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content / app / content_main.cc [blame]
// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/public/app/content_main.h"
#include <memory>
#include <optional>
#include "base/allocator/partition_alloc_support.h"
#include "base/at_exit.h"
#include "base/base_switches.h"
#include "base/command_line.h"
#include "base/compiler_specific.h"
#include "base/debug/debugger.h"
#include "base/debug/stack_trace.h"
#include "base/feature_list.h"
#include "base/i18n/icu_util.h"
#include "base/logging.h"
#include "base/memory/ptr_util.h"
#include "base/message_loop/message_pump_type.h"
#include "base/process/launch.h"
#include "base/process/memory.h"
#include "base/process/process.h"
#include "base/process/set_process_title.h"
#include "base/profiler/sample_metadata.h"
#include "base/run_loop.h"
#include "base/strings/string_number_conversions.h"
#include "base/synchronization/condition_variable.h"
#include "base/task/single_thread_task_executor.h"
#include "base/task/thread_pool/thread_pool_instance.h"
#include "base/threading/platform_thread.h"
#include "base/threading/thread.h"
#include "base/trace_event/trace_config.h"
#include "base/trace_event/trace_log.h"
#include "build/build_config.h"
#include "build/chromeos_buildflags.h"
#include "components/tracing/common/trace_to_console.h"
#include "components/tracing/common/tracing_switches.h"
#include "content/app/content_main_runner_impl.h"
#include "content/public/app/content_main_delegate.h"
#include "content/public/common/content_switches.h"
#include "mojo/core/embedder/configuration.h"
#include "mojo/core/embedder/embedder.h"
#include "mojo/core/embedder/scoped_ipc_support.h"
#include "mojo/public/cpp/platform/platform_channel.h"
#include "partition_alloc/buildflags.h"
#include "sandbox/policy/sandbox_type.h"
#include "ui/base/ui_base_paths.h"
#include "ui/base/ui_base_switches.h"
#if BUILDFLAG(IS_WIN)
#include <windows.h>
#include "base/win/process_startup_helper.h"
#include "base/win/win_util.h"
#include "base/win/windows_version.h"
#include "ui/base/win/atl_module.h"
#include "ui/gfx/switches.h"
#endif
#if BUILDFLAG(IS_POSIX) && !BUILDFLAG(IS_ANDROID)
#include <locale.h>
#include <signal.h>
#include "content/common/shared_file_util.h"
#endif
#if BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_LINUX)
#include "base/files/scoped_file.h"
#endif
#if BUILDFLAG(IS_MAC)
#include "base/apple/scoped_nsautorelease_pool.h"
#include "content/app/mac_init.h"
#endif
#if BUILDFLAG(IS_APPLE)
#if PA_BUILDFLAG(USE_ALLOCATOR_SHIM)
#include "partition_alloc/shim/allocator_shim.h"
#endif
#endif // BUILDFLAG(IS_MAC)
namespace content {
namespace {
#if BUILDFLAG(IS_POSIX) && !BUILDFLAG(IS_ANDROID)
// Setup signal-handling state: resanitize most signals, ignore SIGPIPE.
void SetupSignalHandlers() {
// Always ignore SIGPIPE. We check the return value of write().
CHECK_NE(SIG_ERR, signal(SIGPIPE, SIG_IGN));
if (base::CommandLine::ForCurrentProcess()->HasSwitch(
switches::kDisableInProcessStackTraces)) {
// Don't interfere with sanitizer signal handlers.
return;
}
// Sanitise our signal handling state. Signals that were ignored by our
// parent will also be ignored by us. We also inherit our parent's sigmask.
sigset_t empty_signal_set;
CHECK_EQ(0, sigemptyset(&empty_signal_set));
CHECK_EQ(0, sigprocmask(SIG_SETMASK, &empty_signal_set, nullptr));
struct sigaction sigact;
memset(&sigact, 0, sizeof(sigact));
sigact.sa_handler = SIG_DFL;
static const int signals_to_reset[] = {SIGHUP, SIGINT, SIGQUIT, SIGILL,
SIGABRT, SIGFPE, SIGSEGV, SIGALRM,
SIGTERM, SIGCHLD, SIGBUS, SIGTRAP};
for (int signal_to_reset : signals_to_reset)
CHECK_EQ(0, sigaction(signal_to_reset, &sigact, nullptr));
}
#endif // BUILDFLAG(IS_POSIX) && !BUILDFLAG(IS_ANDROID)
bool IsSubprocess() {
auto type = base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
switches::kProcessType);
return type == switches::kGpuProcess ||
type == switches::kPpapiPluginProcess ||
type == switches::kRendererProcess ||
type == switches::kUtilityProcess || type == switches::kZygoteProcess;
}
void CommonSubprocessInit() {
#if BUILDFLAG(IS_WIN)
// HACK: Let Windows know that we have started. This is needed to suppress
// the IDC_APPSTARTING cursor from being displayed for a prolonged period
// while a subprocess is starting.
