Index: compiler-rt/trunk/lib/asan/asan_win.cc
===================================================================
--- compiler-rt/trunk/lib/asan/asan_win.cc
+++ compiler-rt/trunk/lib/asan/asan_win.cc
@@ -354,6 +354,19 @@
     unsigned long, void *) = asan_thread_init;
 #endif
 
+static void NTAPI asan_thread_exit(void *module, DWORD reason, void *reserved) {
+  if (reason == DLL_THREAD_DETACH) {
+    // Unpoison the thread's stack because the memory may be re-used.
+    NT_TIB *tib = (NT_TIB *)NtCurrentTeb();
+    uptr stackSize = (uptr)tib->StackBase - (uptr)tib->StackLimit;
+    __asan_unpoison_memory_region(tib->StackLimit, stackSize);
+  }
+}
+
+#pragma section(".CRT$XLY", long, read)  // NOLINT
+__declspec(allocate(".CRT$XLY")) void (NTAPI *__asan_tls_exit)(void *,
+    unsigned long, void *) = asan_thread_exit;
+
 WIN_FORCE_LINK(__asan_dso_reg_hook)
 
 // }}}