Add GPU job object restriction

content/common/sandbox_policy.cc

 // Copyright (c) 2011 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_policy.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/debug/debugger.h"
@@ skipping 269 matching lines @@
   return true;
 }
 
 // For the GPU process we gotten as far as USER_LIMITED. The next level
 // which is USER_RESTRICTED breaks both the DirectX backend and the OpenGL
 // backend. Note that the GPU process is connected to the interactive
 // desktop.
 // TODO(cpu): Lock down the sandbox more if possible.
 // TODO(apatrick): Use D3D9Ex to render windowless.
 bool AddPolicyForGPU(CommandLine* cmd_line, sandbox::TargetPolicy* policy) {
-  policy->SetJobLevel(sandbox::JOB_UNPROTECTED, 0);
-
   if (base::win::GetVersion() > base::win::VERSION_XP) {
     policy->SetTokenLevel(sandbox::USER_RESTRICTED_SAME_ACCESS,
                           sandbox::USER_LIMITED);
     if (cmd_line->GetSwitchValueASCII(switches::kUseGL) ==
-          gfx::kGLImplementationDesktopName)
+        gfx::kGLImplementationDesktopName) {
+      policy->SetJobLevel(sandbox::JOB_UNPROTECTED, 0);
+      policy->SetIntegrityLevel(sandbox::INTEGRITY_LEVEL_LOW);
+    } else {
+      // UI restrictions break when we access Windows from outside our job.
+      // However, we don't want a proxy window in this process because it can
+      // introduce deadlocks. So, the only job restriction we pick up here is

[brettw, 2011/08/27 23:06:47]

It might be nice to mention here quickly how such deadlocks can occur, and also
how these settings avoid a proxy window.

[jschuh, 2011/08/29 16:13:58]

Done.

+      // to prevent child processes.
+      policy->SetJobLevel(sandbox::JOB_LIMITED_USER,
+                          JOB_OBJECT_UILIMIT_SYSTEMPARAMETERS |
+                          JOB_OBJECT_UILIMIT_DESKTOP |
+                          JOB_OBJECT_UILIMIT_EXITWINDOWS |
+                          JOB_OBJECT_UILIMIT_DISPLAYSETTINGS);
       policy->SetDelayedIntegrityLevel(sandbox::INTEGRITY_LEVEL_LOW);
-    else
-      policy->SetIntegrityLevel(sandbox::INTEGRITY_LEVEL_LOW);
+    }
   } else {
     policy->SetTokenLevel(sandbox::USER_UNPROTECTED,
                           sandbox::USER_LIMITED);
   }
 
   AddGenericDllEvictionPolicy(policy);
   return true;
 }
 
 void AddPolicyForRenderer(sandbox::TargetPolicy* policy) {
@@ skipping 227 matching lines @@
 
   // Help the process a little. It can't start the debugger by itself if
   // the process is in a sandbox.
   if (child_needs_help)
     base::debug::SpawnDebuggerOnProcess(target.dwProcessId);
 
   return process;
 }
 
 }  // namespace sandbox