_thunk.cc
index f7c9a37bf79..31847efe77a 100644
--- a/libsanitizer/asan/asan_win_dll_thunk.cc
+++ b/libsanitizer/asan/asan_win_dll_thunk.cc
@@ -13,375 +13,41 @@
 // See https://github.com/google/sanitizers/issues/209 for the details.
 //===----------------------------------------------------------------------===//
 
-// Only compile this code when building asan_dll_thunk.lib
-// Using #ifdef rather than relying on Makefiles etc.
-// simplifies the build procedure.
-#ifdef ASAN_DLL_THUNK
+#ifdef SANITIZER_DLL_THUNK
 #include "asan_init_version.h"
 #include "interception/interception.h"
+#include "sanitizer_common/sanitizer_win_defs.h"
+#include "sanitizer_common/sanitizer_win_dll_thunk.h"
 #include "sanitizer_common/sanitizer_platform_interceptors.h"
 
-// ---------- Function interception helper functions and macros ----------- {{{1
-extern "C" {
-void *__stdcall GetModuleHandleA(const char *module_name);
-void *__stdcall GetProcAddress(void *module, const char *proc_name);
-void abort();
-}
-
-using namespace __sanitizer;
-
-static uptr getRealProcAddressOrDie(const char *name) {
-  uptr ret =
-      __interception::InternalGetProcAddress((void *)GetModuleHandleA(0), name);
-  if (!ret)
-    abort();
-  return ret;
-}
-
-// We need to intercept some functions (e.g. ASan interface, memory allocator --
-// let's call them "hooks") exported by the DLL thunk and forward the hooks to
-// the runtime in the main module.
-// However, we don't want to keep two lists of these hooks.
-// To avoid that, the list of hooks should be defined using the
-// INTERCEPT_WHEN_POSSIBLE macro. Then, all these hooks can be intercepted
-// at once by calling INTERCEPT_HOOKS().
-
-// Use macro+template magic to automatically generate the list of hooks.
-// Each hook at line LINE defines a template class with a static
-// FunctionInterceptor<LINE>::Execute() method intercepting the hook.
-// The default implementation of FunctionInterceptor<LINE> is to call
-// the Execute() method corresponding to the previous line.
-template<int LINE>
-struct FunctionInterceptor {
-  static void Execute() { FunctionInterceptor<LINE-1>::Execute(); }
-};
-
-// There shouldn't be any hooks with negative definition line number.
-template<>
-struct FunctionInterceptor<0> {
-  static void Execute() {}
-};
-
-#define INTERCEPT_WHEN_POSSIBLE(main_function, dll_function)                   \
-  template <> struct FunctionInterceptor<__LINE__> {                           \
-    static void Execute() {                                                    \
-      uptr wrapper = getRealProcAddressOrDie(main_function);                   \
-      if (!__interception::OverrideFunction((uptr)dll_function, wrapper, 0))   \
-        abort();                                                               \
-      FunctionInterceptor<__LINE__ - 1>::Execute();                            \
-    }                                                                          \
-  };
-
-// Special case of hooks -- ASan own interface functions.  Those are only called
-// after __asan_init, thus an empty implementation is sufficient.
-#define INTERFACE_FUNCTION(name)                                               \
-  extern "C" __declspec(noinline) void name() {                                \
-    volatile int prevent_icf = (__LINE__ << 8); (void)prevent_icf;             \
-    __debugbreak();                                                            \
-  }                                                                            \
-  INTERCEPT_WHEN_POSSIBLE(#name, name)
-
-// INTERCEPT_HOOKS must be used after the last INTERCEPT_WHEN_POSSIBLE.
-#define INTERCEPT_HOOKS FunctionInterceptor<__LINE__>::Execute
-
-// We can't define our own version of strlen etc. because that would lead to
-// link-time or even type mismatch errors.  Instead, we can declare a function
-// just to be able to get its address.  Me may miss the first few calls to the
-// functions since it can be called before __asan_init, but that would lead to
-// false negatives in the startup code before user's global initializers, which
-// isn't a big deal.
-#define INTERCEPT_LIBRARY_FUNCTION(name)                                       \
-  extern "C" void name();                                                      \
-  INTERCEPT_WHEN_POSSIBLE(WRAPPER_NAME(name), name)
-
-// Disable compiler warnings that show up if we declare our own version
-// of a compiler intrinsic (e.g. strlen).
-#pragma warning(disable: 4391)
-#pragma warning(disable: 4392)
-
-static void InterceptHooks();
-// }}}
-
-// ---------- Function wrapping helpers ----------------------------------- {{{1
-#define WRAP_V_V(name)                                                         \
-  extern "C" void name() {                                                     \
-    typedef void (*fntype)();                                                  \
-    static fntype fn = (fntype)getRealProcAddressOrDie(#name);                 \
-    fn();                                                                      \
-  }                                                                            \
-  INTERCEPT_WHEN_POSSIBLE(#name, name);
-
-#define WRAP_V_W(name)                                                         \
-  extern "C" void name(void *arg) {                                            \
-    typedef void (*fntype)(void *arg);                                         \
-    static fntype fn = (fntype)getRealProcAddressOrDie(#name);                 \
-    fn(arg);                                                                   \
-  }                                                                            \
-  INTERCEPT_WHEN_POSSIBLE(#name, name);
-
-#define WRAP_V_WW(name)                                                        \
-  extern "C" void name(void *arg1, void *arg2) {                               \
-    typedef void (*fntype)(void *, void *);                                    \
-    static fntype fn = (fntype)getRealProcAddressOrDie(#name);                 \
-    fn(arg1, arg2);                                                            \
-  }                                                                            \
-  INTERCEPT_WHEN_POSSIBLE(#name, name);
-
-#define WRAP_V_WWW(name)                                                       \
-  extern "C" void name(void *arg1, void *arg2, void *arg3) {                   \
-    typedef void *(*fntype)(void *, void *, void *);                           \
-    static fntype fn = (fntype)getRealProcAddressOrDie(#name);                 \
-    fn(arg1, arg2, arg3);                                                      \
-  }                                                                            \
-  INTERCEPT_WHEN_POSSIBLE(#name, name);
-
-#define WRAP_W_V(name)                                                         \
-  extern "C" void *name() {                                                    \
-    typedef void *(*fntype)();                                                 \
-    static fntype fn = (fntype)getRealProcAddressOrDie(#name);                 \
-    return fn();                                                               \
-  }                                                                            \
-  INTERCEPT_WHEN_POSSIBLE(#name, name);
-
-#define WRAP_W_W(name)                                                         \
-  extern "C" void *name(void *arg) {                                           \
-    typedef void *(*fntype)(void *arg);                                        \
-    static fntype fn = (fntype)getRealProcAddressOrDie(#name);                 \
-    return fn(arg);                                                            \
-  }                                                                            \
-  INTERCEPT_WHEN_POSSIBLE(#name, name);
-
-#define WRAP_W_WW(name)                                                        \
-  extern "C" void *name(void *arg1, void *arg2) {                              \
-    typedef void *(*fntype)(void *, void *);                                   \
-    static fntype fn = (fntype)getRealProcAddressOrDie(#name);                 \
-    return fn(arg1, arg2);                                                     \
-  }                                                                            \
-  INTERCEPT_WHEN_POSSIBLE(#name, name);
-
-#define WRAP_W_WWW(name)                                                       \
-  extern "C" void *name(void *arg1, void *arg2, void *arg3) {                  \
-    typedef void *(*fntype)(void *, void *, void *);                           \
-    static fntype fn = (fntype)getRealProcAddressOrDie(#name);                 \
-    return fn(arg1, arg2, arg3);                                               \
-  }                                                                            \
-  INTERCEPT_WHEN_POSSIBLE(#name, name);
-
-#define WRAP_W_WWWW(name)                                                      \
-  extern "C" void *name(void *arg1, void *arg2, void *arg3, void *arg4) {      \
-    typedef void *(*fntype)(void *, void *, void *, void *);                   \
-    static fntype fn = (fntype)getRealProcAddressOrDie(#name);                 \
-    return fn(arg1, arg2, arg3, arg4);                                         \
-  }                                                                            \
-  INTERCEPT_WHEN_POSSIBLE(#name, name);
-
-#define WRAP_W_WWWWW(name)                                                     \
-  extern "C" void *name(void *arg1, void *arg2, void *arg3, void *arg4,        \
-                        void *arg5) {                                          \
-    typedef void *(*fntype)(void *, void *, void *, void *, void *);           \
-    static fntype fn = (fntype)getRealProcAddressOrDie(#name);                 \
-    return fn(arg1, arg2, arg3, arg4, arg5);                                   \
-  }                                                                            \
-  INTERCEPT_WHEN_POSSIBLE(#name, name);
-
-#define WRAP_W_WWWWWW(name)                                                    \
-  extern "C" void *name(void *arg1, void *arg2, void *arg3, void *arg4,        \
-                        void *arg5, void *arg6) {                              \
-    typedef void *(*fntype)(void *, void *, void *, void *, void *, void *);   \
-    static fntype fn = (fntype)getRealProcAddressOrDie(#name);                 \
-    return fn(arg1, arg2, arg3, arg4, arg5, arg6);                             \
-  }                                                                            \
-  INTERCEPT_WHEN_POSSIBLE(#name, name);
-// }}}
-
-// ----------------- ASan own interface functions --------------------
-// Don't use the INTERFACE_FUNCTION machinery for this function as we actually
-// want to call it in the __asan_init interceptor.
-WRAP_W_V(__asan_should_detect_stack_use_after_return)
-WRAP_W_V(__asan_get_shadow_memory_dynamic_address)
-
-extern "C" {
-  int __asan_option_detect_stack_use_after_return;
-  uptr __asan_shadow_memory_dynamic_address;
-
-  // Manually wrap __asan_init as we need to initialize
-  // __asan_option_detect_stack_use_after_return afterwards.
-  void __asan_init() {
-    typedef void (*fntype)();
-    static fntype fn = 0;
-    // __asan_init is expected to be called by only one thread.
-    if (fn) return;
-
-    fn = (fntype)getRealProcAddressOrDie("__asan_init");
-    fn();
-    __asan_option_detect_stack_use_after_return =
-        (__asan_should_detect_stack_use_after_return() != 0);
-    __asan_shadow_memory_dynamic_address =
-        (uptr)__asan_get_shadow_memory_dynamic_address();
-    InterceptHooks();
-  }
-}
-
-extern "C" void __asan_version_mismatch_check() {
-  // Do nothing.
-}
-
-INTERFACE_FUNCTION(__asan_handle_no_return)
-
-INTERFACE_FUNCTION(__asan_report_store1)
-INTERFACE_FUNCTION(__asan_report_store2)
-INTERFACE_FUNCTION(__asan_report_store4)
-INTERFACE_FUNCTION(__asan_report_store8)
-INTERFACE_FUNCTION(__asan_report_store16)
-INTERFACE_FUNCTION(__asan_report_store_n)
-
-INTERFACE_FUNCTION(__asan_report_load1)
-INTERFACE_FUNCTION(__asan_report_load2)
-INTERFACE_FUNCTION(__asan_report_load4)
-INTERFACE_FUNCTION(__asan_report_load8)
-INTERFACE_FUNCTION(__asan_report_load16)
-INTERFACE_FUNCTION(__asan_report_load_n)
-
-INTERFACE_FUNCTION(__asan_store1)
-INTERFACE_FUNCTION(__asan_store2)
-INTERFACE_FUNCTION(__asan_store4)
-INTERFACE_FUNCTION(__asan_store8)
-INTERFACE_FUNCTION(__asan_store16)
-INTERFACE_FUNCTION(__asan_storeN)
-
-INTERFACE_FUNCTION(__asan_load1)
-INTERFACE_FUNCTION(__asan_load2)
-INTERFACE_FUNCTION(__asan_load4)
-INTERFACE_FUNCTION(__asan_load8)
-INTERFACE_FUNCTION(__asan_load16)
-INTERFACE_FUNCTION(__asan_loadN)
-
-INTERFACE_FUNCTION(__asan_memcpy);
-INTERFACE_FUNCTION(__asan_memset);
-INTERFACE_FUNCTION(__asan_memmove);
-
-INTERFACE_FUNCTION(__asan_set_shadow_00);
-INTERFACE_FUNCTION(__asan_set_shadow_f1);
-INTERFACE_FUNCTION(__asan_set_shadow_f2);
-INTERFACE_FUNCTION(__asan_set_shadow_f3);
-INTERFACE_FUNCTION(__asan_set_shadow_f5);
-INTERFACE_FUNCTION(__asan_set_shadow_f8);
-
-INTERFACE_FUNCTION(__asan_alloca_poison);
-INTERFACE_FUNCTION(__asan_allocas_unpoison);
-
-INTERFACE_FUNCTION(__asan_register_globals)
-INTERFACE_FUNCTION(__asan_unregister_globals)
-
-INTERFACE_FUNCTION(__asan_before_dynamic_init)
-INTERFACE_FUNCTION(__asan_after_dynamic_init)
-
-INTERFACE_FUNCTION(__asan_poison_stack_memory)
-INTERFACE_FUNCTION(__asan_unpoison_stack_memory)
+// ASan own interface functions.
+#define INTERFACE_FUNCTION(Name) INTERCEPT_SANITIZER_FUNCTION(Name)
+#define INTERFACE_WEAK_FUNCTION(Name) INTERCEPT_SANITIZER_WEAK_FUNCTION(Name)
+#include "asan_interface.inc"
 
-INTERFACE_FUNCTION(__asan_poison_memory_region)
-INTERFACE_FUNCTION(__asan_unpoison_memory_region)
+// Memory allocation functions.
+INTERCEPT_WRAP_V_W(free)
+INTERCEPT_WRAP_V_W(_free_base)
+INTERCEPT_WRAP_V_WW(_free_dbg)
 
-INTERFACE_FUNCTION(__asan_address_is_poisoned)
-INTERFACE_FUNCTION(__asan_region_is_poisoned)
+INTERCEPT_WRAP_W_W(malloc)
+INTERCEPT_WRAP_W_W(_malloc_base)
+INTERCEPT_WRAP_W_WWWW(_malloc_dbg)
 
-INTERFACE_FUNCTION(__asan_get_current_fake_stack)
-INTERFACE_FUNCTION(__asan_addr_is_in_fake_stack)
+INTERCEPT_WRAP_W_WW(calloc)
+INTERCEPT_WRAP_W_WW(_calloc_base)
+INTERCEPT_WRAP_W_WWWWW(_calloc_dbg)
+INTERCEPT_WRAP_W_WWW(_calloc_impl)
 
-INTERFACE_FUNCTION(__asan_stack_malloc_0)
-INTERFACE_FUNCTION(__asan_stack_malloc_1)
-INTERFACE_FUNCTION(__asan_stack_malloc_2)
-INTERFACE_FUNCTION(__asan_stack_malloc_3)
-INTERFACE_FUNCTION(__asan_stack_malloc_4)
-INTERFACE_FUNCTION(__asan_stack_malloc_5)
-INTERFACE_FUNCTION(__asan_stack_malloc_6)
-INTERFACE_FUNCTION(__asan_stack_malloc_7)
-INTERFACE_FUNCTION(__asan_stack_malloc_8)
-INTERFACE_FUNCTION(__asan_stack_malloc_9)
-INTERFACE_FUNCTION(__asan_stack_malloc_10)
+INTERCEPT_WRAP_W_WW(realloc)
+INTERCEPT_WRAP_W_WW(_realloc_base)
+INTERCEPT_WRAP_W_WWW(_realloc_dbg)
+INTERCEPT_WRAP_W_WWW(_recalloc)
+INTERCEPT_WRAP_W_WWW(_recalloc_base)
 
-INTERFACE_FUNCTION(__asan_stack_free_0)
-INTERFACE_FUNCTION(__asan_stack_free_1)
-INTERFACE_FUNCTION(__asan_stack_free_2)
-INTERFACE_FUNCTION(__asan_stack_free_4)
-INTERFACE_FUNCTION(__asan_stack_free_5)
-INTERFACE_FUNCTION(__asan_stack_free_6)
-INTERFACE_FUNCTION(__asan_stack_free_7)
-INTERFACE_FUNCTION(__asan_stack_free_8)
-INTERFACE_FUNCTION(__asan_stack_free_9)
-INTERFACE_FUNCTION(__asan_stack_free_10)
-
-// FIXME: we might want to have a sanitizer_win_dll_thunk?
-INTERFACE_FUNCTION(__sanitizer_annotate_contiguous_container)
-INTERFACE_FUNCTION(__sanitizer_contiguous_container_find_bad_address)
-INTERFACE_FUNCTION(__sanitizer_cov)
-INTERFACE_FUNCTION(__sanitizer_cov_dump)
-INTERFACE_FUNCTION(__sanitizer_cov_indir_call16)
-INTERFACE_FUNCTION(__sanitizer_cov_init)
-INTERFACE_FUNCTION(__sanitizer_cov_module_init)
-INTERFACE_FUNCTION(__sanitizer_cov_trace_basic_block)
-INTERFACE_FUNCTION(__sanitizer_cov_trace_func_enter)
-INTERFACE_FUNCTION(__sanitizer_cov_with_check)
-INTERFACE_FUNCTION(__sanitizer_get_allocated_size)
-INTERFACE_FUNCTION(__sanitizer_get_coverage_guards)
-INTERFACE_FUNCTION(__sanitizer_get_current_allocated_bytes)
-INTERFACE_FUNCTION(__sanitizer_get_estimated_allocated_size)
-INTERFACE_FUNCTION(__sanitizer_get_free_bytes)
-INTERFACE_FUNCTION(__sanitizer_get_heap_size)
-INTERFACE_FUNCTION(__sanitizer_get_ownership)
-INTERFACE_FUNCTION(__sanitizer_get_total_unique_caller_callee_pairs)
-INTERFACE_FUNCTION(__sanitizer_get_total_unique_coverage)
-INTERFACE_FUNCTION(__sanitizer_get_unmapped_bytes)
-INTERFACE_FUNCTION(__sanitizer_maybe_open_cov_file)
-INTERFACE_FUNCTION(__sanitizer_print_stack_trace)
-INTERFACE_FUNCTION(__sanitizer_symbolize_pc)
-INTERFACE_FUNCTION(__sanitizer_symbolize_global)
-INTERFACE_FUNCTION(__sanitizer_ptr_cmp)
-INTERFACE_FUNCTION(__sanitizer_ptr_sub)
-INTERFACE_FUNCTION(__sanitizer_report_error_summary)
-INTERFACE_FUNCTION(__sanitizer_reset_coverage)
-INTERFACE_FUNCTION(__sanitizer_get_number_of_counters)
-INTERFACE_FUNCTION(__sanitizer_update_counter_bitset_and_clear_counters)
-INTERFACE_FUNCTION(__sanitizer_sandbox_on_notify)
-INTERFACE_FUNCTION(__sanitizer_set_death_callback)
-INTERFACE_FUNCTION(__sanitizer_set_report_path)
-INTERFACE_FUNCTION(__sanitizer_set_report_fd)
-INTERFACE_FUNCTION(__sanitizer_unaligned_load16)
-INTERFACE_FUNCTION(__sanitizer_unaligned_load32)
-INTERFACE_FUNCTION(__sanitizer_unaligned_load64)
-INTERFACE_FUNCTION(__sanitizer_unaligned_store16)
-INTERFACE_FUNCTION(__sanitizer_unaligned_store32)
-INTERFACE_FUNCTION(__sanitizer_unaligned_store64)
-INTERFACE_FUNCTION(__sanitizer_verify_contiguous_container)
-INTERFACE_FUNCTION(__sanitizer_install_malloc_and_free_hooks)
-INTERFACE_FUNCTION(__sanitizer_start_switch_fiber)
-INTERFACE_FUNCTION(__sanitizer_finish_switch_fiber)
-
-// TODO(timurrrr): Add more interface functions on the as-needed basis.
-
-// ----------------- Memory allocation functions ---------------------
-WRAP_V_W(free)
-WRAP_V_W(_free_base)
-WRAP_V_WW(_free_dbg)
-
-WRAP_W_W(malloc)
-WRAP_W_W(_malloc_base)
-WRAP_W_WWWW(_malloc_dbg)
-
-WRAP_W_WW(calloc)
-WRAP_W_WW(_calloc_base)
-WRAP_W_WWWWW(_calloc_dbg)
-WRAP_W_WWW(_calloc_impl)
-
-WRAP_W_WW(realloc)
-WRAP_W_WW(_realloc_base)
-WRAP_W_WWW(_realloc_dbg)
-WRAP_W_WWW(_recalloc)
-WRAP_W_WWW(_recalloc_base)
-
-WRAP_W_W(_msize)
-WRAP_W_W(_expand)
-WRAP_W_W(_expand_dbg)
+INTERCEPT_WRAP_W_W(_msize)
+INTERCEPT_WRAP_W_W(_expand)
+INTERCEPT_WRAP_W_W(_expand_dbg)
 
 // TODO(timurrrr): Might want to add support for _aligned_* allocation
 // functions to detect a bit more bugs.  Those functions seem to wrap malloc().
@@ -390,20 +56,6 @@ WRAP_W_W(_expand_dbg)
 
 INTERCEPT_LIBRARY_FUNCTION(atoi);
 INTERCEPT_LIBRARY_FUNCTION(atol);
-
-#ifdef _WIN64
-INTERCEPT_LIBRARY_FUNCTION(__C_specific_handler);
-#else
-INTERCEPT_LIBRARY_FUNCTION(_except_handler3);
-
-// _except_handler4 checks -GS cookie which is different for each module, so we
-// can't use INTERCEPT_LIBRARY_FUNCTION(_except_handler4).
-INTERCEPTOR(int, _except_handler4, void *a, void *b, void *c, void *d) {
-  __asan_handle_no_return();
-  return REAL(_except_handler4)(a, b, c, d);
-}
-#endif
-
 INTERCEPT_LIBRARY_FUNCTION(frexp);
 INTERCEPT_LIBRARY_FUNCTION(longjmp);
 #if SANITIZER_INTERCEPT_MEMCHR
@@ -428,30 +80,71 @@ INTERCEPT_LIBRARY_FUNCTION(strpbrk);
 INTERCEPT_LIBRARY_FUNCTION(strrchr);
 INTERCEPT_LIBRARY_FUNCTION(strspn);
 INTERCEPT_LIBRARY_FUNCTION(strstr);
+INTERCEPT_LIBRARY_FUNCTION(strtok);
 INTERCEPT_LIBRARY_FUNCTION(strtol);
 INTERCEPT_LIBRARY_FUNCTION(wcslen);
+INTERCEPT_LIBRARY_FUNCTION(wcsnlen);
+
+#ifdef _WIN64
+INTERCEPT_LIBRARY_FUNCTION(__C_specific_handler);
+#else
+INTERCEPT_LIBRARY_FUNCTION(_except_handler3);
+// _except_handler4 checks -GS cookie which is different for each module, so we
+// can't use INTERCEPT_LIBRARY_FUNCTION(_except_handler4).
+INTERCEPTOR(int, _except_handler4, void *a, void *b, void *c, void *d) {
+  __asan_handle_no_return();
+  return REAL(_except_handler4)(a, b, c, d);
+}
+#endif
+
+// Window specific functions not included in asan_interface.inc.
+INTERCEPT_WRAP_W_V(__asan_should_detect_stack_use_after_return)
+INTERCEPT_WRAP_W_V(__asan_get_shadow_memory_dynamic_address)
+INTERCEPT_WRAP_W_W(__asan_unhandled_exception_filter)
+
+using namespace __sanitizer;
+
+extern "C" {
+int __asan_option_detect_stack_use_after_return;
+uptr __asan_shadow_memory_dynamic_address;
+} // extern "C"
+
+static int asan_dll_thunk_init() {
+  typedef void (*fntype)();
+  static fntype fn = 0;
+  // asan_dll_thunk_init is expected to be called by only one thread.
+  if (fn) return 0;
+
+  // Ensure all interception was executed.
+  __dll_thunk_init();
+
+  fn = (fntype) dllThunkGetRealAddrOrDie("__asan_init");
+  fn();
+  __asan_option_detect_stack_use_after_return =
+      (__asan_should_detect_stack_use_after_return() != 0);
+  __asan_shadow_memory_dynamic_address =
+      (uptr)__asan_get_shadow_memory_dynamic_address();
 
-// Must be after all the interceptor declarations due to the way INTERCEPT_HOOKS
-// is defined.
-void InterceptHooks() {
-  INTERCEPT_HOOKS();
 #ifndef _WIN64
   INTERCEPT_FUNCTION(_except_handler4);
 #endif
+  // In DLLs, the callbacks are expected to return 0,
+  // otherwise CRT initialization fails.
+  return 0;
 }
 
-// We want to call __asan_init before C/C++ initializers/constructors are
-// executed, otherwise functions like memset might be invoked.
-// For some strange reason, merely linking in asan_preinit.cc doesn't work
-// as the callback is never called...  Is link.exe doing something too smart?
+#pragma section(".CRT$XIB", long, read)  // NOLINT
+__declspec(allocate(".CRT$XIB")) int (*__asan_preinit)() = asan_dll_thunk_init;
 
-// In DLLs, the callbacks are expected to return 0,
-// otherwise CRT initialization fails.
-static int call_asan_init() {
-  __asan_init();
-  return 0;
+static void WINAPI asan_thread_init(void *mod, unsigned long reason,
+                                    void *reserved) {
+  if (reason == /*DLL_PROCESS_ATTACH=*/1) asan_dll_thunk_init();
 }
-#pragma section(".CRT$XIB", long, read)  // NOLINT
-__declspec(allocate(".CRT$XIB")) int (*__asan_preinit)() = call_asan_init;
 
-#endif // ASAN_DLL_THUNK
+#pragma section(".CRT$XLAB", long, read)  // NOLINT
+__declspec(allocate(".CRT$XLAB")) void (WINAPI *__asan_tls_init)(void *,
+    unsigned long, void *) = asan_thread_init;
+
+WIN_FORCE_LINK(__asan_dso_reg_hook)
+
+#endif // SANITIZER_DLL_THUNK
diff --git a/libsanitizer/asan/asan_win_dynamic_runtime_thunk.cc b/libsanitizer/asan/asan_win_dynamic_runtime_thunk.cc
index 8989159cc52..d431b78d605 100644
--- a/libsanitizer/asan/asan_win_dynamic_runtime_thunk.cc
+++ b/libsanitizer/asan/asan_win_dynamic_runtime_thunk.cc
@@ -12,24 +12,31 @@
 // using the default "import library" generated when linking the DLL RTL.
 //
 // This includes:
+//  - creating weak aliases to default implementation imported from asan dll.
 //  - forwarding the detect_stack_use_after_return runtime option
 //  - working around deficiencies of the MD runtime
 //  - installing a custom SEH handler
 //
 //===----------------------------------------------------------------------===//
 
-// Only compile this code when building asan_dynamic_runtime_thunk.lib
-// Using #ifdef rather than relying on Makefiles etc.
-// simplifies the build procedure.
-#ifdef ASAN_DYNAMIC_RUNTIME_THUNK
+#ifdef SANITIZER_DYNAMIC_RUNTIME_THUNK
+#define SANITIZER_IMPORT_INTERFACE 1
+#include "sanitizer_common/sanitizer_win_defs.h"
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 
+// Define weak alias for all weak functions imported from asan dll.
+#define INTERFACE_FUNCTION(Name)
+#define INTERFACE_WEAK_FUNCTION(Name) WIN_WEAK_IMPORT_DEF(Name)
+#include "asan_interface.inc"
+
 // First, declare CRT sections we'll be using in this file
+#pragma section(".CRT$XIB", long, read)  // NOLINT
 #pragma section(".CRT$XID", long, read)  // NOLINT
 #pragma section(".CRT$XCAB", long, read)  // NOLINT
 #pragma section(".CRT$XTW", long, read)  // NOLINT
 #pragma section(".CRT$XTY", long, read)  // NOLINT
+#pragma section(".CRT$XLAB", long, read)  // NOLINT
 
 ////////////////////////////////////////////////////////////////////////////////
 // Define a copy of __asan_option_detect_stack_use_after_return that should be
@@ -44,14 +51,33 @@
 // after initialization anyways.
 extern "C" {
 __declspec(dllimport) int __asan_should_detect_stack_use_after_return();
-int __asan_option_detect_stack_use_after_return =
-    __asan_should_detect_stack_use_after_return();
+int __asan_option_detect_stack_use_after_return;
 
 __declspec(dllimport) void* __asan_get_shadow_memory_dynamic_address();
-void* __asan_shadow_memory_dynamic_address =
+void* __asan_shadow_memory_dynamic_address;
+}
+
+static int InitializeClonedVariables() {
+  __asan_option_detect_stack_use_after_return =
+    __asan_should_detect_stack_use_after_return();
+  __asan_shadow_memory_dynamic_address =
     __asan_get_shadow_memory_dynamic_address();
+  return 0;
 }
 
+static void NTAPI asan_thread_init(void *mod, unsigned long reason,
+    void *reserved) {
+  if (reason == DLL_PROCESS_ATTACH) InitializeClonedVariables();
+}
+
+// Our cloned variables must be initialized before C/C++ constructors.  If TLS
+// is used, our .CRT$XLAB initializer will run first. If not, our .CRT$XIB
+// initializer is needed as a backup.
+__declspec(allocate(".CRT$XIB")) int (*__asan_initialize_cloned_variables)() =
+    InitializeClonedVariables;
+__declspec(allocate(".CRT$XLAB")) void (NTAPI *__asan_tls_init)(void *,
+    unsigned long, void *) = asan_thread_init;
+
 ////////////////////////////////////////////////////////////////////////////////
 // For some reason, the MD CRT doesn't call the C/C++ terminators during on DLL
 // unload or on exit.  ASan relies on LLVM global_dtors to call
@@ -98,4 +124,6 @@ __declspec(allocate(".CRT$XCAB")) int (*__asan_seh_interceptor)() =
     SetSEHFilter;
 }
 
-#endif // ASAN_DYNAMIC_RUNTIME_THUNK
+WIN_FORCE_LINK(__asan_dso_reg_hook)
+
+#endif // SANITIZER_DYNAMIC_RUNTIME_THUNK
diff --git a/libsanitizer/asan/asan_win_weak_interception.cc b/libsanitizer/asan/asan_win_weak_interception.cc
new file mode 100644
index 00000000000..74c1dcdb729
--- /dev/null
+++ b/libsanitizer/asan/asan_win_weak_interception.cc
@@ -0,0 +1,21 @@
+//===-- asan_win_weak_interception.cc -------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This module should be included in Address Sanitizer when it is implemented as
+// a shared library on Windows (dll), in order to delegate the calls of weak
+// functions to the implementation in the main executable when a strong
+// definition is provided.
+//===----------------------------------------------------------------------===//
+#ifdef SANITIZER_DYNAMIC
+#include "sanitizer_common/sanitizer_win_weak_interception.h"
+#include "asan_interface_internal.h"
+// Check if strong definitions for weak functions are present in the main
+// executable. If that is the case, override dll functions to point to strong
+// implementations.
+#define INTERFACE_FUNCTION(Name)
+#define INTERFACE_WEAK_FUNCTION(Name) INTERCEPT_SANITIZER_WEAK_FUNCTION(Name)
+#include "asan_interface.inc"
+#endif // SANITIZER_DYNAMIC
diff --git a/libsanitizer/asan/libtool-version b/libsanitizer/asan/libtool-version
index 0f14ee34185..e3138f3b9f8 100644
--- a/libsanitizer/asan/libtool-version
+++ b/libsanitizer/asan/libtool-version
@@ -3,4 +3,4 @@
 # a separate file so that version updates don't involve re-running
 # automake.
 # CURRENT:REVISION:AGE
-4:0:0
+5:0:0
diff --git a/libsanitizer/builtins/assembly.h b/libsanitizer/builtins/assembly.h
index 5e36b5a5edf..3f5e59b2544 100644
--- a/libsanitizer/builtins/assembly.h
+++ b/libsanitizer/builtins/assembly.h
@@ -44,7 +44,8 @@
 #endif
 #define CONST_SECTION .section .rodata
 
-#if defined(__GNU__) || defined(__ANDROID__) || defined(__FreeBSD__)
+#if defined(__GNU__) || defined(__FreeBSD__) || defined(__Fuchsia__) || \
+    defined(__linux__)
 #define NO_EXEC_STACK_DIRECTIVE .section .note.GNU-stack,"",%progbits
 #else
 #define NO_EXEC_STACK_DIRECTIVE
@@ -67,10 +68,42 @@
 #endif
 
 #if defined(__arm__)
+
+/*
+ * Determine actual [ARM][THUMB[1][2]] ISA using compiler predefined macros:
+ * - for '-mthumb -march=armv6' compiler defines '__thumb__'
+ * - for '-mthumb -march=armv7' compiler defines '__thumb__' and '__thumb2__'
+ */
+#if defined(__thumb2__) || defined(__thumb__)
+#define DEFINE_CODE_STATE .thumb SEPARATOR
+#define DECLARE_FUNC_ENCODING    .thumb_func SEPARATOR
+#if defined(__thumb2__)
+#define USE_THUMB_2
+#define IT(cond)  it cond
+#define ITT(cond) itt cond
+#define ITE(cond) ite cond
+#else
+#define USE_THUMB_1
+#define IT(cond)
+#define ITT(cond)
+#define ITE(cond)
+#endif // defined(__thumb__2)
+#else // !defined(__thumb2__) && !defined(__thumb__)
+#define DEFINE_CODE_STATE .arm SEPARATOR
+#define DECLARE_FUNC_ENCODING
+#define IT(cond)
+#define ITT(cond)
+#define ITE(cond)
+#endif
+
+#if defined(USE_THUMB_1) && defined(USE_THUMB_2)
+#error "USE_THUMB_1 and USE_THUMB_2 can't be defined together."
+#endif
+
 #if defined(__ARM_ARCH_4T__) || __ARM_ARCH >= 5
 #define ARM_HAS_BX
 #endif
-#if !defined(__ARM_FEATURE_CLZ) &&                                             \
+#if !defined(__ARM_FEATURE_CLZ) && !defined(USE_THUMB_1) &&  \
     (__ARM_ARCH >= 6 || (__ARM_ARCH == 5 && !defined(__ARM_ARCH_5__)))
 #define __ARM_FEATURE_CLZ
 #endif
@@ -92,19 +125,14 @@
   JMP(ip)
 #endif
 
-#if __ARM_ARCH_ISA_THUMB == 2
-#define IT(cond)  it cond
-#define ITT(cond) itt cond
-#else
-#define IT(cond)
-#define ITT(cond)
-#endif
-
-#if __ARM_ARCH_ISA_THUMB == 2
+#if defined(USE_THUMB_2)
 #define WIDE(op) op.w
 #else
 #define WIDE(op) op
 #endif
+#else // !defined(__arm)
+#define DECLARE_FUNC_ENCODING
+#define DEFINE_CODE_STATE
 #endif
 
 #define GLUE2(a, b) a##b
@@ -119,13 +147,16 @@
 #endif
 
 #define DEFINE_COMPILERRT_FUNCTION(name)                                       \
+  DEFINE_CODE_STATE                                                            \
   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
   .globl SYMBOL_NAME(name) SEPARATOR                                           \
   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
   DECLARE_SYMBOL_VISIBILITY(name)                                              \
+  DECLARE_FUNC_ENCODING                                                        \
   SYMBOL_NAME(name):
 
 #define DEFINE_COMPILERRT_THUMB_FUNCTION(name)                                 \
+  DEFINE_CODE_STATE                                                            \
   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
   .globl SYMBOL_NAME(name) SEPARATOR                                           \
   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
@@ -134,16 +165,20 @@
   SYMBOL_NAME(name):
 
 #define DEFINE_COMPILERRT_PRIVATE_FUNCTION(name)                               \
+  DEFINE_CODE_STATE                                                            \
   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
   .globl SYMBOL_NAME(name) SEPARATOR                                           \
   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
   HIDDEN(SYMBOL_NAME(name)) SEPARATOR                                          \
+  DECLARE_FUNC_ENCODING                                                        \
   SYMBOL_NAME(name):
 
 #define DEFINE_COMPILERRT_PRIVATE_FUNCTION_UNMANGLED(name)                     \
+  DEFINE_CODE_STATE                                                            \
   .globl name SEPARATOR                                                        \
   SYMBOL_IS_FUNC(name) SEPARATOR                                               \
   HIDDEN(name) SEPARATOR                                                       \
+  DECLARE_FUNC_ENCODING                                                        \
   name:
 
 #define DEFINE_COMPILERRT_FUNCTION_ALIAS(name, target)                         \
diff --git a/libsanitizer/include/sanitizer/asan_interface.h b/libsanitizer/include/sanitizer/asan_interface.h
index 448a0bcba01..ad69ab46c92 100644
--- a/libsanitizer/include/sanitizer/asan_interface.h
+++ b/libsanitizer/include/sanitizer/asan_interface.h
@@ -142,6 +142,10 @@ extern "C" {
   void *__asan_addr_is_in_fake_stack(void *fake_stack, void *addr, void **beg,
                                      void **end);
 
+  // Performs cleanup before a [[noreturn]] function.  Must be called
+  // before things like _exit and execl to avoid false positives on stack.
+  void __asan_handle_no_return(void);
+
 #ifdef __cplusplus
 }  // extern "C"
 #endif
diff --git a/libsanitizer/include/sanitizer/common_interface_defs.h b/libsanitizer/include/sanitizer/common_interface_defs.h
index fd38c55a235..a66c932b0ae 100644
--- a/libsanitizer/include/sanitizer/common_interface_defs.h
+++ b/libsanitizer/include/sanitizer/common_interface_defs.h
@@ -156,8 +156,10 @@ extern "C" {
   // Prints stack traces for all live heap allocations ordered by total
   // allocation size until `top_percent` of total live heap is shown.
   // `top_percent` should be between 1 and 100.
+  // At most `max_number_of_contexts` contexts (stack traces) is printed.
   // Experimental feature currently available only with asan on Linux/x86_64.
-  void __sanitizer_print_memory_profile(size_t top_percent);
+  void __sanitizer_print_memory_profile(size_t top_percent,
+                                        size_t max_number_of_contexts);
 
   // Fiber annotation interface.
   // Before switching to a different stack, one must call
@@ -180,6 +182,13 @@ extern "C" {
   void __sanitizer_finish_switch_fiber(void *fake_stack_save,
                                        const void **bottom_old,
                                        size_t *size_old);
+
+  // Get full module name and calculate pc offset within it.
+  // Returns 1 if pc belongs to some module, 0 if module was not found.
+  int __sanitizer_get_module_and_offset_for_pc(void *pc, char *module_path,
+                                               size_t module_path_len,
+                                               void **pc_offset);
+
 #ifdef __cplusplus
 }  // extern "C"
 #endif
diff --git a/libsanitizer/include/sanitizer/coverage_interface.h b/libsanitizer/include/sanitizer/coverage_interface.h
index ffb956c39db..85447b68a46 100644
--- a/libsanitizer/include/sanitizer/coverage_interface.h
+++ b/libsanitizer/include/sanitizer/coverage_interface.h
@@ -17,45 +17,15 @@
 extern "C" {
 #endif
 
-  // Initialize coverage.
-  void __sanitizer_cov_init();
   // Record and dump coverage info.
   void __sanitizer_cov_dump();
-  // Open <name>.sancov.packed in the coverage directory and return the file
-  // descriptor. Returns -1 on failure, or if coverage dumping is disabled.
-  // This is intended for use by sandboxing code.
-  intptr_t __sanitizer_maybe_open_cov_file(const char *name);
-  // Get the number of unique covered blocks (or edges).
-  // This can be useful for coverage-directed in-process fuzzers.
-  uintptr_t __sanitizer_get_total_unique_coverage();
-  // Get the number of unique indirect caller-callee pairs.
-  uintptr_t __sanitizer_get_total_unique_caller_callee_pairs();
 
-  // Reset the basic-block (edge) coverage to the initial state.
-  // Useful for in-process fuzzing to start collecting coverage from scratch.
-  // Experimental, will likely not work for multi-threaded process.
-  void __sanitizer_reset_coverage();
-  // Set *data to the array of covered PCs and return the size of that array.
-  // Some of the entries in *data will be zero.
-  uintptr_t __sanitizer_get_coverage_guards(uintptr_t **data);
+  // Clear collected coverage info.
+  void __sanitizer_cov_reset();
 
-  // The coverage instrumentation may optionally provide imprecise counters.
-  // Rather than exposing the counter values to the user we instead map
-  // the counters to a bitset.
-  // Every counter is associated with 8 bits in the bitset.
-  // We define 8 value ranges: 1, 2, 3, 4-7, 8-15, 16-31, 32-127, 128+
-  // The i-th bit is set to 1 if the counter value is in the i-th range.
-  // This counter-based coverage implementation is *not* thread-safe.
-
-  // Returns the number of registered coverage counters.
-  uintptr_t __sanitizer_get_number_of_counters();
-  // Updates the counter 'bitset', clears the counters and returns the number of
-  // new bits in 'bitset'.
-  // If 'bitset' is nullptr, only clears the counters.
-  // Otherwise 'bitset' should be at least
-  // __sanitizer_get_number_of_counters bytes long and 8-aligned.
-  uintptr_t
-  __sanitizer_update_counter_bitset_and_clear_counters(uint8_t *bitset);
+  // Dump collected coverage info. Sorts pcs by module into individual .sancov
+  // files.
+  void __sanitizer_dump_coverage(const uintptr_t *pcs, uintptr_t len);
 
 #ifdef __cplusplus
 }  // extern "C"
diff --git a/libsanitizer/include/sanitizer/lsan_interface.h b/libsanitizer/include/sanitizer/lsan_interface.h
index bdbe39084f7..32051e62a00 100644
--- a/libsanitizer/include/sanitizer/lsan_interface.h
+++ b/libsanitizer/include/sanitizer/lsan_interface.h
@@ -62,8 +62,14 @@ extern "C" {
   // for the program it is linked into (if the return value is non-zero). This
   // function must be defined as returning a constant value; any behavior beyond
   // that is unsupported.
+  // To avoid dead stripping, you may need to define this function with
+  // __attribute__((used))
   int __lsan_is_turned_off();
 
+  // This function may be optionally provided by user and should return
+  // a string containing LSan runtime options. See lsan_flags.inc for details.
+  const char *__lsan_default_options();
+
   // This function may be optionally provided by the user and should return
   // a string containing LSan suppressions.
   const char *__lsan_default_suppressions();
diff --git a/libsanitizer/include/sanitizer/tsan_interface.h b/libsanitizer/include/sanitizer/tsan_interface.h
new file mode 100644
index 00000000000..9d9119262f8
--- /dev/null
+++ b/libsanitizer/include/sanitizer/tsan_interface.h
@@ -0,0 +1,136 @@
+//===-- tsan_interface.h ----------------------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of ThreadSanitizer (TSan), a race detector.
+//
+// Public interface header for TSan.
+//===----------------------------------------------------------------------===//
+#ifndef SANITIZER_TSAN_INTERFACE_H
+#define SANITIZER_TSAN_INTERFACE_H
+
+#include <sanitizer/common_interface_defs.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// __tsan_release establishes a happens-before relation with a preceding
+// __tsan_acquire on the same address.
+void __tsan_acquire(void *addr);
+void __tsan_release(void *addr);
+
+// Annotations for custom mutexes.
+// The annotations allow to get better reports (with sets of locked mutexes),
+// detect more types of bugs (e.g. mutex misuses, races between lock/unlock and
+// destruction and potential deadlocks) and improve precision and performance
+// (by ignoring individual atomic operations in mutex code). However, the
+// downside is that annotated mutex code itself is not checked for correctness.
+
+// Mutex creation flags are passed to __tsan_mutex_create annotation.
+// If mutex has no constructor and __tsan_mutex_create is not called,
+// the flags may be passed to __tsan_mutex_pre_lock/__tsan_mutex_post_lock
+// annotations.
+
+// Mutex has static storage duration and no-op constructor and destructor.
+// This effectively makes tsan ignore destroy annotation.
+const unsigned __tsan_mutex_linker_init      = 1 << 0;
+// Mutex is write reentrant.
+const unsigned __tsan_mutex_write_reentrant  = 1 << 1;
+// Mutex is read reentrant.
+const unsigned __tsan_mutex_read_reentrant   = 1 << 2;
+
+// Mutex operation flags:
+
+// Denotes read lock operation.
+const unsigned __tsan_mutex_read_lock        = 1 << 3;
+// Denotes try lock operation.
+const unsigned __tsan_mutex_try_lock         = 1 << 4;
+// Denotes that a try lock operation has failed to acquire the mutex.
+const unsigned __tsan_mutex_try_lock_failed  = 1 << 5;
+// Denotes that the lock operation acquires multiple recursion levels.
+// Number of levels is passed in recursion parameter.
+// This is useful for annotation of e.g. Java builtin monitors,
+// for which wait operation releases all recursive acquisitions of the mutex.
+const unsigned __tsan_mutex_recursive_lock   = 1 << 6;
+// Denotes that the unlock operation releases all recursion levels.
+// Number of released levels is returned and later must be passed to
+// the corresponding __tsan_mutex_post_lock annotation.
+const unsigned __tsan_mutex_recursive_unlock = 1 << 7;
+
+// Annotate creation of a mutex.
+// Supported flags: mutex creation flags.
+void __tsan_mutex_create(void *addr, unsigned flags);
+
+// Annotate destruction of a mutex.
+// Supported flags:
+//   - __tsan_mutex_linker_init
+void __tsan_mutex_destroy(void *addr, unsigned flags);
+
+// Annotate start of lock operation.
+// Supported flags:
+//   - __tsan_mutex_read_lock
+//   - __tsan_mutex_try_lock
+//   - all mutex creation flags
+void __tsan_mutex_pre_lock(void *addr, unsigned flags);
+
+// Annotate end of lock operation.
+// Supported flags:
+//   - __tsan_mutex_read_lock (must match __tsan_mutex_pre_lock)
+//   - __tsan_mutex_try_lock (must match __tsan_mutex_pre_lock)
+//   - __tsan_mutex_try_lock_failed
+//   - __tsan_mutex_recursive_lock
+//   - all mutex creation flags
+void __tsan_mutex_post_lock(void *addr, unsigned flags, int recursion);
+
+// Annotate start of unlock operation.
+// Supported flags:
+//   - __tsan_mutex_read_lock
+//   - __tsan_mutex_recursive_unlock
+int __tsan_mutex_pre_unlock(void *addr, unsigned flags);
+
+// Annotate end of unlock operation.
+// Supported flags:
+//   - __tsan_mutex_read_lock (must match __tsan_mutex_pre_unlock)
+void __tsan_mutex_post_unlock(void *addr, unsigned flags);
+
+// Annotate start/end of notify/signal/broadcast operation.
+// Supported flags: none.
+void __tsan_mutex_pre_signal(void *addr, unsigned flags);
+void __tsan_mutex_post_signal(void *addr, unsigned flags);
+
+// Annotate start/end of a region of code where lock/unlock/signal operation
+// diverts to do something else unrelated to the mutex. This can be used to
+// annotate, for example, calls into cooperative scheduler or contention
+// profiling code.
+// These annotations must be called only from within
+// __tsan_mutex_pre/post_lock, __tsan_mutex_pre/post_unlock,
+// __tsan_mutex_pre/post_signal regions.
+// Supported flags: none.
+void __tsan_mutex_pre_divert(void *addr, unsigned flags);
+void __tsan_mutex_post_divert(void *addr, unsigned flags);
+
+// External race detection API.
+// Can be used by non-instrumented libraries to detect when their objects are
+// being used in an unsafe manner.
+//   - __tsan_external_read/__tsan_external_write annotates the logical reads
+//       and writes of the object at the specified address. 'caller_pc' should
+//       be the PC of the library user, which the library can obtain with e.g.
+//       `__builtin_return_address(0)`.
+//   - __tsan_external_register_tag registers a 'tag' with the specified name,
+//       which is later used in read/write annotations to denote the object type
+//   - __tsan_external_assign_tag can optionally mark a heap object with a tag
+void *__tsan_external_register_tag(const char *object_type);
+void __tsan_external_register_header(void *tag, const char *header);
+void __tsan_external_assign_tag(void *addr, void *tag);
+void __tsan_external_read(void *addr, void *caller_pc, void *tag);
+void __tsan_external_write(void *addr, void *caller_pc, void *tag);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // SANITIZER_TSAN_INTERFACE_H
diff --git a/libsanitizer/interception/interception.h b/libsanitizer/interception/interception.h
index 0db36ddf28e..75631da55ee 100644
--- a/libsanitizer/interception/interception.h
+++ b/libsanitizer/interception/interception.h
@@ -13,8 +13,8 @@
 #ifndef INTERCEPTION_H
 #define INTERCEPTION_H
 
-#if !defined(__linux__) && !defined(__FreeBSD__) && \
-  !defined(__APPLE__) && !defined(_WIN32)
+#if !defined(__linux__) && !defined(__FreeBSD__) && !defined(__APPLE__) && \
+    !defined(__NetBSD__) && !defined(_WIN32) && !defined(__Fuchsia__)
 # error "Interception doesn't work on this operating system."
 #endif
 
@@ -127,7 +127,7 @@ const interpose_substitution substitution_##func_name[] \
     extern "C" ret_type func(__VA_ARGS__);
 # define DECLARE_WRAPPER_WINAPI(ret_type, func, ...) \
     extern "C" __declspec(dllimport) ret_type __stdcall func(__VA_ARGS__);
-#elif defined(__FreeBSD__)
+#elif defined(__FreeBSD__) || defined(__NetBSD__)
 # define WRAP(x) __interceptor_ ## x
 # define WRAPPER_NAME(x) "__interceptor_" #x
 # define INTERCEPTOR_ATTRIBUTE __attribute__((visibility("default")))
@@ -137,7 +137,7 @@ const interpose_substitution substitution_##func_name[] \
 # define DECLARE_WRAPPER(ret_type, func, ...) \
      extern "C" ret_type func(__VA_ARGS__) \
      __attribute__((alias("__interceptor_" #func), visibility("default")));
-#else
+#elif !defined(__Fuchsia__)
 # define WRAP(x) __interceptor_ ## x
 # define WRAPPER_NAME(x) "__interceptor_" #x
 # define INTERCEPTOR_ATTRIBUTE __attribute__((visibility("default")))
@@ -146,7 +146,15 @@ const interpose_substitution substitution_##func_name[] \
     __attribute__((weak, alias("__interceptor_" #func), visibility("default")));
 #endif
 
-#if !defined(__APPLE__)
+#if defined(__Fuchsia__)
+// There is no general interception at all on Fuchsia.
+// Sanitizer runtimes just define functions directly to preempt them,
+// and have bespoke ways to access the underlying libc functions.
+# include <zircon/sanitizer.h>
+# define INTERCEPTOR_ATTRIBUTE __attribute__((visibility("default")))
+# define REAL(x) __unsanitized_##x
+# define DECLARE_REAL(ret_type, func, ...)
+#elif !defined(__APPLE__)
 # define PTR_TO_REAL(x) real_##x
 # define REAL(x) __interception::PTR_TO_REAL(x)
 # define FUNC_TYPE(x) x##_f
@@ -164,15 +172,19 @@ const interpose_substitution substitution_##func_name[] \
 # define ASSIGN_REAL(x, y)
 #endif  // __APPLE__
 
+#if !defined(__Fuchsia__)
 #define DECLARE_REAL_AND_INTERCEPTOR(ret_type, func, ...) \
   DECLARE_REAL(ret_type, func, __VA_ARGS__) \
   extern "C" ret_type WRAP(func)(__VA_ARGS__);
+#else
+#define DECLARE_REAL_AND_INTERCEPTOR(ret_type, func, ...)
+#endif
 
 // Generally, you don't need to use DEFINE_REAL by itself, as INTERCEPTOR
 // macros does its job. In exceptional cases you may need to call REAL(foo)
 // without defining INTERCEPTOR(..., foo, ...). For example, if you override
 // foo with an interceptor for other function.
-#if !defined(__APPLE__)
+#if !defined(__APPLE__) && !defined(__Fuchsia__)
 # define DEFINE_REAL(ret_type, func, ...) \
     typedef ret_type (*FUNC_TYPE(func))(__VA_ARGS__); \
     namespace __interception { \
@@ -182,7 +194,18 @@ const interpose_substitution substitution_##func_name[] \
 # define DEFINE_REAL(ret_type, func, ...)
 #endif
 
-#if !defined(__APPLE__)
+#if defined(__Fuchsia__)
+
+// We need to define the __interceptor_func name just to get
+// sanitizer_common/scripts/gen_dynamic_list.py to export func.
+// But we don't need to export __interceptor_func to get that.
+#define INTERCEPTOR(ret_type, func, ...)                                \
+  extern "C"[[ gnu::alias(#func), gnu::visibility("hidden") ]] ret_type \
+      __interceptor_##func(__VA_ARGS__);                                \
+  extern "C" INTERCEPTOR_ATTRIBUTE ret_type func(__VA_ARGS__)
+
+#elif !defined(__APPLE__)
+
 #define INTERCEPTOR(ret_type, func, ...) \
   DEFINE_REAL(ret_type, func, __VA_ARGS__) \
   DECLARE_WRAPPER(ret_type, func, __VA_ARGS__) \
@@ -239,7 +262,7 @@ typedef unsigned long uptr;  // NOLINT
 
 #define INCLUDED_FROM_INTERCEPTION_LIB
 
-#if defined(__linux__) || defined(__FreeBSD__)
+#if defined(__linux__) || defined(__FreeBSD__) || defined(__NetBSD__)
 # include "interception_linux.h"
 # define INTERCEPT_FUNCTION(func) INTERCEPT_FUNCTION_LINUX_OR_FREEBSD(func)
 # define INTERCEPT_FUNCTION_VER(func, symver) \
@@ -249,7 +272,7 @@ typedef unsigned long uptr;  // NOLINT
 # define INTERCEPT_FUNCTION(func) INTERCEPT_FUNCTION_MAC(func)
 # define INTERCEPT_FUNCTION_VER(func, symver) \
     INTERCEPT_FUNCTION_VER_MAC(func, symver)
-#else  // defined(_WIN32)
+#elif defined(_WIN32)
 # include "interception_win.h"
 # define INTERCEPT_FUNCTION(func) INTERCEPT_FUNCTION_WIN(func)
 # define INTERCEPT_FUNCTION_VER(func, symver) \
diff --git a/libsanitizer/interception/interception_linux.cc b/libsanitizer/interception/interception_linux.cc
index 0a8305b0bf8..888b2ceac13 100644
--- a/libsanitizer/interception/interception_linux.cc
+++ b/libsanitizer/interception/interception_linux.cc
@@ -10,14 +10,22 @@
 // Linux-specific interception methods.
 //===----------------------------------------------------------------------===//
 
-#if defined(__linux__) || defined(__FreeBSD__)
+#if defined(__linux__) || defined(__FreeBSD__) || defined(__NetBSD__)
 #include "interception.h"
 
 #include <dlfcn.h>   // for dlsym() and dlvsym()
 
+#ifdef __NetBSD__
+#include "sanitizer_common/sanitizer_libc.h"
+#endif
+
 namespace __interception {
 bool GetRealFunctionAddress(const char *func_name, uptr *func_addr,
     uptr real, uptr wrapper) {
+#ifdef __NetBSD__
+  // XXX: Find a better way to handle renames
+  if (internal_strcmp(func_name, "sigaction") == 0) func_name = "__sigaction14";
+#endif
   *func_addr = (uptr)dlsym(RTLD_NEXT, func_name);
   return real == wrapper;
 }
@@ -30,5 +38,4 @@ void *GetFuncAddrVer(const char *func_name, const char *ver) {
 
 }  // namespace __interception
 
-
-#endif  // __linux__ || __FreeBSD__
+#endif  // __linux__ || __FreeBSD__ || __NetBSD__
diff --git a/libsanitizer/interception/interception_linux.h b/libsanitizer/interception/interception_linux.h
index 61bf48a7233..f5965180888 100644
--- a/libsanitizer/interception/interception_linux.h
+++ b/libsanitizer/interception/interception_linux.h
@@ -10,7 +10,7 @@
 // Linux-specific interception methods.
 //===----------------------------------------------------------------------===//
 
-#if defined(__linux__) || defined(__FreeBSD__)
+#if defined(__linux__) || defined(__FreeBSD__) || defined(__NetBSD__)
 
 #if !defined(INCLUDED_FROM_INTERCEPTION_LIB)
 # error "interception_linux.h should be included from interception library only"
@@ -42,4 +42,4 @@ void *GetFuncAddrVer(const char *func_name, const char *ver);
 #endif  // !defined(__ANDROID__)
 
 #endif  // INTERCEPTION_LINUX_H
-#endif  // __linux__ || __FreeBSD__
+#endif  // __linux__ || __FreeBSD__ || __NetBSD__
diff --git a/libsanitizer/interception/interception_win.cc b/libsanitizer/interception/interception_win.cc
index fa81162097e..1957397bdad 100644
--- a/libsanitizer/interception/interception_win.cc
+++ b/libsanitizer/interception/interception_win.cc
@@ -146,10 +146,16 @@ static void InterceptionFailed() {
 }
 
 static bool DistanceIsWithin2Gig(uptr from, uptr target) {
+#if SANITIZER_WINDOWS64
   if (from < target)
     return target - from <= (uptr)0x7FFFFFFFU;
   else
     return from - target <= (uptr)0x80000000U;
+#else
+  // In a 32-bit address space, the address calculation will wrap, so this check
+  // is unnecessary.
+  return true;
+#endif
 }
 
 static uptr GetMmapGranularity() {
@@ -215,9 +221,8 @@ static bool IsMemoryPadding(uptr address, uptr size) {
   return true;
 }
 
-static const u8 kHintNop10Bytes[] = {
-  0x66, 0x66, 0x0F, 0x1F, 0x84,
-  0x00, 0x00, 0x00, 0x00, 0x00
+static const u8 kHintNop9Bytes[] = {
+  0x66, 0x0F, 0x1F, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00
 };
 
 template<class T>
@@ -232,8 +237,8 @@ static bool FunctionHasPrefix(uptr address, const T &pattern) {
 static bool FunctionHasPadding(uptr address, uptr size) {
   if (IsMemoryPadding(address - size, size))
     return true;
-  if (size <= sizeof(kHintNop10Bytes) &&
-      FunctionHasPrefix(address, kHintNop10Bytes))
+  if (size <= sizeof(kHintNop9Bytes) &&
+      FunctionHasPrefix(address, kHintNop9Bytes))
     return true;
   return false;
 }
@@ -469,7 +474,7 @@ static size_t GetInstructionSize(uptr address, size_t* rel_offset = nullptr) {
   switch (*(u8*)address) {
     case 0xA1:  // A1 XX XX XX XX XX XX XX XX :
                 //   movabs eax, dword ptr ds:[XXXXXXXX]
-      return 8;
+      return 9;
   }
 
   switch (*(u16*)address) {
@@ -487,6 +492,11 @@ static size_t GetInstructionSize(uptr address, size_t* rel_offset = nullptr) {
     case 0x5741:  // push r15
     case 0x9066:  // Two-byte NOP
       return 2;
+
+    case 0x058B:  // 8B 05 XX XX XX XX : mov eax, dword ptr [XX XX XX XX]
+      if (rel_offset)
+        *rel_offset = 2;
+      return 6;
   }
 
   switch (0x00FFFFFF & *(u32*)address) {
@@ -870,6 +880,8 @@ uptr InternalGetProcAddress(void *module, const char *func_name) {
 
   IMAGE_DATA_DIRECTORY *export_directory =
       &headers->OptionalHeader.DataDirectory[IMAGE_DIRECTORY_ENTRY_EXPORT];
+  if (export_directory->Size == 0)
+    return 0;
   RVAPtr<IMAGE_EXPORT_DIRECTORY> exports(module,
                                          export_directory->VirtualAddress);
   RVAPtr<DWORD> functions(module, exports->AddressOfFunctions);
diff --git a/libsanitizer/lsan/Makefile.am b/libsanitizer/lsan/Makefile.am
index 294342b1926..9638f30da1a 100644
--- a/libsanitizer/lsan/Makefile.am
+++ b/libsanitizer/lsan/Makefile.am
@@ -16,11 +16,15 @@ endif
 
 sanitizer_lsan_files = \
 	lsan_common.cc \
-	lsan_common_linux.cc
+	lsan_common_linux.cc \
+	lsan_common_mac.cc
 
 lsan_files = \
 	$(sanitizer_lsan_files) \
 	lsan.cc \
+	lsan_linux.cc \
+	lsan_mac.cc \
+	lsan_malloc_mac.cc \
 	lsan_allocator.cc \
 	lsan_interceptors.cc \
 	lsan_preinit.cc \
diff --git a/libsanitizer/lsan/Makefile.in b/libsanitizer/lsan/Makefile.in
index d951741c300..f0d1e0f37da 100644
--- a/libsanitizer/lsan/Makefile.in
+++ b/libsanitizer/lsan/Makefile.in
@@ -107,9 +107,10 @@ liblsan_la_DEPENDENCIES =  \
 	$(top_builddir)/sanitizer_common/libsanitizer_common.la \
 	$(top_builddir)/interception/libinterception.la \
 	$(am__append_1) $(am__DEPENDENCIES_1)
-am__objects_1 = lsan_common.lo lsan_common_linux.lo
-am__objects_2 = $(am__objects_1) lsan.lo lsan_allocator.lo \
-	lsan_interceptors.lo lsan_preinit.lo lsan_thread.lo
+am__objects_1 = lsan_common.lo lsan_common_linux.lo lsan_common_mac.lo
+am__objects_2 = $(am__objects_1) lsan.lo lsan_linux.lo lsan_mac.lo \
+	lsan_malloc_mac.lo lsan_allocator.lo lsan_interceptors.lo \
+	lsan_preinit.lo lsan_thread.lo
 am_liblsan_la_OBJECTS = $(am__objects_2)
 liblsan_la_OBJECTS = $(am_liblsan_la_OBJECTS)
 liblsan_la_LINK = $(LIBTOOL) --tag=CXX $(AM_LIBTOOLFLAGS) \
@@ -299,11 +300,15 @@ noinst_LTLIBRARIES = libsanitizer_lsan.la
 @LSAN_SUPPORTED_TRUE@toolexeclib_LTLIBRARIES = liblsan.la
 sanitizer_lsan_files = \
 	lsan_common.cc \
-	lsan_common_linux.cc
+	lsan_common_linux.cc \
+	lsan_common_mac.cc
 
 lsan_files = \
 	$(sanitizer_lsan_files) \
 	lsan.cc \
+	lsan_linux.cc \
+	lsan_mac.cc \
+	lsan_malloc_mac.cc \
 	lsan_allocator.cc \
 	lsan_interceptors.cc \
 	lsan_preinit.cc \
@@ -446,7 +451,11 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/lsan_allocator.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/lsan_common.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/lsan_common_linux.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/lsan_common_mac.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/lsan_interceptors.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/lsan_linux.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/lsan_mac.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/lsan_malloc_mac.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/lsan_preinit.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/lsan_thread.Plo@am__quote@
 
diff --git a/libsanitizer/lsan/lsan.cc b/libsanitizer/lsan/lsan.cc
index 2ded5544c71..7540aeb327b 100644
--- a/libsanitizer/lsan/lsan.cc
+++ b/libsanitizer/lsan/lsan.cc
@@ -54,6 +54,9 @@ static void InitializeFlags() {
   RegisterLsanFlags(&parser, f);
   RegisterCommonFlags(&parser);
 
+  // Override from user-specified string.
+  const char *lsan_default_options = MaybeCallLsanDefaultOptions();
+  parser.ParseString(lsan_default_options);
   parser.ParseString(GetEnv("LSAN_OPTIONS"));
 
   SetVerbosity(common_flags()->verbosity);
@@ -63,6 +66,18 @@ static void InitializeFlags() {
   if (common_flags()->help) parser.PrintFlagDescriptions();
 }
 
+static void OnStackUnwind(const SignalContext &sig, const void *,
+                          BufferedStackTrace *stack) {
+  GetStackTraceWithPcBpAndContext(stack, kStackTraceMax, sig.pc, sig.bp,
+                                  sig.context,
+                                  common_flags()->fast_unwind_on_fatal);
+}
+
+void LsanOnDeadlySignal(int signo, void *siginfo, void *context) {
+  HandleDeadlySignal(siginfo, context, GetCurrentThread(), &OnStackUnwind,
+                     nullptr);
+}
+
 extern "C" void __lsan_init() {
   CHECK(!lsan_init_is_running);
   if (lsan_inited)
@@ -74,9 +89,11 @@ extern "C" void __lsan_init() {
   InitializeFlags();
   InitCommonLsan();
   InitializeAllocator();
+  ReplaceSystemMalloc();
   InitTlsSize();
   InitializeInterceptors();
   InitializeThreadRegistry();
+  InstallDeadlySignalHandlers(LsanOnDeadlySignal);
   u32 tid = ThreadCreate(0, 0, true);
   CHECK_EQ(tid, 0);
   ThreadStart(tid, GetTid());
diff --git a/libsanitizer/lsan/lsan.h b/libsanitizer/lsan/lsan.h
index 6d2d427b27d..1cd1c36dbc4 100644
--- a/libsanitizer/lsan/lsan.h
+++ b/libsanitizer/lsan/lsan.h
@@ -10,24 +10,15 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "lsan_thread.h"
 #include "sanitizer_common/sanitizer_flags.h"
 #include "sanitizer_common/sanitizer_stacktrace.h"
 
-#define GET_STACK_TRACE(max_size, fast)                                        \
-  BufferedStackTrace stack;                                                    \
-  {                                                                            \
-    uptr stack_top = 0, stack_bottom = 0;                                      \
-    ThreadContext *t;                                                          \
-    if (fast && (t = CurrentThreadContext())) {                                \
-      stack_top = t->stack_end();                                              \
-      stack_bottom = t->stack_begin();                                         \
-    }                                                                          \
-    if (!SANITIZER_MIPS ||                                                     \
-        IsValidFrame(GET_CURRENT_FRAME(), stack_top, stack_bottom)) {          \
-      stack.Unwind(max_size, StackTrace::GetCurrentPc(), GET_CURRENT_FRAME(),  \
-                   /* context */ 0, stack_top, stack_bottom, fast);            \
-    }                                                                          \
-  }
+#define GET_STACK_TRACE(max_size, fast)                       \
+  __sanitizer::BufferedStackTrace stack;                      \
+  GetStackTraceWithPcBpAndContext(&stack, max_size,           \
+                                  StackTrace::GetCurrentPc(), \
+                                  GET_CURRENT_FRAME(), nullptr, fast);
 
 #define GET_STACK_TRACE_FATAL \
   GET_STACK_TRACE(kStackTraceMax, common_flags()->fast_unwind_on_fatal)
@@ -36,9 +27,37 @@
   GET_STACK_TRACE(__sanitizer::common_flags()->malloc_context_size, \
                   common_flags()->fast_unwind_on_malloc)
 
+#define GET_STACK_TRACE_THREAD GET_STACK_TRACE(kStackTraceMax, true)
+
 namespace __lsan {
 
 void InitializeInterceptors();
+void ReplaceSystemMalloc();
+
+#define ENSURE_LSAN_INITED do {   \
+  CHECK(!lsan_init_is_running);   \
+  if (!lsan_inited)               \
+    __lsan_init();                \
+} while (0)
+
+// Get the stack trace with the given pc and bp.
+// The pc will be in the position 0 of the resulting stack trace.
+// The bp may refer to the current frame or to the caller's frame.
+ALWAYS_INLINE
+void GetStackTraceWithPcBpAndContext(__sanitizer::BufferedStackTrace *stack,
+                                     __sanitizer::uptr max_depth,
+                                     __sanitizer::uptr pc, __sanitizer::uptr bp,
+                                     void *context, bool fast) {
+  uptr stack_top = 0, stack_bottom = 0;
+  ThreadContext *t;
+  if (fast && (t = CurrentThreadContext())) {
+    stack_top = t->stack_end();
+    stack_bottom = t->stack_begin();
+  }
+  if (!SANITIZER_MIPS || IsValidFrame(bp, stack_top, stack_bottom)) {
+    stack->Unwind(max_depth, pc, bp, context, stack_top, stack_bottom, fast);
+  }
+}
 
 }  // namespace __lsan
 
diff --git a/libsanitizer/lsan/lsan_allocator.cc b/libsanitizer/lsan/lsan_allocator.cc
index 0d2fceac71b..9e166807791 100644
--- a/libsanitizer/lsan/lsan_allocator.cc
+++ b/libsanitizer/lsan/lsan_allocator.cc
@@ -13,7 +13,9 @@
 #include "lsan_allocator.h"
 
 #include "sanitizer_common/sanitizer_allocator.h"
+#include "sanitizer_common/sanitizer_allocator_checks.h"
 #include "sanitizer_common/sanitizer_allocator_interface.h"
+#include "sanitizer_common/sanitizer_errno.h"
 #include "sanitizer_common/sanitizer_internal_defs.h"
 #include "sanitizer_common/sanitizer_stackdepot.h"
 #include "sanitizer_common/sanitizer_stacktrace.h"
@@ -22,51 +24,27 @@
 extern "C" void *memset(void *ptr, int value, uptr num);
 
 namespace __lsan {
-
-struct ChunkMetadata {
-  u8 allocated : 8;  // Must be first.
-  ChunkTag tag : 2;
-  uptr requested_size : 54;
-  u32 stack_trace_id;
-};
-
-#if defined(__mips64) || defined(__aarch64__)
+#if defined(__i386__) || defined(__arm__)
+static const uptr kMaxAllowedMallocSize = 1UL << 30;
+#elif defined(__mips64) || defined(__aarch64__)
 static const uptr kMaxAllowedMallocSize = 4UL << 30;
-static const uptr kRegionSizeLog = 20;
-static const uptr kNumRegions = SANITIZER_MMAP_RANGE_SIZE >> kRegionSizeLog;
-typedef TwoLevelByteMap<(kNumRegions >> 12), 1 << 12> ByteMap;
-typedef CompactSizeClassMap SizeClassMap;
-typedef SizeClassAllocator32<0, SANITIZER_MMAP_RANGE_SIZE,
-    sizeof(ChunkMetadata), SizeClassMap, kRegionSizeLog, ByteMap>
-    PrimaryAllocator;
 #else
 static const uptr kMaxAllowedMallocSize = 8UL << 30;
-
-struct AP64 {  // Allocator64 parameters. Deliberately using a short name.
-  static const uptr kSpaceBeg = 0x600000000000ULL;
-  static const uptr kSpaceSize =  0x40000000000ULL; // 4T.
-  static const uptr kMetadataSize = sizeof(ChunkMetadata);
-  typedef DefaultSizeClassMap SizeClassMap;
-  typedef NoOpMapUnmapCallback MapUnmapCallback;
-  static const uptr kFlags = 0;
-};
-
-typedef SizeClassAllocator64<AP64> PrimaryAllocator;
 #endif
-typedef SizeClassAllocatorLocalCache<PrimaryAllocator> AllocatorCache;
 typedef LargeMmapAllocator<> SecondaryAllocator;
 typedef CombinedAllocator<PrimaryAllocator, AllocatorCache,
           SecondaryAllocator> Allocator;
 
 static Allocator allocator;
-static THREADLOCAL AllocatorCache cache;
 
 void InitializeAllocator() {
-  allocator.InitLinkerInitialized(common_flags()->allocator_may_return_null);
+  SetAllocatorMayReturnNull(common_flags()->allocator_may_return_null);
+  allocator.InitLinkerInitialized(
+      common_flags()->allocator_release_to_os_interval_ms);
 }
 
 void AllocatorThreadFinish() {
-  allocator.SwallowCache(&cache);
+  allocator.SwallowCache(GetAllocatorCache());
 }
 
 static ChunkMetadata *Metadata(const void *p) {
@@ -96,9 +74,9 @@ void *Allocate(const StackTrace &stack, uptr size, uptr alignment,
     size = 1;
   if (size > kMaxAllowedMallocSize) {
     Report("WARNING: LeakSanitizer failed to allocate %zu bytes\n", size);
-    return nullptr;
+    return Allocator::FailureHandler::OnBadRequest();
   }
-  void *p = allocator.Allocate(&cache, size, alignment, false);
+  void *p = allocator.Allocate(GetAllocatorCache(), size, alignment);
   // Do not rely on the allocator to clear the memory (it's slow).
   if (cleared && allocator.FromPrimary(p))
     memset(p, 0, size);
@@ -108,11 +86,18 @@ void *Allocate(const StackTrace &stack, uptr size, uptr alignment,
   return p;
 }
 
+static void *Calloc(uptr nmemb, uptr size, const StackTrace &stack) {
+  if (UNLIKELY(CheckForCallocOverflow(size, nmemb)))
+    return Allocator::FailureHandler::OnBadRequest();
+  size *= nmemb;
+  return Allocate(stack, size, 1, true);
+}
+
 void Deallocate(void *p) {
   if (&__sanitizer_free_hook) __sanitizer_free_hook(p);
   RunFreeHooks(p);
   RegisterDeallocation(p);
-  allocator.Deallocate(&cache, p);
+  allocator.Deallocate(GetAllocatorCache(), p);
 }
 
 void *Reallocate(const StackTrace &stack, void *p, uptr new_size,
@@ -120,17 +105,17 @@ void *Reallocate(const StackTrace &stack, void *p, uptr new_size,
   RegisterDeallocation(p);
   if (new_size > kMaxAllowedMallocSize) {
     Report("WARNING: LeakSanitizer failed to allocate %zu bytes\n", new_size);
-    allocator.Deallocate(&cache, p);
-    return nullptr;
+    allocator.Deallocate(GetAllocatorCache(), p);
+    return Allocator::FailureHandler::OnBadRequest();
   }
-  p = allocator.Reallocate(&cache, p, new_size, alignment);
+  p = allocator.Reallocate(GetAllocatorCache(), p, new_size, alignment);
   RegisterAllocation(stack, p, new_size);
   return p;
 }
 
 void GetAllocatorCacheRange(uptr *begin, uptr *end) {
-  *begin = (uptr)&cache;
-  *end = *begin + sizeof(cache);
+  *begin = (uptr)GetAllocatorCache();
+  *end = *begin + sizeof(AllocatorCache);
 }
 
 uptr GetMallocUsableSize(const void *p) {
@@ -139,6 +124,39 @@ uptr GetMallocUsableSize(const void *p) {
   return m->requested_size;
 }
 
+void *lsan_memalign(uptr alignment, uptr size, const StackTrace &stack) {
+  if (UNLIKELY(!IsPowerOfTwo(alignment))) {
+    errno = errno_EINVAL;
+    return Allocator::FailureHandler::OnBadRequest();
+  }
+  return SetErrnoOnNull(Allocate(stack, size, alignment, kAlwaysClearMemory));
+}
+
+void *lsan_malloc(uptr size, const StackTrace &stack) {
+  return SetErrnoOnNull(Allocate(stack, size, 1, kAlwaysClearMemory));
+}
+
+void lsan_free(void *p) {
+  Deallocate(p);
+}
+
+void *lsan_realloc(void *p, uptr size, const StackTrace &stack) {
+  return SetErrnoOnNull(Reallocate(stack, p, size, 1));
+}
+
+void *lsan_calloc(uptr nmemb, uptr size, const StackTrace &stack) {
+  return SetErrnoOnNull(Calloc(nmemb, size, stack));
+}
+
+void *lsan_valloc(uptr size, const StackTrace &stack) {
+  return SetErrnoOnNull(
+      Allocate(stack, size, GetPageSizeCached(), kAlwaysClearMemory));
+}
+
+uptr lsan_mz_size(const void *p) {
+  return GetMallocUsableSize(p);
+}
+
 ///// Interface to the common LSan module. /////
 
 void LockAllocator() {
@@ -254,4 +272,17 @@ SANITIZER_INTERFACE_ATTRIBUTE
 uptr __sanitizer_get_allocated_size(const void *p) {
   return GetMallocUsableSize(p);
 }
+
+#if !SANITIZER_SUPPORTS_WEAK_HOOKS
+// Provide default (no-op) implementation of malloc hooks.
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+void __sanitizer_malloc_hook(void *ptr, uptr size) {
+  (void)ptr;
+  (void)size;
+}
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+void __sanitizer_free_hook(void *ptr) {
+  (void)ptr;
+}
+#endif
 } // extern "C"
diff --git a/libsanitizer/lsan/lsan_allocator.h b/libsanitizer/lsan/lsan_allocator.h
index aae0d28dc4a..b0c0ec241d9 100644
--- a/libsanitizer/lsan/lsan_allocator.h
+++ b/libsanitizer/lsan/lsan_allocator.h
@@ -13,8 +13,10 @@
 #ifndef LSAN_ALLOCATOR_H
 #define LSAN_ALLOCATOR_H
 
+#include "sanitizer_common/sanitizer_allocator.h"
 #include "sanitizer_common/sanitizer_common.h"
 #include "sanitizer_common/sanitizer_internal_defs.h"
+#include "lsan_common.h"
 
 namespace __lsan {
 
@@ -32,6 +34,61 @@ void GetAllocatorCacheRange(uptr *begin, uptr *end);
 void AllocatorThreadFinish();
 void InitializeAllocator();
 
+const bool kAlwaysClearMemory = true;
+
+struct ChunkMetadata {
+  u8 allocated : 8;  // Must be first.
+  ChunkTag tag : 2;
+#if SANITIZER_WORDSIZE == 64
+  uptr requested_size : 54;
+#else
+  uptr requested_size : 32;
+  uptr padding : 22;
+#endif
+  u32 stack_trace_id;
+};
+
+#if defined(__mips64) || defined(__aarch64__) || defined(__i386__) || \
+    defined(__arm__)
+static const uptr kRegionSizeLog = 20;
+static const uptr kNumRegions = SANITIZER_MMAP_RANGE_SIZE >> kRegionSizeLog;
+typedef TwoLevelByteMap<(kNumRegions >> 12), 1 << 12> ByteMap;
+
+struct AP32 {
+  static const uptr kSpaceBeg = 0;
+  static const u64 kSpaceSize = SANITIZER_MMAP_RANGE_SIZE;
+  static const uptr kMetadataSize = sizeof(ChunkMetadata);
+  typedef __sanitizer::CompactSizeClassMap SizeClassMap;
+  static const uptr kRegionSizeLog = __lsan::kRegionSizeLog;
+  typedef __lsan::ByteMap ByteMap;
+  typedef NoOpMapUnmapCallback MapUnmapCallback;
+  static const uptr kFlags = 0;
+};
+typedef SizeClassAllocator32<AP32> PrimaryAllocator;
+#elif defined(__x86_64__) || defined(__powerpc64__)
+struct AP64 {  // Allocator64 parameters. Deliberately using a short name.
+  static const uptr kSpaceBeg = 0x600000000000ULL;
+  static const uptr kSpaceSize =  0x40000000000ULL; // 4T.
+  static const uptr kMetadataSize = sizeof(ChunkMetadata);
+  typedef DefaultSizeClassMap SizeClassMap;
+  typedef NoOpMapUnmapCallback MapUnmapCallback;
+  static const uptr kFlags = 0;
+};
+
+typedef SizeClassAllocator64<AP64> PrimaryAllocator;
+#endif
+typedef SizeClassAllocatorLocalCache<PrimaryAllocator> AllocatorCache;
+
+AllocatorCache *GetAllocatorCache();
+
+void *lsan_memalign(uptr alignment, uptr size, const StackTrace &stack);
+void *lsan_malloc(uptr size, const StackTrace &stack);
+void lsan_free(void *p);
+void *lsan_realloc(void *p, uptr size, const StackTrace &stack);
+void *lsan_calloc(uptr nmemb, uptr size, const StackTrace &stack);
+void *lsan_valloc(uptr size, const StackTrace &stack);
+uptr lsan_mz_size(const void *p);
+
 }  // namespace __lsan
 
 #endif  // LSAN_ALLOCATOR_H
diff --git a/libsanitizer/lsan/lsan_common.cc b/libsanitizer/lsan/lsan_common.cc
index 41024e11873..a3274d5c1c3 100644
--- a/libsanitizer/lsan/lsan_common.cc
+++ b/libsanitizer/lsan/lsan_common.cc
@@ -30,20 +30,15 @@ namespace __lsan {
 // also to protect the global list of root regions.
 BlockingMutex global_mutex(LINKER_INITIALIZED);
 
-__attribute__((tls_model("initial-exec")))
-THREADLOCAL int disable_counter;
-bool DisabledInThisThread() { return disable_counter > 0; }
-void DisableInThisThread() { disable_counter++; }
-void EnableInThisThread() {
-  if (!disable_counter && common_flags()->detect_leaks) {
+Flags lsan_flags;
+
+void DisableCounterUnderflow() {
+  if (common_flags()->detect_leaks) {
     Report("Unmatched call to __lsan_enable().\n");
     Die();
   }
-  disable_counter--;
 }
 
-Flags lsan_flags;
-
 void Flags::SetDefaults() {
 #define LSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
 #include "lsan_flags.inc"
@@ -71,6 +66,19 @@ ALIGNED(64) static char suppression_placeholder[sizeof(SuppressionContext)];
 static SuppressionContext *suppression_ctx = nullptr;
 static const char kSuppressionLeak[] = "leak";
 static const char *kSuppressionTypes[] = { kSuppressionLeak };
+static const char kStdSuppressions[] =
+#if SANITIZER_SUPPRESS_LEAK_ON_PTHREAD_EXIT
+  // For more details refer to the SANITIZER_SUPPRESS_LEAK_ON_PTHREAD_EXIT
+  // definition.
+  "leak:*pthread_exit*\n"
+#endif  // SANITIZER_SUPPRESS_LEAK_ON_PTHREAD_EXIT
+#if SANITIZER_MAC
+  // For Darwin and os_log/os_trace: https://reviews.llvm.org/D35173
+  "leak:*_os_trace*\n"
+#endif
+  // TLS leak in some glibc versions, described in
+  // https://sourceware.org/bugzilla/show_bug.cgi?id=12650.
+  "leak:*tls_get_addr*\n";
 
 void InitializeSuppressions() {
   CHECK_EQ(nullptr, suppression_ctx);
@@ -79,6 +87,7 @@ void InitializeSuppressions() {
   suppression_ctx->ParseFromFile(flags()->suppressions);
   if (&__lsan_default_suppressions)
     suppression_ctx->Parse(__lsan_default_suppressions());
+  suppression_ctx->Parse(kStdSuppressions);
 }
 
 static SuppressionContext *GetSuppressionContext() {
@@ -86,12 +95,9 @@ static SuppressionContext *GetSuppressionContext() {
   return suppression_ctx;
 }
 
-struct RootRegion {
-  const void *begin;
-  uptr size;
-};
+static InternalMmapVector<RootRegion> *root_regions;
 
-InternalMmapVector<RootRegion> *root_regions;
+InternalMmapVector<RootRegion> const *GetRootRegions() { return root_regions; }
 
 void InitializeRootRegions() {
   CHECK(!root_regions);
@@ -99,6 +105,10 @@ void InitializeRootRegions() {
   root_regions = new(placeholder) InternalMmapVector<RootRegion>(1);
 }
 
+const char *MaybeCallLsanDefaultOptions() {
+  return (&__lsan_default_options) ? __lsan_default_options() : "";
+}
+
 void InitCommonLsan() {
   InitializeRootRegions();
   if (common_flags()->detect_leaks) {
@@ -114,7 +124,6 @@ class Decorator: public __sanitizer::SanitizerCommonDecorator {
   Decorator() : SanitizerCommonDecorator() { }
   const char *Error() { return Red(); }
   const char *Leak() { return Blue(); }
-  const char *End() { return Default(); }
 };
 
 static inline bool CanBeAHeapPointer(uptr p) {
@@ -178,6 +187,23 @@ void ScanRangeForPointers(uptr begin, uptr end,
   }
 }
 
+// Scans a global range for pointers
+void ScanGlobalRange(uptr begin, uptr end, Frontier *frontier) {
+  uptr allocator_begin = 0, allocator_end = 0;
+  GetAllocatorGlobalRange(&allocator_begin, &allocator_end);
+  if (begin <= allocator_begin && allocator_begin < end) {
+    CHECK_LE(allocator_begin, allocator_end);
+    CHECK_LE(allocator_end, end);
+    if (begin < allocator_begin)
+      ScanRangeForPointers(begin, allocator_begin, frontier, "GLOBAL",
+                           kReachable);
+    if (allocator_end < end)
+      ScanRangeForPointers(allocator_end, end, frontier, "GLOBAL", kReachable);
+  } else {
+    ScanRangeForPointers(begin, end, frontier, "GLOBAL", kReachable);
+  }
+}
+
 void ForEachExtraStackRangeCb(uptr begin, uptr end, void* arg) {
   Frontier *frontier = reinterpret_cast<Frontier *>(arg);
   ScanRangeForPointers(begin, end, frontier, "FAKE STACK", kReachable);
@@ -186,11 +212,11 @@ void ForEachExtraStackRangeCb(uptr begin, uptr end, void* arg) {
 // Scans thread data (stacks and TLS) for heap pointers.
 static void ProcessThreads(SuspendedThreadsList const &suspended_threads,
                            Frontier *frontier) {
-  InternalScopedBuffer<uptr> registers(SuspendedThreadsList::RegisterCount());
+  InternalScopedBuffer<uptr> registers(suspended_threads.RegisterCount());
   uptr registers_begin = reinterpret_cast<uptr>(registers.data());
   uptr registers_end = registers_begin + registers.size();
-  for (uptr i = 0; i < suspended_threads.thread_count(); i++) {
-    uptr os_id = static_cast<uptr>(suspended_threads.GetThreadID(i));
+  for (uptr i = 0; i < suspended_threads.ThreadCount(); i++) {
+    tid_t os_id = static_cast<tid_t>(suspended_threads.GetThreadID(i));
     LOG_THREADS("Processing thread %d.\n", os_id);
     uptr stack_begin, stack_end, tls_begin, tls_end, cache_begin, cache_end;
     DTLS *dtls;
@@ -204,11 +230,13 @@ static void ProcessThreads(SuspendedThreadsList const &suspended_threads,
       continue;
     }
     uptr sp;
-    bool have_registers =
-        (suspended_threads.GetRegistersAndSP(i, registers.data(), &sp) == 0);
-    if (!have_registers) {
-      Report("Unable to get registers from thread %d.\n");
-      // If unable to get SP, consider the entire stack to be reachable.
+    PtraceRegistersStatus have_registers =
+        suspended_threads.GetRegistersAndSP(i, registers.data(), &sp);
+    if (have_registers != REGISTERS_AVAILABLE) {
+      Report("Unable to get registers from thread %d.\n", os_id);
+      // If unable to get SP, consider the entire stack to be reachable unless
+      // GetRegistersAndSP failed with ESRCH.
+      if (have_registers == REGISTERS_UNAVAILABLE_FATAL) continue;
       sp = stack_begin;
     }
 
@@ -242,21 +270,23 @@ static void ProcessThreads(SuspendedThreadsList const &suspended_threads,
     }
 
     if (flags()->use_tls) {
-      LOG_THREADS("TLS at %p-%p.\n", tls_begin, tls_end);
-      if (cache_begin == cache_end) {
-        ScanRangeForPointers(tls_begin, tls_end, frontier, "TLS", kReachable);
-      } else {
-        // Because LSan should not be loaded with dlopen(), we can assume
-        // that allocator cache will be part of static TLS image.
-        CHECK_LE(tls_begin, cache_begin);
-        CHECK_GE(tls_end, cache_end);
-        if (tls_begin < cache_begin)
-          ScanRangeForPointers(tls_begin, cache_begin, frontier, "TLS",
-                               kReachable);
-        if (tls_end > cache_end)
-          ScanRangeForPointers(cache_end, tls_end, frontier, "TLS", kReachable);
+      if (tls_begin) {
+        LOG_THREADS("TLS at %p-%p.\n", tls_begin, tls_end);
+        // If the tls and cache ranges don't overlap, scan full tls range,
+        // otherwise, only scan the non-overlapping portions
+        if (cache_begin == cache_end || tls_end < cache_begin ||
+            tls_begin > cache_end) {
+          ScanRangeForPointers(tls_begin, tls_end, frontier, "TLS", kReachable);
+        } else {
+          if (tls_begin < cache_begin)
+            ScanRangeForPointers(tls_begin, cache_begin, frontier, "TLS",
+                                 kReachable);
+          if (tls_end > cache_end)
+            ScanRangeForPointers(cache_end, tls_end, frontier, "TLS",
+                                 kReachable);
+        }
       }
-      if (dtls) {
+      if (dtls && !DTLSInDestruction(dtls)) {
         for (uptr j = 0; j < dtls->dtv_size; ++j) {
           uptr dtls_beg = dtls->dtv[j].beg;
           uptr dtls_end = dtls_beg + dtls->dtv[j].size;
@@ -266,28 +296,36 @@ static void ProcessThreads(SuspendedThreadsList const &suspended_threads,
                                  kReachable);
           }
         }
+      } else {
+        // We are handling a thread with DTLS under destruction. Log about
+        // this and continue.
+        LOG_THREADS("Thread %d has DTLS under destruction.\n", os_id);
       }
     }
   }
 }
 
-static void ProcessRootRegion(Frontier *frontier, uptr root_begin,
-                              uptr root_end) {
-  MemoryMappingLayout proc_maps(/*cache_enabled*/true);
-  uptr begin, end, prot;
-  while (proc_maps.Next(&begin, &end,
-                        /*offset*/ nullptr, /*filename*/ nullptr,
-                        /*filename_size*/ 0, &prot)) {
-    uptr intersection_begin = Max(root_begin, begin);
-    uptr intersection_end = Min(end, root_end);
-    if (intersection_begin >= intersection_end) continue;
-    bool is_readable = prot & MemoryMappingLayout::kProtectionRead;
-    LOG_POINTERS("Root region %p-%p intersects with mapped region %p-%p (%s)\n",
-                 root_begin, root_end, begin, end,
-                 is_readable ? "readable" : "unreadable");
-    if (is_readable)
-      ScanRangeForPointers(intersection_begin, intersection_end, frontier,
-                           "ROOT", kReachable);
+void ScanRootRegion(Frontier *frontier, const RootRegion &root_region,
+                    uptr region_begin, uptr region_end, bool is_readable) {
+  uptr intersection_begin = Max(root_region.begin, region_begin);
+  uptr intersection_end = Min(region_end, root_region.begin + root_region.size);
+  if (intersection_begin >= intersection_end) return;
+  LOG_POINTERS("Root region %p-%p intersects with mapped region %p-%p (%s)\n",
+               root_region.begin, root_region.begin + root_region.size,
+               region_begin, region_end,
+               is_readable ? "readable" : "unreadable");
+  if (is_readable)
+    ScanRangeForPointers(intersection_begin, intersection_end, frontier, "ROOT",
+                         kReachable);
+}
+
+static void ProcessRootRegion(Frontier *frontier,
+                              const RootRegion &root_region) {
+  MemoryMappingLayout proc_maps(/*cache_enabled*/ true);
+  MemoryMappedSegment segment;
+  while (proc_maps.Next(&segment)) {
+    ScanRootRegion(frontier, root_region, segment.start, segment.end,
+                   segment.IsReadable());
   }
 }
 
@@ -296,9 +334,7 @@ static void ProcessRootRegions(Frontier *frontier) {
   if (!flags()->use_root_regions) return;
   CHECK(root_regions);
   for (uptr i = 0; i < root_regions->size(); i++) {
-    RootRegion region = (*root_regions)[i];
-    uptr begin_addr = reinterpret_cast<uptr>(region.begin);
-    ProcessRootRegion(frontier, begin_addr, begin_addr + region.size);
+    ProcessRootRegion(frontier, (*root_regions)[i]);
   }
 }
 
@@ -336,6 +372,72 @@ static void CollectIgnoredCb(uptr chunk, void *arg) {
   }
 }
 
+static uptr GetCallerPC(u32 stack_id, StackDepotReverseMap *map) {
+  CHECK(stack_id);
+  StackTrace stack = map->Get(stack_id);
+  // The top frame is our malloc/calloc/etc. The next frame is the caller.
+  if (stack.size >= 2)
+    return stack.trace[1];
+  return 0;
+}
+
+struct InvalidPCParam {
+  Frontier *frontier;
+  StackDepotReverseMap *stack_depot_reverse_map;
+  bool skip_linker_allocations;
+};
+
+// ForEachChunk callback. If the caller pc is invalid or is within the linker,
+// mark as reachable. Called by ProcessPlatformSpecificAllocations.
+static void MarkInvalidPCCb(uptr chunk, void *arg) {
+  CHECK(arg);
+  InvalidPCParam *param = reinterpret_cast<InvalidPCParam *>(arg);
+  chunk = GetUserBegin(chunk);
+  LsanMetadata m(chunk);
+  if (m.allocated() && m.tag() != kReachable && m.tag() != kIgnored) {
+    u32 stack_id = m.stack_trace_id();
+    uptr caller_pc = 0;
+    if (stack_id > 0)
+      caller_pc = GetCallerPC(stack_id, param->stack_depot_reverse_map);
+    // If caller_pc is unknown, this chunk may be allocated in a coroutine. Mark
+    // it as reachable, as we can't properly report its allocation stack anyway.
+    if (caller_pc == 0 || (param->skip_linker_allocations &&
+                           GetLinker()->containsAddress(caller_pc))) {
+      m.set_tag(kReachable);
+      param->frontier->push_back(chunk);
+    }
+  }
+}
+
+// On Linux, handles dynamically allocated TLS blocks by treating all chunks
+// allocated from ld-linux.so as reachable.
+// Dynamic TLS blocks contain the TLS variables of dynamically loaded modules.
+// They are allocated with a __libc_memalign() call in allocate_and_init()
+// (elf/dl-tls.c). Glibc won't tell us the address ranges occupied by those
+// blocks, but we can make sure they come from our own allocator by intercepting
+// __libc_memalign(). On top of that, there is no easy way to reach them. Their
+// addresses are stored in a dynamically allocated array (the DTV) which is
+// referenced from the static TLS. Unfortunately, we can't just rely on the DTV
+// being reachable from the static TLS, and the dynamic TLS being reachable from
+// the DTV. This is because the initial DTV is allocated before our interception
+// mechanism kicks in, and thus we don't recognize it as allocated memory. We
+// can't special-case it either, since we don't know its size.
+// Our solution is to include in the root set all allocations made from
+// ld-linux.so (which is where allocate_and_init() is implemented). This is
+// guaranteed to include all dynamic TLS blocks (and possibly other allocations
+// which we don't care about).
+// On all other platforms, this simply checks to ensure that the caller pc is
+// valid before reporting chunks as leaked.
+void ProcessPC(Frontier *frontier) {
+  StackDepotReverseMap stack_depot_reverse_map;
+  InvalidPCParam arg;
+  arg.frontier = frontier;
+  arg.stack_depot_reverse_map = &stack_depot_reverse_map;
+  arg.skip_linker_allocations =
+      flags()->use_tls && flags()->use_ld_allocations && GetLinker() != nullptr;
+  ForEachChunk(MarkInvalidPCCb, &arg);
+}
+
 // Sets the appropriate tag on each chunk.
 static void ClassifyAllChunks(SuspendedThreadsList const &suspended_threads) {
   // Holds the flood fill frontier.
@@ -347,11 +449,13 @@ static void ClassifyAllChunks(SuspendedThreadsList const &suspended_threads) {
   ProcessRootRegions(&frontier);
   FloodFillTag(&frontier, kReachable);
 
+  CHECK_EQ(0, frontier.size());
+  ProcessPC(&frontier);
+
   // The check here is relatively expensive, so we do this in a separate flood
   // fill. That way we can skip the check for chunks that are reachable
   // otherwise.
   LOG_POINTERS("Processing platform-specific allocations.\n");
-  CHECK_EQ(0, frontier.size());
   ProcessPlatformSpecificAllocations(&frontier);
   FloodFillTag(&frontier, kReachable);
 
@@ -461,7 +565,7 @@ static bool CheckForLeaks() {
            "\n");
     Printf("%s", d.Error());
     Report("ERROR: LeakSanitizer: detected memory leaks\n");
-    Printf("%s", d.End());
+    Printf("%s", d.Default());
     param.leak_report.ReportTopLeaks(flags()->max_leaks);
   }
   if (common_flags()->print_suppressions)
@@ -473,18 +577,16 @@ static bool CheckForLeaks() {
   return false;
 }
 
+static bool has_reported_leaks = false;
+bool HasReportedLeaks() { return has_reported_leaks; }
+
 void DoLeakCheck() {
   BlockingMutexLock l(&global_mutex);
   static bool already_done;
   if (already_done) return;
   already_done = true;
-  bool have_leaks = CheckForLeaks();
-  if (!have_leaks) {
-    return;
-  }
-  if (common_flags()->exitcode) {
-    Die();
-  }
+  has_reported_leaks = CheckForLeaks();
+  if (has_reported_leaks) HandleLeaks();
 }
 
 static int DoRecoverableLeakCheck() {
@@ -493,6 +595,8 @@ static int DoRecoverableLeakCheck() {
   return have_leaks ? 1 : 0;
 }
 
+void DoRecoverableLeakCheckVoid() { DoRecoverableLeakCheck(); }
+
 static Suppression *GetSuppressionForAddr(uptr addr) {
   Suppression *s = nullptr;
 
@@ -597,7 +701,7 @@ void LeakReport::PrintReportForLeak(uptr index) {
   Printf("%s leak of %zu byte(s) in %zu object(s) allocated from:\n",
          leaks_[index].is_directly_leaked ? "Direct" : "Indirect",
          leaks_[index].total_size, leaks_[index].hit_count);
-  Printf("%s", d.End());
+  Printf("%s", d.Default());
 
   PrintStackTraceById(leaks_[index].stack_trace_id);
 
@@ -655,6 +759,7 @@ uptr LeakReport::UnsuppressedLeakCount() {
 namespace __lsan {
 void InitCommonLsan() { }
 void DoLeakCheck() { }
+void DoRecoverableLeakCheckVoid() { }
 void DisableInThisThread() { }
 void EnableInThisThread() { }
 }
@@ -687,7 +792,7 @@ void __lsan_register_root_region(const void *begin, uptr size) {
 #if CAN_SANITIZE_LEAKS
   BlockingMutexLock l(&global_mutex);
   CHECK(root_regions);
-  RootRegion region = {begin, size};
+  RootRegion region = {reinterpret_cast<uptr>(begin), size};
   root_regions->push_back(region);
   VReport(1, "Registered root region at %p of size %llu\n", begin, size);
 #endif // CAN_SANITIZE_LEAKS
@@ -701,7 +806,7 @@ void __lsan_unregister_root_region(const void *begin, uptr size) {
   bool removed = false;
   for (uptr i = 0; i < root_regions->size(); i++) {
     RootRegion region = (*root_regions)[i];
-    if (region.begin == begin && region.size == size) {
+    if (region.begin == reinterpret_cast<uptr>(begin) && region.size == size) {
       removed = true;
       uptr last_index = root_regions->size() - 1;
       (*root_regions)[i] = (*root_regions)[last_index];
@@ -753,8 +858,18 @@ int __lsan_do_recoverable_leak_check() {
 
 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+const char * __lsan_default_options() {
+  return "";
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
 int __lsan_is_turned_off() {
   return 0;
 }
+
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+const char *__lsan_default_suppressions() {
+  return "";
+}
 #endif
 } // extern "C"
diff --git a/libsanitizer/lsan/lsan_common.h b/libsanitizer/lsan/lsan_common.h
index 1091b84f108..e99cd9e1b52 100644
--- a/libsanitizer/lsan/lsan_common.h
+++ b/libsanitizer/lsan/lsan_common.h
@@ -20,8 +20,24 @@
 #include "sanitizer_common/sanitizer_stoptheworld.h"
 #include "sanitizer_common/sanitizer_symbolizer.h"
 
-#if (SANITIZER_LINUX && !SANITIZER_ANDROID) && (SANITIZER_WORDSIZE == 64) \
-     && (defined(__x86_64__) ||  defined(__mips64) ||  defined(__aarch64__))
+// LeakSanitizer relies on some Glibc's internals (e.g. TLS machinery) thus
+// supported for Linux only. Also, LSan doesn't like 32 bit architectures
+// because of "small" (4 bytes) pointer size that leads to high false negative
+// ratio on large leaks. But we still want to have it for some 32 bit arches
+// (e.g. x86), see https://github.com/google/sanitizers/issues/403.
+// To enable LeakSanitizer on new architecture, one need to implement
+// internal_clone function as well as (probably) adjust TLS machinery for
+// new architecture inside sanitizer library.
+#if (SANITIZER_LINUX && !SANITIZER_ANDROID || SANITIZER_MAC) && \
+    (SANITIZER_WORDSIZE == 64) &&                               \
+    (defined(__x86_64__) || defined(__mips64) || defined(__aarch64__) || \
+     defined(__powerpc64__))
+#define CAN_SANITIZE_LEAKS 1
+#elif defined(__i386__) && \
+    (SANITIZER_LINUX && !SANITIZER_ANDROID || SANITIZER_MAC)
+#define CAN_SANITIZE_LEAKS 1
+#elif defined(__arm__) && \
+    SANITIZER_LINUX && !SANITIZER_ANDROID
 #define CAN_SANITIZE_LEAKS 1
 #else
 #define CAN_SANITIZE_LEAKS 0
@@ -42,6 +58,8 @@ enum ChunkTag {
   kIgnored = 3
 };
 
+const u32 kInvalidTid = (u32) -1;
+
 struct Flags {
 #define LSAN_FLAG(Type, Name, DefaultValue, Description) Type Name;
 #include "lsan_flags.inc"
@@ -99,12 +117,22 @@ typedef InternalMmapVector<uptr> Frontier;
 void InitializePlatformSpecificModules();
 void ProcessGlobalRegions(Frontier *frontier);
 void ProcessPlatformSpecificAllocations(Frontier *frontier);
+
+struct RootRegion {
+  uptr begin;
+  uptr size;
+};
+
+InternalMmapVector<RootRegion> const *GetRootRegions();
+void ScanRootRegion(Frontier *frontier, RootRegion const &region,
+                    uptr region_begin, uptr region_end, bool is_readable);
 // Run stoptheworld while holding any platform-specific locks.
 void DoStopTheWorld(StopTheWorldCallback callback, void* argument);
 
 void ScanRangeForPointers(uptr begin, uptr end,
                           Frontier *frontier,
                           const char *region_type, ChunkTag tag);
+void ScanGlobalRange(uptr begin, uptr end, Frontier *frontier);
 
 enum IgnoreObjectResult {
   kIgnoreObjectSuccess,
@@ -113,8 +141,11 @@ enum IgnoreObjectResult {
 };
 
 // Functions called from the parent tool.
+const char *MaybeCallLsanDefaultOptions();
 void InitCommonLsan();
 void DoLeakCheck();
+void DoRecoverableLeakCheckVoid();
+void DisableCounterUnderflow();
 bool DisabledInThisThread();
 
 // Used to implement __lsan::ScopedDisabler.
@@ -127,13 +158,36 @@ struct ScopedInterceptorDisabler {
   ~ScopedInterceptorDisabler() { EnableInThisThread(); }
 };
 
+// According to Itanium C++ ABI array cookie is a one word containing
+// size of allocated array.
+static inline bool IsItaniumABIArrayCookie(uptr chunk_beg, uptr chunk_size,
+                                           uptr addr) {
+  return chunk_size == sizeof(uptr) && chunk_beg + chunk_size == addr &&
+         *reinterpret_cast<uptr *>(chunk_beg) == 0;
+}
+
+// According to ARM C++ ABI array cookie consists of two words:
+// struct array_cookie {
+//   std::size_t element_size; // element_size != 0
+//   std::size_t element_count;
+// };
+static inline bool IsARMABIArrayCookie(uptr chunk_beg, uptr chunk_size,
+                                       uptr addr) {
+  return chunk_size == 2 * sizeof(uptr) && chunk_beg + chunk_size == addr &&
+         *reinterpret_cast<uptr *>(chunk_beg + sizeof(uptr)) == 0;
+}
+
 // Special case for "new T[0]" where T is a type with DTOR.
-// new T[0] will allocate one word for the array size (0) and store a pointer
-// to the end of allocated chunk.
+// new T[0] will allocate a cookie (one or two words) for the array size (0)
+// and store a pointer to the end of allocated chunk. The actual cookie layout
+// varies between platforms according to their C++ ABI implementation.
 inline bool IsSpecialCaseOfOperatorNew0(uptr chunk_beg, uptr chunk_size,
                                         uptr addr) {
-  return chunk_size == sizeof(uptr) && chunk_beg + chunk_size == addr &&
-         *reinterpret_cast<uptr *>(chunk_beg) == 0;
+#if defined(__arm__)
+  return IsARMABIArrayCookie(chunk_beg, chunk_size, addr);
+#else
+  return IsItaniumABIArrayCookie(chunk_beg, chunk_size, addr);
+#endif
 }
 
 // The following must be implemented in the parent tool.
@@ -149,10 +203,10 @@ bool WordIsPoisoned(uptr addr);
 // Wrappers for ThreadRegistry access.
 void LockThreadRegistry();
 void UnlockThreadRegistry();
-bool GetThreadRangesLocked(uptr os_id, uptr *stack_begin, uptr *stack_end,
+bool GetThreadRangesLocked(tid_t os_id, uptr *stack_begin, uptr *stack_end,
                            uptr *tls_begin, uptr *tls_end, uptr *cache_begin,
                            uptr *cache_end, DTLS **dtls);
-void ForEachExtraStackRange(uptr os_id, RangeIteratorCallback callback,
+void ForEachExtraStackRange(tid_t os_id, RangeIteratorCallback callback,
                             void *arg);
 // If called from the main thread, updates the main thread's TID in the thread
 // registry. We need this to handle processes that fork() without a subsequent
@@ -168,6 +222,16 @@ uptr PointsIntoChunk(void *p);
 uptr GetUserBegin(uptr chunk);
 // Helper for __lsan_ignore_object().
 IgnoreObjectResult IgnoreObjectLocked(const void *p);
+
+// Return the linker module, if valid for the platform.
+LoadedModule *GetLinker();
+
+// Return true if LSan has finished leak checking and reported leaks.
+bool HasReportedLeaks();
+
+// Run platform-specific leak handlers.
+void HandleLeaks();
+
 // Wrapper for chunk metadata operations.
 class LsanMetadata {
  public:
@@ -186,6 +250,9 @@ class LsanMetadata {
 
 extern "C" {
 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+const char *__lsan_default_options();
+
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
 int __lsan_is_turned_off();
 
 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
diff --git a/libsanitizer/lsan/lsan_common_linux.cc b/libsanitizer/lsan/lsan_common_linux.cc
index abbb61f07c9..677727229b1 100644
--- a/libsanitizer/lsan/lsan_common_linux.cc
+++ b/libsanitizer/lsan/lsan_common_linux.cc
@@ -32,6 +32,17 @@ static bool IsLinker(const char* full_name) {
   return LibraryNameIs(full_name, kLinkerName);
 }
 
+__attribute__((tls_model("initial-exec")))
+THREADLOCAL int disable_counter;
+bool DisabledInThisThread() { return disable_counter > 0; }
+void DisableInThisThread() { disable_counter++; }
+void EnableInThisThread() {
+  if (disable_counter == 0) {
+    DisableCounterUnderflow();
+  }
+  disable_counter--;
+}
+
 void InitializePlatformSpecificModules() {
   ListOfModules modules;
   modules.init();
@@ -49,8 +60,10 @@ void InitializePlatformSpecificModules() {
       return;
     }
   }
-  VReport(1, "LeakSanitizer: Dynamic linker not found. "
-             "TLS will not be handled correctly.\n");
+  if (linker == nullptr) {
+    VReport(1, "LeakSanitizer: Dynamic linker not found. "
+               "TLS will not be handled correctly.\n");
+  }
 }
 
 static int ProcessGlobalRegionsCallback(struct dl_phdr_info *info, size_t size,
@@ -65,20 +78,7 @@ static int ProcessGlobalRegionsCallback(struct dl_phdr_info *info, size_t size,
       continue;
     uptr begin = info->dlpi_addr + phdr->p_vaddr;
     uptr end = begin + phdr->p_memsz;
-    uptr allocator_begin = 0, allocator_end = 0;
-    GetAllocatorGlobalRange(&allocator_begin, &allocator_end);
-    if (begin <= allocator_begin && allocator_begin < end) {
-      CHECK_LE(allocator_begin, allocator_end);
-      CHECK_LE(allocator_end, end);
-      if (begin < allocator_begin)
-        ScanRangeForPointers(begin, allocator_begin, frontier, "GLOBAL",
-                             kReachable);
-      if (allocator_end < end)
-        ScanRangeForPointers(allocator_end, end, frontier, "GLOBAL",
-                             kReachable);
-    } else {
-      ScanRangeForPointers(begin, end, frontier, "GLOBAL", kReachable);
-    }
+    ScanGlobalRange(begin, end, frontier);
   }
   return 0;
 }
@@ -89,76 +89,22 @@ void ProcessGlobalRegions(Frontier *frontier) {
   dl_iterate_phdr(ProcessGlobalRegionsCallback, frontier);
 }
 
-static uptr GetCallerPC(u32 stack_id, StackDepotReverseMap *map) {
-  CHECK(stack_id);
-  StackTrace stack = map->Get(stack_id);
-  // The top frame is our malloc/calloc/etc. The next frame is the caller.
-  if (stack.size >= 2)
-    return stack.trace[1];
-  return 0;
-}
+LoadedModule *GetLinker() { return linker; }
 
-struct ProcessPlatformAllocParam {
-  Frontier *frontier;
-  StackDepotReverseMap *stack_depot_reverse_map;
-  bool skip_linker_allocations;
-};
-
-// ForEachChunk callback. Identifies unreachable chunks which must be treated as
-// reachable. Marks them as reachable and adds them to the frontier.
-static void ProcessPlatformSpecificAllocationsCb(uptr chunk, void *arg) {
-  CHECK(arg);
-  ProcessPlatformAllocParam *param =
-      reinterpret_cast<ProcessPlatformAllocParam *>(arg);
-  chunk = GetUserBegin(chunk);
-  LsanMetadata m(chunk);
-  if (m.allocated() && m.tag() != kReachable && m.tag() != kIgnored) {
-    u32 stack_id = m.stack_trace_id();
-    uptr caller_pc = 0;
-    if (stack_id > 0)
-      caller_pc = GetCallerPC(stack_id, param->stack_depot_reverse_map);
-    // If caller_pc is unknown, this chunk may be allocated in a coroutine. Mark
-    // it as reachable, as we can't properly report its allocation stack anyway.
-    if (caller_pc == 0 || (param->skip_linker_allocations &&
-                           linker->containsAddress(caller_pc))) {
-      m.set_tag(kReachable);
-      param->frontier->push_back(chunk);
-    }
-  }
-}
-
-// Handles dynamically allocated TLS blocks by treating all chunks allocated
-// from ld-linux.so as reachable.
-// Dynamic TLS blocks contain the TLS variables of dynamically loaded modules.
-// They are allocated with a __libc_memalign() call in allocate_and_init()
-// (elf/dl-tls.c). Glibc won't tell us the address ranges occupied by those
-// blocks, but we can make sure they come from our own allocator by intercepting
-// __libc_memalign(). On top of that, there is no easy way to reach them. Their
-// addresses are stored in a dynamically allocated array (the DTV) which is
-// referenced from the static TLS. Unfortunately, we can't just rely on the DTV
-// being reachable from the static TLS, and the dynamic TLS being reachable from
-// the DTV. This is because the initial DTV is allocated before our interception
-// mechanism kicks in, and thus we don't recognize it as allocated memory. We
-// can't special-case it either, since we don't know its size.
-// Our solution is to include in the root set all allocations made from
-// ld-linux.so (which is where allocate_and_init() is implemented). This is
-// guaranteed to include all dynamic TLS blocks (and possibly other allocations
-// which we don't care about).
-void ProcessPlatformSpecificAllocations(Frontier *frontier) {
-  StackDepotReverseMap stack_depot_reverse_map;
-  ProcessPlatformAllocParam arg;
-  arg.frontier = frontier;
-  arg.stack_depot_reverse_map = &stack_depot_reverse_map;
-  arg.skip_linker_allocations =
-      flags()->use_tls && flags()->use_ld_allocations && linker != nullptr;
-  ForEachChunk(ProcessPlatformSpecificAllocationsCb, &arg);
-}
+void ProcessPlatformSpecificAllocations(Frontier *frontier) {}
 
 struct DoStopTheWorldParam {
   StopTheWorldCallback callback;
   void *argument;
 };
 
+// While calling Die() here is undefined behavior and can potentially
+// cause race conditions, it isn't possible to intercept exit on linux,
+// so we have no choice but to call Die() from the atexit handler.
+void HandleLeaks() {
+  if (common_flags()->exitcode) Die();
+}
+
 static int DoStopTheWorldCallback(struct dl_phdr_info *info, size_t size,
                                   void *data) {
   DoStopTheWorldParam *param = reinterpret_cast<DoStopTheWorldParam *>(data);
diff --git a/libsanitizer/lsan/lsan_common_mac.cc b/libsanitizer/lsan/lsan_common_mac.cc
new file mode 100644
index 00000000000..e60b3d0f195
--- /dev/null
+++ b/libsanitizer/lsan/lsan_common_mac.cc
@@ -0,0 +1,197 @@
+//=-- lsan_common_mac.cc --------------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of LeakSanitizer.
+// Implementation of common leak checking functionality. Darwin-specific code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_platform.h"
+#include "lsan_common.h"
+
+#if CAN_SANITIZE_LEAKS && SANITIZER_MAC
+
+#include "sanitizer_common/sanitizer_allocator_internal.h"
+#include "lsan_allocator.h"
+
+#include <pthread.h>
+
+#include <mach/mach.h>
+
+namespace __lsan {
+
+typedef struct {
+  int disable_counter;
+  u32 current_thread_id;
+  AllocatorCache cache;
+} thread_local_data_t;
+
+static pthread_key_t key;
+static pthread_once_t key_once = PTHREAD_ONCE_INIT;
+
+// The main thread destructor requires the current thread id,
+// so we can't destroy it until it's been used and reset to invalid tid
+void restore_tid_data(void *ptr) {
+  thread_local_data_t *data = (thread_local_data_t *)ptr;
+  if (data->current_thread_id != kInvalidTid)
+    pthread_setspecific(key, data);
+}
+
+static void make_tls_key() {
+  CHECK_EQ(pthread_key_create(&key, restore_tid_data), 0);
+}
+
+static thread_local_data_t *get_tls_val(bool alloc) {
+  pthread_once(&key_once, make_tls_key);
+
+  thread_local_data_t *ptr = (thread_local_data_t *)pthread_getspecific(key);
+  if (ptr == NULL && alloc) {
+    ptr = (thread_local_data_t *)InternalAlloc(sizeof(*ptr));
+    ptr->disable_counter = 0;
+    ptr->current_thread_id = kInvalidTid;
+    ptr->cache = AllocatorCache();
+    pthread_setspecific(key, ptr);
+  }
+
+  return ptr;
+}
+
+bool DisabledInThisThread() {
+  thread_local_data_t *data = get_tls_val(false);
+  return data ? data->disable_counter > 0 : false;
+}
+
+void DisableInThisThread() { ++get_tls_val(true)->disable_counter; }
+
+void EnableInThisThread() {
+  int *disable_counter = &get_tls_val(true)->disable_counter;
+  if (*disable_counter == 0) {
+    DisableCounterUnderflow();
+  }
+  --*disable_counter;
+}
+
+u32 GetCurrentThread() {
+  thread_local_data_t *data = get_tls_val(false);
+  return data ? data->current_thread_id : kInvalidTid;
+}
+
+void SetCurrentThread(u32 tid) { get_tls_val(true)->current_thread_id = tid; }
+
+AllocatorCache *GetAllocatorCache() { return &get_tls_val(true)->cache; }
+
+LoadedModule *GetLinker() { return nullptr; }
+
+// Required on Linux for initialization of TLS behavior, but should not be
+// required on Darwin.
+void InitializePlatformSpecificModules() {}
+
+// Sections which can't contain contain global pointers. This list errs on the
+// side of caution to avoid false positives, at the expense of performance.
+//
+// Other potentially safe sections include:
+// __all_image_info, __crash_info, __const, __got, __interpose, __objc_msg_break
+//
+// Sections which definitely cannot be included here are:
+// __objc_data, __objc_const, __data, __bss, __common, __thread_data,
+// __thread_bss, __thread_vars, __objc_opt_rw, __objc_opt_ptrs
+static const char *kSkippedSecNames[] = {
+    "__cfstring",       "__la_symbol_ptr",  "__mod_init_func",
+    "__mod_term_func",  "__nl_symbol_ptr",  "__objc_classlist",
+    "__objc_classrefs", "__objc_imageinfo", "__objc_nlclslist",
+    "__objc_protolist", "__objc_selrefs",   "__objc_superrefs"};
+
+// Scans global variables for heap pointers.
+void ProcessGlobalRegions(Frontier *frontier) {
+  for (auto name : kSkippedSecNames) CHECK(ARRAY_SIZE(name) < kMaxSegName);
+
+  MemoryMappingLayout memory_mapping(false);
+  InternalMmapVector<LoadedModule> modules(/*initial_capacity*/ 128);
+  memory_mapping.DumpListOfModules(&modules);
+  for (uptr i = 0; i < modules.size(); ++i) {
+    // Even when global scanning is disabled, we still need to scan
+    // system libraries for stashed pointers
+    if (!flags()->use_globals && modules[i].instrumented()) continue;
+
+    for (const __sanitizer::LoadedModule::AddressRange &range :
+         modules[i].ranges()) {
+      // Sections storing global variables are writable and non-executable
+      if (range.executable || !range.writable) continue;
+
+      for (auto name : kSkippedSecNames) {
+        if (!internal_strcmp(range.name, name)) continue;
+      }
+
+      ScanGlobalRange(range.beg, range.end, frontier);
+    }
+  }
+}
+
+void ProcessPlatformSpecificAllocations(Frontier *frontier) {
+  mach_port_name_t port;
+  if (task_for_pid(mach_task_self(), internal_getpid(), &port)
+      != KERN_SUCCESS) {
+    return;
+  }
+
+  unsigned depth = 1;
+  vm_size_t size = 0;
+  vm_address_t address = 0;
+  kern_return_t err = KERN_SUCCESS;
+  mach_msg_type_number_t count = VM_REGION_SUBMAP_INFO_COUNT_64;
+
+  InternalMmapVector<RootRegion> const *root_regions = GetRootRegions();
+
+  while (err == KERN_SUCCESS) {
+    struct vm_region_submap_info_64 info;
+    err = vm_region_recurse_64(port, &address, &size, &depth,
+                               (vm_region_info_t)&info, &count);
+
+    uptr end_address = address + size;
+
+    // libxpc stashes some pointers in the Kernel Alloc Once page,
+    // make sure not to report those as leaks.
+    if (info.user_tag == VM_MEMORY_OS_ALLOC_ONCE) {
+      ScanRangeForPointers(address, end_address, frontier, "GLOBAL",
+                           kReachable);
+
+      // Recursing over the full memory map is very slow, break out
+      // early if we don't need the full iteration.
+      if (!flags()->use_root_regions || !root_regions->size())
+        break;
+    }
+
+    // This additional root region scan is required on Darwin in order to
+    // detect root regions contained within mmap'd memory regions, because
+    // the Darwin implementation of sanitizer_procmaps traverses images
+    // as loaded by dyld, and not the complete set of all memory regions.
+    //
+    // TODO(fjricci) - remove this once sanitizer_procmaps_mac has the same
+    // behavior as sanitizer_procmaps_linux and traverses all memory regions
+    if (flags()->use_root_regions) {
+      for (uptr i = 0; i < root_regions->size(); i++) {
+        ScanRootRegion(frontier, (*root_regions)[i], address, end_address,
+                       info.protection & kProtectionRead);
+      }
+    }
+
+    address = end_address;
+  }
+}
+
+// On darwin, we can intercept _exit gracefully, and return a failing exit code
+// if required at that point. Calling Die() here is undefined behavior and
+// causes rare race conditions.
+void HandleLeaks() {}
+
+void DoStopTheWorld(StopTheWorldCallback callback, void *argument) {
+  StopTheWorld(callback, argument);
+}
+
+} // namespace __lsan
+
+#endif // CAN_SANITIZE_LEAKS && SANITIZER_MAC
diff --git a/libsanitizer/lsan/lsan_interceptors.cc b/libsanitizer/lsan/lsan_interceptors.cc
index 160ed5979c4..c9279aad676 100644
--- a/libsanitizer/lsan/lsan_interceptors.cc
+++ b/libsanitizer/lsan/lsan_interceptors.cc
@@ -17,13 +17,18 @@
 #include "sanitizer_common/sanitizer_flags.h"
 #include "sanitizer_common/sanitizer_internal_defs.h"
 #include "sanitizer_common/sanitizer_linux.h"
+#include "sanitizer_common/sanitizer_platform_interceptors.h"
+#include "sanitizer_common/sanitizer_platform_limits_netbsd.h"
 #include "sanitizer_common/sanitizer_platform_limits_posix.h"
+#include "sanitizer_common/sanitizer_posix.h"
 #include "sanitizer_common/sanitizer_tls_get_addr.h"
 #include "lsan.h"
 #include "lsan_allocator.h"
 #include "lsan_common.h"
 #include "lsan_thread.h"
 
+#include <stddef.h>
+
 using namespace __lsan;
 
 extern "C" {
@@ -34,29 +39,23 @@ int pthread_key_create(unsigned *key, void (*destructor)(void* v));
 int pthread_setspecific(unsigned key, const void *v);
 }
 
-#define ENSURE_LSAN_INITED do {   \
-  CHECK(!lsan_init_is_running);   \
-  if (!lsan_inited)               \
-    __lsan_init();                \
-} while (0)
-
 ///// Malloc/free interceptors. /////
 
-const bool kAlwaysClearMemory = true;
-
 namespace std {
   struct nothrow_t;
+  enum class align_val_t: size_t;
 }
 
+#if !SANITIZER_MAC
 INTERCEPTOR(void*, malloc, uptr size) {
   ENSURE_LSAN_INITED;
   GET_STACK_TRACE_MALLOC;
-  return Allocate(stack, size, 1, kAlwaysClearMemory);
+  return lsan_malloc(size, stack);
 }
 
 INTERCEPTOR(void, free, void *p) {
   ENSURE_LSAN_INITED;
-  Deallocate(p);
+  lsan_free(p);
 }
 
 INTERCEPTOR(void*, calloc, uptr nmemb, uptr size) {
@@ -71,60 +70,76 @@ INTERCEPTOR(void*, calloc, uptr nmemb, uptr size) {
     CHECK(allocated < kCallocPoolSize);
     return mem;
   }
-  if (CallocShouldReturnNullDueToOverflow(size, nmemb)) return nullptr;
   ENSURE_LSAN_INITED;
   GET_STACK_TRACE_MALLOC;
-  size *= nmemb;
-  return Allocate(stack, size, 1, true);
+  return lsan_calloc(nmemb, size, stack);
 }
 
 INTERCEPTOR(void*, realloc, void *q, uptr size) {
   ENSURE_LSAN_INITED;
   GET_STACK_TRACE_MALLOC;
-  return Reallocate(stack, q, size, 1);
+  return lsan_realloc(q, size, stack);
 }
 
-INTERCEPTOR(void*, memalign, uptr alignment, uptr size) {
+INTERCEPTOR(int, posix_memalign, void **memptr, uptr alignment, uptr size) {
   ENSURE_LSAN_INITED;
   GET_STACK_TRACE_MALLOC;
-  return Allocate(stack, size, alignment, kAlwaysClearMemory);
+  *memptr = lsan_memalign(alignment, size, stack);
+  // FIXME: Return ENOMEM if user requested more than max alloc size.
+  return 0;
 }
 
-INTERCEPTOR(void*, aligned_alloc, uptr alignment, uptr size) {
+INTERCEPTOR(void*, valloc, uptr size) {
   ENSURE_LSAN_INITED;
   GET_STACK_TRACE_MALLOC;
-  return Allocate(stack, size, alignment, kAlwaysClearMemory);
+  return lsan_valloc(size, stack);
 }
+#endif
 
-INTERCEPTOR(int, posix_memalign, void **memptr, uptr alignment, uptr size) {
+#if SANITIZER_INTERCEPT_MEMALIGN
+INTERCEPTOR(void*, memalign, uptr alignment, uptr size) {
   ENSURE_LSAN_INITED;
   GET_STACK_TRACE_MALLOC;
-  *memptr = Allocate(stack, size, alignment, kAlwaysClearMemory);
-  // FIXME: Return ENOMEM if user requested more than max alloc size.
-  return 0;
+  return lsan_memalign(alignment, size, stack);
 }
+#define LSAN_MAYBE_INTERCEPT_MEMALIGN INTERCEPT_FUNCTION(memalign)
 
 INTERCEPTOR(void *, __libc_memalign, uptr alignment, uptr size) {
   ENSURE_LSAN_INITED;
   GET_STACK_TRACE_MALLOC;
-  void *res = Allocate(stack, size, alignment, kAlwaysClearMemory);
+  void *res = lsan_memalign(alignment, size, stack);
   DTLS_on_libc_memalign(res, size);
   return res;
 }
+#define LSAN_MAYBE_INTERCEPT___LIBC_MEMALIGN INTERCEPT_FUNCTION(__libc_memalign)
+#else
+#define LSAN_MAYBE_INTERCEPT_MEMALIGN
+#define LSAN_MAYBE_INTERCEPT___LIBC_MEMALIGN
+#endif // SANITIZER_INTERCEPT_MEMALIGN
 
-INTERCEPTOR(void*, valloc, uptr size) {
+#if SANITIZER_INTERCEPT_ALIGNED_ALLOC
+INTERCEPTOR(void*, aligned_alloc, uptr alignment, uptr size) {
   ENSURE_LSAN_INITED;
   GET_STACK_TRACE_MALLOC;
-  if (size == 0)
-    size = GetPageSizeCached();
-  return Allocate(stack, size, GetPageSizeCached(), kAlwaysClearMemory);
+  return lsan_memalign(alignment, size, stack);
 }
+#define LSAN_MAYBE_INTERCEPT_ALIGNED_ALLOC INTERCEPT_FUNCTION(aligned_alloc)
+#else
+#define LSAN_MAYBE_INTERCEPT_ALIGNED_ALLOC
+#endif
 
+#if SANITIZER_INTERCEPT_MALLOC_USABLE_SIZE
 INTERCEPTOR(uptr, malloc_usable_size, void *ptr) {
   ENSURE_LSAN_INITED;
   return GetMallocUsableSize(ptr);
 }
+#define LSAN_MAYBE_INTERCEPT_MALLOC_USABLE_SIZE \
+        INTERCEPT_FUNCTION(malloc_usable_size)
+#else
+#define LSAN_MAYBE_INTERCEPT_MALLOC_USABLE_SIZE
+#endif
 
+#if SANITIZER_INTERCEPT_MALLOPT_AND_MALLINFO
 struct fake_mallinfo {
   int x[10];
 };
@@ -134,11 +149,18 @@ INTERCEPTOR(struct fake_mallinfo, mallinfo, void) {
   internal_memset(&res, 0, sizeof(res));
   return res;
 }
+#define LSAN_MAYBE_INTERCEPT_MALLINFO INTERCEPT_FUNCTION(mallinfo)
 
 INTERCEPTOR(int, mallopt, int cmd, int value) {
   return -1;
 }
+#define LSAN_MAYBE_INTERCEPT_MALLOPT INTERCEPT_FUNCTION(mallopt)
+#else
+#define LSAN_MAYBE_INTERCEPT_MALLINFO
+#define LSAN_MAYBE_INTERCEPT_MALLOPT
+#endif // SANITIZER_INTERCEPT_MALLOPT_AND_MALLINFO
 
+#if SANITIZER_INTERCEPT_PVALLOC
 INTERCEPTOR(void*, pvalloc, uptr size) {
   ENSURE_LSAN_INITED;
   GET_STACK_TRACE_MALLOC;
@@ -150,26 +172,81 @@ INTERCEPTOR(void*, pvalloc, uptr size) {
   }
   return Allocate(stack, size, GetPageSizeCached(), kAlwaysClearMemory);
 }
+#define LSAN_MAYBE_INTERCEPT_PVALLOC INTERCEPT_FUNCTION(pvalloc)
+#else
+#define LSAN_MAYBE_INTERCEPT_PVALLOC
+#endif // SANITIZER_INTERCEPT_PVALLOC
 
+#if SANITIZER_INTERCEPT_CFREE
 INTERCEPTOR(void, cfree, void *p) ALIAS(WRAPPER_NAME(free));
+#define LSAN_MAYBE_INTERCEPT_CFREE INTERCEPT_FUNCTION(cfree)
+#else
+#define LSAN_MAYBE_INTERCEPT_CFREE
+#endif // SANITIZER_INTERCEPT_CFREE
+
+#if SANITIZER_INTERCEPT_MCHECK_MPROBE
+INTERCEPTOR(int, mcheck, void (*abortfunc)(int mstatus)) {
+  return 0;
+}
+
+INTERCEPTOR(int, mcheck_pedantic, void (*abortfunc)(int mstatus)) {
+  return 0;
+}
 
-#define OPERATOR_NEW_BODY                              \
-  ENSURE_LSAN_INITED;                                  \
-  GET_STACK_TRACE_MALLOC;                              \
-  return Allocate(stack, size, 1, kAlwaysClearMemory);
+INTERCEPTOR(int, mprobe, void *ptr) {
+  return 0;
+}
+#endif // SANITIZER_INTERCEPT_MCHECK_MPROBE
+
+
+// TODO(alekseys): throw std::bad_alloc instead of dying on OOM.
+#define OPERATOR_NEW_BODY(nothrow)                         \
+  ENSURE_LSAN_INITED;                                      \
+  GET_STACK_TRACE_MALLOC;                                  \
+  void *res = lsan_malloc(size, stack);                    \
+  if (!nothrow && UNLIKELY(!res)) DieOnFailure::OnOOM();   \
+  return res;
+#define OPERATOR_NEW_BODY_ALIGN(nothrow)                   \
+  ENSURE_LSAN_INITED;                                      \
+  GET_STACK_TRACE_MALLOC;                                  \
+  void *res = lsan_memalign((uptr)align, size, stack);     \
+  if (!nothrow && UNLIKELY(!res)) DieOnFailure::OnOOM();   \
+  return res;
+
+#define OPERATOR_DELETE_BODY \
+  ENSURE_LSAN_INITED;        \
+  lsan_free(ptr);
+
+// On OS X it's not enough to just provide our own 'operator new' and
+// 'operator delete' implementations, because they're going to be in the runtime
+// dylib, and the main executable will depend on both the runtime dylib and
+// libstdc++, each of has its implementation of new and delete.
+// To make sure that C++ allocation/deallocation operators are overridden on
+// OS X we need to intercept them using their mangled names.
+#if !SANITIZER_MAC
 
 INTERCEPTOR_ATTRIBUTE
-void *operator new(uptr size) { OPERATOR_NEW_BODY; }
+void *operator new(size_t size) { OPERATOR_NEW_BODY(false /*nothrow*/); }
 INTERCEPTOR_ATTRIBUTE
-void *operator new[](uptr size) { OPERATOR_NEW_BODY; }
+void *operator new[](size_t size) { OPERATOR_NEW_BODY(false /*nothrow*/); }
 INTERCEPTOR_ATTRIBUTE
-void *operator new(uptr size, std::nothrow_t const&) { OPERATOR_NEW_BODY; }
+void *operator new(size_t size, std::nothrow_t const&)
+{ OPERATOR_NEW_BODY(true /*nothrow*/); }
 INTERCEPTOR_ATTRIBUTE
-void *operator new[](uptr size, std::nothrow_t const&) { OPERATOR_NEW_BODY; }
-
-#define OPERATOR_DELETE_BODY \
-  ENSURE_LSAN_INITED;        \
-  Deallocate(ptr);
+void *operator new[](size_t size, std::nothrow_t const&)
+{ OPERATOR_NEW_BODY(true /*nothrow*/); }
+INTERCEPTOR_ATTRIBUTE
+void *operator new(size_t size, std::align_val_t align)
+{ OPERATOR_NEW_BODY_ALIGN(false /*nothrow*/); }
+INTERCEPTOR_ATTRIBUTE
+void *operator new[](size_t size, std::align_val_t align)
+{ OPERATOR_NEW_BODY_ALIGN(false /*nothrow*/); }
+INTERCEPTOR_ATTRIBUTE
+void *operator new(size_t size, std::align_val_t align, std::nothrow_t const&)
+{ OPERATOR_NEW_BODY_ALIGN(true /*nothrow*/); }
+INTERCEPTOR_ATTRIBUTE
+void *operator new[](size_t size, std::align_val_t align, std::nothrow_t const&)
+{ OPERATOR_NEW_BODY_ALIGN(true /*nothrow*/); }
 
 INTERCEPTOR_ATTRIBUTE
 void operator delete(void *ptr) NOEXCEPT { OPERATOR_DELETE_BODY; }
@@ -178,9 +255,55 @@ void operator delete[](void *ptr) NOEXCEPT { OPERATOR_DELETE_BODY; }
 INTERCEPTOR_ATTRIBUTE
 void operator delete(void *ptr, std::nothrow_t const&) { OPERATOR_DELETE_BODY; }
 INTERCEPTOR_ATTRIBUTE
-void operator delete[](void *ptr, std::nothrow_t const &) {
-  OPERATOR_DELETE_BODY;
-}
+void operator delete[](void *ptr, std::nothrow_t const &)
+{ OPERATOR_DELETE_BODY; }
+INTERCEPTOR_ATTRIBUTE
+void operator delete(void *ptr, size_t size) NOEXCEPT
+{ OPERATOR_DELETE_BODY; }
+INTERCEPTOR_ATTRIBUTE
+void operator delete[](void *ptr, size_t size) NOEXCEPT
+{ OPERATOR_DELETE_BODY; }
+INTERCEPTOR_ATTRIBUTE
+void operator delete(void *ptr, std::align_val_t) NOEXCEPT
+{ OPERATOR_DELETE_BODY; }
+INTERCEPTOR_ATTRIBUTE
+void operator delete[](void *ptr, std::align_val_t) NOEXCEPT
+{ OPERATOR_DELETE_BODY; }
+INTERCEPTOR_ATTRIBUTE
+void operator delete(void *ptr, std::align_val_t, std::nothrow_t const&)
+{ OPERATOR_DELETE_BODY; }
+INTERCEPTOR_ATTRIBUTE
+void operator delete[](void *ptr, std::align_val_t, std::nothrow_t const&)
+{ OPERATOR_DELETE_BODY; }
+INTERCEPTOR_ATTRIBUTE
+void operator delete(void *ptr, size_t size, std::align_val_t) NOEXCEPT
+{ OPERATOR_DELETE_BODY; }
+INTERCEPTOR_ATTRIBUTE
+void operator delete[](void *ptr, size_t size, std::align_val_t) NOEXCEPT
+{ OPERATOR_DELETE_BODY; }
+
+#else  // SANITIZER_MAC
+
+INTERCEPTOR(void *, _Znwm, size_t size)
+{ OPERATOR_NEW_BODY(false /*nothrow*/); }
+INTERCEPTOR(void *, _Znam, size_t size)
+{ OPERATOR_NEW_BODY(false /*nothrow*/); }
+INTERCEPTOR(void *, _ZnwmRKSt9nothrow_t, size_t size, std::nothrow_t const&)
+{ OPERATOR_NEW_BODY(true /*nothrow*/); }
+INTERCEPTOR(void *, _ZnamRKSt9nothrow_t, size_t size, std::nothrow_t const&)
+{ OPERATOR_NEW_BODY(true /*nothrow*/); }
+
+INTERCEPTOR(void, _ZdlPv, void *ptr)
+{ OPERATOR_DELETE_BODY; }
+INTERCEPTOR(void, _ZdaPv, void *ptr)
+{ OPERATOR_DELETE_BODY; }
+INTERCEPTOR(void, _ZdlPvRKSt9nothrow_t, void *ptr, std::nothrow_t const&)
+{ OPERATOR_DELETE_BODY; }
+INTERCEPTOR(void, _ZdaPvRKSt9nothrow_t, void *ptr, std::nothrow_t const&)
+{ OPERATOR_DELETE_BODY; }
+
+#endif  // !SANITIZER_MAC
+
 
 ///// Thread initialization and finalization. /////
 
@@ -250,7 +373,8 @@ INTERCEPTOR(int, pthread_create, void *th, void *attr,
     res = REAL(pthread_create)(th, attr, __lsan_thread_start_func, &p);
   }
   if (res == 0) {
-    int tid = ThreadCreate(GetCurrentThread(), *(uptr *)th, detached);
+    int tid = ThreadCreate(GetCurrentThread(), *(uptr *)th,
+                           IsStateDetached(detached));
     CHECK_NE(tid, 0);
     atomic_store(&p.tid, tid, memory_order_release);
     while (atomic_load(&p.tid, memory_order_acquire) != 0)
@@ -270,24 +394,36 @@ INTERCEPTOR(int, pthread_join, void *th, void **ret) {
   return res;
 }
 
+INTERCEPTOR(void, _exit, int status) {
+  if (status == 0 && HasReportedLeaks()) status = common_flags()->exitcode;
+  REAL(_exit)(status);
+}
+
+#define COMMON_INTERCEPT_FUNCTION(name) INTERCEPT_FUNCTION(name)
+#include "sanitizer_common/sanitizer_signal_interceptors.inc"
+
 namespace __lsan {
 
 void InitializeInterceptors() {
+  InitializeSignalInterceptors();
+
   INTERCEPT_FUNCTION(malloc);
   INTERCEPT_FUNCTION(free);
-  INTERCEPT_FUNCTION(cfree);
+  LSAN_MAYBE_INTERCEPT_CFREE;
   INTERCEPT_FUNCTION(calloc);
   INTERCEPT_FUNCTION(realloc);
-  INTERCEPT_FUNCTION(memalign);
+  LSAN_MAYBE_INTERCEPT_MEMALIGN;
+  LSAN_MAYBE_INTERCEPT___LIBC_MEMALIGN;
+  LSAN_MAYBE_INTERCEPT_ALIGNED_ALLOC;
   INTERCEPT_FUNCTION(posix_memalign);
-  INTERCEPT_FUNCTION(__libc_memalign);
   INTERCEPT_FUNCTION(valloc);
-  INTERCEPT_FUNCTION(pvalloc);
-  INTERCEPT_FUNCTION(malloc_usable_size);
-  INTERCEPT_FUNCTION(mallinfo);
-  INTERCEPT_FUNCTION(mallopt);
+  LSAN_MAYBE_INTERCEPT_PVALLOC;
+  LSAN_MAYBE_INTERCEPT_MALLOC_USABLE_SIZE;
+  LSAN_MAYBE_INTERCEPT_MALLINFO;
+  LSAN_MAYBE_INTERCEPT_MALLOPT;
   INTERCEPT_FUNCTION(pthread_create);
   INTERCEPT_FUNCTION(pthread_join);
+  INTERCEPT_FUNCTION(_exit);
 
   if (pthread_key_create(&g_thread_finalize_key, &thread_finalize)) {
     Report("LeakSanitizer: failed to create thread key.\n");
diff --git a/libsanitizer/lsan/lsan_linux.cc b/libsanitizer/lsan/lsan_linux.cc
new file mode 100644
index 00000000000..aa6445a9877
--- /dev/null
+++ b/libsanitizer/lsan/lsan_linux.cc
@@ -0,0 +1,31 @@
+//=-- lsan_linux.cc -------------------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of LeakSanitizer. Linux-specific code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_platform.h"
+
+#if SANITIZER_LINUX
+
+#include "lsan_allocator.h"
+
+namespace __lsan {
+
+static THREADLOCAL u32 current_thread_tid = kInvalidTid;
+u32 GetCurrentThread() { return current_thread_tid; }
+void SetCurrentThread(u32 tid) { current_thread_tid = tid; }
+
+static THREADLOCAL AllocatorCache allocator_cache;
+AllocatorCache *GetAllocatorCache() { return &allocator_cache; }
+
+void ReplaceSystemMalloc() {}
+
+} // namespace __lsan
+
+#endif // SANITIZER_LINUX
diff --git a/libsanitizer/lsan/lsan_mac.cc b/libsanitizer/lsan/lsan_mac.cc
new file mode 100644
index 00000000000..ca38c1c6f8a
--- /dev/null
+++ b/libsanitizer/lsan/lsan_mac.cc
@@ -0,0 +1,190 @@
+//===-- lsan_mac.cc -------------------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of LeakSanitizer, a memory leak checker.
+//
+// Mac-specific details.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_platform.h"
+#if SANITIZER_MAC
+
+#include "interception/interception.h"
+#include "lsan.h"
+#include "lsan_allocator.h"
+#include "lsan_thread.h"
+
+#include <pthread.h>
+
+namespace __lsan {
+// Support for the following functions from libdispatch on Mac OS:
+//   dispatch_async_f()
+//   dispatch_async()
+//   dispatch_sync_f()
+//   dispatch_sync()
+//   dispatch_after_f()
+//   dispatch_after()
+//   dispatch_group_async_f()
+//   dispatch_group_async()
+// TODO(glider): libdispatch API contains other functions that we don't support
+// yet.
+//
+// dispatch_sync() and dispatch_sync_f() are synchronous, although chances are
+// they can cause jobs to run on a thread different from the current one.
+// TODO(glider): if so, we need a test for this (otherwise we should remove
+// them).
+//
+// The following functions use dispatch_barrier_async_f() (which isn't a library
+// function but is exported) and are thus supported:
+//   dispatch_source_set_cancel_handler_f()
+//   dispatch_source_set_cancel_handler()
+//   dispatch_source_set_event_handler_f()
+//   dispatch_source_set_event_handler()
+//
+// The reference manual for Grand Central Dispatch is available at
+//   http://developer.apple.com/library/mac/#documentation/Performance/Reference/GCD_libdispatch_Ref/Reference/reference.html
+// The implementation details are at
+//   http://libdispatch.macosforge.org/trac/browser/trunk/src/queue.c
+
+typedef void *dispatch_group_t;
+typedef void *dispatch_queue_t;
+typedef void *dispatch_source_t;
+typedef u64 dispatch_time_t;
+typedef void (*dispatch_function_t)(void *block);
+typedef void *(*worker_t)(void *block);
+
+// A wrapper for the ObjC blocks used to support libdispatch.
+typedef struct {
+  void *block;
+  dispatch_function_t func;
+  u32 parent_tid;
+} lsan_block_context_t;
+
+ALWAYS_INLINE
+void lsan_register_worker_thread(int parent_tid) {
+  if (GetCurrentThread() == kInvalidTid) {
+    u32 tid = ThreadCreate(parent_tid, 0, true);
+    ThreadStart(tid, GetTid());
+    SetCurrentThread(tid);
+  }
+}
+
+// For use by only those functions that allocated the context via
+// alloc_lsan_context().
+extern "C" void lsan_dispatch_call_block_and_release(void *block) {
+  lsan_block_context_t *context = (lsan_block_context_t *)block;
+  VReport(2,
+          "lsan_dispatch_call_block_and_release(): "
+          "context: %p, pthread_self: %p\n",
+          block, pthread_self());
+  lsan_register_worker_thread(context->parent_tid);
+  // Call the original dispatcher for the block.
+  context->func(context->block);
+  lsan_free(context);
+}
+
+}  // namespace __lsan
+
+using namespace __lsan;  // NOLINT
+
+// Wrap |ctxt| and |func| into an lsan_block_context_t.
+// The caller retains control of the allocated context.
+extern "C" lsan_block_context_t *alloc_lsan_context(void *ctxt,
+                                                    dispatch_function_t func) {
+  GET_STACK_TRACE_THREAD;
+  lsan_block_context_t *lsan_ctxt =
+      (lsan_block_context_t *)lsan_malloc(sizeof(lsan_block_context_t), stack);
+  lsan_ctxt->block = ctxt;
+  lsan_ctxt->func = func;
+  lsan_ctxt->parent_tid = GetCurrentThread();
+  return lsan_ctxt;
+}
+
+// Define interceptor for dispatch_*_f function with the three most common
+// parameters: dispatch_queue_t, context, dispatch_function_t.
+#define INTERCEPT_DISPATCH_X_F_3(dispatch_x_f)                        \
+  INTERCEPTOR(void, dispatch_x_f, dispatch_queue_t dq, void *ctxt,    \
+              dispatch_function_t func) {                             \
+    lsan_block_context_t *lsan_ctxt = alloc_lsan_context(ctxt, func); \
+    return REAL(dispatch_x_f)(dq, (void *)lsan_ctxt,                  \
+                              lsan_dispatch_call_block_and_release);  \
+  }
+
+INTERCEPT_DISPATCH_X_F_3(dispatch_async_f)
+INTERCEPT_DISPATCH_X_F_3(dispatch_sync_f)
+INTERCEPT_DISPATCH_X_F_3(dispatch_barrier_async_f)
+
+INTERCEPTOR(void, dispatch_after_f, dispatch_time_t when, dispatch_queue_t dq,
+            void *ctxt, dispatch_function_t func) {
+  lsan_block_context_t *lsan_ctxt = alloc_lsan_context(ctxt, func);
+  return REAL(dispatch_after_f)(when, dq, (void *)lsan_ctxt,
+                                lsan_dispatch_call_block_and_release);
+}
+
+INTERCEPTOR(void, dispatch_group_async_f, dispatch_group_t group,
+            dispatch_queue_t dq, void *ctxt, dispatch_function_t func) {
+  lsan_block_context_t *lsan_ctxt = alloc_lsan_context(ctxt, func);
+  REAL(dispatch_group_async_f)
+  (group, dq, (void *)lsan_ctxt, lsan_dispatch_call_block_and_release);
+}
+
+#if !defined(MISSING_BLOCKS_SUPPORT)
+extern "C" {
+void dispatch_async(dispatch_queue_t dq, void (^work)(void));
+void dispatch_group_async(dispatch_group_t dg, dispatch_queue_t dq,
+                          void (^work)(void));
+void dispatch_after(dispatch_time_t when, dispatch_queue_t queue,
+                    void (^work)(void));
+void dispatch_source_set_cancel_handler(dispatch_source_t ds,
+                                        void (^work)(void));
+void dispatch_source_set_event_handler(dispatch_source_t ds,
+                                       void (^work)(void));
+}
+
+#define GET_LSAN_BLOCK(work)                 \
+  void (^lsan_block)(void);                  \
+  int parent_tid = GetCurrentThread();       \
+  lsan_block = ^(void) {                     \
+    lsan_register_worker_thread(parent_tid); \
+    work();                                  \
+  }
+
+INTERCEPTOR(void, dispatch_async, dispatch_queue_t dq, void (^work)(void)) {
+  GET_LSAN_BLOCK(work);
+  REAL(dispatch_async)(dq, lsan_block);
+}
+
+INTERCEPTOR(void, dispatch_group_async, dispatch_group_t dg,
+            dispatch_queue_t dq, void (^work)(void)) {
+  GET_LSAN_BLOCK(work);
+  REAL(dispatch_group_async)(dg, dq, lsan_block);
+}
+
+INTERCEPTOR(void, dispatch_after, dispatch_time_t when, dispatch_queue_t queue,
+            void (^work)(void)) {
+  GET_LSAN_BLOCK(work);
+  REAL(dispatch_after)(when, queue, lsan_block);
+}
+
+INTERCEPTOR(void, dispatch_source_set_cancel_handler, dispatch_source_t ds,
+            void (^work)(void)) {
+  if (!work) {
+    REAL(dispatch_source_set_cancel_handler)(ds, work);
+    return;
+  }
+  GET_LSAN_BLOCK(work);
+  REAL(dispatch_source_set_cancel_handler)(ds, lsan_block);
+}
+
+INTERCEPTOR(void, dispatch_source_set_event_handler, dispatch_source_t ds,
+            void (^work)(void)) {
+  GET_LSAN_BLOCK(work);
+  REAL(dispatch_source_set_event_handler)(ds, lsan_block);
+}
+#endif
+
+#endif  // SANITIZER_MAC
diff --git a/libsanitizer/lsan/lsan_malloc_mac.cc b/libsanitizer/lsan/lsan_malloc_mac.cc
new file mode 100644
index 00000000000..2d810af841f
--- /dev/null
+++ b/libsanitizer/lsan/lsan_malloc_mac.cc
@@ -0,0 +1,53 @@
+//===-- lsan_malloc_mac.cc ------------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of LeakSanitizer (LSan), a memory leak detector.
+//
+// Mac-specific malloc interception.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_platform.h"
+#if SANITIZER_MAC
+
+#include "lsan.h"
+#include "lsan_allocator.h"
+#include "lsan_thread.h"
+
+using namespace __lsan;
+#define COMMON_MALLOC_ZONE_NAME "lsan"
+#define COMMON_MALLOC_ENTER() ENSURE_LSAN_INITED
+#define COMMON_MALLOC_SANITIZER_INITIALIZED lsan_inited
+#define COMMON_MALLOC_FORCE_LOCK()
+#define COMMON_MALLOC_FORCE_UNLOCK()
+#define COMMON_MALLOC_MEMALIGN(alignment, size) \
+  GET_STACK_TRACE_MALLOC; \
+  void *p = lsan_memalign(alignment, size, stack)
+#define COMMON_MALLOC_MALLOC(size) \
+  GET_STACK_TRACE_MALLOC; \
+  void *p = lsan_malloc(size, stack)
+#define COMMON_MALLOC_REALLOC(ptr, size) \
+  GET_STACK_TRACE_MALLOC; \
+  void *p = lsan_realloc(ptr, size, stack)
+#define COMMON_MALLOC_CALLOC(count, size) \
+  GET_STACK_TRACE_MALLOC; \
+  void *p = lsan_calloc(count, size, stack)
+#define COMMON_MALLOC_VALLOC(size) \
+  GET_STACK_TRACE_MALLOC; \
+  void *p = lsan_valloc(size, stack)
+#define COMMON_MALLOC_FREE(ptr) \
+  lsan_free(ptr)
+#define COMMON_MALLOC_SIZE(ptr) \
+  uptr size = lsan_mz_size(ptr)
+#define COMMON_MALLOC_FILL_STATS(zone, stats)
+#define COMMON_MALLOC_REPORT_UNKNOWN_REALLOC(ptr, zone_ptr, zone_name) \
+  (void)zone_name; \
+  Report("mz_realloc(%p) -- attempting to realloc unallocated memory.\n", ptr);
+#define COMMON_MALLOC_NAMESPACE __lsan
+
+#include "sanitizer_common/sanitizer_malloc_mac.inc"
+
+#endif // SANITIZER_MAC
diff --git a/libsanitizer/lsan/lsan_thread.cc b/libsanitizer/lsan/lsan_thread.cc
index af5ad47913f..e03e8766ae1 100644
--- a/libsanitizer/lsan/lsan_thread.cc
+++ b/libsanitizer/lsan/lsan_thread.cc
@@ -17,13 +17,11 @@
 #include "sanitizer_common/sanitizer_thread_registry.h"
 #include "sanitizer_common/sanitizer_tls_get_addr.h"
 #include "lsan_allocator.h"
+#include "lsan_common.h"
 
 namespace __lsan {
 
-const u32 kInvalidTid = (u32) -1;
-
 static ThreadRegistry *thread_registry;
-static THREADLOCAL u32 current_thread_tid = kInvalidTid;
 
 static ThreadContextBase *CreateThreadContext(u32 tid) {
   void *mem = MmapOrDie(sizeof(ThreadContext), "ThreadContext");
@@ -39,14 +37,6 @@ void InitializeThreadRegistry() {
     ThreadRegistry(CreateThreadContext, kMaxThreads, kThreadQuarantineSize);
 }
 
