Colin Cross | 1369ba4 | 2016-04-26 16:51:32 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2016 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #ifndef LIBMEMUNREACHABLE_SCOPED_SIGNAL_HANDLER_H_ |
| 18 | #define LIBMEMUNREACHABLE_SCOPED_SIGNAL_HANDLER_H_ |
| 19 | |
| 20 | #include <errno.h> |
| 21 | #include <signal.h> |
| 22 | |
| 23 | #include <functional> |
| 24 | |
| 25 | #include "android-base/macros.h" |
| 26 | |
Colin Cross | 8837c72 | 2019-03-20 16:02:54 -0700 | [diff] [blame] | 27 | #include "Allocator.h" |
Colin Cross | 1369ba4 | 2016-04-26 16:51:32 -0700 | [diff] [blame] | 28 | #include "log.h" |
| 29 | |
Colin Cross | 1fa81f5 | 2017-06-21 13:13:00 -0700 | [diff] [blame] | 30 | namespace android { |
| 31 | |
Colin Cross | 1369ba4 | 2016-04-26 16:51:32 -0700 | [diff] [blame] | 32 | class ScopedSignalHandler { |
| 33 | public: |
| 34 | using Fn = std::function<void(ScopedSignalHandler&, int, siginfo_t*, void*)>; |
| 35 | |
Colin Cross | 8837c72 | 2019-03-20 16:02:54 -0700 | [diff] [blame] | 36 | explicit ScopedSignalHandler(Allocator<ScopedSignalHandler> allocator) : signal_(-1) { |
| 37 | if (handler_map_ == nullptr) { |
| 38 | Allocator<SignalFnMap> map_allocator = allocator; |
| 39 | handler_map_ = map_allocator.make_unique(allocator); |
| 40 | } |
| 41 | } |
Colin Cross | 401319a | 2017-06-22 10:50:05 -0700 | [diff] [blame] | 42 | ~ScopedSignalHandler() { reset(); } |
Colin Cross | 1369ba4 | 2016-04-26 16:51:32 -0700 | [diff] [blame] | 43 | |
| 44 | template <class F> |
| 45 | void install(int signal, F&& f) { |
Colin Cross | 3c44484 | 2017-06-29 17:12:01 -0700 | [diff] [blame] | 46 | if (signal_ != -1) MEM_LOG_ALWAYS_FATAL("ScopedSignalHandler already installed"); |
Colin Cross | 1369ba4 | 2016-04-26 16:51:32 -0700 | [diff] [blame] | 47 | |
Colin Cross | 8837c72 | 2019-03-20 16:02:54 -0700 | [diff] [blame] | 48 | if (handler_map_->find(signal) != handler_map_->end()) { |
| 49 | MEM_LOG_ALWAYS_FATAL("ScopedSignalHandler already installed for %d", signal); |
| 50 | } |
| 51 | |
| 52 | (*handler_map_)[signal] = |
| 53 | SignalFn([=](int signal, siginfo_t* si, void* uctx) { f(*this, signal, si, uctx); }); |
Colin Cross | 1369ba4 | 2016-04-26 16:51:32 -0700 | [diff] [blame] | 54 | |
Christopher Ferris | 56b8d86 | 2017-05-03 17:34:29 -0700 | [diff] [blame] | 55 | struct sigaction act {}; |
Colin Cross | 8837c72 | 2019-03-20 16:02:54 -0700 | [diff] [blame] | 56 | act.sa_sigaction = [](int signal, siginfo_t* si, void* uctx) { |
| 57 | ((*handler_map_)[signal])(signal, si, uctx); |
| 58 | }; |
Colin Cross | 1369ba4 | 2016-04-26 16:51:32 -0700 | [diff] [blame] | 59 | act.sa_flags = SA_SIGINFO; |
| 60 | |
| 61 | int ret = sigaction(signal, &act, &old_act_); |
| 62 | if (ret < 0) { |
Christopher Ferris | 56b8d86 | 2017-05-03 17:34:29 -0700 | [diff] [blame] | 63 | MEM_LOG_ALWAYS_FATAL("failed to install segfault handler: %s", strerror(errno)); |
Colin Cross | 1369ba4 | 2016-04-26 16:51:32 -0700 | [diff] [blame] | 64 | } |
| 65 | |
| 66 | signal_ = signal; |
| 67 | } |
| 68 | |
| 69 | void reset() { |
| 70 | if (signal_ != -1) { |
| 71 | int ret = sigaction(signal_, &old_act_, NULL); |
| 72 | if (ret < 0) { |
Christopher Ferris | 56b8d86 | 2017-05-03 17:34:29 -0700 | [diff] [blame] | 73 | MEM_ALOGE("failed to uninstall segfault handler"); |
Colin Cross | 1369ba4 | 2016-04-26 16:51:32 -0700 | [diff] [blame] | 74 | } |
Colin Cross | 8837c72 | 2019-03-20 16:02:54 -0700 | [diff] [blame] | 75 | |
| 76 | handler_map_->erase(signal_); |
| 77 | if (handler_map_->empty()) { |
| 78 | handler_map_.reset(); |
| 79 | } |
Colin Cross | 1369ba4 | 2016-04-26 16:51:32 -0700 | [diff] [blame] | 80 | signal_ = -1; |
| 81 | } |
| 82 | } |
| 83 | |
Colin Cross | 1369ba4 | 2016-04-26 16:51:32 -0700 | [diff] [blame] | 84 | private: |
| 85 | using SignalFn = std::function<void(int, siginfo_t*, void*)>; |
Colin Cross | 8837c72 | 2019-03-20 16:02:54 -0700 | [diff] [blame] | 86 | using SignalFnMap = allocator::unordered_map<int, SignalFn>; |
Colin Cross | 1369ba4 | 2016-04-26 16:51:32 -0700 | [diff] [blame] | 87 | DISALLOW_COPY_AND_ASSIGN(ScopedSignalHandler); |
Colin Cross | 1369ba4 | 2016-04-26 16:51:32 -0700 | [diff] [blame] | 88 | int signal_; |
| 89 | struct sigaction old_act_; |
Colin Cross | 8837c72 | 2019-03-20 16:02:54 -0700 | [diff] [blame] | 90 | static Allocator<SignalFnMap>::unique_ptr handler_map_; |
Colin Cross | 1369ba4 | 2016-04-26 16:51:32 -0700 | [diff] [blame] | 91 | }; |
| 92 | |
Colin Cross | 1fa81f5 | 2017-06-21 13:13:00 -0700 | [diff] [blame] | 93 | } // namespace android |
| 94 | |
Colin Cross | 401319a | 2017-06-22 10:50:05 -0700 | [diff] [blame] | 95 | #endif // LIBMEMUNREACHABLE_SCOPED_SIGNAL_HANDLER_H_ |