blob: 1562c161a76260ab70aa84c1abbaec95149e9b00 [file] [log] [blame]
//===-- sanitizer_win_dll_thunk.cpp ---------------------------------------===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This file defines a family of thunks that should be statically linked into
// the DLLs that have instrumentation in order to delegate the calls to the
// shared runtime that lives in the main binary.
// See for the details.
#include "sanitizer_win_defs.h"
#include "sanitizer_win_dll_thunk.h"
#include "interception/interception.h"
extern "C" {
void *WINAPI GetModuleHandleA(const char *module_name);
void abort();
namespace __sanitizer {
uptr dllThunkGetRealAddrOrDie(const char *name) {
uptr ret =
__interception::InternalGetProcAddress((void *)GetModuleHandleA(0), name);
if (!ret)
return ret;
int dllThunkIntercept(const char* main_function, uptr dll_function) {
uptr wrapper = dllThunkGetRealAddrOrDie(main_function);
if (!__interception::OverrideFunction(dll_function, wrapper, 0))
return 0;
int dllThunkInterceptWhenPossible(const char* main_function,
const char* default_function, uptr dll_function) {
uptr wrapper = __interception::InternalGetProcAddress(
(void *)GetModuleHandleA(0), main_function);
if (!wrapper)
wrapper = dllThunkGetRealAddrOrDie(default_function);
if (!__interception::OverrideFunction(dll_function, wrapper, 0))
return 0;
} // namespace __sanitizer
// Include Sanitizer Common interface.
#include ""
#pragma section(".DLLTH$A", read)
#pragma section(".DLLTH$Z", read)
typedef void (*DllThunkCB)();
extern "C" {
__declspec(allocate(".DLLTH$A")) DllThunkCB __start_dll_thunk;
__declspec(allocate(".DLLTH$Z")) DllThunkCB __stop_dll_thunk;
// Disable compiler warnings that show up if we declare our own version
// of a compiler intrinsic (e.g. strlen).
#pragma warning(disable: 4391)
#pragma warning(disable: 4392)
extern "C" int __dll_thunk_init() {
static bool flag = false;
// __dll_thunk_init is expected to be called by only one thread.
if (flag) return 0;
flag = true;
for (DllThunkCB *it = &__start_dll_thunk; it < &__stop_dll_thunk; ++it)
if (*it)
// In DLLs, the callbacks are expected to return 0,
// otherwise CRT initialization fails.
return 0;
// We want to call dll_thunk_init before C/C++ initializers / constructors are
// executed, otherwise functions like memset might be invoked.
#pragma section(".CRT$XIB", long, read)
__declspec(allocate(".CRT$XIB")) int (*__dll_thunk_preinit)() =
static void WINAPI dll_thunk_thread_init(void *mod, unsigned long reason,
void *reserved) {
if (reason == /*DLL_PROCESS_ATTACH=*/1) __dll_thunk_init();
#pragma section(".CRT$XLAB", long, read)
__declspec(allocate(".CRT$XLAB")) void (WINAPI *__dll_thunk_tls_init)(void *,
unsigned long, void *) = dll_thunk_thread_init;