Non-SFI NaCl: Allow CLOCK_SYSTEM_TRACE on Chrome OS

chrome://tracing uses TimeTicks::NowFromSystemTraceTime in
base/time/time_posix.cc.

TEST=nacl_loader_unittests  # on i686 and ARM Chrome OS
TEST=trybot
BUG=378063

Review URL: https://codereview.chromium.org/298163008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@274784 0039d316-1c4b-4281-b951-d872f2087c98

base/time/time.h

@@ -576,6 +576,14 @@ inline Time TimeDelta::operator+(Time t) const {
 
 class BASE_EXPORT TimeTicks {
  public:
+  // We define this even without OS_CHROMEOS for seccomp sandbox testing.
+#if defined(OS_LINUX)
+  // Force definition of the system trace clock; it is a chromeos-only api
+  // at the moment and surfacing it in the right place requires mucking
+  // with glibc et al.
+  static const clockid_t kClockSystemTrace = 11;
+#endif
+
   TimeTicks() : ticks_(0) {
   }
 

base/time/time_posix.cc

@@ -320,18 +320,19 @@ TimeTicks TimeTicks::ThreadNow() {
 #endif
 }
 
-#if defined(OS_CHROMEOS)
-// Force definition of the system trace clock; it is a chromeos-only api
-// at the moment and surfacing it in the right place requires mucking
-// with glibc et al.
-#define CLOCK_SYSTEM_TRACE 11
-
+// NaCl IRT does not support the Chrome OS specific clock
+// ID. build/common.gypi sets OS_CHROMEOS without any other OS_*
+// macros for untrusted NaCl build so we need to check
+// __native_client__ explicitly.
+// TODO(hamaji): Do not specify OS_CHROMEOS for untrusted NaCl build
+// and remove !defined(__native_client__).
+#if defined(OS_CHROMEOS) && !defined(__native_client__)
 // static
 TimeTicks TimeTicks::NowFromSystemTraceTime() {
   uint64_t absolute_micro;
 
   struct timespec ts;
-  if (clock_gettime(CLOCK_SYSTEM_TRACE, &ts) != 0) {
+  if (clock_gettime(kClockSystemTrace, &ts) != 0) {
     // NB: fall-back for a chrome os build running on linux
     return HighResNow();
   }
@@ -343,14 +344,14 @@ TimeTicks TimeTicks::NowFromSystemTraceTime() {
   return TimeTicks(absolute_micro);
 }
 
-#else // !defined(OS_CHROMEOS)
+#else // !(defined(OS_CHROMEOS) && !defined(__native_client__))
 
 // static
 TimeTicks TimeTicks::NowFromSystemTraceTime() {
   return HighResNow();
 }
 
-#endif // defined(OS_CHROMEOS)
+#endif // defined(OS_CHROMEOS) && !defined(__native_client__)
 
 #endif  // !OS_MACOSX
 

components/nacl/loader/nonsfi/nonsfi_sandbox.cc

@@ -15,6 +15,7 @@
 
 #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"
@@ -80,19 +81,26 @@ ErrorCode RestrictClockID(SandboxBPF* sb) {
   // 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) {

components/nacl/loader/nonsfi/nonsfi_sandbox_unittest.cc

@@ -31,8 +31,10 @@
 #include "base/files/scoped_file.h"
 #include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
+#include "base/time/time.h"
 #include "sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.h"
 #include "sandbox/linux/seccomp-bpf/bpf_tests.h"
+#include "sandbox/linux/services/linux_syscalls.h"
 #include "third_party/lss/linux_syscall_support.h"  // for MAKE_PROCESS_CPUCLOCK
 
 namespace {
@@ -408,6 +410,9 @@ BPF_TEST_C(NaClNonSfiSandboxTest,
   CheckClock(CLOCK_PROCESS_CPUTIME_ID);
   CheckClock(CLOCK_REALTIME);
   CheckClock(CLOCK_THREAD_CPUTIME_ID);
+#if defined(OS_CHROMEOS)
+  CheckClock(base::TimeTicks::kClockSystemTrace);
+#endif
 }
 
 BPF_DEATH_TEST_C(NaClNonSfiSandboxTest,
@@ -418,6 +423,16 @@ BPF_DEATH_TEST_C(NaClNonSfiSandboxTest,
   clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
 }
 
+#if !defined(OS_CHROMEOS)
+BPF_DEATH_TEST_C(NaClNonSfiSandboxTest,
+                 clock_gettime_crash_system_trace,
+                 DEATH_MESSAGE(sandbox::GetErrorMessageContentForTests()),
+                 nacl::nonsfi::NaClNonSfiBPFSandboxPolicy) {
+  struct timespec ts;
+  clock_gettime(base::TimeTicks::kClockSystemTrace, &ts);
+}
+#endif
+
 BPF_DEATH_TEST_C(NaClNonSfiSandboxTest,
                  clock_gettime_crash_cpu_clock,
                  DEATH_MESSAGE(sandbox::GetErrorMessageContentForTests()),