1 //===-- sanitizer_win_dll_thunk.h -----------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // This header provide helper macros to delegate calls to the shared runtime 10 // that lives in the main executable. It should be included to dll_thunks that 11 // will be linked to the dlls, when the sanitizer is a static library included 12 // in the main executable. 13 //===----------------------------------------------------------------------===// 14 #ifndef SANITIZER_WIN_DLL_THUNK_H 15 #define SANITIZER_WIN_DLL_THUNK_H 16 #include "sanitizer_internal_defs.h" 17 18 namespace __sanitizer { 19 uptr dllThunkGetRealAddrOrDie(const char *name); 20 21 int dllThunkIntercept(const char* main_function, uptr dll_function); 22 23 int dllThunkInterceptWhenPossible(const char* main_function, 24 const char* default_function, uptr dll_function); 25 } 26 27 extern "C" int __dll_thunk_init(); 28 29 // ----------------- Function interception helper macros -------------------- // 30 // Override dll_function with main_function from main executable. 31 #define INTERCEPT_OR_DIE(main_function, dll_function) \ 32 static int intercept_##dll_function() { \ 33 return __sanitizer::dllThunkIntercept(main_function, (__sanitizer::uptr) \ 34 dll_function); \ 35 } \ 36 __pragma(section(".DLLTH$M", long, read)) \ 37 __declspec(allocate(".DLLTH$M")) int (*__dll_thunk_##dll_function)() = \ 38 intercept_##dll_function; 39 40 // Try to override dll_function with main_function from main executable. 41 // If main_function is not present, override dll_function with default_function. 42 #define INTERCEPT_WHEN_POSSIBLE(main_function, default_function, dll_function) \ 43 static int intercept_##dll_function() { \ 44 return __sanitizer::dllThunkInterceptWhenPossible(main_function, \ 45 default_function, (__sanitizer::uptr)dll_function); \ 46 } \ 47 __pragma(section(".DLLTH$M", long, read)) \ 48 __declspec(allocate(".DLLTH$M")) int (*__dll_thunk_##dll_function)() = \ 49 intercept_##dll_function; 50 51 // -------------------- Function interception macros ------------------------ // 52 // Special case of hooks -- ASan own interface functions. Those are only called 53 // after __asan_init, thus an empty implementation is sufficient. 54 #define INTERCEPT_SANITIZER_FUNCTION(name) \ 55 extern "C" __declspec(noinline) void name() { \ 56 volatile int prevent_icf = (__LINE__ << 8) ^ __COUNTER__; \ 57 static const char function_name[] = #name; \ 58 for (const char* ptr = &function_name[0]; *ptr; ++ptr) \ 59 prevent_icf ^= *ptr; \ 60 (void)prevent_icf; \ 61 __debugbreak(); \ 62 } \ 63 INTERCEPT_OR_DIE(#name, name) 64 65 // Special case of hooks -- Weak functions, could be redefined in the main 66 // executable, but that is not necessary, so we shouldn't die if we can not find 67 // a reference. Instead, when the function is not present in the main executable 68 // we consider the default impl provided by asan library. 69 #define INTERCEPT_SANITIZER_WEAK_FUNCTION(name) \ 70 extern "C" __declspec(noinline) void name() { \ 71 volatile int prevent_icf = (__LINE__ << 8) ^ __COUNTER__; \ 72 static const char function_name[] = #name; \ 73 for (const char* ptr = &function_name[0]; *ptr; ++ptr) \ 74 prevent_icf ^= *ptr; \ 75 (void)prevent_icf; \ 76 __debugbreak(); \ 77 } \ 78 INTERCEPT_WHEN_POSSIBLE(#name, STRINGIFY(WEAK_EXPORT_NAME(name)), name) 79 80 // We can't define our own version of strlen etc. because that would lead to 81 // link-time or even type mismatch errors. Instead, we can declare a function 82 // just to be able to get its address. Me may miss the first few calls to the 83 // functions since it can be called before __dll_thunk_init, but that would lead 84 // to false negatives in the startup code before user's global initializers, 85 // which isn't a big deal. 86 #define INTERCEPT_LIBRARY_FUNCTION(name) \ 87 extern "C" void name(); \ 88 INTERCEPT_OR_DIE(WRAPPER_NAME(name), name) 89 90 // Use these macros for functions that could be called before __dll_thunk_init() 91 // is executed and don't lead to errors if defined (free, malloc, etc). 