Breakpad coverage for chrome_elf start up

chrome_elf/breakpad.cc

+// Copyright 2014 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.
+
+// This module contains the necessary code to register the Breakpad exception
+// handler. This implementation is based on Chrome's crash reporting code.
+
+#include "chrome_elf/breakpad.h"
+
+#include <sddl.h>
+
+#include "base/macros.h"
+#include "breakpad/src/client/windows/handler/exception_handler.h"
+#include "chrome_elf/chrome_elf_util.h"
+#include "version.h"  // NOLINT
+
+google_breakpad::ExceptionHandler* g_elf_breakpad = NULL;
+
+namespace {
+
+const wchar_t kBreakpadProductName[] = L"ChromeElf";
+const wchar_t kBreakpadVersionEntry[] = L"ver";
+const wchar_t kBreakpadProdEntry[] = L"prod";
+const wchar_t kBreakpadPlatformEntry[] = L"plat";
+const wchar_t kBreakpadPlatformWin32[] = L"Win32";
+
+// The protocol for connecting to the out-of-process Breakpad crash
+// reporter is different for x86-32 and x86-64: the message sizes
+// are different because the message struct contains a pointer.  As
+// a result, there are two different named pipes to connect to.  The
+// 64-bit one is distinguished with an "-x64" suffix.
+const wchar_t kChromePipeName[] = L"\\\\.\\pipe\\ChromeCrashServices\\";
+const wchar_t kGoogleUpdatePipeName[] = L"\\\\.\\pipe\\GoogleCrashServices\\";
+const wchar_t kSystemPrincipalSid[] = L"S-1-5-18";
+
+const wchar_t kNoErrorDialogs[] = L"noerrdialogs";
+const wchar_t kChromeHeadless[] = L"CHROME_HEADLESS";
+
+google_breakpad::CustomClientInfo* GetCustomInfo() {
+  static google_breakpad::CustomInfoEntry ver_entry(
+      kBreakpadVersionEntry, TEXT(CHROME_VERSION_STRING));
+  static google_breakpad::CustomInfoEntry prod_entry(
+      kBreakpadProdEntry, kBreakpadProductName);
+  static google_breakpad::CustomInfoEntry plat_entry(
+      kBreakpadPlatformEntry, kBreakpadPlatformWin32);
+  static google_breakpad::CustomInfoEntry entries[] = {
+      ver_entry, prod_entry, plat_entry  };
+  static google_breakpad::CustomClientInfo custom_info = {
+      entries, arraysize(entries) };
+  return &custom_info;
+}
+
+base::string16 GetUserSidString() {
+  // Get the current token.
+  HANDLE token = NULL;
+  base::string16 user_sid;
+  if (!::OpenProcessToken(::GetCurrentProcess(), TOKEN_QUERY, &token))
+    return user_sid;
+
+  DWORD size = sizeof(TOKEN_USER) + SECURITY_MAX_SID_SIZE;
+  BYTE user_bytes[sizeof(TOKEN_USER) + SECURITY_MAX_SID_SIZE] = {};
+  TOKEN_USER* user = reinterpret_cast<TOKEN_USER*>(user_bytes);
+
+  wchar_t* sid_string;
+  if (::GetTokenInformation(token, TokenUser, user, size, &size) &&
+      user->User.Sid && ::ConvertSidToStringSid(user->User.Sid, &sid_string)) {

[grt (UTC plus 2), 2014/02/17 20:49:39]

nit: i find this a little easier to read with ::ConvertSidToStringSid on the
next line:
  if (A &&
      B &&
      C) {

[Cait (Slow), 2014/02/18 23:03:12]

Done.

+    user_sid = sid_string;
+    ::LocalFree(sid_string);
+  }
+
+  CloseHandle(token);
+  return user_sid;
+}
+
+bool IsHeadless() {
+ DWORD ret = ::GetEnvironmentVariable(L"CHROME_HEADLESS", NULL, 0);
+ bool has_env_var = ret != 0;

[grt (UTC plus 2), 2014/02/17 20:49:39]

  if (ret != 0)
    return true;

[Cait (Slow), 2014/02/18 23:03:12]

Done.

[Cait (Slow), 2014/02/18 23:03:12]

Done.

+
+ wchar_t* command_line = ::GetCommandLine();
+ bool has_flag = (command_line && wcsstr(command_line, kNoErrorDialogs));

[grt (UTC plus 2), 2014/02/17 20:49:39]

i'm a little worried that this will match things that the Chrome code won't
since it's doing a pure substring search rather than checking for a switch with
the given name. please add a comment making that clear, but explaining that it's
probably okay since there are no other switches defined that contain the string
"noerrdialogs".
  return command_line && wcsstr(command_line, kNoErrorDialogs);

[Cait (Slow), 2014/02/18 23:03:12]

Done.

