Notify metrics daemon of kernel crashes.

crash_reporter.cc

 // Copyright (c) 2010 The Chromium OS 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 <string>
 
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/string_util.h"
 #include "crash-reporter/system_logging.h"
 #include "crash-reporter/user_collector.h"
 #include "gflags/gflags.h"
 #include "metrics/metrics_library.h"
 
 #pragma GCC diagnostic ignored "-Wstrict-aliasing"
 DEFINE_bool(init, false, "Initialize crash logging");
 DEFINE_bool(clean_shutdown, false, "Signal clean shutdown");
 DEFINE_bool(crash_test, false, "Crash test");
 DEFINE_string(exec, "", "Executable name crashed");
 DEFINE_int32(pid, -1, "Crashing PID");
 DEFINE_int32(signal, -1, "Signal causing crash");
 DEFINE_bool(unclean_check, true, "Check for unclean shutdown");
 #pragma GCC diagnostic error "-Wstrict-aliasing"
 
 static const char kCrashCounterHistogram[] = "Logging.CrashCounter";
 static const char kUncleanShutdownFile[] =
     "/var/lib/crash_reporter/pending_clean_shutdown";
+static const char kEmpty[] = "";
 
 // Enumeration of kinds of crashes to be used in the CrashCounter histogram.
 enum CrashKinds {
   CRASH_KIND_KERNEL = 1,
   CRASH_KIND_USER   = 2,
   CRASH_KIND_MAX
 };
 
 static MetricsLibrary s_metrics_lib;
 static SystemLoggingImpl s_system_log;
@@ skipping 13 matching lines @@
   s_system_log.LogWarning("Last shutdown was not clean");
   if (IsMetricsCollectionAllowed()) {
     s_metrics_lib.SendEnumToUMA(std::string(kCrashCounterHistogram),
                                 CRASH_KIND_KERNEL,
                                 CRASH_KIND_MAX);
   }
   if (!file_util::Delete(unclean_file_path, false)) {
     s_system_log.LogError("Failed to delete unclean shutdown file %s",
                           kUncleanShutdownFile);
   }
+
+  // Touch a file to notify the metrics daemon that a kernel crash has
+  // been detected so that it can log the time since the last kernel
+  // crash.
+  static const char kKernelCrashDetectedFile[] = "/tmp/kernel-crash-detected";
+  FilePath crash_detected(kKernelCrashDetectedFile);
+  file_util::WriteFile(crash_detected, kEmpty, 0);
 }
 
 static bool PrepareUncleanShutdownCheck() {
-  static const char empty[] = "";
   FilePath file_path(kUncleanShutdownFile);
   file_util::CreateDirectory(file_path.DirName());
-  return file_util::WriteFile(file_path, empty, 0) == 0;
+  return file_util::WriteFile(file_path, kEmpty, 0) == 0;
 }
 
 static void SignalCleanShutdown() {
   s_system_log.LogInfo("Clean shutdown signalled");
   file_util::Delete(FilePath(kUncleanShutdownFile), false);
 }
 
 static void CountUserCrash() {
   CHECK(IsMetricsCollectionAllowed());
   s_metrics_lib.SendEnumToUMA(std::string(kCrashCounterHistogram),
@@ skipping 52 matching lines @@
   // handling a crash.
   if (FLAGS_crash_test) {
     *(char *)0 = 0;
     return 0;
   }
 
   user_collector.HandleCrash(FLAGS_signal, FLAGS_pid, FLAGS_exec);
 
   return 0;
 }