yukijoou/kwin
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
kwin/main.cpp
Martin Gräßlin 72882f6aba [kwin] Add sanity checks for the QPA plugin 
KWin requires the xcb plugin otherwise KWin crashes when the first
xcb/xlib code is called. First KWin tries to set the QT_QPA_PLATFORM
to "xcb", but that doesn't protect against the command line switch.

Thus KWin also verifies that after constructing the QGuiApplication
the platform name is set to xcb, if not it exits gracefully with a
useful error message instead a crash.

To make that work the KWinSelectionOwner has to be changed to a
pointer and be delayed constructed, otherwise the crash already happens
in the KSelectionOwner.

Furthermore a small sanity check on the plugin is performed by checking
whether KWin can get the XDisplay from the QPA. If not it means that the
QPA plugin was compiled with -no-xcb-xlib which KWin doesn't support, it
still uses XLib at various places. If KWin doesn't get the Display, it
exits gracefully with a clear error message.

CCBUG: 331880
REVIEW: 116669
2014-03-10 08:41:53 +01:00

564 lines
19 KiB
C++
Raw Blame History

/********************************************************************
KWin - the KDE window manager
This file is part of the KDE project.
Copyright (C) 1999, 2000 Matthias Ettrich <ettrich@kde.org>
Copyright (C) 2003 Lubos Lunak <l.lunak@kde.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*********************************************************************/
#include "main.h"
#include "config-workspace.h"
// kwin
#include "atoms.h"
#include "options.h"
#include "sm.h"
#include "workspace.h"
#include "xcbutils.h"
// KDE workspace
#include <ksmserver_interface.h>
// KDE
#include <KDE/KAboutData>
#include <KDE/KConfig>
#include <KDE/KConfigGroup>
#include <KDE/KCrash>
#include <KDE/KLocalizedString>
// Qt
#include <qplatformdefs.h>
#include <QDebug>
#include <QComboBox>
#include <qcommandlineparser.h>
#include <QDialog>
#include <QDialogButtonBox>
#include <QLabel>
#include <QPushButton>
#include <QQuickWindow>
#include <QStandardPaths>
#include <QVBoxLayout>
#include <QtDBus/QtDBus>
#include <QX11Info>
// TODO: remove once QX11Info provides the X screen
#include <X11/Xlib.h>
// system
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif // HAVE_UNISTD_H
#ifdef HAVE_MALLOC_H
#include <malloc.h>
#endif // HAVE_MALLOC_H
namespace KWin
{
Options* options;
Atoms* atoms;
int screen_number = -1;
bool is_multihead = false;
//************************************
// KWinSelectionOwner
//************************************
KWinSelectionOwner::KWinSelectionOwner(int screen_P)
: KSelectionOwner(make_selection_atom(screen_P), screen_P)
{
}
xcb_atom_t KWinSelectionOwner::make_selection_atom(int screen_P)
{
if (screen_P < 0)
screen_P = DefaultScreen(display());
QByteArray screen(QByteArrayLiteral("WM_S"));
screen.append(QByteArray::number(screen_P));
ScopedCPointer<xcb_intern_atom_reply_t> atom(xcb_intern_atom_reply(
connection(),
xcb_intern_atom_unchecked(connection(), false, screen.length(), screen.constData()),
nullptr));
if (atom.isNull()) {
return XCB_ATOM_NONE;
}
return atom->atom;
}
void KWinSelectionOwner::getAtoms()
{
KSelectionOwner::getAtoms();
if (xa_version == XCB_ATOM_NONE) {
const QByteArray name(QByteArrayLiteral("VERSION"));
ScopedCPointer<xcb_intern_atom_reply_t> atom(xcb_intern_atom_reply(
connection(),
xcb_intern_atom_unchecked(connection(), false, name.length(), name.constData()),
nullptr));
if (!atom.isNull()) {
xa_version = atom->atom;
}
}
}
void KWinSelectionOwner::replyTargets(xcb_atom_t property_P, xcb_window_t requestor_P)
{
KSelectionOwner::replyTargets(property_P, requestor_P);
xcb_atom_t atoms[ 1 ] = { xa_version };
// PropModeAppend !