92 #define INTERCEPT_WRAP_V_V(name) \ 93 extern "C" void name() { \ 94 typedef decltype(name) *fntype; \ 95 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 96 fn(); \ 97 } \ 98 INTERCEPT_OR_DIE(#name, name); 99 100 #define INTERCEPT_WRAP_V_W(name) \ 101 extern "C" void name(void *arg) { \ 102 typedef decltype(name) *fntype; \ 103 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 104 fn(arg); \ 105 } \ 106 INTERCEPT_OR_DIE(#name, name); 107 108 #define INTERCEPT_WRAP_V_WW(name) \ 109 extern "C" void name(void *arg1, void *arg2) { \ 110 typedef decltype(name) *fntype; \ 111 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 112 fn(arg1, arg2); \ 113 } \ 114 INTERCEPT_OR_DIE(#name, name); 115 116 #define INTERCEPT_WRAP_V_WWW(name) \ 117 extern "C" void name(void *arg1, void *arg2, void *arg3) { \ 118 typedef decltype(name) *fntype; \ 119 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 120 fn(arg1, arg2, arg3); \ 121 } \ 122 INTERCEPT_OR_DIE(#name, name); 123 124 #define INTERCEPT_WRAP_W_V(name) \ 125 extern "C" void *name() { \ 126 typedef decltype(name) *fntype; \ 127 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 128 return fn(); \ 129 } \ 130 INTERCEPT_OR_DIE(#name, name); 131 132 #define INTERCEPT_WRAP_W_W(name) \ 133 extern "C" void *name(void *arg) { \ 134 typedef decltype(name) *fntype; \ 135 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 136 return fn(arg); \ 137 } \ 138 INTERCEPT_OR_DIE(#name, name); 139 140 #define INTERCEPT_WRAP_W_WW(name) \ 141 extern "C" void *name(void *arg1, void *arg2) { \ 142 typedef decltype(name) *fntype; \ 143 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 144 return fn(arg1, arg2); \ 145 } \ 146 INTERCEPT_OR_DIE(#name, name); 147 148 #define INTERCEPT_WRAP_W_WWW(name) \ 149 extern "C" void *name(void *arg1, void *arg2, void *arg3) { \ 150 typedef decltype(name) *fntype; \ 151 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 152 return fn(arg1, arg2, arg3); \ 153 } \ 154 INTERCEPT_OR_DIE(#name, name); 155 156 #define INTERCEPT_WRAP_W_WWWW(name) \ 157 extern "C" void *name(void *arg1, void *arg2, void *arg3, void *arg4) { \ 158 typedef decltype(name) *fntype; \ 159 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 160 return fn(arg1, arg2, arg3, arg4); \ 161 } \ 162 INTERCEPT_OR_DIE(#name, name); 163 164 #define INTERCEPT_WRAP_W_WWWWW(name) \ 165 extern "C" void *name(void *arg1, void *arg2, void *arg3, void *arg4, \ 166 void *arg5) { \ 167 typedef decltype(name) *fntype; \ 168 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 169 return fn(arg1, arg2, arg3, arg4, arg5); \ 170 } \ 171 INTERCEPT_OR_DIE(#name, name); 172 173 #define INTERCEPT_WRAP_W_WWWWWW(name) \ 174 extern "C" void *name(void *arg1, void *arg2, void *arg3, void *arg4, \ 175 void *arg5, void *arg6) { \ 176 typedef decltype(name) *fntype; \ 177 static fntype fn = (fntype)__sanitizer::dllThunkGetRealAddrOrDie(#name); \ 178 return fn(arg1, arg2, arg3, arg4, arg5, arg6); \ 179 } \ 180 INTERCEPT_OR_DIE(#name, name); 181 182 #endif // SANITIZER_WIN_DLL_THUNK_H 183