diff options
Diffstat (limited to 'toolkit/crashreporter/google-breakpad/src/client/mac/handler/exception_handler.cc')
-rw-r--r-- | toolkit/crashreporter/google-breakpad/src/client/mac/handler/exception_handler.cc | 854 |
1 files changed, 854 insertions, 0 deletions
diff --git a/toolkit/crashreporter/google-breakpad/src/client/mac/handler/exception_handler.cc b/toolkit/crashreporter/google-breakpad/src/client/mac/handler/exception_handler.cc new file mode 100644 index 000000000..dd0e1678c --- /dev/null +++ b/toolkit/crashreporter/google-breakpad/src/client/mac/handler/exception_handler.cc @@ -0,0 +1,854 @@ +// Copyright (c) 2006, Google Inc. +// All rights reserved. +// +// 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 <mach/exc.h> +#include <mach/mig.h> +#include <pthread.h> +#include <signal.h> +#include <TargetConditionals.h> + +#include <map> + +#include "client/mac/handler/exception_handler.h" +#include "client/mac/handler/minidump_generator.h" +#include "common/mac/macho_utilities.h" +#include "common/mac/scoped_task_suspend-inl.h" +#include "google_breakpad/common/minidump_exception_mac.h" + +#ifndef __EXCEPTIONS +// This file uses C++ try/catch (but shouldn't). Duplicate the macros from +// <c++/4.2.1/exception_defines.h> allowing this file to work properly with +// exceptions disabled even when other C++ libraries are used. #undef the try +// and catch macros first in case libstdc++ is in use and has already provided +// its own definitions. +#undef try +#define try if (true) +#undef catch +#define catch(X) if (false) +#endif // __EXCEPTIONS + +#ifndef USE_PROTECTED_ALLOCATIONS +#if TARGET_OS_IPHONE +#define USE_PROTECTED_ALLOCATIONS 1 +#else +#define USE_PROTECTED_ALLOCATIONS 0 +#endif +#endif + +// If USE_PROTECTED_ALLOCATIONS is activated then the +// gBreakpadAllocator needs to be setup in other code +// ahead of time. Please see ProtectedMemoryAllocator.h +// for more details. +#if USE_PROTECTED_ALLOCATIONS + #include "protected_memory_allocator.h" + extern ProtectedMemoryAllocator *gBreakpadAllocator; +#endif + +namespace google_breakpad { + +static union { +#if USE_PROTECTED_ALLOCATIONS +#if defined PAGE_MAX_SIZE + char protected_buffer[PAGE_MAX_SIZE] __attribute__((aligned(PAGE_MAX_SIZE))); +#else + char protected_buffer[PAGE_SIZE] __attribute__((aligned(PAGE_SIZE))); +#endif // defined PAGE_MAX_SIZE +#endif // USE_PROTECTED_ALLOCATIONS + google_breakpad::ExceptionHandler *handler; +} gProtectedData; + +using std::map; + +// These structures and techniques are illustrated in +// Mac OS X Internals, Amit Singh, ch 9.7 +struct ExceptionMessage { + mach_msg_header_t header; + mach_msg_body_t body; + mach_msg_port_descriptor_t thread; + mach_msg_port_descriptor_t task; + NDR_record_t ndr; + exception_type_t exception; + mach_msg_type_number_t code_count; + integer_t code[EXCEPTION_CODE_MAX]; + char padding[512]; +}; + +struct ExceptionParameters { + ExceptionParameters() : count(0) {} + mach_msg_type_number_t count; + exception_mask_t masks[EXC_TYPES_COUNT]; + mach_port_t ports[EXC_TYPES_COUNT]; + exception_behavior_t behaviors[EXC_TYPES_COUNT]; + thread_state_flavor_t flavors[EXC_TYPES_COUNT]; +}; + +struct ExceptionReplyMessage { + mach_msg_header_t header; + NDR_record_t ndr; + kern_return_t return_code; +}; + +// Only catch these three exceptions. The other ones are nebulously defined +// and may result in treating a non-fatal exception as fatal. +exception_mask_t s_exception_mask = EXC_MASK_BAD_ACCESS | +EXC_MASK_BAD_INSTRUCTION | EXC_MASK_ARITHMETIC | EXC_MASK_BREAKPOINT; + +#if !TARGET_OS_IPHONE +extern "C" { + // Forward declarations for functions that need "C" style compilation + boolean_t exc_server(mach_msg_header_t* request, + mach_msg_header_t* reply); + + // This symbol must be visible to dlsym() - see + // http://code.google.com/p/google-breakpad/issues/detail?id=345 for details. + kern_return_t catch_exception_raise(mach_port_t target_port, + mach_port_t failed_thread, + mach_port_t task, + exception_type_t exception, + exception_data_t code, + mach_msg_type_number_t code_count) + __attribute__((visibility("default"))); +} +#endif + +kern_return_t ForwardException(mach_port_t task, + mach_port_t failed_thread, + exception_type_t exception, + exception_data_t code, + mach_msg_type_number_t code_count); + +#if TARGET_OS_IPHONE +// Implementation is based on the implementation generated by mig. +boolean_t breakpad_exc_server(mach_msg_header_t* InHeadP, + mach_msg_header_t* OutHeadP) { + OutHeadP->msgh_bits = + MACH_MSGH_BITS(MACH_MSGH_BITS_REMOTE(InHeadP->msgh_bits), 0); + OutHeadP->msgh_remote_port = InHeadP->msgh_remote_port; + /* Minimal size: routine() will update it if different */ + OutHeadP->msgh_size = (mach_msg_size_t)sizeof(mig_reply_error_t); + OutHeadP->msgh_local_port = MACH_PORT_NULL; + OutHeadP->msgh_id = InHeadP->msgh_id + 100; + + if (InHeadP->msgh_id != 2401) { + ((mig_reply_error_t*)OutHeadP)->NDR = NDR_record; + ((mig_reply_error_t*)OutHeadP)->RetCode = MIG_BAD_ID; + return FALSE; + } + +#ifdef __MigPackStructs +#pragma pack(4) +#endif + typedef struct { + mach_msg_header_t Head; + /* start of the kernel processed data */ + mach_msg_body_t msgh_body; + mach_msg_port_descriptor_t thread; + mach_msg_port_descriptor_t task; + /* end of the kernel processed data */ + NDR_record_t NDR; + exception_type_t exception; + mach_msg_type_number_t codeCnt; + integer_t code[2]; + mach_msg_trailer_t trailer; + } Request; + + typedef struct { + mach_msg_header_t Head; + NDR_record_t NDR; + kern_return_t RetCode; + } Reply; +#ifdef __MigPackStructs +#pragma pack() +#endif + + Request* In0P = (Request*)InHeadP; + Reply* OutP = (Reply*)OutHeadP; + + if (In0P->task.name != mach_task_self()) { + return FALSE; + } + OutP->RetCode = ForwardException(In0P->task.name, + In0P->thread.name, + In0P->exception, + In0P->code, + In0P->codeCnt); + OutP->NDR = NDR_record; + return TRUE; +} +#else +boolean_t breakpad_exc_server(mach_msg_header_t* request, + mach_msg_header_t* reply) { + return exc_server(request, reply); +} + +// Callback from exc_server() +kern_return_t catch_exception_raise(mach_port_t port, mach_port_t failed_thread, + mach_port_t task, + exception_type_t exception, + exception_data_t code, + mach_msg_type_number_t code_count) { + if (task != mach_task_self()) { + return KERN_FAILURE; + } + return ForwardException(task, failed_thread, exception, code, code_count); +} +#endif + +ExceptionHandler::ExceptionHandler(const string &dump_path, + FilterCallback filter, + MinidumpCallback callback, + void* callback_context, + bool install_handler, + const char* port_name) + : dump_path_(), + filter_(filter), + callback_(callback), + callback_context_(callback_context), + directCallback_(NULL), + handler_thread_(NULL), + handler_port_(MACH_PORT_NULL), + previous_(NULL), + installed_exception_handler_(false), + is_in_teardown_(false), + last_minidump_write_result_(false), + use_minidump_write_mutex_(false) { + // This will update to the ID and C-string pointers + set_dump_path(dump_path); + MinidumpGenerator::GatherSystemInformation(); +#if !TARGET_OS_IPHONE + if (port_name) + crash_generation_client_.reset(new CrashGenerationClient(port_name)); +#endif + Setup(install_handler); +} + +// special constructor if we want to bypass minidump writing and +// simply get a callback with the exception information +ExceptionHandler::ExceptionHandler(DirectCallback callback, + void* callback_context, + bool install_handler) + : dump_path_(), + filter_(NULL), + callback_(NULL), + callback_context_(callback_context), + directCallback_(callback), + handler_thread_(NULL), + handler_port_(MACH_PORT_NULL), + previous_(NULL), + installed_exception_handler_(false), + is_in_teardown_(false), + last_minidump_write_result_(false), + use_minidump_write_mutex_(false) { + MinidumpGenerator::GatherSystemInformation(); + Setup(install_handler); +} + +ExceptionHandler::~ExceptionHandler() { + Teardown(); +} + +bool ExceptionHandler::WriteMinidump(bool write_exception_stream) { + // If we're currently writing, just return + if (use_minidump_write_mutex_) + return false; + + use_minidump_write_mutex_ = true; + last_minidump_write_result_ = false; + + // Lock the mutex. Since we just created it, this will return immediately. + if (pthread_mutex_lock(&minidump_write_mutex_) == 0) { + // Send an empty message to the handle port so that a minidump will + // be written + bool result = SendMessageToHandlerThread(write_exception_stream ? + kWriteDumpWithExceptionMessage : + kWriteDumpMessage); + if (!result) { + pthread_mutex_unlock(&minidump_write_mutex_); + return false; + } + + // Wait for the minidump writer to complete its writing. It will unlock + // the mutex when completed + pthread_mutex_lock(&minidump_write_mutex_); + } + + use_minidump_write_mutex_ = false; + UpdateNextID(); + return last_minidump_write_result_; +} + +// static +bool ExceptionHandler::WriteMinidump(const string &dump_path, + bool write_exception_stream, + MinidumpCallback callback, + void* callback_context) { + ExceptionHandler handler(dump_path, NULL, callback, callback_context, false, + NULL); + return handler.WriteMinidump(write_exception_stream); +} + +// static +bool ExceptionHandler::WriteMinidumpForChild(mach_port_t child, + mach_port_t child_blamed_thread, + const string &dump_path, + MinidumpCallback callback, + void* callback_context) { + ScopedTaskSuspend suspend(child); + + MinidumpGenerator generator(child, MACH_PORT_NULL); + string dump_id; + string dump_filename = generator.UniqueNameInDirectory(dump_path, &dump_id); + + generator.SetExceptionInformation(EXC_BREAKPOINT, +#if defined(__i386__) || defined(__x86_64__) + EXC_I386_BPT, +#elif defined(__ppc__) || defined(__ppc64__) + EXC_PPC_BREAKPOINT, +#elif defined(__arm__) || defined(__aarch64__) + EXC_ARM_BREAKPOINT, +#else +#error architecture not supported +#endif + 0, + child_blamed_thread); + bool result = generator.Write(dump_filename.c_str()); + + if (callback) { + return callback(dump_path.c_str(), dump_id.c_str(), + callback_context, result); + } + return result; +} + +bool ExceptionHandler::WriteMinidumpWithException( + int exception_type, + int exception_code, + int exception_subcode, + breakpad_ucontext_t* task_context, + mach_port_t thread_name, + bool exit_after_write, + bool report_current_thread) { + bool result = false; + + if (directCallback_) { + if (directCallback_(callback_context_, + exception_type, + exception_code, + exception_subcode, + thread_name) ) { + if (exit_after_write) + _exit(exception_type); + } +#if !TARGET_OS_IPHONE + } else if (IsOutOfProcess()) { + if (exception_type && exception_code) { + // If this is a