xcb_change_property(connection(), XCB_PROP_MODE_APPEND, requestor_P,
property_P, XCB_ATOM_ATOM, 32, 1, atoms);
}
bool KWinSelectionOwner::genericReply(xcb_atom_t target_P, xcb_atom_t property_P, xcb_window_t requestor_P)
{
if (target_P == xa_version) {
int32_t version[] = { 2, 0 };
xcb_change_property(connection(), XCB_PROP_MODE_REPLACE, requestor_P,
property_P, XCB_ATOM_INTEGER, 32, 2, version);
} else
return KSelectionOwner::genericReply(target_P, property_P, requestor_P);
return true;
}
xcb_atom_t KWinSelectionOwner::xa_version = XCB_ATOM_NONE;
class AlternativeWMDialog : public QDialog
{
public:
AlternativeWMDialog()
: QDialog() {
QWidget* mainWidget = new QWidget(this);
QVBoxLayout* layout = new QVBoxLayout(mainWidget);
QString text = i18n(
"KWin is unstable.\n"
"It seems to have crashed several times in a row.\n"
"You can select another window manager to run:");
QLabel* textLabel = new QLabel(text, mainWidget);
layout->addWidget(textLabel);
wmList = new QComboBox(mainWidget);
wmList->setEditable(true);
layout->addWidget(wmList);
addWM(QStringLiteral("metacity"));
addWM(QStringLiteral("openbox"));
addWM(QStringLiteral("fvwm2"));
addWM(QStringLiteral(KWIN_NAME));
QVBoxLayout *mainLayout = new QVBoxLayout(this);
mainLayout->addWidget(mainWidget);
QDialogButtonBox *buttons = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel, this);
buttons->button(QDialogButtonBox::Ok)->setDefault(true);
connect(buttons, &QDialogButtonBox::accepted, this, &QDialog::accept);
connect(buttons, &QDialogButtonBox::rejected, this, &QDialog::reject);
mainLayout->addWidget(buttons);
raise();
}
void addWM(const QString& wm) {
// TODO: Check if WM is installed
if (!QStandardPaths::findExecutable(wm).isEmpty())
wmList->addItem(wm);
}
QString selectedWM() const {
return wmList->currentText();
}
private:
QComboBox* wmList;
};
int Application::crashes = 0;
Application::Application(int &argc, char **argv)
: QApplication(argc, argv)
, owner()
, m_eventFilter(new XcbEventFilter())
, m_replace(false)
, m_configLock(false)
, m_operationMode(OperationModeX11)
{
}
void Application::setConfigLock(bool lock)
{
m_configLock = lock;
}
void Application::setReplace(bool replace)
{
m_replace = replace;
}
Application::OperationMode Application::operationMode() const
{
return m_operationMode;
}
void Application::setOperationMode(OperationMode mode)
{
m_operationMode = mode;
}
bool Application::shouldUseWaylandForCompositing() const
{
return m_operationMode == OperationModeWaylandAndX11;
}
bool Application::requiresCompositing() const
{
return shouldUseWaylandForCompositing();
}
void Application::start()
{
setQuitOnLastWindowClosed(false);
KSharedConfig::Ptr config = KSharedConfig::openConfig();
if (!config->isImmutable() && m_configLock) {
// TODO: This shouldn't be necessary
//config->setReadOnly( true );
config->reparseConfiguration();
}
if (screen_number == -1)
screen_number = QX11Info::appScreen();
owner.reset(new KWinSelectionOwner(screen_number));
connect(owner.data(), &KSelectionOwner::failedToClaimOwnership, []{
fputs(i18n("kwin: unable to claim manager selection, another wm running? (try using --replace)\n").toLocal8Bit().constData(), stderr);
::exit(1);
});
connect(owner.data(), SIGNAL(lostOwnership()), SLOT(lostSelection()));
connect(owner.data(), &KSelectionOwner::claimedOwnership, [this]{
// we want all QQuickWindows with an alpha buffer
QQuickWindow::setDefaultAlphaBuffer(true);
installNativeEventFilter(m_eventFilter.data());
// first load options - done internally by a different thread
options = new Options;
// Check whether another windowmanager is running
const uint32_t maskValues[] = {XCB_EVENT_MASK_SUBSTRUCTURE_REDIRECT};
ScopedCPointer<xcb_generic_error_t> redirectCheck(xcb_request_check(connection(),
xcb_change_window_attributes_checked(connection(),
rootWindow(),
XCB_CW_EVENT_MASK,
maskValues)));
if (!redirectCheck.isNull()) {
fputs(i18n("kwin: another window manager is running (try using --replace)\n").toLocal8Bit().constData(), stderr);
::exit(1);
}
atoms->retrieveHelpers();
// This tries to detect compositing options and can use GLX. GLX problems
// (X errors) shouldn't cause kwin to abort, so this is out of the
// critical startup section where x errors cause kwin to abort.
