| 1 | //===-- asan_win_dynamic_runtime_thunk.cpp --------------------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | // This file is a part of AddressSanitizer, an address sanity checker. |
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| 10 | // |
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| 11 | // This file defines things that need to be present for application modules |
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| 12 | // that are dynamic linked with the C Runtime. |
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| 13 | // |
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| 14 | //===----------------------------------------------------------------------===// |
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| 15 | |
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| 16 | #ifdef SANITIZER_DYNAMIC_RUNTIME_THUNK |
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| 17 | # define WIN32_LEAN_AND_MEAN |
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| 18 | # include <windows.h> |
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| 19 | |
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| 20 | # include "asan_win_common_runtime_thunk.h" |
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| 21 | # include "sanitizer_common/sanitizer_win_defs.h" |
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| 22 | |
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| 23 | //////////////////////////////////////////////////////////////////////////////// |
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| 24 | // For some reason, the MD CRT doesn't call the C/C++ terminators during on DLL |
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| 25 | // unload or on exit. ASan relies on LLVM global_dtors to call |
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| 26 | // __asan_unregister_globals on these events, which unfortunately doesn't work |
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| 27 | // with the MD runtime, see PR22545 for the details. |
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| 28 | // To work around this, for each DLL we schedule a call to UnregisterGlobals |
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| 29 | // using atexit() that calls a small subset of C terminators |
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| 30 | // where LLVM global_dtors is placed. Fingers crossed, no other C terminators |
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| 31 | // are there. |
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| 32 | extern "C" int __cdecl atexit(void(__cdecl *f)(void)); |
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| 33 | extern "C" void __cdecl _initterm(void *a, void *b); |
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| 34 | |
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| 35 | namespace { |
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| 36 | __declspec(allocate(".CRT$XTW" )) void *before_global_dtors = 0; |
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| 37 | __declspec(allocate(".CRT$XTY" )) void *after_global_dtors = 0; |
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| 38 | |
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| 39 | void UnregisterGlobals() { |
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| 40 | _initterm(&before_global_dtors, &after_global_dtors); |
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| 41 | } |
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| 42 | |
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| 43 | int ScheduleUnregisterGlobals() { return atexit(UnregisterGlobals); } |
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| 44 | } // namespace |
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| 45 | |
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| 46 | // We need to call 'atexit(UnregisterGlobals);' as early as possible, but after |
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| 47 | // atexit() is initialized (.CRT$XIC). As this is executed before C++ |
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| 48 | // initializers (think ctors for globals), UnregisterGlobals gets executed after |
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| 49 | // dtors for C++ globals. |
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| 50 | extern "C" __declspec(allocate(".CRT$XID" )) int ( |
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| 51 | *__asan_schedule_unregister_globals)() = ScheduleUnregisterGlobals; |
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| 52 | WIN_FORCE_LINK(__asan_schedule_unregister_globals) |
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| 53 | |
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| 54 | #endif // SANITIZER_DYNAMIC_RUNTIME_THUNK |
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| 55 | |
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