Base: Replace CurrentProcessInfo::CreationTime() with Process::CreationTime().

The new API supports getting the creation time of any process (not just
the current process).

This will be used to get a (pid, creation time) pair identifying a
renderer process and sending it to the resource coordinator service
via Mojo. Ideally, we would send a process handle, but this is not
supported by Mojo, and if it was, it would have undesirable security
implications.

Bug: 885293
Change-Id: Ic3a24c93e5352767eb8e6fb025eeacdbc0d23109
Reviewed-on: https://chromium-review.googlesource.com/c/1273607Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Wez <wez@chromium.org>
Reviewed-by: Sigurður Ásgeirsson <siggi@chromium.org>
Commit-Queue: François Doray <fdoray@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601423}

base/BUILD.gn

@@ -598,9 +598,8 @@ jumbo_component("base") {
 
     #"process/process_handle_openbsd.cc",  # Unused in Chromium build.
     "process/process_handle_win.cc",
+    "process/process_info.cc",
     "process/process_info.h",
-    "process/process_info_linux.cc",
-    "process/process_info_mac.cc",
     "process/process_info_win.cc",
     "process/process_iterator.cc",
     "process/process_iterator.h",
@@ -1340,7 +1339,6 @@ jumbo_component("base") {
       "process/internal_linux.h",
       "process/memory_linux.cc",
       "process/process_handle_linux.cc",
-      "process/process_info_linux.cc",
       "process/process_iterator_linux.cc",
       "process/process_metrics_linux.cc",
       "sys_info_linux.cc",
@@ -1436,7 +1434,6 @@ jumbo_component("base") {
       "process/memory_fuchsia.cc",
       "process/process_fuchsia.cc",
       "process/process_handle_fuchsia.cc",
-      "process/process_info_fuchsia.cc",
       "process/process_iterator_fuchsia.cc",
       "process/process_metrics_fuchsia.cc",
       "process/process_metrics_posix.cc",
@@ -1520,6 +1517,7 @@ jumbo_component("base") {
       "process/kill.h",
       "process/memory.cc",
       "process/memory.h",
+      "process/process_info.cc",
       "process/process_iterator.cc",
       "process/process_iterator.h",
       "process/process_metrics.cc",

base/process/process.h

@@ -98,6 +98,16 @@ class BASE_EXPORT Process {
   // Get the PID for this process.
   ProcessId Pid() const;
 
+#if !defined(OS_ANDROID)
+  // Get the creation time for this process. Since the Pid can be reused after a
+  // process dies, it is useful to use both the Pid and the creation time to
+  // uniquely identify a process.
+  //
+  // Not available on Android because /proc/stat/ cannot be accessed on O+.
+  // https://issuetracker.google.com/issues/37140047
+  Time CreationTime() const;
+#endif  // !defined(OS_ANDROID)
+
   // Returns true if this process is the current process.
   bool is_current() const;
 

base/process/process_fuchsia.cc

@@ -125,6 +125,12 @@ ProcessId Process::Pid() const {
   return GetProcId(Handle());
 }
 
+Time Process::CreationTime() const {
+  // TODO(https://crbug.com/726484): There is no syscall providing this data.
+  NOTIMPLEMENTED();
+  return Time();
+}
+
 bool Process::is_current() const {
   return is_current_process_;
 }

base/process/process_info_fuchsia.cc → base/process/process_info.cc

@@ -4,14 +4,16 @@
 
 #include "base/process/process_info.h"
 
+#include "base/process/process.h"
 #include "base/time/time.h"
 
 namespace base {
 
+#if !defined(OS_ANDROID)
 // static
 const Time CurrentProcessInfo::CreationTime() {
-  // TODO(https://crbug.com/726484): There is no syscall providing this data.
-  return Time();
+  return Process::Current().CreationTime();
 }
+#endif  //! defined(OS_ANDROID)
 
 }  // namespace base

base/process/process_info.h

@@ -12,6 +12,7 @@ namespace base {
 
 class Time;
 
+#if !defined(OS_ANDROID)
 // Vends information about the current process.
 class BASE_EXPORT CurrentProcessInfo {
  public:
@@ -19,6 +20,7 @@ class BASE_EXPORT CurrentProcessInfo {
   // error occurred retrieving the information.
   static const Time CreationTime();
 };
+#endif  // !defined(OS_ANDROID)
 