// create workspace.
(void) new Workspace(isSessionRestored());
Xcb::sync(); // Trigger possible errors, there's still a chance to abort
// Tell KSplash that KWin has started
QDBusMessage ksplashProgressMessage = QDBusMessage::createMethodCall(QStringLiteral("org.kde.KSplash"),
QStringLiteral("/KSplash"),
QStringLiteral("org.kde.KSplash"),
QStringLiteral("setStage"));
ksplashProgressMessage.setArguments(QList<QVariant>() << QStringLiteral("wm"));
QDBusConnection::sessionBus().asyncCall(ksplashProgressMessage);
});
crashChecking();
// we need to do an XSync here, otherwise the QPA might crash us later on
Xcb::sync();
owner->claim(m_replace, true);
atoms = new Atoms;
}
Application::~Application()
{
delete Workspace::self();
if (!owner.isNull() && owner->ownerWindow() != XCB_WINDOW_NONE) // If there was no --replace (no new WM)
Xcb::setInputFocus(XCB_INPUT_FOCUS_POINTER_ROOT);
delete options;
delete atoms;
}
void Application::crashChecking()
{
KCrash::setEmergencySaveFunction(Application::crashHandler);
if (crashes >= 4) {
// Something has gone seriously wrong
AlternativeWMDialog dialog;
QString cmd = QStringLiteral(KWIN_NAME);
if (dialog.exec() == QDialog::Accepted)
cmd = dialog.selectedWM();
else
::exit(1);
if (cmd.length() > 500) {
qDebug() << "Command is too long, truncating";
cmd = cmd.left(500);
}
qDebug() << "Starting" << cmd << "and exiting";
char buf[1024];
sprintf(buf, "%s &", cmd.toAscii().data());
system(buf);
::exit(1);
}
if (crashes >= 2) {
// Disable compositing if we have had too many crashes
qDebug() << "Too many crashes recently, disabling compositing";
KConfigGroup compgroup(KSharedConfig::openConfig(), "Compositing");
compgroup.writeEntry("Enabled", false);
}
// Reset crashes count if we stay up for more that 15 seconds
QTimer::singleShot(15 * 1000, this, SLOT(resetCrashesCount()));
}
void Application::lostSelection()
{
sendPostedEvents();
delete Workspace::self();
// Remove windowmanager privileges
Xcb::selectInput(rootWindow(), XCB_EVENT_MASK_PROPERTY_CHANGE);
quit();
}
bool Application::notify(QObject* o, QEvent* e)
{
if (Workspace::self()->workspaceEvent(e))
return true;
return QApplication::notify(o, e);
}
static void sighandler(int)
{
QApplication::exit();
}
void Application::crashHandler(int signal)
{
crashes++;
fprintf(stderr, "Application::crashHandler() called with signal %d; recent crashes: %d\n", signal, crashes);
char cmd[1024];
sprintf(cmd, "%s --crashes %d &",
QFile::encodeName(QCoreApplication::applicationFilePath()).constData(), crashes);
sleep(1);
system(cmd);
}
void Application::resetCrashesCount()
{
crashes = 0;
}
void Application::setCrashCount(int count)
{
crashes = count;
}
bool Application::wasCrash()
{
return crashes > 0;
}
bool XcbEventFilter::nativeEventFilter(const QByteArray &eventType, void *message, long int *result)
{
Q_UNUSED(result)
if (!Workspace::self()) {
// Workspace not yet created
return false;
}
if (eventType != "xcb_generic_event_t") {
return false;
}
return Workspace::self()->workspaceEvent(static_cast<xcb_generic_event_t *>(message));
}
} // namespace
static const char version[] = KWIN_VERSION_STRING;
static const char description[] = I18N_NOOP("KDE window manager");
extern "C"
KWIN_EXPORT int kdemain(int argc, char * argv[])
{
#ifdef M_TRIM_THRESHOLD
// Prevent fragmentation of the heap by malloc (glibc).
