1 files changed, 29 insertions, 19 deletions

diff --git a/compiler-rt/lib/asan/asan_thread.cpp b/compiler-rt/lib/asan/asan_thread.cpp
index 343fd079fa02..a1734a6f896d 100644
--- a/compiler-rt/lib/asan/asan_thread.cpp
+++ b/compiler-rt/lib/asan/asan_thread.cpp
@@ -41,8 +41,6 @@ void AsanThreadContext::OnFinished() {
 }
 
 static ThreadRegistry *asan_thread_registry;
-static ThreadArgRetval *thread_data;
-
 static Mutex mu_for_thread_context;
 static LowLevelAllocator allocator_for_thread_context;
 
@@ -65,12 +63,9 @@ static void InitThreads() {
   // MIPS requires aligned address
   static ALIGNED(alignof(
       ThreadRegistry)) char thread_registry_placeholder[sizeof(ThreadRegistry)];
-  static ALIGNED(alignof(
-      ThreadArgRetval)) char thread_data_placeholder[sizeof(ThreadArgRetval)];
 
   asan_thread_registry =
       new (thread_registry_placeholder) ThreadRegistry(GetAsanThreadContext);
-  thread_data = new (thread_data_placeholder) ThreadArgRetval();
   initialized = true;
 }
 
@@ -79,11 +74,6 @@ ThreadRegistry &asanThreadRegistry() {
   return *asan_thread_registry;
 }
 
-ThreadArgRetval &asanThreadArgRetval() {
-  InitThreads();
-  return *thread_data;
-}
-
 AsanThreadContext *GetThreadContextByTidLocked(u32 tid) {
   return static_cast<AsanThreadContext *>(
       asanThreadRegistry().GetThreadLocked(tid));
@@ -494,15 +484,9 @@ __asan::AsanThread *GetAsanThreadByOsIDLocked(tid_t os_id) {
 
 // --- Implementation of LSan-specific functions --- {{{1
 namespace __lsan {
-void LockThreadRegistry() {
-  __asan::asanThreadRegistry().Lock();
-  __asan::asanThreadArgRetval().Lock();
-}
+void LockThreadRegistry() { __asan::asanThreadRegistry().Lock(); }
 
-void UnlockThreadRegistry() {
-  __asan::asanThreadArgRetval().Unlock();
-  __asan::asanThreadRegistry().Unlock();
-}
+void UnlockThreadRegistry() { __asan::asanThreadRegistry().Unlock(); }
 
 static ThreadRegistry *GetAsanThreadRegistryLocked() {
   __asan::asanThreadRegistry().CheckLocked();
@@ -557,7 +541,33 @@ void GetThreadExtraStackRangesLocked(InternalMmapVector<Range> *ranges) {
 }
 
 void GetAdditionalThreadContextPtrsLocked(InternalMmapVector<uptr> *ptrs) {
-  __asan::asanThreadArgRetval().GetAllPtrsLocked(ptrs);
+  GetAsanThreadRegistryLocked()->RunCallbackForEachThreadLocked(
+      [](ThreadContextBase *tctx, void *ptrs) {
+        // Look for the arg pointer of threads that have been created or are
+        // running. This is necessary to prevent false positive leaks due to the
+        // AsanThread holding the only live reference to a heap object.  This
+        // can happen because the `pthread_create()` interceptor doesn't wait
+        // for the child thread to start before returning and thus loosing the
+        // the only live reference to the heap object on the stack.
+
+        __asan::AsanThreadContext *atctx =
+            static_cast<__asan::AsanThreadContext *>(tctx);
+
+        // Note ThreadStatusRunning is required because there is a small window
+        // where the thread status switches to `ThreadStatusRunning` but the
+        // `arg` pointer still isn't on the stack yet.
+        if (atctx->status != ThreadStatusCreated &&
+            atctx->status != ThreadStatusRunning)
+          return;
+
+        uptr thread_arg = reinterpret_cast<uptr>(atctx->thread->get_arg());
+        if (!thread_arg)
+          return;
+
+        auto ptrsVec = reinterpret_cast<InternalMmapVector<uptr> *>(ptrs);
+        ptrsVec->push_back(thread_arg);
+      },
+      ptrs);
 }
 
 void GetRunningThreadsLocked(InternalMmapVector<tid_t> *threads) {