 #if defined(OS_WIN)
 enum IntegrityLevel {

base/process/process_info_linux.cc

-// Copyright 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 "base/process/process_info.h"
-
-#include <stdint.h>
-
-#include "base/logging.h"
-#include "base/process/internal_linux.h"
-#include "base/process/process_handle.h"
-#include "base/time/time.h"
-
-namespace base {
-
-// static
-const Time CurrentProcessInfo::CreationTime() {
-  int64_t start_ticks =
-      internal::ReadProcSelfStatsAndGetFieldAsInt64(internal::VM_STARTTIME);
-  if (!start_ticks)
-    return Time();
-  TimeDelta start_offset = internal::ClockTicksToTimeDelta(start_ticks);
-  Time boot_time = internal::GetBootTime();
-  if (boot_time.is_null())
-    return Time();
-  return Time(boot_time + start_offset);
-}
-
-}  // namespace base

base/process/process_info_mac.cc

-// Copyright (c) 2012 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 "base/process/process_info.h"
-
-#include <stddef.h>
-#include <sys/sysctl.h>
-#include <sys/time.h>
-#include <unistd.h>
-
-#include <memory>
-
-#include "base/macros.h"
-#include "base/memory/free_deleter.h"
-#include "base/time/time.h"
-
-namespace base {
-
-// static
-const Time CurrentProcessInfo::CreationTime() {
-  int mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_PID, getpid() };
-  size_t len = 0;
-  if (sysctl(mib, arraysize(mib), NULL, &len, NULL, 0) < 0)
-    return Time();
-
-  std::unique_ptr<struct kinfo_proc, base::FreeDeleter> proc(
-      static_cast<struct kinfo_proc*>(malloc(len)));
-  if (sysctl(mib, arraysize(mib), proc.get(), &len, NULL, 0) < 0)
-    return Time();
-  return Time::FromTimeVal(proc->kp_proc.p_un.__p_starttime);
-}
-
-}  // namespace base

base/process/process_info_win.cc

@@ -25,19 +25,6 @@ HANDLE GetCurrentProcessToken() {
 
 }  // namespace
 
-// static
-const Time CurrentProcessInfo::CreationTime() {
-  FILETIME creation_time = {};
-  FILETIME ignore1 = {};
-  FILETIME ignore2 = {};
-  FILETIME ignore3 = {};
-  if (!::GetProcessTimes(::GetCurrentProcess(), &creation_time, &ignore1,
-                         &ignore2, &ignore3)) {
-    return Time();
-  }
-  return Time::FromFileTime(creation_time);
-}
-
 IntegrityLevel GetCurrentProcessIntegrityLevel() {
   HANDLE process_token(GetCurrentProcessToken());
 

base/process/process_linux.cc

@@ -10,6 +10,7 @@
 #include "base/files/file_util.h"
 #include "base/logging.h"
 #include "base/posix/can_lower_nice_to.h"
+#include "base/process/internal_linux.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/strings/stringprintf.h"
@@ -72,6 +73,21 @@ const int kBackgroundPriority = 5;
 
 }  // namespace
 
+Time Process::CreationTime() const {
+  int64_t start_ticks = is_current()
+                            ? internal::ReadProcSelfStatsAndGetFieldAsInt64(
+                                  internal::VM_STARTTIME)
+                            : internal::ReadProcStatsAndGetFieldAsInt64(
+                                  Pid(), internal::VM_STARTTIME);
+  if (!start_ticks)
+    return Time();
+  TimeDelta start_offset = internal::ClockTicksToTimeDelta(start_ticks);
+  Time boot_time = internal::GetBootTime();
+  if (boot_time.is_null())
+    return Time();
+  return Time(boot_time + start_offset);
+}
+
 // static
 bool Process::CanBackgroundProcesses() {
 #if defined(OS_CHROMEOS)

base/process/process_mac.cc

@@ -5,9 +5,17 @@
 #include "base/process/process.h"
 
 #include <mach/mach.h>
+#include <stddef.h>
+#include <sys/sysctl.h>
+#include <sys/time.h>
+#include <unistd.h>
+
+#include <memory>
 
 #include "base/feature_list.h"
 #include "base/mac/mach_logging.h"
+#include "base/memory/free_deleter.h"
+#include "base/stl_util.h"
 
 namespace base {
 
@@ -15,6 +23,19 @@ namespace base {
 const Feature kMacAllowBackgroundingProcesses{"MacAllowBackgroundingProcesses",
                                               FEATURE_DISABLED_BY_DEFAULT};
 