-u32 GetCurrentThread() {
-  return current_thread_tid;
-}
-
-void SetCurrentThread(u32 tid) {
-  current_thread_tid = tid;
-}
-
 ThreadContext::ThreadContext(int tid)
     : ThreadContextBase(tid),
       stack_begin_(0),
@@ -85,7 +75,7 @@ u32 ThreadCreate(u32 parent_tid, uptr user_id, bool detached) {
                                        /* arg */ nullptr);
 }
 
-void ThreadStart(u32 tid, uptr os_id) {
+void ThreadStart(u32 tid, tid_t os_id, bool workerthread) {
   OnStartedArgs args;
   uptr stack_size = 0;
   uptr tls_size = 0;
@@ -95,11 +85,12 @@ void ThreadStart(u32 tid, uptr os_id) {
   args.tls_end = args.tls_begin + tls_size;
   GetAllocatorCacheRange(&args.cache_begin, &args.cache_end);
   args.dtls = DTLS_Get();
-  thread_registry->StartThread(tid, os_id, &args);
+  thread_registry->StartThread(tid, os_id, workerthread, &args);
 }
 
 void ThreadFinish() {
   thread_registry->FinishThread(GetCurrentThread());
+  SetCurrentThread(kInvalidTid);
 }
 
 ThreadContext *CurrentThreadContext() {
@@ -134,7 +125,7 @@ void EnsureMainThreadIDIsCorrect() {
 
 ///// Interface to the common LSan module. /////
 
-bool GetThreadRangesLocked(uptr os_id, uptr *stack_begin, uptr *stack_end,
+bool GetThreadRangesLocked(tid_t os_id, uptr *stack_begin, uptr *stack_end,
                            uptr *tls_begin, uptr *tls_end, uptr *cache_begin,
                            uptr *cache_end, DTLS **dtls) {
   ThreadContext *context = static_cast<ThreadContext *>(
@@ -150,7 +141,7 @@ bool GetThreadRangesLocked(uptr os_id, uptr *stack_begin, uptr *stack_end,
   return true;
 }
 
-void ForEachExtraStackRange(uptr os_id, RangeIteratorCallback callback,
+void ForEachExtraStackRange(tid_t os_id, RangeIteratorCallback callback,
                             void *arg) {
 }
 
diff --git a/libsanitizer/lsan/lsan_thread.h b/libsanitizer/lsan/lsan_thread.h
index dafd8af0a29..86758347432 100644
--- a/libsanitizer/lsan/lsan_thread.h
+++ b/libsanitizer/lsan/lsan_thread.h
@@ -43,7 +43,7 @@ class ThreadContext : public ThreadContextBase {
 
 void InitializeThreadRegistry();
 
-void ThreadStart(u32 tid, uptr os_id);
+void ThreadStart(u32 tid, tid_t os_id, bool workerthread = false);
 void ThreadFinish();
 u32 ThreadCreate(u32 tid, uptr uid, bool detached);
 void ThreadJoin(u32 tid);
diff --git a/libsanitizer/sanitizer_common/Makefile.am b/libsanitizer/sanitizer_common/Makefile.am
index 92c8419f33d..adaab4cee54 100644
--- a/libsanitizer/sanitizer_common/Makefile.am
+++ b/libsanitizer/sanitizer_common/Makefile.am
@@ -19,13 +19,16 @@ ACLOCAL_AMFLAGS = -I m4
 noinst_LTLIBRARIES = libsanitizer_common.la
 
 sanitizer_common_files = \
+	sancov_flags.cc \
 	sanitizer_allocator.cc \
+	sanitizer_allocator_checks.cc \
 	sanitizer_common.cc \
 	sanitizer_common_libcdep.cc \
-	sanitizer_coverage_libcdep.cc \
-	sanitizer_coverage_mapping_libcdep.cc \
+	sanitizer_coverage_libcdep_new.cc \
 	sanitizer_deadlock_detector1.cc \
 	sanitizer_deadlock_detector2.cc \
+	sanitizer_errno.cc \
+	sanitizer_file.cc \
 	sanitizer_flags.cc \
 	sanitizer_flag_parser.cc \
 	sanitizer_libc.cc \
@@ -34,6 +37,7 @@ sanitizer_common_files = \
 	sanitizer_linux_libcdep.cc \
 	sanitizer_linux_s390.cc \
 	sanitizer_mac.cc \
+	sanitizer_mac_libcdep.cc \
 	sanitizer_persistent_allocator.cc \
 	sanitizer_platform_limits_linux.cc \
 	sanitizer_platform_limits_posix.cc \
@@ -50,6 +54,7 @@ sanitizer_common_files = \
 	sanitizer_symbolizer_mac.cc \
 	sanitizer_stacktrace_printer.cc \
 	sanitizer_stoptheworld_linux_libcdep.cc \
+	sanitizer_stoptheworld_mac.cc \
 	sanitizer_suppressions.cc \
 	sanitizer_symbolizer.cc \
 	sanitizer_symbolizer_libbacktrace.cc \
diff --git a/libsanitizer/sanitizer_common/Makefile.in b/libsanitizer/sanitizer_common/Makefile.in
index c375f63a380..b2acc5caf56 100644
--- a/libsanitizer/sanitizer_common/Makefile.in
+++ b/libsanitizer/sanitizer_common/Makefile.in
@@ -80,15 +80,16 @@ CONFIG_CLEAN_FILES =
 CONFIG_CLEAN_VPATH_FILES =
 LTLIBRARIES = $(noinst_LTLIBRARIES)
 am__DEPENDENCIES_1 =
-am__objects_1 = sanitizer_allocator.lo sanitizer_common.lo \
-	sanitizer_common_libcdep.lo sanitizer_coverage_libcdep.lo \
-	sanitizer_coverage_mapping_libcdep.lo \
+am__objects_1 = sancov_flags.lo sanitizer_allocator.lo \
+	sanitizer_allocator_checks.lo sanitizer_common.lo \
+	sanitizer_common_libcdep.lo sanitizer_coverage_libcdep_new.lo \
 	sanitizer_deadlock_detector1.lo \
-	sanitizer_deadlock_detector2.lo sanitizer_flags.lo \
-	sanitizer_flag_parser.lo sanitizer_libc.lo \
-	sanitizer_libignore.lo sanitizer_linux.lo \
+	sanitizer_deadlock_detector2.lo sanitizer_errno.lo \
+	sanitizer_file.lo sanitizer_flags.lo sanitizer_flag_parser.lo \
+	sanitizer_libc.lo sanitizer_libignore.lo sanitizer_linux.lo \
 	sanitizer_linux_libcdep.lo sanitizer_linux_s390.lo \
-	sanitizer_mac.lo sanitizer_persistent_allocator.lo \
+	sanitizer_mac.lo sanitizer_mac_libcdep.lo \
+	sanitizer_persistent_allocator.lo \
 	sanitizer_platform_limits_linux.lo \
 	sanitizer_platform_limits_posix.lo sanitizer_posix.lo \
 	sanitizer_posix_libcdep.lo sanitizer_printf.lo \
@@ -98,8 +99,8 @@ am__objects_1 = sanitizer_allocator.lo sanitizer_common.lo \
 	sanitizer_stacktrace_libcdep.lo sanitizer_symbolizer_mac.lo \
 	sanitizer_stacktrace_printer.lo \
 	sanitizer_stoptheworld_linux_libcdep.lo \
-	sanitizer_suppressions.lo sanitizer_symbolizer.lo \
-	sanitizer_symbolizer_libbacktrace.lo \
+	sanitizer_stoptheworld_mac.lo sanitizer_suppressions.lo \
+	sanitizer_symbolizer.lo sanitizer_symbolizer_libbacktrace.lo \
 	sanitizer_symbolizer_libcdep.lo \
 	sanitizer_symbolizer_posix_libcdep.lo \
 	sanitizer_symbolizer_win.lo sanitizer_termination.lo \
@@ -300,13 +301,16 @@ AM_CXXFLAGS = -Wall -W -Wno-unused-parameter -Wwrite-strings -pedantic \
 ACLOCAL_AMFLAGS = -I m4
 noinst_LTLIBRARIES = libsanitizer_common.la
 sanitizer_common_files = \
+	sancov_flags.cc \
 	sanitizer_allocator.cc \
+	sanitizer_allocator_checks.cc \
 	sanitizer_common.cc \
 	sanitizer_common_libcdep.cc \
-	sanitizer_coverage_libcdep.cc \
-	sanitizer_coverage_mapping_libcdep.cc \
+	sanitizer_coverage_libcdep_new.cc \
 	sanitizer_deadlock_detector1.cc \
 	sanitizer_deadlock_detector2.cc \
+	sanitizer_errno.cc \
+	sanitizer_file.cc \
 	sanitizer_flags.cc \
 	sanitizer_flag_parser.cc \
 	sanitizer_libc.cc \
@@ -315,6 +319,7 @@ sanitizer_common_files = \
 	sanitizer_linux_libcdep.cc \
 	sanitizer_linux_s390.cc \
 	sanitizer_mac.cc \
+	sanitizer_mac_libcdep.cc \
 	sanitizer_persistent_allocator.cc \
 	sanitizer_platform_limits_linux.cc \
 	sanitizer_platform_limits_posix.cc \
@@ -331,6 +336,7 @@ sanitizer_common_files = \
 	sanitizer_symbolizer_mac.cc \
 	sanitizer_stacktrace_printer.cc \
 	sanitizer_stoptheworld_linux_libcdep.cc \
+	sanitizer_stoptheworld_mac.cc \
 	sanitizer_suppressions.cc \
 	sanitizer_symbolizer.cc \
 	sanitizer_symbolizer_libbacktrace.cc \
@@ -439,13 +445,16 @@ mostlyclean-compile:
 distclean-compile:
 	-rm -f *.tab.c
 
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sancov_flags.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_allocator.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_allocator_checks.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_common.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_common_libcdep.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_coverage_libcdep.Plo@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_coverage_mapping_libcdep.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_coverage_libcdep_new.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_deadlock_detector1.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_deadlock_detector2.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_errno.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_file.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_flag_parser.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_flags.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_libc.Plo@am__quote@
@@ -456,6 +465,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_linux_s390.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_linux_x86_64.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_mac.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_mac_libcdep.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_persistent_allocator.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_platform_limits_linux.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_platform_limits_posix.Plo@am__quote@
@@ -471,6 +481,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_stacktrace_libcdep.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_stacktrace_printer.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_stoptheworld_linux_libcdep.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_stoptheworld_mac.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_suppressions.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_symbolizer.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sanitizer_symbolizer_libbacktrace.Plo@am__quote@
diff --git a/libsanitizer/sanitizer_common/sancov_flags.cc b/libsanitizer/sanitizer_common/sancov_flags.cc
new file mode 100644
index 00000000000..e600cdac33c
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sancov_flags.cc
@@ -0,0 +1,57 @@
+//===-- sancov_flags.cc -----------------------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Sanitizer Coverage runtime flags.
+//
+//===----------------------------------------------------------------------===//
+
+#include "sancov_flags.h"
+#include "sanitizer_flag_parser.h"
+#include "sanitizer_platform.h"
+
+SANITIZER_INTERFACE_WEAK_DEF(const char*, __sancov_default_options, void) {
+  return "";
+}
+
+using namespace __sanitizer;
+
+namespace __sancov {
+
+SancovFlags sancov_flags_dont_use_directly;  // use via flags();
+
+void SancovFlags::SetDefaults() {
+#define SANCOV_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
+#include "sancov_flags.inc"
+#undef SANCOV_FLAG
+}
+
+static void RegisterSancovFlags(FlagParser *parser, SancovFlags *f) {
+#define SANCOV_FLAG(Type, Name, DefaultValue, Description) \
+  RegisterFlag(parser, #Name, Description, &f->Name);
+#include "sancov_flags.inc"
+#undef SANCOV_FLAG
+}
+
+static const char *MaybeCallSancovDefaultOptions() {
+  return (&__sancov_default_options) ? __sancov_default_options() : "";
+}
+
+void InitializeSancovFlags() {
+  SancovFlags *f = sancov_flags();
+  f->SetDefaults();
+
+  FlagParser parser;
+  RegisterSancovFlags(&parser, f);
+
+  parser.ParseString(MaybeCallSancovDefaultOptions());
+  parser.ParseString(GetEnv("SANCOV_OPTIONS"));
+
+  ReportUnrecognizedFlags();
+  if (f->help) parser.PrintFlagDescriptions();
+}
+
+}  // namespace __sancov
diff --git a/libsanitizer/sanitizer_common/sancov_flags.h b/libsanitizer/sanitizer_common/sancov_flags.h
new file mode 100644
index 00000000000..f7e0186c511
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sancov_flags.h
@@ -0,0 +1,38 @@
+//===-- sancov_flags.h ------------------------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Sanitizer Coverage runtime flags.
+//
+//===----------------------------------------------------------------------===//
+#ifndef SANCOV_FLAGS_H
+#define SANCOV_FLAGS_H
+
+#include "sanitizer_flag_parser.h"
+#include "sanitizer_internal_defs.h"
+
+namespace __sancov {
+
+struct SancovFlags {
+#define SANCOV_FLAG(Type, Name, DefaultValue, Description) Type Name;
+#include "sancov_flags.inc"
+#undef SANCOV_FLAG
+
+  void SetDefaults();
+};
+
+extern SancovFlags sancov_flags_dont_use_directly;
+
+inline SancovFlags* sancov_flags() { return &sancov_flags_dont_use_directly; }
+
+void InitializeSancovFlags();
+
+}  // namespace __sancov
+
+extern "C" SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE const char*
+__sancov_default_options();
+
+#endif
diff --git a/libsanitizer/sanitizer_common/sancov_flags.inc b/libsanitizer/sanitizer_common/sancov_flags.inc
new file mode 100644
index 00000000000..a6107cc8583
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sancov_flags.inc
@@ -0,0 +1,19 @@
+//===-- sancov_flags.inc ----------------------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Sanitizer Coverage runtime flags.
+//
+//===----------------------------------------------------------------------===//
+#ifndef SANCOV_FLAG
+#error "Defnine SANCOV_FLAG prior to including this file!"
+#endif
+
+SANCOV_FLAG(bool, symbolize, true,
+            "If set, converage information will be symbolized by sancov tool "
+            "after dumping.")
+
+SANCOV_FLAG(bool, help, false, "Print flags help.")
diff --git a/libsanitizer/sanitizer_common/sanitizer_addrhashmap.h b/libsanitizer/sanitizer_common/sanitizer_addrhashmap.h
index 3bc40ef64f0..a67ec84373e 100644
--- a/libsanitizer/sanitizer_common/sanitizer_addrhashmap.h
+++ b/libsanitizer/sanitizer_common/sanitizer_addrhashmap.h
@@ -71,6 +71,8 @@ class AddrHashMap {
 
     ~Handle();
     T *operator->();
+    T &operator*();
+    const T &operator*() const;
     bool created() const;
     bool exists() const;
 
@@ -134,6 +136,16 @@ T *AddrHashMap<T, kSize>::Handle::operator->() {
   return &cell_->val;
 }
 
+template <typename T, uptr kSize>
+const T &AddrHashMap<T, kSize>::Handle::operator*() const {
+  return cell_->val;
+}
+
+template <typename T, uptr kSize>
+T &AddrHashMap<T, kSize>::Handle::operator*() {
+  return cell_->val;
+}
+
 template<typename T, uptr kSize>
 bool AddrHashMap<T, kSize>::Handle::created() const {
   return created_;
diff --git a/libsanitizer/sanitizer_common/sanitizer_allocator.cc b/libsanitizer/sanitizer_common/sanitizer_allocator.cc
index 2755853acbc..895efcf1be0 100644
--- a/libsanitizer/sanitizer_common/sanitizer_allocator.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_allocator.cc
@@ -12,6 +12,7 @@
 
 #include "sanitizer_allocator.h"
 
+#include "sanitizer_allocator_checks.h"
 #include "sanitizer_allocator_internal.h"
 #include "sanitizer_atomic.h"
 #include "sanitizer_common.h"
@@ -92,7 +93,7 @@ InternalAllocator *internal_allocator() {
     SpinMutexLock l(&internal_alloc_init_mu);
     if (atomic_load(&internal_allocator_initialized, memory_order_relaxed) ==
         0) {
-      internal_allocator_instance->Init(/* may_return_null*/ false);
+      internal_allocator_instance->Init(kReleaseToOSIntervalNever);
       atomic_store(&internal_allocator_initialized, 1, memory_order_release);
     }
   }
@@ -105,9 +106,9 @@ static void *RawInternalAlloc(uptr size, InternalAllocatorCache *cache,
   if (cache == 0) {
     SpinMutexLock l(&internal_allocator_cache_mu);
     return internal_allocator()->Allocate(&internal_allocator_cache, size,
-                                          alignment, false);
+                                          alignment);
   }
-  return internal_allocator()->Allocate(cache, size, alignment, false);
+  return internal_allocator()->Allocate(cache, size, alignment);
 }
 
 static void *RawInternalRealloc(void *ptr, uptr size,
@@ -158,8 +159,8 @@ void *InternalRealloc(void *addr, uptr size, InternalAllocatorCache *cache) {
 }
 
 void *InternalCalloc(uptr count, uptr size, InternalAllocatorCache *cache) {
-  if (CallocShouldReturnNullDueToOverflow(count, size))
-    return internal_allocator()->ReturnNullOrDieOnBadRequest();
+  if (UNLIKELY(CheckForCallocOverflow(count, size)))
+    return InternalAllocator::FailureHandler::OnBadRequest();
   void *p = InternalAlloc(count * size, cache);
   if (p) internal_memset(p, 0, count * size);
   return p;
@@ -200,18 +201,15 @@ void SetLowLevelAllocateCallback(LowLevelAllocateCallback callback) {
   low_level_alloc_callback = callback;
 }
 
-bool CallocShouldReturnNullDueToOverflow(uptr size, uptr n) {
-  if (!size) return false;
-  uptr max = (uptr)-1L;
-  return (max / size) < n;
-}
-
-static atomic_uint8_t reporting_out_of_memory = {0};
+static atomic_uint8_t allocator_out_of_memory = {0};
+static atomic_uint8_t allocator_may_return_null = {0};
 
-bool IsReportingOOM() { return atomic_load_relaxed(&reporting_out_of_memory); }
+bool IsAllocatorOutOfMemory() {
+  return atomic_load_relaxed(&allocator_out_of_memory);
+}
 
-void NORETURN ReportAllocatorCannotReturnNull(bool out_of_memory) {
-  if (out_of_memory) atomic_store_relaxed(&reporting_out_of_memory, 1);
+// Prints error message and kills the program.
+void NORETURN ReportAllocatorCannotReturnNull() {
   Report("%s's allocator is terminating the process instead of returning 0\n",
          SanitizerToolName);
   Report("If you don't like this behavior set allocator_may_return_null=1\n");
@@ -219,4 +217,35 @@ void NORETURN ReportAllocatorCannotReturnNull(bool out_of_memory) {
   Die();
 }
 
+bool AllocatorMayReturnNull() {
+  return atomic_load(&allocator_may_return_null, memory_order_relaxed);
+}
+
+void SetAllocatorMayReturnNull(bool may_return_null) {
+  atomic_store(&allocator_may_return_null, may_return_null,
+               memory_order_relaxed);
+}
+
+void *ReturnNullOrDieOnFailure::OnBadRequest() {
+  if (AllocatorMayReturnNull())
+    return nullptr;
+  ReportAllocatorCannotReturnNull();
+}
+
+void *ReturnNullOrDieOnFailure::OnOOM() {
+  atomic_store_relaxed(&allocator_out_of_memory, 1);
+  if (AllocatorMayReturnNull())
+    return nullptr;
+  ReportAllocatorCannotReturnNull();
+}
+
+void NORETURN *DieOnFailure::OnBadRequest() {
+  ReportAllocatorCannotReturnNull();
+}
+
+void NORETURN *DieOnFailure::OnOOM() {
+  atomic_store_relaxed(&allocator_out_of_memory, 1);
+  ReportAllocatorCannotReturnNull();
+}
+
 } // namespace __sanitizer
diff --git a/libsanitizer/sanitizer_common/sanitizer_allocator.h b/libsanitizer/sanitizer_common/sanitizer_allocator.h
index ba50acddbbf..523578a9d60 100644
--- a/libsanitizer/sanitizer_common/sanitizer_allocator.h
+++ b/libsanitizer/sanitizer_common/sanitizer_allocator.h
@@ -22,12 +22,28 @@
 
 namespace __sanitizer {
 
-// Returns true if ReportAllocatorCannotReturnNull(true) was called.
-// Can be use to avoid memory hungry operations.
-bool IsReportingOOM();
+// Since flags are immutable and allocator behavior can be changed at runtime
+// (unit tests or ASan on Android are some examples), allocator_may_return_null
+// flag value is cached here and can be altered later.
+bool AllocatorMayReturnNull();
+void SetAllocatorMayReturnNull(bool may_return_null);
 
-// Prints error message and kills the program.
-void NORETURN ReportAllocatorCannotReturnNull(bool out_of_memory);
+// Allocator failure handling policies:
+// Implements AllocatorMayReturnNull policy, returns null when the flag is set,
+// dies otherwise.
+struct ReturnNullOrDieOnFailure {
+  static void *OnBadRequest();
+  static void *OnOOM();
+};
+// Always dies on the failure.
+struct DieOnFailure {
+  static void NORETURN *OnBadRequest();
+  static void NORETURN *OnOOM();
+};
+
+// Returns true if allocator detected OOM condition. Can be used to avoid memory
+// hungry operations. Set when AllocatorReturnNullOrDieOnOOM() is called.
+bool IsAllocatorOutOfMemory();
 
 // Allocators call these callbacks on mmap/munmap.
 struct NoOpMapUnmapCallback {
@@ -38,9 +54,6 @@ struct NoOpMapUnmapCallback {
 // Callback type for iterating over chunks.
 typedef void (*ForEachChunkCallback)(uptr chunk, void *arg);
 
-// Returns true if calloc(size, n) should return 0 due to overflow in size*n.
-bool CallocShouldReturnNullDueToOverflow(uptr size, uptr n);
-
 #include "sanitizer_allocator_size_class_map.h"
 #include "sanitizer_allocator_stats.h"
 #include "sanitizer_allocator_primary64.h"
diff --git a/libsanitizer/sanitizer_common/sanitizer_allocator_checks.cc b/libsanitizer/sanitizer_common/sanitizer_allocator_checks.cc
new file mode 100644
index 00000000000..3e6eb61a7d5
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_allocator_checks.cc
@@ -0,0 +1,21 @@
+//===-- sanitizer_allocator_checks.cc ---------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Various checks shared between ThreadSanitizer, MemorySanitizer, etc. memory
+// allocators.
+//
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_errno.h"
+
+namespace __sanitizer {
+
+void SetErrnoToENOMEM() {
+  errno = errno_ENOMEM;
+}
+
+} // namespace __sanitizer
diff --git a/libsanitizer/sanitizer_common/sanitizer_allocator_checks.h b/libsanitizer/sanitizer_common/sanitizer_allocator_checks.h
new file mode 100644
index 00000000000..978813222b5
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_allocator_checks.h
@@ -0,0 +1,73 @@
+//===-- sanitizer_allocator_checks.h ----------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Various checks shared between ThreadSanitizer, MemorySanitizer, etc. memory
+// allocators.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SANITIZER_ALLOCATOR_CHECKS_H
+#define SANITIZER_ALLOCATOR_CHECKS_H
+
+#include "sanitizer_internal_defs.h"
+#include "sanitizer_common.h"
+#include "sanitizer_platform.h"
+
+namespace __sanitizer {
+
+// The following is defined in a separate compilation unit to avoid pulling in
+// sanitizer_errno.h in this header, which leads to conflicts when other system
+// headers include errno.h. This is usually the result of an unlikely event,
+// and as such we do not care as much about having it inlined.
+void SetErrnoToENOMEM();
+
+// A common errno setting logic shared by almost all sanitizer allocator APIs.
+INLINE void *SetErrnoOnNull(void *ptr) {
+  if (UNLIKELY(!ptr))
+    SetErrnoToENOMEM();
+  return ptr;
+}
+
+// In case of the check failure, the caller of the following Check... functions
+// should "return POLICY::OnBadRequest();" where POLICY is the current allocator
+// failure handling policy.
+
+// Checks aligned_alloc() parameters, verifies that the alignment is a power of
+// two and that the size is a multiple of alignment for POSIX implementation,
+// and a bit relaxed requirement for non-POSIX ones, that the size is a multiple
+// of alignment.
+INLINE bool CheckAlignedAllocAlignmentAndSize(uptr alignment, uptr size) {
+#if SANITIZER_POSIX
+  return IsPowerOfTwo(alignment) && (size & (alignment - 1)) == 0;
+#else
+  return size % alignment == 0;
+#endif
+}
+
+// Checks posix_memalign() parameters, verifies that alignment is a power of two
+// and a multiple of sizeof(void *).
+INLINE bool CheckPosixMemalignAlignment(uptr alignment) {
+  return IsPowerOfTwo(alignment) && (alignment % sizeof(void *)) == 0; // NOLINT
+}
+
+// Returns true if calloc(size, n) call overflows on size*n calculation.
+INLINE bool CheckForCallocOverflow(uptr size, uptr n) {
+  if (!size)
+    return false;
+  uptr max = (uptr)-1L;
+  return (max / size) < n;
+}
+
+// Returns true if the size passed to pvalloc overflows when rounded to the next
+// multiple of page_size.
+INLINE bool CheckForPvallocOverflow(uptr size, uptr page_size) {
+  return RoundUpTo(size, page_size) < size;
+}
+
+} // namespace __sanitizer
+
+#endif  // SANITIZER_ALLOCATOR_CHECKS_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_allocator_combined.h b/libsanitizer/sanitizer_common/sanitizer_allocator_combined.h
index 4dc9ca7401f..99e411f4378 100644
--- a/libsanitizer/sanitizer_common/sanitizer_allocator_combined.h
+++ b/libsanitizer/sanitizer_common/sanitizer_allocator_combined.h
@@ -22,72 +22,57 @@ template <class PrimaryAllocator, class AllocatorCache,
           class SecondaryAllocator>  // NOLINT
 class CombinedAllocator {
  public:
-  void InitCommon(bool may_return_null) {
-    primary_.Init();
-    atomic_store(&may_return_null_, may_return_null, memory_order_relaxed);
-  }
+  typedef typename SecondaryAllocator::FailureHandler FailureHandler;
 
-  void InitLinkerInitialized(bool may_return_null) {
-    secondary_.InitLinkerInitialized(may_return_null);
+  void InitLinkerInitialized(s32 release_to_os_interval_ms) {
+    primary_.Init(release_to_os_interval_ms);
+    secondary_.InitLinkerInitialized();
     stats_.InitLinkerInitialized();
-    InitCommon(may_return_null);
   }
 
-  void Init(bool may_return_null) {
-    secondary_.Init(may_return_null);
+  void Init(s32 release_to_os_interval_ms) {
+    primary_.Init(release_to_os_interval_ms);
+    secondary_.Init();
     stats_.Init();
-    InitCommon(may_return_null);
   }
 
-  void *Allocate(AllocatorCache *cache, uptr size, uptr alignment,
-                 bool cleared = false, bool check_rss_limit = false) {
+  void *Allocate(AllocatorCache *cache, uptr size, uptr alignment) {
     // Returning 0 on malloc(0) may break a lot of code.
     if (size == 0)
       size = 1;
-    if (size + alignment < size) return ReturnNullOrDieOnBadRequest();
-    if (check_rss_limit && RssLimitIsExceeded()) return ReturnNullOrDieOnOOM();
+    if (size + alignment < size)
+      return FailureHandler::OnBadRequest();
+    uptr original_size = size;
+    // If alignment requirements are to be fulfilled by the frontend allocator
+    // rather than by the primary or secondary, passing an alignment lower than
+    // or equal to 8 will prevent any further rounding up, as well as the later
+    // alignment check.
     if (alignment > 8)
       size = RoundUpTo(size, alignment);
+    // The primary allocator should return a 2^x aligned allocation when
+    // requested 2^x bytes, hence using the rounded up 'size' when being
+    // serviced by the primary (this is no longer true when the primary is
+    // using a non-fixed base address). The secondary takes care of the
+    // alignment without such requirement, and allocating 'size' would use
+    // extraneous memory, so we employ 'original_size'.
     void *res;
-    bool from_primary = primary_.CanAllocate(size, alignment);
-    if (from_primary)
+    if (primary_.CanAllocate(size, alignment))
       res = cache->Allocate(&primary_, primary_.ClassID(size));
     else
-      res = secondary_.Allocate(&stats_, size, alignment);
+      res = secondary_.Allocate(&stats_, original_size, alignment);
+    if (!res)
+      return FailureHandler::OnOOM();
     if (alignment > 8)
       CHECK_EQ(reinterpret_cast<uptr>(res) & (alignment - 1), 0);
-    if (cleared && res && from_primary)
-      internal_bzero_aligned16(res, RoundUpTo(size, 16));
     return res;
   }
 
-  bool MayReturnNull() const {
-    return atomic_load(&may_return_null_, memory_order_acquire);
-  }
-
-  void *ReturnNullOrDieOnBadRequest() {
-    if (MayReturnNull())
-      return nullptr;
-    ReportAllocatorCannotReturnNull(false);
-  }
-
-  void *ReturnNullOrDieOnOOM() {
-    if (MayReturnNull()) return nullptr;
-    ReportAllocatorCannotReturnNull(true);
+  s32 ReleaseToOSIntervalMs() const {
+    return primary_.ReleaseToOSIntervalMs();
   }
 
-  void SetMayReturnNull(bool may_return_null) {
-    secondary_.SetMayReturnNull(may_return_null);
-    atomic_store(&may_return_null_, may_return_null, memory_order_release);
-  }
-
-  bool RssLimitIsExceeded() {
-    return atomic_load(&rss_limit_is_exceeded_, memory_order_acquire);
-  }
-
-  void SetRssLimitIsExceeded(bool rss_limit_is_exceeded) {
-    atomic_store(&rss_limit_is_exceeded_, rss_limit_is_exceeded,
-                 memory_order_release);
+  void SetReleaseToOSIntervalMs(s32 release_to_os_interval_ms) {
+    primary_.SetReleaseToOSIntervalMs(release_to_os_interval_ms);
   }
 
   void Deallocate(AllocatorCache *cache, void *p) {
@@ -191,8 +176,6 @@ class CombinedAllocator {
     primary_.ForceUnlock();
   }
 
-  void ReleaseToOS() { primary_.ReleaseToOS(); }
-
   // Iterate over all existing chunks.
   // The allocator must be locked when calling this function.
   void ForEachChunk(ForEachChunkCallback callback, void *arg) {
@@ -204,6 +187,4 @@ class CombinedAllocator {
   PrimaryAllocator primary_;
   SecondaryAllocator secondary_;
   AllocatorGlobalStats stats_;
-  atomic_uint8_t may_return_null_;
-  atomic_uint8_t rss_limit_is_exceeded_;
 };
diff --git a/libsanitizer/sanitizer_common/sanitizer_allocator_interface.h b/libsanitizer/sanitizer_common/sanitizer_allocator_interface.h
index 166f8c22049..fa74f8ca640 100644
--- a/libsanitizer/sanitizer_common/sanitizer_allocator_interface.h
+++ b/libsanitizer/sanitizer_common/sanitizer_allocator_interface.h
@@ -32,13 +32,12 @@ SANITIZER_INTERFACE_ATTRIBUTE int __sanitizer_install_malloc_and_free_hooks(
     void (*free_hook)(const void *));
 
 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-    /* OPTIONAL */ void __sanitizer_malloc_hook(void *ptr, uptr size);
+    void __sanitizer_malloc_hook(void *ptr, uptr size);
 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-    /* OPTIONAL */ void __sanitizer_free_hook(void *ptr);
+    void __sanitizer_free_hook(void *ptr);
 
-
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-    void __sanitizer_print_memory_profile(int top_percent);
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE void
+__sanitizer_print_memory_profile(uptr top_percent, uptr max_number_of_contexts);
 }  // extern "C"
 
 #endif  // SANITIZER_ALLOCATOR_INTERFACE_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_allocator_internal.h b/libsanitizer/sanitizer_common/sanitizer_allocator_internal.h
index 6a8da8f3584..f1aed0f3bec 100644
--- a/libsanitizer/sanitizer_common/sanitizer_allocator_internal.h
+++ b/libsanitizer/sanitizer_common/sanitizer_allocator_internal.h
@@ -21,27 +21,32 @@ namespace __sanitizer {
 // purposes.
 typedef CompactSizeClassMap InternalSizeClassMap;
 
-static const uptr kInternalAllocatorSpace = 0;
-static const u64 kInternalAllocatorSize = SANITIZER_MMAP_RANGE_SIZE;
 static const uptr kInternalAllocatorRegionSizeLog = 20;
-#if SANITIZER_WORDSIZE == 32
 static const uptr kInternalAllocatorNumRegions =
-    kInternalAllocatorSize >> kInternalAllocatorRegionSizeLog;
+    SANITIZER_MMAP_RANGE_SIZE >> kInternalAllocatorRegionSizeLog;
+#if SANITIZER_WORDSIZE == 32
 typedef FlatByteMap<kInternalAllocatorNumRegions> ByteMap;
 #else
-static const uptr kInternalAllocatorNumRegions =
-    kInternalAllocatorSize >> kInternalAllocatorRegionSizeLog;
 typedef TwoLevelByteMap<(kInternalAllocatorNumRegions >> 12), 1 << 12> ByteMap;
 #endif
-typedef SizeClassAllocator32<
-    kInternalAllocatorSpace, kInternalAllocatorSize, 0, InternalSizeClassMap,
-    kInternalAllocatorRegionSizeLog, ByteMap> PrimaryInternalAllocator;
+struct AP32 {
+  static const uptr kSpaceBeg = 0;
+  static const u64 kSpaceSize = SANITIZER_MMAP_RANGE_SIZE;
+  static const uptr kMetadataSize = 0;
+  typedef InternalSizeClassMap SizeClassMap;
+  static const uptr kRegionSizeLog = kInternalAllocatorRegionSizeLog;
+  typedef __sanitizer::ByteMap ByteMap;
+  typedef NoOpMapUnmapCallback MapUnmapCallback;
+  static const uptr kFlags = 0;
+};
+typedef SizeClassAllocator32<AP32> PrimaryInternalAllocator;
 
 typedef SizeClassAllocatorLocalCache<PrimaryInternalAllocator>
     InternalAllocatorCache;
 
 typedef CombinedAllocator<PrimaryInternalAllocator, InternalAllocatorCache,
-                          LargeMmapAllocator<> > InternalAllocator;
+                          LargeMmapAllocator<NoOpMapUnmapCallback, DieOnFailure>
+                         > InternalAllocator;
 
 void *InternalAlloc(uptr size, InternalAllocatorCache *cache = nullptr,
                     uptr alignment = 0);
diff --git a/libsanitizer/sanitizer_common/sanitizer_allocator_local_cache.h b/libsanitizer/sanitizer_common/sanitizer_allocator_local_cache.h
index 40ef0781adb..99013e37f8a 100644
--- a/libsanitizer/sanitizer_common/sanitizer_allocator_local_cache.h
+++ b/libsanitizer/sanitizer_common/sanitizer_allocator_local_cache.h
@@ -24,9 +24,6 @@ struct SizeClassAllocatorLocalCache
 template <class SizeClassAllocator>
 struct SizeClassAllocator64LocalCache {
   typedef SizeClassAllocator Allocator;
-  static const uptr kNumClasses = SizeClassAllocator::kNumClasses;
-  typedef typename Allocator::SizeClassMapT SizeClassMap;
-  typedef typename Allocator::CompactPtrT CompactPtrT;
 
   void Init(AllocatorGlobalStats *s) {
     stats_.Init();
@@ -43,10 +40,12 @@ struct SizeClassAllocator64LocalCache {
   void *Allocate(SizeClassAllocator *allocator, uptr class_id) {
     CHECK_NE(class_id, 0UL);
     CHECK_LT(class_id, kNumClasses);
-    stats_.Add(AllocatorStatAllocated, Allocator::ClassIdToSize(class_id));
     PerClass *c = &per_class_[class_id];
-    if (UNLIKELY(c->count == 0))
-      Refill(c, allocator, class_id);
+    if (UNLIKELY(c->count == 0)) {
+      if (UNLIKELY(!Refill(c, allocator, class_id)))
+        return nullptr;
+    }
+    stats_.Add(AllocatorStatAllocated, c->class_size);
     CHECK_GT(c->count, 0);
     CompactPtrT chunk = c->chunks[--c->count];
     void *res = reinterpret_cast<void *>(allocator->CompactPtrToPointer(
@@ -60,8 +59,8 @@ struct SizeClassAllocator64LocalCache {
     // If the first allocator call on a new thread is a deallocation, then
     // max_count will be zero, leading to check failure.
     InitCache();
-    stats_.Sub(AllocatorStatAllocated, Allocator::ClassIdToSize(class_id));
     PerClass *c = &per_class_[class_id];
+    stats_.Sub(AllocatorStatAllocated, c->class_size);
     CHECK_NE(c->max_count, 0UL);
     if (UNLIKELY(c->count == c->max_count))
       Drain(c, allocator, class_id, c->max_count / 2);
@@ -72,38 +71,46 @@ struct SizeClassAllocator64LocalCache {
   }
 
   void Drain(SizeClassAllocator *allocator) {
-    for (uptr class_id = 0; class_id < kNumClasses; class_id++) {
-      PerClass *c = &per_class_[class_id];
+    for (uptr i = 0; i < kNumClasses; i++) {
+      PerClass *c = &per_class_[i];
       while (c->count > 0)
-        Drain(c, allocator, class_id, c->count);
+        Drain(c, allocator, i, c->count);
     }
   }
 
-  // private:
+ private:
+  typedef typename Allocator::SizeClassMapT SizeClassMap;
+  static const uptr kNumClasses = SizeClassMap::kNumClasses;
+  typedef typename Allocator::CompactPtrT CompactPtrT;
+
   struct PerClass {
     u32 count;
     u32 max_count;
+    uptr class_size;
     CompactPtrT chunks[2 * SizeClassMap::kMaxNumCachedHint];
   };
   PerClass per_class_[kNumClasses];
   AllocatorStats stats_;
 
   void InitCache() {
-    if (per_class_[1].max_count)
+    if (LIKELY(per_class_[1].max_count))
       return;
     for (uptr i = 0; i < kNumClasses; i++) {
       PerClass *c = &per_class_[i];
       c->max_count = 2 * SizeClassMap::MaxCachedHint(i);
+      c->class_size = Allocator::ClassIdToSize(i);
     }
   }
 
-  NOINLINE void Refill(PerClass *c, SizeClassAllocator *allocator,
+  NOINLINE bool Refill(PerClass *c, SizeClassAllocator *allocator,
                        uptr class_id) {
     InitCache();
-    uptr num_requested_chunks = SizeClassMap::MaxCachedHint(class_id);
-    allocator->GetFromAllocator(&stats_, class_id, c->chunks,
-                                num_requested_chunks);
+    uptr num_requested_chunks = c->max_count / 2;
+    if (UNLIKELY(!allocator->GetFromAllocator(&stats_, class_id, c->chunks,
+                                              num_requested_chunks)))
+      return false;
     c->count = num_requested_chunks;
+    return true;
   }
 
   NOINLINE void Drain(PerClass *c, SizeClassAllocator *allocator, uptr class_id,
@@ -122,7 +129,6 @@ template <class SizeClassAllocator>
 struct SizeClassAllocator32LocalCache {
   typedef SizeClassAllocator Allocator;
   typedef typename Allocator::TransferBatch TransferBatch;
-  static const uptr kNumClasses = SizeClassAllocator::kNumClasses;
 
   void Init(AllocatorGlobalStats *s) {
     stats_.Init();
@@ -130,6 +136,21 @@ struct SizeClassAllocator32LocalCache {
       s->Register(&stats_);
   }
 
+  // Returns a TransferBatch suitable for class_id.
+  TransferBatch *CreateBatch(uptr class_id, SizeClassAllocator *allocator,
+                             TransferBatch *b) {
+    if (uptr batch_class_id = per_class_[class_id].batch_class_id)
+      return (TransferBatch*)Allocate(allocator, batch_class_id);
+    return b;
+  }
+
+  // Destroys TransferBatch b.
+  void DestroyBatch(uptr class_id, SizeClassAllocator *allocator,
+                    TransferBatch *b) {
+    if (uptr batch_class_id = per_class_[class_id].batch_class_id)
+      Deallocate(allocator, batch_class_id, b);
+  }
+
   void Destroy(SizeClassAllocator *allocator, AllocatorGlobalStats *s) {
     Drain(allocator);
     if (s)
@@ -139,10 +160,12 @@ struct SizeClassAllocator32LocalCache {
   void *Allocate(SizeClassAllocator *allocator, uptr class_id) {
     CHECK_NE(class_id, 0UL);
     CHECK_LT(class_id, kNumClasses);
-    stats_.Add(AllocatorStatAllocated, Allocator::ClassIdToSize(class_id));
     PerClass *c = &per_class_[class_id];
-    if (UNLIKELY(c->count == 0))
-      Refill(allocator, class_id);
+    if (UNLIKELY(c->count == 0)) {
+      if (UNLIKELY(!Refill(allocator, class_id)))
+        return nullptr;
+    }
+    stats_.Add(AllocatorStatAllocated, c->class_size);
     void *res = c->batch[--c->count];
     PREFETCH(c->batch[c->count - 1]);
     return res;
@@ -154,8 +177,8 @@ struct SizeClassAllocator32LocalCache {
     // If the first allocator call on a new thread is a deallocation, then
     // max_count will be zero, leading to check failure.
     InitCache();
-    stats_.Sub(AllocatorStatAllocated, Allocator::ClassIdToSize(class_id));
     PerClass *c = &per_class_[class_id];
+    stats_.Sub(AllocatorStatAllocated, c->class_size);
     CHECK_NE(c->max_count, 0UL);
     if (UNLIKELY(c->count == c->max_count))
       Drain(allocator, class_id);
@@ -163,72 +186,68 @@ struct SizeClassAllocator32LocalCache {
   }
 
   void Drain(SizeClassAllocator *allocator) {
-    for (uptr class_id = 0; class_id < kNumClasses; class_id++) {
-      PerClass *c = &per_class_[class_id];
+    for (uptr i = 0; i < kNumClasses; i++) {
+      PerClass *c = &per_class_[i];
       while (c->count > 0)
-        Drain(allocator, class_id);
+        Drain(allocator, i);
     }
   }
 
-  // private:
-  typedef typename SizeClassAllocator::SizeClassMapT SizeClassMap;
+ private:
+  typedef typename Allocator::SizeClassMapT SizeClassMap;
+  static const uptr kBatchClassID = SizeClassMap::kBatchClassID;
+  static const uptr kNumClasses = SizeClassMap::kNumClasses;
+  // If kUseSeparateSizeClassForBatch is true, all TransferBatch objects are
+  // allocated from kBatchClassID size class (except for those that are needed
+  // for kBatchClassID itself). The goal is to have TransferBatches in a totally
+  // different region of RAM to improve security.
+  static const bool kUseSeparateSizeClassForBatch =
+      Allocator::kUseSeparateSizeClassForBatch;
+
   struct PerClass {
     uptr count;
     uptr max_count;
+    uptr class_size;
+    uptr batch_class_id;
     void *batch[2 * TransferBatch::kMaxNumCached];
   };
   PerClass per_class_[kNumClasses];
   AllocatorStats stats_;
 
   void InitCache() {
-    if (per_class_[1].max_count)
+    if (LIKELY(per_class_[1].max_count))
       return;
+    const uptr batch_class_id = SizeClassMap::ClassID(sizeof(TransferBatch));
     for (uptr i = 0; i < kNumClasses; i++) {
       PerClass *c = &per_class_[i];
-      c->max_count = 2 * TransferBatch::MaxCached(i);
+      uptr max_cached = TransferBatch::MaxCached(i);
+      c->max_count = 2 * max_cached;
+      c->class_size = Allocator::ClassIdToSize(i);
+      // Precompute the class id to use to store batches for the current class
+      // id. 0 means the class size is large enough to store a batch within one
+      // of the chunks. If using a separate size class, it will always be
+      // kBatchClassID, except for kBatchClassID itself.
+      if (kUseSeparateSizeClassForBatch) {
+        c->batch_class_id = (i == kBatchClassID) ? 0 : kBatchClassID;
+      } else {
+        c->batch_class_id = (c->class_size <
+          TransferBatch::AllocationSizeRequiredForNElements(max_cached)) ?
+              batch_class_id : 0;
+      }
     }
   }
 
-  // TransferBatch class is declared in SizeClassAllocator.
-  // We transfer chunks between central and thread-local free lists in batches.
-  // For small size classes we allocate batches separately.
-  // For large size classes we may use one of the chunks to store the batch.
-  // sizeof(TransferBatch) must be a power of 2 for more efficient allocation.
-  static uptr SizeClassForTransferBatch(uptr class_id) {
-    if (Allocator::ClassIdToSize(class_id) <
-        TransferBatch::AllocationSizeRequiredForNElements(
-            TransferBatch::MaxCached(class_id)))
-      return SizeClassMap::ClassID(sizeof(TransferBatch));
-    return 0;
-  }
-
-  // Returns a TransferBatch suitable for class_id.
-  // For small size classes allocates the batch from the allocator.
-  // For large size classes simply returns b.
-  TransferBatch *CreateBatch(uptr class_id, SizeClassAllocator *allocator,
-                             TransferBatch *b) {
-    if (uptr batch_class_id = SizeClassForTransferBatch(class_id))
-      return (TransferBatch*)Allocate(allocator, batch_class_id);
-    return b;
-  }
-
-  // Destroys TransferBatch b.
-  // For small size classes deallocates b to the allocator.
-  // Does notthing for large size classes.
-  void DestroyBatch(uptr class_id, SizeClassAllocator *allocator,
-                    TransferBatch *b) {
-    if (uptr batch_class_id = SizeClassForTransferBatch(class_id))
-      Deallocate(allocator, batch_class_id, b);
-  }
-
-  NOINLINE void Refill(SizeClassAllocator *allocator, uptr class_id) {
+  NOINLINE bool Refill(SizeClassAllocator *allocator, uptr class_id) {
     InitCache();
     PerClass *c = &per_class_[class_id];
     TransferBatch *b = allocator->AllocateBatch(&stats_, this, class_id);
+    if (UNLIKELY(!b))
+      return false;
     CHECK_GT(b->Count(), 0);
     b->CopyToArray(c->batch);
     c->count = b->Count();
     DestroyBatch(class_id, allocator, b);
+    return true;
   }
 
   NOINLINE void Drain(SizeClassAllocator *allocator, uptr class_id) {
@@ -238,6 +257,10 @@ struct SizeClassAllocator32LocalCache {
     uptr first_idx_to_drain = c->count - cnt;
     TransferBatch *b = CreateBatch(
         class_id, allocator, (TransferBatch *)c->batch[first_idx_to_drain]);
+    // Failure to allocate a batch while releasing memory is non recoverable.
+    // TODO(alekseys): Figure out how to do it without allocating a new batch.
+    if (UNLIKELY(!b))
+      DieOnFailure::OnOOM();
     b->SetFromArray(allocator->GetRegionBeginBySizeClass(class_id),
                     &c->batch[first_idx_to_drain], cnt);
     c->count -= cnt;
diff --git a/libsanitizer/sanitizer_common/sanitizer_allocator_primary32.h b/libsanitizer/sanitizer_common/sanitizer_allocator_primary32.h
index 989b87a1923..90a57dbb6cf 100644
--- a/libsanitizer/sanitizer_common/sanitizer_allocator_primary32.h
+++ b/libsanitizer/sanitizer_common/sanitizer_allocator_primary32.h
@@ -22,7 +22,8 @@ template<class SizeClassAllocator> struct SizeClassAllocator32LocalCache;
 // be returned by MmapOrDie().
 //
 // Region:
-//   a result of a single call to MmapAlignedOrDie(kRegionSize, kRegionSize).
+//   a result of a single call to MmapAlignedOrDieOnFatalError(kRegionSize,
+//                                                             kRegionSize).
 // Since the regions are aligned by kRegionSize, there are exactly
 // kNumPossibleRegions possible regions in the address space and so we keep
 // a ByteMap possible_regions to store the size classes of each Region.
@@ -34,13 +35,30 @@ template<class SizeClassAllocator> struct SizeClassAllocator32LocalCache;
 //
 // In order to avoid false sharing the objects of this class should be
 // chache-line aligned.
-template <const uptr kSpaceBeg, const u64 kSpaceSize,
-          const uptr kMetadataSize, class SizeClassMap,
-          const uptr kRegionSizeLog,
-          class ByteMap,
-          class MapUnmapCallback = NoOpMapUnmapCallback>
+
+struct SizeClassAllocator32FlagMasks {  //  Bit masks.
+  enum {
+    kRandomShuffleChunks = 1,
+    kUseSeparateSizeClassForBatch = 2,
+  };
+};
+
+template <class Params>
 class SizeClassAllocator32 {
  public:
+  static const uptr kSpaceBeg = Params::kSpaceBeg;
+  static const u64 kSpaceSize = Params::kSpaceSize;
+  static const uptr kMetadataSize = Params::kMetadataSize;
+  typedef typename Params::SizeClassMap SizeClassMap;
+  static const uptr kRegionSizeLog = Params::kRegionSizeLog;
+  typedef typename Params::ByteMap ByteMap;
+  typedef typename Params::MapUnmapCallback MapUnmapCallback;
+
+  static const bool kRandomShuffleChunks = Params::kFlags &
+      SizeClassAllocator32FlagMasks::kRandomShuffleChunks;
+  static const bool kUseSeparateSizeClassForBatch = Params::kFlags &
+      SizeClassAllocator32FlagMasks::kUseSeparateSizeClassForBatch;
+
   struct TransferBatch {
     static const uptr kMaxNumCached = SizeClassMap::kMaxNumCachedHint - 2;
     void SetFromArray(uptr region_beg_unused, void *batch[], uptr count) {
@@ -77,24 +95,30 @@ class SizeClassAllocator32 {
 
   static const uptr kBatchSize = sizeof(TransferBatch);
   COMPILER_CHECK((kBatchSize & (kBatchSize - 1)) == 0);
-  COMPILER_CHECK(sizeof(TransferBatch) ==
-                 SizeClassMap::kMaxNumCachedHint * sizeof(uptr));
+  COMPILER_CHECK(kBatchSize == SizeClassMap::kMaxNumCachedHint * sizeof(uptr));
 
   static uptr ClassIdToSize(uptr class_id) {
-    return SizeClassMap::Size(class_id);
+    return (class_id == SizeClassMap::kBatchClassID) ?
+        kBatchSize : SizeClassMap::Size(class_id);
   }
 
-  typedef SizeClassAllocator32<kSpaceBeg, kSpaceSize, kMetadataSize,
-      SizeClassMap, kRegionSizeLog, ByteMap, MapUnmapCallback> ThisT;
+  typedef SizeClassAllocator32<Params> ThisT;
   typedef SizeClassAllocator32LocalCache<ThisT> AllocatorCache;
 
-  void Init() {
+  void Init(s32 release_to_os_interval_ms) {
     possible_regions.TestOnlyInit();
     internal_memset(size_class_info_array, 0, sizeof(size_class_info_array));
   }
 
+  s32 ReleaseToOSIntervalMs() const {
+    return kReleaseToOSIntervalNever;
+  }
+
+  void SetReleaseToOSIntervalMs(s32 release_to_os_interval_ms) {
+    // This is empty here. Currently only implemented in 64-bit allocator.
+  }
+
   void *MapWithCallback(uptr size) {
-    size = RoundUpTo(size, GetPageSizeCached());
     void *res = MmapOrDie(size, "SizeClassAllocator32");
     MapUnmapCallback().OnMap((uptr)res, size);
     return res;
@@ -126,8 +150,9 @@ class SizeClassAllocator32 {
     CHECK_LT(class_id, kNumClasses);
     SizeClassInfo *sci = GetSizeClassInfo(class_id);
     SpinMutexLock l(&sci->mutex);
-    if (sci->free_list.empty())
-      PopulateFreeList(stat, c, sci, class_id);
+    if (sci->free_list.empty() &&
+        UNLIKELY(!PopulateFreeList(stat, c, sci, class_id)))
+      return nullptr;
     CHECK(!sci->free_list.empty());
     TransferBatch *b = sci->free_list.front();
     sci->free_list.pop_front();
@@ -137,9 +162,9 @@ class SizeClassAllocator32 {
   NOINLINE void DeallocateBatch(AllocatorStats *stat, uptr class_id,
                                 TransferBatch *b) {
     CHECK_LT(class_id, kNumClasses);
+    CHECK_GT(b->Count(), 0);
     SizeClassInfo *sci = GetSizeClassInfo(class_id);
     SpinMutexLock l(&sci->mutex);
-    CHECK_GT(b->Count(), 0);
     sci->free_list.push_front(b);
   }
 
@@ -227,10 +252,6 @@ class SizeClassAllocator32 {
     return 0;
   }
 
-  // This is empty here. Currently only implemented in 64-bit allocator.
-  void ReleaseToOS() { }
-
-
   typedef SizeClassMap SizeClassMapT;
   static const uptr kNumClasses = SizeClassMap::kNumClasses;
 
@@ -258,11 +279,13 @@ class SizeClassAllocator32 {
 
   uptr AllocateRegion(AllocatorStats *stat, uptr class_id) {
     CHECK_LT(class_id, kNumClasses);
-    uptr res = reinterpret_cast<uptr>(MmapAlignedOrDie(kRegionSize, kRegionSize,
-                                      "SizeClassAllocator32"));
+    uptr res = reinterpret_cast<uptr>(MmapAlignedOrDieOnFatalError(
+        kRegionSize, kRegionSize, "SizeClassAllocator32"));
+    if (UNLIKELY(!res))
+      return 0;
     MapUnmapCallback().OnMap(res, kRegionSize);
     stat->Add(AllocatorStatMapped, kRegionSize);
-    CHECK_EQ(0U, (res & (kRegionSize - 1)));
+    CHECK(IsAligned(res, kRegionSize));
     possible_regions.set(ComputeRegionId(res), static_cast<u8>(class_id));
     return res;
   }
@@ -272,21 +295,25 @@ class SizeClassAllocator32 {
     return &size_class_info_array[class_id];
   }
 
-  void PopulateFreeList(AllocatorStats *stat, AllocatorCache *c,
+  bool PopulateFreeList(AllocatorStats *stat, AllocatorCache *c,
                         SizeClassInfo *sci, uptr class_id) {
     uptr size = ClassIdToSize(class_id);
     uptr reg = AllocateRegion(stat, class_id);
+    if (UNLIKELY(!reg))
+      return false;
     uptr n_chunks = kRegionSize / (size + kMetadataSize);
     uptr max_count = TransferBatch::MaxCached(class_id);
+    CHECK_GT(max_count, 0);
     TransferBatch *b = nullptr;
     for (uptr i = reg; i < reg + n_chunks * size; i += size) {
       if (!b) {
         b = c->CreateBatch(class_id, this, (TransferBatch*)i);
+        if (UNLIKELY(!b))
+          return false;
         b->Clear();
       }
       b->Add((void*)i);
       if (b->Count() == max_count) {
-        CHECK_GT(b->Count(), 0);
         sci->free_list.push_back(b);
         b = nullptr;
       }
@@ -295,6 +322,7 @@ class SizeClassAllocator32 {
       CHECK_GT(b->Count(), 0);
       sci->free_list.push_back(b);
     }
+    return true;
   }
 
   ByteMap possible_regions;
diff --git a/libsanitizer/sanitizer_common/sanitizer_allocator_primary64.h b/libsanitizer/sanitizer_common/sanitizer_allocator_primary64.h
index 620639afbfd..4ae59c8b6b1 100644
--- a/libsanitizer/sanitizer_common/sanitizer_allocator_primary64.h
+++ b/libsanitizer/sanitizer_common/sanitizer_allocator_primary64.h
@@ -60,14 +60,14 @@ class SizeClassAllocator64 {
   // as a 4-byte integer (offset from the region start shifted right by 4).
   typedef u32 CompactPtrT;
   static const uptr kCompactPtrScale = 4;
-  CompactPtrT PointerToCompactPtr(uptr base, uptr ptr) {
+  CompactPtrT PointerToCompactPtr(uptr base, uptr ptr) const {
     return static_cast<CompactPtrT>((ptr - base) >> kCompactPtrScale);
   }
-  uptr CompactPtrToPointer(uptr base, CompactPtrT ptr32) {
+  uptr CompactPtrToPointer(uptr base, CompactPtrT ptr32) const {
     return base + (static_cast<uptr>(ptr32) << kCompactPtrScale);
   }
 
-  void Init() {
+  void Init(s32 release_to_os_interval_ms) {
     uptr TotalSpaceSize = kSpaceSize + AdditionalSize();
     if (kUsingConstantSpaceBeg) {
       CHECK_EQ(kSpaceBeg, reinterpret_cast<uptr>(
@@ -77,17 +77,17 @@ class SizeClassAllocator64 {
           reinterpret_cast<uptr>(MmapNoAccess(TotalSpaceSize));
       CHECK_NE(NonConstSpaceBeg, ~(uptr)0);
     }
-    MapWithCallback(SpaceEnd(), AdditionalSize());
+    SetReleaseToOSIntervalMs(release_to_os_interval_ms);
+    MapWithCallbackOrDie(SpaceEnd(), AdditionalSize());
   }
 
-  void MapWithCallback(uptr beg, uptr size) {
-    CHECK_EQ(beg, reinterpret_cast<uptr>(MmapFixedOrDie(beg, size)));
-    MapUnmapCallback().OnMap(beg, size);
+  s32 ReleaseToOSIntervalMs() const {
+    return atomic_load(&release_to_os_interval_ms_, memory_order_relaxed);
   }
 
-  void UnmapWithCallback(uptr beg, uptr size) {
-    MapUnmapCallback().OnUnmap(beg, size);
-    UnmapOrDie(reinterpret_cast<void *>(beg), size);
+  void SetReleaseToOSIntervalMs(s32 release_to_os_interval_ms) {
+    atomic_store(&release_to_os_interval_ms_, release_to_os_interval_ms,
+                 memory_order_relaxed);
   }
 
   static bool CanAllocate(uptr size, uptr alignment) {
@@ -104,14 +104,20 @@ class SizeClassAllocator64 {
     BlockingMutexLock l(&region->mutex);
     uptr old_num_chunks = region->num_freed_chunks;
     uptr new_num_freed_chunks = old_num_chunks + n_chunks;
-    EnsureFreeArraySpace(region, region_beg, new_num_freed_chunks);
+    // Failure to allocate free array space while releasing memory is non
+    // recoverable.
+    if (UNLIKELY(!EnsureFreeArraySpace(region, region_beg,
+                                       new_num_freed_chunks)))
+      DieOnFailure::OnOOM();
     for (uptr i = 0; i < n_chunks; i++)
       free_array[old_num_chunks + i] = chunks[i];
     region->num_freed_chunks = new_num_freed_chunks;
-    region->n_freed += n_chunks;
+    region->stats.n_freed += n_chunks;
+
+    MaybeReleaseToOS(class_id);
   }
 
-  NOINLINE void GetFromAllocator(AllocatorStats *stat, uptr class_id,
+  NOINLINE bool GetFromAllocator(AllocatorStats *stat, uptr class_id,
                                  CompactPtrT *chunks, uptr n_chunks) {
     RegionInfo *region = GetRegionInfo(class_id);
     uptr region_beg = GetRegionBeginBySizeClass(class_id);
@@ -119,18 +125,19 @@ class SizeClassAllocator64 {
 
     BlockingMutexLock l(&region->mutex);
     if (UNLIKELY(region->num_freed_chunks < n_chunks)) {
-      PopulateFreeArray(stat, class_id, region,
-                        n_chunks - region->num_freed_chunks);
+      if (UNLIKELY(!PopulateFreeArray(stat, class_id, region,
+                                      n_chunks - region->num_freed_chunks)))
+        return false;
       CHECK_GE(region->num_freed_chunks, n_chunks);
     }
     region->num_freed_chunks -= n_chunks;
     uptr base_idx = region->num_freed_chunks;
     for (uptr i = 0; i < n_chunks; i++)
       chunks[i] = free_array[base_idx + i];
-    region->n_allocated += n_chunks;
+    region->stats.n_allocated += n_chunks;
+    return true;
   }
 
-
   bool PointerIsMine(const void *p) {
     uptr P = reinterpret_cast<uptr>(p);
     if (kUsingConstantSpaceBeg && (kSpaceBeg % kSpaceSize) == 0)
@@ -146,7 +153,7 @@ class SizeClassAllocator64 {
         space_beg;
   }
 
-  uptr GetRegionBeginBySizeClass(uptr class_id) {
+  uptr GetRegionBeginBySizeClass(uptr class_id) const {
     return SpaceBeg() + kRegionSize * class_id;
   }
 
@@ -197,7 +204,7 @@ class SizeClassAllocator64 {
 
   // Test-only.
   void TestOnlyUnmap() {
-    UnmapWithCallback(SpaceBeg(), kSpaceSize + AdditionalSize());
+    UnmapWithCallbackOrDie(SpaceBeg(), kSpaceSize + AdditionalSize());
   }
 
   static void FillMemoryProfile(uptr start, uptr rss, bool file, uptr *stats,
@@ -210,16 +217,18 @@ class SizeClassAllocator64 {
   void PrintStats(uptr class_id, uptr rss) {
     RegionInfo *region = GetRegionInfo(class_id);
     if (region->mapped_user == 0) return;
-    uptr in_use = region->n_allocated - region->n_freed;
+    uptr in_use = region->stats.n_allocated - region->stats.n_freed;
     uptr avail_chunks = region->allocated_user / ClassIdToSize(class_id);
     Printf(
-        "  %02zd (%zd): mapped: %zdK allocs: %zd frees: %zd inuse: %zd "
-        "num_freed_chunks %zd"
-        " avail: %zd rss: %zdK releases: %zd\n",
-        class_id, ClassIdToSize(class_id), region->mapped_user >> 10,
-        region->n_allocated, region->n_freed, in_use,
-        region->num_freed_chunks, avail_chunks, rss >> 10,
-        region->rtoi.num_releases);
+        "%s %02zd (%6zd): mapped: %6zdK allocs: %7zd frees: %7zd inuse: %6zd "
+        "num_freed_chunks %7zd avail: %6zd rss: %6zdK releases: %6zd "
+        "last released: %6zdK region: 0x%zx\n",
+        region->exhausted ? "F" : " ", class_id, ClassIdToSize(class_id),
+        region->mapped_user >> 10, region->stats.n_allocated,
+        region->stats.n_freed, in_use, region->num_freed_chunks, avail_chunks,
+        rss >> 10, region->rtoi.num_releases,
+        region->rtoi.last_released_bytes >> 10,
+        SpaceBeg() + kRegionSize * class_id);
   }
 
   void PrintStats() {
@@ -229,8 +238,8 @@ class SizeClassAllocator64 {
     for (uptr class_id = 1; class_id < kNumClasses; class_id++) {
       RegionInfo *region = GetRegionInfo(class_id);
       total_mapped += region->mapped_user;
-      n_allocated += region->n_allocated;
-      n_freed += region->n_freed;
+      n_allocated += region->stats.n_allocated;
+      n_freed += region->stats.n_freed;
     }
     Printf("Stats: SizeClassAllocator64: %zdM mapped in %zd allocations; "
            "remains %zd\n",
@@ -282,16 +291,244 @@ class SizeClassAllocator64 {
                      GetPageSizeCached());
   }
 
-  void ReleaseToOS() {
-    for (uptr class_id = 1; class_id < kNumClasses; class_id++)
-      ReleaseToOS(class_id);
-  }
-
   typedef SizeClassMap SizeClassMapT;
   static const uptr kNumClasses = SizeClassMap::kNumClasses;
   static const uptr kNumClassesRounded = SizeClassMap::kNumClassesRounded;
 
+  // A packed array of counters. Each counter occupies 2^n bits, enough to store
+  // counter's max_value. Ctor will try to allocate the required buffer via
+  // mapper->MapPackedCounterArrayBuffer and the caller is expected to check
+  // whether the initialization was successful by checking IsAllocated() result.
+  // For the performance sake, none of the accessors check the validity of the
+  // arguments, it is assumed that index is always in [0, n) range and the value
+  // is not incremented past max_value.
+  template<class MemoryMapperT>
+  class PackedCounterArray {
+   public:
+    PackedCounterArray(u64 num_counters, u64 max_value, MemoryMapperT *mapper)
+        : n(num_counters), memory_mapper(mapper) {
+      CHECK_GT(num_counters, 0);
+      CHECK_GT(max_value, 0);
+      constexpr u64 kMaxCounterBits = sizeof(*buffer) * 8ULL;
+      // Rounding counter storage size up to the power of two allows for using
+      // bit shifts calculating particular counter's index and offset.
+      uptr counter_size_bits =
+          RoundUpToPowerOfTwo(MostSignificantSetBitIndex(max_value) + 1);
+      CHECK_LE(counter_size_bits, kMaxCounterBits);
+      counter_size_bits_log = Log2(counter_size_bits);
+      counter_mask = ~0ULL >> (kMaxCounterBits - counter_size_bits);
+
+      uptr packing_ratio = kMaxCounterBits >> counter_size_bits_log;
+      CHECK_GT(packing_ratio, 0);
+      packing_ratio_log = Log2(packing_ratio);
+      bit_offset_mask = packing_ratio - 1;
+
+      buffer_size =
+          (RoundUpTo(n, 1ULL << packing_ratio_log) >> packing_ratio_log) *
+          sizeof(*buffer);
+      buffer = reinterpret_cast<u64*>(
+          memory_mapper->MapPackedCounterArrayBuffer(buffer_size));
+    }
+    ~PackedCounterArray() {
+      if (buffer) {
+        memory_mapper->UnmapPackedCounterArrayBuffer(
+            reinterpret_cast<uptr>(buffer), buffer_size);
+      }
+    }
+
+    bool IsAllocated() const {
+      return !!buffer;
+    }
+
+    u64 GetCount() const {
+      return n;
+    }
+
+    uptr Get(uptr i) const {
+      DCHECK_LT(i, n);
+      uptr index = i >> packing_ratio_log;
+      uptr bit_offset = (i & bit_offset_mask) << counter_size_bits_log;
+      return (buffer[index] >> bit_offset) & counter_mask;
+    }
+
+    void Inc(uptr i) const {
+      DCHECK_LT(Get(i), counter_mask);
+      uptr index = i >> packing_ratio_log;
+      uptr bit_offset = (i & bit_offset_mask) << counter_size_bits_log;
+      buffer[index] += 1ULL << bit_offset;
+    }
+
+    void IncRange(uptr from, uptr to) const {
+      DCHECK_LE(from, to);
+      for (uptr i = from; i <= to; i++)
+        Inc(i);
+    }
+
+   private:
+    const u64 n;
+    u64 counter_size_bits_log;
+    u64 counter_mask;
+    u64 packing_ratio_log;
+    u64 bit_offset_mask;
+
+    MemoryMapperT* const memory_mapper;
+    u64 buffer_size;
+    u64* buffer;
+  };
+
+  template<class MemoryMapperT>
+  class FreePagesRangeTracker {
+   public:
+    explicit FreePagesRangeTracker(MemoryMapperT* mapper)
+        : memory_mapper(mapper),
+          page_size_scaled_log(Log2(GetPageSizeCached() >> kCompactPtrScale)),
+          in_the_range(false), current_page(0), current_range_start_page(0) {}
+
+    void NextPage(bool freed) {
+      if (freed) {
+        if (!in_the_range) {
+          current_range_start_page = current_page;
+          in_the_range = true;
+        }
+      } else {
+        CloseOpenedRange();
+      }
+      current_page++;
+    }
+
+    void Done() {
+      CloseOpenedRange();
+    }
+
+   private:
+    void CloseOpenedRange() {
+      if (in_the_range) {
+        memory_mapper->ReleasePageRangeToOS(
+            current_range_start_page << page_size_scaled_log,
+            current_page << page_size_scaled_log);
+        in_the_range = false;
+      }
+    }
+
+    MemoryMapperT* const memory_mapper;
+    const uptr page_size_scaled_log;
+    bool in_the_range;
+    uptr current_page;
+    uptr current_range_start_page;
+  };
+
+  // Iterates over the free_array to identify memory pages containing freed
+  // chunks only and returns these pages back to OS.
+  // allocated_pages_count is the total number of pages allocated for the
+  // current bucket.
+  template<class MemoryMapperT>
+  static void ReleaseFreeMemoryToOS(CompactPtrT *free_array,
+                                    uptr free_array_count, uptr chunk_size,
+                                    uptr allocated_pages_count,
+                                    MemoryMapperT *memory_mapper) {
+    const uptr page_size = GetPageSizeCached();
+
+    // Figure out the number of chunks per page and whether we can take a fast
+    // path (the number of chunks per page is the same for all pages).
+    uptr full_pages_chunk_count_max;
+    bool same_chunk_count_per_page;
+    if (chunk_size <= page_size && page_size % chunk_size == 0) {
+      // Same number of chunks per page, no cross overs.
+      full_pages_chunk_count_max = page_size / chunk_size;
+      same_chunk_count_per_page = true;
+    } else if (chunk_size <= page_size && page_size % chunk_size != 0 &&
+        chunk_size % (page_size % chunk_size) == 0) {
+      // Some chunks are crossing page boundaries, which means that the page
+      // contains one or two partial chunks, but all pages contain the same
+      // number of chunks.
+      full_pages_chunk_count_max = page_size / chunk_size + 1;
+      same_chunk_count_per_page = true;
+    } else if (chunk_size <= page_size) {
+      // Some chunks are crossing page boundaries, which means that the page
+      // contains one or two partial chunks.
+      full_pages_chunk_count_max = page_size / chunk_size + 2;
+      same_chunk_count_per_page = false;
+    } else if (chunk_size > page_size && chunk_size % page_size == 0) {
+      // One chunk covers multiple pages, no cross overs.
+      full_pages_chunk_count_max = 1;
+      same_chunk_count_per_page = true;
+    } else if (chunk_size > page_size) {
+      // One chunk covers multiple pages, Some chunks are crossing page
+      // boundaries. Some pages contain one chunk, some contain two.
+      full_pages_chunk_count_max = 2;
+      same_chunk_count_per_page = false;
+    } else {
+      UNREACHABLE("All chunk_size/page_size ratios must be handled.");
+    }
+
+    PackedCounterArray<MemoryMapperT> counters(allocated_pages_count,
+                                               full_pages_chunk_count_max,
+                                               memory_mapper);
+    if (!counters.IsAllocated())
+      return;
+
+    const uptr chunk_size_scaled = chunk_size >> kCompactPtrScale;
+    const uptr page_size_scaled = page_size >> kCompactPtrScale;
+    const uptr page_size_scaled_log = Log2(page_size_scaled);
+
+    // Iterate over free chunks and count how many free chunks affect each
+    // allocated page.
+    if (chunk_size <= page_size && page_size % chunk_size == 0) {
+      // Each chunk affects one page only.
+      for (uptr i = 0; i < free_array_count; i++)
+        counters.Inc(free_array[i] >> page_size_scaled_log);
+    } else {
+      // In all other cases chunks might affect more than one page.
+      for (uptr i = 0; i < free_array_count; i++) {
+        counters.IncRange(
+            free_array[i] >> page_size_scaled_log,
+            (free_array[i] + chunk_size_scaled - 1) >> page_size_scaled_log);
+      }
+    }
+
+    // Iterate over pages detecting ranges of pages with chunk counters equal
+    // to the expected number of chunks for the particular page.
+    FreePagesRangeTracker<MemoryMapperT> range_tracker(memory_mapper);
+    if (same_chunk_count_per_page) {
+      // Fast path, every page has the same number of chunks affecting it.
+      for (uptr i = 0; i < counters.GetCount(); i++)
+        range_tracker.NextPage(counters.Get(i) == full_pages_chunk_count_max);
+    } else {
+      // Show path, go through the pages keeping count how many chunks affect
+      // each page.
+      const uptr pn =
+          chunk_size < page_size ? page_size_scaled / chunk_size_scaled : 1;
+      const uptr pnc = pn * chunk_size_scaled;
+      // The idea is to increment the current page pointer by the first chunk
+      // size, middle portion size (the portion of the page covered by chunks
+      // except the first and the last one) and then the last chunk size, adding
+      // up the number of chunks on the current page and checking on every step
+      // whether the page boundary was crossed.
+      uptr prev_page_boundary = 0;
+      uptr current_boundary = 0;
+      for (uptr i = 0; i < counters.GetCount(); i++) {
+        uptr page_boundary = prev_page_boundary + page_size_scaled;
+        uptr chunks_per_page = pn;
+        if (current_boundary < page_boundary) {
+          if (current_boundary > prev_page_boundary)
+            chunks_per_page++;
+          current_boundary += pnc;
+          if (current_boundary < page_boundary) {
+            chunks_per_page++;
+            current_boundary += chunk_size_scaled;
+          }
+        }
+        prev_page_boundary = page_boundary;
+
+        range_tracker.NextPage(counters.Get(i) == chunks_per_page);
+      }
+    }
+    range_tracker.Done();
+  }
+
  private:
+  friend class MemoryMapper;
+
   static const uptr kRegionSize = kSpaceSize / kNumClassesRounded;
   // FreeArray is the array of free-d chunks (stored as 4-byte offsets).
   // In the worst case it may reguire kRegionSize/SizeClassMap::kMinSize
@@ -315,12 +552,19 @@ class SizeClassAllocator64 {
   static const uptr kMetaMapSize = 1 << 16;
   // Call mmap for free array memory with at least this size.
   static const uptr kFreeArrayMapSize = 1 << 16;
-  // Granularity of ReleaseToOs (aka madvise).
-  static const uptr kReleaseToOsGranularity = 1 << 12;
+
+  atomic_sint32_t release_to_os_interval_ms_;
+
+  struct Stats {
+    uptr n_allocated;
+    uptr n_freed;
+  };
 
   struct ReleaseToOsInfo {
     uptr n_freed_at_last_release;
     uptr num_releases;
+    u64 last_release_at_ns;
+    u64 last_released_bytes;
   };
 
   struct RegionInfo {
@@ -331,8 +575,9 @@ class SizeClassAllocator64 {
     uptr allocated_meta;  // Bytes allocated for metadata.
     uptr mapped_user;  // Bytes mapped for user memory.
     uptr mapped_meta;  // Bytes mapped for metadata.
-    u32 rand_state; // Seed for random shuffle, used if kRandomShuffleChunks.
-    uptr n_allocated, n_freed;  // Just stats.
+    u32 rand_state;  // Seed for random shuffle, used if kRandomShuffleChunks.
+    bool exhausted;  // Whether region is out of space for new chunks.
+    Stats stats;
     ReleaseToOsInfo rtoi;
   };
   COMPILER_CHECK(sizeof(RegionInfo) >= kCacheLineSize);
@@ -349,18 +594,18 @@ class SizeClassAllocator64 {
       Swap(a[i], a[RandN(rand_state, i + 1)]);
   }
 
-  RegionInfo *GetRegionInfo(uptr class_id) {
+  RegionInfo *GetRegionInfo(uptr class_id) const {
     CHECK_LT(class_id, kNumClasses);
     RegionInfo *regions =
         reinterpret_cast<RegionInfo *>(SpaceBeg() + kSpaceSize);
     return &regions[class_id];
   }
 
-  uptr GetMetadataEnd(uptr region_beg) {
+  uptr GetMetadataEnd(uptr region_beg) const {
     return region_beg + kRegionSize - kFreeArraySize;
   }
 
-  uptr GetChunkIdx(uptr chunk, uptr size) {
+  uptr GetChunkIdx(uptr chunk, uptr size) const {
     if (!kUsingConstantSpaceBeg)
       chunk -= SpaceBeg();
 
@@ -372,132 +617,205 @@ class SizeClassAllocator64 {
     return (u32)offset / (u32)size;
   }
 
-  CompactPtrT *GetFreeArray(uptr region_beg) {
-    return reinterpret_cast<CompactPtrT *>(region_beg + kRegionSize -
-                                           kFreeArraySize);
+  CompactPtrT *GetFreeArray(uptr region_beg) const {
+    return reinterpret_cast<CompactPtrT *>(GetMetadataEnd(region_beg));
   }
 
-  void EnsureFreeArraySpace(RegionInfo *region, uptr region_beg,
+  bool MapWithCallback(uptr beg, uptr size) {
+    uptr mapped = reinterpret_cast<uptr>(MmapFixedOrDieOnFatalError(beg, size));
+    if (UNLIKELY(!mapped))
+      return false;
+    CHECK_EQ(beg, mapped);
+    MapUnmapCallback().OnMap(beg, size);
+    return true;
+  }
+
+  void MapWithCallbackOrDie(uptr beg, uptr size) {
+    CHECK_EQ(beg, reinterpret_cast<uptr>(MmapFixedOrDie(beg, size)));
+    MapUnmapCallback().OnMap(beg, size);
+  }
+
+  void UnmapWithCallbackOrDie(uptr beg, uptr size) {
+    MapUnmapCallback().OnUnmap(beg, size);
+    UnmapOrDie(reinterpret_cast<void *>(beg), size);
+  }
+
+  bool EnsureFreeArraySpace(RegionInfo *region, uptr region_beg,
                             uptr num_freed_chunks) {
     uptr needed_space = num_freed_chunks * sizeof(CompactPtrT);
     if (region->mapped_free_array < needed_space) {
-      CHECK_LE(needed_space, kFreeArraySize);
       uptr new_mapped_free_array = RoundUpTo(needed_space, kFreeArrayMapSize);
+      CHECK_LE(new_mapped_free_array, kFreeArraySize);
       uptr current_map_end = reinterpret_cast<uptr>(GetFreeArray(region_beg)) +
                              region->mapped_free_array;
       uptr new_map_size = new_mapped_free_array - region->mapped_free_array;
-      MapWithCallback(current_map_end, new_map_size);
+      if (UNLIKELY(!MapWithCallback(current_map_end, new_map_size)))
+        return false;
       region->mapped_free_array = new_mapped_free_array;
     }
+    return true;
   }
 
-
-  NOINLINE void PopulateFreeArray(AllocatorStats *stat, uptr class_id,
+  NOINLINE bool PopulateFreeArray(AllocatorStats *stat, uptr class_id,
                                   RegionInfo *region, uptr requested_count) {
     // region->mutex is held.
-    uptr size = ClassIdToSize(class_id);
-    uptr beg_idx = region->allocated_user;
-    uptr end_idx = beg_idx + requested_count * size;
-    uptr region_beg = GetRegionBeginBySizeClass(class_id);
-    if (end_idx > region->mapped_user) {
+    const uptr size = ClassIdToSize(class_id);
+    const uptr new_space_beg = region->allocated_user;
+    const uptr new_space_end = new_space_beg + requested_count * size;
+    const uptr region_beg = GetRegionBeginBySizeClass(class_id);
+
+    // Map more space for chunks, if necessary.
+    if (new_space_end > region->mapped_user) {
       if (!kUsingConstantSpaceBeg && region->mapped_user == 0)
         region->rand_state = static_cast<u32>(region_beg >> 12);  // From ASLR.
       // Do the mmap for the user memory.
       uptr map_size = kUserMapSize;
-      while (end_idx > region->mapped_user + map_size)
+      while (new_space_end > region->mapped_user + map_size)
         map_size += kUserMapSize;
-      CHECK_GE(region->mapped_user + map_size, end_idx);
-      MapWithCallback(region_beg + region->mapped_user, map_size);
+      CHECK_GE(region->mapped_user + map_size, new_space_end);
+      if (UNLIKELY(!MapWithCallback(region_beg + region->mapped_user,
+                                    map_size)))
+        return false;
       stat->Add(AllocatorStatMapped, map_size);
       region->mapped_user += map_size;
     }
-    CompactPtrT *free_array = GetFreeArray(region_beg);
-    uptr total_count = (region->mapped_user - beg_idx) / size;
-    uptr num_freed_chunks = region->num_freed_chunks;
-    EnsureFreeArraySpace(region, region_beg, num_freed_chunks + total_count);
-    for (uptr i = 0; i < total_count; i++) {
-      uptr chunk = beg_idx + i * size;
-      free_array[num_freed_chunks + total_count - 1 - i] =
-          PointerToCompactPtr(0, chunk);
+    const uptr new_chunks_count = (region->mapped_user - new_space_beg) / size;
+
+    // Calculate the required space for metadata.
+    const uptr requested_allocated_meta =
+        region->allocated_meta + new_chunks_count * kMetadataSize;
+    uptr requested_mapped_meta = region->mapped_meta;
+    while (requested_allocated_meta > requested_mapped_meta)
+      requested_mapped_meta += kMetaMapSize;
+    // Check whether this size class is exhausted.
+    if (region->mapped_user + requested_mapped_meta >
+        kRegionSize - kFreeArraySize) {
+      if (!region->exhausted) {
+        region->exhausted = true;
+        Printf("%s: Out of memory. ", SanitizerToolName);
+        Printf("The process has exhausted %zuMB for size class %zu.\n",
+               kRegionSize >> 20, size);
+      }
+      return false;
+    }
+    // Map more space for metadata, if necessary.
+    if (requested_mapped_meta > region->mapped_meta) {
+      if (UNLIKELY(!MapWithCallback(
+              GetMetadataEnd(region_beg) - requested_mapped_meta,
+              requested_mapped_meta - region->mapped_meta)))
+        return false;
+      region->mapped_meta = requested_mapped_meta;
     }
+
+    // If necessary, allocate more space for the free array and populate it with
+    // newly allocated chunks.
+    const uptr total_freed_chunks = region->num_freed_chunks + new_chunks_count;
+    if (UNLIKELY(!EnsureFreeArraySpace(region, region_beg, total_freed_chunks)))
+      return false;
+    CompactPtrT *free_array = GetFreeArray(region_beg);
+    for (uptr i = 0, chunk = new_space_beg; i < new_chunks_count;
+         i++, chunk += size)
+      free_array[total_freed_chunks - 1 - i] = PointerToCompactPtr(0, chunk);
     if (kRandomShuffleChunks)
-      RandomShuffle(&free_array[num_freed_chunks], total_count,
+      RandomShuffle(&free_array[region->num_freed_chunks], new_chunks_count,
                     &region->rand_state);
-    region->num_freed_chunks += total_count;
-    region->allocated_user += total_count * size;
-    CHECK_LE(region->allocated_user, region->mapped_user);
 
-    region->allocated_meta += total_count * kMetadataSize;
-    if (region->allocated_meta > region->mapped_meta) {
-      uptr map_size = kMetaMapSize;
-      while (region->allocated_meta > region->mapped_meta + map_size)
-        map_size += kMetaMapSize;
-      // Do the mmap for the metadata.
-      CHECK_GE(region->mapped_meta + map_size, region->allocated_meta);
-      MapWithCallback(GetMetadataEnd(region_beg) -
-                      region->mapped_meta - map_size, map_size);
-      region->mapped_meta += map_size;
-    }
+    // All necessary memory is mapped and now it is safe to advance all
+    // 'allocated_*' counters.
+    region->num_freed_chunks += new_chunks_count;
+    region->allocated_user += new_chunks_count * size;
+    CHECK_LE(region->allocated_user, region->mapped_user);
+    region->allocated_meta = requested_allocated_meta;
     CHECK_LE(region->allocated_meta, region->mapped_meta);
-    if (region->mapped_user + region->mapped_meta >
-        kRegionSize - kFreeArraySize) {
-      Printf("%s: Out of memory. Dying. ", SanitizerToolName);
-      Printf("The process has exhausted %zuMB for size class %zu.\n",
-          kRegionSize / 1024 / 1024, size);
-      Die();
-    }
-  }
+    region->exhausted = false;
+
+    // TODO(alekseyshl): Consider bumping last_release_at_ns here to prevent
+    // MaybeReleaseToOS from releasing just allocated pages or protect these
+    // not yet used chunks some other way.
 
-  bool MaybeReleaseChunkRange(uptr region_beg, uptr chunk_size,
-                              CompactPtrT first, CompactPtrT last) {
-    uptr beg_ptr = CompactPtrToPointer(region_beg, first);
-    uptr end_ptr = CompactPtrToPointer(region_beg, last) + chunk_size;
-    CHECK_GE(end_ptr - beg_ptr, kReleaseToOsGranularity);
-    beg_ptr = RoundUpTo(beg_ptr, kReleaseToOsGranularity);
-    end_ptr = RoundDownTo(end_ptr, kReleaseToOsGranularity);
-    if (end_ptr == beg_ptr) return false;
-    ReleaseMemoryToOS(beg_ptr, end_ptr - beg_ptr);
     return true;
   }
 
-  // Releases some RAM back to OS.
-  // Algorithm:
-  // * Lock the region.
-  // * Sort the chunks.
-  // * Find ranges fully covered by free-d chunks
-  // * Release them to OS with madvise.
-  //
-  // TODO(kcc): make sure we don't do it too frequently.
-  void ReleaseToOS(uptr class_id) {
+  class MemoryMapper {
+   public:
+    MemoryMapper(const ThisT& base_allocator, uptr class_id)
+        : allocator(base_allocator),
+          region_base(base_allocator.GetRegionBeginBySizeClass(class_id)),
+          released_ranges_count(0),
+          released_bytes(0) {
+    }
+
+    uptr GetReleasedRangesCount() const {
+      return released_ranges_count;
+    }
+
+    uptr GetReleasedBytes() const {
+      return released_bytes;
+    }
+
+    uptr MapPackedCounterArrayBuffer(uptr buffer_size) {
+      // TODO(alekseyshl): The idea to explore is to check if we have enough
+      // space between num_freed_chunks*sizeof(CompactPtrT) and
+      // mapped_free_array to fit buffer_size bytes and use that space instead
+      // of mapping a temporary one.
+      return reinterpret_cast<uptr>(
+          MmapOrDieOnFatalError(buffer_size, "ReleaseToOSPageCounters"));
+    }
+
+    void UnmapPackedCounterArrayBuffer(uptr buffer, uptr buffer_size) {
+      UnmapOrDie(reinterpret_cast<void *>(buffer), buffer_size);
+    }
+
+    // Releases [from, to) range of pages back to OS.
+    void ReleasePageRangeToOS(CompactPtrT from, CompactPtrT to) {
+      const uptr from_page = allocator.CompactPtrToPointer(region_base, from);
+      const uptr to_page = allocator.CompactPtrToPointer(region_base, to);
+      ReleaseMemoryPagesToOS(from_page, to_page);
+      released_ranges_count++;
+      released_bytes += to_page - from_page;
+    }
+
+   private:
+    const ThisT& allocator;
+    const uptr region_base;
+    uptr released_ranges_count;
+    uptr released_bytes;
+  };
+
+  // Attempts to release RAM occupied by freed chunks back to OS. The region is
+  // expected to be locked.
+  void MaybeReleaseToOS(uptr class_id) {
     RegionInfo *region = GetRegionInfo(class_id);
-    uptr region_beg = GetRegionBeginBySizeClass(class_id);
-    CompactPtrT *free_array = GetFreeArray(region_beg);
-    uptr chunk_size = ClassIdToSize(class_id);
-    uptr scaled_chunk_size = chunk_size >> kCompactPtrScale;
-    const uptr kScaledGranularity = kReleaseToOsGranularity >> kCompactPtrScale;
-    BlockingMutexLock l(&region->mutex);
+    const uptr chunk_size = ClassIdToSize(class_id);
+    const uptr page_size = GetPageSizeCached();
+
     uptr n = region->num_freed_chunks;
-    if (n * chunk_size < kReleaseToOsGranularity)
-      return;   // No chance to release anything.
-    if ((region->rtoi.n_freed_at_last_release - region->n_freed) * chunk_size <
-        kReleaseToOsGranularity)
+    if (n * chunk_size < page_size)
+      return;  // No chance to release anything.
+    if ((region->stats.n_freed -
+         region->rtoi.n_freed_at_last_release) * chunk_size < page_size) {
       return;  // Nothing new to release.
-    SortArray(free_array, n);
-    uptr beg = free_array[0];
-    uptr prev = free_array[0];
-    for (uptr i = 1; i < n; i++) {
-      uptr chunk = free_array[i];
-      CHECK_GT(chunk, prev);
-      if (chunk - prev != scaled_chunk_size) {
-        CHECK_GT(chunk - prev, scaled_chunk_size);
-        if (prev + scaled_chunk_size - beg >= kScaledGranularity) {
-          MaybeReleaseChunkRange(region_beg, chunk_size, beg, prev);
-          region->rtoi.n_freed_at_last_release = region->n_freed;
-          region->rtoi.num_releases++;
-        }
-        beg = chunk;
-      }
-      prev = chunk;
     }
+
+    s32 interval_ms = ReleaseToOSIntervalMs();
+    if (interval_ms < 0)
+      return;
+
+    if (region->rtoi.last_release_at_ns + interval_ms * 1000000ULL > NanoTime())
+      return;  // Memory was returned recently.
+
+    MemoryMapper memory_mapper(*this, class_id);
+
+    ReleaseFreeMemoryToOS<MemoryMapper>(
+        GetFreeArray(GetRegionBeginBySizeClass(class_id)), n, chunk_size,
+        RoundUpTo(region->allocated_user, page_size) / page_size,
+        &memory_mapper);
+
+    if (memory_mapper.GetReleasedRangesCount() > 0) {
+      region->rtoi.n_freed_at_last_release = region->stats.n_freed;
+      region->rtoi.num_releases += memory_mapper.GetReleasedRangesCount();
+      region->rtoi.last_released_bytes = memory_mapper.GetReleasedBytes();
+    }
+    region->rtoi.last_release_at_ns = NanoTime();
   }
 };
diff --git a/libsanitizer/sanitizer_common/sanitizer_allocator_secondary.h b/libsanitizer/sanitizer_common/sanitizer_allocator_secondary.h
index 91c2ecc5b26..9a9b83a884f 100644
--- a/libsanitizer/sanitizer_common/sanitizer_allocator_secondary.h
+++ b/libsanitizer/sanitizer_common/sanitizer_allocator_secondary.h
@@ -15,17 +15,19 @@
 // This class can (de)allocate only large chunks of memory using mmap/unmap.
 // The main purpose of this allocator is to cover large and rare allocation
 // sizes not covered by more efficient allocators (e.g. SizeClassAllocator64).
-template <class MapUnmapCallback = NoOpMapUnmapCallback>
+template <class MapUnmapCallback = NoOpMapUnmapCallback,
+          class FailureHandlerT = ReturnNullOrDieOnFailure>
 class LargeMmapAllocator {
  public:
-  void InitLinkerInitialized(bool may_return_null) {
+  typedef FailureHandlerT FailureHandler;
+
+  void InitLinkerInitialized() {
     page_size_ = GetPageSizeCached();
-    atomic_store(&may_return_null_, may_return_null, memory_order_relaxed);
   }
 
-  void Init(bool may_return_null) {
+  void Init() {
     internal_memset(this, 0, sizeof(*this));
-    InitLinkerInitialized(may_return_null);
+    InitLinkerInitialized();
   }
 
   void *Allocate(AllocatorStats *stat, uptr size, uptr alignment) {
@@ -34,9 +36,12 @@ class LargeMmapAllocator {
     if (alignment > page_size_)
       map_size += alignment;
     // Overflow.
-    if (map_size < size) return ReturnNullOrDieOnBadRequest();
+    if (map_size < size)
+      return FailureHandler::OnBadRequest();
     uptr map_beg = reinterpret_cast<uptr>(
-        MmapOrDie(map_size, "LargeMmapAllocator"));
+        MmapOrDieOnFatalError(map_size, "LargeMmapAllocator"));
+    if (!map_beg)
+      return FailureHandler::OnOOM();
     CHECK(IsAligned(map_beg, page_size_));
     MapUnmapCallback().OnMap(map_beg, map_size);
     uptr map_end = map_beg + map_size;
@@ -70,24 +75,6 @@ class LargeMmapAllocator {
     return reinterpret_cast<void*>(res);
   }
 
-  bool MayReturnNull() const {
-    return atomic_load(&may_return_null_, memory_order_acquire);
-  }
-
-  void *ReturnNullOrDieOnBadRequest() {
-    if (MayReturnNull()) return nullptr;
-    ReportAllocatorCannotReturnNull(false);
-  }
-
-  void *ReturnNullOrDieOnOOM() {
-    if (MayReturnNull()) return nullptr;
-    ReportAllocatorCannotReturnNull(true);
-  }
-
-  void SetMayReturnNull(bool may_return_null) {
-    atomic_store(&may_return_null_, may_return_null, memory_order_release);
-  }
-
   void Deallocate(AllocatorStats *stat, void *p) {
     Header *h = GetHeader(p);
     {
@@ -159,6 +146,14 @@ class LargeMmapAllocator {
     return GetUser(h);
   }
 
+  void EnsureSortedChunks() {
+    if (chunks_sorted_) return;
+    SortArray(reinterpret_cast<uptr*>(chunks_), n_chunks_);
+    for (uptr i = 0; i < n_chunks_; i++)
+      chunks_[i]->chunk_idx = i;
+    chunks_sorted_ = true;
+  }
+
   // This function does the same as GetBlockBegin, but is much faster.
   // Must be called with the allocator locked.
   void *GetBlockBeginFastLocked(void *ptr) {
@@ -166,16 +161,10 @@ class LargeMmapAllocator {
     uptr p = reinterpret_cast<uptr>(ptr);
     uptr n = n_chunks_;
     if (!n) return nullptr;
-    if (!chunks_sorted_) {
-      // Do one-time sort. chunks_sorted_ is reset in Allocate/Deallocate.
-      SortArray(reinterpret_cast<uptr*>(chunks_), n);
-      for (uptr i = 0; i < n; i++)
-        chunks_[i]->chunk_idx = i;
-      chunks_sorted_ = true;
-      min_mmap_ = reinterpret_cast<uptr>(chunks_[0]);
-      max_mmap_ = reinterpret_cast<uptr>(chunks_[n - 1]) +
-          chunks_[n - 1]->map_size;
-    }
+    EnsureSortedChunks();
+    auto min_mmap_ = reinterpret_cast<uptr>(chunks_[0]);
+    auto max_mmap_ =
+        reinterpret_cast<uptr>(chunks_[n - 1]) + chunks_[n - 1]->map_size;
     if (p < min_mmap_ || p >= max_mmap_)
       return nullptr;
     uptr beg = 0, end = n - 1;
@@ -228,8 +217,14 @@ class LargeMmapAllocator {
   // Iterate over all existing chunks.
   // The allocator must be locked when calling this function.
   void ForEachChunk(ForEachChunkCallback callback, void *arg) {
-    for (uptr i = 0; i < n_chunks_; i++)
+    EnsureSortedChunks();  // Avoid doing the sort while iterating.
+    for (uptr i = 0; i < n_chunks_; i++) {
+      auto t = chunks_[i];
       callback(reinterpret_cast<uptr>(GetUser(chunks_[i])), arg);
+      // Consistency check: verify that the array did not change.
+      CHECK_EQ(chunks_[i], t);
+      CHECK_EQ(chunks_[i]->chunk_idx, i);
+    }
   }
 
  private:
@@ -261,11 +256,9 @@ class LargeMmapAllocator {
   uptr page_size_;
   Header *chunks_[kMaxNumChunks];
   uptr n_chunks_;
-  uptr min_mmap_, max_mmap_;
   bool chunks_sorted_;
   struct Stats {
     uptr n_allocs, n_frees, currently_allocated, max_allocated, by_size_log[64];
   } stats;
-  atomic_uint8_t may_return_null_;
   SpinMutex mutex_;
 };
diff --git a/libsanitizer/sanitizer_common/sanitizer_allocator_size_class_map.h b/libsanitizer/sanitizer_common/sanitizer_allocator_size_class_map.h
index 4cda021a947..19af55138d1 100644
--- a/libsanitizer/sanitizer_common/sanitizer_allocator_size_class_map.h
+++ b/libsanitizer/sanitizer_common/sanitizer_allocator_size_class_map.h
@@ -132,8 +132,9 @@ class SizeClassMap {
 
   static const uptr kMaxSize = 1UL << kMaxSizeLog;
   static const uptr kNumClasses =
-      kMidClass + ((kMaxSizeLog - kMidSizeLog) << S) + 1;
+      kMidClass + ((kMaxSizeLog - kMidSizeLog) << S) + 1 + 1;
   static const uptr kLargestClassID = kNumClasses - 2;
+  static const uptr kBatchClassID = kNumClasses - 1;
   COMPILER_CHECK(kNumClasses >= 16 && kNumClasses <= 256);
   static const uptr kNumClassesRounded =
       kNumClasses <= 32  ? 32 :
@@ -141,6 +142,11 @@ class SizeClassMap {
       kNumClasses <= 128 ? 128 : 256;
 
   static uptr Size(uptr class_id) {
+    // Estimate the result for kBatchClassID because this class does not know
+    // the exact size of TransferBatch. It's OK since we are using the actual
+    // sizeof(TransferBatch) where it matters.
+    if (UNLIKELY(class_id == kBatchClassID))
+      return kMaxNumCachedHint * sizeof(uptr);
     if (class_id <= kMidClass)
       return kMinSize * class_id;
     class_id -= kMidClass;
@@ -149,9 +155,10 @@ class SizeClassMap {
   }
 
   static uptr ClassID(uptr size) {
+    if (UNLIKELY(size > kMaxSize))
+      return 0;
     if (size <= kMidSize)
       return (size + kMinSize - 1) >> kMinSizeLog;
-    if (size > kMaxSize) return 0;
     uptr l = MostSignificantSetBitIndex(size);
     uptr hbits = (size >> (l - S)) & M;
     uptr lbits = size & ((1 << (l - S)) - 1);
@@ -160,7 +167,13 @@ class SizeClassMap {
   }
 
   static uptr MaxCachedHint(uptr class_id) {
-    if (class_id == 0) return 0;
+    // Estimate the result for kBatchClassID because this class does not know
+    // the exact size of TransferBatch. We need to cache fewer batches than user
+    // chunks, so this number can be small.
+    if (UNLIKELY(class_id == kBatchClassID))
+      return 16;
+    if (UNLIKELY(class_id == 0))
+      return 0;
     uptr n = (1UL << kMaxBytesCachedLog) / Size(class_id);
     return Max<uptr>(1, Min(kMaxNumCachedHint, n));
   }
@@ -176,6 +189,8 @@ class SizeClassMap {
       uptr p = prev_s ? (d * 100 / prev_s) : 0;
       uptr l = s ? MostSignificantSetBitIndex(s) : 0;
       uptr cached = MaxCachedHint(i) * s;
+      if (i == kBatchClassID)
+        d = p = l = 0;
       Printf("c%02zd => s: %zd diff: +%zd %02zd%% l %zd "
              "cached: %zd %zd; id %zd\n",
              i, Size(i), d, p, l, MaxCachedHint(i), cached, ClassID(s));
@@ -190,12 +205,13 @@ class SizeClassMap {
       // Printf("Validate: c%zd\n", c);
       uptr s = Size(c);
       CHECK_NE(s, 0U);
+      if (c == kBatchClassID)
+        continue;
       CHECK_EQ(ClassID(s), c);
-      if (c != kNumClasses - 1)
+      if (c < kLargestClassID)
         CHECK_EQ(ClassID(s + 1), c + 1);
       CHECK_EQ(ClassID(s - 1), c);
-      if (c)
-        CHECK_GT(Size(c), Size(c-1));
+      CHECK_GT(Size(c), Size(c - 1));
     }
     CHECK_EQ(ClassID(kMaxSize + 1), 0);
 
@@ -205,7 +221,7 @@ class SizeClassMap {
       CHECK_LT(c, kNumClasses);
       CHECK_GE(Size(c), s);
       if (c > 0)
-        CHECK_LT(Size(c-1), s);
+        CHECK_LT(Size(c - 1), s);
     }
   }
 };
diff --git a/libsanitizer/sanitizer_common/sanitizer_atomic.h b/libsanitizer/sanitizer_common/sanitizer_atomic.h
index 4973b7d4e88..82de0c6d446 100644
--- a/libsanitizer/sanitizer_common/sanitizer_atomic.h
+++ b/libsanitizer/sanitizer_common/sanitizer_atomic.h
@@ -35,6 +35,11 @@ struct atomic_uint16_t {
   volatile Type val_dont_use;
 };
 
+struct atomic_sint32_t {
+  typedef s32 Type;
+  volatile Type val_dont_use;
+};
+
 struct atomic_uint32_t {
   typedef u32 Type;
   volatile Type val_dont_use;
diff --git a/libsanitizer/sanitizer_common/sanitizer_atomic_clang.h b/libsanitizer/sanitizer_common/sanitizer_atomic_clang.h
index c600999e67a..dcdcd0ea4ad 100644
--- a/libsanitizer/sanitizer_common/sanitizer_atomic_clang.h
+++ b/libsanitizer/sanitizer_common/sanitizer_atomic_clang.h
@@ -69,16 +69,25 @@ INLINE typename T::Type atomic_exchange(volatile T *a,
   return v;
 }
 
-template<typename T>
-INLINE bool atomic_compare_exchange_strong(volatile T *a,
-                                           typename T::Type *cmp,
+template <typename T>
+INLINE bool atomic_compare_exchange_strong(volatile T *a, typename T::Type *cmp,
                                            typename T::Type xchg,
                                            memory_order mo) {
   typedef typename T::Type Type;
   Type cmpv = *cmp;
-  Type prev = __sync_val_compare_and_swap(&a->val_dont_use, cmpv, xchg);
-  if (prev == cmpv)
-    return true;
+  Type prev;
+#if defined(_MIPS_SIM) && _MIPS_SIM == _ABIO32
+  if (sizeof(*a) == 8) {
+    Type volatile *val_ptr = const_cast<Type volatile *>(&a->val_dont_use);
+    prev = __mips_sync_val_compare_and_swap<u64>(
+        reinterpret_cast<u64 volatile *>(val_ptr), (u64)cmpv, (u64)xchg);
+  } else {
+    prev = __sync_val_compare_and_swap(&a->val_dont_use, cmpv, xchg);
+  }
+#else
+  prev = __sync_val_compare_and_swap(&a->val_dont_use, cmpv, xchg);
+#endif
+  if (prev == cmpv) return true;
   *cmp = prev;
   return false;
 }
diff --git a/libsanitizer/sanitizer_common/sanitizer_atomic_clang_other.h b/libsanitizer/sanitizer_common/sanitizer_atomic_clang_other.h
index c66c0992e1b..a0605bbbd82 100644
--- a/libsanitizer/sanitizer_common/sanitizer_atomic_clang_other.h
+++ b/libsanitizer/sanitizer_common/sanitizer_atomic_clang_other.h
@@ -15,6 +15,56 @@
 
 namespace __sanitizer {
 
+// MIPS32 does not support atomic > 4 bytes. To address this lack of
+// functionality, the sanitizer library provides helper methods which use an
+// internal spin lock mechanism to emulate atomic oprations when the size is
+// 8 bytes.
+#if defined(_MIPS_SIM) && _MIPS_SIM == _ABIO32
+static void __spin_lock(volatile int *lock) {
+  while (__sync_lock_test_and_set(lock, 1))
+    while (*lock) {
+    }
+}
+
+static void __spin_unlock(volatile int *lock) { __sync_lock_release(lock); }
+
+
+// Make sure the lock is on its own cache line to prevent false sharing.
+// Put it inside a struct that is aligned and padded to the typical MIPS
+// cacheline which is 32 bytes.
+static struct {
+  int lock;
+  char pad[32 - sizeof(int)];
+} __attribute__((aligned(32))) lock = {0};
+
+template <class T>
+T __mips_sync_fetch_and_add(volatile T *ptr, T val) {
+  T ret;
+
+  __spin_lock(&lock.lock);
+
+  ret = *ptr;
+  *ptr = ret + val;
+
+  __spin_unlock(&lock.lock);
+
+  return ret;
+}
+
+template <class T>
+T __mips_sync_val_compare_and_swap(volatile T *ptr, T oldval, T newval) {
+  T ret;
+  __spin_lock(&lock.lock);
+
+  ret = *ptr;
+  if (ret == oldval) *ptr = newval;
+
+  __spin_unlock(&lock.lock);
+
+  return ret;
+}
+#endif
+
 INLINE void proc_yield(int cnt) {
   __asm__ __volatile__("" ::: "memory");
 }
@@ -51,8 +101,15 @@ INLINE typename T::Type atomic_load(
     // 64-bit load on 32-bit platform.
     // Gross, but simple and reliable.
     // Assume that it is not in read-only memory.
+#if defined(_MIPS_SIM) && _MIPS_SIM == _ABIO32
+    typename T::Type volatile *val_ptr =
+        const_cast<typename T::Type volatile *>(&a->val_dont_use);
+    v = __mips_sync_fetch_and_add<u64>(
+        reinterpret_cast<u64 volatile *>(val_ptr), 0);
+#else
     v = __sync_fetch_and_add(
         const_cast<typename T::Type volatile *>(&a->val_dont_use), 0);
+#endif
   }
   return v;
 }
@@ -82,7 +139,14 @@ INLINE void atomic_store(volatile T *a, typename T::Type v, memory_order mo) {
     typename T::Type cmp = a->val_dont_use;
     typename T::Type cur;
     for (;;) {
+#if defined(_MIPS_SIM) && _MIPS_SIM == _ABIO32
+      typename T::Type volatile *val_ptr =
+          const_cast<typename T::Type volatile *>(&a->val_dont_use);
+      cur = __mips_sync_val_compare_and_swap<u64>(
+          reinterpret_cast<u64 volatile *>(val_ptr), (u64)cmp, (u64)v);
+#else
       cur = __sync_val_compare_and_swap(&a->val_dont_use, cmp, v);
+#endif
       if (cmp == v)
         break;
       cmp = cur;
diff --git a/libsanitizer/sanitizer_common/sanitizer_common.cc b/libsanitizer/sanitizer_common/sanitizer_common.cc
index b445f613b85..8d7e9fae64e 100644
--- a/libsanitizer/sanitizer_common/sanitizer_common.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_common.cc
@@ -25,72 +25,6 @@ const char *SanitizerToolName = "SanitizerTool";
 atomic_uint32_t current_verbosity;
 uptr PageSizeCached;
 
-StaticSpinMutex report_file_mu;
-ReportFile report_file = {&report_file_mu, kStderrFd, "", "", 0};
-
-void RawWrite(const char *buffer) {
-  report_file.Write(buffer, internal_strlen(buffer));
-}
-
-void ReportFile::ReopenIfNecessary() {
-  mu->CheckLocked();
-  if (fd == kStdoutFd || fd == kStderrFd) return;
-
-  uptr pid = internal_getpid();
-  // If in tracer, use the parent's file.
-  if (pid == stoptheworld_tracer_pid)
-    pid = stoptheworld_tracer_ppid;
-  if (fd != kInvalidFd) {
-    // If the report file is already opened by the current process,
-    // do nothing. Otherwise the report file was opened by the parent
-    // process, close it now.
-    if (fd_pid == pid)
-      return;
-    else
-      CloseFile(fd);
-  }
-
-  const char *exe_name = GetProcessName();
-  if (common_flags()->log_exe_name && exe_name) {
-    internal_snprintf(full_path, kMaxPathLength, "%s.%s.%zu", path_prefix,
-                      exe_name, pid);
-  } else {
-    internal_snprintf(full_path, kMaxPathLength, "%s.%zu", path_prefix, pid);
-  }
-  fd = OpenFile(full_path, WrOnly);
-  if (fd == kInvalidFd) {
-    const char *ErrorMsgPrefix = "ERROR: Can't open file: ";
-    WriteToFile(kStderrFd, ErrorMsgPrefix, internal_strlen(ErrorMsgPrefix));
-    WriteToFile(kStderrFd, full_path, internal_strlen(full_path));
-    Die();
-  }
-  fd_pid = pid;
-}
-
-void ReportFile::SetReportPath(const char *path) {
-  if (!path)
-    return;
-  uptr len = internal_strlen(path);
-  if (len > sizeof(path_prefix) - 100) {
-    Report("ERROR: Path is too long: %c%c%c%c%c%c%c%c...\n",
-           path[0], path[1], path[2], path[3],
-           path[4], path[5], path[6], path[7]);
-    Die();
-  }
-
-  SpinMutexLock l(mu);
-  if (fd != kStdoutFd && fd != kStderrFd && fd != kInvalidFd)
-    CloseFile(fd);
-  fd = kInvalidFd;
-  if (internal_strcmp(path, "stdout") == 0) {
-    fd = kStdoutFd;
-  } else if (internal_strcmp(path, "stderr") == 0) {
-    fd = kStderrFd;
-  } else {
-    internal_snprintf(path_prefix, kMaxPathLength, "%s", path);
-  }
-}
-
 // PID of the tracer task in StopTheWorld. It shares the address space with the
 // main process, but has a different PID and thus requires special handling.
 uptr stoptheworld_tracer_pid = 0;
@@ -98,6 +32,8 @@ uptr stoptheworld_tracer_pid = 0;
 // writing to the same log file.
 uptr stoptheworld_tracer_ppid = 0;
 
+StaticSpinMutex CommonSanitizerReportMutex;
+
 void NORETURN ReportMmapFailureAndDie(uptr size, const char *mem_type,
                                       const char *mmap_type, error_t err,
                                       bool raw_report) {
@@ -118,42 +54,6 @@ void NORETURN ReportMmapFailureAndDie(uptr size, const char *mem_type,
   UNREACHABLE("unable to mmap");
 }
 
-bool ReadFileToBuffer(const char *file_name, char **buff, uptr *buff_size,
-                      uptr *read_len, uptr max_len, error_t *errno_p) {
-  uptr PageSize = GetPageSizeCached();
-  uptr kMinFileLen = PageSize;
-  *buff = nullptr;
-  *buff_size = 0;
-  *read_len = 0;
-  // The files we usually open are not seekable, so try different buffer sizes.
-  for (uptr size = kMinFileLen; size <= max_len; size *= 2) {
-    fd_t fd = OpenFile(file_name, RdOnly, errno_p);
-    if (fd == kInvalidFd) return false;
-    UnmapOrDie(*buff, *buff_size);
-    *buff = (char*)MmapOrDie(size, __func__);
-    *buff_size = size;
-    *read_len = 0;
-    // Read up to one page at a time.
-    bool reached_eof = false;
-    while (*read_len + PageSize <= size) {
-      uptr just_read;
-      if (!ReadFromFile(fd, *buff + *read_len, PageSize, &just_read, errno_p)) {
-        UnmapOrDie(*buff, *buff_size);
-        return false;
-      }
-      if (just_read == 0) {
-        reached_eof = true;
-        break;
-      }
-      *read_len += just_read;
-    }
-    CloseFile(fd);
-    if (reached_eof)  // We've read the whole file.
-      break;
-  }
-  return true;
-}
-
 typedef bool UptrComparisonFunction(const uptr &a, const uptr &b);
 typedef bool U32ComparisonFunction(const u32 &a, const u32 &b);
 
@@ -197,23 +97,24 @@ const char *StripModuleName(const char *module) {
   return module;
 }
 
-void ReportErrorSummary(const char *error_message) {
+void ReportErrorSummary(const char *error_message, const char *alt_tool_name) {
   if (!common_flags()->print_summary)
     return;
   InternalScopedString buff(kMaxSummaryLength);
-  buff.append("SUMMARY: %s: %s", SanitizerToolName, error_message);
+  buff.append("SUMMARY: %s: %s",
+              alt_tool_name ? alt_tool_name : SanitizerToolName, error_message);
   __sanitizer_report_error_summary(buff.data());
 }
 
 #if !SANITIZER_GO
-void ReportErrorSummary(const char *error_type, const AddressInfo &info) {
-  if (!common_flags()->print_summary)
-    return;
+void ReportErrorSummary(const char *error_type, const AddressInfo &info,
+                        const char *alt_tool_name) {
+  if (!common_flags()->print_summary) return;
   InternalScopedString buff(kMaxSummaryLength);
   buff.append("%s ", error_type);
   RenderFrame(&buff, "%L %F", 0, info, common_flags()->symbolize_vs_style,
               common_flags()->strip_path_prefix);
-  ReportErrorSummary(buff.data());
+  ReportErrorSummary(buff.data(), alt_tool_name);
 }
 #endif
 
@@ -257,9 +158,23 @@ void LoadedModule::set(const char *module_name, uptr base_address) {
   base_address_ = base_address;
 }
 
+void LoadedModule::set(const char *module_name, uptr base_address,
+                       ModuleArch arch, u8 uuid[kModuleUUIDSize],
+                       bool instrumented) {
+  set(module_name, base_address);
+  arch_ = arch;
+  internal_memcpy(uuid_, uuid, sizeof(uuid_));
+  instrumented_ = instrumented;
+}
+
 void LoadedModule::clear() {
   InternalFree(full_name_);
+  base_address_ = 0;
+  max_executable_address_ = 0;
   full_name_ = nullptr;
+  arch_ = kModuleArchUnknown;
+  internal_memset(uuid_, 0, kModuleUUIDSize);
+  instrumented_ = false;
   while (!ranges_.empty()) {
     AddressRange *r = ranges_.front();
     ranges_.pop_front();
@@ -267,10 +182,14 @@ void LoadedModule::clear() {
   }
 }
 
-void LoadedModule::addAddressRange(uptr beg, uptr end, bool executable) {
+void LoadedModule::addAddressRange(uptr beg, uptr end, bool executable,
+                                   bool writable, const char *name) {
   void *mem = InternalAlloc(sizeof(AddressRange));
-  AddressRange *r = new(mem) AddressRange(beg, end, executable);
+  AddressRange *r =
+      new(mem) AddressRange(beg, end, executable, writable, name);
   ranges_.push_back(r);
+  if (executable && end > max_executable_address_)
+    max_executable_address_ = end;
 }
 
 bool LoadedModule::containsAddress(uptr address) const {
@@ -339,36 +258,6 @@ bool TemplateMatch(const char *templ, const char *str) {
   return true;
 }
 
-static const char kPathSeparator = SANITIZER_WINDOWS ? ';' : ':';
-
-char *FindPathToBinary(const char *name) {
-  if (FileExists(name)) {
-    return internal_strdup(name);
-  }
-
-  const char *path = GetEnv("PATH");
-  if (!path)
-    return nullptr;
-  uptr name_len = internal_strlen(name);
-  InternalScopedBuffer<char> buffer(kMaxPathLength);
-  const char *beg = path;
-  while (true) {
-    const char *end = internal_strchrnul(beg, kPathSeparator);
-    uptr prefix_len = end - beg;
-    if (prefix_len + name_len + 2 <= kMaxPathLength) {
-      internal_memcpy(buffer.data(), beg, prefix_len);
-      buffer[prefix_len] = '/';
-      internal_memcpy(&buffer[prefix_len + 1], name, name_len);
-      buffer[prefix_len + 1 + name_len] = '\0';
-      if (FileExists(buffer.data()))
-        return internal_strdup(buffer.data());
-    }
-    if (*end == '\0') break;
-    beg = end + 1;
-  }
-  return nullptr;
-}
-
 static char binary_name_cache_str[kMaxPathLength];
 static char process_name_cache_str[kMaxPathLength];
 
@@ -462,16 +351,8 @@ static int InstallMallocFreeHooks(void (*malloc_hook)(const void *, uptr),
 using namespace __sanitizer;  // NOLINT
 
 extern "C" {
-void __sanitizer_set_report_path(const char *path) {
-  report_file.SetReportPath(path);
-}
-
-void __sanitizer_set_report_fd(void *fd) {
-  report_file.fd = (fd_t)reinterpret_cast<uptr>(fd);
-  report_file.fd_pid = internal_getpid();
-}
-
-void __sanitizer_report_error_summary(const char *error_summary) {
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_report_error_summary,
+                             const char *error_summary) {
   Printf("%s\n", error_summary);
 }
 
@@ -486,11 +367,4 @@ int __sanitizer_install_malloc_and_free_hooks(void (*malloc_hook)(const void *,
                                               void (*free_hook)(const void *)) {
   return InstallMallocFreeHooks(malloc_hook, free_hook);
 }
-
-#if !SANITIZER_GO && !SANITIZER_SUPPORTS_WEAK_HOOKS
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void __sanitizer_print_memory_profile(int top_percent) {
-  (void)top_percent;
-}
-#endif
 } // extern "C"
diff --git a/libsanitizer/sanitizer_common/sanitizer_common.h b/libsanitizer/sanitizer_common/sanitizer_common.h
index 3e079ab7ad1..dd207d72e29 100644
--- a/libsanitizer/sanitizer_common/sanitizer_common.h
+++ b/libsanitizer/sanitizer_common/sanitizer_common.h
@@ -27,8 +27,11 @@ extern "C" void _ReadWriteBarrier();
 #endif
 
 namespace __sanitizer {
-struct StackTrace;
+
 struct AddressInfo;
+struct BufferedStackTrace;
+struct SignalContext;
+struct StackTrace;
 
 // Constants.
 const uptr kWordSize = SANITIZER_WORDSIZE / 8;
@@ -70,7 +73,7 @@ INLINE uptr GetPageSizeCached() {
 uptr GetMmapGranularity();
 uptr GetMaxVirtualAddress();
 // Threads
-uptr GetTid();
+tid_t GetTid();
 uptr GetThreadSelf();
 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
                                 uptr *stack_bottom);
@@ -83,25 +86,36 @@ INLINE void *MmapOrDieQuietly(uptr size, const char *mem_type) {
   return MmapOrDie(size, mem_type, /*raw_report*/ true);
 }
 void UnmapOrDie(void *addr, uptr size);
+// Behaves just like MmapOrDie, but tolerates out of memory condition, in that
+// case returns nullptr.
+void *MmapOrDieOnFatalError(uptr size, const char *mem_type);
 void *MmapFixedNoReserve(uptr fixed_addr, uptr size,
                          const char *name = nullptr);
 void *MmapNoReserveOrDie(uptr size, const char *mem_type);
 void *MmapFixedOrDie(uptr fixed_addr, uptr size);
+// Behaves just like MmapFixedOrDie, but tolerates out of memory condition, in
+// that case returns nullptr.
+void *MmapFixedOrDieOnFatalError(uptr fixed_addr, uptr size);
 void *MmapFixedNoAccess(uptr fixed_addr, uptr size, const char *name = nullptr);
 void *MmapNoAccess(uptr size);
 // Map aligned chunk of address space; size and alignment are powers of two.
-void *MmapAlignedOrDie(uptr size, uptr alignment, const char *mem_type);
+// Dies on all but out of memory errors, in the latter case returns nullptr.
+void *MmapAlignedOrDieOnFatalError(uptr size, uptr alignment,
+                                   const char *mem_type);
 // Disallow access to a memory range.  Use MmapFixedNoAccess to allocate an
 // unaccessible memory.
 bool MprotectNoAccess(uptr addr, uptr size);
 bool MprotectReadOnly(uptr addr, uptr size);
 
 // Find an available address space.
-uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding);
+uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding,
+                              uptr *largest_gap_found);
 
 // Used to check if we can map shadow memory to a fixed location.
 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end);
-void ReleaseMemoryToOS(uptr addr, uptr size);
+// Releases memory pages entirely within the [beg, end] address range. Noop if
+// the provided range does not contain at least one entire page.
+void ReleaseMemoryPagesToOS(uptr beg, uptr end);
 void IncreaseTotalMmap(uptr size);
 void DecreaseTotalMmap(uptr size);
 uptr GetRSS();
@@ -112,6 +126,14 @@ void CheckVMASize();
 void RunMallocHooks(const void *ptr, uptr size);
 void RunFreeHooks(const void *ptr);
 
+typedef void (*fill_profile_f)(uptr start, uptr rss, bool file,
+                               /*out*/uptr *stats, uptr stats_size);
+
+// Parse the contents of /proc/self/smaps and generate a memory profile.
+// |cb| is a tool-specific callback that fills the |stats| array containing
+// |stats_size| elements.
+void GetMemoryProfile(fill_profile_f cb, uptr *stats, uptr stats_size);
+
 // InternalScopedBuffer can be used instead of large stack arrays to
 // keep frame size low.
 // FIXME: use InternalAlloc instead of MmapOrDie once
@@ -172,6 +194,7 @@ typedef void (*LowLevelAllocateCallback)(uptr ptr, uptr size);
 void SetLowLevelAllocateCallback(LowLevelAllocateCallback callback);
 
 // IO
+void CatastrophicErrorWrite(const char *buffer, uptr length);
 void RawWrite(const char *buffer);
 bool ColorizeReports();
 void RemoveANSIEscapeSequencesFromString(char *buffer);
@@ -188,66 +211,21 @@ void SetPrintfAndReportCallback(void (*callback)(const char *));
   } while (0)
 
 // Can be used to prevent mixing error reports from different sanitizers.
+// FIXME: Replace with ScopedErrorReportLock and hide.
 extern StaticSpinMutex CommonSanitizerReportMutex;
 
-struct ReportFile {
-  void Write(const char *buffer, uptr length);
-  bool SupportsColors();
-  void SetReportPath(const char *path);
-
-  // Don't use fields directly. They are only declared public to allow
-  // aggregate initialization.
-
-  // Protects fields below.
-  StaticSpinMutex *mu;
-  // Opened file descriptor. Defaults to stderr. It may be equal to
-  // kInvalidFd, in which case new file will be opened when necessary.
-  fd_t fd;
-  // Path prefix of report file, set via __sanitizer_set_report_path.
-  char path_prefix[kMaxPathLength];
-  // Full path to report, obtained as <path_prefix>.PID
-  char full_path[kMaxPathLength];
-  // PID of the process that opened fd. If a fork() occurs,
-  // the PID of child will be different from fd_pid.
-  uptr fd_pid;
+// Lock sanitizer error reporting and protects against nested errors.
+class ScopedErrorReportLock {
+ public:
+  ScopedErrorReportLock();
+  ~ScopedErrorReportLock();
 
- private:
-  void ReopenIfNecessary();
+  static void CheckLocked();
 };
-extern ReportFile report_file;
 
 extern uptr stoptheworld_tracer_pid;
 extern uptr stoptheworld_tracer_ppid;
 
-enum FileAccessMode {
-  RdOnly,
-  WrOnly,
-  RdWr
-};
-
-// Returns kInvalidFd on error.
-fd_t OpenFile(const char *filename, FileAccessMode mode,
-              error_t *errno_p = nullptr);
-void CloseFile(fd_t);
-
-// Return true on success, false on error.
-bool ReadFromFile(fd_t fd, void *buff, uptr buff_size,
-                  uptr *bytes_read = nullptr, error_t *error_p = nullptr);
-bool WriteToFile(fd_t fd, const void *buff, uptr buff_size,
-                 uptr *bytes_written = nullptr, error_t *error_p = nullptr);
-
-bool RenameFile(const char *oldpath, const char *newpath,
-                error_t *error_p = nullptr);
-
-// Scoped file handle closer.
-struct FileCloser {
-  explicit FileCloser(fd_t fd) : fd(fd) {}
-  ~FileCloser() { CloseFile(fd); }
-  fd_t fd;
-};
-
-bool SupportsColoredOutput(fd_t fd);
-
 // Opens the file 'file_name" and reads up to 'max_len' bytes.
 // The resulting buffer is mmaped and stored in '*buff'.
 // The size of the mmaped region is stored in '*buff_size'.
@@ -256,11 +234,6 @@ bool SupportsColoredOutput(fd_t fd);
 bool ReadFileToBuffer(const char *file_name, char **buff, uptr *buff_size,
                       uptr *read_len, uptr max_len = 1 << 26,
                       error_t *errno_p = nullptr);
-// Maps given file to virtual memory, and returns pointer to it
-// (or NULL if mapping fails). Stores the size of mmaped region
-// in '*buff_size'.
-void *MapFileToMemory(const char *file_name, uptr *buff_size);
-void *MapWritableFileToMemory(void *addr, uptr size, fd_t fd, OFF_T offset);
 
 bool IsAccessibleMemoryRange(uptr beg, uptr size);
 
@@ -279,27 +252,9 @@ void UpdateProcessName();
 void CacheBinaryName();
 void DisableCoreDumperIfNecessary();
 void DumpProcessMap();
-bool FileExists(const char *filename);
+void PrintModuleMap();
 const char *GetEnv(const char *name);
 bool SetEnv(const char *name, const char *value);
-const char *GetPwd();
-char *FindPathToBinary(const char *name);
-bool IsPathSeparator(const char c);
-bool IsAbsolutePath(const char *path);
-// Starts a subprocess and returs its pid.
-// If *_fd parameters are not kInvalidFd their corresponding input/output
-// streams will be redirect to the file. The files will always be closed
-// in parent process even in case of an error.
-// The child process will close all fds after STDERR_FILENO
-// before passing control to a program.
-pid_t StartSubprocess(const char *filename, const char *const argv[],
-                      fd_t stdin_fd = kInvalidFd, fd_t stdout_fd = kInvalidFd,
-                      fd_t stderr_fd = kInvalidFd);
-// Checks if specified process is still running
-bool IsProcessRunning(pid_t pid);
-// Waits for the process to finish and returns its exit code.
-// Returns -1 in case of an error.
-int WaitForProcess(pid_t pid);
 
 u32 GetUid();
 void ReExec();
@@ -312,15 +267,9 @@ bool AddressSpaceIsUnlimited();
 void SetAddressSpaceUnlimited();
 void AdjustStackSize(void *attr);
 void PrepareForSandboxing(__sanitizer_sandbox_arguments *args);
-void CovPrepareForSandboxing(__sanitizer_sandbox_arguments *args);
 void SetSandboxingCallback(void (*f)());
 
-void CoverageUpdateMapping();
-void CovBeforeFork();
-void CovAfterFork(int child_pid);
-
 void InitializeCoverage(bool enabled, const char *coverage_dir);
-void ReInitializeCoverage(bool enabled, const char *coverage_dir);
 
 void InitTlsSize();
 uptr GetTlsSize();
@@ -373,16 +322,28 @@ void SetCheckFailedCallback(CheckFailedCallbackType callback);
 // The callback should be registered once at the tool init time.
 void SetSoftRssLimitExceededCallback(void (*Callback)(bool exceeded));
 
-// Callback to be called when we want to try releasing unused allocator memory
-// back to the OS.
-typedef void (*AllocatorReleaseToOSCallback)();
-// The callback should be registered once at the tool init time.
-void SetAllocatorReleaseToOSCallback(AllocatorReleaseToOSCallback Callback);
-
 // Functions related to signal handling.
 typedef void (*SignalHandlerType)(int, void *, void *);
-bool IsHandledDeadlySignal(int signum);
+HandleSignalMode GetHandleSignalMode(int signum);
 void InstallDeadlySignalHandlers(SignalHandlerType handler);
+
+// Signal reporting.
+// Each sanitizer uses slightly different implementation of stack unwinding.
+typedef void (*UnwindSignalStackCallbackType)(const SignalContext &sig,
+                                              const void *callback_context,
+                                              BufferedStackTrace *stack);
+// Print deadly signal report and die.
+void HandleDeadlySignal(void *siginfo, void *context, u32 tid,
+                        UnwindSignalStackCallbackType unwind,
+                        const void *unwind_context);
+
+// Part of HandleDeadlySignal, exposed for asan.
+void StartReportDeadlySignal();
+// Part of HandleDeadlySignal, exposed for asan.
+void ReportDeadlySignal(const SignalContext &sig, u32 tid,
+                        UnwindSignalStackCallbackType unwind,
+                        const void *unwind_context);
+
 // Alternative signal stack (POSIX-only).
 void SetAlternateSignalStack();
 void UnsetAlternateSignalStack();
@@ -392,12 +353,16 @@ const int kMaxSummaryLength = 1024;
 // Construct a one-line string:
 //   SUMMARY: SanitizerToolName: error_message
 // and pass it to __sanitizer_report_error_summary.
-void ReportErrorSummary(const char *error_message);
+// If alt_tool_name is provided, it's used in place of SanitizerToolName.
+void ReportErrorSummary(const char *error_message,
+                        const char *alt_tool_name = nullptr);
 // Same as above, but construct error_message as:
 //   error_type file:line[:column][ function]
-void ReportErrorSummary(const char *error_type, const AddressInfo &info);
+void ReportErrorSummary(const char *error_type, const AddressInfo &info,
+                        const char *alt_tool_name = nullptr);
 // Same as above, but obtains AddressInfo by symbolizing top stack trace frame.
-void ReportErrorSummary(const char *error_type, const StackTrace *trace);
+void ReportErrorSummary(const char *error_type, const StackTrace *trace,
+                        const char *alt_tool_name = nullptr);
 
 // Math
 #if SANITIZER_WINDOWS && !defined(__clang__) && !defined(__GNUC__)
@@ -549,6 +514,13 @@ class InternalMmapVectorNoCtor {
   uptr capacity() const {
     return capacity_;
   }
+  void resize(uptr new_size) {
+    Resize(new_size);
+    if (new_size > size_) {
+      internal_memset(&data_[size_], 0, sizeof(T) * (new_size - size_));
+    }
+    size_ = new_size;
+  }
 
   void clear() { size_ = 0; }
   bool empty() const { return size() == 0; }
@@ -633,43 +605,108 @@ void InternalSort(Container *v, uptr size, Compare comp) {
   }
 }
 
-template<class Container, class Value, class Compare>
-uptr InternalBinarySearch(const Container &v, uptr first, uptr last,
-                          const Value &val, Compare comp) {
-  uptr not_found = last + 1;
-  while (last >= first) {
+// Works like std::lower_bound: finds the first element that is not less
+// than the val.
+template <class Container, class Value, class Compare>
+uptr InternalLowerBound(const Container &v, uptr first, uptr last,
+                        const Value &val, Compare comp) {
+  while (last > first) {
     uptr mid = (first + last) / 2;
     if (comp(v[mid], val))
       first = mid + 1;
-    else if (comp(val, v[mid]))
-      last = mid - 1;
     else
-      return mid;
+      last = mid;
+  }
+  return first;
+}
+
+enum ModuleArch {
+  kModuleArchUnknown,
+  kModuleArchI386,
+  kModuleArchX86_64,
+  kModuleArchX86_64H,
+  kModuleArchARMV6,
+  kModuleArchARMV7,
+  kModuleArchARMV7S,
+  kModuleArchARMV7K,
+  kModuleArchARM64
+};
+
+// When adding a new architecture, don't forget to also update
+// script/asan_symbolize.py and sanitizer_symbolizer_libcdep.cc.
+inline const char *ModuleArchToString(ModuleArch arch) {
+  switch (arch) {
+    case kModuleArchUnknown:
+      return "";
+    case kModuleArchI386:
+      return "i386";
+    case kModuleArchX86_64:
+      return "x86_64";
+    case kModuleArchX86_64H:
+      return "x86_64h";
+    case kModuleArchARMV6:
+      return "armv6";
+    case kModuleArchARMV7:
+      return "armv7";
+    case kModuleArchARMV7S:
+      return "armv7s";
+    case kModuleArchARMV7K:
+      return "armv7k";
+    case kModuleArchARM64:
+      return "arm64";
   }
-  return not_found;
+  CHECK(0 && "Invalid module arch");
+  return "";
 }
 
+const uptr kModuleUUIDSize = 16;
+const uptr kMaxSegName = 16;
+
 // Represents a binary loaded into virtual memory (e.g. this can be an
 // executable or a shared object).
 class LoadedModule {
  public:
-  LoadedModule() : full_name_(nullptr), base_address_(0) { ranges_.clear(); }
+  LoadedModule()
+      : full_name_(nullptr),
+        base_address_(0),
+        max_executable_address_(0),
+        arch_(kModuleArchUnknown),
+        instrumented_(false) {
+    internal_memset(uuid_, 0, kModuleUUIDSize);
+    ranges_.clear();
+  }
   void set(const char *module_name, uptr base_address);
+  void set(const char *module_name, uptr base_address, ModuleArch arch,
+           u8 uuid[kModuleUUIDSize], bool instrumented);
   void clear();
-  void addAddressRange(uptr beg, uptr end, bool executable);
+  void addAddressRange(uptr beg, uptr end, bool executable, bool writable,
+                       const char *name = nullptr);
   bool containsAddress(uptr address) const;
 
   const char *full_name() const { return full_name_; }
   uptr base_address() const { return base_address_; }
+  uptr max_executable_address() const { return max_executable_address_; }
+  ModuleArch arch() const { return arch_; }
+  const u8 *uuid() const { return uuid_; }
+  bool instrumented() const { return instrumented_; }
 
   struct AddressRange {
     AddressRange *next;
     uptr beg;
     uptr end;
     bool executable;
-
-    AddressRange(uptr beg, uptr end, bool executable)
-        : next(nullptr), beg(beg), end(end), executable(executable) {}
+    bool writable;
+    char name[kMaxSegName];
+
+    AddressRange(uptr beg, uptr end, bool executable, bool writable,
+                 const char *name)
+        : next(nullptr),
+          beg(beg),
+          end(end),
+          executable(executable),
+          writable(writable) {
+      internal_strncpy(this->name, (name ? name : ""), ARRAY_SIZE(this->name));
+    }
   };
 
   const IntrusiveList<AddressRange> &ranges() const { return ranges_; }
@@ -677,6 +714,10 @@ class LoadedModule {
  private:
   char *full_name_;  // Owned.
   uptr base_address_;
+  uptr max_executable_address_;
+  ModuleArch arch_;
+  u8 uuid_[kModuleUUIDSize];
+  bool instrumented_;
   IntrusiveList<AddressRange> ranges_;
 };
 
@@ -684,9 +725,10 @@ class LoadedModule {
 // filling this information.
 class ListOfModules {
  public:
-  ListOfModules() : modules_(kInitialCapacity) {}
+  ListOfModules() : initialized(false) {}
   ~ListOfModules() { clear(); }
   void init();
+  void fallbackInit();  // Uses fallback init if available, otherwise clears
   const LoadedModule *begin() const { return modules_.begin(); }
   LoadedModule *begin() { return modules_.begin(); }
   const LoadedModule *end() const { return modules_.end(); }
@@ -702,10 +744,15 @@ class ListOfModules {
     for (auto &module : modules_) module.clear();
     modules_.clear();
   }
+  void clearOrInit() {
+    initialized ? clear() : modules_.Initialize(kInitialCapacity);
+    initialized = true;
+  }
 
-  InternalMmapVector<LoadedModule> modules_;
+  InternalMmapVectorNoCtor<LoadedModule> modules_;
   // We rarely have more than 16K loaded modules.
   static const uptr kInitialCapacity = 1 << 14;
+  bool initialized;
 };
 
 // Callback type for iterating over a set of memory ranges.
@@ -737,8 +784,11 @@ INLINE void LogMessageOnPrintf(const char *str) {}
 #if SANITIZER_LINUX
 // Initialize Android logging. Any writes before this are silently lost.
 void AndroidLogInit();
+void SetAbortMessage(const char *);
 #else
 INLINE void AndroidLogInit() {}
+// FIXME: MacOS implementation could use CRSetCrashLogMessage.
+INLINE void SetAbortMessage(const char *) {}
 #endif
 
 #if SANITIZER_ANDROID
@@ -778,33 +828,49 @@ static inline void SanitizerBreakOptimization(void *arg) {
 }
 
 struct SignalContext {
+  void *siginfo;
   void *context;
   uptr addr;
   uptr pc;
   uptr sp;
   uptr bp;
   bool is_memory_access;
-
   enum WriteFlag { UNKNOWN, READ, WRITE } write_flag;
 
-  SignalContext(void *context, uptr addr, uptr pc, uptr sp, uptr bp,
-                bool is_memory_access, WriteFlag write_flag)
-      : context(context),
-        addr(addr),
-        pc(pc),
-        sp(sp),
-        bp(bp),
-        is_memory_access(is_memory_access),
-        write_flag(write_flag) {}
+  // VS2013 doesn't implement unrestricted unions, so we need a trivial default
+  // constructor
+  SignalContext() = default;
 
   // Creates signal context in a platform-specific manner.
-  static SignalContext Create(void *siginfo, void *context);
+  // SignalContext is going to keep pointers to siginfo and context without
+  // owning them.
+  SignalContext(void *siginfo, void *context)
+      : siginfo(siginfo),
+        context(context),
+        addr(GetAddress()),
+        is_memory_access(IsMemoryAccess()),
+        write_flag(GetWriteFlag()) {
+    InitPcSpBp();
+  }
 
-  // Returns true if the "context" indicates a memory write.
-  static WriteFlag GetWriteFlag(void *context);
-};
+  static void DumpAllRegisters(void *context);
+
+  // Type of signal e.g. SIGSEGV or EXCEPTION_ACCESS_VIOLATION.
+  int GetType() const;
+
+  // String description of the signal.
+  const char *Describe() const;
+
+  // Returns true if signal is stack overflow.
+  bool IsStackOverflow() const;
 
-void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp);
+ private:
+  // Platform specific initialization.
+  void InitPcSpBp();
+  uptr GetAddress() const;
+  WriteFlag GetWriteFlag() const;
+  bool IsMemoryAccess() const;
+};
 
 void MaybeReexec();
 
@@ -840,6 +906,16 @@ struct StackDepotStats {
   uptr allocated;
 };
 
