Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 990 insertions, 0 deletions

diff --git a/toolkit/crashreporter/breakpad-client/mac/handler/exception_handler.cc b/toolkit/crashreporter/breakpad-client/mac/handler/exception_handler.cc
new file mode 100644
index 0000000000..c39d66ba41
--- /dev/null
+++ b/toolkit/crashreporter/breakpad-client/mac/handler/exception_handler.cc
@@ -0,0 +1,990 @@
+// 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 "mac/handler/exception_handler.h"
+#include "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"
+#include "mozilla/Assertions.h"
+
+#ifdef MOZ_PHC
+#include "replace_malloc_bridge.h"
+#endif
+
+#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
+#pragma pack(push, 4)
+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;
+  mach_exception_data_type_t  code[EXCEPTION_CODE_MAX];
+  char                        padding[512];
+};
+#pragma pack(pop)
+
+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];
+};
+
+#pragma pack(push, 4)
+struct ExceptionReplyMessage {
+  mach_msg_header_t  header;
+  NDR_record_t       ndr;
+  kern_return_t      return_code;
+};
+#pragma pack(pop)
+
+// 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 |
+EXC_MASK_CRASH | EXC_MASK_RESOURCE | EXC_MASK_GUARD;
+
+kern_return_t ForwardException(mach_port_t task,
+                               mach_port_t failed_thread,
+                               exception_type_t exception,
+                               mach_exception_data_t code,
+                               mach_msg_type_number_t code_count);
+
+// The contents of mach_exc_server() and mach_exception_raise() are derived
+// from /usr/include/mach/mach_exc.defs, as follows:
+//
+// 1) Run 'mig mach_exc.defs' which creates the following files:
+//    mach_exc.h
+//    mach_excServer.c
+//    mach_excUser.c
+// 2) The relevant code for mach_exc_server() comes from the following methods
+//    in mach_excServer.c:
+//      mach_exc_server()
+//      _Xmach_exception_raise()
+// 3) The relevant code for mach_exception_raise() comes from the following
+//    method in mach_excUser.c:
+//      mach_exception_raise()
+boolean_t mach_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: mach_exception_raise() 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;
+  OutHeadP->msgh_reserved = 0;
+
+  if (InHeadP->msgh_id != 2405) {
+    ((mig_reply_error_t*)OutHeadP)->NDR = NDR_record;
+    ((mig_reply_error_t*)OutHeadP)->RetCode = MIG_BAD_ID;
+    return FALSE;
+  }
+
+#pragma pack(push, 4)
+  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;
+    int64_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;
+#pragma pack(pop)
+
+  Request* In0P = (Request*)InHeadP;
+  Reply* OutP = (Reply*)OutHeadP;
+
+  if (In0P->task.name != mach_task_self()) {
+    // This exception was not meant for us, we avoid forwarding it (because it
+    // could cause a loop in the exception handler) and simply ignore it
+    // instead.
+    return TRUE;
+  }
+
+  OutP->RetCode = ForwardException(In0P->task.name,
+                                   In0P->thread.name,
+                                   In0P->exception,
+                                   In0P->code,
+                                   In0P->codeCnt);
+  OutP->NDR = NDR_record;
+  return TRUE;
+}
+
+kern_return_t mach_exception_raise(mach_port_t exception_port,
+                                   mach_port_t thread,
+                                   mach_port_t task,
+                                   exception_type_t exception,
+                                   mach_exception_data_t code,
+                                   mach_msg_type_number_t codeCnt)
+{
+#pragma pack(push, 4)
+  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;
+    int64_t code[2];
+  } Request;
+
+  typedef struct {
+    mach_msg_header_t Head;
+    NDR_record_t NDR;
+    kern_return_t RetCode;
+    mach_msg_trailer_t trailer;
+  } Reply;
+#pragma pack(pop)
+
+  Request In;
+  Request *InP = &In;
+
+  mach_msg_return_t msg_result;
+  unsigned int msgh_size;
+
+  InP->msgh_body.msgh_descriptor_count = 2;
+  InP->thread.name = thread;
+  InP->thread.disposition = 19;
+  InP->thread.type = MACH_MSG_PORT_DESCRIPTOR;
+  InP->task.name = task;
+  InP->task.disposition = 19;
+  InP->task.type = MACH_MSG_PORT_DESCRIPTOR;
+
+  InP->NDR = NDR_record;
+
+  InP->exception = exception;
+
+  if (codeCnt > 2) {
+    { return MIG_ARRAY_TOO_LARGE; }
+  }
+  (void)memcpy((char *) InP->code, (const char *) code, 8 * codeCnt);
+
+  InP->codeCnt = codeCnt;
+
+  msgh_size = (mach_msg_size_t)(sizeof(Request) - 16) + ((8 * codeCnt));
+  InP->Head.msgh_bits = MACH_MSGH_BITS_COMPLEX |
+    MACH_MSGH_BITS(19, MACH_MSG_TYPE_MAKE_SEND_ONCE);
+  /* msgh_size passed as argument */
+  InP->Head.msgh_remote_port = exception_port;
+  InP->Head.msgh_local_port = mig_get_reply_port();
+  InP->Head.msgh_id = 2405;
+  InP->Head.msgh_reserved = 0;
+
+  msg_result = mach_msg(&InP->Head,
+                        MACH_SEND_MSG|MACH_RCV_MSG|MACH_MSG_OPTION_NONE,
+                        msgh_size,
+                        (mach_msg_size_t)sizeof(Reply),
+                        InP->Head.msgh_local_port,
+                        MACH_MSG_TIMEOUT_NONE,
+                        MACH_PORT_NULL);
+
+  if (msg_result != MACH_MSG_SUCCESS) {
+    fprintf(stderr, "** mach_msg() error forwarding exception!!\n");
+    return msg_result;
+  }
+
+  return KERN_SUCCESS;
+}
+
+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, nullptr, result);
+  }
+  return result;
+}
+
+#ifdef MOZ_PHC
+static void GetPHCAddrInfo(int exception_type, int64_t exception_subcode,
+                           mozilla::phc::AddrInfo* addr_info) {
+  // Is this a crash involving a PHC allocation?
