Crashpad Windows: Use the Crashpad client instead of Breakpad on Windows

components/crash/content/app/crashpad_win.cc

+// Copyright 2015 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 "components/crash/content/app/crashpad.h"
+
+#include "base/environment.h"
+#include "base/lazy_instance.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/numerics/safe_conversions.h"
+#include "base/path_service.h"
+#include "base/strings/string16.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/utf_string_conversions.h"
+#include "build/build_config.h"
+#include "components/crash/content/app/crash_reporter_client.h"
+#include "third_party/crashpad/crashpad/client/crashpad_client.h"
+#include "third_party/crashpad/crashpad/client/crashpad_info.h"
+
+namespace crash_reporter {
+namespace internal {
+
+namespace {
+
+base::LazyInstance<crashpad::CrashpadClient>::Leaky g_crashpad_client =
+    LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+base::FilePath PlatformCrashpadInitialization(bool initial_client,
+                                              bool browser_process) {
+  base::FilePath database_path;  // Only valid in the browser process.
+  bool result;
+
+  const char kPipeNameVar[] = "CHROME_CRASHPAD_PIPE_NAME";
+  scoped_ptr<base::Environment> env(base::Environment::Create());
+
+  DCHECK_EQ(initial_client, browser_process);
+
+  if (initial_client) {
+    CrashReporterClient* crash_reporter_client = GetCrashReporterClient();
+    crash_reporter_client->GetCrashDumpLocation(&database_path);
+
+    base::FilePath exe_file;
+    CHECK(PathService::Get(base::FILE_EXE, &exe_file));
+    base::string16 product_name, version, special_build, channel_name;
+    crash_reporter_client->GetProductNameAndVersion(
+        exe_file, &product_name, &version, &special_build, &channel_name);
+    std::map<std::string, std::string> process_annotations;
+    process_annotations["prod"] = base::UTF16ToUTF8(product_name);
+    process_annotations["ver"] = base::UTF16ToUTF8(version);
+    process_annotations["channel"] = base::UTF16ToUTF8(channel_name);
+    if (!special_build.empty())
+      process_annotations["special"] = base::UTF16ToUTF8(special_build);
+#if defined(ARCH_CPU_X86)
+    process_annotations["plat"] = std::string("Win32");
+#elif defined(ARCH_CPU_X86_64)
+    process_annotations["plat"] = std::string("Win64");
+#endif
+#if defined(GOOGLE_CHROME_BUILD)
+    std::string url = "https://clients2.google.com/cr/report";
+#else
+    std::string url = "";

[Mark Mentovai, 2015/11/19 22:21:38]

Without the = "" should be slightly cheaper.

[scottmg, 2015/11/20 19:52:48]

Done.

+#endif
+
+    std::vector<std::string> arguments;
+
+    // In test binaries, use crashpad_handler directly. Otherwise, we launch
+    // chrome.exe with --type=crashpad-handler.
+    if (exe_file.BaseName().value() != FILE_PATH_LITERAL("chrome.exe")) {
+      base::FilePath exe_dir;
+      CHECK(PathService::Get(base::DIR_EXE, &exe_dir));
+      exe_file = exe_dir.Append(FILE_PATH_LITERAL("crashpad_handler.exe"));
+    } else {
+      arguments.push_back("--type=crashpad-handler");
+    }
+
+    result = g_crashpad_client.Get().StartHandler(
+        exe_file, database_path, url, process_annotations, arguments, false);
+
+    // If we're the browser, push the pipe name into the environment so child
+    // processes can connect to it.
+    DCHECK(!env->HasVar(kPipeNameVar));

[Mark Mentovai, 2015/11/19 22:21:37]

If the browser restarts itself (like after a change in about:flags), will this
be tripped?

[scottmg, 2015/11/20 19:52:48]

Possibly. It looks like some similar failures in browser_tests once I got past
the more generic failures.

https://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel...

I guess if it's set, we don't want to start at all even if we otherwise think
we're the first client.

[Mark Mentovai, 2015/11/20 20:00:23]

scottmg wrote:
I don’t agree. I think that if we’re the browser, we should always start a
crashpad_handler.

What if the restart happened because a new Chrome version was installed? We want
to talk to the new crashpad_handler, which may have been updated. We also want
to start a new crashpad_handler because the version annotation goes to
crashpad_handler as an argument.

[scottmg, 2015/11/20 21:30:10]

OK, makes sense. In the test case, it's browser_tests (which starts a
crashpad_handler) launching a sub-test consisting of a browser_tests
--as-browser, which is going to start a crashpad_handler. But that seems OK. So,
I've just removed the DCHECK here.