+
+ return has_env_var || has_flag;
+}
+
+}  // namespace
+
+int GenerateCrashDump(EXCEPTION_POINTERS* exinfo) {
+  DWORD code = exinfo->ExceptionRecord->ExceptionCode;
+  if (code == EXCEPTION_BREAKPOINT || code == EXCEPTION_SINGLE_STEP)
+    return EXCEPTION_CONTINUE_SEARCH;
+
+  if (g_elf_breakpad != NULL)
+    g_elf_breakpad->WriteMinidumpForException(exinfo);
+  return EXCEPTION_CONTINUE_SEARCH;
+}
+
+void InitializeCrashReporting() {
+  wchar_t exe_path[MAX_PATH] = {};
+  if(!::GetModuleFileName(NULL, exe_path, arraysize(exe_path)))
+    return;
+
+  // Do not set up crash reporting if the user has not consented to it.
+  if (!AreUsageStatsEnabled(exe_path))

[grt (UTC plus 2), 2014/02/17 20:49:39]

policy trumps usagestats, so only check this if !use_policy down below.

[Cait (Slow), 2014/02/18 23:03:12]

Done.

+    return;
+
+  // Disable the message box for assertions.
+  _CrtSetReportMode(_CRT_ASSERT, 0);
+
+  // Get the alternate dump directory. We use the temp path.
+  // N.B. We don't use base::GetTempDir() here to avoid running more code then
+  //      necessary before crashes can be properly reported.
+  wchar_t temp_directory[MAX_PATH + 1] = {};
+  DWORD length = GetTempPath(MAX_PATH, temp_directory);
+  if (length == 0)
+    return;
+
+  // Minidump with stacks, PEB, TEBs and unloaded module list.
+  MINIDUMP_TYPE dump_type = static_cast<MINIDUMP_TYPE>(
+      MiniDumpWithProcessThreadData |  // Get PEB and TEB.
+      MiniDumpWithUnloadedModules |  // Get unloaded modules when available.
+      MiniDumpWithIndirectlyReferencedMemory);  // Get memory referenced by
+                                                // stack.
+
+  base::string16 pipe_name;
+
+  bool enabled;

[grt (UTC plus 2), 2014/02/17 20:49:39]

nit: initialize to something. also, consider renaming to enabled_by_policy

[Cait (Slow), 2014/02/18 23:03:12]

Done.

+  bool use_policy = ReportingIsEnforcedByPolicy(&enabled);
+
+  if (!use_policy && IsHeadless()) {
+    pipe_name = kChromePipeName;
+  } else {

[grt (UTC plus 2), 2014/02/17 20:49:39]

consider:
  } else if (use_policy ? enabled : AreUsageStatsEnabled(exe_path)) {
  } else {
    // Either reporting is disabled by policy or the user has not given consent.
    return;
  }

[Cait (Slow), 2014/02/18 23:03:12]

Done.

+    // Build the pipe name. It can be one of:
+    // 32-bit system: \\.\pipe\GoogleCrashServices\S-1-5-18
+    // 32-bit user: \\.\pipe\GoogleCrashServices\<user SID>
+    // 64-bit system: \\.\pipe\GoogleCrashServices\S-1-5-18-x64
+    // 64-bit user: \\.\pipe\GoogleCrashServices\<user SID>-x64
+    base::string16 user_sid = IsSystemInstall(exe_path) ? kSystemPrincipalSid :
+                                                          GetUserSidString();
+    if (user_sid.empty())
+      return;
+
+    base::string16 pipe_name = kGoogleUpdatePipeName;
+    pipe_name += user_sid;
+
+#if defined(_WIN64)
+    pipe_name += L"-x64";
+#endif
+  }
+
+  g_elf_breakpad = new google_breakpad::ExceptionHandler(
+      temp_directory,
+      NULL,
+      NULL,
+      NULL,
+      google_breakpad::ExceptionHandler::HANDLER_ALL,
+      dump_type,
+      pipe_name.c_str(),
+      GetCustomInfo());
+
+  if (g_elf_breakpad->IsOutOfProcess()) {
+    // Tells breakpad to handle breakpoint and single step exceptions.
+    g_elf_breakpad->set_handle_debug_exceptions(true);
+  }
+}