+Time Process::CreationTime() const {
+  int mib[] = {CTL_KERN, KERN_PROC, KERN_PROC_PID, Pid()};
+  size_t len = 0;
+  if (sysctl(mib, size(mib), NULL, &len, NULL, 0) < 0)
+    return Time();
+
+  std::unique_ptr<struct kinfo_proc, base::FreeDeleter> proc(
+      static_cast<struct kinfo_proc*>(malloc(len)));
+  if (sysctl(mib, size(mib), proc.get(), &len, NULL, 0) < 0)
+    return Time();
+  return Time::FromTimeVal(proc->kp_proc.p_un.__p_starttime);
+}
+
 bool Process::CanBackgroundProcesses() {
   return FeatureList::IsEnabled(kMacAllowBackgroundingProcesses);
 }

base/process/process_unittest.cc

@@ -20,11 +20,13 @@
 namespace {
 
 #if defined(OS_WIN)
-const int kExpectedStillRunningExitCode = 0x102;
+constexpr int kExpectedStillRunningExitCode = 0x102;
 #else
-const int kExpectedStillRunningExitCode = 0;
+constexpr int kExpectedStillRunningExitCode = 0;
 #endif
 
+constexpr int kDummyExitCode = 42;
+
 #if defined(OS_MACOSX)
 // Fake port provider that returns the calling process's
 // task port, ignoring its argument.
@@ -129,11 +131,41 @@ MULTIPROCESS_TEST_MAIN(SleepyChildProcess) {
   return 0;
 }
 
+// TODO(https://crbug.com/726484): Enable these tests on Fuchsia when
+// CreationTime() is implemented.
+//
+// Disabled on Android because Process::CreationTime() is not supported.
+// https://issuetracker.google.com/issues/37140047
+#if !defined(OS_FUCHSIA) && !defined(OS_ANDROID)
+TEST_F(ProcessTest, CreationTimeCurrentProcess) {
+  // The current process creation time should be less than or equal to the
+  // current time.
+  EXPECT_LE(Process::Current().CreationTime(), Time::Now());
+}
+
+TEST_F(ProcessTest, CreationTimeOtherProcess) {
+  // The creation time of a process should be between a time recorded before it
+  // was spawned and a time recorded after it was spawned. However, since the
+  // base::Time and process creation clocks don't match, tolerate a 1 second
+  // range. (On Linux, process creation time is relative to boot time which as a
+  // 1-second resolution. On Windows, process creation time is based on the
+  // system clock while Time::Now() can be a combination of system clock and
+  // QueryPerformanceCounter().)
+  constexpr base::TimeDelta kTolerance = base::TimeDelta::FromSeconds(1);
+  const Time before_creation = Time::Now();
+  Process process(SpawnChild("SleepyChildProcess"));
+  const Time after_creation = Time::Now();
+  const Time creation = process.CreationTime();
+  EXPECT_LE(before_creation - kTolerance, creation);
+  EXPECT_LE(creation, after_creation + kTolerance);
+  EXPECT_TRUE(process.Terminate(kDummyExitCode, true));
+}
+#endif  // !defined(OS_FUCHSIA)
+
 TEST_F(ProcessTest, Terminate) {
   Process process(SpawnChild("SleepyChildProcess"));
   ASSERT_TRUE(process.IsValid());
 
-  const int kDummyExitCode = 42;
   int exit_code = kDummyExitCode;
   EXPECT_EQ(TERMINATION_STATUS_STILL_RUNNING,
             GetTerminationStatus(process.Handle(), &exit_code));

base/process/process_win.cc

@@ -125,6 +125,18 @@ ProcessId Process::Pid() const {
   return GetProcId(Handle());
 }
 
+Time Process::CreationTime() const {
+  FILETIME creation_time = {};
+  FILETIME ignore1 = {};
+  FILETIME ignore2 = {};
+  FILETIME ignore3 = {};
+  if (!::GetProcessTimes(Handle(), &creation_time, &ignore1, &ignore2,
+                         &ignore3)) {
+    return Time();
+  }
+  return Time::FromFileTime(creation_time);
+}
+
 bool Process::is_current() const {
   return is_current_process_;
 }