+    env->SetVar(kPipeNameVar,
+                base::UTF16ToUTF8(g_crashpad_client.Get().GetHandlerIPCPipe()));
+  } else {
+    std::string pipe_name_utf8;
+    result = env->GetVar(kPipeNameVar, &pipe_name_utf8);
+    if (result) {
+      result = g_crashpad_client.Get().SetHandlerIPCPipe(
+          base::UTF8ToUTF16(pipe_name_utf8));
+    }
+  }
+
+  if (result) {
+    result = g_crashpad_client.Get().UseHandler();
+  }
+
+  return database_path;
+}
+
+// Crashes the process after generating a dump for the provided exception. Note
+// that the crash reporter should be initialized before calling this function
+// for it to do anything.
+// NOTE: This function is used by SyzyASAN to invoke a crash. If you change the
+// the name or signature of this function you will break SyzyASAN instrumented
+// releases of Chrome. Please contact syzygy-team@chromium.org before doing so!
+extern "C" int __declspec(dllexport) CrashForException(

[Mark Mentovai, 2015/11/19 22:21:37]

This and the other functions after this point (except where noted) can come out
of the namespace (since you’re not really using the namespacing at all) and
share a big extern "C" {}.

[scottmg, 2015/11/20 19:52:48]

Done.

+    EXCEPTION_POINTERS* info) {
+  g_crashpad_client.Get().DumpAndCrash(info);
+  return EXCEPTION_CONTINUE_SEARCH;
+}
+
+#if defined(ARCH_CPU_X86_64)
+int CrashForExceptionInNonABICompliantCodeRange(

[Mark Mentovai, 2015/11/19 22:21:37]

This can be in an anonymous namespace.

[scottmg, 2015/11/20 19:52:48]

How about static because of the inter-function calls?

+    PEXCEPTION_RECORD ExceptionRecord,
+    ULONG64 EstablisherFrame,
+    PCONTEXT ContextRecord,
+    PDISPATCHER_CONTEXT DispatcherContext) {
+  EXCEPTION_POINTERS info = { ExceptionRecord, ContextRecord };
+  return CrashForException(&info);
+}
+
+// See https://msdn.microsoft.com/en-us/library/ddssxxy8.aspx
+typedef struct _UNWIND_INFO {
+  unsigned char Version : 3;
+  unsigned char Flags : 5;
+  unsigned char SizeOfProlog;
+  unsigned char CountOfCodes;
+  unsigned char FrameRegister : 4;
+  unsigned char FrameOffset : 4;
+  ULONG ExceptionHandler;
+} UNWIND_INFO, *PUNWIND_INFO;
+
+struct ExceptionHandlerRecord {
+  RUNTIME_FUNCTION runtime_function;
+  UNWIND_INFO unwind_info;
+  unsigned char thunk[12];
+};
+
+// These are GetProcAddress()d from V8 binding code.
+extern "C" void __declspec(dllexport) __cdecl
+RegisterNonABICompliantCodeRange(void* start, size_t size_in_bytes) {
+  ExceptionHandlerRecord* record =
+      reinterpret_cast<ExceptionHandlerRecord*>(start);
+
+  // We assume that the first page of the code range is executable and
+  // committed and reserved for breakpad. What could possibly go wrong?
+
+  // All addresses are 32bit relative offsets to start.
+  record->runtime_function.BeginAddress = 0;
+  record->runtime_function.EndAddress =
+      base::checked_cast<DWORD>(size_in_bytes);
+  record->runtime_function.UnwindData =
+      offsetof(ExceptionHandlerRecord, unwind_info);
+
+  // Create unwind info that only specifies an exception handler.
+  record->unwind_info.Version = 1;
+  record->unwind_info.Flags = UNW_FLAG_EHANDLER;
+  record->unwind_info.SizeOfProlog = 0;
+  record->unwind_info.CountOfCodes = 0;
+  record->unwind_info.FrameRegister = 0;
+  record->unwind_info.FrameOffset = 0;
+  record->unwind_info.ExceptionHandler =
+      offsetof(ExceptionHandlerRecord, thunk);
+
+  // Hardcoded thunk.
+  // mov imm64, rax
+  record->thunk[0] = 0x48;
+  record->thunk[1] = 0xb8;
+  void* handler = &CrashForExceptionInNonABICompliantCodeRange;
+  memcpy(&record->thunk[2], &handler, 8);
+
+  // jmp rax
+  record->thunk[10] = 0xff;
+  record->thunk[11] = 0xe0;
+
+  // Protect reserved page against modifications.
+  DWORD old_protect;
+  CHECK(VirtualProtect(
+      start, sizeof(ExceptionHandlerRecord), PAGE_EXECUTE_READ, &old_protect));
+  CHECK(RtlAddFunctionTable(
+      &record->runtime_function, 1, reinterpret_cast<DWORD64>(start)));
+}
+
+extern "C" void __declspec(dllexport) __cdecl
+UnregisterNonABICompliantCodeRange(void* start) {
+  ExceptionHandlerRecord* record =
+      reinterpret_cast<ExceptionHandlerRecord*>(start);
+
+  CHECK(RtlDeleteFunctionTable(&record->runtime_function));
+}
+#endif  // ARCH_CPU_X86_64
+
+}  // namespace internal
+}  // namespace crash_reporter