foundationdb/flow/SignalSafeUnwind.cpp

59 lines
1.7 KiB
C++

/*
* SignalSafeUnwind.cpp
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "flow/SignalSafeUnwind.h"
int64_t dl_iterate_phdr_calls = 0;
#ifdef __linux__
#include <link.h>
#include <mutex>
static int (*chain_dl_iterate_phdr)(
int (*callback) (struct dl_phdr_info *info, size_t size, void *data),
void *data) = nullptr;
static void initChain() {
static std::once_flag flag;
// Ensure that chain_dl_iterate_phdr points to the "real" function that we are overriding
std::call_once(flag, [](){ *(void**)&chain_dl_iterate_phdr = dlsym(RTLD_NEXT, "dl_iterate_phdr"); });
if (!chain_dl_iterate_phdr) {
criticalError(FDB_EXIT_ERROR, "SignalSafeUnwindError", "Unable to find dl_iterate_phdr symbol");
}
}
// This overrides the function in libc!
extern "C" int dl_iterate_phdr(
int (*callback) (struct dl_phdr_info *info, size_t size, void *data),
void *data)
{
interlockedIncrement64(&dl_iterate_phdr_calls);
initChain();
setProfilingEnabled(0);
int result = chain_dl_iterate_phdr(callback, data);
setProfilingEnabled(1);
return result;
}
#endif