real exception, give the filter (if any) a chance to + // decide if this should be sent. + if (filter_ && !filter_(callback_context_)) + return false; + result = crash_generation_client_->RequestDumpForException( + exception_type, + exception_code, + exception_subcode, + thread_name); + if (result && exit_after_write) { + _exit(exception_type); + } + } +#endif + } else { + string minidump_id; + + // Putting the MinidumpGenerator in its own context will ensure that the + // destructor is executed, closing the newly created minidump file. + if (!dump_path_.empty()) { + MinidumpGenerator md(mach_task_self(), + report_current_thread ? MACH_PORT_NULL : + mach_thread_self()); + md.SetTaskContext(task_context); + if (exception_type && exception_code) { + // If this is a real exception, give the filter (if any) a chance to + // decide if this should be sent. + if (filter_ && !filter_(callback_context_)) + return false; + + md.SetExceptionInformation(exception_type, exception_code, + exception_subcode, thread_name); + } + + result = md.Write(next_minidump_path_c_); + } + + // Call user specified callback (if any) + if (callback_) { + // If the user callback returned true and we're handling an exception + // (rather than just writing out the file), then we should exit without + // forwarding the exception to the next handler. + if (callback_(dump_path_c_, next_minidump_id_c_, callback_context_, + result)) { + if (exit_after_write) + _exit(exception_type); + } + } + } + + return result; +} + +kern_return_t ForwardException(mach_port_t task, mach_port_t failed_thread, + exception_type_t exception, + exception_data_t code, + mach_msg_type_number_t code_count) { + // At this time, we should have called Uninstall() on the exception handler + // so that the current exception ports are the ones that we should be + // forwarding to. + ExceptionParameters current; + + current.count = EXC_TYPES_COUNT; + mach_port_t current_task = mach_task_self(); + task_get_exception_ports(current_task, + s_exception_mask, + current.masks, + ¤t.count, + current.ports, + current.behaviors, + current.flavors); + + // Find the first exception handler that matches the exception + unsigned int found; + for (found = 0; found < current.count; ++found) { + if (current.masks[found] & (1 << exception)) { + break; + } + } + + // Nothing to forward + if (found == current.count) { + fprintf(stderr, "** No previous ports for forwarding!! \n"); + exit(KERN_FAILURE); + } + + mach_port_t target_port = current.ports[found]; + exception_behavior_t target_behavior = current.behaviors[found]; + + kern_return_t result; + // TODO: Handle the case where |target_behavior| has MACH_EXCEPTION_CODES + // set. https://code.google.com/p/google-breakpad/issues/detail?id=551 + switch (target_behavior) { + case EXCEPTION_DEFAULT: + result = exception_raise(target_port, failed_thread, task, exception, + code, code_count); + break; + default: + fprintf(stderr, "** Unknown exception behavior: %d\n", target_behavior); + result = KERN_FAILURE; + break; + } + + return result; +} + +// static +void* ExceptionHandler::WaitForMessage(void* exception_handler_class) { + ExceptionHandler* self = + reinterpret_cast<ExceptionHandler*>(exception_handler_class); + ExceptionMessage receive; + + // Wait for the exception info + while (1) { + receive.header.msgh_local_port = self->handler_port_; + receive.header.msgh_size = static_cast<mach_msg_size_t>(sizeof(receive)); + kern_return_t result = mach_msg(&(receive.header), + MACH_RCV_MSG | MACH_RCV_LARGE, 