kwin/main_wayland.cpp

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/********************************************************************
KWin - the KDE window manager
This file is part of the KDE project.
Copyright (C) 2014 Martin Gräßlin <mgraesslin@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_wayland.h"
#include "composite.h"
#include "virtualkeyboard.h"
#include "workspace.h"
#include <config-kwin.h>
// kwin
#include "platform.h"
#include "effects.h"
#include "tabletmodemanager.h"
#include "wayland_server.h"
#include "xwl/xwayland.h"
// KWayland
#include <KWayland/Server/display.h>
#include <KWayland/Server/seat_interface.h>
// KDE
#include <KLocalizedString>
#include <KPluginLoader>
#include <KPluginMetaData>
#include <KCrash>
#include <KQuickAddons/QtQuickSettings>
// Qt
#include <qplatformdefs.h>
#include <QCommandLineParser>
#include <QFileInfo>
#include <QProcess>
#include <QStyle>
#include <QDebug>
#include <QWindow>
// system
#if HAVE_SYS_PRCTL_H
#include <sys/prctl.h>
#endif
#if HAVE_SYS_PROCCTL_H
#include <sys/procctl.h>
#endif
Use real-time scheduling policy for kwin_wayland Summary: The base idea behind this change is to keep the system responsive no matter what other processes do. All input and rendering needs to go through the windowing system, so keeping it responsive is important. Currently KWin competes with all other processes for resources and this can render the system unusable. Consider some processes running amok. In this case the user might not be able to easily close the applications as KWin does not get the cpu time to perform the input tasks requested by the user. Or in the case of playing a demanding game it is important that KWin gets scheduled to forward the pointer input events. The user doesn't want that the game (or another process) wins against the windowing sytem. The disadvantage is that KWin always wins against other processes with real time scheduling. This could result in KWin running amok stalling the system. On the other hand this is no change to the current situation as if KWin runs amok the sytem is unusable. The change uses libcap to set CAP_SYS_NICE on kwin_wayland executable. KWin_wayland on start sets the scheduling policy to SCHED_RR with the lowest possible priority. Thus any other SCHED_RR process will win against KWin. So real time processes are not affected by this change! After adjusting the scheduling (which requires CAP_SYS_NICE) KWin drops this capability again. Test Plan: Verified that KWin adjusts the scheduler, that it is not passed to child processes, that the capability gets dropped and not passed to child processes. Reviewers: #kwin, #plasma Subscribers: plasma-devel, kwin Tags: #kwin Differential Revision: https://phabricator.kde.org/D7757
2017-09-10 10:05:29 +00:00
#if HAVE_LIBCAP
#include <sys/capability.h>
#endif
#include <sched.h>
#include <iostream>
#include <iomanip>
namespace KWin
{
static void sighandler(int)
{
QApplication::exit();
}
void disableDrKonqi()
{
KCrash::setDrKonqiEnabled(false);
}
// run immediately, before Q_CORE_STARTUP functions
// that would enable drkonqi
Q_CONSTRUCTOR_FUNCTION(disableDrKonqi)
enum class RealTimeFlags
{
DontReset,
ResetOnFork
};
namespace {
void gainRealTime(RealTimeFlags flags = RealTimeFlags::DontReset)
{
#if HAVE_SCHED_RESET_ON_FORK
const int minPriority = sched_get_priority_min(SCHED_RR);
struct sched_param sp;
sp.sched_priority = minPriority;
int policy = SCHED_RR;
if (flags == RealTimeFlags::ResetOnFork) {
policy |= SCHED_RESET_ON_FORK;