//
// The default threshold is 128*1024, which can result in a large memory usage
// due to fragmentation especially if we use the raster graphicssystem. On the
// otherside if the threshold is too low, free() starts to permanently ask the kernel
// about shrinking the heap.
#ifdef HAVE_UNISTD_H
const int pagesize = sysconf(_SC_PAGESIZE);
#else
const int pagesize = 4*1024;
#endif // HAVE_UNISTD_H
mallopt(M_TRIM_THRESHOLD, 5*pagesize);
#endif // M_TRIM_THRESHOLD
QLoggingCategory::setFilterRules(QStringLiteral("aurorae.debug = true\n") +
QStringLiteral("kwineffects.debug = true"));
int primaryScreen = 0;
xcb_connection_t *c = xcb_connect(nullptr, &primaryScreen);
if (!c || xcb_connection_has_error(c)) {
fprintf(stderr, "%s: FATAL ERROR while trying to open display %s\n",
argv[0], qgetenv("DISPLAY").constData());
exit(1);
}
const int number_of_screens = xcb_setup_roots_length(xcb_get_setup(c));
// multi head
auto isMultiHead = []() -> bool {
QByteArray multiHead = qgetenv("KDE_MULTIHEAD");
if (!multiHead.isEmpty()) {
return (multiHead.toLower() == "true");
}
return true;
};
if (number_of_screens != 1 && isMultiHead()) {
KWin::is_multihead = true;
KWin::screen_number = primaryScreen;
int pos; // Temporarily needed to reconstruct DISPLAY var if multi-head
QByteArray display_name = qgetenv("DISPLAY");
xcb_disconnect(c);
c = nullptr;
if ((pos = display_name.lastIndexOf('.')) != -1)
display_name.remove(pos, 10); // 10 is enough to be sure we removed ".s"
QString envir;
for (int i = 0; i < number_of_screens; i++) {
// If execution doesn't pass by here, then kwin
// acts exactly as previously
if (i != KWin::screen_number && fork() == 0) {
KWin::screen_number = i;
// Break here because we are the child process, we don't
// want to fork() anymore
break;
}
}
// In the next statement, display_name shouldn't contain a screen
// number. If it had it, it was removed at the "pos" check
envir.sprintf("DISPLAY=%s.%d", display_name.data(), KWin::screen_number);
if (putenv(strdup(envir.toAscii().constData()))) {
fprintf(stderr, "%s: WARNING: unable to set DISPLAY environment variable\n", argv[0]);
perror("putenv()");
}
}
if (signal(SIGTERM, KWin::sighandler) == SIG_IGN)
signal(SIGTERM, SIG_IGN);
if (signal(SIGINT, KWin::sighandler) == SIG_IGN)
signal(SIGINT, SIG_IGN);
if (signal(SIGHUP, KWin::sighandler) == SIG_IGN)
signal(SIGHUP, SIG_IGN);
// Disable the glib event loop integration, since it seems to be responsible
// for several bug reports about high CPU usage (bug #239963)
setenv("QT_NO_GLIB", "1", true);
// enforce xcb plugin, unfortunately command line switch has precedence
setenv("QT_QPA_PLATFORM", "xcb", true);
org::kde::KSMServerInterface ksmserver(QStringLiteral("org.kde.ksmserver"), QStringLiteral("/KSMServer"), QDBusConnection::sessionBus());
ksmserver.suspendStartup(QStringLiteral(KWIN_NAME));
KWin::Application a(argc, argv);
a.setApplicationName(QStringLiteral(KWIN_NAME));
a.setApplicationVersion(QStringLiteral(KWIN_VERSION_STRING));
