ba5d9ff6d9
Vendor blobs on ryu mprotect heap pages, causing segfaults when dumping unreachable memory. Handle segfaults within HeapWalker by mapping a zero page over any unreadable pages. HeapWalker runs in the forked process, so the mapping will not affect the original process. Bug: 28269332 Change-Id: I16245af722123f2ad467cbc6f245a70666c55544
84 lines
2.4 KiB
C++
84 lines
2.4 KiB
C++
/*
|
|
* Copyright (C) 2016 The Android Open Source Project
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#ifndef LIBMEMUNREACHABLE_SCOPED_SIGNAL_HANDLER_H_
|
|
#define LIBMEMUNREACHABLE_SCOPED_SIGNAL_HANDLER_H_
|
|
|
|
#include <errno.h>
|
|
#include <signal.h>
|
|
|
|
#include <functional>
|
|
|
|
#include "android-base/macros.h"
|
|
|
|
#include "log.h"
|
|
|
|
class ScopedSignalHandler {
|
|
public:
|
|
using Fn = std::function<void(ScopedSignalHandler&, int, siginfo_t*, void*)>;
|
|
|
|
ScopedSignalHandler(Allocator<Fn> allocator) : allocator_(allocator), signal_(-1) {}
|
|
~ScopedSignalHandler() {
|
|
reset();
|
|
}
|
|
|
|
template <class F>
|
|
void install(int signal, F&& f) {
|
|
LOG_ALWAYS_FATAL_IF(signal_ != -1, "ScopedSignalHandler already installed");
|
|
|
|
handler_ = SignalFn(std::allocator_arg, allocator_,
|
|
[=](int signal, siginfo_t* si, void* uctx) {
|
|
f(*this, signal, si, uctx);
|
|
});
|
|
|
|
struct sigaction act{};
|
|
act.sa_sigaction = [](int signal, siginfo_t* si, void* uctx) {
|
|
handler_(signal, si, uctx);
|
|
};
|
|
act.sa_flags = SA_SIGINFO;
|
|
|
|
int ret = sigaction(signal, &act, &old_act_);
|
|
if (ret < 0) {
|
|
LOG_ALWAYS_FATAL("failed to install segfault handler: %s", strerror(errno));
|
|
}
|
|
|
|
signal_ = signal;
|
|
}
|
|
|
|
void reset() {
|
|
if (signal_ != -1) {
|
|
int ret = sigaction(signal_, &old_act_, NULL);
|
|
if (ret < 0) {
|
|
ALOGE("failed to uninstall segfault handler");
|
|
}
|
|
handler_ = SignalFn{};
|
|
signal_ = -1;
|
|
}
|
|
}
|
|
|
|
|
|
private:
|
|
using SignalFn = std::function<void(int, siginfo_t*, void*)>;
|
|
DISALLOW_COPY_AND_ASSIGN(ScopedSignalHandler);
|
|
Allocator<Fn> allocator_;
|
|
int signal_;
|
|
struct sigaction old_act_;
|
|
// TODO(ccross): to support multiple ScopedSignalHandlers handler_ would need
|
|
// to be a static map of signals to handlers, but allocated with Allocator.
|
|
static SignalFn handler_;
|
|
};
|
|
|
|
#endif // LIBMEMUNREACHABLE_SCOPED_SIGNAL_HANDLER_H_
|