}
sched_setscheduler(0, policy, &sp);
#else
Q_UNUSED(flags);
#endif
}
}
//************************************
// ApplicationWayland
//************************************
ApplicationWayland::ApplicationWayland(int &argc, char **argv)
: ApplicationWaylandAbstract(OperationModeWaylandOnly, argc, argv)
{
}
ApplicationWayland::~ApplicationWayland()
{
setTerminating();
if (!waylandServer()) {
return;
}
if (auto *platform = kwinApp()->platform()) {
platform->prepareShutdown();
}
// need to unload all effects prior to destroying X connection as they might do X calls
if (effects) {
static_cast<EffectsHandlerImpl*>(effects)->unloadAllEffects();
}
if (m_xwayland) {
// needs to be done before workspace gets destroyed
m_xwayland->prepareDestroy();
}
wayland: Terminate client connections before Workspace is destroyed Summary: When ShellClient tears down, it needs to access RuleBook in order to discard temporary rules. The problem is that WaylandServer outlives Workspace and therefore so does ShellClient. We can't guard against the case when RuleBook::self() is nullptr as it is vital to discard temporary rules. This change adjusts termination sequence so all shell clients are destroyed before Workspace(and thus RuleBook) is gone. ASAN output: ==19922==ERROR: AddressSanitizer: heap-use-after-free on address 0x606000142060 at pc 0x7fbc0fb878bb bp 0x7ffd7d464520 sp 0x7ffd7d464518 READ of size 8 at 0x606000142060 thread T0 #0 0x7fbc0fb878ba in QList<KWin::Rules*>::detach() /usr/include/qt5/QtCore/qlist.h:172 #1 0x7fbc0fb8538d in QList<KWin::Rules*>::begin() /usr/include/qt5/QtCore/qlist.h:324 #2 0x7fbc0fb808b6 in KWin::RuleBook::discardUsed(KWin::AbstractClient*, bool) /home/jenkins/workspace/Plasma/kwin/kf5-qt5 SUSEQt5.12/rules.cpp:1144 #3 0x7fbc0fe36e32 in KWin::ShellClient::destroyClient() /home/jenkins/workspace/Plasma/kwin/kf5-qt5 SUSEQt5.12/shell_client.cpp:435 #4 0x7fbc0fe7a726 in QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, void (KWin::ShellClient::*)()>::call(void (KWin::ShellClient::*)(), KWin::ShellClient*, void**) /usr/include/qt5/QtCore/qobjectdefs_impl.h:152 #5 0x7fbc0fe784c3 in void QtPrivate::FunctionPointer<void (KWin::ShellClient::*)()>::call<QtPrivate::List<>, void>(void (KWin::ShellClient::*)(), KWin::ShellClient*, void**) /usr/include/qt5/QtCore/qobjectdefs_impl.h:185 #6 0x7fbc0fe74de9 in QtPrivate::QSlotObject<void (KWin::ShellClient::*)(), QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*) (/home/jenkins/install-prefix/lib64/libkwin.so.5+0x1677de9) #7 0x7fbc04f27357 in QMetaObject::activate(QObject*, int, int, void**) (/usr/lib64/libQt5Core.so.5+0x2b3357) #8 0x7fbc074e1970 in KWayland::Server::Resource::unbound() /home/jenkins/workspace/Administration/Dependency Build Plasma kf5-qt5 SUSEQt5.12/kwayland/build/src/server/KF5WaylandServer_autogen/EWIEGA46WW/moc_resource.cpp:142 #9 0x7fbc0766b4b4 in KWayland::Server::Resource::Private::unbind(wl_resource*) /home/jenkins/workspace/Administration/Dependency Build Plasma kf5-qt5 SUSEQt5.12/kwayland/src/server/resource.cpp:68 #10 0x7fbc00bdc2ae (/usr/lib64/libwayland-server.so.0+0x92ae) #11 0x7fbc00bdc32f in wl_resource_destroy (/usr/lib64/libwayland-server.so.0+0x932f) #12 0x7fbc0766b53f in KWayland::Server::Resource::Private::resourceDestroyedCallback(wl_client*, wl_resource*) /home/jenkins/workspace/Administration/Dependency Build Plasma kf5-qt5 SUSEQt5.12/kwayland/src/server/resource.cpp:76 #13 0x7fbbff481d8c (/usr/lib64/libffi.so.7+0x6d8c) #14 0x7fbbff481179 (/usr/lib64/libffi.so.7+0x6179) #15 