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Diffstat (limited to 'src/client/linux/handler/exception_handler.cc')
| -rw-r--r-- | src/client/linux/handler/exception_handler.cc | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/src/client/linux/handler/exception_handler.cc b/src/client/linux/handler/exception_handler.cc new file mode 100644 index 00000000..59b50df7 --- /dev/null +++ b/src/client/linux/handler/exception_handler.cc @@ -0,0 +1,236 @@ +// Copyright (c) 2006, Google Inc. +// All rights reserved. +// +// Author: Li Liu +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#include <asm/sigcontext.h> +#include <signal.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> + +#include <cassert> +#include <cstdlib> +#include <ctime> + +#include "client/linux/handler/exception_handler.h" +#include "common/linux/guid_creator.h" +#include "google_breakpad/common/minidump_format.h" + +namespace google_breakpad { + +// Signals that we are interested. +int SigTable[] = { +#if defined(SIGSEGV) + SIGSEGV, +#endif +#ifdef SIGABRT + SIGABRT, +#endif +#ifdef SIGFPE + SIGFPE, +#endif +#ifdef SIGILL + SIGILL, +#endif +#ifdef SIGBUS + SIGBUS, +#endif +}; + +std::vector<ExceptionHandler*> *ExceptionHandler::handler_stack_ = NULL; +int ExceptionHandler::handler_stack_index_ = 0; +pthread_mutex_t ExceptionHandler::handler_stack_mutex_ = +PTHREAD_MUTEX_INITIALIZER; + +ExceptionHandler::ExceptionHandler(const string &dump_path, + FilterCallback filter, + MinidumpCallback callback, + void *callback_context, + bool install_handler) + : filter_(filter), + callback_(callback), + callback_context_(callback_context), + dump_path_(), + installed_handler_(install_handler) { + set_dump_path(dump_path); + + if (install_handler) { + SetupHandler(); + pthread_mutex_lock(&handler_stack_mutex_); + if (handler_stack_ == NULL) + handler_stack_ = new std::vector<ExceptionHandler *>; + handler_stack_->push_back(this); + pthread_mutex_unlock(&handler_stack_mutex_); + } +} + +ExceptionHandler::~ExceptionHandler() { + TeardownAllHandler(); + pthread_mutex_lock(&handler_stack_mutex_); + if (handler_stack_->back() == this) { + handler_stack_->pop_back(); + } else { + fprintf(stderr, "warning: removing Breakpad handler out of order\n"); + for (std::vector<ExceptionHandler *>::iterator iterator = + handler_stack_->begin(); + iterator != handler_stack_->end(); + ++iterator) { + if (*iterator == this) { + handler_stack_->erase(iterator); + } + } + } + + if (handler_stack_->empty()) { + // When destroying the last ExceptionHandler that installed a handler, + // clean up the handler stack. + delete handler_stack_; + handler_stack_ = NULL; + } + pthread_mutex_unlock(&handler_stack_mutex_); +} + +bool ExceptionHandler::WriteMinidump() { + return InternalWriteMinidump(0, NULL); +} + +// static +bool ExceptionHandler::WriteMinidump(const string &dump_path, + MinidumpCallback callback, + void *callback_context) { + ExceptionHandler handler(dump_path, NULL, callback, + callback_context, false); + return handler.InternalWriteMinidump(0, NULL); +} + +void ExceptionHandler::SetupHandler() { + // Signal on a different stack to avoid using the stack + // of the crashing thread. + struct sigaltstack sig_stack; + sig_stack.ss_sp = malloc(MINSIGSTKSZ); + if (sig_stack.ss_sp == NULL) + return; + sig_stack.ss_size = MINSIGSTKSZ; + sig_stack.ss_flags = 0; + + if (sigaltstack(&sig_stack, NULL) < 0) + return; + for (size_t i = 0; i < sizeof(SigTable) / sizeof(SigTable[0]); ++i) + SetupHandler(SigTable[i]); +} + +void ExceptionHandler::SetupHandler(int signo) { + struct sigaction act, old_act; + act.sa_handler = HandleException; + act.sa_flags = SA_ONSTACK; + if (sigaction(signo, &act, &old_act) < 0) + return; + old_handlers_[signo] = old_act.sa_handler; +} + +void ExceptionHandler::TeardownHandler(int signo) { + if (old_handlers_.find(signo) != old_handlers_.end()) { + struct sigaction act; + act.sa_handler = old_handlers_[signo]; + act.sa_flags = 0; + sigaction(signo, &act, 0); + } +} + +void ExceptionHandler::TeardownAllHandler() { + for (size_t i = 0; i < sizeof(SigTable) / sizeof(SigTable[0]); ++i) { + TeardownHandler(SigTable[i]); + } +} + +// static +void ExceptionHandler::HandleException(int signo) { + // In Linux, the context information about the signal is put on the stack of + // the signal handler frame as value parameter. For some reasons, the + // prototype of the handler doesn't declare this information as parameter, we + // will do it by hand. It is the second parameter above the signal number. + const struct sigcontext *sig_ctx = + reinterpret_cast<const struct sigcontext *>(&signo + 1); + pthread_mutex_lock(&handler_stack_mutex_); + ExceptionHandler *current_handler = + handler_stack_->at(handler_stack_->size() - ++handler_stack_index_); + pthread_mutex_unlock(&handler_stack_mutex_); + + // Restore original handler. + current_handler->TeardownHandler(signo); + if (current_handler->InternalWriteMinidump(signo, sig_ctx)) { + // Fully handled this exception, safe to exit. + exit(EXIT_FAILURE); + } else { + // Exception not fully handled, will call the next handler in stack to + // process it. + typedef void (*SignalHandler)(int signo, struct sigcontext); + SignalHandler old_handler = + reinterpret_cast<SignalHandler>(current_handler->old_handlers_[signo]); + if (old_handler != NULL) + old_handler(signo, *sig_ctx); + } + + pthread_mutex_lock(&handler_stack_mutex_); + current_handler->SetupHandler(signo); + --handler_stack_index_; + // All the handlers in stack have been invoked to handle the exception, + // normally the process should be terminated and should not reach here. + // In case we got here, ask the OS to handle it to avoid endless loop, + // normally the OS will generate a core and termiate the process. This + // may be desired to debug the program. + if (handler_stack_index_ == 0) + signal(signo, SIG_DFL); + pthread_mutex_unlock(&handler_stack_mutex_); +} + +bool ExceptionHandler::InternalWriteMinidump(int signo, + const struct sigcontext *sig_ctx) { + if (filter_ && !filter_(callback_context_)) + return false; + + GUID guid; + bool success = false;; + char guid_str[kGUIDStringLength + 1]; + if (CreateGUID(&guid) && GUIDToString(&guid, guid_str, sizeof(guid_str))) { + char minidump_path[PATH_MAX]; + snprintf(minidump_path, sizeof(minidump_path), "%s/%s.dmp", + dump_path_c_, + guid_str); + success = minidump_generator_.WriteMinidumpToFile( + minidump_path, signo, sig_ctx); + if (callback_) + success = callback_(dump_path_c_, guid_str, + callback_context_, success); + } + return success; +} + +} // namespace google_breakpad |