Add DropPrivileges()

tools/exception_port_tool.cc

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 16 matching lines @@
 
 #include "base/basictypes.h"
 #include "base/mac/mach_logging.h"
 #include "base/mac/scoped_mach_port.h"
 #include "base/strings/stringprintf.h"
 #include "tools/tool_support.h"
 #include "util/mach/exception_ports.h"
 #include "util/mach/mach_extensions.h"
 #include "util/mach/symbolic_constants_mach.h"
 #include "util/mach/task_for_pid.h"
+#include "util/posix/drop_privileges.h"
 #include "util/stdlib/string_number_conversion.h"
 
 namespace crashpad {
 namespace {
 
 //! \brief Manages a pool of Mach send rights, deallocating all send rights upon
 //!     destruction.
 //!
 //! This class effectively implements what a vector of
 //! base::mac::ScopedMachSendRight objects would be.
@@ skipping 449 matching lines @@
       return kExitFailure;
     }
 
     options.alternate_task = TaskForPID(options.pid);
     if (options.alternate_task == TASK_NULL) {
       return kExitFailure;
     }
     alternate_task_owner.reset(options.alternate_task);
   }
 
+  // This tool may have been installed as a setuid binary so that TaskForPID()
+  // could succeed. Drop any privileges now that they’re no longer necessary.
+  DropPrivileges();
+
   MachSendRightPool mach_send_right_pool;
 
   // Show bootstrap services requested.
   for (const char* service : options.show_bootstrap) {
     ShowBootstrapService(service, &mach_send_right_pool);
   }
 
   // Show the original exception ports.
   if (options.show_host) {
     ShowExceptionPorts(
@@ skipping 64 matching lines @@
 
   return kExitSuccess;
 }
 
 }  // namespace
 }  // namespace crashpad
 
 int main(int argc, char* argv[]) {
   return crashpad::ExceptionPortToolMain(argc, argv);
 }