+// The default value for allocator_release_to_os_interval_ms common flag to
+// indicate that sanitizer allocator should not attempt to release memory to OS.
+const s32 kReleaseToOSIntervalNever = -1;
+
+void CheckNoDeepBind(const char *filename, int flag);
+
+// Returns the requested amount of random data (up to 256 bytes) that can then
+// be used to seed a PRNG. Defaults to blocking like the underlying syscall.
+bool GetRandom(void *buffer, uptr length, bool blocking = true);
+
 }  // namespace __sanitizer
 
 inline void *operator new(__sanitizer::operator_new_size_type size,
diff --git a/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc b/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc
index 195014022a0..3f32b2f78ef 100644
--- a/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc
@@ -22,32 +22,34 @@
 //   COMMON_INTERCEPTOR_SET_THREAD_NAME
 //   COMMON_INTERCEPTOR_ON_DLOPEN
 //   COMMON_INTERCEPTOR_ON_EXIT
-//   COMMON_INTERCEPTOR_MUTEX_LOCK
+//   COMMON_INTERCEPTOR_MUTEX_PRE_LOCK
+//   COMMON_INTERCEPTOR_MUTEX_POST_LOCK
 //   COMMON_INTERCEPTOR_MUTEX_UNLOCK
 //   COMMON_INTERCEPTOR_MUTEX_REPAIR
 //   COMMON_INTERCEPTOR_SET_PTHREAD_NAME
 //   COMMON_INTERCEPTOR_HANDLE_RECVMSG
 //   COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED
+//   COMMON_INTERCEPTOR_MEMSET_IMPL
+//   COMMON_INTERCEPTOR_MEMMOVE_IMPL
+//   COMMON_INTERCEPTOR_MEMCPY_IMPL
+//   COMMON_INTERCEPTOR_COPY_STRING
+//   COMMON_INTERCEPTOR_STRNDUP_IMPL
 //===----------------------------------------------------------------------===//
 
 #include "interception/interception.h"
 #include "sanitizer_addrhashmap.h"
+#include "sanitizer_errno.h"
 #include "sanitizer_placement_new.h"
 #include "sanitizer_platform_interceptors.h"
+#include "sanitizer_symbolizer.h"
 #include "sanitizer_tls_get_addr.h"
 
 #include <stdarg.h>
 
 #if SANITIZER_INTERCEPTOR_HOOKS
-#define CALL_WEAK_INTERCEPTOR_HOOK(f, ...)                                     \
-  do {                                                                         \
-    if (f)                                                                     \
-      f(__VA_ARGS__);                                                          \
-  } while (false);
-#define DECLARE_WEAK_INTERCEPTOR_HOOK(f, ...)                                  \
-  extern "C" {                                                                 \
-  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE void f(__VA_ARGS__);  \
-  } // extern "C"
+#define CALL_WEAK_INTERCEPTOR_HOOK(f, ...) f(__VA_ARGS__);
+#define DECLARE_WEAK_INTERCEPTOR_HOOK(f, ...) \
+  SANITIZER_INTERFACE_WEAK_DEF(void, f, __VA_ARGS__) {}
 #else
 #define DECLARE_WEAK_INTERCEPTOR_HOOK(f, ...)
 #define CALL_WEAK_INTERCEPTOR_HOOK(f, ...)
@@ -65,6 +67,19 @@
 #define iconv __bsd_iconv
 #endif
 
+// Platform-specific options.
+#if SANITIZER_MAC
+namespace __sanitizer {
+bool PlatformHasDifferentMemcpyAndMemmove();
+}
+#define PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE \
+  (__sanitizer::PlatformHasDifferentMemcpyAndMemmove())
+#elif SANITIZER_WINDOWS64
+#define PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE false
+#else
+#define PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE true
+#endif  // SANITIZER_MAC
+
 #ifndef COMMON_INTERCEPTOR_INITIALIZE_RANGE
 #define COMMON_INTERCEPTOR_INITIALIZE_RANGE(p, size) {}
 #endif
@@ -77,8 +92,12 @@
 #define COMMON_INTERCEPTOR_FD_ACCESS(ctx, fd) {}
 #endif
 
-#ifndef COMMON_INTERCEPTOR_MUTEX_LOCK
-#define COMMON_INTERCEPTOR_MUTEX_LOCK(ctx, m) {}
+#ifndef COMMON_INTERCEPTOR_MUTEX_PRE_LOCK
+#define COMMON_INTERCEPTOR_MUTEX_PRE_LOCK(ctx, m) {}
+#endif
+
+#ifndef COMMON_INTERCEPTOR_MUTEX_POST_LOCK
+#define COMMON_INTERCEPTOR_MUTEX_POST_LOCK(ctx, m) {}
 #endif
 
 #ifndef COMMON_INTERCEPTOR_MUTEX_UNLOCK
@@ -122,15 +141,13 @@
 #define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED (0)
 #endif
 
-#define COMMON_INTERCEPTOR_READ_STRING_OF_LEN(ctx, s, len, n)       \
-    COMMON_INTERCEPTOR_READ_RANGE((ctx), (s),                       \
-      common_flags()->strict_string_checks ? (len) + 1 : (n) )
-
 #define COMMON_INTERCEPTOR_READ_STRING(ctx, s, n)                   \
-    COMMON_INTERCEPTOR_READ_STRING_OF_LEN((ctx), (s), REAL(strlen)(s), (n))
+    COMMON_INTERCEPTOR_READ_RANGE((ctx), (s),                       \
+      common_flags()->strict_string_checks ? (REAL(strlen)(s)) + 1 : (n) )
 
 #ifndef COMMON_INTERCEPTOR_ON_DLOPEN
-#define COMMON_INTERCEPTOR_ON_DLOPEN(filename, flag) {}
+#define COMMON_INTERCEPTOR_ON_DLOPEN(filename, flag) \
+  CheckNoDeepBind(filename, flag);
 #endif
 
 #ifndef COMMON_INTERCEPTOR_GET_TLS_RANGE
@@ -161,6 +178,65 @@
     COMMON_INTERCEPT_FUNCTION(fn)
 #endif
 
+#ifndef COMMON_INTERCEPTOR_MEMSET_IMPL
+#define COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, dst, v, size) \
+  {                                                       \
+    if (COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED)        \
+      return internal_memset(dst, v, size);               \
+    COMMON_INTERCEPTOR_ENTER(ctx, memset, dst, v, size);  \
+    if (common_flags()->intercept_intrin)                 \
+      COMMON_INTERCEPTOR_WRITE_RANGE(ctx, dst, size);     \
+    return REAL(memset)(dst, v, size);                    \
+  }
+#endif
+
+#ifndef COMMON_INTERCEPTOR_MEMMOVE_IMPL
+#define COMMON_INTERCEPTOR_MEMMOVE_IMPL(ctx, dst, src, size) \
+  {                                                          \
+    if (COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED)           \
+      return internal_memmove(dst, src, size);               \
+    COMMON_INTERCEPTOR_ENTER(ctx, memmove, dst, src, size);  \
+    if (common_flags()->intercept_intrin) {                  \
+      COMMON_INTERCEPTOR_WRITE_RANGE(ctx, dst, size);        \
+      COMMON_INTERCEPTOR_READ_RANGE(ctx, src, size);         \
+    }                                                        \
+    return REAL(memmove)(dst, src, size);                    \
+  }
+#endif
+
+#ifndef COMMON_INTERCEPTOR_MEMCPY_IMPL
+#define COMMON_INTERCEPTOR_MEMCPY_IMPL(ctx, dst, src, size) \
+  {                                                         \
+    if (COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED) {        \
+      return internal_memmove(dst, src, size);              \
+    }                                                       \
+    COMMON_INTERCEPTOR_ENTER(ctx, memcpy, dst, src, size);  \
+    if (common_flags()->intercept_intrin) {                 \
+      COMMON_INTERCEPTOR_WRITE_RANGE(ctx, dst, size);       \
+      COMMON_INTERCEPTOR_READ_RANGE(ctx, src, size);        \
+    }                                                       \
+    return REAL(memcpy)(dst, src, size);                    \
+  }
+#endif
+
+#ifndef COMMON_INTERCEPTOR_COPY_STRING
+#define COMMON_INTERCEPTOR_COPY_STRING(ctx, to, from, size) {}
+#endif
+
+#ifndef COMMON_INTERCEPTOR_STRNDUP_IMPL
+#define COMMON_INTERCEPTOR_STRNDUP_IMPL(ctx, s, size)                         \
+  COMMON_INTERCEPTOR_ENTER(ctx, strndup, s, size);                            \
+  uptr copy_length = internal_strnlen(s, size);                               \
+  char *new_mem = (char *)WRAP(malloc)(copy_length + 1);                      \
+  if (common_flags()->intercept_strndup) {                                    \
+    COMMON_INTERCEPTOR_READ_STRING(ctx, s, Min(size, copy_length + 1));       \
+  }                                                                           \
+  COMMON_INTERCEPTOR_COPY_STRING(ctx, new_mem, s, copy_length);               \
+  internal_memcpy(new_mem, s, copy_length);                                   \
+  new_mem[copy_length] = '\0';                                                \
+  return new_mem;
+#endif
+
 struct FileMetadata {
   // For open_memstream().
   char **addr;
@@ -181,7 +257,7 @@ typedef AddrHashMap<CommonInterceptorMetadata, 31051> MetadataHashMap;
 
 static MetadataHashMap *interceptor_metadata_map;
 
-#if SI_NOT_WINDOWS
+#if SI_POSIX
 UNUSED static void SetInterceptorMetadata(__sanitizer_FILE *addr,
                                           const FileMetadata &file) {
   MetadataHashMap::Handle h(interceptor_metadata_map, (uptr)addr);
@@ -208,7 +284,7 @@ UNUSED static void DeleteInterceptorMetadata(void *addr) {
   MetadataHashMap::Handle h(interceptor_metadata_map, (uptr)addr, true);
   CHECK(h.exists());
 }
-#endif  // SI_NOT_WINDOWS
+#endif  // SI_POSIX
 
 #if SANITIZER_INTERCEPT_STRLEN
 INTERCEPTOR(SIZE_T, strlen, const char *s) {
@@ -244,11 +320,31 @@ INTERCEPTOR(SIZE_T, strnlen, const char *s, SIZE_T maxlen) {
 #define INIT_STRNLEN
 #endif
 
+#if SANITIZER_INTERCEPT_STRNDUP
+INTERCEPTOR(char*, strndup, const char *s, uptr size) {
+  void *ctx;
+  COMMON_INTERCEPTOR_STRNDUP_IMPL(ctx, s, size);
+}
+#define INIT_STRNDUP COMMON_INTERCEPT_FUNCTION(strndup)
+#else
+#define INIT_STRNDUP
+#endif // SANITIZER_INTERCEPT_STRNDUP
+
+#if SANITIZER_INTERCEPT___STRNDUP
+INTERCEPTOR(char*, __strndup, const char *s, uptr size) {
+  void *ctx;
+  COMMON_INTERCEPTOR_STRNDUP_IMPL(ctx, s, size);
+}
+#define INIT___STRNDUP COMMON_INTERCEPT_FUNCTION(__strndup)
+#else
+#define INIT___STRNDUP
+#endif // SANITIZER_INTERCEPT___STRNDUP
+
 #if SANITIZER_INTERCEPT_TEXTDOMAIN
 INTERCEPTOR(char*, textdomain, const char *domainname) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, textdomain, domainname);
-  COMMON_INTERCEPTOR_READ_STRING(ctx, domainname, 0);
+  if (domainname) COMMON_INTERCEPTOR_READ_STRING(ctx, domainname, 0);
   char *domain = REAL(textdomain)(domainname);
   if (domain) {
     COMMON_INTERCEPTOR_INITIALIZE_RANGE(domain, REAL(strlen)(domain) + 1);
@@ -302,8 +398,14 @@ INTERCEPTOR(int, strncmp, const char *s1, const char *s2, uptr size) {
     c2 = (unsigned char)s2[i];
     if (c1 != c2 || c1 == '\0') break;
   }
-  COMMON_INTERCEPTOR_READ_STRING(ctx, s1, Min(i + 1, size));
-  COMMON_INTERCEPTOR_READ_STRING(ctx, s2, Min(i + 1, size));
+  uptr i1 = i;
+  uptr i2 = i;
+  if (common_flags()->strict_string_checks) {
+    for (; i1 < size && s1[i1]; i1++) {}
+    for (; i2 < size && s2[i2]; i2++) {}
+  }
+  COMMON_INTERCEPTOR_READ_RANGE((ctx), (s1), Min(i1 + 1, size));
+  COMMON_INTERCEPTOR_READ_RANGE((ctx), (s2), Min(i2 + 1, size));
   int result = CharCmpX(c1, c2);
   CALL_WEAK_INTERCEPTOR_HOOK(__sanitizer_weak_hook_strncmp, GET_CALLER_PC(), s1,
                              s2, size, result);
@@ -346,24 +448,30 @@ INTERCEPTOR(int, strcasecmp, const char *s1, const char *s2) {
 }
 
 DECLARE_WEAK_INTERCEPTOR_HOOK(__sanitizer_weak_hook_strncasecmp, uptr called_pc,
-                              const char *s1, const char *s2, uptr n,
+                              const char *s1, const char *s2, uptr size,
                               int result)
 
-INTERCEPTOR(int, strncasecmp, const char *s1, const char *s2, SIZE_T n) {
+INTERCEPTOR(int, strncasecmp, const char *s1, const char *s2, SIZE_T size) {
   void *ctx;
-  COMMON_INTERCEPTOR_ENTER(ctx, strncasecmp, s1, s2, n);
+  COMMON_INTERCEPTOR_ENTER(ctx, strncasecmp, s1, s2, size);
   unsigned char c1 = 0, c2 = 0;
   uptr i;
-  for (i = 0; i < n; i++) {
+  for (i = 0; i < size; i++) {
     c1 = (unsigned char)s1[i];
     c2 = (unsigned char)s2[i];
     if (CharCaseCmp(c1, c2) != 0 || c1 == '\0') break;
   }
-  COMMON_INTERCEPTOR_READ_RANGE(ctx, s1, Min(i + 1, n));
-  COMMON_INTERCEPTOR_READ_RANGE(ctx, s2, Min(i + 1, n));
+  uptr i1 = i;
+  uptr i2 = i;
+  if (common_flags()->strict_string_checks) {
+    for (; i1 < size && s1[i1]; i1++) {}
+    for (; i2 < size && s2[i2]; i2++) {}
+  }
+  COMMON_INTERCEPTOR_READ_RANGE((ctx), (s1), Min(i1 + 1, size));
+  COMMON_INTERCEPTOR_READ_RANGE((ctx), (s2), Min(i2 + 1, size));
   int result = CharCaseCmp(c1, c2);
   CALL_WEAK_INTERCEPTOR_HOOK(__sanitizer_weak_hook_strncasecmp, GET_CALLER_PC(),
-                             s1, s2, n, result);
+                             s1, s2, size, result);
   return result;
 }
 
@@ -379,8 +487,7 @@ static inline void StrstrCheck(void *ctx, char *r, const char *s1,
                                const char *s2) {
     uptr len1 = REAL(strlen)(s1);
     uptr len2 = REAL(strlen)(s2);
-    COMMON_INTERCEPTOR_READ_STRING_OF_LEN(ctx, s1, len1,
-                                          r ? r - s1 + len2 : len1 + 1);
+    COMMON_INTERCEPTOR_READ_STRING(ctx, s1, r ? r - s1 + len2 : len1 + 1);
     COMMON_INTERCEPTOR_READ_RANGE(ctx, s2, len2 + 1);
 }
 #endif
@@ -429,6 +536,52 @@ INTERCEPTOR(char*, strcasestr, const char *s1, const char *s2) {
 #define INIT_STRCASESTR
 #endif
 
+#if SANITIZER_INTERCEPT_STRTOK
+
+INTERCEPTOR(char*, strtok, char *str, const char *delimiters) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, strtok, str, delimiters);
+  if (!common_flags()->intercept_strtok) {
+    return REAL(strtok)(str, delimiters);
+  }
+  if (common_flags()->strict_string_checks) {
+    // If strict_string_checks is enabled, we check the whole first argument
+    // string on the first call (strtok saves this string in a static buffer
+    // for subsequent calls). We do not need to check strtok's result.
+    // As the delimiters can change, we check them every call.
+    if (str != nullptr) {
+      COMMON_INTERCEPTOR_READ_RANGE(ctx, str, REAL(strlen)(str) + 1);
+    }
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, delimiters,
+                                  REAL(strlen)(delimiters) + 1);
+    return REAL(strtok)(str, delimiters);
+  } else {
+    // However, when strict_string_checks is disabled we cannot check the
+    // whole string on the first call. Instead, we check the result string
+    // which is guaranteed to be a NULL-terminated substring of the first
+    // argument. We also conservatively check one character of str and the
+    // delimiters.
+    if (str != nullptr) {
+      COMMON_INTERCEPTOR_READ_STRING(ctx, str, 1);
+    }
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, delimiters, 1);
+    char *result = REAL(strtok)(str, delimiters);
+    if (result != nullptr) {
+      COMMON_INTERCEPTOR_READ_RANGE(ctx, result, REAL(strlen)(result) + 1);
+    } else if (str != nullptr) {
+      // No delimiter were found, it's safe to assume that the entire str was
+      // scanned.
+      COMMON_INTERCEPTOR_READ_RANGE(ctx, str, REAL(strlen)(str) + 1);
+    }
+    return result;
+  }
+}
+
+#define INIT_STRTOK COMMON_INTERCEPT_FUNCTION(strtok)
+#else
+#define INIT_STRTOK
+#endif
+
 #if SANITIZER_INTERCEPT_MEMMEM
 DECLARE_WEAK_INTERCEPTOR_HOOK(__sanitizer_weak_hook_memmem, uptr called_pc,
                               const void *s1, SIZE_T len1, const void *s2,
@@ -460,10 +613,11 @@ INTERCEPTOR(char*, strchr, const char *s, int c) {
     return internal_strchr(s, c);
   COMMON_INTERCEPTOR_ENTER(ctx, strchr, s, c);
   char *result = REAL(strchr)(s, c);
-  uptr len = internal_strlen(s);
-  uptr n = result ? result - s + 1 : len + 1;
-  if (common_flags()->intercept_strchr)
-    COMMON_INTERCEPTOR_READ_STRING_OF_LEN(ctx, s, len, n);
+  if (common_flags()->intercept_strchr) {
+    // Keep strlen as macro argument, as macro may ignore it.
+    COMMON_INTERCEPTOR_READ_STRING(ctx, s,
+      (result ? result - s : REAL(strlen)(s)) + 1);
+  }
   return result;
 }
 #define INIT_STRCHR COMMON_INTERCEPT_FUNCTION(strchr)
@@ -492,9 +646,8 @@ INTERCEPTOR(char*, strrchr, const char *s, int c) {
   if (COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED)
     return internal_strrchr(s, c);
   COMMON_INTERCEPTOR_ENTER(ctx, strrchr, s, c);
-  uptr len = internal_strlen(s);
   if (common_flags()->intercept_strchr)
-    COMMON_INTERCEPTOR_READ_STRING_OF_LEN(ctx, s, len, len + 1);
+    COMMON_INTERCEPTOR_READ_RANGE(ctx, s, REAL(strlen)(s) + 1);
   return REAL(strrchr)(s, c);
 }
 #define INIT_STRRCHR COMMON_INTERCEPT_FUNCTION(strrchr)
@@ -551,14 +704,9 @@ INTERCEPTOR(char *, strpbrk, const char *s1, const char *s2) {
 #endif
 
 #if SANITIZER_INTERCEPT_MEMSET
-INTERCEPTOR(void*, memset, void *dst, int v, uptr size) {
-  if (COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED)
-    return internal_memset(dst, v, size);
+INTERCEPTOR(void *, memset, void *dst, int v, uptr size) {
   void *ctx;
-  COMMON_INTERCEPTOR_ENTER(ctx, memset, dst, v, size);
-  if (common_flags()->intercept_intrin)
-    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, dst, size);
-  return REAL(memset)(dst, v, size);
+  COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, dst, v, size);
 }
 
 #define INIT_MEMSET COMMON_INTERCEPT_FUNCTION(memset)
@@ -567,16 +715,9 @@ INTERCEPTOR(void*, memset, void *dst, int v, uptr size) {
 #endif
 
 #if SANITIZER_INTERCEPT_MEMMOVE
-INTERCEPTOR(void*, memmove, void *dst, const void *src, uptr size) {
-  if (COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED)
-    return internal_memmove(dst, src, size);
+INTERCEPTOR(void *, memmove, void *dst, const void *src, uptr size) {
   void *ctx;
-  COMMON_INTERCEPTOR_ENTER(ctx, memmove, dst, src, size);
-  if (common_flags()->intercept_intrin) {
-    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, dst, size);
-    COMMON_INTERCEPTOR_READ_RANGE(ctx, src, size);
-  }
-  return REAL(memmove)(dst, src, size);
+  COMMON_INTERCEPTOR_MEMMOVE_IMPL(ctx, dst, src, size);
 }
 
 #define INIT_MEMMOVE COMMON_INTERCEPT_FUNCTION(memmove)
@@ -585,25 +726,30 @@ INTERCEPTOR(void*, memmove, void *dst, const void *src, uptr size) {
 #endif
 
 #if SANITIZER_INTERCEPT_MEMCPY
-INTERCEPTOR(void*, memcpy, void *dst, const void *src, uptr size) {
-  if (COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED) {
-    // On OS X, calling internal_memcpy here will cause memory corruptions,
-    // because memcpy and memmove are actually aliases of the same
-    // implementation.  We need to use internal_memmove here.
-    return internal_memmove(dst, src, size);
-  }
-  void *ctx;
-  COMMON_INTERCEPTOR_ENTER(ctx, memcpy, dst, src, size);
-  if (common_flags()->intercept_intrin) {
-    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, dst, size);
-    COMMON_INTERCEPTOR_READ_RANGE(ctx, src, size);
-  }
+INTERCEPTOR(void *, memcpy, void *dst, const void *src, uptr size) {
+  // On OS X, calling internal_memcpy here will cause memory corruptions,
+  // because memcpy and memmove are actually aliases of the same
+  // implementation.  We need to use internal_memmove here.
   // N.B.: If we switch this to internal_ we'll have to use internal_memmove
   // due to memcpy being an alias of memmove on OS X.
-  return REAL(memcpy)(dst, src, size);
+  void *ctx;
+  if (PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE) {
+    COMMON_INTERCEPTOR_MEMCPY_IMPL(ctx, dst, src, size);
+  } else {
+    COMMON_INTERCEPTOR_MEMMOVE_IMPL(ctx, dst, src, size);
+  }
 }
 
-#define INIT_MEMCPY COMMON_INTERCEPT_FUNCTION(memcpy)
+#define INIT_MEMCPY                                  \
+  do {                                               \
+    if (PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE) { \
+      COMMON_INTERCEPT_FUNCTION(memcpy);             \
+    } else {                                         \
+      ASSIGN_REAL(memcpy, memmove);                  \
+    }                                                \
+    CHECK(REAL(memcpy));                             \
+  } while (false)
+
 #else
 #define INIT_MEMCPY
 #endif
@@ -739,7 +885,7 @@ INTERCEPTOR(long double, frexpl, long double x, int *exp) {
 #define INIT_FREXPF_FREXPL
 #endif  // SANITIZER_INTERCEPT_FREXPF_FREXPL
 
-#if SI_NOT_WINDOWS
+#if SI_POSIX
 static void write_iovec(void *ctx, struct __sanitizer_iovec *iovec,
                         SIZE_T iovlen, SIZE_T maxlen) {
   for (SIZE_T i = 0; i < iovlen && maxlen; ++i) {
@@ -778,6 +924,23 @@ INTERCEPTOR(SSIZE_T, read, int fd, void *ptr, SIZE_T count) {
 #define INIT_READ
 #endif
 
+#if SANITIZER_INTERCEPT_FREAD
+INTERCEPTOR(SIZE_T, fread, void *ptr, SIZE_T size, SIZE_T nmemb, void *file) {
+  // libc file streams can call user-supplied functions, see fopencookie.
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, fread, ptr, size, nmemb, file);
+  // FIXME: under ASan the call below may write to freed memory and corrupt
+  // its metadata. See
+  // https://github.com/google/sanitizers/issues/321.
+  SIZE_T res = REAL(fread)(ptr, size, nmemb, file);
+  if (res > 0) COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, res * size);
+  return res;
+}
+#define INIT_FREAD COMMON_INTERCEPT_FUNCTION(fread)
+#else
+#define INIT_FREAD
+#endif
+
 #if SANITIZER_INTERCEPT_PREAD
 INTERCEPTOR(SSIZE_T, pread, int fd, void *ptr, SIZE_T count, OFF_T offset) {
   void *ctx;
@@ -878,6 +1041,20 @@ INTERCEPTOR(SSIZE_T, write, int fd, void *ptr, SIZE_T count) {
 #define INIT_WRITE
 #endif
 
+#if SANITIZER_INTERCEPT_FWRITE
+INTERCEPTOR(SIZE_T, fwrite, const void *p, uptr size, uptr nmemb, void *file) {
+  // libc file streams can call user-supplied functions, see fopencookie.
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, fwrite, p, size, nmemb, file);
+  SIZE_T res = REAL(fwrite)(p, size, nmemb, file);
+  if (res > 0) COMMON_INTERCEPTOR_READ_RANGE(ctx, p, res * size);
+  return res;
+}
+#define INIT_FWRITE COMMON_INTERCEPT_FUNCTION(fwrite)
+#else
+#define INIT_FWRITE
+#endif
+
 #if SANITIZER_INTERCEPT_PWRITE
 INTERCEPTOR(SSIZE_T, pwrite, int fd, void *ptr, SIZE_T count, OFF_T offset) {
   void *ctx;
@@ -1225,12 +1402,12 @@ FORMAT_INTERCEPTOR_IMPL(__isoc99_sscanf, __isoc99_vsscanf, str, format)
 
 #if SANITIZER_INTERCEPT_SCANF
 #define INIT_SCANF                    \
-  COMMON_INTERCEPT_FUNCTION(scanf);   \
-  COMMON_INTERCEPT_FUNCTION(sscanf);  \
-  COMMON_INTERCEPT_FUNCTION(fscanf);  \
-  COMMON_INTERCEPT_FUNCTION(vscanf);  \
-  COMMON_INTERCEPT_FUNCTION(vsscanf); \
-  COMMON_INTERCEPT_FUNCTION(vfscanf);
+  COMMON_INTERCEPT_FUNCTION_LDBL(scanf);   \
+  COMMON_INTERCEPT_FUNCTION_LDBL(sscanf);  \
+  COMMON_INTERCEPT_FUNCTION_LDBL(fscanf);  \
+  COMMON_INTERCEPT_FUNCTION_LDBL(vscanf);  \
+  COMMON_INTERCEPT_FUNCTION_LDBL(vsscanf); \
+  COMMON_INTERCEPT_FUNCTION_LDBL(vfscanf);
 #else
 #define INIT_SCANF
 #endif
@@ -1403,16 +1580,16 @@ FORMAT_INTERCEPTOR_IMPL(__isoc99_snprintf, __isoc99_vsnprintf, str, size,
 
 #if SANITIZER_INTERCEPT_PRINTF
 #define INIT_PRINTF                     \
-  COMMON_INTERCEPT_FUNCTION(printf);    \
-  COMMON_INTERCEPT_FUNCTION(sprintf);   \
-  COMMON_INTERCEPT_FUNCTION(snprintf);  \
-  COMMON_INTERCEPT_FUNCTION(asprintf);  \
-  COMMON_INTERCEPT_FUNCTION(fprintf);   \
-  COMMON_INTERCEPT_FUNCTION(vprintf);   \
-  COMMON_INTERCEPT_FUNCTION(vsprintf);  \
-  COMMON_INTERCEPT_FUNCTION(vsnprintf); \
-  COMMON_INTERCEPT_FUNCTION(vasprintf); \
-  COMMON_INTERCEPT_FUNCTION(vfprintf);
+  COMMON_INTERCEPT_FUNCTION_LDBL(printf);    \
+  COMMON_INTERCEPT_FUNCTION_LDBL(sprintf);   \
+  COMMON_INTERCEPT_FUNCTION_LDBL(snprintf);  \
+  COMMON_INTERCEPT_FUNCTION_LDBL(asprintf);  \
+  COMMON_INTERCEPT_FUNCTION_LDBL(fprintf);   \
+  COMMON_INTERCEPT_FUNCTION_LDBL(vprintf);   \
+  COMMON_INTERCEPT_FUNCTION_LDBL(vsprintf);  \
+  COMMON_INTERCEPT_FUNCTION_LDBL(vsnprintf); \
+  COMMON_INTERCEPT_FUNCTION_LDBL(vasprintf); \
+  COMMON_INTERCEPT_FUNCTION_LDBL(vfprintf);
 #else
 #define INIT_PRINTF
 #endif
@@ -3187,6 +3364,30 @@ INTERCEPTOR(char *, strerror, int errnum) {
 #endif
 
 #if SANITIZER_INTERCEPT_STRERROR_R
+// There are 2 versions of strerror_r:
+//  * POSIX version returns 0 on success, negative error code on failure,
+//    writes message to buf.
+//  * GNU version returns message pointer, which points to either buf or some
+//    static storage.
+#if ((_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !_GNU_SOURCE) || \
+    SANITIZER_MAC || SANITIZER_ANDROID
+// POSIX version. Spec is not clear on whether buf is NULL-terminated.
+// At least on OSX, buf contents are valid even when the call fails.
+INTERCEPTOR(int, strerror_r, int errnum, char *buf, SIZE_T buflen) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, strerror_r, errnum, buf, buflen);
+  // FIXME: under ASan the call below may write to freed memory and corrupt
+  // its metadata. See
+  // https://github.com/google/sanitizers/issues/321.
+  int res = REAL(strerror_r)(errnum, buf, buflen);
+
+  SIZE_T sz = internal_strnlen(buf, buflen);
+  if (sz < buflen) ++sz;
+  COMMON_INTERCEPTOR_WRITE_RANGE(ctx, buf, sz);
+  return res;
+}
+#else
+// GNU version.
 INTERCEPTOR(char *, strerror_r, int errnum, char *buf, SIZE_T buflen) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, strerror_r, errnum, buf, buflen);
@@ -3194,24 +3395,14 @@ INTERCEPTOR(char *, strerror_r, int errnum, char *buf, SIZE_T buflen) {
   // its metadata. See
   // https://github.com/google/sanitizers/issues/321.
   char *res = REAL(strerror_r)(errnum, buf, buflen);
-  // There are 2 versions of strerror_r:
-  //  * POSIX version returns 0 on success, negative error code on failure,
-  //    writes message to buf.
-  //  * GNU version returns message pointer, which points to either buf or some
-  //    static storage.
-  SIZE_T posix_res = (SIZE_T)res;
-  if (posix_res < 1024 || posix_res > (SIZE_T) - 1024) {
-    // POSIX version. Spec is not clear on whether buf is NULL-terminated.
-    // At least on OSX, buf contents are valid even when the call fails.
-    SIZE_T sz = internal_strnlen(buf, buflen);
-    if (sz < buflen) ++sz;
-    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, buf, sz);
-  } else {
-    // GNU version.
+  if (res == buf)
     COMMON_INTERCEPTOR_WRITE_RANGE(ctx, res, REAL(strlen)(res) + 1);
-  }
+  else
+    COMMON_INTERCEPTOR_INITIALIZE_RANGE(res, REAL(strlen)(res) + 1);
   return res;
 }
+#endif //(_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !_GNU_SOURCE ||
+       //SANITIZER_MAC
 #define INIT_STRERROR_R COMMON_INTERCEPT_FUNCTION(strerror_r);
 #else
 #define INIT_STRERROR_R
@@ -3397,7 +3588,7 @@ INTERCEPTOR(int, ppoll, __sanitizer_pollfd *fds, __sanitizer_nfds_t nfds,
   if (fds && nfds) read_pollfd(ctx, fds, nfds);
   if (timeout_ts)
     COMMON_INTERCEPTOR_READ_RANGE(ctx, timeout_ts, struct_timespec_sz);
-  // FIXME: read sigmask when all of sigemptyset, etc are intercepted.
+  if (sigmask) COMMON_INTERCEPTOR_READ_RANGE(ctx, sigmask, sizeof(*sigmask));
   int res =
       COMMON_INTERCEPTOR_BLOCK_REAL(ppoll)(fds, nfds, timeout_ts, sigmask);
   if (fds && nfds) write_pollfd(ctx, fds, nfds);
@@ -3438,7 +3629,7 @@ INTERCEPTOR(int, wordexp, char *s, __sanitizer_wordexp_t *p, int flags) {
 INTERCEPTOR(int, sigwait, __sanitizer_sigset_t *set, int *sig) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, sigwait, set, sig);
-  // FIXME: read sigset_t when all of sigemptyset, etc are intercepted
+  if (set) COMMON_INTERCEPTOR_READ_RANGE(ctx, set, sizeof(*set));
   // FIXME: under ASan the call below may write to freed memory and corrupt
   // its metadata. See
   // https://github.com/google/sanitizers/issues/321.
@@ -3455,7 +3646,7 @@ INTERCEPTOR(int, sigwait, __sanitizer_sigset_t *set, int *sig) {
 INTERCEPTOR(int, sigwaitinfo, __sanitizer_sigset_t *set, void *info) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, sigwaitinfo, set, info);
-  // FIXME: read sigset_t when all of sigemptyset, etc are intercepted
+  if (set) COMMON_INTERCEPTOR_READ_RANGE(ctx, set, sizeof(*set));
   // FIXME: under ASan the call below may write to freed memory and corrupt
   // its metadata. See
   // https://github.com/google/sanitizers/issues/321.
@@ -3474,7 +3665,7 @@ INTERCEPTOR(int, sigtimedwait, __sanitizer_sigset_t *set, void *info,
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, sigtimedwait, set, info, timeout);
   if (timeout) COMMON_INTERCEPTOR_READ_RANGE(ctx, timeout, struct_timespec_sz);
-  // FIXME: read sigset_t when all of sigemptyset, etc are intercepted
+  if (set) COMMON_INTERCEPTOR_READ_RANGE(ctx, set, sizeof(*set));
   // FIXME: under ASan the call below may write to freed memory and corrupt
   // its metadata. See
   // https://github.com/google/sanitizers/issues/321.
@@ -3537,7 +3728,7 @@ INTERCEPTOR(int, sigprocmask, int how, __sanitizer_sigset_t *set,
             __sanitizer_sigset_t *oldset) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, sigprocmask, how, set, oldset);
-  // FIXME: read sigset_t when all of sigemptyset, etc are intercepted
+  if (set) COMMON_INTERCEPTOR_READ_RANGE(ctx, set, sizeof(*set));
   // FIXME: under ASan the call below may write to freed memory and corrupt
   // its metadata. See
   // https://github.com/google/sanitizers/issues/321.
@@ -3606,11 +3797,12 @@ INTERCEPTOR(void, _exit, int status) {
 INTERCEPTOR(int, pthread_mutex_lock, void *m) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, pthread_mutex_lock, m);
+  COMMON_INTERCEPTOR_MUTEX_PRE_LOCK(ctx, m);
   int res = REAL(pthread_mutex_lock)(m);
   if (res == errno_EOWNERDEAD)
     COMMON_INTERCEPTOR_MUTEX_REPAIR(ctx, m);
   if (res == 0 || res == errno_EOWNERDEAD)
-    COMMON_INTERCEPTOR_MUTEX_LOCK(ctx, m);
+    COMMON_INTERCEPTOR_MUTEX_POST_LOCK(ctx, m);
   if (res == errno_EINVAL)
     COMMON_INTERCEPTOR_MUTEX_INVALID(ctx, m);
   return res;
@@ -4484,7 +4676,7 @@ INTERCEPTOR(SIZE_T, iconv, void *cd, char **inbuf, SIZE_T *inbytesleft,
   // its metadata. See
   // https://github.com/google/sanitizers/issues/321.
   SIZE_T res = REAL(iconv)(cd, inbuf, inbytesleft, outbuf, outbytesleft);
-  if (res != (SIZE_T) - 1 && outbuf && *outbuf > outbuf_orig) {
+  if (outbuf && *outbuf > outbuf_orig) {
     SIZE_T sz = (char *)*outbuf - (char *)outbuf_orig;
     COMMON_INTERCEPTOR_WRITE_RANGE(ctx, outbuf_orig, sz);
   }
@@ -4839,47 +5031,67 @@ INTERCEPTOR(int, capset, void *hdrp, const void *datap) {
 #endif
 
 #if SANITIZER_INTERCEPT_AEABI_MEM
-DECLARE_REAL_AND_INTERCEPTOR(void *, memmove, void *, const void *, uptr)
-DECLARE_REAL_AND_INTERCEPTOR(void *, memcpy, void *, const void *, uptr)
-DECLARE_REAL_AND_INTERCEPTOR(void *, memset, void *, int, uptr)
-
 INTERCEPTOR(void *, __aeabi_memmove, void *to, const void *from, uptr size) {
-  return WRAP(memmove)(to, from, size);
+  void *ctx;
+  COMMON_INTERCEPTOR_MEMMOVE_IMPL(ctx, to, from, size);
 }
+
 INTERCEPTOR(void *, __aeabi_memmove4, void *to, const void *from, uptr size) {
-  return WRAP(memmove)(to, from, size);
+  void *ctx;
+  COMMON_INTERCEPTOR_MEMMOVE_IMPL(ctx, to, from, size);
 }
+
 INTERCEPTOR(void *, __aeabi_memmove8, void *to, const void *from, uptr size) {
-  return WRAP(memmove)(to, from, size);
+  void *ctx;
+  COMMON_INTERCEPTOR_MEMMOVE_IMPL(ctx, to, from, size);
 }
+
 INTERCEPTOR(void *, __aeabi_memcpy, void *to, const void *from, uptr size) {
-  return WRAP(memcpy)(to, from, size);
+  void *ctx;
+  COMMON_INTERCEPTOR_MEMCPY_IMPL(ctx, to, from, size);
 }
+
 INTERCEPTOR(void *, __aeabi_memcpy4, void *to, const void *from, uptr size) {
-  return WRAP(memcpy)(to, from, size);
+  void *ctx;
+  COMMON_INTERCEPTOR_MEMCPY_IMPL(ctx, to, from, size);
 }
+
 INTERCEPTOR(void *, __aeabi_memcpy8, void *to, const void *from, uptr size) {
-  return WRAP(memcpy)(to, from, size);
+  void *ctx;
+  COMMON_INTERCEPTOR_MEMCPY_IMPL(ctx, to, from, size);
 }
+
 // Note the argument order.
 INTERCEPTOR(void *, __aeabi_memset, void *block, uptr size, int c) {
-  return WRAP(memset)(block, c, size);
+  void *ctx;
+  COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, c, size);
 }
+
 INTERCEPTOR(void *, __aeabi_memset4, void *block, uptr size, int c) {
-  return WRAP(memset)(block, c, size);
+  void *ctx;
+  COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, c, size);
 }
+
 INTERCEPTOR(void *, __aeabi_memset8, void *block, uptr size, int c) {
-  return WRAP(memset)(block, c, size);
+  void *ctx;
+  COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, c, size);
 }
+
 INTERCEPTOR(void *, __aeabi_memclr, void *block, uptr size) {
-  return WRAP(memset)(block, 0, size);
+  void *ctx;
+  COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, 0, size);
 }
+
 INTERCEPTOR(void *, __aeabi_memclr4, void *block, uptr size) {
-  return WRAP(memset)(block, 0, size);
+  void *ctx;
+  COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, 0, size);
 }
+
 INTERCEPTOR(void *, __aeabi_memclr8, void *block, uptr size) {
-  return WRAP(memset)(block, 0, size);
+  void *ctx;
+  COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, 0, size);
 }
+
 #define INIT_AEABI_MEM                         \
   COMMON_INTERCEPT_FUNCTION(__aeabi_memmove);  \
   COMMON_INTERCEPT_FUNCTION(__aeabi_memmove4); \
@@ -4898,11 +5110,11 @@ INTERCEPTOR(void *, __aeabi_memclr8, void *block, uptr size) {
 #endif  // SANITIZER_INTERCEPT_AEABI_MEM
 
 #if SANITIZER_INTERCEPT___BZERO
-DECLARE_REAL_AND_INTERCEPTOR(void *, memset, void *, int, uptr);
-
 INTERCEPTOR(void *, __bzero, void *block, uptr size) {
-  return WRAP(memset)(block, 0, size);
+  void *ctx;
+  COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, 0, size);
 }
+
 #define INIT___BZERO COMMON_INTERCEPT_FUNCTION(__bzero);
 #else
 #define INIT___BZERO
@@ -5362,6 +5574,7 @@ INTERCEPTOR(void*, dlopen, const char *filename, int flag) {
   if (filename) COMMON_INTERCEPTOR_READ_STRING(ctx, filename, 0);
   COMMON_INTERCEPTOR_ON_DLOPEN(filename, flag);
   void *res = REAL(dlopen)(filename, flag);
+  Symbolizer::GetOrInit()->InvalidateModuleList();
   COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, res);
   return res;
 }
@@ -5370,6 +5583,7 @@ INTERCEPTOR(int, dlclose, void *handle) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER_NOIGNORE(ctx, dlclose, handle);
   int res = REAL(dlclose)(handle);
+  Symbolizer::GetOrInit()->InvalidateModuleList();
   COMMON_INTERCEPTOR_LIBRARY_UNLOADED();
   return res;
 }
@@ -5892,6 +6106,152 @@ INTERCEPTOR(int, __lxstat64, int version, const char *path, void *buf) {
 
 // FIXME: add other *stat interceptor
 
+#if SANITIZER_INTERCEPT_UTMP
+INTERCEPTOR(void *, getutent, int dummy) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getutent, dummy);
+  void *res = REAL(getutent)(dummy);
+  if (res)
+    COMMON_INTERCEPTOR_INITIALIZE_RANGE(res, __sanitizer::struct_utmp_sz);
+  return res;
+}
+INTERCEPTOR(void *, getutid, void *ut) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getutid, ut);
+  void *res = REAL(getutid)(ut);
+  if (res)
+    COMMON_INTERCEPTOR_INITIALIZE_RANGE(res, __sanitizer::struct_utmp_sz);
+  return res;
+}
+INTERCEPTOR(void *, getutline, void *ut) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getutline, ut);
+  void *res = REAL(getutline)(ut);
+  if (res)
+    COMMON_INTERCEPTOR_INITIALIZE_RANGE(res, __sanitizer::struct_utmp_sz);
+  return res;
+}
+#define INIT_UTMP                      \
+  COMMON_INTERCEPT_FUNCTION(getutent); \
+  COMMON_INTERCEPT_FUNCTION(getutid);  \
+  COMMON_INTERCEPT_FUNCTION(getutline);
+#else
+#define INIT_UTMP
+#endif
+
+#if SANITIZER_INTERCEPT_UTMPX
+INTERCEPTOR(void *, getutxent, int dummy) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getutxent, dummy);
+  void *res = REAL(getutxent)(dummy);
+  if (res)
+    COMMON_INTERCEPTOR_INITIALIZE_RANGE(res, __sanitizer::struct_utmpx_sz);
+  return res;
+}
+INTERCEPTOR(void *, getutxid, void *ut) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getutxid, ut);
+  void *res = REAL(getutxid)(ut);
+  if (res)
+    COMMON_INTERCEPTOR_INITIALIZE_RANGE(res, __sanitizer::struct_utmpx_sz);
+  return res;
+}
+INTERCEPTOR(void *, getutxline, void *ut) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getutxline, ut);
+  void *res = REAL(getutxline)(ut);
+  if (res)
+    COMMON_INTERCEPTOR_INITIALIZE_RANGE(res, __sanitizer::struct_utmpx_sz);
+  return res;
+}
+#define INIT_UTMPX                      \
+  COMMON_INTERCEPT_FUNCTION(getutxent); \
+  COMMON_INTERCEPT_FUNCTION(getutxid);  \
+  COMMON_INTERCEPT_FUNCTION(getutxline);
+#else
+#define INIT_UTMPX
+#endif
+
+#if SANITIZER_INTERCEPT_GETLOADAVG
+INTERCEPTOR(int, getloadavg, double *loadavg, int nelem) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, getloadavg, loadavg, nelem);
+  int res = REAL(getloadavg)(loadavg, nelem);
+  if (res > 0)
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, loadavg, res * sizeof(*loadavg));
+  return res;
+}
+#define INIT_GETLOADAVG                      \
+  COMMON_INTERCEPT_FUNCTION(getloadavg);
+#else
+#define INIT_GETLOADAVG
+#endif
+
+#if SANITIZER_INTERCEPT_MCHECK_MPROBE
+INTERCEPTOR(int, mcheck, void (*abortfunc)(int mstatus)) {
+  return 0;
+}
+
+INTERCEPTOR(int, mcheck_pedantic, void (*abortfunc)(int mstatus)) {
+  return 0;
+}
+
+INTERCEPTOR(int, mprobe, void *ptr) {
+  return 0;
+}
+#endif
+
+INTERCEPTOR(SIZE_T, wcslen, const wchar_t *s) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, wcslen, s);
+  SIZE_T res = REAL(wcslen)(s);
+  COMMON_INTERCEPTOR_READ_RANGE(ctx, s, sizeof(wchar_t) * (res + 1));
+  return res;
+}
+
+INTERCEPTOR(SIZE_T, wcsnlen, const wchar_t *s, SIZE_T n) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, wcsnlen, s, n);
+  SIZE_T res = REAL(wcsnlen)(s, n);
+  COMMON_INTERCEPTOR_READ_RANGE(ctx, s, sizeof(wchar_t) * Min(res + 1, n));
+  return res;
+}
+#define INIT_WCSLEN                  \
+  COMMON_INTERCEPT_FUNCTION(wcslen); \
+  COMMON_INTERCEPT_FUNCTION(wcsnlen);
+
+#if SANITIZER_INTERCEPT_WCSCAT
+INTERCEPTOR(wchar_t *, wcscat, wchar_t *dst, const wchar_t *src) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, wcscat, dst, src);
+  SIZE_T src_size = REAL(wcslen)(src);
+  SIZE_T dst_size = REAL(wcslen)(dst);
+  COMMON_INTERCEPTOR_READ_RANGE(ctx, src, (src_size + 1) * sizeof(wchar_t));
+  COMMON_INTERCEPTOR_READ_RANGE(ctx, dst, (dst_size + 1) * sizeof(wchar_t));
+  COMMON_INTERCEPTOR_WRITE_RANGE(ctx, dst + dst_size,
+                                 (src_size + 1) * sizeof(wchar_t));
+  return REAL(wcscat)(dst, src);  // NOLINT
+}
+
+INTERCEPTOR(wchar_t *, wcsncat, wchar_t *dst, const wchar_t *src, SIZE_T n) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, wcsncat, dst, src, n);
+  SIZE_T src_size = REAL(wcsnlen)(src, n);
+  SIZE_T dst_size = REAL(wcslen)(dst);
+  COMMON_INTERCEPTOR_READ_RANGE(ctx, src,
+                                Min(src_size + 1, n) * sizeof(wchar_t));
+  COMMON_INTERCEPTOR_READ_RANGE(ctx, dst, (dst_size + 1) * sizeof(wchar_t));
+  COMMON_INTERCEPTOR_WRITE_RANGE(ctx, dst + dst_size,
+                                 (src_size + 1) * sizeof(wchar_t));
+  return REAL(wcsncat)(dst, src, n);  // NOLINT
+}
+#define INIT_WCSCAT                  \
+  COMMON_INTERCEPT_FUNCTION(wcscat); \
+  COMMON_INTERCEPT_FUNCTION(wcsncat);
+#else
+#define INIT_WCSCAT
+#endif
+
 static void InitializeCommonInterceptors() {
   static u64 metadata_mem[sizeof(MetadataHashMap) / sizeof(u64) + 1];
   interceptor_metadata_map = new((void *)&metadata_mem) MetadataHashMap();
@@ -5899,6 +6259,8 @@ static void InitializeCommonInterceptors() {
   INIT_TEXTDOMAIN;
   INIT_STRLEN;
   INIT_STRNLEN;
+  INIT_STRNDUP;
+  INIT___STRNDUP;
   INIT_STRCMP;
   INIT_STRNCMP;
   INIT_STRCASECMP;
@@ -5909,6 +6271,7 @@ static void InitializeCommonInterceptors() {
   INIT_STRCHRNUL;
   INIT_STRRCHR;
   INIT_STRSPN;
+  INIT_STRTOK;
   INIT_STRPBRK;
   INIT_MEMSET;
   INIT_MEMMOVE;
@@ -5918,12 +6281,14 @@ static void InitializeCommonInterceptors() {
   INIT_MEMRCHR;
   INIT_MEMMEM;
   INIT_READ;
+  INIT_FREAD;
   INIT_PREAD;
   INIT_PREAD64;
   INIT_READV;
   INIT_PREADV;
   INIT_PREADV64;
   INIT_WRITE;
+  INIT_FWRITE;
   INIT_PWRITE;
   INIT_PWRITE64;
   INIT_WRITEV;
@@ -6088,4 +6453,9 @@ static void InitializeCommonInterceptors() {
   INIT___LXSTAT;
   INIT___LXSTAT64;
   // FIXME: add other *stat interceptors.
+  INIT_UTMP;
+  INIT_UTMPX;
+  INIT_GETLOADAVG;
+  INIT_WCSLEN;
+  INIT_WCSCAT;
 }
diff --git a/libsanitizer/sanitizer_common/sanitizer_common_interceptors_format.inc b/libsanitizer/sanitizer_common/sanitizer_common_interceptors_format.inc
index 9133be7097d..30927d2a229 100644
--- a/libsanitizer/sanitizer_common/sanitizer_common_interceptors_format.inc
+++ b/libsanitizer/sanitizer_common/sanitizer_common_interceptors_format.inc
@@ -323,8 +323,8 @@ static void scanf_common(void *ctx, int n_inputs, bool allowGnuMalloc,
       continue;
     int size = scanf_get_value_size(&dir);
     if (size == FSS_INVALID) {
-      Report("WARNING: unexpected format specifier in scanf interceptor: "
-        "%.*s\n", dir.end - dir.begin, dir.begin);
+      Report("%s: WARNING: unexpected format specifier in scanf interceptor: ",
+             SanitizerToolName, "%.*s\n", dir.end - dir.begin, dir.begin);
       break;
     }
     void *argp = va_arg(aq, void *);
@@ -433,10 +433,6 @@ static const char *printf_parse_next(const char *p, PrintfDirective *dir) {
 }
 
 static int printf_get_value_size(PrintfDirective *dir) {
-  if (dir->convSpecifier == 'm') {
-    return sizeof(char *);
-  }
-
   if (char_is_one_of(dir->convSpecifier, "cCsS")) {
     unsigned charSize =
         format_get_char_size(dir->convSpecifier, dir->lengthModifier);
@@ -517,10 +513,17 @@ static void printf_common(void *ctx, const char *format, va_list aq) {
       // Dynamic precision
       SKIP_SCALAR_ARG(&aq, 'd', sizeof(int));
     }
+    // %m does not require an argument: strlen(errno).
+    if (dir.convSpecifier == 'm')
+      continue;
     int size = printf_get_value_size(&dir);
     if (size == FSS_INVALID) {
-      Report("WARNING: unexpected format specifier in printf "
-             "interceptor: %.*s\n", dir.end - dir.begin, dir.begin);
+      static int ReportedOnce;
+      if (!ReportedOnce++)
+        Report(
+            "%s: WARNING: unexpected format specifier in printf "
+            "interceptor: %.*s (reported once per process)\n",
+            SanitizerToolName, dir.end - dir.begin, dir.begin);
       break;
     }
     if (dir.convSpecifier == 'n') {
diff --git a/libsanitizer/sanitizer_common/sanitizer_common_interface.inc b/libsanitizer/sanitizer_common/sanitizer_common_interface.inc
new file mode 100644
index 00000000000..bd296f6dece
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_common_interface.inc
@@ -0,0 +1,37 @@
+//===-- sanitizer_common_interface.inc ------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// Sanitizer Common interface list.
+//===----------------------------------------------------------------------===//
+INTERFACE_FUNCTION(__sanitizer_annotate_contiguous_container)
+INTERFACE_FUNCTION(__sanitizer_contiguous_container_find_bad_address)
+INTERFACE_FUNCTION(__sanitizer_set_death_callback)
+INTERFACE_FUNCTION(__sanitizer_set_report_path)
+INTERFACE_FUNCTION(__sanitizer_set_report_fd)
+INTERFACE_FUNCTION(__sanitizer_verify_contiguous_container)
+INTERFACE_WEAK_FUNCTION(__sanitizer_report_error_summary)
+INTERFACE_WEAK_FUNCTION(__sanitizer_sandbox_on_notify)
+// Sanitizer weak hooks
+INTERFACE_WEAK_FUNCTION(__sanitizer_weak_hook_memcmp)
+INTERFACE_WEAK_FUNCTION(__sanitizer_weak_hook_strcmp)
+INTERFACE_WEAK_FUNCTION(__sanitizer_weak_hook_strncmp)
+INTERFACE_WEAK_FUNCTION(__sanitizer_weak_hook_strstr)
+// Stacktrace interface.
+INTERFACE_FUNCTION(__sanitizer_get_module_and_offset_for_pc)
+INTERFACE_FUNCTION(__sanitizer_symbolize_global)
+INTERFACE_FUNCTION(__sanitizer_symbolize_pc)
+// Allocator interface.
+INTERFACE_FUNCTION(__sanitizer_get_allocated_size)
+INTERFACE_FUNCTION(__sanitizer_get_current_allocated_bytes)
+INTERFACE_FUNCTION(__sanitizer_get_estimated_allocated_size)
+INTERFACE_FUNCTION(__sanitizer_get_free_bytes)
+INTERFACE_FUNCTION(__sanitizer_get_heap_size)
+INTERFACE_FUNCTION(__sanitizer_get_ownership)
+INTERFACE_FUNCTION(__sanitizer_get_unmapped_bytes)
+INTERFACE_FUNCTION(__sanitizer_install_malloc_and_free_hooks)
+INTERFACE_FUNCTION(__sanitizer_print_memory_profile)
+INTERFACE_WEAK_FUNCTION(__sanitizer_free_hook)
+INTERFACE_WEAK_FUNCTION(__sanitizer_malloc_hook)
diff --git a/libsanitizer/sanitizer_common/sanitizer_common_interface_posix.inc b/libsanitizer/sanitizer_common/sanitizer_common_interface_posix.inc
new file mode 100644
index 00000000000..d3b72a8eeb7
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_common_interface_posix.inc
@@ -0,0 +1,12 @@
+//===-- sanitizer_common_interface_posix.inc ------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// Sanitizer Common interface list only available for Posix systems.
+//===----------------------------------------------------------------------===//
+INTERFACE_WEAK_FUNCTION(__sanitizer_symbolize_code)
+INTERFACE_WEAK_FUNCTION(__sanitizer_symbolize_data)
+INTERFACE_WEAK_FUNCTION(__sanitizer_symbolize_demangle)
+INTERFACE_WEAK_FUNCTION(__sanitizer_symbolize_flush)
diff --git a/libsanitizer/sanitizer_common/sanitizer_common_libcdep.cc b/libsanitizer/sanitizer_common/sanitizer_common_libcdep.cc
index 8c9fa98f835..a3f35319e23 100644
--- a/libsanitizer/sanitizer_common/sanitizer_common_libcdep.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_common_libcdep.cc
@@ -12,7 +12,10 @@
 #include "sanitizer_common.h"
 
 #include "sanitizer_allocator_interface.h"
+#include "sanitizer_file.h"
 #include "sanitizer_flags.h"
+#include "sanitizer_procmaps.h"
+#include "sanitizer_report_decorator.h"
 #include "sanitizer_stackdepot.h"
 #include "sanitizer_stacktrace.h"
 #include "sanitizer_symbolizer.h"
@@ -23,12 +26,25 @@
 
 namespace __sanitizer {
 
+#if !SANITIZER_FUCHSIA
+
 bool ReportFile::SupportsColors() {
   SpinMutexLock l(mu);
   ReopenIfNecessary();
   return SupportsColoredOutput(fd);
 }
 
+static INLINE bool ReportSupportsColors() {
+  return report_file.SupportsColors();
+}
+
+#else  // SANITIZER_FUCHSIA
+
+// Fuchsia's logs always go through post-processing that handles colorization.
+static INLINE bool ReportSupportsColors() { return true; }
+
+#endif  // !SANITIZER_FUCHSIA
+
 bool ColorizeReports() {
   // FIXME: Add proper Windows support to AnsiColorDecorator and re-enable color
   // printing on Windows.
@@ -37,7 +53,7 @@ bool ColorizeReports() {
 
   const char *flag = common_flags()->color;
   return internal_strcmp(flag, "always") == 0 ||
-         (internal_strcmp(flag, "auto") == 0 && report_file.SupportsColors());
+         (internal_strcmp(flag, "auto") == 0 && ReportSupportsColors());
 }
 
 static void (*sandboxing_callback)();
@@ -45,7 +61,8 @@ void SetSandboxingCallback(void (*f)()) {
   sandboxing_callback = f;
 }
 
-void ReportErrorSummary(const char *error_type, const StackTrace *stack) {
+void ReportErrorSummary(const char *error_type, const StackTrace *stack,
+                        const char *alt_tool_name) {
 #if !SANITIZER_GO
   if (!common_flags()->print_summary)
     return;
@@ -57,7 +74,7 @@ void ReportErrorSummary(const char *error_type, const StackTrace *stack) {
   // Maybe sometimes we need to choose another frame (e.g. skip memcpy/etc).
   uptr pc = StackTrace::GetPreviousInstructionPc(stack->trace[0]);
   SymbolizedStack *frame = Symbolizer::GetOrInit()->SymbolizePC(pc);
-  ReportErrorSummary(error_type, frame->info);
+  ReportErrorSummary(error_type, frame->info, alt_tool_name);
   frame->ClearAll();
 #endif
 }
@@ -68,18 +85,11 @@ void SetSoftRssLimitExceededCallback(void (*Callback)(bool exceeded)) {
   SoftRssLimitExceededCallback = Callback;
 }
 
-static AllocatorReleaseToOSCallback ReleseCallback;
-void SetAllocatorReleaseToOSCallback(AllocatorReleaseToOSCallback Callback) {
-  CHECK_EQ(ReleseCallback, nullptr);
-  ReleseCallback = Callback;
-}
-
 #if SANITIZER_LINUX && !SANITIZER_GO
 void BackgroundThread(void *arg) {
   uptr hard_rss_limit_mb = common_flags()->hard_rss_limit_mb;
   uptr soft_rss_limit_mb = common_flags()->soft_rss_limit_mb;
   bool heap_profile = common_flags()->heap_profile;
-  bool allocator_release_to_os = common_flags()->allocator_release_to_os;
   uptr prev_reported_rss = 0;
   uptr prev_reported_stack_depot_size = 0;
   bool reached_soft_rss_limit = false;
@@ -125,17 +135,137 @@ void BackgroundThread(void *arg) {
           SoftRssLimitExceededCallback(false);
       }
     }
-    if (allocator_release_to_os && ReleseCallback) ReleseCallback();
     if (heap_profile &&
         current_rss_mb > rss_during_last_reported_profile * 1.1) {
       Printf("\n\nHEAP PROFILE at RSS %zdMb\n", current_rss_mb);
-      __sanitizer_print_memory_profile(90);
+      __sanitizer_print_memory_profile(90, 20);
       rss_during_last_reported_profile = current_rss_mb;
     }
   }
 }
 #endif
 
+#if !SANITIZER_FUCHSIA && !SANITIZER_GO
+void StartReportDeadlySignal() {
+  // Write the first message using fd=2, just in case.
+  // It may actually fail to write in case stderr is closed.
+  CatastrophicErrorWrite(SanitizerToolName, internal_strlen(SanitizerToolName));
+  static const char kDeadlySignal[] = ":DEADLYSIGNAL\n";
+  CatastrophicErrorWrite(kDeadlySignal, sizeof(kDeadlySignal) - 1);
+}
+
+static void MaybeReportNonExecRegion(uptr pc) {
+#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
+  MemoryMappingLayout proc_maps(/*cache_enabled*/ true);
+  MemoryMappedSegment segment;
+  while (proc_maps.Next(&segment)) {
+    if (pc >= segment.start && pc < segment.end && !segment.IsExecutable())
+      Report("Hint: PC is at a non-executable region. Maybe a wild jump?\n");
+  }
+#endif
+}
+
+static void PrintMemoryByte(InternalScopedString *str, const char *before,
+                            u8 byte) {
+  SanitizerCommonDecorator d;
+  str->append("%s%s%x%x%s ", before, d.MemoryByte(), byte >> 4, byte & 15,
+              d.Default());
+}
+
+static void MaybeDumpInstructionBytes(uptr pc) {
+  if (!common_flags()->dump_instruction_bytes || (pc < GetPageSizeCached()))
+    return;
+  InternalScopedString str(1024);
+  str.append("First 16 instruction bytes at pc: ");
+  if (IsAccessibleMemoryRange(pc, 16)) {
+    for (int i = 0; i < 16; ++i) {
+      PrintMemoryByte(&str, "", ((u8 *)pc)[i]);
+    }
+    str.append("\n");
+  } else {
+    str.append("unaccessible\n");
+  }
+  Report("%s", str.data());
+}
+
+static void MaybeDumpRegisters(void *context) {
+  if (!common_flags()->dump_registers) return;
+  SignalContext::DumpAllRegisters(context);
+}
+
+static void ReportStackOverflowImpl(const SignalContext &sig, u32 tid,
+                                    UnwindSignalStackCallbackType unwind,
+                                    const void *unwind_context) {
+  SanitizerCommonDecorator d;
+  Printf("%s", d.Warning());
+  static const char kDescription[] = "stack-overflow";
+  Report("ERROR: %s: %s on address %p (pc %p bp %p sp %p T%d)\n",
+         SanitizerToolName, kDescription, (void *)sig.addr, (void *)sig.pc,
+         (void *)sig.bp, (void *)sig.sp, tid);
+  Printf("%s", d.Default());
+  InternalScopedBuffer<BufferedStackTrace> stack_buffer(1);
+  BufferedStackTrace *stack = stack_buffer.data();
+  stack->Reset();
+  unwind(sig, unwind_context, stack);
+  stack->Print();
+  ReportErrorSummary(kDescription, stack);
+}
+
+static void ReportDeadlySignalImpl(const SignalContext &sig, u32 tid,
+                                   UnwindSignalStackCallbackType unwind,
+                                   const void *unwind_context) {
+  SanitizerCommonDecorator d;
+  Printf("%s", d.Warning());
+  const char *description = sig.Describe();
+  Report("ERROR: %s: %s on unknown address %p (pc %p bp %p sp %p T%d)\n",
+         SanitizerToolName, description, (void *)sig.addr, (void *)sig.pc,
+         (void *)sig.bp, (void *)sig.sp, tid);
+  Printf("%s", d.Default());
+  if (sig.pc < GetPageSizeCached())
+    Report("Hint: pc points to the zero page.\n");
+  if (sig.is_memory_access) {
+    const char *access_type =
+        sig.write_flag == SignalContext::WRITE
+            ? "WRITE"
+            : (sig.write_flag == SignalContext::READ ? "READ" : "UNKNOWN");
+    Report("The signal is caused by a %s memory access.\n", access_type);
+    if (sig.addr < GetPageSizeCached())
+      Report("Hint: address points to the zero page.\n");
+  }
+  MaybeReportNonExecRegion(sig.pc);
+  InternalScopedBuffer<BufferedStackTrace> stack_buffer(1);
+  BufferedStackTrace *stack = stack_buffer.data();
+  stack->Reset();
+  unwind(sig, unwind_context, stack);
+  stack->Print();
+  MaybeDumpInstructionBytes(sig.pc);
+  MaybeDumpRegisters(sig.context);
+  Printf("%s can not provide additional info.\n", SanitizerToolName);
+  ReportErrorSummary(description, stack);
+}
+
+void ReportDeadlySignal(const SignalContext &sig, u32 tid,
+                        UnwindSignalStackCallbackType unwind,
+                        const void *unwind_context) {
+  if (sig.IsStackOverflow())
+    ReportStackOverflowImpl(sig, tid, unwind, unwind_context);
+  else
+    ReportDeadlySignalImpl(sig, tid, unwind, unwind_context);
+}
+
+void HandleDeadlySignal(void *siginfo, void *context, u32 tid,
+                        UnwindSignalStackCallbackType unwind,
+                        const void *unwind_context) {
+  StartReportDeadlySignal();
+  ScopedErrorReportLock rl;
+  SignalContext sig(siginfo, context);
+  ReportDeadlySignal(sig, tid, unwind, unwind_context);
+  Report("ABORTING\n");
+  Die();
+}
+
+#endif  // !SANITIZER_FUCHSIA && !SANITIZER_GO
+
 void WriteToSyslog(const char *msg) {
   InternalScopedString msg_copy(kErrorMessageBufferSize);
   msg_copy.append("%s", msg);
@@ -160,17 +290,56 @@ void MaybeStartBackgroudThread() {
   // Start the background thread if one of the rss limits is given.
   if (!common_flags()->hard_rss_limit_mb &&
       !common_flags()->soft_rss_limit_mb &&
-      !common_flags()->allocator_release_to_os &&
       !common_flags()->heap_profile) return;
   if (!&real_pthread_create) return;  // Can't spawn the thread anyway.
   internal_start_thread(BackgroundThread, nullptr);
 #endif
 }
 
+static atomic_uintptr_t reporting_thread = {0};
+
+ScopedErrorReportLock::ScopedErrorReportLock() {
+  uptr current = GetThreadSelf();
+  for (;;) {
+    uptr expected = 0;
+    if (atomic_compare_exchange_strong(&reporting_thread, &expected, current,
+                                       memory_order_relaxed)) {
+      // We've claimed reporting_thread so proceed.
+      CommonSanitizerReportMutex.Lock();
+      return;
+    }
+
+    if (expected == current) {
+      // This is either asynch signal or nested error during error reporting.
+      // Fail simple to avoid deadlocks in Report().
+
+      // Can't use Report() here because of potential deadlocks in nested
+      // signal handlers.
+      CatastrophicErrorWrite(SanitizerToolName,
+                             internal_strlen(SanitizerToolName));
+      static const char msg[] = ": nested bug in the same thread, aborting.\n";
+      CatastrophicErrorWrite(msg, sizeof(msg) - 1);
+
+      internal__exit(common_flags()->exitcode);
+    }
+
+    internal_sched_yield();
+  }
+}
+
+ScopedErrorReportLock::~ScopedErrorReportLock() {
+  CommonSanitizerReportMutex.Unlock();
+  atomic_store_relaxed(&reporting_thread, 0);
+}
+
+void ScopedErrorReportLock::CheckLocked() {
+  CommonSanitizerReportMutex.CheckLocked();
+}
+
 }  // namespace __sanitizer
 
-void NOINLINE
-__sanitizer_sandbox_on_notify(__sanitizer_sandbox_arguments *args) {
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_sandbox_on_notify,
+                             __sanitizer_sandbox_arguments *args) {
   __sanitizer::PrepareForSandboxing(args);
   if (__sanitizer::sandboxing_callback)
     __sanitizer::sandboxing_callback();
diff --git a/libsanitizer/sanitizer_common/sanitizer_common_nolibc.cc b/libsanitizer/sanitizer_common/sanitizer_common_nolibc.cc
new file mode 100644
index 00000000000..7397a011098
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_common_nolibc.cc
@@ -0,0 +1,34 @@
+//===-- sanitizer_common_nolibc.cc ----------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains stubs for libc function to facilitate optional use of
+// libc in no-libcdep sources.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+#include "sanitizer_common.h"
+#include "sanitizer_libc.h"
+
+namespace __sanitizer {
+
+// The Windows implementations of these functions use the win32 API directly,
+// bypassing libc.
+#if !SANITIZER_WINDOWS
+#if SANITIZER_LINUX
+bool ShouldLogAfterPrintf() { return false; }
+void LogMessageOnPrintf(const char *str) {}
+#endif
+void WriteToSyslog(const char *buffer) {}
+void Abort() { internal__exit(1); }
+void SleepForSeconds(int seconds) { internal_sleep(seconds); }
+#endif // !SANITIZER_WINDOWS
+
+#if !SANITIZER_WINDOWS && !SANITIZER_MAC
+void ListOfModules::init() {}
+#endif
+
+}  // namespace __sanitizer
diff --git a/libsanitizer/sanitizer_common/sanitizer_coverage_fuchsia.cc b/libsanitizer/sanitizer_common/sanitizer_coverage_fuchsia.cc
new file mode 100644
index 00000000000..7f294512e9a
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_coverage_fuchsia.cc
@@ -0,0 +1,238 @@
+//===-- sanitizer_coverage_fuchsia.cc ------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===---------------------------------------------------------------------===//
+//
+// Sanitizer Coverage Controller for Trace PC Guard, Fuchsia-specific version.
+//
+// This Fuchsia-specific implementation uses the same basic scheme and the
+// same simple '.sancov' file format as the generic implementation.  The
+// difference is that we just produce a single blob of output for the whole
+// program, not a separate one per DSO.  We do not sort the PC table and do
+// not prune the zeros, so the resulting file is always as large as it
+// would be to report 100% coverage.  Implicit tracing information about
+// the address ranges of DSOs allows offline tools to split the one big
+// blob into separate files that the 'sancov' tool can understand.
+//
+// Unlike the traditional implementation that uses an atexit hook to write
+// out data files at the end, the results on Fuchsia do not go into a file
+// per se.  The 'coverage_dir' option is ignored.  Instead, they are stored
+// directly into a shared memory object (a Zircon VMO).  At exit, that VMO
+// is handed over to a system service that's responsible for getting the
+// data out to somewhere that it can be fed into the sancov tool (where and
+// how is not our problem).
+
+#include "sanitizer_platform.h"
+#if SANITIZER_FUCHSIA
+#include "sanitizer_atomic.h"
+#include "sanitizer_common.h"
+#include "sanitizer_internal_defs.h"
+
+#include <zircon/process.h>
+#include <zircon/sanitizer.h>
+#include <zircon/syscalls.h>
+
+using namespace __sanitizer;  // NOLINT
+
+namespace __sancov {
+namespace {
+
+// TODO(mcgrathr): Move the constant into a header shared with other impls.
+constexpr u64 Magic64 = 0xC0BFFFFFFFFFFF64ULL;
+static_assert(SANITIZER_WORDSIZE == 64, "Fuchsia is always LP64");
+
+constexpr const char kSancovSinkName[] = "sancov";
+
+// Collects trace-pc guard coverage.
+// This class relies on zero-initialization.
+class TracePcGuardController {
+ public:
+  // For each PC location being tracked, there is a u32 reserved in global
+  // data called the "guard".  At startup, we assign each guard slot a
+  // unique index into the big results array.  Later during runtime, the
+  // first call to TracePcGuard (below) will store the corresponding PC at
+  // that index in the array.  (Each later call with the same guard slot is
+  // presumed to be from the same PC.)  Then it clears the guard slot back
+  // to zero, which tells the compiler not to bother calling in again.  At
+  // the end of the run, we have a big array where each element is either
+  // zero or is a tracked PC location that was hit in the trace.
+
+  // This is called from global constructors.  Each translation unit has a
+  // contiguous array of guard slots, and a constructor that calls here
+  // with the bounds of its array.  Those constructors are allowed to call
+  // here more than once for the same array.  Usually all of these
+  // constructors run in the initial thread, but it's possible that a
+  // dlopen call on a secondary thread will run constructors that get here.
+  void InitTracePcGuard(u32 *start, u32 *end) {
+    if (end > start && *start == 0 && common_flags()->coverage) {
+      // Complete the setup before filling in any guards with indices.
+      // This avoids the possibility of code called from Setup reentering
+      // TracePcGuard.
+      u32 idx = Setup(end - start);
+      for (u32 *p = start; p < end; ++p) {
+        *p = idx++;
+      }
+    }
+  }
+
+  void TracePcGuard(u32 *guard, uptr pc) {
+    atomic_uint32_t *guard_ptr = reinterpret_cast<atomic_uint32_t *>(guard);
+    u32 idx = atomic_exchange(guard_ptr, 0, memory_order_relaxed);
+    if (idx > 0) array_[idx] = pc;
+  }
+
+  void Dump() {
+    BlockingMutexLock locked(&setup_lock_);
+    if (array_) {
+      CHECK_NE(vmo_, ZX_HANDLE_INVALID);
+
+      // Publish the VMO to the system, where it can be collected and
+      // analyzed after this process exits.  This always consumes the VMO
+      // handle.  Any failure is just logged and not indicated to us.
+      __sanitizer_publish_data(kSancovSinkName, vmo_);
+      vmo_ = ZX_HANDLE_INVALID;
+
+      // This will route to __sanitizer_log_write, which will ensure that
+      // information about shared libraries is written out.  This message
+      // uses the `dumpfile` symbolizer markup element to highlight the
+      // dump.  See the explanation for this in:
+      // https://fuchsia.googlesource.com/zircon/+/master/docs/symbolizer_markup.md
+      Printf("SanitizerCoverage: {{{dumpfile:%s:%s}}} with up to %u PCs\n",
+             kSancovSinkName, vmo_name_, next_index_ - 1);
+    }
+  }
+
+ private:
+  // We map in the largest possible view into the VMO: one word
+  // for every possible 32-bit index value.  This avoids the need
+  // to change the mapping when increasing the size of the VMO.
+  // We can always spare the 32G of address space.
+  static constexpr size_t MappingSize = sizeof(uptr) << 32;
+
+  BlockingMutex setup_lock_;
+  uptr *array_;
+  u32 next_index_;
+  zx_handle_t vmo_;
+  char vmo_name_[ZX_MAX_NAME_LEN];
+
+  size_t DataSize() const { return next_index_ * sizeof(uintptr_t); }
+
+  u32 Setup(u32 num_guards) {
+    BlockingMutexLock locked(&setup_lock_);
+    DCHECK(common_flags()->coverage);
+
+    if (next_index_ == 0) {
+      CHECK_EQ(vmo_, ZX_HANDLE_INVALID);
+      CHECK_EQ(array_, nullptr);
+
+      // The first sample goes at [1] to reserve [0] for the magic number.
+      next_index_ = 1 + num_guards;
+
+      zx_status_t status = _zx_vmo_create(DataSize(), 0, &vmo_);
+      CHECK_EQ(status, ZX_OK);
+
+      // Give the VMO a name including our process KOID so it's easy to spot.
+      internal_snprintf(vmo_name_, sizeof(vmo_name_), "%s.%zu", kSancovSinkName,
+                        internal_getpid());
+      _zx_object_set_property(vmo_, ZX_PROP_NAME, vmo_name_,
+                              internal_strlen(vmo_name_));
+
+      // Map the largest possible view we might need into the VMO.  Later
+      // we might need to increase the VMO's size before we can use larger
+      // indices, but we'll never move the mapping address so we don't have
+      // any multi-thread synchronization issues with that.
+      uintptr_t mapping;
+      status =
+          _zx_vmar_map(_zx_vmar_root_self(), 0, vmo_, 0, MappingSize,
+                       ZX_VM_FLAG_PERM_READ | ZX_VM_FLAG_PERM_WRITE, &mapping);
+      CHECK_EQ(status, ZX_OK);
+
+      // Hereafter other threads are free to start storing into
+      // elements [1, next_index_) of the big array.
+      array_ = reinterpret_cast<uptr *>(mapping);
+
+      // Store the magic number.
+      // Hereafter, the VMO serves as the contents of the '.sancov' file.
+      array_[0] = Magic64;
+
+      return 1;
+    } else {
+      // The VMO is already mapped in, but it's not big enough to use the
+      // new indices.  So increase the size to cover the new maximum index.
+
+      CHECK_NE(vmo_, ZX_HANDLE_INVALID);
+      CHECK_NE(array_, nullptr);
+
+      uint32_t first_index = next_index_;
+      next_index_ += num_guards;
+
+      zx_status_t status = _zx_vmo_set_size(vmo_, DataSize());
+      CHECK_EQ(status, ZX_OK);
+
+      return first_index;
+    }
+  }
+};
+
+static TracePcGuardController pc_guard_controller;
+
+}  // namespace
+}  // namespace __sancov
+
+namespace __sanitizer {
+void InitializeCoverage(bool enabled, const char *dir) {
+  CHECK_EQ(enabled, common_flags()->coverage);
+  CHECK_EQ(dir, common_flags()->coverage_dir);
+
+  static bool coverage_enabled = false;
+  if (!coverage_enabled) {
+    coverage_enabled = enabled;
+    Atexit(__sanitizer_cov_dump);
+    AddDieCallback(__sanitizer_cov_dump);
+  }
+}
+}  // namespace __sanitizer
+
+extern "C" {
+SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_dump_coverage(  // NOLINT
+    const uptr *pcs, uptr len) {
+  UNIMPLEMENTED();
+}
+
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard, u32 *guard) {
+  if (!*guard) return;
+  __sancov::pc_guard_controller.TracePcGuard(guard, GET_CALLER_PC() - 1);
+}
+
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard_init,
+                             u32 *start, u32 *end) {
+  if (start == end || *start) return;
+  __sancov::pc_guard_controller.InitTracePcGuard(start, end);
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_dump_trace_pc_guard_coverage() {
+  __sancov::pc_guard_controller.Dump();
+}
+SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_dump() {
+  __sanitizer_dump_trace_pc_guard_coverage();
+}
+// Default empty implementations (weak). Users should redefine them.
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_cmp, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_cmp1, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_cmp2, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_cmp4, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_cmp8, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_const_cmp1, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_const_cmp2, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_const_cmp4, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_const_cmp8, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_switch, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_div4, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_div8, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_gep, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_indir, void) {}
+}  // extern "C"
+
+#endif  // !SANITIZER_FUCHSIA
diff --git a/libsanitizer/sanitizer_common/sanitizer_coverage_interface.inc b/libsanitizer/sanitizer_common/sanitizer_coverage_interface.inc
new file mode 100644
index 00000000000..fb78cc00f70
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_coverage_interface.inc
@@ -0,0 +1,31 @@
+//===-- sanitizer_coverage_interface.inc ----------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// Sanitizer Coverage interface list.
+//===----------------------------------------------------------------------===//
+INTERFACE_FUNCTION(__sanitizer_cov_dump)
+INTERFACE_FUNCTION(__sanitizer_cov_reset)
+INTERFACE_FUNCTION(__sanitizer_dump_coverage)
+INTERFACE_FUNCTION(__sanitizer_dump_trace_pc_guard_coverage)
+INTERFACE_WEAK_FUNCTION(__sancov_default_options)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_cmp)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_cmp1)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_cmp2)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_cmp4)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_cmp8)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_const_cmp1)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_const_cmp2)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_const_cmp4)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_const_cmp8)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_div4)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_div8)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_gep)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_pc_guard)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_pc_guard_init)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_pc_indir)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_trace_switch)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_8bit_counters_init)
+INTERFACE_WEAK_FUNCTION(__sanitizer_cov_pcs_init)
diff --git a/libsanitizer/sanitizer_common/sanitizer_coverage_libcdep.cc b/libsanitizer/sanitizer_common/sanitizer_coverage_libcdep.cc
deleted file mode 100644
index dd8620beaac..00000000000
--- a/libsanitizer/sanitizer_common/sanitizer_coverage_libcdep.cc
+++ /dev/null
@@ -1,1043 +0,0 @@
-//===-- sanitizer_coverage.cc ---------------------------------------------===//
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// Sanitizer Coverage.
-// This file implements run-time support for a poor man's coverage tool.
-//
-// Compiler instrumentation:
-// For every interesting basic block the compiler injects the following code:
-// if (Guard < 0) {
-//    __sanitizer_cov(&Guard);
-// }
-// At the module start up time __sanitizer_cov_module_init sets the guards
-// to consecutive negative numbers (-1, -2, -3, ...).
-// It's fine to call __sanitizer_cov more than once for a given block.
-//
-// Run-time:
-//  - __sanitizer_cov(): record that we've executed the PC (GET_CALLER_PC).
-//    and atomically set Guard to -Guard.
-//  - __sanitizer_cov_dump: dump the coverage data to disk.
-//  For every module of the current process that has coverage data
-//  this will create a file module_name.PID.sancov.
-//
-// The file format is simple: the first 8 bytes is the magic,
-// one of 0xC0BFFFFFFFFFFF64 and 0xC0BFFFFFFFFFFF32. The last byte of the
-// magic defines the size of the following offsets.
-// The rest of the data is the offsets in the module.
-//
-// Eventually, this coverage implementation should be obsoleted by a more
-// powerful general purpose Clang/LLVM coverage instrumentation.
-// Consider this implementation as prototype.
-//
-// FIXME: support (or at least test with) dlclose.
-//===----------------------------------------------------------------------===//
-
-#include "sanitizer_allocator_internal.h"
-#include "sanitizer_common.h"
-#include "sanitizer_libc.h"
-#include "sanitizer_mutex.h"
-#include "sanitizer_procmaps.h"
-#include "sanitizer_stacktrace.h"
-#include "sanitizer_symbolizer.h"
-#include "sanitizer_flags.h"
-
-using namespace __sanitizer;
-
-static const u64 kMagic64 = 0xC0BFFFFFFFFFFF64ULL;
-static const u64 kMagic32 = 0xC0BFFFFFFFFFFF32ULL;
-static const uptr kNumWordsForMagic = SANITIZER_WORDSIZE == 64 ? 1 : 2;
-static const u64 kMagic = SANITIZER_WORDSIZE == 64 ? kMagic64 : kMagic32;
-
-static atomic_uint32_t dump_once_guard;  // Ensure that CovDump runs only once.
-
-static atomic_uintptr_t coverage_counter;
-static atomic_uintptr_t caller_callee_counter;
-
-static void ResetGlobalCounters() {
-  return atomic_store(&coverage_counter, 0, memory_order_relaxed);
-  return atomic_store(&caller_callee_counter, 0, memory_order_relaxed);
-}
-
-// pc_array is the array containing the covered PCs.
-// To make the pc_array thread- and async-signal-safe it has to be large enough.
-// 128M counters "ought to be enough for anybody" (4M on 32-bit).
-
-// With coverage_direct=1 in ASAN_OPTIONS, pc_array memory is mapped to a file.
-// In this mode, __sanitizer_cov_dump does nothing, and CovUpdateMapping()
-// dump current memory layout to another file.
-
-static bool cov_sandboxed = false;
-static fd_t cov_fd = kInvalidFd;
-static unsigned int cov_max_block_size = 0;
-static bool coverage_enabled = false;
-static const char *coverage_dir;
-
-namespace __sanitizer {
-
-class CoverageData {
- public:
-  void Init();
-  void Enable();
-  void Disable();
-  void ReInit();
-  void BeforeFork();
-  void AfterFork(int child_pid);
-  void Extend(uptr npcs);
-  void Add(uptr pc, u32 *guard);
-  void IndirCall(uptr caller, uptr callee, uptr callee_cache[],
-                 uptr cache_size);
-  void DumpCallerCalleePairs();
-  void DumpTrace();
-  void DumpAsBitSet();
-  void DumpCounters();
-  void DumpOffsets();
-  void DumpAll();
-
-  ALWAYS_INLINE
-  void TraceBasicBlock(u32 *id);
-
-  void InitializeGuardArray(s32 *guards);
-  void InitializeGuards(s32 *guards, uptr n, const char *module_name,
-                        uptr caller_pc);
-  void InitializeCounters(u8 *counters, uptr n);
-  void ReinitializeGuards();
-  uptr GetNumberOf8bitCounters();
-  uptr Update8bitCounterBitsetAndClearCounters(u8 *bitset);
-
-  uptr *data();
-  uptr size() const;
-
- private:
-  struct NamedPcRange {
-    const char *copied_module_name;
-    uptr beg, end; // elements [beg,end) in pc_array.
-  };
-
-  void DirectOpen();
-  void UpdateModuleNameVec(uptr caller_pc, uptr range_beg, uptr range_end);
-  void GetRangeOffsets(const NamedPcRange& r, Symbolizer* s,
-      InternalMmapVector<uptr>* offsets) const;
-
-  // Maximal size pc array may ever grow.
-  // We MmapNoReserve this space to ensure that the array is contiguous.
-  static const uptr kPcArrayMaxSize =
-      FIRST_32_SECOND_64(1 << (SANITIZER_ANDROID ? 24 : 26), 1 << 27);
-  // The amount file mapping for the pc array is grown by.
-  static const uptr kPcArrayMmapSize = 64 * 1024;
-
-  // pc_array is allocated with MmapNoReserveOrDie and so it uses only as
-  // much RAM as it really needs.
-  uptr *pc_array;
-  // Index of the first available pc_array slot.
-  atomic_uintptr_t pc_array_index;
-  // Array size.
-  atomic_uintptr_t pc_array_size;
-  // Current file mapped size of the pc array.
-  uptr pc_array_mapped_size;
-  // Descriptor of the file mapped pc array.
-  fd_t pc_fd;
-
-  // Vector of coverage guard arrays, protected by mu.
-  InternalMmapVectorNoCtor<s32*> guard_array_vec;
-
-  // Vector of module and compilation unit pc ranges.
-  InternalMmapVectorNoCtor<NamedPcRange> comp_unit_name_vec;
-  InternalMmapVectorNoCtor<NamedPcRange> module_name_vec;
-
-  struct CounterAndSize {
-    u8 *counters;
-    uptr n;
-  };
-
-  InternalMmapVectorNoCtor<CounterAndSize> counters_vec;
-  uptr num_8bit_counters;
-
-  // Caller-Callee (cc) array, size and current index.
-  static const uptr kCcArrayMaxSize = FIRST_32_SECOND_64(1 << 18, 1 << 24);
-  uptr **cc_array;
-  atomic_uintptr_t cc_array_index;
-  atomic_uintptr_t cc_array_size;
-
-  // Tracing event array, size and current pointer.
-  // We record all events (basic block entries) in a global buffer of u32
-  // values. Each such value is the index in pc_array.
-  // So far the tracing is highly experimental:
-  //   - not thread-safe;
-  //   - does not support long traces;
-  //   - not tuned for performance.
-  static const uptr kTrEventArrayMaxSize = FIRST_32_SECOND_64(1 << 22, 1 << 30);
-  u32 *tr_event_array;
-  uptr tr_event_array_size;
-  u32 *tr_event_pointer;
-  static const uptr kTrPcArrayMaxSize    = FIRST_32_SECOND_64(1 << 22, 1 << 27);
-
-  StaticSpinMutex mu;
-};
-
-static CoverageData coverage_data;
-
-void CovUpdateMapping(const char *path, uptr caller_pc = 0);
-
-void CoverageData::DirectOpen() {
-  InternalScopedString path(kMaxPathLength);
-  internal_snprintf((char *)path.data(), path.size(), "%s/%zd.sancov.raw",
-                    coverage_dir, internal_getpid());
-  pc_fd = OpenFile(path.data(), RdWr);
-  if (pc_fd == kInvalidFd) {
-    Report("Coverage: failed to open %s for reading/writing\n", path.data());
-    Die();
-  }
-
-  pc_array_mapped_size = 0;
-  CovUpdateMapping(coverage_dir);
-}
-
-void CoverageData::Init() {
-  pc_fd = kInvalidFd;
-}
-
-void CoverageData::Enable() {
-  if (pc_array)
-    return;
-  pc_array = reinterpret_cast<uptr *>(
-      MmapNoReserveOrDie(sizeof(uptr) * kPcArrayMaxSize, "CovInit"));
-  atomic_store(&pc_array_index, 0, memory_order_relaxed);
-  if (common_flags()->coverage_direct) {
-    atomic_store(&pc_array_size, 0, memory_order_relaxed);
-  } else {
-    atomic_store(&pc_array_size, kPcArrayMaxSize, memory_order_relaxed);
-  }
-
-  cc_array = reinterpret_cast<uptr **>(MmapNoReserveOrDie(
-      sizeof(uptr *) * kCcArrayMaxSize, "CovInit::cc_array"));
-  atomic_store(&cc_array_size, kCcArrayMaxSize, memory_order_relaxed);
-  atomic_store(&cc_array_index, 0, memory_order_relaxed);
-
-  // Allocate tr_event_array with a guard page at the end.
-  tr_event_array = reinterpret_cast<u32 *>(MmapNoReserveOrDie(
-      sizeof(tr_event_array[0]) * kTrEventArrayMaxSize + GetMmapGranularity(),
-      "CovInit::tr_event_array"));
-  MprotectNoAccess(
-      reinterpret_cast<uptr>(&tr_event_array[kTrEventArrayMaxSize]),
-      GetMmapGranularity());
-  tr_event_array_size = kTrEventArrayMaxSize;
-  tr_event_pointer = tr_event_array;
-
-  num_8bit_counters = 0;
-}
-
-void CoverageData::InitializeGuardArray(s32 *guards) {
-  Enable();  // Make sure coverage is enabled at this point.
-  s32 n = guards[0];
-  for (s32 j = 1; j <= n; j++) {
-    uptr idx = atomic_load_relaxed(&pc_array_index);
-    atomic_store_relaxed(&pc_array_index, idx + 1);
-    guards[j] = -static_cast<s32>(idx + 1);
-  }
-}
-
-void CoverageData::Disable() {
-  if (pc_array) {
-    UnmapOrDie(pc_array, sizeof(uptr) * kPcArrayMaxSize);
-    pc_array = nullptr;
-  }
-  if (cc_array) {
-    UnmapOrDie(cc_array, sizeof(uptr *) * kCcArrayMaxSize);
-    cc_array = nullptr;
-  }
-  if (tr_event_array) {
-    UnmapOrDie(tr_event_array,
-               sizeof(tr_event_array[0]) * kTrEventArrayMaxSize +
-                   GetMmapGranularity());
-    tr_event_array = nullptr;
-    tr_event_pointer = nullptr;
-  }
-  if (pc_fd != kInvalidFd) {
-    CloseFile(pc_fd);
-    pc_fd = kInvalidFd;
-  }
-}
-
-void CoverageData::ReinitializeGuards() {
-  // Assuming single thread.
-  atomic_store(&pc_array_index, 0, memory_order_relaxed);
-  for (uptr i = 0; i < guard_array_vec.size(); i++)
-    InitializeGuardArray(guard_array_vec[i]);
-}
-
-void CoverageData::ReInit() {
-  Disable();
-  if (coverage_enabled) {
-    if (common_flags()->coverage_direct) {
-      // In memory-mapped mode we must extend the new file to the known array
-      // size.
-      uptr size = atomic_load(&pc_array_size, memory_order_relaxed);
-      uptr npcs = size / sizeof(uptr);
-      Enable();
-      if (size) Extend(npcs);
-      if (coverage_enabled) CovUpdateMapping(coverage_dir);
-    } else {
-      Enable();
-    }
-  }
-  // Re-initialize the guards.
-  // We are single-threaded now, no need to grab any lock.
-  CHECK_EQ(atomic_load(&pc_array_index, memory_order_relaxed), 0);
-  ReinitializeGuards();
-}
-
-void CoverageData::BeforeFork() {
-  mu.Lock();
-}
-
-void CoverageData::AfterFork(int child_pid) {
-  // We are single-threaded so it's OK to release the lock early.
-  mu.Unlock();
-  if (child_pid == 0) ReInit();
-}
-
-// Extend coverage PC array to fit additional npcs elements.
-void CoverageData::Extend(uptr npcs) {
-  if (!common_flags()->coverage_direct) return;
-  SpinMutexLock l(&mu);
-
-  uptr size = atomic_load(&pc_array_size, memory_order_relaxed);
-  size += npcs * sizeof(uptr);
-
-  if (coverage_enabled && size > pc_array_mapped_size) {
-    if (pc_fd == kInvalidFd) DirectOpen();
-    CHECK_NE(pc_fd, kInvalidFd);
-
-    uptr new_mapped_size = pc_array_mapped_size;
-    while (size > new_mapped_size) new_mapped_size += kPcArrayMmapSize;
-    CHECK_LE(new_mapped_size, sizeof(uptr) * kPcArrayMaxSize);
-
-    // Extend the file and map the new space at the end of pc_array.
-    uptr res = internal_ftruncate(pc_fd, new_mapped_size);
-    int err;
-    if (internal_iserror(res, &err)) {
-      Printf("failed to extend raw coverage file: %d\n", err);
-      Die();
-    }
-
-    uptr next_map_base = ((uptr)pc_array) + pc_array_mapped_size;
-    void *p = MapWritableFileToMemory((void *)next_map_base,
-                                      new_mapped_size - pc_array_mapped_size,
-                                      pc_fd, pc_array_mapped_size);
-    CHECK_EQ((uptr)p, next_map_base);
-    pc_array_mapped_size = new_mapped_size;
-  }
-
-  atomic_store(&pc_array_size, size, memory_order_release);
-}
-
-void CoverageData::InitializeCounters(u8 *counters, uptr n) {
-  if (!counters) return;
-  CHECK_EQ(reinterpret_cast<uptr>(counters) % 16, 0);
-  n = RoundUpTo(n, 16); // The compiler must ensure that counters is 16-aligned.
-  SpinMutexLock l(&mu);
-  counters_vec.push_back({counters, n});
-  num_8bit_counters += n;
-}
-
-void CoverageData::UpdateModuleNameVec(uptr caller_pc, uptr range_beg,
-                                       uptr range_end) {
-  auto sym = Symbolizer::GetOrInit();
-  if (!sym)
-    return;
-  const char *module_name = sym->GetModuleNameForPc(caller_pc);
-  if (!module_name) return;
-  if (module_name_vec.empty() ||
-      module_name_vec.back().copied_module_name != module_name)
-    module_name_vec.push_back({module_name, range_beg, range_end});
-  else
-    module_name_vec.back().end = range_end;
-}
-
-void CoverageData::InitializeGuards(s32 *guards, uptr n,
-                                    const char *comp_unit_name,
-                                    uptr caller_pc) {
-  // The array 'guards' has n+1 elements, we use the element zero
-  // to store 'n'.
-  CHECK_LT(n, 1 << 30);
-  guards[0] = static_cast<s32>(n);
-  InitializeGuardArray(guards);
-  SpinMutexLock l(&mu);
-  uptr range_end = atomic_load(&pc_array_index, memory_order_relaxed);
-  uptr range_beg = range_end - n;
-  comp_unit_name_vec.push_back({comp_unit_name, range_beg, range_end});
-  guard_array_vec.push_back(guards);
-  UpdateModuleNameVec(caller_pc, range_beg, range_end);
-}
-
-static const uptr kBundleCounterBits = 16;
-
-// When coverage_order_pcs==true and SANITIZER_WORDSIZE==64
-// we insert the global counter into the first 16 bits of the PC.
-uptr BundlePcAndCounter(uptr pc, uptr counter) {
-  if (SANITIZER_WORDSIZE != 64 || !common_flags()->coverage_order_pcs)
-    return pc;
-  static const uptr kMaxCounter = (1 << kBundleCounterBits) - 1;
-  if (counter > kMaxCounter)
-    counter = kMaxCounter;
-  CHECK_EQ(0, pc >> (SANITIZER_WORDSIZE - kBundleCounterBits));
-  return pc | (counter << (SANITIZER_WORDSIZE - kBundleCounterBits));
-}
-
-uptr UnbundlePc(uptr bundle) {
-  if (SANITIZER_WORDSIZE != 64 || !common_flags()->coverage_order_pcs)
-    return bundle;
-  return (bundle << kBundleCounterBits) >> kBundleCounterBits;
-}
-
-uptr UnbundleCounter(uptr bundle) {
-  if (SANITIZER_WORDSIZE != 64 || !common_flags()->coverage_order_pcs)
-    return 0;
-  return bundle >> (SANITIZER_WORDSIZE - kBundleCounterBits);
-}
-
-// If guard is negative, atomically set it to -guard and store the PC in
-// pc_array.
-void CoverageData::Add(uptr pc, u32 *guard) {
-  atomic_uint32_t *atomic_guard = reinterpret_cast<atomic_uint32_t*>(guard);
-  s32 guard_value = atomic_load(atomic_guard, memory_order_relaxed);
-  if (guard_value >= 0) return;
-
-  atomic_store(atomic_guard, -guard_value, memory_order_relaxed);
-  if (!pc_array) return;
-
-  uptr idx = -guard_value - 1;
-  if (idx >= atomic_load(&pc_array_index, memory_order_acquire))
-    return;  // May happen after fork when pc_array_index becomes 0.
-  CHECK_LT(idx * sizeof(uptr),
-           atomic_load(&pc_array_size, memory_order_acquire));
-  uptr counter = atomic_fetch_add(&coverage_counter, 1, memory_order_relaxed);
-  pc_array[idx] = BundlePcAndCounter(pc, counter);
-}
-
-// Registers a pair caller=>callee.
-// When a given caller is seen for the first time, the callee_cache is added
-// to the global array cc_array, callee_cache[0] is set to caller and
-// callee_cache[1] is set to cache_size.
-// Then we are trying to add callee to callee_cache [2,cache_size) if it is
-// not there yet.
-// If the cache is full we drop the callee (may want to fix this later).
-void CoverageData::IndirCall(uptr caller, uptr callee, uptr callee_cache[],
-                             uptr cache_size) {
-  if (!cc_array) return;
-  atomic_uintptr_t *atomic_callee_cache =
-      reinterpret_cast<atomic_uintptr_t *>(callee_cache);
-  uptr zero = 0;
-  if (atomic_compare_exchange_strong(&atomic_callee_cache[0], &zero, caller,
-                                     memory_order_seq_cst)) {
-    uptr idx = atomic_fetch_add(&cc_array_index, 1, memory_order_relaxed);
-    CHECK_LT(idx * sizeof(uptr),
-             atomic_load(&cc_array_size, memory_order_acquire));
-    callee_cache[1] = cache_size;
-    cc_array[idx] = callee_cache;
-  }
-  CHECK_EQ(atomic_load(&atomic_callee_cache[0], memory_order_relaxed), caller);
-  for (uptr i = 2; i < cache_size; i++) {
-    uptr was = 0;
-    if (atomic_compare_exchange_strong(&atomic_callee_cache[i], &was, callee,
-                                       memory_order_seq_cst)) {
-      atomic_fetch_add(&caller_callee_counter, 1, memory_order_relaxed);
-      return;
-    }
-    if (was == callee)  // Already have this callee.
-      return;
-  }
-}
-
-uptr CoverageData::GetNumberOf8bitCounters() {
-  return num_8bit_counters;
-}
-
-// Map every 8bit counter to a 8-bit bitset and clear the counter.
-uptr CoverageData::Update8bitCounterBitsetAndClearCounters(u8 *bitset) {
-  uptr num_new_bits = 0;
-  uptr cur = 0;
-  // For better speed we map 8 counters to 8 bytes of bitset at once.
-  static const uptr kBatchSize = 8;
-  CHECK_EQ(reinterpret_cast<uptr>(bitset) % kBatchSize, 0);
-  for (uptr i = 0, len = counters_vec.size(); i < len; i++) {
-    u8 *c = counters_vec[i].counters;
-    uptr n = counters_vec[i].n;
-    CHECK_EQ(n % 16, 0);
-    CHECK_EQ(cur % kBatchSize, 0);
-    CHECK_EQ(reinterpret_cast<uptr>(c) % kBatchSize, 0);
-    if (!bitset) {
-      internal_bzero_aligned16(c, n);
-      cur += n;
-      continue;
-    }
-    for (uptr j = 0; j < n; j += kBatchSize, cur += kBatchSize) {
-      CHECK_LT(cur, num_8bit_counters);
-      u64 *pc64 = reinterpret_cast<u64*>(c + j);
-      u64 *pb64 = reinterpret_cast<u64*>(bitset + cur);
-      u64 c64 = *pc64;
-      u64 old_bits_64 = *pb64;
-      u64 new_bits_64 = old_bits_64;
-      if (c64) {
-        *pc64 = 0;
-        for (uptr k = 0; k < kBatchSize; k++) {
-          u64 x = (c64 >> (8 * k)) & 0xff;
-          if (x) {
-            u64 bit = 0;
-            /**/ if (x >= 128) bit = 128;
-            else if (x >= 32) bit = 64;
-            else if (x >= 16) bit = 32;
-            else if (x >= 8) bit = 16;
-            else if (x >= 4) bit = 8;
-            else if (x >= 3) bit = 4;
-            else if (x >= 2) bit = 2;
-            else if (x >= 1) bit = 1;
-            u64 mask = bit << (8 * k);
-            if (!(new_bits_64 & mask)) {
-              num_new_bits++;
-              new_bits_64 |= mask;
-            }
-          }
-        }
-        *pb64 = new_bits_64;
-      }
-    }
-  }
-  CHECK_EQ(cur, num_8bit_counters);
-  return num_new_bits;
-}
-
-uptr *CoverageData::data() {
-  return pc_array;
-}
-
-uptr CoverageData::size() const {
-  return atomic_load(&pc_array_index, memory_order_relaxed);
-}
-
-// Block layout for packed file format: header, followed by module name (no
-// trailing zero), followed by data blob.
-struct CovHeader {
-  int pid;
-  unsigned int module_name_length;
-  unsigned int data_length;
-};
-
-static void CovWritePacked(int pid, const char *module, const void *blob,
-                           unsigned int blob_size) {
-  if (cov_fd == kInvalidFd) return;
-  unsigned module_name_length = internal_strlen(module);
-  CovHeader header = {pid, module_name_length, blob_size};
-
-  if (cov_max_block_size == 0) {
-    // Writing to a file. Just go ahead.
-    WriteToFile(cov_fd, &header, sizeof(header));
-    WriteToFile(cov_fd, module, module_name_length);
-    WriteToFile(cov_fd, blob, blob_size);
-  } else {
-    // Writing to a socket. We want to split the data into appropriately sized
-    // blocks.
-    InternalScopedBuffer<char> block(cov_max_block_size);
-    CHECK_EQ((uptr)block.data(), (uptr)(CovHeader *)block.data());
-    uptr header_size_with_module = sizeof(header) + module_name_length;
-    CHECK_LT(header_size_with_module, cov_max_block_size);
-    unsigned int max_payload_size =
-        cov_max_block_size - header_size_with_module;
-    char *block_pos = block.data();
-    internal_memcpy(block_pos, &header, sizeof(header));
-    block_pos += sizeof(header);
-    internal_memcpy(block_pos, module, module_name_length);
-    block_pos += module_name_length;
-    char *block_data_begin = block_pos;
-    const char *blob_pos = (const char *)blob;
-    while (blob_size > 0) {
-      unsigned int payload_size = Min(blob_size, max_payload_size);
-      blob_size -= payload_size;
-      internal_memcpy(block_data_begin, blob_pos, payload_size);
-      blob_pos += payload_size;
-      ((CovHeader *)block.data())->data_length = payload_size;
-      WriteToFile(cov_fd, block.data(), header_size_with_module + payload_size);
-    }
-  }
-}
-
-// If packed = false: <name>.<pid>.<sancov> (name = module name).
-// If packed = true and name == 0: <pid>.<sancov>.<packed>.
-// If packed = true and name != 0: <name>.<sancov>.<packed> (name is
-// user-supplied).
-static fd_t CovOpenFile(InternalScopedString *path, bool packed,
-                       const char *name, const char *extension = "sancov") {
-  path->clear();
-  if (!packed) {
-    CHECK(name);
-    path->append("%s/%s.%zd.%s", coverage_dir, name, internal_getpid(),
-                extension);
-  } else {
-    if (!name)
-      path->append("%s/%zd.%s.packed", coverage_dir, internal_getpid(),
-                  extension);
-    else
-      path->append("%s/%s.%s.packed", coverage_dir, name, extension);
-  }
-  error_t err;
-  fd_t fd = OpenFile(path->data(), WrOnly, &err);
-  if (fd == kInvalidFd)
-    Report("SanitizerCoverage: failed to open %s for writing (reason: %d)\n",
-           path->data(), err);
-  return fd;
-}
-
-// Dump trace PCs and trace events into two separate files.
-void CoverageData::DumpTrace() {
-  uptr max_idx = tr_event_pointer - tr_event_array;
-  if (!max_idx) return;
-  auto sym = Symbolizer::GetOrInit();
-  if (!sym)
-    return;
-  InternalScopedString out(32 << 20);
-  for (uptr i = 0, n = size(); i < n; i++) {
-    const char *module_name = "<unknown>";
-    uptr module_address = 0;
-    sym->GetModuleNameAndOffsetForPC(UnbundlePc(pc_array[i]), &module_name,
-                                     &module_address);
-    out.append("%s 0x%zx\n", module_name, module_address);
-  }
-  InternalScopedString path(kMaxPathLength);
-  fd_t fd = CovOpenFile(&path, false, "trace-points");
-  if (fd == kInvalidFd) return;
-  WriteToFile(fd, out.data(), out.length());
-  CloseFile(fd);
-
-  fd = CovOpenFile(&path, false, "trace-compunits");
-  if (fd == kInvalidFd) return;
-  out.clear();
-  for (uptr i = 0; i < comp_unit_name_vec.size(); i++)
-    out.append("%s\n", comp_unit_name_vec[i].copied_module_name);
-  WriteToFile(fd, out.data(), out.length());
-  CloseFile(fd);
-
-  fd = CovOpenFile(&path, false, "trace-events");
-  if (fd == kInvalidFd) return;
-  uptr bytes_to_write = max_idx * sizeof(tr_event_array[0]);
-  u8 *event_bytes = reinterpret_cast<u8*>(tr_event_array);
-  // The trace file could be huge, and may not be written with a single syscall.
-  while (bytes_to_write) {
-    uptr actually_written;
-    if (WriteToFile(fd, event_bytes, bytes_to_write, &actually_written) &&
-        actually_written <= bytes_to_write) {
-      bytes_to_write -= actually_written;
-      event_bytes += actually_written;
-    } else {
-      break;
-    }
-  }
-  CloseFile(fd);
-  VReport(1, " CovDump: Trace: %zd PCs written\n", size());
-  VReport(1, " CovDump: Trace: %zd Events written\n", max_idx);
-}
-
-// This function dumps the caller=>callee pairs into a file as a sequence of
-// lines like "module_name offset".
-void CoverageData::DumpCallerCalleePairs() {
-  uptr max_idx = atomic_load(&cc_array_index, memory_order_relaxed);
-  if (!max_idx) return;
-  auto sym = Symbolizer::GetOrInit();
-  if (!sym)
-    return;
-  InternalScopedString out(32 << 20);
-  uptr total = 0;
-  for (uptr i = 0; i < max_idx; i++) {
-    uptr *cc_cache = cc_array[i];
-    CHECK(cc_cache);
-    uptr caller = cc_cache[0];
-    uptr n_callees = cc_cache[1];
-    const char *caller_module_name = "<unknown>";
-    uptr caller_module_address = 0;
-    sym->GetModuleNameAndOffsetForPC(caller, &caller_module_name,
-                                     &caller_module_address);
-    for (uptr j = 2; j < n_callees; j++) {
-      uptr callee = cc_cache[j];
-      if (!callee) break;
-      total++;
-      const char *callee_module_name = "<unknown>";
-      uptr callee_module_address = 0;
-      sym->GetModuleNameAndOffsetForPC(callee, &callee_module_name,
-                                       &callee_module_address);
-      out.append("%s 0x%zx\n%s 0x%zx\n", caller_module_name,
-                 caller_module_address, callee_module_name,
-                 callee_module_address);
-    }
-  }
-  InternalScopedString path(kMaxPathLength);
-  fd_t fd = CovOpenFile(&path, false, "caller-callee");
-  if (fd == kInvalidFd) return;
-  WriteToFile(fd, out.data(), out.length());
-  CloseFile(fd);
-  VReport(1, " CovDump: %zd caller-callee pairs written\n", total);
-}
-
-// Record the current PC into the event buffer.
-// Every event is a u32 value (index in tr_pc_array_index) so we compute
-// it once and then cache in the provided 'cache' storage.
-//
-// This function will eventually be inlined by the compiler.
-void CoverageData::TraceBasicBlock(u32 *id) {
-  // Will trap here if
-  //  1. coverage is not enabled at run-time.
-  //  2. The array tr_event_array is full.
-  *tr_event_pointer = *id - 1;
-  tr_event_pointer++;
-}
-
-void CoverageData::DumpCounters() {
-  if (!common_flags()->coverage_counters) return;
-  uptr n = coverage_data.GetNumberOf8bitCounters();
-  if (!n) return;
-  InternalScopedBuffer<u8> bitset(n);
-  coverage_data.Update8bitCounterBitsetAndClearCounters(bitset.data());
-  InternalScopedString path(kMaxPathLength);
-
-  for (uptr m = 0; m < module_name_vec.size(); m++) {
-    auto r = module_name_vec[m];
-    CHECK(r.copied_module_name);
-    CHECK_LE(r.beg, r.end);
-    CHECK_LE(r.end, size());
-    const char *base_name = StripModuleName(r.copied_module_name);
-    fd_t fd =
-        CovOpenFile(&path, /* packed */ false, base_name, "counters-sancov");
-    if (fd == kInvalidFd) return;
-    WriteToFile(fd, bitset.data() + r.beg, r.end - r.beg);
-    CloseFile(fd);
-    VReport(1, " CovDump: %zd counters written for '%s'\n", r.end - r.beg,
-            base_name);
-  }
-}
-
-void CoverageData::DumpAsBitSet() {
-  if (!common_flags()->coverage_bitset) return;
-  if (!size()) return;
-  InternalScopedBuffer<char> out(size());
-  InternalScopedString path(kMaxPathLength);
-  for (uptr m = 0; m < module_name_vec.size(); m++) {
-    uptr n_set_bits = 0;
-    auto r = module_name_vec[m];
-    CHECK(r.copied_module_name);
-    CHECK_LE(r.beg, r.end);
-    CHECK_LE(r.end, size());
-    for (uptr i = r.beg; i < r.end; i++) {
-      uptr pc = UnbundlePc(pc_array[i]);
-      out[i] = pc ? '1' : '0';
-      if (pc)
-        n_set_bits++;
-    }
-    const char *base_name = StripModuleName(r.copied_module_name);
-    fd_t fd = CovOpenFile(&path, /* packed */false, base_name, "bitset-sancov");
-    if (fd == kInvalidFd) return;
-    WriteToFile(fd, out.data() + r.beg, r.end - r.beg);
-    CloseFile(fd);
-    VReport(1,
-            " CovDump: bitset of %zd bits written for '%s', %zd bits are set\n",
-            r.end - r.beg, base_name, n_set_bits);
-  }
-}
-
-
-void CoverageData::GetRangeOffsets(const NamedPcRange& r, Symbolizer* sym,
-    InternalMmapVector<uptr>* offsets) const {
-  offsets->clear();
-  for (uptr i = 0; i < kNumWordsForMagic; i++)
-    offsets->push_back(0);
-  CHECK(r.copied_module_name);
-  CHECK_LE(r.beg, r.end);
-  CHECK_LE(r.end, size());
-  for (uptr i = r.beg; i < r.end; i++) {
-    uptr pc = UnbundlePc(pc_array[i]);
-    uptr counter = UnbundleCounter(pc_array[i]);
-    if (!pc) continue; // Not visited.
-    uptr offset = 0;
-    sym->GetModuleNameAndOffsetForPC(pc, nullptr, &offset);
-    offsets->push_back(BundlePcAndCounter(offset, counter));
-  }
-
-  CHECK_GE(offsets->size(), kNumWordsForMagic);
-  SortArray(offsets->data(), offsets->size());
-  for (uptr i = 0; i < offsets->size(); i++)
-    (*offsets)[i] = UnbundlePc((*offsets)[i]);
-}
-
-static void GenerateHtmlReport(const InternalMmapVector<char *> &cov_files) {
-  if (!common_flags()->html_cov_report) {
-    return;
-  }
-  char *sancov_path = FindPathToBinary(common_flags()->sancov_path);
-  if (sancov_path == nullptr) {
-    return;
-  }
-
-  InternalMmapVector<char *> sancov_argv(cov_files.size() * 2 + 3);
-  sancov_argv.push_back(sancov_path);
-  sancov_argv.push_back(internal_strdup("-html-report"));
-  auto argv_deleter = at_scope_exit([&] {
-    for (uptr i = 0; i < sancov_argv.size(); ++i) {
-      InternalFree(sancov_argv[i]);
-    }
-  });
-
-  for (const auto &cov_file : cov_files) {
-    sancov_argv.push_back(internal_strdup(cov_file));
-  }
-
-  {
-    ListOfModules modules;
-    modules.init();
-    for (const LoadedModule &module : modules) {
-      sancov_argv.push_back(internal_strdup(module.full_name()));
-    }
-  }
-
-  InternalScopedString report_path(kMaxPathLength);
-  fd_t report_fd =
-      CovOpenFile(&report_path, false /* packed */, GetProcessName(), "html");
-  int pid = StartSubprocess(sancov_argv[0], sancov_argv.data(),
-                            kInvalidFd /* stdin */, report_fd /* std_out */);
-  if (pid > 0) {
-    int result = WaitForProcess(pid);
-    if (result == 0)
-      Printf("coverage report generated to %s\n", report_path.data());
-  }
-}
-
-void CoverageData::DumpOffsets() {
-  auto sym = Symbolizer::GetOrInit();
-  if (!common_flags()->coverage_pcs) return;
-  CHECK_NE(sym, nullptr);
-  InternalMmapVector<uptr> offsets(0);
-  InternalScopedString path(kMaxPathLength);
-
-  InternalMmapVector<char *> cov_files(module_name_vec.size());
-  auto cov_files_deleter = at_scope_exit([&] {
-    for (uptr i = 0; i < cov_files.size(); ++i) {
-      InternalFree(cov_files[i]);
-    }
-  });
-
-  for (uptr m = 0; m < module_name_vec.size(); m++) {
-    auto r = module_name_vec[m];
-    GetRangeOffsets(r, sym, &offsets);
-
-    uptr num_offsets = offsets.size() - kNumWordsForMagic;
-    u64 *magic_p = reinterpret_cast<u64*>(offsets.data());
-    CHECK_EQ(*magic_p, 0ULL);
-    // FIXME: we may want to write 32-bit offsets even in 64-mode
-    // if all the offsets are small enough.
-    *magic_p = kMagic;
-
-    const char *module_name = StripModuleName(r.copied_module_name);
-    if (cov_sandboxed) {
-      if (cov_fd != kInvalidFd) {
-        CovWritePacked(internal_getpid(), module_name, offsets.data(),
-                       offsets.size() * sizeof(offsets[0]));
-        VReport(1, " CovDump: %zd PCs written to packed file\n", num_offsets);
-      }
-    } else {
-      // One file per module per process.
-      fd_t fd = CovOpenFile(&path, false /* packed */, module_name);
-      if (fd == kInvalidFd) continue;
-      WriteToFile(fd, offsets.data(), offsets.size() * sizeof(offsets[0]));
-      CloseFile(fd);
-      cov_files.push_back(internal_strdup(path.data()));
-      VReport(1, " CovDump: %s: %zd PCs written\n", path.data(), num_offsets);
-    }
-  }
-  if (cov_fd != kInvalidFd)
-    CloseFile(cov_fd);
-
-  GenerateHtmlReport(cov_files);
-}
-
-void CoverageData::DumpAll() {
-  if (!coverage_enabled || common_flags()->coverage_direct) return;
-  if (atomic_fetch_add(&dump_once_guard, 1, memory_order_relaxed))
-    return;
-  DumpAsBitSet();
-  DumpCounters();
-  DumpTrace();
-  DumpOffsets();
-  DumpCallerCalleePairs();
-}
-
-void CovPrepareForSandboxing(__sanitizer_sandbox_arguments *args) {
-  if (!args) return;
-  if (!coverage_enabled) return;
-  cov_sandboxed = args->coverage_sandboxed;
-  if (!cov_sandboxed) return;
-  cov_max_block_size = args->coverage_max_block_size;
-  if (args->coverage_fd >= 0) {
-    cov_fd = (fd_t)args->coverage_fd;
-  } else {
-    InternalScopedString path(kMaxPathLength);
-    // Pre-open the file now. The sandbox won't allow us to do it later.
-    cov_fd = CovOpenFile(&path, true /* packed */, nullptr);
-  }
-}
-
-fd_t MaybeOpenCovFile(const char *name) {
-  CHECK(name);
-  if (!coverage_enabled) return kInvalidFd;
-  InternalScopedString path(kMaxPathLength);
-  return CovOpenFile(&path, true /* packed */, name);
-}
-
-void CovBeforeFork() {
-  coverage_data.BeforeFork();
-}
-
-void CovAfterFork(int child_pid) {
-  coverage_data.AfterFork(child_pid);
-}
-
-static void MaybeDumpCoverage() {
-  if (common_flags()->coverage)
-    __sanitizer_cov_dump();
-}
-
-void InitializeCoverage(bool enabled, const char *dir) {
-  if (coverage_enabled)
-    return;  // May happen if two sanitizer enable coverage in the same process.
-  coverage_enabled = enabled;
-  coverage_dir = dir;
-  coverage_data.Init();
-  if (enabled) coverage_data.Enable();
-  if (!common_flags()->coverage_direct) Atexit(__sanitizer_cov_dump);
-  AddDieCallback(MaybeDumpCoverage);
-}
-
-void ReInitializeCoverage(bool enabled, const char *dir) {
-  coverage_enabled = enabled;
-  coverage_dir = dir;
-  coverage_data.ReInit();
-}
-
-void CoverageUpdateMapping() {
-  if (coverage_enabled)
-    CovUpdateMapping(coverage_dir);
-}
-
-} // namespace __sanitizer
-
-extern "C" {
-SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov(u32 *guard) {
-  coverage_data.Add(StackTrace::GetPreviousInstructionPc(GET_CALLER_PC()),
-                    guard);
-}
-SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_with_check(u32 *guard) {
-  atomic_uint32_t *atomic_guard = reinterpret_cast<atomic_uint32_t*>(guard);
-  if (static_cast<s32>(
-          __sanitizer::atomic_load(atomic_guard, memory_order_relaxed)) < 0)
-    __sanitizer_cov(guard);
-}
-SANITIZER_INTERFACE_ATTRIBUTE void
-__sanitizer_cov_indir_call16(uptr callee, uptr callee_cache16[]) {
-  coverage_data.IndirCall(StackTrace::GetPreviousInstructionPc(GET_CALLER_PC()),
-                          callee, callee_cache16, 16);
-}
-SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_init() {
-  coverage_enabled = true;
-  coverage_dir = common_flags()->coverage_dir;
-  coverage_data.Init();
-}
-SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_dump() {
-  coverage_data.DumpAll();
-}
-SANITIZER_INTERFACE_ATTRIBUTE void
-__sanitizer_cov_module_init(s32 *guards, uptr npcs, u8 *counters,
-                            const char *comp_unit_name) {
-  coverage_data.InitializeGuards(guards, npcs, comp_unit_name, GET_CALLER_PC());
-  coverage_data.InitializeCounters(counters, npcs);
-  if (!common_flags()->coverage_direct) return;
-  if (SANITIZER_ANDROID && coverage_enabled) {
-    // dlopen/dlclose interceptors do not work on Android, so we rely on
-    // Extend() calls to update .sancov.map.
-    CovUpdateMapping(coverage_dir, GET_CALLER_PC());
-  }
-  coverage_data.Extend(npcs);
-}
-SANITIZER_INTERFACE_ATTRIBUTE
-sptr __sanitizer_maybe_open_cov_file(const char *name) {
-  return (sptr)MaybeOpenCovFile(name);
-}
-SANITIZER_INTERFACE_ATTRIBUTE
-uptr __sanitizer_get_total_unique_coverage() {
-  return atomic_load(&coverage_counter, memory_order_relaxed);
-}
-
-SANITIZER_INTERFACE_ATTRIBUTE
-uptr __sanitizer_get_total_unique_caller_callee_pairs() {
-  return atomic_load(&caller_callee_counter, memory_order_relaxed);
-}
-
-SANITIZER_INTERFACE_ATTRIBUTE
-void __sanitizer_cov_trace_func_enter(u32 *id) {
-  __sanitizer_cov_with_check(id);
-  coverage_data.TraceBasicBlock(id);
-}
-SANITIZER_INTERFACE_ATTRIBUTE
-void __sanitizer_cov_trace_basic_block(u32 *id) {
-  __sanitizer_cov_with_check(id);
-  coverage_data.TraceBasicBlock(id);
-}
-SANITIZER_INTERFACE_ATTRIBUTE
-void __sanitizer_reset_coverage() {
-  ResetGlobalCounters();
-  coverage_data.ReinitializeGuards();
-  internal_bzero_aligned16(
-      coverage_data.data(),
-      RoundUpTo(coverage_data.size() * sizeof(coverage_data.data()[0]), 16));
-}
-SANITIZER_INTERFACE_ATTRIBUTE
-uptr __sanitizer_get_coverage_guards(uptr **data) {
-  *data = coverage_data.data();
-  return coverage_data.size();
-}
-
-SANITIZER_INTERFACE_ATTRIBUTE
-uptr __sanitizer_get_number_of_counters() {
-  return coverage_data.GetNumberOf8bitCounters();
-}
-
-SANITIZER_INTERFACE_ATTRIBUTE
-uptr __sanitizer_update_counter_bitset_and_clear_counters(u8 *bitset) {
-  return coverage_data.Update8bitCounterBitsetAndClearCounters(bitset);
-}
-// Default empty implementations (weak). Users should redefine them.
-#if !SANITIZER_WINDOWS  // weak does not work on Windows.
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void __sanitizer_cov_trace_cmp() {}
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void __sanitizer_cov_trace_cmp1() {}
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void __sanitizer_cov_trace_cmp2() {}
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void __sanitizer_cov_trace_cmp4() {}
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void __sanitizer_cov_trace_cmp8() {}
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void __sanitizer_cov_trace_switch() {}
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void __sanitizer_cov_trace_div4() {}
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void __sanitizer_cov_trace_div8() {}
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void __sanitizer_cov_trace_gep() {}
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void __sanitizer_cov_trace_pc_guard() {}
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void __sanitizer_cov_trace_pc_indir() {}
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void __sanitizer_cov_trace_pc_guard_init() {}
-#endif  // !SANITIZER_WINDOWS
-} // extern "C"
diff --git a/libsanitizer/sanitizer_common/sanitizer_coverage_libcdep_new.cc b/libsanitizer/sanitizer_common/sanitizer_coverage_libcdep_new.cc
new file mode 100644
index 00000000000..25a5001bd3e
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_coverage_libcdep_new.cc
@@ -0,0 +1,218 @@
+//===-- sanitizer_coverage_libcdep_new.cc ---------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// Sanitizer Coverage Controller for Trace PC Guard.
+
+#include "sanitizer_platform.h"
+
+#if !SANITIZER_FUCHSIA
+#include "sancov_flags.h"
+#include "sanitizer_allocator_internal.h"
+#include "sanitizer_atomic.h"
+#include "sanitizer_common.h"
+#include "sanitizer_file.h"
+#include "sanitizer_symbolizer.h"
+
+using namespace __sanitizer;
+
+using AddressRange = LoadedModule::AddressRange;
+
+namespace __sancov {
+namespace {
+
+static const u64 Magic64 = 0xC0BFFFFFFFFFFF64ULL;
+static const u64 Magic32 = 0xC0BFFFFFFFFFFF32ULL;
+static const u64 Magic = SANITIZER_WORDSIZE == 64 ? Magic64 : Magic32;
+
+static fd_t OpenFile(const char* path) {
+  error_t err;
+  fd_t fd = OpenFile(path, WrOnly, &err);
+  if (fd == kInvalidFd)
+    Report("SanitizerCoverage: failed to open %s for writing (reason: %d)\n",
+           path, err);
+  return fd;
+}
+
+static void GetCoverageFilename(char* path, const char* name,
+                                const char* extension) {
+  CHECK(name);
+  internal_snprintf(path, kMaxPathLength, "%s/%s.%zd.%s",
+                    common_flags()->coverage_dir, name, internal_getpid(),
+                    extension);
+}
+
+static void WriteModuleCoverage(char* file_path, const char* module_name,
+                                const uptr* pcs, uptr len) {
+  GetCoverageFilename(file_path, StripModuleName(module_name), "sancov");
+  fd_t fd = OpenFile(file_path);
+  WriteToFile(fd, &Magic, sizeof(Magic));
+  WriteToFile(fd, pcs, len * sizeof(*pcs));
+  CloseFile(fd);
+  Printf("SanitizerCoverage: %s: %zd PCs written\n", file_path, len);
+}
+
+static void SanitizerDumpCoverage(const uptr* unsorted_pcs, uptr len) {
+  if (!len) return;
+
+  char* file_path = static_cast<char*>(InternalAlloc(kMaxPathLength));
+  char* module_name = static_cast<char*>(InternalAlloc(kMaxPathLength));
+  uptr* pcs = static_cast<uptr*>(InternalAlloc(len * sizeof(uptr)));
+
+  internal_memcpy(pcs, unsorted_pcs, len * sizeof(uptr));
+  SortArray(pcs, len);
+
+  bool module_found = false;
+  uptr last_base = 0;
+  uptr module_start_idx = 0;
+
+  for (uptr i = 0; i < len; ++i) {
+    const uptr pc = pcs[i];
+    if (!pc) continue;
+
+    if (!__sanitizer_get_module_and_offset_for_pc(pc, nullptr, 0, &pcs[i])) {
+      Printf("ERROR: unknown pc 0x%x (may happen if dlclose is used)\n", pc);
+      continue;
+    }
+    uptr module_base = pc - pcs[i];
+
+    if (module_base != last_base || !module_found) {
+      if (module_found) {
+        WriteModuleCoverage(file_path, module_name, &pcs[module_start_idx],
+                            i - module_start_idx);
+      }
+
+      last_base = module_base;
+      module_start_idx = i;
+      module_found = true;
+      __sanitizer_get_module_and_offset_for_pc(pc, module_name, kMaxPathLength,
+                                               &pcs[i]);
+    }
+  }
+
+  if (module_found) {
+    WriteModuleCoverage(file_path, module_name, &pcs[module_start_idx],
+                        len - module_start_idx);
+  }
+
+  InternalFree(file_path);
+  InternalFree(module_name);
+  InternalFree(pcs);
+}
+
+// Collects trace-pc guard coverage.
+// This class relies on zero-initialization.
+class TracePcGuardController {
+ public:
+  void Initialize() {
+    CHECK(!initialized);
+
+    initialized = true;
+    InitializeSancovFlags();
+
+    pc_vector.Initialize(0);
+  }
+
+  void InitTracePcGuard(u32* start, u32* end) {
+    if (!initialized) Initialize();
+    CHECK(!*start);
+    CHECK_NE(start, end);
+
+    u32 i = pc_vector.size();
+    for (u32* p = start; p < end; p++) *p = ++i;
+    pc_vector.resize(i);
+  }
+
+  void TracePcGuard(u32* guard, uptr pc) {
+    u32 idx = *guard;
+    if (!idx) return;
+    // we start indices from 1.
+    atomic_uintptr_t* pc_ptr =
+        reinterpret_cast<atomic_uintptr_t*>(&pc_vector[idx - 1]);
+    if (atomic_load(pc_ptr, memory_order_relaxed) == 0)
+      atomic_store(pc_ptr, pc, memory_order_relaxed);
+  }
+
+  void Reset() {
+    internal_memset(&pc_vector[0], 0, sizeof(pc_vector[0]) * pc_vector.size());
+  }
+
+  void Dump() {
+    if (!initialized || !common_flags()->coverage) return;
+    __sanitizer_dump_coverage(pc_vector.data(), pc_vector.size());
+  }
+
+ private:
+  bool initialized;
+  InternalMmapVectorNoCtor<uptr> pc_vector;
+};
+
+static TracePcGuardController pc_guard_controller;
+
+}  // namespace
+}  // namespace __sancov
+
+namespace __sanitizer {
+void InitializeCoverage(bool enabled, const char *dir) {
+  static bool coverage_enabled = false;
+  if (coverage_enabled)
+    return;  // May happen if two sanitizer enable coverage in the same process.
+  coverage_enabled = enabled;
+  Atexit(__sanitizer_cov_dump);
+  AddDieCallback(__sanitizer_cov_dump);
+}
+} // namespace __sanitizer
+
+extern "C" {
+SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_dump_coverage(  // NOLINT
+    const uptr* pcs, uptr len) {
+  return __sancov::SanitizerDumpCoverage(pcs, len);
+}
+
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard, u32* guard) {
+  if (!*guard) return;
+  __sancov::pc_guard_controller.TracePcGuard(guard, GET_CALLER_PC() - 1);
+}
+
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard_init,
+                             u32* start, u32* end) {
+  if (start == end || *start) return;
+  __sancov::pc_guard_controller.InitTracePcGuard(start, end);
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_dump_trace_pc_guard_coverage() {
+  __sancov::pc_guard_controller.Dump();
+}
+SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_dump() {
+  __sanitizer_dump_trace_pc_guard_coverage();
+}
+SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_reset() {
+  __sancov::pc_guard_controller.Reset();
+}
+// Default empty implementations (weak). Users should redefine them.
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_cmp, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_cmp1, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_cmp2, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_cmp4, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_cmp8, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_const_cmp1, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_const_cmp2, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_const_cmp4, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_const_cmp8, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_switch, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_div4, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_div8, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_gep, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_indir, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_8bit_counters_init, void) {}
+SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_pcs_init, void) {}
+}  // extern "C"
+// Weak definition for code instrumented with -fsanitize-coverage=stack-depth
+// and later linked with code containing a strong definition.
+// E.g., -fsanitize=fuzzer-no-link
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+SANITIZER_TLS_INITIAL_EXEC_ATTRIBUTE uptr __sancov_lowest_stack;
+
+#endif  // !SANITIZER_FUCHSIA
diff --git a/libsanitizer/sanitizer_common/sanitizer_coverage_mapping_libcdep.cc b/libsanitizer/sanitizer_common/sanitizer_coverage_mapping_libcdep.cc
deleted file mode 100644
index b2e724ab221..00000000000
--- a/libsanitizer/sanitizer_common/sanitizer_coverage_mapping_libcdep.cc
+++ /dev/null
@@ -1,120 +0,0 @@
-//===-- sanitizer_coverage_mapping.cc -------------------------------------===//
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// Mmap-based implementation of sanitizer coverage.
-//
-// This is part of the implementation of code coverage that does not require
-// __sanitizer_cov_dump() call. Data is stored in 2 files per process.
-//
-// $pid.sancov.map describes process memory layout in the following text-based
-// format:
-// <pointer size in bits>  // 1 line, 32 or 64
-// <mapping start> <mapping end> <base address> <dso name> // repeated
-// ...
-// Mapping lines are NOT sorted. This file is updated every time memory layout
-// is changed (i.e. in dlopen() and dlclose() interceptors).
-//
-// $pid.sancov.raw is a binary dump of PC values, sizeof(uptr) each. Again, not
-// sorted. This file is extended by 64Kb at a time and mapped into memory. It
-// contains one or more 0 words at the end, up to the next 64Kb aligned offset.
-//
-// To convert these 2 files to the usual .sancov format, run sancov.py rawunpack
-// $pid.sancov.raw.
-//
-//===----------------------------------------------------------------------===//
-
-#include "sanitizer_allocator_internal.h"
-#include "sanitizer_libc.h"
-#include "sanitizer_procmaps.h"
-
-namespace __sanitizer {
-
-static const uptr kMaxTextSize = 64 * 1024;
-
-struct CachedMapping {
- public:
-  bool NeedsUpdate(uptr pc) {
-    int new_pid = internal_getpid();
-    if (last_pid == new_pid && pc && pc >= last_range_start &&
-        pc < last_range_end)
-      return false;
-    last_pid = new_pid;
-    return true;
-  }
-
-  void SetModuleRange(uptr start, uptr end) {
-    last_range_start = start;
-    last_range_end = end;
-  }
-
- private:
-  uptr last_range_start, last_range_end;
-  int last_pid;
-};
-
-static CachedMapping cached_mapping;
-static StaticSpinMutex mapping_mu;
-
-void CovUpdateMapping(const char *coverage_dir, uptr caller_pc) {
-  if (!common_flags()->coverage_direct) return;
-
-  SpinMutexLock l(&mapping_mu);
-
-  if (!cached_mapping.NeedsUpdate(caller_pc))
-    return;
-
-  InternalScopedString text(kMaxTextSize);
-
-  {
-    text.append("%d\n", sizeof(uptr) * 8);
-    ListOfModules modules;
-    modules.init();
-    for (const LoadedModule &module : modules) {
-      const char *module_name = StripModuleName(module.full_name());
-      uptr base = module.base_address();
-      for (const auto &range : module.ranges()) {
-        if (range.executable) {
-          uptr start = range.beg;
-          uptr end = range.end;
-          text.append("%zx %zx %zx %s\n", start, end, base, module_name);
-          if (caller_pc && caller_pc >= start && caller_pc < end)
-            cached_mapping.SetModuleRange(start, end);
-        }
-      }
-    }
-  }
-
-  error_t err;
-  InternalScopedString tmp_path(64 + internal_strlen(coverage_dir));
-  uptr res = internal_snprintf((char *)tmp_path.data(), tmp_path.size(),
-                               "%s/%zd.sancov.map.tmp", coverage_dir,
-                               internal_getpid());
-  CHECK_LE(res, tmp_path.size());
-  fd_t map_fd = OpenFile(tmp_path.data(), WrOnly, &err);
-  if (map_fd == kInvalidFd) {
-    Report("Coverage: failed to open %s for writing: %d\n", tmp_path.data(),
-           err);
-    Die();
-  }
-
-  if (!WriteToFile(map_fd, text.data(), text.length(), nullptr, &err)) {
-    Printf("sancov.map write failed: %d\n", err);
-    Die();
-  }
-  CloseFile(map_fd);
-
-  InternalScopedString path(64 + internal_strlen(coverage_dir));
-  res = internal_snprintf((char *)path.data(), path.size(), "%s/%zd.sancov.map",
-                          coverage_dir, internal_getpid());
-  CHECK_LE(res, path.size());
-  if (!RenameFile(tmp_path.data(), path.data(), &err)) {
-    Printf("sancov.map rename failed: %d\n", err);
-    Die();
-  }
-}
-
-} // namespace __sanitizer
diff --git a/libsanitizer/sanitizer_common/sanitizer_coverage_win_dll_thunk.cc b/libsanitizer/sanitizer_common/sanitizer_coverage_win_dll_thunk.cc
new file mode 100644
index 00000000000..5aea1203dbf
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_coverage_win_dll_thunk.cc
@@ -0,0 +1,19 @@
+//===-- sanitizer_coverage_win_dll_thunk.cc -------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a family of thunks that should be statically linked into
+// the DLLs that have instrumentation in order to delegate the calls to the
+// shared runtime that lives in the main binary.
+// See https://github.com/google/sanitizers/issues/209 for the details.
+//===----------------------------------------------------------------------===//
+#ifdef SANITIZER_DLL_THUNK
+#include "sanitizer_win_dll_thunk.h"
+// Sanitizer Coverage interface functions.
+#define INTERFACE_FUNCTION(Name) INTERCEPT_SANITIZER_FUNCTION(Name)
+#define INTERFACE_WEAK_FUNCTION(Name) INTERCEPT_SANITIZER_WEAK_FUNCTION(Name)
+#include "sanitizer_coverage_interface.inc"
+#endif // SANITIZER_DLL_THUNK
diff --git a/libsanitizer/sanitizer_common/sanitizer_coverage_win_dynamic_runtime_thunk.cc b/libsanitizer/sanitizer_common/sanitizer_coverage_win_dynamic_runtime_thunk.cc
new file mode 100644
index 00000000000..939f395071b
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_coverage_win_dynamic_runtime_thunk.cc
@@ -0,0 +1,19 @@
+//===-- sanitizer_coverage_win_dynamic_runtime_thunk.cc -------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines things that need to be present in the application modules
+// to interact with Sanitizer Coverage, when it is included in a dll.
+//
+//===----------------------------------------------------------------------===//
+#ifdef SANITIZER_DYNAMIC_RUNTIME_THUNK
+#define SANITIZER_IMPORT_INTERFACE 1
+#include "sanitizer_win_defs.h"
+// Define weak alias for all weak functions imported from sanitizer coverage.
+#define INTERFACE_FUNCTION(Name)
+#define INTERFACE_WEAK_FUNCTION(Name) WIN_WEAK_IMPORT_DEF(Name)
+#include "sanitizer_coverage_interface.inc"
+#endif // SANITIZER_DYNAMIC_RUNTIME_THUNK
diff --git a/libsanitizer/sanitizer_common/sanitizer_coverage_win_sections.cc b/libsanitizer/sanitizer_common/sanitizer_coverage_win_sections.cc
new file mode 100644
index 00000000000..485dd45e14b
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_coverage_win_sections.cc
@@ -0,0 +1,20 @@
+//===-- sanitizer_coverage_win_sections.cc --------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines delimiters for Sanitizer Coverage's section.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+#if SANITIZER_WINDOWS
+#include <stdint.h>
+#pragma section(".SCOV$A", read, write)  // NOLINT
+#pragma section(".SCOV$Z", read, write)  // NOLINT
+extern "C" {
+__declspec(allocate(".SCOV$A")) uint32_t __start___sancov_guards = 0;
+__declspec(allocate(".SCOV$Z")) uint32_t __stop___sancov_guards = 0;
+}
+#endif // SANITIZER_WINDOWS
diff --git a/libsanitizer/sanitizer_common/sanitizer_coverage_win_weak_interception.cc b/libsanitizer/sanitizer_common/sanitizer_coverage_win_weak_interception.cc
new file mode 100644
index 00000000000..64718dfc507
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_coverage_win_weak_interception.cc
@@ -0,0 +1,22 @@
+//===-- sanitizer_coverage_win_weak_interception.cc -----------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This module should be included in Sanitizer Coverage when it implemented as a
+// shared library on Windows (dll), in order to delegate the calls of weak
+// functions to the implementation in the main executable when a strong
+// definition is provided.
+//===----------------------------------------------------------------------===//
+#ifdef SANITIZER_DYNAMIC
+#include "sanitizer_win_weak_interception.h"
+#include "sanitizer_interface_internal.h"
+#include "sancov_flags.h"
+// Check if strong definitions for weak functions are present in the main
+// executable. If that is the case, override dll functions to point to strong
+// implementations.
+#define INTERFACE_FUNCTION(Name)
+#define INTERFACE_WEAK_FUNCTION(Name) INTERCEPT_SANITIZER_WEAK_FUNCTION(Name)
+#include "sanitizer_coverage_interface.inc"
+#endif // SANITIZER_DYNAMIC
diff --git a/libsanitizer/sanitizer_common/sanitizer_dbghelp.h b/libsanitizer/sanitizer_common/sanitizer_dbghelp.h
new file mode 100644
index 00000000000..bad17a91eb8
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_dbghelp.h
@@ -0,0 +1,40 @@
+//===-- sanitizer_dbghelp.h ------------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Wrappers for lazy loaded dbghelp.dll. Provides function pointers and a
+// callback to initialize them.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SANITIZER_SYMBOLIZER_WIN_H
+#define SANITIZER_SYMBOLIZER_WIN_H
+
+#if !SANITIZER_WINDOWS
+#error "sanitizer_dbghelp.h is a Windows-only header"
+#endif
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#include <dbghelp.h>
+
+namespace __sanitizer {
+
+extern decltype(::StackWalk64) *StackWalk64;
+extern decltype(::SymCleanup) *SymCleanup;
+extern decltype(::SymFromAddr) *SymFromAddr;
+extern decltype(::SymFunctionTableAccess64) *SymFunctionTableAccess64;
+extern decltype(::SymGetLineFromAddr64) *SymGetLineFromAddr64;
+extern decltype(::SymGetModuleBase64) *SymGetModuleBase64;
+extern decltype(::SymGetSearchPathW) *SymGetSearchPathW;
+extern decltype(::SymInitialize) *SymInitialize;
+extern decltype(::SymSetOptions) *SymSetOptions;
+extern decltype(::SymSetSearchPathW) *SymSetSearchPathW;
+extern decltype(::UnDecorateSymbolName) *UnDecorateSymbolName;
+
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_SYMBOLIZER_WIN_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_errno.cc b/libsanitizer/sanitizer_common/sanitizer_errno.cc
new file mode 100644
index 00000000000..b65f0e7ddf1
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_errno.cc
@@ -0,0 +1,33 @@
+//===-- sanitizer_errno.cc --------------------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is shared between sanitizers run-time libraries.
+//
+// Defines errno to avoid including errno.h and its dependencies into other
+// files (e.g. interceptors are not supposed to include any system headers).
+//
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_errno_codes.h"
+#include "sanitizer_internal_defs.h"
+
+#include <errno.h>
+
+namespace __sanitizer {
+
+COMPILER_CHECK(errno_ENOMEM == ENOMEM);
+COMPILER_CHECK(errno_EBUSY == EBUSY);
+COMPILER_CHECK(errno_EINVAL == EINVAL);
+
+// EOWNERDEAD is not present in some older platforms.
+#if defined(EOWNERDEAD)
+extern const int errno_EOWNERDEAD = EOWNERDEAD;
+#else
+extern const int errno_EOWNERDEAD = -1;
+#endif
+
+}  // namespace __sanitizer
diff --git a/libsanitizer/sanitizer_common/sanitizer_errno.h b/libsanitizer/sanitizer_common/sanitizer_errno.h
new file mode 100644
index 00000000000..e9fc00f6c2a
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_errno.h
@@ -0,0 +1,35 @@
+//===-- sanitizer_errno.h ---------------------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is shared between sanitizers run-time libraries.
+//
+// Defines errno to avoid including errno.h and its dependencies into sensitive
+// files (e.g. interceptors are not supposed to include any system headers).
+// It's ok to use errno.h directly when your file already depend on other system
+// includes though.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SANITIZER_ERRNO_H
+#define SANITIZER_ERRNO_H
+
+#include "sanitizer_errno_codes.h"
+#include "sanitizer_platform.h"
+
+#if SANITIZER_FREEBSD || SANITIZER_MAC
+#  define __errno_location __error
+#elif SANITIZER_ANDROID || SANITIZER_NETBSD
+#  define __errno_location __errno
+#elif SANITIZER_WINDOWS
+#  define __errno_location _errno
+#endif
+
+extern "C" int *__errno_location();
+
+#define errno (*__errno_location())
+
+#endif  // SANITIZER_ERRNO_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_errno_codes.h b/libsanitizer/sanitizer_common/sanitizer_errno_codes.h
new file mode 100644
index 00000000000..709f43b7689
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_errno_codes.h
@@ -0,0 +1,32 @@
+//===-- sanitizer_errno_codes.h ---------------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is shared between sanitizers run-time libraries.
+//
+// Defines errno codes to avoid including errno.h and its dependencies into
+// sensitive files (e.g. interceptors are not supposed to include any system
+// headers).
+// It's ok to use errno.h directly when your file already depend on other system
+// includes though.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SANITIZER_ERRNO_CODES_H
+#define SANITIZER_ERRNO_CODES_H
+
+namespace __sanitizer {
+
+#define errno_ENOMEM 12
+#define errno_EBUSY 16
+#define errno_EINVAL 22
+
+// Those might not present or their value differ on different platforms.
+extern const int errno_EOWNERDEAD;
+
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_ERRNO_CODES_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_file.cc b/libsanitizer/sanitizer_common/sanitizer_file.cc
new file mode 100644
index 00000000000..8740dbb5b6f
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_file.cc
@@ -0,0 +1,175 @@
+//===-- sanitizer_file.cc ------------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===---------------------------------------------------------------------===//
+//
+// This file is shared between AddressSanitizer and ThreadSanitizer
+// run-time libraries.  It defines filesystem-related interfaces.  This
+// is separate from sanitizer_common.cc so that it's simpler to disable
+// all the filesystem support code for a port that doesn't use it.
+//
+//===---------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+
+#if !SANITIZER_FUCHSIA
+
+#include "sanitizer_common.h"
+#include "sanitizer_file.h"
+
+namespace __sanitizer {
+
+void CatastrophicErrorWrite(const char *buffer, uptr length) {
+  WriteToFile(kStderrFd, buffer, length);
+}
+
+StaticSpinMutex report_file_mu;
+ReportFile report_file = {&report_file_mu, kStderrFd, "", "", 0};
+
+void RawWrite(const char *buffer) {
+  report_file.Write(buffer, internal_strlen(buffer));
+}
+
+void ReportFile::ReopenIfNecessary() {
+  mu->CheckLocked();
+  if (fd == kStdoutFd || fd == kStderrFd) return;
+
+  uptr pid = internal_getpid();
+  // If in tracer, use the parent's file.
+  if (pid == stoptheworld_tracer_pid)
+    pid = stoptheworld_tracer_ppid;
+  if (fd != kInvalidFd) {
+    // If the report file is already opened by the current process,
+    // do nothing. Otherwise the report file was opened by the parent
+    // process, close it now.
+    if (fd_pid == pid)
+      return;
+    else
+      CloseFile(fd);
+  }
+
+  const char *exe_name = GetProcessName();
+  if (common_flags()->log_exe_name && exe_name) {
+    internal_snprintf(full_path, kMaxPathLength, "%s.%s.%zu", path_prefix,
+                      exe_name, pid);
+  } else {
+    internal_snprintf(full_path, kMaxPathLength, "%s.%zu", path_prefix, pid);
+  }
+  fd = OpenFile(full_path, WrOnly);
+  if (fd == kInvalidFd) {
+    const char *ErrorMsgPrefix = "ERROR: Can't open file: ";
+    WriteToFile(kStderrFd, ErrorMsgPrefix, internal_strlen(ErrorMsgPrefix));
+    WriteToFile(kStderrFd, full_path, internal_strlen(full_path));
+    Die();
+  }
+  fd_pid = pid;
+}
+
+void ReportFile::SetReportPath(const char *path) {
+  if (!path)
+    return;
+  uptr len = internal_strlen(path);
+  if (len > sizeof(path_prefix) - 100) {
+    Report("ERROR: Path is too long: %c%c%c%c%c%c%c%c...\n",
+           path[0], path[1], path[2], path[3],
+           path[4], path[5], path[6], path[7]);
+    Die();
+  }
+
+  SpinMutexLock l(mu);
+  if (fd != kStdoutFd && fd != kStderrFd && fd != kInvalidFd)
+    CloseFile(fd);
+  fd = kInvalidFd;
+  if (internal_strcmp(path, "stdout") == 0) {
+    fd = kStdoutFd;
+  } else if (internal_strcmp(path, "stderr") == 0) {
+    fd = kStderrFd;
+  } else {
+    internal_snprintf(path_prefix, kMaxPathLength, "%s", path);
+  }
+}
+
+bool ReadFileToBuffer(const char *file_name, char **buff, uptr *buff_size,
+                      uptr *read_len, uptr max_len, error_t *errno_p) {
+  uptr PageSize = GetPageSizeCached();
+  uptr kMinFileLen = PageSize;
+  *buff = nullptr;
+  *buff_size = 0;
+  *read_len = 0;
+  // The files we usually open are not seekable, so try different buffer sizes.
+  for (uptr size = kMinFileLen; size <= max_len; size *= 2) {
+    fd_t fd = OpenFile(file_name, RdOnly, errno_p);
+    if (fd == kInvalidFd) return false;
+    UnmapOrDie(*buff, *buff_size);
+    *buff = (char*)MmapOrDie(size, __func__);
+    *buff_size = size;
+    *read_len = 0;
+    // Read up to one page at a time.
+    bool reached_eof = false;
+    while (*read_len + PageSize <= size) {
+      uptr just_read;
+      if (!ReadFromFile(fd, *buff + *read_len, PageSize, &just_read, errno_p)) {
+        UnmapOrDie(*buff, *buff_size);
+        return false;
+      }
+      if (just_read == 0) {
+        reached_eof = true;
+        break;
+      }
+      *read_len += just_read;
+    }
+    CloseFile(fd);
+    if (reached_eof)  // We've read the whole file.
+      break;
+  }
+  return true;
+}
+
+static const char kPathSeparator = SANITIZER_WINDOWS ? ';' : ':';
+
+char *FindPathToBinary(const char *name) {
+  if (FileExists(name)) {
+    return internal_strdup(name);
+  }
+
+  const char *path = GetEnv("PATH");
+  if (!path)
+    return nullptr;
+  uptr name_len = internal_strlen(name);
+  InternalScopedBuffer<char> buffer(kMaxPathLength);
+  const char *beg = path;
+  while (true) {
+    const char *end = internal_strchrnul(beg, kPathSeparator);
+    uptr prefix_len = end - beg;
+    if (prefix_len + name_len + 2 <= kMaxPathLength) {
+      internal_memcpy(buffer.data(), beg, prefix_len);
+      buffer[prefix_len] = '/';
+      internal_memcpy(&buffer[prefix_len + 1], name, name_len);
+      buffer[prefix_len + 1 + name_len] = '\0';
+      if (FileExists(buffer.data()))
+        return internal_strdup(buffer.data());
+    }
+    if (*end == '\0') break;
+    beg = end + 1;
+  }
+  return nullptr;
+}
+
+} // namespace __sanitizer
+
+using namespace __sanitizer;  // NOLINT
+
+extern "C" {
+void __sanitizer_set_report_path(const char *path) {
+  report_file.SetReportPath(path);
+}
+
+void __sanitizer_set_report_fd(void *fd) {
+  report_file.fd = (fd_t)reinterpret_cast<uptr>(fd);
+  report_file.fd_pid = internal_getpid();
+}
+} // extern "C"
+
+#endif  // !SANITIZER_FUCHSIA
diff --git a/libsanitizer/sanitizer_common/sanitizer_file.h b/libsanitizer/sanitizer_common/sanitizer_file.h
new file mode 100644
index 00000000000..3f9e8ab2849
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_file.h
@@ -0,0 +1,108 @@
+//===-- sanitizer_file.h ---------------------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===---------------------------------------------------------------------===//
+//
+// This file is shared between run-time libraries of sanitizers.
+// It declares filesystem-related interfaces.  This is separate from
+// sanitizer_common.h so that it's simpler to disable all the filesystem
+// support code for a port that doesn't use it.
+//
+//===---------------------------------------------------------------------===//
+#ifndef SANITIZER_FILE_H
+#define SANITIZER_FILE_H
+
+#include "sanitizer_interface_internal.h"
+#include "sanitizer_internal_defs.h"
+#include "sanitizer_libc.h"
+#include "sanitizer_mutex.h"
+
+namespace __sanitizer {
+
+struct ReportFile {
+  void Write(const char *buffer, uptr length);
+  bool SupportsColors();
+  void SetReportPath(const char *path);
+
+  // Don't use fields directly. They are only declared public to allow
+  // aggregate initialization.
+
+  // Protects fields below.
+  StaticSpinMutex *mu;
+  // Opened file descriptor. Defaults to stderr. It may be equal to
+  // kInvalidFd, in which case new file will be opened when necessary.
+  fd_t fd;
+  // Path prefix of report file, set via __sanitizer_set_report_path.
+  char path_prefix[kMaxPathLength];
+  // Full path to report, obtained as <path_prefix>.PID
+  char full_path[kMaxPathLength];
+  // PID of the process that opened fd. If a fork() occurs,
+  // the PID of child will be different from fd_pid.
+  uptr fd_pid;
+
+ private:
+  void ReopenIfNecessary();
+};
+extern ReportFile report_file;
+
+enum FileAccessMode {
+  RdOnly,
+  WrOnly,
+  RdWr
+};
+
+// Returns kInvalidFd on error.
+fd_t OpenFile(const char *filename, FileAccessMode mode,
+              error_t *errno_p = nullptr);
+void CloseFile(fd_t);
+
+// Return true on success, false on error.
+bool ReadFromFile(fd_t fd, void *buff, uptr buff_size,
+                  uptr *bytes_read = nullptr, error_t *error_p = nullptr);
+bool WriteToFile(fd_t fd, const void *buff, uptr buff_size,
+                 uptr *bytes_written = nullptr, error_t *error_p = nullptr);
+
+bool RenameFile(const char *oldpath, const char *newpath,
+                error_t *error_p = nullptr);
+
+// Scoped file handle closer.
+struct FileCloser {
+  explicit FileCloser(fd_t fd) : fd(fd) {}
+  ~FileCloser() { CloseFile(fd); }
+  fd_t fd;
+};
+
+bool SupportsColoredOutput(fd_t fd);
+
+// OS
+const char *GetPwd();
+bool FileExists(const char *filename);
+char *FindPathToBinary(const char *name);
+bool IsPathSeparator(const char c);
+bool IsAbsolutePath(const char *path);
+// Starts a subprocess and returs its pid.
+// If *_fd parameters are not kInvalidFd their corresponding input/output
+// streams will be redirect to the file. The files will always be closed
+// in parent process even in case of an error.
+// The child process will close all fds after STDERR_FILENO
+// before passing control to a program.
+pid_t StartSubprocess(const char *filename, const char *const argv[],
+                      fd_t stdin_fd = kInvalidFd, fd_t stdout_fd = kInvalidFd,
+                      fd_t stderr_fd = kInvalidFd);
+// Checks if specified process is still running
+bool IsProcessRunning(pid_t pid);
+// Waits for the process to finish and returns its exit code.
+// Returns -1 in case of an error.
+int WaitForProcess(pid_t pid);
+
+// Maps given file to virtual memory, and returns pointer to it
+// (or NULL if mapping fails). Stores the size of mmaped region
+// in '*buff_size'.
+void *MapFileToMemory(const char *file_name, uptr *buff_size);
+void *MapWritableFileToMemory(void *addr, uptr size, fd_t fd, OFF_T offset);
+
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_FILE_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_flag_parser.h b/libsanitizer/sanitizer_common/sanitizer_flag_parser.h
index 7827d735770..13677c0ea68 100644
--- a/libsanitizer/sanitizer_common/sanitizer_flag_parser.h
+++ b/libsanitizer/sanitizer_common/sanitizer_flag_parser.h
@@ -32,27 +32,48 @@ class FlagHandler : public FlagHandlerBase {
   bool Parse(const char *value) final;
 };
 
