Posix: Fix --utility-cmd-prefix to not run /proc/self/exe.

content/browser/utility_process_host_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/utility_process_host_impl.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/message_loop.h"
@@ skipping 93 matching lines @@
   if (is_batch_mode_)
     return true;
   // Name must be set or metrics_service will crash in any test which
   // launches a UtilityProcessHost.
   process_->SetName(ASCIIToUTF16("utility process"));
 
   std::string channel_id = process_->GetHost()->CreateChannel();
   if (channel_id.empty())
     return false;
 
-  FilePath exe_path = ChildProcessHost::GetChildPath(child_flags_);
+  const CommandLine& browser_command_line = *CommandLine::ForCurrentProcess();
+  int child_flags = child_flags_;
+
+#if defined(OS_POSIX)
+  bool has_cmd_prefix = browser_command_line.HasSwitch(
+      switches::kUtilityCmdPrefix);
+
+  // When running under gdb, forking /proc/self/exe ends up forking the gdb
+  // executable instead of Chromium. It is almost safe to assume that no
+  // updates will happen while a developer is running with
+  // |switches::kUtilityCmdPrefix|. See ChildProcessHost::GetChildPath() for
+  // a similar case with Valgrind.
+  if (has_cmd_prefix)
+    child_flags = ChildProcessHost::CHILD_NORMAL;
+#endif
+
+  FilePath exe_path = ChildProcessHost::GetChildPath(child_flags);
   if (exe_path.empty()) {
     NOTREACHED() << "Unable to get utility process binary name.";
     return false;
   }
 
   CommandLine* cmd_line = new CommandLine(exe_path);
   cmd_line->AppendSwitchASCII(switches::kProcessType,
                               switches::kUtilityProcess);
   cmd_line->AppendSwitchASCII(switches::kProcessChannelID, channel_id);
   std::string locale =
       content::GetContentClient()->browser()->GetApplicationLocale();
   cmd_line->AppendSwitchASCII(switches::kLang, locale);
 
-  const CommandLine& browser_command_line = *CommandLine::ForCurrentProcess();
   if (browser_command_line.HasSwitch(switches::kChromeFrame))
     cmd_line->AppendSwitch(switches::kChromeFrame);
   if (no_sandbox_ || browser_command_line.HasSwitch(switches::kNoSandbox))
     cmd_line->AppendSwitch(switches::kNoSandbox);
   if (browser_command_line.HasSwitch(switches::kDebugPluginLoading))
     cmd_line->AppendSwitch(switches::kDebugPluginLoading);
 
 #if defined(OS_POSIX)
   // TODO(port): Sandbox this on Linux.  Also, zygote this to work with
   // Linux updating.
-  bool has_cmd_prefix = browser_command_line.HasSwitch(
-      switches::kUtilityCmdPrefix);
   if (has_cmd_prefix) {
     // launch the utility child process with some prefix (usually "xterm -e gdb
     // --args").
     cmd_line->PrependWrapper(browser_command_line.GetSwitchValueNative(
         switches::kUtilityCmdPrefix));
   }
 
   cmd_line->AppendSwitchPath(switches::kUtilityProcessAllowedDir, exposed_dir_);
 #endif
 
@@ skipping 23 matching lines @@
           message));
   return true;
 }
 
 void UtilityProcessHostImpl::OnProcessCrashed(int exit_code) {
   BrowserThread::PostTask(
       client_thread_id_, FROM_HERE,
       base::Bind(&UtilityProcessHostClient::OnProcessCrashed, client_.get(),
             exit_code));
 }