Linux sandbox: restrict setpriority() in baseline policy.

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

 // Copyright (c) 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 "sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <fcntl.h>
 #include <linux/futex.h>
 #include <linux/net.h>
 #include <sched.h>
 #include <signal.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
 #include <sys/prctl.h>
+#include <sys/resource.h>
 #include <sys/stat.h>
+#include <sys/time.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "build/build_config.h"
 #include "sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.h"
 #include "sandbox/linux/seccomp-bpf/linux_seccomp.h"
 #include "sandbox/linux/seccomp-bpf/sandbox_bpf.h"
@@ skipping 207 matching lines @@
               FUTEX_WAKE,
               FUTEX_REQUEUE,
               FUTEX_CMP_REQUEUE,
               FUTEX_WAKE_OP,
               FUTEX_WAIT_BITSET,
               FUTEX_WAKE_BITSET),
              Allow())
       .Default(CrashSIGSYSFutex());
 }
 
+ResultExpr RestrictGetSetpriority(pid_t target_pid) {
+  const Arg<int> which(0);
+  const Arg<int> who(1);
+  return If(which == PRIO_PROCESS,
+            If(who == 0 || who == target_pid, Allow()).Else(Error(EPERM)))
+      .Else(CrashSIGSYS());
+}
+
 }  // namespace sandbox.