-template <>
-inline bool FlagHandler<bool>::Parse(const char *value) {
+inline bool ParseBool(const char *value, bool *b) {
   if (internal_strcmp(value, "0") == 0 ||
       internal_strcmp(value, "no") == 0 ||
       internal_strcmp(value, "false") == 0) {
-    *t_ = false;
+    *b = false;
     return true;
   }
   if (internal_strcmp(value, "1") == 0 ||
       internal_strcmp(value, "yes") == 0 ||
       internal_strcmp(value, "true") == 0) {
-    *t_ = true;
+    *b = true;
     return true;
   }
+  return false;
+}
+
+template <>
+inline bool FlagHandler<bool>::Parse(const char *value) {
+  if (ParseBool(value, t_)) return true;
   Printf("ERROR: Invalid value for bool option: '%s'\n", value);
   return false;
 }
 
 template <>
+inline bool FlagHandler<HandleSignalMode>::Parse(const char *value) {
+  bool b;
+  if (ParseBool(value, &b)) {
+    *t_ = b ? kHandleSignalYes : kHandleSignalNo;
+    return true;
+  }
+  if (internal_strcmp(value, "2") == 0 ||
+      internal_strcmp(value, "exclusive") == 0) {
+    *t_ = kHandleSignalExclusive;
+    return true;
+  }
+  Printf("ERROR: Invalid value for signal handler option: '%s'\n", value);
+  return false;
+}
+
+template <>
 inline bool FlagHandler<const char *>::Parse(const char *value) {
-  *t_ = internal_strdup(value);
+  *t_ = value;
   return true;
 }
 
diff --git a/libsanitizer/sanitizer_common/sanitizer_flags.h b/libsanitizer/sanitizer_common/sanitizer_flags.h
index ff64af10ff5..2e3739e915d 100644
--- a/libsanitizer/sanitizer_common/sanitizer_flags.h
+++ b/libsanitizer/sanitizer_common/sanitizer_flags.h
@@ -16,6 +16,12 @@
 
 namespace __sanitizer {
 
+enum HandleSignalMode {
+  kHandleSignalNo,
+  kHandleSignalYes,
+  kHandleSignalExclusive,
+};
+
 struct CommonFlags {
 #define COMMON_FLAG(Type, Name, DefaultValue, Description) Type Name;
 #include "sanitizer_flags.inc"
diff --git a/libsanitizer/sanitizer_common/sanitizer_flags.inc b/libsanitizer/sanitizer_common/sanitizer_flags.inc
index ccc0e416f4a..9e9b8a7daa6 100644
--- a/libsanitizer/sanitizer_common/sanitizer_flags.inc
+++ b/libsanitizer/sanitizer_common/sanitizer_flags.inc
@@ -60,7 +60,7 @@ COMMON_FLAG(
 COMMON_FLAG(
     int, verbosity, 0,
     "Verbosity level (0 - silent, 1 - a bit of output, 2+ - more output).")
-COMMON_FLAG(bool, detect_leaks, true, "Enable memory leak detection.")
+COMMON_FLAG(bool, detect_leaks, !SANITIZER_MAC, "Enable memory leak detection.")
 COMMON_FLAG(
     bool, leak_check_at_exit, true,
     "Invoke leak checking in an atexit handler. Has no effect if "
@@ -72,18 +72,28 @@ COMMON_FLAG(bool, allocator_may_return_null, false,
 COMMON_FLAG(bool, print_summary, true,
             "If false, disable printing error summaries in addition to error "
             "reports.")
+COMMON_FLAG(int, print_module_map, 0,
+            "OS X only (0 - don't print, 1 - print only once before process "
+            "exits, 2 - print after each report).")
 COMMON_FLAG(bool, check_printf, true, "Check printf arguments.")
-COMMON_FLAG(bool, handle_segv, true,
-            "If set, registers the tool's custom SIGSEGV/SIGBUS handler.")
-COMMON_FLAG(bool, handle_abort, false,
-            "If set, registers the tool's custom SIGABRT handler.")
-COMMON_FLAG(bool, handle_sigill, false,
-            "If set, registers the tool's custom SIGILL handler.")
-COMMON_FLAG(bool, handle_sigfpe, true,
-            "If set, registers the tool's custom SIGFPE handler.")
-COMMON_FLAG(bool, allow_user_segv_handler, false,
-            "If set, allows user to register a SEGV handler even if the tool "
-            "registers one.")
+#define COMMON_FLAG_HANDLE_SIGNAL_HELP(signal) \
+    "Controls custom tool's " #signal " handler (0 - do not registers the " \
+    "handler, 1 - register the handler and allow user to set own, " \
+    "2 - registers the handler and block user from changing it). "
+COMMON_FLAG(HandleSignalMode, handle_segv, kHandleSignalYes,
+            COMMON_FLAG_HANDLE_SIGNAL_HELP(SIGSEGV))
+COMMON_FLAG(HandleSignalMode, handle_sigbus, kHandleSignalYes,
+            COMMON_FLAG_HANDLE_SIGNAL_HELP(SIGBUS))
+COMMON_FLAG(HandleSignalMode, handle_abort, kHandleSignalNo,
+            COMMON_FLAG_HANDLE_SIGNAL_HELP(SIGABRT))
+COMMON_FLAG(HandleSignalMode, handle_sigill, kHandleSignalNo,
+            COMMON_FLAG_HANDLE_SIGNAL_HELP(SIGILL))
+COMMON_FLAG(HandleSignalMode, handle_sigfpe, kHandleSignalYes,
+            COMMON_FLAG_HANDLE_SIGNAL_HELP(SIGFPE))
+#undef COMMON_FLAG_HANDLE_SIGNAL_HELP
+COMMON_FLAG(bool, allow_user_segv_handler, true,
+            "Deprecated. True has no effect, use handle_sigbus=1. If false, "
+            "handle_*=1 will be upgraded to handle_*=2.")
 COMMON_FLAG(bool, use_sigaltstack, true,
             "If set, uses alternate stack for signal handling.")
 COMMON_FLAG(bool, detect_deadlocks, false,
@@ -117,9 +127,11 @@ COMMON_FLAG(uptr, soft_rss_limit_mb, 0,
             " This limit does not affect memory allocations other than"
             " malloc/new.")
 COMMON_FLAG(bool, heap_profile, false, "Experimental heap profiler, asan-only")
-COMMON_FLAG(bool, allocator_release_to_os, false,
-            "Experimental. If true, try to periodically release unused"
-            " memory to the OS.\n")
+COMMON_FLAG(s32, allocator_release_to_os_interval_ms, kReleaseToOSIntervalNever,
+            "Experimental. Only affects a 64-bit allocator. If set, tries to "
+            "release unused memory to the OS, but not more often than this "
+            "interval (in milliseconds). Negative values mean do not attempt "
+            "to release memory to the OS.\n")
 COMMON_FLAG(bool, can_use_proc_maps_statm, true,
             "If false, do not attempt to read /proc/maps/statm."
             " Mostly useful for testing sanitizers.")
@@ -127,22 +139,6 @@ COMMON_FLAG(
     bool, coverage, false,
     "If set, coverage information will be dumped at program shutdown (if the "
     "coverage instrumentation was enabled at compile time).")
-COMMON_FLAG(bool, coverage_pcs, true,
-            "If set (and if 'coverage' is set too), the coverage information "
-            "will be dumped as a set of PC offsets for every module.")
-COMMON_FLAG(bool, coverage_order_pcs, false,
-             "If true, the PCs will be dumped in the order they've"
-             " appeared during the execution.")
-COMMON_FLAG(bool, coverage_bitset, false,
-            "If set (and if 'coverage' is set too), the coverage information "
-            "will also be dumped as a bitset to a separate file.")
-COMMON_FLAG(bool, coverage_counters, false,
-            "If set (and if 'coverage' is set too), the bitmap that corresponds"
-            " to coverage counters will be dumped.")
-COMMON_FLAG(bool, coverage_direct, SANITIZER_ANDROID,
-            "If set, coverage information will be dumped directly to a memory "
-            "mapped file. This way data is not lost even if the process is "
-            "suddenly killed.")
 COMMON_FLAG(const char *, coverage_dir, ".",
             "Target directory for coverage dumps. Defaults to the current "
             "directory.")
@@ -183,12 +179,18 @@ COMMON_FLAG(bool, intercept_strstr, true,
 COMMON_FLAG(bool, intercept_strspn, true,
             "If set, uses custom wrappers for strspn and strcspn function "
             "to find more errors.")
+COMMON_FLAG(bool, intercept_strtok, true,
+            "If set, uses a custom wrapper for the strtok function "
+            "to find more errors.")
 COMMON_FLAG(bool, intercept_strpbrk, true,
             "If set, uses custom wrappers for strpbrk function "
             "to find more errors.")
 COMMON_FLAG(bool, intercept_strlen, true,
             "If set, uses custom wrappers for strlen and strnlen functions "
             "to find more errors.")
+COMMON_FLAG(bool, intercept_strndup, true,
+            "If set, uses custom wrappers for strndup functions "
+            "to find more errors.")
 COMMON_FLAG(bool, intercept_strchr, true,
             "If set, uses custom wrappers for strchr, strchrnul, and strrchr "
             "functions to find more errors.")
@@ -225,3 +227,8 @@ COMMON_FLAG(bool, print_cmdline, false, "Print command line on crash "
             "(asan only).")
 COMMON_FLAG(bool, html_cov_report, false, "Generate html coverage report.")
 COMMON_FLAG(const char *, sancov_path, "sancov", "Sancov tool location.")
+COMMON_FLAG(bool, dump_instruction_bytes, false,
+          "If true, dump 16 bytes starting at the instruction that caused SEGV")
+COMMON_FLAG(bool, dump_registers, true,
+          "If true, dump values of CPU registers when SEGV happens. Only "
+          "available on OS X for now.")
diff --git a/libsanitizer/sanitizer_common/sanitizer_fuchsia.cc b/libsanitizer/sanitizer_common/sanitizer_fuchsia.cc
new file mode 100644
index 00000000000..da7018ca33d
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_fuchsia.cc
@@ -0,0 +1,517 @@
+//===-- sanitizer_fuchsia.cc ---------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===---------------------------------------------------------------------===//
+//
+// This file is shared between AddressSanitizer and other sanitizer
+// run-time libraries and implements Fuchsia-specific functions from
+// sanitizer_common.h.
+//===---------------------------------------------------------------------===//
+
+#include "sanitizer_fuchsia.h"
+#if SANITIZER_FUCHSIA
+
+#include "sanitizer_common.h"
+#include "sanitizer_libc.h"
+#include "sanitizer_mutex.h"
+#include "sanitizer_stacktrace.h"
+
+#include <limits.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <unwind.h>
+#include <zircon/errors.h>
+#include <zircon/process.h>
+#include <zircon/syscalls.h>
+
+namespace __sanitizer {
+
+void NORETURN internal__exit(int exitcode) { _zx_process_exit(exitcode); }
+
+uptr internal_sched_yield() {
+  zx_status_t status = _zx_nanosleep(0);
+  CHECK_EQ(status, ZX_OK);
+  return 0;  // Why doesn't this return void?
+}
+
+static void internal_nanosleep(zx_time_t ns) {
+  zx_status_t status = _zx_nanosleep(_zx_deadline_after(ns));
+  CHECK_EQ(status, ZX_OK);
+}
+
+unsigned int internal_sleep(unsigned int seconds) {
+  internal_nanosleep(ZX_SEC(seconds));
+  return 0;
+}
+
+u64 NanoTime() { return _zx_time_get(ZX_CLOCK_UTC); }
+
+uptr internal_getpid() {
+  zx_info_handle_basic_t info;
+  zx_status_t status =
+      _zx_object_get_info(_zx_process_self(), ZX_INFO_HANDLE_BASIC, &info,
+                          sizeof(info), NULL, NULL);
+  CHECK_EQ(status, ZX_OK);
+  uptr pid = static_cast<uptr>(info.koid);
+  CHECK_EQ(pid, info.koid);
+  return pid;
+}
+
+uptr GetThreadSelf() { return reinterpret_cast<uptr>(thrd_current()); }
+
+uptr GetTid() { return GetThreadSelf(); }
+
+void Abort() { abort(); }
+
+int Atexit(void (*function)(void)) { return atexit(function); }
+
+void SleepForSeconds(int seconds) { internal_sleep(seconds); }
+
+void SleepForMillis(int millis) { internal_nanosleep(ZX_MSEC(millis)); }
+
+void GetThreadStackTopAndBottom(bool, uptr *stack_top, uptr *stack_bottom) {
+  pthread_attr_t attr;
+  CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0);
+  void *base;
+  size_t size;
+  CHECK_EQ(pthread_attr_getstack(&attr, &base, &size), 0);
+  CHECK_EQ(pthread_attr_destroy(&attr), 0);
+
+  *stack_bottom = reinterpret_cast<uptr>(base);
+  *stack_top = *stack_bottom + size;
+}
+
+void MaybeReexec() {}
+void PrepareForSandboxing(__sanitizer_sandbox_arguments *args) {}
+void DisableCoreDumperIfNecessary() {}
+void InstallDeadlySignalHandlers(SignalHandlerType handler) {}
+void StartReportDeadlySignal() {}
+void ReportDeadlySignal(const SignalContext &sig, u32 tid,
+                        UnwindSignalStackCallbackType unwind,
+                        const void *unwind_context) {}
+void SetAlternateSignalStack() {}
+void UnsetAlternateSignalStack() {}
+void InitTlsSize() {}
+
+void PrintModuleMap() {}
+
+bool SignalContext::IsStackOverflow() const { return false; }
+void SignalContext::DumpAllRegisters(void *context) { UNIMPLEMENTED(); }
+const char *SignalContext::Describe() const { UNIMPLEMENTED(); }
+
+struct UnwindTraceArg {
+  BufferedStackTrace *stack;
+  u32 max_depth;
+};
+
+_Unwind_Reason_Code Unwind_Trace(struct _Unwind_Context *ctx, void *param) {
+  UnwindTraceArg *arg = static_cast<UnwindTraceArg *>(param);
+  CHECK_LT(arg->stack->size, arg->max_depth);
+  uptr pc = _Unwind_GetIP(ctx);
+  if (pc < PAGE_SIZE) return _URC_NORMAL_STOP;
+  arg->stack->trace_buffer[arg->stack->size++] = pc;
+  return (arg->stack->size == arg->max_depth ? _URC_NORMAL_STOP
+                                             : _URC_NO_REASON);
+}
+
+void BufferedStackTrace::SlowUnwindStack(uptr pc, u32 max_depth) {
+  CHECK_GE(max_depth, 2);
+  size = 0;
+  UnwindTraceArg arg = {this, Min(max_depth + 1, kStackTraceMax)};
+  _Unwind_Backtrace(Unwind_Trace, &arg);
+  CHECK_GT(size, 0);
+  // We need to pop a few frames so that pc is on top.
+  uptr to_pop = LocatePcInTrace(pc);
+  // trace_buffer[0] belongs to the current function so we always pop it,
+  // unless there is only 1 frame in the stack trace (1 frame is always better
+  // than 0!).
+  PopStackFrames(Min(to_pop, static_cast<uptr>(1)));
+  trace_buffer[0] = pc;
+}
+
+void BufferedStackTrace::SlowUnwindStackWithContext(uptr pc, void *context,
+                                                    u32 max_depth) {
+  CHECK_NE(context, nullptr);
+  UNREACHABLE("signal context doesn't exist");
+}
+
+enum MutexState : int { MtxUnlocked = 0, MtxLocked = 1, MtxSleeping = 2 };
+
+BlockingMutex::BlockingMutex() {
+  // NOTE!  It's important that this use internal_memset, because plain
+  // memset might be intercepted (e.g., actually be __asan_memset).
+  // Defining this so the compiler initializes each field, e.g.:
+  //   BlockingMutex::BlockingMutex() : BlockingMutex(LINKER_INITIALIZED) {}
+  // might result in the compiler generating a call to memset, which would
+  // have the same problem.
+  internal_memset(this, 0, sizeof(*this));
+}
+
+void BlockingMutex::Lock() {
+  CHECK_EQ(owner_, 0);
+  atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
+  if (atomic_exchange(m, MtxLocked, memory_order_acquire) == MtxUnlocked)
+    return;
+  while (atomic_exchange(m, MtxSleeping, memory_order_acquire) != MtxUnlocked) {
+    zx_status_t status = _zx_futex_wait(reinterpret_cast<zx_futex_t *>(m),
+                                        MtxSleeping, ZX_TIME_INFINITE);
+    if (status != ZX_ERR_BAD_STATE)  // Normal race.
+      CHECK_EQ(status, ZX_OK);
+  }
+}
+
+void BlockingMutex::Unlock() {
+  atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
+  u32 v = atomic_exchange(m, MtxUnlocked, memory_order_release);
+  CHECK_NE(v, MtxUnlocked);
+  if (v == MtxSleeping) {
+    zx_status_t status = _zx_futex_wake(reinterpret_cast<zx_futex_t *>(m), 1);
+    CHECK_EQ(status, ZX_OK);
+  }
+}
+
+void BlockingMutex::CheckLocked() {
+  atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
+  CHECK_NE(MtxUnlocked, atomic_load(m, memory_order_relaxed));
+}
+
+uptr GetPageSize() { return PAGE_SIZE; }
+
+uptr GetMmapGranularity() { return PAGE_SIZE; }
+
+sanitizer_shadow_bounds_t ShadowBounds;
+
+uptr GetMaxVirtualAddress() {
+  ShadowBounds = __sanitizer_shadow_bounds();
+  return ShadowBounds.memory_limit - 1;
+}
+
+static void *DoAnonymousMmapOrDie(uptr size, const char *mem_type,
+                                  bool raw_report, bool die_for_nomem) {
+  size = RoundUpTo(size, PAGE_SIZE);
+
+  zx_handle_t vmo;
+  zx_status_t status = _zx_vmo_create(size, 0, &vmo);
+  if (status != ZX_OK) {
+    if (status != ZX_ERR_NO_MEMORY || die_for_nomem)
+      ReportMmapFailureAndDie(size, mem_type, "zx_vmo_create", status,
+                              raw_report);
+    return nullptr;
+  }
+  _zx_object_set_property(vmo, ZX_PROP_NAME, mem_type,
+                          internal_strlen(mem_type));
+
+  // TODO(mcgrathr): Maybe allocate a VMAR for all sanitizer heap and use that?
+  uintptr_t addr;
+  status = _zx_vmar_map(_zx_vmar_root_self(), 0, vmo, 0, size,
+                        ZX_VM_FLAG_PERM_READ | ZX_VM_FLAG_PERM_WRITE, &addr);
+  _zx_handle_close(vmo);
+
+  if (status != ZX_OK) {
+    if (status != ZX_ERR_NO_MEMORY || die_for_nomem)
+      ReportMmapFailureAndDie(size, mem_type, "zx_vmar_map", status,
+                              raw_report);
+    return nullptr;
+  }
+
+  IncreaseTotalMmap(size);
+
+  return reinterpret_cast<void *>(addr);
+}
+
+void *MmapOrDie(uptr size, const char *mem_type, bool raw_report) {
+  return DoAnonymousMmapOrDie(size, mem_type, raw_report, true);
+}
+
+void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
+  return MmapOrDie(size, mem_type);
+}
+
+void *MmapOrDieOnFatalError(uptr size, const char *mem_type) {
+  return DoAnonymousMmapOrDie(size, mem_type, false, false);
+}
+
+// MmapNoAccess and MmapFixedOrDie are used only by sanitizer_allocator.
+// Instead of doing exactly what they say, we make MmapNoAccess actually
+// just allocate a VMAR to reserve the address space.  Then MmapFixedOrDie
+// uses that VMAR instead of the root.
+
+zx_handle_t allocator_vmar = ZX_HANDLE_INVALID;
+uintptr_t allocator_vmar_base;
+size_t allocator_vmar_size;
+
+void *MmapNoAccess(uptr size) {
+  size = RoundUpTo(size, PAGE_SIZE);
+  CHECK_EQ(allocator_vmar, ZX_HANDLE_INVALID);
+  uintptr_t base;
+  zx_status_t status =
+      _zx_vmar_allocate(_zx_vmar_root_self(), 0, size,
+                        ZX_VM_FLAG_CAN_MAP_READ | ZX_VM_FLAG_CAN_MAP_WRITE |
+                            ZX_VM_FLAG_CAN_MAP_SPECIFIC,
+                        &allocator_vmar, &base);
+  if (status != ZX_OK)
+    ReportMmapFailureAndDie(size, "sanitizer allocator address space",
+                            "zx_vmar_allocate", status);
+
+  allocator_vmar_base = base;
+  allocator_vmar_size = size;
+  return reinterpret_cast<void *>(base);
+}
+
+constexpr const char kAllocatorVmoName[] = "sanitizer_allocator";
+
+static void *DoMmapFixedOrDie(uptr fixed_addr, uptr size, bool die_for_nomem) {
+  size = RoundUpTo(size, PAGE_SIZE);
+
+  zx_handle_t vmo;
+  zx_status_t status = _zx_vmo_create(size, 0, &vmo);
+  if (status != ZX_OK) {
+    if (status != ZX_ERR_NO_MEMORY || die_for_nomem)
+      ReportMmapFailureAndDie(size, kAllocatorVmoName, "zx_vmo_create", status);
+    return nullptr;
+  }
+  _zx_object_set_property(vmo, ZX_PROP_NAME, kAllocatorVmoName,
+                          sizeof(kAllocatorVmoName) - 1);
+
+  DCHECK_GE(fixed_addr, allocator_vmar_base);
+  uintptr_t offset = fixed_addr - allocator_vmar_base;
+  DCHECK_LE(size, allocator_vmar_size);
+  DCHECK_GE(allocator_vmar_size - offset, size);
+
+  uintptr_t addr;
+  status = _zx_vmar_map(
+      allocator_vmar, offset, vmo, 0, size,
+      ZX_VM_FLAG_PERM_READ | ZX_VM_FLAG_PERM_WRITE | ZX_VM_FLAG_SPECIFIC,
+      &addr);
+  _zx_handle_close(vmo);
+  if (status != ZX_OK) {
+    if (status != ZX_ERR_NO_MEMORY || die_for_nomem)
+      ReportMmapFailureAndDie(size, kAllocatorVmoName, "zx_vmar_map", status);
+    return nullptr;
+  }
+
+  IncreaseTotalMmap(size);
+
+  return reinterpret_cast<void *>(addr);
+}
+
+void *MmapFixedOrDie(uptr fixed_addr, uptr size) {
+  return DoMmapFixedOrDie(fixed_addr, size, true);
+}
+
+void *MmapFixedOrDieOnFatalError(uptr fixed_addr, uptr size) {
+  return DoMmapFixedOrDie(fixed_addr, size, false);
+}
+
+// This should never be called.
+void *MmapFixedNoAccess(uptr fixed_addr, uptr size, const char *name) {
+  UNIMPLEMENTED();
+}
+
+void *MmapAlignedOrDieOnFatalError(uptr size, uptr alignment,
+                                   const char *mem_type) {
+  CHECK_GE(size, PAGE_SIZE);
+  CHECK(IsPowerOfTwo(size));
+  CHECK(IsPowerOfTwo(alignment));
+
+  zx_handle_t vmo;
+  zx_status_t status = _zx_vmo_create(size, 0, &vmo);
+  if (status != ZX_OK) {
+    if (status != ZX_ERR_NO_MEMORY)
+      ReportMmapFailureAndDie(size, mem_type, "zx_vmo_create", status, false);
+    return nullptr;
+  }
+  _zx_object_set_property(vmo, ZX_PROP_NAME, mem_type,
+                          internal_strlen(mem_type));
+
+  // TODO(mcgrathr): Maybe allocate a VMAR for all sanitizer heap and use that?
+
+  // Map a larger size to get a chunk of address space big enough that
+  // it surely contains an aligned region of the requested size.  Then
+  // overwrite the aligned middle portion with a mapping from the
+  // beginning of the VMO, and unmap the excess before and after.
+  size_t map_size = size + alignment;
+  uintptr_t addr;
+  status = _zx_vmar_map(_zx_vmar_root_self(), 0, vmo, 0, map_size,
+                        ZX_VM_FLAG_PERM_READ | ZX_VM_FLAG_PERM_WRITE, &addr);
+  if (status == ZX_OK) {
+    uintptr_t map_addr = addr;
+    uintptr_t map_end = map_addr + map_size;
+    addr = RoundUpTo(map_addr, alignment);
+    uintptr_t end = addr + size;
+    if (addr != map_addr) {
+      zx_info_vmar_t info;
+      status = _zx_object_get_info(_zx_vmar_root_self(), ZX_INFO_VMAR, &info,
+                                   sizeof(info), NULL, NULL);
+      if (status == ZX_OK) {
+        uintptr_t new_addr;
+        status =
+            _zx_vmar_map(_zx_vmar_root_self(), addr - info.base, vmo, 0, size,
+                         ZX_VM_FLAG_PERM_READ | ZX_VM_FLAG_PERM_WRITE |
+                             ZX_VM_FLAG_SPECIFIC_OVERWRITE,
+                         &new_addr);
+        if (status == ZX_OK) CHECK_EQ(new_addr, addr);
+      }
+    }
+    if (status == ZX_OK && addr != map_addr)
+      status = _zx_vmar_unmap(_zx_vmar_root_self(), map_addr, addr - map_addr);
+    if (status == ZX_OK && end != map_end)
+      status = _zx_vmar_unmap(_zx_vmar_root_self(), end, map_end - end);
+  }
+  _zx_handle_close(vmo);
+
+  if (status != ZX_OK) {
+    if (status != ZX_ERR_NO_MEMORY)
+      ReportMmapFailureAndDie(size, mem_type, "zx_vmar_map", status, false);
+    return nullptr;
+  }
+
+  IncreaseTotalMmap(size);
+
+  return reinterpret_cast<void *>(addr);
+}
+
+void UnmapOrDie(void *addr, uptr size) {
+  if (!addr || !size) return;
+  size = RoundUpTo(size, PAGE_SIZE);
+
+  zx_status_t status = _zx_vmar_unmap(_zx_vmar_root_self(),
+                                      reinterpret_cast<uintptr_t>(addr), size);
+  if (status != ZX_OK) {
+    Report("ERROR: %s failed to deallocate 0x%zx (%zd) bytes at address %p\n",
+           SanitizerToolName, size, size, addr);
+    CHECK("unable to unmap" && 0);
+  }
+
+  DecreaseTotalMmap(size);
+}
+
+// This is used on the shadow mapping, which cannot be changed.
+// Zircon doesn't have anything like MADV_DONTNEED.
+void ReleaseMemoryPagesToOS(uptr beg, uptr end) {}
+
+void DumpProcessMap() {
+  UNIMPLEMENTED();  // TODO(mcgrathr): write it
+}
+
+bool IsAccessibleMemoryRange(uptr beg, uptr size) {
+  // TODO(mcgrathr): Figure out a better way.
+  zx_handle_t vmo;
+  zx_status_t status = _zx_vmo_create(size, 0, &vmo);
+  if (status == ZX_OK) {
+    while (size > 0) {
+      size_t wrote;
+      status = _zx_vmo_write(vmo, reinterpret_cast<const void *>(beg), 0, size,
+                             &wrote);
+      if (status != ZX_OK) break;
+      CHECK_GT(wrote, 0);
+      CHECK_LE(wrote, size);
+      beg += wrote;
+      size -= wrote;
+    }
+    _zx_handle_close(vmo);
+  }
+  return status == ZX_OK;
+}
+
+// FIXME implement on this platform.
+void GetMemoryProfile(fill_profile_f cb, uptr *stats, uptr stats_size) {}
+
+bool ReadFileToBuffer(const char *file_name, char **buff, uptr *buff_size,
+                      uptr *read_len, uptr max_len, error_t *errno_p) {
+  zx_handle_t vmo;
+  zx_status_t status = __sanitizer_get_configuration(file_name, &vmo);
+  if (status == ZX_OK) {
+    uint64_t vmo_size;
+    status = _zx_vmo_get_size(vmo, &vmo_size);
+    if (status == ZX_OK) {
+      if (vmo_size < max_len) max_len = vmo_size;
+      size_t map_size = RoundUpTo(max_len, PAGE_SIZE);
+      uintptr_t addr;
+      status = _zx_vmar_map(_zx_vmar_root_self(), 0, vmo, 0, map_size,
+                            ZX_VM_FLAG_PERM_READ, &addr);
+      if (status == ZX_OK) {
+        *buff = reinterpret_cast<char *>(addr);
+        *buff_size = map_size;
+        *read_len = max_len;
+      }
+    }
+    _zx_handle_close(vmo);
+  }
+  if (status != ZX_OK && errno_p) *errno_p = status;
+  return status == ZX_OK;
+}
+
+void RawWrite(const char *buffer) {
+  __sanitizer_log_write(buffer, internal_strlen(buffer));
+}
+
+void CatastrophicErrorWrite(const char *buffer, uptr length) {
+  __sanitizer_log_write(buffer, length);
+}
+
+char **StoredArgv;
+char **StoredEnviron;
+
+char **GetArgv() { return StoredArgv; }
+
+const char *GetEnv(const char *name) {
+  if (StoredEnviron) {
+    uptr NameLen = internal_strlen(name);
+    for (char **Env = StoredEnviron; *Env != 0; Env++) {
+      if (internal_strncmp(*Env, name, NameLen) == 0 && (*Env)[NameLen] == '=')
+        return (*Env) + NameLen + 1;
+    }
+  }
+  return nullptr;
+}
+
+uptr ReadBinaryName(/*out*/ char *buf, uptr buf_len) {
+  const char *argv0 = StoredArgv[0];
+  if (!argv0) argv0 = "<UNKNOWN>";
+  internal_strncpy(buf, argv0, buf_len);
+  return internal_strlen(buf);
+}
+
+uptr ReadLongProcessName(/*out*/ char *buf, uptr buf_len) {
+  return ReadBinaryName(buf, buf_len);
+}
+
+uptr MainThreadStackBase, MainThreadStackSize;
+
+bool GetRandom(void *buffer, uptr length, bool blocking) {
+  CHECK_LE(length, ZX_CPRNG_DRAW_MAX_LEN);
+  size_t size;
+  CHECK_EQ(_zx_cprng_draw(buffer, length, &size), ZX_OK);
+  CHECK_EQ(size, length);
+  return true;
+}
+
+}  // namespace __sanitizer
+
+using namespace __sanitizer;  // NOLINT
+
+extern "C" {
+void __sanitizer_startup_hook(int argc, char **argv, char **envp,
+                              void *stack_base, size_t stack_size) {
+  __sanitizer::StoredArgv = argv;
+  __sanitizer::StoredEnviron = envp;
+  __sanitizer::MainThreadStackBase = reinterpret_cast<uintptr_t>(stack_base);
+  __sanitizer::MainThreadStackSize = stack_size;
+}
+
+void __sanitizer_set_report_path(const char *path) {
+  // Handle the initialization code in each sanitizer, but no other calls.
+  // This setting is never consulted on Fuchsia.
+  DCHECK_EQ(path, common_flags()->log_path);
+}
+
+void __sanitizer_set_report_fd(void *fd) {
+  UNREACHABLE("not available on Fuchsia");
+}
+}  // extern "C"
+
+#endif  // SANITIZER_FUCHSIA
diff --git a/libsanitizer/sanitizer_common/sanitizer_fuchsia.h b/libsanitizer/sanitizer_common/sanitizer_fuchsia.h
new file mode 100644
index 00000000000..59b679d6c7f
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_fuchsia.h
@@ -0,0 +1,29 @@
+//===-- sanitizer_fuchsia.h ------------------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===---------------------------------------------------------------------===//
+//
+// Fuchsia-specific sanitizer support.
+//
+//===---------------------------------------------------------------------===//
+#ifndef SANITIZER_FUCHSIA_H
+#define SANITIZER_FUCHSIA_H
+
+#include "sanitizer_platform.h"
+#if SANITIZER_FUCHSIA
+
+#include "sanitizer_common.h"
+
+#include <zircon/sanitizer.h>
+
+namespace __sanitizer {
+
+extern uptr MainThreadStackBase, MainThreadStackSize;
+extern sanitizer_shadow_bounds_t ShadowBounds;
+
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_FUCHSIA
+#endif  // SANITIZER_FUCHSIA_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_interface_internal.h b/libsanitizer/sanitizer_common/sanitizer_interface_internal.h
index 34e80c3b50f..08c110c707c 100644
--- a/libsanitizer/sanitizer_common/sanitizer_interface_internal.h
+++ b/libsanitizer/sanitizer_common/sanitizer_interface_internal.h
@@ -45,7 +45,10 @@ extern "C" {
   void __sanitizer_report_error_summary(const char *error_summary);
 
   SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_dump();
-  SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov_init();
+  SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_dump_coverage(
+      const __sanitizer::uptr *pcs, const __sanitizer::uptr len);
+  SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_dump_trace_pc_guard_coverage();
+
   SANITIZER_INTERFACE_ATTRIBUTE void __sanitizer_cov(__sanitizer::u32 *guard);
   SANITIZER_INTERFACE_ATTRIBUTE
   void __sanitizer_annotate_contiguous_container(const void *beg,
@@ -58,6 +61,49 @@ extern "C" {
   SANITIZER_INTERFACE_ATTRIBUTE
   const void *__sanitizer_contiguous_container_find_bad_address(
       const void *beg, const void *mid, const void *end);
-  } // extern "C"
+
+  SANITIZER_INTERFACE_ATTRIBUTE
+  int __sanitizer_get_module_and_offset_for_pc(
+      __sanitizer::uptr pc, char *module_path,
+      __sanitizer::uptr module_path_len, __sanitizer::uptr *pc_offset);
+
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_cmp();
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_cmp1();
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_cmp2();
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_cmp4();
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_cmp8();
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_const_cmp1();
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_const_cmp2();
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_const_cmp4();
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_const_cmp8();
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_switch();
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_div4();
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_div8();
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_gep();
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_pc_indir();
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_pc_guard(__sanitizer::u32*);
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_trace_pc_guard_init(__sanitizer::u32*,
+                                           __sanitizer::u32*);
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_8bit_counters_init();
+  SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+  void __sanitizer_cov_pcs_init();
+} // extern "C"
 
 #endif  // SANITIZER_INTERFACE_INTERNAL_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_internal_defs.h b/libsanitizer/sanitizer_common/sanitizer_internal_defs.h
index 676ade143d8..ef405dec048 100644
--- a/libsanitizer/sanitizer_common/sanitizer_internal_defs.h
+++ b/libsanitizer/sanitizer_common/sanitizer_internal_defs.h
@@ -19,8 +19,11 @@
 
 // Only use SANITIZER_*ATTRIBUTE* before the function return type!
 #if SANITIZER_WINDOWS
+#if SANITIZER_IMPORT_INTERFACE
+# define SANITIZER_INTERFACE_ATTRIBUTE __declspec(dllimport)
+#else
 # define SANITIZER_INTERFACE_ATTRIBUTE __declspec(dllexport)
-// FIXME find out what we need on Windows, if anything.
+#endif
 # define SANITIZER_WEAK_ATTRIBUTE
 #elif SANITIZER_GO
 # define SANITIZER_INTERFACE_ATTRIBUTE
@@ -30,11 +33,56 @@
 # define SANITIZER_WEAK_ATTRIBUTE  __attribute__((weak))
 #endif
 
-#if (SANITIZER_LINUX || SANITIZER_WINDOWS) && !SANITIZER_GO
+// TLS is handled differently on different platforms
+#if SANITIZER_LINUX
+# define SANITIZER_TLS_INITIAL_EXEC_ATTRIBUTE \
+    __attribute__((tls_model("initial-exec"))) thread_local
+#else
+# define SANITIZER_TLS_INITIAL_EXEC_ATTRIBUTE
+#endif
+
+//--------------------------- WEAK FUNCTIONS ---------------------------------//
+// When working with weak functions, to simplify the code and make it more
+// portable, when possible define a default implementation using this macro:
+//
+// SANITIZER_INTERFACE_WEAK_DEF(<return_type>, <name>, <parameter list>)
+//
+// For example:
+//   SANITIZER_INTERFACE_WEAK_DEF(bool, compare, int a, int b) { return a > b; }
+//
+#if SANITIZER_WINDOWS
+#include "sanitizer_win_defs.h"
+# define SANITIZER_INTERFACE_WEAK_DEF(ReturnType, Name, ...)                   \
+  WIN_WEAK_EXPORT_DEF(ReturnType, Name, __VA_ARGS__)
+#else
+# define SANITIZER_INTERFACE_WEAK_DEF(ReturnType, Name, ...)                   \
+  extern "C" SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE            \
+  ReturnType Name(__VA_ARGS__)
+#endif
+
+// SANITIZER_SUPPORTS_WEAK_HOOKS means that we support real weak functions that
+// will evaluate to a null pointer when not defined.
+#ifndef SANITIZER_SUPPORTS_WEAK_HOOKS
+#if (SANITIZER_LINUX || SANITIZER_MAC) && !SANITIZER_GO
 # define SANITIZER_SUPPORTS_WEAK_HOOKS 1
 #else
 # define SANITIZER_SUPPORTS_WEAK_HOOKS 0
 #endif
+#endif // SANITIZER_SUPPORTS_WEAK_HOOKS
+// For some weak hooks that will be called very often and we want to avoid the
+// overhead of executing the default implementation when it is not necessary,
+// we can use the flag SANITIZER_SUPPORTS_WEAK_HOOKS to only define the default
+// implementation for platforms that doesn't support weak symbols. For example:
+//
+//   #if !SANITIZER_SUPPORT_WEAK_HOOKS
+//     SANITIZER_INTERFACE_WEAK_DEF(bool, compare_hook, int a, int b) {
+//       return a > b;
+//     }
+//   #endif
+//
+// And then use it as: if (compare_hook) compare_hook(a, b);
+//----------------------------------------------------------------------------//
+
 
 // We can use .preinit_array section on Linux to call sanitizer initialization
 // functions very early in the process startup (unless PIC macro is defined).
@@ -89,12 +137,8 @@ typedef int error_t;
 #endif
 typedef int pid_t;
 
-// WARNING: OFF_T may be different from OS type off_t, depending on the value of
-// _FILE_OFFSET_BITS. This definition of OFF_T matches the ABI of system calls
-// like pread and mmap, as opposed to pread64 and mmap64.
-// FreeBSD, Mac and Linux/x86-64 are special.
-#if SANITIZER_FREEBSD || SANITIZER_MAC || \
-  (SANITIZER_LINUX && defined(__x86_64__))
+#if SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_MAC || \
+    (SANITIZER_LINUX && defined(__x86_64__))
 typedef u64 OFF_T;
 #else
 typedef uptr OFF_T;
@@ -112,6 +156,12 @@ typedef u32 operator_new_size_type;
 # endif
 #endif
 
+#if SANITIZER_MAC
+// On Darwin, thread IDs are 64-bit even on 32-bit systems.
+typedef u64 tid_t;
+#else
+typedef uptr tid_t;
+#endif
 
 // ----------- ATTENTION -------------
 // This header should NOT include any other headers to avoid portability issues.
@@ -211,8 +261,8 @@ void NORETURN CheckFailed(const char *file, int line, const char *cond,
 
 #define CHECK_IMPL(c1, op, c2) \
   do { \
-    __sanitizer::u64 v1 = (u64)(c1); \
-    __sanitizer::u64 v2 = (u64)(c2); \
+    __sanitizer::u64 v1 = (__sanitizer::u64)(c1); \
+    __sanitizer::u64 v2 = (__sanitizer::u64)(c2); \
     if (UNLIKELY(!(v1 op v2))) \
       __sanitizer::CheckFailed(__FILE__, __LINE__, \
         "(" #c1 ") " #op " (" #c2 ")", v1, v2); \
@@ -287,13 +337,13 @@ void NORETURN CheckFailed(const char *file, int line, const char *cond,
 enum LinkerInitialized { LINKER_INITIALIZED = 0 };
 
 #if !defined(_MSC_VER) || defined(__clang__)
-# if SANITIZER_S390_31
-#  define GET_CALLER_PC() \
-  (uptr)__builtin_extract_return_addr(__builtin_return_address(0))
-# else
-#  define GET_CALLER_PC() (uptr)__builtin_return_address(0)
-# endif
-# define GET_CURRENT_FRAME() (uptr)__builtin_frame_address(0)
+#if SANITIZER_S390_31
+#define GET_CALLER_PC() \
+  (__sanitizer::uptr) __builtin_extract_return_addr(__builtin_return_address(0))
+#else
+#define GET_CALLER_PC() (__sanitizer::uptr) __builtin_return_address(0)
+#endif
+#define GET_CURRENT_FRAME() (__sanitizer::uptr) __builtin_frame_address(0)
 inline void Trap() {
   __builtin_trap();
 }
@@ -302,9 +352,10 @@ extern "C" void* _ReturnAddress(void);
 extern "C" void* _AddressOfReturnAddress(void);
 # pragma intrinsic(_ReturnAddress)
 # pragma intrinsic(_AddressOfReturnAddress)
-# define GET_CALLER_PC() (uptr)_ReturnAddress()
+#define GET_CALLER_PC() (__sanitizer::uptr) _ReturnAddress()
 // CaptureStackBackTrace doesn't need to know BP on Windows.
-# define GET_CURRENT_FRAME() (((uptr)_AddressOfReturnAddress()) + sizeof(uptr))
+#define GET_CURRENT_FRAME() \
+  (((__sanitizer::uptr)_AddressOfReturnAddress()) + sizeof(__sanitizer::uptr))
 
 extern "C" void __ud2(void);
 # pragma intrinsic(__ud2)
@@ -322,11 +373,11 @@ inline void Trap() {
   }
 
 // Forces the compiler to generate a frame pointer in the function.
-#define ENABLE_FRAME_POINTER                                       \
-  do {                                                             \
-    volatile uptr enable_fp;                                       \
-    enable_fp = GET_CURRENT_FRAME();                               \
-    (void)enable_fp;                                               \
+#define ENABLE_FRAME_POINTER              \
+  do {                                    \
+    volatile __sanitizer::uptr enable_fp; \
+    enable_fp = GET_CURRENT_FRAME();      \
+    (void)enable_fp;                      \
   } while (0)
 
 }  // namespace __sanitizer
diff --git a/libsanitizer/sanitizer_common/sanitizer_libignore.cc b/libsanitizer/sanitizer_common/sanitizer_libignore.cc
index 4b8cbed5ee3..e20c7559b8e 100644
--- a/libsanitizer/sanitizer_common/sanitizer_libignore.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_libignore.cc
@@ -7,7 +7,7 @@
 
 #include "sanitizer_platform.h"
 
-#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_MAC
+#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_MAC || SANITIZER_NETBSD
 
 #include "sanitizer_libignore.h"
 #include "sanitizer_flags.h"
@@ -48,23 +48,23 @@ void LibIgnore::OnLibraryLoaded(const char *name) {
   }
 
   // Scan suppressions list and find newly loaded and unloaded libraries.
-  MemoryMappingLayout proc_maps(/*cache_enabled*/false);
-  InternalScopedString module(kMaxPathLength);
+  ListOfModules modules;
+  modules.init();
   for (uptr i = 0; i < count_; i++) {
     Lib *lib = &libs_[i];
     bool loaded = false;
-    proc_maps.Reset();
-    uptr b, e, off, prot;
-    while (proc_maps.Next(&b, &e, &off, module.data(), module.size(), &prot)) {
-      if ((prot & MemoryMappingLayout::kProtectionExecute) == 0)
-        continue;
-      if (TemplateMatch(lib->templ, module.data()) ||
-          (lib->real_name &&
-          internal_strcmp(lib->real_name, module.data()) == 0)) {
+    for (const auto &mod : modules) {
+      for (const auto &range : mod.ranges()) {
+        if (!range.executable)
+          continue;
+        if (!TemplateMatch(lib->templ, mod.full_name()) &&
+            !(lib->real_name &&
+            internal_strcmp(lib->real_name, mod.full_name()) == 0))
+          continue;
         if (loaded) {
           Report("%s: called_from_lib suppression '%s' is matched against"
                  " 2 libraries: '%s' and '%s'\n",
-                 SanitizerToolName, lib->templ, lib->name, module.data());
+                 SanitizerToolName, lib->templ, lib->name, mod.full_name());
           Die();
         }
         loaded = true;
@@ -73,13 +73,16 @@ void LibIgnore::OnLibraryLoaded(const char *name) {
         VReport(1,
                 "Matched called_from_lib suppression '%s' against library"
                 " '%s'\n",
-                lib->templ, module.data());
+                lib->templ, mod.full_name());
         lib->loaded = true;
-        lib->name = internal_strdup(module.data());
-        const uptr idx = atomic_load(&loaded_count_, memory_order_relaxed);
-        code_ranges_[idx].begin = b;
-        code_ranges_[idx].end = e;
-        atomic_store(&loaded_count_, idx + 1, memory_order_release);
+        lib->name = internal_strdup(mod.full_name());
+        const uptr idx =
+            atomic_load(&ignored_ranges_count_, memory_order_relaxed);
+        CHECK_LT(idx, kMaxLibs);
+        ignored_code_ranges_[idx].begin = range.beg;
+        ignored_code_ranges_[idx].end = range.end;
+        atomic_store(&ignored_ranges_count_, idx + 1, memory_order_release);
+        break;
       }
     }
     if (lib->loaded && !loaded) {
@@ -89,6 +92,29 @@ void LibIgnore::OnLibraryLoaded(const char *name) {
       Die();
     }
   }
+
+  // Track instrumented ranges.
+  if (track_instrumented_libs_) {
+    for (const auto &mod : modules) {
+      if (!mod.instrumented())
+        continue;
+      for (const auto &range : mod.ranges()) {
+        if (!range.executable)
+          continue;
+        if (IsPcInstrumented(range.beg) && IsPcInstrumented(range.end - 1))
+          continue;
+        VReport(1, "Adding instrumented range %p-%p from library '%s'\n",
+                range.beg, range.end, mod.full_name());
+        const uptr idx =
+            atomic_load(&instrumented_ranges_count_, memory_order_relaxed);
+        CHECK_LT(idx, kMaxLibs);
+        instrumented_code_ranges_[idx].begin = range.beg;
+        instrumented_code_ranges_[idx].end = range.end;
+        atomic_store(&instrumented_ranges_count_, idx + 1,
+                     memory_order_release);
+      }
+    }
+  }
 }
 
 void LibIgnore::OnLibraryUnloaded() {
@@ -97,4 +123,5 @@ void LibIgnore::OnLibraryUnloaded() {
 
 } // namespace __sanitizer
 
-#endif // #if SANITIZER_FREEBSD || SANITIZER_LINUX
+#endif  // SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_MAC ||
+        // SANITIZER_NETBSD
diff --git a/libsanitizer/sanitizer_common/sanitizer_libignore.h b/libsanitizer/sanitizer_common/sanitizer_libignore.h
index 84419d14fed..e7627ee0256 100644
--- a/libsanitizer/sanitizer_common/sanitizer_libignore.h
+++ b/libsanitizer/sanitizer_common/sanitizer_libignore.h
@@ -28,6 +28,9 @@ class LibIgnore {
 
   // Must be called during initialization.
   void AddIgnoredLibrary(const char *name_templ);
+  void IgnoreNoninstrumentedModules(bool enable) {
+    track_instrumented_libs_ = enable;
+  }
 
   // Must be called after a new dynamic library is loaded.
   void OnLibraryLoaded(const char *name);
@@ -35,8 +38,14 @@ class LibIgnore {
   // Must be called after a dynamic library is unloaded.
   void OnLibraryUnloaded();
 
-  // Checks whether the provided PC belongs to one of the ignored libraries.
-  bool IsIgnored(uptr pc) const;
+  // Checks whether the provided PC belongs to one of the ignored libraries or
+  // the PC should be ignored because it belongs to an non-instrumented module
+  // (when ignore_noninstrumented_modules=1). Also returns true via
+  // "pc_in_ignored_lib" if the PC is in an ignored library, false otherwise.
+  bool IsIgnored(uptr pc, bool *pc_in_ignored_lib) const;
+
+  // Checks whether the provided PC belongs to an instrumented module.
+  bool IsPcInstrumented(uptr pc) const;
 
  private:
   struct Lib {
@@ -51,26 +60,48 @@ class LibIgnore {
     uptr end;
   };
 
+  inline bool IsInRange(uptr pc, const LibCodeRange &range) const {
+    return (pc >= range.begin && pc < range.end);
+  }
+
   static const uptr kMaxLibs = 128;
 
   // Hot part:
-  atomic_uintptr_t loaded_count_;
-  LibCodeRange code_ranges_[kMaxLibs];
+  atomic_uintptr_t ignored_ranges_count_;
+  LibCodeRange ignored_code_ranges_[kMaxLibs];
+
+  atomic_uintptr_t instrumented_ranges_count_;
+  LibCodeRange instrumented_code_ranges_[kMaxLibs];
 
   // Cold part:
   BlockingMutex mutex_;
   uptr count_;
   Lib libs_[kMaxLibs];
+  bool track_instrumented_libs_;
 
   // Disallow copying of LibIgnore objects.
   LibIgnore(const LibIgnore&);  // not implemented
   void operator = (const LibIgnore&);  // not implemented
 };
 
-inline bool LibIgnore::IsIgnored(uptr pc) const {
-  const uptr n = atomic_load(&loaded_count_, memory_order_acquire);
+inline bool LibIgnore::IsIgnored(uptr pc, bool *pc_in_ignored_lib) const {
+  const uptr n = atomic_load(&ignored_ranges_count_, memory_order_acquire);
+  for (uptr i = 0; i < n; i++) {
+    if (IsInRange(pc, ignored_code_ranges_[i])) {
+      *pc_in_ignored_lib = true;
+      return true;
+    }
+  }
+  *pc_in_ignored_lib = false;
+  if (track_instrumented_libs_ && !IsPcInstrumented(pc))
+    return true;
+  return false;
+}
+
+inline bool LibIgnore::IsPcInstrumented(uptr pc) const {
+  const uptr n = atomic_load(&instrumented_ranges_count_, memory_order_acquire);
   for (uptr i = 0; i < n; i++) {
-    if (pc >= code_ranges_[i].begin && pc < code_ranges_[i].end)
+    if (IsInRange(pc, instrumented_code_ranges_[i]))
       return true;
   }
   return false;
diff --git a/libsanitizer/sanitizer_common/sanitizer_linux.cc b/libsanitizer/sanitizer_common/sanitizer_linux.cc
index 5b6f18602e7..2826cc89e20 100644
--- a/libsanitizer/sanitizer_common/sanitizer_linux.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_linux.cc
@@ -12,7 +12,7 @@
 
 #include "sanitizer_platform.h"
 
-#if SANITIZER_FREEBSD || SANITIZER_LINUX
+#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
 
 #include "sanitizer_common.h"
 #include "sanitizer_flags.h"
@@ -25,10 +25,14 @@
 #include "sanitizer_stacktrace.h"
 #include "sanitizer_symbolizer.h"
 
-#if !SANITIZER_FREEBSD
+#if SANITIZER_LINUX
 #include <asm/param.h>
 #endif
 
+#if SANITIZER_NETBSD
+#include <lwp.h>
+#endif
+
 // For mips64, syscall(__NR_stat) fills the buffer in the 'struct kernel_stat'
 // format. Struct kernel_stat is defined as 'struct stat' in asm/stat.h. To
 // access stat from asm/stat.h, without conflicting with definition in
@@ -57,11 +61,17 @@
 #include <ucontext.h>
 #include <unistd.h>
 
+#if SANITIZER_LINUX
+#include <sys/utsname.h>
+#endif
+
+#if SANITIZER_LINUX && !SANITIZER_ANDROID
+#include <sys/personality.h>
+#endif
+
 #if SANITIZER_FREEBSD
 #include <sys/exec.h>
 #include <sys/sysctl.h>
-#include <vm/vm_param.h>
-#include <vm/pmap.h>
 #include <machine/atomic.h>
 extern "C" {
 // <sys/umtx.h> must be included after <errno.h> and <sys/types.h> on
@@ -71,10 +81,30 @@ extern "C" {
 extern char **environ;  // provided by crt1
 #endif  // SANITIZER_FREEBSD
 
+#if SANITIZER_NETBSD
+#include <limits.h>  // For NAME_MAX
+#include <sys/sysctl.h>
+extern char **environ;  // provided by crt1
+#endif                  // SANITIZER_NETBSD
+
 #if !SANITIZER_ANDROID
 #include <sys/signal.h>
 #endif
 
+#ifndef __GLIBC_PREREQ
+#define __GLIBC_PREREQ(x, y) 0
+#endif
+
+#if SANITIZER_LINUX && __GLIBC_PREREQ(2, 16)
+# define SANITIZER_USE_GETAUXVAL 1
+#else
+# define SANITIZER_USE_GETAUXVAL 0
+#endif
+
+#if SANITIZER_USE_GETAUXVAL
+#include <sys/auxv.h>
+#endif
+
 #if SANITIZER_LINUX
 // <linux/time.h>
 struct kernel_timeval {
@@ -103,6 +133,15 @@ extern void internal_sigreturn();
 }
 #endif
 
+#if SANITIZER_LINUX && defined(__NR_getrandom)
+# if !defined(GRND_NONBLOCK)
+#  define GRND_NONBLOCK 1
+# endif
+# define SANITIZER_USE_GETRANDOM 1
+#else
+# define SANITIZER_USE_GETRANDOM 0
+#endif  // SANITIZER_LINUX && defined(__NR_getrandom)
+
 namespace __sanitizer {
 
 #if SANITIZER_LINUX && defined(__x86_64__)
@@ -117,7 +156,10 @@ namespace __sanitizer {
 #if !SANITIZER_S390
 uptr internal_mmap(void *addr, uptr length, int prot, int flags, int fd,
                    OFF_T offset) {
-#if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
+#if SANITIZER_NETBSD
+  return internal_syscall_ptr(SYSCALL(mmap), addr, length, prot, flags, fd,
+                              (long)0, offset);
+#elif SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
   return internal_syscall(SYSCALL(mmap), (uptr)addr, length, prot, flags, fd,
                           offset);
 #else
@@ -160,26 +202,38 @@ uptr internal_open(const char *filename, int flags, u32 mode) {
 
 uptr internal_read(fd_t fd, void *buf, uptr count) {
   sptr res;
+#if SANITIZER_NETBSD
+  HANDLE_EINTR(res, internal_syscall_ptr(SYSCALL(read), fd, buf, count));
+#else
   HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(read), fd, (uptr)buf,
                count));
+#endif
   return res;
 }
 
 uptr internal_write(fd_t fd, const void *buf, uptr count) {
   sptr res;
+#if SANITIZER_NETBSD
+  HANDLE_EINTR(res, internal_syscall_ptr(SYSCALL(write), fd, buf, count));
+#else
   HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(write), fd, (uptr)buf,
                count));
+#endif
   return res;
 }
 
 uptr internal_ftruncate(fd_t fd, uptr size) {
   sptr res;
+#if SANITIZER_NETBSD
+  HANDLE_EINTR(res, internal_syscall(SYSCALL(ftruncate), fd, 0, (s64)size));
+#else
   HANDLE_EINTR(res, (sptr)internal_syscall(SYSCALL(ftruncate), fd,
                (OFF_T)size));
+#endif
   return res;
 }
 
-#if !SANITIZER_LINUX_USES_64BIT_SYSCALLS && !SANITIZER_FREEBSD
+#if !SANITIZER_LINUX_USES_64BIT_SYSCALLS && SANITIZER_LINUX
 static void stat64_to_stat(struct stat64 *in, struct stat *out) {
   internal_memset(out, 0, sizeof(*out));
   out->st_dev = in->st_dev;
@@ -195,11 +249,25 @@ static void stat64_to_stat(struct stat64 *in, struct stat *out) {
   out->st_atime = in->st_atime;
   out->st_mtime = in->st_mtime;
   out->st_ctime = in->st_ctime;
-  out->st_ino = in->st_ino;
 }
 #endif
 
 #if defined(__mips64)
+// Undefine compatibility macros from <sys/stat.h>
+// so that they would not clash with the kernel_stat
+// st_[a|m|c]time fields
+#undef st_atime
+#undef st_mtime
+#undef st_ctime
+#if defined(SANITIZER_ANDROID)
+// Bionic sys/stat.h defines additional macros
+// for compatibility with the old NDKs and
+// they clash with the kernel_stat structure
+// st_[a|m|c]time_nsec fields.
+#undef st_atime_nsec
+#undef st_mtime_nsec
+#undef st_ctime_nsec
+#endif
 static void kernel_stat_to_stat(struct kernel_stat *in, struct stat *out) {
   internal_memset(out, 0, sizeof(*out));
   out->st_dev = in->st_dev;
@@ -212,16 +280,30 @@ static void kernel_stat_to_stat(struct kernel_stat *in, struct stat *out) {
   out->st_size = in->st_size;
   out->st_blksize = in->st_blksize;
   out->st_blocks = in->st_blocks;
-  out->st_atime = in->st_atime_nsec;
-  out->st_mtime = in->st_mtime_nsec;
-  out->st_ctime = in->st_ctime_nsec;
-  out->st_ino = in->st_ino;
+#if defined(__USE_MISC)     || \
+    defined(__USE_XOPEN2K8) || \
+    defined(SANITIZER_ANDROID)
+  out->st_atim.tv_sec = in->st_atime;
+  out->st_atim.tv_nsec = in->st_atime_nsec;
+  out->st_mtim.tv_sec = in->st_mtime;
+  out->st_mtim.tv_nsec = in->st_mtime_nsec;
+  out->st_ctim.tv_sec = in->st_ctime;
+  out->st_ctim.tv_nsec = in->st_ctime_nsec;
+#else
+  out->st_atime = in->st_atime;
+  out->st_atimensec = in->st_atime_nsec;
+  out->st_mtime = in->st_mtime;
+  out->st_mtimensec = in->st_mtime_nsec;
+  out->st_ctime = in->st_ctime;
+  out->st_atimensec = in->st_ctime_nsec;
+#endif
 }
 #endif
 
 uptr internal_stat(const char *path, void *buf) {
-#if SANITIZER_FREEBSD
-  return internal_syscall(SYSCALL(stat), path, buf);
+#if SANITIZER_FREEBSD || SANITIZER_NETBSD
+  return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path,
+                          (uptr)buf, 0);
 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
   return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path,
                           (uptr)buf, 0);
@@ -244,8 +326,11 @@ uptr internal_stat(const char *path, void *buf) {
 }
 
 uptr internal_lstat(const char *path, void *buf) {
-#if SANITIZER_FREEBSD
+#if SANITIZER_NETBSD
   return internal_syscall(SYSCALL(lstat), path, buf);
+#elif SANITIZER_FREEBSD
+  return internal_syscall(SYSCALL(fstatat), AT_FDCWD, (uptr)path,
+                          (uptr)buf, AT_SYMLINK_NOFOLLOW);
 #elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
   return internal_syscall(SYSCALL(newfstatat), AT_FDCWD, (uptr)path,
                          (uptr)buf, AT_SYMLINK_NOFOLLOW);
@@ -268,7 +353,7 @@ uptr internal_lstat(const char *path, void *buf) {
 }
 
 uptr internal_fstat(fd_t fd, void *buf) {
-#if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS
+#if SANITIZER_FREEBSD || SANITIZER_LINUX_USES_64BIT_SYSCALLS || SANITIZER_NETBSD
 # if SANITIZER_MIPS64
   // For mips64, fstat syscall fills buffer in the format of kernel_stat
   struct kernel_stat kbuf;
@@ -302,7 +387,9 @@ uptr internal_dup2(int oldfd, int newfd) {
 }
 
 uptr internal_readlink(const char *path, char *buf, uptr bufsize) {
-#if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
+#if SANITIZER_NETBSD
+  return internal_syscall_ptr(SYSCALL(readlink), path, buf, bufsize);
+#elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
   return internal_syscall(SYSCALL(readlinkat), AT_FDCWD,
                           (uptr)path, (uptr)buf, bufsize);
 #else
@@ -332,7 +419,7 @@ uptr internal_sched_yield() {
 }
 
 void internal__exit(int exitcode) {
-#if SANITIZER_FREEBSD
+#if SANITIZER_FREEBSD || SANITIZER_NETBSD
   internal_syscall(SYSCALL(exit), exitcode);
 #else
   internal_syscall(SYSCALL(exit_group), exitcode);
@@ -368,22 +455,28 @@ bool FileExists(const char *filename) {
   return S_ISREG(st.st_mode);
 }
 
-uptr GetTid() {
+tid_t GetTid() {
 #if SANITIZER_FREEBSD
   return (uptr)pthread_self();
+#elif SANITIZER_NETBSD
+  return _lwp_self();
 #else
   return internal_syscall(SYSCALL(gettid));
 #endif
 }
 
 u64 NanoTime() {
-#if SANITIZER_FREEBSD
+#if SANITIZER_FREEBSD || SANITIZER_NETBSD
   timeval tv;
 #else
   kernel_timeval tv;
 #endif
   internal_memset(&tv, 0, sizeof(tv));
+#if SANITIZER_NETBSD
+  internal_syscall_ptr(SYSCALL(gettimeofday), &tv, NULL);
+#else
   internal_syscall(SYSCALL(gettimeofday), (uptr)&tv, 0);
+#endif
   return (u64)tv.tv_sec * 1000*1000*1000 + tv.tv_usec * 1000;
 }
 
@@ -391,7 +484,7 @@ u64 NanoTime() {
 // 'environ' array (on FreeBSD) and does not use libc. This function should be
 // called first inside __asan_init.
 const char *GetEnv(const char *name) {
-#if SANITIZER_FREEBSD
+#if SANITIZER_FREEBSD || SANITIZER_NETBSD
   if (::environ != 0) {
     uptr NameLen = internal_strlen(name);
     for (char **Env = ::environ; *Env != 0; Env++) {
@@ -525,6 +618,8 @@ void BlockingMutex::Lock() {
   while (atomic_exchange(m, MtxSleeping, memory_order_acquire) != MtxUnlocked) {
 #if SANITIZER_FREEBSD
     _umtx_op(m, UMTX_OP_WAIT_UINT, MtxSleeping, 0, 0);
+#elif SANITIZER_NETBSD
+    sched_yield(); /* No userspace futex-like synchromization */
 #else
     internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAIT, MtxSleeping, 0, 0, 0);
 #endif
@@ -533,11 +628,13 @@ void BlockingMutex::Lock() {
 
 void BlockingMutex::Unlock() {
   atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
-  u32 v = atomic_exchange(m, MtxUnlocked, memory_order_relaxed);
+  u32 v = atomic_exchange(m, MtxUnlocked, memory_order_release);
   CHECK_NE(v, MtxUnlocked);
   if (v == MtxSleeping) {
 #if SANITIZER_FREEBSD
     _umtx_op(m, UMTX_OP_WAKE, 1, 0, 0);
+#elif SANITIZER_NETBSD
+                   /* No userspace futex-like synchromization */
 #else
     internal_syscall(SYSCALL(futex), (uptr)m, FUTEX_WAKE, 1, 0, 0, 0);
 #endif
@@ -553,6 +650,17 @@ void BlockingMutex::CheckLocked() {
 // The actual size of this structure is specified by d_reclen.
 // Note that getdents64 uses a different structure format. We only provide the
 // 32-bit syscall here.
+#if SANITIZER_NETBSD
+// struct dirent is different for Linux and us. At this moment, we use only
+// d_fileno (Linux call this d_ino), d_reclen, and d_name.
+struct linux_dirent {
+  u64 d_ino;  // d_fileno
+  u16 d_reclen;
+  u16 d_namlen;  // not used
+  u8 d_type;     // not used
+  char d_name[NAME_MAX + 1];
+};
+#else
 struct linux_dirent {
 #if SANITIZER_X32 || defined(__aarch64__)
   u64 d_ino;
@@ -567,16 +675,34 @@ struct linux_dirent {
 #endif
   char               d_name[256];
 };
+#endif
 
 // Syscall wrappers.
 uptr internal_ptrace(int request, int pid, void *addr, void *data) {
+#if SANITIZER_NETBSD
+  // XXX We need additional work for ptrace:
+  //   - for request, we use PT_FOO whereas Linux uses PTRACE_FOO
+  //   - data is int for us, but void * for Linux
+  //   - Linux sometimes uses data in the case where we use addr instead
+  // At this moment, this function is used only within
+  // "#if SANITIZER_LINUX && defined(__x86_64__)" block in
+  // sanitizer_stoptheworld_linux_libcdep.cc.
+  return internal_syscall_ptr(SYSCALL(ptrace), request, pid, (uptr)addr,
+                              (uptr)data);
+#else
   return internal_syscall(SYSCALL(ptrace), request, pid, (uptr)addr,
                           (uptr)data);
+#endif
 }
 
 uptr internal_waitpid(int pid, int *status, int options) {
+#if SANITIZER_NETBSD
+  return internal_syscall(SYSCALL(wait4), pid, status, options,
+                          NULL /* rusage */);
+#else
   return internal_syscall(SYSCALL(wait4), pid, (uptr)status, options,
                           0 /* rusage */);
+#endif
 }
 
 uptr internal_getpid() {
@@ -588,7 +714,11 @@ uptr internal_getppid() {
 }
 
 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) {
-#if SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
+#if SANITIZER_NETBSD
+  return internal_syscall(SYSCALL(getdents), fd, dirp, (uptr)count);
+#elif SANITIZER_FREEBSD
+  return internal_syscall(SYSCALL(getdirentries), fd, (uptr)dirp, count, NULL);
+#elif SANITIZER_USES_CANONICAL_LINUX_SYSCALLS
   return internal_syscall(SYSCALL(getdents64), fd, (uptr)dirp, count);
 #else
   return internal_syscall(SYSCALL(getdents), fd, (uptr)dirp, count);
@@ -596,7 +726,11 @@ uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count) {
 }
 
 uptr internal_lseek(fd_t fd, OFF_T offset, int whence) {
+#if SANITIZER_NETBSD
+  return internal_syscall64(SYSCALL(lseek), fd, 0, offset, whence);
+#else
   return internal_syscall(SYSCALL(lseek), fd, offset, whence);
+#endif
 }
 
 #if SANITIZER_LINUX
@@ -687,7 +821,7 @@ int internal_sigaction_syscall(int signum, const void *act, void *oldact) {
 
 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
     __sanitizer_sigset_t *oldset) {
-#if SANITIZER_FREEBSD
+#if SANITIZER_FREEBSD || SANITIZER_NETBSD
   return internal_syscall(SYSCALL(sigprocmask), how, set, oldset);
 #else
   __sanitizer_kernel_sigset_t *k_set = (__sanitizer_kernel_sigset_t *)set;
@@ -796,20 +930,94 @@ bool ThreadLister::GetDirectoryEntries() {
   return true;
 }
 
+#if SANITIZER_WORDSIZE == 32
+// Take care of unusable kernel area in top gigabyte.
+static uptr GetKernelAreaSize() {
+#if SANITIZER_LINUX && !SANITIZER_X32
+  const uptr gbyte = 1UL << 30;
+
+  // Firstly check if there are writable segments
+  // mapped to top gigabyte (e.g. stack).
+  MemoryMappingLayout proc_maps(/*cache_enabled*/true);
+  MemoryMappedSegment segment;
+  while (proc_maps.Next(&segment)) {
+    if ((segment.end >= 3 * gbyte) && segment.IsWritable()) return 0;
+  }
+
+#if !SANITIZER_ANDROID
+  // Even if nothing is mapped, top Gb may still be accessible
+  // if we are running on 64-bit kernel.
+  // Uname may report misleading results if personality type
+  // is modified (e.g. under schroot) so check this as well.
+  struct utsname uname_info;
+  int pers = personality(0xffffffffUL);
+  if (!(pers & PER_MASK)
+      && uname(&uname_info) == 0
+      && internal_strstr(uname_info.machine, "64"))
+    return 0;
+#endif  // SANITIZER_ANDROID
+
+  // Top gigabyte is reserved for kernel.
+  return gbyte;
+#else
+  return 0;
+#endif  // SANITIZER_LINUX && !SANITIZER_X32
+}
+#endif  // SANITIZER_WORDSIZE == 32
+
+uptr GetMaxVirtualAddress() {
+#if SANITIZER_NETBSD && defined(__x86_64__)
+  return 0x7f7ffffff000ULL;  // (0x00007f8000000000 - PAGE_SIZE)
+#elif SANITIZER_WORDSIZE == 64
+# if defined(__powerpc64__) || defined(__aarch64__)
+  // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
+  // We somehow need to figure out which one we are using now and choose
+  // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
+  // Note that with 'ulimit -s unlimited' the stack is moved away from the top
+  // of the address space, so simply checking the stack address is not enough.
+  // This should (does) work for both PowerPC64 Endian modes.
+  // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
+  return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
+# elif defined(__mips64)
+  return (1ULL << 40) - 1;  // 0x000000ffffffffffUL;
+# elif defined(__s390x__)
+  return (1ULL << 53) - 1;  // 0x001fffffffffffffUL;
+# else
+  return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
+# endif
+#else  // SANITIZER_WORDSIZE == 32
+# if defined(__s390__)
+  return (1ULL << 31) - 1;  // 0x7fffffff;
+# else
+  uptr res = (1ULL << 32) - 1;  // 0xffffffff;
+  if (!common_flags()->full_address_space)
+    res -= GetKernelAreaSize();
+  CHECK_LT(reinterpret_cast<uptr>(&res), res);
+  return res;
+# endif
+#endif  // SANITIZER_WORDSIZE
+}
+
 uptr GetPageSize() {
 // Android post-M sysconf(_SC_PAGESIZE) crashes if called from .preinit_array.
 #if SANITIZER_ANDROID
   return 4096;
 #elif SANITIZER_LINUX && (defined(__x86_64__) || defined(__i386__))
   return EXEC_PAGESIZE;
+#elif SANITIZER_USE_GETAUXVAL
+  return getauxval(AT_PAGESZ);
 #else
   return sysconf(_SC_PAGESIZE);  // EXEC_PAGESIZE may not be trustworthy.
 #endif
 }
 
 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
+#if SANITIZER_FREEBSD || SANITIZER_NETBSD
 #if SANITIZER_FREEBSD
-  const int Mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
+  const int Mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
+#else
+  const int Mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME};
+#endif
   const char *default_module_name = "kern.proc.pathname";
   size_t Size = buf_len;
   bool IsErr = (sysctl(Mib, ARRAY_SIZE(Mib), buf, &Size, NULL, 0) != 0);
@@ -1094,36 +1302,50 @@ uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
                    int *parent_tidptr, void *newtls, int *child_tidptr) {
   long long res;
-/* Stack frame offsets.  */
-#if _CALL_ELF != 2
-#define FRAME_MIN_SIZE         112
-#define FRAME_TOC_SAVE         40
+// Stack frame structure.
+#if SANITIZER_PPC64V1
+//   Back chain == 0        (SP + 112)
+// Frame (112 bytes):
+//   Parameter save area    (SP + 48), 8 doublewords
+//   TOC save area          (SP + 40)
+//   Link editor doubleword (SP + 32)
+//   Compiler doubleword    (SP + 24)
+//   LR save area           (SP + 16)
+//   CR save area           (SP + 8)
+//   Back chain             (SP + 0)
+# define FRAME_SIZE 112
+# define FRAME_TOC_SAVE_OFFSET 40
+#elif SANITIZER_PPC64V2
+//   Back chain == 0        (SP + 32)
+// Frame (32 bytes):
+//   TOC save area          (SP + 24)
+//   LR save area           (SP + 16)
+//   CR save area           (SP + 8)
+//   Back chain             (SP + 0)
+# define FRAME_SIZE 32
+# define FRAME_TOC_SAVE_OFFSET 24
 #else
-#define FRAME_MIN_SIZE         32
-#define FRAME_TOC_SAVE         24
+# error "Unsupported PPC64 ABI"
 #endif
   if (!fn || !child_stack)
     return -EINVAL;
   CHECK_EQ(0, (uptr)child_stack % 16);
-  child_stack = (char *)child_stack - 2 * sizeof(unsigned long long);
-  ((unsigned long long *)child_stack)[0] = (uptr)fn;
-  ((unsigned long long *)child_stack)[1] = (uptr)arg;
 
   register int (*__fn)(void *) __asm__("r3") = fn;
   register void *__cstack      __asm__("r4") = child_stack;
   register int __flags         __asm__("r5") = flags;
-  register void * __arg        __asm__("r6") = arg;
-  register int * __ptidptr     __asm__("r7") = parent_tidptr;
-  register void * __newtls     __asm__("r8") = newtls;
-  register int * __ctidptr     __asm__("r9") = child_tidptr;
+  register void *__arg         __asm__("r6") = arg;
+  register int *__ptidptr      __asm__("r7") = parent_tidptr;
+  register void *__newtls      __asm__("r8") = newtls;
+  register int *__ctidptr      __asm__("r9") = child_tidptr;
 
  __asm__ __volatile__(
-           /* fn, arg, child_stack are saved acrVoss the syscall */
+           /* fn and arg are saved across the syscall */
            "mr 28, %5\n\t"
-           "mr 29, %6\n\t"
            "mr 27, %8\n\t"
 
            /* syscall
+             r0 == __NR_clone
              r3 == flags
              r4 == child_stack
              r5 == parent_tidptr
@@ -1141,15 +1363,21 @@ uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
            "crandc cr1*4+eq, cr1*4+eq, cr0*4+so\n\t"
            "bne-   cr1, 1f\n\t"
 
+           /* Set up stack frame */
+           "li    29, 0\n\t"
+           "stdu  29, -8(1)\n\t"
+           "stdu  1, -%12(1)\n\t"
            /* Do the function call */
            "std   2, %13(1)\n\t"
-#if _CALL_ELF != 2
+#if SANITIZER_PPC64V1
            "ld    0, 0(28)\n\t"
            "ld    2, 8(28)\n\t"
            "mtctr 0\n\t"
-#else
+#elif SANITIZER_PPC64V2
            "mr    12, 28\n\t"
            "mtctr 12\n\t"
+#else
+# error "Unsupported PPC64 ABI"
 #endif
            "mr    3, 27\n\t"
            "bctrl\n\t"
@@ -1163,13 +1391,151 @@ uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
            "1:\n\t"
            "mr %0, 3\n\t"
              : "=r" (res)
-             : "0" (-1), "i" (EINVAL),
-               "i" (__NR_clone), "i" (__NR_exit),
-               "r" (__fn), "r" (__cstack), "r" (__flags),
-               "r" (__arg), "r" (__ptidptr), "r" (__newtls),
-               "r" (__ctidptr), "i" (FRAME_MIN_SIZE), "i" (FRAME_TOC_SAVE)
-             : "cr0", "cr1", "memory", "ctr",
-               "r0", "r29", "r27", "r28");
+             : "0" (-1),
+               "i" (EINVAL),
+               "i" (__NR_clone),
+               "i" (__NR_exit),
+               "r" (__fn),
+               "r" (__cstack),
+               "r" (__flags),
+               "r" (__arg),
+               "r" (__ptidptr),
+               "r" (__newtls),
+               "r" (__ctidptr),
+               "i" (FRAME_SIZE),
+               "i" (FRAME_TOC_SAVE_OFFSET)
+             : "cr0", "cr1", "memory", "ctr", "r0", "r27", "r28", "r29");
+  return res;
+}
+#elif defined(__i386__) && SANITIZER_LINUX
+uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
+                    int *parent_tidptr, void *newtls, int *child_tidptr) {
+  int res;
+  if (!fn || !child_stack)
+    return -EINVAL;
+  CHECK_EQ(0, (uptr)child_stack % 16);
+  child_stack = (char *)child_stack - 7 * sizeof(unsigned int);
+  ((unsigned int *)child_stack)[0] = (uptr)flags;
+  ((unsigned int *)child_stack)[1] = (uptr)0;
+  ((unsigned int *)child_stack)[2] = (uptr)fn;
+  ((unsigned int *)child_stack)[3] = (uptr)arg;
+  __asm__ __volatile__(
+                       /* %eax = syscall(%eax = SYSCALL(clone),
+                        *                %ebx = flags,
+                        *                %ecx = child_stack,
+                        *                %edx = parent_tidptr,
+                        *                %esi  = new_tls,
+                        *                %edi = child_tidptr)
+                        */
+
+                        /* Obtain flags */
+                        "movl    (%%ecx), %%ebx\n"
+                        /* Do the system call */
+                        "pushl   %%ebx\n"
+                        "pushl   %%esi\n"
+                        "pushl   %%edi\n"
+                        /* Remember the flag value.  */
+                        "movl    %%ebx, (%%ecx)\n"
+                        "int     $0x80\n"
+                        "popl    %%edi\n"
+                        "popl    %%esi\n"
+                        "popl    %%ebx\n"
+
+                        /* if (%eax != 0)
+                         *   return;
+                         */
+
+                        "test    %%eax,%%eax\n"
+                        "jnz    1f\n"
+
+                        /* terminate the stack frame */
+                        "xorl   %%ebp,%%ebp\n"
+                        /* Call FN. */
+                        "call    *%%ebx\n"
+#ifdef PIC
+                        "call    here\n"
+                        "here:\n"
+                        "popl    %%ebx\n"
+                        "addl    $_GLOBAL_OFFSET_TABLE_+[.-here], %%ebx\n"
+#endif
+                        /* Call exit */
+                        "movl    %%eax, %%ebx\n"
+                        "movl    %2, %%eax\n"
+                        "int     $0x80\n"
+                        "1:\n"
+                       : "=a" (res)
+                       : "a"(SYSCALL(clone)), "i"(SYSCALL(exit)),
+                         "c"(child_stack),
+                         "d"(parent_tidptr),
+                         "S"(newtls),
+                         "D"(child_tidptr)
+                       : "memory");
+  return res;
+}
+#elif defined(__arm__) && SANITIZER_LINUX
+uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
+                    int *parent_tidptr, void *newtls, int *child_tidptr) {
+  unsigned int res;
+  if (!fn || !child_stack)
+    return -EINVAL;
+  child_stack = (char *)child_stack - 2 * sizeof(unsigned int);
+  ((unsigned int *)child_stack)[0] = (uptr)fn;
+  ((unsigned int *)child_stack)[1] = (uptr)arg;
+  register int r0 __asm__("r0") = flags;
+  register void *r1 __asm__("r1") = child_stack;
+  register int *r2 __asm__("r2") = parent_tidptr;
+  register void *r3 __asm__("r3") = newtls;
+  register int *r4 __asm__("r4") = child_tidptr;
+  register int r7 __asm__("r7") = __NR_clone;
+
+#if __ARM_ARCH > 4 || defined (__ARM_ARCH_4T__)
+# define ARCH_HAS_BX
+#endif
+#if __ARM_ARCH > 4
+# define ARCH_HAS_BLX
+#endif
+
+#ifdef ARCH_HAS_BX
+# ifdef ARCH_HAS_BLX
+#  define BLX(R) "blx "  #R "\n"
+# else
+#  define BLX(R) "mov lr, pc; bx " #R "\n"
+# endif
+#else
+# define BLX(R)  "mov lr, pc; mov pc," #R "\n"
+#endif
+
+  __asm__ __volatile__(
+                       /* %r0 = syscall(%r7 = SYSCALL(clone),
+                        *               %r0 = flags,
+                        *               %r1 = child_stack,
+                        *               %r2 = parent_tidptr,
+                        *               %r3  = new_tls,
+                        *               %r4 = child_tidptr)
+                        */
+
+                       /* Do the system call */
+                       "swi 0x0\n"
+
+                       /* if (%r0 != 0)
+                        *   return %r0;
+                        */
+                       "cmp r0, #0\n"
+                       "bne 1f\n"
+
+                       /* In the child, now. Call "fn(arg)". */
+                       "ldr r0, [sp, #4]\n"
+                       "ldr ip, [sp], #8\n"
+                       BLX(ip)
+                       /* Call _exit(%r0). */
+                       "mov r7, %7\n"
+                       "swi 0x0\n"
+                       "1:\n"
+                       "mov %0, r0\n"
+                       : "=r"(res)
+                       : "r"(r0), "r"(r1), "r"(r2), "r"(r3), "r"(r4), "r"(r7),
+                         "i"(__NR_exit)
+                       : "memory");
   return res;
 }
 #endif  // defined(__x86_64__) && SANITIZER_LINUX
@@ -1217,14 +1583,27 @@ AndroidApiLevel AndroidGetApiLevel() {
 
 #endif
 
-bool IsHandledDeadlySignal(int signum) {
-  if (common_flags()->handle_abort && signum == SIGABRT)
-    return true;
-  if (common_flags()->handle_sigill && signum == SIGILL)
-    return true;
-  if (common_flags()->handle_sigfpe && signum == SIGFPE)
-    return true;
-  return (signum == SIGSEGV || signum == SIGBUS) && common_flags()->handle_segv;
+static HandleSignalMode GetHandleSignalModeImpl(int signum) {
+  switch (signum) {
+    case SIGABRT:
+      return common_flags()->handle_abort;
+    case SIGILL:
+      return common_flags()->handle_sigill;
+    case SIGFPE:
+      return common_flags()->handle_sigfpe;
+    case SIGSEGV:
+      return common_flags()->handle_segv;
+    case SIGBUS:
+      return common_flags()->handle_sigbus;
+  }
+  return kHandleSignalNo;
+}
+
+HandleSignalMode GetHandleSignalMode(int signum) {
+  HandleSignalMode result = GetHandleSignalModeImpl(signum);
+  if (result == kHandleSignalYes && !common_flags()->allow_user_segv_handler)
+    return kHandleSignalExclusive;
+  return result;
 }
 
 #if !SANITIZER_GO
@@ -1276,12 +1655,14 @@ static bool Aarch64GetESR(ucontext_t *ucontext, u64 *esr) {
 }
 #endif
 
-SignalContext::WriteFlag SignalContext::GetWriteFlag(void *context) {
+SignalContext::WriteFlag SignalContext::GetWriteFlag() const {
   ucontext_t *ucontext = (ucontext_t *)context;
 #if defined(__x86_64__) || defined(__i386__)
   static const uptr PF_WRITE = 1U << 1;
 #if SANITIZER_FREEBSD
   uptr err = ucontext->uc_mcontext.mc_err;
+#elif SANITIZER_NETBSD
+  uptr err = ucontext->uc_mcontext.__gregs[_REG_ERR];
 #else
   uptr err = ucontext->uc_mcontext.gregs[REG_ERR];
 #endif
@@ -1301,7 +1682,11 @@ SignalContext::WriteFlag SignalContext::GetWriteFlag(void *context) {
 #endif
 }
 
-void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
+void SignalContext::DumpAllRegisters(void *context) {
+  // FIXME: Implement this.
+}
+
+static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
 #if defined(__arm__)
   ucontext_t *ucontext = (ucontext_t*)context;
   *pc = ucontext->uc_mcontext.arm_pc;
@@ -1324,6 +1709,11 @@ void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
   *pc = ucontext->uc_mcontext.mc_rip;
   *bp = ucontext->uc_mcontext.mc_rbp;
   *sp = ucontext->uc_mcontext.mc_rsp;
+#elif SANITIZER_NETBSD
+  ucontext_t *ucontext = (ucontext_t *)context;
+  *pc = ucontext->uc_mcontext.__gregs[_REG_RIP];
+  *bp = ucontext->uc_mcontext.__gregs[_REG_RBP];
+  *sp = ucontext->uc_mcontext.__gregs[_REG_RSP];
 # else
   ucontext_t *ucontext = (ucontext_t*)context;
   *pc = ucontext->uc_mcontext.gregs[REG_RIP];
@@ -1336,6 +1726,11 @@ void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
   *pc = ucontext->uc_mcontext.mc_eip;
   *bp = ucontext->uc_mcontext.mc_ebp;
   *sp = ucontext->uc_mcontext.mc_esp;
+#elif SANITIZER_NETBSD
+  ucontext_t *ucontext = (ucontext_t *)context;
+  *pc = ucontext->uc_mcontext.__gregs[_REG_EIP];
+  *bp = ucontext->uc_mcontext.__gregs[_REG_EBP];
+  *sp = ucontext->uc_mcontext.__gregs[_REG_ESP];
 # else
   ucontext_t *ucontext = (ucontext_t*)context;
   *pc = ucontext->uc_mcontext.gregs[REG_EIP];
@@ -1382,15 +1777,63 @@ void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
 #endif
 }
 
+void SignalContext::InitPcSpBp() { GetPcSpBp(context, &pc, &sp, &bp); }
+
 void MaybeReexec() {
   // No need to re-exec on Linux.
 }
 
-uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding) {
+void PrintModuleMap() { }
+
+void CheckNoDeepBind(const char *filename, int flag) {
+#ifdef RTLD_DEEPBIND
+  if (flag & RTLD_DEEPBIND) {
+    Report(
+        "You are trying to dlopen a %s shared library with RTLD_DEEPBIND flag"
+        " which is incompatibe with sanitizer runtime "
+        "(see https://github.com/google/sanitizers/issues/611 for details"
+        "). If you want to run %s library under sanitizers please remove "
+        "RTLD_DEEPBIND from dlopen flags.\n",
+        filename, filename);
+    Die();
+  }
+#endif
+}
+
+uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding,
+                              uptr *largest_gap_found) {
   UNREACHABLE("FindAvailableMemoryRange is not available");
   return 0;
 }
 
+bool GetRandom(void *buffer, uptr length, bool blocking) {
+  if (!buffer || !length || length > 256)
+    return false;
+#if SANITIZER_USE_GETRANDOM
+  static atomic_uint8_t skip_getrandom_syscall;
+  if (!atomic_load_relaxed(&skip_getrandom_syscall)) {
+    // Up to 256 bytes, getrandom will not be interrupted.
+    uptr res = internal_syscall(SYSCALL(getrandom), buffer, length,
+                                blocking ? 0 : GRND_NONBLOCK);
+    int rverrno = 0;
+    if (internal_iserror(res, &rverrno) && rverrno == ENOSYS)
+      atomic_store_relaxed(&skip_getrandom_syscall, 1);
+    else if (res == length)
+      return true;
+  }
+#endif  // SANITIZER_USE_GETRANDOM
+  // Up to 256 bytes, a read off /dev/urandom will not be interrupted.
+  // blocking is moot here, O_NONBLOCK has no effect when opening /dev/urandom.
+  uptr fd = internal_open("/dev/urandom", O_RDONLY);
+  if (internal_iserror(fd))
+    return false;
+  uptr res = internal_read(fd, buffer, length);
+  if (internal_iserror(res))
+    return false;
+  internal_close(fd);
+  return true;
+}
+
 } // namespace __sanitizer
 
-#endif // SANITIZER_FREEBSD || SANITIZER_LINUX
+#endif  // SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
diff --git a/libsanitizer/sanitizer_common/sanitizer_linux.h b/libsanitizer/sanitizer_common/sanitizer_linux.h
index a42df576405..910703d8b29 100644
--- a/libsanitizer/sanitizer_common/sanitizer_linux.h
+++ b/libsanitizer/sanitizer_common/sanitizer_linux.h
@@ -12,11 +12,12 @@
 #define SANITIZER_LINUX_H
 
 #include "sanitizer_platform.h"
-#if SANITIZER_FREEBSD || SANITIZER_LINUX
+#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
 #include "sanitizer_common.h"
 #include "sanitizer_internal_defs.h"
-#include "sanitizer_posix.h"
+#include "sanitizer_platform_limits_netbsd.h"
 #include "sanitizer_platform_limits_posix.h"
+#include "sanitizer_posix.h"
 
 struct link_map;  // Opaque type returned by dlopen().
 
@@ -25,6 +26,19 @@ namespace __sanitizer {
 // the one in <dirent.h>, which is used by readdir().
 struct linux_dirent;
 
+struct ProcSelfMapsBuff {
+  char *data;
+  uptr mmaped_size;
+  uptr len;
+};
+
+struct MemoryMappingLayoutData {
+  ProcSelfMapsBuff proc_self_maps;
+  const char *current;
+};
+
+void ReadProcMaps(ProcSelfMapsBuff *proc_maps);
+
 // Syscall wrappers.
 uptr internal_getdents(fd_t fd, struct linux_dirent *dirp, unsigned int count);
 uptr internal_sigaltstack(const void* ss, void* oss);
@@ -44,7 +58,8 @@ int internal_sigaction_syscall(int signum, const void *act, void *oldact);
 #endif
 void internal_sigdelset(__sanitizer_sigset_t *set, int signum);
 #if defined(__x86_64__) || defined(__mips__) || defined(__aarch64__) \
-  || defined(__powerpc64__) || defined(__s390__)
+  || defined(__powerpc64__) || defined(__s390__) || defined(__i386__) \
+  || defined(__arm__)
 uptr internal_clone(int (*fn)(void *), void *child_stack, int flags, void *arg,
                     int *parent_tidptr, void *newtls, int *child_tidptr);
 #endif
@@ -83,7 +98,47 @@ bool LibraryNameIs(const char *full_name, const char *base_name);
 
 // Call cb for each region mapped by map.
 void ForEachMappedRegion(link_map *map, void (*cb)(const void *, uptr));
+
+#if SANITIZER_ANDROID
+
+#if defined(__aarch64__)
+# define __get_tls() \
+    ({ void** __v; __asm__("mrs %0, tpidr_el0" : "=r"(__v)); __v; })
+#elif defined(__arm__)
+# define __get_tls() \
+    ({ void** __v; __asm__("mrc p15, 0, %0, c13, c0, 3" : "=r"(__v)); __v; })
+#elif defined(__mips__)
+// On mips32r1, this goes via a kernel illegal instruction trap that's
+// optimized for v1.
+# define __get_tls() \
+    ({ register void** __v asm("v1"); \
+       __asm__(".set    push\n" \
+               ".set    mips32r2\n" \
+               "rdhwr   %0,$29\n" \
+               ".set    pop\n" : "=r"(__v)); \
+       __v; })
+#elif defined(__i386__)
+# define __get_tls() \
+    ({ void** __v; __asm__("movl %%gs:0, %0" : "=r"(__v)); __v; })
+#elif defined(__x86_64__)
+# define __get_tls() \
+    ({ void** __v; __asm__("mov %%fs:0, %0" : "=r"(__v)); __v; })
+#else
+#error "Unsupported architecture."
+#endif
+
+// The Android Bionic team has allocated a TLS slot for TSan starting with N,
+// given that Android currently doesn't support ELF TLS. It is used to store
+// Sanitizers thread specific data.
+static const int TLS_SLOT_TSAN = 8;
+
+ALWAYS_INLINE uptr *get_android_tls_ptr() {
+  return reinterpret_cast<uptr *>(&__get_tls()[TLS_SLOT_TSAN]);
+}
+
+#endif  // SANITIZER_ANDROID
+
 }  // namespace __sanitizer
 
-#endif  // SANITIZER_FREEBSD || SANITIZER_LINUX
+#endif  // SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
 #endif  // SANITIZER_LINUX_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cc b/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cc
index 63e70660cf3..b279cf3135f 100644
--- a/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cc
@@ -12,11 +12,12 @@
 
 #include "sanitizer_platform.h"
 
-#if SANITIZER_FREEBSD || SANITIZER_LINUX
+#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
 
 #include "sanitizer_allocator_internal.h"
 #include "sanitizer_atomic.h"
 #include "sanitizer_common.h"
+#include "sanitizer_file.h"
 #include "sanitizer_flags.h"
 #include "sanitizer_freebsd.h"
 #include "sanitizer_linux.h"
@@ -24,10 +25,7 @@
 #include "sanitizer_procmaps.h"
 #include "sanitizer_stacktrace.h"
 
-#if SANITIZER_ANDROID || SANITIZER_FREEBSD
 #include <dlfcn.h>  // for dlsym()
-#endif
-
 #include <link.h>
 #include <pthread.h>
 #include <signal.h>
@@ -82,28 +80,25 @@ void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
 
     // Find the mapping that contains a stack variable.
     MemoryMappingLayout proc_maps(/*cache_enabled*/true);
-    uptr start, end, offset;
+    MemoryMappedSegment segment;
     uptr prev_end = 0;
-    while (proc_maps.Next(&start, &end, &offset, nullptr, 0,
-          /* protection */nullptr)) {
-      if ((uptr)&rl < end)
-        break;
-      prev_end = end;
+    while (proc_maps.Next(&segment)) {
+      if ((uptr)&rl < segment.end) break;
+      prev_end = segment.end;
     }
-    CHECK((uptr)&rl >= start && (uptr)&rl < end);
+    CHECK((uptr)&rl >= segment.start && (uptr)&rl < segment.end);
 
     // Get stacksize from rlimit, but clip it so that it does not overlap
     // with other mappings.
     uptr stacksize = rl.rlim_cur;
-    if (stacksize > end - prev_end)
-      stacksize = end - prev_end;
+    if (stacksize > segment.end - prev_end) stacksize = segment.end - prev_end;
     // When running with unlimited stack size, we still want to set some limit.
     // The unlimited stack size is caused by 'ulimit -s unlimited'.
     // Also, for some reason, GNU make spawns subprocesses with unlimited stack.
     if (stacksize > kMaxThreadStackSize)
       stacksize = kMaxThreadStackSize;
-    *stack_top = end;
-    *stack_bottom = end - stacksize;
+    *stack_top = segment.end;
+    *stack_bottom = segment.end - stacksize;
     return;
   }
   pthread_attr_t attr;
@@ -114,7 +109,6 @@ void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
   my_pthread_attr_getstack(&attr, &stackaddr, &stacksize);
   pthread_attr_destroy(&attr);
 
-  CHECK_LE(stacksize, kMaxThreadStackSize);  // Sanity check.
   *stack_top = (uptr)stackaddr + stacksize;
   *stack_bottom = (uptr)stackaddr;
 }
@@ -153,7 +147,8 @@ bool SanitizerGetThreadName(char *name, int max_len) {
 #endif
 }
 
-#if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO
+#if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO && \
+    !SANITIZER_NETBSD
 static uptr g_tls_size;
 
 #ifdef __i386__
@@ -181,11 +176,12 @@ void InitTlsSize() {
 }
 #else
 void InitTlsSize() { }
-#endif  // !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO
+#endif  // !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO &&
+        // !SANITIZER_NETBSD
 
 #if (defined(__x86_64__) || defined(__i386__) || defined(__mips__) \
-    || defined(__aarch64__) || defined(__powerpc64__) || defined(__s390__)) \
-    && SANITIZER_LINUX && !SANITIZER_ANDROID
+    || defined(__aarch64__) || defined(__powerpc64__) || defined(__s390__) \
+    || defined(__arm__)) && SANITIZER_LINUX && !SANITIZER_ANDROID
 // sizeof(struct pthread) from glibc.
 static atomic_uintptr_t kThreadDescriptorSize;
 
@@ -193,14 +189,14 @@ uptr ThreadDescriptorSize() {
   uptr val = atomic_load(&kThreadDescriptorSize, memory_order_relaxed);
   if (val)
     return val;
-#if defined(__x86_64__) || defined(__i386__)
+#if defined(__x86_64__) || defined(__i386__) || defined(__arm__)
 #ifdef _CS_GNU_LIBC_VERSION
   char buf[64];
   uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf));
   if (len < sizeof(buf) && internal_strncmp(buf, "glibc 2.", 8) == 0) {
     char *end;
     int minor = internal_simple_strtoll(buf + 8, &end, 10);
-    if (end != buf + 8 && (*end == '\0' || *end == '.')) {
+    if (end != buf + 8 && (*end == '\0' || *end == '.' || *end == '-')) {
       int patch = 0;
       if (*end == '.')
         // strtoll will return 0 if no valid conversion could be performed
@@ -209,6 +205,9 @@ uptr ThreadDescriptorSize() {
       /* sizeof(struct pthread) values from various glibc versions.  */
       if (SANITIZER_X32)
         val = 1728;  // Assume only one particular version for x32.
+      // For ARM sizeof(struct pthread) changed in Glibc 2.23.
+      else if (SANITIZER_ARM)
+        val = minor <= 22 ? 1120 : 1216;
       else if (minor <= 3)
         val = FIRST_32_SECOND_64(1104, 1696);
       else if (minor == 4)
@@ -271,9 +270,7 @@ static uptr TlsPreTcbSize() {
 # endif
   const uptr kTlsAlign = 16;
   const uptr kTlsPreTcbSize =
-    (ThreadDescriptorSize() + kTcbHead + kTlsAlign - 1) & ~(kTlsAlign - 1);
-  InitTlsSize();
-  g_tls_size = (g_tls_size + kTlsPreTcbSize + kTlsAlign -1) & ~(kTlsAlign - 1);
+      RoundUpTo(ThreadDescriptorSize() + kTcbHead, kTlsAlign);
   return kTlsPreTcbSize;
 }
 #endif
@@ -296,7 +293,7 @@ uptr ThreadSelf() {
                 rdhwr %0,$29;\
                 .set pop" : "=r" (thread_pointer));
   descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize();
-# elif defined(__aarch64__)
+# elif defined(__aarch64__) || defined(__arm__)
   descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer()) -
                                       ThreadDescriptorSize();
 # elif defined(__s390__)
@@ -335,7 +332,9 @@ static void **ThreadSelfSegbase() {
 uptr ThreadSelf() {
   return (uptr)ThreadSelfSegbase()[2];
 }
-#endif  // SANITIZER_FREEBSD
+#elif SANITIZER_NETBSD
+uptr ThreadSelf() { return (uptr)pthread_self(); }
+#endif  // SANITIZER_NETBSD
 
 #if !SANITIZER_GO
 static void GetTls(uptr *addr, uptr *size) {
@@ -345,7 +344,8 @@ static void GetTls(uptr *addr, uptr *size) {
   *size = GetTlsSize();
   *addr -= *size;
   *addr += ThreadDescriptorSize();
-# elif defined(__mips__) || defined(__aarch64__) || defined(__powerpc64__)
+# elif defined(__mips__) || defined(__aarch64__) || defined(__powerpc64__) \
+    || defined(__arm__)
   *addr = ThreadSelf();
   *size = GetTlsSize();
 # else
@@ -365,7 +365,7 @@ static void GetTls(uptr *addr, uptr *size) {
     *addr = (uptr) dtv[2];
     *size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]);
   }
-#elif SANITIZER_ANDROID
+#elif SANITIZER_ANDROID || SANITIZER_NETBSD
   *addr = 0;
   *size = 0;
 #else
@@ -376,10 +376,12 @@ static void GetTls(uptr *addr, uptr *size) {
 
 #if !SANITIZER_GO
 uptr GetTlsSize() {
-#if SANITIZER_FREEBSD || SANITIZER_ANDROID
+#if SANITIZER_FREEBSD || SANITIZER_ANDROID || SANITIZER_NETBSD
   uptr addr, size;
   GetTls(&addr, &size);
   return size;
+#elif defined(__mips__) || defined(__powerpc64__)
+  return RoundUpTo(g_tls_size + TlsPreTcbSize(), 16);
 #else
   return g_tls_size;
 #endif
@@ -420,7 +422,7 @@ typedef ElfW(Phdr) Elf_Phdr;
 # endif
 
 struct DlIteratePhdrData {
-  InternalMmapVector<LoadedModule> *modules;
+  InternalMmapVectorNoCtor<LoadedModule> *modules;
   bool first;
 };
 
@@ -444,7 +446,9 @@ static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) {
       uptr cur_beg = info->dlpi_addr + phdr->p_vaddr;
       uptr cur_end = cur_beg + phdr->p_memsz;
       bool executable = phdr->p_flags & PF_X;
-      cur_module.addAddressRange(cur_beg, cur_end, executable);
+      bool writable = phdr->p_flags & PF_W;
+      cur_module.addAddressRange(cur_beg, cur_end, executable,
+                                 writable);
     }
   }
   data->modules->push_back(cur_module);
@@ -456,21 +460,41 @@ extern "C" __attribute__((weak)) int dl_iterate_phdr(
     int (*)(struct dl_phdr_info *, size_t, void *), void *);
 #endif
 
-void ListOfModules::init() {
-  clear();
+static bool requiresProcmaps() {
 #if SANITIZER_ANDROID && __ANDROID_API__ <= 22
-  u32 api_level = AndroidGetApiLevel();
   // Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken.
   // The runtime check allows the same library to work with
   // both K and L (and future) Android releases.
-  if (api_level <= ANDROID_LOLLIPOP_MR1) { // L or earlier
-    MemoryMappingLayout memory_mapping(false);
-    memory_mapping.DumpListOfModules(&modules_);
-    return;
-  }
+  return AndroidGetApiLevel() <= ANDROID_LOLLIPOP_MR1;
+#else
+  return false;
 #endif
-  DlIteratePhdrData data = {&modules_, true};
-  dl_iterate_phdr(dl_iterate_phdr_cb, &data);
+}
+
+static void procmapsInit(InternalMmapVectorNoCtor<LoadedModule> *modules) {
+  MemoryMappingLayout memory_mapping(/*cache_enabled*/true);
+  memory_mapping.DumpListOfModules(modules);
+}
+
+void ListOfModules::init() {
+  clearOrInit();
+  if (requiresProcmaps()) {
+    procmapsInit(&modules_);
+  } else {
+    DlIteratePhdrData data = {&modules_, true};
+    dl_iterate_phdr(dl_iterate_phdr_cb, &data);
+  }
+}
+
+// When a custom loader is used, dl_iterate_phdr may not contain the full
+// list of modules. Allow callers to fall back to using procmaps.
+void ListOfModules::fallbackInit() {
+  if (!requiresProcmaps()) {
+    clearOrInit();
+    procmapsInit(&modules_);
+  } else {
+    clear();
+  }
 }
 
 // getrusage does not give us the current RSS, only the max RSS.
@@ -547,6 +571,15 @@ void LogMessageOnPrintf(const char *str) {
     WriteToSyslog(str);
 }
 
+#if SANITIZER_ANDROID
+extern "C" __attribute__((weak)) void android_set_abort_message(const char *);
+void SetAbortMessage(const char *str) {
+  if (&android_set_abort_message) android_set_abort_message(str);
+}
+#else
+void SetAbortMessage(const char *str) {}
+#endif
+
 #endif // SANITIZER_LINUX
 
 } // namespace __sanitizer
diff --git a/libsanitizer/sanitizer_common/sanitizer_linux_s390.cc b/libsanitizer/sanitizer_common/sanitizer_linux_s390.cc
index 3faaa1c26ac..b836447bd5d 100644
--- a/libsanitizer/sanitizer_common/sanitizer_linux_s390.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_linux_s390.cc
@@ -176,6 +176,13 @@ static bool FixedCVE_2016_2143() {
     // 4.4.6+ is OK.
     if (minor == 4 && patch >= 6)
       return true;
+    if (minor == 4 && patch == 0 && ptr[0] == '-' &&
+        internal_strstr(buf.version, "Ubuntu")) {
+      // Check Ubuntu 16.04
+      int r1 = internal_simple_strtoll(ptr+1, &ptr, 10);
+      if (r1 >= 13) // 4.4.0-13 or later
+        return true;
+    }
     // Otherwise, OK if 4.5+.
     return minor >= 5;
   } else {
diff --git a/libsanitizer/sanitizer_common/sanitizer_list.h b/libsanitizer/sanitizer_common/sanitizer_list.h
index 190c7e67cf0..d7e8b501a6e 100644
--- a/libsanitizer/sanitizer_common/sanitizer_list.h
+++ b/libsanitizer/sanitizer_common/sanitizer_list.h
@@ -68,6 +68,17 @@ struct IntrusiveList {
     size_--;
   }
 
+  void extract(Item *prev, Item *x) {
+    CHECK(!empty());
+    CHECK_NE(prev, nullptr);
+    CHECK_NE(x, nullptr);
+    CHECK_EQ(prev->next, x);
+    prev->next = x->next;
+    if (last_ == x)
+      last_ = prev;
+    size_--;
+  }
+
   Item *front() { return first_; }
   const Item *front() const { return first_; }
   Item *back() { return last_; }
diff --git a/libsanitizer/sanitizer_common/sanitizer_mac.cc b/libsanitizer/sanitizer_common/sanitizer_mac.cc
index 2a05102e968..8c78494e81a 100644
--- a/libsanitizer/sanitizer_common/sanitizer_mac.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_mac.cc
@@ -21,6 +21,7 @@
 #include <stdio.h>
 
 #include "sanitizer_common.h"
+#include "sanitizer_file.h"
 #include "sanitizer_flags.h"
 #include "sanitizer_internal_defs.h"
 #include "sanitizer_libc.h"
@@ -100,12 +101,12 @@ extern "C" int __munmap(void *, size_t) SANITIZER_WEAK_ATTRIBUTE;
 uptr internal_mmap(void *addr, size_t length, int prot, int flags,
                    int fd, u64 offset) {
   if (fd == -1) fd = VM_MAKE_TAG(VM_MEMORY_ANALYSIS_TOOL);
-  if (__mmap) return (uptr)__mmap(addr, length, prot, flags, fd, offset);
+  if (&__mmap) return (uptr)__mmap(addr, length, prot, flags, fd, offset);
   return (uptr)mmap(addr, length, prot, flags, fd, offset);
 }
 
 uptr internal_munmap(void *addr, uptr length) {
-  if (__munmap) return __munmap(addr, length);
+  if (&__munmap) return __munmap(addr, length);
   return munmap(addr, length);
 }
 
@@ -189,14 +190,15 @@ void internal_sigfillset(__sanitizer_sigset_t *set) { sigfillset(set); }
 
 uptr internal_sigprocmask(int how, __sanitizer_sigset_t *set,
                           __sanitizer_sigset_t *oldset) {
-  return sigprocmask(how, set, oldset);
+  // Don't use sigprocmask here, because it affects all threads.
+  return pthread_sigmask(how, set, oldset);
 }
 
 // Doesn't call pthread_atfork() handlers (but not available on 10.6).
 extern "C" pid_t __fork(void) SANITIZER_WEAK_ATTRIBUTE;
 
 int internal_fork() {
-  if (__fork)
+  if (&__fork)
     return __fork();
   return fork();
 }
@@ -250,9 +252,8 @@ bool FileExists(const char *filename) {
   return S_ISREG(st.st_mode);
 }
 
-uptr GetTid() {
-  // FIXME: This can potentially get truncated on 32-bit, where uptr is 4 bytes.
-  uint64_t tid;
+tid_t GetTid() {
+  tid_t tid;
   pthread_threadid_np(nullptr, &tid);
   return tid;
 }
@@ -346,20 +347,16 @@ BlockingMutex::BlockingMutex() {
 void BlockingMutex::Lock() {
   CHECK(sizeof(OSSpinLock) <= sizeof(opaque_storage_));
   CHECK_EQ(OS_SPINLOCK_INIT, 0);
-  CHECK_NE(owner_, (uptr)pthread_self());
+  CHECK_EQ(owner_, 0);
   OSSpinLockLock((OSSpinLock*)&opaque_storage_);
-  CHECK(!owner_);
-  owner_ = (uptr)pthread_self();
 }
 
 void BlockingMutex::Unlock() {
-  CHECK(owner_ == (uptr)pthread_self());
-  owner_ = 0;
   OSSpinLockUnlock((OSSpinLock*)&opaque_storage_);
 }
 
 void BlockingMutex::CheckLocked() {
-  CHECK_EQ((uptr)pthread_self(), owner_);
+  CHECK_NE(*(OSSpinLock*)&opaque_storage_, 0);
 }
 
 u64 NanoTime() {
@@ -373,6 +370,27 @@ uptr GetTlsSize() {
 void InitTlsSize() {
 }
 
+uptr TlsBaseAddr() {
+  uptr segbase = 0;
+#if defined(__x86_64__)
+  asm("movq %%gs:0,%0" : "=r"(segbase));
+#elif defined(__i386__)
+  asm("movl %%gs:0,%0" : "=r"(segbase));
+#endif
+  return segbase;
+}
+
+// The size of the tls on darwin does not appear to be well documented,
+// however the vm memory map suggests that it is 1024 uptrs in size,
+// with a size of 0x2000 bytes on x86_64 and 0x1000 bytes on i386.
+uptr TlsSize() {
+#if defined(__x86_64__) || defined(__i386__)
+  return 1024 * sizeof(uptr);
+#else
+  return 0;
+#endif
+}
+
 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
                           uptr *tls_addr, uptr *tls_size) {
 #if !SANITIZER_GO
@@ -380,8 +398,8 @@ void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
   GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
   *stk_addr = stack_bottom;
   *stk_size = stack_top - stack_bottom;
-  *tls_addr = 0;
-  *tls_size = 0;
+  *tls_addr = TlsBaseAddr();
+  *tls_size = TlsSize();
 #else
   *stk_addr = 0;
   *stk_size = 0;
@@ -391,18 +409,37 @@ void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
 }
 
 void ListOfModules::init() {
-  clear();
+  clearOrInit();
   MemoryMappingLayout memory_mapping(false);
   memory_mapping.DumpListOfModules(&modules_);
 }
 
-bool IsHandledDeadlySignal(int signum) {
+void ListOfModules::fallbackInit() { clear(); }
+
+static HandleSignalMode GetHandleSignalModeImpl(int signum) {
+  switch (signum) {
+    case SIGABRT:
+      return common_flags()->handle_abort;
+    case SIGILL:
+      return common_flags()->handle_sigill;
+    case SIGFPE:
+      return common_flags()->handle_sigfpe;
+    case SIGSEGV:
+      return common_flags()->handle_segv;
+    case SIGBUS:
+      return common_flags()->handle_sigbus;
+  }
+  return kHandleSignalNo;
+}
+
+HandleSignalMode GetHandleSignalMode(int signum) {
+  // Handling fatal signals on watchOS and tvOS devices is disallowed.
   if ((SANITIZER_WATCHOS || SANITIZER_TVOS) && !(SANITIZER_IOSSIM))
-    // Handling fatal signals on watchOS and tvOS devices is disallowed.
-    return false;
-  if (common_flags()->handle_abort && signum == SIGABRT)
-    return true;
-  return (signum == SIGSEGV || signum == SIGBUS) && common_flags()->handle_segv;
+    return kHandleSignalNo;
+  HandleSignalMode result = GetHandleSignalModeImpl(signum);
+  if (result == kHandleSignalYes && !common_flags()->allow_user_segv_handler)
+    return kHandleSignalExclusive;
+  return result;
 }
 
 MacosVersion cached_macos_version = MACOS_VERSION_UNINITIALIZED;
@@ -448,6 +485,15 @@ MacosVersion GetMacosVersion() {
   return result;
 }
 
+bool PlatformHasDifferentMemcpyAndMemmove() {
+  // On OS X 10.7 memcpy() and memmove() are both resolved
+  // into memmove$VARIANT$sse42.
+  // See also https://github.com/google/sanitizers/issues/34.
+  // TODO(glider): need to check dynamically that memcpy() and memmove() are
+  // actually the same function.
+  return GetMacosVersion() == MACOS_VERSION_SNOW_LEOPARD;
+}
+
 uptr GetRSS() {
   struct task_basic_info info;
   unsigned count = TASK_BASIC_INFO_COUNT;
@@ -528,7 +574,7 @@ void LogFullErrorReport(const char *buffer) {
 #endif
 }
 
-SignalContext::WriteFlag SignalContext::GetWriteFlag(void *context) {
+SignalContext::WriteFlag SignalContext::GetWriteFlag() const {
 #if defined(__x86_64__) || defined(__i386__)
   ucontext_t *ucontext = static_cast<ucontext_t*>(context);
   return ucontext->uc_mcontext->__es.__err & 2 /*T_PF_WRITE*/ ? WRITE : READ;
@@ -537,7 +583,7 @@ SignalContext::WriteFlag SignalContext::GetWriteFlag(void *context) {
 #endif
 }
 
-void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
+static void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
   ucontext_t *ucontext = (ucontext_t*)context;
 # if defined(__aarch64__)
   *pc = ucontext->uc_mcontext->__ss.__pc;
@@ -564,6 +610,8 @@ void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) {
 # endif
 }
 
+void SignalContext::InitPcSpBp() { GetPcSpBp(context, &pc, &sp, &bp); }
+
 #if !SANITIZER_GO
 static const char kDyldInsertLibraries[] = "DYLD_INSERT_LIBRARIES";
 LowLevelAllocator allocator_for_env;
@@ -755,9 +803,69 @@ char **GetArgv() {
   return *_NSGetArgv();
 }
 
+#if defined(__aarch64__) && SANITIZER_IOS && !SANITIZER_IOSSIM
+// The task_vm_info struct is normally provided by the macOS SDK, but we need
+// fields only available in 10.12+. Declare the struct manually to be able to
+// build against older SDKs.
+struct __sanitizer_task_vm_info {
+  mach_vm_size_t virtual_size;
+  integer_t region_count;
+  integer_t page_size;
+  mach_vm_size_t resident_size;
+  mach_vm_size_t resident_size_peak;
+  mach_vm_size_t device;
+  mach_vm_size_t device_peak;
+  mach_vm_size_t internal;
+  mach_vm_size_t internal_peak;
+  mach_vm_size_t external;
+  mach_vm_size_t external_peak;
+  mach_vm_size_t reusable;
+  mach_vm_size_t reusable_peak;
+  mach_vm_size_t purgeable_volatile_pmap;
+  mach_vm_size_t purgeable_volatile_resident;
+  mach_vm_size_t purgeable_volatile_virtual;
+  mach_vm_size_t compressed;
+  mach_vm_size_t compressed_peak;
+  mach_vm_size_t compressed_lifetime;
+  mach_vm_size_t phys_footprint;
+  mach_vm_address_t min_address;
+  mach_vm_address_t max_address;
+};
+#define __SANITIZER_TASK_VM_INFO_COUNT ((mach_msg_type_number_t) \
+    (sizeof(__sanitizer_task_vm_info) / sizeof(natural_t)))
+
+uptr GetTaskInfoMaxAddress() {
+  __sanitizer_task_vm_info vm_info = {};
+  mach_msg_type_number_t count = __SANITIZER_TASK_VM_INFO_COUNT;
+  int err = task_info(mach_task_self(), TASK_VM_INFO, (int *)&vm_info, &count);
+  if (err == 0) {
+    return vm_info.max_address - 1;
+  } else {
+    // xnu cannot provide vm address limit
+    return 0x200000000 - 1;
+  }
+}
+#endif
+
+uptr GetMaxVirtualAddress() {
+#if SANITIZER_WORDSIZE == 64
+# if defined(__aarch64__) && SANITIZER_IOS && !SANITIZER_IOSSIM
+  // Get the maximum VM address
+  static uptr max_vm = GetTaskInfoMaxAddress();
+  CHECK(max_vm);
+  return max_vm;
+# else
+  return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
+# endif
+#else  // SANITIZER_WORDSIZE == 32
+  return (1ULL << 32) - 1;  // 0xffffffff;
+#endif  // SANITIZER_WORDSIZE
+}
+
 uptr FindAvailableMemoryRange(uptr shadow_size,
                               uptr alignment,
-                              uptr left_padding) {
+                              uptr left_padding,
+                              uptr *largest_gap_found) {
   typedef vm_region_submap_short_info_data_64_t RegionInfo;
   enum { kRegionInfoSize = VM_REGION_SUBMAP_SHORT_INFO_COUNT_64 };
   // Start searching for available memory region past PAGEZERO, which is
@@ -768,6 +876,7 @@ uptr FindAvailableMemoryRange(uptr shadow_size,
   mach_vm_address_t address = start_address;
   mach_vm_address_t free_begin = start_address;
   kern_return_t kr = KERN_SUCCESS;
+  if (largest_gap_found) *largest_gap_found = 0;
   while (kr == KERN_SUCCESS) {
     mach_vm_size_t vmsize = 0;
     natural_t depth = 0;
@@ -777,10 +886,15 @@ uptr FindAvailableMemoryRange(uptr shadow_size,
                                 (vm_region_info_t)&vminfo, &count);
     if (free_begin != address) {
       // We found a free region [free_begin..address-1].
-      uptr shadow_address = RoundUpTo((uptr)free_begin + left_padding,
-                                      alignment);
-      if (shadow_address + shadow_size < (uptr)address) {
-        return shadow_address;
+      uptr gap_start = RoundUpTo((uptr)free_begin + left_padding, alignment);
+      uptr gap_end = RoundDownTo((uptr)address, alignment);
+      uptr gap_size = gap_end > gap_start ? gap_end - gap_start : 0;
+      if (shadow_size < gap_size) {
+        return gap_start;
+      }
+
+      if (largest_gap_found && *largest_gap_found < gap_size) {
+        *largest_gap_found = gap_size;
       }
     }
     // Move to the next region.
@@ -795,6 +909,95 @@ uptr FindAvailableMemoryRange(uptr shadow_size,
 // FIXME implement on this platform.
 void GetMemoryProfile(fill_profile_f cb, uptr *stats, uptr stats_size) { }
 
+void SignalContext::DumpAllRegisters(void *context) {
+  Report("Register values:\n");
+
+  ucontext_t *ucontext = (ucontext_t*)context;
+# define DUMPREG64(r) \
+    Printf("%s = 0x%016llx  ", #r, ucontext->uc_mcontext->__ss.__ ## r);
+# define DUMPREG32(r) \
+    Printf("%s = 0x%08x  ", #r, ucontext->uc_mcontext->__ss.__ ## r);
+# define DUMPREG_(r)   Printf(" "); DUMPREG(r);
+# define DUMPREG__(r)  Printf("  "); DUMPREG(r);
+# define DUMPREG___(r) Printf("   "); DUMPREG(r);
+
+# if defined(__x86_64__)
+#  define DUMPREG(r) DUMPREG64(r)
+  DUMPREG(rax); DUMPREG(rbx); DUMPREG(rcx); DUMPREG(rdx); Printf("\n");
+  DUMPREG(rdi); DUMPREG(rsi); DUMPREG(rbp); DUMPREG(rsp); Printf("\n");
+  DUMPREG_(r8); DUMPREG_(r9); DUMPREG(r10); DUMPREG(r11); Printf("\n");
+  DUMPREG(r12); DUMPREG(r13); DUMPREG(r14); DUMPREG(r15); Printf("\n");
+# elif defined(__i386__)
+#  define DUMPREG(r) DUMPREG32(r)
+  DUMPREG(eax); DUMPREG(ebx); DUMPREG(ecx); DUMPREG(edx); Printf("\n");
+  DUMPREG(edi); DUMPREG(esi); DUMPREG(ebp); DUMPREG(esp); Printf("\n");
+# elif defined(__aarch64__)
+#  define DUMPREG(r) DUMPREG64(r)
+  DUMPREG_(x[0]); DUMPREG_(x[1]); DUMPREG_(x[2]); DUMPREG_(x[3]); Printf("\n");
+  DUMPREG_(x[4]); DUMPREG_(x[5]); DUMPREG_(x[6]); DUMPREG_(x[7]); Printf("\n");
+  DUMPREG_(x[8]); DUMPREG_(x[9]); DUMPREG(x[10]); DUMPREG(x[11]); Printf("\n");
+  DUMPREG(x[12]); DUMPREG(x[13]); DUMPREG(x[14]); DUMPREG(x[15]); Printf("\n");
+  DUMPREG(x[16]); DUMPREG(x[17]); DUMPREG(x[18]); DUMPREG(x[19]); Printf("\n");
+  DUMPREG(x[20]); DUMPREG(x[21]); DUMPREG(x[22]); DUMPREG(x[23]); Printf("\n");
+  DUMPREG(x[24]); DUMPREG(x[25]); DUMPREG(x[26]); DUMPREG(x[27]); Printf("\n");
+  DUMPREG(x[28]); DUMPREG___(fp); DUMPREG___(lr); DUMPREG___(sp); Printf("\n");
+# elif defined(__arm__)
+#  define DUMPREG(r) DUMPREG32(r)
+  DUMPREG_(r[0]); DUMPREG_(r[1]); DUMPREG_(r[2]); DUMPREG_(r[3]); Printf("\n");
+  DUMPREG_(r[4]); DUMPREG_(r[5]); DUMPREG_(r[6]); DUMPREG_(r[7]); Printf("\n");
+  DUMPREG_(r[8]); DUMPREG_(r[9]); DUMPREG(r[10]); DUMPREG(r[11]); Printf("\n");
+  DUMPREG(r[12]); DUMPREG___(sp); DUMPREG___(lr); DUMPREG___(pc); Printf("\n");
+# else
+# error "Unknown architecture"
+# endif
+
+# undef DUMPREG64
+# undef DUMPREG32
+# undef DUMPREG_
+# undef DUMPREG__
+# undef DUMPREG___
+# undef DUMPREG
+}
+
+static inline bool CompareBaseAddress(const LoadedModule &a,
+                                      const LoadedModule &b) {
+  return a.base_address() < b.base_address();
+}
+
+void FormatUUID(char *out, uptr size, const u8 *uuid) {
+  internal_snprintf(out, size,
+                    "<%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-"
+                    "%02X%02X%02X%02X%02X%02X>",
+                    uuid[0], uuid[1], uuid[2], uuid[3], uuid[4], uuid[5],
+                    uuid[6], uuid[7], uuid[8], uuid[9], uuid[10], uuid[11],
+                    uuid[12], uuid[13], uuid[14], uuid[15]);
+}
+
+void PrintModuleMap() {
+  Printf("Process module map:\n");
+  MemoryMappingLayout memory_mapping(false);
+  InternalMmapVector<LoadedModule> modules(/*initial_capacity*/ 128);
+  memory_mapping.DumpListOfModules(&modules);
+  InternalSort(&modules, modules.size(), CompareBaseAddress);
+  for (uptr i = 0; i < modules.size(); ++i) {
+    char uuid_str[128];
+    FormatUUID(uuid_str, sizeof(uuid_str), modules[i].uuid());
+    Printf("0x%zx-0x%zx %s (%s) %s\n", modules[i].base_address(),
+           modules[i].max_executable_address(), modules[i].full_name(),
+           ModuleArchToString(modules[i].arch()), uuid_str);
+  }
+  Printf("End of module map.\n");
+}
+
+void CheckNoDeepBind(const char *filename, int flag) {
+  // Do nothing.
+}
+
+// FIXME: implement on this platform.
+bool GetRandom(void *buffer, uptr length, bool blocking) {
+  UNIMPLEMENTED();
+}
+
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_MAC
diff --git a/libsanitizer/sanitizer_common/sanitizer_mac.h b/libsanitizer/sanitizer_common/sanitizer_mac.h
index 4bea069189f..4881b62ff57 100644
--- a/libsanitizer/sanitizer_common/sanitizer_mac.h
+++ b/libsanitizer/sanitizer_common/sanitizer_mac.h
@@ -18,6 +18,17 @@
 
 namespace __sanitizer {
 
+struct MemoryMappingLayoutData {
+  int current_image;
+  u32 current_magic;
+  u32 current_filetype;
+  ModuleArch current_arch;
+  u8 current_uuid[kModuleUUIDSize];
+  int current_load_cmd_count;
+  char *current_load_cmd_addr;
+  bool current_instrumented;
+};
+
 enum MacosVersion {
   MACOS_VERSION_UNINITIALIZED = 0,
   MACOS_VERSION_UNKNOWN,
@@ -34,6 +45,8 @@ MacosVersion GetMacosVersion();
 
 char **GetEnviron();
 
+void RestrictMemoryToMaxAddress(uptr max_address);
+
 }  // namespace __sanitizer
 
 extern "C" {
diff --git a/libsanitizer/sanitizer_common/sanitizer_mac_libcdep.cc b/libsanitizer/sanitizer_common/sanitizer_mac_libcdep.cc
new file mode 100644
index 00000000000..b376a0710b9
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_mac_libcdep.cc
@@ -0,0 +1,28 @@
+//===-- sanitizer_mac_libcdep.cc ------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is shared between various sanitizers' runtime libraries and
+// implements OSX-specific functions.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+#if SANITIZER_MAC
+#include "sanitizer_mac.h"
+
+#include <sys/mman.h>
+
+namespace __sanitizer {
+
+void RestrictMemoryToMaxAddress(uptr max_address) {
+  uptr size_to_mmap = GetMaxVirtualAddress() + 1 - max_address;
+  void *res = MmapFixedNoAccess(max_address, size_to_mmap, "high gap");
+  CHECK(res != MAP_FAILED);
+}
+
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_MAC
diff --git a/libsanitizer/sanitizer_common/sanitizer_malloc_mac.inc b/libsanitizer/sanitizer_common/sanitizer_malloc_mac.inc
index 93fb19e922c..2ca4e061464 100644
--- a/libsanitizer/sanitizer_common/sanitizer_malloc_mac.inc
+++ b/libsanitizer/sanitizer_common/sanitizer_malloc_mac.inc
@@ -44,9 +44,48 @@ INTERCEPTOR(malloc_zone_t *, malloc_create_zone,
     // This matches the behavior of malloc_create_zone() on OSX 10.7 and higher.
     mprotect(new_zone, allocated_size, PROT_READ);
   }
+  // We're explicitly *NOT* registering the zone.
   return new_zone;
 }
 
+INTERCEPTOR(void, malloc_destroy_zone, malloc_zone_t *zone) {
+  COMMON_MALLOC_ENTER();
+  // We don't need to do anything here.  We're not registering new zones, so we
+  // don't to unregister.  Just un-mprotect and free() the zone.
+  if (GetMacosVersion() >= MACOS_VERSION_LION) {
+    uptr page_size = GetPageSizeCached();
+    uptr allocated_size = RoundUpTo(sizeof(sanitizer_zone), page_size);
+    mprotect(zone, allocated_size, PROT_READ | PROT_WRITE);
+  }
+  if (zone->zone_name) {
+    COMMON_MALLOC_FREE((void *)zone->zone_name);
+  }
+  COMMON_MALLOC_FREE(zone);
+}
+
+extern unsigned malloc_num_zones;
+extern malloc_zone_t **malloc_zones;
+
+// We need to make sure that sanitizer_zone is registered as malloc_zones[0]. If
+// libmalloc tries to set up a different zone as malloc_zones[0], it will call
+// mprotect(malloc_zones, ..., PROT_READ).  This interceptor will catch that and
+// make sure we are still the first (default) zone.
+INTERCEPTOR(int, mprotect, void *addr, size_t len, int prot) {
+  if (addr == malloc_zones && prot == PROT_READ) {
+    if (malloc_num_zones > 1 && malloc_zones[0] != &sanitizer_zone) {
+      for (unsigned i = 1; i < malloc_num_zones; i++) {
+        if (malloc_zones[i] == &sanitizer_zone) {
+          // Swap malloc_zones[0] and malloc_zones[i].
+          malloc_zones[i] = malloc_zones[0];
+          malloc_zones[0] = &sanitizer_zone;
+          break;
+        }
+      }
+    }
+  }
+  return REAL(mprotect)(addr, len, prot);
+}
+
 INTERCEPTOR(malloc_zone_t *, malloc_default_zone, void) {
   COMMON_MALLOC_ENTER();
   return &sanitizer_zone;
diff --git a/libsanitizer/sanitizer_common/sanitizer_mutex.h b/libsanitizer/sanitizer_common/sanitizer_mutex.h
index 75f495a4d65..1ec409def41 100644
--- a/libsanitizer/sanitizer_common/sanitizer_mutex.h
+++ b/libsanitizer/sanitizer_common/sanitizer_mutex.h
@@ -81,6 +81,14 @@ class BlockingMutex {
   BlockingMutex();
   void Lock();
   void Unlock();
+
+  // This function does not guarantee an explicit check that the calling thread
+  // is the thread which owns the mutex. This behavior, while more strictly
+  // correct, causes problems in cases like StopTheWorld, where a parent thread
+  // owns the mutex but a child checks that it is locked. Rather than
+  // maintaining complex state to work around those situations, the check only
+  // checks that the mutex is owned, and assumes callers to be generally
+  // well-behaved.
   void CheckLocked();
  private:
   uptr opaque_storage_[10];
diff --git a/libsanitizer/sanitizer_common/sanitizer_platform.h b/libsanitizer/sanitizer_common/sanitizer_platform.h
index 428709d55ec..1eb4d0c61c6 100644
--- a/libsanitizer/sanitizer_common/sanitizer_platform.h
+++ b/libsanitizer/sanitizer_common/sanitizer_platform.h
@@ -11,8 +11,8 @@
 #ifndef SANITIZER_PLATFORM_H
 #define SANITIZER_PLATFORM_H
 
-#if !defined(__linux__) && !defined(__FreeBSD__) && \
-  !defined(__APPLE__) && !defined(_WIN32)
+#if !defined(__linux__) && !defined(__FreeBSD__) && !defined(__NetBSD__) && \
+  !defined(__APPLE__) && !defined(_WIN32) && !defined(__Fuchsia__)
 # error "This operating system is not supported"
 #endif
 
@@ -28,6 +28,12 @@
 # define SANITIZER_FREEBSD 0
 #endif
 
+#if defined(__NetBSD__)
+# define SANITIZER_NETBSD 1
+#else
+# define SANITIZER_NETBSD 0
+#endif
+
 #if defined(__APPLE__)
 # define SANITIZER_MAC     1
 # include <TargetConditionals.h>
@@ -77,7 +83,14 @@
 # define SANITIZER_ANDROID 0
 #endif
 
-#define SANITIZER_POSIX (SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_MAC)
+#if defined(__Fuchsia__)
+# define SANITIZER_FUCHSIA 1
+#else
+# define SANITIZER_FUCHSIA 0
+#endif
+
+#define SANITIZER_POSIX \
+  (SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_MAC || SANITIZER_NETBSD)
 
 #if __LP64__ || defined(_WIN64)
 #  define SANITIZER_WORDSIZE 64
@@ -160,13 +173,19 @@
 # define SANITIZER_PPC64V2 0
 #endif
 
+#if defined(__arm__)
+# define SANITIZER_ARM 1
+#else
+# define SANITIZER_ARM 0
+#endif
+
 // By default we allow to use SizeClassAllocator64 on 64-bit platform.
 // But in some cases (e.g. AArch64's 39-bit address space) SizeClassAllocator64
 // does not work well and we need to fallback to SizeClassAllocator32.
 // For such platforms build this code with -DSANITIZER_CAN_USE_ALLOCATOR64=0 or
 // change the definition of SANITIZER_CAN_USE_ALLOCATOR64 here.
 #ifndef SANITIZER_CAN_USE_ALLOCATOR64
-# if SANITIZER_ANDROID && defined(__aarch64__)
+# if (SANITIZER_ANDROID && defined(__aarch64__)) || SANITIZER_FUCHSIA
 #  define SANITIZER_CAN_USE_ALLOCATOR64 1
 # elif defined(__mips64) || defined(__aarch64__)
 #  define SANITIZER_CAN_USE_ALLOCATOR64 0
@@ -251,4 +270,15 @@
 # define SANITIZER_GO 0
 #endif
 
+// On PowerPC and ARM Thumb, calling pthread_exit() causes LSan to detect leaks.
+// pthread_exit() performs unwinding that leads to dlopen'ing libgcc_s.so.
+// dlopen mallocs "libgcc_s.so" string which confuses LSan, it fails to realize
+// that this allocation happens in dynamic linker and should be ignored.
+#if SANITIZER_PPC || defined(__thumb__)
+# define SANITIZER_SUPPRESS_LEAK_ON_PTHREAD_EXIT 1
+#else
+# define SANITIZER_SUPPRESS_LEAK_ON_PTHREAD_EXIT 0
+#endif
+
+
 #endif // SANITIZER_PLATFORM_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_platform_interceptors.h b/libsanitizer/sanitizer_common/sanitizer_platform_interceptors.h
index 6b2ba31a2bf..b9eb09ad3bd 100644
--- a/libsanitizer/sanitizer_common/sanitizer_platform_interceptors.h
+++ b/libsanitizer/sanitizer_common/sanitizer_platform_interceptors.h
@@ -14,11 +14,25 @@
 
 #include "sanitizer_internal_defs.h"
 
+#if SANITIZER_POSIX
+# define SI_POSIX 1
+#else
+# define SI_POSIX 0
+#endif
+
 #if !SANITIZER_WINDOWS
-# define SI_NOT_WINDOWS 1
-# include "sanitizer_platform_limits_posix.h"
+# define SI_WINDOWS 0
 #else
-# define SI_NOT_WINDOWS 0
+# define SI_WINDOWS 1
+#endif
+
+#if (SI_POSIX != 0) == (SI_WINDOWS != 0) && !SANITIZER_FUCHSIA
+# error "Windows is not POSIX!"
+#endif
+
+#if SI_POSIX
+# include "sanitizer_platform_limits_netbsd.h"
+# include "sanitizer_platform_limits_posix.h"
 #endif
 
 #if SANITIZER_LINUX && !SANITIZER_ANDROID
@@ -39,6 +53,12 @@
 # define SI_FREEBSD 0
 #endif
 
+#if SANITIZER_NETBSD
+# define SI_NETBSD 1
+#else
+# define SI_NETBSD 0
+#endif
+
 #if SANITIZER_LINUX
 # define SI_LINUX 1
 #else
@@ -59,28 +79,43 @@
 # define SI_IOS 0
 #endif
 
-#if !SANITIZER_WINDOWS && !SANITIZER_MAC
-# define SI_UNIX_NOT_MAC 1
+#if SANITIZER_FUCHSIA
+# define SI_NOT_FUCHSIA 0
+#else
+# define SI_NOT_FUCHSIA 1
+#endif
+
+#if SANITIZER_POSIX && !SANITIZER_MAC
+# define SI_POSIX_NOT_MAC 1
 #else
-# define SI_UNIX_NOT_MAC 0
+# define SI_POSIX_NOT_MAC 0
+#endif
+
+#if SANITIZER_LINUX && !SANITIZER_FREEBSD
+# define SI_LINUX_NOT_FREEBSD 1
+# else
+# define SI_LINUX_NOT_FREEBSD 0
 #endif
 
-#define SANITIZER_INTERCEPT_STRLEN 1
-#define SANITIZER_INTERCEPT_STRNLEN SI_NOT_MAC
-#define SANITIZER_INTERCEPT_STRCMP 1
-#define SANITIZER_INTERCEPT_STRSTR 1
-#define SANITIZER_INTERCEPT_STRCASESTR SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_STRCHR 1
-#define SANITIZER_INTERCEPT_STRCHRNUL SI_UNIX_NOT_MAC
-#define SANITIZER_INTERCEPT_STRRCHR 1
-#define SANITIZER_INTERCEPT_STRSPN 1
-#define SANITIZER_INTERCEPT_STRPBRK 1
+#define SANITIZER_INTERCEPT_STRLEN SI_NOT_FUCHSIA
+#define SANITIZER_INTERCEPT_STRNLEN (SI_NOT_MAC && SI_NOT_FUCHSIA)
+#define SANITIZER_INTERCEPT_STRCMP SI_NOT_FUCHSIA
+#define SANITIZER_INTERCEPT_STRSTR SI_NOT_FUCHSIA
+#define SANITIZER_INTERCEPT_STRCASESTR SI_POSIX
+#define SANITIZER_INTERCEPT_STRTOK SI_NOT_FUCHSIA
+#define SANITIZER_INTERCEPT_STRCHR SI_NOT_FUCHSIA
+#define SANITIZER_INTERCEPT_STRCHRNUL SI_POSIX_NOT_MAC
+#define SANITIZER_INTERCEPT_STRRCHR SI_NOT_FUCHSIA
+#define SANITIZER_INTERCEPT_STRSPN SI_NOT_FUCHSIA
+#define SANITIZER_INTERCEPT_STRPBRK SI_NOT_FUCHSIA
 #define SANITIZER_INTERCEPT_TEXTDOMAIN SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_STRCASECMP SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_STRCASECMP SI_POSIX
 #define SANITIZER_INTERCEPT_MEMSET 1
 #define SANITIZER_INTERCEPT_MEMMOVE 1
 #define SANITIZER_INTERCEPT_MEMCPY 1
-#define SANITIZER_INTERCEPT_MEMCMP 1
+#define SANITIZER_INTERCEPT_MEMCMP SI_NOT_FUCHSIA
+#define SANITIZER_INTERCEPT_STRNDUP SI_POSIX
+#define SANITIZER_INTERCEPT___STRNDUP SI_LINUX_NOT_FREEBSD
 #if defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && \
     __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1070
 # define SI_MAC_DEPLOYMENT_BELOW_10_7 1
@@ -89,78 +124,83 @@
 #endif
 // memmem on Darwin doesn't exist on 10.6
 // FIXME: enable memmem on Windows.
-#define SANITIZER_INTERCEPT_MEMMEM \
-  SI_NOT_WINDOWS && !SI_MAC_DEPLOYMENT_BELOW_10_7
-#define SANITIZER_INTERCEPT_MEMCHR 1
-#define SANITIZER_INTERCEPT_MEMRCHR SI_FREEBSD || SI_LINUX
+#define SANITIZER_INTERCEPT_MEMMEM (SI_POSIX && !SI_MAC_DEPLOYMENT_BELOW_10_7)
+#define SANITIZER_INTERCEPT_MEMCHR SI_NOT_FUCHSIA
+#define SANITIZER_INTERCEPT_MEMRCHR (SI_FREEBSD || SI_LINUX || SI_NETBSD)
 
