libsanitizer/sanitizer_common/sanitizer_win_dll_thunk.h

   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(WRAPPER_NAME(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