+  if (exception_type == EXC_BAD_ACCESS) {
+    // `exception_subcode` is only non-zero when it's a bad access, in which
+    // case it holds the address of the bad access.
+    char* addr = reinterpret_cast<char*>(exception_subcode);
+    ReplaceMalloc::IsPHCAllocation(addr, addr_info);
+  }
+}
+#endif
+
+bool ExceptionHandler::WriteMinidumpWithException(
+    int exception_type,
+    int64_t exception_code,
+    int64_t exception_subcode,
+    breakpad_ucontext_t* task_context,
+    mach_port_t thread_name,
+    mach_port_t task_name,
+    bool exit_after_write,
+    bool report_current_thread) {
+  bool result = false;
+
+#if TARGET_OS_IPHONE
+  // _exit() should never be called on iOS.
+  exit_after_write = false;
+#endif
+
+    mozilla::phc::AddrInfo addr_info;
+#ifdef MOZ_PHC
+    GetPHCAddrInfo(exception_type, exception_subcode, &addr_info);
+#endif
+
+  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,
+          task_name);
+
+      if (callback_) {
+        result = callback_(dump_path_c_, next_minidump_id_c_, callback_context_,
+                           &addr_info, result);
+      }
+
+      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_) {
+      result = callback_(dump_path_c_, next_minidump_id_c_, callback_context_,
+                         &addr_info, result);
+      // 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 (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,
+                               mach_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,
+                           &current.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;
+  switch (target_behavior & ~MACH_EXCEPTION_CODES) {
+    case EXCEPTION_DEFAULT:
+      result = mach_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) {
+  pthread_setname_np("Breakpad ExceptionHandler");
+
+  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;
+        int64_t 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, mach_task_self(),
+                                           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 {
+        bool crash_reported = false;
+
+        // 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 (receive.task.name == mach_task_self()) {
+          self->SuspendThreads();
+
+#if USE_PROTECTED_ALLOCATIONS
+          if (gBreakpadAllocator)
+            gBreakpadAllocator->Unprotect();
+#endif
+
+          mach_exception_data_type_t subcode = 0;
+          if (receive.code_count > 1) {
+            switch (receive.exception) {
+              case EXC_BAD_ACCESS:
+              case EXC_CRASH:
+              case EXC_RESOURCE:
+              case EXC_GUARD:
+                subcode = receive.code[1];
+                break;
+              default:
+                subcode = 0;
+            }
+          }
+
+          // Generate the minidump with the exception data.
+          crash_reported =
+            self->WriteMinidumpWithException(receive.exception, receive.code[0],
+                                             subcode, NULL, receive.thread.name,
+                                             mach_task_self(),  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
+        }
+
+        ExceptionReplyMessage reply;
+        if (!mach_exc_server(&receive.header, &reply.header)) {
+          MOZ_CRASH_UNSAFE_PRINTF("Mach message id: %d crash reported = %d",
+                                  receive.header.msgh_id, crash_reported);
+        }
+
+        // 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(),
+      mach_task_self(),
+      true,
+      true);
+#if USE_PROTECTED_ALLOCATIONS
+  if (gBreakpadAllocator)
+    gBreakpadAllocator->Protect();
+#endif
+}
+
+// static
+bool ExceptionHandler::WriteForwardedExceptionMinidump(int exception_type,
+						       int64_t exception_code,
+						       int64_t exception_subcode,
+						       mach_port_t thread,
+						       mach_port_t task)
+{
+  if (!gProtectedData.handler) {
+    return false;
+  }
+  return gProtectedData.handler->WriteMinidumpWithException(exception_type, exception_code,
+							    exception_subcode, NULL, thread, task,
+							    /* exit_after_write = */ false,
+							    /* report_current_thread = */ true);
+}
+
+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.  Such documentation as exists for
+  // task_set_exception_port() and friends can be found in the source code for
+  // xnu.  Apple's implementation is available at https://opensource.apple.com/.
+  if (result == KERN_SUCCESS)
+    result = task_set_exception_ports(current_task, s_exception_mask,
+                                      handler_port_,
+                                      EXCEPTION_DEFAULT | MACH_EXCEPTION_CODES,
+                                      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
+    // If we're handling an exception, leak the sigaction struct
+    // because it is unsafe to delete objects while in exception
+    // handling context.
+    if (in_exception) {
+      old_handler_.release();
+    } else {
+      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