Non-SFI NaCl: Allow CLOCK_SYSTEM_TRACE on Chrome OS

components/nacl/loader/nonsfi/nonsfi_sandbox.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 "components/nacl/loader/nonsfi/nonsfi_sandbox.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <linux/net.h>
 #include <sys/prctl.h>
 #include <sys/ptrace.h>
 #include <sys/mman.h>
 #include <sys/socket.h>
 #include <sys/syscall.h>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
+#include "base/time/time.h"
 #include "build/build_config.h"
 #include "content/public/common/sandbox_init.h"
 #include "sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.h"
 #include "sandbox/linux/seccomp-bpf/sandbox_bpf.h"
 #include "sandbox/linux/seccomp-bpf/sandbox_bpf_policy.h"
 #include "sandbox/linux/seccomp-bpf/trap.h"
 #include "sandbox/linux/services/linux_syscalls.h"
 
 #if defined(__arm__) && !defined(MAP_STACK)
 // Chrome OS Daisy (ARM) build environment has old headers.
@@ skipping 45 matching lines @@
          sb->Trap(sandbox::CrashSIGSYS_Handler, NULL))));
 }
 
 ErrorCode RestrictClockID(SandboxBPF* sb) {
   // We allow accessing only CLOCK_MONOTONIC, CLOCK_PROCESS_CPUTIME_ID,
   // CLOCK_REALTIME, and CLOCK_THREAD_CPUTIME_ID.  In particular, this disallows
   // access to arbitrary per-{process,thread} CPU-time clock IDs (such as those
   // returned by {clock,pthread}_getcpuclockid), which can leak information
   // about the state of the host OS.
   COMPILE_ASSERT(4 == sizeof(clockid_t), clockid_is_not_32bit);
-  return sb->Cond(0, ErrorCode::TP_32BIT,
-                  ErrorCode::OP_EQUAL, CLOCK_MONOTONIC,
-                  ErrorCode(ErrorCode::ERR_ALLOWED),
-         sb->Cond(0, ErrorCode::TP_32BIT,
-                  ErrorCode::OP_EQUAL, CLOCK_PROCESS_CPUTIME_ID,
-                  ErrorCode(ErrorCode::ERR_ALLOWED),
-         sb->Cond(0, ErrorCode::TP_32BIT,
-                  ErrorCode::OP_EQUAL, CLOCK_REALTIME,
-                  ErrorCode(ErrorCode::ERR_ALLOWED),
-         sb->Cond(0, ErrorCode::TP_32BIT,
-                  ErrorCode::OP_EQUAL, CLOCK_THREAD_CPUTIME_ID,
-                  ErrorCode(ErrorCode::ERR_ALLOWED),
-         sb->Trap(sandbox::CrashSIGSYS_Handler, NULL)))));
+  ErrorCode result = sb->Cond(0, ErrorCode::TP_32BIT,
+                              ErrorCode::OP_EQUAL, CLOCK_MONOTONIC,
+                              ErrorCode(ErrorCode::ERR_ALLOWED),
+                     sb->Cond(0, ErrorCode::TP_32BIT,
+                              ErrorCode::OP_EQUAL, CLOCK_PROCESS_CPUTIME_ID,
+                              ErrorCode(ErrorCode::ERR_ALLOWED),
+                     sb->Cond(0, ErrorCode::TP_32BIT,
+                              ErrorCode::OP_EQUAL, CLOCK_REALTIME,
+                              ErrorCode(ErrorCode::ERR_ALLOWED),
+                     sb->Cond(0, ErrorCode::TP_32BIT,
+                              ErrorCode::OP_EQUAL, CLOCK_THREAD_CPUTIME_ID,
+                              ErrorCode(ErrorCode::ERR_ALLOWED),
+                     sb->Trap(sandbox::CrashSIGSYS_Handler, NULL)))));
+#if defined(OS_CHROMEOS)
+  // Allow the special clock for Chrome OS used by Chrome tracing.
+  result = sb->Cond(0, ErrorCode::TP_32BIT,
+                    ErrorCode::OP_EQUAL, base::TimeTicks::kClockSystemTrace,
+                    ErrorCode(ErrorCode::ERR_ALLOWED), result);
+#endif
+  return result;
 }
 
 ErrorCode RestrictClone(SandboxBPF* sb) {
   // We allow clone only for new thread creation.
   return sb->Cond(0, ErrorCode::TP_32BIT, ErrorCode::OP_EQUAL,
                   CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND |
                   CLONE_THREAD | CLONE_SYSVSEM | CLONE_SETTLS |
                   CLONE_PARENT_SETTID | CLONE_CHILD_CLEARTID,
                   ErrorCode(ErrorCode::ERR_ALLOWED),
          sb->Trap(sandbox::SIGSYSCloneFailure, NULL));
@@ skipping 227 matching lines @@
       scoped_ptr<sandbox::SandboxBPFPolicy>(
           new nacl::nonsfi::NaClNonSfiBPFSandboxPolicy()));
   if (!sandbox_is_initialized)
     return false;
   RunSandboxSanityChecks();
   return true;
 }
 
 }  // namespace nonsfi
 }  // namespace nacl