-#define SANITIZER_INTERCEPT_READ   SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_PREAD  SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_WRITE  SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_PWRITE SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_READ SI_POSIX
+#define SANITIZER_INTERCEPT_PREAD SI_POSIX
+#define SANITIZER_INTERCEPT_WRITE SI_POSIX
+#define SANITIZER_INTERCEPT_PWRITE SI_POSIX
+
+#define SANITIZER_INTERCEPT_FREAD SI_POSIX
+#define SANITIZER_INTERCEPT_FWRITE SI_POSIX
 
 #define SANITIZER_INTERCEPT_PREAD64 SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_PWRITE64 SI_LINUX_NOT_ANDROID
 
-#define SANITIZER_INTERCEPT_READV SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_WRITEV SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_READV SI_POSIX
+#define SANITIZER_INTERCEPT_WRITEV SI_POSIX
 
-#define SANITIZER_INTERCEPT_PREADV SI_FREEBSD || SI_LINUX_NOT_ANDROID
+#define SANITIZER_INTERCEPT_PREADV \
+  (SI_FREEBSD || SI_NETBSD || SI_LINUX_NOT_ANDROID)
 #define SANITIZER_INTERCEPT_PWRITEV SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_PREADV64 SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_PWRITEV64 SI_LINUX_NOT_ANDROID
 
 #define SANITIZER_INTERCEPT_PRCTL   SI_LINUX
 
-#define SANITIZER_INTERCEPT_LOCALTIME_AND_FRIENDS SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_STRPTIME SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_LOCALTIME_AND_FRIENDS SI_POSIX
+#define SANITIZER_INTERCEPT_STRPTIME SI_POSIX
 
-#define SANITIZER_INTERCEPT_SCANF SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_SCANF SI_POSIX
 #define SANITIZER_INTERCEPT_ISOC99_SCANF SI_LINUX_NOT_ANDROID
 
 #ifndef SANITIZER_INTERCEPT_PRINTF
-# define SANITIZER_INTERCEPT_PRINTF SI_NOT_WINDOWS
-# define SANITIZER_INTERCEPT_PRINTF_L SI_FREEBSD
+# define SANITIZER_INTERCEPT_PRINTF SI_POSIX
+# define SANITIZER_INTERCEPT_PRINTF_L (SI_FREEBSD || SI_NETBSD)
 # define SANITIZER_INTERCEPT_ISOC99_PRINTF SI_LINUX_NOT_ANDROID
 #endif
 
-#define SANITIZER_INTERCEPT_FREXP 1
-#define SANITIZER_INTERCEPT_FREXPF_FREXPL SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_FREXP SI_NOT_FUCHSIA
+#define SANITIZER_INTERCEPT_FREXPF_FREXPL SI_POSIX
 
-#define SANITIZER_INTERCEPT_GETPWNAM_AND_FRIENDS SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_GETPWNAM_AND_FRIENDS SI_POSIX
 #define SANITIZER_INTERCEPT_GETPWNAM_R_AND_FRIENDS \
-  SI_FREEBSD || SI_MAC || SI_LINUX_NOT_ANDROID
+  (SI_FREEBSD || SI_NETBSD || SI_MAC || SI_LINUX_NOT_ANDROID)
 #define SANITIZER_INTERCEPT_GETPWENT \
-  SI_FREEBSD || SI_MAC || SI_LINUX_NOT_ANDROID
+  (SI_FREEBSD || SI_NETBSD || SI_MAC || SI_LINUX_NOT_ANDROID)
 #define SANITIZER_INTERCEPT_FGETPWENT SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_GETPWENT_R SI_FREEBSD || SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_SETPWENT SI_MAC || SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_CLOCK_GETTIME SI_FREEBSD || SI_LINUX
-#define SANITIZER_INTERCEPT_GETITIMER SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_TIME SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_GETPWENT_R \
+  (SI_FREEBSD || SI_NETBSD || SI_LINUX_NOT_ANDROID)
+#define SANITIZER_INTERCEPT_SETPWENT (SI_MAC || SI_LINUX_NOT_ANDROID)
+#define SANITIZER_INTERCEPT_CLOCK_GETTIME (SI_FREEBSD || SI_NETBSD || SI_LINUX)
+#define SANITIZER_INTERCEPT_GETITIMER SI_POSIX
+#define SANITIZER_INTERCEPT_TIME SI_POSIX
 #define SANITIZER_INTERCEPT_GLOB SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_WAIT SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_INET SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_PTHREAD_GETSCHEDPARAM SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_GETADDRINFO SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_GETNAMEINFO SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_GETSOCKNAME SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_GETHOSTBYNAME SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_GETHOSTBYNAME_R SI_FREEBSD || SI_LINUX
-#define SANITIZER_INTERCEPT_GETHOSTBYNAME2_R SI_FREEBSD || SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_GETHOSTBYADDR_R SI_FREEBSD || SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_GETHOSTENT_R SI_FREEBSD || SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_GETSOCKOPT SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_ACCEPT SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_WAIT SI_POSIX
+#define SANITIZER_INTERCEPT_INET SI_POSIX
+#define SANITIZER_INTERCEPT_PTHREAD_GETSCHEDPARAM SI_POSIX
+#define SANITIZER_INTERCEPT_GETADDRINFO SI_POSIX
+#define SANITIZER_INTERCEPT_GETNAMEINFO SI_POSIX
+#define SANITIZER_INTERCEPT_GETSOCKNAME SI_POSIX
+#define SANITIZER_INTERCEPT_GETHOSTBYNAME SI_POSIX
+#define SANITIZER_INTERCEPT_GETHOSTBYNAME_R (SI_FREEBSD || SI_LINUX)
+#define SANITIZER_INTERCEPT_GETHOSTBYNAME2_R \
+  (SI_FREEBSD || SI_LINUX_NOT_ANDROID)
+#define SANITIZER_INTERCEPT_GETHOSTBYADDR_R (SI_FREEBSD || SI_LINUX_NOT_ANDROID)
+#define SANITIZER_INTERCEPT_GETHOSTENT_R (SI_FREEBSD || SI_LINUX_NOT_ANDROID)
+#define SANITIZER_INTERCEPT_GETSOCKOPT SI_POSIX
+#define SANITIZER_INTERCEPT_ACCEPT SI_POSIX
 #define SANITIZER_INTERCEPT_ACCEPT4 SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_MODF SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_RECVMSG SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_SENDMSG SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_GETPEERNAME SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_IOCTL SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_INET_ATON SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_MODF SI_POSIX
+#define SANITIZER_INTERCEPT_RECVMSG SI_POSIX
+#define SANITIZER_INTERCEPT_SENDMSG SI_POSIX
+#define SANITIZER_INTERCEPT_GETPEERNAME SI_POSIX
+#define SANITIZER_INTERCEPT_IOCTL SI_POSIX
+#define SANITIZER_INTERCEPT_INET_ATON SI_POSIX
 #define SANITIZER_INTERCEPT_SYSINFO SI_LINUX
-#define SANITIZER_INTERCEPT_READDIR SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_READDIR SI_POSIX
 #define SANITIZER_INTERCEPT_READDIR64 SI_LINUX_NOT_ANDROID
 #if SI_LINUX_NOT_ANDROID && \
   (defined(__i386) || defined(__x86_64) || defined(__mips64) || \
@@ -170,109 +210,116 @@
 #else
 #define SANITIZER_INTERCEPT_PTRACE 0
 #endif
-#define SANITIZER_INTERCEPT_SETLOCALE SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_GETCWD SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_SETLOCALE SI_POSIX
+#define SANITIZER_INTERCEPT_GETCWD SI_POSIX
 #define SANITIZER_INTERCEPT_GET_CURRENT_DIR_NAME SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_STRTOIMAX SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_MBSTOWCS SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_MBSNRTOWCS SI_MAC || SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_WCSTOMBS SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_STRTOIMAX SI_POSIX
+#define SANITIZER_INTERCEPT_MBSTOWCS SI_POSIX
+#define SANITIZER_INTERCEPT_MBSNRTOWCS (SI_MAC || SI_LINUX_NOT_ANDROID)
+#define SANITIZER_INTERCEPT_WCSTOMBS SI_POSIX
 #define SANITIZER_INTERCEPT_WCSNRTOMBS \
-  SI_FREEBSD || SI_MAC || SI_LINUX_NOT_ANDROID
+  (SI_FREEBSD || SI_NETBSD || SI_MAC || SI_LINUX_NOT_ANDROID)
 #define SANITIZER_INTERCEPT_WCRTOMB \
-  SI_FREEBSD || SI_MAC || SI_LINUX_NOT_ANDROID
+  (SI_FREEBSD || SI_NETBSD || SI_MAC || SI_LINUX_NOT_ANDROID)
 #define SANITIZER_INTERCEPT_TCGETATTR SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_REALPATH SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_REALPATH SI_POSIX
 #define SANITIZER_INTERCEPT_CANONICALIZE_FILE_NAME SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_CONFSTR \
-  SI_FREEBSD || SI_MAC || SI_LINUX_NOT_ANDROID
+  (SI_FREEBSD || SI_NETBSD || SI_MAC || SI_LINUX_NOT_ANDROID)
 #define SANITIZER_INTERCEPT_SCHED_GETAFFINITY SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_SCHED_GETPARAM SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_STRERROR SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_STRERROR_R SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_STRERROR SI_POSIX
+#define SANITIZER_INTERCEPT_STRERROR_R SI_POSIX
 #define SANITIZER_INTERCEPT_XPG_STRERROR_R SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_SCANDIR \
-  SI_FREEBSD || SI_LINUX_NOT_ANDROID
+  (SI_FREEBSD || SI_NETBSD || SI_LINUX_NOT_ANDROID)
 #define SANITIZER_INTERCEPT_SCANDIR64 SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_GETGROUPS SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_POLL SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_GETGROUPS SI_POSIX
+#define SANITIZER_INTERCEPT_POLL SI_POSIX
 #define SANITIZER_INTERCEPT_PPOLL SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_WORDEXP \
-  SI_FREEBSD || (SI_MAC && !SI_IOS) || SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_SIGWAIT SI_NOT_WINDOWS
+  (SI_FREEBSD || SI_NETBSD || (SI_MAC && !SI_IOS) || SI_LINUX_NOT_ANDROID)
+#define SANITIZER_INTERCEPT_SIGWAIT SI_POSIX
 #define SANITIZER_INTERCEPT_SIGWAITINFO SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_SIGTIMEDWAIT SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_SIGSETOPS \
-  SI_FREEBSD || SI_MAC || SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_SIGPENDING SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_SIGPROCMASK SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_BACKTRACE SI_FREEBSD || SI_LINUX_NOT_ANDROID
+  (SI_FREEBSD || SI_NETBSD || SI_MAC || SI_LINUX_NOT_ANDROID)
+#define SANITIZER_INTERCEPT_SIGPENDING SI_POSIX
+#define SANITIZER_INTERCEPT_SIGPROCMASK SI_POSIX
+#define SANITIZER_INTERCEPT_BACKTRACE \
+  (SI_FREEBSD || SI_NETBSD || SI_LINUX_NOT_ANDROID)
 #define SANITIZER_INTERCEPT_GETMNTENT SI_LINUX
 #define SANITIZER_INTERCEPT_GETMNTENT_R SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_STATFS SI_FREEBSD || SI_MAC || SI_LINUX_NOT_ANDROID
+#define SANITIZER_INTERCEPT_STATFS \
+  (SI_FREEBSD || SI_MAC || SI_LINUX_NOT_ANDROID)
 #define SANITIZER_INTERCEPT_STATFS64 \
-  (SI_MAC && !SI_IOS) || SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_STATVFS SI_FREEBSD || SI_LINUX_NOT_ANDROID
+  ((SI_MAC && !SI_IOS) || SI_LINUX_NOT_ANDROID)
+#define SANITIZER_INTERCEPT_STATVFS \
+  (SI_FREEBSD || SI_NETBSD || SI_LINUX_NOT_ANDROID)
 #define SANITIZER_INTERCEPT_STATVFS64 SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_INITGROUPS SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_ETHER_NTOA_ATON SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_INITGROUPS SI_POSIX
+#define SANITIZER_INTERCEPT_ETHER_NTOA_ATON SI_POSIX
 #define SANITIZER_INTERCEPT_ETHER_HOST \
-  SI_FREEBSD || SI_MAC || SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_ETHER_R SI_FREEBSD || SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_SHMCTL \
-  ((SI_FREEBSD || SI_LINUX_NOT_ANDROID) && SANITIZER_WORDSIZE == 64)
+  (SI_FREEBSD || SI_MAC || SI_LINUX_NOT_ANDROID)
+#define SANITIZER_INTERCEPT_ETHER_R (SI_FREEBSD || SI_LINUX_NOT_ANDROID)
+#define SANITIZER_INTERCEPT_SHMCTL                       \
+  (SI_NETBSD || ((SI_FREEBSD || SI_LINUX_NOT_ANDROID) && \
+                 SANITIZER_WORDSIZE == 64))  // NOLINT
 #define SANITIZER_INTERCEPT_RANDOM_R SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_PTHREAD_ATTR_GET SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_PTHREAD_ATTR_GET SI_POSIX
 #define SANITIZER_INTERCEPT_PTHREAD_ATTR_GETINHERITSCHED \
-  SI_FREEBSD || SI_MAC || SI_LINUX_NOT_ANDROID
+  (SI_FREEBSD || SI_NETBSD || SI_MAC || SI_LINUX_NOT_ANDROID)
 #define SANITIZER_INTERCEPT_PTHREAD_ATTR_GETAFFINITY_NP SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_PTHREAD_MUTEXATTR_GETPSHARED SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_PTHREAD_MUTEXATTR_GETTYPE SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_PTHREAD_MUTEXATTR_GETPSHARED SI_POSIX
+#define SANITIZER_INTERCEPT_PTHREAD_MUTEXATTR_GETTYPE SI_POSIX
 #define SANITIZER_INTERCEPT_PTHREAD_MUTEXATTR_GETPROTOCOL \
-  SI_MAC || SI_LINUX_NOT_ANDROID
+  (SI_MAC || SI_NETBSD || SI_LINUX_NOT_ANDROID)
 #define SANITIZER_INTERCEPT_PTHREAD_MUTEXATTR_GETPRIOCEILING \
-  SI_MAC || SI_LINUX_NOT_ANDROID
+  (SI_MAC || SI_NETBSD || SI_LINUX_NOT_ANDROID)
 #define SANITIZER_INTERCEPT_PTHREAD_MUTEXATTR_GETROBUST SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_PTHREAD_MUTEXATTR_GETROBUST_NP SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_PTHREAD_RWLOCKATTR_GETPSHARED SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_PTHREAD_RWLOCKATTR_GETPSHARED SI_POSIX
 #define SANITIZER_INTERCEPT_PTHREAD_RWLOCKATTR_GETKIND_NP SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_PTHREAD_CONDATTR_GETPSHARED SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_PTHREAD_CONDATTR_GETPSHARED SI_POSIX
 #define SANITIZER_INTERCEPT_PTHREAD_CONDATTR_GETCLOCK SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_PTHREAD_BARRIERATTR_GETPSHARED SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_TMPNAM SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_TMPNAM SI_POSIX
 #define SANITIZER_INTERCEPT_TMPNAM_R SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_TTYNAME_R SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_TEMPNAM SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_TTYNAME_R SI_POSIX
+#define SANITIZER_INTERCEPT_TEMPNAM SI_POSIX
 #define SANITIZER_INTERCEPT_SINCOS SI_LINUX
-#define SANITIZER_INTERCEPT_REMQUO SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_LGAMMA SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_LGAMMA_R SI_FREEBSD || SI_LINUX
+#define SANITIZER_INTERCEPT_REMQUO SI_POSIX
+#define SANITIZER_INTERCEPT_LGAMMA SI_POSIX
+#define SANITIZER_INTERCEPT_LGAMMA_R (SI_FREEBSD || SI_LINUX)
 #define SANITIZER_INTERCEPT_LGAMMAL_R SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_DRAND48_R SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_RAND_R \
-  SI_FREEBSD || SI_MAC || SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_ICONV SI_FREEBSD || SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_TIMES SI_NOT_WINDOWS
+  (SI_FREEBSD || SI_NETBSD || SI_MAC || SI_LINUX_NOT_ANDROID)
+#define SANITIZER_INTERCEPT_ICONV \
+  (SI_FREEBSD || SI_NETBSD || SI_LINUX_NOT_ANDROID)
+#define SANITIZER_INTERCEPT_TIMES SI_POSIX
 
 // FIXME: getline seems to be available on OSX 10.7
-#define SANITIZER_INTERCEPT_GETLINE SI_FREEBSD || SI_LINUX_NOT_ANDROID
+#define SANITIZER_INTERCEPT_GETLINE \
+  (SI_FREEBSD || SI_NETBSD || SI_LINUX_NOT_ANDROID)
 
-#define SANITIZER_INTERCEPT__EXIT SI_LINUX || SI_FREEBSD || SI_MAC
+#define SANITIZER_INTERCEPT__EXIT \
+  (SI_LINUX || SI_FREEBSD || SI_NETBSD || SI_MAC)
 
-#define SANITIZER_INTERCEPT_PHTREAD_MUTEX SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_PHTREAD_MUTEX SI_POSIX
 #define SANITIZER_INTERCEPT_PTHREAD_SETNAME_NP \
-  SI_FREEBSD || SI_LINUX_NOT_ANDROID
+  (SI_FREEBSD || SI_NETBSD || SI_LINUX_NOT_ANDROID)
 
 #define SANITIZER_INTERCEPT_TLS_GET_ADDR \
-  SI_FREEBSD || SI_LINUX_NOT_ANDROID
+  (SI_FREEBSD || SI_NETBSD || SI_LINUX_NOT_ANDROID)
 
 #define SANITIZER_INTERCEPT_LISTXATTR SI_LINUX
 #define SANITIZER_INTERCEPT_GETXATTR SI_LINUX
 #define SANITIZER_INTERCEPT_GETRESID SI_LINUX
 #define SANITIZER_INTERCEPT_GETIFADDRS \
-  SI_FREEBSD || SI_LINUX_NOT_ANDROID || SI_MAC
+  (SI_FREEBSD || SI_NETBSD || SI_LINUX_NOT_ANDROID || SI_MAC)
 #define SANITIZER_INTERCEPT_IF_INDEXTONAME \
-  SI_FREEBSD || SI_LINUX_NOT_ANDROID || SI_MAC
+  (SI_FREEBSD || SI_NETBSD || SI_LINUX_NOT_ANDROID || SI_MAC)
 #define SANITIZER_INTERCEPT_CAPGET SI_LINUX_NOT_ANDROID
 #if SI_LINUX && defined(__arm__)
 #define SANITIZER_INTERCEPT_AEABI_MEM 1
@@ -280,42 +327,67 @@
 #define SANITIZER_INTERCEPT_AEABI_MEM 0
 #endif
 #define SANITIZER_INTERCEPT___BZERO SI_MAC
-#define SANITIZER_INTERCEPT_FTIME !SI_FREEBSD && SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_FTIME (!SI_FREEBSD && !SI_NETBSD && SI_POSIX)
 #define SANITIZER_INTERCEPT_XDR SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_TSEARCH SI_LINUX_NOT_ANDROID || SI_MAC
+#define SANITIZER_INTERCEPT_TSEARCH \
+  (SI_LINUX_NOT_ANDROID || SI_MAC || SI_NETBSD)
 #define SANITIZER_INTERCEPT_LIBIO_INTERNALS SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_FOPEN SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_FOPEN SI_POSIX
 #define SANITIZER_INTERCEPT_FOPEN64 SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_OPEN_MEMSTREAM SI_LINUX_NOT_ANDROID
+#define SANITIZER_INTERCEPT_OPEN_MEMSTREAM (SI_LINUX_NOT_ANDROID || SI_NETBSD)
 #define SANITIZER_INTERCEPT_OBSTACK SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_FFLUSH SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_FCLOSE SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_FFLUSH SI_POSIX
+#define SANITIZER_INTERCEPT_FCLOSE SI_POSIX
 
 #ifndef SANITIZER_INTERCEPT_DLOPEN_DLCLOSE
 #define SANITIZER_INTERCEPT_DLOPEN_DLCLOSE \
-    SI_FREEBSD || SI_LINUX_NOT_ANDROID || SI_MAC
+  (SI_FREEBSD || SI_NETBSD || SI_LINUX_NOT_ANDROID || SI_MAC)
 #endif
 
-#define SANITIZER_INTERCEPT_GETPASS SI_LINUX_NOT_ANDROID || SI_MAC
+#define SANITIZER_INTERCEPT_GETPASS \
+  (SI_LINUX_NOT_ANDROID || SI_MAC || SI_NETBSD)
 #define SANITIZER_INTERCEPT_TIMERFD SI_LINUX_NOT_ANDROID
 
-#define SANITIZER_INTERCEPT_MLOCKX SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_MLOCKX SI_POSIX
 #define SANITIZER_INTERCEPT_FOPENCOOKIE SI_LINUX_NOT_ANDROID
-#define SANITIZER_INTERCEPT_SEM SI_LINUX || SI_FREEBSD
-#define SANITIZER_INTERCEPT_PTHREAD_SETCANCEL SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_MINCORE SI_LINUX
+#define SANITIZER_INTERCEPT_SEM (SI_LINUX || SI_FREEBSD || SI_NETBSD)
+#define SANITIZER_INTERCEPT_PTHREAD_SETCANCEL SI_POSIX
+#define SANITIZER_INTERCEPT_MINCORE (SI_LINUX || SI_NETBSD)
 #define SANITIZER_INTERCEPT_PROCESS_VM_READV SI_LINUX
-#define SANITIZER_INTERCEPT_CTERMID SI_LINUX || SI_MAC || SI_FREEBSD
-#define SANITIZER_INTERCEPT_CTERMID_R SI_MAC || SI_FREEBSD
+#define SANITIZER_INTERCEPT_CTERMID \
+  (SI_LINUX || SI_MAC || SI_FREEBSD || SI_NETBSD)
+#define SANITIZER_INTERCEPT_CTERMID_R (SI_MAC || SI_FREEBSD)
 
-#define SANITIZER_INTERCEPTOR_HOOKS SI_LINUX
-#define SANITIZER_INTERCEPT_RECV_RECVFROM SI_NOT_WINDOWS
-#define SANITIZER_INTERCEPT_SEND_SENDTO SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPTOR_HOOKS (SI_LINUX || SI_MAC || SI_WINDOWS)
+#define SANITIZER_INTERCEPT_RECV_RECVFROM SI_POSIX
+#define SANITIZER_INTERCEPT_SEND_SENDTO SI_POSIX
 #define SANITIZER_INTERCEPT_EVENTFD_READ_WRITE SI_LINUX
 
-#define SANITIZER_INTERCEPT_STAT (SI_FREEBSD || SI_MAC || SI_ANDROID)
-#define SANITIZER_INTERCEPT___XSTAT !SANITIZER_INTERCEPT_STAT && SI_NOT_WINDOWS
+#define SANITIZER_INTERCEPT_STAT \
+  (SI_FREEBSD || SI_MAC || SI_ANDROID || SI_NETBSD)
+#define SANITIZER_INTERCEPT___XSTAT (!SANITIZER_INTERCEPT_STAT && SI_POSIX)
 #define SANITIZER_INTERCEPT___XSTAT64 SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT___LXSTAT SANITIZER_INTERCEPT___XSTAT
 #define SANITIZER_INTERCEPT___LXSTAT64 SI_LINUX_NOT_ANDROID
+
+#define SANITIZER_INTERCEPT_UTMP (SI_POSIX && !SI_MAC && !SI_FREEBSD)
+#define SANITIZER_INTERCEPT_UTMPX (SI_LINUX_NOT_ANDROID || SI_MAC || SI_FREEBSD)
+
+#define SANITIZER_INTERCEPT_GETLOADAVG \
+  (SI_LINUX_NOT_ANDROID || SI_MAC || SI_FREEBSD || SI_NETBSD)
+
+#define SANITIZER_INTERCEPT_MALLOPT_AND_MALLINFO \
+  (!SI_FREEBSD && !SI_MAC && !SI_NETBSD && SI_NOT_FUCHSIA)
+#define SANITIZER_INTERCEPT_MEMALIGN (!SI_FREEBSD && !SI_MAC && !SI_NETBSD)
+#define SANITIZER_INTERCEPT_PVALLOC \
+  (!SI_FREEBSD && !SI_MAC && !SI_NETBSD && SI_NOT_FUCHSIA)
+#define SANITIZER_INTERCEPT_CFREE \
+  (!SI_FREEBSD && !SI_MAC && !SI_NETBSD && SI_NOT_FUCHSIA)
+#define SANITIZER_INTERCEPT_ALIGNED_ALLOC (!SI_MAC)
+#define SANITIZER_INTERCEPT_MALLOC_USABLE_SIZE (!SI_MAC)
+#define SANITIZER_INTERCEPT_MCHECK_MPROBE SI_LINUX_NOT_ANDROID
+#define SANITIZER_INTERCEPT_WCSCAT SI_POSIX
+#define SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION (!SI_WINDOWS && SI_NOT_FUCHSIA)
+#define SANITIZER_INTERCEPT_BSD_SIGNAL SI_ANDROID
+
 #endif  // #ifndef SANITIZER_PLATFORM_INTERCEPTORS_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_platform_limits_netbsd.cc b/libsanitizer/sanitizer_common/sanitizer_platform_limits_netbsd.cc
new file mode 100644
index 00000000000..3c18ca6ce25
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_platform_limits_netbsd.cc
@@ -0,0 +1,357 @@
+//===-- sanitizer_platform_limits_netbsd.cc -------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of Sanitizer common code.
+//
+// Sizes and layouts of platform-specific NetBSD data structures.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+
+#if SANITIZER_NETBSD
+#include <arpa/inet.h>
+#include <dirent.h>
+#include <glob.h>
+#include <grp.h>
+#include <ifaddrs.h>
+#include <limits.h>
+#include <link_elf.h>
+#include <net/if.h>
+#include <net/if_ether.h>
+#include <net/ppp_defs.h>
+#include <net/route.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <netinet/ip_mroute.h>
+#include <poll.h>
+#include <pthread.h>
+#include <pwd.h>
+#include <semaphore.h>
+#include <signal.h>
+#include <stddef.h>
+#include <sys/filio.h>
+#include <sys/ipc.h>
+#include <sys/mman.h>
+#include <sys/mount.h>
+#include <sys/mqueue.h>
+#include <sys/msg.h>
+#include <sys/mtio.h>
+#include <sys/ptrace.h>
+#include <sys/resource.h>
+#include <sys/shm.h>
+#include <sys/signal.h>
+#include <sys/socket.h>
+#include <sys/sockio.h>
+#include <sys/soundcard.h>
+#include <sys/stat.h>
+#include <sys/statvfs.h>
+#include <sys/time.h>
+#include <sys/timeb.h>
+#include <sys/times.h>
+#include <sys/timespec.h>
+#include <sys/timex.h>
+#include <sys/types.h>
+#include <sys/ucontext.h>
+#include <sys/utsname.h>
+#include <term.h>
+#include <termios.h>
+#include <time.h>
+#include <utime.h>
+#include <utmp.h>
+#include <utmpx.h>
+#include <wchar.h>
+#include <wordexp.h>
+
+// Include these after system headers to avoid name clashes and ambiguities.
+#include "sanitizer_internal_defs.h"
+#include "sanitizer_platform_limits_netbsd.h"
+
+namespace __sanitizer {
+unsigned struct_utsname_sz = sizeof(struct utsname);
+unsigned struct_stat_sz = sizeof(struct stat);
+unsigned struct_rusage_sz = sizeof(struct rusage);
+unsigned struct_tm_sz = sizeof(struct tm);
+unsigned struct_passwd_sz = sizeof(struct passwd);
+unsigned struct_group_sz = sizeof(struct group);
+unsigned siginfo_t_sz = sizeof(siginfo_t);
+unsigned struct_sigaction_sz = sizeof(struct sigaction);
+unsigned struct_itimerval_sz = sizeof(struct itimerval);
+unsigned pthread_t_sz = sizeof(pthread_t);
+unsigned pthread_cond_t_sz = sizeof(pthread_cond_t);
+unsigned pid_t_sz = sizeof(pid_t);
+unsigned timeval_sz = sizeof(timeval);
+unsigned uid_t_sz = sizeof(uid_t);
+unsigned gid_t_sz = sizeof(gid_t);
+unsigned mbstate_t_sz = sizeof(mbstate_t);
+unsigned sigset_t_sz = sizeof(sigset_t);
+unsigned struct_timezone_sz = sizeof(struct timezone);
+unsigned struct_tms_sz = sizeof(struct tms);
+unsigned struct_sigevent_sz = sizeof(struct sigevent);
+unsigned struct_sched_param_sz = sizeof(struct sched_param);
+unsigned struct_sockaddr_sz = sizeof(struct sockaddr);
+unsigned ucontext_t_sz = sizeof(ucontext_t);
+unsigned struct_rlimit_sz = sizeof(struct rlimit);
+unsigned struct_timespec_sz = sizeof(struct timespec);
+unsigned struct_utimbuf_sz = sizeof(struct utimbuf);
+unsigned struct_itimerspec_sz = sizeof(struct itimerspec);
+unsigned struct_timex_sz = sizeof(struct timex);
+unsigned struct_msqid_ds_sz = sizeof(struct msqid_ds);
+unsigned struct_mq_attr_sz = sizeof(struct mq_attr);
+unsigned struct_statvfs_sz = sizeof(struct statvfs);
+
+uptr sig_ign = (uptr)SIG_IGN;
+uptr sig_dfl = (uptr)SIG_DFL;
+uptr sa_siginfo = (uptr)SA_SIGINFO;
+
+int shmctl_ipc_stat = (int)IPC_STAT;
+
+unsigned struct_utmp_sz = sizeof(struct utmp);
+unsigned struct_utmpx_sz = sizeof(struct utmpx);
+
+int map_fixed = MAP_FIXED;
+
+int af_inet = (int)AF_INET;
+int af_inet6 = (int)AF_INET6;
+
+uptr __sanitizer_in_addr_sz(int af) {
+  if (af == AF_INET)
+    return sizeof(struct in_addr);
+  else if (af == AF_INET6)
+    return sizeof(struct in6_addr);
+  else
+    return 0;
+}
+
+int glob_nomatch = GLOB_NOMATCH;
+int glob_altdirfunc = GLOB_ALTDIRFUNC;
+
+unsigned path_max = PATH_MAX;
+
+// ioctl arguments
+unsigned struct_ifreq_sz = sizeof(struct ifreq);
+unsigned struct_termios_sz = sizeof(struct termios);
+unsigned struct_winsize_sz = sizeof(struct winsize);
+unsigned struct_mtget_sz = sizeof(struct mtget);
+unsigned struct_mtop_sz = sizeof(struct mtop);
+unsigned struct_audio_buf_info_sz = sizeof(struct audio_buf_info);
+unsigned struct_ppp_stats_sz = sizeof(struct ppp_stats);
+unsigned struct_sioc_sg_req_sz = sizeof(struct sioc_sg_req);
+unsigned struct_sioc_vif_req_sz = sizeof(struct sioc_vif_req);
+
+const unsigned IOCTL_NOT_PRESENT = 0;
+
+unsigned IOCTL_FIOASYNC = FIOASYNC;
+unsigned IOCTL_FIOCLEX = FIOCLEX;
+unsigned IOCTL_FIOGETOWN = FIOGETOWN;
+unsigned IOCTL_FIONBIO = FIONBIO;
+unsigned IOCTL_FIONCLEX = FIONCLEX;
+unsigned IOCTL_FIOSETOWN = FIOSETOWN;
+unsigned IOCTL_SIOCADDMULTI = SIOCADDMULTI;
+unsigned IOCTL_SIOCATMARK = SIOCATMARK;
+unsigned IOCTL_SIOCDELMULTI = SIOCDELMULTI;
+unsigned IOCTL_SIOCGIFADDR = SIOCGIFADDR;
+unsigned IOCTL_SIOCGIFBRDADDR = SIOCGIFBRDADDR;
+unsigned IOCTL_SIOCGIFCONF = SIOCGIFCONF;
+unsigned IOCTL_SIOCGIFDSTADDR = SIOCGIFDSTADDR;
+unsigned IOCTL_SIOCGIFFLAGS = SIOCGIFFLAGS;
+unsigned IOCTL_SIOCGIFMETRIC = SIOCGIFMETRIC;
+unsigned IOCTL_SIOCGIFMTU = SIOCGIFMTU;
+unsigned IOCTL_SIOCGIFNETMASK = SIOCGIFNETMASK;
+unsigned IOCTL_SIOCGPGRP = SIOCGPGRP;
+unsigned IOCTL_SIOCSIFADDR = SIOCSIFADDR;
+unsigned IOCTL_SIOCSIFBRDADDR = SIOCSIFBRDADDR;
+unsigned IOCTL_SIOCSIFDSTADDR = SIOCSIFDSTADDR;
+unsigned IOCTL_SIOCSIFFLAGS = SIOCSIFFLAGS;
+unsigned IOCTL_SIOCSIFMETRIC = SIOCSIFMETRIC;
+unsigned IOCTL_SIOCSIFMTU = SIOCSIFMTU;
+unsigned IOCTL_SIOCSIFNETMASK = SIOCSIFNETMASK;
+unsigned IOCTL_SIOCSPGRP = SIOCSPGRP;
+unsigned IOCTL_TIOCCONS = TIOCCONS;
+unsigned IOCTL_TIOCEXCL = TIOCEXCL;
+unsigned IOCTL_TIOCGETD = TIOCGETD;
+unsigned IOCTL_TIOCGPGRP = TIOCGPGRP;
+unsigned IOCTL_TIOCGWINSZ = TIOCGWINSZ;
+unsigned IOCTL_TIOCMBIC = TIOCMBIC;
+unsigned IOCTL_TIOCMBIS = TIOCMBIS;
+unsigned IOCTL_TIOCMGET = TIOCMGET;
+unsigned IOCTL_TIOCMSET = TIOCMSET;
+unsigned IOCTL_TIOCNOTTY = TIOCNOTTY;
+unsigned IOCTL_TIOCNXCL = TIOCNXCL;
+unsigned IOCTL_TIOCOUTQ = TIOCOUTQ;
+unsigned IOCTL_TIOCPKT = TIOCPKT;
+unsigned IOCTL_TIOCSCTTY = TIOCSCTTY;
+unsigned IOCTL_TIOCSETD = TIOCSETD;
+unsigned IOCTL_TIOCSPGRP = TIOCSPGRP;
+unsigned IOCTL_TIOCSTI = TIOCSTI;
+unsigned IOCTL_TIOCSWINSZ = TIOCSWINSZ;
+unsigned IOCTL_SIOCGETSGCNT = SIOCGETSGCNT;
+unsigned IOCTL_SIOCGETVIFCNT = SIOCGETVIFCNT;
+
+const int si_SEGV_MAPERR = SEGV_MAPERR;
+const int si_SEGV_ACCERR = SEGV_ACCERR;
+}  // namespace __sanitizer
+
+using namespace __sanitizer;
+
+COMPILER_CHECK(sizeof(__sanitizer_pthread_attr_t) >= sizeof(pthread_attr_t));
+
+COMPILER_CHECK(sizeof(socklen_t) == sizeof(unsigned));
+CHECK_TYPE_SIZE(pthread_key_t);
+
+// There are more undocumented fields in dl_phdr_info that we are not interested
+// in.
+COMPILER_CHECK(sizeof(__sanitizer_dl_phdr_info) <= sizeof(dl_phdr_info));
+CHECK_SIZE_AND_OFFSET(dl_phdr_info, dlpi_addr);
+CHECK_SIZE_AND_OFFSET(dl_phdr_info, dlpi_name);
+CHECK_SIZE_AND_OFFSET(dl_phdr_info, dlpi_phdr);
+CHECK_SIZE_AND_OFFSET(dl_phdr_info, dlpi_phnum);
+
+CHECK_TYPE_SIZE(glob_t);
+CHECK_SIZE_AND_OFFSET(glob_t, gl_pathc);
+CHECK_SIZE_AND_OFFSET(glob_t, gl_pathv);
+CHECK_SIZE_AND_OFFSET(glob_t, gl_offs);
+CHECK_SIZE_AND_OFFSET(glob_t, gl_flags);
+CHECK_SIZE_AND_OFFSET(glob_t, gl_closedir);
+CHECK_SIZE_AND_OFFSET(glob_t, gl_readdir);
+CHECK_SIZE_AND_OFFSET(glob_t, gl_opendir);
+CHECK_SIZE_AND_OFFSET(glob_t, gl_lstat);
+CHECK_SIZE_AND_OFFSET(glob_t, gl_stat);
+
+CHECK_TYPE_SIZE(addrinfo);
+CHECK_SIZE_AND_OFFSET(addrinfo, ai_flags);
+CHECK_SIZE_AND_OFFSET(addrinfo, ai_family);
+CHECK_SIZE_AND_OFFSET(addrinfo, ai_socktype);
+CHECK_SIZE_AND_OFFSET(addrinfo, ai_protocol);
+CHECK_SIZE_AND_OFFSET(addrinfo, ai_protocol);
+CHECK_SIZE_AND_OFFSET(addrinfo, ai_addrlen);
+CHECK_SIZE_AND_OFFSET(addrinfo, ai_canonname);
+CHECK_SIZE_AND_OFFSET(addrinfo, ai_addr);
+
+CHECK_TYPE_SIZE(hostent);
+CHECK_SIZE_AND_OFFSET(hostent, h_name);
+CHECK_SIZE_AND_OFFSET(hostent, h_aliases);
+CHECK_SIZE_AND_OFFSET(hostent, h_addrtype);
+CHECK_SIZE_AND_OFFSET(hostent, h_length);
+CHECK_SIZE_AND_OFFSET(hostent, h_addr_list);
+
+CHECK_TYPE_SIZE(iovec);
+CHECK_SIZE_AND_OFFSET(iovec, iov_base);
+CHECK_SIZE_AND_OFFSET(iovec, iov_len);
+
+CHECK_TYPE_SIZE(msghdr);
+CHECK_SIZE_AND_OFFSET(msghdr, msg_name);
+CHECK_SIZE_AND_OFFSET(msghdr, msg_namelen);
+CHECK_SIZE_AND_OFFSET(msghdr, msg_iov);
+CHECK_SIZE_AND_OFFSET(msghdr, msg_iovlen);
+CHECK_SIZE_AND_OFFSET(msghdr, msg_control);
+CHECK_SIZE_AND_OFFSET(msghdr, msg_controllen);
+CHECK_SIZE_AND_OFFSET(msghdr, msg_flags);
+
+CHECK_TYPE_SIZE(cmsghdr);
+CHECK_SIZE_AND_OFFSET(cmsghdr, cmsg_len);
+CHECK_SIZE_AND_OFFSET(cmsghdr, cmsg_level);
+CHECK_SIZE_AND_OFFSET(cmsghdr, cmsg_type);
+
+COMPILER_CHECK(sizeof(__sanitizer_dirent) <= sizeof(dirent));
+CHECK_SIZE_AND_OFFSET(dirent, d_fileno);
+CHECK_SIZE_AND_OFFSET(dirent, d_reclen);
+
+CHECK_TYPE_SIZE(ifconf);
+CHECK_SIZE_AND_OFFSET(ifconf, ifc_len);
+CHECK_SIZE_AND_OFFSET(ifconf, ifc_ifcu);
+
+CHECK_TYPE_SIZE(pollfd);
+CHECK_SIZE_AND_OFFSET(pollfd, fd);
+CHECK_SIZE_AND_OFFSET(pollfd, events);
+CHECK_SIZE_AND_OFFSET(pollfd, revents);
+
+CHECK_TYPE_SIZE(nfds_t);
+
+CHECK_TYPE_SIZE(sigset_t);
+
+COMPILER_CHECK(sizeof(__sanitizer_sigaction) == sizeof(struct sigaction));
+// Can't write checks for sa_handler and sa_sigaction due to them being
+// preprocessor macros.
+CHECK_STRUCT_SIZE_AND_OFFSET(sigaction, sa_mask);
+
+CHECK_TYPE_SIZE(wordexp_t);
+CHECK_SIZE_AND_OFFSET(wordexp_t, we_wordc);
+CHECK_SIZE_AND_OFFSET(wordexp_t, we_wordv);
+CHECK_SIZE_AND_OFFSET(wordexp_t, we_offs);
+
+CHECK_TYPE_SIZE(tm);
+CHECK_SIZE_AND_OFFSET(tm, tm_sec);
+CHECK_SIZE_AND_OFFSET(tm, tm_min);
+CHECK_SIZE_AND_OFFSET(tm, tm_hour);
+CHECK_SIZE_AND_OFFSET(tm, tm_mday);
+CHECK_SIZE_AND_OFFSET(tm, tm_mon);
+CHECK_SIZE_AND_OFFSET(tm, tm_year);
+CHECK_SIZE_AND_OFFSET(tm, tm_wday);
+CHECK_SIZE_AND_OFFSET(tm, tm_yday);
+CHECK_SIZE_AND_OFFSET(tm, tm_isdst);
+CHECK_SIZE_AND_OFFSET(tm, tm_gmtoff);
+CHECK_SIZE_AND_OFFSET(tm, tm_zone);
+
+CHECK_TYPE_SIZE(ether_addr);
+
+CHECK_TYPE_SIZE(ipc_perm);
+CHECK_SIZE_AND_OFFSET(ipc_perm, _key);
+CHECK_SIZE_AND_OFFSET(ipc_perm, _seq);
+CHECK_SIZE_AND_OFFSET(ipc_perm, uid);
+CHECK_SIZE_AND_OFFSET(ipc_perm, gid);
+CHECK_SIZE_AND_OFFSET(ipc_perm, cuid);
+CHECK_SIZE_AND_OFFSET(ipc_perm, cgid);
+CHECK_SIZE_AND_OFFSET(ipc_perm, mode);
+
+CHECK_TYPE_SIZE(shmid_ds);
+CHECK_SIZE_AND_OFFSET(shmid_ds, shm_perm);
+CHECK_SIZE_AND_OFFSET(shmid_ds, shm_segsz);
+CHECK_SIZE_AND_OFFSET(shmid_ds, shm_atime);
+CHECK_SIZE_AND_OFFSET(shmid_ds, shm_dtime);
+CHECK_SIZE_AND_OFFSET(shmid_ds, shm_ctime);
+CHECK_SIZE_AND_OFFSET(shmid_ds, shm_cpid);
+CHECK_SIZE_AND_OFFSET(shmid_ds, shm_lpid);
+CHECK_SIZE_AND_OFFSET(shmid_ds, shm_nattch);
+
+CHECK_TYPE_SIZE(clock_t);
+
+CHECK_TYPE_SIZE(ifaddrs);
+CHECK_SIZE_AND_OFFSET(ifaddrs, ifa_next);
+CHECK_SIZE_AND_OFFSET(ifaddrs, ifa_name);
+CHECK_SIZE_AND_OFFSET(ifaddrs, ifa_addr);
+CHECK_SIZE_AND_OFFSET(ifaddrs, ifa_netmask);
+// Compare against the union, because we can't reach into the union in a
+// compliant way.
+#ifdef ifa_dstaddr
+#undef ifa_dstaddr
+#endif
+CHECK_SIZE_AND_OFFSET(ifaddrs, ifa_dstaddr);
+CHECK_SIZE_AND_OFFSET(ifaddrs, ifa_data);
+
+CHECK_TYPE_SIZE(timeb);
+CHECK_SIZE_AND_OFFSET(timeb, time);
+CHECK_SIZE_AND_OFFSET(timeb, millitm);
+CHECK_SIZE_AND_OFFSET(timeb, timezone);
+CHECK_SIZE_AND_OFFSET(timeb, dstflag);
+
+CHECK_TYPE_SIZE(passwd);
+CHECK_SIZE_AND_OFFSET(passwd, pw_name);
+CHECK_SIZE_AND_OFFSET(passwd, pw_passwd);
+CHECK_SIZE_AND_OFFSET(passwd, pw_uid);
+CHECK_SIZE_AND_OFFSET(passwd, pw_gid);
+CHECK_SIZE_AND_OFFSET(passwd, pw_dir);
+CHECK_SIZE_AND_OFFSET(passwd, pw_shell);
+
+CHECK_SIZE_AND_OFFSET(passwd, pw_gecos);
+
+CHECK_TYPE_SIZE(group);
+CHECK_SIZE_AND_OFFSET(group, gr_name);
+CHECK_SIZE_AND_OFFSET(group, gr_passwd);
+CHECK_SIZE_AND_OFFSET(group, gr_gid);
+CHECK_SIZE_AND_OFFSET(group, gr_mem);
+
+#endif  // SANITIZER_NETBSD
diff --git a/libsanitizer/sanitizer_common/sanitizer_platform_limits_netbsd.h b/libsanitizer/sanitizer_common/sanitizer_platform_limits_netbsd.h
new file mode 100644
index 00000000000..e7034ed6b52
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_platform_limits_netbsd.h
@@ -0,0 +1,566 @@
+//===-- sanitizer_platform_limits_netbsd.h --------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of Sanitizer common code.
+//
+// Sizes and layouts of platform-specific NetBSD data structures.
+//===----------------------------------------------------------------------===//
+
+#ifndef SANITIZER_PLATFORM_LIMITS_NETBSD_H
+#define SANITIZER_PLATFORM_LIMITS_NETBSD_H
+
+#if SANITIZER_NETBSD
+
+#include "sanitizer_internal_defs.h"
+#include "sanitizer_platform.h"
+
+#define _GET_LINK_MAP_BY_DLOPEN_HANDLE(handle, shift) \
+  ((link_map *)((handle) == nullptr ? nullptr : ((char *)(handle) + (shift))))
+
+#if defined(__x86_64__)
+#define GET_LINK_MAP_BY_DLOPEN_HANDLE(handle) \
+  _GET_LINK_MAP_BY_DLOPEN_HANDLE(handle, 608)
+#elif defined(__i386__)
+#define GET_LINK_MAP_BY_DLOPEN_HANDLE(handle) \
+  _GET_LINK_MAP_BY_DLOPEN_HANDLE(handle, 324)
+#endif
+
+namespace __sanitizer {
+extern unsigned struct_utsname_sz;
+extern unsigned struct_stat_sz;
+extern unsigned struct_rusage_sz;
+extern unsigned siginfo_t_sz;
+extern unsigned struct_itimerval_sz;
+extern unsigned pthread_t_sz;
+extern unsigned pthread_cond_t_sz;
+extern unsigned pid_t_sz;
+extern unsigned timeval_sz;
+extern unsigned uid_t_sz;
+extern unsigned gid_t_sz;
+extern unsigned mbstate_t_sz;
+extern unsigned struct_timezone_sz;
+extern unsigned struct_tms_sz;
+extern unsigned struct_itimerspec_sz;
+extern unsigned struct_sigevent_sz;
+extern unsigned struct_sched_param_sz;
+extern unsigned struct_statfs_sz;
+extern unsigned struct_sockaddr_sz;
+extern unsigned ucontext_t_sz;
+
+extern unsigned struct_rlimit_sz;
+extern unsigned struct_utimbuf_sz;
+extern unsigned struct_timespec_sz;
+
+struct __sanitizer_iocb {
+  u64 aio_offset;
+  uptr aio_buf;
+  long aio_nbytes;
+  u32 aio_fildes;
+  u32 aio_lio_opcode;
+  long aio_reqprio;
+#if SANITIZER_WORDSIZE == 64
+  u8 aio_sigevent[32];
+#else
+  u8 aio_sigevent[20];
+#endif
+  u32 _state;
+  u32 _errno;
+  long _retval;
+};
+
+struct __sanitizer___sysctl_args {
+  int *name;
+  int nlen;
+  void *oldval;
+  uptr *oldlenp;
+  void *newval;
+  uptr newlen;
+};
+
+struct __sanitizer_sem_t {
+  uptr data[5];
+};
+
+struct __sanitizer_ipc_perm {
+  u32 uid;
+  u32 gid;
+  u32 cuid;
+  u32 cgid;
+  u32 mode;
+  unsigned short _seq;
+  long _key;
+};
+
+struct __sanitizer_shmid_ds {
+  __sanitizer_ipc_perm shm_perm;
+  unsigned long shm_segsz;
+  u32 shm_lpid;
+  u32 shm_cpid;
+  unsigned int shm_nattch;
+  u64 shm_atime;
+  u64 shm_dtime;
+  u64 shm_ctime;
+  void *_shm_internal;
+};
+
+extern unsigned struct_msqid_ds_sz;
+extern unsigned struct_mq_attr_sz;
+extern unsigned struct_timex_sz;
+extern unsigned struct_statvfs_sz;
+
+struct __sanitizer_iovec {
+  void *iov_base;
+  uptr iov_len;
+};
+
+struct __sanitizer_ifaddrs {
+  struct __sanitizer_ifaddrs *ifa_next;
+  char *ifa_name;
+  unsigned int ifa_flags;
+  void *ifa_addr;     // (struct sockaddr *)
+  void *ifa_netmask;  // (struct sockaddr *)
+  void *ifa_dstaddr;  // (struct sockaddr *)
+  void *ifa_data;
+  unsigned int ifa_addrflags;
+};
+
+typedef unsigned __sanitizer_pthread_key_t;
+
+typedef long long __sanitizer_time_t;
+
+struct __sanitizer_passwd {
+  char *pw_name;
+  char *pw_passwd;
+  int pw_uid;
+  int pw_gid;
+  __sanitizer_time_t pw_change;
+  char *pw_class;
+  char *pw_gecos;
+  char *pw_dir;
+  char *pw_shell;
+  __sanitizer_time_t pw_expire;
+};
+
+struct __sanitizer_group {
+  char *gr_name;
+  char *gr_passwd;
+  int gr_gid;
+  char **gr_mem;
+};
+
+struct __sanitizer_timeb {
+  __sanitizer_time_t time;
+  unsigned short millitm;
+  short timezone;
+  short dstflag;
+};
+
+struct __sanitizer_ether_addr {
+  u8 octet[6];
+};
+
+struct __sanitizer_tm {
+  int tm_sec;
+  int tm_min;
+  int tm_hour;
+  int tm_mday;
+  int tm_mon;
+  int tm_year;
+  int tm_wday;
+  int tm_yday;
+  int tm_isdst;
+  long int tm_gmtoff;
+  const char *tm_zone;
+};
+
+struct __sanitizer_msghdr {
+  void *msg_name;
+  unsigned msg_namelen;
+  struct __sanitizer_iovec *msg_iov;
+  unsigned msg_iovlen;
+  void *msg_control;
+  unsigned msg_controllen;
+  int msg_flags;
+};
+struct __sanitizer_cmsghdr {
+  unsigned cmsg_len;
+  int cmsg_level;
+  int cmsg_type;
+};
+
+struct __sanitizer_dirent {
+  u64 d_fileno;
+  u16 d_reclen;
+  // more fields that we don't care about
+};
+
+typedef int __sanitizer_clock_t;
+typedef int __sanitizer_clockid_t;
+
+typedef u32 __sanitizer___kernel_uid_t;
+typedef u32 __sanitizer___kernel_gid_t;
+typedef u64 __sanitizer___kernel_off_t;
+typedef struct {
+  u32 fds_bits[8];
+} __sanitizer___kernel_fd_set;
+
+typedef struct {
+  unsigned int pta_magic;
+  int pta_flags;
+  void *pta_private;
+} __sanitizer_pthread_attr_t;
+
+struct __sanitizer_sigset_t {
+  // uint32_t * 4
+  unsigned int __bits[4];
+};
+
+struct __sanitizer_sigaction {
+  union {
+    void (*handler)(int sig);
+    void (*sigaction)(int sig, void *siginfo, void *uctx);
+  };
+  __sanitizer_sigset_t sa_mask;
+  int sa_flags;
+};
+
+typedef __sanitizer_sigset_t __sanitizer_kernel_sigset_t;
+
+struct __sanitizer_kernel_sigaction_t {
+  union {
+    void (*handler)(int signo);
+    void (*sigaction)(int signo, void *info, void *ctx);
+  };
+  unsigned long sa_flags;
+  void (*sa_restorer)(void);
+  __sanitizer_kernel_sigset_t sa_mask;
+};
+
+extern uptr sig_ign;
+extern uptr sig_dfl;
+extern uptr sa_siginfo;
+
+extern int af_inet;
+extern int af_inet6;
+uptr __sanitizer_in_addr_sz(int af);
+
+struct __sanitizer_dl_phdr_info {
+  uptr dlpi_addr;
+  const char *dlpi_name;
+  const void *dlpi_phdr;
+  short dlpi_phnum;
+};
+
+extern unsigned struct_ElfW_Phdr_sz;
+
+struct __sanitizer_addrinfo {
+  int ai_flags;
+  int ai_family;
+  int ai_socktype;
+  int ai_protocol;
+  unsigned ai_addrlen;
+  char *ai_canonname;
+  void *ai_addr;
+  struct __sanitizer_addrinfo *ai_next;
+};
+
+struct __sanitizer_hostent {
+  char *h_name;
+  char **h_aliases;
+  int h_addrtype;
+  int h_length;
+  char **h_addr_list;
+};
+
+struct __sanitizer_pollfd {
+  int fd;
+  short events;
+  short revents;
+};
+
+typedef unsigned __sanitizer_nfds_t;
+
+struct __sanitizer_glob_t {
+  uptr gl_pathc;
+  uptr gl_matchc;
+  uptr gl_offs;
+  int gl_flags;
+  char **gl_pathv;
+  int (*gl_errfunc)(const char *, int);
+  void (*gl_closedir)(void *dirp);
+  struct dirent *(*gl_readdir)(void *dirp);
+  void *(*gl_opendir)(const char *);
+  int (*gl_lstat)(const char *, void * /* struct stat* */);
+  int (*gl_stat)(const char *, void * /* struct stat* */);
+};
+
+extern int glob_nomatch;
+extern int glob_altdirfunc;
+
+extern unsigned path_max;
+
+struct __sanitizer_wordexp_t {
+  uptr we_wordc;
+  char **we_wordv;
+  uptr we_offs;
+  char *we_strings;
+  uptr we_nbytes;
+};
+
+typedef void __sanitizer_FILE;
+#define SANITIZER_HAS_STRUCT_FILE 0
+
+extern int shmctl_ipc_stat;
+
+// This simplifies generic code
+#define struct_shminfo_sz -1
+#define struct_shm_info_sz -1
+#define shmctl_shm_stat -1
+#define shmctl_ipc_info -1
+#define shmctl_shm_info -1
+
+extern unsigned struct_utmp_sz;
+extern unsigned struct_utmpx_sz;
+
+extern int map_fixed;
+
+// ioctl arguments
+struct __sanitizer_ifconf {
+  int ifc_len;
+  union {
+    void *ifcu_req;
+  } ifc_ifcu;
+};
+
+#define IOC_NRBITS 8
+#define IOC_TYPEBITS 8
+#define IOC_SIZEBITS 14
+#define IOC_DIRBITS 2
+#define IOC_NONE 0U
+#define IOC_WRITE 1U
+#define IOC_READ 2U
+#define IOC_NRMASK ((1 << IOC_NRBITS) - 1)
+#define IOC_TYPEMASK ((1 << IOC_TYPEBITS) - 1)
+#define IOC_SIZEMASK ((1 << IOC_SIZEBITS) - 1)
+#undef IOC_DIRMASK
+#define IOC_DIRMASK ((1 << IOC_DIRBITS) - 1)
+#define IOC_NRSHIFT 0
+#define IOC_TYPESHIFT (IOC_NRSHIFT + IOC_NRBITS)
+#define IOC_SIZESHIFT (IOC_TYPESHIFT + IOC_TYPEBITS)
+#define IOC_DIRSHIFT (IOC_SIZESHIFT + IOC_SIZEBITS)
+#define EVIOC_EV_MAX 0x1f
+#define EVIOC_ABS_MAX 0x3f
+
+#define IOC_DIR(nr) (((nr) >> IOC_DIRSHIFT) & IOC_DIRMASK)
+#define IOC_TYPE(nr) (((nr) >> IOC_TYPESHIFT) & IOC_TYPEMASK)
+#define IOC_NR(nr) (((nr) >> IOC_NRSHIFT) & IOC_NRMASK)
+#define IOC_SIZE(nr) (((nr) >> IOC_SIZESHIFT) & IOC_SIZEMASK)
+
+extern unsigned struct_ifreq_sz;
+extern unsigned struct_termios_sz;
+extern unsigned struct_winsize_sz;
+
+extern unsigned struct_arpreq_sz;
+
+extern unsigned struct_mtget_sz;
+extern unsigned struct_mtop_sz;
+extern unsigned struct_rtentry_sz;
+extern unsigned struct_sbi_instrument_sz;
+extern unsigned struct_seq_event_rec_sz;
+extern unsigned struct_synth_info_sz;
+extern unsigned struct_vt_mode_sz;
+extern unsigned struct_audio_buf_info_sz;
+extern unsigned struct_ppp_stats_sz;
+extern unsigned struct_sioc_sg_req_sz;
+extern unsigned struct_sioc_vif_req_sz;
+
+// ioctl request identifiers
+
+// A special value to mark ioctls that are not present on the target platform,
+// when it can not be determined without including any system headers.
+extern const unsigned IOCTL_NOT_PRESENT;
+
+extern unsigned IOCTL_FIOASYNC;
+extern unsigned IOCTL_FIOCLEX;
+extern unsigned IOCTL_FIOGETOWN;
+extern unsigned IOCTL_FIONBIO;
+extern unsigned IOCTL_FIONCLEX;
+extern unsigned IOCTL_FIOSETOWN;
+extern unsigned IOCTL_SIOCADDMULTI;
+extern unsigned IOCTL_SIOCATMARK;
+extern unsigned IOCTL_SIOCDELMULTI;
+extern unsigned IOCTL_SIOCGIFADDR;
+extern unsigned IOCTL_SIOCGIFBRDADDR;
+extern unsigned IOCTL_SIOCGIFCONF;
+extern unsigned IOCTL_SIOCGIFDSTADDR;
+extern unsigned IOCTL_SIOCGIFFLAGS;
+extern unsigned IOCTL_SIOCGIFMETRIC;
+extern unsigned IOCTL_SIOCGIFMTU;
+extern unsigned IOCTL_SIOCGIFNETMASK;
+extern unsigned IOCTL_SIOCGPGRP;
+extern unsigned IOCTL_SIOCSIFADDR;
+extern unsigned IOCTL_SIOCSIFBRDADDR;
+extern unsigned IOCTL_SIOCSIFDSTADDR;
+extern unsigned IOCTL_SIOCSIFFLAGS;
+extern unsigned IOCTL_SIOCSIFMETRIC;
+extern unsigned IOCTL_SIOCSIFMTU;
+extern unsigned IOCTL_SIOCSIFNETMASK;
+extern unsigned IOCTL_SIOCSPGRP;
+extern unsigned IOCTL_TIOCCONS;
+extern unsigned IOCTL_TIOCEXCL;
+extern unsigned IOCTL_TIOCGETD;
+extern unsigned IOCTL_TIOCGPGRP;
+extern unsigned IOCTL_TIOCGWINSZ;
+extern unsigned IOCTL_TIOCMBIC;
+extern unsigned IOCTL_TIOCMBIS;
+extern unsigned IOCTL_TIOCMGET;
+extern unsigned IOCTL_TIOCMSET;
+extern unsigned IOCTL_TIOCNOTTY;
+extern unsigned IOCTL_TIOCNXCL;
+extern unsigned IOCTL_TIOCOUTQ;
+extern unsigned IOCTL_TIOCPKT;
+extern unsigned IOCTL_TIOCSCTTY;
+extern unsigned IOCTL_TIOCSETD;
+extern unsigned IOCTL_TIOCSPGRP;
+extern unsigned IOCTL_TIOCSTI;
+extern unsigned IOCTL_TIOCSWINSZ;
+extern unsigned IOCTL_SIOCGETSGCNT;
+extern unsigned IOCTL_SIOCGETVIFCNT;
+extern unsigned IOCTL_MTIOCGET;
+extern unsigned IOCTL_MTIOCTOP;
+extern unsigned IOCTL_SIOCADDRT;
+extern unsigned IOCTL_SIOCDELRT;
+extern unsigned IOCTL_SNDCTL_DSP_GETBLKSIZE;
+extern unsigned IOCTL_SNDCTL_DSP_GETFMTS;
+extern unsigned IOCTL_SNDCTL_DSP_NONBLOCK;
+extern unsigned IOCTL_SNDCTL_DSP_POST;
+extern unsigned IOCTL_SNDCTL_DSP_RESET;
+extern unsigned IOCTL_SNDCTL_DSP_SETFMT;
+extern unsigned IOCTL_SNDCTL_DSP_SETFRAGMENT;
+extern unsigned IOCTL_SNDCTL_DSP_SPEED;
+extern unsigned IOCTL_SNDCTL_DSP_STEREO;
+extern unsigned IOCTL_SNDCTL_DSP_SUBDIVIDE;
+extern unsigned IOCTL_SNDCTL_DSP_SYNC;
+extern unsigned IOCTL_SNDCTL_FM_4OP_ENABLE;
+extern unsigned IOCTL_SNDCTL_FM_LOAD_INSTR;
+extern unsigned IOCTL_SNDCTL_MIDI_INFO;
+extern unsigned IOCTL_SNDCTL_MIDI_PRETIME;
+extern unsigned IOCTL_SNDCTL_SEQ_CTRLRATE;
+extern unsigned IOCTL_SNDCTL_SEQ_GETINCOUNT;
+extern unsigned IOCTL_SNDCTL_SEQ_GETOUTCOUNT;
+extern unsigned IOCTL_SNDCTL_SEQ_NRMIDIS;
+extern unsigned IOCTL_SNDCTL_SEQ_NRSYNTHS;
+extern unsigned IOCTL_SNDCTL_SEQ_OUTOFBAND;
+extern unsigned IOCTL_SNDCTL_SEQ_PANIC;
+extern unsigned IOCTL_SNDCTL_SEQ_PERCMODE;
+extern unsigned IOCTL_SNDCTL_SEQ_RESET;
+extern unsigned IOCTL_SNDCTL_SEQ_RESETSAMPLES;
+extern unsigned IOCTL_SNDCTL_SEQ_SYNC;
+extern unsigned IOCTL_SNDCTL_SEQ_TESTMIDI;
+extern unsigned IOCTL_SNDCTL_SEQ_THRESHOLD;
+extern unsigned IOCTL_SNDCTL_SYNTH_INFO;
+extern unsigned IOCTL_SNDCTL_SYNTH_MEMAVL;
+extern unsigned IOCTL_SNDCTL_TMR_CONTINUE;
+extern unsigned IOCTL_SNDCTL_TMR_METRONOME;
+extern unsigned IOCTL_SNDCTL_TMR_SELECT;
+extern unsigned IOCTL_SNDCTL_TMR_SOURCE;
+extern unsigned IOCTL_SNDCTL_TMR_START;
+extern unsigned IOCTL_SNDCTL_TMR_STOP;
+extern unsigned IOCTL_SNDCTL_TMR_TEMPO;
+extern unsigned IOCTL_SNDCTL_TMR_TIMEBASE;
+extern unsigned IOCTL_SOUND_MIXER_READ_ALTPCM;
+extern unsigned IOCTL_SOUND_MIXER_READ_BASS;
+extern unsigned IOCTL_SOUND_MIXER_READ_CAPS;
+extern unsigned IOCTL_SOUND_MIXER_READ_CD;
+extern unsigned IOCTL_SOUND_MIXER_READ_DEVMASK;
+extern unsigned IOCTL_SOUND_MIXER_READ_ENHANCE;
+extern unsigned IOCTL_SOUND_MIXER_READ_IGAIN;
+extern unsigned IOCTL_SOUND_MIXER_READ_IMIX;
+extern unsigned IOCTL_SOUND_MIXER_READ_LINE1;
+extern unsigned IOCTL_SOUND_MIXER_READ_LINE2;
+extern unsigned IOCTL_SOUND_MIXER_READ_LINE3;
+extern unsigned IOCTL_SOUND_MIXER_READ_LINE;
+extern unsigned IOCTL_SOUND_MIXER_READ_LOUD;
+extern unsigned IOCTL_SOUND_MIXER_READ_MIC;
+extern unsigned IOCTL_SOUND_MIXER_READ_MUTE;
+extern unsigned IOCTL_SOUND_MIXER_READ_OGAIN;
+extern unsigned IOCTL_SOUND_MIXER_READ_PCM;
+extern unsigned IOCTL_SOUND_MIXER_READ_RECLEV;
+extern unsigned IOCTL_SOUND_MIXER_READ_RECMASK;
+extern unsigned IOCTL_SOUND_MIXER_READ_RECSRC;
+extern unsigned IOCTL_SOUND_MIXER_READ_SPEAKER;
+extern unsigned IOCTL_SOUND_MIXER_READ_STEREODEVS;
+extern unsigned IOCTL_SOUND_MIXER_READ_SYNTH;
+extern unsigned IOCTL_SOUND_MIXER_READ_TREBLE;
+extern unsigned IOCTL_SOUND_MIXER_READ_VOLUME;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_ALTPCM;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_BASS;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_CD;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_ENHANCE;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_IGAIN;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_IMIX;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_LINE1;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_LINE2;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_LINE3;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_LINE;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_LOUD;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_MIC;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_MUTE;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_OGAIN;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_PCM;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_RECLEV;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_RECSRC;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_SPEAKER;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_SYNTH;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_TREBLE;
+extern unsigned IOCTL_SOUND_MIXER_WRITE_VOLUME;
+extern unsigned IOCTL_SOUND_PCM_READ_BITS;
+extern unsigned IOCTL_SOUND_PCM_READ_CHANNELS;
+extern unsigned IOCTL_SOUND_PCM_READ_FILTER;
+extern unsigned IOCTL_SOUND_PCM_READ_RATE;
+extern unsigned IOCTL_SOUND_PCM_WRITE_CHANNELS;
+extern unsigned IOCTL_SOUND_PCM_WRITE_FILTER;
+extern unsigned IOCTL_VT_ACTIVATE;
+extern unsigned IOCTL_VT_GETMODE;
+extern unsigned IOCTL_VT_OPENQRY;
+extern unsigned IOCTL_VT_RELDISP;
+extern unsigned IOCTL_VT_SETMODE;
+extern unsigned IOCTL_VT_WAITACTIVE;
+extern unsigned IOCTL_KDDISABIO;
+extern unsigned IOCTL_KDENABIO;
+extern unsigned IOCTL_KDGETLED;
+extern unsigned IOCTL_KDGKBMODE;
+extern unsigned IOCTL_KDGKBTYPE;
+extern unsigned IOCTL_KDMKTONE;
+extern unsigned IOCTL_KDSETLED;
+extern unsigned IOCTL_KDSETMODE;
+extern unsigned IOCTL_KDSKBMODE;
+
+extern const int si_SEGV_MAPERR;
+extern const int si_SEGV_ACCERR;
+}  // namespace __sanitizer
+
+#define CHECK_TYPE_SIZE(TYPE) \
+  COMPILER_CHECK(sizeof(__sanitizer_##TYPE) == sizeof(TYPE))
+
+#define CHECK_SIZE_AND_OFFSET(CLASS, MEMBER)                      \
+  COMPILER_CHECK(sizeof(((__sanitizer_##CLASS *)NULL)->MEMBER) == \
+                 sizeof(((CLASS *)NULL)->MEMBER));                \
+  COMPILER_CHECK(offsetof(__sanitizer_##CLASS, MEMBER) ==         \
+                 offsetof(CLASS, MEMBER))
+
+// For sigaction, which is a function and struct at the same time,
+// and thus requires explicit "struct" in sizeof() expression.
+#define CHECK_STRUCT_SIZE_AND_OFFSET(CLASS, MEMBER)                      \
+  COMPILER_CHECK(sizeof(((struct __sanitizer_##CLASS *)NULL)->MEMBER) == \
+                 sizeof(((struct CLASS *)NULL)->MEMBER));                \
+  COMPILER_CHECK(offsetof(struct __sanitizer_##CLASS, MEMBER) ==         \
+                 offsetof(struct CLASS, MEMBER))
+
+#endif  // SANITIZER_NETBSD
+
+#endif
diff --git a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
index 31a5e697eae..858bb218450 100644
--- a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
@@ -23,7 +23,6 @@
 #endif
 #include <arpa/inet.h>
 #include <dirent.h>
-#include <errno.h>
 #include <grp.h>
 #include <limits.h>
 #include <net/if.h>
@@ -44,6 +43,9 @@
 #include <termios.h>
 #include <time.h>
 #include <wchar.h>
+#if !SANITIZER_MAC && !SANITIZER_FREEBSD
+#include <utmp.h>
+#endif
 
 #if !SANITIZER_IOS
 #include <net/route.h>
@@ -52,6 +54,7 @@
 #if !SANITIZER_ANDROID
 #include <sys/mount.h>
 #include <sys/timeb.h>
+#include <utmpx.h>
 #endif
 
 #if SANITIZER_LINUX
@@ -277,6 +280,13 @@ namespace __sanitizer {
   int shmctl_shm_stat = (int)SHM_STAT;
 #endif
 
+#if !SANITIZER_MAC && !SANITIZER_FREEBSD
+  unsigned struct_utmp_sz = sizeof(struct utmp);
+#endif
+#if !SANITIZER_ANDROID
+  unsigned struct_utmpx_sz = sizeof(struct utmpx);
+#endif
+
   int map_fixed = MAP_FIXED;
 
   int af_inet = (int)AF_INET;
@@ -918,14 +928,6 @@ unsigned struct_ElfW_Phdr_sz = sizeof(Elf_Phdr);
   unsigned IOCTL_SNDCTL_DSP_GETOSPACE = SNDCTL_DSP_GETOSPACE;
 #endif // (SANITIZER_LINUX || SANITIZER_FREEBSD) && !SANITIZER_ANDROID
 
-  const int errno_EINVAL = EINVAL;
-// EOWNERDEAD is not present in some older platforms.
-#if defined(EOWNERDEAD)
-  const int errno_EOWNERDEAD = EOWNERDEAD;
-#else
-  const int errno_EOWNERDEAD = -1;
-#endif
-
   const int si_SEGV_MAPERR = SEGV_MAPERR;
   const int si_SEGV_ACCERR = SEGV_ACCERR;
 } // namespace __sanitizer
diff --git a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h
index c139322839a..4d11d071776 100644
--- a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h
+++ b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h
@@ -13,6 +13,8 @@
 #ifndef SANITIZER_PLATFORM_LIMITS_POSIX_H
 #define SANITIZER_PLATFORM_LIMITS_POSIX_H
 
+#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_MAC
+
 #include "sanitizer_internal_defs.h"
 #include "sanitizer_platform.h"
 
@@ -21,6 +23,9 @@
 // incorporates the map structure.
 # define GET_LINK_MAP_BY_DLOPEN_HANDLE(handle) \
     ((link_map*)((handle) == nullptr ? nullptr : ((char*)(handle) + 544)))
+// Get sys/_types.h, because that tells us whether 64-bit inodes are
+// used in struct dirent below.
+#include <sys/_types.h>
 #else
 # define GET_LINK_MAP_BY_DLOPEN_HANDLE(handle) ((link_map*)(handle))
 #endif  // !SANITIZER_FREEBSD
@@ -81,7 +86,7 @@ namespace __sanitizer {
 #elif defined(__mips__)
   const unsigned struct_kernel_stat_sz =
                  SANITIZER_ANDROID ? FIRST_32_SECOND_64(104, 128) :
-                                     FIRST_32_SECOND_64(144, 216);
+                                     FIRST_32_SECOND_64(160, 216);
   const unsigned struct_kernel_stat64_sz = 104;
 #elif defined(__s390__) && !defined(__s390x__)
   const unsigned struct_kernel_stat_sz = 64;
@@ -204,24 +209,24 @@ namespace __sanitizer {
     unsigned __seq;
     u64 __unused1;
     u64 __unused2;
-#elif defined(__mips__) || defined(__aarch64__) || defined(__s390x__)
-    unsigned int mode;
-    unsigned short __seq;
-    unsigned short __pad1;
-    unsigned long __unused1;
-    unsigned long __unused2;
 #elif defined(__sparc__)
-# if defined(__arch64__)
+#if defined(__arch64__)
     unsigned mode;
     unsigned short __pad1;
-# else
+#else
     unsigned short __pad1;
     unsigned short mode;
     unsigned short __pad2;
-# endif
+#endif
     unsigned short __seq;
     unsigned long long __unused1;
     unsigned long long __unused2;
+#elif defined(__mips__) || defined(__aarch64__) || defined(__s390x__)
+    unsigned int mode;
+    unsigned short __seq;
+    unsigned short __pad1;
+    unsigned long __unused1;
+    unsigned long __unused2;
 #else
     unsigned short mode;
     unsigned short __pad1;
@@ -240,17 +245,17 @@ namespace __sanitizer {
   struct __sanitizer_shmid_ds {
     __sanitizer_ipc_perm shm_perm;
   #if defined(__sparc__)
-  # if !defined(__arch64__)
+  #if !defined(__arch64__)
     u32 __pad1;
-  # endif
+  #endif
     long shm_atime;
-  # if !defined(__arch64__)
+  #if !defined(__arch64__)
     u32 __pad2;
-  # endif
+  #endif
     long shm_dtime;
-  # if !defined(__arch64__)
+  #if !defined(__arch64__)
     u32 __pad3;
-  # endif
+  #endif
     long shm_ctime;
     uptr shm_segsz;
     int shm_cpid;
@@ -483,7 +488,12 @@ namespace __sanitizer {
   };
 #elif SANITIZER_FREEBSD
   struct __sanitizer_dirent {
+#if defined(__INO64)
+    unsigned long long d_fileno;
+    unsigned long long d_off;
+#else
     unsigned int d_fileno;
+#endif
     unsigned short d_reclen;
     // more fields that we don't care about
   };
@@ -863,6 +873,13 @@ namespace __sanitizer {
   extern int shmctl_shm_stat;
 #endif
 
+#if !SANITIZER_MAC && !SANITIZER_FREEBSD
+  extern unsigned struct_utmp_sz;
+#endif
+#if !SANITIZER_ANDROID
+  extern unsigned struct_utmpx_sz;
+#endif
+
   extern int map_fixed;
 
   // ioctl arguments
@@ -908,7 +925,8 @@ struct __sanitizer_cookie_io_functions_t {
 
 #define IOC_NRBITS 8
 #define IOC_TYPEBITS 8
-#if defined(__powerpc__) || defined(__powerpc64__) || defined(__mips__) || defined(__sparc__)
+#if defined(__powerpc__) || defined(__powerpc64__) || defined(__mips__) || \
+    defined(__sparc__)
 #define IOC_SIZEBITS 13
 #define IOC_DIRBITS 3
 #define IOC_NONE 1U
@@ -943,9 +961,8 @@ struct __sanitizer_cookie_io_functions_t {
 // In sparc the 14 bits SIZE field overlaps with the
 // least significant bit of DIR, so either IOC_READ or
 // IOC_WRITE shall be 1 in order to get a non-zero SIZE.
-# define IOC_SIZE(nr)                       \
-  ((((((nr) >> 29) & 0x7) & (4U|2U)) == 0)? \
-   0 : (((nr) >> 16) & 0x3fff))
+#define IOC_SIZE(nr) \
+  ((((((nr) >> 29) & 0x7) & (4U | 2U)) == 0) ? 0 : (((nr) >> 16) & 0x3fff))
 #else
 #define IOC_SIZE(nr) (((nr) >> IOC_SIZESHIFT) & IOC_SIZEMASK)
 #endif
@@ -1447,9 +1464,6 @@ struct __sanitizer_cookie_io_functions_t {
   extern unsigned IOCTL_PIO_SCRNMAP;
 #endif
 
-  extern const int errno_EINVAL;
-  extern const int errno_EOWNERDEAD;
-
   extern const int si_SEGV_MAPERR;
   extern const int si_SEGV_ACCERR;
 }  // namespace __sanitizer
@@ -1471,4 +1485,6 @@ struct __sanitizer_cookie_io_functions_t {
   COMPILER_CHECK(offsetof(struct __sanitizer_##CLASS, MEMBER) ==          \
                  offsetof(struct CLASS, MEMBER))
 
+#endif  // SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_MAC
+
 #endif
diff --git a/libsanitizer/sanitizer_common/sanitizer_posix.cc b/libsanitizer/sanitizer_common/sanitizer_posix.cc
index d10213d917f..8f59deb23b3 100644
--- a/libsanitizer/sanitizer_common/sanitizer_posix.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_posix.cc
@@ -15,23 +15,17 @@
 #if SANITIZER_POSIX
 
 #include "sanitizer_common.h"
+#include "sanitizer_file.h"
 #include "sanitizer_libc.h"
 #include "sanitizer_posix.h"
 #include "sanitizer_procmaps.h"
 #include "sanitizer_stacktrace.h"
 
+#include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <sys/mman.h>
 
-#if SANITIZER_LINUX
-#include <sys/utsname.h>
-#endif
-
-#if SANITIZER_LINUX && !SANITIZER_ANDROID
-#include <sys/personality.h>
-#endif
-
 #if SANITIZER_FREEBSD
 // The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before
 // that, it was never implemented.  So just define it to zero.
@@ -46,87 +40,13 @@ uptr GetMmapGranularity() {
   return GetPageSize();
 }
 
-#if SANITIZER_WORDSIZE == 32
-// Take care of unusable kernel area in top gigabyte.
-static uptr GetKernelAreaSize() {
-#if SANITIZER_LINUX && !SANITIZER_X32
-  const uptr gbyte = 1UL << 30;
-
-  // Firstly check if there are writable segments
-  // mapped to top gigabyte (e.g. stack).
-  MemoryMappingLayout proc_maps(/*cache_enabled*/true);
-  uptr end, prot;
-  while (proc_maps.Next(/*start*/nullptr, &end,
-                        /*offset*/nullptr, /*filename*/nullptr,
-                        /*filename_size*/0, &prot)) {
-    if ((end >= 3 * gbyte)
-        && (prot & MemoryMappingLayout::kProtectionWrite) != 0)
-      return 0;
-  }
-
-#if !SANITIZER_ANDROID
-  // Even if nothing is mapped, top Gb may still be accessible
-  // if we are running on 64-bit kernel.
-  // Uname may report misleading results if personality type
-  // is modified (e.g. under schroot) so check this as well.
-  struct utsname uname_info;
-  int pers = personality(0xffffffffUL);
-  if (!(pers & PER_MASK)
-      && uname(&uname_info) == 0
-      && internal_strstr(uname_info.machine, "64"))
-    return 0;
-#endif  // SANITIZER_ANDROID
-
-  // Top gigabyte is reserved for kernel.
-  return gbyte;
-#else
-  return 0;
-#endif  // SANITIZER_LINUX && !SANITIZER_X32
-}
-#endif  // SANITIZER_WORDSIZE == 32
-
-uptr GetMaxVirtualAddress() {
-#if SANITIZER_WORDSIZE == 64
-# if defined(__aarch64__) && SANITIZER_IOS && !SANITIZER_IOSSIM
-  // Ideally, we would derive the upper bound from MACH_VM_MAX_ADDRESS. The
-  // upper bound can change depending on the device.
-  return 0x200000000 - 1;
-# elif defined(__powerpc64__) || defined(__aarch64__)
-  // On PowerPC64 we have two different address space layouts: 44- and 46-bit.
-  // We somehow need to figure out which one we are using now and choose
-  // one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
-  // Note that with 'ulimit -s unlimited' the stack is moved away from the top
-  // of the address space, so simply checking the stack address is not enough.
-  // This should (does) work for both PowerPC64 Endian modes.
-  // Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
-  return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
-# elif defined(__mips64)
-  return (1ULL << 40) - 1;  // 0x000000ffffffffffUL;
-# elif defined(__s390x__)
-  return (1ULL << 53) - 1;  // 0x001fffffffffffffUL;
-# else
-  return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
-# endif
-#else  // SANITIZER_WORDSIZE == 32
-# if defined(__s390__)
-  return (1ULL << 31) - 1;  // 0x7fffffff;
-# else
-  uptr res = (1ULL << 32) - 1;  // 0xffffffff;
-  if (!common_flags()->full_address_space)
-    res -= GetKernelAreaSize();
-  CHECK_LT(reinterpret_cast<uptr>(&res), res);
-  return res;
-# endif
-#endif  // SANITIZER_WORDSIZE
-}
-
 void *MmapOrDie(uptr size, const char *mem_type, bool raw_report) {
   size = RoundUpTo(size, GetPageSizeCached());
   uptr res = internal_mmap(nullptr, size,
                            PROT_READ | PROT_WRITE,
                            MAP_PRIVATE | MAP_ANON, -1, 0);
   int reserrno;
-  if (internal_iserror(res, &reserrno))
+  if (UNLIKELY(internal_iserror(res, &reserrno)))
     ReportMmapFailureAndDie(size, mem_type, "allocate", reserrno, raw_report);
   IncreaseTotalMmap(size);
   return (void *)res;
@@ -135,7 +55,7 @@ void *MmapOrDie(uptr size, const char *mem_type, bool raw_report) {
 void UnmapOrDie(void *addr, uptr size) {
   if (!addr || !size) return;
   uptr res = internal_munmap(addr, size);
-  if (internal_iserror(res)) {
+  if (UNLIKELY(internal_iserror(res))) {
     Report("ERROR: %s failed to deallocate 0x%zx (%zd) bytes at address %p\n",
            SanitizerToolName, size, size, addr);
     CHECK("unable to unmap" && 0);
@@ -143,21 +63,39 @@ void UnmapOrDie(void *addr, uptr size) {
   DecreaseTotalMmap(size);
 }
 
+void *MmapOrDieOnFatalError(uptr size, const char *mem_type) {
+  size = RoundUpTo(size, GetPageSizeCached());
+  uptr res = internal_mmap(nullptr, size,
+                           PROT_READ | PROT_WRITE,
+                           MAP_PRIVATE | MAP_ANON, -1, 0);
+  int reserrno;
+  if (UNLIKELY(internal_iserror(res, &reserrno))) {
+    if (reserrno == ENOMEM)
+      return nullptr;
+    ReportMmapFailureAndDie(size, mem_type, "allocate", reserrno);
+  }
+  IncreaseTotalMmap(size);
+  return (void *)res;
+}
+
 // We want to map a chunk of address space aligned to 'alignment'.
-// We do it by maping a bit more and then unmaping redundant pieces.
+// We do it by mapping a bit more and then unmapping redundant pieces.
 // We probably can do it with fewer syscalls in some OS-dependent way.
-void *MmapAlignedOrDie(uptr size, uptr alignment, const char *mem_type) {
+void *MmapAlignedOrDieOnFatalError(uptr size, uptr alignment,
+                                   const char *mem_type) {
   CHECK(IsPowerOfTwo(size));
   CHECK(IsPowerOfTwo(alignment));
   uptr map_size = size + alignment;
-  uptr map_res = (uptr)MmapOrDie(map_size, mem_type);
+  uptr map_res = (uptr)MmapOrDieOnFatalError(map_size, mem_type);
+  if (UNLIKELY(!map_res))
+    return nullptr;
   uptr map_end = map_res + map_size;
   uptr res = map_res;
-  if (res & (alignment - 1))  // Not aligned.
-    res = (map_res + alignment) & ~(alignment - 1);
-  uptr end = res + size;
-  if (res != map_res)
+  if (!IsAligned(res, alignment)) {
+    res = (map_res + alignment - 1) & ~(alignment - 1);
     UnmapOrDie((void*)map_res, res - map_res);
+  }
+  uptr end = res + size;
   if (end != map_end)
     UnmapOrDie((void*)end, map_end - end);
   return (void*)res;
@@ -171,13 +109,13 @@ void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
                          MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
                          -1, 0);
   int reserrno;
-  if (internal_iserror(p, &reserrno))
+  if (UNLIKELY(internal_iserror(p, &reserrno)))
     ReportMmapFailureAndDie(size, mem_type, "allocate noreserve", reserrno);
   IncreaseTotalMmap(size);
   return (void *)p;
 }
 
-void *MmapFixedOrDie(uptr fixed_addr, uptr size) {
+void *MmapFixedImpl(uptr fixed_addr, uptr size, bool tolerate_enomem) {
   uptr PageSize = GetPageSizeCached();
   uptr p = internal_mmap((void*)(fixed_addr & ~(PageSize - 1)),
       RoundUpTo(size, PageSize),
@@ -185,8 +123,10 @@ void *MmapFixedOrDie(uptr fixed_addr, uptr size) {
       MAP_PRIVATE | MAP_ANON | MAP_FIXED,
       -1, 0);
   int reserrno;
-  if (internal_iserror(p, &reserrno)) {
-    char mem_type[30];
+  if (UNLIKELY(internal_iserror(p, &reserrno))) {
+    if (tolerate_enomem && reserrno == ENOMEM)
+      return nullptr;
+    char mem_type[40];
     internal_snprintf(mem_type, sizeof(mem_type), "memory at address 0x%zx",
                       fixed_addr);
     ReportMmapFailureAndDie(size, mem_type, "allocate", reserrno);
@@ -195,6 +135,14 @@ void *MmapFixedOrDie(uptr fixed_addr, uptr size) {
   return (void *)p;
 }
 
+void *MmapFixedOrDie(uptr fixed_addr, uptr size) {
+  return MmapFixedImpl(fixed_addr, size, false /*tolerate_enomem*/);
+}
+
+void *MmapFixedOrDieOnFatalError(uptr fixed_addr, uptr size) {
+  return MmapFixedImpl(fixed_addr, size, true /*tolerate_enomem*/);
+}
+
 bool MprotectNoAccess(uptr addr, uptr size) {
   return 0 == internal_mprotect((void*)addr, size, PROT_NONE);
 }
@@ -282,13 +230,12 @@ static inline bool IntervalsAreSeparate(uptr start1, uptr end1,
 // memory).
 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
-  uptr start, end;
-  while (proc_maps.Next(&start, &end,
-                        /*offset*/nullptr, /*filename*/nullptr,
-                        /*filename_size*/0, /*protection*/nullptr)) {
-    if (start == end) continue;  // Empty range.
-    CHECK_NE(0, end);
-    if (!IntervalsAreSeparate(start, end - 1, range_start, range_end))
+  MemoryMappedSegment segment;
+  while (proc_maps.Next(&segment)) {
+    if (segment.start == segment.end) continue;  // Empty range.
+    CHECK_NE(0, segment.end);
+    if (!IntervalsAreSeparate(segment.start, segment.end - 1, range_start,
+                              range_end))
       return false;
   }
   return true;
@@ -296,13 +243,13 @@ bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
 
 void DumpProcessMap() {
   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
-  uptr start, end;
   const sptr kBufSize = 4095;
   char *filename = (char*)MmapOrDie(kBufSize, __func__);
+  MemoryMappedSegment segment(filename, kBufSize);
   Report("Process memory map follows:\n");
-  while (proc_maps.Next(&start, &end, /* file_offset */nullptr,
-                        filename, kBufSize, /* protection */nullptr)) {
-    Printf("\t%p-%p\t%s\n", (void*)start, (void*)end, filename);
+  while (proc_maps.Next(&segment)) {
+    Printf("\t%p-%p\t%s\n", (void *)segment.start, (void *)segment.end,
+           segment.filename);
   }
   Report("End of process memory map.\n");
   UnmapOrDie(filename, kBufSize);
@@ -332,28 +279,48 @@ void ReportFile::Write(const char *buffer, uptr length) {
 }
 
 bool GetCodeRangeForFile(const char *module, uptr *start, uptr *end) {
-  uptr s, e, off, prot;
-  InternalScopedString buff(kMaxPathLength);
   MemoryMappingLayout proc_maps(/*cache_enabled*/false);
-  while (proc_maps.Next(&s, &e, &off, buff.data(), buff.size(), &prot)) {
-    if ((prot & MemoryMappingLayout::kProtectionExecute) != 0
-        && internal_strcmp(module, buff.data()) == 0) {
-      *start = s;
-      *end = e;
+  InternalScopedString buff(kMaxPathLength);
+  MemoryMappedSegment segment(buff.data(), kMaxPathLength);
+  while (proc_maps.Next(&segment)) {
+    if (segment.IsExecutable() &&
+        internal_strcmp(module, segment.filename) == 0) {
+      *start = segment.start;
+      *end = segment.end;
       return true;
     }
   }
   return false;
 }
 
-SignalContext SignalContext::Create(void *siginfo, void *context) {
-  auto si = (siginfo_t *)siginfo;
-  uptr addr = (uptr)si->si_addr;
-  uptr pc, sp, bp;
-  GetPcSpBp(context, &pc, &sp, &bp);
-  WriteFlag write_flag = GetWriteFlag(context);
-  bool is_memory_access = si->si_signo == SIGSEGV;
-  return SignalContext(context, addr, pc, sp, bp, is_memory_access, write_flag);
+uptr SignalContext::GetAddress() const {
+  auto si = static_cast<const siginfo_t *>(siginfo);
+  return (uptr)si->si_addr;
+}
+
+bool SignalContext::IsMemoryAccess() const {
+  auto si = static_cast<const siginfo_t *>(siginfo);
+  return si->si_signo == SIGSEGV;
+}
+
+int SignalContext::GetType() const {
+  return static_cast<const siginfo_t *>(siginfo)->si_signo;
+}
+
+const char *SignalContext::Describe() const {
+  switch (GetType()) {
+    case SIGFPE:
+      return "FPE";
+    case SIGILL:
+      return "ILL";
+    case SIGABRT:
+      return "ABRT";
+    case SIGSEGV:
+      return "SEGV";
+    case SIGBUS:
+      return "BUS";
+  }
+  return "UNKNOWN SIGNAL";
 }
 
 } // namespace __sanitizer
diff --git a/libsanitizer/sanitizer_common/sanitizer_posix.h b/libsanitizer/sanitizer_common/sanitizer_posix.h
index 68b34babdeb..9626654e53a 100644
--- a/libsanitizer/sanitizer_common/sanitizer_posix.h
+++ b/libsanitizer/sanitizer_common/sanitizer_posix.h
@@ -14,6 +14,7 @@
 // ----------- ATTENTION -------------
 // This header should NOT include any other headers from sanitizer runtime.
 #include "sanitizer_internal_defs.h"
+#include "sanitizer_platform_limits_netbsd.h"
 #include "sanitizer_platform_limits_posix.h"
 
 #if !SANITIZER_POSIX
@@ -85,6 +86,9 @@ bool internal_sigismember(__sanitizer_sigset_t *set, int signum);
 
 uptr internal_execve(const char *filename, char *const argv[],
                      char *const envp[]);
+
+bool IsStateDetached(int state);
+
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_POSIX_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_posix_libcdep.cc b/libsanitizer/sanitizer_common/sanitizer_posix_libcdep.cc
index 335aad1660e..1a37118c299 100644
--- a/libsanitizer/sanitizer_common/sanitizer_posix_libcdep.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_posix_libcdep.cc
@@ -16,6 +16,7 @@
 
 #include "sanitizer_common.h"
 #include "sanitizer_flags.h"
+#include "sanitizer_platform_limits_netbsd.h"
 #include "sanitizer_platform_limits_posix.h"
 #include "sanitizer_posix.h"
 #include "sanitizer_procmaps.h"
@@ -54,8 +55,12 @@ uptr GetThreadSelf() {
   return (uptr)pthread_self();
 }
 
-void ReleaseMemoryToOS(uptr addr, uptr size) {
-  madvise((void*)addr, size, MADV_DONTNEED);
+void ReleaseMemoryPagesToOS(uptr beg, uptr end) {
+  uptr page_size = GetPageSizeCached();
+  uptr beg_aligned = RoundUpTo(beg, page_size);
+  uptr end_aligned = RoundDownTo(end, page_size);
+  if (beg_aligned < end_aligned)
+    madvise((void*)beg_aligned, end_aligned - beg_aligned, MADV_DONTNEED);
 }
 
 void NoHugePagesInRegion(uptr addr, uptr size) {
@@ -128,7 +133,8 @@ void SleepForMillis(int millis) {
 void Abort() {
 #if !SANITIZER_GO
   // If we are handling SIGABRT, unhandle it first.
-  if (IsHandledDeadlySignal(SIGABRT)) {
+  // TODO(vitalybuka): Check if handler belongs to sanitizer.
+  if (GetHandleSignalMode(SIGABRT) != kHandleSignalNo) {
     struct sigaction sigact;
     internal_memset(&sigact, 0, sizeof(sigact));
     sigact.sa_sigaction = (sa_sigaction_t)SIG_DFL;
@@ -182,8 +188,8 @@ void UnsetAlternateSignalStack() {
 
 static void MaybeInstallSigaction(int signum,
                                   SignalHandlerType handler) {
-  if (!IsHandledDeadlySignal(signum))
-    return;
+  if (GetHandleSignalMode(signum) == kHandleSignalNo) return;
+
   struct sigaction sigact;
   internal_memset(&sigact, 0, sizeof(sigact));
   sigact.sa_sigaction = (sa_sigaction_t)handler;
@@ -206,6 +212,53 @@ void InstallDeadlySignalHandlers(SignalHandlerType handler) {
   MaybeInstallSigaction(SIGFPE, handler);
   MaybeInstallSigaction(SIGILL, handler);
 }
+
+bool SignalContext::IsStackOverflow() const {
+  // Access at a reasonable offset above SP, or slightly below it (to account
+  // for x86_64 or PowerPC redzone, ARM push of multiple registers, etc) is
+  // probably a stack overflow.
+#ifdef __s390__
+  // On s390, the fault address in siginfo points to start of the page, not
+  // to the precise word that was accessed.  Mask off the low bits of sp to
+  // take it into account.
+  bool IsStackAccess = addr >= (sp & ~0xFFF) && addr < sp + 0xFFFF;
+#else
+  bool IsStackAccess = addr + 512 > sp && addr < sp + 0xFFFF;
+#endif
+
+#if __powerpc__
+  // Large stack frames can be allocated with e.g.
+  //   lis r0,-10000
+  //   stdux r1,r1,r0 # store sp to [sp-10000] and update sp by -10000
+  // If the store faults then sp will not have been updated, so test above
+  // will not work, because the fault address will be more than just "slightly"
+  // below sp.
+  if (!IsStackAccess && IsAccessibleMemoryRange(pc, 4)) {
+    u32 inst = *(unsigned *)pc;
+    u32 ra = (inst >> 16) & 0x1F;
+    u32 opcd = inst >> 26;
+    u32 xo = (inst >> 1) & 0x3FF;
+    // Check for store-with-update to sp. The instructions we accept are:
+    //   stbu rs,d(ra)          stbux rs,ra,rb
+    //   sthu rs,d(ra)          sthux rs,ra,rb
+    //   stwu rs,d(ra)          stwux rs,ra,rb
+    //   stdu rs,ds(ra)         stdux rs,ra,rb
+    // where ra is r1 (the stack pointer).
+    if (ra == 1 &&
+        (opcd == 39 || opcd == 45 || opcd == 37 || opcd == 62 ||
+         (opcd == 31 && (xo == 247 || xo == 439 || xo == 183 || xo == 181))))
+      IsStackAccess = true;
+  }
+#endif  // __powerpc__
+
+  // We also check si_code to filter out SEGV caused by something else other
+  // then hitting the guard page or unmapped memory, like, for example,
+  // unaligned memory access.
+  auto si = static_cast<const siginfo_t *>(siginfo);
+  return IsStackAccess &&
+         (si->si_code == si_SEGV_MAPERR || si->si_code == si_SEGV_ACCERR);
+}
+
 #endif  // SANITIZER_GO
 
 bool IsAccessibleMemoryRange(uptr beg, uptr size) {
@@ -239,7 +292,6 @@ void PrepareForSandboxing(__sanitizer_sandbox_arguments *args) {
   // Same for /proc/self/exe in the symbolizer.
 #if !SANITIZER_GO
   Symbolizer::GetOrInit()->PrepareForSandboxing();
-  CovPrepareForSandboxing(args);
 #endif
 }
 
@@ -412,6 +464,10 @@ int WaitForProcess(pid_t pid) {
   return process_status;
 }
 
+bool IsStateDetached(int state) {
+  return state == PTHREAD_CREATE_DETACHED;
+}
+
 } // namespace __sanitizer
 
 #endif // SANITIZER_POSIX
diff --git a/libsanitizer/sanitizer_common/sanitizer_printf.cc b/libsanitizer/sanitizer_common/sanitizer_printf.cc
index c11113da244..1456c765b2c 100644
--- a/libsanitizer/sanitizer_common/sanitizer_printf.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_printf.cc
@@ -26,8 +26,6 @@
 
 namespace __sanitizer {
 
-StaticSpinMutex CommonSanitizerReportMutex;
-
 static int AppendChar(char **buff, const char *buff_end, char c) {
   if (*buff < buff_end) {
     **buff = c;
@@ -41,7 +39,7 @@ static int AppendChar(char **buff, const char *buff_end, char c) {
 // on the value of |pad_with_zero|.
 static int AppendNumber(char **buff, const char *buff_end, u64 absolute_value,
                         u8 base, u8 minimal_num_length, bool pad_with_zero,
-                        bool negative) {
+                        bool negative, bool uppercase) {
   uptr const kMaxLen = 30;
   RAW_CHECK(base == 10 || base == 16);
   RAW_CHECK(base == 10 || !negative);
@@ -74,23 +72,25 @@ static int AppendNumber(char **buff, const char *buff_end, u64 absolute_value,
   if (negative && !pad_with_zero) result += AppendChar(buff, buff_end, '-');
   for (; pos >= 0; pos--) {
     char digit = static_cast<char>(num_buffer[pos]);
-    result += AppendChar(buff, buff_end, (digit < 10) ? '0' + digit
-                                                      : 'a' + digit - 10);
+    digit = (digit < 10) ? '0' + digit : (uppercase ? 'A' : 'a') + digit - 10;
+    result += AppendChar(buff, buff_end, digit);
   }
   return result;
 }
 
 static int AppendUnsigned(char **buff, const char *buff_end, u64 num, u8 base,
-                          u8 minimal_num_length, bool pad_with_zero) {
+                          u8 minimal_num_length, bool pad_with_zero,
+                          bool uppercase) {
   return AppendNumber(buff, buff_end, num, base, minimal_num_length,
-                      pad_with_zero, false /* negative */);
+                      pad_with_zero, false /* negative */, uppercase);
 }
 
 static int AppendSignedDecimal(char **buff, const char *buff_end, s64 num,
                                u8 minimal_num_length, bool pad_with_zero) {
   bool negative = (num < 0);
   return AppendNumber(buff, buff_end, (u64)(negative ? -num : num), 10,
-                      minimal_num_length, pad_with_zero, negative);
+                      minimal_num_length, pad_with_zero, negative,
+                      false /* uppercase */);
 }
 
 static int AppendString(char **buff, const char *buff_end, int precision,
@@ -110,14 +110,16 @@ static int AppendPointer(char **buff, const char *buff_end, u64 ptr_value) {
   int result = 0;
   result += AppendString(buff, buff_end, -1, "0x");
   result += AppendUnsigned(buff, buff_end, ptr_value, 16,
-                           SANITIZER_POINTER_FORMAT_LENGTH, true);
+                           SANITIZER_POINTER_FORMAT_LENGTH,
+                           true /* pad_with_zero */, false /* uppercase */);
   return result;
 }
 
 int VSNPrintf(char *buff, int buff_length,
               const char *format, va_list args) {
   static const char *kPrintfFormatsHelp =
-    "Supported Printf formats: %([0-9]*)?(z|ll)?{d,u,x}; %p; %(\\.\\*)?s; %c\n";
+      "Supported Printf formats: %([0-9]*)?(z|ll)?{d,u,x,X}; %p; %(\\.\\*)?s; "
+      "%c\n";
   RAW_CHECK(format);
   RAW_CHECK(buff_length > 0);
   const char *buff_end = &buff[buff_length - 1];
@@ -162,12 +164,14 @@ int VSNPrintf(char *buff, int buff_length,
         break;
       }
       case 'u':
-      case 'x': {
+      case 'x':
+      case 'X': {
         uval = have_ll ? va_arg(args, u64)
              : have_z ? va_arg(args, uptr)
              : va_arg(args, unsigned);
-        result += AppendUnsigned(&buff, buff_end, uval,
-                                 (*cur == 'u') ? 10 : 16, width, pad_with_zero);
+        bool uppercase = (*cur == 'X');
+        result += AppendUnsigned(&buff, buff_end, uval, (*cur == 'u') ? 10 : 16,
+                                 width, pad_with_zero, uppercase);
         break;
       }
       case 'p': {
@@ -206,15 +210,11 @@ void SetPrintfAndReportCallback(void (*callback)(const char *)) {
 }
 
 // Can be overriden in frontend.
-#if SANITIZER_SUPPORTS_WEAK_HOOKS
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-void OnPrint(const char *str) {
-  (void)str;
-}
-#elif SANITIZER_GO && defined(TSAN_EXTERNAL_HOOKS)
-void OnPrint(const char *str);
+#if SANITIZER_GO && defined(TSAN_EXTERNAL_HOOKS)
+// Implementation must be defined in frontend.
+extern "C" void OnPrint(const char *str);
 #else
-void OnPrint(const char *str) {
+SANITIZER_INTERFACE_WEAK_DEF(void, OnPrint, const char *str) {
   (void)str;
 }
 #endif
@@ -225,19 +225,16 @@ static void CallPrintfAndReportCallback(const char *str) {
     PrintfAndReportCallback(str);
 }
 
-static void SharedPrintfCode(bool append_pid, const char *format,
-                             va_list args) {
+static void NOINLINE SharedPrintfCodeNoBuffer(bool append_pid,
+                                              char *local_buffer,
+                                              int buffer_size,
+                                              const char *format,
+                                              va_list args) {
   va_list args2;
   va_copy(args2, args);
   const int kLen = 16 * 1024;
-  // |local_buffer| is small enough not to overflow the stack and/or violate
-  // the stack limit enforced by TSan (-Wframe-larger-than=512). On the other
-  // hand, the bigger the buffer is, the more the chance the error report will
-  // fit into it.
-  char local_buffer[400];
   int needed_length;
   char *buffer = local_buffer;
-  int buffer_size = ARRAY_SIZE(local_buffer);
   // First try to print a message using a local buffer, and then fall back to
   // mmaped buffer.
   for (int use_mmap = 0; use_mmap < 2; use_mmap++) {
@@ -255,7 +252,9 @@ static void SharedPrintfCode(bool append_pid, const char *format,
         RAW_CHECK_MSG(needed_length < kLen, \
                       "Buffer in Report is too short!\n"); \
       }
-    if (append_pid) {
+    // Fuchsia's logging infrastructure always keeps track of the logging
+    // process, thread, and timestamp, so never prepend such information.
+    if (!SANITIZER_FUCHSIA && append_pid) {
       int pid = internal_getpid();
       const char *exe_name = GetProcessName();
       if (common_flags()->log_exe_name && exe_name) {
@@ -263,9 +262,8 @@ static void SharedPrintfCode(bool append_pid, const char *format,
                                            "==%s", exe_name);
         CHECK_NEEDED_LENGTH
       }
-      needed_length += internal_snprintf(buffer + needed_length,
-                                         buffer_size - needed_length,
-                                         "==%d==", pid);
+      needed_length += internal_snprintf(
+          buffer + needed_length, buffer_size - needed_length, "==%d==", pid);
       CHECK_NEEDED_LENGTH
     }
     needed_length += VSNPrintf(buffer + needed_length,
@@ -288,6 +286,17 @@ static void SharedPrintfCode(bool append_pid, const char *format,
   va_end(args2);
 }
 
+static void NOINLINE SharedPrintfCode(bool append_pid, const char *format,
+                                      va_list args) {
+  // |local_buffer| is small enough not to overflow the stack and/or violate
+  // the stack limit enforced by TSan (-Wframe-larger-than=512). On the other
+  // hand, the bigger the buffer is, the more the chance the error report will
+  // fit into it.
+  char local_buffer[400];
+  SharedPrintfCodeNoBuffer(append_pid, local_buffer, ARRAY_SIZE(local_buffer),
+                           format, args);
+}
+
 FORMAT(1, 2)
 void Printf(const char *format, ...) {
   va_list args;
diff --git a/libsanitizer/sanitizer_common/sanitizer_procmaps.h b/libsanitizer/sanitizer_common/sanitizer_procmaps.h
index 0183a094111..040f6940f17 100644
--- a/libsanitizer/sanitizer_common/sanitizer_procmaps.h
+++ b/libsanitizer/sanitizer_common/sanitizer_procmaps.h
@@ -12,29 +12,61 @@
 #ifndef SANITIZER_PROCMAPS_H
 #define SANITIZER_PROCMAPS_H
 
+#include "sanitizer_platform.h"
+
+#if SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD || SANITIZER_MAC
+
 #include "sanitizer_common.h"
 #include "sanitizer_internal_defs.h"
+#include "sanitizer_linux.h"
+#include "sanitizer_mac.h"
 #include "sanitizer_mutex.h"
 
 namespace __sanitizer {
 
-#if SANITIZER_FREEBSD || SANITIZER_LINUX
-struct ProcSelfMapsBuff {
-  char *data;
-  uptr mmaped_size;
-  uptr len;
-};
 
-// Reads process memory map in an OS-specific way.
-void ReadProcMaps(ProcSelfMapsBuff *proc_maps);
-#endif  // SANITIZER_FREEBSD || SANITIZER_LINUX
+// Memory protection masks.
+static const uptr kProtectionRead = 1;
+static const uptr kProtectionWrite = 2;
+static const uptr kProtectionExecute = 4;
+static const uptr kProtectionShared = 8;
+
+struct MemoryMappedSegmentData;
+
+class MemoryMappedSegment {
+ public:
+  MemoryMappedSegment(char *buff = nullptr, uptr size = 0)
+      : filename(buff), filename_size(size), data_(nullptr) {}
+  ~MemoryMappedSegment() {}
+
+  bool IsReadable() const { return protection & kProtectionRead; }
+  bool IsWritable() const { return protection & kProtectionWrite; }
+  bool IsExecutable() const { return protection & kProtectionExecute; }
+  bool IsShared() const { return protection & kProtectionShared; }
+
+  void AddAddressRanges(LoadedModule *module);
+
+  uptr start;
+  uptr end;
+  uptr offset;
+  char *filename;  // owned by caller
+  uptr filename_size;
+  uptr protection;
+  ModuleArch arch;
+  u8 uuid[kModuleUUIDSize];
+
+ private:
+  friend class MemoryMappingLayout;
+
+  // This field is assigned and owned by MemoryMappingLayout if needed
+  MemoryMappedSegmentData *data_;
+};
 
 class MemoryMappingLayout {
  public:
   explicit MemoryMappingLayout(bool cache_enabled);
   ~MemoryMappingLayout();
-  bool Next(uptr *start, uptr *end, uptr *offset,
-            char filename[], uptr filename_size, uptr *protection);
+  bool Next(MemoryMappedSegment *segment);
   void Reset();
   // In some cases, e.g. when running under a sandbox on Linux, ASan is unable
   // to obtain the memory mappings. It should fall back to pre-cached data
@@ -42,47 +74,14 @@ class MemoryMappingLayout {
   static void CacheMemoryMappings();
 
   // Adds all mapped objects into a vector.
-  void DumpListOfModules(InternalMmapVector<LoadedModule> *modules);
-
-  // Memory protection masks.
-  static const uptr kProtectionRead = 1;
-  static const uptr kProtectionWrite = 2;
-  static const uptr kProtectionExecute = 4;
-  static const uptr kProtectionShared = 8;
+  void DumpListOfModules(InternalMmapVectorNoCtor<LoadedModule> *modules);
 
  private:
   void LoadFromCache();
 
-  // FIXME: Hide implementation details for different platforms in
-  // platform-specific files.
-# if SANITIZER_FREEBSD || SANITIZER_LINUX
-  ProcSelfMapsBuff proc_self_maps_;
-  const char *current_;
-
-  // Static mappings cache.
-  static ProcSelfMapsBuff cached_proc_self_maps_;
-  static StaticSpinMutex cache_lock_;  // protects cached_proc_self_maps_.
-# elif SANITIZER_MAC
-  template<u32 kLCSegment, typename SegmentCommand>
-  bool NextSegmentLoad(uptr *start, uptr *end, uptr *offset,
-                       char filename[], uptr filename_size,
-                       uptr *protection);
-  int current_image_;
-  u32 current_magic_;
-  u32 current_filetype_;
-  int current_load_cmd_count_;
-  char *current_load_cmd_addr_;
-# endif
+  MemoryMappingLayoutData data_;
 };
 
-typedef void (*fill_profile_f)(uptr start, uptr rss, bool file,
-                               /*out*/uptr *stats, uptr stats_size);
-
-// Parse the contents of /proc/self/smaps and generate a memory profile.
-// |cb| is a tool-specific callback that fills the |stats| array containing
-// |stats_size| elements.
-void GetMemoryProfile(fill_profile_f cb, uptr *stats, uptr stats_size);
-
 // Returns code range for the specified module.
 bool GetCodeRangeForFile(const char *module, uptr *start, uptr *end);
 
@@ -93,4 +92,6 @@ uptr ParseHex(const char **p);
 
 }  // namespace __sanitizer
 
+#endif  // SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD ||
+        // SANITIZER_MAC
 #endif  // SANITIZER_PROCMAPS_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_procmaps_common.cc b/libsanitizer/sanitizer_common/sanitizer_procmaps_common.cc
index c725c2e7b66..36b97b1166e 100644
--- a/libsanitizer/sanitizer_common/sanitizer_procmaps_common.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_procmaps_common.cc
@@ -10,7 +10,7 @@
 
 #include "sanitizer_platform.h"
 
-#if SANITIZER_FREEBSD || SANITIZER_LINUX
+#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
 
 #include "sanitizer_common.h"
 #include "sanitizer_placement_new.h"
@@ -18,9 +18,8 @@
 
 namespace __sanitizer {
 
-// Linker initialized.
-ProcSelfMapsBuff MemoryMappingLayout::cached_proc_self_maps_;
-StaticSpinMutex MemoryMappingLayout::cache_lock_;  // Linker initialized.
+static ProcSelfMapsBuff cached_proc_self_maps;
+static StaticSpinMutex cache_lock;
 
 static int TranslateDigit(char c) {
   if (c >= '0' && c <= '9')
@@ -62,15 +61,21 @@ uptr ParseHex(const char **p) {
   return ParseNumber(p, 16);
 }
 
+void MemoryMappedSegment::AddAddressRanges(LoadedModule *module) {
+  // data_ should be unused on this platform
+  CHECK(!data_);
+  module->addAddressRange(start, end, IsExecutable(), IsWritable());
+}
+
 MemoryMappingLayout::MemoryMappingLayout(bool cache_enabled) {
-  ReadProcMaps(&proc_self_maps_);
+  ReadProcMaps(&data_.proc_self_maps);
   if (cache_enabled) {
-    if (proc_self_maps_.mmaped_size == 0) {
+    if (data_.proc_self_maps.mmaped_size == 0) {
       LoadFromCache();
-      CHECK_GT(proc_self_maps_.len, 0);
+      CHECK_GT(data_.proc_self_maps.len, 0);
     }
   } else {
-    CHECK_GT(proc_self_maps_.mmaped_size, 0);
+    CHECK_GT(data_.proc_self_maps.mmaped_size, 0);
   }
   Reset();
   // FIXME: in the future we may want to cache the mappings on demand only.
@@ -81,24 +86,22 @@ MemoryMappingLayout::MemoryMappingLayout(bool cache_enabled) {
 MemoryMappingLayout::~MemoryMappingLayout() {
   // Only unmap the buffer if it is different from the cached one. Otherwise
   // it will be unmapped when the cache is refreshed.
-  if (proc_self_maps_.data != cached_proc_self_maps_.data) {
-    UnmapOrDie(proc_self_maps_.data, proc_self_maps_.mmaped_size);
+  if (data_.proc_self_maps.data != cached_proc_self_maps.data) {
+    UnmapOrDie(data_.proc_self_maps.data, data_.proc_self_maps.mmaped_size);
   }
 }
 
-void MemoryMappingLayout::Reset() {
-  current_ = proc_self_maps_.data;
-}
+void MemoryMappingLayout::Reset() { data_.current = data_.proc_self_maps.data; }
 
 // static
 void MemoryMappingLayout::CacheMemoryMappings() {
-  SpinMutexLock l(&cache_lock_);
+  SpinMutexLock l(&cache_lock);
   // Don't invalidate the cache if the mappings are unavailable.
   ProcSelfMapsBuff old_proc_self_maps;
-  old_proc_self_maps = cached_proc_self_maps_;
-  ReadProcMaps(&cached_proc_self_maps_);
-  if (cached_proc_self_maps_.mmaped_size == 0) {
-    cached_proc_self_maps_ = old_proc_self_maps;
+  old_proc_self_maps = cached_proc_self_maps;
+  ReadProcMaps(&cached_proc_self_maps);
+  if (cached_proc_self_maps.mmaped_size == 0) {
+    cached_proc_self_maps = old_proc_self_maps;
   } else {
     if (old_proc_self_maps.mmaped_size) {
       UnmapOrDie(old_proc_self_maps.data,
@@ -108,21 +111,19 @@ void MemoryMappingLayout::CacheMemoryMappings() {
 }
 
 void MemoryMappingLayout::LoadFromCache() {
-  SpinMutexLock l(&cache_lock_);
-  if (cached_proc_self_maps_.data) {
-    proc_self_maps_ = cached_proc_self_maps_;
+  SpinMutexLock l(&cache_lock);
+  if (cached_proc_self_maps.data) {
+    data_.proc_self_maps = cached_proc_self_maps;
   }
 }
 
 void MemoryMappingLayout::DumpListOfModules(
-    InternalMmapVector<LoadedModule> *modules) {
+    InternalMmapVectorNoCtor<LoadedModule> *modules) {
   Reset();
-  uptr cur_beg, cur_end, cur_offset, prot;
   InternalScopedString module_name(kMaxPathLength);
-  for (uptr i = 0; Next(&cur_beg, &cur_end, &cur_offset, module_name.data(),
-                        module_name.size(), &prot);
-       i++) {
-    const char *cur_name = module_name.data();
+  MemoryMappedSegment segment(module_name.data(), module_name.size());
+  for (uptr i = 0; Next(&segment); i++) {
+    const char *cur_name = segment.filename;
     if (cur_name[0] == '\0')
       continue;
     // Don't subtract 'cur_beg' from the first entry:
@@ -136,10 +137,10 @@ void MemoryMappingLayout::DumpListOfModules(
     //   mapped high at address space (in particular, higher than
     //   shadow memory of the tool), so the module can't be the
     //   first entry.
-    uptr base_address = (i ? cur_beg : 0) - cur_offset;
+    uptr base_address = (i ? segment.start : 0) - segment.offset;
     LoadedModule cur_module;
     cur_module.set(cur_name, base_address);
-    cur_module.addAddressRange(cur_beg, cur_end, prot & kProtectionExecute);
+    segment.AddAddressRanges(&cur_module);
     modules->push_back(cur_module);
   }
 }
@@ -170,4 +171,4 @@ void GetMemoryProfile(fill_profile_f cb, uptr *stats, uptr stats_size) {
 
 } // namespace __sanitizer
 
-#endif // SANITIZER_FREEBSD || SANITIZER_LINUX
+#endif // SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
diff --git a/libsanitizer/sanitizer_common/sanitizer_procmaps_freebsd.cc b/libsanitizer/sanitizer_common/sanitizer_procmaps_freebsd.cc
index fbc55203ab4..ba5d1449c0e 100644
--- a/libsanitizer/sanitizer_common/sanitizer_procmaps_freebsd.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_procmaps_freebsd.cc
@@ -5,18 +5,22 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// Information about the process mappings (FreeBSD-specific parts).
+// Information about the process mappings (FreeBSD and NetBSD-specific parts).
 //===----------------------------------------------------------------------===//
 
 #include "sanitizer_platform.h"
-#if SANITIZER_FREEBSD
+#if SANITIZER_FREEBSD || SANITIZER_NETBSD
 #include "sanitizer_common.h"
+#if SANITIZER_FREEBSD
 #include "sanitizer_freebsd.h"
+#endif
 #include "sanitizer_procmaps.h"
 
 #include <unistd.h>
 #include <sys/sysctl.h>
+#if SANITIZER_FREEBSD
 #include <sys/user.h>
+#endif
 
 // Fix 'kinfo_vmentry' definition on FreeBSD prior v9.2 in 32-bit mode.
 #if SANITIZER_FREEBSD && (SANITIZER_WORDSIZE == 32)
@@ -29,16 +33,30 @@
 namespace __sanitizer {
 
 void ReadProcMaps(ProcSelfMapsBuff *proc_maps) {
-  const int Mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_VMMAP, getpid() };
+  const int Mib[] = {
+#if SANITIZER_FREEBSD
+    CTL_KERN,
+    KERN_PROC,
+    KERN_PROC_VMMAP,
+    getpid()
+#else
+    CTL_VM,
+    VM_PROC,
+    VM_PROC_MAP,
+    getpid(),
+    sizeof(struct kinfo_vmentry)
+#endif
+  };
+
   size_t Size = 0;
-  int Err = sysctl(Mib, 4, NULL, &Size, NULL, 0);
+  int Err = sysctl(Mib, ARRAY_SIZE(Mib), NULL, &Size, NULL, 0);
   CHECK_EQ(Err, 0);
   CHECK_GT(Size, 0);
 
   size_t MmapedSize = Size * 4 / 3;
   void *VmMap = MmapOrDie(MmapedSize, "ReadProcMaps()");
   Size = MmapedSize;
-  Err = sysctl(Mib, 4, VmMap, &Size, NULL, 0);
+  Err = sysctl(Mib, ARRAY_SIZE(Mib), VmMap, &Size, NULL, 0);
   CHECK_EQ(Err, 0);
 
   proc_maps->data = (char*)VmMap;
@@ -46,41 +64,38 @@ void ReadProcMaps(ProcSelfMapsBuff *proc_maps) {
   proc_maps->len = Size;
 }
 
-bool MemoryMappingLayout::Next(uptr *start, uptr *end, uptr *offset,
-                               char filename[], uptr filename_size,
-                               uptr *protection) {
-  char *last = proc_self_maps_.data + proc_self_maps_.len;
-  if (current_ >= last) return false;
-  uptr dummy;
-  if (!start) start = &dummy;
-  if (!end) end = &dummy;
-  if (!offset) offset = &dummy;
-  if (!protection) protection = &dummy;
-  struct kinfo_vmentry *VmEntry = (struct kinfo_vmentry*)current_;
-
-  *start = (uptr)VmEntry->kve_start;
-  *end = (uptr)VmEntry->kve_end;
-  *offset = (uptr)VmEntry->kve_offset;
-
-  *protection = 0;
+bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) {
+  char *last = data_.proc_self_maps.data + data_.proc_self_maps.len;
+  if (data_.current >= last) return false;
+  struct kinfo_vmentry *VmEntry = (struct kinfo_vmentry *)data_.current;
+
+  segment->start = (uptr)VmEntry->kve_start;
+  segment->end = (uptr)VmEntry->kve_end;
+  segment->offset = (uptr)VmEntry->kve_offset;
+
+  segment->protection = 0;
   if ((VmEntry->kve_protection & KVME_PROT_READ) != 0)
-    *protection |= kProtectionRead;
+    segment->protection |= kProtectionRead;
   if ((VmEntry->kve_protection & KVME_PROT_WRITE) != 0)
-    *protection |= kProtectionWrite;
+    segment->protection |= kProtectionWrite;
   if ((VmEntry->kve_protection & KVME_PROT_EXEC) != 0)
-    *protection |= kProtectionExecute;
+    segment->protection |= kProtectionExecute;
 
-  if (filename != NULL && filename_size > 0) {
-    internal_snprintf(filename,
-                      Min(filename_size, (uptr)PATH_MAX),
-                      "%s", VmEntry->kve_path);
+  if (segment->filename != NULL && segment->filename_size > 0) {
+    internal_snprintf(segment->filename,
+                      Min(segment->filename_size, (uptr)PATH_MAX), "%s",
+                      VmEntry->kve_path);
   }
 
-  current_ += VmEntry->kve_structsize;
+#if SANITIZER_FREEBSD
+  data_.current += VmEntry->kve_structsize;
+#else
+  data_.current += sizeof(*VmEntry);
+#endif
 
   return true;
 }
 
 }  // namespace __sanitizer
 
-#endif  // SANITIZER_FREEBSD
+#endif  // SANITIZER_FREEBSD || SANITIZER_NETBSD
diff --git a/libsanitizer/sanitizer_common/sanitizer_procmaps_linux.cc b/libsanitizer/sanitizer_common/sanitizer_procmaps_linux.cc
index 10918e54398..b97d5f62dd2 100644
--- a/libsanitizer/sanitizer_common/sanitizer_procmaps_linux.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_procmaps_linux.cc
@@ -16,70 +16,57 @@
 namespace __sanitizer {
 
 void ReadProcMaps(ProcSelfMapsBuff *proc_maps) {
-  CHECK(ReadFileToBuffer("/proc/self/maps", &proc_maps->data,
-                         &proc_maps->mmaped_size, &proc_maps->len));
+  ReadFileToBuffer("/proc/self/maps", &proc_maps->data, &proc_maps->mmaped_size,
+                   &proc_maps->len);
 }
 
 static bool IsOneOf(char c, char c1, char c2) {
   return c == c1 || c == c2;
 }
 
-bool MemoryMappingLayout::Next(uptr *start, uptr *end, uptr *offset,
-                               char filename[], uptr filename_size,
-                               uptr *protection) {
-  char *last = proc_self_maps_.data + proc_self_maps_.len;
-  if (current_ >= last) return false;
-  uptr dummy;
-  if (!start) start = &dummy;
-  if (!end) end = &dummy;
-  if (!offset) offset = &dummy;
-  if (!protection) protection = &dummy;
-  char *next_line = (char*)internal_memchr(current_, '\n', last - current_);
+bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) {
+  char *last = data_.proc_self_maps.data + data_.proc_self_maps.len;
+  if (data_.current >= last) return false;
+  char *next_line =
+      (char *)internal_memchr(data_.current, '\n', last - data_.current);
   if (next_line == 0)
     next_line = last;
   // Example: 08048000-08056000 r-xp 00000000 03:0c 64593   /foo/bar
-  *start = ParseHex(&current_);
-  CHECK_EQ(*current_++, '-');
-  *end = ParseHex(&current_);
-  CHECK_EQ(*current_++, ' ');
-  CHECK(IsOneOf(*current_, '-', 'r'));
-  *protection = 0;
-  if (*current_++ == 'r')
-    *protection |= kProtectionRead;
-  CHECK(IsOneOf(*current_, '-', 'w'));
-  if (*current_++ == 'w')
-    *protection |= kProtectionWrite;
-  CHECK(IsOneOf(*current_, '-', 'x'));
-  if (*current_++ == 'x')
-    *protection |= kProtectionExecute;
-  CHECK(IsOneOf(*current_, 's', 'p'));
-  if (*current_++ == 's')
-    *protection |= kProtectionShared;
-  CHECK_EQ(*current_++, ' ');
-  *offset = ParseHex(&current_);
-  CHECK_EQ(*current_++, ' ');
-  ParseHex(&current_);
-  CHECK_EQ(*current_++, ':');
-  ParseHex(&current_);
-  CHECK_EQ(*current_++, ' ');
-  while (IsDecimal(*current_))
-    current_++;
+  segment->start = ParseHex(&data_.current);
+  CHECK_EQ(*data_.current++, '-');
+  segment->end = ParseHex(&data_.current);
+  CHECK_EQ(*data_.current++, ' ');
+  CHECK(IsOneOf(*data_.current, '-', 'r'));
+  segment->protection = 0;
+  if (*data_.current++ == 'r') segment->protection |= kProtectionRead;
+  CHECK(IsOneOf(*data_.current, '-', 'w'));
+  if (*data_.current++ == 'w') segment->protection |= kProtectionWrite;
+  CHECK(IsOneOf(*data_.current, '-', 'x'));
+  if (*data_.current++ == 'x') segment->protection |= kProtectionExecute;
+  CHECK(IsOneOf(*data_.current, 's', 'p'));
+  if (*data_.current++ == 's') segment->protection |= kProtectionShared;
+  CHECK_EQ(*data_.current++, ' ');
+  segment->offset = ParseHex(&data_.current);
+  CHECK_EQ(*data_.current++, ' ');
+  ParseHex(&data_.current);
+  CHECK_EQ(*data_.current++, ':');
+  ParseHex(&data_.current);
+  CHECK_EQ(*data_.current++, ' ');
+  while (IsDecimal(*data_.current)) data_.current++;
   // Qemu may lack the trailing space.
   // https://github.com/google/sanitizers/issues/160
-  // CHECK_EQ(*current_++, ' ');
+  // CHECK_EQ(*data_.current++, ' ');
   // Skip spaces.
-  while (current_ < next_line && *current_ == ' ')
-    current_++;
+  while (data_.current < next_line && *data_.current == ' ') data_.current++;
   // Fill in the filename.
-  uptr i = 0;
-  while (current_ < next_line) {
-    if (filename && i < filename_size - 1)
-      filename[i++] = *current_;
-    current_++;
+  if (segment->filename) {
+    uptr len =
+        Min((uptr)(next_line - data_.current), segment->filename_size - 1);
+    internal_strncpy(segment->filename, data_.current, len);
+    segment->filename[len] = 0;
   }
-  if (filename && i < filename_size)
-    filename[i] = 0;
-  current_ = next_line + 1;
+
+  data_.current = next_line + 1;
   return true;
 }
 
diff --git a/libsanitizer/sanitizer_common/sanitizer_procmaps_mac.cc b/libsanitizer/sanitizer_common/sanitizer_procmaps_mac.cc
index 81829a7c284..34f0c207b09 100644
--- a/libsanitizer/sanitizer_common/sanitizer_procmaps_mac.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_procmaps_mac.cc
@@ -16,9 +16,69 @@
 
 #include <mach-o/dyld.h>
 #include <mach-o/loader.h>
+#include <mach/mach.h>
+
+// These are not available in older macOS SDKs.
+#ifndef CPU_SUBTYPE_X86_64_H
+#define CPU_SUBTYPE_X86_64_H  ((cpu_subtype_t)8)   /* Haswell */
+#endif
+#ifndef CPU_SUBTYPE_ARM_V7S
+#define CPU_SUBTYPE_ARM_V7S   ((cpu_subtype_t)11)  /* Swift */
+#endif
+#ifndef CPU_SUBTYPE_ARM_V7K
+#define CPU_SUBTYPE_ARM_V7K   ((cpu_subtype_t)12)
+#endif
+#ifndef CPU_TYPE_ARM64
+#define CPU_TYPE_ARM64        (CPU_TYPE_ARM | CPU_ARCH_ABI64)
+#endif
 
 namespace __sanitizer {
 
+// Contains information used to iterate through sections.
+struct MemoryMappedSegmentData {
+  char name[kMaxSegName];
+  uptr nsects;
+  char *current_load_cmd_addr;
+  u32 lc_type;
+  uptr base_virt_addr;
+  uptr addr_mask;
+};
+
+template <typename Section>
+static void NextSectionLoad(LoadedModule *module, MemoryMappedSegmentData *data,
+                            bool isWritable) {
+  const Section *sc = (const Section *)data->current_load_cmd_addr;
+  data->current_load_cmd_addr += sizeof(Section);
+
+  uptr sec_start = (sc->addr & data->addr_mask) + data->base_virt_addr;
+  uptr sec_end = sec_start + sc->size;
+  module->addAddressRange(sec_start, sec_end, /*executable=*/false, isWritable,
+                          sc->sectname);
+}
+
+void MemoryMappedSegment::AddAddressRanges(LoadedModule *module) {
+  // Don't iterate over sections when the caller hasn't set up the
+  // data pointer, when there are no sections, or when the segment
+  // is executable. Avoid iterating over executable sections because
+  // it will confuse libignore, and because the extra granularity
+  // of information is not needed by any sanitizers.
+  if (!data_ || !data_->nsects || IsExecutable()) {
+    module->addAddressRange(start, end, IsExecutable(), IsWritable(),
+                            data_ ? data_->name : nullptr);
+    return;
+  }
+
+  do {
+    if (data_->lc_type == LC_SEGMENT) {
+      NextSectionLoad<struct section>(module, data_, IsWritable());
+#ifdef MH_MAGIC_64
+    } else if (data_->lc_type == LC_SEGMENT_64) {
+      NextSectionLoad<struct section_64>(module, data_, IsWritable());
+#endif
+    }
+  } while (--data_->nsects);
+}
+
 MemoryMappingLayout::MemoryMappingLayout(bool cache_enabled) {
   Reset();
 }
@@ -46,13 +106,22 @@ void MemoryMappingLayout::Reset() {
   // _dyld_image_count is thread-unsafe. We need to register callbacks for
   // adding and removing images which will invalidate the MemoryMappingLayout
   // state.
-  current_image_ = _dyld_image_count();
-  current_load_cmd_count_ = -1;
-  current_load_cmd_addr_ = 0;
-  current_magic_ = 0;
-  current_filetype_ = 0;
+  data_.current_image = _dyld_image_count();
+  data_.current_load_cmd_count = -1;
+  data_.current_load_cmd_addr = 0;
+  data_.current_magic = 0;
+  data_.current_filetype = 0;
+  data_.current_arch = kModuleArchUnknown;
+  internal_memset(data_.current_uuid, 0, kModuleUUIDSize);
 }
 
+// The dyld load address should be unchanged throughout process execution,
+// and it is expensive to compute once many libraries have been loaded,
+// so cache it here and do not reset.
+static mach_header *dyld_hdr = 0;
+static const char kDyldPath[] = "/usr/lib/dyld";
+static const int kDyldImageIdx = -1;
+
 // static
 void MemoryMappingLayout::CacheMemoryMappings() {
   // No-op on Mac for now.
@@ -62,6 +131,48 @@ void MemoryMappingLayout::LoadFromCache() {
   // No-op on Mac for now.
 }
 
+// _dyld_get_image_header() and related APIs don't report dyld itself.
+// We work around this by manually recursing through the memory map
+// until we hit a Mach header matching dyld instead. These recurse
+// calls are expensive, but the first memory map generation occurs
+// early in the process, when dyld is one of the only images loaded,
+// so it will be hit after only a few iterations.
+static mach_header *get_dyld_image_header() {
+  mach_port_name_t port;
+  if (task_for_pid(mach_task_self(), internal_getpid(), &port) !=
+      KERN_SUCCESS) {
+    return nullptr;
+  }
+
+  unsigned depth = 1;
+  vm_size_t size = 0;
+  vm_address_t address = 0;
+  kern_return_t err = KERN_SUCCESS;
+  mach_msg_type_number_t count = VM_REGION_SUBMAP_INFO_COUNT_64;
+
+  while (true) {
+    struct vm_region_submap_info_64 info;
+    err = vm_region_recurse_64(port, &address, &size, &depth,
+                               (vm_region_info_t)&info, &count);
+    if (err != KERN_SUCCESS) return nullptr;
+
+    if (size >= sizeof(mach_header) && info.protection & kProtectionRead) {
+      mach_header *hdr = (mach_header *)address;
+      if ((hdr->magic == MH_MAGIC || hdr->magic == MH_MAGIC_64) &&
+          hdr->filetype == MH_DYLINKER) {
+        return hdr;
+      }
+    }
+    address += size;
+  }
+}
+
+const mach_header *get_dyld_hdr() {
+  if (!dyld_hdr) dyld_hdr = get_dyld_image_header();
+
+  return dyld_hdr;
+}
+
 // Next and NextSegmentLoad were inspired by base/sysinfo.cc in
 // Google Perftools, https://github.com/gperftools/gperftools.
 