0x7fbc00bdfa5f (/usr/lib64/libwayland-server.so.0+0xca5f) #16 0x7fbc00bdc6d1 (/usr/lib64/libwayland-server.so.0+0x96d1) #17 0x7fbc00bddc71 in wl_event_loop_dispatch (/usr/lib64/libwayland-server.so.0+0xac71) #18 0x7fbc07541e50 in KWayland::Server::Display::Private::dispatch() /home/jenkins/workspace/Administration/Dependency Build Plasma kf5-qt5 SUSEQt5.12/kwayland/src/server/display.cpp:148 #19 0x7fbc075432de in KWayland::Server::Display::dispatchEvents(int) /home/jenkins/workspace/Administration/Dependency Build Plasma kf5-qt5 SUSEQt5.12/kwayland/src/server/display.cpp:220 #20 0x7fbc0fe864ca in KWin::WaylandServer::dispatch() /home/jenkins/workspace/Plasma/kwin/kf5-qt5 SUSEQt5.12/wayland_server.cpp:616 #21 0x451ce0 in KWin::WaylandTestApplication::~WaylandTestApplication() /home/jenkins/workspace/Plasma/kwin/kf5-qt5 SUSEQt5.12/autotests/integration/kwin_wayland_test.cpp:91 #22 0x42faa1 in main /home/jenkins/workspace/Plasma/kwin/kf5-qt5 SUSEQt5.12/autotests/integration/globalshortcuts_test.cpp:381 #23 0x7fbc04796bca in __libc_start_main (/lib64/libc.so.6+0x26bca) #24 0x413ea9 in _start (/home/jenkins/workspace/Plasma/kwin/kf5-qt5 SUSEQt5.12/build/bin/testGlobalShortcuts+0x413ea9) Reviewers: #kwin, davidedmundson Reviewed By: #kwin, davidedmundson Subscribers: kwin Tags: #kwin Differential Revision: https://phabricator.kde.org/D22821
2019-07-30 08:40:18 +00:00
destroyWorkspace();
waylandServer()->dispatch();
wayland: Terminate client connections before Workspace is destroyed Summary: When ShellClient tears down, it needs to access RuleBook in order to discard temporary rules. The problem is that WaylandServer outlives Workspace and therefore so does ShellClient. We can't guard against the case when RuleBook::self() is nullptr as it is vital to discard temporary rules. This change adjusts termination sequence so all shell clients are destroyed before Workspace(and thus RuleBook) is gone. ASAN output: ==19922==ERROR: AddressSanitizer: heap-use-after-free on address 0x606000142060 at pc 0x7fbc0fb878bb bp 0x7ffd7d464520 sp 0x7ffd7d464518 READ of size 8 at 0x606000142060 thread T0 #0 0x7fbc0fb878ba in QList<KWin::Rules*>::detach() /usr/include/qt5/QtCore/qlist.h:172 #1 0x7fbc0fb8538d in QList<KWin::Rules*>::begin() /usr/include/qt5/QtCore/qlist.h:324 #2 0x7fbc0fb808b6 in KWin::RuleBook::discardUsed(KWin::AbstractClient*, bool) /home/jenkins/workspace/Plasma/kwin/kf5-qt5 SUSEQt5.12/rules.cpp:1144 #3 0x7fbc0fe36e32 in KWin::ShellClient::destroyClient() /home/jenkins/workspace/Plasma/kwin/kf5-qt5 SUSEQt5.12/shell_client.cpp:435 #4 0x7fbc0fe7a726 in QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, void (KWin::ShellClient::*)()>::call(void (KWin::ShellClient::*)(), KWin::ShellClient*, void**) /usr/include/qt5/QtCore/qobjectdefs_impl.h:152 #5 0x7fbc0fe784c3 in void QtPrivate::FunctionPointer<void (KWin::ShellClient::*)()>::call<QtPrivate::List<>, void>(void (KWin::ShellClient::*)(), KWin::ShellClient*, void**) /usr/include/qt5/QtCore/qobjectdefs_impl.h:185 #6 0x7fbc0fe74de9 in QtPrivate::QSlotObject<void (KWin::ShellClient::*)(), QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*) (/home/jenkins/install-prefix/lib64/libkwin.so.5+0x1677de9) #7 0x7fbc04f27357 in QMetaObject::activate(QObject*, int, int, void**) (/usr/lib64/libQt5Core.so.5+0x2b3357) #8 0x7fbc074e1970 in KWayland::Server::Resource::unbound() /home/jenkins/workspace/Administration/Dependency Build Plasma kf5-qt5 SUSEQt5.12/kwayland/build/src/server/KF5WaylandServer_autogen/EWIEGA46WW/moc_resource.cpp:142 #9 0x7fbc0766b4b4 in KWayland::Server::Resource::Private::unbind(wl_resource*) /home/jenkins/workspace/Administration/Dependency Build Plasma kf5-qt5 SUSEQt5.12/kwayland/src/server/resource.cpp:68 #10 0x7fbc00bdc2ae (/usr/lib64/libwayland-server.so.0+0x92ae) #11 0x7fbc00bdc32f in wl_resource_destroy (/usr/lib64/libwayland-server.so.0+0x932f) #12 0x7fbc0766b53f in KWayland::Server::Resource::Private::resourceDestroyedCallback(wl_client*, wl_resource*) /home/jenkins/workspace/Administration/Dependency Build Plasma kf5-qt5 SUSEQt5.12/kwayland/src/server/resource.cpp:76 #13 0x7fbbff481d8c (/usr/lib64/libffi.so.7+0x6d8c) #14 0x7fbbff481179 (/usr/lib64/libffi.so.7+0x6179) #15 0x7fbc00bdfa5f (/usr/lib64/libwayland-server.so.0+0xca5f) #16 0x7fbc00bdc6d1 (/usr/lib64/libwayland-server.so.0+0x96d1) #17 0x7fbc00bddc71 in wl_event_loop_dispatch (/usr/lib64/libwayland-server.so.0+0xac71) #18 0x7fbc07541e50 in KWayland::Server::Display::Private::dispatch() /home/jenkins/workspace/Administration/Dependency Build Plasma kf5-qt5 SUSEQt5.12/kwayland/src/server/display.cpp:148 #19 0x7fbc075432de in KWayland::Server::Display::dispatchEvents(int) /home/jenkins/workspace/Administration/Dependency Build Plasma kf5-qt5 SUSEQt5.12/kwayland/src/server/display.cpp:220 #20 0x7fbc0fe864ca in KWin::WaylandServer::dispatch() /home/jenkins/workspace/Plasma/kwin/kf5-qt5 SUSEQt5.12/wayland_server.cpp:616 #21 0x451ce0 in KWin::WaylandTestApplication::~WaylandTestApplication() /home/jenkins/workspace/Plasma/kwin/kf5-qt5 SUSEQt5.12/autotests/integration/kwin_wayland_test.cpp:91 #22 0x42faa1 in main /home/jenkins/workspace/Plasma/kwin/kf5-qt5 SUSEQt5.12/autotests/integration/globalshortcuts_test.cpp:381 #23 0x7fbc04796bca in __libc_start_main (/lib64/libc.so.6+0x26bca) #24 0x413ea9 in _start (/home/jenkins/workspace/Plasma/kwin/kf5-qt5 SUSEQt5.12/build/bin/testGlobalShortcuts+0x413ea9) Reviewers: #kwin, davidedmundson Reviewed By: #kwin, davidedmundson Subscribers: kwin Tags: #kwin Differential Revision: https://phabricator.kde.org/D22821
2019-07-30 08:40:18 +00:00
if (QStyle *s = style()) {
s->unpolish(this);
}
// kill Xwayland before terminating its connection
delete m_xwayland;
m_xwayland = nullptr;
waylandServer()->terminateClientConnections();
destroyCompositor();
}
void ApplicationWayland::performStartup()
{
if (m_startXWayland) {
setOperationMode(OperationModeXwayland);
}
// first load options - done internally by a different thread
createOptions();
waylandServer()->createInternalConnection();
// try creating the Wayland Backend
createInput();
// now libinput thread has been created, adjust scheduler to not leak into other processes
gainRealTime(RealTimeFlags::ResetOnFork);
VirtualKeyboard::create(this);
createBackend();
TabletModeManager::create(this);
}
void ApplicationWayland::createBackend()
{
2016-04-07 07:18:10 +00:00
connect(platform(), &Platform::screensQueried, this, &ApplicationWayland::continueStartupWithScreens);
connect(platform(), &Platform::initFailed, this,
[] () {
std::cerr << "FATAL ERROR: backend failed to initialize, exiting now" << std::endl;
QCoreApplication::exit(1);
}
);
2016-04-07 07:18:10 +00:00
platform()->init();
}
void ApplicationWayland::continueStartupWithScreens()
{
2016-04-07 07:18:10 +00:00
disconnect(kwinApp()->platform(), &Platform::screensQueried, this, &ApplicationWayland::continueStartupWithScreens);
createScreens();
WaylandCompositor::create();
connect(Compositor::self(), &Compositor::sceneCreated, this, &ApplicationWayland::continueStartupWithScene);
