Clarify the process title of GPU broker process.

content/common/sandbox_linux/bpf_gpu_policy_linux.cc

 // Copyright (c) 2013 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/common/sandbox_linux/bpf_gpu_policy_linux.h"
 
 #include <dlfcn.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 #include <string>
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "build/build_config.h"
 #include "content/common/sandbox_linux/sandbox_bpf_base_policy_linux.h"
 #include "content/common/sandbox_linux/sandbox_seccomp_bpf_linux.h"
+#include "content/common/set_process_title.h"
 #include "content/public/common/content_switches.h"
 #include "sandbox/linux/seccomp-bpf-helpers/syscall_sets.h"
 #include "sandbox/linux/seccomp-bpf/sandbox_bpf.h"
 #include "sandbox/linux/services/broker_process.h"
 #include "sandbox/linux/services/linux_syscalls.h"
 
 using sandbox::BrokerProcess;
 using sandbox::ErrorCode;
 using sandbox::SandboxBPF;
 using sandbox::SyscallSets;
@@ skipping 94 matching lines @@
   switch (sysno) {
     case __NR_access:
     case __NR_open:
     case __NR_openat:
       return ErrorCode(ErrorCode::ERR_ALLOWED);
     default:
       return GpuProcessPolicy::EvaluateSyscall(sandbox, sysno);
   }
 }
 
+static void UpdateProcessTitle() {

[jln (very slow on Chromium), 2014/02/20 00:29:57]

UpdateProcessTypeToGpuBroker() instead?

[dshwang, 2014/02/20 20:36:31]

Done

+  CommandLine::StringVector exec = CommandLine::ForCurrentProcess()->GetArgs();
+  CommandLine::Reset();
+  CommandLine::Init(0, NULL);
+  CommandLine::ForCurrentProcess()->InitFromArgv(exec);
+  CommandLine::ForCurrentProcess()->AppendSwitchASCII(switches::kProcessType,
+                                                      "gpu-broker");
+
+  // Update the process title. The argv was already cached by the call to
+  // SetProcessTitleFromCommandLine in content_main_runner.cc, so we can pass

[Jorge Lucangeli Obes, 2014/02/20 00:33:05]

Is this comment still accurate?

[dshwang, 2014/02/20 20:36:31]

Yes. but there is some logic jump. Browser process cached argv in
SetProcessTitleFromCommandLine and then fork process to gpu process. So GPU
process also cached argv, and then fork to broker process. So broker process
also cached argv.
I copy this comment from zygote_linux.cc

+  // NULL here (we don't have the original argv at this point).
+  SetProcessTitleFromCommandLine(NULL);
+}
+
 bool EnableGpuBrokerPolicyCallback() {

[jln (very slow on Chromium), 2014/02/20 00:29:57]

Let's rename to GpuBrokerChildInitCallback or something similar.

[dshwang, 2014/02/20 20:36:31]

Done

+  UpdateProcessTitle();
   return SandboxSeccompBPF::StartSandboxWithExternalPolicy(
       scoped_ptr<sandbox::SandboxBPFPolicy>(new GpuBrokerProcessPolicy));
 }
 
 }  // namespace
 
 GpuProcessPolicy::GpuProcessPolicy() : broker_process_(NULL) {}
 
 GpuProcessPolicy::~GpuProcessPolicy() {}
 
@@ skipping 89 matching lines @@
                          write_whitelist_extra.end());
 
   broker_process_ = new BrokerProcess(GetFSDeniedErrno(),
                                       read_whitelist,
                                       write_whitelist);
   // Initialize the broker process and give it a sandbox callback.
   CHECK(broker_process_->Init(broker_sandboxer_callback));
 }
 
 }  // namespace content