@@ -69,79 +180,165 @@ void MemoryMappingLayout::LoadFromCache() {
 // and returns the start and end addresses and file offset of the corresponding
 // segment.
 // Note that the segment addresses are not necessarily sorted.
-template<u32 kLCSegment, typename SegmentCommand>
-bool MemoryMappingLayout::NextSegmentLoad(
-    uptr *start, uptr *end, uptr *offset,
-    char filename[], uptr filename_size, uptr *protection) {
-  const char* lc = current_load_cmd_addr_;
-  current_load_cmd_addr_ += ((const load_command *)lc)->cmdsize;
+template <u32 kLCSegment, typename SegmentCommand>
+static bool NextSegmentLoad(MemoryMappedSegment *segment,
+MemoryMappedSegmentData *seg_data, MemoryMappingLayoutData &layout_data) {
+  const char *lc = layout_data.current_load_cmd_addr;
+  layout_data.current_load_cmd_addr += ((const load_command *)lc)->cmdsize;
   if (((const load_command *)lc)->cmd == kLCSegment) {
-    const sptr dlloff = _dyld_get_image_vmaddr_slide(current_image_);
     const SegmentCommand* sc = (const SegmentCommand *)lc;
-    if (start) *start = sc->vmaddr + dlloff;
-    if (protection) {
-      // Return the initial protection.
-      *protection = sc->initprot;
+    uptr base_virt_addr, addr_mask;
+    if (layout_data.current_image == kDyldImageIdx) {
+      base_virt_addr = (uptr)get_dyld_hdr();
+      // vmaddr is masked with 0xfffff because on macOS versions < 10.12,
+      // it contains an absolute address rather than an offset for dyld.
+      // To make matters even more complicated, this absolute address
+      // isn't actually the absolute segment address, but the offset portion
+      // of the address is accurate when combined with the dyld base address,
+      // and the mask will give just this offset.
+      addr_mask = 0xfffff;
+    } else {
+      base_virt_addr =
+          (uptr)_dyld_get_image_vmaddr_slide(layout_data.current_image);
+      addr_mask = ~0;
     }
-    if (end) *end = sc->vmaddr + sc->vmsize + dlloff;
-    if (offset) {
-      if (current_filetype_ == /*MH_EXECUTE*/ 0x2) {
-        *offset = sc->vmaddr;
-      } else {
-        *offset = sc->fileoff;
-      }
+
+    segment->start = (sc->vmaddr & addr_mask) + base_virt_addr;
+    segment->end = segment->start + sc->vmsize;
+    // Most callers don't need section information, so only fill this struct
+    // when required.
+    if (seg_data) {
+      seg_data->nsects = sc->nsects;
+      seg_data->current_load_cmd_addr =
+          (char *)lc + sizeof(SegmentCommand);
+      seg_data->lc_type = kLCSegment;
+      seg_data->base_virt_addr = base_virt_addr;
+      seg_data->addr_mask = addr_mask;
+      internal_strncpy(seg_data->name, sc->segname,
+                       ARRAY_SIZE(seg_data->name));
     }
-    if (filename) {
-      internal_strncpy(filename, _dyld_get_image_name(current_image_),
-                       filename_size);
+
+    // Return the initial protection.
+    segment->protection = sc->initprot;
+    segment->offset = (layout_data.current_filetype ==
+                       /*MH_EXECUTE*/ 0x2)
+                          ? sc->vmaddr
+                          : sc->fileoff;
+    if (segment->filename) {
+      const char *src = (layout_data.current_image == kDyldImageIdx)
+                            ? kDyldPath
+                            : _dyld_get_image_name(layout_data.current_image);
+      internal_strncpy(segment->filename, src, segment->filename_size);
     }
+    segment->arch = layout_data.current_arch;
+    internal_memcpy(segment->uuid, layout_data.current_uuid, kModuleUUIDSize);
     return true;
   }
   return false;
 }
 
-bool MemoryMappingLayout::Next(uptr *start, uptr *end, uptr *offset,
-                               char filename[], uptr filename_size,
-                               uptr *protection) {
-  for (; current_image_ >= 0; current_image_--) {
-    const mach_header* hdr = _dyld_get_image_header(current_image_);
+ModuleArch ModuleArchFromCpuType(cpu_type_t cputype, cpu_subtype_t cpusubtype) {
+  cpusubtype = cpusubtype & ~CPU_SUBTYPE_MASK;
+  switch (cputype) {
+    case CPU_TYPE_I386:
+      return kModuleArchI386;
+    case CPU_TYPE_X86_64:
+      if (cpusubtype == CPU_SUBTYPE_X86_64_ALL) return kModuleArchX86_64;
+      if (cpusubtype == CPU_SUBTYPE_X86_64_H) return kModuleArchX86_64H;
+      CHECK(0 && "Invalid subtype of x86_64");
+      return kModuleArchUnknown;
+    case CPU_TYPE_ARM:
+      if (cpusubtype == CPU_SUBTYPE_ARM_V6) return kModuleArchARMV6;
+      if (cpusubtype == CPU_SUBTYPE_ARM_V7) return kModuleArchARMV7;
+      if (cpusubtype == CPU_SUBTYPE_ARM_V7S) return kModuleArchARMV7S;
+      if (cpusubtype == CPU_SUBTYPE_ARM_V7K) return kModuleArchARMV7K;
+      CHECK(0 && "Invalid subtype of ARM");
+      return kModuleArchUnknown;
+    case CPU_TYPE_ARM64:
+      return kModuleArchARM64;
+    default:
+      CHECK(0 && "Invalid CPU type");
+      return kModuleArchUnknown;
+  }
+}
+
+static const load_command *NextCommand(const load_command *lc) {
+  return (const load_command *)((char *)lc + lc->cmdsize);
+}
+
+static void FindUUID(const load_command *first_lc, u8 *uuid_output) {
+  for (const load_command *lc = first_lc; lc->cmd != 0; lc = NextCommand(lc)) {
+    if (lc->cmd != LC_UUID) continue;
+
+    const uuid_command *uuid_lc = (const uuid_command *)lc;
+    const uint8_t *uuid = &uuid_lc->uuid[0];
+    internal_memcpy(uuid_output, uuid, kModuleUUIDSize);
+    return;
+  }
+}
+
+static bool IsModuleInstrumented(const load_command *first_lc) {
+  for (const load_command *lc = first_lc; lc->cmd != 0; lc = NextCommand(lc)) {
+    if (lc->cmd != LC_LOAD_DYLIB) continue;
+
+    const dylib_command *dylib_lc = (const dylib_command *)lc;
+    uint32_t dylib_name_offset = dylib_lc->dylib.name.offset;
+    const char *dylib_name = ((const char *)dylib_lc) + dylib_name_offset;
+    dylib_name = StripModuleName(dylib_name);
+    if (dylib_name != 0 && (internal_strstr(dylib_name, "libclang_rt."))) {
+      return true;
+    }
+  }
+  return false;
+}
+
+bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) {
+  for (; data_.current_image >= kDyldImageIdx; data_.current_image--) {
+    const mach_header *hdr = (data_.current_image == kDyldImageIdx)
+                                 ? get_dyld_hdr()
+                                 : _dyld_get_image_header(data_.current_image);
     if (!hdr) continue;
-    if (current_load_cmd_count_ < 0) {
+    if (data_.current_load_cmd_count < 0) {
       // Set up for this image;
-      current_load_cmd_count_ = hdr->ncmds;
-      current_magic_ = hdr->magic;
-      current_filetype_ = hdr->filetype;
-      switch (current_magic_) {
+      data_.current_load_cmd_count = hdr->ncmds;
+      data_.current_magic = hdr->magic;
+      data_.current_filetype = hdr->filetype;
+      data_.current_arch = ModuleArchFromCpuType(hdr->cputype, hdr->cpusubtype);
+      switch (data_.current_magic) {
 #ifdef MH_MAGIC_64
         case MH_MAGIC_64: {
-          current_load_cmd_addr_ = (char*)hdr + sizeof(mach_header_64);
+          data_.current_load_cmd_addr = (char *)hdr + sizeof(mach_header_64);
           break;
         }
 #endif
         case MH_MAGIC: {
-          current_load_cmd_addr_ = (char*)hdr + sizeof(mach_header);
+          data_.current_load_cmd_addr = (char *)hdr + sizeof(mach_header);
           break;
         }
         default: {
           continue;
         }
       }
+      FindUUID((const load_command *)data_.current_load_cmd_addr,
+               data_.current_uuid);
+      data_.current_instrumented = IsModuleInstrumented(
+          (const load_command *)data_.current_load_cmd_addr);
     }
 
-    for (; current_load_cmd_count_ >= 0; current_load_cmd_count_--) {
-      switch (current_magic_) {
-        // current_magic_ may be only one of MH_MAGIC, MH_MAGIC_64.
+    for (; data_.current_load_cmd_count >= 0; data_.current_load_cmd_count--) {
+      switch (data_.current_magic) {
+        // data_.current_magic may be only one of MH_MAGIC, MH_MAGIC_64.
 #ifdef MH_MAGIC_64
         case MH_MAGIC_64: {
           if (NextSegmentLoad<LC_SEGMENT_64, struct segment_command_64>(
-                  start, end, offset, filename, filename_size, protection))
+          segment, segment->data_, data_))
             return true;
           break;
         }
 #endif
         case MH_MAGIC: {
           if (NextSegmentLoad<LC_SEGMENT, struct segment_command>(
-                  start, end, offset, filename, filename_size, protection))
+          segment, segment->data_, data_))
             return true;
           break;
         }
@@ -154,26 +351,25 @@ bool MemoryMappingLayout::Next(uptr *start, uptr *end, uptr *offset,
 }
 
 void MemoryMappingLayout::DumpListOfModules(
-    InternalMmapVector<LoadedModule> *modules) {
+    InternalMmapVectorNoCtor<LoadedModule> *modules) {
   Reset();
-  uptr cur_beg, cur_end, prot;
   InternalScopedString module_name(kMaxPathLength);
-  for (uptr i = 0; Next(&cur_beg, &cur_end, 0, module_name.data(),
-                        module_name.size(), &prot);
-       i++) {
-    const char *cur_name = module_name.data();
-    if (cur_name[0] == '\0')
-      continue;
+  MemoryMappedSegment segment(module_name.data(), kMaxPathLength);
+  MemoryMappedSegmentData data;
+  segment.data_ = &data;
+  while (Next(&segment)) {
+    if (segment.filename[0] == '\0') continue;
     LoadedModule *cur_module = nullptr;
     if (!modules->empty() &&
-        0 == internal_strcmp(cur_name, modules->back().full_name())) {
+        0 == internal_strcmp(segment.filename, modules->back().full_name())) {
       cur_module = &modules->back();
     } else {
       modules->push_back(LoadedModule());
       cur_module = &modules->back();
-      cur_module->set(cur_name, cur_beg);
+      cur_module->set(segment.filename, segment.start, segment.arch,
+                      segment.uuid, data_.current_instrumented);
     }
-    cur_module->addAddressRange(cur_beg, cur_end, prot & kProtectionExecute);
+    segment.AddAddressRanges(cur_module);
   }
 }
 
diff --git a/libsanitizer/sanitizer_common/sanitizer_quarantine.h b/libsanitizer/sanitizer_common/sanitizer_quarantine.h
index 9e9268f2a5d..a90c8e3bdb8 100644
--- a/libsanitizer/sanitizer_common/sanitizer_quarantine.h
+++ b/libsanitizer/sanitizer_common/sanitizer_quarantine.h
@@ -29,6 +29,40 @@ struct QuarantineBatch {
   uptr size;
   uptr count;
   void *batch[kSize];
+
+  void init(void *ptr, uptr size) {
+    count = 1;
+    batch[0] = ptr;
+    this->size = size + sizeof(QuarantineBatch);  // Account for the batch size.
+  }
+
+  // The total size of quarantined nodes recorded in this batch.
+  uptr quarantined_size() const {
+    return size - sizeof(QuarantineBatch);
+  }
+
+  void push_back(void *ptr, uptr size) {
+    CHECK_LT(count, kSize);
+    batch[count++] = ptr;
+    this->size += size;
+  }
+
+  bool can_merge(const QuarantineBatch* const from) const {
+    return count + from->count <= kSize;
+  }
+
+  void merge(QuarantineBatch* const from) {
+    CHECK_LE(count + from->count, kSize);
+    CHECK_GE(size, sizeof(QuarantineBatch));
+
+    for (uptr i = 0; i < from->count; ++i)
+      batch[count + i] = from->batch[i];
+    count += from->count;
+    size += from->quarantined_size();
+
+    from->count = 0;
+    from->size = sizeof(QuarantineBatch);
+  }
 };
 
 COMPILER_CHECK(sizeof(QuarantineBatch) <= (1 << 13));  // 8Kb.
@@ -47,17 +81,31 @@ class Quarantine {
   }
 
   void Init(uptr size, uptr cache_size) {
-    atomic_store(&max_size_, size, memory_order_release);
+    // Thread local quarantine size can be zero only when global quarantine size
+    // is zero (it allows us to perform just one atomic read per Put() call).
+    CHECK((size == 0 && cache_size == 0) || cache_size != 0);
+
+    atomic_store(&max_size_, size, memory_order_relaxed);
     atomic_store(&min_size_, size / 10 * 9,
-                 memory_order_release); // 90% of max size.
-    max_cache_size_ = cache_size;
+                 memory_order_relaxed);  // 90% of max size.
+    atomic_store(&max_cache_size_, cache_size, memory_order_relaxed);
   }
 
-  uptr GetSize() const { return atomic_load(&max_size_, memory_order_acquire); }
+  uptr GetSize() const { return atomic_load(&max_size_, memory_order_relaxed); }
+  uptr GetCacheSize() const {
+    return atomic_load(&max_cache_size_, memory_order_relaxed);
+  }
 
   void Put(Cache *c, Callback cb, Node *ptr, uptr size) {
-    c->Enqueue(cb, ptr, size);
-    if (c->Size() > max_cache_size_)
+    uptr cache_size = GetCacheSize();
+    if (cache_size) {
+      c->Enqueue(cb, ptr, size);
+    } else {
+      // GetCacheSize() == 0 only when GetSize() == 0 (see Init).
+      cb.Recycle(ptr);
+    }
+    // Check cache size anyway to accommodate for runtime cache_size change.
+    if (c->Size() > cache_size)
       Drain(c, cb);
   }
 
@@ -70,12 +118,19 @@ class Quarantine {
       Recycle(cb);
   }
 
+  void PrintStats() const {
+    // It assumes that the world is stopped, just as the allocator's PrintStats.
+    Printf("Quarantine limits: global: %zdMb; thread local: %zdKb\n",
+           GetSize() >> 20, GetCacheSize() >> 10);
+    cache_.PrintStats();
+  }
+
  private:
   // Read-only data.
   char pad0_[kCacheLineSize];
   atomic_uintptr_t max_size_;
   atomic_uintptr_t min_size_;
-  uptr max_cache_size_;
+  atomic_uintptr_t max_cache_size_;
   char pad1_[kCacheLineSize];
   SpinMutex cache_mutex_;
   SpinMutex recycle_mutex_;
@@ -84,12 +139,30 @@ class Quarantine {
 
   void NOINLINE Recycle(Callback cb) {
     Cache tmp;
-    uptr min_size = atomic_load(&min_size_, memory_order_acquire);
+    uptr min_size = atomic_load(&min_size_, memory_order_relaxed);
     {
       SpinMutexLock l(&cache_mutex_);
+      // Go over the batches and merge partially filled ones to
+      // save some memory, otherwise batches themselves (since the memory used
+      // by them is counted against quarantine limit) can overcome the actual
+      // user's quarantined chunks, which diminishes the purpose of the
+      // quarantine.
+      uptr cache_size = cache_.Size();
+      uptr overhead_size = cache_.OverheadSize();
+      CHECK_GE(cache_size, overhead_size);
+      // Do the merge only when overhead exceeds this predefined limit (might
+      // require some tuning). It saves us merge attempt when the batch list
+      // quarantine is unlikely to contain batches suitable for merge.
+      const uptr kOverheadThresholdPercents = 100;
+      if (cache_size > overhead_size &&
+          overhead_size * (100 + kOverheadThresholdPercents) >
+              cache_size * kOverheadThresholdPercents) {
+        cache_.MergeBatches(&tmp);
+      }
+      // Extract enough chunks from the quarantine to get below the max
+      // quarantine size and leave some leeway for the newly quarantined chunks.
       while (cache_.Size() > min_size) {
-        QuarantineBatch *b = cache_.DequeueBatch();
-        tmp.EnqueueBatch(b);
+        tmp.EnqueueBatch(cache_.DequeueBatch());
       }
     }
     recycle_mutex_.Unlock();
@@ -124,26 +197,33 @@ class QuarantineCache {
     list_.clear();
   }
 
+  // Total memory used, including internal accounting.
   uptr Size() const {
     return atomic_load(&size_, memory_order_relaxed);
   }
 
+  // Memory used for internal accounting.
+  uptr OverheadSize() const {
+    return list_.size() * sizeof(QuarantineBatch);
+  }
+
   void Enqueue(Callback cb, void *ptr, uptr size) {
     if (list_.empty() || list_.back()->count == QuarantineBatch::kSize) {
-      AllocBatch(cb);
-      size += sizeof(QuarantineBatch);  // Count the batch in Quarantine size.
+      QuarantineBatch *b = (QuarantineBatch *)cb.Allocate(sizeof(*b));
+      CHECK(b);
+      b->init(ptr, size);
+      EnqueueBatch(b);
+    } else {
+      list_.back()->push_back(ptr, size);
+      SizeAdd(size);
     }
-    QuarantineBatch *b = list_.back();
-    CHECK(b);
-    b->batch[b->count++] = ptr;
-    b->size += size;
-    SizeAdd(size);
   }
 
-  void Transfer(QuarantineCache *c) {
-    list_.append_back(&c->list_);
-    SizeAdd(c->Size());
-    atomic_store(&c->size_, 0, memory_order_relaxed);
+  void Transfer(QuarantineCache *from_cache) {
+    list_.append_back(&from_cache->list_);
+    SizeAdd(from_cache->Size());
+
+    atomic_store(&from_cache->size_, 0, memory_order_relaxed);
   }
 
   void EnqueueBatch(QuarantineBatch *b) {
@@ -160,8 +240,57 @@ class QuarantineCache {
     return b;
   }
 
+  void MergeBatches(QuarantineCache *to_deallocate) {
+    uptr extracted_size = 0;
+    QuarantineBatch *current = list_.front();
+    while (current && current->next) {
+      if (current->can_merge(current->next)) {
+        QuarantineBatch *extracted = current->next;
+        // Move all the chunks into the current batch.
+        current->merge(extracted);
+        CHECK_EQ(extracted->count, 0);
+        CHECK_EQ(extracted->size, sizeof(QuarantineBatch));
+        // Remove the next batch from the list and account for its size.
+        list_.extract(current, extracted);
+        extracted_size += extracted->size;
+        // Add it to deallocation list.
+        to_deallocate->EnqueueBatch(extracted);
+      } else {
+        current = current->next;
+      }
+    }
+    SizeSub(extracted_size);
+  }
+
+  void PrintStats() const {
+    uptr batch_count = 0;
+    uptr total_overhead_bytes = 0;
+    uptr total_bytes = 0;
+    uptr total_quarantine_chunks = 0;
+    for (List::ConstIterator it = list_.begin(); it != list_.end(); ++it) {
+      batch_count++;
+      total_bytes += (*it).size;
+      total_overhead_bytes += (*it).size - (*it).quarantined_size();
+      total_quarantine_chunks += (*it).count;
+    }
+    uptr quarantine_chunks_capacity = batch_count * QuarantineBatch::kSize;
+    int chunks_usage_percent = quarantine_chunks_capacity == 0 ?
+        0 : total_quarantine_chunks * 100 / quarantine_chunks_capacity;
+    uptr total_quarantined_bytes = total_bytes - total_overhead_bytes;
+    int memory_overhead_percent = total_quarantined_bytes == 0 ?
+        0 : total_overhead_bytes * 100 / total_quarantined_bytes;
+    Printf("Global quarantine stats: batches: %zd; bytes: %zd (user: %zd); "
+           "chunks: %zd (capacity: %zd); %d%% chunks used; %d%% memory overhead"
+           "\n",
+           batch_count, total_bytes, total_quarantined_bytes,
+           total_quarantine_chunks, quarantine_chunks_capacity,
+           chunks_usage_percent, memory_overhead_percent);
+  }
+
  private:
-  IntrusiveList<QuarantineBatch> list_;
+  typedef IntrusiveList<QuarantineBatch> List;
+
+  List list_;
   atomic_uintptr_t size_;
 
   void SizeAdd(uptr add) {
@@ -170,16 +299,8 @@ class QuarantineCache {
   void SizeSub(uptr sub) {
     atomic_store(&size_, Size() - sub, memory_order_relaxed);
   }
-
-  NOINLINE QuarantineBatch* AllocBatch(Callback cb) {
-    QuarantineBatch *b = (QuarantineBatch *)cb.Allocate(sizeof(*b));
-    CHECK(b);
-    b->count = 0;
-    b->size = 0;
-    list_.push_back(b);
-    return b;
-  }
 };
+
 } // namespace __sanitizer
 
 #endif // SANITIZER_QUARANTINE_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_report_decorator.h b/libsanitizer/sanitizer_common/sanitizer_report_decorator.h
index e9be29fb3d5..c0edfcf7437 100644
--- a/libsanitizer/sanitizer_common/sanitizer_report_decorator.h
+++ b/libsanitizer/sanitizer_common/sanitizer_report_decorator.h
@@ -25,8 +25,9 @@ class SanitizerCommonDecorator {
   SanitizerCommonDecorator() : ansi_(ColorizeReports()) {}
   const char *Bold()    const { return ansi_ ? "\033[1m" : ""; }
   const char *Default() const { return ansi_ ? "\033[1m\033[0m"  : ""; }
-  const char *Warning()    { return Red(); }
-  const char *EndWarning() { return Default(); }
+  const char *Warning() const { return Red(); }
+  const char *MemoryByte() { return Magenta(); }
+
  protected:
   const char *Black()   const { return ansi_ ? "\033[1m\033[30m" : ""; }
   const char *Red()     const { return ansi_ ? "\033[1m\033[31m" : ""; }
diff --git a/libsanitizer/sanitizer_common/sanitizer_signal_interceptors.inc b/libsanitizer/sanitizer_common/sanitizer_signal_interceptors.inc
new file mode 100644
index 00000000000..b278f82ce03
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_signal_interceptors.inc
@@ -0,0 +1,65 @@
+//===-- sanitizer_signal_interceptors.inc -----------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Signal interceptors for sanitizers.
+//
+//===----------------------------------------------------------------------===//
+
+#include "interception/interception.h"
+#include "sanitizer_common.h"
+#include "sanitizer_internal_defs.h"
+#include "sanitizer_platform_interceptors.h"
+
+using namespace __sanitizer;
+
+#if SANITIZER_INTERCEPT_BSD_SIGNAL
+INTERCEPTOR(void *, bsd_signal, int signum, void *handler) {
+  if (GetHandleSignalMode(signum) == kHandleSignalExclusive) return 0;
+  return REAL(bsd_signal)(signum, handler);
+}
+#define INIT_BSD_SIGNAL COMMON_INTERCEPT_FUNCTION(bsd_signal)
+#else  // SANITIZER_INTERCEPT_BSD_SIGNAL
+#define INIT_BSD_SIGNAL
+#endif  // SANITIZER_INTERCEPT_BSD_SIGNAL
+
+#if SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION
+INTERCEPTOR(void *, signal, int signum, void *handler) {
+  if (GetHandleSignalMode(signum) == kHandleSignalExclusive) return nullptr;
+  return REAL(signal)(signum, handler);
+}
+#define INIT_SIGNAL COMMON_INTERCEPT_FUNCTION(signal)
+
+INTERCEPTOR(int, sigaction, int signum, const struct sigaction *act,
+            struct sigaction *oldact) {
+  if (GetHandleSignalMode(signum) == kHandleSignalExclusive) return 0;
+  return REAL(sigaction)(signum, act, oldact);
+}
+#define INIT_SIGACTION COMMON_INTERCEPT_FUNCTION(sigaction)
+
+namespace __sanitizer {
+int real_sigaction(int signum, const void *act, void *oldact) {
+  return REAL(sigaction)(signum, (const struct sigaction *)act,
+                         (struct sigaction *)oldact);
+}
+}  // namespace __sanitizer
+#else  // SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION
+#define INIT_SIGNAL
+#define INIT_SIGACTION
+// We need to have defined REAL(sigaction) on other systems.
+DEFINE_REAL(int, sigaction, int signum, const struct sigaction *act,
+            struct sigaction *oldact)
+#endif  // SANITIZER_INTERCEPT_SIGNAL_AND_SIGACTION
+
+static void InitializeSignalInterceptors() {
+  static bool was_called_once;
+  CHECK(!was_called_once);
+  was_called_once = true;
+
+  INIT_BSD_SIGNAL;
+  INIT_SIGNAL;
+  INIT_SIGACTION;
+}
diff --git a/libsanitizer/sanitizer_common/sanitizer_stackdepot.cc b/libsanitizer/sanitizer_common/sanitizer_stackdepot.cc
index 3c5313c3ae4..816a35cfb46 100644
--- a/libsanitizer/sanitizer_common/sanitizer_stackdepot.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_stackdepot.cc
@@ -151,9 +151,9 @@ StackTrace StackDepotReverseMap::Get(u32 id) {
   if (!map_.size())
     return StackTrace();
   IdDescPair pair = {id, nullptr};
-  uptr idx = InternalBinarySearch(map_, 0, map_.size(), pair,
-                                  IdDescPair::IdComparator);
-  if (idx > map_.size())
+  uptr idx =
+      InternalLowerBound(map_, 0, map_.size(), pair, IdDescPair::IdComparator);
+  if (idx > map_.size() || map_[idx].id != id)
     return StackTrace();
   return map_[idx].desc->load();
 }
diff --git a/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc b/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc
index cbb3af270b6..83309d6ee38 100644
--- a/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_stacktrace.cc
@@ -104,10 +104,6 @@ void BufferedStackTrace::FastUnwindStack(uptr pc, uptr bp, uptr stack_top,
   }
 }
 
-static bool MatchPc(uptr cur_pc, uptr trace_pc, uptr threshold) {
-  return cur_pc - trace_pc <= threshold || trace_pc - cur_pc <= threshold;
-}
-
 void BufferedStackTrace::PopStackFrames(uptr count) {
   CHECK_LT(count, size);
   size -= count;
@@ -116,15 +112,14 @@ void BufferedStackTrace::PopStackFrames(uptr count) {
   }
 }
 
+static uptr Distance(uptr a, uptr b) { return a < b ? b - a : a - b; }
+
 uptr BufferedStackTrace::LocatePcInTrace(uptr pc) {
-  // Use threshold to find PC in stack trace, as PC we want to unwind from may
-  // slightly differ from return address in the actual unwinded stack trace.
-  const int kPcThreshold = 350;
-  for (uptr i = 0; i < size; ++i) {
-    if (MatchPc(pc, trace[i], kPcThreshold))
-      return i;
+  uptr best = 0;
+  for (uptr i = 1; i < size; ++i) {
+    if (Distance(trace[i], pc) < Distance(trace[best], pc)) best = i;
   }
-  return 0;
+  return best;
 }
 
 }  // namespace __sanitizer
diff --git a/libsanitizer/sanitizer_common/sanitizer_stacktrace.h b/libsanitizer/sanitizer_common/sanitizer_stacktrace.h
index c59dbd55883..31e99f6b9db 100644
--- a/libsanitizer/sanitizer_common/sanitizer_stacktrace.h
+++ b/libsanitizer/sanitizer_common/sanitizer_stacktrace.h
@@ -95,6 +95,11 @@ struct BufferedStackTrace : public StackTrace {
   void Unwind(u32 max_depth, uptr pc, uptr bp, void *context, uptr stack_top,
               uptr stack_bottom, bool request_fast_unwind);
 
+  void Reset() {
+    *static_cast<StackTrace *>(this) = StackTrace(trace_buffer, 0);
+    top_frame_bp = 0;
+  }
+
  private:
   void FastUnwindStack(uptr pc, uptr bp, uptr stack_top, uptr stack_bottom,
                        u32 max_depth);
@@ -104,8 +109,8 @@ struct BufferedStackTrace : public StackTrace {
   void PopStackFrames(uptr count);
   uptr LocatePcInTrace(uptr pc);
 
-  BufferedStackTrace(const BufferedStackTrace &);
-  void operator=(const BufferedStackTrace &);
+  BufferedStackTrace(const BufferedStackTrace &) = delete;
+  void operator=(const BufferedStackTrace &) = delete;
 };
 
 // Check if given pointer points into allocated stack area.
diff --git a/libsanitizer/sanitizer_common/sanitizer_stacktrace_libcdep.cc b/libsanitizer/sanitizer_common/sanitizer_stacktrace_libcdep.cc
index ac3ee3a019c..f4c0f31b2af 100644
--- a/libsanitizer/sanitizer_common/sanitizer_stacktrace_libcdep.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_stacktrace_libcdep.cc
@@ -41,7 +41,8 @@ void StackTrace::Print() const {
       if (dedup_frames-- > 0) {
         if (dedup_token.length())
           dedup_token.append("--");
-        dedup_token.append(cur->info.function);
+        if (cur->info.function != nullptr)
+          dedup_token.append(cur->info.function);
       }
     }
     frames->ClearAll();
@@ -80,6 +81,21 @@ void BufferedStackTrace::Unwind(u32 max_depth, uptr pc, uptr bp, void *context,
   }
 }
 
+static int GetModuleAndOffsetForPc(uptr pc, char *module_name,
+                                   uptr module_name_len, uptr *pc_offset) {
+  const char *found_module_name = nullptr;
+  bool ok = Symbolizer::GetOrInit()->GetModuleNameAndOffsetForPC(
+      pc, &found_module_name, pc_offset);
+
+  if (!ok) return false;
+
+  if (module_name && module_name_len) {
+    internal_strncpy(module_name, found_module_name, module_name_len);
+    module_name[module_name_len - 1] = '\x00';
+  }
+  return true;
+}
+
 }  // namespace __sanitizer
 using namespace __sanitizer;
 
@@ -115,4 +131,11 @@ void __sanitizer_symbolize_global(uptr data_addr, const char *fmt,
   internal_strncpy(out_buf, data_desc.data(), out_buf_size);
   out_buf[out_buf_size - 1] = 0;
 }
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __sanitizer_get_module_and_offset_for_pc( // NOLINT
+    uptr pc, char *module_name, uptr module_name_len, uptr *pc_offset) {
+  return __sanitizer::GetModuleAndOffsetForPc(pc, module_name, module_name_len,
+                                              pc_offset);
+}
 }  // extern "C"
diff --git a/libsanitizer/sanitizer_common/sanitizer_stacktrace_printer.cc b/libsanitizer/sanitizer_common/sanitizer_stacktrace_printer.cc
index de78c7ac8d1..3c5bed3d75a 100644
--- a/libsanitizer/sanitizer_common/sanitizer_stacktrace_printer.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_stacktrace_printer.cc
@@ -10,9 +10,14 @@
 //===----------------------------------------------------------------------===//
 
 #include "sanitizer_stacktrace_printer.h"
+#include "sanitizer_file.h"
+#include "sanitizer_fuchsia.h"
 
 namespace __sanitizer {
 
+// sanitizer_symbolizer_fuchsia.cc implements these differently for Fuchsia.
+#if !SANITIZER_FUCHSIA
+
 static const char *StripFunctionName(const char *function, const char *prefix) {
   if (!function) return nullptr;
   if (!prefix) return function;
@@ -91,7 +96,7 @@ void RenderFrame(InternalScopedString *buffer, const char *format, int frame_no,
                              vs_style, strip_path_prefix);
       } else if (info.module) {
         RenderModuleLocation(buffer, info.module, info.module_offset,
-                             strip_path_prefix);
+                             info.module_arch, strip_path_prefix);
       } else {
         buffer->append("(<unknown module>)");
       }
@@ -101,8 +106,9 @@ void RenderFrame(InternalScopedString *buffer, const char *format, int frame_no,
       if (info.address & kExternalPCBit)
         {} // There PCs are not meaningful.
       else if (info.module)
-        buffer->append("(%s+%p)", StripModuleName(info.module),
-                       (void *)info.module_offset);
+        // Always strip the module name for %M.
+        RenderModuleLocation(buffer, StripModuleName(info.module),
+                             info.module_offset, info.module_arch, "");
       else
         buffer->append("(%p)", (void *)info.address);
       break;
@@ -143,6 +149,8 @@ void RenderData(InternalScopedString *buffer, const char *format,
   }
 }
 
+#endif  // !SANITIZER_FUCHSIA
+
 void RenderSourceLocation(InternalScopedString *buffer, const char *file,
                           int line, int column, bool vs_style,
                           const char *strip_path_prefix) {
@@ -163,9 +171,13 @@ void RenderSourceLocation(InternalScopedString *buffer, const char *file,
 }
 
 void RenderModuleLocation(InternalScopedString *buffer, const char *module,
-                          uptr offset, const char *strip_path_prefix) {
-  buffer->append("(%s+0x%zx)", StripPathPrefix(module, strip_path_prefix),
-                 offset);
+                          uptr offset, ModuleArch arch,
+                          const char *strip_path_prefix) {
+  buffer->append("(%s", StripPathPrefix(module, strip_path_prefix));
+  if (arch != kModuleArchUnknown) {
+    buffer->append(":%s", ModuleArchToString(arch));
+  }
+  buffer->append("+0x%zx)", offset);
 }
 
 } // namespace __sanitizer
diff --git a/libsanitizer/sanitizer_common/sanitizer_stacktrace_printer.h b/libsanitizer/sanitizer_common/sanitizer_stacktrace_printer.h
index 6726f141f22..cf3cd4292dd 100644
--- a/libsanitizer/sanitizer_common/sanitizer_stacktrace_printer.h
+++ b/libsanitizer/sanitizer_common/sanitizer_stacktrace_printer.h
@@ -55,7 +55,8 @@ void RenderSourceLocation(InternalScopedString *buffer, const char *file,
                           const char *strip_path_prefix);
 
 void RenderModuleLocation(InternalScopedString *buffer, const char *module,
-                          uptr offset, const char *strip_path_prefix);
+                          uptr offset, ModuleArch arch,
+                          const char *strip_path_prefix);
 
 // Same as RenderFrame, but for data section (global variables).
 // Accepts %s, %l from above.
diff --git a/libsanitizer/sanitizer_common/sanitizer_stoptheworld.h b/libsanitizer/sanitizer_common/sanitizer_stoptheworld.h
index c3245266fb9..8c3d2c05557 100644
--- a/libsanitizer/sanitizer_common/sanitizer_stoptheworld.h
+++ b/libsanitizer/sanitizer_common/sanitizer_stoptheworld.h
@@ -16,36 +16,32 @@
 #include "sanitizer_common.h"
 
 namespace __sanitizer {
-typedef int SuspendedThreadID;
+
+enum PtraceRegistersStatus {
+  REGISTERS_UNAVAILABLE_FATAL = -1,
+  REGISTERS_UNAVAILABLE = 0,
+  REGISTERS_AVAILABLE = 1
+};
 
 // Holds the list of suspended threads and provides an interface to dump their
 // register contexts.
 class SuspendedThreadsList {
  public:
-  SuspendedThreadsList()
-    : thread_ids_(1024) {}
-  SuspendedThreadID GetThreadID(uptr index) const {
-    CHECK_LT(index, thread_ids_.size());
-    return thread_ids_[index];
+  SuspendedThreadsList() = default;
+
+  // Can't declare pure virtual functions in sanitizer runtimes:
+  // __cxa_pure_virtual might be unavailable. Use UNIMPLEMENTED() instead.
+  virtual PtraceRegistersStatus GetRegistersAndSP(uptr index, uptr *buffer,
+                                                  uptr *sp) const {
+    UNIMPLEMENTED();
   }
-  int GetRegistersAndSP(uptr index, uptr *buffer, uptr *sp) const;
+
   // The buffer in GetRegistersAndSP should be at least this big.
-  static uptr RegisterCount();
-  uptr thread_count() const { return thread_ids_.size(); }
-  bool Contains(SuspendedThreadID thread_id) const {
-    for (uptr i = 0; i < thread_ids_.size(); i++) {
-      if (thread_ids_[i] == thread_id)
-        return true;
-    }
-    return false;
-  }
-  void Append(SuspendedThreadID thread_id) {
-    thread_ids_.push_back(thread_id);
-  }
+  virtual uptr RegisterCount() const { UNIMPLEMENTED(); }
+  virtual uptr ThreadCount() const { UNIMPLEMENTED(); }
+  virtual tid_t GetThreadID(uptr index) const { UNIMPLEMENTED(); }
 
  private:
-  InternalMmapVector<SuspendedThreadID> thread_ids_;
-
   // Prohibit copy and assign.
   SuspendedThreadsList(const SuspendedThreadsList&);
   void operator=(const SuspendedThreadsList&);
diff --git a/libsanitizer/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc b/libsanitizer/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc
index 234e8c652c6..d746fa5403a 100644
--- a/libsanitizer/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cc
@@ -14,7 +14,8 @@
 
 #if SANITIZER_LINUX && (defined(__x86_64__) || defined(__mips__) || \
                         defined(__aarch64__) || defined(__powerpc64__) || \
-                        defined(__s390__))
+                        defined(__s390__) || defined(__i386__) || \
+                        defined(__arm__))
 
 #include "sanitizer_stoptheworld.h"
 
@@ -29,17 +30,13 @@
 #include <sys/types.h> // for pid_t
 #include <sys/uio.h> // for iovec
 #include <elf.h> // for NT_PRSTATUS
-#if SANITIZER_ANDROID && defined(__arm__)
-# include <linux/user.h>  // for pt_regs
-#else
-# ifdef __aarch64__
+#if defined(__aarch64__) && !SANITIZER_ANDROID
 // GLIBC 2.20+ sys/user does not include asm/ptrace.h
-#  include <asm/ptrace.h>
-# endif
-# include <sys/user.h>  // for user_regs_struct
-# if SANITIZER_ANDROID && SANITIZER_MIPS
-#   include <asm/reg.h>  // for mips SP register in sys/user.h
-# endif
+# include <asm/ptrace.h>
+#endif
+#include <sys/user.h>  // for user_regs_struct
+#if SANITIZER_ANDROID && SANITIZER_MIPS
+# include <asm/reg.h>  // for mips SP register in sys/user.h
 #endif
 #include <sys/wait.h> // for signal-related stuff
 
@@ -79,7 +76,22 @@
 
 namespace __sanitizer {
 
-COMPILER_CHECK(sizeof(SuspendedThreadID) == sizeof(pid_t));
+class SuspendedThreadsListLinux : public SuspendedThreadsList {
+ public:
+  SuspendedThreadsListLinux() : thread_ids_(1024) {}
+
+  tid_t GetThreadID(uptr index) const;
+  uptr ThreadCount() const;
+  bool ContainsTid(tid_t thread_id) const;
+  void Append(tid_t tid);
+
+  PtraceRegistersStatus GetRegistersAndSP(uptr index, uptr *buffer,
+                                          uptr *sp) const;
+  uptr RegisterCount() const;
+
+ private:
+  InternalMmapVector<tid_t> thread_ids_;
+};
 
 // Structure for passing arguments into the tracer thread.
 struct TracerThreadArgument {
@@ -104,31 +116,31 @@ class ThreadSuspender {
   bool SuspendAllThreads();
   void ResumeAllThreads();
   void KillAllThreads();
-  SuspendedThreadsList &suspended_threads_list() {
+  SuspendedThreadsListLinux &suspended_threads_list() {
     return suspended_threads_list_;
   }
   TracerThreadArgument *arg;
  private:
-  SuspendedThreadsList suspended_threads_list_;
+  SuspendedThreadsListLinux suspended_threads_list_;
   pid_t pid_;
-  bool SuspendThread(SuspendedThreadID thread_id);
+  bool SuspendThread(tid_t thread_id);
 };
 
-bool ThreadSuspender::SuspendThread(SuspendedThreadID tid) {
+bool ThreadSuspender::SuspendThread(tid_t tid) {
   // Are we already attached to this thread?
   // Currently this check takes linear time, however the number of threads is
   // usually small.
-  if (suspended_threads_list_.Contains(tid))
-    return false;
+  if (suspended_threads_list_.ContainsTid(tid)) return false;
   int pterrno;
   if (internal_iserror(internal_ptrace(PTRACE_ATTACH, tid, nullptr, nullptr),
                        &pterrno)) {
     // Either the thread is dead, or something prevented us from attaching.
     // Log this event and move on.
-    VReport(1, "Could not attach to thread %d (errno %d).\n", tid, pterrno);
+    VReport(1, "Could not attach to thread %zu (errno %d).\n", (uptr)tid,
+            pterrno);
     return false;
   } else {
-    VReport(2, "Attached to thread %d.\n", tid);
+    VReport(2, "Attached to thread %zu.\n", (uptr)tid);
     // The thread is not guaranteed to stop before ptrace returns, so we must
     // wait on it. Note: if the thread receives a signal concurrently,
     // we can get notification about the signal before notification about stop.
@@ -146,8 +158,8 @@ bool ThreadSuspender::SuspendThread(SuspendedThreadID tid) {
       if (internal_iserror(waitpid_status, &wperrno)) {
         // Got a ECHILD error. I don't think this situation is possible, but it
         // doesn't hurt to report it.
-        VReport(1, "Waiting on thread %d failed, detaching (errno %d).\n",
-                tid, wperrno);
+        VReport(1, "Waiting on thread %zu failed, detaching (errno %d).\n",
+                (uptr)tid, wperrno);
         internal_ptrace(PTRACE_DETACH, tid, nullptr, nullptr);
         return false;
       }
@@ -164,7 +176,7 @@ bool ThreadSuspender::SuspendThread(SuspendedThreadID tid) {
 }
 
 void ThreadSuspender::ResumeAllThreads() {
-  for (uptr i = 0; i < suspended_threads_list_.thread_count(); i++) {
+  for (uptr i = 0; i < suspended_threads_list_.ThreadCount(); i++) {
     pid_t tid = suspended_threads_list_.GetThreadID(i);
     int pterrno;
     if (!internal_iserror(internal_ptrace(PTRACE_DETACH, tid, nullptr, nullptr),
@@ -180,7 +192,7 @@ void ThreadSuspender::ResumeAllThreads() {
 }
 
 void ThreadSuspender::KillAllThreads() {
-  for (uptr i = 0; i < suspended_threads_list_.thread_count(); i++)
+  for (uptr i = 0; i < suspended_threads_list_.ThreadCount(); i++)
     internal_ptrace(PTRACE_KILL, suspended_threads_list_.GetThreadID(i),
                     nullptr, nullptr);
 }
@@ -232,7 +244,7 @@ static void TracerThreadDieCallback() {
 
 // Signal handler to wake up suspended threads when the tracer thread dies.
 static void TracerThreadSignalHandler(int signum, void *siginfo, void *uctx) {
-  SignalContext ctx = SignalContext::Create(siginfo, uctx);
+  SignalContext ctx(siginfo, uctx);
   Printf("Tracer caught signal %d: addr=0x%zx pc=0x%zx sp=0x%zx\n", signum,
          ctx.addr, ctx.pc, ctx.sp);
   ThreadSuspender *inst = thread_suspender_instance;
@@ -249,7 +261,7 @@ static void TracerThreadSignalHandler(int signum, void *siginfo, void *uctx) {
 }
 
 // Size of alternative stack for signal handlers in the tracer thread.
-static const int kHandlerStackSize = 4096;
+static const int kHandlerStackSize = 8192;
 
 // This function will be run as a cloned task.
 static int TracerThread(void* argument) {
@@ -491,9 +503,28 @@ typedef _user_regs_struct regs_struct;
 #error "Unsupported architecture"
 #endif // SANITIZER_ANDROID && defined(__arm__)
 
-int SuspendedThreadsList::GetRegistersAndSP(uptr index,
-                                            uptr *buffer,
-                                            uptr *sp) const {
+tid_t SuspendedThreadsListLinux::GetThreadID(uptr index) const {
+  CHECK_LT(index, thread_ids_.size());
+  return thread_ids_[index];
+}
+
+uptr SuspendedThreadsListLinux::ThreadCount() const {
+  return thread_ids_.size();
+}
+
+bool SuspendedThreadsListLinux::ContainsTid(tid_t thread_id) const {
+  for (uptr i = 0; i < thread_ids_.size(); i++) {
+    if (thread_ids_[i] == thread_id) return true;
+  }
+  return false;
+}
+
+void SuspendedThreadsListLinux::Append(tid_t tid) {
+  thread_ids_.push_back(tid);
+}
+
+PtraceRegistersStatus SuspendedThreadsListLinux::GetRegistersAndSP(
+    uptr index, uptr *buffer, uptr *sp) const {
   pid_t tid = GetThreadID(index);
   regs_struct regs;
   int pterrno;
@@ -511,19 +542,23 @@ int SuspendedThreadsList::GetRegistersAndSP(uptr index,
   if (isErr) {
     VReport(1, "Could not get registers from thread %d (errno %d).\n", tid,
             pterrno);
-    return -1;
+    // ESRCH means that the given thread is not suspended or already dead.
+    // Therefore it's unsafe to inspect its data (e.g. walk through stack) and
+    // we should notify caller about this.
+    return pterrno == ESRCH ? REGISTERS_UNAVAILABLE_FATAL
+                            : REGISTERS_UNAVAILABLE;
   }
 
   *sp = regs.REG_SP;
   internal_memcpy(buffer, &regs, sizeof(regs));
-  return 0;
+  return REGISTERS_AVAILABLE;
 }
 
-uptr SuspendedThreadsList::RegisterCount() {
+uptr SuspendedThreadsListLinux::RegisterCount() const {
   return sizeof(regs_struct) / sizeof(uptr);
 }
 } // namespace __sanitizer
 
 #endif  // SANITIZER_LINUX && (defined(__x86_64__) || defined(__mips__)
         // || defined(__aarch64__) || defined(__powerpc64__)
-        // || defined(__s390__)
+        // || defined(__s390__) || defined(__i386__) || defined(__arm__)
diff --git a/libsanitizer/sanitizer_common/sanitizer_stoptheworld_mac.cc b/libsanitizer/sanitizer_common/sanitizer_stoptheworld_mac.cc
new file mode 100644
index 00000000000..6282694fa8c
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_stoptheworld_mac.cc
@@ -0,0 +1,176 @@
+//===-- sanitizer_stoptheworld_mac.cc -------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// See sanitizer_stoptheworld.h for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+
+#if SANITIZER_MAC && (defined(__x86_64__) || defined(__aarch64__) || \
+                      defined(__i386))
+
+#include <mach/mach.h>
+#include <mach/thread_info.h>
+#include <pthread.h>
+
+#include "sanitizer_stoptheworld.h"
+
+namespace __sanitizer {
+typedef struct {
+  tid_t tid;
+  thread_t thread;
+} SuspendedThreadInfo;
+
+class SuspendedThreadsListMac : public SuspendedThreadsList {
+ public:
+  SuspendedThreadsListMac() : threads_(1024) {}
+
+  tid_t GetThreadID(uptr index) const;
+  thread_t GetThread(uptr index) const;
+  uptr ThreadCount() const;
+  bool ContainsThread(thread_t thread) const;
+  void Append(thread_t thread);
+
+  PtraceRegistersStatus GetRegistersAndSP(uptr index, uptr *buffer,
+                                          uptr *sp) const;
+  uptr RegisterCount() const;
+
+ private:
+  InternalMmapVector<SuspendedThreadInfo> threads_;
+};
+
+struct RunThreadArgs {
+  StopTheWorldCallback callback;
+  void *argument;
+};
+
+void RunThread(void *arg) {
+  struct RunThreadArgs *run_args = (struct RunThreadArgs *)arg;
+  SuspendedThreadsListMac suspended_threads_list;
+
+  thread_array_t threads;
+  mach_msg_type_number_t num_threads;
+  kern_return_t err = task_threads(mach_task_self(), &threads, &num_threads);
+  if (err != KERN_SUCCESS) {
+    VReport(1, "Failed to get threads for task (errno %d).\n", err);
+    return;
+  }
+
+  thread_t thread_self = mach_thread_self();
+  for (unsigned int i = 0; i < num_threads; ++i) {
+    if (threads[i] == thread_self) continue;
+
+    thread_suspend(threads[i]);
+    suspended_threads_list.Append(threads[i]);
+  }
+
+  run_args->callback(suspended_threads_list, run_args->argument);
+
+  uptr num_suspended = suspended_threads_list.ThreadCount();
+  for (unsigned int i = 0; i < num_suspended; ++i) {
+    thread_resume(suspended_threads_list.GetThread(i));
+  }
+}
+
+void StopTheWorld(StopTheWorldCallback callback, void *argument) {
+  struct RunThreadArgs arg = {callback, argument};
+  pthread_t run_thread = (pthread_t)internal_start_thread(RunThread, &arg);
+  internal_join_thread(run_thread);
+}
+
+#if defined(__x86_64__)
+typedef x86_thread_state64_t regs_struct;
+
+#define SP_REG __rsp
+
+#elif defined(__aarch64__)
+typedef arm_thread_state64_t regs_struct;
+
+# if __DARWIN_UNIX03
+#  define SP_REG __sp
+# else
+#  define SP_REG sp
+# endif
+
+#elif defined(__i386)
+typedef x86_thread_state32_t regs_struct;
+
+#define SP_REG __esp
+
+#else
+#error "Unsupported architecture"
+#endif
+
+tid_t SuspendedThreadsListMac::GetThreadID(uptr index) const {
+  CHECK_LT(index, threads_.size());
+  return threads_[index].tid;
+}
+
+thread_t SuspendedThreadsListMac::GetThread(uptr index) const {
+  CHECK_LT(index, threads_.size());
+  return threads_[index].thread;
+}
+
+uptr SuspendedThreadsListMac::ThreadCount() const {
+  return threads_.size();
+}
+
+bool SuspendedThreadsListMac::ContainsThread(thread_t thread) const {
+  for (uptr i = 0; i < threads_.size(); i++) {
+    if (threads_[i].thread == thread) return true;
+  }
+  return false;
+}
+
+void SuspendedThreadsListMac::Append(thread_t thread) {
+  thread_identifier_info_data_t info;
+  mach_msg_type_number_t info_count = THREAD_IDENTIFIER_INFO_COUNT;
+  kern_return_t err = thread_info(thread, THREAD_IDENTIFIER_INFO,
+                                  (thread_info_t)&info, &info_count);
+  if (err != KERN_SUCCESS) {
+    VReport(1, "Error - unable to get thread ident for a thread\n");
+    return;
+  }
+  threads_.push_back({info.thread_id, thread});
+}
+
+PtraceRegistersStatus SuspendedThreadsListMac::GetRegistersAndSP(
+    uptr index, uptr *buffer, uptr *sp) const {
+  thread_t thread = GetThread(index);
+  regs_struct regs;
+  int err;
+  mach_msg_type_number_t reg_count = MACHINE_THREAD_STATE_COUNT;
+  err = thread_get_state(thread, MACHINE_THREAD_STATE, (thread_state_t)&regs,
+                         &reg_count);
+  if (err != KERN_SUCCESS) {
+    VReport(1, "Error - unable to get registers for a thread\n");
+    // KERN_INVALID_ARGUMENT indicates that either the flavor is invalid,
+    // or the thread does not exist. The other possible error case,
+    // MIG_ARRAY_TOO_LARGE, means that the state is too large, but it's
+    // still safe to proceed.
+    return err == KERN_INVALID_ARGUMENT ? REGISTERS_UNAVAILABLE_FATAL
+                                        : REGISTERS_UNAVAILABLE;
+  }
+
+  internal_memcpy(buffer, &regs, sizeof(regs));
+  *sp = regs.SP_REG;
+
+  // On x86_64 and aarch64, we must account for the stack redzone, which is 128
+  // bytes.
+  if (SANITIZER_WORDSIZE == 64) *sp -= 128;
+
+  return REGISTERS_AVAILABLE;
+}
+
+uptr SuspendedThreadsListMac::RegisterCount() const {
+  return MACHINE_THREAD_STATE_COUNT;
+}
+} // namespace __sanitizer
+
+#endif  // SANITIZER_MAC && (defined(__x86_64__) || defined(__aarch64__)) ||
+        //                   defined(__i386))
diff --git a/libsanitizer/sanitizer_common/sanitizer_suppressions.cc b/libsanitizer/sanitizer_common/sanitizer_suppressions.cc
index bfdff59a35c..4095a0942a3 100644
--- a/libsanitizer/sanitizer_common/sanitizer_suppressions.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_suppressions.cc
@@ -14,6 +14,7 @@
 #include "sanitizer_allocator_internal.h"
 #include "sanitizer_common.h"
 #include "sanitizer_flags.h"
+#include "sanitizer_file.h"
 #include "sanitizer_libc.h"
 #include "sanitizer_placement_new.h"
 
@@ -48,6 +49,7 @@ void SuppressionContext::ParseFromFile(const char *filename) {
   if (filename[0] == '\0')
     return;
 
+#if !SANITIZER_FUCHSIA
   // If we cannot find the file, check if its location is relative to
   // the location of the executable.
   InternalScopedString new_file_path(kMaxPathLength);
@@ -56,6 +58,7 @@ void SuppressionContext::ParseFromFile(const char *filename) {
                                           new_file_path.size())) {
     filename = new_file_path.data();
   }
+#endif  // !SANITIZER_FUCHSIA
 
   // Read the file.
   VPrintf(1, "%s: reading suppressions file at %s\n",
diff --git a/libsanitizer/sanitizer_common/sanitizer_symbolizer.cc b/libsanitizer/sanitizer_common/sanitizer_symbolizer.cc
index 3557415aeab..9d3e0115eb2 100644
--- a/libsanitizer/sanitizer_common/sanitizer_symbolizer.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_symbolizer.cc
@@ -31,9 +31,11 @@ void AddressInfo::Clear() {
   function_offset = kUnknown;
 }
 
-void AddressInfo::FillModuleInfo(const char *mod_name, uptr mod_offset) {
+void AddressInfo::FillModuleInfo(const char *mod_name, uptr mod_offset,
+                                 ModuleArch mod_arch) {
   module = internal_strdup(mod_name);
   module_offset = mod_offset;
+  module_arch = mod_arch;
 }
 
 SymbolizedStack::SymbolizedStack() : next(nullptr), info() {}
@@ -67,6 +69,10 @@ Symbolizer *Symbolizer::symbolizer_;
 StaticSpinMutex Symbolizer::init_mu_;
 LowLevelAllocator Symbolizer::symbolizer_allocator_;
 
+void Symbolizer::InvalidateModuleList() {
+  modules_fresh_ = false;
+}
+
 void Symbolizer::AddHooks(Symbolizer::StartSymbolizationHook start_hook,
                           Symbolizer::EndSymbolizationHook end_hook) {
   CHECK(start_hook_ == 0 && end_hook_ == 0);
diff --git a/libsanitizer/sanitizer_common/sanitizer_symbolizer.h b/libsanitizer/sanitizer_common/sanitizer_symbolizer.h
index 2b90b42e2ba..5e2c843d86e 100644
--- a/libsanitizer/sanitizer_common/sanitizer_symbolizer.h
+++ b/libsanitizer/sanitizer_common/sanitizer_symbolizer.h
@@ -29,6 +29,7 @@ struct AddressInfo {
 
   char *module;
   uptr module_offset;
+  ModuleArch module_arch;
 
   static const uptr kUnknown = ~(uptr)0;
   char *function;
@@ -41,7 +42,7 @@ struct AddressInfo {
   AddressInfo();
   // Deletes all strings and resets all fields.
   void Clear();
-  void FillModuleInfo(const char *mod_name, uptr mod_offset);
+  void FillModuleInfo(const char *mod_name, uptr mod_offset, ModuleArch arch);
 };
 
 // Linked list of symbolized frames (each frame is described by AddressInfo).
@@ -63,6 +64,8 @@ struct DataInfo {
   // (de)allocated using sanitizer internal allocator.
   char *module;
   uptr module_offset;
+  ModuleArch module_arch;
+
   char *file;
   uptr line;
   char *name;
@@ -114,8 +117,11 @@ class Symbolizer final {
   void AddHooks(StartSymbolizationHook start_hook,
                 EndSymbolizationHook end_hook);
 
+  void RefreshModules();
   const LoadedModule *FindModuleForAddress(uptr address);
 
+  void InvalidateModuleList();
+
  private:
   // GetModuleNameAndOffsetForPC has to return a string to the caller.
   // Since the corresponding module might get unloaded later, we should create
@@ -141,8 +147,10 @@ class Symbolizer final {
   static Symbolizer *PlatformInit();
 
   bool FindModuleNameAndOffsetForAddress(uptr address, const char **module_name,
-                                         uptr *module_offset);
+                                         uptr *module_offset,
+                                         ModuleArch *module_arch);
   ListOfModules modules_;
+  ListOfModules fallback_modules_;
   // If stale, need to reload the modules before looking up addresses.
   bool modules_fresh_;
 
diff --git a/libsanitizer/sanitizer_common/sanitizer_symbolizer_fuchsia.cc b/libsanitizer/sanitizer_common/sanitizer_symbolizer_fuchsia.cc
new file mode 100644
index 00000000000..04263205e16
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_symbolizer_fuchsia.cc
@@ -0,0 +1,105 @@
+//===-- sanitizer_symbolizer_fuchsia.cc -----------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is shared between various sanitizers' runtime libraries.
+//
+// Implementation of Fuchsia-specific symbolizer.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+#if SANITIZER_FUCHSIA
+
+#include "sanitizer_fuchsia.h"
+#include "sanitizer_symbolizer.h"
+
+namespace __sanitizer {
+
+// For Fuchsia we don't do any actual symbolization per se.
+// Instead, we emit text containing raw addresses and raw linkage
+// symbol names, embedded in Fuchsia's symbolization markup format.
+// Fuchsia's logging infrastructure emits enough information about
+// process memory layout that a post-processing filter can do the
+// symbolization and pretty-print the markup.  See the spec at:
+// https://fuchsia.googlesource.com/zircon/+/master/docs/symbolizer_markup.md
+
+// This is used by UBSan for type names, and by ASan for global variable names.
+constexpr const char *kFormatDemangle = "{{{symbol:%s}}}";
+constexpr uptr kFormatDemangleMax = 1024;  // Arbitrary.
+
+// Function name or equivalent from PC location.
+constexpr const char *kFormatFunction = "{{{pc:%p}}}";
+constexpr uptr kFormatFunctionMax = 64;  // More than big enough for 64-bit hex.
+
+// Global variable name or equivalent from data memory address.
+constexpr const char *kFormatData = "{{{data:%p}}}";
+
+// One frame in a backtrace (printed on a line by itself).
+constexpr const char *kFormatFrame = "{{{bt:%u:%p}}}";
+
+// This is used by UBSan for type names, and by ASan for global variable names.
+// It's expected to return a static buffer that will be reused on each call.
+const char *Symbolizer::Demangle(const char *name) {
+  static char buffer[kFormatDemangleMax];
+  internal_snprintf(buffer, sizeof(buffer), kFormatDemangle, name);
+  return buffer;
+}
+
+// This is used mostly for suppression matching.  Making it work
+// would enable "interceptor_via_lib" suppressions.  It's also used
+// once in UBSan to say "in module ..." in a message that also
+// includes an address in the module, so post-processing can already
+// pretty-print that so as to indicate the module.
+bool Symbolizer::GetModuleNameAndOffsetForPC(uptr pc, const char **module_name,
+                                             uptr *module_address) {
+  return false;
+}
+
+// This is used in some places for suppression checking, which we
+// don't really support for Fuchsia.  It's also used in UBSan to
+// identify a PC location to a function name, so we always fill in
+// the function member with a string containing markup around the PC
+// value.
+// TODO(mcgrathr): Under SANITIZER_GO, it's currently used by TSan
+// to render stack frames, but that should be changed to use
+// RenderStackFrame.
+SymbolizedStack *Symbolizer::SymbolizePC(uptr addr) {
+  SymbolizedStack *s = SymbolizedStack::New(addr);
+  char buffer[kFormatFunctionMax];
+  internal_snprintf(buffer, sizeof(buffer), kFormatFunction, addr);
+  s->info.function = internal_strdup(buffer);
+  return s;
+}
+
+// Always claim we succeeded, so that RenderDataInfo will be called.
+bool Symbolizer::SymbolizeData(uptr addr, DataInfo *info) {
+  info->Clear();
+  info->start = addr;
+  return true;
+}
+
+// We ignore the format argument to __sanitizer_symbolize_global.
+void RenderData(InternalScopedString *buffer, const char *format,
+                const DataInfo *DI, const char *strip_path_prefix) {
+  buffer->append(kFormatData, DI->start);
+}
+
+// We don't support the stack_trace_format flag at all.
+void RenderFrame(InternalScopedString *buffer, const char *format, int frame_no,
+                 const AddressInfo &info, bool vs_style,
+                 const char *strip_path_prefix, const char *strip_func_prefix) {
+  buffer->append(kFormatFrame, frame_no, info.address);
+}
+
+Symbolizer *Symbolizer::PlatformInit() {
+  return new (symbolizer_allocator_) Symbolizer({});
+}
+
+void Symbolizer::LateInitialize() { Symbolizer::GetOrInit(); }
+
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_FUCHSIA
diff --git a/libsanitizer/sanitizer_common/sanitizer_symbolizer_internal.h b/libsanitizer/sanitizer_common/sanitizer_symbolizer_internal.h
index 119cb688463..eae7509576e 100644
--- a/libsanitizer/sanitizer_common/sanitizer_symbolizer_internal.h
+++ b/libsanitizer/sanitizer_common/sanitizer_symbolizer_internal.h
@@ -13,6 +13,7 @@
 #define SANITIZER_SYMBOLIZER_INTERNAL_H
 
 #include "sanitizer_symbolizer.h"
+#include "sanitizer_file.h"
 
 namespace __sanitizer {
 
@@ -122,8 +123,8 @@ class LLVMSymbolizer : public SymbolizerTool {
   bool SymbolizeData(uptr addr, DataInfo *info) override;
 
  private:
-  const char *SendCommand(bool is_data, const char *module_name,
-                          uptr module_offset);
+  const char *FormatAndSendCommand(bool is_data, const char *module_name,
+                                   uptr module_offset, ModuleArch arch);
 
   LLVMSymbolizerProcess *symbolizer_process_;
   static const uptr kBufferSize = 16 * 1024;
diff --git a/libsanitizer/sanitizer_common/sanitizer_symbolizer_libbacktrace.cc b/libsanitizer/sanitizer_common/sanitizer_symbolizer_libbacktrace.cc
index b5bcfdbc089..eebc30b124d 100644
--- a/libsanitizer/sanitizer_common/sanitizer_symbolizer_libbacktrace.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_symbolizer_libbacktrace.cc
@@ -93,7 +93,8 @@ struct SymbolizeCodeCallbackArg {
     if (frames_symbolized > 0) {
       SymbolizedStack *cur = SymbolizedStack::New(addr);
       AddressInfo *info = &cur->info;
-      info->FillModuleInfo(first->info.module, first->info.module_offset);
+      info->FillModuleInfo(first->info.module, first->info.module_offset,
+                           first->info.module_arch);
       last->next = cur;
       last = cur;
     }
diff --git a/libsanitizer/sanitizer_common/sanitizer_symbolizer_libcdep.cc b/libsanitizer/sanitizer_common/sanitizer_symbolizer_libcdep.cc
index 45eb11a4d3b..df934412146 100644
--- a/libsanitizer/sanitizer_common/sanitizer_symbolizer_libcdep.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_symbolizer_libcdep.cc
@@ -15,6 +15,18 @@
 
 namespace __sanitizer {
 
+Symbolizer *Symbolizer::GetOrInit() {
+  SpinMutexLock l(&init_mu_);
+  if (symbolizer_)
+    return symbolizer_;
+  symbolizer_ = PlatformInit();
+  CHECK(symbolizer_);
+  return symbolizer_;
+}
+
+// See sanitizer_symbolizer_fuchsia.cc.
+#if !SANITIZER_FUCHSIA
+
 const char *ExtractToken(const char *str, const char *delims, char **result) {
   uptr prefix_len = internal_strcspn(str, delims);
   *result = (char*)InternalAlloc(prefix_len + 1);
@@ -62,11 +74,13 @@ SymbolizedStack *Symbolizer::SymbolizePC(uptr addr) {
   BlockingMutexLock l(&mu_);
   const char *module_name;
   uptr module_offset;
+  ModuleArch arch;
   SymbolizedStack *res = SymbolizedStack::New(addr);
-  if (!FindModuleNameAndOffsetForAddress(addr, &module_name, &module_offset))
+  if (!FindModuleNameAndOffsetForAddress(addr, &module_name, &module_offset,
+                                         &arch))
     return res;
   // Always fill data about module name and offset.
-  res->info.FillModuleInfo(module_name, module_offset);
+  res->info.FillModuleInfo(module_name, module_offset, arch);
   for (auto &tool : tools_) {
     SymbolizerScope sym_scope(this);
     if (tool.SymbolizePC(addr, res)) {
@@ -80,11 +94,14 @@ bool Symbolizer::SymbolizeData(uptr addr, DataInfo *info) {
   BlockingMutexLock l(&mu_);
   const char *module_name;
   uptr module_offset;
-  if (!FindModuleNameAndOffsetForAddress(addr, &module_name, &module_offset))
+  ModuleArch arch;
+  if (!FindModuleNameAndOffsetForAddress(addr, &module_name, &module_offset,
+                                         &arch))
     return false;
   info->Clear();
   info->module = internal_strdup(module_name);
   info->module_offset = module_offset;
+  info->module_arch = arch;
   for (auto &tool : tools_) {
     SymbolizerScope sym_scope(this);
     if (tool.SymbolizeData(addr, info)) {
@@ -98,8 +115,9 @@ bool Symbolizer::GetModuleNameAndOffsetForPC(uptr pc, const char **module_name,
                                              uptr *module_address) {
   BlockingMutexLock l(&mu_);
   const char *internal_module_name = nullptr;
+  ModuleArch arch;
   if (!FindModuleNameAndOffsetForAddress(pc, &internal_module_name,
-                                         module_address))
+                                         module_address, &arch))
     return false;
 
   if (module_name)
@@ -132,46 +150,58 @@ void Symbolizer::PrepareForSandboxing() {
 
 bool Symbolizer::FindModuleNameAndOffsetForAddress(uptr address,
                                                    const char **module_name,
-                                                   uptr *module_offset) {
+                                                   uptr *module_offset,
+                                                   ModuleArch *module_arch) {
   const LoadedModule *module = FindModuleForAddress(address);
   if (module == nullptr)
     return false;
   *module_name = module->full_name();
   *module_offset = address - module->base_address();
+  *module_arch = module->arch();
   return true;
 }
 
+void Symbolizer::RefreshModules() {
+  modules_.init();
+  fallback_modules_.fallbackInit();
+  RAW_CHECK(modules_.size() > 0);
+  modules_fresh_ = true;
+}
+
+static const LoadedModule *SearchForModule(const ListOfModules &modules,
+                                           uptr address) {
+  for (uptr i = 0; i < modules.size(); i++) {
+    if (modules[i].containsAddress(address)) {
+      return &modules[i];
+    }
+  }
+  return nullptr;
+}
+
 const LoadedModule *Symbolizer::FindModuleForAddress(uptr address) {
   bool modules_were_reloaded = false;
   if (!modules_fresh_) {
-    modules_.init();
-    RAW_CHECK(modules_.size() > 0);
-    modules_fresh_ = true;
+    RefreshModules();
     modules_were_reloaded = true;
   }
-  for (uptr i = 0; i < modules_.size(); i++) {
-    if (modules_[i].containsAddress(address)) {
-      return &modules_[i];
-    }
-  }
-  // Reload the modules and look up again, if we haven't tried it yet.
+  const LoadedModule *module = SearchForModule(modules_, address);
+  if (module) return module;
+
+  // dlopen/dlclose interceptors invalidate the module list, but when
+  // interception is disabled, we need to retry if the lookup fails in
+  // case the module list changed.
+#if !SANITIZER_INTERCEPT_DLOPEN_DLCLOSE
   if (!modules_were_reloaded) {
-    // FIXME: set modules_fresh_ from dlopen()/dlclose() interceptors.
-    // It's too aggressive to reload the list of modules each time we fail
-    // to find a module for a given address.
-    modules_fresh_ = false;
-    return FindModuleForAddress(address);
+    RefreshModules();
+    module = SearchForModule(modules_, address);
+    if (module) return module;
   }
-  return 0;
-}
+#endif
 
-Symbolizer *Symbolizer::GetOrInit() {
-  SpinMutexLock l(&init_mu_);
-  if (symbolizer_)
-    return symbolizer_;
-  symbolizer_ = PlatformInit();
-  CHECK(symbolizer_);
-  return symbolizer_;
+  if (fallback_modules_.size()) {
+    module = SearchForModule(fallback_modules_, address);
+  }
+  return module;
 }
 
 // For now we assume the following protocol:
@@ -195,6 +225,8 @@ class LLVMSymbolizerProcess : public SymbolizerProcess {
            buffer[length - 2] == '\n';
   }
 
+  // When adding a new architecture, don't forget to also update
+  // script/asan_symbolize.py and sanitizer_common.h.
   void GetArgV(const char *path_to_binary,
                const char *(&argv)[kArgVMax]) const override {
 #if defined(__x86_64h__)
@@ -240,25 +272,21 @@ static const char *ParseFileLineInfo(AddressInfo *info, const char *str) {
   char *file_line_info = 0;
   str = ExtractToken(str, "\n", &file_line_info);
   CHECK(file_line_info);
-  // Parse the last :<int>, which must be there.
-  char *last_colon = internal_strrchr(file_line_info, ':');
-  CHECK(last_colon);
-  int line_or_column = internal_atoll(last_colon + 1);
-  // Truncate the string at the last colon and find the next-to-last colon.
-  *last_colon = '\0';
-  last_colon = internal_strrchr(file_line_info, ':');
-  if (last_colon && IsDigit(last_colon[1])) {
-    // If the second-to-last colon is followed by a digit, it must be the line
-    // number, and the previous parsed number was a column.
-    info->line = internal_atoll(last_colon + 1);
-    info->column = line_or_column;
-    *last_colon = '\0';
-  } else {
-    // Otherwise, we have line info but no column info.
-    info->line = line_or_column;
-    info->column = 0;
+
+  if (uptr size = internal_strlen(file_line_info)) {
+    char *back = file_line_info + size - 1;
+    for (int i = 0; i < 2; ++i) {
+      while (back > file_line_info && IsDigit(*back)) --back;
+      if (*back != ':' || !IsDigit(back[1])) break;
+      info->column = info->line;
+      info->line = internal_atoll(back + 1);
+      // Truncate the string at the colon to keep only filename.
+      *back = '\0';
+      --back;
+    }
+    ExtractToken(file_line_info, "", &info->file);
   }
-  ExtractToken(file_line_info, "", &info->file);
+
   InternalFree(file_line_info);
   return str;
 }
@@ -286,7 +314,8 @@ void ParseSymbolizePCOutput(const char *str, SymbolizedStack *res) {
       top_frame = false;
     } else {
       cur = SymbolizedStack::New(res->info.address);
-      cur->info.FillModuleInfo(res->info.module, res->info.module_offset);
+      cur->info.FillModuleInfo(res->info.module, res->info.module_offset,
+                               res->info.module_arch);
       last->next = cur;
       last = cur;
     }
@@ -319,8 +348,10 @@ void ParseSymbolizeDataOutput(const char *str, DataInfo *info) {
 }
 
 bool LLVMSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
-  if (const char *buf = SendCommand(/*is_data*/ false, stack->info.module,
-                                    stack->info.module_offset)) {
+  AddressInfo *info = &stack->info;
+  const char *buf = FormatAndSendCommand(
+      /*is_data*/ false, info->module, info->module_offset, info->module_arch);
+  if (buf) {
     ParseSymbolizePCOutput(buf, stack);
     return true;
   }
@@ -328,8 +359,9 @@ bool LLVMSymbolizer::SymbolizePC(uptr addr, SymbolizedStack *stack) {
 }
 
 bool LLVMSymbolizer::SymbolizeData(uptr addr, DataInfo *info) {
-  if (const char *buf =
-          SendCommand(/*is_data*/ true, info->module, info->module_offset)) {
+  const char *buf = FormatAndSendCommand(
+      /*is_data*/ true, info->module, info->module_offset, info->module_arch);
+  if (buf) {
     ParseSymbolizeDataOutput(buf, info);
     info->start += (addr - info->module_offset); // Add the base address.
     return true;
@@ -337,11 +369,27 @@ bool LLVMSymbolizer::SymbolizeData(uptr addr, DataInfo *info) {
   return false;
 }
 
-const char *LLVMSymbolizer::SendCommand(bool is_data, const char *module_name,
-                                        uptr module_offset) {
+const char *LLVMSymbolizer::FormatAndSendCommand(bool is_data,
+                                                 const char *module_name,
+                                                 uptr module_offset,
+                                                 ModuleArch arch) {
   CHECK(module_name);
-  internal_snprintf(buffer_, kBufferSize, "%s\"%s\" 0x%zx\n",
-                    is_data ? "DATA " : "", module_name, module_offset);
+  const char *is_data_str = is_data ? "DATA " : "";
+  if (arch == kModuleArchUnknown) {
+    if (internal_snprintf(buffer_, kBufferSize, "%s\"%s\" 0x%zx\n", is_data_str,
+                          module_name,
+                          module_offset) >= static_cast<int>(kBufferSize)) {
+      Report("WARNING: Command buffer too small");
+      return nullptr;
+    }
+  } else {
+    if (internal_snprintf(buffer_, kBufferSize, "%s\"%s:%s\" 0x%zx\n",
+                          is_data_str, module_name, ModuleArchToString(arch),
+                          module_offset) >= static_cast<int>(kBufferSize)) {
+      Report("WARNING: Command buffer too small");
+      return nullptr;
+    }
+  }
   return symbolizer_process_->SendCommand(buffer_);
 }
 
@@ -357,7 +405,23 @@ SymbolizerProcess::SymbolizerProcess(const char *path, bool use_forkpty)
   CHECK_NE(path_[0], '\0');
 }
 
+static bool IsSameModule(const char* path) {
+  if (const char* ProcessName = GetProcessName()) {
+    if (const char* SymbolizerName = StripModuleName(path)) {
+      return !internal_strcmp(ProcessName, SymbolizerName);
+    }
+  }
+  return false;
+}
+
 const char *SymbolizerProcess::SendCommand(const char *command) {
+  if (failed_to_start_)
+    return nullptr;
+  if (IsSameModule(path_)) {
+    Report("WARNING: Symbolizer was blocked from starting itself!\n");
+    failed_to_start_ = true;
+    return nullptr;
+  }
   for (; times_restarted_ < kMaxTimesRestarted; times_restarted_++) {
     // Start or restart symbolizer if we failed to send command to it.
     if (const char *res = SendCommandImpl(command))
@@ -406,6 +470,11 @@ bool SymbolizerProcess::ReadFromSymbolizer(char *buffer, uptr max_length) {
     read_len += just_read;
     if (ReachedEndOfOutput(buffer, read_len))
       break;
+    if (read_len + 1 == max_length) {
+      Report("WARNING: Symbolizer buffer too small\n");
+      read_len = 0;
+      break;
+    }
   }
   buffer[read_len] = '\0';
   return true;
@@ -423,4 +492,6 @@ bool SymbolizerProcess::WriteToSymbolizer(const char *buffer, uptr length) {
   return true;
 }
 
+#endif  // !SANITIZER_FUCHSIA
+
 }  // namespace __sanitizer
diff --git a/libsanitizer/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc b/libsanitizer/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc
index 3fcd7d04880..afd6bbe7fbf 100644
--- a/libsanitizer/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_symbolizer_posix_libcdep.cc
@@ -14,6 +14,7 @@
 #if SANITIZER_POSIX
 #include "sanitizer_allocator_internal.h"
 #include "sanitizer_common.h"
+#include "sanitizer_file.h"
 #include "sanitizer_flags.h"
 #include "sanitizer_internal_defs.h"
 #include "sanitizer_linux.h"
@@ -53,7 +54,7 @@ const char *DemangleCXXABI(const char *name) {
   // own demangler (libc++abi's implementation could be adapted so that
   // it does not allocate). For now, we just call it anyway, and we leak
   // the returned value.
-  if (__cxxabiv1::__cxa_demangle)
+  if (&__cxxabiv1::__cxa_demangle)
     if (const char *demangled_name =
           __cxxabiv1::__cxa_demangle(name, 0, 0, 0))
       return demangled_name;
@@ -99,6 +100,46 @@ const char *DemangleSwiftAndCXX(const char *name) {
   return DemangleCXXABI(name);
 }
 
+static bool CreateTwoHighNumberedPipes(int *infd_, int *outfd_) {
+  int *infd = NULL;
+  int *outfd = NULL;
+  // The client program may close its stdin and/or stdout and/or stderr
+  // thus allowing socketpair to reuse file descriptors 0, 1 or 2.
+  // In this case the communication between the forked processes may be
+  // broken if either the parent or the child tries to close or duplicate
+  // these descriptors. The loop below produces two pairs of file
+  // descriptors, each greater than 2 (stderr).
+  int sock_pair[5][2];
+  for (int i = 0; i < 5; i++) {
+    if (pipe(sock_pair[i]) == -1) {
+      for (int j = 0; j < i; j++) {
+        internal_close(sock_pair[j][0]);
+        internal_close(sock_pair[j][1]);
+      }
+      return false;
+    } else if (sock_pair[i][0] > 2 && sock_pair[i][1] > 2) {
+      if (infd == NULL) {
+        infd = sock_pair[i];
+      } else {
+        outfd = sock_pair[i];
+        for (int j = 0; j < i; j++) {
+          if (sock_pair[j] == infd) continue;
+          internal_close(sock_pair[j][0]);
+          internal_close(sock_pair[j][1]);
+        }
+        break;
+      }
+    }
+  }
+  CHECK(infd);
+  CHECK(outfd);
+  infd_[0] = infd[0];
+  infd_[1] = infd[1];
+  outfd_[0] = outfd[0];
+  outfd_[1] = outfd[1];
+  return true;
+}
+
 bool SymbolizerProcess::StartSymbolizerSubprocess() {
   if (!FileExists(path_)) {
     if (!reported_invalid_path_) {
@@ -108,7 +149,18 @@ bool SymbolizerProcess::StartSymbolizerSubprocess() {
     return false;
   }
 
-  int pid;
+  int pid = -1;
+
+  int infd[2];
+  internal_memset(&infd, 0, sizeof(infd));
+  int outfd[2];
+  internal_memset(&outfd, 0, sizeof(outfd));
+  if (!CreateTwoHighNumberedPipes(infd, outfd)) {
+    Report("WARNING: Can't create a socket pair to start "
+           "external symbolizer (errno: %d)\n", errno);
+    return false;
+  }
+
   if (use_forkpty_) {
 #if SANITIZER_MAC
     fd_t fd = kInvalidFd;
@@ -119,6 +171,10 @@ bool SymbolizerProcess::StartSymbolizerSubprocess() {
     int saved_stderr = dup(STDERR_FILENO);
     CHECK_GE(saved_stderr, 0);
 
+    // We only need one pipe, for stdin of the child.
+    close(outfd[0]);
+    close(outfd[1]);
+
     // Use forkpty to disable buffering in the new terminal.
     pid = internal_forkpty(&fd);
     if (pid == -1) {
@@ -129,6 +185,13 @@ bool SymbolizerProcess::StartSymbolizerSubprocess() {
     } else if (pid == 0) {
       // Child subprocess.
 
+      // infd[0] is the child's reading end.
+      close(infd[1]);
+
+      // Set up stdin to read from the pipe.
+      CHECK_GE(dup2(infd[0], STDIN_FILENO), 0);
+      close(infd[0]);
+
       // Restore stderr.
       CHECK_GE(dup2(saved_stderr, STDERR_FILENO), 0);
       close(saved_stderr);
@@ -139,8 +202,12 @@ bool SymbolizerProcess::StartSymbolizerSubprocess() {
       internal__exit(1);
     }
 
+    // Input for the child, infd[1] is our writing end.
+    output_fd_ = infd[1];
+    close(infd[0]);
+
     // Continue execution in parent process.
-    input_fd_ = output_fd_ = fd;
+    input_fd_ = fd;
 
     close(saved_stderr);
 
@@ -154,41 +221,6 @@ bool SymbolizerProcess::StartSymbolizerSubprocess() {
     UNIMPLEMENTED();
 #endif  // SANITIZER_MAC
   } else {
-    int *infd = NULL;
-    int *outfd = NULL;
-    // The client program may close its stdin and/or stdout and/or stderr
-    // thus allowing socketpair to reuse file descriptors 0, 1 or 2.
-    // In this case the communication between the forked processes may be
-    // broken if either the parent or the child tries to close or duplicate
-    // these descriptors. The loop below produces two pairs of file
-    // descriptors, each greater than 2 (stderr).
-    int sock_pair[5][2];
-    for (int i = 0; i < 5; i++) {
-      if (pipe(sock_pair[i]) == -1) {
-        for (int j = 0; j < i; j++) {
-          internal_close(sock_pair[j][0]);
-          internal_close(sock_pair[j][1]);
-        }
-        Report("WARNING: Can't create a socket pair to start "
-               "external symbolizer (errno: %d)\n", errno);
-        return false;
-      } else if (sock_pair[i][0] > 2 && sock_pair[i][1] > 2) {
-        if (infd == NULL) {
-          infd = sock_pair[i];
-        } else {
-          outfd = sock_pair[i];
-          for (int j = 0; j < i; j++) {
-            if (sock_pair[j] == infd) continue;
-            internal_close(sock_pair[j][0]);
-            internal_close(sock_pair[j][1]);
-          }
-          break;
-        }
-      }
-    }
-    CHECK(infd);
-    CHECK(outfd);
-
     const char *argv[kArgVMax];
     GetArgV(path_, argv);
     pid = StartSubprocess(path_, argv, /* stdin */ outfd[0],
@@ -203,6 +235,8 @@ bool SymbolizerProcess::StartSymbolizerSubprocess() {
     output_fd_ = outfd[1];
   }
 
+  CHECK_GT(pid, 0);
+
   // Check that symbolizer subprocess started successfully.
   SleepForMillis(kSymbolizerStartupTimeMillis);
   if (!IsProcessRunning(pid)) {
@@ -236,6 +270,10 @@ class Addr2LineProcess : public SymbolizerProcess {
   bool ReadFromSymbolizer(char *buffer, uptr max_length) override {
     if (!SymbolizerProcess::ReadFromSymbolizer(buffer, max_length))
       return false;
+    // The returned buffer is empty when output is valid, but exceeds
+    // max_length.
+    if (*buffer == '\0')
+      return true;
     // We should cut out output_terminator_ at the end of given buffer,
     // appended by addr2line to mark the end of its meaningful output.
     // We cannot scan buffer from it's beginning, because it is legal for it
@@ -389,7 +427,6 @@ class InternalSymbolizer : public SymbolizerTool {
   InternalSymbolizer() { }
 
   static const int kBufferSize = 16 * 1024;
-  static const int kMaxDemangledNameSize = 1024;
   char buffer_[kBufferSize];
 };
 #else  // SANITIZER_SUPPORTS_WEAK_HOOKS
@@ -436,16 +473,16 @@ static SymbolizerTool *ChooseExternalSymbolizer(LowLevelAllocator *allocator) {
 
   // Otherwise symbolizer program is unknown, let's search $PATH
   CHECK(path == nullptr);
-  if (const char *found_path = FindPathToBinary("llvm-symbolizer")) {
-    VReport(2, "Using llvm-symbolizer found at: %s\n", found_path);
-    return new(*allocator) LLVMSymbolizer(found_path, allocator);
-  }
 #if SANITIZER_MAC
   if (const char *found_path = FindPathToBinary("atos")) {
     VReport(2, "Using atos found at: %s\n", found_path);
     return new(*allocator) AtosSymbolizer(found_path, allocator);
   }
 #endif  // SANITIZER_MAC
+  if (const char *found_path = FindPathToBinary("llvm-symbolizer")) {
+    VReport(2, "Using llvm-symbolizer found at: %s\n", found_path);
+    return new(*allocator) LLVMSymbolizer(found_path, allocator);
+  }
   if (common_flags()->allow_addr2line) {
     if (const char *found_path = FindPathToBinary("addr2line")) {
       VReport(2, "Using addr2line found at: %s\n", found_path);
@@ -461,7 +498,7 @@ static void ChooseSymbolizerTools(IntrusiveList<SymbolizerTool> *list,
     VReport(2, "Symbolizer is disabled.\n");
     return;
   }
-  if (IsReportingOOM()) {
+  if (IsAllocatorOutOfMemory()) {
     VReport(2, "Cannot use internal symbolizer: out of memory\n");
   } else if (SymbolizerTool *tool = InternalSymbolizer::get(allocator)) {
     VReport(2, "Using internal symbolizer.\n");
diff --git a/libsanitizer/sanitizer_common/sanitizer_symbolizer_win.cc b/libsanitizer/sanitizer_common/sanitizer_symbolizer_win.cc
index 95fda7ec42e..06375fc2f4e 100644
--- a/libsanitizer/sanitizer_common/sanitizer_symbolizer_win.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_symbolizer_win.cc
@@ -12,15 +12,24 @@
 
 #include "sanitizer_platform.h"
 #if SANITIZER_WINDOWS
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-#include <dbghelp.h>
-#pragma comment(lib, "dbghelp.lib")
 
+#include "sanitizer_dbghelp.h"
 #include "sanitizer_symbolizer_internal.h"
 
 namespace __sanitizer {
 
+decltype(::StackWalk64) *StackWalk64;
+decltype(::SymCleanup) *SymCleanup;
+decltype(::SymFromAddr) *SymFromAddr;
+decltype(::SymFunctionTableAccess64) *SymFunctionTableAccess64;
+decltype(::SymGetLineFromAddr64) *SymGetLineFromAddr64;
+decltype(::SymGetModuleBase64) *SymGetModuleBase64;
+decltype(::SymGetSearchPathW) *SymGetSearchPathW;
+decltype(::SymInitialize) *SymInitialize;
+decltype(::SymSetOptions) *SymSetOptions;
+decltype(::SymSetSearchPathW) *SymSetSearchPathW;
+decltype(::UnDecorateSymbolName) *UnDecorateSymbolName;
+
 namespace {
 
 class WinSymbolizerTool : public SymbolizerTool {
@@ -48,6 +57,29 @@ bool TrySymInitialize() {
 void InitializeDbgHelpIfNeeded() {
   if (is_dbghelp_initialized)
     return;
+
+  HMODULE dbghelp = LoadLibraryA("dbghelp.dll");
+  CHECK(dbghelp && "failed to load dbghelp.dll");
+
+#define DBGHELP_IMPORT(name)                                                  \
+  do {                                                                        \
+    name =                                                                    \
+        reinterpret_cast<decltype(::name) *>(GetProcAddress(dbghelp, #name)); \
+    CHECK(name != nullptr);                                                   \
+  } while (0)
+  DBGHELP_IMPORT(StackWalk64);
+  DBGHELP_IMPORT(SymCleanup);
+  DBGHELP_IMPORT(SymFromAddr);
+  DBGHELP_IMPORT(SymFunctionTableAccess64);
+  DBGHELP_IMPORT(SymGetLineFromAddr64);
+  DBGHELP_IMPORT(SymGetModuleBase64);
+  DBGHELP_IMPORT(SymGetSearchPathW);
+  DBGHELP_IMPORT(SymInitialize);
+  DBGHELP_IMPORT(SymSetOptions);
+  DBGHELP_IMPORT(SymSetSearchPathW);
+  DBGHELP_IMPORT(UnDecorateSymbolName);
+#undef DBGHELP_IMPORT
+
   if (!TrySymInitialize()) {
     // OK, maybe the client app has called SymInitialize already.
     // That's a bit unfortunate for us as all the DbgHelp functions are
diff --git a/libsanitizer/sanitizer_common/sanitizer_syscall_generic.inc b/libsanitizer/sanitizer_common/sanitizer_syscall_generic.inc
index 3bc50d972a4..7c9a2719eea 100644
--- a/libsanitizer/sanitizer_common/sanitizer_syscall_generic.inc
+++ b/libsanitizer/sanitizer_common/sanitizer_syscall_generic.inc
@@ -5,17 +5,41 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// Generic implementations of internal_syscall and internal_iserror.
+// Generic implementations of internal_syscall* and internal_iserror.
 //
 //===----------------------------------------------------------------------===//
 
-#if SANITIZER_FREEBSD || SANITIZER_MAC
+#if SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_NETBSD
 # define SYSCALL(name) SYS_ ## name
 #else
 # define SYSCALL(name) __NR_ ## name
 #endif
 
-#if (SANITIZER_FREEBSD || SANITIZER_MAC) && defined(__x86_64__)
+#if SANITIZER_NETBSD
+// We use 3 kinds of internal_syscall's for different types of retval in order
+// to address differences in calling conventions (e.g. registers to place the
+// return value in).
+//   - internal_syscall     for 32-bit length (int, pid_t)
+//   - internal_syscall64   for 64-bit length (off_t)
+//   - internal_syscall_ptr for pointer and (s)size_t
+# define  internal_syscall      syscall
+# define  internal_syscall64    __syscall
+// Handle syscall renames manually
+# define SYS_stat SYS___stat50
+# define SYS_lstat SYS___lstat50
+# define SYS_fstat SYS___fstat50
+# define SYS_gettimeofday SYS___gettimeofday50
+# define SYS_wait4 SYS___wait450
+# define SYS_getdents SYS___getdents30
+# define SYS_sigaltstack SYS___sigaltstack14
+# define SYS_sigprocmask SYS___sigprocmask14
+# define SYS_nanosleep SYS___nanosleep50
+# if SANITIZER_WORDSIZE == 64
+#  define internal_syscall_ptr  __syscall
+# else
+#  define internal_syscall_ptr  syscall
+# endif
+#elif defined(__x86_64__) && (SANITIZER_FREEBSD || SANITIZER_MAC)
 # define internal_syscall __syscall
 # else
 # define internal_syscall syscall
diff --git a/libsanitizer/sanitizer_common/sanitizer_thread_registry.cc b/libsanitizer/sanitizer_common/sanitizer_thread_registry.cc
index c865d2cad84..d58c93983c5 100644
--- a/libsanitizer/sanitizer_common/sanitizer_thread_registry.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_thread_registry.cc
@@ -17,7 +17,7 @@ namespace __sanitizer {
 ThreadContextBase::ThreadContextBase(u32 tid)
     : tid(tid), unique_id(0), reuse_count(), os_id(0), user_id(0),
       status(ThreadStatusInvalid),
-      detached(false), parent_tid(0), next(0) {
+      detached(false), workerthread(false), parent_tid(0), next(0) {
   name[0] = '\0';
 }
 
@@ -52,14 +52,19 @@ void ThreadContextBase::SetJoined(void *arg) {
 }
 
 void ThreadContextBase::SetFinished() {
-  if (!detached)
-    status = ThreadStatusFinished;
+  // ThreadRegistry::FinishThread calls here in ThreadStatusCreated state
+  // for a thread that never actually started.  In that case the thread
+  // should go to ThreadStatusFinished regardless of whether it was created
+  // as detached.
+  if (!detached || status == ThreadStatusCreated) status = ThreadStatusFinished;
   OnFinished();
 }
 
-void ThreadContextBase::SetStarted(uptr _os_id, void *arg) {
+void ThreadContextBase::SetStarted(tid_t _os_id, bool _workerthread,
+                                   void *arg) {
   status = ThreadStatusRunning;
   os_id = _os_id;
+  workerthread = _workerthread;
   OnStarted(arg);
 }
 
@@ -190,7 +195,7 @@ static bool FindThreadContextByOsIdCallback(ThreadContextBase *tctx,
       tctx->status != ThreadStatusDead);
 }
 
-ThreadContextBase *ThreadRegistry::FindThreadContextByOsIDLocked(uptr os_id) {
+ThreadContextBase *ThreadRegistry::FindThreadContextByOsIDLocked(tid_t os_id) {
   return FindThreadContextLocked(FindThreadContextByOsIdCallback,
                                  (void *)os_id);
 }
@@ -200,7 +205,8 @@ void ThreadRegistry::SetThreadName(u32 tid, const char *name) {
   CHECK_LT(tid, n_contexts_);
   ThreadContextBase *tctx = threads_[tid];
   CHECK_NE(tctx, 0);
-  CHECK_EQ(ThreadStatusRunning, tctx->status);
+  CHECK_EQ(SANITIZER_FUCHSIA ? ThreadStatusCreated : ThreadStatusRunning,
+           tctx->status);
   tctx->SetName(name);
 }
 
@@ -247,31 +253,43 @@ void ThreadRegistry::JoinThread(u32 tid, void *arg) {
   QuarantinePush(tctx);
 }
 
+// Normally this is called when the thread is about to exit.  If
+// called in ThreadStatusCreated state, then this thread was never
+// really started.  We just did CreateThread for a prospective new
+// thread before trying to create it, and then failed to actually
+// create it, and so never called StartThread.
 void ThreadRegistry::FinishThread(u32 tid) {
   BlockingMutexLock l(&mtx_);
   CHECK_GT(alive_threads_, 0);
   alive_threads_--;
-  CHECK_GT(running_threads_, 0);
-  running_threads_--;
   CHECK_LT(tid, n_contexts_);
   ThreadContextBase *tctx = threads_[tid];
   CHECK_NE(tctx, 0);
-  CHECK_EQ(ThreadStatusRunning, tctx->status);
+  bool dead = tctx->detached;
+  if (tctx->status == ThreadStatusRunning) {
+    CHECK_GT(running_threads_, 0);
+    running_threads_--;
+  } else {
+    // The thread never really existed.
+    CHECK_EQ(tctx->status, ThreadStatusCreated);
+    dead = true;
+  }
   tctx->SetFinished();
-  if (tctx->detached) {
+  if (dead) {
     tctx->SetDead();
     QuarantinePush(tctx);
   }
 }
 
-void ThreadRegistry::StartThread(u32 tid, uptr os_id, void *arg) {
+void ThreadRegistry::StartThread(u32 tid, tid_t os_id, bool workerthread,
+                                 void *arg) {
   BlockingMutexLock l(&mtx_);
   running_threads_++;
   CHECK_LT(tid, n_contexts_);
   ThreadContextBase *tctx = threads_[tid];
   CHECK_NE(tctx, 0);
   CHECK_EQ(ThreadStatusCreated, tctx->status);
-  tctx->SetStarted(os_id, arg);
+  tctx->SetStarted(os_id, workerthread, arg);
 }
 
 void ThreadRegistry::QuarantinePush(ThreadContextBase *tctx) {
diff --git a/libsanitizer/sanitizer_common/sanitizer_thread_registry.h b/libsanitizer/sanitizer_common/sanitizer_thread_registry.h
index 8d5f1ea3988..16c2f86e1f9 100644
--- a/libsanitizer/sanitizer_common/sanitizer_thread_registry.h
+++ b/libsanitizer/sanitizer_common/sanitizer_thread_registry.h
@@ -37,12 +37,13 @@ class ThreadContextBase {
   const u32 tid;  // Thread ID. Main thread should have tid = 0.
   u64 unique_id;  // Unique thread ID.
   u32 reuse_count;  // Number of times this tid was reused.
-  uptr os_id;     // PID (used for reporting).
+  tid_t os_id;     // PID (used for reporting).
   uptr user_id;   // Some opaque user thread id (e.g. pthread_t).
   char name[64];  // As annotated by user.
 
   ThreadStatus status;
   bool detached;
+  bool workerthread;
 
   u32 parent_tid;
   ThreadContextBase *next;  // For storing thread contexts in a list.
@@ -52,7 +53,7 @@ class ThreadContextBase {
   void SetDead();
   void SetJoined(void *arg);
   void SetFinished();
-  void SetStarted(uptr _os_id, void *arg);
+  void SetStarted(tid_t _os_id, bool _workerthread, void *arg);
   void SetCreated(uptr _user_id, u64 _unique_id, bool _detached,
                   u32 _parent_tid, void *arg);
   void Reset();
@@ -106,14 +107,14 @@ class ThreadRegistry {
   // is found.
   ThreadContextBase *FindThreadContextLocked(FindThreadCallback cb,
                                              void *arg);
-  ThreadContextBase *FindThreadContextByOsIDLocked(uptr os_id);
+  ThreadContextBase *FindThreadContextByOsIDLocked(tid_t os_id);
 
   void SetThreadName(u32 tid, const char *name);
   void SetThreadNameByUserId(uptr user_id, const char *name);
   void DetachThread(u32 tid, void *arg);
   void JoinThread(u32 tid, void *arg);
   void FinishThread(u32 tid);
-  void StartThread(u32 tid, uptr os_id, void *arg);
+  void StartThread(u32 tid, tid_t os_id, bool workerthread, void *arg);
 
  private:
   const ThreadContextFactory context_factory_;
diff --git a/libsanitizer/sanitizer_common/sanitizer_tls_get_addr.cc b/libsanitizer/sanitizer_common/sanitizer_tls_get_addr.cc
index 229225d95dd..ebf5ec09444 100644
--- a/libsanitizer/sanitizer_common/sanitizer_tls_get_addr.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_tls_get_addr.cc
@@ -43,7 +43,7 @@ static const uptr kDestroyedThread = -1;
 
 static inline void DTLS_Deallocate(DTLS::DTV *dtv, uptr size) {
   if (!size) return;
-  VPrintf(2, "__tls_get_addr: DTLS_Deallocate %p %zd\n", dtv, size);
+  VReport(2, "__tls_get_addr: DTLS_Deallocate %p %zd\n", dtv, size);
   UnmapOrDie(dtv, size * sizeof(DTLS::DTV));
   atomic_fetch_sub(&number_of_live_dtls, 1, memory_order_relaxed);
 }
@@ -56,7 +56,7 @@ static inline void DTLS_Resize(uptr new_size) {
       (DTLS::DTV *)MmapOrDie(new_size * sizeof(DTLS::DTV), "DTLS_Resize");
   uptr num_live_dtls =
       atomic_fetch_add(&number_of_live_dtls, 1, memory_order_relaxed);
-  VPrintf(2, "__tls_get_addr: DTLS_Resize %p %zd\n", &dtls, num_live_dtls);
+  VReport(2, "__tls_get_addr: DTLS_Resize %p %zd\n", &dtls, num_live_dtls);
   CHECK_LT(num_live_dtls, 1 << 20);
   uptr old_dtv_size = dtls.dtv_size;
   DTLS::DTV *old_dtv = dtls.dtv;
@@ -70,7 +70,7 @@ static inline void DTLS_Resize(uptr new_size) {
 
 void DTLS_Destroy() {
   if (!common_flags()->intercept_tls_get_addr) return;
-  VPrintf(2, "__tls_get_addr: DTLS_Destroy %p %zd\n", &dtls, dtls.dtv_size);
+  VReport(2, "__tls_get_addr: DTLS_Destroy %p %zd\n", &dtls, dtls.dtv_size);
   uptr s = dtls.dtv_size;
   dtls.dtv_size = kDestroyedThread;  // Do this before unmap for AS-safety.
   DTLS_Deallocate(dtls.dtv, s);
@@ -95,28 +95,28 @@ DTLS::DTV *DTLS_on_tls_get_addr(void *arg_void, void *res,
   if (dtls.dtv[dso_id].beg) return 0;
   uptr tls_size = 0;
   uptr tls_beg = reinterpret_cast<uptr>(res) - arg->offset - kDtvOffset;
-  VPrintf(2, "__tls_get_addr: %p {%p,%p} => %p; tls_beg: %p; sp: %p "
+  VReport(2, "__tls_get_addr: %p {%p,%p} => %p; tls_beg: %p; sp: %p "
              "num_live_dtls %zd\n",
           arg, arg->dso_id, arg->offset, res, tls_beg, &tls_beg,
           atomic_load(&number_of_live_dtls, memory_order_relaxed));
   if (dtls.last_memalign_ptr == tls_beg) {
     tls_size = dtls.last_memalign_size;
-    VPrintf(2, "__tls_get_addr: glibc <=2.18 suspected; tls={%p,%p}\n",
+    VReport(2, "__tls_get_addr: glibc <=2.18 suspected; tls={%p,%p}\n",
         tls_beg, tls_size);
   } else if (tls_beg >= static_tls_begin && tls_beg < static_tls_end) {
     // This is the static TLS block which was initialized / unpoisoned at thread
     // creation.
-    VPrintf(2, "__tls_get_addr: static tls: %p\n", tls_beg);
+    VReport(2, "__tls_get_addr: static tls: %p\n", tls_beg);
     tls_size = 0;
   } else if ((tls_beg % 4096) == sizeof(Glibc_2_19_tls_header)) {
     // We may want to check gnu_get_libc_version().
     Glibc_2_19_tls_header *header = (Glibc_2_19_tls_header *)tls_beg - 1;
     tls_size = header->size;
     tls_beg = header->start;
-    VPrintf(2, "__tls_get_addr: glibc >=2.19 suspected; tls={%p %p}\n",
+    VReport(2, "__tls_get_addr: glibc >=2.19 suspected; tls={%p %p}\n",
         tls_beg, tls_size);
   } else {
-    VPrintf(2, "__tls_get_addr: Can't guess glibc version\n");
+    VReport(2, "__tls_get_addr: Can't guess glibc version\n");
     // This may happen inside the DTOR of main thread, so just ignore it.
     tls_size = 0;
   }
@@ -127,18 +127,26 @@ DTLS::DTV *DTLS_on_tls_get_addr(void *arg_void, void *res,
 
 void DTLS_on_libc_memalign(void *ptr, uptr size) {
   if (!common_flags()->intercept_tls_get_addr) return;
-  VPrintf(2, "DTLS_on_libc_memalign: %p %p\n", ptr, size);
+  VReport(2, "DTLS_on_libc_memalign: %p %p\n", ptr, size);
   dtls.last_memalign_ptr = reinterpret_cast<uptr>(ptr);
   dtls.last_memalign_size = size;
 }
 
 DTLS *DTLS_Get() { return &dtls; }
 
+bool DTLSInDestruction(DTLS *dtls) {
+  return dtls->dtv_size == kDestroyedThread;
+}
+
 #else
 void DTLS_on_libc_memalign(void *ptr, uptr size) {}
 DTLS::DTV *DTLS_on_tls_get_addr(void *arg, void *res) { return 0; }
 DTLS *DTLS_Get() { return 0; }
 void DTLS_Destroy() {}
+bool DTLSInDestruction(DTLS *dtls) {
+  UNREACHABLE("dtls is unsupported on this platform!");
+}
+
 #endif  // SANITIZER_INTERCEPT_TLS_GET_ADDR
 
 }  // namespace __sanitizer
diff --git a/libsanitizer/sanitizer_common/sanitizer_tls_get_addr.h b/libsanitizer/sanitizer_common/sanitizer_tls_get_addr.h
index e4f8c0c535e..19c8472c481 100644
--- a/libsanitizer/sanitizer_common/sanitizer_tls_get_addr.h
+++ b/libsanitizer/sanitizer_common/sanitizer_tls_get_addr.h
@@ -53,6 +53,8 @@ DTLS::DTV *DTLS_on_tls_get_addr(void *arg, void *res, uptr static_tls_begin,
 void DTLS_on_libc_memalign(void *ptr, uptr size);
 DTLS *DTLS_Get();
 void DTLS_Destroy();  // Make sure to call this before the thread is destroyed.
+// Returns true if DTLS of suspended thread is in destruction process.
+bool DTLSInDestruction(DTLS *dtls);
 
 }  // namespace __sanitizer
 
diff --git a/libsanitizer/sanitizer_common/sanitizer_unwind_linux_libcdep.cc b/libsanitizer/sanitizer_common/sanitizer_unwind_linux_libcdep.cc
index eb1c133e4f4..7dba9e7ccd2 100644
--- a/libsanitizer/sanitizer_common/sanitizer_unwind_linux_libcdep.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_unwind_linux_libcdep.cc
@@ -6,11 +6,11 @@
 //===----------------------------------------------------------------------===//
 //
 // This file contains the unwind.h-based (aka "slow") stack unwinding routines
-// available to the tools on Linux, Android, and FreeBSD.
+// available to the tools on Linux, Android, NetBSD and FreeBSD.
 //===----------------------------------------------------------------------===//
 
 #include "sanitizer_platform.h"
-#if SANITIZER_FREEBSD || SANITIZER_LINUX
+#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
 #include "sanitizer_common.h"
 #include "sanitizer_stacktrace.h"
 
@@ -76,7 +76,8 @@ void SanitizerInitializeUnwinder() {
 }
 #endif
 
-#ifdef __arm__
+#if defined(__arm__) && !SANITIZER_NETBSD
+// NetBSD uses dwarf EH
 #define UNWIND_STOP _URC_END_OF_STACK
 #define UNWIND_CONTINUE _URC_NO_REASON
 #else
@@ -163,4 +164,4 @@ void BufferedStackTrace::SlowUnwindStackWithContext(uptr pc, void *context,
 
 }  // namespace __sanitizer
 
-#endif  // SANITIZER_FREEBSD || SANITIZER_LINUX
+#endif  // SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
diff --git a/libsanitizer/sanitizer_common/sanitizer_win.cc b/libsanitizer/sanitizer_common/sanitizer_win.cc
index 785883ce767..84e66b43c99 100644
--- a/libsanitizer/sanitizer_common/sanitizer_win.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_win.cc
@@ -16,18 +16,34 @@
 #define WIN32_LEAN_AND_MEAN
 #define NOGDI
 #include <windows.h>
-#include <dbghelp.h>
 #include <io.h>
 #include <psapi.h>
 #include <stdlib.h>
 
 #include "sanitizer_common.h"
+#include "sanitizer_dbghelp.h"
+#include "sanitizer_file.h"
 #include "sanitizer_libc.h"
 #include "sanitizer_mutex.h"
 #include "sanitizer_placement_new.h"
-#include "sanitizer_procmaps.h"
 #include "sanitizer_stacktrace.h"
 #include "sanitizer_symbolizer.h"
+#include "sanitizer_win_defs.h"
+
+// A macro to tell the compiler that this part of the code cannot be reached,
+// if the compiler supports this feature. Since we're using this in
+// code that is called when terminating the process, the expansion of the
+// macro should not terminate the process to avoid infinite recursion.
+#if defined(__clang__)
+# define BUILTIN_UNREACHABLE() __builtin_unreachable()
+#elif defined(__GNUC__) && \
+    (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5))
+# define BUILTIN_UNREACHABLE() __builtin_unreachable()
+#elif defined(_MSC_VER)
+# define BUILTIN_UNREACHABLE() __assume(0)
+#else
+# define BUILTIN_UNREACHABLE()
+#endif
 
 namespace __sanitizer {
 
@@ -62,7 +78,7 @@ uptr internal_getpid() {
 
 // In contrast to POSIX, on Windows GetCurrentThreadId()
 // returns a system-unique identifier.
-uptr GetTid() {
+tid_t GetTid() {
   return GetCurrentThreadId();
 }
 
@@ -113,8 +129,24 @@ void UnmapOrDie(void *addr, uptr size) {
   }
 }
 
+static void *ReturnNullptrOnOOMOrDie(uptr size, const char *mem_type,
+                                     const char *mmap_type) {
+  error_t last_error = GetLastError();
+  if (last_error == ERROR_NOT_ENOUGH_MEMORY)
+    return nullptr;
+  ReportMmapFailureAndDie(size, mem_type, mmap_type, last_error);
+}
+
+void *MmapOrDieOnFatalError(uptr size, const char *mem_type) {
+  void *rv = VirtualAlloc(0, size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
+  if (rv == 0)
+    return ReturnNullptrOnOOMOrDie(size, mem_type, "allocate");
+  return rv;
+}
+
 // We want to map a chunk of address space aligned to 'alignment'.
-void *MmapAlignedOrDie(uptr size, uptr alignment, const char *mem_type) {
+void *MmapAlignedOrDieOnFatalError(uptr size, uptr alignment,
+                                   const char *mem_type) {
   CHECK(IsPowerOfTwo(size));
   CHECK(IsPowerOfTwo(alignment));
 
@@ -124,7 +156,7 @@ void *MmapAlignedOrDie(uptr size, uptr alignment, const char *mem_type) {
   uptr mapped_addr =
       (uptr)VirtualAlloc(0, size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
   if (!mapped_addr)
-    ReportMmapFailureAndDie(size, mem_type, "allocate aligned", GetLastError());
+    return ReturnNullptrOnOOMOrDie(size, mem_type, "allocate aligned");
 
   // If we got it right on the first try, return. Otherwise, unmap it and go to
   // the slow path.
@@ -144,8 +176,7 @@ void *MmapAlignedOrDie(uptr size, uptr alignment, const char *mem_type) {
     mapped_addr =
         (uptr)VirtualAlloc(0, size + alignment, MEM_RESERVE, PAGE_NOACCESS);
     if (!mapped_addr)
-      ReportMmapFailureAndDie(size, mem_type, "allocate aligned",
-                              GetLastError());
+      return ReturnNullptrOnOOMOrDie(size, mem_type, "allocate aligned");
 
     // Find the aligned address.
     uptr aligned_addr = RoundUpTo(mapped_addr, alignment);
@@ -163,7 +194,7 @@ void *MmapAlignedOrDie(uptr size, uptr alignment, const char *mem_type) {
 
   // Fail if we can't make this work quickly.
   if (retries == kMaxRetries && mapped_addr == 0)
-    ReportMmapFailureAndDie(size, mem_type, "allocate aligned", GetLastError());
+    return ReturnNullptrOnOOMOrDie(size, mem_type, "allocate aligned");
 
   return (void *)mapped_addr;
 }
@@ -202,6 +233,18 @@ void *MmapFixedOrDie(uptr fixed_addr, uptr size) {
   return p;
 }
 
+void *MmapFixedOrDieOnFatalError(uptr fixed_addr, uptr size) {
+  void *p = VirtualAlloc((LPVOID)fixed_addr, size,
+      MEM_COMMIT, PAGE_READWRITE);
+  if (p == 0) {
+    char mem_type[30];
+    internal_snprintf(mem_type, sizeof(mem_type), "memory at address 0x%zx",
+                      fixed_addr);
+    return ReturnNullptrOnOOMOrDie(size, mem_type, "allocate");
+  }
+  return p;
+}
+
 void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
   // FIXME: make this really NoReserve?
   return MmapOrDie(size, mem_type);
@@ -232,8 +275,7 @@ bool MprotectNoAccess(uptr addr, uptr size) {
   return VirtualProtect((LPVOID)addr, size, PAGE_NOACCESS, &old_protection);
 }
 
-
-void ReleaseMemoryToOS(uptr addr, uptr size) {
+void ReleaseMemoryPagesToOS(uptr beg, uptr end) {
   // This is almost useless on 32-bits.
   // FIXME: add madvise-analog when we move to 64-bits.
 }
@@ -247,7 +289,8 @@ void DontDumpShadowMemory(uptr addr, uptr length) {
   // FIXME: add madvise-analog when we move to 64-bits.
 }
 
-uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding) {
+uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding,
+                              uptr *largest_gap_found) {
   uptr address = 0;
   while (true) {
     MEMORY_BASIC_INFORMATION info;
@@ -372,6 +415,8 @@ void DumpProcessMap() {
 }
 #endif
 
+void PrintModuleMap() { }
+
 void DisableCoreDumperIfNecessary() {
   // Do nothing.
 }
@@ -381,9 +426,6 @@ void ReExec() {
 }
 
 void PrepareForSandboxing(__sanitizer_sandbox_arguments *args) {
-#if !SANITIZER_GO
-  CovPrepareForSandboxing(args);
-#endif
 }
 
 bool StackSizeIsUnlimited() {
@@ -423,8 +465,6 @@ u64 NanoTime() {
 }
 
 void Abort() {
-  if (::IsDebuggerPresent())
-    __debugbreak();
   internal__exit(3);
 }
 
@@ -482,7 +522,7 @@ static uptr GetPreferredBase(const char *modname) {
 }
 
 void ListOfModules::init() {
-  clear();
+  clearOrInit();
   HANDLE cur_process = GetCurrentProcess();
 
   // Query the list of modules.  Start by assuming there are no more than 256
@@ -536,11 +576,14 @@ void ListOfModules::init() {
     LoadedModule cur_module;
     cur_module.set(module_name, adjusted_base);
     // We add the whole module as one single address range.
-    cur_module.addAddressRange(base_address, end_address, /*executable*/ true);
+    cur_module.addAddressRange(base_address, end_address, /*executable*/ true,
+                               /*writable*/ true);
     modules_.push_back(cur_module);
   }
   UnmapOrDie(hmodules, modules_buffer_size);
-};
+}
+
+void ListOfModules::fallbackInit() { clear(); }
 
 // We can't use atexit() directly at __asan_init time as the CRT is not fully
 // initialized at this point.  Place the functions into a vector and use
@@ -654,7 +697,13 @@ uptr internal_sched_yield() {
 }
 
 void internal__exit(int exitcode) {
-  ExitProcess(exitcode);
+  // ExitProcess runs some finalizers, so use TerminateProcess to avoid that.
+  // The debugger doesn't stop on TerminateProcess like it does on ExitProcess,
+  // so add our own breakpoint here.
+  if (::IsDebuggerPresent())
+    __debugbreak();
+  TerminateProcess(GetCurrentProcess(), exitcode);
+  BUILTIN_UNREACHABLE();
 }
 
 uptr internal_ftruncate(fd_t fd, uptr size) {
@@ -776,8 +825,8 @@ void BufferedStackTrace::SlowUnwindStackWithContext(uptr pc, void *context,
   stack_frame.AddrFrame.Mode = AddrModeFlat;
   stack_frame.AddrStack.Mode = AddrModeFlat;
   while (StackWalk64(machine_type, GetCurrentProcess(), GetCurrentThread(),
-                     &stack_frame, &ctx, NULL, &SymFunctionTableAccess64,
-                     &SymGetModuleBase64, NULL) &&
+                     &stack_frame, &ctx, NULL, SymFunctionTableAccess64,
+                     SymGetModuleBase64, NULL) &&
          size < Min(max_depth, kStackTraceMax)) {
     trace_buffer[size++] = (uptr)stack_frame.AddrPC.Offset;
   }
@@ -808,8 +857,35 @@ void InstallDeadlySignalHandlers(SignalHandlerType handler) {
   // FIXME: Decide what to do on Windows.
 }
 
-bool IsHandledDeadlySignal(int signum) {
+HandleSignalMode GetHandleSignalMode(int signum) {
   // FIXME: Decide what to do on Windows.
+  return kHandleSignalNo;
+}
+
+// Check based on flags if we should handle this exception.
+bool IsHandledDeadlyException(DWORD exceptionCode) {
+  switch (exceptionCode) {
+    case EXCEPTION_ACCESS_VIOLATION:
+    case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
+    case EXCEPTION_STACK_OVERFLOW:
+    case EXCEPTION_DATATYPE_MISALIGNMENT:
+    case EXCEPTION_IN_PAGE_ERROR:
+      return common_flags()->handle_segv;
+    case EXCEPTION_ILLEGAL_INSTRUCTION:
+    case EXCEPTION_PRIV_INSTRUCTION:
+    case EXCEPTION_BREAKPOINT:
+      return common_flags()->handle_sigill;
+    case EXCEPTION_FLT_DENORMAL_OPERAND:
+    case EXCEPTION_FLT_DIVIDE_BY_ZERO:
+    case EXCEPTION_FLT_INEXACT_RESULT:
+    case EXCEPTION_FLT_INVALID_OPERATION:
+    case EXCEPTION_FLT_OVERFLOW:
+    case EXCEPTION_FLT_STACK_CHECK:
+    case EXCEPTION_FLT_UNDERFLOW:
+    case EXCEPTION_INT_DIVIDE_BY_ZERO:
+    case EXCEPTION_INT_OVERFLOW:
+      return common_flags()->handle_sigfpe;
+  }
   return false;
 }
 
@@ -838,33 +914,99 @@ bool IsAccessibleMemoryRange(uptr beg, uptr size) {
   return true;
 }
 
-SignalContext SignalContext::Create(void *siginfo, void *context) {
+bool SignalContext::IsStackOverflow() const {
+  return GetType() == EXCEPTION_STACK_OVERFLOW;
+}
+
+void SignalContext::InitPcSpBp() {
   EXCEPTION_RECORD *exception_record = (EXCEPTION_RECORD *)siginfo;
   CONTEXT *context_record = (CONTEXT *)context;
 
-  uptr pc = (uptr)exception_record->ExceptionAddress;
+  pc = (uptr)exception_record->ExceptionAddress;
 #ifdef _WIN64
-  uptr bp = (uptr)context_record->Rbp;
-  uptr sp = (uptr)context_record->Rsp;
+  bp = (uptr)context_record->Rbp;
+  sp = (uptr)context_record->Rsp;
 #else
-  uptr bp = (uptr)context_record->Ebp;
-  uptr sp = (uptr)context_record->Esp;
+  bp = (uptr)context_record->Ebp;
+  sp = (uptr)context_record->Esp;
 #endif
-  uptr access_addr = exception_record->ExceptionInformation[1];
+}
 
+uptr SignalContext::GetAddress() const {
+  EXCEPTION_RECORD *exception_record = (EXCEPTION_RECORD *)siginfo;
+  return exception_record->ExceptionInformation[1];
+}
+
+bool SignalContext::IsMemoryAccess() const {
+  return GetWriteFlag() != SignalContext::UNKNOWN;
+}
+
+SignalContext::WriteFlag SignalContext::GetWriteFlag() const {
+  EXCEPTION_RECORD *exception_record = (EXCEPTION_RECORD *)siginfo;
   // The contents of this array are documented at
   // https://msdn.microsoft.com/en-us/library/windows/desktop/aa363082(v=vs.85).aspx
   // The first element indicates read as 0, write as 1, or execute as 8.  The
   // second element is the faulting address.
-  WriteFlag write_flag = SignalContext::UNKNOWN;
   switch (exception_record->ExceptionInformation[0]) {
-  case 0: write_flag = SignalContext::READ; break;
-  case 1: write_flag = SignalContext::WRITE; break;
-  case 8: write_flag = SignalContext::UNKNOWN; break;
+    case 0:
+      return SignalContext::READ;
+    case 1:
+      return SignalContext::WRITE;
+    case 8:
+      return SignalContext::UNKNOWN;
   }
-  bool is_memory_access = write_flag != SignalContext::UNKNOWN;
-  return SignalContext(context, access_addr, pc, sp, bp, is_memory_access,
-                       write_flag);
+  return SignalContext::UNKNOWN;
+}
+
+void SignalContext::DumpAllRegisters(void *context) {
+  // FIXME: Implement this.
+}
+
+int SignalContext::GetType() const {
+  return static_cast<const EXCEPTION_RECORD *>(siginfo)->ExceptionCode;
+}
+
+const char *SignalContext::Describe() const {
+  unsigned code = GetType();
+  // Get the string description of the exception if this is a known deadly
+  // exception.
+  switch (code) {
+    case EXCEPTION_ACCESS_VIOLATION:
+      return "access-violation";
+    case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
+      return "array-bounds-exceeded";
+    case EXCEPTION_STACK_OVERFLOW:
+      return "stack-overflow";
+    case EXCEPTION_DATATYPE_MISALIGNMENT:
+      return "datatype-misalignment";
+    case EXCEPTION_IN_PAGE_ERROR:
+      return "in-page-error";
+    case EXCEPTION_ILLEGAL_INSTRUCTION:
+      return "illegal-instruction";
+    case EXCEPTION_PRIV_INSTRUCTION:
+      return "priv-instruction";
+    case EXCEPTION_BREAKPOINT:
+      return "breakpoint";
+    case EXCEPTION_FLT_DENORMAL_OPERAND:
+      return "flt-denormal-operand";
+    case EXCEPTION_FLT_DIVIDE_BY_ZERO:
+      return "flt-divide-by-zero";
+    case EXCEPTION_FLT_INEXACT_RESULT:
+      return "flt-inexact-result";
+    case EXCEPTION_FLT_INVALID_OPERATION:
+      return "flt-invalid-operation";
+    case EXCEPTION_FLT_OVERFLOW:
+      return "flt-overflow";
+    case EXCEPTION_FLT_STACK_CHECK:
+      return "flt-stack-check";
+    case EXCEPTION_FLT_UNDERFLOW:
+      return "flt-underflow";
+    case EXCEPTION_INT_DIVIDE_BY_ZERO:
+      return "int-divide-by-zero";
+    case EXCEPTION_INT_OVERFLOW:
+      return "int-overflow";
+  }
+  return "unknown exception";
 }
 
 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
@@ -910,21 +1052,15 @@ int WaitForProcess(pid_t pid) { return -1; }
 // FIXME implement on this platform.
 void GetMemoryProfile(fill_profile_f cb, uptr *stats, uptr stats_size) { }
 
+void CheckNoDeepBind(const char *filename, int flag) {
+  // Do nothing.
+}
 
-}  // namespace __sanitizer
-
-#if !SANITIZER_GO
-// Workaround to implement weak hooks on Windows. COFF doesn't directly support
-// weak symbols, but it does support /alternatename, which is similar. If the
-// user does not override the hook, we will use this default definition instead
-// of null.
-extern "C" void __sanitizer_print_memory_profile(int top_percent) {}
+// FIXME: implement on this platform.
+bool GetRandom(void *buffer, uptr length, bool blocking) {
+  UNIMPLEMENTED();
+}
 
-#ifdef _WIN64
-#pragma comment(linker, "/alternatename:__sanitizer_print_memory_profile=__sanitizer_default_print_memory_profile") // NOLINT
-#else
-#pragma comment(linker, "/alternatename:___sanitizer_print_memory_profile=___sanitizer_default_print_memory_profile") // NOLINT
-#endif
-#endif
+}  // namespace __sanitizer
 
 #endif  // _WIN32
diff --git a/libsanitizer/sanitizer_common/sanitizer_win.h b/libsanitizer/sanitizer_common/sanitizer_win.h
new file mode 100644
index 00000000000..c2d53a46fed
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_win.h
@@ -0,0 +1,24 @@
+//===-- sanitizer_win.h -----------------------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Windows-specific declarations.
+//
+//===----------------------------------------------------------------------===//
+#ifndef SANITIZER_WIN_H
+#define SANITIZER_WIN_H
+
+#include "sanitizer_platform.h"
+#if SANITIZER_WINDOWS
+#include "sanitizer_internal_defs.h"
+
+namespace __sanitizer {
+// Check based on flags if we should handle the exception.
+bool IsHandledDeadlyException(DWORD exceptionCode);
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_WINDOWS
+#endif  // SANITIZER_WIN_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_win_defs.h b/libsanitizer/sanitizer_common/sanitizer_win_defs.h
new file mode 100644
index 00000000000..e71081db575
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_win_defs.h
@@ -0,0 +1,151 @@
+//===-- sanitizer_win_defs.h ------------------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Common definitions for Windows-specific code.
+//
+//===----------------------------------------------------------------------===//
+#ifndef SANITIZER_WIN_DEFS_H
+#define SANITIZER_WIN_DEFS_H
+
+#include "sanitizer_platform.h"
+#if SANITIZER_WINDOWS
+
+#ifndef WINAPI
+#ifdef _M_IX86
+#define WINAPI __stdcall
+#else
+#define WINAPI
+#endif
+#endif
+
+#if defined(_WIN64)
+#define WIN_SYM_PREFIX
+#else
+#define WIN_SYM_PREFIX "_"
+#endif
+
+// Intermediate macro to ensure the parameter is expanded before stringified.
+#define STRINGIFY_(A) #A
+#define STRINGIFY(A) STRINGIFY_(A)
+
+// ----------------- A workaround for the absence of weak symbols --------------
+// We don't have a direct equivalent of weak symbols when using MSVC, but we can
+// use the /alternatename directive to tell the linker to default a specific
+// symbol to a specific value.
+// Take into account that this is a pragma directive for the linker, so it will
+// be ignored by the compiler and the function will be marked as UNDEF in the
+// symbol table of the resulting object file. The linker won't find the default
+// implementation until it links with that object file.
+// So, suppose we provide a default implementation "fundef" for "fun", and this
+// is compiled into the object file "test.obj" including the pragma directive.
+// If we have some code with references to "fun" and we link that code with
+// "test.obj", it will work because the linker always link object files.
+// But, if "test.obj" is included in a static library, like "test.lib", then the
+// liker will only link to "test.obj" if necessary. If we only included the
+// definition of "fun", it won't link to "test.obj" (from test.lib) because
+// "fun" appears as UNDEF, so it doesn't resolve the symbol "fun", and will
+// result in a link error (the linker doesn't find the pragma directive).
+// So, a workaround is to force linkage with the modules that include weak
+// definitions, with the following macro: WIN_FORCE_LINK()
+
+#define WIN_WEAK_ALIAS(Name, Default)                                          \
+  __pragma(comment(linker, "/alternatename:" WIN_SYM_PREFIX STRINGIFY(Name) "="\
+                                             WIN_SYM_PREFIX STRINGIFY(Default)))
+
+#define WIN_FORCE_LINK(Name)                                                   \
+  __pragma(comment(linker, "/include:" WIN_SYM_PREFIX STRINGIFY(Name)))
+
+#define WIN_EXPORT(ExportedName, Name)                                         \
+  __pragma(comment(linker, "/export:" WIN_SYM_PREFIX STRINGIFY(ExportedName)   \
+                                  "=" WIN_SYM_PREFIX STRINGIFY(Name)))
+
+// We cannot define weak functions on Windows, but we can use WIN_WEAK_ALIAS()
+// which defines an alias to a default implementation, and only works when
+// linking statically.
+// So, to define a weak function "fun", we define a default implementation with
+// a different name "fun__def" and we create a "weak alias" fun = fun__def.
+// Then, users can override it just defining "fun".
+// We impose "extern "C"" because otherwise WIN_WEAK_ALIAS() will fail because
+// of name mangling.
+
+// Dummy name for default implementation of weak function.
+# define WEAK_DEFAULT_NAME(Name) Name##__def
+// Name for exported implementation of weak function.
+# define WEAK_EXPORT_NAME(Name) Name##__dll
+
+// Use this macro when you need to define and export a weak function from a
+// library. For example:
+//   WIN_WEAK_EXPORT_DEF(bool, compare, int a, int b) { return a > b; }
+# define WIN_WEAK_EXPORT_DEF(ReturnType, Name, ...)                            \
+  WIN_WEAK_ALIAS(Name, WEAK_DEFAULT_NAME(Name))                                \
+  WIN_EXPORT(WEAK_EXPORT_NAME(Name), Name)                                     \
+  extern "C" ReturnType Name(__VA_ARGS__);                                     \
+  extern "C" ReturnType WEAK_DEFAULT_NAME(Name)(__VA_ARGS__)
+
+// Use this macro when you need to import a weak function from a library. It
+// defines a weak alias to the imported function from the dll. For example:
+//   WIN_WEAK_IMPORT_DEF(compare)
+# define WIN_WEAK_IMPORT_DEF(Name)                                             \
+  WIN_WEAK_ALIAS(Name, WEAK_EXPORT_NAME(Name))
+
+// So, for Windows we provide something similar to weak symbols in Linux, with
+// some differences:
+// + A default implementation must always be provided.
+//
+// + When linking statically it works quite similarly. For example:
+//
+//   // libExample.cc
+//   WIN_WEAK_EXPORT_DEF(bool, compare, int a, int b) { return a > b; }
+//
+//   // client.cc
+//   // We can use the default implementation from the library:
+//   compare(1, 2);
+//   // Or we can override it:
+//   extern "C" bool compare (int a, int b) { return a >= b; }
+//
+//  And it will work fine. If we don't override the function, we need to ensure
+//  that the linker includes the object file with the default implementation.
+//  We can do so with the linker option "-wholearchive:".
+//
+// + When linking dynamically with a library (dll), weak functions are exported
+//  with "__dll" suffix. Clients can use the macro WIN_WEAK_IMPORT_DEF(fun)
+//  which defines a "weak alias" fun = fun__dll.
+//
+//   // libExample.cc
+//   WIN_WEAK_EXPORT_DEF(bool, compare, int a, int b) { return a > b; }
+//
+//   // client.cc
+//   WIN_WEAK_IMPORT_DEF(compare)
+//   // We can use the default implementation from the library:
+//   compare(1, 2);
+//   // Or we can override it:
+//   extern "C" bool compare (int a, int b) { return a >= b; }
+//
+//  But if we override the function, the dlls don't have access to it (which
+//  is different in linux). If that is desired, the strong definition must be
+//  exported and interception can be used from the rest of the dlls.
+//
+//   // libExample.cc
+//   WIN_WEAK_EXPORT_DEF(bool, compare, int a, int b) { return a > b; }
+//   // When initialized, check if the main executable defined "compare".
+//   int libExample_init() {
+//     uptr fnptr = __interception::InternalGetProcAddress(
+//         (void *)GetModuleHandleA(0), "compare");
+//     if (fnptr && !__interception::OverrideFunction((uptr)compare, fnptr, 0))
+//       abort();
+//     return 0;
+//   }
+//
+//   // client.cc
+//   WIN_WEAK_IMPORT_DEF(compare)
+//   // We override and export compare:
+//   extern "C" __declspec(dllexport) bool compare (int a, int b) {
+//     return a >= b;
+//   }
+//
+#endif // SANITIZER_WINDOWS
+#endif // SANITIZER_WIN_DEFS_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_win_dll_thunk.cc b/libsanitizer/sanitizer_common/sanitizer_win_dll_thunk.cc
new file mode 100644
index 00000000000..6577a3606d1
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_win_dll_thunk.cc
@@ -0,0 +1,100 @@
+//===-- sanitizer_win_dll_thunk.cc ----------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This file defines a family of thunks that should be statically linked into
+// the DLLs that have instrumentation in order to delegate the calls to the
+// shared runtime that lives in the main binary.
+// See https://github.com/google/sanitizers/issues/209 for the details.
+//===----------------------------------------------------------------------===//
+
+#ifdef SANITIZER_DLL_THUNK
+#include "sanitizer_win_defs.h"
+#include "sanitizer_win_dll_thunk.h"
+#include "interception/interception.h"
+
+extern "C" {
+void *WINAPI GetModuleHandleA(const char *module_name);
+void abort();
+}
+
+namespace __sanitizer {
+uptr dllThunkGetRealAddrOrDie(const char *name) {
+  uptr ret =
+      __interception::InternalGetProcAddress((void *)GetModuleHandleA(0), name);
+  if (!ret)
+    abort();
+  return ret;
+}
+
+int dllThunkIntercept(const char* main_function, uptr dll_function) {
+  uptr wrapper = dllThunkGetRealAddrOrDie(main_function);
+  if (!__interception::OverrideFunction(dll_function, wrapper, 0))
+    abort();
+  return 0;
+}
+
+int dllThunkInterceptWhenPossible(const char* main_function,
+    const char* default_function, uptr dll_function) {
+  uptr wrapper = __interception::InternalGetProcAddress(
+    (void *)GetModuleHandleA(0), main_function);
+  if (!wrapper)
+    wrapper = dllThunkGetRealAddrOrDie(default_function);
+  if (!__interception::OverrideFunction(dll_function, wrapper, 0))
+    abort();
+  return 0;
+}
+} // namespace __sanitizer
+
+// Include Sanitizer Common interface.
+#define INTERFACE_FUNCTION(Name) INTERCEPT_SANITIZER_FUNCTION(Name)
+#define INTERFACE_WEAK_FUNCTION(Name) INTERCEPT_SANITIZER_WEAK_FUNCTION(Name)
+#include "sanitizer_common_interface.inc"
+
+#pragma section(".DLLTH$A", read)  // NOLINT
+#pragma section(".DLLTH$Z", read)  // NOLINT
+
+typedef void (*DllThunkCB)();
+extern "C" {
+__declspec(allocate(".DLLTH$A")) DllThunkCB __start_dll_thunk;
+__declspec(allocate(".DLLTH$Z")) DllThunkCB __stop_dll_thunk;
+}
+
+// Disable compiler warnings that show up if we declare our own version
+// of a compiler intrinsic (e.g. strlen).
+#pragma warning(disable: 4391)
+#pragma warning(disable: 4392)
+
+extern "C" int __dll_thunk_init() {
+  static bool flag = false;
+  // __dll_thunk_init is expected to be called by only one thread.
+  if (flag) return 0;
+  flag = true;
+
+  for (DllThunkCB *it = &__start_dll_thunk; it < &__stop_dll_thunk; ++it)
+    if (*it)
+      (*it)();
+
+  // In DLLs, the callbacks are expected to return 0,
+  // otherwise CRT initialization fails.
+  return 0;
+}
+
+// We want to call dll_thunk_init before C/C++ initializers / constructors are
+// executed, otherwise functions like memset might be invoked.
+#pragma section(".CRT$XIB", long, read)  // NOLINT
+__declspec(allocate(".CRT$XIB")) int (*__dll_thunk_preinit)() =
+    __dll_thunk_init;
+
+static void WINAPI dll_thunk_thread_init(void *mod, unsigned long reason,
+                                         void *reserved) {
+  if (reason == /*DLL_PROCESS_ATTACH=*/1) __dll_thunk_init();
+}
+
+#pragma section(".CRT$XLAB", long, read)  // NOLINT
+__declspec(allocate(".CRT$XLAB")) void (WINAPI *__dll_thunk_tls_init)(void *,
+    unsigned long, void *) = dll_thunk_thread_init;
+
+#endif // SANITIZER_DLL_THUNK
diff --git a/libsanitizer/sanitizer_common/sanitizer_win_dll_thunk.h b/libsanitizer/sanitizer_common/sanitizer_win_dll_thunk.h
new file mode 100644
index 00000000000..5a475e0798e
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_win_dll_thunk.h
@@ -0,0 +1,180 @@
+//===-- sanitizer_win_dll_thunk.h -----------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This header provide helper macros to delegate calls to the shared runtime
+// that lives in the main executable. It should be included to dll_thunks that
+// will be linked to the dlls, when the sanitizer is a static library included
+// in the main executable.
+//===----------------------------------------------------------------------===//
+#ifndef SANITIZER_WIN_DLL_THUNK_H
+#define SANITIZER_WIN_DLL_THUNK_H
+#include "sanitizer_internal_defs.h"
+
+namespace __sanitizer {
+uptr dllThunkGetRealAddrOrDie(const char *name);
+
+int dllThunkIntercept(const char* main_function, uptr dll_function);
+
+int dllThunkInterceptWhenPossible(const char* main_function,
+    const char* default_function, uptr dll_function);
+}
+
+extern "C" int __dll_thunk_init();
+
+// ----------------- Function interception helper macros -------------------- //
+// Override dll_function with main_function from main executable.
+#define INTERCEPT_OR_DIE(main_function, dll_function)                          \
+  static int intercept_##dll_function() {                                      \
+    return __sanitizer::dllThunkIntercept(main_function, (__sanitizer::uptr)   \
+        dll_function);                                                         \
+  }                                                                            \
+  __pragma(section(".DLLTH$M", long, read))                                    \
+  __declspec(allocate(".DLLTH$M")) int (*__dll_thunk_##dll_function)() =       \
+    intercept_##dll_function;
+
+// Try to override dll_function with main_function from main executable.
+// If main_function is not present, override dll_function with default_function.
+#define INTERCEPT_WHEN_POSSIBLE(main_function, default_function, dll_function) \
+  static int intercept_##dll_function() {                                      \
+    return __sanitizer::dllThunkInterceptWhenPossible(main_function,           \
+        default_function, (__sanitizer::uptr)dll_function);                    \
+  }                                                                            \
+  __pragma(section(".DLLTH$M", long, read))                                    \
+  __declspec(allocate(".DLLTH$M")) int (*__dll_thunk_##dll_function)() =       \
+    intercept_##dll_function;
+
+// -------------------- Function interception macros ------------------------ //
+// Special case of hooks -- ASan own interface functions.  Those are only called
+// after __asan_init, thus an empty implementation is sufficient.
+#define INTERCEPT_SANITIZER_FUNCTION(name)                                     \
+  extern "C" __declspec(noinline) void name() {                                \
+    volatile int prevent_icf = (__LINE__ << 8) ^ __COUNTER__;                  \
+    static const char function_name[] = #name;                                 \
+    for (const char* ptr = &function_name[0]; *ptr; ++ptr)                     \
+      prevent_icf ^= *ptr;                                                     \
+    (void)prevent_icf;                                                         \
+    __debugbreak();                                                            \
+  }                                                                            \
+  INTERCEPT_OR_DIE(#name, name)
+
+// Special case of hooks -- Weak functions, could be redefined in the main
+// executable, but that is not necessary, so we shouldn't die if we can not find
+// a reference. Instead, when the function is not present in the main executable
+// we consider the default impl provided by asan library.
+#define INTERCEPT_SANITIZER_WEAK_FUNCTION(name)                                \
+  extern "C" __declspec(noinline) void name() {                                \
+    volatile int prevent_icf = (__LINE__ << 8) ^ __COUNTER__;                  \
+    static const char function_name[] = #name;                                 \
+    for (const char* ptr = &function_name[0]; *ptr; ++ptr)                     \
+      prevent_icf ^= *ptr;                                                     \
+    (void)prevent_icf;                                                         \
+    __debugbreak();                                                            \
+  }                                                                            \
+  INTERCEPT_WHEN_POSSIBLE(#name, STRINGIFY(WEAK_EXPORT_NAME(name)), name)
+
+// We can't define our own version of strlen etc. because that would lead to
+// link-time or even type mismatch errors.  Instead, we can declare a function
+// just to be able to get its address.  Me may miss the first few calls to the
+// functions since it can be called before __dll_thunk_init, but that would lead
+// to false negatives in the startup code before user's global initializers,
+// which isn't a big deal.
+#define INTERCEPT_LIBRARY_FUNCTION(name)                                       \
+  extern "C" void name();                                                      \
+  INTERCEPT_OR_DIE(WRAPPER_NAME(name), name)
+
+// Use these macros for functions that could be called before __dll_thunk_init()
+// is executed and don't lead to errors if defined (free, malloc, etc).
+#define INTERCEPT_WRAP_V_V(name)                                               \
+  extern "C" void name() {                                                     \
+    typedef decltype(name) *fntype;                                            \
+    static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name);   \
+    fn();                                                                      \
+  }                                                                            \
+  INTERCEPT_OR_DIE(#name, name);
+
+#define INTERCEPT_WRAP_V_W(name)                                               \
+  extern "C" void name(void *arg) {                                            \
+    typedef decltype(name) *fntype;                                            \
+    static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name);   \
+    fn(arg);                                                                   \
+  }                                                                            \
+  INTERCEPT_OR_DIE(#name, name);
+
+#define INTERCEPT_WRAP_V_WW(name)                                              \
+  extern "C" void name(void *arg1, void *arg2) {                               \
+    typedef decltype(name) *fntype;                                            \
+    static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name);   \
+    fn(arg1, arg2);                                                            \
+  }                                                                            \
+  INTERCEPT_OR_DIE(#name, name);
+
+#define INTERCEPT_WRAP_V_WWW(name)                                             \
+  extern "C" void name(void *arg1, void *arg2, void *arg3) {                   \
+    typedef decltype(name) *fntype;                                            \
+    static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name);   \
+    fn(arg1, arg2, arg3);                                                      \
+  }                                                                            \
+  INTERCEPT_OR_DIE(#name, name);
+
+#define INTERCEPT_WRAP_W_V(name)                                               \
+  extern "C" void *name() {                                                    \
+    typedef decltype(name) *fntype;                                            \
+    static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name);   \
+    return fn();                                                               \
+  }                                                                            \
+  INTERCEPT_OR_DIE(#name, name);
+
+#define INTERCEPT_WRAP_W_W(name)                                               \
+  extern "C" void *name(void *arg) {                                           \
+    typedef decltype(name) *fntype;                                            \
+    static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name);   \
+    return fn(arg);                                                            \
+  }                                                                            \
+  INTERCEPT_OR_DIE(#name, name);
+
+#define INTERCEPT_WRAP_W_WW(name)                                              \
+  extern "C" void *name(void *arg1, void *arg2) {                              \
+    typedef decltype(name) *fntype;                                            \
+    static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name);   \
+    return fn(arg1, arg2);                                                     \
+  }                                                                            \
+  INTERCEPT_OR_DIE(#name, name);
+
+#define INTERCEPT_WRAP_W_WWW(name)                                             \
+  extern "C" void *name(void *arg1, void *arg2, void *arg3) {                  \
+    typedef decltype(name) *fntype;                                            \
+    static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name);   \
+    return fn(arg1, arg2, arg3);                                               \
+  }                                                                            \
+  INTERCEPT_OR_DIE(#name, name);
+
+#define INTERCEPT_WRAP_W_WWWW(name)                                            \
+  extern "C" void *name(void *arg1, void *arg2, void *arg3, void *arg4) {      \
+    typedef decltype(name) *fntype;                                            \
+    static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name);   \
+    return fn(arg1, arg2, arg3, arg4);                                         \
+  }                                                                            \
+  INTERCEPT_OR_DIE(#name, name);
+
+#define INTERCEPT_WRAP_W_WWWWW(name)                                           \
+  extern "C" void *name(void *arg1, void *arg2, void *arg3, void *arg4,        \
+                        void *arg5) {                                          \
+    typedef decltype(name) *fntype;                                            \
+    static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name);   \
+    return fn(arg1, arg2, arg3, arg4, arg5);                                   \
+  }                                                                            \
+  INTERCEPT_OR_DIE(#name, name);
+
+#define INTERCEPT_WRAP_W_WWWWWW(name)                                          \
+  extern "C" void *name(void *arg1, void *arg2, void *arg3, void *arg4,        \
+                        void *arg5, void *arg6) {                              \
+    typedef decltype(name) *fntype;                                            \
+    static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name);   \
+    return fn(arg1, arg2, arg3, arg4, arg5, arg6);                             \
+  }                                                                            \
+  INTERCEPT_OR_DIE(#name, name);
+
+#endif // SANITIZER_WIN_DLL_THUNK_H
diff --git a/libsanitizer/sanitizer_common/sanitizer_win_dynamic_runtime_thunk.cc b/libsanitizer/sanitizer_common/sanitizer_win_dynamic_runtime_thunk.cc
new file mode 100644
index 00000000000..f3b3037b276
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_win_dynamic_runtime_thunk.cc
@@ -0,0 +1,19 @@
+//===-- santizer_win_dynamic_runtime_thunk.cc -----------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines things that need to be present in the application modules
+// to interact with Sanitizer Common, when it is included in a dll.
+//
+//===----------------------------------------------------------------------===//
+#ifdef SANITIZER_DYNAMIC_RUNTIME_THUNK
+#define SANITIZER_IMPORT_INTERFACE 1
+#include "sanitizer_win_defs.h"
+// Define weak alias for all weak functions imported from sanitizer common.
+#define INTERFACE_FUNCTION(Name)
+#define INTERFACE_WEAK_FUNCTION(Name) WIN_WEAK_IMPORT_DEF(Name)
+#include "sanitizer_common_interface.inc"
+#endif // SANITIZER_DYNAMIC_RUNTIME_THUNK
diff --git a/libsanitizer/sanitizer_common/sanitizer_win_weak_interception.cc b/libsanitizer/sanitizer_common/sanitizer_win_weak_interception.cc
new file mode 100644
index 00000000000..dffec0c7943
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_win_weak_interception.cc
@@ -0,0 +1,92 @@
+//===-- sanitizer_win_weak_interception.cc --------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This module should be included in the sanitizer when it is implemented as a
+// shared library on Windows (dll), in order to delegate the calls of weak
+// functions to the implementation in the main executable when a strong
+// definition is provided.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_platform.h"
+#if SANITIZER_WINDOWS && SANITIZER_DYNAMIC
+#include "sanitizer_win_weak_interception.h"
+#include "sanitizer_allocator_interface.h"
+#include "sanitizer_interface_internal.h"
+#include "sanitizer_win_defs.h"
+#include "interception/interception.h"
+
+extern "C" {
+void *WINAPI GetModuleHandleA(const char *module_name);
+void abort();
+}
+
+namespace __sanitizer {
+// Try to get a pointer to real_function in the main module and override
+// dll_function with that pointer. If the function isn't found, nothing changes.
+int interceptWhenPossible(uptr dll_function, const char *real_function) {
+  uptr real = __interception::InternalGetProcAddress(
+      (void *)GetModuleHandleA(0), real_function);
+  if (real && !__interception::OverrideFunction((uptr)dll_function, real, 0))
+    abort();
+  return 0;
+}
+} // namespace __sanitizer
+
+// Declare weak hooks.
+extern "C" {
+void __sanitizer_weak_hook_memcmp(uptr called_pc, const void *s1,
+                                  const void *s2, uptr n, int result);
+void __sanitizer_weak_hook_strcmp(uptr called_pc, const char *s1,
+                                  const char *s2, int result);
+void __sanitizer_weak_hook_strncmp(uptr called_pc, const char *s1,
+                                   const char *s2, uptr n, int result);
+void __sanitizer_weak_hook_strstr(uptr called_pc, const char *s1,
+                                  const char *s2, char *result);
+}
+
+// Include Sanitizer Common interface.
+#define INTERFACE_FUNCTION(Name)
+#define INTERFACE_WEAK_FUNCTION(Name) INTERCEPT_SANITIZER_WEAK_FUNCTION(Name)
+#include "sanitizer_common_interface.inc"
+
+#pragma section(".WEAK$A", read)  // NOLINT
+#pragma section(".WEAK$Z", read)  // NOLINT
+
+typedef void (*InterceptCB)();
+extern "C" {
+__declspec(allocate(".WEAK$A")) InterceptCB __start_weak_list;
+__declspec(allocate(".WEAK$Z")) InterceptCB __stop_weak_list;
+}
+
+static int weak_intercept_init() {
+  static bool flag = false;
+  // weak_interception_init is expected to be called by only one thread.
+  if (flag) return 0;
+  flag = true;
+
+  for (InterceptCB *it = &__start_weak_list; it < &__stop_weak_list; ++it)
+    if (*it)
+      (*it)();
+
+  // In DLLs, the callbacks are expected to return 0,
+  // otherwise CRT initialization fails.
+  return 0;
+}
+
+#pragma section(".CRT$XIB", long, read)  // NOLINT
+__declspec(allocate(".CRT$XIB")) int (*__weak_intercept_preinit)() =
+    weak_intercept_init;
+
+static void WINAPI weak_intercept_thread_init(void *mod, unsigned long reason,
+                                              void *reserved) {
+  if (reason == /*DLL_PROCESS_ATTACH=*/1) weak_intercept_init();
+}
+
+#pragma section(".CRT$XLAB", long, read)  // NOLINT
+__declspec(allocate(".CRT$XLAB")) void(WINAPI *__weak_intercept_tls_init)(
+    void *, unsigned long, void *) = weak_intercept_thread_init;
+
+#endif // SANITIZER_WINDOWS && SANITIZER_DYNAMIC
diff --git a/libsanitizer/sanitizer_common/sanitizer_win_weak_interception.h b/libsanitizer/sanitizer_common/sanitizer_win_weak_interception.h
new file mode 100644
index 00000000000..873f9b822ab
--- /dev/null
+++ b/libsanitizer/sanitizer_common/sanitizer_win_weak_interception.h
@@ -0,0 +1,31 @@
+//===-- sanitizer_win_weak_interception.h ---------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This header provide helper macros to delegate calls of weak functions to the
+// implementation in the main executable when a strong definition is present.
+//===----------------------------------------------------------------------===//
+#ifndef SANITIZER_WIN_WEAK_INTERCEPTION_H
+#define SANITIZER_WIN_WEAK_INTERCEPTION_H
+#include "sanitizer_internal_defs.h"
+
+namespace __sanitizer {
+int interceptWhenPossible(uptr dll_function, const char *real_function);
+}
+
+// ----------------- Function interception helper macros -------------------- //
+// Weak functions, could be redefined in the main executable, but that is not
+// necessary, so we shouldn't die if we can not find a reference.
+#define INTERCEPT_WEAK(Name) interceptWhenPossible((uptr) Name, #Name);
+
+#define INTERCEPT_SANITIZER_WEAK_FUNCTION(Name)                                \
+  static int intercept_##Name() {                                              \
+    return __sanitizer::interceptWhenPossible((__sanitizer::uptr) Name, #Name);\
+  }                                                                            \
+  __pragma(section(".WEAK$M", long, read))                                     \
+  __declspec(allocate(".WEAK$M")) int (*__weak_intercept_##Name)() =           \
+      intercept_##Name;
+
+#endif // SANITIZER_WIN_WEAK_INTERCEPTION_H
diff --git a/libsanitizer/tsan/Makefile.am b/libsanitizer/tsan/Makefile.am
index 53a8d1cb0cd..c218983e2fe 100644
--- a/libsanitizer/tsan/Makefile.am
+++ b/libsanitizer/tsan/Makefile.am
@@ -15,6 +15,7 @@ nodist_toolexeclib_HEADERS = libtsan_preinit.o
 tsan_files = \
 	tsan_clock.cc \
 	tsan_debugging.cc \
+	tsan_external.cc \
 	tsan_fd.cc \
 	tsan_flags.cc \
 	tsan_ignoreset.cc \
diff --git a/libsanitizer/tsan/Makefile.in b/libsanitizer/tsan/Makefile.in
index 770c053e64f..e32e9c0bfa1 100644
--- a/libsanitizer/tsan/Makefile.in
+++ b/libsanitizer/tsan/Makefile.in
@@ -106,18 +106,19 @@ am__installdirs = "$(DESTDIR)$(toolexeclibdir)" \
 	"$(DESTDIR)$(toolexeclibdir)"
 LTLIBRARIES = $(toolexeclib_LTLIBRARIES)
 am__DEPENDENCIES_1 =
-am__objects_1 = tsan_clock.lo tsan_debugging.lo tsan_fd.lo \
-	tsan_flags.lo tsan_ignoreset.lo tsan_interceptors.lo \
-	tsan_interceptors_mac.lo tsan_interface_ann.lo \
-	tsan_interface_atomic.lo tsan_interface.lo \
-	tsan_interface_java.lo tsan_libdispatch_mac.lo \
-	tsan_malloc_mac.lo tsan_md5.lo tsan_mman.lo tsan_mutex.lo \
-	tsan_mutexset.lo tsan_new_delete.lo tsan_platform_linux.lo \
-	tsan_platform_mac.lo tsan_platform_posix.lo \
-	tsan_platform_windows.lo tsan_report.lo tsan_rtl.lo \
-	tsan_rtl_mutex.lo tsan_rtl_proc.lo tsan_rtl_report.lo \
-	tsan_rtl_thread.lo tsan_stack_trace.lo tsan_stat.lo \
-	tsan_suppressions.lo tsan_symbolize.lo tsan_sync.lo
+am__objects_1 = tsan_clock.lo tsan_debugging.lo tsan_external.lo \
+	tsan_fd.lo tsan_flags.lo tsan_ignoreset.lo \
+	tsan_interceptors.lo tsan_interceptors_mac.lo \
+	tsan_interface_ann.lo tsan_interface_atomic.lo \
+	tsan_interface.lo tsan_interface_java.lo \
+	tsan_libdispatch_mac.lo tsan_malloc_mac.lo tsan_md5.lo \
+	tsan_mman.lo tsan_mutex.lo tsan_mutexset.lo tsan_new_delete.lo \
+	tsan_platform_linux.lo tsan_platform_mac.lo \
+	tsan_platform_posix.lo tsan_platform_windows.lo tsan_report.lo \
+	tsan_rtl.lo tsan_rtl_mutex.lo tsan_rtl_proc.lo \
+	tsan_rtl_report.lo tsan_rtl_thread.lo tsan_stack_trace.lo \
+	tsan_stat.lo tsan_suppressions.lo tsan_symbolize.lo \
+	tsan_sync.lo
 am_libtsan_la_OBJECTS = $(am__objects_1)
 libtsan_la_OBJECTS = $(am_libtsan_la_OBJECTS)
 libtsan_la_LINK = $(LIBTOOL) --tag=CXX $(AM_LIBTOOLFLAGS) \
@@ -319,6 +320,7 @@ nodist_toolexeclib_HEADERS = libtsan_preinit.o
 tsan_files = \
 	tsan_clock.cc \
 	tsan_debugging.cc \
+	tsan_external.cc \
 	tsan_fd.cc \
 	tsan_flags.cc \
 	tsan_ignoreset.cc \
@@ -480,6 +482,7 @@ distclean-compile:
 
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/tsan_clock.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/tsan_debugging.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/tsan_external.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/tsan_fd.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/tsan_flags.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/tsan_ignoreset.Plo@am__quote@
diff --git a/libsanitizer/tsan/tsan_clock.cc b/libsanitizer/tsan/tsan_clock.cc
index 23f9228a672..c2b5b582ca3 100644
--- a/libsanitizer/tsan/tsan_clock.cc
+++ b/libsanitizer/tsan/tsan_clock.cc
@@ -59,20 +59,13 @@
 // an exclusive lock; ThreadClock's are private to respective threads and so
 // do not need any protection.
 //
-// Description of ThreadClock state:
-// clk_ - fixed size vector clock.
-// nclk_ - effective size of the vector clock (the rest is zeros).
-// tid_ - index of the thread associated with he clock ("current thread").
-// last_acquire_ - current thread time when it acquired something from
-//   other threads.
-//
 // Description of SyncClock state:
 // clk_ - variable size vector clock, low kClkBits hold timestamp,
 //   the remaining bits hold "acquired" flag (the actual value is thread's
 //   reused counter);
 //   if acquried == thr->reused_, then the respective thread has already
-//   acquired this clock (except possibly dirty_tids_).
-// dirty_tids_ - holds up to two indeces in the vector clock that other threads
+//   acquired this clock (except possibly for dirty elements).
+// dirty_ - holds up to two indeces in the vector clock that other threads
 //   need to acquire regardless of "acquired" flag value;
 // release_store_tid_ - denotes that the clock state is a result of
 //   release-store operation by the thread with release_store_tid_ index.
@@ -88,18 +81,51 @@
 
 namespace __tsan {
 
+static atomic_uint32_t *ref_ptr(ClockBlock *cb) {
+  return reinterpret_cast<atomic_uint32_t *>(&cb->table[ClockBlock::kRefIdx]);
+}
+
+// Drop reference to the first level block idx.
+static void UnrefClockBlock(ClockCache *c, u32 idx, uptr blocks) {
+  ClockBlock *cb = ctx->clock_alloc.Map(idx);
+  atomic_uint32_t *ref = ref_ptr(cb);
+  u32 v = atomic_load(ref, memory_order_acquire);
+  for (;;) {
+    CHECK_GT(v, 0);
+    if (v == 1)
+      break;
+    if (atomic_compare_exchange_strong(ref, &v, v - 1, memory_order_acq_rel))
+      return;
+  }
+  // First level block owns second level blocks, so them as well.
+  for (uptr i = 0; i < blocks; i++)
+    ctx->clock_alloc.Free(c, cb->table[ClockBlock::kBlockIdx - i]);
+  ctx->clock_alloc.Free(c, idx);
+}
+
 ThreadClock::ThreadClock(unsigned tid, unsigned reused)
     : tid_(tid)
-    , reused_(reused + 1) {  // 0 has special meaning
+    , reused_(reused + 1)  // 0 has special meaning
+    , cached_idx_()
+    , cached_size_()
+    , cached_blocks_() {
   CHECK_LT(tid, kMaxTidInClock);
   CHECK_EQ(reused_, ((u64)reused_ << kClkBits) >> kClkBits);
   nclk_ = tid_ + 1;
   last_acquire_ = 0;
   internal_memset(clk_, 0, sizeof(clk_));
-  clk_[tid_].reused = reused_;
 }
 