}
void ApplicationWayland::finalizeStartup()
{
if (m_xwayland) {
disconnect(m_xwayland, &Xwl::Xwayland::initialized, this, &ApplicationWayland::finalizeStartup);
}
startSession();
createWorkspace();
}
void ApplicationWayland::continueStartupWithScene()
{
disconnect(Compositor::self(), &Compositor::sceneCreated, this, &ApplicationWayland::continueStartupWithScene);
if (operationMode() == OperationModeWaylandOnly) {
finalizeStartup();
return;
}
m_xwayland = new Xwl::Xwayland(this);
connect(m_xwayland, &Xwl::Xwayland::criticalError, this, [](int code) {
// we currently exit on Xwayland errors always directly
// TODO: restart Xwayland
std::cerr << "Xwayland had a critical error. Going to exit now." << std::endl;
exit(code);
});
connect(m_xwayland, &Xwl::Xwayland::initialized, this, &ApplicationWayland::finalizeStartup);
m_xwayland->init();
}
void ApplicationWayland::startSession()
{
if (!m_inputMethodServerToStart.isEmpty()) {
int socket = dup(waylandServer()->createInputMethodConnection());
if (socket >= 0) {
QProcessEnvironment environment = processStartupEnvironment();
environment.insert(QStringLiteral("WAYLAND_SOCKET"), QByteArray::number(socket));
environment.insert(QStringLiteral("QT_QPA_PLATFORM"), QStringLiteral("wayland"));
environment.remove("DISPLAY");
environment.remove("WAYLAND_DISPLAY");
QProcess *p = new Process(this);
p->setProcessChannelMode(QProcess::ForwardedErrorChannel);
auto finishedSignal = static_cast<void (QProcess::*)(int, QProcess::ExitStatus)>(&QProcess::finished);
connect(p, finishedSignal, this,
[this, p] {
if (waylandServer()) {
waylandServer()->destroyInputMethodConnection();
}
p->deleteLater();
}
);
p->setProcessEnvironment(environment);
p->start(m_inputMethodServerToStart);
p->waitForStarted();
}
}
// start session
if (!m_sessionArgument.isEmpty()) {
QProcess *p = new Process(this);
p->setProcessChannelMode(QProcess::ForwardedErrorChannel);
p->setProcessEnvironment(processStartupEnvironment());
auto finishedSignal = static_cast<void (QProcess::*)(int, QProcess::ExitStatus)>(&QProcess::finished);
connect(p, finishedSignal, this, [](int code, QProcess::ExitStatus status) {
if (status == QProcess::CrashExit) {
qWarning() << "Session process has crashed";
QCoreApplication::exit(-1);
return;
}
if (code) {
qWarning() << "Session process exited with code" << code;
}
QCoreApplication::exit(code);
});
p->start(m_sessionArgument);
}
// start the applications passed to us as command line arguments
if (!m_applicationsToStart.isEmpty()) {
for (const QString &application: m_applicationsToStart) {
// note: this will kill the started process when we exit
// this is going to happen anyway as we are the wayland and X server the app connects to
QProcess *p = new Process(this);
p->setProcessChannelMode(QProcess::ForwardedErrorChannel);
p->setProcessEnvironment(processStartupEnvironment());
p->start(application);
}
}
}
static const QString s_waylandPlugin = QStringLiteral("KWinWaylandWaylandBackend");
static const QString s_x11Plugin = QStringLiteral("KWinWaylandX11Backend");
static const QString s_fbdevPlugin = QStringLiteral("KWinWaylandFbdevBackend");
#if HAVE_DRM
static const QString s_drmPlugin = QStringLiteral("KWinWaylandDrmBackend");
#endif
#if HAVE_LIBHYBRIS
static const QString s_hwcomposerPlugin = QStringLiteral("KWinWaylandHwcomposerBackend");
#endif
static const QString s_virtualPlugin = QStringLiteral("KWinWaylandVirtualBackend");
static QString automaticBackendSelection()
{
if (qEnvironmentVariableIsSet("WAYLAND_DISPLAY")) {
return s_waylandPlugin;
