1 //===-- sanitizer_win_dll_thunk.h -----------------------------------------===// 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 // This header provide helper macros to delegate calls to the shared runtime 9 // that lives in the main executable. It should be included to dll_thunks that 10 // will be linked to the dlls, when the sanitizer is a static library included 11 // in the main executable. 12 //===----------------------------------------------------------------------===// 13 #ifndef SANITIZER_WIN_DLL_THUNK_H 14 #define SANITIZER_WIN_DLL_THUNK_H 15 #include "sanitizer_internal_defs.h" 16 17 namespace __sanitizer { 18 uptr dllThunkGetRealAddrOrDie(const char *name); 19 20 int dllThunkIntercept(const char* main_function, uptr dll_function); 21 22 int dllThunkInterceptWhenPossible(const char* main_function, 23 const char* default_function, uptr dll_function); 24 } 25 26 extern "C" int __dll_thunk_init(); 27 28 // ----------------- Function interception helper macros -------------------- // 29 // Override dll_function with main_function from main executable. 30 #define INTERCEPT_OR_DIE(main_function, dll_function) \ 31 static int intercept_##dll_function() { \ 32 return __sanitizer::dllThunkIntercept(main_function, (__sanitizer::uptr) \ 33 dll_function); \ 34 } \ 35 __pragma(section(".DLLTH$M", long, read)) \ 36 __declspec(allocate(".DLLTH$M")) int (*__dll_thunk_##dll_function)() = \ 37 intercept_##dll_function; 38 39 // Try to override dll_function with main_function from main executable. 40 // If main_function is not present, override dll_function with default_function. 41 #define INTERCEPT_WHEN_POSSIBLE(main_function, default_function, dll_function) \ 42 static int intercept_##dll_function() { \ 43 return __sanitizer::dllThunkInterceptWhenPossible(main_function, \ 44 default_function, (__sanitizer::uptr)dll_function); \ 45 } \ 46 __pragma(section(".DLLTH$M", long, read)) \ 47 __declspec(allocate(".DLLTH$M")) int (*__dll_thunk_##dll_function)() = \ 48 intercept_##dll_function; 49 50 // -------------------- Function interception macros ------------------------ // 51 // Special case of hooks -- ASan own interface functions. Those are only called 52 // after __asan_init, thus an empty implementation is sufficient. 53 #define INTERCEPT_SANITIZER_FUNCTION(name) \ 54 extern "C" __declspec(noinline) void name() { \ 55 volatile int prevent_icf = (__LINE__ << 8) ^ __COUNTER__; \ 56 static const char function_name[] = #name; \ 57 for (const char* ptr = &function_name[0]; *ptr; ++ptr) \ 58 prevent_icf ^= *ptr; \ 59 (void)prevent_icf; \ 60 __debugbreak(); \ 61 } \ 62 INTERCEPT_OR_DIE(#name, name) 63 64 // Special case of hooks -- Weak functions, could be redefined in the main 65 // executable, but that is not necessary, so we shouldn't die if we can not find 66 // a reference. Instead, when the function is not present in the main executable 67 // we consider the default impl provided by asan library. 68 #define INTERCEPT_SANITIZER_WEAK_FUNCTION(name) \ 69 extern "C" __declspec(noinline) void name() { \ 70 volatile int prevent_icf = (__LINE__ << 8) ^ __COUNTER__; \ 71 static const char function_name[] = #name; \ 72 for (const char* ptr = &function_name[0]; *ptr; ++ptr) \ 73 prevent_icf ^= *ptr; \ 74 (void)prevent_icf; \ 75 __debugbreak(); \ 76 } \ 77 INTERCEPT_WHEN_POSSIBLE(#name, STRINGIFY(WEAK_EXPORT_NAME(name)), name) 78 79 // We can't define our own version of strlen etc. because that would lead to 80 // link-time or even type mismatch errors. Instead, we can declare a function 81 // just to be able to get its address. Me may miss the first few calls to the 82 // functions since it can be called before __dll_thunk_init, but that would lead 83 // to false negatives in the startup code before user's global initializers, 84 // which isn't a big deal. 85 #define INTERCEPT_LIBRARY_FUNCTION(name) \ 86 extern "C" void name(); \ 87 INTERCEPT_OR_DIE(STRINGIFY(WRAP(name)), name) 88 89 // Use these macros for functions that could be called before __dll_thunk_init() 90 // is executed and don't lead to errors if defined (free, malloc, etc). 