1 //===-- asan_win_common_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-exception 6 // 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 in the application modules 12 // to interact with the ASan DLL runtime correctly and can't be implemented 13 // using the default "import library" generated when linking the DLL. 14 // 15 // This includes: 16 // - Cloning shadow memory dynamic address from ASAN DLL 17 // - Creating weak aliases to default implementation imported from asan dll 18 // - Forwarding the detect_stack_use_after_return runtime option 19 // - installing a custom SEH handler 20 // 21 //===----------------------------------------------------------------------===// 22 23 #if defined(SANITIZER_DYNAMIC_RUNTIME_THUNK) || \ 24 defined(SANITIZER_STATIC_RUNTIME_THUNK) 25 # define SANITIZER_IMPORT_INTERFACE 1 26 # define WIN32_LEAN_AND_MEAN 27 # include "asan_win_common_runtime_thunk.h" 28 29 # include <windows.h> 30 31 # include "sanitizer_common/sanitizer_win_defs.h" 32 # include "sanitizer_common/sanitizer_win_thunk_interception.h" 33 34 // Define weak alias for all weak functions imported from asan dll. 35 # define INTERFACE_FUNCTION(Name) 36 # define INTERFACE_WEAK_FUNCTION(Name) REGISTER_WEAK_FUNCTION(Name) 37 # include "asan_interface.inc" 38 39 //////////////////////////////////////////////////////////////////////////////// 40 // Define a copy of __asan_option_detect_stack_use_after_return that should be 41 // used when linking an MD runtime with a set of object files on Windows. 42 // 43 // The ASan MD runtime dllexports '__asan_option_detect_stack_use_after_return', 44 // so normally we would just dllimport it. Unfortunately, the dllimport 45 // attribute adds __imp_ prefix to the symbol name of a variable. 46 // Since in general we don't know if a given TU is going to be used 47 // with a MT or MD runtime and we don't want to use ugly __imp_ names on Windows 48 // just to work around this issue, let's clone the variable that is constant 49 // after initialization anyways. 50 51 extern "C" { 52 __declspec(dllimport) int __asan_should_detect_stack_use_after_return(); 53 int __asan_option_detect_stack_use_after_return; 54 55 __declspec(dllimport) void *__asan_get_shadow_memory_dynamic_address(); 56 void *__asan_shadow_memory_dynamic_address; 57 58 static void __asan_initialize_cloned_variables() { 59 __asan_option_detect_stack_use_after_return = 60 __asan_should_detect_stack_use_after_return(); 61 __asan_shadow_memory_dynamic_address = 62 __asan_get_shadow_memory_dynamic_address(); 63 } 64 } 65 66 static int asan_thunk_init() { 67 __asan_initialize_cloned_variables(); 68 69 # ifdef SANITIZER_STATIC_RUNTIME_THUNK 70 __asan_initialize_static_thunk(); 71 # endif 72 73 return 0; 74 } 75 76 static void WINAPI asan_thread_init(void *mod, unsigned long reason, 77 void *reserved) { 78 if (reason == DLL_PROCESS_ATTACH) { 79 asan_thunk_init(); 80 } 81 } 82 83 // Our cloned variables must be initialized before C/C++ constructors. If TLS 84 // is used, our .CRT$XLAB initializer will run first. If not, our .CRT$XIB 85 // initializer is needed as a backup. 86 extern "C" __declspec(allocate(".CRT$XIB")) int (*__asan_thunk_init)() = 87 asan_thunk_init; 88 WIN_FORCE_LINK(__asan_thunk_init) 89 90 extern "C" __declspec(allocate(".CRT$XLAB")) void(WINAPI *__asan_tls_init)( 91 void *, unsigned long, void *) = asan_thread_init; 92 WIN_FORCE_LINK(__asan_tls_init) 93 94 //////////////////////////////////////////////////////////////////////////////// 95 // ASan SEH handling. 96 // We need to set the ASan-specific SEH handler at the end of CRT initialization 97 // of each module (see also asan_win.cpp). 98 extern "C" { 99 __declspec(dllimport) int __asan_set_seh_filter(); 100 static int SetSEHFilter() { return __asan_set_seh_filter(); } 101 102 // Unfortunately, putting a pointer to __asan_set_seh_filter into 103 // __asan_intercept_seh gets optimized out, so we have to use an extra function. 104 extern "C" __declspec(allocate(".CRT$XCAB")) int (*__asan_seh_interceptor)() = 105 SetSEHFilter; 106 WIN_FORCE_LINK(__asan_seh_interceptor) 107 } 108 109 WIN_FORCE_LINK(__asan_dso_reg_hook) 110 111 #endif // defined(SANITIZER_DYNAMIC_RUNTIME_THUNK) || 112 // defined(SANITIZER_STATIC_RUNTIME_THUNK) 113