}
if (qEnvironmentVariableIsSet("DISPLAY")) {
return s_x11Plugin;
}
#if HAVE_LIBHYBRIS
if (qEnvironmentVariableIsSet("ANDROID_ROOT")) {
return s_hwcomposerPlugin;
}
#endif
#if HAVE_DRM
return s_drmPlugin;
#endif
return s_fbdevPlugin;
}
static void disablePtrace()
{
#if HAVE_PR_SET_DUMPABLE
// check whether we are running under a debugger
const QFileInfo parent(QStringLiteral("/proc/%1/exe").arg(getppid()));
if (parent.isSymLink() &&
(parent.symLinkTarget().endsWith(QLatin1String("/gdb")) ||
parent.symLinkTarget().endsWith(QLatin1String("/gdbserver")) ||
parent.symLinkTarget().endsWith(QLatin1String("/lldb-server")))) {
// debugger, don't adjust
return;
}
// disable ptrace in kwin_wayland
prctl(PR_SET_DUMPABLE, 0);
#endif
#if HAVE_PROC_TRACE_CTL
// FreeBSD's rudimentary procfs does not support /proc/<pid>/exe
// We could use the P_TRACED flag of the process to find out
// if the process is being debugged ond FreeBSD.
int mode = PROC_TRACE_CTL_DISABLE;
procctl(P_PID, getpid(), PROC_TRACE_CTL, &mode);
#endif
}
static void unsetDumpable(int sig)
{
#if HAVE_PR_SET_DUMPABLE
prctl(PR_SET_DUMPABLE, 1);
#endif
signal(sig, SIG_IGN);
raise(sig);
return;
}
Use real-time scheduling policy for kwin_wayland Summary: The base idea behind this change is to keep the system responsive no matter what other processes do. All input and rendering needs to go through the windowing system, so keeping it responsive is important. Currently KWin competes with all other processes for resources and this can render the system unusable. Consider some processes running amok. In this case the user might not be able to easily close the applications as KWin does not get the cpu time to perform the input tasks requested by the user. Or in the case of playing a demanding game it is important that KWin gets scheduled to forward the pointer input events. The user doesn't want that the game (or another process) wins against the windowing sytem. The disadvantage is that KWin always wins against other processes with real time scheduling. This could result in KWin running amok stalling the system. On the other hand this is no change to the current situation as if KWin runs amok the sytem is unusable. The change uses libcap to set CAP_SYS_NICE on kwin_wayland executable. KWin_wayland on start sets the scheduling policy to SCHED_RR with the lowest possible priority. Thus any other SCHED_RR process will win against KWin. So real time processes are not affected by this change! After adjusting the scheduling (which requires CAP_SYS_NICE) KWin drops this capability again. Test Plan: Verified that KWin adjusts the scheduler, that it is not passed to child processes, that the capability gets dropped and not passed to child processes. Reviewers: #kwin, #plasma Subscribers: plasma-devel, kwin Tags: #kwin Differential Revision: https://phabricator.kde.org/D7757
2017-09-10 10:05:29 +00:00
void dropNiceCapability()
{
#if HAVE_LIBCAP
cap_t caps = cap_get_proc();
if (!caps) {
return;
}
cap_value_t capList[] = { CAP_SYS_NICE };
if (cap_set_flag(caps, CAP_PERMITTED, 1, capList, CAP_CLEAR) == -1) {
cap_free(caps);
return;
}
if (cap_set_flag(caps, CAP_EFFECTIVE, 1, capList, CAP_CLEAR) == -1) {
cap_free(caps);
return;
}
cap_set_proc(caps);
cap_free(caps);
#endif
}
} // namespace
int main(int argc, char * argv[])
{
if (getuid() == 0) {
std::cerr << "kwin_wayland does not support running as root." << std::endl;
return 1;
}
KWin::disablePtrace();
KWin::Application::setupMalloc();
KWin::Application::setupLocalizedString();