91 #define INTERCEPT_WRAP_V_V(name) \ 92 extern "C" void name() { \ 93 typedef decltype(name) *fntype; \ 94 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 95 fn(); \ 96 } \ 97 INTERCEPT_OR_DIE(#name, name); 98 99 #define INTERCEPT_WRAP_V_W(name) \ 100 extern "C" void name(void *arg) { \ 101 typedef decltype(name) *fntype; \ 102 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 103 fn(arg); \ 104 } \ 105 INTERCEPT_OR_DIE(#name, name); 106 107 #define INTERCEPT_WRAP_V_WW(name) \ 108 extern "C" void name(void *arg1, void *arg2) { \ 109 typedef decltype(name) *fntype; \ 110 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 111 fn(arg1, arg2); \ 112 } \ 113 INTERCEPT_OR_DIE(#name, name); 114 115 #define INTERCEPT_WRAP_V_WWW(name) \ 116 extern "C" void name(void *arg1, void *arg2, void *arg3) { \ 117 typedef decltype(name) *fntype; \ 118 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 119 fn(arg1, arg2, arg3); \ 120 } \ 121 INTERCEPT_OR_DIE(#name, name); 122 123 #define INTERCEPT_WRAP_W_V(name) \ 124 extern "C" void *name() { \ 125 typedef decltype(name) *fntype; \ 126 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 127 return fn(); \ 128 } \ 129 INTERCEPT_OR_DIE(#name, name); 130 131 #define INTERCEPT_WRAP_W_W(name) \ 132 extern "C" void *name(void *arg) { \ 133 typedef decltype(name) *fntype; \ 134 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 135 return fn(arg); \ 136 } \ 137 INTERCEPT_OR_DIE(#name, name); 138 139 #define INTERCEPT_WRAP_W_WW(name) \ 140 extern "C" void *name(void *arg1, void *arg2) { \ 141 typedef decltype(name) *fntype; \ 142 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 143 return fn(arg1, arg2); \ 144 } \ 145 INTERCEPT_OR_DIE(#name, name); 146 147 #define INTERCEPT_WRAP_W_WWW(name) \ 148 extern "C" void *name(void *arg1, void *arg2, void *arg3) { \ 149 typedef decltype(name) *fntype; \ 150 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 151 return fn(arg1, arg2, arg3); \ 152 } \ 153 INTERCEPT_OR_DIE(#name, name); 154 155 #define INTERCEPT_WRAP_W_WWWW(name) \ 156 extern "C" void *name(void *arg1, void *arg2, void *arg3, void *arg4) { \ 157 typedef decltype(name) *fntype; \ 158 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 159 return fn(arg1, arg2, arg3, arg4); \ 160 } \ 161 INTERCEPT_OR_DIE(#name, name); 162 163 #define INTERCEPT_WRAP_W_WWWWW(name) \ 164 extern "C" void *name(void *arg1, void *arg2, void *arg3, void *arg4, \ 165 void *arg5) { \ 166 typedef decltype(name) *fntype; \ 167 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 168 return fn(arg1, arg2, arg3, arg4, arg5); \ 169 } \ 170 INTERCEPT_OR_DIE(#name, name); 171 172 #define INTERCEPT_WRAP_W_WWWWWW(name) \ 173 extern "C" void *name(void *arg1, void *arg2, void *arg3, void *arg4, \ 174 void *arg5, void *arg6) { \ 175 typedef decltype(name) *fntype; \ 176 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 177 return fn(arg1, arg2, arg3, arg4, arg5, arg6); \ 178 } \ 179 INTERCEPT_OR_DIE(#name, name); 180 181 #endif // SANITIZER_WIN_DLL_THUNK_H 182
Indexes created Sat Feb 28 05:31:39 UTC 2026