base/process/launch_mac.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/process/launch.h"
   6
   7 #include <mach/mach.h>
   8 #include <servers/bootstrap.h>
   9
  10 #include "base/logging.h"
  11
  12 namespace base {
  13
  14 void RestoreDefaultExceptionHandler() {
  15   // This function is tailored to remove the Breakpad exception handler.
  16   // exception_mask matches s_exception_mask in
  17   // breakpad/src/client/mac/handler/exception_handler.cc
  18   const exception_mask_t exception_mask = EXC_MASK_BAD_ACCESS |
  19                                           EXC_MASK_BAD_INSTRUCTION |
  20                                           EXC_MASK_ARITHMETIC |
  21                                           EXC_MASK_BREAKPOINT;
  22
  23   // Setting the exception port to MACH_PORT_NULL may not be entirely
  24   // kosher to restore the default exception handler, but in practice,
  25   // it results in the exception port being set to Apple Crash Reporter,
  26   // the desired behavior.
  27   task_set_exception_ports(mach_task_self(), exception_mask, MACH_PORT_NULL,
  28                            EXCEPTION_DEFAULT, THREAD_STATE_NONE);
  29 }
  30
  31 void ReplaceBootstrapPort(const std::string& new_bootstrap_name) {
  32   // This function is called between fork() and exec(), so it should take care
  33   // to run properly in that situation.
  34
  35   mach_port_t port = MACH_PORT_NULL;
  36   kern_return_t kr = bootstrap_look_up(bootstrap_port,
  37       new_bootstrap_name.c_str(), &port);
  38   if (kr != KERN_SUCCESS) {
  39     RAW_LOG(FATAL, "Failed to look up replacement bootstrap port.");
  40   }
  41
  42   kr = task_set_bootstrap_port(mach_task_self(), port);
  43   if (kr != KERN_SUCCESS) {
  44     RAW_LOG(FATAL, "Failed to replace bootstrap port.");
  45   }
  46
  47   // On OS X 10.10 and higher, libxpc uses the port stash to transfer the
  48   // XPC root port. This is effectively the same connection as the Mach
  49   // bootstrap port, but not transferred using the task special port.
  50   // Therefore, stash the replacement bootstrap port, so that on 10.10 it
  51   // will be retrieved by the XPC code and used as a replacement for the
  52   // XPC root port as well.
  53   kr = mach_ports_register(mach_task_self(), &port, 1);
  54   if (kr != KERN_SUCCESS) {
  55     RAW_LOG(ERROR, "Failed to register replacement bootstrap port.");
  56   }
  57 }
  58
  59 }  // namespace base