Add lsan interceptors for libdispatch functions on darwin

Summary:
This is required for standalone LSan to work with libdispatch worker threads,
and is a slimmed down version of the functionality provided for ASan
in asan_mac.cc.

Reviewers: alekseyshl, kubamracek, glider, kcc

Subscribers: mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D34247

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@305695 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 199 insertions, 5 deletions

diff --git a/lib/lsan/CMakeLists.txt b/lib/lsan/CMakeLists.txt
index 55c825f5c..bd3a96f32 100644
--- a/lib/lsan/CMakeLists.txt
+++ b/lib/lsan/CMakeLists.txt
@@ -13,6 +13,7 @@ set(LSAN_SOURCES
   lsan_allocator.cc
   lsan_linux.cc
   lsan_interceptors.cc
+  lsan_mac.cc
   lsan_malloc_mac.cc
   lsan_preinit.cc
   lsan_thread.cc)
diff --git a/lib/lsan/lsan.h b/lib/lsan/lsan.h
index 1061d2fcf..7446e9507 100644
--- a/lib/lsan/lsan.h
+++ b/lib/lsan/lsan.h
@@ -38,6 +38,8 @@
   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();
diff --git a/lib/lsan/lsan_common_mac.cc b/lib/lsan/lsan_common_mac.cc
index 114dd8c90..adde3a1b4 100644
--- a/lib/lsan/lsan_common_mac.cc
+++ b/lib/lsan/lsan_common_mac.cc
@@ -79,8 +79,7 @@ void EnableInThisThread() {
 
 u32 GetCurrentThread() {
   thread_local_data_t *data = get_tls_val(false);
-  CHECK(data);
-  return data->current_thread_id;
+  return data ? data->current_thread_id : kInvalidTid;
 }
 
 void SetCurrentThread(u32 tid) { get_tls_val(true)->current_thread_id = tid; }
diff --git a/lib/lsan/lsan_mac.cc b/lib/lsan/lsan_mac.cc
new file mode 100644
index 000000000..1a6f5f489
--- /dev/null
+++ b/lib/lsan/lsan_mac.cc
@@ -0,0 +1,192 @@
+//===-- lsan_mac.cc -------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// 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/lib/lsan/lsan_thread.cc b/lib/lsan/lsan_thread.cc
index 0ea7a6e97..4404c8cc5 100644
--- a/lib/lsan/lsan_thread.cc
+++ b/lib/lsan/lsan_thread.cc
@@ -77,7 +77,7 @@ u32 ThreadCreate(u32 parent_tid, uptr user_id, bool detached) {
                                        /* arg */ nullptr);
 }
 
-void ThreadStart(u32 tid, tid_t os_id) {
+void ThreadStart(u32 tid, tid_t os_id, bool workerthread) {
   OnStartedArgs args;
   uptr stack_size = 0;
   uptr tls_size = 0;
@@ -87,7 +87,7 @@ void ThreadStart(u32 tid, tid_t 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, /*workerthread*/ false, &args);
+  thread_registry->StartThread(tid, os_id, workerthread, &args);
 }
 
 void ThreadFinish() {
diff --git a/lib/lsan/lsan_thread.h b/lib/lsan/lsan_thread.h
index 73e080e26..b16d3d915 100644
--- a/lib/lsan/lsan_thread.h
+++ b/lib/lsan/lsan_thread.h
@@ -45,7 +45,7 @@ class ThreadContext : public ThreadContextBase {
 
 void InitializeThreadRegistry();
 
-void ThreadStart(u32 tid, tid_t 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);