[winasan] Unpoison the stack in NtTerminateThread
In long-running builds we've seen some ASan complaints during thread creation that we suspect are due to leftover poisoning from previous threads whose stacks occupied that memory. This patch adds a hook that unpoisons the stack just before the NtTerminateThread syscall.
@@ -154,6 +154,14 @@ INTERCEPTOR_WINAPI(DWORD, CreateThread,
asan_thread_start, t, thr_flags, tid);
}
+INTERCEPTOR_WINAPI(void, NtTerminateThread, void *rcx) {
+ // Unpoison the terminating 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);
+ return REAL(NtTerminateThread(rcx));
+}
+
// }}}
namespace __asan {
@@ -161,7 +169,9 @@ namespace __asan {
void InitializePlatformInterceptors() {
ASAN_INTERCEPT_FUNC(CreateThread);
ASAN_INTERCEPT_FUNC(SetUnhandledExceptionFilter);
-
+ CHECK(::__interception::OverrideFunction("NtTerminateThread",
+ (uptr)WRAP(NtTerminateThread),
+ (uptr *)&REAL(NtTerminateThread)));
#ifdef _WIN64
ASAN_INTERCEPT_FUNC(__C_specific_handler);
#else
