Index: lib/tsan/rtl/tsan_debugging.cc
===================================================================
--- lib/tsan/rtl/tsan_debugging.cc
+++ lib/tsan/rtl/tsan_debugging.cc
@@ -15,6 +15,8 @@
 #include "tsan_report.h"
 #include "tsan_rtl.h"
 
+#include "sanitizer_common/sanitizer_stackdepot.h"
+
 using namespace __tsan;
 
 static const char *ReportTypeDescription(ReportType typ) {
@@ -160,3 +162,26 @@
   *tid = rep->unique_tids[idx];
   return 1;
 }
+
+SANITIZER_INTERFACE_ATTRIBUTE
+int __tsan_get_alloc_stack(uptr addr, uptr *trace, uptr size, int *thread_id,
+                           uptr *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;
+}
Index: lib/tsan/rtl/tsan_interface.h
===================================================================
--- lib/tsan/rtl/tsan_interface.h
+++ lib/tsan/rtl/tsan_interface.h
@@ -136,6 +136,10 @@
 SANITIZER_INTERFACE_ATTRIBUTE
 int __tsan_get_report_unique_tid(void *report, uptr idx, int *tid);
 
+SANITIZER_INTERFACE_ATTRIBUTE
+int __tsan_get_alloc_stack(uptr addr, uptr *trace, uptr size, int *thread_id,
+                           uptr *os_id);
+
 #endif  // SANITIZER_GO
 
 #ifdef __cplusplus
Index: test/tsan/debug_alloc_stack.cc
===================================================================
--- test/tsan/debug_alloc_stack.cc
+++ test/tsan/debug_alloc_stack.cc
@@ -0,0 +1,80 @@
+// RUN: %clangxx_tsan -O0 %s -o %t
+// RUN: env %env_tsan_opts=stack_trace_format=DEFAULT %deflake %run %t 2>&1 | FileCheck %s
+
+#include "test.h"
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#if !__APPLE__
+#include <sys/types.h>
+#endif
+
+extern "C" int __tsan_get_alloc_stack(void *addr, void **trace, size_t size,
+                                      int *thread_id, void *os_id);
+
+char *mem;
+void alloc_func() { mem = (char *)malloc(10); }
+
+void *AllocThread(void *context) {
+  uint64_t tid;
+#if __APPLE__
+  pthread_threadid_np(NULL, &tid);
+#else
+  tid = gettid();
+#endif
+  fprintf(stderr, "alloc stack thread os id = 0x%llx\n", tid);
+  // CHECK: alloc stack thread os id = [[THREAD_OS_ID:0x[0-9a-f]+]]
+  alloc_func();
+  return NULL;
+}
+
+void *RaceThread(void *context) {
+  *mem = 'a';
+  barrier_wait(&barrier);
+  return NULL;
+}
+
+int main() {
+  pthread_t t;
+  barrier_init(&barrier, 2);
+
+  pthread_create(&t, NULL, AllocThread, NULL);
+  pthread_join(t, NULL);
+
+  void *trace[100];
+  size_t num_frames = 100;
+  int thread_id;
+  void *thread_os_id;
+  num_frames =
+      __tsan_get_alloc_stack(mem, trace, num_frames, &thread_id, &thread_os_id);
+
+  fprintf(stderr, "alloc stack retval %s\n",
+          (num_frames > 0 && num_frames < 10) ? "ok" : "");
+  // CHECK: alloc stack retval ok
+  fprintf(stderr, "thread id = %d\n", thread_id);
+  // CHECK: thread id = 1
+  fprintf(stderr, "thread os id = 0x%llx\n", (uint64_t)thread_os_id);
+  // CHECK: thread os id = [[THREAD_OS_ID]]
+  fprintf(stderr, "%p\n", trace[0]);
+  // CHECK: [[ALLOC_FRAME_0:0x[0-9a-f]+]]
+  fprintf(stderr, "%p\n", trace[1]);
+  // CHECK: [[ALLOC_FRAME_1:0x[0-9a-f]+]]
+  fprintf(stderr, "%p\n", trace[2]);
+  // CHECK: [[ALLOC_FRAME_2:0x[0-9a-f]+]]
+
+  pthread_create(&t, NULL, RaceThread, NULL);
+  barrier_wait(&barrier);
+  mem[0] = 'b';
+  pthread_join(t, NULL);
+
+  free(mem);
+
+  return 0;
+}
+
+// CHECK: WARNING: ThreadSanitizer: data race
+// CHECK: Location is heap block of size 10 at {{.*}} allocated by thread T1
+// CHECK: #0 [[ALLOC_FRAME_0]]
+// CHECK: #1 [[ALLOC_FRAME_1]] in alloc_func
+// CHECK: #2 [[ALLOC_FRAME_2]] in AllocThread