if (base::win::IsUser32AndGdi32Available()) {
PostThreadMessage(GetCurrentThreadId(), WM_NULL, 0, 0);
MSG msg;
PeekMessage(&msg, nullptr, 0, 0, PM_REMOVE);
}
#endif
#if !defined(OFFICIAL_BUILD) && BUILDFLAG(IS_WIN)
base::RouteStdioToConsole(false);
LoadLibraryA("dbghelp.dll");
#endif
}
void InitTimeTicksAtUnixEpoch() {
const auto* command_line = base::CommandLine::ForCurrentProcess();
if (!command_line->HasSwitch(switches::kTimeTicksAtUnixEpoch)) {
return;
}
std::string time_ticks_at_unix_epoch_as_string =
command_line->GetSwitchValueASCII(switches::kTimeTicksAtUnixEpoch);
int64_t time_ticks_at_unix_epoch_delta_micro;
if (!base::StringToInt64(time_ticks_at_unix_epoch_as_string,
&time_ticks_at_unix_epoch_delta_micro)) {
return;
}
base::TimeDelta time_ticks_at_unix_epoch_delta =
base::Microseconds(time_ticks_at_unix_epoch_delta_micro);
base::TimeTicks time_ticks_at_unix_epoch =
base::TimeTicks() + time_ticks_at_unix_epoch_delta;
base::TimeTicks::SetSharedUnixEpoch(time_ticks_at_unix_epoch);
}
// Apply metadata to samples collected by the StackSamplingProfiler when tracing
// is enabled. This helps distinguish profiles with tracing overhead, e.g. due
// to background tracing, from those without.
class TracingEnabledStateObserver
: public base::trace_event::TraceLog::EnabledStateObserver {
public:
void OnTraceLogEnabled() override {
apply_sample_metadata_.emplace("TracingEnabled", 1,
base::SampleMetadataScope::kProcess);
}
void OnTraceLogDisabled() override { apply_sample_metadata_.reset(); }
private:
std::optional<base::ScopedSampleMetadata> apply_sample_metadata_;
};
} // namespace
ContentMainParams::ContentMainParams(ContentMainDelegate* delegate)
: delegate(delegate) {}
ContentMainParams::~ContentMainParams() = default;
ContentMainParams::ContentMainParams(ContentMainParams&&) = default;
ContentMainParams& ContentMainParams::operator=(ContentMainParams&&) = default;
// This function must be marked with NO_STACK_PROTECTOR or it may crash on
// return, see the --change-stack-guard-on-fork command line flag.
NO_STACK_PROTECTOR int RunContentProcess(
ContentMainParams params,
ContentMainRunner* content_main_runner) {
base::FeatureList::FailOnFeatureAccessWithoutFeatureList();
#if BUILDFLAG(IS_CHROMEOS_LACROS)
// Lacros is launched with inherited priority. Revert to normal priority
// before spawning more processes.
base::PlatformThread::SetCurrentThreadType(base::ThreadType::kDefault);
#endif
int exit_code = -1;
#if BUILDFLAG(IS_MAC)
base::apple::ScopedNSAutoreleasePool autorelease_pool;
#endif
// A flag to indicate whether Main() has been called before. On Android, we
// may re-run Main() without restarting the browser process. This flag
// prevents initializing things more than once.
static bool is_initialized = false;
#if !BUILDFLAG(IS_ANDROID)
DCHECK(!is_initialized);
#endif
if (is_initialized) {
content_main_runner->ReInitializeParams(std::move(params));
} else {
is_initialized = true;
#if BUILDFLAG(IS_APPLE) && PA_BUILDFLAG(USE_ALLOCATOR_SHIM)
allocator_shim::InitializeAllocatorShim();
#endif
base::EnableTerminationOnOutOfMemory();
logging::RegisterAbslAbortHook();
#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
// The various desktop environments set this environment variable that
// allows the dbus client library to connect directly to the bus. When this
// variable is not set (test environments like xvfb-run), the dbus client
// library will fall back to auto-launch mode. Auto-launch is dangerous as
// it can cause hangs (crbug.com/715658) . This one line disables the dbus
// auto-launch, by clobbering the DBUS_SESSION_BUS_ADDRESS env variable if
// not already set. The old auto-launch behavior, if needed, can be restored
// by setting DBUS_SESSION_BUS_ADDRESS="autolaunch:" before launching
// chrome.
