//===-- sanitizer_win_weak_interception.cc --------------------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // This module should be included in the sanitizer when it is implemented as a // shared library on Windows (dll), in order to delegate the calls of weak // functions to the implementation in the main executable when a strong // definition is provided. //===----------------------------------------------------------------------===// #include "sanitizer_platform.h" #if SANITIZER_WINDOWS && SANITIZER_DYNAMIC #include "sanitizer_win_weak_interception.h" #include "sanitizer_allocator_interface.h" #include "sanitizer_interface_internal.h" #include "sanitizer_win_defs.h" #include "interception/interception.h" extern "C" { void *WINAPI GetModuleHandleA(const char *module_name); void abort(); } namespace __sanitizer { // Try to get a pointer to real_function in the main module and override // dll_function with that pointer. If the function isn't found, nothing changes. int interceptWhenPossible(uptr dll_function, const char *real_function) { uptr real = __interception::InternalGetProcAddress( (void *)GetModuleHandleA(0), real_function); if (real && !__interception::OverrideFunction((uptr)dll_function, real, 0)) abort(); return 0; } } // namespace __sanitizer // Declare weak hooks. extern "C" { void __sanitizer_weak_hook_memcmp(uptr called_pc, const void *s1, const void *s2, uptr n, int result); void __sanitizer_weak_hook_strcmp(uptr called_pc, const char *s1, const char *s2, int result); void __sanitizer_weak_hook_strncmp(uptr called_pc, const char *s1, const char *s2, uptr n, int result); void __sanitizer_weak_hook_strstr(uptr called_pc, const char *s1, const char *s2, char *result); } // Include Sanitizer Common interface. #define INTERFACE_FUNCTION(Name) #define INTERFACE_WEAK_FUNCTION(Name) INTERCEPT_SANITIZER_WEAK_FUNCTION(Name) #include "sanitizer_common_interface.inc" #pragma section(".WEAK$A", read) // NOLINT #pragma section(".WEAK$Z", read) // NOLINT typedef void (*InterceptCB)(); extern "C" { __declspec(allocate(".WEAK$A")) InterceptCB __start_weak_list; __declspec(allocate(".WEAK$Z")) InterceptCB __stop_weak_list; } static int weak_intercept_init() { static bool flag = false; // weak_interception_init is expected to be called by only one thread. if (flag) return 0; flag = true; for (InterceptCB *it = &__start_weak_list; it < &__stop_weak_list; ++it) if (*it) (*it)(); // In DLLs, the callbacks are expected to return 0, // otherwise CRT initialization fails. return 0; } #pragma section(".CRT$XIB", long, read) // NOLINT __declspec(allocate(".CRT$XIB")) int (*__weak_intercept_preinit)() = weak_intercept_init; static void WINAPI weak_intercept_thread_init(void *mod, unsigned long reason, void *reserved) { if (reason == /*DLL_PROCESS_ATTACH=*/1) weak_intercept_init(); } #pragma section(".CRT$XLAB", long, read) // NOLINT __declspec(allocate(".CRT$XLAB")) void(WINAPI *__weak_intercept_tls_init)( void *, unsigned long, void *) = weak_intercept_thread_init; #endif // SANITIZER_WINDOWS && SANITIZER_DYNAMIC |