-void ThreadClock::acquire(ClockCache *c, const SyncClock *src) {
+void ThreadClock::ResetCached(ClockCache *c) {
+  if (cached_idx_) {
+    UnrefClockBlock(c, cached_idx_, cached_blocks_);
+    cached_idx_ = 0;
+    cached_size_ = 0;
+    cached_blocks_ = 0;
+  }
+}
+
+void ThreadClock::acquire(ClockCache *c, SyncClock *src) {
   DCHECK_LE(nclk_, kMaxTid);
   DCHECK_LE(src->size_, kMaxTid);
   CPP_STAT_INC(StatClockAcquire);
@@ -111,52 +137,46 @@ void ThreadClock::acquire(ClockCache *c, const SyncClock *src) {
     return;
   }
 
-  // Check if we've already acquired src after the last release operation on src
   bool acquired = false;
-  if (nclk > tid_) {
-    CPP_STAT_INC(StatClockAcquireLarge);
-    if (src->elem(tid_).reused == reused_) {
-      CPP_STAT_INC(StatClockAcquireRepeat);
-      for (unsigned i = 0; i < kDirtyTids; i++) {
-        unsigned tid = src->dirty_tids_[i];
-        if (tid != kInvalidTid) {
-          u64 epoch = src->elem(tid).epoch;
-          if (clk_[tid].epoch < epoch) {
-            clk_[tid].epoch = epoch;
-            acquired = true;
-          }
-        }
-      }
-      if (acquired) {
-        CPP_STAT_INC(StatClockAcquiredSomething);
-        last_acquire_ = clk_[tid_].epoch;
+  for (unsigned i = 0; i < kDirtyTids; i++) {
+    SyncClock::Dirty dirty = src->dirty_[i];
+    unsigned tid = dirty.tid;
+    if (tid != kInvalidTid) {
+      if (clk_[tid] < dirty.epoch) {
+        clk_[tid] = dirty.epoch;
+        acquired = true;
       }
-      return;
     }
   }
 
-  // O(N) acquire.
-  CPP_STAT_INC(StatClockAcquireFull);
-  nclk_ = max(nclk_, nclk);
-  for (uptr i = 0; i < nclk; i++) {
-    u64 epoch = src->elem(i).epoch;
-    if (clk_[i].epoch < epoch) {
-      clk_[i].epoch = epoch;
-      acquired = true;
+  // Check if we've already acquired src after the last release operation on src
+  if (tid_ >= nclk || src->elem(tid_).reused != reused_) {
+    // O(N) acquire.
+    CPP_STAT_INC(StatClockAcquireFull);
+    nclk_ = max(nclk_, nclk);
+    u64 *dst_pos = &clk_[0];
+    for (ClockElem &src_elem : *src) {
+      u64 epoch = src_elem.epoch;
+      if (*dst_pos < epoch) {
+        *dst_pos = epoch;
+        acquired = true;
+      }
+      dst_pos++;
     }
-  }
 
-  // Remember that this thread has acquired this clock.
-  if (nclk > tid_)
-    src->elem(tid_).reused = reused_;
+    // Remember that this thread has acquired this clock.
+    if (nclk > tid_)
+      src->elem(tid_).reused = reused_;
+  }
 
   if (acquired) {
     CPP_STAT_INC(StatClockAcquiredSomething);
-    last_acquire_ = clk_[tid_].epoch;
+    last_acquire_ = clk_[tid_];
+    ResetCached(c);
   }
 }
 
-void ThreadClock::release(ClockCache *c, SyncClock *dst) const {
+void ThreadClock::release(ClockCache *c, SyncClock *dst) {
   DCHECK_LE(nclk_, kMaxTid);
   DCHECK_LE(dst->size_, kMaxTid);
 
@@ -176,7 +196,7 @@ void ThreadClock::release(ClockCache *c, SyncClock *dst) const {
   // since the last release on dst. If so, we need to update
   // only dst->elem(tid_).
   if (dst->elem(tid_).epoch > last_acquire_) {
-    UpdateCurrentThread(dst);
+    UpdateCurrentThread(c, dst);
     if (dst->release_store_tid_ != tid_ ||
         dst->release_store_reused_ != reused_)
       dst->release_store_tid_ = kInvalidTid;
@@ -185,23 +205,24 @@ void ThreadClock::release(ClockCache *c, SyncClock *dst) const {
 
   // O(N) release.
   CPP_STAT_INC(StatClockReleaseFull);
+  dst->Unshare(c);
   // First, remember whether we've acquired dst.
   bool acquired = IsAlreadyAcquired(dst);
   if (acquired)
     CPP_STAT_INC(StatClockReleaseAcquired);
   // Update dst->clk_.
-  for (uptr i = 0; i < nclk_; i++) {
-    ClockElem &ce = dst->elem(i);
-    ce.epoch = max(ce.epoch, clk_[i].epoch);
+  dst->FlushDirty();
+  uptr i = 0;
+  for (ClockElem &ce : *dst) {
+    ce.epoch = max(ce.epoch, clk_[i]);
     ce.reused = 0;
+    i++;
   }
   // Clear 'acquired' flag in the remaining elements.
   if (nclk_ < dst->size_)
     CPP_STAT_INC(StatClockReleaseClearTail);
   for (uptr i = nclk_; i < dst->size_; i++)
     dst->elem(i).reused = 0;
-  for (unsigned i = 0; i < kDirtyTids; i++)
-    dst->dirty_tids_[i] = kInvalidTid;
   dst->release_store_tid_ = kInvalidTid;
   dst->release_store_reused_ = 0;
   // If we've acquired dst, remember this fact,
@@ -210,11 +231,37 @@ void ThreadClock::release(ClockCache *c, SyncClock *dst) const {
     dst->elem(tid_).reused = reused_;
 }
 
-void ThreadClock::ReleaseStore(ClockCache *c, SyncClock *dst) const {
+void ThreadClock::ReleaseStore(ClockCache *c, SyncClock *dst) {
   DCHECK_LE(nclk_, kMaxTid);
   DCHECK_LE(dst->size_, kMaxTid);
   CPP_STAT_INC(StatClockStore);
 
+  if (dst->size_ == 0 && cached_idx_ != 0) {
+    // Reuse the cached clock.
+    // Note: we could reuse/cache the cached clock in more cases:
+    // we could update the existing clock and cache it, or replace it with the
+    // currently cached clock and release the old one. And for a shared
+    // existing clock, we could replace it with the currently cached;
+    // or unshare, update and cache. But, for simplicity, we currnetly reuse
+    // cached clock only when the target clock is empty.
+    dst->tab_ = ctx->clock_alloc.Map(cached_idx_);
+    dst->tab_idx_ = cached_idx_;
+    dst->size_ = cached_size_;
+    dst->blocks_ = cached_blocks_;
+    CHECK_EQ(dst->dirty_[0].tid, kInvalidTid);
+    // The cached clock is shared (immutable),
+    // so this is where we store the current clock.
+    dst->dirty_[0].tid = tid_;
+    dst->dirty_[0].epoch = clk_[tid_];
+    dst->release_store_tid_ = tid_;
+    dst->release_store_reused_ = reused_;
+    // Rememeber that we don't need to acquire it in future.
+    dst->elem(tid_).reused = reused_;
+    // Grab a reference.
+    atomic_fetch_add(ref_ptr(dst->tab_), 1, memory_order_relaxed);
+    return;
+  }
+
   // Check if we need to resize dst.
   if (dst->size_ < nclk_)
     dst->Resize(c, nclk_);
@@ -223,32 +270,41 @@ void ThreadClock::ReleaseStore(ClockCache *c, SyncClock *dst) const {
       dst->release_store_reused_ == reused_ &&
       dst->elem(tid_).epoch > last_acquire_) {
     CPP_STAT_INC(StatClockStoreFast);
-    UpdateCurrentThread(dst);
+    UpdateCurrentThread(c, dst);
     return;
   }
 
   // O(N) release-store.
   CPP_STAT_INC(StatClockStoreFull);
-  for (uptr i = 0; i < nclk_; i++) {
-    ClockElem &ce = dst->elem(i);
-    ce.epoch = clk_[i].epoch;
+  dst->Unshare(c);
+  // Note: dst can be larger than this ThreadClock.
+  // This is fine since clk_ beyond size is all zeros.
+  uptr i = 0;
+  for (ClockElem &ce : *dst) {
+    ce.epoch = clk_[i];
     ce.reused = 0;
+    i++;
   }
-  // Clear the tail of dst->clk_.
-  if (nclk_ < dst->size_) {
-    for (uptr i = nclk_; i < dst->size_; i++) {
-      ClockElem &ce = dst->elem(i);
-      ce.epoch = 0;
-      ce.reused = 0;
-    }
-    CPP_STAT_INC(StatClockStoreTail);
-  }
-  for (unsigned i = 0; i < kDirtyTids; i++)
-    dst->dirty_tids_[i] = kInvalidTid;
+  for (uptr i = 0; i < kDirtyTids; i++)
+    dst->dirty_[i].tid = kInvalidTid;
   dst->release_store_tid_ = tid_;
   dst->release_store_reused_ = reused_;
   // Rememeber that we don't need to acquire it in future.
   dst->elem(tid_).reused = reused_;
+
+  // If the resulting clock is cachable, cache it for future release operations.
+  // The clock is always cachable if we released to an empty sync object.
+  if (cached_idx_ == 0 && dst->Cachable()) {
+    // Grab a reference to the ClockBlock.
+    atomic_uint32_t *ref = ref_ptr(dst->tab_);
+    if (atomic_load(ref, memory_order_acquire) == 1)
+      atomic_store_relaxed(ref, 2);
+    else
+      atomic_fetch_add(ref_ptr(dst->tab_), 1, memory_order_relaxed);
+    cached_idx_ = dst->tab_idx_;
+    cached_size_ = dst->size_;
+    cached_blocks_ = dst->blocks_;
+  }
 }
 
 void ThreadClock::acq_rel(ClockCache *c, SyncClock *dst) {
@@ -258,157 +314,248 @@ void ThreadClock::acq_rel(ClockCache *c, SyncClock *dst) {
 }
 
 // Updates only single element related to the current thread in dst->clk_.
-void ThreadClock::UpdateCurrentThread(SyncClock *dst) const {
+void ThreadClock::UpdateCurrentThread(ClockCache *c, SyncClock *dst) const {
   // Update the threads time, but preserve 'acquired' flag.
-  dst->elem(tid_).epoch = clk_[tid_].epoch;
-
   for (unsigned i = 0; i < kDirtyTids; i++) {
-    if (dst->dirty_tids_[i] == tid_) {
-      CPP_STAT_INC(StatClockReleaseFast1);
-      return;
-    }
-    if (dst->dirty_tids_[i] == kInvalidTid) {
-      CPP_STAT_INC(StatClockReleaseFast2);
-      dst->dirty_tids_[i] = tid_;
+    SyncClock::Dirty *dirty = &dst->dirty_[i];
+    const unsigned tid = dirty->tid;
+    if (tid == tid_ || tid == kInvalidTid) {
+      CPP_STAT_INC(StatClockReleaseFast);
+      dirty->tid = tid_;
+      dirty->epoch = clk_[tid_];
       return;
     }
   }
   // Reset all 'acquired' flags, O(N).
+  // We are going to touch dst elements, so we need to unshare it.
+  dst->Unshare(c);
   CPP_STAT_INC(StatClockReleaseSlow);
+  dst->elem(tid_).epoch = clk_[tid_];
   for (uptr i = 0; i < dst->size_; i++)
     dst->elem(i).reused = 0;
-  for (unsigned i = 0; i < kDirtyTids; i++)
-    dst->dirty_tids_[i] = kInvalidTid;
+  dst->FlushDirty();
 }
 
-// Checks whether the current threads has already acquired src.
+// Checks whether the current thread has already acquired src.
 bool ThreadClock::IsAlreadyAcquired(const SyncClock *src) const {
   if (src->elem(tid_).reused != reused_)
     return false;
   for (unsigned i = 0; i < kDirtyTids; i++) {
-    unsigned tid = src->dirty_tids_[i];
-    if (tid != kInvalidTid) {
-      if (clk_[tid].epoch < src->elem(tid).epoch)
+    SyncClock::Dirty dirty = src->dirty_[i];
+    if (dirty.tid != kInvalidTid) {
+      if (clk_[dirty.tid] < dirty.epoch)
         return false;
     }
   }
   return true;
 }
 
+// Sets a single element in the vector clock.
+// This function is called only from weird places like AcquireGlobal.
+void ThreadClock::set(ClockCache *c, unsigned tid, u64 v) {
+  DCHECK_LT(tid, kMaxTid);
+  DCHECK_GE(v, clk_[tid]);
+  clk_[tid] = v;
+  if (nclk_ <= tid)
+    nclk_ = tid + 1;
+  last_acquire_ = clk_[tid_];
+  ResetCached(c);
+}
+
+void ThreadClock::DebugDump(int(*printf)(const char *s, ...)) {
+  printf("clock=[");
+  for (uptr i = 0; i < nclk_; i++)
+    printf("%s%llu", i == 0 ? "" : ",", clk_[i]);
+  printf("] tid=%u/%u last_acq=%llu", tid_, reused_, last_acquire_);
+}
+
+SyncClock::SyncClock() {
+  ResetImpl();
+}
+
+SyncClock::~SyncClock() {
+  // Reset must be called before dtor.
+  CHECK_EQ(size_, 0);
+  CHECK_EQ(blocks_, 0);
+  CHECK_EQ(tab_, 0);
+  CHECK_EQ(tab_idx_, 0);
+}
+
+void SyncClock::Reset(ClockCache *c) {
+  if (size_)
+    UnrefClockBlock(c, tab_idx_, blocks_);
+  ResetImpl();
+}
+
+void SyncClock::ResetImpl() {
+  tab_ = 0;
+  tab_idx_ = 0;
+  size_ = 0;
+  blocks_ = 0;
+  release_store_tid_ = kInvalidTid;
+  release_store_reused_ = 0;
+  for (uptr i = 0; i < kDirtyTids; i++)
+    dirty_[i].tid = kInvalidTid;
+}
+
 void SyncClock::Resize(ClockCache *c, uptr nclk) {
   CPP_STAT_INC(StatClockReleaseResize);
-  if (RoundUpTo(nclk, ClockBlock::kClockCount) <=
-      RoundUpTo(size_, ClockBlock::kClockCount)) {
-    // Growing within the same block.
+  Unshare(c);
+  if (nclk <= capacity()) {
     // Memory is already allocated, just increase the size.
     size_ = nclk;
     return;
   }
-  if (nclk <= ClockBlock::kClockCount) {
+  if (size_ == 0) {
     // Grow from 0 to one-level table.
     CHECK_EQ(size_, 0);
+    CHECK_EQ(blocks_, 0);
     CHECK_EQ(tab_, 0);
     CHECK_EQ(tab_idx_, 0);
-    size_ = nclk;
     tab_idx_ = ctx->clock_alloc.Alloc(c);
     tab_ = ctx->clock_alloc.Map(tab_idx_);
     internal_memset(tab_, 0, sizeof(*tab_));
-    return;
-  }
-  // Growing two-level table.
-  if (size_ == 0) {
-    // Allocate first level table.
-    tab_idx_ = ctx->clock_alloc.Alloc(c);
-    tab_ = ctx->clock_alloc.Map(tab_idx_);
-    internal_memset(tab_, 0, sizeof(*tab_));
-  } else if (size_ <= ClockBlock::kClockCount) {
-    // Transform one-level table to two-level table.
-    u32 old = tab_idx_;
-    tab_idx_ = ctx->clock_alloc.Alloc(c);
-    tab_ = ctx->clock_alloc.Map(tab_idx_);
-    internal_memset(tab_, 0, sizeof(*tab_));
-    tab_->table[0] = old;
+    atomic_store_relaxed(ref_ptr(tab_), 1);
+    size_ = 1;
+  } else if (size_ > blocks_ * ClockBlock::kClockCount) {
+    u32 idx = ctx->clock_alloc.Alloc(c);
+    ClockBlock *new_cb = ctx->clock_alloc.Map(idx);
+    uptr top = size_ - blocks_ * ClockBlock::kClockCount;
+    CHECK_LT(top, ClockBlock::kClockCount);
+    const uptr move = top * sizeof(tab_->clock[0]);
+    internal_memcpy(&new_cb->clock[0], tab_->clock, move);
+    internal_memset(&new_cb->clock[top], 0, sizeof(*new_cb) - move);
+    internal_memset(tab_->clock, 0, move);
+    append_block(idx);
   }
-  // At this point we have first level table allocated.
+  // At this point we have first level table allocated and all clock elements
+  // are evacuated from it to a second level block.
   // Add second level tables as necessary.
-  for (uptr i = RoundUpTo(size_, ClockBlock::kClockCount);
-      i < nclk; i += ClockBlock::kClockCount) {
+  while (nclk > capacity()) {
     u32 idx = ctx->clock_alloc.Alloc(c);
     ClockBlock *cb = ctx->clock_alloc.Map(idx);
     internal_memset(cb, 0, sizeof(*cb));
-    CHECK_EQ(tab_->table[i/ClockBlock::kClockCount], 0);
-    tab_->table[i/ClockBlock::kClockCount] = idx;
+    append_block(idx);
   }
   size_ = nclk;
 }
 
-// Sets a single element in the vector clock.
-// This function is called only from weird places like AcquireGlobal.
-void ThreadClock::set(unsigned tid, u64 v) {
-  DCHECK_LT(tid, kMaxTid);
-  DCHECK_GE(v, clk_[tid].epoch);
-  clk_[tid].epoch = v;
-  if (nclk_ <= tid)
-    nclk_ = tid + 1;
-  last_acquire_ = clk_[tid_].epoch;
-}
-
-void ThreadClock::DebugDump(int(*printf)(const char *s, ...)) {
-  printf("clock=[");
-  for (uptr i = 0; i < nclk_; i++)
-    printf("%s%llu", i == 0 ? "" : ",", clk_[i].epoch);
-  printf("] reused=[");
-  for (uptr i = 0; i < nclk_; i++)
-    printf("%s%llu", i == 0 ? "" : ",", clk_[i].reused);
-  printf("] tid=%u/%u last_acq=%llu",
-      tid_, reused_, last_acquire_);
+// Flushes all dirty elements into the main clock array.
+void SyncClock::FlushDirty() {
+  for (unsigned i = 0; i < kDirtyTids; i++) {
+    Dirty *dirty = &dirty_[i];
+    if (dirty->tid != kInvalidTid) {
+      CHECK_LT(dirty->tid, size_);
+      elem(dirty->tid).epoch = dirty->epoch;
+      dirty->tid = kInvalidTid;
+    }
+  }
 }
 
-SyncClock::SyncClock()
-    : release_store_tid_(kInvalidTid)
-    , release_store_reused_()
-    , tab_()
-    , tab_idx_()
-    , size_() {
-  for (uptr i = 0; i < kDirtyTids; i++)
-    dirty_tids_[i] = kInvalidTid;
+bool SyncClock::IsShared() const {
+  if (size_ == 0)
+    return false;
+  atomic_uint32_t *ref = ref_ptr(tab_);
+  u32 v = atomic_load(ref, memory_order_acquire);
+  CHECK_GT(v, 0);
+  return v > 1;
 }
 
-SyncClock::~SyncClock() {
-  // Reset must be called before dtor.
-  CHECK_EQ(size_, 0);
-  CHECK_EQ(tab_, 0);
-  CHECK_EQ(tab_idx_, 0);
+// Unshares the current clock if it's shared.
+// Shared clocks are immutable, so they need to be unshared before any updates.
+// Note: this does not apply to dirty entries as they are not shared.
+void SyncClock::Unshare(ClockCache *c) {
+  if (!IsShared())
+    return;
+  // First, copy current state into old.
+  SyncClock old;
+  old.tab_ = tab_;
+  old.tab_idx_ = tab_idx_;
+  old.size_ = size_;
+  old.blocks_ = blocks_;
+  old.release_store_tid_ = release_store_tid_;
+  old.release_store_reused_ = release_store_reused_;
+  for (unsigned i = 0; i < kDirtyTids; i++)
+    old.dirty_[i] = dirty_[i];
+  // Then, clear current object.
+  ResetImpl();
+  // Allocate brand new clock in the current object.
+  Resize(c, old.size_);
+  // Now copy state back into this object.
+  Iter old_iter(&old);
+  for (ClockElem &ce : *this) {
+    ce = *old_iter;
+    ++old_iter;
+  }
+  release_store_tid_ = old.release_store_tid_;
+  release_store_reused_ = old.release_store_reused_;
+  for (unsigned i = 0; i < kDirtyTids; i++)
+    dirty_[i] = old.dirty_[i];
+  // Drop reference to old and delete if necessary.
+  old.Reset(c);
 }
 
-void SyncClock::Reset(ClockCache *c) {
-  if (size_ == 0) {
-    // nothing
-  } else if (size_ <= ClockBlock::kClockCount) {
-    // One-level table.
-    ctx->clock_alloc.Free(c, tab_idx_);
-  } else {
-    // Two-level table.
-    for (uptr i = 0; i < size_; i += ClockBlock::kClockCount)
-      ctx->clock_alloc.Free(c, tab_->table[i / ClockBlock::kClockCount]);
-    ctx->clock_alloc.Free(c, tab_idx_);
+// Can we cache this clock for future release operations?
+ALWAYS_INLINE bool SyncClock::Cachable() const {
+  if (size_ == 0)
+    return false;
+  for (unsigned i = 0; i < kDirtyTids; i++) {
+    if (dirty_[i].tid != kInvalidTid)
+      return false;
   }
-  tab_ = 0;
-  tab_idx_ = 0;
-  size_ = 0;
-  release_store_tid_ = kInvalidTid;
-  release_store_reused_ = 0;
-  for (uptr i = 0; i < kDirtyTids; i++)
-    dirty_tids_[i] = kInvalidTid;
+  return atomic_load_relaxed(ref_ptr(tab_)) == 1;
 }
 
-ClockElem &SyncClock::elem(unsigned tid) const {
+// elem linearizes the two-level structure into linear array.
+// Note: this is used only for one time accesses, vector operations use
+// the iterator as it is much faster.
+ALWAYS_INLINE ClockElem &SyncClock::elem(unsigned tid) const {
   DCHECK_LT(tid, size_);
-  if (size_ <= ClockBlock::kClockCount)
+  const uptr block = tid / ClockBlock::kClockCount;
+  DCHECK_LE(block, blocks_);
+  tid %= ClockBlock::kClockCount;
+  if (block == blocks_)
     return tab_->clock[tid];
-  u32 idx = tab_->table[tid / ClockBlock::kClockCount];
+  u32 idx = get_block(block);
   ClockBlock *cb = ctx->clock_alloc.Map(idx);
-  return cb->clock[tid % ClockBlock::kClockCount];
+  return cb->clock[tid];
+}
+
+ALWAYS_INLINE uptr SyncClock::capacity() const {
+  if (size_ == 0)
+    return 0;
+  uptr ratio = sizeof(ClockBlock::clock[0]) / sizeof(ClockBlock::table[0]);
+  // How many clock elements we can fit into the first level block.
+  // +1 for ref counter.
+  uptr top = ClockBlock::kClockCount - RoundUpTo(blocks_ + 1, ratio) / ratio;
+  return blocks_ * ClockBlock::kClockCount + top;
+}
+
+ALWAYS_INLINE u32 SyncClock::get_block(uptr bi) const {
+  DCHECK(size_);
+  DCHECK_LT(bi, blocks_);
+  return tab_->table[ClockBlock::kBlockIdx - bi];
+}
+
+ALWAYS_INLINE void SyncClock::append_block(u32 idx) {
+  uptr bi = blocks_++;
+  CHECK_EQ(get_block(bi), 0);
+  tab_->table[ClockBlock::kBlockIdx - bi] = idx;
+}
+
+// Used only by tests.
+u64 SyncClock::get(unsigned tid) const {
+  for (unsigned i = 0; i < kDirtyTids; i++) {
+    Dirty dirty = dirty_[i];
+    if (dirty.tid == tid)
+      return dirty.epoch;
+  }
+  return elem(tid).epoch;
+}
+
+// Used only by Iter test.
+u64 SyncClock::get_clean(unsigned tid) const {
+  return elem(tid).epoch;
 }
 
 void SyncClock::DebugDump(int(*printf)(const char *s, ...)) {
@@ -418,8 +565,32 @@ void SyncClock::DebugDump(int(*printf)(const char *s, ...)) {
   printf("] reused=[");
   for (uptr i = 0; i < size_; i++)
     printf("%s%llu", i == 0 ? "" : ",", elem(i).reused);
-  printf("] release_store_tid=%d/%d dirty_tids=%d/%d",
+  printf("] release_store_tid=%d/%d dirty_tids=%d[%llu]/%d[%llu]",
       release_store_tid_, release_store_reused_,
-      dirty_tids_[0], dirty_tids_[1]);
+      dirty_[0].tid, dirty_[0].epoch,
+      dirty_[1].tid, dirty_[1].epoch);
+}
+
+void SyncClock::Iter::Next() {
+  // Finished with the current block, move on to the next one.
+  block_++;
+  if (block_ < parent_->blocks_) {
+    // Iterate over the next second level block.
+    u32 idx = parent_->get_block(block_);
+    ClockBlock *cb = ctx->clock_alloc.Map(idx);
+    pos_ = &cb->clock[0];
+    end_ = pos_ + min(parent_->size_ - block_ * ClockBlock::kClockCount,
+        ClockBlock::kClockCount);
+    return;
+  }
+  if (block_ == parent_->blocks_ &&
+      parent_->size_ > parent_->blocks_ * ClockBlock::kClockCount) {
+    // Iterate over elements in the first level block.
+    pos_ = &parent_->tab_->clock[0];
+    end_ = pos_ + min(parent_->size_ - block_ * ClockBlock::kClockCount,
+        ClockBlock::kClockCount);
+    return;
+  }
+  parent_ = nullptr;  // denotes end
 }
 }  // namespace __tsan
diff --git a/libsanitizer/tsan/tsan_clock.h b/libsanitizer/tsan/tsan_clock.h
index 3deb7f5198c..c8eb8ee2d1a 100644
--- a/libsanitizer/tsan/tsan_clock.h
+++ b/libsanitizer/tsan/tsan_clock.h
@@ -16,25 +16,6 @@
 
 namespace __tsan {
 
-struct ClockElem {
-  u64 epoch  : kClkBits;
-  u64 reused : 64 - kClkBits;
-};
-
-struct ClockBlock {
-  static const uptr kSize = 512;
-  static const uptr kTableSize = kSize / sizeof(u32);
-  static const uptr kClockCount = kSize / sizeof(ClockElem);
-
-  union {
-    u32       table[kTableSize];
-    ClockElem clock[kClockCount];
-  };
-
-  ClockBlock() {
-  }
-};
-
 typedef DenseSlabAlloc<ClockBlock, 1<<16, 1<<10> ClockAlloc;
 typedef DenseSlabAllocCache ClockCache;
 
@@ -44,84 +25,200 @@ class SyncClock {
   SyncClock();
   ~SyncClock();
 
-  uptr size() const {
-    return size_;
-  }
+  uptr size() const;
 
-  u64 get(unsigned tid) const {
-    return elem(tid).epoch;
-  }
+  // These are used only in tests.
+  u64 get(unsigned tid) const;
+  u64 get_clean(unsigned tid) const;
 
   void Resize(ClockCache *c, uptr nclk);
   void Reset(ClockCache *c);
 
   void DebugDump(int(*printf)(const char *s, ...));
 
+  // Clock element iterator.
+  // Note: it iterates only over the table without regard to dirty entries.
+  class Iter {
+   public:
+    explicit Iter(SyncClock* parent);
+    Iter& operator++();
+    bool operator!=(const Iter& other);
+    ClockElem &operator*();
+
+   private:
+    SyncClock *parent_;
+    // [pos_, end_) is the current continuous range of clock elements.
+    ClockElem *pos_;
+    ClockElem *end_;
+    int block_;  // Current number of second level block.
+
+    NOINLINE void Next();
+  };
+
+  Iter begin();
+  Iter end();
+
  private:
-  friend struct ThreadClock;
+  friend class ThreadClock;
+  friend class Iter;
   static const uptr kDirtyTids = 2;
 
+  struct Dirty {
+    u64 epoch  : kClkBits;
+    u64 tid : 64 - kClkBits;  // kInvalidId if not active
+  };
+
   unsigned release_store_tid_;
   unsigned release_store_reused_;
-  unsigned dirty_tids_[kDirtyTids];
-  // tab_ contains indirect pointer to a 512b block using DenseSlabAlloc.
-  // If size_ <= 64, then tab_ points to an array with 64 ClockElem's.
-  // Otherwise, tab_ points to an array with 128 u32 elements,
+  Dirty dirty_[kDirtyTids];
+  // If size_ is 0, tab_ is nullptr.
+  // If size <= 64 (kClockCount), tab_ contains pointer to an array with
+  // 64 ClockElem's (ClockBlock::clock).
+  // Otherwise, tab_ points to an array with up to 127 u32 elements,
   // each pointing to the second-level 512b block with 64 ClockElem's.
+  // Unused space in the first level ClockBlock is used to store additional
+  // clock elements.
+  // The last u32 element in the first level ClockBlock is always used as
+  // reference counter.
+  //
+  // See the following scheme for details.
+  // All memory blocks are 512 bytes (allocated from ClockAlloc).
+  // Clock (clk) elements are 64 bits.
+  // Idx and ref are 32 bits.
+  //
+  // tab_
+  //    |
+  //    \/
+  //    +----------------------------------------------------+
+  //    | clk128 | clk129 | ...unused... | idx1 | idx0 | ref |
+  //    +----------------------------------------------------+
+  //                                        |      |
+  //                                        |      \/
+  //                                        |      +----------------+
+  //                                        |      | clk0 ... clk63 |
+  //                                        |      +----------------+
+  //                                        \/
+  //                                        +------------------+
+  //                                        | clk64 ... clk127 |
+  //                                        +------------------+
+  //
+  // Note: dirty entries, if active, always override what's stored in the clock.
   ClockBlock *tab_;
   u32 tab_idx_;
-  u32 size_;
-
+  u16 size_;
+  u16 blocks_;  // Number of second level blocks.
+
+  void Unshare(ClockCache *c);
+  bool IsShared() const;
+  bool Cachable() const;
+  void ResetImpl();
+  void FlushDirty();
+  uptr capacity() const;
+  u32 get_block(uptr bi) const;
+  void append_block(u32 idx);
   ClockElem &elem(unsigned tid) const;
 };
 
 // The clock that lives in threads.
-struct ThreadClock {
+class ThreadClock {
  public:
   typedef DenseSlabAllocCache Cache;
 
   explicit ThreadClock(unsigned tid, unsigned reused = 0);
 
-  u64 get(unsigned tid) const {
-    DCHECK_LT(tid, kMaxTidInClock);
-    return clk_[tid].epoch;
-  }
-
-  void set(unsigned tid, u64 v);
-
-  void set(u64 v) {
-    DCHECK_GE(v, clk_[tid_].epoch);
-    clk_[tid_].epoch = v;
-  }
+  u64 get(unsigned tid) const;
+  void set(ClockCache *c, unsigned tid, u64 v);
+  void set(u64 v);
+  void tick();
+  uptr size() const;
 
-  void tick() {
-    clk_[tid_].epoch++;
-  }
-
-  uptr size() const {
-    return nclk_;
-  }
-
-  void acquire(ClockCache *c, const SyncClock *src);
-  void release(ClockCache *c, SyncClock *dst) const;
+  void acquire(ClockCache *c, SyncClock *src);
+  void release(ClockCache *c, SyncClock *dst);
   void acq_rel(ClockCache *c, SyncClock *dst);
-  void ReleaseStore(ClockCache *c, SyncClock *dst) const;
+  void ReleaseStore(ClockCache *c, SyncClock *dst);
+  void ResetCached(ClockCache *c);
 
   void DebugReset();
   void DebugDump(int(*printf)(const char *s, ...));
 
  private:
   static const uptr kDirtyTids = SyncClock::kDirtyTids;
+  // Index of the thread associated with he clock ("current thread").
   const unsigned tid_;
-  const unsigned reused_;
+  const unsigned reused_;  // tid_ reuse count.
+  // Current thread time when it acquired something from other threads.
   u64 last_acquire_;
+
+  // Cached SyncClock (without dirty entries and release_store_tid_).
+  // We reuse it for subsequent store-release operations without intervening
+  // acquire operations. Since it is shared (and thus constant), clock value
+  // for the current thread is then stored in dirty entries in the SyncClock.
+  // We host a refernece to the table while it is cached here.
+  u32 cached_idx_;
+  u16 cached_size_;
+  u16 cached_blocks_;
+
+  // Number of active elements in the clk_ table (the rest is zeros).
   uptr nclk_;
-  ClockElem clk_[kMaxTidInClock];
+  u64 clk_[kMaxTidInClock];  // Fixed size vector clock.
 
   bool IsAlreadyAcquired(const SyncClock *src) const;
-  void UpdateCurrentThread(SyncClock *dst) const;
+  void UpdateCurrentThread(ClockCache *c, SyncClock *dst) const;
 };
 
+ALWAYS_INLINE u64 ThreadClock::get(unsigned tid) const {
+  DCHECK_LT(tid, kMaxTidInClock);
+  return clk_[tid];
+}
+
+ALWAYS_INLINE void ThreadClock::set(u64 v) {
+  DCHECK_GE(v, clk_[tid_]);
+  clk_[tid_] = v;
+}
+
+ALWAYS_INLINE void ThreadClock::tick() {
+  clk_[tid_]++;
+}
+
+ALWAYS_INLINE uptr ThreadClock::size() const {
+  return nclk_;
+}
+
+ALWAYS_INLINE SyncClock::Iter SyncClock::begin() {
+  return Iter(this);
+}
+
+ALWAYS_INLINE SyncClock::Iter SyncClock::end() {
+  return Iter(nullptr);
+}
+
+ALWAYS_INLINE uptr SyncClock::size() const {
+  return size_;
+}
+
+ALWAYS_INLINE SyncClock::Iter::Iter(SyncClock* parent)
+    : parent_(parent)
+    , pos_(nullptr)
+    , end_(nullptr)
+    , block_(-1) {
+  if (parent)
+    Next();
+}
+
+ALWAYS_INLINE SyncClock::Iter& SyncClock::Iter::operator++() {
+  pos_++;
+  if (UNLIKELY(pos_ >= end_))
+    Next();
+  return *this;
+}
+
+ALWAYS_INLINE bool SyncClock::Iter::operator!=(const SyncClock::Iter& other) {
+  return parent_ != other.parent_;
+}
+
+ALWAYS_INLINE ClockElem &SyncClock::Iter::operator*() {
+  return *pos_;
+}
 }  // namespace __tsan
 
 #endif  // TSAN_CLOCK_H
diff --git a/libsanitizer/tsan/tsan_debugging.cc b/libsanitizer/tsan/tsan_debugging.cc
index d26d4828b15..9a9c67fc42e 100644
--- a/libsanitizer/tsan/tsan_debugging.cc
+++ b/libsanitizer/tsan/tsan_debugging.cc
@@ -13,6 +13,8 @@
 #include "tsan_report.h"
 #include "tsan_rtl.h"
 
+#include "sanitizer_common/sanitizer_stackdepot.h"
+
 using namespace __tsan;
 
 static const char *ReportTypeDescription(ReportType typ) {
@@ -20,6 +22,7 @@ static const char *ReportTypeDescription(ReportType typ) {
   if (typ == ReportTypeVptrRace) return "data-race-vptr";
   if (typ == ReportTypeUseAfterFree) return "heap-use-after-free";
   if (typ == ReportTypeVptrUseAfterFree) return "heap-use-after-free-vptr";
+  if (typ == ReportTypeExternalRace) return "external-race";
   if (typ == ReportTypeThreadLeak) return "thread-leak";
   if (typ == ReportTypeMutexDestroyLocked) return "locked-mutex-destroy";
   if (typ == ReportTypeMutexDoubleLock) return "mutex-double-lock";
@@ -123,6 +126,16 @@ int __tsan_get_report_loc(void *report, uptr idx, const char **type,
 }
 
 SANITIZER_INTERFACE_ATTRIBUTE
+int __tsan_get_report_loc_object_type(void *report, uptr idx,
+                                      const char **object_type) {
+  const ReportDesc *rep = (ReportDesc *)report;
+  CHECK_LT(idx, rep->locs.Size());
+  ReportLocation *loc = rep->locs[idx];
+  *object_type = GetObjectTypeFromTag(loc->external_tag);
+  return 1;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
 int __tsan_get_report_mutex(void *report, uptr idx, uptr *mutex_id, void **addr,
                             int *destroyed, void **trace, uptr trace_size) {
   const ReportDesc *rep = (ReportDesc *)report;
@@ -136,7 +149,7 @@ int __tsan_get_report_mutex(void *report, uptr idx, uptr *mutex_id, void **addr,
 }
 
 SANITIZER_INTERFACE_ATTRIBUTE
-int __tsan_get_report_thread(void *report, uptr idx, int *tid, uptr *os_id,
+int __tsan_get_report_thread(void *report, uptr idx, int *tid, tid_t *os_id,
                              int *running, const char **name, int *parent_tid,
                              void **trace, uptr trace_size) {
   const ReportDesc *rep = (ReportDesc *)report;
@@ -158,3 +171,78 @@ int __tsan_get_report_unique_tid(void *report, uptr idx, int *tid) {
   *tid = rep->unique_tids[idx];
   return 1;
 }
+
+SANITIZER_INTERFACE_ATTRIBUTE
+const char *__tsan_locate_address(uptr addr, char *name, uptr name_size,
+                                  uptr *region_address_ptr,
+                                  uptr *region_size_ptr) {
+  uptr region_address = 0;
+  uptr region_size = 0;
+  const char *region_kind = nullptr;
+  if (name && name_size > 0) name[0] = 0;
+
+  if (IsMetaMem(addr)) {
+    region_kind = "meta shadow";
+  } else if (IsShadowMem(addr)) {
+    region_kind = "shadow";
+  } else {
+    bool is_stack = false;
+    MBlock *b = 0;
+    Allocator *a = allocator();
+    if (a->PointerIsMine((void *)addr)) {
+      void *block_begin = a->GetBlockBegin((void *)addr);
+      if (block_begin) b = ctx->metamap.GetBlock((uptr)block_begin);
+    }
+
+    if (b != 0) {
+      region_address = (uptr)allocator()->GetBlockBegin((void *)addr);
+      region_size = b->siz;
+      region_kind = "heap";
+    } else {
+      // TODO(kuba.brecka): We should not lock. This is supposed to be called
+      // from within the debugger when other threads are stopped.
+      ctx->thread_registry->Lock();
+      ThreadContext *tctx = IsThreadStackOrTls(addr, &is_stack);
+      ctx->thread_registry->Unlock();
+      if (tctx) {
+        region_kind = is_stack ? "stack" : "tls";
+      } else {
+        region_kind = "global";
+        DataInfo info;
+        if (Symbolizer::GetOrInit()->SymbolizeData(addr, &info)) {
+          internal_strncpy(name, info.name, name_size);
+          region_address = info.start;
+          region_size = info.size;
+        }
+      }
+    }
+  }
+
+  CHECK(region_kind);
+  if (region_address_ptr) *region_address_ptr = region_address;
+  if (region_size_ptr) *region_size_ptr = region_size;
+  return region_kind;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __tsan_get_alloc_stack(uptr addr, uptr *trace, uptr size, int *thread_id,
+                           tid_t *os_id) {
+  MBlock *b = 0;
+  Allocator *a = allocator();
+  if (a->PointerIsMine((void *)addr)) {
+    void *block_begin = a->GetBlockBegin((void *)addr);
+    if (block_begin) b = ctx->metamap.GetBlock((uptr)block_begin);
+  }
+  if (b == 0) return 0;
+
+  *thread_id = b->tid;
+  // No locking.  This is supposed to be called from within the debugger when
+  // other threads are stopped.
+  ThreadContextBase *tctx = ctx->thread_registry->GetThreadLocked(b->tid);
+  *os_id = tctx->os_id;
+
+  StackTrace stack = StackDepotGet(b->stk);
+  size = Min(size, (uptr)stack.size);
+  for (uptr i = 0; i < size; i++) trace[i] = stack.trace[stack.size - i - 1];
+  return size;
+}
diff --git a/libsanitizer/tsan/tsan_defs.h b/libsanitizer/tsan/tsan_defs.h
index e540526caa2..2c7eda69f92 100644
--- a/libsanitizer/tsan/tsan_defs.h
+++ b/libsanitizer/tsan/tsan_defs.h
@@ -36,15 +36,40 @@
 
 namespace __tsan {
 
+const int kClkBits = 42;
+const unsigned kMaxTidReuse = (1 << (64 - kClkBits)) - 1;
+
+struct ClockElem {
+  u64 epoch  : kClkBits;
+  u64 reused : 64 - kClkBits;  // tid reuse count
+};
+
+struct ClockBlock {
+  static const uptr kSize = 512;
+  static const uptr kTableSize = kSize / sizeof(u32);
+  static const uptr kClockCount = kSize / sizeof(ClockElem);
+  static const uptr kRefIdx = kTableSize - 1;
+  static const uptr kBlockIdx = kTableSize - 2;
+
+  union {
+    u32       table[kTableSize];
+    ClockElem clock[kClockCount];
+  };
+
+  ClockBlock() {
+  }
+};
+
 const int kTidBits = 13;
-const unsigned kMaxTid = 1 << kTidBits;
+// Reduce kMaxTid by kClockCount because one slot in ClockBlock table is
+// occupied by reference counter, so total number of elements we can store
+// in SyncClock is kClockCount * (kTableSize - 1).
+const unsigned kMaxTid = (1 << kTidBits) - ClockBlock::kClockCount;
 #if !SANITIZER_GO
 const unsigned kMaxTidInClock = kMaxTid * 2;  // This includes msb 'freed' bit.
 #else
 const unsigned kMaxTidInClock = kMaxTid;  // Go does not track freed memory.
 #endif
-const int kClkBits = 42;
-const unsigned kMaxTidReuse = (1 << (64 - kClkBits)) - 1;
 const uptr kShadowStackSize = 64 * 1024;
 
 // Count of shadow values in a shadow cell.
@@ -72,7 +97,7 @@ const bool kCollectHistory = false;
 const bool kCollectHistory = true;
 #endif
 
-const unsigned kInvalidTid = (unsigned)-1;
+const u16 kInvalidTid = kMaxTid + 1;
 
 // The following "build consistency" machinery ensures that all source files
 // are built in the same configuration. Inconsistent builds lead to
@@ -147,13 +172,23 @@ class RegionAlloc;
 
 // Descriptor of user's memory block.
 struct MBlock {
-  u64  siz;
+  u64  siz : 48;
+  u64  tag : 16;
   u32  stk;
   u16  tid;
 };
 
 COMPILER_CHECK(sizeof(MBlock) == 16);
 
+enum ExternalTag : uptr {
+  kExternalTagNone = 0,
+  kExternalTagSwiftModifyingAccess = 1,
+  kExternalTagFirstUserAvailable = 2,
+  kExternalTagMax = 1024,
+  // Don't set kExternalTagMax over 65,536, since MBlock only stores tags
+  // as 16-bit values, see tsan_defs.h.
+};
+
 }  // namespace __tsan
 
 #endif  // TSAN_DEFS_H
diff --git a/libsanitizer/tsan/tsan_dense_alloc.h b/libsanitizer/tsan/tsan_dense_alloc.h
index 780ff6f4c8e..197b96fdeed 100644
--- a/libsanitizer/tsan/tsan_dense_alloc.h
+++ b/libsanitizer/tsan/tsan_dense_alloc.h
@@ -37,7 +37,7 @@ class DenseSlabAlloc {
   typedef DenseSlabAllocCache Cache;
   typedef typename Cache::IndexT IndexT;
 
-  DenseSlabAlloc() {
+  explicit DenseSlabAlloc(const char *name) {
     // Check that kL1Size and kL2Size are sane.
     CHECK_EQ(kL1Size & (kL1Size - 1), 0);
     CHECK_EQ(kL2Size & (kL2Size - 1), 0);
@@ -47,6 +47,7 @@ class DenseSlabAlloc {
     internal_memset(map_, 0, sizeof(map_));
     freelist_ = 0;
     fillpos_ = 0;
+    name_ = name;
   }
 
   ~DenseSlabAlloc() {
@@ -94,15 +95,19 @@ class DenseSlabAlloc {
   SpinMutex mtx_;
   IndexT freelist_;
   uptr fillpos_;
+  const char *name_;
 
   void Refill(Cache *c) {
     SpinMutexLock lock(&mtx_);
     if (freelist_ == 0) {
       if (fillpos_ == kL1Size) {
-        Printf("ThreadSanitizer: DenseSlabAllocator overflow. Dying.\n");
+        Printf("ThreadSanitizer: %s overflow (%zu*%zu). Dying.\n",
+            name_, kL1Size, kL2Size);
         Die();
       }
-      T *batch = (T*)MmapOrDie(kL2Size * sizeof(T), "DenseSlabAllocator");
+      VPrintf(2, "ThreadSanitizer: growing %s: %zu out of %zu*%zu\n",
+          name_, fillpos_, kL1Size, kL2Size);
+      T *batch = (T*)MmapOrDie(kL2Size * sizeof(T), name_);
       // Reserve 0 as invalid index.
       IndexT start = fillpos_ == 0 ? 1 : 0;
       for (IndexT i = start; i < kL2Size; i++) {
diff --git a/libsanitizer/tsan/tsan_external.cc b/libsanitizer/tsan/tsan_external.cc
new file mode 100644
index 00000000000..3dddc3a4f64
--- /dev/null
+++ b/libsanitizer/tsan/tsan_external.cc
@@ -0,0 +1,123 @@
+//===-- tsan_external.cc --------------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of ThreadSanitizer (TSan), a race detector.
+//
+//===----------------------------------------------------------------------===//
+#include "tsan_rtl.h"
+#include "tsan_interceptors.h"
+
+namespace __tsan {
+
+#define CALLERPC ((uptr)__builtin_return_address(0))
+
+struct TagData {
+  const char *object_type;
+  const char *header;
+};
+
+static TagData registered_tags[kExternalTagMax] = {
+  {},
+  {"Swift variable", "Swift access race"},
+};
+static atomic_uint32_t used_tags{kExternalTagFirstUserAvailable};  // NOLINT.
+static TagData *GetTagData(uptr tag) {
+  // Invalid/corrupted tag?  Better return NULL and let the caller deal with it.
+  if (tag >= atomic_load(&used_tags, memory_order_relaxed)) return nullptr;
+  return &registered_tags[tag];
+}
+
+const char *GetObjectTypeFromTag(uptr tag) {
+  TagData *tag_data = GetTagData(tag);
+  return tag_data ? tag_data->object_type : nullptr;
+}
+
+const char *GetReportHeaderFromTag(uptr tag) {
+  TagData *tag_data = GetTagData(tag);
+  return tag_data ? tag_data->header : nullptr;
+}
+
+void InsertShadowStackFrameForTag(ThreadState *thr, uptr tag) {
+  FuncEntry(thr, (uptr)&registered_tags[tag]);
+}
+
+uptr TagFromShadowStackFrame(uptr pc) {
+  uptr tag_count = atomic_load(&used_tags, memory_order_relaxed);
+  void *pc_ptr = (void *)pc;
+  if (pc_ptr < GetTagData(0) || pc_ptr > GetTagData(tag_count - 1))
+    return 0;
+  return (TagData *)pc_ptr - GetTagData(0);
+}
+
+#if !SANITIZER_GO
+
+typedef void(*AccessFunc)(ThreadState *, uptr, uptr, int);
+void ExternalAccess(void *addr, void *caller_pc, void *tag, AccessFunc access) {
+  CHECK_LT(tag, atomic_load(&used_tags, memory_order_relaxed));
+  ThreadState *thr = cur_thread();
+  if (caller_pc) FuncEntry(thr, (uptr)caller_pc);
+  InsertShadowStackFrameForTag(thr, (uptr)tag);
+  bool in_ignored_lib;
+  if (!caller_pc || !libignore()->IsIgnored((uptr)caller_pc, &in_ignored_lib)) {
+    access(thr, CALLERPC, (uptr)addr, kSizeLog1);
+  }
+  FuncExit(thr);
+  if (caller_pc) FuncExit(thr);
+}
+
+extern "C" {
+SANITIZER_INTERFACE_ATTRIBUTE
+void *__tsan_external_register_tag(const char *object_type) {
+  uptr new_tag = atomic_fetch_add(&used_tags, 1, memory_order_relaxed);
+  CHECK_LT(new_tag, kExternalTagMax);
+  GetTagData(new_tag)->object_type = internal_strdup(object_type);
+  char header[127] = {0};
+  internal_snprintf(header, sizeof(header), "race on %s", object_type);
+  GetTagData(new_tag)->header = internal_strdup(header);
+  return (void *)new_tag;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+void __tsan_external_register_header(void *tag, const char *header) {
+  CHECK_GE((uptr)tag, kExternalTagFirstUserAvailable);
+  CHECK_LT((uptr)tag, kExternalTagMax);
+  atomic_uintptr_t *header_ptr =
+      (atomic_uintptr_t *)&GetTagData((uptr)tag)->header;
+  header = internal_strdup(header);
+  char *old_header =
+      (char *)atomic_exchange(header_ptr, (uptr)header, memory_order_seq_cst);
+  if (old_header) internal_free(old_header);
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+void __tsan_external_assign_tag(void *addr, void *tag) {
+  CHECK_LT(tag, atomic_load(&used_tags, memory_order_relaxed));
+  Allocator *a = allocator();
+  MBlock *b = nullptr;
+  if (a->PointerIsMine((void *)addr)) {
+    void *block_begin = a->GetBlockBegin((void *)addr);
+    if (block_begin) b = ctx->metamap.GetBlock((uptr)block_begin);
+  }
+  if (b) {
+    b->tag = (uptr)tag;
+  }
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+void __tsan_external_read(void *addr, void *caller_pc, void *tag) {
+  ExternalAccess(addr, caller_pc, tag, MemoryRead);
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
+void __tsan_external_write(void *addr, void *caller_pc, void *tag) {
+  ExternalAccess(addr, caller_pc, tag, MemoryWrite);
+}
+}  // extern "C"
+
+#endif  // !SANITIZER_GO
+
+}  // namespace __tsan
diff --git a/libsanitizer/tsan/tsan_fd.cc b/libsanitizer/tsan/tsan_fd.cc
index 8f75a28200d..effa35ddeb5 100644
--- a/libsanitizer/tsan/tsan_fd.cc
+++ b/libsanitizer/tsan/tsan_fd.cc
@@ -46,8 +46,8 @@ static bool bogusfd(int fd) {
 }
 
 static FdSync *allocsync(ThreadState *thr, uptr pc) {
-  FdSync *s = (FdSync*)user_alloc(thr, pc, sizeof(FdSync), kDefaultAlignment,
-      false);
+  FdSync *s = (FdSync*)user_alloc_internal(thr, pc, sizeof(FdSync),
+      kDefaultAlignment, false);
   atomic_store(&s->rc, 1, memory_order_relaxed);
   return s;
 }
@@ -77,7 +77,7 @@ static FdDesc *fddesc(ThreadState *thr, uptr pc, int fd) {
   if (l1 == 0) {
     uptr size = kTableSizeL2 * sizeof(FdDesc);
     // We need this to reside in user memory to properly catch races on it.
-    void *p = user_alloc(thr, pc, size, kDefaultAlignment, false);
+    void *p = user_alloc_internal(thr, pc, size, kDefaultAlignment, false);
     internal_memset(p, 0, size);
     MemoryResetRange(thr, (uptr)&fddesc, (uptr)p, size);
     if (atomic_compare_exchange_strong(pl1, &l1, (uptr)p, memory_order_acq_rel))
diff --git a/libsanitizer/tsan/tsan_flags.cc b/libsanitizer/tsan/tsan_flags.cc
index 5064a0fe653..4217691658e 100644
--- a/libsanitizer/tsan/tsan_flags.cc
+++ b/libsanitizer/tsan/tsan_flags.cc
@@ -19,10 +19,6 @@
 
 namespace __tsan {
 
-Flags *flags() {
-  return &ctx->flags;
-}
-
 // Can be overriden in frontend.
 #ifdef TSAN_EXTERNAL_HOOKS
 extern "C" const char* __tsan_default_options();
diff --git a/libsanitizer/tsan/tsan_flags.h b/libsanitizer/tsan/tsan_flags.h
index 3d58ff3793e..35b0efc1c6b 100644
--- a/libsanitizer/tsan/tsan_flags.h
+++ b/libsanitizer/tsan/tsan_flags.h
@@ -26,7 +26,6 @@ struct Flags : DDFlags {
   void ParseFromString(const char *str);
 };
 
-Flags *flags();
 void InitializeFlags(Flags *flags, const char *env);
 }  // namespace __tsan
 
diff --git a/libsanitizer/tsan/tsan_flags.inc b/libsanitizer/tsan/tsan_flags.inc
index 78f5e80fd5c..e9873f16ce4 100644
--- a/libsanitizer/tsan/tsan_flags.inc
+++ b/libsanitizer/tsan/tsan_flags.inc
@@ -77,5 +77,8 @@ TSAN_FLAG(bool, die_after_fork, true,
 TSAN_FLAG(const char *, suppressions, "", "Suppressions file name.")
 TSAN_FLAG(bool, ignore_interceptors_accesses, false,
           "Ignore reads and writes from all interceptors.")
+TSAN_FLAG(bool, ignore_noninstrumented_modules, SANITIZER_MAC ? true : false,
+          "Interceptors should only detect races when called from instrumented "
+          "modules.")
 TSAN_FLAG(bool, shared_ptr_interceptor, true,
           "Track atomic reference counting in libc++ shared_ptr and weak_ptr.")
diff --git a/libsanitizer/tsan/tsan_interceptors.cc b/libsanitizer/tsan/tsan_interceptors.cc
index bf5f2d5b66c..15f20d4b668 100644
--- a/libsanitizer/tsan/tsan_interceptors.cc
+++ b/libsanitizer/tsan/tsan_interceptors.cc
@@ -12,10 +12,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "sanitizer_common/sanitizer_atomic.h"
+#include "sanitizer_common/sanitizer_errno.h"
 #include "sanitizer_common/sanitizer_libc.h"
 #include "sanitizer_common/sanitizer_linux.h"
+#include "sanitizer_common/sanitizer_platform_limits_netbsd.h"
 #include "sanitizer_common/sanitizer_platform_limits_posix.h"
 #include "sanitizer_common/sanitizer_placement_new.h"
+#include "sanitizer_common/sanitizer_posix.h"
 #include "sanitizer_common/sanitizer_stacktrace.h"
 #include "sanitizer_common/sanitizer_tls_get_addr.h"
 #include "interception/interception.h"
@@ -27,30 +30,25 @@
 #include "tsan_mman.h"
 #include "tsan_fd.h"
 
-#if SANITIZER_POSIX
-#include "sanitizer_common/sanitizer_posix.h"
-#endif
 
 using namespace __tsan;  // NOLINT
 
 #if SANITIZER_FREEBSD || SANITIZER_MAC
-#define __errno_location __error
 #define stdout __stdoutp
 #define stderr __stderrp
 #endif
 
-#if SANITIZER_ANDROID
-#define __errno_location __errno
-#define mallopt(a, b)
+#if SANITIZER_NETBSD
+#define dirfd(dirp) (*(int *)(dirp))
+#define fileno_unlocked fileno
+#define stdout __sF[1]
+#define stderr __sF[2]
 #endif
 
-#if SANITIZER_LINUX || SANITIZER_FREEBSD
-#define PTHREAD_CREATE_DETACHED 1
-#elif SANITIZER_MAC
-#define PTHREAD_CREATE_DETACHED 2
+#if SANITIZER_ANDROID
+#define mallopt(a, b)
 #endif
 
-
 #ifdef __mips__
 const int kSigCount = 129;
 #else
@@ -91,24 +89,26 @@ DECLARE_REAL_AND_INTERCEPTOR(void *, malloc, uptr size)
 DECLARE_REAL_AND_INTERCEPTOR(void, free, void *ptr)
 extern "C" void *pthread_self();
 extern "C" void _exit(int status);
-extern "C" int *__errno_location();
 extern "C" int fileno_unlocked(void *stream);
+#if !SANITIZER_NETBSD
 extern "C" int dirfd(void *dirp);
-#if !SANITIZER_FREEBSD && !SANITIZER_ANDROID
+#endif
+#if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_NETBSD
 extern "C" int mallopt(int param, int value);
 #endif
+#if SANITIZER_NETBSD
+extern __sanitizer_FILE **__sF;
+#else
 extern __sanitizer_FILE *stdout, *stderr;
-#if !SANITIZER_FREEBSD && !SANITIZER_MAC
+#endif
+#if !SANITIZER_FREEBSD && !SANITIZER_MAC && !SANITIZER_NETBSD
 const int PTHREAD_MUTEX_RECURSIVE = 1;
 const int PTHREAD_MUTEX_RECURSIVE_NP = 1;
 #else
 const int PTHREAD_MUTEX_RECURSIVE = 2;
 const int PTHREAD_MUTEX_RECURSIVE_NP = 2;
 #endif
-const int EINVAL = 22;
-const int EBUSY = 16;
-const int EOWNERDEAD = 130;
-#if !SANITIZER_FREEBSD && !SANITIZER_MAC
+#if !SANITIZER_FREEBSD && !SANITIZER_MAC && !SANITIZER_NETBSD
 const int EPOLL_CTL_ADD = 1;
 #endif
 const int SIGILL = 4;
@@ -117,7 +117,7 @@ const int SIGFPE = 8;
 const int SIGSEGV = 11;
 const int SIGPIPE = 13;
 const int SIGTERM = 15;
-#if defined(__mips__) || SANITIZER_FREEBSD || SANITIZER_MAC
+#if defined(__mips__) || SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_NETBSD
 const int SIGBUS = 10;
 const int SIGSYS = 12;
 #else
@@ -125,7 +125,9 @@ const int SIGBUS = 7;
 const int SIGSYS = 31;
 #endif
 void *const MAP_FAILED = (void*)-1;
-#if !SANITIZER_MAC
+#if SANITIZER_NETBSD
+const int PTHREAD_BARRIER_SERIAL_THREAD = 1234567;
+#elif !SANITIZER_MAC
 const int PTHREAD_BARRIER_SERIAL_THREAD = -1;
 #endif
 const int MAP_FIXED = 0x10;
@@ -137,8 +139,6 @@ typedef long long_t;  // NOLINT
 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
 # define F_TEST  3      /* Test a region for other processes locks.  */
 
-#define errno (*__errno_location())
-
 typedef void (*sighandler_t)(int sig);
 typedef void (*sigactionhandler_t)(int sig, my_siginfo_t *siginfo, void *uctx);
 
@@ -152,6 +152,15 @@ struct sigaction_t {
   __sanitizer_sigset_t sa_mask;
   void (*sa_restorer)();
 };
+#elif SANITIZER_NETBSD
+struct sigaction_t {
+  union {
+    sighandler_t sa_handler;
+    sigactionhandler_t sa_sigaction;
+  };
+  __sanitizer_sigset_t sa_mask;
+  int sa_flags;
+};
 #else
 struct sigaction_t {
 #ifdef __mips__
@@ -180,7 +189,7 @@ struct sigaction_t {
 const sighandler_t SIG_DFL = (sighandler_t)0;
 const sighandler_t SIG_IGN = (sighandler_t)1;
 const sighandler_t SIG_ERR = (sighandler_t)-1;
-#if SANITIZER_FREEBSD || SANITIZER_MAC
+#if SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_NETBSD
 const int SA_SIGINFO = 0x40;
 const int SIG_SETMASK = 3;
 #elif defined(__mips__)
@@ -217,7 +226,7 @@ struct ThreadSignalContext {
 // The object is 64-byte aligned, because we want hot data to be located in
 // a single cache line if possible (it's accessed in every interceptor).
 static ALIGNED(64) char libignore_placeholder[sizeof(LibIgnore)];
-static LibIgnore *libignore() {
+LibIgnore *libignore() {
   return reinterpret_cast<LibIgnore*>(&libignore_placeholder[0]);
 }
 
@@ -229,6 +238,8 @@ void InitializeLibIgnore() {
     if (0 == internal_strcmp(s->type, kSuppressionLib))
       libignore()->AddIgnoredLibrary(s->templ);
   }
+  if (flags()->ignore_noninstrumented_modules)
+    libignore()->IgnoreNoninstrumentedModules(true);
   libignore()->OnLibraryLoaded(0);
 }
 
@@ -250,31 +261,20 @@ static unsigned g_thread_finalize_key;
 
 ScopedInterceptor::ScopedInterceptor(ThreadState *thr, const char *fname,
                                      uptr pc)
-    : thr_(thr)
-    , pc_(pc)
-    , in_ignored_lib_(false) {
+    : thr_(thr), pc_(pc), in_ignored_lib_(false), ignoring_(false) {
   Initialize(thr);
-  if (!thr_->is_inited)
-    return;
-  if (!thr_->ignore_interceptors)
-    FuncEntry(thr, pc);
+  if (!thr_->is_inited) return;
+  if (!thr_->ignore_interceptors) FuncEntry(thr, pc);
   DPrintf("#%d: intercept %s()\n", thr_->tid, fname);
-  if (!thr_->in_ignored_lib && libignore()->IsIgnored(pc)) {
-    in_ignored_lib_ = true;
-    thr_->in_ignored_lib = true;
-    ThreadIgnoreBegin(thr_, pc_);
-  }
-  if (flags()->ignore_interceptors_accesses) ThreadIgnoreBegin(thr_, pc_);
+  ignoring_ =
+      !thr_->in_ignored_lib && (flags()->ignore_interceptors_accesses ||
+                                libignore()->IsIgnored(pc, &in_ignored_lib_));
+  EnableIgnores();
 }
 
 ScopedInterceptor::~ScopedInterceptor() {
-  if (!thr_->is_inited)
-    return;
-  if (flags()->ignore_interceptors_accesses) ThreadIgnoreEnd(thr_, pc_);
-  if (in_ignored_lib_) {
-    thr_->in_ignored_lib = false;
-    ThreadIgnoreEnd(thr_, pc_);
-  }
+  if (!thr_->is_inited) return;
+  DisableIgnores();
   if (!thr_->ignore_interceptors) {
     ProcessPendingSignals(thr_);
     FuncExit(thr_);
@@ -282,24 +282,30 @@ ScopedInterceptor::~ScopedInterceptor() {
   }
 }
 
-void ScopedInterceptor::UserCallbackStart() {
-  if (flags()->ignore_interceptors_accesses) ThreadIgnoreEnd(thr_, pc_);
-  if (in_ignored_lib_) {
-    thr_->in_ignored_lib = false;
-    ThreadIgnoreEnd(thr_, pc_);
+void ScopedInterceptor::EnableIgnores() {
+  if (ignoring_) {
+    ThreadIgnoreBegin(thr_, pc_, /*save_stack=*/false);
+    if (flags()->ignore_noninstrumented_modules) thr_->suppress_reports++;
+    if (in_ignored_lib_) {
+      DCHECK(!thr_->in_ignored_lib);
+      thr_->in_ignored_lib = true;
+    }
   }
 }
 
-void ScopedInterceptor::UserCallbackEnd() {
-  if (in_ignored_lib_) {
-    thr_->in_ignored_lib = true;
-    ThreadIgnoreBegin(thr_, pc_);
+void ScopedInterceptor::DisableIgnores() {
+  if (ignoring_) {
+    ThreadIgnoreEnd(thr_, pc_);
+    if (flags()->ignore_noninstrumented_modules) thr_->suppress_reports--;
+    if (in_ignored_lib_) {
+      DCHECK(thr_->in_ignored_lib);
+      thr_->in_ignored_lib = false;
+    }
   }
-  if (flags()->ignore_interceptors_accesses) ThreadIgnoreBegin(thr_, pc_);
 }
 
 #define TSAN_INTERCEPT(func) INTERCEPT_FUNCTION(func)
-#if SANITIZER_FREEBSD
+#if SANITIZER_FREEBSD || SANITIZER_NETBSD
 # define TSAN_INTERCEPT_VER(func, ver) INTERCEPT_FUNCTION(func)
 #else
 # define TSAN_INTERCEPT_VER(func, ver) INTERCEPT_FUNCTION_VER(func, ver)
@@ -363,6 +369,11 @@ TSAN_INTERCEPTOR(int, nanosleep, void *req, void *rem) {
   return res;
 }
 
+TSAN_INTERCEPTOR(int, pause) {
+  SCOPED_TSAN_INTERCEPTOR(pause);
+  return BLOCK_REAL(pause)();
+}
+
 // The sole reason tsan wraps atexit callbacks is to establish synchronization
 // between callback setup and callback execution.
 struct AtExitCtx {
@@ -476,8 +487,14 @@ static void SetJmp(ThreadState *thr, uptr sp, uptr mangled_sp) {
 static void LongJmp(ThreadState *thr, uptr *env) {
 #ifdef __powerpc__
   uptr mangled_sp = env[0];
-#elif SANITIZER_FREEBSD || SANITIZER_MAC
+#elif SANITIZER_FREEBSD || SANITIZER_NETBSD
   uptr mangled_sp = env[2];
+#elif SANITIZER_MAC
+# ifdef __aarch64__
+    uptr mangled_sp = env[13];
+# else
+    uptr mangled_sp = env[2];
+# endif
 #elif defined(SANITIZER_LINUX)
 # ifdef __aarch64__
   uptr mangled_sp = env[13];
@@ -595,7 +612,7 @@ TSAN_INTERCEPTOR(void*, malloc, uptr size) {
 
 TSAN_INTERCEPTOR(void*, __libc_memalign, uptr align, uptr sz) {
   SCOPED_TSAN_INTERCEPTOR(__libc_memalign, align, sz);
-  return user_alloc(thr, pc, sz, align);
+  return user_memalign(thr, pc, align, sz);
 }
 
 TSAN_INTERCEPTOR(void*, calloc, uptr size, uptr n) {
@@ -675,7 +692,7 @@ static bool fix_mmap_addr(void **addr, long_t sz, int flags) {
   if (*addr) {
     if (!IsAppMem((uptr)*addr) || !IsAppMem((uptr)*addr + sz - 1)) {
       if (flags & MAP_FIXED) {
-        errno = EINVAL;
+        errno = errno_EINVAL;
         return false;
       } else {
         *addr = 0;
@@ -741,7 +758,7 @@ TSAN_INTERCEPTOR(int, munmap, void *addr, long_t sz) {
 #if SANITIZER_LINUX
 TSAN_INTERCEPTOR(void*, memalign, uptr align, uptr sz) {
   SCOPED_INTERCEPTOR_RAW(memalign, align, sz);
-  return user_alloc(thr, pc, sz, align);
+  return user_memalign(thr, pc, align, sz);
 }
 #define TSAN_MAYBE_INTERCEPT_MEMALIGN TSAN_INTERCEPT(memalign)
 #else
@@ -750,21 +767,20 @@ TSAN_INTERCEPTOR(void*, memalign, uptr align, uptr sz) {
 
 #if !SANITIZER_MAC
 TSAN_INTERCEPTOR(void*, aligned_alloc, uptr align, uptr sz) {
-  SCOPED_INTERCEPTOR_RAW(memalign, align, sz);
-  return user_alloc(thr, pc, sz, align);
+  SCOPED_INTERCEPTOR_RAW(aligned_alloc, align, sz);
+  return user_aligned_alloc(thr, pc, align, sz);
 }
 
 TSAN_INTERCEPTOR(void*, valloc, uptr sz) {
   SCOPED_INTERCEPTOR_RAW(valloc, sz);
-  return user_alloc(thr, pc, sz, GetPageSizeCached());
+  return user_valloc(thr, pc, sz);
 }
 #endif
 
 #if SANITIZER_LINUX
 TSAN_INTERCEPTOR(void*, pvalloc, uptr sz) {
   SCOPED_INTERCEPTOR_RAW(pvalloc, sz);
-  sz = RoundUp(sz, GetPageSizeCached());
-  return user_alloc(thr, pc, sz, GetPageSizeCached());
+  return user_pvalloc(thr, pc, sz);
 }
 #define TSAN_MAYBE_INTERCEPT_PVALLOC TSAN_INTERCEPT(pvalloc)
 #else
@@ -774,8 +790,7 @@ TSAN_INTERCEPTOR(void*, pvalloc, uptr sz) {
 #if !SANITIZER_MAC
 TSAN_INTERCEPTOR(int, posix_memalign, void **memptr, uptr align, uptr sz) {
   SCOPED_INTERCEPTOR_RAW(posix_memalign, memptr, align, sz);
-  *memptr = user_alloc(thr, pc, sz, align);
-  return 0;
+  return user_posix_memalign(thr, pc, memptr, align, sz);
 }
 #endif
 
@@ -884,7 +899,7 @@ extern "C" void *__tsan_thread_start_func(void *arg) {
       internal_sched_yield();
     Processor *proc = ProcCreate();
     ProcWire(proc, thr);
-    ThreadStart(thr, tid, GetTid());
+    ThreadStart(thr, tid, GetTid(), /*workerthread*/ false);
     atomic_store(&p->tid, 0, memory_order_release);
   }
   void *res = callback(param);
@@ -931,8 +946,7 @@ TSAN_INTERCEPTOR(int, pthread_create,
     ThreadIgnoreEnd(thr, pc);
   }
   if (res == 0) {
-    int tid = ThreadCreate(thr, pc, *(uptr*)th,
-                           detached == PTHREAD_CREATE_DETACHED);
+    int tid = ThreadCreate(thr, pc, *(uptr*)th, IsStateDetached(detached));
     CHECK_NE(tid, 0);
     // Synchronization on p.tid serves two purposes:
     // 1. ThreadCreate must finish before the new thread starts.
@@ -1028,7 +1042,7 @@ static void cond_mutex_unlock(CondMutexUnlockCtx *arg) {
   ThreadSignalContext *ctx = SigCtx(arg->thr);
   CHECK_EQ(atomic_load(&ctx->in_blocking_func, memory_order_relaxed), 1);
   atomic_store(&ctx->in_blocking_func, 0, memory_order_relaxed);
-  MutexLock(arg->thr, arg->pc, (uptr)arg->m);
+  MutexPostLock(arg->thr, arg->pc, (uptr)arg->m, MutexFlagDoPreLockOnPostLock);
   // Undo BlockingCall ctor effects.
   arg->thr->ignore_interceptors--;
   arg->si->~ScopedInterceptor();
@@ -1057,7 +1071,7 @@ static int cond_wait(ThreadState *thr, uptr pc, ScopedInterceptor *si,
         fn, c, m, t, (void (*)(void *arg))cond_mutex_unlock, &arg);
   }
   if (res == errno_EOWNERDEAD) MutexRepair(thr, pc, (uptr)m);
-  MutexLock(thr, pc, (uptr)m);
+  MutexPostLock(thr, pc, (uptr)m, MutexFlagDoPreLockOnPostLock);
   return res;
 }
 
@@ -1117,14 +1131,15 @@ TSAN_INTERCEPTOR(int, pthread_mutex_init, void *m, void *a) {
   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_init, m, a);
   int res = REAL(pthread_mutex_init)(m, a);
   if (res == 0) {
-    bool recursive = false;
+    u32 flagz = 0;
     if (a) {
       int type = 0;
       if (REAL(pthread_mutexattr_gettype)(a, &type) == 0)
-        recursive = (type == PTHREAD_MUTEX_RECURSIVE
-            || type == PTHREAD_MUTEX_RECURSIVE_NP);
+        if (type == PTHREAD_MUTEX_RECURSIVE ||
+            type == PTHREAD_MUTEX_RECURSIVE_NP)
+          flagz |= MutexFlagWriteReentrant;
     }
-    MutexCreate(thr, pc, (uptr)m, false, recursive, false);
+    MutexCreate(thr, pc, (uptr)m, flagz);
   }
   return res;
 }
@@ -1132,7 +1147,7 @@ TSAN_INTERCEPTOR(int, pthread_mutex_init, void *m, void *a) {
 TSAN_INTERCEPTOR(int, pthread_mutex_destroy, void *m) {
   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_destroy, m);
   int res = REAL(pthread_mutex_destroy)(m);
-  if (res == 0 || res == EBUSY) {
+  if (res == 0 || res == errno_EBUSY) {
     MutexDestroy(thr, pc, (uptr)m);
   }
   return res;
@@ -1141,10 +1156,10 @@ TSAN_INTERCEPTOR(int, pthread_mutex_destroy, void *m) {
 TSAN_INTERCEPTOR(int, pthread_mutex_trylock, void *m) {
   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_trylock, m);
   int res = REAL(pthread_mutex_trylock)(m);
-  if (res == EOWNERDEAD)
+  if (res == errno_EOWNERDEAD)
     MutexRepair(thr, pc, (uptr)m);
-  if (res == 0 || res == EOWNERDEAD)
-    MutexLock(thr, pc, (uptr)m, /*rec=*/1, /*try_lock=*/true);
+  if (res == 0 || res == errno_EOWNERDEAD)
+    MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
   return res;
 }
 
@@ -1153,7 +1168,7 @@ TSAN_INTERCEPTOR(int, pthread_mutex_timedlock, void *m, void *abstime) {
   SCOPED_TSAN_INTERCEPTOR(pthread_mutex_timedlock, m, abstime);
   int res = REAL(pthread_mutex_timedlock)(m, abstime);
   if (res == 0) {
-    MutexLock(thr, pc, (uptr)m);
+    MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
   }
   return res;
 }
@@ -1164,7 +1179,7 @@ TSAN_INTERCEPTOR(int, pthread_spin_init, void *m, int pshared) {
   SCOPED_TSAN_INTERCEPTOR(pthread_spin_init, m, pshared);
   int res = REAL(pthread_spin_init)(m, pshared);
   if (res == 0) {
-    MutexCreate(thr, pc, (uptr)m, false, false, false);
+    MutexCreate(thr, pc, (uptr)m);
   }
   return res;
 }
@@ -1180,9 +1195,10 @@ TSAN_INTERCEPTOR(int, pthread_spin_destroy, void *m) {
 
 TSAN_INTERCEPTOR(int, pthread_spin_lock, void *m) {
   SCOPED_TSAN_INTERCEPTOR(pthread_spin_lock, m);
+  MutexPreLock(thr, pc, (uptr)m);
   int res = REAL(pthread_spin_lock)(m);
   if (res == 0) {
-    MutexLock(thr, pc, (uptr)m);
+    MutexPostLock(thr, pc, (uptr)m);
   }
   return res;
 }
@@ -1191,7 +1207,7 @@ TSAN_INTERCEPTOR(int, pthread_spin_trylock, void *m) {
   SCOPED_TSAN_INTERCEPTOR(pthread_spin_trylock, m);
   int res = REAL(pthread_spin_trylock)(m);
   if (res == 0) {
-    MutexLock(thr, pc, (uptr)m, /*rec=*/1, /*try_lock=*/true);
+    MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
   }
   return res;
 }
@@ -1208,7 +1224,7 @@ TSAN_INTERCEPTOR(int, pthread_rwlock_init, void *m, void *a) {
   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_init, m, a);
   int res = REAL(pthread_rwlock_init)(m, a);
   if (res == 0) {
-    MutexCreate(thr, pc, (uptr)m, true, false, false);
+    MutexCreate(thr, pc, (uptr)m);
   }
   return res;
 }
@@ -1224,9 +1240,10 @@ TSAN_INTERCEPTOR(int, pthread_rwlock_destroy, void *m) {
 
 TSAN_INTERCEPTOR(int, pthread_rwlock_rdlock, void *m) {
   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_rdlock, m);
+  MutexPreReadLock(thr, pc, (uptr)m);
   int res = REAL(pthread_rwlock_rdlock)(m);
   if (res == 0) {
-    MutexReadLock(thr, pc, (uptr)m);
+    MutexPostReadLock(thr, pc, (uptr)m);
   }
   return res;
 }
@@ -1235,7 +1252,7 @@ TSAN_INTERCEPTOR(int, pthread_rwlock_tryrdlock, void *m) {
   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_tryrdlock, m);
   int res = REAL(pthread_rwlock_tryrdlock)(m);
   if (res == 0) {
-    MutexReadLock(thr, pc, (uptr)m, /*try_lock=*/true);
+    MutexPostReadLock(thr, pc, (uptr)m, MutexFlagTryLock);
   }
   return res;
 }
@@ -1245,7 +1262,7 @@ TSAN_INTERCEPTOR(int, pthread_rwlock_timedrdlock, void *m, void *abstime) {
   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_timedrdlock, m, abstime);
   int res = REAL(pthread_rwlock_timedrdlock)(m, abstime);
   if (res == 0) {
-    MutexReadLock(thr, pc, (uptr)m);
+    MutexPostReadLock(thr, pc, (uptr)m);
   }
   return res;
 }
@@ -1253,9 +1270,10 @@ TSAN_INTERCEPTOR(int, pthread_rwlock_timedrdlock, void *m, void *abstime) {
 
 TSAN_INTERCEPTOR(int, pthread_rwlock_wrlock, void *m) {
   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_wrlock, m);
+  MutexPreLock(thr, pc, (uptr)m);
   int res = REAL(pthread_rwlock_wrlock)(m);
   if (res == 0) {
-    MutexLock(thr, pc, (uptr)m);
+    MutexPostLock(thr, pc, (uptr)m);
   }
   return res;
 }
@@ -1264,7 +1282,7 @@ TSAN_INTERCEPTOR(int, pthread_rwlock_trywrlock, void *m) {
   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_trywrlock, m);
   int res = REAL(pthread_rwlock_trywrlock)(m);
   if (res == 0) {
-    MutexLock(thr, pc, (uptr)m, /*rec=*/1, /*try_lock=*/true);
+    MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
   }
   return res;
 }
@@ -1274,7 +1292,7 @@ TSAN_INTERCEPTOR(int, pthread_rwlock_timedwrlock, void *m, void *abstime) {
   SCOPED_TSAN_INTERCEPTOR(pthread_rwlock_timedwrlock, m, abstime);
   int res = REAL(pthread_rwlock_timedwrlock)(m, abstime);
   if (res == 0) {
-    MutexLock(thr, pc, (uptr)m);
+    MutexPostLock(thr, pc, (uptr)m, MutexFlagTryLock);
   }
   return res;
 }
@@ -1318,7 +1336,7 @@ TSAN_INTERCEPTOR(int, pthread_barrier_wait, void *b) {
 TSAN_INTERCEPTOR(int, pthread_once, void *o, void (*f)()) {
   SCOPED_INTERCEPTOR_RAW(pthread_once, o, f);
   if (o == 0 || f == 0)
-    return EINVAL;
+    return errno_EINVAL;
   atomic_uint32_t *a;
   if (!SANITIZER_MAC)
     a = static_cast<atomic_uint32_t*>(o);
@@ -1355,7 +1373,7 @@ TSAN_INTERCEPTOR(int, __fxstat, int version, int fd, void *buf) {
 #endif
 
 TSAN_INTERCEPTOR(int, fstat, int fd, void *buf) {
-#if SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_ANDROID
+#if SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_ANDROID || SANITIZER_NETBSD
   SCOPED_TSAN_INTERCEPTOR(fstat, fd, buf);
   if (fd > 0)
     FdAccess(thr, pc, fd);
@@ -1647,24 +1665,6 @@ TSAN_INTERCEPTOR(void*, tmpfile64, int fake) {
 #define TSAN_MAYBE_INTERCEPT_TMPFILE64
 #endif
 
-TSAN_INTERCEPTOR(uptr, fread, void *ptr, uptr size, uptr nmemb, void *f) {
-  // libc file streams can call user-supplied functions, see fopencookie.
-  {
-    SCOPED_TSAN_INTERCEPTOR(fread, ptr, size, nmemb, f);
-    MemoryAccessRange(thr, pc, (uptr)ptr, size * nmemb, true);
-  }
-  return REAL(fread)(ptr, size, nmemb, f);
-}
-
-TSAN_INTERCEPTOR(uptr, fwrite, const void *p, uptr size, uptr nmemb, void *f) {
-  // libc file streams can call user-supplied functions, see fopencookie.
-  {
-    SCOPED_TSAN_INTERCEPTOR(fwrite, p, size, nmemb, f);
-    MemoryAccessRange(thr, pc, (uptr)p, size * nmemb, false);
-  }
-  return REAL(fwrite)(p, size, nmemb, f);
-}
-
 static void FlushStreams() {
   // Flushing all the streams here may freeze the process if a child thread is
   // performing file stream operations at the same time.
@@ -1954,7 +1954,7 @@ TSAN_INTERCEPTOR(int, sigaction, int sig, sigaction_t *act, sigaction_t *old) {
   sigactions[sig].sa_flags = *(volatile int*)&act->sa_flags;
   internal_memcpy(&sigactions[sig].sa_mask, &act->sa_mask,
       sizeof(sigactions[sig].sa_mask));
-#if !SANITIZER_FREEBSD && !SANITIZER_MAC
+#if !SANITIZER_FREEBSD && !SANITIZER_MAC && !SANITIZER_NETBSD
   sigactions[sig].sa_restorer = act->sa_restorer;
 #endif
   sigaction_t newact;
@@ -2254,8 +2254,12 @@ static void HandleRecvmsg(ThreadState *thr, uptr pc,
 #define COMMON_INTERCEPTOR_ON_EXIT(ctx) \
   OnExit(((TsanInterceptorContext *) ctx)->thr)
 
-#define COMMON_INTERCEPTOR_MUTEX_LOCK(ctx, m) \
-  MutexLock(((TsanInterceptorContext *)ctx)->thr, \
+#define COMMON_INTERCEPTOR_MUTEX_PRE_LOCK(ctx, m) \
+  MutexPreLock(((TsanInterceptorContext *)ctx)->thr, \
+            ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
+
+#define COMMON_INTERCEPTOR_MUTEX_POST_LOCK(ctx, m) \
+  MutexPostLock(((TsanInterceptorContext *)ctx)->thr, \
             ((TsanInterceptorContext *)ctx)->pc, (uptr)m)
 
 #define COMMON_INTERCEPTOR_MUTEX_UNLOCK(ctx, m) \
@@ -2312,7 +2316,7 @@ struct ScopedSyscall {
   }
 };
 
-#if !SANITIZER_FREEBSD && !SANITIZER_MAC
+#if !SANITIZER_FREEBSD && !SANITIZER_MAC && !SANITIZER_NETBSD
 static void syscall_access_range(uptr pc, uptr p, uptr s, bool write) {
   TSAN_SYSCALL();
   MemoryAccessRange(thr, pc, p, s, write);
@@ -2582,6 +2586,7 @@ void InitializeInterceptors() {
   TSAN_INTERCEPT(sleep);
   TSAN_INTERCEPT(usleep);
   TSAN_INTERCEPT(nanosleep);
+  TSAN_INTERCEPT(pause);
   TSAN_INTERCEPT(gettimeofday);
   TSAN_INTERCEPT(getaddrinfo);
 
diff --git a/libsanitizer/tsan/tsan_interceptors.h b/libsanitizer/tsan/tsan_interceptors.h
index a0f9a0753a6..de47466501d 100644
--- a/libsanitizer/tsan/tsan_interceptors.h
+++ b/libsanitizer/tsan/tsan_interceptors.h
@@ -10,14 +10,17 @@ class ScopedInterceptor {
  public:
   ScopedInterceptor(ThreadState *thr, const char *fname, uptr pc);
   ~ScopedInterceptor();
-  void UserCallbackStart();
-  void UserCallbackEnd();
+  void DisableIgnores();
+  void EnableIgnores();
  private:
   ThreadState *const thr_;
   const uptr pc_;
   bool in_ignored_lib_;
+  bool ignoring_;
 };
 
+LibIgnore *libignore();
+
 }  // namespace __tsan
 
 #define SCOPED_INTERCEPTOR_RAW(func, ...) \
@@ -39,10 +42,10 @@ class ScopedInterceptor {
 /**/
 
 #define SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START() \
-    si.UserCallbackStart();
+    si.DisableIgnores();
 
 #define SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END() \
-    si.UserCallbackEnd();
+    si.EnableIgnores();
 
 #define TSAN_INTERCEPTOR(ret, func, ...) INTERCEPTOR(ret, func, __VA_ARGS__)
 
diff --git a/libsanitizer/tsan/tsan_interceptors_mac.cc b/libsanitizer/tsan/tsan_interceptors_mac.cc
index eaf866d6c75..913e9ed0e14 100644
--- a/libsanitizer/tsan/tsan_interceptors_mac.cc
+++ b/libsanitizer/tsan/tsan_interceptors_mac.cc
@@ -19,7 +19,10 @@
 #include "tsan_interface_ann.h"
 
 #include <libkern/OSAtomic.h>
+
+#if defined(__has_include) && __has_include(<xpc/xpc.h>)
 #include <xpc/xpc.h>
+#endif  // #if defined(__has_include) && __has_include(<xpc/xpc.h>)
 
 typedef long long_t;  // NOLINT
 
@@ -233,6 +236,8 @@ TSAN_INTERCEPTOR(void, os_lock_unlock, void *lock) {
   REAL(os_lock_unlock)(lock);
 }
 
+#if defined(__has_include) && __has_include(<xpc/xpc.h>)
+
 TSAN_INTERCEPTOR(void, xpc_connection_set_event_handler,
                  xpc_connection_t connection, xpc_handler_t handler) {
   SCOPED_TSAN_INTERCEPTOR(xpc_connection_set_event_handler, connection,
@@ -279,6 +284,14 @@ TSAN_INTERCEPTOR(void, xpc_connection_send_message_with_reply,
   (connection, message, replyq, new_handler);
 }
 
+TSAN_INTERCEPTOR(void, xpc_connection_cancel, xpc_connection_t connection) {
+  SCOPED_TSAN_INTERCEPTOR(xpc_connection_cancel, connection);
+  Release(thr, pc, (uptr)connection);
+  REAL(xpc_connection_cancel)(connection);
+}
+
+#endif  // #if defined(__has_include) && __has_include(<xpc/xpc.h>)
+
 // On macOS, libc++ is always linked dynamically, so intercepting works the
 // usual way.
 #define STDCXX_INTERCEPTOR TSAN_INTERCEPTOR
@@ -295,18 +308,20 @@ struct fake_shared_weak_count {
 };
 }  // namespace
 
-// This adds a libc++ interceptor for:
+// The following code adds libc++ interceptors for:
 //     void __shared_weak_count::__release_shared() _NOEXCEPT;
+//     bool __shared_count::__release_shared() _NOEXCEPT;
 // Shared and weak pointers in C++ maintain reference counts via atomics in
 // libc++.dylib, which are TSan-invisible, and this leads to false positives in
-// destructor code.  This interceptor re-implements the whole function so that
+// destructor code. These interceptors re-implements the whole functions so that
 // the mo_acq_rel semantics of the atomic decrement are visible.
 //
-// Unfortunately, this interceptor cannot simply Acquire/Release some sync
+// Unfortunately, the interceptors cannot simply Acquire/Release some sync
 // object and call the original function, because it would have a race between
 // the sync and the destruction of the object.  Calling both under a lock will
 // not work because the destructor can invoke this interceptor again (and even
 // in a different thread, so recursive locks don't help).
+
 STDCXX_INTERCEPTOR(void, _ZNSt3__119__shared_weak_count16__release_sharedEv,
                    fake_shared_weak_count *o) {
   if (!flags()->shared_ptr_interceptor)
@@ -325,6 +340,20 @@ STDCXX_INTERCEPTOR(void, _ZNSt3__119__shared_weak_count16__release_sharedEv,
   }
 }
 
+STDCXX_INTERCEPTOR(bool, _ZNSt3__114__shared_count16__release_sharedEv,
+                   fake_shared_weak_count *o) {
+  if (!flags()->shared_ptr_interceptor)
+    return REAL(_ZNSt3__114__shared_count16__release_sharedEv)(o);
+
+  SCOPED_TSAN_INTERCEPTOR(_ZNSt3__114__shared_count16__release_sharedEv, o);
+  if (__tsan_atomic64_fetch_add(&o->shared_owners, -1, mo_release) == 0) {
+    Acquire(thr, pc, (uptr)&o->shared_owners);
+    o->on_zero_shared();
+    return true;
+  }
+  return false;
+}
+
 namespace {
 struct call_once_callback_args {
   void (*orig_func)(void *arg);
diff --git a/libsanitizer/tsan/tsan_interface.cc b/libsanitizer/tsan/tsan_interface.cc
index ee9a627076b..d98ff15f562 100644
--- a/libsanitizer/tsan/tsan_interface.cc
+++ b/libsanitizer/tsan/tsan_interface.cc
@@ -26,6 +26,10 @@ void __tsan_init() {
   Initialize(cur_thread());
 }
 
+void __tsan_flush_memory() {
+  FlushShadowMemory();
+}
+
 void __tsan_read16(void *addr) {
   MemoryRead(cur_thread(), CALLERPC, (uptr)addr, kSizeLog8);
   MemoryRead(cur_thread(), CALLERPC, (uptr)addr + 8, kSizeLog8);
diff --git a/libsanitizer/tsan/tsan_interface.h b/libsanitizer/tsan/tsan_interface.h
index 066dde6f543..7dc67655276 100644
--- a/libsanitizer/tsan/tsan_interface.h
+++ b/libsanitizer/tsan/tsan_interface.h
@@ -16,6 +16,7 @@
 
 #include <sanitizer_common/sanitizer_internal_defs.h>
 using __sanitizer::uptr;
+using __sanitizer::tid_t;
 
 // This header should NOT include any other headers.
 // All functions in this header are extern "C" and start with __tsan_.
@@ -30,6 +31,8 @@ extern "C" {
 // before any instrumented code is executed and before any call to malloc.
 SANITIZER_INTERFACE_ATTRIBUTE void __tsan_init();
 
+SANITIZER_INTERFACE_ATTRIBUTE void __tsan_flush_memory();
+
 SANITIZER_INTERFACE_ATTRIBUTE void __tsan_read1(void *addr);
 SANITIZER_INTERFACE_ATTRIBUTE void __tsan_read2(void *addr);
 SANITIZER_INTERFACE_ATTRIBUTE void __tsan_read4(void *addr);
@@ -71,6 +74,20 @@ void __tsan_vptr_update(void **vptr_p, void *new_val);
 SANITIZER_INTERFACE_ATTRIBUTE void __tsan_func_entry(void *call_pc);
 SANITIZER_INTERFACE_ATTRIBUTE void __tsan_func_exit();
 
+SANITIZER_INTERFACE_ATTRIBUTE void __tsan_ignore_thread_begin();
+SANITIZER_INTERFACE_ATTRIBUTE void __tsan_ignore_thread_end();
+
+SANITIZER_INTERFACE_ATTRIBUTE
+void *__tsan_external_register_tag(const char *object_type);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __tsan_external_register_header(void *tag, const char *header);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __tsan_external_assign_tag(void *addr, void *tag);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __tsan_external_read(void *addr, void *caller_pc, void *tag);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __tsan_external_write(void *addr, void *caller_pc, void *tag);
+
 SANITIZER_INTERFACE_ATTRIBUTE
 void __tsan_read_range(void *addr, unsigned long size);  // NOLINT
 SANITIZER_INTERFACE_ATTRIBUTE
@@ -116,6 +133,10 @@ int __tsan_get_report_loc(void *report, uptr idx, const char **type,
                           int *fd, int *suppressable, void **trace,
                           uptr trace_size);
 
+SANITIZER_INTERFACE_ATTRIBUTE
+int __tsan_get_report_loc_object_type(void *report, uptr idx,
+                                      const char **object_type);
+
 // Returns information about mutexes included in the report.
 SANITIZER_INTERFACE_ATTRIBUTE
 int __tsan_get_report_mutex(void *report, uptr idx, uptr *mutex_id, void **addr,
@@ -123,7 +144,7 @@ int __tsan_get_report_mutex(void *report, uptr idx, uptr *mutex_id, void **addr,
 
 // Returns information about threads included in the report.
 SANITIZER_INTERFACE_ATTRIBUTE
-int __tsan_get_report_thread(void *report, uptr idx, int *tid, uptr *os_id,
+int __tsan_get_report_thread(void *report, uptr idx, int *tid, tid_t *os_id,
                              int *running, const char **name, int *parent_tid,
                              void **trace, uptr trace_size);
 
@@ -131,6 +152,17 @@ int __tsan_get_report_thread(void *report, uptr idx, int *tid, uptr *os_id,
 SANITIZER_INTERFACE_ATTRIBUTE
 int __tsan_get_report_unique_tid(void *report, uptr idx, int *tid);
 
+// Returns the type of the pointer (heap, stack, global, ...) and if possible
+// also the starting address (e.g. of a heap allocation) and size.
+SANITIZER_INTERFACE_ATTRIBUTE
+const char *__tsan_locate_address(uptr addr, char *name, uptr name_size,
+                                  uptr *region_address, uptr *region_size);
+
+// Returns the allocation stack for a heap pointer.
+SANITIZER_INTERFACE_ATTRIBUTE
+int __tsan_get_alloc_stack(uptr addr, uptr *trace, uptr size, int *thread_id,
+                           tid_t *os_id);
+
 #endif  // SANITIZER_GO
 
 #ifdef __cplusplus
diff --git a/libsanitizer/tsan/tsan_interface_ann.cc b/libsanitizer/tsan/tsan_interface_ann.cc
index 19ff4050abc..083138fc046 100644
--- a/libsanitizer/tsan/tsan_interface_ann.cc
+++ b/libsanitizer/tsan/tsan_interface_ann.cc
@@ -29,11 +29,10 @@ namespace __tsan {
 
 class ScopedAnnotation {
  public:
-  ScopedAnnotation(ThreadState *thr, const char *aname, const char *f, int l,
-                   uptr pc)
+  ScopedAnnotation(ThreadState *thr, const char *aname, uptr pc)
       : thr_(thr) {
     FuncEntry(thr_, pc);
-    DPrintf("#%d: annotation %s() %s:%d\n", thr_->tid, aname, f, l);
+    DPrintf("#%d: annotation %s()\n", thr_->tid, aname);
   }
 
   ~ScopedAnnotation() {
@@ -44,18 +43,20 @@ class ScopedAnnotation {
   ThreadState *const thr_;
 };
 
-#define SCOPED_ANNOTATION(typ) \
+#define SCOPED_ANNOTATION_RET(typ, ret) \
     if (!flags()->enable_annotations) \
-      return; \
+      return ret; \
     ThreadState *thr = cur_thread(); \
     const uptr caller_pc = (uptr)__builtin_return_address(0); \
     StatInc(thr, StatAnnotation); \
     StatInc(thr, Stat##typ); \
-    ScopedAnnotation sa(thr, __func__, f, l, caller_pc); \
+    ScopedAnnotation sa(thr, __func__, caller_pc); \
     const uptr pc = StackTrace::GetCurrentPc(); \
     (void)pc; \
 /**/
 
+#define SCOPED_ANNOTATION(typ) SCOPED_ANNOTATION_RET(typ, )
+
 static const int kMaxDescLen = 128;
 
 struct ExpectRace {
@@ -250,12 +251,12 @@ void INTERFACE_ATTRIBUTE AnnotateCondVarWait(char *f, int l, uptr cv,
 
 void INTERFACE_ATTRIBUTE AnnotateRWLockCreate(char *f, int l, uptr m) {
   SCOPED_ANNOTATION(AnnotateRWLockCreate);
-  MutexCreate(thr, pc, m, true, true, false);
+  MutexCreate(thr, pc, m, MutexFlagWriteReentrant);
 }
 
 void INTERFACE_ATTRIBUTE AnnotateRWLockCreateStatic(char *f, int l, uptr m) {
   SCOPED_ANNOTATION(AnnotateRWLockCreateStatic);
-  MutexCreate(thr, pc, m, true, true, true);
+  MutexCreate(thr, pc, m, MutexFlagWriteReentrant | MutexFlagLinkerInit);
 }
 
 void INTERFACE_ATTRIBUTE AnnotateRWLockDestroy(char *f, int l, uptr m) {
@@ -267,9 +268,9 @@ void INTERFACE_ATTRIBUTE AnnotateRWLockAcquired(char *f, int l, uptr m,
                                                 uptr is_w) {
   SCOPED_ANNOTATION(AnnotateRWLockAcquired);
   if (is_w)
-    MutexLock(thr, pc, m);
+    MutexPostLock(thr, pc, m, MutexFlagDoPreLockOnPostLock);
   else
-    MutexReadLock(thr, pc, m);
+    MutexPostReadLock(thr, pc, m, MutexFlagDoPreLockOnPostLock);
 }
 
 void INTERFACE_ATTRIBUTE AnnotateRWLockReleased(char *f, int l, uptr m,
@@ -456,4 +457,95 @@ void INTERFACE_ATTRIBUTE
 AnnotateMemoryIsInitialized(char *f, int l, uptr mem, uptr sz) {}
 void INTERFACE_ATTRIBUTE
 AnnotateMemoryIsUninitialized(char *f, int l, uptr mem, uptr sz) {}
+
+// Note: the parameter is called flagz, because flags is already taken
+// by the global function that returns flags.
+INTERFACE_ATTRIBUTE
+void __tsan_mutex_create(void *m, unsigned flagz) {
+  SCOPED_ANNOTATION(__tsan_mutex_create);
+  MutexCreate(thr, pc, (uptr)m, flagz & MutexCreationFlagMask);
+}
+
+INTERFACE_ATTRIBUTE
+void __tsan_mutex_destroy(void *m, unsigned flagz) {
+  SCOPED_ANNOTATION(__tsan_mutex_destroy);
+  MutexDestroy(thr, pc, (uptr)m, flagz);
+}
+
+INTERFACE_ATTRIBUTE
+void __tsan_mutex_pre_lock(void *m, unsigned flagz) {
+  SCOPED_ANNOTATION(__tsan_mutex_pre_lock);
+  if (!(flagz & MutexFlagTryLock)) {
+    if (flagz & MutexFlagReadLock)
+      MutexPreReadLock(thr, pc, (uptr)m);
+    else
+      MutexPreLock(thr, pc, (uptr)m);
+  }
+  ThreadIgnoreBegin(thr, pc, /*save_stack=*/false);
+  ThreadIgnoreSyncBegin(thr, pc, /*save_stack=*/false);
+}
+
+INTERFACE_ATTRIBUTE
+void __tsan_mutex_post_lock(void *m, unsigned flagz, int rec) {
+  SCOPED_ANNOTATION(__tsan_mutex_post_lock);
+  ThreadIgnoreSyncEnd(thr, pc);
+  ThreadIgnoreEnd(thr, pc);
+  if (!(flagz & MutexFlagTryLockFailed)) {
+    if (flagz & MutexFlagReadLock)
+      MutexPostReadLock(thr, pc, (uptr)m, flagz);
+    else
+      MutexPostLock(thr, pc, (uptr)m, flagz, rec);
+  }
+}
+
+INTERFACE_ATTRIBUTE
+int __tsan_mutex_pre_unlock(void *m, unsigned flagz) {
+  SCOPED_ANNOTATION_RET(__tsan_mutex_pre_unlock, 0);
+  int ret = 0;
+  if (flagz & MutexFlagReadLock) {
+    CHECK(!(flagz & MutexFlagRecursiveUnlock));
+    MutexReadUnlock(thr, pc, (uptr)m);
+  } else {
+    ret = MutexUnlock(thr, pc, (uptr)m, flagz);
+  }
+  ThreadIgnoreBegin(thr, pc, /*save_stack=*/false);
+  ThreadIgnoreSyncBegin(thr, pc, /*save_stack=*/false);
+  return ret;
+}
+
+INTERFACE_ATTRIBUTE
+void __tsan_mutex_post_unlock(void *m, unsigned flagz) {
+  SCOPED_ANNOTATION(__tsan_mutex_post_unlock);
+  ThreadIgnoreSyncEnd(thr, pc);
+  ThreadIgnoreEnd(thr, pc);
+}
+
+INTERFACE_ATTRIBUTE
+void __tsan_mutex_pre_signal(void *addr, unsigned flagz) {
+  SCOPED_ANNOTATION(__tsan_mutex_pre_signal);
+  ThreadIgnoreBegin(thr, pc, /*save_stack=*/false);
+  ThreadIgnoreSyncBegin(thr, pc, /*save_stack=*/false);
+}
+
+INTERFACE_ATTRIBUTE
+void __tsan_mutex_post_signal(void *addr, unsigned flagz) {
+  SCOPED_ANNOTATION(__tsan_mutex_post_signal);
+  ThreadIgnoreSyncEnd(thr, pc);
+  ThreadIgnoreEnd(thr, pc);
+}
+
+INTERFACE_ATTRIBUTE
+void __tsan_mutex_pre_divert(void *addr, unsigned flagz) {
+  SCOPED_ANNOTATION(__tsan_mutex_pre_divert);
+  // Exit from ignore region started in __tsan_mutex_pre_lock/unlock/signal.
+  ThreadIgnoreSyncEnd(thr, pc);
+  ThreadIgnoreEnd(thr, pc);
+}
+
+INTERFACE_ATTRIBUTE
+void __tsan_mutex_post_divert(void *addr, unsigned flagz) {
+  SCOPED_ANNOTATION(__tsan_mutex_post_divert);
+  ThreadIgnoreBegin(thr, pc, /*save_stack=*/false);
+  ThreadIgnoreSyncBegin(thr, pc, /*save_stack=*/false);
+}
 }  // extern "C"
diff --git a/libsanitizer/tsan/tsan_interface_atomic.cc b/libsanitizer/tsan/tsan_interface_atomic.cc
index deb4206a624..c175d614764 100644
--- a/libsanitizer/tsan/tsan_interface_atomic.cc
+++ b/libsanitizer/tsan/tsan_interface_atomic.cc
@@ -218,8 +218,7 @@ static a128 NoTsanAtomicLoad(const volatile a128 *a, morder mo) {
 #endif
 
 template<typename T>
-static T AtomicLoad(ThreadState *thr, uptr pc, const volatile T *a,
-    morder mo) {
+static T AtomicLoad(ThreadState *thr, uptr pc, const volatile T *a, morder mo) {
   CHECK(IsLoadOrder(mo));
   // This fast-path is critical for performance.
   // Assume the access is atomic.
@@ -227,10 +226,17 @@ static T AtomicLoad(ThreadState *thr, uptr pc, const volatile T *a,
     MemoryReadAtomic(thr, pc, (uptr)a, SizeLog<T>());
     return NoTsanAtomicLoad(a, mo);
   }
-  SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, (uptr)a, false);
-  AcquireImpl(thr, pc, &s->clock);
+  // Don't create sync object if it does not exist yet. For example, an atomic
+  // pointer is initialized to nullptr and then periodically acquire-loaded.
   T v = NoTsanAtomicLoad(a, mo);
-  s->mtx.ReadUnlock();
+  SyncVar *s = ctx->metamap.GetIfExistsAndLock((uptr)a, false);
+  if (s) {
+    AcquireImpl(thr, pc, &s->clock);
+    // Re-read under sync mutex because we need a consistent snapshot
+    // of the value and the clock we acquire.
+    v = NoTsanAtomicLoad(a, mo);
+    s->mtx.ReadUnlock();
+  }
   MemoryReadAtomic(thr, pc, (uptr)a, SizeLog<T>());
   return v;
 }
@@ -265,7 +271,7 @@ static void AtomicStore(ThreadState *thr, uptr pc, volatile T *a, T v,
   thr->fast_state.IncrementEpoch();
   // Can't increment epoch w/o writing to the trace as well.
   TraceAddEvent(thr, thr->fast_state, EventTypeMop, 0);
-  ReleaseImpl(thr, pc, &s->clock);
+  ReleaseStoreImpl(thr, pc, &s->clock);
   NoTsanAtomicStore(a, v, mo);
   s->mtx.Unlock();
 }
@@ -448,7 +454,7 @@ static void AtomicFence(ThreadState *thr, uptr pc, morder mo) {
 
 // C/C++
 
-static morder covert_morder(morder mo) {
+static morder convert_morder(morder mo) {
   if (flags()->force_seq_cst_atomics)
     return (morder)mo_seq_cst;
 
@@ -466,12 +472,14 @@ static morder covert_morder(morder mo) {
 }
 
 #define SCOPED_ATOMIC(func, ...) \
-    const uptr callpc = (uptr)__builtin_return_address(0); \
-    uptr pc = StackTrace::GetCurrentPc(); \
-    mo = covert_morder(mo); \
     ThreadState *const thr = cur_thread(); \
-    if (thr->ignore_interceptors) \
+    if (thr->ignore_sync || thr->ignore_interceptors) { \
+      ProcessPendingSignals(thr); \
       return NoTsanAtomic##func(__VA_ARGS__); \
+    } \
+    const uptr callpc = (uptr)__builtin_return_address(0); \
+    uptr pc = StackTrace::GetCurrentPc(); \
+    mo = convert_morder(mo); \
     AtomicStatInc(thr, sizeof(*a), mo, StatAtomic##func); \
     ScopedAtomic sa(thr, callpc, a, mo, __func__); \
     return Atomic##func(thr, pc, __VA_ARGS__); \
diff --git a/libsanitizer/tsan/tsan_interface_inl.h b/libsanitizer/tsan/tsan_interface_inl.h
index 67a91aa341a..bf70cdce34b 100644
--- a/libsanitizer/tsan/tsan_interface_inl.h
+++ b/libsanitizer/tsan/tsan_interface_inl.h
@@ -106,6 +106,14 @@ void __tsan_func_exit() {
   FuncExit(cur_thread());
 }
 
+void __tsan_ignore_thread_begin() {
+  ThreadIgnoreBegin(cur_thread(), CALLERPC);
+}
+
+void __tsan_ignore_thread_end() {
+  ThreadIgnoreEnd(cur_thread(), CALLERPC);
+}
+
 void __tsan_read_range(void *addr, uptr size) {
   MemoryAccessRange(cur_thread(), CALLERPC, (uptr)addr, size, false);
 }
diff --git a/libsanitizer/tsan/tsan_interface_java.cc b/libsanitizer/tsan/tsan_interface_java.cc
index d1638f2aa9d..d3f35a9bc82 100644
--- a/libsanitizer/tsan/tsan_interface_java.cc
+++ b/libsanitizer/tsan/tsan_interface_java.cc
@@ -148,6 +148,23 @@ void __tsan_java_move(jptr src, jptr dst, jptr size) {
   }
 }
 
+jptr __tsan_java_find(jptr *from_ptr, jptr to) {
+  SCOPED_JAVA_FUNC(__tsan_java_find);
+  DPrintf("#%d: java_find(&%p, %p)\n", *from_ptr, to);
+  CHECK_EQ((*from_ptr) % kHeapAlignment, 0);
+  CHECK_EQ(to % kHeapAlignment, 0);
+  CHECK_GE(*from_ptr, jctx->heap_begin);
+  CHECK_LE(to, jctx->heap_begin + jctx->heap_size);
+  for (uptr from = *from_ptr; from < to; from += kHeapAlignment) {
+    MBlock *b = ctx->metamap.GetBlock(from);
+    if (b) {
+      *from_ptr = from;
+      return b->siz;
+    }
+  }
+  return 0;
+}
+
 void __tsan_java_finalize() {
   SCOPED_JAVA_FUNC(__tsan_java_finalize);
   DPrintf("#%d: java_mutex_finalize()\n", thr->tid);
@@ -161,8 +178,8 @@ void __tsan_java_mutex_lock(jptr addr) {
   CHECK_GE(addr, jctx->heap_begin);
   CHECK_LT(addr, jctx->heap_begin + jctx->heap_size);
 
-  MutexCreate(thr, pc, addr, true, true, true);
-  MutexLock(thr, pc, addr);
+  MutexPostLock(thr, pc, addr, MutexFlagLinkerInit | MutexFlagWriteReentrant |
+      MutexFlagDoPreLockOnPostLock);
 }
 
 void __tsan_java_mutex_unlock(jptr addr) {
@@ -182,8 +199,8 @@ void __tsan_java_mutex_read_lock(jptr addr) {
   CHECK_GE(addr, jctx->heap_begin);
   CHECK_LT(addr, jctx->heap_begin + jctx->heap_size);
 
-  MutexCreate(thr, pc, addr, true, true, true);
-  MutexReadLock(thr, pc, addr);
+  MutexPostReadLock(thr, pc, addr, MutexFlagLinkerInit |
+      MutexFlagWriteReentrant | MutexFlagDoPreLockOnPostLock);
 }
 
 void __tsan_java_mutex_read_unlock(jptr addr) {
@@ -204,8 +221,8 @@ void __tsan_java_mutex_lock_rec(jptr addr, int rec) {
   CHECK_LT(addr, jctx->heap_begin + jctx->heap_size);
   CHECK_GT(rec, 0);
 
-  MutexCreate(thr, pc, addr, true, true, true);
-  MutexLock(thr, pc, addr, rec);
+  MutexPostLock(thr, pc, addr, MutexFlagLinkerInit | MutexFlagWriteReentrant |
+      MutexFlagDoPreLockOnPostLock | MutexFlagRecursiveLock, rec);
 }
 
 int __tsan_java_mutex_unlock_rec(jptr addr) {
@@ -215,7 +232,7 @@ int __tsan_java_mutex_unlock_rec(jptr addr) {
   CHECK_GE(addr, jctx->heap_begin);
   CHECK_LT(addr, jctx->heap_begin + jctx->heap_size);
 
-  return MutexUnlock(thr, pc, addr, true);
+  return MutexUnlock(thr, pc, addr, MutexFlagRecursiveUnlock);
 }
 
 void __tsan_java_acquire(jptr addr) {
diff --git a/libsanitizer/tsan/tsan_interface_java.h b/libsanitizer/tsan/tsan_interface_java.h
index 04e52031dd3..2dd49f05c68 100644
--- a/libsanitizer/tsan/tsan_interface_java.h
+++ b/libsanitizer/tsan/tsan_interface_java.h
@@ -55,6 +55,10 @@ void __tsan_java_move(jptr src, jptr dst, jptr size) INTERFACE_ATTRIBUTE;
 // It ensures necessary synchronization between
 // java object creation and finalization.
 void __tsan_java_finalize() INTERFACE_ATTRIBUTE;
+// Finds the first allocated memory block in the [*from_ptr, to) range, saves
+// its address in *from_ptr and returns its size. Returns 0 if there are no
+// allocated memory blocks in the range.
+jptr __tsan_java_find(jptr *from_ptr, jptr to) INTERFACE_ATTRIBUTE;
 
 // Mutex lock.
 // Addr is any unique address associated with the mutex.
diff --git a/libsanitizer/tsan/tsan_libdispatch_mac.cc b/libsanitizer/tsan/tsan_libdispatch_mac.cc
index 10c70a831c6..5200a791fc2 100644
--- a/libsanitizer/tsan/tsan_libdispatch_mac.cc
+++ b/libsanitizer/tsan/tsan_libdispatch_mac.cc
@@ -66,13 +66,17 @@ static bool IsQueueSerial(dispatch_queue_t q) {
   return width == 1;
 }
 
-static dispatch_queue_t GetTargetQueueFromSource(dispatch_source_t source) {
+static dispatch_queue_t GetTargetQueueFromQueue(dispatch_queue_t q) {
   CHECK_EQ(dispatch_queue_offsets.dqo_target_queue_size, 8);
-  dispatch_queue_t target_queue =
-      *(dispatch_queue_t *)(((uptr)source) +
-                            dispatch_queue_offsets.dqo_target_queue);
-  CHECK_NE(target_queue, 0);
-  return target_queue;
+  dispatch_queue_t tq = *(
+      dispatch_queue_t *)(((uptr)q) + dispatch_queue_offsets.dqo_target_queue);
+  return tq;
+}
+
+static dispatch_queue_t GetTargetQueueFromSource(dispatch_source_t source) {
+  dispatch_queue_t tq = GetTargetQueueFromQueue((dispatch_queue_t)source);
+  CHECK_NE(tq, 0);
+  return tq;
 }
 
 static tsan_block_context_t *AllocContext(ThreadState *thr, uptr pc,
@@ -80,37 +84,66 @@ static tsan_block_context_t *AllocContext(ThreadState *thr, uptr pc,
                                           void *orig_context,
                                           dispatch_function_t orig_work) {
   tsan_block_context_t *new_context =
-      (tsan_block_context_t *)user_alloc(thr, pc, sizeof(tsan_block_context_t));
+      (tsan_block_context_t *)user_alloc_internal(thr, pc,
+                                                  sizeof(tsan_block_context_t));
   new_context->queue = queue;
   new_context->orig_context = orig_context;
   new_context->orig_work = orig_work;
   new_context->free_context_in_callback = true;
   new_context->submitted_synchronously = false;
   new_context->is_barrier_block = false;
+  new_context->non_queue_sync_object = 0;
   return new_context;
 }
 
+#define GET_QUEUE_SYNC_VARS(context, q)                                  \
+  bool is_queue_serial = q && IsQueueSerial(q);                          \
+  uptr sync_ptr = (uptr)q ?: context->non_queue_sync_object;             \
+  uptr serial_sync = (uptr)sync_ptr;                                     \
+  uptr concurrent_sync = sync_ptr ? ((uptr)sync_ptr) + sizeof(uptr) : 0; \
+  bool serial_task = context->is_barrier_block || is_queue_serial
+
+static void dispatch_sync_pre_execute(ThreadState *thr, uptr pc,
+                                      tsan_block_context_t *context) {
+  uptr submit_sync = (uptr)context;
+  Acquire(thr, pc, submit_sync);
+
+  dispatch_queue_t q = context->queue;
+  do {
+    GET_QUEUE_SYNC_VARS(context, q);
+    if (serial_sync) Acquire(thr, pc, serial_sync);
+    if (serial_task && concurrent_sync) Acquire(thr, pc, concurrent_sync);
+
+    if (q) q = GetTargetQueueFromQueue(q);
+  } while (q);
+}
+
+static void dispatch_sync_post_execute(ThreadState *thr, uptr pc,
+                                       tsan_block_context_t *context) {
+  uptr submit_sync = (uptr)context;
+  if (context->submitted_synchronously) Release(thr, pc, submit_sync);
+
+  dispatch_queue_t q = context->queue;
+  do {
+    GET_QUEUE_SYNC_VARS(context, q);
+    if (serial_task && serial_sync) Release(thr, pc, serial_sync);
+    if (!serial_task && concurrent_sync) Release(thr, pc, concurrent_sync);
+
+    if (q) q = GetTargetQueueFromQueue(q);
+  } while (q);
+}
+
 static void dispatch_callback_wrap(void *param) {
   SCOPED_INTERCEPTOR_RAW(dispatch_callback_wrap);
   tsan_block_context_t *context = (tsan_block_context_t *)param;
-  bool is_queue_serial = context->queue && IsQueueSerial(context->queue);
-  uptr sync_ptr = (uptr)context->queue ?: context->non_queue_sync_object;
-
-  uptr serial_sync = (uptr)sync_ptr;
-  uptr concurrent_sync = ((uptr)sync_ptr) + sizeof(uptr);
-  uptr submit_sync = (uptr)context;
-  bool serial_task = context->is_barrier_block || is_queue_serial;
 
-  Acquire(thr, pc, submit_sync);
-  Acquire(thr, pc, serial_sync);
-  if (serial_task) Acquire(thr, pc, concurrent_sync);
+  dispatch_sync_pre_execute(thr, pc, context);
 
   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();
   context->orig_work(context->orig_context);
   SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_END();
 
-  Release(thr, pc, serial_task ? serial_sync : concurrent_sync);
-  if (context->submitted_synchronously) Release(thr, pc, submit_sync);
+  dispatch_sync_post_execute(thr, pc, context);
 
   if (context->free_context_in_callback) user_free(thr, pc, context);
 }
@@ -142,7 +175,8 @@ static void invoke_and_release_block(void *param) {
   }
 
 #define DISPATCH_INTERCEPT_SYNC_B(name, barrier)                             \
-  TSAN_INTERCEPTOR(void, name, dispatch_queue_t q, dispatch_block_t block) { \
+  TSAN_INTERCEPTOR(void, name, dispatch_queue_t q,                           \
+                   DISPATCH_NOESCAPE dispatch_block_t block) {               \
     SCOPED_TSAN_INTERCEPTOR(name, q, block);                                 \
     SCOPED_TSAN_INTERCEPTOR_USER_CALLBACK_START();                           \
     dispatch_block_t heap_block = Block_copy(block);                         \
@@ -232,7 +266,7 @@ TSAN_INTERCEPTOR(void, dispatch_after_f, dispatch_time_t when,
 // need to undefine the macro.
 #undef dispatch_once
 TSAN_INTERCEPTOR(void, dispatch_once, dispatch_once_t *predicate,
-                 dispatch_block_t block) {
+                 DISPATCH_NOESCAPE dispatch_block_t block) {
   SCOPED_INTERCEPTOR_RAW(dispatch_once, predicate, block);
   atomic_uint32_t *a = reinterpret_cast<atomic_uint32_t *>(predicate);
   u32 v = atomic_load(a, memory_order_acquire);
@@ -442,7 +476,8 @@ TSAN_INTERCEPTOR(void, dispatch_source_set_registration_handler_f,
 }
 
 TSAN_INTERCEPTOR(void, dispatch_apply, size_t iterations,
-                 dispatch_queue_t queue, void (^block)(size_t)) {
+                 dispatch_queue_t queue,
+                 DISPATCH_NOESCAPE void (^block)(size_t)) {
   SCOPED_TSAN_INTERCEPTOR(dispatch_apply, iterations, queue, block);
 
   void *parent_to_child_sync = nullptr;
@@ -674,6 +709,15 @@ TSAN_INTERCEPTOR(void, dispatch_io_close, dispatch_io_t channel,
   return REAL(dispatch_io_close)(channel, flags);
 }
 
+// Resuming a suspended queue needs to synchronize with all subsequent
+// executions of blocks in that queue.
+TSAN_INTERCEPTOR(void, dispatch_resume, dispatch_object_t o) {
+  SCOPED_TSAN_INTERCEPTOR(dispatch_resume, o);
+  Release(thr, pc, (uptr)o);  // Synchronizes with the Acquire() on serial_sync
+                              // in dispatch_sync_pre_execute
+  return REAL(dispatch_resume)(o);
+}
+
 }  // namespace __tsan
 
 #endif  // SANITIZER_MAC
diff --git a/libsanitizer/tsan/tsan_malloc_mac.cc b/libsanitizer/tsan/tsan_malloc_mac.cc
index cc1031a584f..b418a211b58 100644
--- a/libsanitizer/tsan/tsan_malloc_mac.cc
+++ b/libsanitizer/tsan/tsan_malloc_mac.cc
@@ -24,7 +24,7 @@ using namespace __tsan;
 #define COMMON_MALLOC_FORCE_UNLOCK()
 #define COMMON_MALLOC_MEMALIGN(alignment, size) \
   void *p =                                     \
-      user_alloc(cur_thread(), StackTrace::GetCurrentPc(), size, alignment)
+      user_memalign(cur_thread(), StackTrace::GetCurrentPc(), alignment, size)
 #define COMMON_MALLOC_MALLOC(size)                             \
   if (cur_thread()->in_symbolizer) return InternalAlloc(size); \
   SCOPED_INTERCEPTOR_RAW(malloc, size);                        \
@@ -41,7 +41,7 @@ using namespace __tsan;
   if (cur_thread()->in_symbolizer)                            \
     return InternalAlloc(size, nullptr, GetPageSizeCached()); \
   SCOPED_INTERCEPTOR_RAW(valloc, size);                       \
-  void *p = user_alloc(thr, pc, size, GetPageSizeCached())
+  void *p = user_valloc(thr, pc, size)
 #define COMMON_MALLOC_FREE(ptr)                              \
   if (cur_thread()->in_symbolizer) return InternalFree(ptr); \
   SCOPED_INTERCEPTOR_RAW(free, ptr);                         \
diff --git a/libsanitizer/tsan/tsan_mman.cc b/libsanitizer/tsan/tsan_mman.cc
index 152c2de28d8..18505aca70e 100644
--- a/libsanitizer/tsan/tsan_mman.cc
+++ b/libsanitizer/tsan/tsan_mman.cc
@@ -8,8 +8,10 @@
 // This file is a part of ThreadSanitizer (TSan), a race detector.
 //
 //===----------------------------------------------------------------------===//
+#include "sanitizer_common/sanitizer_allocator_checks.h"
 #include "sanitizer_common/sanitizer_allocator_interface.h"
 #include "sanitizer_common/sanitizer_common.h"
+#include "sanitizer_common/sanitizer_errno.h"
 #include "sanitizer_common/sanitizer_placement_new.h"
 #include "tsan_mman.h"
 #include "tsan_rtl.h"
@@ -52,7 +54,8 @@ struct MapUnmapCallback {
     diff = p + size - RoundDown(p + size, kPageSize);
     if (diff != 0)
       size -= diff;
-    ReleaseMemoryToOS((uptr)MemToMeta(p), size / kMetaRatio);
+    uptr p_meta = (uptr)MemToMeta(p);
+    ReleaseMemoryPagesToOS(p_meta, p_meta + size / kMetaRatio);
   }
 };
 
@@ -109,7 +112,8 @@ ScopedGlobalProcessor::~ScopedGlobalProcessor() {
 }
 
 void InitializeAllocator() {
-  allocator()->Init(common_flags()->allocator_may_return_null);
+  SetAllocatorMayReturnNull(common_flags()->allocator_may_return_null);
+  allocator()->Init(common_flags()->allocator_release_to_os_interval_ms);
 }
 
 void InitializeAllocatorLate() {
@@ -144,11 +148,12 @@ static void SignalUnsafeCall(ThreadState *thr, uptr pc) {
   OutputReport(thr, rep);
 }
 
-void *user_alloc(ThreadState *thr, uptr pc, uptr sz, uptr align, bool signal) {
+void *user_alloc_internal(ThreadState *thr, uptr pc, uptr sz, uptr align,
+                          bool signal) {
   if ((sz >= (1ull << 40)) || (align >= (1ull << 40)))
-    return allocator()->ReturnNullOrDieOnBadRequest();
+    return Allocator::FailureHandler::OnBadRequest();
   void *p = allocator()->Allocate(&thr->proc()->alloc_cache, sz, align);
-  if (p == 0)
+  if (UNLIKELY(p == 0))
     return 0;
   if (ctx && ctx->initialized)
     OnUserAlloc(thr, pc, (uptr)p, sz, true);
@@ -157,15 +162,6 @@ void *user_alloc(ThreadState *thr, uptr pc, uptr sz, uptr align, bool signal) {
   return p;
 }
 
-void *user_calloc(ThreadState *thr, uptr pc, uptr size, uptr n) {
-  if (CallocShouldReturnNullDueToOverflow(size, n))
-    return allocator()->ReturnNullOrDieOnBadRequest();
-  void *p = user_alloc(thr, pc, n * size);
-  if (p)
-    internal_memset(p, 0, n * size);
-  return p;
-}
-
 void user_free(ThreadState *thr, uptr pc, void *p, bool signal) {
   ScopedGlobalProcessor sgp;
   if (ctx && ctx->initialized)
@@ -175,6 +171,19 @@ void user_free(ThreadState *thr, uptr pc, void *p, bool signal) {
     SignalUnsafeCall(thr, pc);
 }
 
+void *user_alloc(ThreadState *thr, uptr pc, uptr sz) {
+  return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, kDefaultAlignment));
+}
+
+void *user_calloc(ThreadState *thr, uptr pc, uptr size, uptr n) {
+  if (UNLIKELY(CheckForCallocOverflow(size, n)))
+    return SetErrnoOnNull(Allocator::FailureHandler::OnBadRequest());
+  void *p = user_alloc_internal(thr, pc, n * size);
+  if (p)
+    internal_memset(p, 0, n * size);
+  return SetErrnoOnNull(p);
+}
+
 void OnUserAlloc(ThreadState *thr, uptr pc, uptr p, uptr sz, bool write) {
   DPrintf("#%d: alloc(%zu) = %p\n", thr->tid, sz, p);
   ctx->metamap.AllocBlock(thr, pc, p, sz);
@@ -195,15 +204,64 @@ void OnUserFree(ThreadState *thr, uptr pc, uptr p, bool write) {
 void *user_realloc(ThreadState *thr, uptr pc, void *p, uptr sz) {
   // FIXME: Handle "shrinking" more efficiently,
   // it seems that some software actually does this.
-  void *p2 = user_alloc(thr, pc, sz);
-  if (p2 == 0)
-    return 0;
-  if (p) {
-    uptr oldsz = user_alloc_usable_size(p);
-    internal_memcpy(p2, p, min(oldsz, sz));
+  if (!p)
+    return SetErrnoOnNull(user_alloc_internal(thr, pc, sz));
+  if (!sz) {
     user_free(thr, pc, p);
+    return nullptr;
+  }
+  void *new_p = user_alloc_internal(thr, pc, sz);
+  if (new_p) {
+    uptr old_sz = user_alloc_usable_size(p);
+    internal_memcpy(new_p, p, min(old_sz, sz));
+    user_free(thr, pc, p);
+  }
+  return SetErrnoOnNull(new_p);
+}
+
+void *user_memalign(ThreadState *thr, uptr pc, uptr align, uptr sz) {
+  if (UNLIKELY(!IsPowerOfTwo(align))) {
+    errno = errno_EINVAL;
+    return Allocator::FailureHandler::OnBadRequest();
+  }
+  return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, align));
+}
+
+int user_posix_memalign(ThreadState *thr, uptr pc, void **memptr, uptr align,
+                        uptr sz) {
+  if (UNLIKELY(!CheckPosixMemalignAlignment(align))) {
+    Allocator::FailureHandler::OnBadRequest();
+    return errno_EINVAL;
+  }
+  void *ptr = user_alloc_internal(thr, pc, sz, align);
+  if (UNLIKELY(!ptr))
+    return errno_ENOMEM;
+  CHECK(IsAligned((uptr)ptr, align));
+  *memptr = ptr;
+  return 0;
+}
+
+void *user_aligned_alloc(ThreadState *thr, uptr pc, uptr align, uptr sz) {
+  if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(align, sz))) {
+    errno = errno_EINVAL;
+    return Allocator::FailureHandler::OnBadRequest();
+  }
+  return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, align));
+}
+
+void *user_valloc(ThreadState *thr, uptr pc, uptr sz) {
+  return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, GetPageSizeCached()));
+}
+
+void *user_pvalloc(ThreadState *thr, uptr pc, uptr sz) {
+  uptr PageSize = GetPageSizeCached();
+  if (UNLIKELY(CheckForPvallocOverflow(sz, PageSize))) {
+    errno = errno_ENOMEM;
+    return Allocator::FailureHandler::OnBadRequest();
   }
-  return p2;
+  // pvalloc(0) should allocate one page.
+  sz = sz ? RoundUpTo(sz, PageSize) : PageSize;
+  return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, PageSize));
 }
 
 uptr user_alloc_usable_size(const void *p) {
@@ -290,6 +348,8 @@ uptr __sanitizer_get_allocated_size(const void *p) {
 
 void __tsan_on_thread_idle() {
   ThreadState *thr = cur_thread();
+  thr->clock.ResetCached(&thr->proc()->clock_cache);
+  thr->last_sleep_clock.ResetCached(&thr->proc()->clock_cache);
   allocator()->SwallowCache(&thr->proc()->alloc_cache);
   internal_allocator()->SwallowCache(&thr->proc()->internal_alloc_cache);
   ctx->metamap.OnProcIdle(thr->proc());
diff --git a/libsanitizer/tsan/tsan_mman.h b/libsanitizer/tsan/tsan_mman.h
index d49c9a9e9f2..3443cb0d8f9 100644
--- a/libsanitizer/tsan/tsan_mman.h
+++ b/libsanitizer/tsan/tsan_mman.h
@@ -25,13 +25,20 @@ void AllocatorProcFinish(Processor *proc);
 void AllocatorPrintStats();
 
 // For user allocations.
-void *user_alloc(ThreadState *thr, uptr pc, uptr sz,
-                 uptr align = kDefaultAlignment, bool signal = true);
-void *user_calloc(ThreadState *thr, uptr pc, uptr sz, uptr n);
+void *user_alloc_internal(ThreadState *thr, uptr pc, uptr sz,
+                          uptr align = kDefaultAlignment, bool signal = true);
 // Does not accept NULL.
 void user_free(ThreadState *thr, uptr pc, void *p, bool signal = true);
+// Interceptor implementations.
+void *user_alloc(ThreadState *thr, uptr pc, uptr sz);
+void *user_calloc(ThreadState *thr, uptr pc, uptr sz, uptr n);
 void *user_realloc(ThreadState *thr, uptr pc, void *p, uptr sz);
-void *user_alloc_aligned(ThreadState *thr, uptr pc, uptr sz, uptr align);
+void *user_memalign(ThreadState *thr, uptr pc, uptr align, uptr sz);
+int user_posix_memalign(ThreadState *thr, uptr pc, void **memptr, uptr align,
+                        uptr sz);
+void *user_aligned_alloc(ThreadState *thr, uptr pc, uptr align, uptr sz);
+void *user_valloc(ThreadState *thr, uptr pc, uptr sz);
+void *user_pvalloc(ThreadState *thr, uptr pc, uptr sz);
 uptr user_alloc_usable_size(const void *p);
 
 // Invoking malloc/free hooks that may be installed by the user.
diff --git a/libsanitizer/tsan/tsan_new_delete.cc b/libsanitizer/tsan/tsan_new_delete.cc
index 606cdd659f4..65ae61b8164 100644
--- a/libsanitizer/tsan/tsan_new_delete.cc
+++ b/libsanitizer/tsan/tsan_new_delete.cc
@@ -10,6 +10,7 @@
 // Interceptors for operators new and delete.
 //===----------------------------------------------------------------------===//
 #include "interception/interception.h"
+#include "sanitizer_common/sanitizer_allocator.h"
 #include "sanitizer_common/sanitizer_internal_defs.h"
 #include "tsan_interceptors.h"
 
@@ -22,13 +23,15 @@ struct nothrow_t {};
 DECLARE_REAL(void *, malloc, uptr size)
 DECLARE_REAL(void, free, void *ptr)
 
-#define OPERATOR_NEW_BODY(mangled_name) \
+// TODO(alekseys): throw std::bad_alloc instead of dying on OOM.
+#define OPERATOR_NEW_BODY(mangled_name, nothrow) \
   if (cur_thread()->in_symbolizer) \
     return InternalAlloc(size); \
   void *p = 0; \
   {  \
     SCOPED_INTERCEPTOR_RAW(mangled_name, size); \
     p = user_alloc(thr, pc, size); \
+    if (!nothrow && UNLIKELY(!p)) DieOnFailure::OnOOM(); \
   }  \
   invoke_malloc_hook(p, size);  \
   return p;
@@ -36,25 +39,25 @@ DECLARE_REAL(void, free, void *ptr)
 SANITIZER_INTERFACE_ATTRIBUTE
 void *operator new(__sanitizer::uptr size);
 void *operator new(__sanitizer::uptr size) {
-  OPERATOR_NEW_BODY(_Znwm);
+  OPERATOR_NEW_BODY(_Znwm, false /*nothrow*/);
 }
 
 SANITIZER_INTERFACE_ATTRIBUTE
 void *operator new[](__sanitizer::uptr size);
 void *operator new[](__sanitizer::uptr size) {
-  OPERATOR_NEW_BODY(_Znam);
+  OPERATOR_NEW_BODY(_Znam, false /*nothrow*/);
 }
 
 SANITIZER_INTERFACE_ATTRIBUTE
 void *operator new(__sanitizer::uptr size, std::nothrow_t const&);
 void *operator new(__sanitizer::uptr size, std::nothrow_t const&) {
-  OPERATOR_NEW_BODY(_ZnwmRKSt9nothrow_t);
+  OPERATOR_NEW_BODY(_ZnwmRKSt9nothrow_t, true /*nothrow*/);
 }
 
 SANITIZER_INTERFACE_ATTRIBUTE
 void *operator new[](__sanitizer::uptr size, std::nothrow_t const&);
 void *operator new[](__sanitizer::uptr size, std::nothrow_t const&) {
-  OPERATOR_NEW_BODY(_ZnamRKSt9nothrow_t);
+  OPERATOR_NEW_BODY(_ZnamRKSt9nothrow_t, true /*nothrow*/);
 }
 
 #define OPERATOR_DELETE_BODY(mangled_name) \
diff --git a/libsanitizer/tsan/tsan_platform.h b/libsanitizer/tsan/tsan_platform.h
index 368edc21ce4..ddf4b13d05a 100644
--- a/libsanitizer/tsan/tsan_platform.h
+++ b/libsanitizer/tsan/tsan_platform.h
@@ -98,6 +98,37 @@ struct Mapping {
 };
 
 #define TSAN_MID_APP_RANGE 1
+#elif defined(__aarch64__) && defined(__APPLE__)
+/*
+C/C++ on Darwin/iOS/ARM64 (36-bit VMA, 64 GB VM)
+0000 0000 00 - 0100 0000 00: -                                    (4 GB)
+0100 0000 00 - 0200 0000 00: main binary, modules, thread stacks  (4 GB)
+0200 0000 00 - 0300 0000 00: heap                                 (4 GB)
+0300 0000 00 - 0400 0000 00: -                                    (4 GB)
+0400 0000 00 - 0c00 0000 00: shadow memory                       (32 GB)
+0c00 0000 00 - 0d00 0000 00: -                                    (4 GB)
+0d00 0000 00 - 0e00 0000 00: metainfo                             (4 GB)
+0e00 0000 00 - 0f00 0000 00: -                                    (4 GB)
+0f00 0000 00 - 1000 0000 00: traces                               (4 GB)
+*/
+struct Mapping {
+  static const uptr kLoAppMemBeg   = 0x0100000000ull;
+  static const uptr kLoAppMemEnd   = 0x0200000000ull;
+  static const uptr kHeapMemBeg    = 0x0200000000ull;
+  static const uptr kHeapMemEnd    = 0x0300000000ull;
+  static const uptr kShadowBeg     = 0x0400000000ull;
+  static const uptr kShadowEnd     = 0x0c00000000ull;
+  static const uptr kMetaShadowBeg = 0x0d00000000ull;
+  static const uptr kMetaShadowEnd = 0x0e00000000ull;
+  static const uptr kTraceMemBeg   = 0x0f00000000ull;
+  static const uptr kTraceMemEnd   = 0x1000000000ull;
+  static const uptr kHiAppMemBeg   = 0x1000000000ull;
+  static const uptr kHiAppMemEnd   = 0x1000000000ull;
+  static const uptr kAppMemMsk     =          0x0ull;
+  static const uptr kAppMemXor     =          0x0ull;
+  static const uptr kVdsoBeg       = 0x7000000000000000ull;
+};
+
 #elif defined(__aarch64__)
 // AArch64 supports multiple VMA which leads to multiple address transformation
 // functions.  To support these multiple VMAS transformations and mappings TSAN
@@ -387,7 +418,7 @@ uptr MappingImpl(void) {
 
 template<int Type>
 uptr MappingArchImpl(void) {
-#ifdef __aarch64__
+#if defined(__aarch64__) && !defined(__APPLE__)
   switch (vmaSize) {
     case 39: return MappingImpl<Mapping39, Type>();
     case 42: return MappingImpl<Mapping42, Type>();
@@ -540,7 +571,7 @@ bool IsAppMemImpl(uptr mem) {
 
 ALWAYS_INLINE
 bool IsAppMem(uptr mem) {
-#ifdef __aarch64__
+#if defined(__aarch64__) && !defined(__APPLE__)
   switch (vmaSize) {
     case 39: return IsAppMemImpl<Mapping39>(mem);
     case 42: return IsAppMemImpl<Mapping42>(mem);
@@ -567,7 +598,7 @@ bool IsShadowMemImpl(uptr mem) {
 
 ALWAYS_INLINE
 bool IsShadowMem(uptr mem) {
-#ifdef __aarch64__
+#if defined(__aarch64__) && !defined(__APPLE__)
   switch (vmaSize) {
     case 39: return IsShadowMemImpl<Mapping39>(mem);
     case 42: return IsShadowMemImpl<Mapping42>(mem);
@@ -594,7 +625,7 @@ bool IsMetaMemImpl(uptr mem) {
 
 ALWAYS_INLINE
 bool IsMetaMem(uptr mem) {
-#ifdef __aarch64__
+#if defined(__aarch64__) && !defined(__APPLE__)
   switch (vmaSize) {
     case 39: return IsMetaMemImpl<Mapping39>(mem);
     case 42: return IsMetaMemImpl<Mapping42>(mem);
@@ -631,7 +662,7 @@ uptr MemToShadowImpl(uptr x) {
 
 ALWAYS_INLINE
 uptr MemToShadow(uptr x) {
-#ifdef __aarch64__
+#if defined(__aarch64__) && !defined(__APPLE__)
   switch (vmaSize) {
     case 39: return MemToShadowImpl<Mapping39>(x);
     case 42: return MemToShadowImpl<Mapping42>(x);
@@ -670,7 +701,7 @@ u32 *MemToMetaImpl(uptr x) {
 
 ALWAYS_INLINE
 u32 *MemToMeta(uptr x) {
-#ifdef __aarch64__
+#if defined(__aarch64__) && !defined(__APPLE__)
   switch (vmaSize) {
     case 39: return MemToMetaImpl<Mapping39>(x);
     case 42: return MemToMetaImpl<Mapping42>(x);
@@ -722,7 +753,7 @@ uptr ShadowToMemImpl(uptr s) {
 
 ALWAYS_INLINE
 uptr ShadowToMem(uptr s) {
-#ifdef __aarch64__
+#if defined(__aarch64__) && !defined(__APPLE__)
   switch (vmaSize) {
     case 39: return ShadowToMemImpl<Mapping39>(s);
     case 42: return ShadowToMemImpl<Mapping42>(s);
@@ -757,7 +788,7 @@ uptr GetThreadTraceImpl(int tid) {
 
 ALWAYS_INLINE
 uptr GetThreadTrace(int tid) {
-#ifdef __aarch64__
+#if defined(__aarch64__) && !defined(__APPLE__)
   switch (vmaSize) {
     case 39: return GetThreadTraceImpl<Mapping39>(tid);
     case 42: return GetThreadTraceImpl<Mapping42>(tid);
@@ -787,7 +818,7 @@ uptr GetThreadTraceHeaderImpl(int tid) {
 
 ALWAYS_INLINE
 uptr GetThreadTraceHeader(int tid) {
-#ifdef __aarch64__
+#if defined(__aarch64__) && !defined(__APPLE__)
   switch (vmaSize) {
     case 39: return GetThreadTraceHeaderImpl<Mapping39>(tid);
     case 42: return GetThreadTraceHeaderImpl<Mapping42>(tid);
@@ -814,6 +845,7 @@ void FlushShadowMemory();
 void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive);
 int ExtractResolvFDs(void *state, int *fds, int nfd);
 int ExtractRecvmsgFDs(void *msg, int *fds, int nfd);
+void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size);
 
 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
     void *abstime), void *c, void *m, void *abstime,
diff --git a/libsanitizer/tsan/tsan_platform_linux.cc b/libsanitizer/tsan/tsan_platform_linux.cc
index 6f972ab0dd6..f8ae2567478 100644
--- a/libsanitizer/tsan/tsan_platform_linux.cc
+++ b/libsanitizer/tsan/tsan_platform_linux.cc
@@ -45,7 +45,6 @@
 #include <sys/resource.h>
 #include <sys/stat.h>
 #include <unistd.h>
-#include <errno.h>
 #include <sched.h>
 #include <dlfcn.h>
 #if SANITIZER_LINUX
@@ -132,7 +131,7 @@ void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive) {
 void FlushShadowMemoryCallback(
     const SuspendedThreadsList &suspended_threads_list,
     void *argument) {
-  ReleaseMemoryToOS(ShadowBeg(), ShadowEnd() - ShadowBeg());
+  ReleaseMemoryPagesToOS(ShadowBeg(), ShadowEnd());
 }
 #endif
 
@@ -180,17 +179,15 @@ static void MapRodata() {
   }
   // Map the file into shadow of .rodata sections.
   MemoryMappingLayout proc_maps(/*cache_enabled*/true);
-  uptr start, end, offset, prot;
   // Reusing the buffer 'name'.
-  while (proc_maps.Next(&start, &end, &offset, name, ARRAY_SIZE(name), &prot)) {
-    if (name[0] != 0 && name[0] != '['
-        && (prot & MemoryMappingLayout::kProtectionRead)
-        && (prot & MemoryMappingLayout::kProtectionExecute)
-        && !(prot & MemoryMappingLayout::kProtectionWrite)
-        && IsAppMem(start)) {
+  MemoryMappedSegment segment(name, ARRAY_SIZE(name));
+  while (proc_maps.Next(&segment)) {
+    if (segment.filename[0] != 0 && segment.filename[0] != '[' &&
+        segment.IsReadable() && segment.IsExecutable() &&
+        !segment.IsWritable() && IsAppMem(segment.start)) {
       // Assume it's .rodata
-      char *shadow_start = (char*)MemToShadow(start);
-      char *shadow_end = (char*)MemToShadow(end);
+      char *shadow_start = (char *)MemToShadow(segment.start);
+      char *shadow_end = (char *)MemToShadow(segment.end);
       for (char *p = shadow_start; p < shadow_end; p += marker.size()) {
         internal_mmap(p, Min<uptr>(marker.size(), shadow_end - p),
                       PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, 0);
@@ -318,6 +315,20 @@ int ExtractRecvmsgFDs(void *msgp, int *fds, int nfd) {
   return res;
 }
 
+void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
+  // Check that the thr object is in tls;
+  const uptr thr_beg = (uptr)thr;
+  const uptr thr_end = (uptr)thr + sizeof(*thr);
+  CHECK_GE(thr_beg, tls_addr);
+  CHECK_LE(thr_beg, tls_addr + tls_size);
+  CHECK_GE(thr_end, tls_addr);
+  CHECK_LE(thr_end, tls_addr + tls_size);
+  // Since the thr object is huge, skip it.
+  MemoryRangeImitateWrite(thr, /*pc=*/2, tls_addr, thr_beg - tls_addr);
+  MemoryRangeImitateWrite(thr, /*pc=*/2, thr_end,
+                          tls_addr + tls_size - thr_end);
+}
+
 // Note: this function runs with async signals enabled,
 // so it must not touch any tsan state.
 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
@@ -339,36 +350,22 @@ void ReplaceSystemMalloc() { }
 
 #if !SANITIZER_GO
 #if SANITIZER_ANDROID
-
-#if defined(__aarch64__)
-# define __get_tls() \
-    ({ void** __val; __asm__("mrs %0, tpidr_el0" : "=r"(__val)); __val; })
-#elif defined(__x86_64__)
-# define __get_tls() \
-    ({ void** __val; __asm__("mov %%fs:0, %0" : "=r"(__val)); __val; })
-#else
-#error unsupported architecture
-#endif
-
-// On Android, __thread is not supported. So we store the pointer to ThreadState
-// in TLS_SLOT_TSAN, which is the tls slot allocated by Android bionic for tsan.
-static const int TLS_SLOT_TSAN = 8;
 // On Android, one thread can call intercepted functions after
 // DestroyThreadState(), so add a fake thread state for "dead" threads.
 static ThreadState *dead_thread_state = nullptr;
 
 ThreadState *cur_thread() {
-  ThreadState* thr = (ThreadState*)__get_tls()[TLS_SLOT_TSAN];
+  ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
   if (thr == nullptr) {
     __sanitizer_sigset_t emptyset;
     internal_sigfillset(&emptyset);
     __sanitizer_sigset_t oldset;
     CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
-    thr = reinterpret_cast<ThreadState*>(__get_tls()[TLS_SLOT_TSAN]);
+    thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
     if (thr == nullptr) {
       thr = reinterpret_cast<ThreadState*>(MmapOrDie(sizeof(ThreadState),
                                                      "ThreadState"));
-      __get_tls()[TLS_SLOT_TSAN] = thr;
+      *get_android_tls_ptr() = reinterpret_cast<uptr>(thr);
       if (dead_thread_state == nullptr) {
         dead_thread_state = reinterpret_cast<ThreadState*>(
             MmapOrDie(sizeof(ThreadState), "ThreadState"));
@@ -390,9 +387,9 @@ void cur_thread_finalize() {
   internal_sigfillset(&emptyset);
   __sanitizer_sigset_t oldset;
   CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
-  ThreadState* thr = (ThreadState*)__get_tls()[TLS_SLOT_TSAN];
+  ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
   if (thr != dead_thread_state) {
-    __get_tls()[TLS_SLOT_TSAN] = dead_thread_state;
+    *get_android_tls_ptr() = reinterpret_cast<uptr>(dead_thread_state);
     UnmapOrDie(thr, sizeof(ThreadState));
   }
   CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
diff --git a/libsanitizer/tsan/tsan_platform_mac.cc b/libsanitizer/tsan/tsan_platform_mac.cc
index ff5131e75bb..8eb22fa58ea 100644
--- a/libsanitizer/tsan/tsan_platform_mac.cc
+++ b/libsanitizer/tsan/tsan_platform_mac.cc
@@ -18,10 +18,12 @@
 #include "sanitizer_common/sanitizer_libc.h"
 #include "sanitizer_common/sanitizer_posix.h"
 #include "sanitizer_common/sanitizer_procmaps.h"
+#include "sanitizer_common/sanitizer_stackdepot.h"
 #include "tsan_platform.h"
 #include "tsan_rtl.h"
 #include "tsan_flags.h"
 
