Linux sandbox: always restrict clone() in baseline policy.

content/common/sandbox_linux/bpf_ppapi_policy_linux.cc

 // 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.
 
 #include "content/common/sandbox_linux/bpf_ppapi_policy_linux.h"
 
 #include <errno.h>
 
 #include "base/basictypes.h"
 #include "build/build_config.h"
 #include "content/common/sandbox_linux/sandbox_linux.h"
 #include "sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.h"
 #include "sandbox/linux/seccomp-bpf-helpers/syscall_sets.h"
 #include "sandbox/linux/seccomp-bpf/sandbox_bpf_policy.h"
 #include "sandbox/linux/services/linux_syscalls.h"
 
 using sandbox::SyscallSets;
 
 namespace content {
 
 PpapiProcessPolicy::PpapiProcessPolicy() {}
 PpapiProcessPolicy::~PpapiProcessPolicy() {}
 
 ErrorCode PpapiProcessPolicy::EvaluateSyscall(SandboxBPF* sandbox,
                                               int sysno) const {
   switch (sysno) {
-    case __NR_clone:
-      return sandbox::RestrictCloneToThreadsAndEPERMFork(sandbox);
     case __NR_pread64:
     case __NR_pwrite64:
     case __NR_sched_get_priority_max:
     case __NR_sched_get_priority_min:
     case __NR_sched_getaffinity:
     case __NR_sched_getparam:
     case __NR_sched_getscheduler:
     case __NR_sched_setscheduler:
     case __NR_times:
       return ErrorCode(ErrorCode::ERR_ALLOWED);
     case __NR_ioctl:
       return ErrorCode(ENOTTY);  // Flash Access.
     default:
       // Default on the baseline policy.
       return SandboxBPFBasePolicy::EvaluateSyscall(sandbox, sysno);
   }
 }
 
 }  // namespace content