Switch chrome_elf exception handling from breakpad to crashpad

chrome_elf/chrome_elf_main.cc

Index: chrome_elf/chrome_elf_main.cc
diff --git a/chrome_elf/chrome_elf_main.cc b/chrome_elf/chrome_elf_main.cc
index 7a1a92de9e59dcd6e6b83502cbe0bef2fff7603b..1a125f0cdb6c0cbf061e132a1050f18e1a1fe8bb 100644
--- a/chrome_elf/chrome_elf_main.cc
+++ b/chrome_elf/chrome_elf_main.cc
@@ -5,25 +5,121 @@
 #include "chrome_elf/chrome_elf_main.h"
 
 #include <windows.h>
+#include <algorithm>
 
+#include "base/lazy_instance.h"
+#include "base/strings/string16.h"
+#include "base/win/iat_patch_function.h"
+#include "build/build_config.h"
+#include "chrome/app/chrome_crash_reporter_client_win.h"
 #include "chrome/install_static/install_util.h"
 #include "chrome_elf/blacklist/blacklist.h"
-#include "chrome_elf/breakpad/breakpad.h"
+#include "chrome_elf/blacklist/crashpad_helper.h"
+#include "chrome_elf/chrome_elf_constants.h"
+#include "components/crash/content/app/crashpad.h"
+#include "components/crash/core/common/crash_keys.h"
+
+namespace {
+
+base::LazyInstance<std::vector<crash_reporter::Report>>::Leaky g_crash_reports =
+    LAZY_INSTANCE_INITIALIZER;
+
+// Gets the exe name from the full path of the exe.
+base::string16 GetExeName() {
+  wchar_t file_path[MAX_PATH] = {};
+  if (!::GetModuleFileName(nullptr, file_path, arraysize(file_path))) {
+    assert(false);
+    return base::string16();
+  }
+  base::string16 file_name_string = file_path;
+  size_t last_slash_pos = file_name_string.find_last_of(L'\\');
+  if (last_slash_pos != base::string16::npos) {
+    file_name_string = file_name_string.substr(
+        last_slash_pos + 1, file_name_string.length() - last_slash_pos);
+  }
+  std::transform(file_name_string.begin(), file_name_string.end(),
+                 file_name_string.begin(), ::tolower);
+  return file_name_string;
+}
+
+void InitializeCrashReportingForProcess() {
+  // We want to initialize crash reporting only in chrome.exe
+  if (GetExeName() != L"chrome.exe")
+    return;
+  ChromeCrashReporterClient::InitializeCrashReportingForProcess();
+}
+
+// chrome_elf loads early in the process and initializes Crashpad. That in turn
+// uses the SetUnhandledExceptionFilter API to set a top level exception
+// handler for the process. When the process eventually initializes, CRT sets
+// an exception handler which calls TerminateProcess which effectively bypasses
+// us. Ideally we want to be at the top of the unhandled exception filter
+// chain. However we don't have a good way of intercepting the
+// SetUnhandledExceptionFilter API in the sandbox. EAT patching kernel32 or
+// kernelbase should ideally work. However the kernel32 kernelbase dlls are
+// prebound which causes EAT patching to not work. Sidestep works. However it
+// is only supported for 32 bit. For now we use IAT patching for the
+// executable.
+// TODO(ananta).
+// Check if it is possible to fix EAT patching or use sidestep patching for
+// 32 bit and 64 bit for this purpose.
+base::win::IATPatchFunction g_set_unhandled_exception_filter;
+
+LPTOP_LEVEL_EXCEPTION_FILTER WINAPI
+SetUnhandledExceptionFilterPatch(LPTOP_LEVEL_EXCEPTION_FILTER filter) {
+  // Don't set the exception filter. Please see above for comments.
+  return nullptr;
+}
+
+// Please refer above to more information about why we intercept the
+// SetUnhandledExceptionFilter API.
+void DisableSetUnhandledExceptionFilter() {
+  DWORD patched = g_set_unhandled_exception_filter.PatchFromModule(
+      GetModuleHandle(nullptr), "kernel32.dll", "SetUnhandledExceptionFilter",
+      SetUnhandledExceptionFilterPatch);
+  CHECK(patched == 0);
+}
+
+}  // namespace
 
 void SignalChromeElf() {
   blacklist::ResetBeacon();
 }
 
+// This helper is invoked by code in chrome.dll to retrieve the crash reports.
+// See CrashUploadListCrashpad. Note that we do not pass an std::vector here,
+// because we do not want to allocate/free in different modules. The returned
+// pointer is read-only.
+extern "C" __declspec(dllexport) void GetCrashReportsImpl(
+    const crash_reporter::Report** reports,
+    size_t* report_count) {
+  crash_reporter::GetReports(g_crash_reports.Pointer());
+  *reports = g_crash_reports.Pointer()->data();
+  *report_count = g_crash_reports.Pointer()->size();
+}
+
+// This helper is invoked by debugging code in chrome to register the client
+// id.
+extern "C" __declspec(dllexport) void SetMetricsClientId(
+    const char* client_id) {
+  if (client_id)
+    crash_keys::SetMetricsClientIdFromGUID(client_id);
+}
+
 BOOL APIENTRY DllMain(HMODULE module, DWORD reason, LPVOID reserved) {
   if (reason == DLL_PROCESS_ATTACH) {
+    InitializeCrashReportingForProcess();
+    // CRT on initialization installs an exception filter which calls
+    // TerminateProcess. We need to hook CRT's attempt to set an exception
+    // handler and ignore it.
+    DisableSetUnhandledExceptionFilter();
+
     install_static::InitializeProcessType();
-    InitializeCrashReporting();
 
     __try {
       blacklist::Initialize(false);  // Don't force, abort if beacon is present.
     } __except(GenerateCrashDump(GetExceptionInformation())) {
     }
   }
-
   return TRUE;
 }