Ensure seccomp-bpf cannot be silently disabled for non-SFI NaCl

chrome/browser/chrome_content_browser_client.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 "chrome/browser/chrome_content_browser_client.h"
 
 #include <set>
 #include <utility>
 #include <vector>
 
@@ skipping 1620 matching lines @@
       switches::kMemoryProfiling,
       switches::kSilentDumpOnDCHECK,
     };
 
     command_line->CopySwitchesFrom(browser_command_line, kSwitchNames,
                                    arraysize(kSwitchNames));
   } else if (process_type == switches::kZygoteProcess) {
     static const char* const kSwitchNames[] = {
       // Load (in-process) Pepper plugins in-process in the zygote pre-sandbox.
       switches::kDisableBundledPpapiFlash,
+      switches::kNaClDangerousNoSandboxNonSfi,

[jln (very slow on Chromium), 2014/04/10 19:08:24]

I don't know what this is, but it shouldn't be needed. Flags such as
switches::kDisableSeccompFilterSandbox don't seem to require it.

[hamaji, 2014/04/10 19:17:55]

This is necessary to transfer the flag from browser process to zygote process.

switches::kDisableSeccompFilterSandbox is handled in
content/browser/zygote_host/zygote_host_impl_linux.cc. As
zygote_host_impl_linux.cc is in content/, we cannot refer switches in
component/. OTOH, kDisableSeccompFilterSandbox is a content_switch, so it can be
directly referred in zygote_host_impl_linux.cc.

It seems some other NaCl related flags are also using this file. You can see
kEnableNaCl is listed in line 1592 to pass it from browser to renderer, for
example.

[jln (very slow on Chromium), 2014/04/10 19:19:33]

Ahh right, thanks!

       switches::kPpapiFlashPath,
       switches::kPpapiFlashVersion,
     };
 
     command_line->CopySwitchesFrom(browser_command_line, kSwitchNames,
                                    arraysize(kSwitchNames));
   } else if (process_type == switches::kGpuProcess) {
     // If --ignore-gpu-blacklist is passed in, don't send in crash reports
     // because GPU is expected to be unreliable.
     if (browser_command_line.HasSwitch(switches::kIgnoreGpuBlacklist) &&
@@ skipping 1108 matching lines @@
       switches::kDisableWebRtcEncryption,
     };
     to_command_line->CopySwitchesFrom(from_command_line,
                                       kWebRtcDevSwitchNames,
                                       arraysize(kWebRtcDevSwitchNames));
   }
 }
 #endif  // defined(ENABLE_WEBRTC)
 
 }  // namespace chrome