Linux sandbox: whitelist allowed Futex operations.

sandbox/linux/seccomp-bpf-helpers/baseline_policy_unittest.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 "sandbox/linux/seccomp-bpf-helpers/baseline_policy.h"
 
 #include <errno.h>
 #include <linux/futex.h>
 #include <sched.h>
 #include <signal.h>
@@ skipping 253 matching lines @@
   _exit(1);
 }
 
 BPF_DEATH_TEST_C(BaselinePolicy,
                  FutexWithRequeuePriorityInheritencePrivate,
                  DEATH_MESSAGE(GetFutexErrorMessageContentForTests()),
                  BaselinePolicy) {
   syscall(__NR_futex, NULL, FUTEX_CMP_REQUEUE_PI_PRIVATE, 0, NULL, NULL, 0);
   _exit(1);
 }
+
+BPF_DEATH_TEST_C(BaselinePolicy,
+                 FutexWithUnlockPIPrivate,
+                 DEATH_MESSAGE(GetFutexErrorMessageContentForTests()),
+                 BaselinePolicy) {
+  syscall(__NR_futex, NULL, FUTEX_UNLOCK_PI_PRIVATE, 0, NULL, NULL, 0);
+  _exit(1);
+}
 #endif  // !defined(OS_ANDROID)
 
 BPF_TEST_C(BaselinePolicy, PrctlDumpable, BaselinePolicy) {
   const int is_dumpable = prctl(PR_GET_DUMPABLE, 0, 0, 0, 0);
   BPF_ASSERT(is_dumpable == 1 || is_dumpable == 0);
   const int prctl_ret = prctl(PR_SET_DUMPABLE, is_dumpable, 0, 0, 0, 0);
   BPF_ASSERT_EQ(0, prctl_ret);
 }
 
 // Workaround incomplete Android headers.
 #if !defined(PR_CAPBSET_READ)
 #define PR_CAPBSET_READ 23
 #endif
 
 BPF_DEATH_TEST_C(BaselinePolicy,
                  PrctlSigsys,
                  DEATH_SEGV_MESSAGE(GetPrctlErrorMessageContentForTests()),
                  BaselinePolicy) {
   prctl(PR_CAPBSET_READ, 0, 0, 0, 0);
   _exit(1);
 }
 
 }  // namespace
 
 }  // namespace sandbox