11553Srgrimes//===-- sanitizer_win_weak_interception.cpp -------------------------------===// 21553Srgrimes// 31553Srgrimes// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 41553Srgrimes// See https://llvm.org/LICENSE.txt for license information. 51553Srgrimes// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 61553Srgrimes// 71553Srgrimes//===----------------------------------------------------------------------===// 81553Srgrimes// This module should be included in the sanitizer when it is implemented as a 91553Srgrimes// shared library on Windows (dll), in order to delegate the calls of weak 101553Srgrimes// functions to the implementation in the main executable when a strong 111553Srgrimes// definition is provided. 121553Srgrimes//===----------------------------------------------------------------------===// 13121300Sphk 141553Srgrimes#include "sanitizer_platform.h" 151553Srgrimes#if SANITIZER_WINDOWS && SANITIZER_DYNAMIC 161553Srgrimes#include "sanitizer_win_weak_interception.h" 171553Srgrimes#include "sanitizer_allocator_interface.h" 181553Srgrimes#include "sanitizer_interface_internal.h" 191553Srgrimes#include "sanitizer_win_defs.h" 201553Srgrimes#include "interception/interception.h" 211553Srgrimes 221553Srgrimesextern "C" { 231553Srgrimesvoid *WINAPI GetModuleHandleA(const char *module_name); 241553Srgrimesvoid abort(); 251553Srgrimes} 261553Srgrimes 271553Srgrimesnamespace __sanitizer { 281553Srgrimes// Try to get a pointer to real_function in the main module and override 291553Srgrimes// dll_function with that pointer. If the function isn't found, nothing changes. 30114601Sobrienint interceptWhenPossible(uptr dll_function, const char *real_function) { 311553Srgrimes uptr real = __interception::InternalGetProcAddress( 321553Srgrimes (void *)GetModuleHandleA(0), real_function); 33114601Sobrien if (real && !__interception::OverrideFunction((uptr)dll_function, real, 0)) 3430027Scharnier abort(); 35114601Sobrien return 0; 36114601Sobrien} 371553Srgrimes} // namespace __sanitizer 381553Srgrimes 391553Srgrimes// Declare weak hooks. 4030027Scharnierextern "C" { 4130027Scharniervoid __sanitizer_on_print(const char *str); 4230027Scharniervoid __sanitizer_weak_hook_memcmp(uptr called_pc, const void *s1, 431553Srgrimes const void *s2, uptr n, int result); 4430027Scharniervoid __sanitizer_weak_hook_strcmp(uptr called_pc, const char *s1, 451553Srgrimes const char *s2, int result); 4630027Scharniervoid __sanitizer_weak_hook_strncmp(uptr called_pc, const char *s1, 471553Srgrimes const char *s2, uptr n, int result); 4842561Sjkoshyvoid __sanitizer_weak_hook_strstr(uptr called_pc, const char *s1, 491553Srgrimes const char *s2, char *result); 501553Srgrimes} 511553Srgrimes 521553Srgrimes// Include Sanitizer Common interface. 531553Srgrimes#define INTERFACE_FUNCTION(Name) 5499800Salfred#define INTERFACE_WEAK_FUNCTION(Name) INTERCEPT_SANITIZER_WEAK_FUNCTION(Name) 5599800Salfred#include "sanitizer_common_interface.inc" 561553Srgrimes 571553Srgrimes#pragma section(".WEAK$A", read) 58121299Sphk#pragma section(".WEAK$Z", read) 591553Srgrimes 60121299Sphktypedef void (*InterceptCB)(); 61121299Sphkextern "C" { 621553Srgrimes__declspec(allocate(".WEAK$A")) InterceptCB __start_weak_list; 631553Srgrimes__declspec(allocate(".WEAK$Z")) InterceptCB __stop_weak_list; 641553Srgrimes} 651553Srgrimes 662860Srgrimesstatic int weak_intercept_init() { 671553Srgrimes static bool flag = false; 681553Srgrimes // weak_interception_init is expected to be called by only one thread. 691553Srgrimes if (flag) return 0; 701553Srgrimes flag = true; 711553Srgrimes 721553Srgrimes for (InterceptCB *it = &__start_weak_list; it < &__stop_weak_list; ++it) 731553Srgrimes if (*it) 741553Srgrimes (*it)(); 751553Srgrimes 761553Srgrimes // In DLLs, the callbacks are expected to return 0, 7730027Scharnier // otherwise CRT initialization fails. 781553Srgrimes return 0; 791553Srgrimes} 801553Srgrimes 811553Srgrimes#pragma section(".CRT$XIB", long, read) 821553Srgrimes__declspec(allocate(".CRT$XIB")) int (*__weak_intercept_preinit)() = 831553Srgrimes weak_intercept_init; 841553Srgrimes 851553Srgrimesstatic void WINAPI weak_intercept_thread_init(void *mod, unsigned long reason, 861553Srgrimes void *reserved) { 871553Srgrimes if (reason == /*DLL_PROCESS_ATTACH=*/1) weak_intercept_init(); 881553Srgrimes} 891553Srgrimes 901553Srgrimes#pragma section(".CRT$XLAB", long, read) 911553Srgrimes__declspec(allocate(".CRT$XLAB")) void(WINAPI *__weak_intercept_tls_init)( 921553Srgrimes void *, unsigned long, void *) = weak_intercept_thread_init; 931553Srgrimes 941553Srgrimes#endif // SANITIZER_WINDOWS && SANITIZER_DYNAMIC 951553Srgrimes