Linux GPU sandbox: only allocate broker policy in the broker.

content/common/sandbox_linux/bpf_gpu_policy_linux.h

 // Copyright 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.
 
 #ifndef CONTENT_COMMON_SANDBOX_LINUX_BPF_GPU_POLICY_LINUX_H_
 #define CONTENT_COMMON_SANDBOX_LINUX_BPF_GPU_POLICY_LINUX_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 11 matching lines @@
   GpuProcessPolicy();
   virtual ~GpuProcessPolicy();
 
   virtual ErrorCode EvaluateSyscall(SandboxBPF* sandbox_compiler,
                                     int system_call_number) const OVERRIDE;
 
   virtual bool PreSandboxHook() OVERRIDE;
 
  protected:
   // Start a broker process to handle open() inside the sandbox.
-  // |broker_sandboxer_callback| is a callback that will enable a suitable
-  // sandbox for the broker process itself.
+  // |broker_sandboxer_allocator| is a function pointer which can allocate a
+  // suitable sandbox policy for the broker process itself.
   // |read_whitelist_extra| and |write_whitelist_extra| are lists of file
   // names that should be whitelisted by the broker process, in addition to
   // the basic ones.
   void InitGpuBrokerProcess(
-      const base::Callback<bool(void)>& broker_sandboxer_callback,
+      sandbox::SandboxBPFPolicy* (*broker_sandboxer_allocator)(void),

[Jorge Lucangeli Obes, 2014/04/28 23:43:53]

It was nice to have base::Callback's instead of function pointers, they're
definitely easier to read. But I guess this way you can just pass the static
method directly.

[jln (very slow on Chromium), 2014/04/28 23:53:18]

We could still make it a CallBack if we really wanted to, but the CallBack
taking a CallBack as a parameter that goes across fork() seemed too complicated
to follow.

       const std::vector<std::string>& read_whitelist_extra,
       const std::vector<std::string>& write_whitelist_extra);
 
   sandbox::BrokerProcess* broker_process() { return broker_process_; }
 
  private:
   // A BrokerProcess is a helper that is started before the sandbox is engaged
   // and will serve requests to access files over an IPC channel. The client of
   // this runs from a SIGSYS handler triggered by the seccomp-bpf sandbox.
   // This should never be destroyed, as after the sandbox is started it is
   // vital to the process.
   // This is allocated by InitGpuBrokerProcess, called from PreSandboxHook(),
   // which executes iff the sandbox is going to be enabled afterwards.
   sandbox::BrokerProcess* broker_process_;
   DISALLOW_COPY_AND_ASSIGN(GpuProcessPolicy);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_SANDBOX_LINUX_BPF_GPU_POLICY_LINUX_H_