| //===-- asan_win_dynamic_runtime_thunk.cc ---------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file is a part of AddressSanitizer, an address sanity checker. |
| // |
| // This file defines things that need to be present in the application modules |
| // to interact with the ASan DLL runtime correctly and can't be implemented |
| // using the default "import library" generated when linking the DLL RTL. |
| // |
| // This includes: |
| // - creating weak aliases to default implementation imported from asan dll. |
| // - forwarding the detect_stack_use_after_return runtime option |
| // - working around deficiencies of the MD runtime |
| // - installing a custom SEH handler |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifdef SANITIZER_DYNAMIC_RUNTIME_THUNK |
| #define SANITIZER_IMPORT_INTERFACE 1 |
| #include "sanitizer_common/sanitizer_win_defs.h" |
| #define WIN32_LEAN_AND_MEAN |
| #include <windows.h> |
| |
| // Define weak alias for all weak functions imported from asan dll. |
| #define INTERFACE_FUNCTION(Name) |
| #define INTERFACE_WEAK_FUNCTION(Name) WIN_WEAK_IMPORT_DEF(Name) |
| #include "asan_interface.inc" |
| |
| // First, declare CRT sections we'll be using in this file |
| #pragma section(".CRT$XIB", long, read) // NOLINT |
| #pragma section(".CRT$XID", long, read) // NOLINT |
| #pragma section(".CRT$XCAB", long, read) // NOLINT |
| #pragma section(".CRT$XTW", long, read) // NOLINT |
| #pragma section(".CRT$XTY", long, read) // NOLINT |
| #pragma section(".CRT$XLAB", long, read) // NOLINT |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // Define a copy of __asan_option_detect_stack_use_after_return that should be |
| // used when linking an MD runtime with a set of object files on Windows. |
| // |
| // The ASan MD runtime dllexports '__asan_option_detect_stack_use_after_return', |
| // so normally we would just dllimport it. Unfortunately, the dllimport |
| // attribute adds __imp_ prefix to the symbol name of a variable. |
| // Since in general we don't know if a given TU is going to be used |
| // with a MT or MD runtime and we don't want to use ugly __imp_ names on Windows |
| // just to work around this issue, let's clone the variable that is constant |
| // after initialization anyways. |
| extern "C" { |
| __declspec(dllimport) int __asan_should_detect_stack_use_after_return(); |
| int __asan_option_detect_stack_use_after_return; |
| |
| __declspec(dllimport) void* __asan_get_shadow_memory_dynamic_address(); |
| void* __asan_shadow_memory_dynamic_address; |
| } |
| |
| static int InitializeClonedVariables() { |
| __asan_option_detect_stack_use_after_return = |
| __asan_should_detect_stack_use_after_return(); |
| __asan_shadow_memory_dynamic_address = |
| __asan_get_shadow_memory_dynamic_address(); |
| return 0; |
| } |
| |
| static void NTAPI asan_thread_init(void *mod, unsigned long reason, |
| void *reserved) { |
| if (reason == DLL_PROCESS_ATTACH) InitializeClonedVariables(); |
| } |
| |
| // Our cloned variables must be initialized before C/C++ constructors. If TLS |
| // is used, our .CRT$XLAB initializer will run first. If not, our .CRT$XIB |
| // initializer is needed as a backup. |
| __declspec(allocate(".CRT$XIB")) int (*__asan_initialize_cloned_variables)() = |
| InitializeClonedVariables; |
| __declspec(allocate(".CRT$XLAB")) void (NTAPI *__asan_tls_init)(void *, |
| unsigned long, void *) = asan_thread_init; |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // For some reason, the MD CRT doesn't call the C/C++ terminators during on DLL |
| // unload or on exit. ASan relies on LLVM global_dtors to call |
| // __asan_unregister_globals on these events, which unfortunately doesn't work |
| // with the MD runtime, see PR22545 for the details. |
| // To work around this, for each DLL we schedule a call to UnregisterGlobals |
| // using atexit() that calls a small subset of C terminators |
| // where LLVM global_dtors is placed. Fingers crossed, no other C terminators |
| // are there. |
| extern "C" int __cdecl atexit(void (__cdecl *f)(void)); |
| extern "C" void __cdecl _initterm(void *a, void *b); |
| |
| namespace { |
| __declspec(allocate(".CRT$XTW")) void* before_global_dtors = 0; |
| __declspec(allocate(".CRT$XTY")) void* after_global_dtors = 0; |
| |
| void UnregisterGlobals() { |
| _initterm(&before_global_dtors, &after_global_dtors); |
| } |
| |
| int ScheduleUnregisterGlobals() { |
| return atexit(UnregisterGlobals); |
| } |
| } // namespace |
| |
| // We need to call 'atexit(UnregisterGlobals);' as early as possible, but after |
| // atexit() is initialized (.CRT$XIC). As this is executed before C++ |
| // initializers (think ctors for globals), UnregisterGlobals gets executed after |
| // dtors for C++ globals. |
| __declspec(allocate(".CRT$XID")) |
| int (*__asan_schedule_unregister_globals)() = ScheduleUnregisterGlobals; |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // ASan SEH handling. |
| // We need to set the ASan-specific SEH handler at the end of CRT initialization |
| // of each module (see also asan_win.cc). |
| extern "C" { |
| __declspec(dllimport) int __asan_set_seh_filter(); |
| static int SetSEHFilter() { return __asan_set_seh_filter(); } |
| |
| // Unfortunately, putting a pointer to __asan_set_seh_filter into |
| // __asan_intercept_seh gets optimized out, so we have to use an extra function. |
| __declspec(allocate(".CRT$XCAB")) int (*__asan_seh_interceptor)() = |
| SetSEHFilter; |
| } |
| |
| WIN_FORCE_LINK(__asan_dso_reg_hook) |
| |
| #endif // SANITIZER_DYNAMIC_RUNTIME_THUNK |