Allow coarse clocks in clock_get{res,time} calls.

sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions_unittests.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/syscall_parameters_restrictions.h"
 
 #include <errno.h>
 #include <sched.h>
 #include <sys/resource.h>
 #include <sys/syscall.h>
@@ skipping 43 matching lines @@
         return RestrictClockID();
       default:
         return Allow();
     }
   }
 };
 
 void CheckClock(clockid_t clockid) {
   struct timespec ts;
   ts.tv_sec = ts.tv_nsec = -1;
+  BPF_ASSERT_EQ(0, clock_getres(clockid, &ts));
+  BPF_ASSERT_EQ(0, ts.tv_sec);
+  BPF_ASSERT_LE(0, ts.tv_nsec);
+  ts.tv_sec = ts.tv_nsec = -1;

[jln (very slow on Chromium), 2015/05/07 19:22:40]

Style: please break in two expressions.

   BPF_ASSERT_EQ(0, clock_gettime(clockid, &ts));
   BPF_ASSERT_LE(0, ts.tv_sec);
   BPF_ASSERT_LE(0, ts.tv_nsec);
 }
 
 BPF_TEST_C(ParameterRestrictions,
            clock_gettime_allowed,
            RestrictClockIdPolicy) {
   CheckClock(CLOCK_MONOTONIC);
+  CheckClock(CLOCK_MONOTONIC_COARSE);
   CheckClock(CLOCK_PROCESS_CPUTIME_ID);
   CheckClock(CLOCK_REALTIME);
+  CheckClock(CLOCK_REALTIME_COARSE);
   CheckClock(CLOCK_THREAD_CPUTIME_ID);
 }
 
 BPF_DEATH_TEST_C(ParameterRestrictions,
                  clock_gettime_crash_monotonic_raw,
                  DEATH_SEGV_MESSAGE(sandbox::GetErrorMessageContentForTests()),
                  RestrictClockIdPolicy) {
   struct timespec ts;
   clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
 }
@@ skipping 179 matching lines @@
                  getrusage_crash_not_self,
                  DEATH_SEGV_MESSAGE(sandbox::GetErrorMessageContentForTests()),
                  RestrictGetrusagePolicy) {
   struct rusage usage;
   getrusage(RUSAGE_CHILDREN, &usage);
 }
 
 }  // namespace
 
 }  // namespace sandbox