0, + receive.header.msgh_size, + self->handler_port_, + MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL); + + + if (result == KERN_SUCCESS) { + // Uninstall our handler so that we don't get in a loop if the process of + // writing out a minidump causes an exception. However, if the exception + // was caused by a fork'd process, don't uninstall things + + // If the actual exception code is zero, then we're calling this handler + // in a way that indicates that we want to either exit this thread or + // generate a minidump + // + // While reporting, all threads (except this one) must be suspended + // to avoid misleading stacks. If appropriate they will be resumed + // afterwards. + if (!receive.exception) { + // Don't touch self, since this message could have been sent + // from its destructor. + if (receive.header.msgh_id == kShutdownMessage) + return NULL; + + self->SuspendThreads(); + +#if USE_PROTECTED_ALLOCATIONS + if (gBreakpadAllocator) + gBreakpadAllocator->Unprotect(); +#endif + + mach_port_t thread = MACH_PORT_NULL; + int exception_type = 0; + int exception_code = 0; + if (receive.header.msgh_id == kWriteDumpWithExceptionMessage) { + thread = receive.thread.name; + exception_type = EXC_BREAKPOINT; +#if defined(__i386__) || defined(__x86_64__) + exception_code = EXC_I386_BPT; +#elif defined(__ppc__) || defined(__ppc64__) + exception_code = EXC_PPC_BREAKPOINT; +#elif defined(__arm__) || defined(__aarch64__) + exception_code = EXC_ARM_BREAKPOINT; +#else +#error architecture not supported +#endif + } + + // Write out the dump and save the result for later retrieval + self->last_minidump_write_result_ = + self->WriteMinidumpWithException(exception_type, exception_code, + 0, NULL, thread, + false, false); + +#if USE_PROTECTED_ALLOCATIONS + if (gBreakpadAllocator) + gBreakpadAllocator->Protect(); +#endif + + self->ResumeThreads(); + + if (self->use_minidump_write_mutex_) + pthread_mutex_unlock(&self->minidump_write_mutex_); + } else { + // When forking a child process with the exception handler installed, + // if the child crashes, it will send the exception back to the parent + // process. The check for task == self_task() ensures that only + // exceptions that occur in the parent process are caught and + // processed. If the exception was not caused by this task, we + // still need to call into the exception server and have it return + // KERN_FAILURE (see catch_exception_raise) in order for the kernel + // to move onto the host exception handler for the child task + if (receive.task.name == mach_task_self()) { + self->SuspendThreads(); + +#if USE_PROTECTED_ALLOCATIONS + if (gBreakpadAllocator) + gBreakpadAllocator->Unprotect(); +#endif + + int subcode = 0; + if (receive.exception == EXC_BAD_ACCESS && receive.code_count > 1) + subcode = receive.code[1]; + + // Generate the minidump with the exception data. + self->WriteMinidumpWithException(receive.exception, receive.code[0], + subcode, NULL, receive.thread.name, + true, false); + +#if USE_PROTECTED_ALLOCATIONS + // This may have become protected again within + // WriteMinidumpWithException, but it needs to be unprotected for + // UninstallHandler. + if (gBreakpadAllocator) + gBreakpadAllocator->Unprotect(); +#endif + + self->UninstallHandler(true); + +#if USE_PROTECTED_ALLOCATIONS + if (gBreakpadAllocator) + gBreakpadAllocator->Protect(); +#endif + } + // Pass along the exception to the server, which will setup the + // message and call catch_exception_raise() and put the return + // code into the reply. + ExceptionReplyMessage reply; + if (!breakpad_exc_server(&receive.header, &reply.header)) + exit(1); + + // Send a reply and exit + mach_msg(&(reply.header), MACH_SEND_MSG, + reply.header.msgh_size, 0, MACH_PORT_NULL, + MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL); + } + } + } + + return NULL; +} + +// static +void ExceptionHandler::SignalHandler(int sig, siginfo_t* info, void* uc) { +#if USE_PROTECTED_ALLOCATIONS + if (gBreakpadAllocator) + gBreakpadAllocator->Unprotect(); +#endif + gProtectedData.handler->WriteMinidumpWithException( + EXC_SOFTWARE, + MD_EXCEPTION_CODE_MAC_ABORT, + 0, + static_cast<breakpad_ucontext_t*>(uc), + mach_thread_self(), + true, + true); +#if USE_PROTECTED_ALLOCATIONS + if (gBreakpadAllocator) + gBreakpadAllocator->Protect(); +#endif +} + +bool ExceptionHandler::InstallHandler() { + // If a handler is already installed, something is really wrong. + if (gProtectedData.handler != NULL) { + return false; + } + + struct sigaction sa; + memset(&sa, 0, sizeof(sa)); + sigemptyset(&sa.sa_mask); + sigaddset(&sa.sa_mask, SIGABRT); + sa.sa_sigaction = ExceptionHandler::SignalHandler; + sa.sa_flags = SA_SIGINFO; + + scoped_ptr<struct sigaction> old(new struct sigaction); + if (sigaction(SIGABRT, &sa, old.get()) == -1) { + return false; + } + old_handler_.swap(old); + gProtectedData.handler = this; +#if USE_PROTECTED_ALLOCATIONS + assert(((size_t)(gProtectedData.protected_buffer) & PAGE_MASK) == 0); + mprotect(gProtectedData.protected_buffer, PAGE_SIZE, PROT_READ); +#endif + + try { +#if USE_PROTECTED_ALLOCATIONS + previous_ = new (gBreakpadAllocator->Allocate(sizeof(ExceptionParameters)) ) + ExceptionParameters(); +#else + previous_ = new ExceptionParameters(); +#endif + } + catch (std::bad_alloc) { + return false; + } + + // Save the current exception ports so that we can forward to them + previous_->count = EXC_TYPES_COUNT; + mach_port_t current_task = mach_task_self(); + kern_return_t result = task_get_exception_ports(current_task, + s_exception_mask, + previous_->masks, + &previous_->count, + previous_->ports, + previous_->behaviors, + previous_->flavors); + + // Setup the exception ports on this task + if (result == KERN_SUCCESS) + result = task_set_exception_ports(current_task, s_exception_mask, + handler_port_, EXCEPTION_DEFAULT, + THREAD_STATE_NONE); + + installed_exception_handler_ = (result == KERN_SUCCESS); + + return installed_exception_handler_; +} + +bool ExceptionHandler::UninstallHandler(bool in_exception) { + kern_return_t result = KERN_SUCCESS; + + if (old_handler_.get()) { + sigaction(SIGABRT, old_handler_.get(), NULL); +#if USE_PROTECTED_ALLOCATIONS + mprotect(gProtectedData.protected_buffer, PAGE_SIZE, + PROT_READ | PROT_WRITE); +#endif + old_handler_.reset(); + gProtectedData.handler = NULL; + } + + if (installed_exception_handler_) { + mach_port_t current_task = mach_task_self(); + + // Restore the previous ports + for (unsigned int i = 0; i < previous_->count; ++i) { + result = task_set_exception_ports(current_task, previous_->masks[i], + previous_->ports[i], + previous_->behaviors[i], + previous_->flavors[i]); + if (result != KERN_SUCCESS) + return false; + } + + // this delete should NOT happen if an exception just occurred! + if (!in_exception) { +#if USE_PROTECTED_ALLOCATIONS + previous_->~ExceptionParameters(); +#else + delete previous_; +#endif + } + + previous_ = NULL; + installed_exception_handler_ = false; + } + + return result == KERN_SUCCESS; +} + +bool ExceptionHandler::Setup(bool install_handler) { + if (pthread_mutex_init(&minidump_write_mutex_, NULL)) + return false; + + // Create a