Capture a report on failed browser rendez-vous.

chrome/chrome_watcher/kasko_util.cc

+// Copyright 2016 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 "chrome/chrome_watcher/kasko_util.h"
+
+#include <sddl.h>
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "base/base_paths.h"
+#include "base/bind.h"
+#include "base/callback_helpers.h"
+#include "base/environment.h"
+#include "base/files/file_path.h"
+#include "base/path_service.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/win/win_util.h"
+
+#include "chrome/chrome_watcher/chrome_watcher_main_api.h"
+
+#if BUILDFLAG(ENABLE_KASKO)
+#include "components/crash/content/app/crashpad.h"
+#include "syzygy/kasko/api/reporter.h"
+#endif
+
+#if BUILDFLAG(ENABLE_KASKO)
+
+namespace {
+
+// Helper function for determining the crash server to use. Defaults to the
+// standard crash server, but can be overridden via an environment variable.
+// Enables easy integration testing.
+base::string16 GetKaskoCrashServerUrl() {
+  static const char kKaskoCrashServerUrl[] = "KASKO_CRASH_SERVER_URL";
+  static const wchar_t kDefaultKaskoCrashServerUrl[] =
+      L"https://clients2.google.com/cr/report";
+
+  std::unique_ptr<base::Environment> env(base::Environment::Create());
+  std::string env_var;
+  if (env->GetVar(kKaskoCrashServerUrl, &env_var)) {
+    return base::UTF8ToUTF16(env_var);
+  }
+  return kDefaultKaskoCrashServerUrl;
+}
+
+// Helper function for determining the crash reports directory to use. Defaults
+// to the browser data directory, but can be overridden via an environment
+// variable. Enables easy integration testing.
+base::FilePath GetKaskoCrashReportsBaseDir(
+    const base::char16* browser_data_directory) {
+  static const char kKaskoCrashReportBaseDir[] = "KASKO_CRASH_REPORTS_BASE_DIR";
+  std::unique_ptr<base::Environment> env(base::Environment::Create());
+  std::string env_var;
+  if (env->GetVar(kKaskoCrashReportBaseDir, &env_var)) {
+    return base::FilePath(base::UTF8ToUTF16(env_var));
+  }
+  return base::FilePath(browser_data_directory);
+}
+
+struct EventSourceDeregisterer {
+  using pointer = HANDLE;
+  void operator()(HANDLE event_source_handle) {

[grt (UTC plus 2), 2016/04/06 19:50:36]

const method

[manzagop (departed), 2016/04/06 20:44:54]

Done.

+    if (!::DeregisterEventSource(event_source_handle))
+      DPLOG(ERROR) << "DeregisterEventSource";
+  }
+};
+using ScopedEventSourceHandle =
+    std::unique_ptr<HANDLE, EventSourceDeregisterer>;
+
+struct SidDeleter {
+  using pointer = PSID;
+  void operator()(PSID sid) {

[grt (UTC plus 2), 2016/04/06 19:50:35]

const method

[manzagop (departed), 2016/04/06 20:44:53]

Done.

+    if (::LocalFree(sid) != nullptr)
+      DPLOG(ERROR) << "LocalFree";
+  }
+};
+using ScopedSid = std::unique_ptr<PSID, SidDeleter>;
+
+void OnCrashReportUpload(void* context,
+                         const base::char16* report_id,
+                         const base::char16* minidump_path,
+                         const base::char16* const* keys,
+                         const base::char16* const* values) {
+  // Open the event source.
+  ScopedEventSourceHandle event_source_handle(
+      ::RegisterEventSource(nullptr, L"Chrome"));
+  if (!event_source_handle) {
+    PLOG(ERROR) << "RegisterEventSource";
+    return;
+  }
+
+  // Get the user's SID for the log record.
+  base::string16 sid_string;
+  PSID sid = nullptr;
+  if (base::win::GetUserSidString(&sid_string) && !sid_string.empty()) {
+    if (!::ConvertStringSidToSid(sid_string.c_str(), &sid))
+      DPLOG(ERROR) << "ConvertStringSidToSid";
+    DCHECK(sid);
+  }
+  // Ensure cleanup on scope exit.
+  ScopedSid scoped_sid;
+  if (sid)
+    scoped_sid.reset(sid);
+
+  // Generate the message.
+  // Note that the format of this message must match the consumer in
+  // chrome/browser/crash_upload_list_win.cc.
+  base::string16 message =
+      L"Crash uploaded. Id=" + base::string16(report_id) + L".";
+
+  // Matches Omaha.
+  const int kCrashUploadEventId = 2;
+
+  // Report the event.
+  const base::char16* strings[] = {message.c_str()};
+  if (!::ReportEvent(event_source_handle.get(), EVENTLOG_INFORMATION_TYPE,
+                     0,  // category
+                     kCrashUploadEventId, sid,
+                     1,  // count
+                     0, strings, nullptr)) {
+    DPLOG(ERROR);
+  }
+}
+
+void AddCrashKey(const wchar_t *key, const wchar_t *value,
+                 std::vector<kasko::api::CrashKey> *crash_keys) {
+  DCHECK(key);
+  DCHECK(value);
+  DCHECK(crash_keys);
+
+  kasko::api::CrashKey crash_key;
+  std::wcsncpy(crash_key.name, key, kasko::api::CrashKey::kNameMaxLength - 1);
+  std::wcsncpy(crash_key.value, value,
+               kasko::api::CrashKey::kValueMaxLength - 1);
+  crash_keys->push_back(crash_key);
+}
+
+}  // namespace
+
+bool InitializeKaskoReporter(const base::string16& endpoint,
+                             const base::char16* browser_data_directory) {
+  base::string16 crash_server = GetKaskoCrashServerUrl();
+  base::FilePath crash_reports_base_dir =
+      GetKaskoCrashReportsBaseDir(browser_data_directory);
+
+  return kasko::api::InitializeReporter(
+      endpoint.c_str(),
+      crash_server.c_str(),
+      crash_reports_base_dir.Append(L"Crash Reports").value().c_str(),
+      crash_reports_base_dir.Append(kPermanentlyFailedReportsSubdir)
+          .value()
+          .c_str(),
+      &OnCrashReportUpload,
+      nullptr);
+}
+
+void ShutdownKaskoReporter() {
+  kasko::api::ShutdownReporter();
+}
+
+bool EnsureTargetProcessValidForCapture(const base::Process& process) {
+  // Ensure the target process shares the current process's executable name.
+  base::FilePath exe_self;
+  if (!PathService::Get(base::FILE_EXE, &exe_self))
+    return false;
+  wchar_t exe_name_other[MAX_PATH];
+  DWORD exe_name_other_len = MAX_PATH;
+  if (QueryFullProcessImageName(process.Handle(), 0, exe_name_other,
+                                &exe_name_other_len) == 0) {

