55 lines · cpp
1//===-- asan_win_dynamic_runtime_thunk.cpp --------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// This file is a part of AddressSanitizer, an address sanity checker.10//11// This file defines things that need to be present for application modules12// that are dynamic linked with the C Runtime.13//14//===----------------------------------------------------------------------===//15 16#ifdef SANITIZER_DYNAMIC_RUNTIME_THUNK17# define WIN32_LEAN_AND_MEAN18# include <windows.h>19 20# include "asan_win_common_runtime_thunk.h"21# include "sanitizer_common/sanitizer_win_defs.h"22 23////////////////////////////////////////////////////////////////////////////////24// For some reason, the MD CRT doesn't call the C/C++ terminators during on DLL25// unload or on exit. ASan relies on LLVM global_dtors to call26// __asan_unregister_globals on these events, which unfortunately doesn't work27// with the MD runtime, see PR22545 for the details.28// To work around this, for each DLL we schedule a call to UnregisterGlobals29// using atexit() that calls a small subset of C terminators30// where LLVM global_dtors is placed. Fingers crossed, no other C terminators31// are there.32extern "C" int __cdecl atexit(void(__cdecl *f)(void));33extern "C" void __cdecl _initterm(void *a, void *b);34 35namespace {36__declspec(allocate(".CRT$XTW")) void *before_global_dtors = 0;37__declspec(allocate(".CRT$XTY")) void *after_global_dtors = 0;38 39void UnregisterGlobals() {40 _initterm(&before_global_dtors, &after_global_dtors);41}42 43int ScheduleUnregisterGlobals() { return atexit(UnregisterGlobals); }44} // namespace45 46// We need to call 'atexit(UnregisterGlobals);' as early as possible, but after47// atexit() is initialized (.CRT$XIC). As this is executed before C++48// initializers (think ctors for globals), UnregisterGlobals gets executed after49// dtors for C++ globals.50extern "C" __declspec(allocate(".CRT$XID")) int (51 *__asan_schedule_unregister_globals)() = ScheduleUnregisterGlobals;52WIN_FORCE_LINK(__asan_schedule_unregister_globals)53 54#endif // SANITIZER_DYNAMIC_RUNTIME_THUNK55