receive right + mach_port_t current_task = mach_task_self(); + kern_return_t result = mach_port_allocate(current_task, + MACH_PORT_RIGHT_RECEIVE, + &handler_port_); + // Add send right + if (result == KERN_SUCCESS) + result = mach_port_insert_right(current_task, handler_port_, handler_port_, + MACH_MSG_TYPE_MAKE_SEND); + + if (install_handler && result == KERN_SUCCESS) + if (!InstallHandler()) + return false; + + if (result == KERN_SUCCESS) { + // Install the handler in its own thread, detached as we won't be joining. + pthread_attr_t attr; + pthread_attr_init(&attr); + pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); + int thread_create_result = pthread_create(&handler_thread_, &attr, + &WaitForMessage, this); + pthread_attr_destroy(&attr); + result = thread_create_result ? KERN_FAILURE : KERN_SUCCESS; + } + + return result == KERN_SUCCESS; +} + +bool ExceptionHandler::Teardown() { + kern_return_t result = KERN_SUCCESS; + is_in_teardown_ = true; + + if (!UninstallHandler(false)) + return false; + + // Send an empty message so that the handler_thread exits + if (SendMessageToHandlerThread(kShutdownMessage)) { + mach_port_t current_task = mach_task_self(); + result = mach_port_deallocate(current_task, handler_port_); + if (result != KERN_SUCCESS) + return false; + } else { + return false; + } + + handler_thread_ = NULL; + handler_port_ = MACH_PORT_NULL; + pthread_mutex_destroy(&minidump_write_mutex_); + + return result == KERN_SUCCESS; +} + +bool ExceptionHandler::SendMessageToHandlerThread( + HandlerThreadMessage message_id) { + ExceptionMessage msg; + memset(&msg, 0, sizeof(msg)); + msg.header.msgh_id = message_id; + if (message_id == kWriteDumpMessage || + message_id == kWriteDumpWithExceptionMessage) { + // Include this thread's port. + msg.thread.name = mach_thread_self(); + msg.thread.disposition = MACH_MSG_TYPE_PORT_SEND; + msg.thread.type = MACH_MSG_PORT_DESCRIPTOR; + } + msg.header.msgh_size = sizeof(msg) - sizeof(msg.padding); + msg.header.msgh_remote_port = handler_port_; + msg.header.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_COPY_SEND, + MACH_MSG_TYPE_MAKE_SEND_ONCE); + kern_return_t result = mach_msg(&(msg.header), + MACH_SEND_MSG | MACH_SEND_TIMEOUT, + msg.header.msgh_size, 0, 0, + MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL); + + return result == KERN_SUCCESS; +} + +void ExceptionHandler::UpdateNextID() { + next_minidump_path_ = + (MinidumpGenerator::UniqueNameInDirectory(dump_path_, &next_minidump_id_)); + + next_minidump_path_c_ = next_minidump_path_.c_str(); + next_minidump_id_c_ = next_minidump_id_.c_str(); +} + +bool ExceptionHandler::SuspendThreads() { + thread_act_port_array_t threads_for_task; + mach_msg_type_number_t thread_count; + + if (task_threads(mach_task_self(), &threads_for_task, &thread_count)) + return false; + + // suspend all of the threads except for this one + for (unsigned int i = 0; i < thread_count; ++i) { + if (threads_for_task[i] != mach_thread_self()) { + if (thread_suspend(threads_for_task[i])) + return false; + } + } + + return true; +} + +bool ExceptionHandler::ResumeThreads() { + thread_act_port_array_t threads_for_task; + mach_msg_type_number_t thread_count; + + if (task_threads(mach_task_self(), &threads_for_task, &thread_count)) + return false; + + // resume all of the threads except for this one + for (unsigned int i = 0; i < thread_count; ++i) { + if (threads_for_task[i] != mach_thread_self()) { + if (thread_resume(threads_for_task[i])) + return false; + } + } + + return true; +} + +} // namespace google_breakpad |