[msan] Introduce MsanThread. Move thread-local allocator cache out of TLS.

This reduces .tbss from 109K down to almost nothing.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@205618 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 40 insertions, 13 deletions

diff --git a/lib/msan/msan_allocator.cc b/lib/msan/msan_allocator.cc
index 3c74142bc..90b9b31fb 100644
--- a/lib/msan/msan_allocator.cc
+++ b/lib/msan/msan_allocator.cc
@@ -15,6 +15,8 @@
 #include "sanitizer_common/sanitizer_allocator.h"
 #include "sanitizer_common/sanitizer_stackdepot.h"
 #include "msan.h"
+#include "msan_allocator.h"
+#include "msan_thread.h"
 
 namespace __msan {
 
@@ -48,8 +50,9 @@ typedef LargeMmapAllocator<MsanMapUnmapCallback> SecondaryAllocator;
 typedef CombinedAllocator<PrimaryAllocator, AllocatorCache,
                           SecondaryAllocator> Allocator;
 
-static THREADLOCAL AllocatorCache cache;
 static Allocator allocator;
+static AllocatorCache fallback_allocator_cache;
+static SpinMutex fallback_mutex;
 
 static int inited = 0;
 
@@ -60,35 +63,51 @@ static inline void Init() {
   allocator.Init();
 }
 
-void MsanAllocatorThreadFinish() {
-  allocator.SwallowCache(&cache);
+AllocatorCache *GetAllocatorCache(MsanThreadLocalMallocStorage *ms) {
+  CHECK(ms);
+  CHECK_LE(sizeof(AllocatorCache), sizeof(ms->allocator_cache));
+  return reinterpret_cast<AllocatorCache *>(ms->allocator_cache);
 }
 
-static void *MsanAllocate(StackTrace *stack, uptr size,
-                          uptr alignment, bool zeroise) {
+void MsanThreadLocalMallocStorage::CommitBack() {
+  allocator.SwallowCache(GetAllocatorCache(this));
+}
+
+static void *MsanAllocate(StackTrace *stack, uptr size, uptr alignment,
+                          bool zeroise) {
   Init();
   if (size > kMaxAllowedMallocSize) {
     Report("WARNING: MemorySanitizer failed to allocate %p bytes\n",
            (void *)size);
     return AllocatorReturnNull();
   }
-  void *res = allocator.Allocate(&cache, size, alignment, false);
-  Metadata *meta = reinterpret_cast<Metadata*>(allocator.GetMetaData(res));
+  MsanThread *t = GetCurrentThread();
+  void *allocated;
+  if (t) {
+    AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
+    allocated = allocator.Allocate(cache, size, alignment, false);
+  } else {
+    SpinMutexLock l(&fallback_mutex);
+    AllocatorCache *cache = &fallback_allocator_cache;
+    allocated = allocator.Allocate(cache, size, alignment, false);
+  }
+  Metadata *meta =
+      reinterpret_cast<Metadata *>(allocator.GetMetaData(allocated));
   meta->requested_size = size;
   if (zeroise) {
-    __msan_clear_and_unpoison(res, size);
+    __msan_clear_and_unpoison(allocated, size);
   } else if (flags()->poison_in_malloc) {
-    __msan_poison(res, size);
+    __msan_poison(allocated, size);
     if (__msan_get_track_origins()) {
       u32 stack_id = StackDepotPut(stack->trace, stack->size);
       CHECK(stack_id);
       CHECK_EQ((stack_id >> 31),
                0);  // Higher bit is occupied by stack origins.
-      __msan_set_origin(res, size, stack_id);
+      __msan_set_origin(allocated, size, stack_id);
     }
   }
-  MSAN_MALLOC_HOOK(res, size);
-  return res;
+  MSAN_MALLOC_HOOK(allocated, size);
+  return allocated;
 }
 
 void MsanDeallocate(StackTrace *stack, void *p) {
@@ -110,7 +129,15 @@ void MsanDeallocate(StackTrace *stack, void *p) {
       __msan_set_origin(p, size, stack_id);
     }
   }
-  allocator.Deallocate(&cache, p);
+  MsanThread *t = GetCurrentThread();
+  if (t) {
+    AllocatorCache *cache = GetAllocatorCache(&t->malloc_storage());
+    allocator.Deallocate(cache, p);
+  } else {
+    SpinMutexLock l(&fallback_mutex);
+    AllocatorCache *cache = &fallback_allocator_cache;
+    allocator.Deallocate(cache, p);
+  }
 }
 
 void *MsanReallocate(StackTrace *stack, void *old_p, uptr new_size,