[grt (UTC plus 2), 2016/04/06 19:50:36]

do you need to check exe_name_other_len after the call to be sure that
exe_name_other was big enough?

[manzagop (departed), 2016/04/06 20:44:54]

I'm not sure. I see that paths can sometimes be longer than MAX_PATH. The doc
for QueryFullProcessImageName doesn't say anything about a buffer that is too
small. I do know that GetModuleFileNameEx can succeed when the buffer is too
small, and return a truncated result.

Let's be conservative and return false if the whole buffer is used.

+    DPLOG(ERROR) << "Failed to get executable name for other process";
+    return false;
+  }
+  return base::FilePath::CompareEqualIgnoreCase(exe_self.value(),
+                                                exe_name_other);
+}
+
+void DumpHungProcess(DWORD main_thread_id, const base::string16& channel,
+                     const base::char16* key, const base::Process& process) {
+  // Read the Crashpad module annotations for the process.
+  std::vector<kasko::api::CrashKey> annotations;
+  crash_reporter::ReadMainModuleAnnotationsForKasko(process, &annotations);
+  AddCrashKey(key, L"1", &annotations);
+
+  std::vector<const base::char16*> key_buffers;
+  std::vector<const base::char16*> value_buffers;
+  for (const auto& crash_key : annotations) {
+    key_buffers.push_back(crash_key.name);
+    value_buffers.push_back(crash_key.value);
+  }
+  key_buffers.push_back(nullptr);
+  value_buffers.push_back(nullptr);
+
+  // Synthesize an exception for the main thread. Populate the record with the
+  // current context of the thread to get the stack trace bucketed on the crash
+  // backend.
+  CONTEXT thread_context = {};
+  EXCEPTION_RECORD exception_record = {};
+  exception_record.ExceptionCode = EXCEPTION_ARRAY_BOUNDS_EXCEEDED;
+  EXCEPTION_POINTERS exception_pointers = {&exception_record, &thread_context};
+
+  base::win::ScopedHandle main_thread(::OpenThread(
+      THREAD_SUSPEND_RESUME | THREAD_GET_CONTEXT | THREAD_QUERY_INFORMATION,
+      FALSE, main_thread_id));
+
+  bool have_context = false;
+  if (main_thread.IsValid()) {
+    DWORD suspend_count = ::SuspendThread(main_thread.Get());
+    const DWORD kSuspendFailed = static_cast<DWORD>(-1);
+    if (suspend_count != kSuspendFailed) {
+      // Best effort capture of the context.
+      thread_context.ContextFlags = CONTEXT_FLOATING_POINT | CONTEXT_SEGMENTS |
+                                    CONTEXT_INTEGER | CONTEXT_CONTROL;
+      if (::GetThreadContext(main_thread.Get(), &thread_context) == TRUE)
+        have_context = true;
+
+      ::ResumeThread(main_thread.Get());
+    }
+  }
+
+  // TODO(manzagop): consider making the dump-type channel-dependent.
+  if (have_context) {
+    kasko::api::SendReportForProcess(
+        process.Handle(), main_thread_id, &exception_pointers,
+        kasko::api::LARGER_DUMP_TYPE, key_buffers.data(), value_buffers.data());
+  } else {
+    kasko::api::SendReportForProcess(process.Handle(), 0, nullptr,
+                                     kasko::api::LARGER_DUMP_TYPE,
+                                     key_buffers.data(), value_buffers.data());
+  }
+}
+
+#endif  // BUILDFLAG(ENABLE_KASKO)