Linux sandbox: change seccomp detection and initialization.

components/nacl/loader/sandbox_linux/nacl_sandbox_linux.cc

 // Copyright 2014 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 "components/nacl/loader/sandbox_linux/nacl_sandbox_linux.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <sys/types.h>
@@ skipping 44 matching lines @@
 NaClSandbox::NaClSandbox()
     : layer_one_enabled_(false),
       layer_one_sealed_(false),
       layer_two_enabled_(false),
       layer_two_is_nonsfi_(false),
       proc_fd_(-1),
       setuid_sandbox_client_(sandbox::SetuidSandboxClient::Create()) {
   proc_fd_.reset(
       HANDLE_EINTR(open("/proc", O_DIRECTORY | O_RDONLY | O_CLOEXEC)));
   PCHECK(proc_fd_.is_valid());
-  // Determine if the kernel supports seccomp-bpf and let it cache the
-  // result. This must be done before any sandbox is engaged.
-  sandbox::SandboxBPF::SupportsSeccompSandbox();
 }
 
 NaClSandbox::~NaClSandbox() {
 }
 
 bool NaClSandbox::IsSingleThreaded() {
   CHECK(proc_fd_.is_valid());
   base::ScopedFD proc_self_task(GetProcSelfTask(proc_fd_.get()));
   return sandbox::ThreadHelpers::IsSingleThreaded(proc_self_task.get());
 }
@@ skipping 93 matching lines @@
     static const char kNoBpfMsg[] =
         "The seccomp-bpf sandbox is not engaged for NaCl:";
     if (can_be_no_sandbox)
       LOG(ERROR) << kNoBpfMsg << kItIsDangerousMsg;
     else
       LOG(FATAL) << kNoBpfMsg << kItIsNotAllowedMsg;
   }
 }
 
 }  // namespace nacl