a.setApplicationDisplayName(i18n("KWin"));
KAboutData aboutData(QStringLiteral(KWIN_NAME), // The program name used internally
QString(), // The message catalog name. If null, program name is used instead
i18n("KWin"), // A displayable program name string
QStringLiteral(KWIN_VERSION_STRING), // The program version string
i18n(description), // Short description of what the app does
KAboutData::License_GPL, // The license this code is released under
i18n("(c) 1999-2013, The KDE Developers")); // Copyright Statement
aboutData.addAuthor(i18n("Matthias Ettrich"), QString(), QStringLiteral("ettrich@kde.org"));
aboutData.addAuthor(i18n("Cristian Tibirna"), QString(), QStringLiteral("tibirna@kde.org"));
aboutData.addAuthor(i18n("Daniel M. Duley"), QString(), QStringLiteral("mosfet@kde.org"));
aboutData.addAuthor(i18n("Luboš Luňák"), QString(), QStringLiteral("l.lunak@kde.org"));
aboutData.addAuthor(i18n("Martin Gräßlin"), i18n("Maintainer"), QStringLiteral("mgraesslin@kde.org"));
QCommandLineOption lockOption(QStringLiteral("lock"), i18n("Disable configuration options"));
QCommandLineOption replaceOption(QStringLiteral("replace"), i18n("Replace already-running ICCCM2.0-compliant window manager"));
QCommandLineOption crashesOption(QStringLiteral("crashes"), i18n("Indicate that KWin has recently crashed n times"), QStringLiteral("n"));
QCommandLineParser parser;
parser.setApplicationDescription(i18n("KDE window manager"));
parser.addVersionOption();
parser.addHelpOption();
parser.addOption(lockOption);
parser.addOption(replaceOption);
parser.addOption(crashesOption);
parser.process(a);
KWin::Application::setCrashCount(parser.value(crashesOption).toInt());
a.setConfigLock(parser.isSet(lockOption));
a.setReplace(parser.isSet(replaceOption));
// perform sanity checks
if (a.platformName().toLower() != QStringLiteral("xcb")) {
fprintf(stderr, "%s: FATAL ERROR expecting platform xcb but got platform %s\n",
argv[0], qPrintable(a.platformName()));
exit(1);
}
if (!KWin::display()) {
fprintf(stderr, "%s: FATAL ERROR KWin requires Xlib support in the xcb plugin. Do not configure Qt with -no-xcb-xlib\n",
argv[0]);
exit(1);
}
a.start();
ksmserver.resumeStartup(QStringLiteral(KWIN_NAME));
#warning SessionManager needs porting
#if KWIN_QT5_PORTING
KWin::SessionManager weAreIndeed;
#endif
KWin::SessionSaveDoneHelper helper;
#warning insertCatalog needs porting
#if KWIN_QT5_PORTING
KGlobal::locale()->insertCatalog("kwin_effects");
KGlobal::locale()->insertCatalog("kwin_scripts");
KGlobal::locale()->insertCatalog("kwin_scripting");
#endif
QString appname;
if (KWin::screen_number == 0)
appname = QStringLiteral("org.kde.kwin");
else
appname.sprintf("org.kde.kwin-screen-%d", KWin::screen_number);
QDBusConnection::sessionBus().interface()->registerService(
appname, QDBusConnectionInterface::DontQueueService);
return a.exec();
}
#include "main.moc"
Reference in a new issue View git blame Copy permalink