Distinguish in the browser between renderer crashes and kills

components/crash/content/app/breakpad_linux.cc

Index: components/crash/content/app/breakpad_linux.cc
diff --git a/components/crash/content/app/breakpad_linux.cc b/components/crash/content/app/breakpad_linux.cc
index 62888ad9ff5fa9f6d88feb8e640bb66d886070a3..1d24f009fa6fcfcec42c363e35ffba4736088b82 100644
--- a/components/crash/content/app/breakpad_linux.cc
+++ b/components/crash/content/app/breakpad_linux.cc
@@ -96,8 +96,10 @@ ExceptionHandler* g_breakpad = nullptr;
 const char* g_asan_report_str = nullptr;
 #endif
 #if defined(OS_ANDROID)
+const char kWebViewProcessType[] = "webview";
 char* g_process_type = nullptr;
 ExceptionHandler* g_microdump = nullptr;
+int g_signal_code_pipe_fd = -1;
 
 class MicrodumpInfo {
  public:
@@ -737,7 +739,22 @@ bool MicrodumpCrashDone(const MinidumpDescriptor& minidump,
 
   const bool is_browser_process = (context != nullptr);
   return FinalizeCrashDoneAndroid(is_browser_process);
- }
+}
+
+bool WriteSignalCodeToPipe(const void* crash_context,
+                           size_t crash_context_size,
+                           void* context) {
+  if (g_signal_code_pipe_fd == -1 ||
+      crash_context_size != sizeof(ExceptionHandler::CrashContext))
+    return false;
+  const ExceptionHandler::CrashContext* eh_context =
+      static_cast<const ExceptionHandler::CrashContext*>(crash_context);
+  int signo = eh_context->siginfo.si_signo;
+  sys_write(g_signal_code_pipe_fd, &signo, sizeof(signo));
+  IGNORE_RET(sys_close(g_signal_code_pipe_fd));
+  g_signal_code_pipe_fd = -1;
+  return false;
+}
 
 bool CrashDoneInProcessNoUpload(
     const google_breakpad::MinidumpDescriptor& descriptor,
@@ -830,7 +847,8 @@ void MicrodumpInfo::Initialize(const std::string& process_type,
                                const char* android_build_fp) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(!g_microdump);
-  bool is_browser_process = process_type.empty() || process_type == "webview";
+  bool is_browser_process =
+      process_type.empty() || process_type == kWebViewProcessType;
 
   MinidumpDescriptor descriptor(MinidumpDescriptor::kMicrodumpOnConsole);
 
@@ -859,7 +877,7 @@ void MicrodumpInfo::Initialize(const std::string& process_type,
                            true,  // Install handlers.
                            -1);   // Server file descriptor. -1 for in-process.
 
-  if (process_type == "webview") {
+  if (process_type == kWebViewProcessType) {
     // We do not use |DumpProcess()| for handling programatically
     // generated dumps for WebView because we only know the file
     // descriptor to which we are dumping at the time of the call to
@@ -869,6 +887,11 @@ void MicrodumpInfo::Initialize(const std::string& process_type,
     // time.
     base::debug::SetDumpWithoutCrashingFunction(
         &GenerateMinidumpOnDemandForAndroid);
+  } else if (!process_type.empty()) {
+    g_signal_code_pipe_fd =
+        GetCrashReporterClient()->GetAndroidMinidumpDescriptor();
+    if (g_signal_code_pipe_fd != -1)
+      g_microdump->set_crash_handler(WriteSignalCodeToPipe);

[Torne, 2015/12/16 14:48:35]

When does the crash handler set her get called? After the dump has been
generated? Ideally we would want to write the signal to the pipe as early as
possible, in case we fail somehow while doing the dump..

[mnaganov (inactive), 2015/12/16 19:10:12]

Before generating the dump, actually. In fact, the handler can even prevent it
by returning "true". Only "FilterCallback" gets called earlier than
"CrashHandler", but on the other hand, the filter doesn't receive the crash
context. Although we don't use the context right now, but it might be useful for
passing the signal number to the browser.

   }
 }