const int kNoOverrideIfAlreadySet = 0;
setenv("DBUS_SESSION_BUS_ADDRESS", "disabled:", kNoOverrideIfAlreadySet);
#endif
#if BUILDFLAG(IS_WIN)
base::win::RegisterInvalidParamHandler();
ui::win::CreateATLModuleIfNeeded();
#endif // BUILDFLAG(IS_WIN)
#if !BUILDFLAG(IS_ANDROID)
// On Android, the command line is initialized when library is loaded.
int argc = 0;
const char** argv = nullptr;
#if !BUILDFLAG(IS_WIN)
// argc/argv are ignored on Windows; see command_line.h for details.
argc = params.argc;
argv = params.argv;
#endif
base::CommandLine::Init(argc, argv);
#if BUILDFLAG(IS_POSIX)
PopulateFileDescriptorStoreFromFdTable();
#endif
base::EnableTerminationOnHeapCorruption();
base::SetProcessTitleFromCommandLine(argv);
#endif // !BUILDFLAG(IS_ANDROID)
InitTimeTicksAtUnixEpoch();
// On Android setlocale() is not supported, and we don't override the signal
// handlers so we can get a stack trace when crashing.
#if BUILDFLAG(IS_POSIX) && !BUILDFLAG(IS_ANDROID)
// Set C library locale to make sure CommandLine can parse
// argument values in the correct encoding and to make sure
// generated file names (think downloads) are in the file system's
// encoding.
setlocale(LC_ALL, "");
// For numbers we never want the C library's locale sensitive
// conversion from number to string because the only thing it
// changes is the decimal separator which is not good enough for
// the UI and can be harmful elsewhere. User interface number
// conversions need to go through ICU. Other conversions need to
// be locale insensitive so we force the number locale back to the
// default, "C", locale.
setlocale(LC_NUMERIC, "C");
SetupSignalHandlers();
#endif
#if BUILDFLAG(IS_WIN)
base::win::SetupCRT(*base::CommandLine::ForCurrentProcess());
#endif
#if BUILDFLAG(IS_MAC)
// We need this pool for all the objects created before we get to the event
// loop, but we don't want to leave them hanging around until the app quits.
// Each "main" needs to flush this pool right before it goes into its main
// event loop to get rid of the cruft. TODO(crbug.com/40260311): This
// is not safe. Each main loop should create and destroy its own pool; it
// should not be flushing the pool at the base of the autorelease pool
// stack.
params.autorelease_pool = &autorelease_pool;
InitializeMac();
#endif
#if BUILDFLAG(IS_IOS)
base::ConditionVariable::InitializeFeatures();
base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
command_line->AppendSwitch(switches::kEnableViewport);
command_line->AppendSwitch(switches::kUseMobileUserAgent);
#endif
#if (BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_LINUX)) && !defined(COMPONENT_BUILD)
base::subtle::EnableFDOwnershipEnforcement(true);
#endif
ui::RegisterPathProvider();
exit_code = content_main_runner->Initialize(std::move(params));
if (exit_code >= 0) {
return exit_code;
}
#if BUILDFLAG(IS_WIN)
base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
if (command_line->HasSwitch(switches::kHeadless)) {
// When running in headless mode we want stdio routed however if
// console does not exist we should not create one.
base::RouteStdioToConsole(/*create_console_if_not_found*/ false);
} else if (command_line->HasSwitch(switches::kEnableLogging)) {
// Route stdio to parent console (if any) or create one, do not create a
// console in children if handles are being passed.
bool create_console = command_line->GetSwitchValueASCII(
switches::kEnableLogging) != "handle";
base::RouteStdioToConsole(create_console);
}
#endif
base::trace_event::TraceLog::GetInstance()->AddOwnedEnabledStateObserver(
base::WrapUnique(new TracingEnabledStateObserver));
if (base::CommandLine::ForCurrentProcess()->HasSwitch(
::switches::kTraceToConsole)) {
base::trace_event::TraceConfig trace_config =
tracing::GetConfigForTraceToConsole();
base::trace_event::TraceLog::GetInstance()->SetEnabled(
trace_config, base::trace_event::TraceLog::RECORDING_MODE);
}
}
if (IsSubprocess())
CommonSubprocessInit();
exit_code = content_main_runner->Run();
#if !BUILDFLAG(IS_ANDROID) && !BUILDFLAG(IS_IOS)
content_main_runner->Shutdown();
#endif
return exit_code;
}
// This function must be marked with NO_STACK_PROTECTOR or it may crash on
// return, see the --change-stack-guard-on-fork command line flag.
NO_STACK_PROTECTOR int ContentMain(ContentMainParams params) {
auto runner = ContentMainRunner::Create();
return RunContentProcess(std::move(params), runner.get());
}
} // namespace content