Merge 274934 "Linux sandbox: restrict futex operations."

sandbox/linux/seccomp-bpf-helpers/baseline_policy.cc

Index: sandbox/linux/seccomp-bpf-helpers/baseline_policy.cc
===================================================================
--- sandbox/linux/seccomp-bpf-helpers/baseline_policy.cc	(revision 275489)
+++ sandbox/linux/seccomp-bpf-helpers/baseline_policy.cc	(working copy)
@@ -32,13 +32,13 @@
          SyscallSets::IsAllowedBasicScheduler(sysno) ||
          SyscallSets::IsAllowedEpoll(sysno) ||
          SyscallSets::IsAllowedFileSystemAccessViaFd(sysno) ||
+         SyscallSets::IsAllowedFutex(sysno) ||
          SyscallSets::IsAllowedGeneralIo(sysno) ||
          SyscallSets::IsAllowedGetOrModifySocket(sysno) ||
          SyscallSets::IsAllowedGettime(sysno) ||
          SyscallSets::IsAllowedPrctl(sysno) ||
          SyscallSets::IsAllowedProcessStartOrDeath(sysno) ||
          SyscallSets::IsAllowedSignalHandling(sysno) ||
-         SyscallSets::IsFutex(sysno) ||
          SyscallSets::IsGetSimpleId(sysno) ||
          SyscallSets::IsKernelInternalApi(sysno) ||
 #if defined(__arm__)
@@ -111,6 +111,9 @@
   }
 #endif
 
+  if (sysno == __NR_futex)
+    return RestrictFutex(sandbox);
+
   if (sysno == __NR_madvise) {
     // Only allow MADV_DONTNEED (aka MADV_FREE).
     return sandbox->Cond(2, ErrorCode::TP_32BIT,