1//===-- sanitizer_win_weak_interception.cc --------------------------------===// 2// 3// This file is distributed under the University of Illinois Open Source 4// License. See LICENSE.TXT for details. 5// 6//===----------------------------------------------------------------------===// 7// This module should be included in the sanitizer when it is implemented as a 8// shared library on Windows (dll), in order to delegate the calls of weak 9// functions to the implementation in the main executable when a strong 10// definition is provided. 11//===----------------------------------------------------------------------===// 12 13#include "sanitizer_platform.h" 14#if SANITIZER_WINDOWS && SANITIZER_DYNAMIC 15#include "sanitizer_win_weak_interception.h" 16#include "sanitizer_allocator_interface.h" 17#include "sanitizer_interface_internal.h" 18#include "sanitizer_win_defs.h" 19#include "interception/interception.h" 20 21extern "C" { 22void *WINAPI GetModuleHandleA(const char *module_name); 23void abort(); 24} 25 26namespace __sanitizer { 27// Try to get a pointer to real_function in the main module and override 28// dll_function with that pointer. If the function isn't found, nothing changes. 29int interceptWhenPossible(uptr dll_function, const char *real_function) { 30 uptr real = __interception::InternalGetProcAddress( 31 (void *)GetModuleHandleA(0), real_function); 32 if (real && !__interception::OverrideFunction((uptr)dll_function, real, 0)) 33 abort(); 34 return 0; 35} 36} // namespace __sanitizer 37 38// Declare weak hooks. 39extern "C" { 40void __sanitizer_weak_hook_memcmp(uptr called_pc, const void *s1, 41 const void *s2, uptr n, int result); 42void __sanitizer_weak_hook_strcmp(uptr called_pc, const char *s1, 43 const char *s2, int result); 44void __sanitizer_weak_hook_strncmp(uptr called_pc, const char *s1, 45 const char *s2, uptr n, int result); 46void __sanitizer_weak_hook_strstr(uptr called_pc, const char *s1, 47 const char *s2, char *result); 48} 49 50// Include Sanitizer Common interface. 51#define INTERFACE_FUNCTION(Name) 52#define INTERFACE_WEAK_FUNCTION(Name) INTERCEPT_SANITIZER_WEAK_FUNCTION(Name) 53#include "sanitizer_common_interface.inc" 54 55#pragma section(".WEAK$A", read) // NOLINT 56#pragma section(".WEAK$Z", read) // NOLINT 57 58typedef void (*InterceptCB)(); 59extern "C" { 60__declspec(allocate(".WEAK$A")) InterceptCB __start_weak_list; 61__declspec(allocate(".WEAK$Z")) InterceptCB __stop_weak_list; 62} 63 64static int weak_intercept_init() { 65 static bool flag = false; 66 // weak_interception_init is expected to be called by only one thread. 67 if (flag) return 0; 68 flag = true; 69 70 for (InterceptCB *it = &__start_weak_list; it < &__stop_weak_list; ++it) 71 if (*it) 72 (*it)(); 73 74 // In DLLs, the callbacks are expected to return 0, 75 // otherwise CRT initialization fails. 76 return 0; 77} 78 79#pragma section(".CRT$XIB", long, read) // NOLINT 80__declspec(allocate(".CRT$XIB")) int (*__weak_intercept_preinit)() = 81 weak_intercept_init; 82 83static void WINAPI weak_intercept_thread_init(void *mod, unsigned long reason, 84 void *reserved) { 85 if (reason == /*DLL_PROCESS_ATTACH=*/1) weak_intercept_init(); 86} 87 88#pragma section(".CRT$XLAB", long, read) // NOLINT 89__declspec(allocate(".CRT$XLAB")) void(WINAPI *__weak_intercept_tls_init)( 90 void *, unsigned long, void *) = weak_intercept_thread_init; 91 92#endif // SANITIZER_WINDOWS && SANITIZER_DYNAMIC 93