+#include <mach/mach.h>
 #include <pthread.h>
 #include <signal.h>
 #include <stdio.h>
@@ -71,12 +73,18 @@ static void *SignalSafeGetOrAllocate(uptr *dst, uptr size) {
 static uptr main_thread_identity = 0;
 ALIGNED(64) static char main_thread_state[sizeof(ThreadState)];
 
+ThreadState **cur_thread_location() {
+  ThreadState **thread_identity = (ThreadState **)pthread_self();
+  return ((uptr)thread_identity == main_thread_identity) ? nullptr
+                                                         : thread_identity;
+}
+
 ThreadState *cur_thread() {
-  uptr thread_identity = (uptr)pthread_self();
-  if (thread_identity == main_thread_identity || main_thread_identity == 0) {
+  ThreadState **thr_state_loc = cur_thread_location();
+  if (thr_state_loc == nullptr || main_thread_identity == 0) {
     return (ThreadState *)&main_thread_state;
   }
-  ThreadState **fake_tls = (ThreadState **)MemToShadow(thread_identity);
+  ThreadState **fake_tls = (ThreadState **)MemToShadow((uptr)thr_state_loc);
   ThreadState *thr = (ThreadState *)SignalSafeGetOrAllocate(
       (uptr *)fake_tls, sizeof(ThreadState));
   return thr;
@@ -86,26 +94,92 @@ ThreadState *cur_thread() {
 // munmap first and then clear `fake_tls`; if we receive a signal in between,
 // handler will try to access the unmapped ThreadState.
 void cur_thread_finalize() {
-  uptr thread_identity = (uptr)pthread_self();
-  if (thread_identity == main_thread_identity) {
+  ThreadState **thr_state_loc = cur_thread_location();
+  if (thr_state_loc == nullptr) {
     // Calling dispatch_main() or xpc_main() actually invokes pthread_exit to
     // exit the main thread. Let's keep the main thread's ThreadState.
     return;
   }
-  ThreadState **fake_tls = (ThreadState **)MemToShadow(thread_identity);
+  ThreadState **fake_tls = (ThreadState **)MemToShadow((uptr)thr_state_loc);
   internal_munmap(*fake_tls, sizeof(ThreadState));
   *fake_tls = nullptr;
 }
 #endif
 
-uptr GetShadowMemoryConsumption() {
-  return 0;
+void FlushShadowMemory() {
 }
 
-void FlushShadowMemory() {
+static void RegionMemUsage(uptr start, uptr end, uptr *res, uptr *dirty) {
+  vm_address_t address = start;
+  vm_address_t end_address = end;
+  uptr resident_pages = 0;
+  uptr dirty_pages = 0;
+  while (address < end_address) {
+    vm_size_t vm_region_size;
+    mach_msg_type_number_t count = VM_REGION_EXTENDED_INFO_COUNT;
+    vm_region_extended_info_data_t vm_region_info;
+    mach_port_t object_name;
+    kern_return_t ret = vm_region_64(
+        mach_task_self(), &address, &vm_region_size, VM_REGION_EXTENDED_INFO,
+        (vm_region_info_t)&vm_region_info, &count, &object_name);
+    if (ret != KERN_SUCCESS) break;
+
+    resident_pages += vm_region_info.pages_resident;
+    dirty_pages += vm_region_info.pages_dirtied;
+
+    address += vm_region_size;
+  }
+  *res = resident_pages * GetPageSizeCached();
+  *dirty = dirty_pages * GetPageSizeCached();
 }
 
 void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive) {
+  uptr shadow_res, shadow_dirty;
+  uptr meta_res, meta_dirty;
+  uptr trace_res, trace_dirty;
+  RegionMemUsage(ShadowBeg(), ShadowEnd(), &shadow_res, &shadow_dirty);
+  RegionMemUsage(MetaShadowBeg(), MetaShadowEnd(), &meta_res, &meta_dirty);
+  RegionMemUsage(TraceMemBeg(), TraceMemEnd(), &trace_res, &trace_dirty);
+
+#if !SANITIZER_GO
+  uptr low_res, low_dirty;
+  uptr high_res, high_dirty;
+  uptr heap_res, heap_dirty;
+  RegionMemUsage(LoAppMemBeg(), LoAppMemEnd(), &low_res, &low_dirty);
+  RegionMemUsage(HiAppMemBeg(), HiAppMemEnd(), &high_res, &high_dirty);
+  RegionMemUsage(HeapMemBeg(), HeapMemEnd(), &heap_res, &heap_dirty);
+#else  // !SANITIZER_GO
+  uptr app_res, app_dirty;
+  RegionMemUsage(AppMemBeg(), AppMemEnd(), &app_res, &app_dirty);
+#endif
+
+  StackDepotStats *stacks = StackDepotGetStats();
+  internal_snprintf(buf, buf_size,
+    "shadow   (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
+    "meta     (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
+    "traces   (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
+#if !SANITIZER_GO
+    "low app  (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
+    "high app (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
+    "heap     (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
+#else  // !SANITIZER_GO
+    "app      (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
+#endif
+    "stacks: %zd unique IDs, %zd kB allocated\n"
+    "threads: %zd total, %zd live\n"
+    "------------------------------\n",
+    ShadowBeg(), ShadowEnd(), shadow_res / 1024, shadow_dirty / 1024,
+    MetaShadowBeg(), MetaShadowEnd(), meta_res / 1024, meta_dirty / 1024,
+    TraceMemBeg(), TraceMemEnd(), trace_res / 1024, trace_dirty / 1024,
+#if !SANITIZER_GO
+    LoAppMemBeg(), LoAppMemEnd(), low_res / 1024, low_dirty / 1024,
+    HiAppMemBeg(), HiAppMemEnd(), high_res / 1024, high_dirty / 1024,
+    HeapMemBeg(), HeapMemEnd(), heap_res / 1024, heap_dirty / 1024,
+#else  // !SANITIZER_GO
+    AppMemBeg(), AppMemEnd(), app_res / 1024, app_dirty / 1024,
+#endif
+    stacks->n_uniq_ids, stacks->allocated / 1024,
+    nthread, nlive);
 }
 
 #if !SANITIZER_GO
@@ -137,7 +211,7 @@ static void my_pthread_introspection_hook(unsigned int event, pthread_t thread,
       ThreadState *parent_thread_state = nullptr;  // No parent.
       int tid = ThreadCreate(parent_thread_state, 0, (uptr)thread, true);
       CHECK_NE(tid, 0);
-      ThreadStart(thr, tid, GetTid());
+      ThreadStart(thr, tid, GetTid(), /*workerthread*/ true);
     }
   } else if (event == PTHREAD_INTROSPECTION_THREAD_TERMINATE) {
     if (thread == pthread_self()) {
@@ -154,6 +228,14 @@ static void my_pthread_introspection_hook(unsigned int event, pthread_t thread,
 #endif
 
 void InitializePlatformEarly() {
+#if defined(__aarch64__)
+  uptr max_vm = GetMaxVirtualAddress() + 1;
+  if (max_vm != Mapping::kHiAppMemEnd) {
+    Printf("ThreadSanitizer: unsupported vm address limit %p, expected %p.\n",
+           max_vm, Mapping::kHiAppMemEnd);
+    Die();
+  }
+#endif
 }
 
 void InitializePlatform() {
@@ -170,6 +252,29 @@ void InitializePlatform() {
 }
 
 #if !SANITIZER_GO
+void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
+  // The pointer to the ThreadState object is stored in the shadow memory
+  // of the tls.
+  uptr tls_end = tls_addr + tls_size;
+  ThreadState **thr_state_loc = cur_thread_location();
+  if (thr_state_loc == nullptr) {
+    MemoryRangeImitateWrite(thr, /*pc=*/2, tls_addr, tls_size);
+  } else {
+    uptr thr_state_start = (uptr)thr_state_loc;
+    uptr thr_state_end = thr_state_start + sizeof(uptr);
+    CHECK_GE(thr_state_start, tls_addr);
+    CHECK_LE(thr_state_start, tls_addr + tls_size);
+    CHECK_GE(thr_state_end, tls_addr);
+    CHECK_LE(thr_state_end, tls_addr + tls_size);
+    MemoryRangeImitateWrite(thr, /*pc=*/2, tls_addr,
+                            thr_state_start - tls_addr);
+    MemoryRangeImitateWrite(thr, /*pc=*/2, thr_state_end,
+                            tls_end - thr_state_end);
+  }
+}
+#endif
+
+#if !SANITIZER_GO
 // Note: this function runs with async signals enabled,
 // so it must not touch any tsan state.
 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
diff --git a/libsanitizer/tsan/tsan_platform_posix.cc b/libsanitizer/tsan/tsan_platform_posix.cc
index 0a3b61a08dc..6e62575f1ec 100644
--- a/libsanitizer/tsan/tsan_platform_posix.cc
+++ b/libsanitizer/tsan/tsan_platform_posix.cc
@@ -44,6 +44,9 @@ void InitializeShadowMemory() {
 #elif defined(__mips64)
   const uptr kMadviseRangeBeg  = 0xff00000000ull;
   const uptr kMadviseRangeSize = 0x0100000000ull;
+#elif defined(__aarch64__) && defined(__APPLE__)
+  uptr kMadviseRangeBeg = LoAppMemBeg();
+  uptr kMadviseRangeSize = LoAppMemEnd() - LoAppMemBeg();
 #elif defined(__aarch64__)
   uptr kMadviseRangeBeg = 0;
   uptr kMadviseRangeSize = 0;
@@ -113,21 +116,24 @@ static void ProtectRange(uptr beg, uptr end) {
 void CheckAndProtect() {
   // Ensure that the binary is indeed compiled with -pie.
   MemoryMappingLayout proc_maps(true);
-  uptr p, end, prot;
-  while (proc_maps.Next(&p, &end, 0, 0, 0, &prot)) {
-    if (IsAppMem(p))
+  MemoryMappedSegment segment;
+  while (proc_maps.Next(&segment)) {
+    if (IsAppMem(segment.start)) continue;
+    if (segment.start >= HeapMemEnd() && segment.start < HeapEnd()) continue;
+    if (segment.protection == 0)  // Zero page or mprotected.
       continue;
-    if (p >= HeapMemEnd() &&
-        p < HeapEnd())
-      continue;
-    if (prot == 0)  // Zero page or mprotected.
-      continue;
-    if (p >= VdsoBeg())  // vdso
+    if (segment.start >= VdsoBeg())  // vdso
       break;
-    Printf("FATAL: ThreadSanitizer: unexpected memory mapping %p-%p\n", p, end);
+    Printf("FATAL: ThreadSanitizer: unexpected memory mapping %p-%p\n",
+           segment.start, segment.end);
     Die();
   }
 
+#if defined(__aarch64__) && defined(__APPLE__)
+  ProtectRange(HeapMemEnd(), ShadowBeg());
+  ProtectRange(ShadowEnd(), MetaShadowBeg());
+  ProtectRange(MetaShadowEnd(), TraceMemBeg());
+#else
   ProtectRange(LoAppMemEnd(), ShadowBeg());
   ProtectRange(ShadowEnd(), MetaShadowBeg());
 #ifdef TSAN_MID_APP_RANGE
@@ -141,6 +147,7 @@ void CheckAndProtect() {
   ProtectRange(TraceMemBeg(), TraceMemEnd());
   ProtectRange(TraceMemEnd(), HeapMemBeg());
   ProtectRange(HeapEnd(), HiAppMemBeg());
+#endif
 }
 #endif
 
diff --git a/libsanitizer/tsan/tsan_platform_windows.cc b/libsanitizer/tsan/tsan_platform_windows.cc
index 54ec6a655df..76883caabf1 100644
--- a/libsanitizer/tsan/tsan_platform_windows.cc
+++ b/libsanitizer/tsan/tsan_platform_windows.cc
@@ -19,10 +19,6 @@
 
 namespace __tsan {
 
-uptr GetShadowMemoryConsumption() {
-  return 0;
-}
-
 void FlushShadowMemory() {
 }
 
diff --git a/libsanitizer/tsan/tsan_report.cc b/libsanitizer/tsan/tsan_report.cc
index ba3e34fbfa5..f8cb3e73ca4 100644
--- a/libsanitizer/tsan/tsan_report.cc
+++ b/libsanitizer/tsan/tsan_report.cc
@@ -11,6 +11,7 @@
 #include "tsan_report.h"
 #include "tsan_platform.h"
 #include "tsan_rtl.h"
+#include "sanitizer_common/sanitizer_file.h"
 #include "sanitizer_common/sanitizer_placement_new.h"
 #include "sanitizer_common/sanitizer_report_decorator.h"
 #include "sanitizer_common/sanitizer_stacktrace_printer.h"
@@ -36,22 +37,16 @@ ReportLocation *ReportLocation::New(ReportLocationType type) {
 class Decorator: public __sanitizer::SanitizerCommonDecorator {
  public:
   Decorator() : SanitizerCommonDecorator() { }
-  const char *Warning()    { return Red(); }
-  const char *EndWarning() { return Default(); }
   const char *Access()     { return Blue(); }
-  const char *EndAccess()  { return Default(); }
   const char *ThreadDescription()    { return Cyan(); }
-  const char *EndThreadDescription() { return Default(); }
   const char *Location()   { return Green(); }
-  const char *EndLocation() { return Default(); }
   const char *Sleep()   { return Yellow(); }
-  const char *EndSleep() { return Default(); }
   const char *Mutex()   { return Magenta(); }
-  const char *EndMutex() { return Default(); }
 };
 
 ReportDesc::ReportDesc()
-    : stacks(MBlockReportStack)
+    : tag(kExternalTagNone)
+    , stacks(MBlockReportStack)
     , mops(MBlockReportMop)
     , locs(MBlockReportLoc)
     , mutexes(MBlockReportMutex)
@@ -79,7 +74,7 @@ const char *thread_name(char *buf, int tid) {
   return buf;
 }
 
-static const char *ReportTypeString(ReportType typ) {
+static const char *ReportTypeString(ReportType typ, uptr tag) {
   if (typ == ReportTypeRace)
     return "data race";
   if (typ == ReportTypeVptrRace)
@@ -88,6 +83,10 @@ static const char *ReportTypeString(ReportType typ) {
     return "heap-use-after-free";
   if (typ == ReportTypeVptrUseAfterFree)
     return "heap-use-after-free (virtual call vs free)";
+  if (typ == ReportTypeExternalRace) {
+    const char *str = GetReportHeaderFromTag(tag);
+    return str ? str : "race on external object";
+  }
   if (typ == ReportTypeThreadLeak)
     return "thread leak";
   if (typ == ReportTypeMutexDestroyLocked)
@@ -150,17 +149,30 @@ static const char *MopDesc(bool first, bool write, bool atomic) {
                 : (write ? "Previous write" : "Previous read"));
 }
 
+static const char *ExternalMopDesc(bool first, bool write) {
+  return first ? (write ? "Modifying" : "Read-only")
+               : (write ? "Previous modifying" : "Previous read-only");
+}
+
 static void PrintMop(const ReportMop *mop, bool first) {
   Decorator d;
   char thrbuf[kThreadBufSize];
   Printf("%s", d.Access());
-  Printf("  %s of size %d at %p by %s",
-      MopDesc(first, mop->write, mop->atomic),
-      mop->size, (void*)mop->addr,
-      thread_name(thrbuf, mop->tid));
+  if (mop->external_tag == kExternalTagNone) {
+    Printf("  %s of size %d at %p by %s",
+           MopDesc(first, mop->write, mop->atomic), mop->size,
+           (void *)mop->addr, thread_name(thrbuf, mop->tid));
+  } else {
+    const char *object_type = GetObjectTypeFromTag(mop->external_tag);
+    if (object_type == nullptr)
+        object_type = "external object";
+    Printf("  %s access of %s at %p by %s",
+           ExternalMopDesc(first, mop->write), object_type,
+           (void *)mop->addr, thread_name(thrbuf, mop->tid));
+  }
   PrintMutexSet(mop->mset);
   Printf(":\n");
-  Printf("%s", d.EndAccess());
+  Printf("%s", d.Default());
   PrintStack(mop->stack);
 }
 
@@ -181,9 +193,16 @@ static void PrintLocation(const ReportLocation *loc) {
              global.module_offset);
   } else if (loc->type == ReportLocationHeap) {
     char thrbuf[kThreadBufSize];
-    Printf("  Location is heap block of size %zu at %p allocated by %s:\n",
-           loc->heap_chunk_size, loc->heap_chunk_start,
-           thread_name(thrbuf, loc->tid));
+    const char *object_type = GetObjectTypeFromTag(loc->external_tag);
+    if (!object_type) {
+      Printf("  Location is heap block of size %zu at %p allocated by %s:\n",
+             loc->heap_chunk_size, loc->heap_chunk_start,
+             thread_name(thrbuf, loc->tid));
+    } else {
+      Printf("  Location is %s of size %zu at %p allocated by %s:\n",
+             object_type, loc->heap_chunk_size, loc->heap_chunk_start,
+             thread_name(thrbuf, loc->tid));
+    }
     print_stack = true;
   } else if (loc->type == ReportLocationStack) {
     Printf("  Location is stack of %s.\n\n", thread_name(thrbuf, loc->tid));
@@ -194,20 +213,20 @@ static void PrintLocation(const ReportLocation *loc) {
         loc->fd, thread_name(thrbuf, loc->tid));
     print_stack = true;
   }
-  Printf("%s", d.EndLocation());
+  Printf("%s", d.Default());
   if (print_stack)
     PrintStack(loc->stack);
 }
 
 static void PrintMutexShort(const ReportMutex *rm, const char *after) {
   Decorator d;
-  Printf("%sM%zd%s%s", d.Mutex(), rm->id, d.EndMutex(), after);
+  Printf("%sM%zd%s%s", d.Mutex(), rm->id, d.Default(), after);
 }
 
 static void PrintMutexShortWithAddress(const ReportMutex *rm,
                                        const char *after) {
   Decorator d;
-  Printf("%sM%zd (%p)%s%s", d.Mutex(), rm->id, rm->addr, d.EndMutex(), after);
+  Printf("%sM%zd (%p)%s%s", d.Mutex(), rm->id, rm->addr, d.Default(), after);
 }
 
 static void PrintMutex(const ReportMutex *rm) {
@@ -215,11 +234,11 @@ static void PrintMutex(const ReportMutex *rm) {
   if (rm->destroyed) {
     Printf("%s", d.Mutex());
     Printf("  Mutex M%llu is already destroyed.\n\n", rm->id);
-    Printf("%s", d.EndMutex());
+    Printf("%s", d.Default());
   } else {
     Printf("%s", d.Mutex());
     Printf("  Mutex M%llu (%p) created at:\n", rm->id, rm->addr);
-    Printf("%s", d.EndMutex());
+    Printf("%s", d.Default());
     PrintStack(rm->stack);
   }
 }
@@ -233,13 +252,19 @@ static void PrintThread(const ReportThread *rt) {
   if (rt->name && rt->name[0] != '\0')
     Printf(" '%s'", rt->name);
   char thrbuf[kThreadBufSize];
-  Printf(" (tid=%zu, %s) created by %s",
-    rt->os_id, rt->running ? "running" : "finished",
-    thread_name(thrbuf, rt->parent_tid));
+  const char *thread_status = rt->running ? "running" : "finished";
+  if (rt->workerthread) {
+    Printf(" (tid=%zu, %s) is a GCD worker thread\n", rt->os_id, thread_status);
+    Printf("\n");
+    Printf("%s", d.Default());
+    return;
+  }
+  Printf(" (tid=%zu, %s) created by %s", rt->os_id, thread_status,
+         thread_name(thrbuf, rt->parent_tid));
   if (rt->stack)
     Printf(" at:");
   Printf("\n");
-  Printf("%s", d.EndThreadDescription());
+  Printf("%s", d.Default());
   PrintStack(rt->stack);
 }
 
@@ -247,7 +272,7 @@ static void PrintSleep(const ReportStack *s) {
   Decorator d;
   Printf("%s", d.Sleep());
   Printf("  As if synchronized via sleep:\n");
-  Printf("%s", d.EndSleep());
+  Printf("%s", d.Default());
   PrintStack(s);
 }
 
@@ -287,11 +312,11 @@ static SymbolizedStack *SkipTsanInternalFrames(SymbolizedStack *frames) {
 void PrintReport(const ReportDesc *rep) {
   Decorator d;
   Printf("==================\n");
-  const char *rep_typ_str = ReportTypeString(rep->typ);
+  const char *rep_typ_str = ReportTypeString(rep->typ, rep->tag);
   Printf("%s", d.Warning());
   Printf("WARNING: ThreadSanitizer: %s (pid=%d)\n", rep_typ_str,
          (int)internal_getpid());
-  Printf("%s", d.EndWarning());
+  Printf("%s", d.Default());
 
   if (rep->typ == ReportTypeDeadlock) {
     char thrbuf[kThreadBufSize];
@@ -309,7 +334,7 @@ void PrintReport(const ReportDesc *rep) {
       PrintMutexShort(rep->mutexes[i], " in ");
       Printf("%s", d.ThreadDescription());
       Printf("%s:\n", thread_name(thrbuf, rep->unique_tids[i]));
-      Printf("%s", d.EndThreadDescription());
+      Printf("%s", d.Default());
       if (flags()->second_deadlock_stack) {
         PrintStack(rep->stacks[2*i]);
         Printf("  Mutex ");
@@ -356,6 +381,8 @@ void PrintReport(const ReportDesc *rep) {
       ReportErrorSummary(rep_typ_str, frame->info);
   }
 
+  if (common_flags()->print_module_map == 2) PrintModuleMap();
+
   Printf("==================\n");
 }
 
diff --git a/libsanitizer/tsan/tsan_report.h b/libsanitizer/tsan/tsan_report.h
index e51ed4f50f8..6eb043fc866 100644
--- a/libsanitizer/tsan/tsan_report.h
+++ b/libsanitizer/tsan/tsan_report.h
@@ -22,6 +22,7 @@ enum ReportType {
   ReportTypeVptrRace,
   ReportTypeUseAfterFree,
   ReportTypeVptrUseAfterFree,
+  ReportTypeExternalRace,
   ReportTypeThreadLeak,
   ReportTypeMutexDestroyLocked,
   ReportTypeMutexDoubleLock,
@@ -54,6 +55,7 @@ struct ReportMop {
   int size;
   bool write;
   bool atomic;
+  uptr external_tag;
   Vector<ReportMopMutex> mset;
   ReportStack *stack;
 
@@ -73,6 +75,7 @@ struct ReportLocation {
   DataInfo global;
   uptr heap_chunk_start;
   uptr heap_chunk_size;
+  uptr external_tag;
   int tid;
   int fd;
   bool suppressable;
@@ -85,10 +88,11 @@ struct ReportLocation {
 
 struct ReportThread {
   int id;
-  uptr os_id;
+  tid_t os_id;
   bool running;
+  bool workerthread;
   char *name;
-  int parent_tid;
+  u32 parent_tid;
   ReportStack *stack;
 };
 
@@ -102,6 +106,7 @@ struct ReportMutex {
 class ReportDesc {
  public:
   ReportType typ;
+  uptr tag;
   Vector<ReportStack*> stacks;
   Vector<ReportMop*> mops;
   Vector<ReportLocation*> locs;
diff --git a/libsanitizer/tsan/tsan_rtl.cc b/libsanitizer/tsan/tsan_rtl.cc
index 5be28ce5502..4a1f50061a6 100644
--- a/libsanitizer/tsan/tsan_rtl.cc
+++ b/libsanitizer/tsan/tsan_rtl.cc
@@ -12,6 +12,7 @@
 
 #include "sanitizer_common/sanitizer_atomic.h"
 #include "sanitizer_common/sanitizer_common.h"
+#include "sanitizer_common/sanitizer_file.h"
 #include "sanitizer_common/sanitizer_libc.h"
 #include "sanitizer_common/sanitizer_stackdepot.h"
 #include "sanitizer_common/sanitizer_placement_new.h"
@@ -43,7 +44,7 @@ extern "C" void __tsan_resume() {
 namespace __tsan {
 
 #if !SANITIZER_GO && !SANITIZER_MAC
-  __attribute__((tls_model("initial-exec")))
+__attribute__((tls_model("initial-exec")))
 THREADLOCAL char cur_thread_placeholder[sizeof(ThreadState)] ALIGNED(64);
 #endif
 static char ctx_placeholder[sizeof(Context)] ALIGNED(64);
@@ -102,7 +103,8 @@ Context::Context()
   , racy_stacks(MBlockRacyStacks)
   , racy_addresses(MBlockRacyAddresses)
   , fired_suppressions_mtx(MutexTypeFired, StatMtxFired)
-  , fired_suppressions(8) {
+  , fired_suppressions(8)
+  , clock_alloc("clock allocator") {
 }
 
 // The objects are allocated in TLS, so one may rely on zero-initialization.
@@ -232,9 +234,7 @@ static void StopBackgroundThread() {
 #endif
 
 void DontNeedShadowFor(uptr addr, uptr size) {
-  uptr shadow_beg = MemToShadow(addr);
-  uptr shadow_end = MemToShadow(addr + size);
-  ReleaseMemoryToOS(shadow_beg, shadow_end - shadow_beg);
+  ReleaseMemoryPagesToOS(MemToShadow(addr), MemToShadow(addr + size));
 }
 
 void MapShadow(uptr addr, uptr size) {
@@ -381,7 +381,7 @@ void Initialize(ThreadState *thr) {
   // Initialize thread 0.
   int tid = ThreadCreate(thr, 0, 0, true);
   CHECK_EQ(tid, 0);
-  ThreadStart(thr, tid, internal_getpid());
+  ThreadStart(thr, tid, GetTid(), /*workerthread*/ false);
 #if TSAN_CONTAINS_UBSAN
   __ubsan::InitAsPlugin();
 #endif
@@ -404,6 +404,8 @@ void Initialize(ThreadState *thr) {
 int Finalize(ThreadState *thr) {
   bool failed = false;
 
+  if (common_flags()->print_module_map == 1) PrintModuleMap();
+
   if (flags()->atexit_sleep_ms > 0 && ThreadCount(thr) > 1)
     SleepForMillis(flags()->atexit_sleep_ms);
 
@@ -864,9 +866,8 @@ static void MemoryRangeSet(ThreadState *thr, uptr pc, uptr addr, uptr size,
   // Don't want to touch lots of shadow memory.
   // If a program maps 10MB stack, there is no need reset the whole range.
   size = (size + (kShadowCell - 1)) & ~(kShadowCell - 1);
-  // UnmapOrDie/MmapFixedNoReserve does not work on Windows,
-  // so we do it only for C/C++.
-  if (SANITIZER_GO || size < common_flags()->clear_shadow_mmap_threshold) {
+  // UnmapOrDie/MmapFixedNoReserve does not work on Windows.
+  if (SANITIZER_WINDOWS || size < common_flags()->clear_shadow_mmap_threshold) {
     u64 *p = (u64*)MemToShadow(addr);
     CHECK(IsShadowMem((uptr)p));
     CHECK(IsShadowMem((uptr)(p + size * kShadowCnt / kShadowCell - 1)));
@@ -978,21 +979,21 @@ void FuncExit(ThreadState *thr) {
   thr->shadow_stack_pos--;
 }
 
-void ThreadIgnoreBegin(ThreadState *thr, uptr pc) {
+void ThreadIgnoreBegin(ThreadState *thr, uptr pc, bool save_stack) {
   DPrintf("#%d: ThreadIgnoreBegin\n", thr->tid);
   thr->ignore_reads_and_writes++;
   CHECK_GT(thr->ignore_reads_and_writes, 0);
   thr->fast_state.SetIgnoreBit();
 #if !SANITIZER_GO
-  if (!ctx->after_multithreaded_fork)
+  if (save_stack && !ctx->after_multithreaded_fork)
     thr->mop_ignore_set.Add(CurrentStackId(thr, pc));
 #endif
 }
 
 void ThreadIgnoreEnd(ThreadState *thr, uptr pc) {
   DPrintf("#%d: ThreadIgnoreEnd\n", thr->tid);
+  CHECK_GT(thr->ignore_reads_and_writes, 0);
   thr->ignore_reads_and_writes--;
-  CHECK_GE(thr->ignore_reads_and_writes, 0);
   if (thr->ignore_reads_and_writes == 0) {
     thr->fast_state.ClearIgnoreBit();
 #if !SANITIZER_GO
@@ -1001,20 +1002,28 @@ void ThreadIgnoreEnd(ThreadState *thr, uptr pc) {
   }
 }
 
-void ThreadIgnoreSyncBegin(ThreadState *thr, uptr pc) {
+#if !SANITIZER_GO
+extern "C" SANITIZER_INTERFACE_ATTRIBUTE
+uptr __tsan_testonly_shadow_stack_current_size() {
+  ThreadState *thr = cur_thread();
+  return thr->shadow_stack_pos - thr->shadow_stack;
+}
+#endif
+
+void ThreadIgnoreSyncBegin(ThreadState *thr, uptr pc, bool save_stack) {
   DPrintf("#%d: ThreadIgnoreSyncBegin\n", thr->tid);
   thr->ignore_sync++;
   CHECK_GT(thr->ignore_sync, 0);
 #if !SANITIZER_GO
-  if (!ctx->after_multithreaded_fork)
+  if (save_stack && !ctx->after_multithreaded_fork)
     thr->sync_ignore_set.Add(CurrentStackId(thr, pc));
 #endif
 }
 
 void ThreadIgnoreSyncEnd(ThreadState *thr, uptr pc) {
   DPrintf("#%d: ThreadIgnoreSyncEnd\n", thr->tid);
+  CHECK_GT(thr->ignore_sync, 0);
   thr->ignore_sync--;
-  CHECK_GE(thr->ignore_sync, 0);
 #if !SANITIZER_GO
   if (thr->ignore_sync == 0)
     thr->sync_ignore_set.Reset();
diff --git a/libsanitizer/tsan/tsan_rtl.h b/libsanitizer/tsan/tsan_rtl.h
index 522c76002a1..7dd9779e42b 100644
--- a/libsanitizer/tsan/tsan_rtl.h
+++ b/libsanitizer/tsan/tsan_rtl.h
@@ -53,16 +53,22 @@ namespace __tsan {
 #if !SANITIZER_GO
 struct MapUnmapCallback;
 #if defined(__mips64) || defined(__aarch64__) || defined(__powerpc__)
-static const uptr kAllocatorSpace = 0;
-static const uptr kAllocatorSize = SANITIZER_MMAP_RANGE_SIZE;
 static const uptr kAllocatorRegionSizeLog = 20;
 static const uptr kAllocatorNumRegions =
-    kAllocatorSize >> kAllocatorRegionSizeLog;
+    SANITIZER_MMAP_RANGE_SIZE >> kAllocatorRegionSizeLog;
 typedef TwoLevelByteMap<(kAllocatorNumRegions >> 12), 1 << 12,
     MapUnmapCallback> ByteMap;
-typedef SizeClassAllocator32<kAllocatorSpace, kAllocatorSize, 0,
-    CompactSizeClassMap, kAllocatorRegionSizeLog, ByteMap,
-    MapUnmapCallback> PrimaryAllocator;
+struct AP32 {
+  static const uptr kSpaceBeg = 0;
+  static const u64 kSpaceSize = SANITIZER_MMAP_RANGE_SIZE;
+  static const uptr kMetadataSize = 0;
+  typedef __sanitizer::CompactSizeClassMap SizeClassMap;
+  static const uptr kRegionSizeLog = kAllocatorRegionSizeLog;
+  typedef __tsan::ByteMap ByteMap;
+  typedef __tsan::MapUnmapCallback MapUnmapCallback;
+  static const uptr kFlags = 0;
+};
+typedef SizeClassAllocator32<AP32> PrimaryAllocator;
 #else
 struct AP64 {  // Allocator64 parameters. Deliberately using a short name.
   static const uptr kSpaceBeg = Mapping::kHeapMemBeg;
@@ -379,6 +385,7 @@ struct ThreadState {
   // for better performance.
   int ignore_reads_and_writes;
   int ignore_sync;
+  int suppress_reports;
   // Go does not support ignores.
 #if !SANITIZER_GO
   IgnoreSet mop_ignore_set;
@@ -543,6 +550,10 @@ struct Context {
 
 extern Context *ctx;  // The one and the only global runtime context.
 
+ALWAYS_INLINE Flags *flags() {
+  return &ctx->flags;
+}
+
 struct ScopedIgnoreInterceptors {
   ScopedIgnoreInterceptors() {
 #if !SANITIZER_GO
@@ -557,12 +568,16 @@ struct ScopedIgnoreInterceptors {
   }
 };
 
+const char *GetObjectTypeFromTag(uptr tag);
+const char *GetReportHeaderFromTag(uptr tag);
+uptr TagFromShadowStackFrame(uptr pc);
+
 class ScopedReport {
  public:
-  explicit ScopedReport(ReportType typ);
+  explicit ScopedReport(ReportType typ, uptr tag = kExternalTagNone);
   ~ScopedReport();
 
-  void AddMemoryAccess(uptr addr, Shadow s, StackTrace stack,
+  void AddMemoryAccess(uptr addr, uptr external_tag, Shadow s, StackTrace stack,
                        const MutexSet *mset);
   void AddStack(StackTrace stack, bool suppressable = false);
   void AddThread(const ThreadContext *tctx, bool suppressable = false);
@@ -588,11 +603,28 @@ class ScopedReport {
   void operator = (const ScopedReport&);
 };
 
+ThreadContext *IsThreadStackOrTls(uptr addr, bool *is_stack);
 void RestoreStack(int tid, const u64 epoch, VarSizeStackTrace *stk,
-                  MutexSet *mset);
+                  MutexSet *mset, uptr *tag = nullptr);
+
+// The stack could look like:
+//   <start> | <main> | <foo> | tag | <bar>
+// This will extract the tag and keep:
+//   <start> | <main> | <foo> | <bar>
+template<typename StackTraceTy>
+void ExtractTagFromStack(StackTraceTy *stack, uptr *tag = nullptr) {
+  if (stack->size < 2) return;
+  uptr possible_tag_pc = stack->trace[stack->size - 2];
+  uptr possible_tag = TagFromShadowStackFrame(possible_tag_pc);
+  if (possible_tag == kExternalTagNone) return;
+  stack->trace_buffer[stack->size - 2] = stack->trace_buffer[stack->size - 1];
+  stack->size -= 1;
+  if (tag) *tag = possible_tag;
+}
 
 template<typename StackTraceTy>
-void ObtainCurrentStack(ThreadState *thr, uptr toppc, StackTraceTy *stack) {
+void ObtainCurrentStack(ThreadState *thr, uptr toppc, StackTraceTy *stack,
+                        uptr *tag = nullptr) {
   uptr size = thr->shadow_stack_pos - thr->shadow_stack;
   uptr start = 0;
   if (size + !!toppc > kStackTraceMax) {
@@ -600,6 +632,7 @@ void ObtainCurrentStack(ThreadState *thr, uptr toppc, StackTraceTy *stack) {
     size = kStackTraceMax - !!toppc;
   }
   stack->Init(&thr->shadow_stack[start], size, toppc);
+  ExtractTagFromStack(stack, tag);
 }
 
 
@@ -701,16 +734,16 @@ void MemoryResetRange(ThreadState *thr, uptr pc, uptr addr, uptr size);
 void MemoryRangeFreed(ThreadState *thr, uptr pc, uptr addr, uptr size);
 void MemoryRangeImitateWrite(ThreadState *thr, uptr pc, uptr addr, uptr size);
 
-void ThreadIgnoreBegin(ThreadState *thr, uptr pc);
+void ThreadIgnoreBegin(ThreadState *thr, uptr pc, bool save_stack = true);
 void ThreadIgnoreEnd(ThreadState *thr, uptr pc);
-void ThreadIgnoreSyncBegin(ThreadState *thr, uptr pc);
+void ThreadIgnoreSyncBegin(ThreadState *thr, uptr pc, bool save_stack = true);
 void ThreadIgnoreSyncEnd(ThreadState *thr, uptr pc);
 
 void FuncEntry(ThreadState *thr, uptr pc);
 void FuncExit(ThreadState *thr);
 
 int ThreadCreate(ThreadState *thr, uptr pc, uptr uid, bool detached);
-void ThreadStart(ThreadState *thr, int tid, uptr os_id);
+void ThreadStart(ThreadState *thr, int tid, tid_t os_id, bool workerthread);
 void ThreadFinish(ThreadState *thr);
 int ThreadTid(ThreadState *thr, uptr pc, uptr uid);
 void ThreadJoin(ThreadState *thr, uptr pc, int tid);
@@ -725,13 +758,16 @@ void ProcDestroy(Processor *proc);
 void ProcWire(Processor *proc, ThreadState *thr);
 void ProcUnwire(Processor *proc, ThreadState *thr);
 
-void MutexCreate(ThreadState *thr, uptr pc, uptr addr,
-                 bool rw, bool recursive, bool linker_init);
-void MutexDestroy(ThreadState *thr, uptr pc, uptr addr);
-void MutexLock(ThreadState *thr, uptr pc, uptr addr, int rec = 1,
-               bool try_lock = false);
-int  MutexUnlock(ThreadState *thr, uptr pc, uptr addr, bool all = false);
-void MutexReadLock(ThreadState *thr, uptr pc, uptr addr, bool try_lock = false);
+// Note: the parameter is called flagz, because flags is already taken
+// by the global function that returns flags.
+void MutexCreate(ThreadState *thr, uptr pc, uptr addr, u32 flagz = 0);
+void MutexDestroy(ThreadState *thr, uptr pc, uptr addr, u32 flagz = 0);
+void MutexPreLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz = 0);
+void MutexPostLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz = 0,
+    int rec = 1);
+int  MutexUnlock(ThreadState *thr, uptr pc, uptr addr, u32 flagz = 0);
+void MutexPreReadLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz = 0);
+void MutexPostReadLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz = 0);
 void MutexReadUnlock(ThreadState *thr, uptr pc, uptr addr);
 void MutexReadOrWriteUnlock(ThreadState *thr, uptr pc, uptr addr);
 void MutexRepair(ThreadState *thr, uptr pc, uptr addr);  // call on EOWNERDEAD
@@ -787,7 +823,7 @@ void ALWAYS_INLINE TraceAddEvent(ThreadState *thr, FastState fs,
     return;
   DCHECK_GE((int)typ, 0);
   DCHECK_LE((int)typ, 7);
-  DCHECK_EQ(GetLsb(addr, 61), addr);
+  DCHECK_EQ(GetLsb(addr, kEventPCBits), addr);
   StatInc(thr, StatEvents);
   u64 pos = fs.GetTracePos();
   if (UNLIKELY((pos % kTracePartSize) == 0)) {
@@ -799,7 +835,7 @@ void ALWAYS_INLINE TraceAddEvent(ThreadState *thr, FastState fs,
   }
   Event *trace = (Event*)GetThreadTrace(fs.tid());
   Event *evp = &trace[pos];
-  Event ev = (u64)addr | ((u64)typ << 61);
+  Event ev = (u64)addr | ((u64)typ << kEventPCBits);
   *evp = ev;
 }
 
diff --git a/libsanitizer/tsan/tsan_rtl_aarch64.S b/libsanitizer/tsan/tsan_rtl_aarch64.S
index ef06f0444ae..61171d635c1 100644
--- a/libsanitizer/tsan/tsan_rtl_aarch64.S
+++ b/libsanitizer/tsan/tsan_rtl_aarch64.S
@@ -1,13 +1,46 @@
+// The content of this file is AArch64-only:
+#if defined(__aarch64__)
+
 #include "sanitizer_common/sanitizer_asm.h"
 
+#if !defined(__APPLE__)
 .section .bss
 .type	__tsan_pointer_chk_guard, %object
-.size	__tsan_pointer_chk_guard, 8
+ASM_SIZE(ASM_TSAN_SYMBOL_INTERCEPTOR(__tsan_pointer_chk_guard))
 __tsan_pointer_chk_guard:
 .zero	8
+#endif
+
+#if defined(__APPLE__)
+.align  2
+
+.section  __DATA,__nl_symbol_ptr,non_lazy_symbol_pointers
+.long _setjmp$non_lazy_ptr
+_setjmp$non_lazy_ptr:
+.indirect_symbol _setjmp
+.long 0
+
+.section  __DATA,__nl_symbol_ptr,non_lazy_symbol_pointers
+.long __setjmp$non_lazy_ptr
+__setjmp$non_lazy_ptr:
+.indirect_symbol __setjmp
+.long 0
+
+.section  __DATA,__nl_symbol_ptr,non_lazy_symbol_pointers
+.long _sigsetjmp$non_lazy_ptr
+_sigsetjmp$non_lazy_ptr:
+.indirect_symbol _sigsetjmp
+.long 0
+#endif
 
+#if !defined(__APPLE__)
 .section .text
+#else
+.section __TEXT,__text
+.align 3
+#endif
 
+#if !defined(__APPLE__)
 // GLIBC mangles the function pointers in jmp_buf (used in {set,long}*jmp
 // functions) by XORing them with a random guard pointer.  For AArch64 it is a
 // global variable rather than a TCB one (as for x86_64/powerpc) and althought
@@ -16,9 +49,9 @@ __tsan_pointer_chk_guard:
 // not stable). So InitializeGuardPtr obtains the pointer guard value by
 // issuing a setjmp and checking the resulting pointers values against the
 // original ones.
-.hidden _Z18InitializeGuardPtrv
+ASM_HIDDEN(_Z18InitializeGuardPtrv)
 .global _Z18InitializeGuardPtrv
-.type _Z18InitializeGuardPtrv, @function
+ASM_TYPE_FUNCTION(ASM_TSAN_SYMBOL_INTERCEPTOR(_Z18InitializeGuardPtrv))
 _Z18InitializeGuardPtrv:
   CFI_STARTPROC
   // Allocates a jmp_buf for the setjmp call.
@@ -55,12 +88,14 @@ _Z18InitializeGuardPtrv:
   CFI_DEF_CFA (31, 0)
   ret
   CFI_ENDPROC
-.size _Z18InitializeGuardPtrv, .-_Z18InitializeGuardPtrv
+ASM_SIZE(ASM_TSAN_SYMBOL_INTERCEPTOR(_Z18InitializeGuardPtrv))
+#endif
 
-.hidden __tsan_setjmp
+ASM_HIDDEN(__tsan_setjmp)
 .comm _ZN14__interception11real_setjmpE,8,8
-.type setjmp, @function
-setjmp:
+.globl ASM_TSAN_SYMBOL_INTERCEPTOR(setjmp)
+ASM_TYPE_FUNCTION(ASM_TSAN_SYMBOL_INTERCEPTOR(setjmp))
+ASM_TSAN_SYMBOL_INTERCEPTOR(setjmp):
   CFI_STARTPROC
 
   // save env parameters for function call
@@ -78,14 +113,19 @@ setjmp:
   CFI_OFFSET (19, -16)
   mov     x19, x0
 
+#if !defined(__APPLE__)
   // SP pointer mangling (see glibc setjmp)
   adrp    x2, __tsan_pointer_chk_guard
   ldr     x2, [x2, #:lo12:__tsan_pointer_chk_guard]
   add     x0, x29, 32
   eor     x1, x2, x0
+#else
+  add     x0, x29, 32
+  mov     x1, x0
+#endif
 
   // call tsan interceptor
-  bl      __tsan_setjmp
+  bl      ASM_TSAN_SYMBOL(__tsan_setjmp)
 
   // restore env parameter
   mov     x0, x19
@@ -96,18 +136,24 @@ setjmp:
   CFI_DEF_CFA (31, 0)
 
   // tail jump to libc setjmp
+#if !defined(__APPLE__)
   adrp    x1, :got:_ZN14__interception11real_setjmpE
   ldr     x1, [x1, #:got_lo12:_ZN14__interception11real_setjmpE]
   ldr     x1, [x1]
+#else
+  adrp    x1, _setjmp$non_lazy_ptr@page
+  add     x1, x1, _setjmp$non_lazy_ptr@pageoff
+  ldr     x1, [x1]
+#endif
   br      x1
 
   CFI_ENDPROC
-.size setjmp, .-setjmp
+ASM_SIZE(ASM_TSAN_SYMBOL_INTERCEPTOR(setjmp))
 
 .comm _ZN14__interception12real__setjmpE,8,8
-.globl _setjmp
-.type _setjmp, @function
-_setjmp:
+.globl ASM_TSAN_SYMBOL_INTERCEPTOR(_setjmp)
+ASM_TYPE_FUNCTION(ASM_TSAN_SYMBOL_INTERCEPTOR(_setjmp))
+ASM_TSAN_SYMBOL_INTERCEPTOR(_setjmp):
   CFI_STARTPROC
 
   // save env parameters for function call
@@ -125,14 +171,19 @@ _setjmp:
   CFI_OFFSET (19, -16)
   mov     x19, x0
 
+#if !defined(__APPLE__)
   // SP pointer mangling (see glibc setjmp)
   adrp    x2, __tsan_pointer_chk_guard
   ldr     x2, [x2, #:lo12:__tsan_pointer_chk_guard]
   add     x0, x29, 32
   eor     x1, x2, x0
+#else
+  add     x0, x29, 32
+  mov     x1, x0
+#endif
 
   // call tsan interceptor
-  bl      __tsan_setjmp
+  bl      ASM_TSAN_SYMBOL(__tsan_setjmp)
 
   // Restore jmp_buf parameter
   mov     x0, x19
@@ -143,18 +194,24 @@ _setjmp:
   CFI_DEF_CFA (31, 0)
 
   // tail jump to libc setjmp
+#if !defined(__APPLE__)
   adrp    x1, :got:_ZN14__interception12real__setjmpE
   ldr     x1, [x1, #:got_lo12:_ZN14__interception12real__setjmpE]
   ldr     x1, [x1]
+#else
+  adrp    x1, __setjmp$non_lazy_ptr@page
+  add     x1, x1, __setjmp$non_lazy_ptr@pageoff
+  ldr     x1, [x1]
+#endif
   br      x1
 
   CFI_ENDPROC
-.size _setjmp, .-_setjmp
+ASM_SIZE(ASM_TSAN_SYMBOL_INTERCEPTOR(_setjmp))
 
 .comm _ZN14__interception14real_sigsetjmpE,8,8
-.globl sigsetjmp
-.type sigsetjmp, @function
-sigsetjmp:
+.globl ASM_TSAN_SYMBOL_INTERCEPTOR(sigsetjmp)
+ASM_TYPE_FUNCTION(ASM_TSAN_SYMBOL_INTERCEPTOR(sigsetjmp))
+ASM_TSAN_SYMBOL_INTERCEPTOR(sigsetjmp):
   CFI_STARTPROC
 
   // save env parameters for function call
@@ -174,14 +231,19 @@ sigsetjmp:
   mov     w20, w1
   mov     x19, x0
 
+#if !defined(__APPLE__)
   // SP pointer mangling (see glibc setjmp)
   adrp    x2, __tsan_pointer_chk_guard
   ldr     x2, [x2, #:lo12:__tsan_pointer_chk_guard]
   add     x0, x29, 32
   eor     x1, x2, x0
+#else
+  add     x0, x29, 32
+  mov     x1, x0
+#endif
 
   // call tsan interceptor
-  bl      __tsan_setjmp
+  bl      ASM_TSAN_SYMBOL(__tsan_setjmp)
 
   // restore env parameter
   mov     w1, w20
@@ -195,17 +257,24 @@ sigsetjmp:
   CFI_DEF_CFA (31, 0)
 
   // tail jump to libc sigsetjmp
+#if !defined(__APPLE__)
   adrp    x2, :got:_ZN14__interception14real_sigsetjmpE
   ldr     x2, [x2, #:got_lo12:_ZN14__interception14real_sigsetjmpE]
   ldr     x2, [x2]
+#else
+  adrp    x2, _sigsetjmp$non_lazy_ptr@page
+  add     x2, x2, _sigsetjmp$non_lazy_ptr@pageoff
+  ldr     x2, [x2]
+#endif
   br      x2
   CFI_ENDPROC
-.size sigsetjmp, .-sigsetjmp
+ASM_SIZE(ASM_TSAN_SYMBOL_INTERCEPTOR(sigsetjmp))
 
+#if !defined(__APPLE__)
 .comm _ZN14__interception16real___sigsetjmpE,8,8
-.globl __sigsetjmp
-.type __sigsetjmp, @function
-__sigsetjmp:
+.globl ASM_TSAN_SYMBOL_INTERCEPTOR(__sigsetjmp)
+ASM_TYPE_FUNCTION(ASM_TSAN_SYMBOL_INTERCEPTOR(__sigsetjmp))
+ASM_TSAN_SYMBOL_INTERCEPTOR(__sigsetjmp):
   CFI_STARTPROC
 
   // save env parameters for function call
@@ -225,14 +294,16 @@ __sigsetjmp:
   mov     w20, w1
   mov     x19, x0
 
+#if !defined(__APPLE__)
   // SP pointer mangling (see glibc setjmp)
   adrp    x2, __tsan_pointer_chk_guard
   ldr     x2, [x2, #:lo12:__tsan_pointer_chk_guard]
   add     x0, x29, 32
   eor     x1, x2, x0
+#endif
 
   // call tsan interceptor
-  bl      __tsan_setjmp
+  bl      ASM_TSAN_SYMBOL(__tsan_setjmp)
 
   mov     w1, w20
   mov     x0, x19
@@ -245,14 +316,22 @@ __sigsetjmp:
   CFI_DEF_CFA (31, 0)
 
   // tail jump to libc __sigsetjmp
+#if !defined(__APPLE__)
   adrp    x2, :got:_ZN14__interception16real___sigsetjmpE
   ldr     x2, [x2, #:got_lo12:_ZN14__interception16real___sigsetjmpE]
   ldr     x2, [x2]
+#else
+  adrp    x2, ASM_TSAN_SYMBOL(__sigsetjmp)@page
+  add     x2, x2, ASM_TSAN_SYMBOL(__sigsetjmp)@pageoff
+#endif
   br      x2
   CFI_ENDPROC
-.size __sigsetjmp, .-__sigsetjmp
+ASM_SIZE(ASM_TSAN_SYMBOL_INTERCEPTOR(__sigsetjmp))
+#endif
 
 #if defined(__linux__)
 /* We do not need executable stack.  */
 .section        .note.GNU-stack,"",@progbits
 #endif
+
+#endif
diff --git a/libsanitizer/tsan/tsan_rtl_amd64.S b/libsanitizer/tsan/tsan_rtl_amd64.S
index caa832375e5..98947fd2a1b 100644
--- a/libsanitizer/tsan/tsan_rtl_amd64.S
+++ b/libsanitizer/tsan/tsan_rtl_amd64.S
@@ -1,4 +1,8 @@
+// The content of this file is x86_64-only:
+#if defined(__x86_64__)
+
 #include "sanitizer_common/sanitizer_asm.h"
+
 #if !defined(__APPLE__)
 .section .text
 #else
@@ -357,3 +361,5 @@ ASM_SIZE(ASM_TSAN_SYMBOL_INTERCEPTOR(__sigsetjmp))
 /* We do not need executable stack.  */
 .section        .note.GNU-stack,"",@progbits
 #endif
+
+#endif
diff --git a/libsanitizer/tsan/tsan_rtl_mutex.cc b/libsanitizer/tsan/tsan_rtl_mutex.cc
index e575bbfb7e9..d10a87374ba 100644
--- a/libsanitizer/tsan/tsan_rtl_mutex.cc
+++ b/libsanitizer/tsan/tsan_rtl_mutex.cc
@@ -60,32 +60,29 @@ static void ReportMutexMisuse(ThreadState *thr, uptr pc, ReportType typ,
   OutputReport(thr, rep);
 }
 
-void MutexCreate(ThreadState *thr, uptr pc, uptr addr,
-                 bool rw, bool recursive, bool linker_init) {
-  DPrintf("#%d: MutexCreate %zx\n", thr->tid, addr);
+void MutexCreate(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
+  DPrintf("#%d: MutexCreate %zx flagz=0x%x\n", thr->tid, addr, flagz);
   StatInc(thr, StatMutexCreate);
-  if (!linker_init && IsAppMem(addr)) {
+  if (!(flagz & MutexFlagLinkerInit) && IsAppMem(addr)) {
     CHECK(!thr->is_freeing);
     thr->is_freeing = true;
     MemoryWrite(thr, pc, addr, kSizeLog1);
     thr->is_freeing = false;
   }
   SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, true);
-  s->is_rw = rw;
-  s->is_recursive = recursive;
-  s->is_linker_init = linker_init;
+  s->SetFlags(flagz & MutexCreationFlagMask);
   if (!SANITIZER_GO && s->creation_stack_id == 0)
     s->creation_stack_id = CurrentStackId(thr, pc);
   s->mtx.Unlock();
 }
 
-void MutexDestroy(ThreadState *thr, uptr pc, uptr addr) {
+void MutexDestroy(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
   DPrintf("#%d: MutexDestroy %zx\n", thr->tid, addr);
   StatInc(thr, StatMutexDestroy);
   SyncVar *s = ctx->metamap.GetIfExistsAndLock(addr, true);
   if (s == 0)
     return;
-  if (s->is_linker_init) {
+  if ((flagz & MutexFlagLinkerInit) || s->IsFlagSet(MutexFlagLinkerInit)) {
     // Destroy is no-op for linker-initialized mutexes.
     s->mtx.Unlock();
     return;
@@ -98,8 +95,8 @@ void MutexDestroy(ThreadState *thr, uptr pc, uptr addr) {
   bool unlock_locked = false;
   if (flags()->report_destroy_locked
       && s->owner_tid != SyncVar::kInvalidTid
-      && !s->is_broken) {
-    s->is_broken = true;
+      && !s->IsFlagSet(MutexFlagBroken)) {
+    s->SetFlags(MutexFlagBroken);
     unlock_locked = true;
   }
   u64 mid = s->GetId();
@@ -139,12 +136,33 @@ void MutexDestroy(ThreadState *thr, uptr pc, uptr addr) {
   // s will be destroyed and freed in MetaMap::FreeBlock.
 }
 
-void MutexLock(ThreadState *thr, uptr pc, uptr addr, int rec, bool try_lock) {
-  DPrintf("#%d: MutexLock %zx rec=%d\n", thr->tid, addr, rec);
-  CHECK_GT(rec, 0);
+void MutexPreLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
+  DPrintf("#%d: MutexPreLock %zx flagz=0x%x\n", thr->tid, addr, flagz);
+  if (!(flagz & MutexFlagTryLock) && common_flags()->detect_deadlocks) {
+    SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, false);
+    s->UpdateFlags(flagz);
+    if (s->owner_tid != thr->tid) {
+      Callback cb(thr, pc);
+      ctx->dd->MutexBeforeLock(&cb, &s->dd, true);
+      s->mtx.ReadUnlock();
+      ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
+    } else {
+      s->mtx.ReadUnlock();
+    }
+  }
+}
+
+void MutexPostLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz, int rec) {
+  DPrintf("#%d: MutexPostLock %zx flag=0x%x rec=%d\n",
+      thr->tid, addr, flagz, rec);
+  if (flagz & MutexFlagRecursiveLock)
+    CHECK_GT(rec, 0);
+  else
+    rec = 1;
   if (IsAppMem(addr))
     MemoryReadAtomic(thr, pc, addr, kSizeLog1);
   SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, true);
+  s->UpdateFlags(flagz);
   thr->fast_state.IncrementEpoch();
   TraceAddEvent(thr, thr->fast_state, EventTypeLock, s->GetId());
   bool report_double_lock = false;
@@ -154,38 +172,43 @@ void MutexLock(ThreadState *thr, uptr pc, uptr addr, int rec, bool try_lock) {
     s->last_lock = thr->fast_state.raw();
   } else if (s->owner_tid == thr->tid) {
     CHECK_GT(s->recursion, 0);
-  } else if (flags()->report_mutex_bugs && !s->is_broken) {
-    s->is_broken = true;
+  } else if (flags()->report_mutex_bugs && !s->IsFlagSet(MutexFlagBroken)) {
+    s->SetFlags(MutexFlagBroken);
     report_double_lock = true;
   }
-  if (s->recursion == 0) {
+  const bool first = s->recursion == 0;
+  s->recursion += rec;
+  if (first) {
     StatInc(thr, StatMutexLock);
     AcquireImpl(thr, pc, &s->clock);
     AcquireImpl(thr, pc, &s->read_clock);
-  } else if (!s->is_recursive) {
+  } else if (!s->IsFlagSet(MutexFlagWriteReentrant)) {
     StatInc(thr, StatMutexRecLock);
   }
-  s->recursion += rec;
   thr->mset.Add(s->GetId(), true, thr->fast_state.epoch());
-  if (common_flags()->detect_deadlocks && (s->recursion - rec) == 0) {
+  bool pre_lock = false;
+  if (first && common_flags()->detect_deadlocks) {
+    pre_lock = (flagz & MutexFlagDoPreLockOnPostLock) &&
+        !(flagz & MutexFlagTryLock);
     Callback cb(thr, pc);
-    if (!try_lock)
+    if (pre_lock)
       ctx->dd->MutexBeforeLock(&cb, &s->dd, true);
-    ctx->dd->MutexAfterLock(&cb, &s->dd, true, try_lock);
+    ctx->dd->MutexAfterLock(&cb, &s->dd, true, flagz & MutexFlagTryLock);
   }
   u64 mid = s->GetId();
   s->mtx.Unlock();
   // Can't touch s after this point.
+  s = 0;
   if (report_double_lock)
     ReportMutexMisuse(thr, pc, ReportTypeMutexDoubleLock, addr, mid);
-  if (common_flags()->detect_deadlocks) {
+  if (first && pre_lock && common_flags()->detect_deadlocks) {
     Callback cb(thr, pc);
     ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
   }
 }
 
-int MutexUnlock(ThreadState *thr, uptr pc, uptr addr, bool all) {
-  DPrintf("#%d: MutexUnlock %zx all=%d\n", thr->tid, addr, all);
+int MutexUnlock(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
+  DPrintf("#%d: MutexUnlock %zx flagz=0x%x\n", thr->tid, addr, flagz);
   if (IsAppMem(addr))
     MemoryReadAtomic(thr, pc, addr, kSizeLog1);
   SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, true);
@@ -194,12 +217,12 @@ int MutexUnlock(ThreadState *thr, uptr pc, uptr addr, bool all) {
   int rec = 0;
   bool report_bad_unlock = false;
   if (!SANITIZER_GO && (s->recursion == 0 || s->owner_tid != thr->tid)) {
-    if (flags()->report_mutex_bugs && !s->is_broken) {
-      s->is_broken = true;
+    if (flags()->report_mutex_bugs && !s->IsFlagSet(MutexFlagBroken)) {
+      s->SetFlags(MutexFlagBroken);
       report_bad_unlock = true;
     }
   } else {
-    rec = all ? s->recursion : 1;
+    rec = (flagz & MutexFlagRecursiveUnlock) ? s->recursion : 1;
     s->recursion -= rec;
     if (s->recursion == 0) {
       StatInc(thr, StatMutexUnlock);
@@ -227,36 +250,53 @@ int MutexUnlock(ThreadState *thr, uptr pc, uptr addr, bool all) {
   return rec;
 }
 
-void MutexReadLock(ThreadState *thr, uptr pc, uptr addr, bool trylock) {
-  DPrintf("#%d: MutexReadLock %zx\n", thr->tid, addr);
+void MutexPreReadLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
+  DPrintf("#%d: MutexPreReadLock %zx flagz=0x%x\n", thr->tid, addr, flagz);
+  if (!(flagz & MutexFlagTryLock) && common_flags()->detect_deadlocks) {
+    SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, false);
+    s->UpdateFlags(flagz);
+    Callback cb(thr, pc);
+    ctx->dd->MutexBeforeLock(&cb, &s->dd, false);
+    s->mtx.ReadUnlock();
+    ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
+  }
+}
+
+void MutexPostReadLock(ThreadState *thr, uptr pc, uptr addr, u32 flagz) {
+  DPrintf("#%d: MutexPostReadLock %zx flagz=0x%x\n", thr->tid, addr, flagz);
   StatInc(thr, StatMutexReadLock);
   if (IsAppMem(addr))
     MemoryReadAtomic(thr, pc, addr, kSizeLog1);
   SyncVar *s = ctx->metamap.GetOrCreateAndLock(thr, pc, addr, false);
+  s->UpdateFlags(flagz);
   thr->fast_state.IncrementEpoch();
   TraceAddEvent(thr, thr->fast_state, EventTypeRLock, s->GetId());
   bool report_bad_lock = false;
   if (s->owner_tid != SyncVar::kInvalidTid) {
-    if (flags()->report_mutex_bugs && !s->is_broken) {
-      s->is_broken = true;
+    if (flags()->report_mutex_bugs && !s->IsFlagSet(MutexFlagBroken)) {
+      s->SetFlags(MutexFlagBroken);
       report_bad_lock = true;
     }
   }
   AcquireImpl(thr, pc, &s->clock);
   s->last_lock = thr->fast_state.raw();
   thr->mset.Add(s->GetId(), false, thr->fast_state.epoch());
-  if (common_flags()->detect_deadlocks && s->recursion == 0) {
+  bool pre_lock = false;
+  if (common_flags()->detect_deadlocks) {
+    pre_lock = (flagz & MutexFlagDoPreLockOnPostLock) &&
+        !(flagz & MutexFlagTryLock);
     Callback cb(thr, pc);
-    if (!trylock)
+    if (pre_lock)
       ctx->dd->MutexBeforeLock(&cb, &s->dd, false);
-    ctx->dd->MutexAfterLock(&cb, &s->dd, false, trylock);
+    ctx->dd->MutexAfterLock(&cb, &s->dd, false, flagz & MutexFlagTryLock);
   }
   u64 mid = s->GetId();
   s->mtx.ReadUnlock();
   // Can't touch s after this point.
+  s = 0;
   if (report_bad_lock)
     ReportMutexMisuse(thr, pc, ReportTypeMutexBadReadLock, addr, mid);
-  if (common_flags()->detect_deadlocks) {
+  if (pre_lock  && common_flags()->detect_deadlocks) {
     Callback cb(thr, pc);
     ReportDeadlock(thr, pc, ctx->dd->GetReport(&cb));
   }
@@ -272,8 +312,8 @@ void MutexReadUnlock(ThreadState *thr, uptr pc, uptr addr) {
   TraceAddEvent(thr, thr->fast_state, EventTypeRUnlock, s->GetId());
   bool report_bad_unlock = false;
   if (s->owner_tid != SyncVar::kInvalidTid) {
-    if (flags()->report_mutex_bugs && !s->is_broken) {
-      s->is_broken = true;
+    if (flags()->report_mutex_bugs && !s->IsFlagSet(MutexFlagBroken)) {
+      s->SetFlags(MutexFlagBroken);
       report_bad_unlock = true;
     }
   }
@@ -321,8 +361,8 @@ void MutexReadOrWriteUnlock(ThreadState *thr, uptr pc, uptr addr) {
     } else {
       StatInc(thr, StatMutexRecUnlock);
     }
-  } else if (!s->is_broken) {
-    s->is_broken = true;
+  } else if (!s->IsFlagSet(MutexFlagBroken)) {
+    s->SetFlags(MutexFlagBroken);
     report_bad_unlock = true;
   }
   thr->mset.Del(s->GetId(), write);
@@ -371,10 +411,10 @@ void Acquire(ThreadState *thr, uptr pc, uptr addr) {
 static void UpdateClockCallback(ThreadContextBase *tctx_base, void *arg) {
   ThreadState *thr = reinterpret_cast<ThreadState*>(arg);
   ThreadContext *tctx = static_cast<ThreadContext*>(tctx_base);
+  u64 epoch = tctx->epoch1;
   if (tctx->status == ThreadStatusRunning)
-    thr->clock.set(tctx->tid, tctx->thr->fast_state.epoch());
-  else
-    thr->clock.set(tctx->tid, tctx->epoch1);
+    epoch = tctx->thr->fast_state.epoch();
+  thr->clock.set(&thr->proc()->clock_cache, tctx->tid, epoch);
 }
 
 void AcquireGlobal(ThreadState *thr, uptr pc) {
@@ -414,10 +454,10 @@ void ReleaseStore(ThreadState *thr, uptr pc, uptr addr) {
 static void UpdateSleepClockCallback(ThreadContextBase *tctx_base, void *arg) {
   ThreadState *thr = reinterpret_cast<ThreadState*>(arg);
   ThreadContext *tctx = static_cast<ThreadContext*>(tctx_base);
+  u64 epoch = tctx->epoch1;
   if (tctx->status == ThreadStatusRunning)
-    thr->last_sleep_clock.set(tctx->tid, tctx->thr->fast_state.epoch());
-  else
-    thr->last_sleep_clock.set(tctx->tid, tctx->epoch1);
+    epoch = tctx->thr->fast_state.epoch();
+  thr->last_sleep_clock.set(&thr->proc()->clock_cache, tctx->tid, epoch);
 }
 
 void AfterSleep(ThreadState *thr, uptr pc) {
diff --git a/libsanitizer/tsan/tsan_rtl_report.cc b/libsanitizer/tsan/tsan_rtl_report.cc
index 8f2882485e6..a961139b61d 100644
--- a/libsanitizer/tsan/tsan_rtl_report.cc
+++ b/libsanitizer/tsan/tsan_rtl_report.cc
@@ -141,11 +141,12 @@ static ReportStack *SymbolizeStack(StackTrace trace) {
   return stack;
 }
 
-ScopedReport::ScopedReport(ReportType typ) {
+ScopedReport::ScopedReport(ReportType typ, uptr tag) {
   ctx->thread_registry->CheckLocked();
   void *mem = internal_alloc(MBlockReport, sizeof(ReportDesc));
   rep_ = new(mem) ReportDesc;
   rep_->typ = typ;
+  rep_->tag = tag;
   ctx->report_mtx.Lock();
   CommonSanitizerReportMutex.Lock();
 }
@@ -162,8 +163,8 @@ void ScopedReport::AddStack(StackTrace stack, bool suppressable) {
   (*rs)->suppressable = suppressable;
 }
 
-void ScopedReport::AddMemoryAccess(uptr addr, Shadow s, StackTrace stack,
-                                   const MutexSet *mset) {
+void ScopedReport::AddMemoryAccess(uptr addr, uptr external_tag, Shadow s,
+                                   StackTrace stack, const MutexSet *mset) {
   void *mem = internal_alloc(MBlockReportMop, sizeof(ReportMop));
   ReportMop *mop = new(mem) ReportMop;
   rep_->mops.PushBack(mop);
@@ -173,6 +174,7 @@ void ScopedReport::AddMemoryAccess(uptr addr, Shadow s, StackTrace stack,
   mop->write = s.IsWrite();
   mop->atomic = s.IsAtomic();
   mop->stack = SymbolizeStack(stack);
+  mop->external_tag = external_tag;
   if (mop->stack)
     mop->stack->suppressable = true;
   for (uptr i = 0; i < mset->Size(); i++) {
@@ -200,6 +202,7 @@ void ScopedReport::AddThread(const ThreadContext *tctx, bool suppressable) {
   rt->running = (tctx->status == ThreadStatusRunning);
   rt->name = internal_strdup(tctx->name);
   rt->parent_tid = tctx->parent_tid;
+  rt->workerthread = tctx->workerthread;
   rt->stack = 0;
   rt->stack = SymbolizeStackId(tctx->creation_stack_id);
   if (rt->stack)
@@ -309,7 +312,7 @@ void ScopedReport::AddLocation(uptr addr, uptr size) {
     return;
 #if !SANITIZER_GO
   int fd = -1;
-  int creat_tid = -1;
+  int creat_tid = kInvalidTid;
   u32 creat_stack = 0;
   if (FdLocation(addr, &fd, &creat_tid, &creat_stack)) {
     ReportLocation *loc = ReportLocation::New(ReportLocationFD);
@@ -334,6 +337,7 @@ void ScopedReport::AddLocation(uptr addr, uptr size) {
     ReportLocation *loc = ReportLocation::New(ReportLocationHeap);
     loc->heap_chunk_start = (uptr)allocator()->GetBlockBegin((void *)addr);
     loc->heap_chunk_size = b->siz;
+    loc->external_tag = b->tag;
     loc->tid = tctx ? tctx->tid : b->tid;
     loc->stack = SymbolizeStackId(b->stk);
     rep_->locs.PushBack(loc);
@@ -372,7 +376,7 @@ const ReportDesc *ScopedReport::GetReport() const {
 }
 
 void RestoreStack(int tid, const u64 epoch, VarSizeStackTrace *stk,
-                  MutexSet *mset) {
+                  MutexSet *mset, uptr *tag) {
   // This function restores stack trace and mutex set for the thread/epoch.
   // It does so by getting stack trace and mutex set at the beginning of
   // trace part, and then replaying the trace till the given epoch.
@@ -400,8 +404,8 @@ void RestoreStack(int tid, const u64 epoch, VarSizeStackTrace *stk,
   Event *events = (Event*)GetThreadTrace(tid);
   for (uptr i = ebegin; i <= eend; i++) {
     Event ev = events[i];
-    EventType typ = (EventType)(ev >> 61);
-    uptr pc = (uptr)(ev & ((1ull << 61) - 1));
+    EventType typ = (EventType)(ev >> kEventPCBits);
+    uptr pc = (uptr)(ev & ((1ull << kEventPCBits) - 1));
     DPrintf2("  %zu typ=%d pc=%zx\n", i, typ, pc);
     if (typ == EventTypeMop) {
       stack[pos] = pc;
@@ -431,6 +435,7 @@ void RestoreStack(int tid, const u64 epoch, VarSizeStackTrace *stk,
     return;
   pos++;
   stk->Init(&stack[0], pos);
+  ExtractTagFromStack(stk, tag);
 }
 
 static bool HandleRacyStacks(ThreadState *thr, VarSizeStackTrace traces[2],
@@ -495,7 +500,7 @@ static void AddRacyStacks(ThreadState *thr, VarSizeStackTrace traces[2],
 }
 
 bool OutputReport(ThreadState *thr, const ScopedReport &srep) {
-  if (!flags()->report_bugs)
+  if (!flags()->report_bugs || thr->suppress_reports)
     return false;
   atomic_store_relaxed(&ctx->last_symbolize_time_ns, NanoTime());
   const ReportDesc *rep = srep.GetReport();
@@ -626,8 +631,29 @@ void ReportRace(ThreadState *thr) {
 
   const uptr kMop = 2;
   VarSizeStackTrace traces[kMop];
-  const uptr toppc = TraceTopPC(thr);
-  ObtainCurrentStack(thr, toppc, &traces[0]);
+  uptr tags[kMop] = {kExternalTagNone};
+  uptr toppc = TraceTopPC(thr);
+  if (toppc >> kEventPCBits) {
+    // This is a work-around for a known issue.
+    // The scenario where this happens is rather elaborate and requires
+    // an instrumented __sanitizer_report_error_summary callback and
+    // a __tsan_symbolize_external callback and a race during a range memory
+    // access larger than 8 bytes. MemoryAccessRange adds the current PC to
+    // the trace and starts processing memory accesses. A first memory access
+    // triggers a race, we report it and call the instrumented
+    // __sanitizer_report_error_summary, which adds more stuff to the trace
+    // since it is intrumented. Then a second memory access in MemoryAccessRange
+    // also triggers a race and we get here and call TraceTopPC to get the
+    // current PC, however now it contains some unrelated events from the
+    // callback. Most likely, TraceTopPC will now return a EventTypeFuncExit
+    // event. Later we subtract -1 from it (in GetPreviousInstructionPc)
+    // and the resulting PC has kExternalPCBit set, so we pass it to
+    // __tsan_symbolize_external. __tsan_symbolize_external is within its rights
+    // to crash since the PC is completely bogus.
+    // test/tsan/double_race.cc contains a test case for this.
+    toppc = 0;
+  }
+  ObtainCurrentStack(thr, toppc, &traces[0], &tags[0]);
   if (IsFiredSuppression(ctx, typ, traces[0]))
     return;
 
@@ -637,18 +663,29 @@ void ReportRace(ThreadState *thr) {
   MutexSet *mset2 = new(&mset_buffer[0]) MutexSet();
 
   Shadow s2(thr->racy_state[1]);
-  RestoreStack(s2.tid(), s2.epoch(), &traces[1], mset2);
+  RestoreStack(s2.tid(), s2.epoch(), &traces[1], mset2, &tags[1]);
   if (IsFiredSuppression(ctx, typ, traces[1]))
     return;
 
   if (HandleRacyStacks(thr, traces, addr_min, addr_max))
     return;
 
+  // If any of the accesses has a tag, treat this as an "external" race.
+  uptr tag = kExternalTagNone;
+  for (uptr i = 0; i < kMop; i++) {
+    if (tags[i] != kExternalTagNone) {
+      typ = ReportTypeExternalRace;
+      tag = tags[i];
+      break;
+    }
+  }
+
   ThreadRegistryLock l0(ctx->thread_registry);
-  ScopedReport rep(typ);
+  ScopedReport rep(typ, tag);
   for (uptr i = 0; i < kMop; i++) {
     Shadow s(thr->racy_state[i]);
-    rep.AddMemoryAccess(addr, s, traces[i], i == 0 ? &thr->mset : mset2);
+    rep.AddMemoryAccess(addr, tags[i], s, traces[i],
+                        i == 0 ? &thr->mset : mset2);
   }
 
   for (uptr i = 0; i < kMop; i++) {
diff --git a/libsanitizer/tsan/tsan_rtl_thread.cc b/libsanitizer/tsan/tsan_rtl_thread.cc
index 6c4b74e2a76..e81669d3b77 100644
--- a/libsanitizer/tsan/tsan_rtl_thread.cc
+++ b/libsanitizer/tsan/tsan_rtl_thread.cc
@@ -66,7 +66,8 @@ void ThreadContext::OnCreated(void *arg) {
 
 void ThreadContext::OnReset() {
   CHECK_EQ(sync.size(), 0);
-  ReleaseMemoryToOS(GetThreadTrace(tid), TraceSize() * sizeof(Event));
+  uptr trace_p = GetThreadTrace(tid);
+  ReleaseMemoryPagesToOS(trace_p, trace_p + TraceSize() * sizeof(Event));
   //!!! ReleaseMemoryToOS(GetThreadTraceHeader(tid), sizeof(Trace));
 }
 
@@ -139,6 +140,10 @@ void ThreadContext::OnFinished() {
 
   if (common_flags()->detect_deadlocks)
     ctx->dd->DestroyLogicalThread(thr->dd_lt);
+  thr->clock.ResetCached(&thr->proc()->clock_cache);
+#if !SANITIZER_GO
+  thr->last_sleep_clock.ResetCached(&thr->proc()->clock_cache);
+#endif
   thr->~ThreadState();
 #if TSAN_COLLECT_STATS
   StatAggregate(ctx->stat, thr->stat);
@@ -233,7 +238,7 @@ int ThreadCreate(ThreadState *thr, uptr pc, uptr uid, bool detached) {
   return tid;
 }
 
-void ThreadStart(ThreadState *thr, int tid, uptr os_id) {
+void ThreadStart(ThreadState *thr, int tid, tid_t os_id, bool workerthread) {
   uptr stk_addr = 0;
   uptr stk_size = 0;
   uptr tls_addr = 0;
@@ -245,25 +250,13 @@ void ThreadStart(ThreadState *thr, int tid, uptr os_id) {
     if (stk_addr && stk_size)
       MemoryRangeImitateWrite(thr, /*pc=*/ 1, stk_addr, stk_size);
 
-    if (tls_addr && tls_size) {
-      // Check that the thr object is in tls;
-      const uptr thr_beg = (uptr)thr;
-      const uptr thr_end = (uptr)thr + sizeof(*thr);
-      CHECK_GE(thr_beg, tls_addr);
-      CHECK_LE(thr_beg, tls_addr + tls_size);
-      CHECK_GE(thr_end, tls_addr);
-      CHECK_LE(thr_end, tls_addr + tls_size);
-      // Since the thr object is huge, skip it.
-      MemoryRangeImitateWrite(thr, /*pc=*/ 2, tls_addr, thr_beg - tls_addr);
-      MemoryRangeImitateWrite(thr, /*pc=*/ 2,
-          thr_end, tls_addr + tls_size - thr_end);
-    }
+    if (tls_addr && tls_size) ImitateTlsWrite(thr, tls_addr, tls_size);
   }
 #endif
 
   ThreadRegistry *tr = ctx->thread_registry;
   OnStartedArgs args = { thr, stk_addr, stk_size, tls_addr, tls_size };
-  tr->StartThread(tid, os_id, &args);
+  tr->StartThread(tid, os_id, workerthread, &args);
 
   tr->Lock();
   thr->tctx = (ThreadContext*)tr->GetThreadLocked(tid);
@@ -354,6 +347,7 @@ void MemoryAccessRange(ThreadState *thr, uptr pc, uptr addr,
   StatInc(thr, StatMopRange);
 
   if (*shadow_mem == kShadowRodata) {
+    DCHECK(!is_write);
     // Access to .rodata section, no races here.
     // Measurements show that it can be 10-20% of all memory accesses.
     StatInc(thr, StatMopRangeRodata);
diff --git a/libsanitizer/tsan/tsan_stat.cc b/libsanitizer/tsan/tsan_stat.cc
index 740cb86c69e..decb7a20b84 100644
--- a/libsanitizer/tsan/tsan_stat.cc
+++ b/libsanitizer/tsan/tsan_stat.cc
@@ -73,14 +73,11 @@ void StatOutput(u64 *stat) {
   name[StatClockAcquire]                 = "Clock acquire                     ";
   name[StatClockAcquireEmpty]            = "  empty clock                     ";
   name[StatClockAcquireFastRelease]      = "  fast from release-store         ";
-  name[StatClockAcquireLarge]            = "  contains my tid                 ";
-  name[StatClockAcquireRepeat]           = "  repeated (fast)                 ";
   name[StatClockAcquireFull]             = "  full (slow)                     ";
   name[StatClockAcquiredSomething]       = "  acquired something              ";
   name[StatClockRelease]                 = "Clock release                     ";
   name[StatClockReleaseResize]           = "  resize                          ";
-  name[StatClockReleaseFast1]            = "  fast1                           ";
-  name[StatClockReleaseFast2]            = "  fast2                           ";
+  name[StatClockReleaseFast]             = "  fast                            ";
   name[StatClockReleaseSlow]             = "  dirty overflow (slow)           ";
   name[StatClockReleaseFull]             = "  full (slow)                     ";
   name[StatClockReleaseAcquired]         = "  was acquired                    ";
@@ -151,6 +148,16 @@ void StatOutput(u64 *stat) {
   name[StatAnnotatePublishMemoryRange]   = "  PublishMemoryRange              ";
   name[StatAnnotateUnpublishMemoryRange] = "  UnpublishMemoryRange            ";
   name[StatAnnotateThreadName]           = "  ThreadName                      ";
+  name[Stat__tsan_mutex_create]          = "  __tsan_mutex_create             ";
+  name[Stat__tsan_mutex_destroy]         = "  __tsan_mutex_destroy            ";
+  name[Stat__tsan_mutex_pre_lock]        = "  __tsan_mutex_pre_lock           ";
+  name[Stat__tsan_mutex_post_lock]       = "  __tsan_mutex_post_lock          ";
+  name[Stat__tsan_mutex_pre_unlock]      = "  __tsan_mutex_pre_unlock         ";
+  name[Stat__tsan_mutex_post_unlock]     = "  __tsan_mutex_post_unlock        ";
+  name[Stat__tsan_mutex_pre_signal]      = "  __tsan_mutex_pre_signal         ";
+  name[Stat__tsan_mutex_post_signal]     = "  __tsan_mutex_post_signal        ";
+  name[Stat__tsan_mutex_pre_divert]      = "  __tsan_mutex_pre_divert         ";
+  name[Stat__tsan_mutex_post_divert]     = "  __tsan_mutex_post_divert        ";
 
   name[StatMtxTotal]                     = "Contentionz                       ";
   name[StatMtxTrace]                     = "  Trace                           ";
diff --git a/libsanitizer/tsan/tsan_stat.h b/libsanitizer/tsan/tsan_stat.h
index 788adeb56ea..c4859df52b0 100644
--- a/libsanitizer/tsan/tsan_stat.h
+++ b/libsanitizer/tsan/tsan_stat.h
@@ -72,15 +72,12 @@ enum StatType {
   StatClockAcquire,
   StatClockAcquireEmpty,
   StatClockAcquireFastRelease,
-  StatClockAcquireLarge,
-  StatClockAcquireRepeat,
   StatClockAcquireFull,
   StatClockAcquiredSomething,
   // Clocks - release.
   StatClockRelease,
   StatClockReleaseResize,
-  StatClockReleaseFast1,
-  StatClockReleaseFast2,
+  StatClockReleaseFast,
   StatClockReleaseSlow,
   StatClockReleaseFull,
   StatClockReleaseAcquired,
@@ -155,6 +152,16 @@ enum StatType {
   StatAnnotatePublishMemoryRange,
   StatAnnotateUnpublishMemoryRange,
   StatAnnotateThreadName,
+  Stat__tsan_mutex_create,
+  Stat__tsan_mutex_destroy,
+  Stat__tsan_mutex_pre_lock,
+  Stat__tsan_mutex_post_lock,
+  Stat__tsan_mutex_pre_unlock,
+  Stat__tsan_mutex_post_unlock,
+  Stat__tsan_mutex_pre_signal,
+  Stat__tsan_mutex_post_signal,
+  Stat__tsan_mutex_pre_divert,
+  Stat__tsan_mutex_post_divert,
 
   // Internal mutex contentionz.
   StatMtxTotal,
diff --git a/libsanitizer/tsan/tsan_suppressions.cc b/libsanitizer/tsan/tsan_suppressions.cc
index dc862b1b9ad..e40eb70ceec 100644
--- a/libsanitizer/tsan/tsan_suppressions.cc
+++ b/libsanitizer/tsan/tsan_suppressions.cc
@@ -72,6 +72,8 @@ static const char *conv(ReportType typ) {
     return kSuppressionRace;
   else if (typ == ReportTypeVptrUseAfterFree)
     return kSuppressionRace;
+  else if (typ == ReportTypeExternalRace)
+    return kSuppressionRace;
   else if (typ == ReportTypeThreadLeak)
     return kSuppressionThread;
   else if (typ == ReportTypeMutexDestroyLocked)
diff --git a/libsanitizer/tsan/tsan_sync.cc b/libsanitizer/tsan/tsan_sync.cc
index 0ee2295e69e..0f840de1f11 100644
--- a/libsanitizer/tsan/tsan_sync.cc
+++ b/libsanitizer/tsan/tsan_sync.cc
@@ -40,10 +40,7 @@ void SyncVar::Reset(Processor *proc) {
   owner_tid = kInvalidTid;
   last_lock = 0;
   recursion = 0;
-  is_rw = 0;
-  is_recursive = 0;
-  is_broken = 0;
-  is_linker_init = 0;
+  atomic_store_relaxed(&flags, 0);
 
   if (proc == 0) {
     CHECK_EQ(clock.size(), 0);
@@ -54,7 +51,9 @@ void SyncVar::Reset(Processor *proc) {
   }
 }
 
-MetaMap::MetaMap() {
+MetaMap::MetaMap()
+    : block_alloc_("heap block allocator")
+    , sync_alloc_("sync allocator") {
   atomic_store(&uid_gen_, 0, memory_order_relaxed);
 }
 
@@ -62,6 +61,7 @@ void MetaMap::AllocBlock(ThreadState *thr, uptr pc, uptr p, uptr sz) {
   u32 idx = block_alloc_.Alloc(&thr->proc()->block_cache);
   MBlock *b = block_alloc_.Map(idx);
   b->siz = sz;
+  b->tag = 0;
   b->tid = thr->tid;
   b->stk = CurrentStackId(thr, pc);
   u32 *meta = MemToMeta(p);
diff --git a/libsanitizer/tsan/tsan_sync.h b/libsanitizer/tsan/tsan_sync.h
index 48d7027b428..195279fc1f2 100644
--- a/libsanitizer/tsan/tsan_sync.h
+++ b/libsanitizer/tsan/tsan_sync.h
@@ -21,6 +21,29 @@
 
 namespace __tsan {
 
+// These need to match __tsan_mutex_* flags defined in tsan_interface.h.
+// See documentation there as well.
+enum MutexFlags {
+  MutexFlagLinkerInit          = 1 << 0, // __tsan_mutex_linker_init
+  MutexFlagWriteReentrant      = 1 << 1, // __tsan_mutex_write_reentrant
+  MutexFlagReadReentrant       = 1 << 2, // __tsan_mutex_read_reentrant
+  MutexFlagReadLock            = 1 << 3, // __tsan_mutex_read_lock
+  MutexFlagTryLock             = 1 << 4, // __tsan_mutex_try_lock
+  MutexFlagTryLockFailed       = 1 << 5, // __tsan_mutex_try_lock_failed
+  MutexFlagRecursiveLock       = 1 << 6, // __tsan_mutex_recursive_lock
+  MutexFlagRecursiveUnlock     = 1 << 7, // __tsan_mutex_recursive_unlock
+
+  // The following flags are runtime private.
+  // Mutex API misuse was detected, so don't report any more.
+  MutexFlagBroken              = 1 << 30,
+  // We did not intercept pre lock event, so handle it on post lock.
+  MutexFlagDoPreLockOnPostLock = 1 << 29,
+  // Must list all mutex creation flags.
+  MutexCreationFlagMask        = MutexFlagLinkerInit |
+                                 MutexFlagWriteReentrant |
+                                 MutexFlagReadReentrant,
+};
+
 struct SyncVar {
   SyncVar();
 
@@ -33,10 +56,7 @@ struct SyncVar {
   int owner_tid;  // Set only by exclusive owners.
   u64 last_lock;
   int recursion;
-  bool is_rw;
-  bool is_recursive;
-  bool is_broken;
-  bool is_linker_init;
+  atomic_uint32_t flags;
   u32 next;  // in MetaMap
   DDMutex dd;
   SyncClock read_clock;  // Used for rw mutexes only.
@@ -59,6 +79,26 @@ struct SyncVar {
     *uid = id >> 48;
     return (uptr)GetLsb(id, 48);
   }
+
+  bool IsFlagSet(u32 f) const {
+    return atomic_load_relaxed(&flags) & f;
+  }
+
+  void SetFlags(u32 f) {
+    atomic_store_relaxed(&flags, atomic_load_relaxed(&flags) | f);
+  }
+
+  void UpdateFlags(u32 flagz) {
+    // Filter out operation flags.
+    if (!(flagz & MutexCreationFlagMask))
+      return;
+    u32 current = atomic_load_relaxed(&flags);
+    if (current & MutexCreationFlagMask)
+      return;
+    // Note: this can be called from MutexPostReadLock which holds only read
+    // lock on the SyncVar.
+    atomic_store_relaxed(&flags, current | (flagz & MutexCreationFlagMask));
+  }
 };
 
 /* MetaMap allows to map arbitrary user pointers onto various descriptors.
diff --git a/libsanitizer/tsan/tsan_trace.h b/libsanitizer/tsan/tsan_trace.h
index 1ea733bfd07..5cc3f8f3498 100644
--- a/libsanitizer/tsan/tsan_trace.h
+++ b/libsanitizer/tsan/tsan_trace.h
@@ -39,6 +39,8 @@ enum EventType {
 // u64 addr : 61;  // Associated pc.
 typedef u64 Event;
 
+const uptr kEventPCBits = 61;
+
 struct TraceHeader {
 #if !SANITIZER_GO
   BufferedStackTrace stack0;  // Start stack for the trace.
diff --git a/libsanitizer/ubsan/Makefile.am b/libsanitizer/ubsan/Makefile.am
index cb27091137a..cce728ceeca 100644
--- a/libsanitizer/ubsan/Makefile.am
+++ b/libsanitizer/ubsan/Makefile.am
@@ -3,7 +3,7 @@ AM_CPPFLAGS = -I $(top_srcdir) -I $(top_srcdir)/include
 # May be used by toolexeclibdir.
 gcc_version := $(shell @get_gcc_base_ver@ $(top_srcdir)/../gcc/BASE-VER)
 
-DEFS = -D_GNU_SOURCE -D_DEBUG -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -DPIC -DCAN_SANITIZE_UB=1
+DEFS = -D_GNU_SOURCE -D_DEBUG -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -DPIC -DCAN_SANITIZE_UB=1 -DUBSAN_CAN_USE_CXXABI=1
 AM_CXXFLAGS = -Wall -W -Wno-unused-parameter -Wwrite-strings -pedantic -Wno-long-long  -fPIC -fno-builtin -fno-exceptions -fno-rtti -fomit-frame-pointer -funwind-tables -fvisibility=hidden -Wno-variadic-macros
 AM_CXXFLAGS += $(LIBSTDCXX_RAW_CXX_CXXFLAGS)
 AM_CXXFLAGS += -std=gnu++11
@@ -24,7 +24,8 @@ ubsan_plugin_files = \
 
 ubsan_files = \
 	$(ubsan_plugin_files) \
-	ubsan_init_standalone.cc
+	ubsan_init_standalone.cc \
+	ubsan_signals_standalone.cc
 
 libubsan_la_SOURCES = $(ubsan_files) 
 libubsan_la_LIBADD = $(top_builddir)/sanitizer_common/libsanitizer_common.la 
diff --git a/libsanitizer/ubsan/Makefile.in b/libsanitizer/ubsan/Makefile.in
index 1664ce9497e..9552ec1425d 100644
--- a/libsanitizer/ubsan/Makefile.in
+++ b/libsanitizer/ubsan/Makefile.in
@@ -111,7 +111,8 @@ am__objects_1 = ubsan_diag.lo ubsan_flags.lo ubsan_handlers.lo \
 	ubsan_handlers_cxx.lo ubsan_init.lo ubsan_type_hash.lo \
 	ubsan_type_hash_itanium.lo ubsan_type_hash_win.lo \
 	ubsan_value.lo
-am__objects_2 = $(am__objects_1) ubsan_init_standalone.lo
+am__objects_2 = $(am__objects_1) ubsan_init_standalone.lo \
+	ubsan_signals_standalone.lo
 am_libubsan_la_OBJECTS = $(am__objects_2)
 libubsan_la_OBJECTS = $(am_libubsan_la_OBJECTS)
 libubsan_la_LINK = $(LIBTOOL) --tag=CXX $(AM_LIBTOOLFLAGS) \
@@ -162,7 +163,7 @@ CXXCPP = @CXXCPP@
 CXXDEPMODE = @CXXDEPMODE@
 CXXFLAGS = @CXXFLAGS@
 CYGPATH_W = @CYGPATH_W@
-DEFS = -D_GNU_SOURCE -D_DEBUG -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -DPIC -DCAN_SANITIZE_UB=1
+DEFS = -D_GNU_SOURCE -D_DEBUG -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -DPIC -DCAN_SANITIZE_UB=1 -DUBSAN_CAN_USE_CXXABI=1
 DEPDIR = @DEPDIR@
 DSYMUTIL = @DSYMUTIL@
 DUMPBIN = @DUMPBIN@
@@ -307,7 +308,8 @@ ubsan_plugin_files = \
 
 ubsan_files = \
 	$(ubsan_plugin_files) \
-	ubsan_init_standalone.cc
+	ubsan_init_standalone.cc \
+	ubsan_signals_standalone.cc
 
 libubsan_la_SOURCES = $(ubsan_files) 
 libubsan_la_LIBADD =  \
@@ -435,6 +437,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ubsan_handlers_cxx.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ubsan_init.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ubsan_init_standalone.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ubsan_signals_standalone.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ubsan_type_hash.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ubsan_type_hash_itanium.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ubsan_type_hash_win.Plo@am__quote@
diff --git a/libsanitizer/ubsan/libtool-version b/libsanitizer/ubsan/libtool-version
index 204fdd2d8e5..4b494765130 100644
--- a/libsanitizer/ubsan/libtool-version
+++ b/libsanitizer/ubsan/libtool-version
@@ -3,4 +3,4 @@
 # a separate file so that version updates don't involve re-running
 # automake.
 # CURRENT:REVISION:AGE
-0:0:0
+1:0:0
diff --git a/libsanitizer/ubsan/ubsan_checks.inc b/libsanitizer/ubsan/ubsan_checks.inc
index 31e9495e301..c4459245f3e 100644
--- a/libsanitizer/ubsan/ubsan_checks.inc
+++ b/libsanitizer/ubsan/ubsan_checks.inc
@@ -27,6 +27,7 @@ UBSAN_CHECK(UnsignedIntegerOverflow, "unsigned-integer-overflow",
 UBSAN_CHECK(IntegerDivideByZero, "integer-divide-by-zero",
             "integer-divide-by-zero")
 UBSAN_CHECK(FloatDivideByZero, "float-divide-by-zero", "float-divide-by-zero")
+UBSAN_CHECK(InvalidBuiltin, "invalid-builtin-use", "invalid-builtin-use")
 UBSAN_CHECK(InvalidShiftBase, "invalid-shift-base", "shift-base")
 UBSAN_CHECK(InvalidShiftExponent, "invalid-shift-exponent", "shift-exponent")
 UBSAN_CHECK(OutOfBoundsIndex, "out-of-bounds-index", "bounds")
diff --git a/libsanitizer/ubsan/ubsan_diag.cc b/libsanitizer/ubsan/ubsan_diag.cc
index b6e982a170e..978d966f1c3 100644
--- a/libsanitizer/ubsan/ubsan_diag.cc
+++ b/libsanitizer/ubsan/ubsan_diag.cc
@@ -24,20 +24,25 @@
 
 using namespace __ubsan;
 
+void __ubsan::GetStackTraceWithPcBpAndContext(BufferedStackTrace *stack,
+                                              uptr max_depth, uptr pc, uptr bp,
+                                              void *context, bool fast) {
+  uptr top = 0;
+  uptr bottom = 0;
+  if (fast)
+    GetThreadStackTopAndBottom(false, &top, &bottom);
+  stack->Unwind(max_depth, pc, bp, context, top, bottom, fast);
+}
+
 static void MaybePrintStackTrace(uptr pc, uptr bp) {
   // We assume that flags are already parsed, as UBSan runtime
   // will definitely be called when we print the first diagnostics message.
   if (!flags()->print_stacktrace)
     return;
-  // We can only use slow unwind, as we don't have any information about stack
-  // top/bottom.
-  // FIXME: It's better to respect "fast_unwind_on_fatal" runtime flag and
-  // fetch stack top/bottom information if we have it (e.g. if we're running
-  // under ASan).
-  if (StackTrace::WillUseFastUnwind(false))
-    return;
+
   BufferedStackTrace stack;
-  stack.Unwind(kStackTraceMax, pc, bp, 0, 0, 0, false);
+  GetStackTraceWithPcBpAndContext(&stack, kStackTraceMax, pc, bp, nullptr,
+                                  common_flags()->fast_unwind_on_fatal);
   stack.Print();
 }
 
@@ -77,16 +82,16 @@ static void MaybeReportErrorSummary(Location Loc, ErrorType Type) {
       AI.line = SLoc.getLine();
       AI.column = SLoc.getColumn();
       AI.function = internal_strdup("");  // Avoid printing ?? as function name.
-      ReportErrorSummary(ErrorKind, AI);
+      ReportErrorSummary(ErrorKind, AI, GetSanititizerToolName());
       AI.Clear();
       return;
     }
   } else if (Loc.isSymbolizedStack()) {
     const AddressInfo &AI = Loc.getSymbolizedStack()->info;
-    ReportErrorSummary(ErrorKind, AI);
+    ReportErrorSummary(ErrorKind, AI, GetSanititizerToolName());
     return;
   }
-  ReportErrorSummary(ErrorKind);
+  ReportErrorSummary(ErrorKind, GetSanititizerToolName());
 }
 
 namespace {
@@ -94,9 +99,7 @@ class Decorator : public SanitizerCommonDecorator {
  public:
   Decorator() : SanitizerCommonDecorator() {}
   const char *Highlight() const { return Green(); }
-  const char *EndHighlight() const { return Default(); }
   const char *Note() const { return Black(); }
-  const char *EndNote() const { return Default(); }
 };
 }
 
@@ -155,7 +158,7 @@ static void RenderLocation(InternalScopedString *Buffer, Location Loc) {
                            common_flags()->strip_path_prefix);
     else if (Info.module)
       RenderModuleLocation(Buffer, Info.module, Info.module_offset,
-                           common_flags()->strip_path_prefix);
+                           Info.module_arch, common_flags()->strip_path_prefix);
     else
       Buffer->append("%p", Info.address);
     return;
@@ -292,7 +295,7 @@ static void PrintMemorySnippet(const Decorator &Decor, MemoryLocation Loc,
     Buffer.append("%c", P == Loc ? '^' : Byte);
     Buffer.append("%c", Byte);
   }
-  Buffer.append("%s\n", Decor.EndHighlight());
+  Buffer.append("%s\n", Decor.Default());
 
   // Go over the line again, and print names for the ranges.
   InRange = 0;
@@ -332,7 +335,7 @@ static void PrintMemorySnippet(const Decorator &Decor, MemoryLocation Loc,
 
 Diag::~Diag() {
   // All diagnostics should be printed under report mutex.
-  CommonSanitizerReportMutex.CheckLocked();
+  ScopedReport::CheckLocked();
   Decorator Decor;
   InternalScopedString Buffer(1024);
 
@@ -342,12 +345,12 @@ Diag::~Diag() {
 
   switch (Level) {
   case DL_Error:
-    Buffer.append("%s runtime error: %s%s", Decor.Warning(), Decor.EndWarning(),
+    Buffer.append("%s runtime error: %s%s", Decor.Warning(), Decor.Default(),
                   Decor.Bold());
     break;
 
   case DL_Note:
-    Buffer.append("%s note: %s", Decor.Note(), Decor.EndNote());
+    Buffer.append("%s note: %s", Decor.Note(), Decor.Default());
     break;
   }
 
@@ -360,17 +363,15 @@ Diag::~Diag() {
     PrintMemorySnippet(Decor, Loc.getMemoryLocation(), Ranges, NumRanges, Args);
 }
 
+ScopedReport::Initializer::Initializer() { InitAsStandaloneIfNecessary(); }
+
 ScopedReport::ScopedReport(ReportOptions Opts, Location SummaryLoc,
                            ErrorType Type)
-    : Opts(Opts), SummaryLoc(SummaryLoc), Type(Type) {
-  InitAsStandaloneIfNecessary();
-  CommonSanitizerReportMutex.Lock();
-}
+    : Opts(Opts), SummaryLoc(SummaryLoc), Type(Type) {}
 
 ScopedReport::~ScopedReport() {
   MaybePrintStackTrace(Opts.pc, Opts.bp);
   MaybeReportErrorSummary(SummaryLoc, Type);
-  CommonSanitizerReportMutex.Unlock();
   if (flags()->halt_on_error)
     Die();
 }
diff --git a/libsanitizer/ubsan/ubsan_diag.h b/libsanitizer/ubsan/ubsan_diag.h
index 3456aaa72c5..e9e5ab67e3e 100644
--- a/libsanitizer/ubsan/ubsan_diag.h
+++ b/libsanitizer/ubsan/ubsan_diag.h
@@ -229,10 +229,20 @@ bool ignoreReport(SourceLocation SLoc, ReportOptions Opts, ErrorType ET);
     GET_CALLER_PC_BP; \
     ReportOptions Opts = {unrecoverable_handler, pc, bp}
 
+void GetStackTraceWithPcBpAndContext(BufferedStackTrace *stack, uptr max_depth,
+                                     uptr pc, uptr bp, void *context,
+                                     bool fast);
+
 /// \brief Instantiate this class before printing diagnostics in the error
 /// report. This class ensures that reports from different threads and from
 /// different sanitizers won't be mixed.
 class ScopedReport {
+  struct Initializer {
+    Initializer();
+  };
+  Initializer initializer_;
+  ScopedErrorReportLock report_lock_;
+
   ReportOptions Opts;
   Location SummaryLoc;
   ErrorType Type;
@@ -240,6 +250,8 @@ class ScopedReport {
 public:
   ScopedReport(ReportOptions Opts, Location SummaryLoc, ErrorType Type);
   ~ScopedReport();
+
+  static void CheckLocked() { ScopedErrorReportLock::CheckLocked(); }
 };
 
 void InitializeSuppressions();
diff --git a/libsanitizer/ubsan/ubsan_diag_standalone.cc b/libsanitizer/ubsan/ubsan_diag_standalone.cc
new file mode 100644
index 00000000000..ddc1be7018c
--- /dev/null
+++ b/libsanitizer/ubsan/ubsan_diag_standalone.cc
@@ -0,0 +1,36 @@
+//===-- ubsan_diag_standalone.cc ------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Diagnostic reporting for the standalone UBSan runtime.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ubsan_platform.h"
+#if CAN_SANITIZE_UB
+#include "ubsan_diag.h"
+
+using namespace __ubsan;
+
+extern "C" {
+SANITIZER_INTERFACE_ATTRIBUTE
+void __sanitizer_print_stack_trace() {
+  uptr top = 0;
+  uptr bottom = 0;
+  bool request_fast_unwind = common_flags()->fast_unwind_on_fatal;
+  if (request_fast_unwind)
+    __sanitizer::GetThreadStackTopAndBottom(false, &top, &bottom);
+
+  GET_CURRENT_PC_BP_SP;
+  (void)sp;
+  BufferedStackTrace stack;
+  stack.Unwind(kStackTraceMax, pc, bp, nullptr, top, bottom,
+               request_fast_unwind);
+  stack.Print();
+}
+} // extern "C"
+
+#endif  // CAN_SANITIZE_UB
diff --git a/libsanitizer/ubsan/ubsan_flags.cc b/libsanitizer/ubsan/ubsan_flags.cc
index 19f5de1727e..9a3ea4b51e5 100644
--- a/libsanitizer/ubsan/ubsan_flags.cc
+++ b/libsanitizer/ubsan/ubsan_flags.cc
@@ -43,6 +43,7 @@ void InitializeFlags() {
     CommonFlags cf;
     cf.CopyFrom(*common_flags());
     cf.print_summary = false;
+    cf.external_symbolizer_path = GetEnv("UBSAN_SYMBOLIZER_PATH");
     OverrideCommonFlags(cf);
   }
 
@@ -65,22 +66,8 @@ void InitializeFlags() {
 
 }  // namespace __ubsan
 
-extern "C" {
-
-#if !SANITIZER_SUPPORTS_WEAK_HOOKS
-SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
-const char *__ubsan_default_options() { return ""; }
-#endif
-
-#if SANITIZER_WINDOWS
-const char *__ubsan_default_default_options() { return ""; }
-# ifdef _WIN64
-#  pragma comment(linker, "/alternatename:__ubsan_default_options=__ubsan_default_default_options")
-# else
-#  pragma comment(linker, "/alternatename:___ubsan_default_options=___ubsan_default_default_options")
-# endif
-#endif
-
-}  // extern "C"
+SANITIZER_INTERFACE_WEAK_DEF(const char *, __ubsan_default_options, void) {
+  return "";
+}
 
 #endif  // CAN_SANITIZE_UB
diff --git a/libsanitizer/ubsan/ubsan_handlers.cc b/libsanitizer/ubsan/ubsan_handlers.cc
index 761ccef63f3..4d29832ae0d 100644
--- a/libsanitizer/ubsan/ubsan_handlers.cc
+++ b/libsanitizer/ubsan/ubsan_handlers.cc
@@ -36,17 +36,18 @@ bool ignoreReport(SourceLocation SLoc, ReportOptions Opts, ErrorType ET) {
 const char *TypeCheckKinds[] = {
     "load of", "store to", "reference binding to", "member access within",
     "member call on", "constructor call on", "downcast of", "downcast of",
-    "upcast of", "cast to virtual base of"};
+    "upcast of", "cast to virtual base of", "_Nonnull binding to"};
 }
 
 static void handleTypeMismatchImpl(TypeMismatchData *Data, ValueHandle Pointer,
                                    ReportOptions Opts) {
   Location Loc = Data->Loc.acquire();
 
+  uptr Alignment = (uptr)1 << Data->LogAlignment;
   ErrorType ET;
   if (!Pointer)
     ET = ErrorType::NullPointerUse;
-  else if (Data->Alignment && (Pointer & (Data->Alignment - 1)))
+  else if (Pointer & (Alignment - 1))
     ET = ErrorType::MisalignedPointerUse;
   else
     ET = ErrorType::InsufficientObjectSize;
@@ -72,8 +73,8 @@ static void handleTypeMismatchImpl(TypeMismatchData *Data, ValueHandle Pointer,
   case ErrorType::MisalignedPointerUse:
     Diag(Loc, DL_Error, "%0 misaligned address %1 for type %3, "
                         "which requires %2 byte alignment")
-        << TypeCheckKinds[Data->TypeCheckKind] << (void *)Pointer
-        << Data->Alignment << Data->Type;
+        << TypeCheckKinds[Data->TypeCheckKind] << (void *)Pointer << Alignment
+        << Data->Type;
     break;
   case ErrorType::InsufficientObjectSize:
     Diag(Loc, DL_Error, "%0 address %1 with insufficient space "
@@ -88,13 +89,13 @@ static void handleTypeMismatchImpl(TypeMismatchData *Data, ValueHandle Pointer,
     Diag(Pointer, DL_Note, "pointer points here");
 }
 
-void __ubsan::__ubsan_handle_type_mismatch(TypeMismatchData *Data,
-                                           ValueHandle Pointer) {
+void __ubsan::__ubsan_handle_type_mismatch_v1(TypeMismatchData *Data,
+                                              ValueHandle Pointer) {
   GET_REPORT_OPTIONS(false);
   handleTypeMismatchImpl(Data, Pointer, Opts);
 }
-void __ubsan::__ubsan_handle_type_mismatch_abort(TypeMismatchData *Data,
-                                                 ValueHandle Pointer) {
+void __ubsan::__ubsan_handle_type_mismatch_v1_abort(TypeMismatchData *Data,
+                                                    ValueHandle Pointer) {
   GET_REPORT_OPTIONS(true);
   handleTypeMismatchImpl(Data, Pointer, Opts);
   Die();
@@ -387,7 +388,7 @@ static void handleFloatCastOverflow(void *DataPtr, ValueHandle From,
   ScopedReport R(Opts, Loc, ET);
 
   Diag(Loc, DL_Error,
-       "value %0 is outside the range of representable values of type %2")
+       "%0 is outside the range of representable values of type %2")
       << Value(*FromType, From) << *FromType << *ToType;
 }
 
@@ -407,7 +408,8 @@ static void handleLoadInvalidValue(InvalidValueData *Data, ValueHandle Val,
   SourceLocation Loc = Data->Loc.acquire();
   // This check could be more precise if we used different handlers for
   // -fsanitize=bool and -fsanitize=enum.
-  bool IsBool = (0 == internal_strcmp(Data->Type.getTypeName(), "'bool'"));
+  bool IsBool = (0 == internal_strcmp(Data->Type.getTypeName(), "'bool'")) ||
+                (0 == internal_strncmp(Data->Type.getTypeName(), "'BOOL'", 6));
   ErrorType ET =
       IsBool ? ErrorType::InvalidBoolLoad : ErrorType::InvalidEnumLoad;
 
@@ -433,6 +435,30 @@ void __ubsan::__ubsan_handle_load_invalid_value_abort(InvalidValueData *Data,
   Die();
 }
 
+static void handleInvalidBuiltin(InvalidBuiltinData *Data, ReportOptions Opts) {
+  SourceLocation Loc = Data->Loc.acquire();
+  ErrorType ET = ErrorType::InvalidBuiltin;
+
+  if (ignoreReport(Loc, Opts, ET))
+    return;
+
+  ScopedReport R(Opts, Loc, ET);
+
+  Diag(Loc, DL_Error,
+       "passing zero to %0, which is not a valid argument")
+    << ((Data->Kind == BCK_CTZPassedZero) ? "ctz()" : "clz()");
+}
+
+void __ubsan::__ubsan_handle_invalid_builtin(InvalidBuiltinData *Data) {
+  GET_REPORT_OPTIONS(true);
+  handleInvalidBuiltin(Data, Opts);
+}
+void __ubsan::__ubsan_handle_invalid_builtin_abort(InvalidBuiltinData *Data) {
+  GET_REPORT_OPTIONS(true);
+  handleInvalidBuiltin(Data, Opts);
+  Die();
+}
+
 static void handleFunctionTypeMismatch(FunctionTypeMismatchData *Data,
                                        ValueHandle Function,
                                        ReportOptions Opts) {
@@ -469,8 +495,12 @@ void __ubsan::__ubsan_handle_function_type_mismatch_abort(
   Die();
 }
 
-static void handleNonNullReturn(NonNullReturnData *Data, ReportOptions Opts) {
-  SourceLocation Loc = Data->Loc.acquire();
+static void handleNonNullReturn(NonNullReturnData *Data, SourceLocation *LocPtr,
+                                ReportOptions Opts, bool IsAttr) {
+  if (!LocPtr)
+    UNREACHABLE("source location pointer is null!");
+
+  SourceLocation Loc = LocPtr->acquire();
   ErrorType ET = ErrorType::InvalidNullReturn;
 
   if (ignoreReport(Loc, Opts, ET))
@@ -481,21 +511,39 @@ static void handleNonNullReturn(NonNullReturnData *Data, ReportOptions Opts) {
   Diag(Loc, DL_Error, "null pointer returned from function declared to never "
                       "return null");
   if (!Data->AttrLoc.isInvalid())
-    Diag(Data->AttrLoc, DL_Note, "returns_nonnull attribute specified here");
+    Diag(Data->AttrLoc, DL_Note, "%0 specified here")
+        << (IsAttr ? "returns_nonnull attribute"
+                   : "_Nonnull return type annotation");
+}
+
+void __ubsan::__ubsan_handle_nonnull_return_v1(NonNullReturnData *Data,
+                                               SourceLocation *LocPtr) {
+  GET_REPORT_OPTIONS(false);
+  handleNonNullReturn(Data, LocPtr, Opts, true);
 }
 
-void __ubsan::__ubsan_handle_nonnull_return(NonNullReturnData *Data) {
+void __ubsan::__ubsan_handle_nonnull_return_v1_abort(NonNullReturnData *Data,
+                                                     SourceLocation *LocPtr) {
+  GET_REPORT_OPTIONS(true);
+  handleNonNullReturn(Data, LocPtr, Opts, true);
+  Die();
+}
+
+void __ubsan::__ubsan_handle_nullability_return_v1(NonNullReturnData *Data,
+                                                   SourceLocation *LocPtr) {
   GET_REPORT_OPTIONS(false);
-  handleNonNullReturn(Data, Opts);
+  handleNonNullReturn(Data, LocPtr, Opts, false);
 }
 
-void __ubsan::__ubsan_handle_nonnull_return_abort(NonNullReturnData *Data) {
+void __ubsan::__ubsan_handle_nullability_return_v1_abort(
+    NonNullReturnData *Data, SourceLocation *LocPtr) {
   GET_REPORT_OPTIONS(true);
-  handleNonNullReturn(Data, Opts);
+  handleNonNullReturn(Data, LocPtr, Opts, false);
   Die();
 }
 
-static void handleNonNullArg(NonNullArgData *Data, ReportOptions Opts) {
+static void handleNonNullArg(NonNullArgData *Data, ReportOptions Opts,
+                             bool IsAttr) {
   SourceLocation Loc = Data->Loc.acquire();
   ErrorType ET = ErrorType::InvalidNullArgument;
 
@@ -504,20 +552,34 @@ static void handleNonNullArg(NonNullArgData *Data, ReportOptions Opts) {
 
   ScopedReport R(Opts, Loc, ET);
 
-  Diag(Loc, DL_Error, "null pointer passed as argument %0, which is declared to "
-       "never be null") << Data->ArgIndex;
+  Diag(Loc, DL_Error,
+       "null pointer passed as argument %0, which is declared to "
+       "never be null")
+      << Data->ArgIndex;
   if (!Data->AttrLoc.isInvalid())
-    Diag(Data->AttrLoc, DL_Note, "nonnull attribute specified here");
+    Diag(Data->AttrLoc, DL_Note, "%0 specified here")
+        << (IsAttr ? "nonnull attribute" : "_Nonnull type annotation");
 }
 
 void __ubsan::__ubsan_handle_nonnull_arg(NonNullArgData *Data) {
   GET_REPORT_OPTIONS(false);
-  handleNonNullArg(Data, Opts);
+  handleNonNullArg(Data, Opts, true);
 }
 
 void __ubsan::__ubsan_handle_nonnull_arg_abort(NonNullArgData *Data) {
   GET_REPORT_OPTIONS(true);
-  handleNonNullArg(Data, Opts);
+  handleNonNullArg(Data, Opts, true);
+  Die();
+}
+
+void __ubsan::__ubsan_handle_nullability_arg(NonNullArgData *Data) {
+  GET_REPORT_OPTIONS(false);
+  handleNonNullArg(Data, Opts, false);
+}
+
+void __ubsan::__ubsan_handle_nullability_arg_abort(NonNullArgData *Data) {
+  GET_REPORT_OPTIONS(true);
+  handleNonNullArg(Data, Opts, false);
   Die();
 }
 
@@ -533,8 +595,19 @@ static void handlePointerOverflowImpl(PointerOverflowData *Data,
 
   ScopedReport R(Opts, Loc, ET);
 
-  Diag(Loc, DL_Error, "pointer index expression with base %0 overflowed to %1")
-    << (void *)Base << (void*)Result;
+  if ((sptr(Base) >= 0) == (sptr(Result) >= 0)) {
+    if (Base > Result)
+      Diag(Loc, DL_Error, "addition of unsigned offset to %0 overflowed to %1")
+          << (void *)Base << (void *)Result;
+    else
+      Diag(Loc, DL_Error,
+           "subtraction of unsigned offset from %0 overflowed to %1")
+          << (void *)Base << (void *)Result;
+  } else {
+    Diag(Loc, DL_Error,
+         "pointer index expression with base %0 overflowed to %1")
+        << (void *)Base << (void *)Result;
+  }
 }
 
 void __ubsan::__ubsan_handle_pointer_overflow(PointerOverflowData *Data,
@@ -577,32 +650,33 @@ static void handleCFIBadIcall(CFICheckFailData *Data, ValueHandle Function,
 }
 
 namespace __ubsan {
+
 #ifdef UBSAN_CAN_USE_CXXABI
-SANITIZER_WEAK_ATTRIBUTE
-void HandleCFIBadType(CFICheckFailData *Data, ValueHandle Vtable,
-                      bool ValidVtable, ReportOptions Opts);
-#else
-static void HandleCFIBadType(CFICheckFailData *Data, ValueHandle Vtable,
-                             bool ValidVtable, ReportOptions Opts) {
+
+#ifdef _WIN32
+
+extern "C" void __ubsan_handle_cfi_bad_type_default(CFICheckFailData *Data,
+                                                    ValueHandle Vtable,
+                                                    bool ValidVtable,
+                                                    ReportOptions Opts) {
   Die();
 }
-#endif
-}  // namespace __ubsan
 
-void __ubsan::__ubsan_handle_cfi_bad_icall(CFIBadIcallData *CallData,
-                                           ValueHandle Function) {
-  GET_REPORT_OPTIONS(false);
-  CFICheckFailData Data = {CFITCK_ICall, CallData->Loc, CallData->Type};
-  handleCFIBadIcall(&Data, Function, Opts);
-}
+WIN_WEAK_ALIAS(__ubsan_handle_cfi_bad_type, __ubsan_handle_cfi_bad_type_default)
+#else
+SANITIZER_WEAK_ATTRIBUTE
+#endif
+void __ubsan_handle_cfi_bad_type(CFICheckFailData *Data, ValueHandle Vtable,
+                                 bool ValidVtable, ReportOptions Opts);
 
-void __ubsan::__ubsan_handle_cfi_bad_icall_abort(CFIBadIcallData *CallData,
-                                                 ValueHandle Function) {
-  GET_REPORT_OPTIONS(true);
-  CFICheckFailData Data = {CFITCK_ICall, CallData->Loc, CallData->Type};
-  handleCFIBadIcall(&Data, Function, Opts);
+#else
+void __ubsan_handle_cfi_bad_type(CFICheckFailData *Data, ValueHandle Vtable,
+                                 bool ValidVtable, ReportOptions Opts) {
   Die();
 }
+#endif
+
+}  // namespace __ubsan
 
 void __ubsan::__ubsan_handle_cfi_check_fail(CFICheckFailData *Data,
                                             ValueHandle Value,
@@ -611,7 +685,7 @@ void __ubsan::__ubsan_handle_cfi_check_fail(CFICheckFailData *Data,
   if (Data->CheckKind == CFITCK_ICall)
     handleCFIBadIcall(Data, Value, Opts);
   else
-    HandleCFIBadType(Data, Value, ValidVtable, Opts);
+    __ubsan_handle_cfi_bad_type(Data, Value, ValidVtable, Opts);
 }
 
 void __ubsan::__ubsan_handle_cfi_check_fail_abort(CFICheckFailData *Data,
@@ -621,7 +695,7 @@ void __ubsan::__ubsan_handle_cfi_check_fail_abort(CFICheckFailData *Data,
   if (Data->CheckKind == CFITCK_ICall)
     handleCFIBadIcall(Data, Value, Opts);
   else
-    HandleCFIBadType(Data, Value, ValidVtable, Opts);
+    __ubsan_handle_cfi_bad_type(Data, Value, ValidVtable, Opts);
   Die();
 }
 
diff --git a/libsanitizer/ubsan/ubsan_handlers.h b/libsanitizer/ubsan/ubsan_handlers.h
index d04554acee3..c5e499cd68e 100644
--- a/libsanitizer/ubsan/ubsan_handlers.h
+++ b/libsanitizer/ubsan/ubsan_handlers.h
@@ -18,7 +18,7 @@ namespace __ubsan {
 struct TypeMismatchData {
   SourceLocation Loc;
   const TypeDescriptor &Type;
-  uptr Alignment;
+  unsigned char LogAlignment;
   unsigned char TypeCheckKind;
 };
 
@@ -35,7 +35,7 @@ struct TypeMismatchData {
 /// \brief Handle a runtime type check failure, caused by either a misaligned
 /// pointer, a null pointer, or a pointer to insufficient storage for the
 /// type.
-RECOVERABLE(type_mismatch, TypeMismatchData *Data, ValueHandle Pointer)
+RECOVERABLE(type_mismatch_v1, TypeMismatchData *Data, ValueHandle Pointer)
 
 struct OverflowData {
   SourceLocation Loc;
@@ -120,6 +120,21 @@ struct InvalidValueData {
 /// \brief Handle a load of an invalid value for the type.
 RECOVERABLE(load_invalid_value, InvalidValueData *Data, ValueHandle Val)
 
+/// Known builtin check kinds.
+/// Keep in sync with the enum of the same name in CodeGenFunction.h
+enum BuiltinCheckKind : unsigned char {
+  BCK_CTZPassedZero,
+  BCK_CLZPassedZero,
+};
+
+struct InvalidBuiltinData {
+  SourceLocation Loc;
+  unsigned char Kind;
+};
+
+/// Handle a builtin called in an invalid way.
+RECOVERABLE(invalid_builtin, InvalidBuiltinData *Data)
+
 struct FunctionTypeMismatchData {
   SourceLocation Loc;
   const TypeDescriptor &Type;
@@ -130,12 +145,13 @@ RECOVERABLE(function_type_mismatch,
             ValueHandle Val)
 
 struct NonNullReturnData {
-  SourceLocation Loc;
   SourceLocation AttrLoc;
 };
 
-/// \brief Handle returning null from function with returns_nonnull attribute.
-RECOVERABLE(nonnull_return, NonNullReturnData *Data)
+/// \brief Handle returning null from function with the returns_nonnull
+/// attribute, or a return type annotated with _Nonnull.
+RECOVERABLE(nonnull_return_v1, NonNullReturnData *Data, SourceLocation *Loc)
+RECOVERABLE(nullability_return_v1, NonNullReturnData *Data, SourceLocation *Loc)
 
 struct NonNullArgData {
   SourceLocation Loc;
@@ -143,8 +159,10 @@ struct NonNullArgData {
   int ArgIndex;
 };
 
-/// \brief Handle passing null pointer to function with nonnull attribute.
+/// \brief Handle passing null pointer to a function parameter with the nonnull
+/// attribute, or a _Nonnull type annotation.
 RECOVERABLE(nonnull_arg, NonNullArgData *Data)
+RECOVERABLE(nullability_arg, NonNullArgData *Data)
 
 struct PointerOverflowData {
   SourceLocation Loc;
@@ -163,23 +181,22 @@ enum CFITypeCheckKind : unsigned char {
   CFITCK_ICall,
 };
 
-struct CFIBadIcallData {
-  SourceLocation Loc;
-  const TypeDescriptor &Type;
-};
-
 struct CFICheckFailData {
   CFITypeCheckKind CheckKind;
   SourceLocation Loc;
   const TypeDescriptor &Type;
 };
 
-/// \brief Handle control flow integrity failure for indirect function calls.
-RECOVERABLE(cfi_bad_icall, CFIBadIcallData *Data, ValueHandle Function)
-
 /// \brief Handle control flow integrity failures.
 RECOVERABLE(cfi_check_fail, CFICheckFailData *Data, ValueHandle Function,
             uptr VtableIsValid)
+
+struct ReportOptions;
+
+extern "C" SANITIZER_INTERFACE_ATTRIBUTE void __ubsan_handle_cfi_bad_type(
+    CFICheckFailData *Data, ValueHandle Vtable, bool ValidVtable,
+    ReportOptions Opts);
+
 }
 
 #endif // UBSAN_HANDLERS_H
diff --git a/libsanitizer/ubsan/ubsan_handlers_cxx.cc b/libsanitizer/ubsan/ubsan_handlers_cxx.cc
index 007a1d6d0c2..bf729db6ce0 100644
--- a/libsanitizer/ubsan/ubsan_handlers_cxx.cc
+++ b/libsanitizer/ubsan/ubsan_handlers_cxx.cc
@@ -93,8 +93,8 @@ void __ubsan::__ubsan_handle_dynamic_type_cache_miss_abort(
 }
 
 namespace __ubsan {
-void HandleCFIBadType(CFICheckFailData *Data, ValueHandle Vtable,
-                      bool ValidVtable, ReportOptions Opts) {
+void __ubsan_handle_cfi_bad_type(CFICheckFailData *Data, ValueHandle Vtable,
+                                 bool ValidVtable, ReportOptions Opts) {
   SourceLocation Loc = Data->Loc.acquire();
   ErrorType ET = ErrorType::CFIBadType;
 
@@ -121,6 +121,7 @@ void HandleCFIBadType(CFICheckFailData *Data, ValueHandle Vtable,
     CheckKindStr = "cast to unrelated type";
     break;
   case CFITCK_ICall:
+  default:
     Die();
   }
 
@@ -142,22 +143,4 @@ void HandleCFIBadType(CFICheckFailData *Data, ValueHandle Vtable,
 }
 }  // namespace __ubsan
 
-void __ubsan::__ubsan_handle_cfi_bad_type(CFIBadTypeData *TypeData,
-                                          ValueHandle Vtable) {
-  GET_REPORT_OPTIONS(false);
-  CFITypeCheckKind TypeCheckKind
-    = static_cast<CFITypeCheckKind> (TypeData->TypeCheckKind);
-  CFICheckFailData Data = {TypeCheckKind, TypeData->Loc, TypeData->Type};
-  HandleCFIBadType(&Data, Vtable, false, Opts);
-}
-
-void __ubsan::__ubsan_handle_cfi_bad_type_abort(CFIBadTypeData *TypeData,
-                                                ValueHandle Vtable) {
-  GET_REPORT_OPTIONS(true);
-  CFITypeCheckKind TypeCheckKind
-    = static_cast<CFITypeCheckKind> (TypeData->TypeCheckKind);
-  CFICheckFailData Data = {TypeCheckKind, TypeData->Loc, TypeData->Type};
-  HandleCFIBadType(&Data, Vtable, false, Opts);
-}
-
 #endif // CAN_SANITIZE_UB
diff --git a/libsanitizer/ubsan/ubsan_handlers_cxx.h b/libsanitizer/ubsan/ubsan_handlers_cxx.h
index 6ace2b3472b..37382359b1e 100644
--- a/libsanitizer/ubsan/ubsan_handlers_cxx.h
+++ b/libsanitizer/ubsan/ubsan_handlers_cxx.h
@@ -23,12 +23,6 @@ struct DynamicTypeCacheMissData {
   unsigned char TypeCheckKind;
 };
 
-struct CFIBadTypeData {
-  SourceLocation Loc;
-  const TypeDescriptor &Type;
-  unsigned char TypeCheckKind;
-};
-
 /// \brief Handle a runtime type check failure, caused by an incorrect vptr.
 /// When this handler is called, all we know is that the type was not in the
 /// cache; this does not necessarily imply the existence of a bug.
@@ -38,13 +32,6 @@ void __ubsan_handle_dynamic_type_cache_miss(
 extern "C" SANITIZER_INTERFACE_ATTRIBUTE
 void __ubsan_handle_dynamic_type_cache_miss_abort(
   DynamicTypeCacheMissData *Data, ValueHandle Pointer, ValueHandle Hash);
-
-/// \brief Handle a control flow integrity check failure by printing a
-/// diagnostic.
-extern "C" SANITIZER_INTERFACE_ATTRIBUTE void
-__ubsan_handle_cfi_bad_type(CFIBadTypeData *Data, ValueHandle Vtable);
-extern "C" SANITIZER_INTERFACE_ATTRIBUTE void
-__ubsan_handle_cfi_bad_type_abort(CFIBadTypeData *Data, ValueHandle Vtable);
 }
 
 #endif // UBSAN_HANDLERS_H
diff --git a/libsanitizer/ubsan/ubsan_init.cc b/libsanitizer/ubsan/ubsan_init.cc
index 07f748109e7..9ae17f59ea1 100644
--- a/libsanitizer/ubsan/ubsan_init.cc
+++ b/libsanitizer/ubsan/ubsan_init.cc
@@ -21,11 +21,11 @@
 
 using namespace __ubsan;
 
-static enum {
-  UBSAN_MODE_UNKNOWN = 0,
-  UBSAN_MODE_STANDALONE,
-  UBSAN_MODE_PLUGIN
-} ubsan_mode;
+const char *__ubsan::GetSanititizerToolName() {
+  return "UndefinedBehaviorSanitizer";
+}
+
+static bool ubsan_initialized;
 static StaticSpinMutex ubsan_init_mu;
 
 static void CommonInit() {
@@ -33,45 +33,31 @@ static void CommonInit() {
 }
 
 static void CommonStandaloneInit() {
-  SanitizerToolName = "UndefinedBehaviorSanitizer";
-  InitializeFlags();
+  SanitizerToolName = GetSanititizerToolName();
   CacheBinaryName();
+  InitializeFlags();
   __sanitizer_set_report_path(common_flags()->log_path);
   AndroidLogInit();
   InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
   CommonInit();
-  ubsan_mode = UBSAN_MODE_STANDALONE;
 }
 
 void __ubsan::InitAsStandalone() {
-  if (SANITIZER_CAN_USE_PREINIT_ARRAY) {
-    CHECK_EQ(UBSAN_MODE_UNKNOWN, ubsan_mode);
-    CommonStandaloneInit();
-    return;
-  }
   SpinMutexLock l(&ubsan_init_mu);
-  CHECK_NE(UBSAN_MODE_PLUGIN, ubsan_mode);
-  if (ubsan_mode == UBSAN_MODE_UNKNOWN)
+  if (!ubsan_initialized) {
     CommonStandaloneInit();
-}
-
-void __ubsan::InitAsStandaloneIfNecessary() {
-  if (SANITIZER_CAN_USE_PREINIT_ARRAY) {
-    CHECK_NE(UBSAN_MODE_UNKNOWN, ubsan_mode);
-    return;
+    ubsan_initialized = true;
   }
-  SpinMutexLock l(&ubsan_init_mu);
-  if (ubsan_mode == UBSAN_MODE_UNKNOWN)
-    CommonStandaloneInit();
 }
 
+void __ubsan::InitAsStandaloneIfNecessary() { return InitAsStandalone(); }
+
 void __ubsan::InitAsPlugin() {
-#if !SANITIZER_CAN_USE_PREINIT_ARRAY
   SpinMutexLock l(&ubsan_init_mu);
-#endif
-  CHECK_EQ(UBSAN_MODE_UNKNOWN, ubsan_mode);
-  CommonInit();
-  ubsan_mode = UBSAN_MODE_PLUGIN;
+  if (!ubsan_initialized) {
+    CommonInit();
+    ubsan_initialized = true;
+  }
 }
 
 #endif  // CAN_SANITIZE_UB
diff --git a/libsanitizer/ubsan/ubsan_init.h b/libsanitizer/ubsan/ubsan_init.h
index 6a8366f82bf..73bd3f3580f 100644
--- a/libsanitizer/ubsan/ubsan_init.h
+++ b/libsanitizer/ubsan/ubsan_init.h
@@ -13,6 +13,9 @@
 
 namespace __ubsan {
 
+// Get the full tool name for UBSan.
+const char *GetSanititizerToolName();
+
 // Initialize UBSan as a standalone tool. Typically should be called early
 // during initialization.
 void InitAsStandalone();
diff --git a/libsanitizer/ubsan/ubsan_init_standalone.cc b/libsanitizer/ubsan/ubsan_init_standalone.cc
index 1630fd724fb..67223bea629 100644
--- a/libsanitizer/ubsan/ubsan_init_standalone.cc
+++ b/libsanitizer/ubsan/ubsan_init_standalone.cc
@@ -16,17 +16,17 @@
 
 #include "sanitizer_common/sanitizer_internal_defs.h"
 #include "ubsan_init.h"
+#include "ubsan_signals_standalone.h"
+
+namespace __ubsan {
 
-#if SANITIZER_CAN_USE_PREINIT_ARRAY
-__attribute__((section(".preinit_array"), used))
-void (*__local_ubsan_preinit)(void) = __ubsan::InitAsStandalone;
-#else
-// Use a dynamic initializer.
 class UbsanStandaloneInitializer {
  public:
   UbsanStandaloneInitializer() {
-    __ubsan::InitAsStandalone();
+    InitAsStandalone();
+    InitializeDeadlySignals();
   }
 };
 static UbsanStandaloneInitializer ubsan_standalone_initializer;
-#endif  // SANITIZER_CAN_USE_PREINIT_ARRAY
+
+} // namespace __ubsan
diff --git a/libsanitizer/ubsan/ubsan_init_standalone_preinit.cc b/libsanitizer/ubsan/ubsan_init_standalone_preinit.cc
new file mode 100644
index 00000000000..80b2f3c3fd4
--- /dev/null
+++ b/libsanitizer/ubsan/ubsan_init_standalone_preinit.cc
@@ -0,0 +1,35 @@
+//===-- ubsan_init_standalone_preinit.cc
+//------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Initialization of standalone UBSan runtime.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ubsan_platform.h"
+#if !CAN_SANITIZE_UB
+#error "UBSan is not supported on this platform!"
+#endif
+
+#include "sanitizer_common/sanitizer_internal_defs.h"
+#include "ubsan_init.h"
+#include "ubsan_signals_standalone.h"
+
+#if SANITIZER_CAN_USE_PREINIT_ARRAY
+
+namespace __ubsan {
+
+static void PreInitAsStandalone() {
+  InitAsStandalone();
+  InitializeDeadlySignals();
+}
+
+} // namespace __ubsan
+
+__attribute__((section(".preinit_array"), used)) void (*__local_ubsan_preinit)(
+    void) = __ubsan::PreInitAsStandalone;
+#endif // SANITIZER_CAN_USE_PREINIT_ARRAY
diff --git a/libsanitizer/ubsan/ubsan_interface.inc b/libsanitizer/ubsan/ubsan_interface.inc
new file mode 100644
index 00000000000..1b0bc425da7
--- /dev/null
+++ b/libsanitizer/ubsan/ubsan_interface.inc
@@ -0,0 +1,52 @@
+//===-- ubsan_interface.inc -----------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// Ubsan interface list.
+//===----------------------------------------------------------------------===//
+INTERFACE_FUNCTION(__ubsan_handle_add_overflow)
+INTERFACE_FUNCTION(__ubsan_handle_add_overflow_abort)
+INTERFACE_FUNCTION(__ubsan_handle_builtin_unreachable)
+INTERFACE_FUNCTION(__ubsan_handle_cfi_bad_type)
+INTERFACE_FUNCTION(__ubsan_handle_cfi_check_fail)
+INTERFACE_FUNCTION(__ubsan_handle_cfi_check_fail_abort)
+INTERFACE_FUNCTION(__ubsan_handle_divrem_overflow)
+INTERFACE_FUNCTION(__ubsan_handle_divrem_overflow_abort)
+INTERFACE_FUNCTION(__ubsan_handle_dynamic_type_cache_miss)
+INTERFACE_FUNCTION(__ubsan_handle_dynamic_type_cache_miss_abort)
+INTERFACE_FUNCTION(__ubsan_handle_float_cast_overflow)
+INTERFACE_FUNCTION(__ubsan_handle_float_cast_overflow_abort)
+INTERFACE_FUNCTION(__ubsan_handle_function_type_mismatch)
+INTERFACE_FUNCTION(__ubsan_handle_function_type_mismatch_abort)
+INTERFACE_FUNCTION(__ubsan_handle_invalid_builtin)
+INTERFACE_FUNCTION(__ubsan_handle_invalid_builtin_abort)
+INTERFACE_FUNCTION(__ubsan_handle_load_invalid_value)
+INTERFACE_FUNCTION(__ubsan_handle_load_invalid_value_abort)
+INTERFACE_FUNCTION(__ubsan_handle_missing_return)
+INTERFACE_FUNCTION(__ubsan_handle_mul_overflow)
+INTERFACE_FUNCTION(__ubsan_handle_mul_overflow_abort)
+INTERFACE_FUNCTION(__ubsan_handle_negate_overflow)
+INTERFACE_FUNCTION(__ubsan_handle_negate_overflow_abort)
+INTERFACE_FUNCTION(__ubsan_handle_nonnull_arg)
+INTERFACE_FUNCTION(__ubsan_handle_nonnull_arg_abort)
+INTERFACE_FUNCTION(__ubsan_handle_nonnull_return_v1)
+INTERFACE_FUNCTION(__ubsan_handle_nonnull_return_v1_abort)
+INTERFACE_FUNCTION(__ubsan_handle_nullability_arg)
+INTERFACE_FUNCTION(__ubsan_handle_nullability_arg_abort)
+INTERFACE_FUNCTION(__ubsan_handle_nullability_return_v1)
+INTERFACE_FUNCTION(__ubsan_handle_nullability_return_v1_abort)
+INTERFACE_FUNCTION(__ubsan_handle_out_of_bounds)
+INTERFACE_FUNCTION(__ubsan_handle_out_of_bounds_abort)
+INTERFACE_FUNCTION(__ubsan_handle_pointer_overflow)
+INTERFACE_FUNCTION(__ubsan_handle_pointer_overflow_abort)
+INTERFACE_FUNCTION(__ubsan_handle_shift_out_of_bounds)
+INTERFACE_FUNCTION(__ubsan_handle_shift_out_of_bounds_abort)
+INTERFACE_FUNCTION(__ubsan_handle_sub_overflow)
+INTERFACE_FUNCTION(__ubsan_handle_sub_overflow_abort)
+INTERFACE_FUNCTION(__ubsan_handle_type_mismatch_v1)
+INTERFACE_FUNCTION(__ubsan_handle_type_mismatch_v1_abort)
+INTERFACE_FUNCTION(__ubsan_handle_vla_bound_not_positive)
+INTERFACE_FUNCTION(__ubsan_handle_vla_bound_not_positive_abort)
+INTERFACE_WEAK_FUNCTION(__ubsan_default_options)
diff --git a/libsanitizer/ubsan/ubsan_platform.h b/libsanitizer/ubsan/ubsan_platform.h
index fa4e1a191aa..e73df632302 100644
--- a/libsanitizer/ubsan/ubsan_platform.h
+++ b/libsanitizer/ubsan/ubsan_platform.h
@@ -13,12 +13,13 @@
 
 #ifndef CAN_SANITIZE_UB
 // Other platforms should be easy to add, and probably work as-is.
-#if (defined(__linux__) || defined(__FreeBSD__) || defined(__APPLE__)) && \
-    (defined(__x86_64__) || defined(__i386__) || defined(__arm__) || \
-     defined(__aarch64__) || defined(__mips__) || defined(__powerpc64__) || \
+#if (defined(__linux__) || defined(__FreeBSD__) || defined(__APPLE__) ||       \
+     defined(__NetBSD__)) &&                                                   \
+    (defined(__x86_64__) || defined(__i386__) || defined(__arm__) ||           \
+     defined(__aarch64__) || defined(__mips__) || defined(__powerpc64__) ||    \
      defined(__s390__))
 # define CAN_SANITIZE_UB 1
-#elif defined(_WIN32)
+#elif defined(_WIN32) || defined(__Fuchsia__)
 # define CAN_SANITIZE_UB 1
 #else
 # define CAN_SANITIZE_UB 0
diff --git a/libsanitizer/ubsan/ubsan_signals_standalone.cc b/libsanitizer/ubsan/ubsan_signals_standalone.cc
new file mode 100644
index 00000000000..eb9b99ce9ac
--- /dev/null
+++ b/libsanitizer/ubsan/ubsan_signals_standalone.cc
@@ -0,0 +1,52 @@
+//=-- ubsan_signals_standalone.cc
+//------------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Installs signal handlers and related interceptors for UBSan standalone.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ubsan_platform.h"
+#if CAN_SANITIZE_UB
+#include "interception/interception.h"
+#include "sanitizer_common/sanitizer_stacktrace.h"
+#include "ubsan_diag.h"
+#include "ubsan_init.h"
+
+#define COMMON_INTERCEPT_FUNCTION(name) INTERCEPT_FUNCTION(name)
+#include "sanitizer_common/sanitizer_signal_interceptors.inc"
+
+namespace __ubsan {
+
+#if SANITIZER_FUCHSIA
+void InitializeDeadlySignals() {}
+#else
+static void OnStackUnwind(const SignalContext &sig, const void *,
+                          BufferedStackTrace *stack) {
+  GetStackTraceWithPcBpAndContext(stack, kStackTraceMax, sig.pc, sig.bp,
+                                  sig.context,
+                                  common_flags()->fast_unwind_on_fatal);
+}
+
+static void UBsanOnDeadlySignal(int signo, void *siginfo, void *context) {
+  HandleDeadlySignal(siginfo, context, GetTid(), &OnStackUnwind, nullptr);
+}
+
+static bool is_initialized = false;
+
+void InitializeDeadlySignals() {
+  if (is_initialized)
+    return;
+  is_initialized = true;
+  InitializeSignalInterceptors();
+  InstallDeadlySignalHandlers(&UBsanOnDeadlySignal);
+}
+#endif
+
+} // namespace __ubsan
+
+#endif // CAN_SANITIZE_UB
diff --git a/libsanitizer/ubsan/ubsan_signals_standalone.h b/libsanitizer/ubsan/ubsan_signals_standalone.h
new file mode 100644
index 00000000000..65e64f205ca
--- /dev/null
+++ b/libsanitizer/ubsan/ubsan_signals_standalone.h
@@ -0,0 +1,23 @@
+//=-- ubsan_signals_standalone.h
+//------------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Installs signal handlers and related interceptors for UBSan standalone.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef UBSAN_SIGNALS_STANDALONE_H
+#define UBSAN_SIGNALS_STANDALONE_H
+
+namespace __ubsan {
+
+// Initializes signal handlers and interceptors.
+void InitializeDeadlySignals();
+
+} // namespace __ubsan
+
+#endif // UBSAN_SIGNALS_STANDALONE_H
diff --git a/libsanitizer/ubsan/ubsan_type_hash_itanium.cc b/libsanitizer/ubsan/ubsan_type_hash_itanium.cc
index 790b126815d..9df316e14be 100644
--- a/libsanitizer/ubsan/ubsan_type_hash_itanium.cc
+++ b/libsanitizer/ubsan/ubsan_type_hash_itanium.cc
@@ -195,9 +195,9 @@ struct VtablePrefix {
 };
 VtablePrefix *getVtablePrefix(void *Vtable) {
   VtablePrefix *Vptr = reinterpret_cast<VtablePrefix*>(Vtable);
-  if (!Vptr)
-    return nullptr;
   VtablePrefix *Prefix = Vptr - 1;
+  if (!IsAccessibleMemoryRange((uptr)Prefix, sizeof(VtablePrefix)))
+    return nullptr;
   if (!Prefix->TypeInfo)
     // This can't possibly be a valid vtable.
     return nullptr;
diff --git a/libsanitizer/ubsan/ubsan_win_dll_thunk.cc b/libsanitizer/ubsan/ubsan_win_dll_thunk.cc
new file mode 100644
index 00000000000..1091ac0351a
--- /dev/null
+++ b/libsanitizer/ubsan/ubsan_win_dll_thunk.cc
@@ -0,0 +1,19 @@
+//===-- ubsan_win_dll_thunk.cc --------------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a family of thunks that should be statically linked into
+// the DLLs that have instrumentation in order to delegate the calls to the
+// shared runtime that lives in the main binary.
+// See https://github.com/google/sanitizers/issues/209 for the details.
+//===----------------------------------------------------------------------===//
+#ifdef SANITIZER_DLL_THUNK
+#include "sanitizer_common/sanitizer_win_dll_thunk.h"
+// Ubsan interface functions.
+#define INTERFACE_FUNCTION(Name) INTERCEPT_SANITIZER_FUNCTION(Name)
+#define INTERFACE_WEAK_FUNCTION(Name) INTERCEPT_SANITIZER_WEAK_FUNCTION(Name)
+#include "ubsan_interface.inc"
+#endif // SANITIZER_DLL_THUNK
diff --git a/libsanitizer/ubsan/ubsan_win_dynamic_runtime_thunk.cc b/libsanitizer/ubsan/ubsan_win_dynamic_runtime_thunk.cc
new file mode 100644
index 00000000000..6ab5ae388a3
--- /dev/null
+++ b/libsanitizer/ubsan/ubsan_win_dynamic_runtime_thunk.cc
@@ -0,0 +1,19 @@
+//===-- ubsan_win_dynamic_runtime_thunk.cc --------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines things that need to be present in the application modules
+// to interact with Ubsan, when it is included in a dll.
+//
+//===----------------------------------------------------------------------===//
+#ifdef SANITIZER_DYNAMIC_RUNTIME_THUNK
+#define SANITIZER_IMPORT_INTERFACE 1
+#include "sanitizer_common/sanitizer_win_defs.h"
+// Define weak alias for all weak functions imported from ubsan.
+#define INTERFACE_FUNCTION(Name)
+#define INTERFACE_WEAK_FUNCTION(Name) WIN_WEAK_IMPORT_DEF(Name)
+#include "ubsan_interface.inc"
+#endif // SANITIZER_DYNAMIC_RUNTIME_THUNK
diff --git a/libsanitizer/ubsan/ubsan_win_weak_interception.cc b/libsanitizer/ubsan/ubsan_win_weak_interception.cc
new file mode 100644
index 00000000000..98c8c27b2fa
--- /dev/null
+++ b/libsanitizer/ubsan/ubsan_win_weak_interception.cc
@@ -0,0 +1,21 @@
+//===-- ubsan_win_weak_interception.cc ------------------------------------===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This module should be included in Ubsan when it is implemented as a shared
+// library on Windows (dll), in order to delegate the calls of weak functions to
+// the implementation in the main executable when a strong definition is
+// provided.
+//===----------------------------------------------------------------------===//
+#ifdef SANITIZER_DYNAMIC
+#include "sanitizer_common/sanitizer_win_weak_interception.h"
+#include "ubsan_flags.h"
+// Check if strong definitions for weak functions are present in the main
+// executable. If that is the case, override dll functions to point to strong
+// implementations.
+#define INTERFACE_FUNCTION(Name)
+#define INTERFACE_WEAK_FUNCTION(Name) INTERCEPT_SANITIZER_WEAK_FUNCTION(Name)
+#include "ubsan_interface.inc"
+#endif // SANITIZER_DYNAMIC