Use real-time scheduling policy for kwin_wayland Summary: The base idea behind this change is to keep the system responsive no matter what other processes do. All input and rendering needs to go through the windowing system, so keeping it responsive is important. Currently KWin competes with all other processes for resources and this can render the system unusable. Consider some processes running amok. In this case the user might not be able to easily close the applications as KWin does not get the cpu time to perform the input tasks requested by the user. Or in the case of playing a demanding game it is important that KWin gets scheduled to forward the pointer input events. The user doesn't want that the game (or another process) wins against the windowing sytem. The disadvantage is that KWin always wins against other processes with real time scheduling. This could result in KWin running amok stalling the system. On the other hand this is no change to the current situation as if KWin runs amok the sytem is unusable. The change uses libcap to set CAP_SYS_NICE on kwin_wayland executable. KWin_wayland on start sets the scheduling policy to SCHED_RR with the lowest possible priority. Thus any other SCHED_RR process will win against KWin. So real time processes are not affected by this change! After adjusting the scheduling (which requires CAP_SYS_NICE) KWin drops this capability again. Test Plan: Verified that KWin adjusts the scheduler, that it is not passed to child processes, that the capability gets dropped and not passed to child processes. Reviewers: #kwin, #plasma Subscribers: plasma-devel, kwin Tags: #kwin Differential Revision: https://phabricator.kde.org/D7757
2017-09-10 10:05:29 +00:00
KWin::gainRealTime();
KWin::dropNiceCapability();
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);
signal(SIGABRT, KWin::unsetDumpable);
signal(SIGSEGV, KWin::unsetDumpable);
signal(SIGPIPE, SIG_IGN);
// ensure that no thread takes SIGUSR
sigset_t userSignals;
sigemptyset(&userSignals);
sigaddset(&userSignals, SIGUSR1);
sigaddset(&userSignals, SIGUSR2);
pthread_sigmask(SIG_BLOCK, &userSignals, nullptr);
QProcessEnvironment environment = QProcessEnvironment::systemEnvironment();
// enforce our internal qpa plugin, unfortunately command line switch has precedence
setenv("QT_QPA_PLATFORM", "wayland-org.kde.kwin.qpa", true);
qunsetenv("QT_DEVICE_PIXEL_RATIO");
qputenv("QT_IM_MODULE", "qtvirtualkeyboard");
qputenv("QSG_RENDER_LOOP", "basic");
QCoreApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
KWin::ApplicationWayland a(argc, argv);
a.setupTranslator();
// reset QT_QPA_PLATFORM to a sane value for any processes started from KWin
setenv("QT_QPA_PLATFORM", "wayland", true);
KWin::Application::createAboutData();
KQuickAddons::QtQuickSettings::init();
const auto availablePlugins = KPluginLoader::findPlugins(QStringLiteral("org.kde.kwin.waylandbackends"));
auto hasPlugin = [&availablePlugins] (const QString &name) {
return std::any_of(availablePlugins.begin(), availablePlugins.end(),
[name] (const KPluginMetaData &plugin) {
return plugin.pluginId() == name;
}
);
};
const bool hasSizeOption = hasPlugin(KWin::s_x11Plugin) || hasPlugin(KWin::s_virtualPlugin);
const bool hasOutputCountOption = hasPlugin(KWin::s_x11Plugin);
const bool hasX11Option = hasPlugin(KWin::s_x11Plugin);
const bool hasVirtualOption = hasPlugin(KWin::s_virtualPlugin);
const bool hasWaylandOption = hasPlugin(KWin::s_waylandPlugin);
const bool hasFramebufferOption = hasPlugin(KWin::s_fbdevPlugin);
#if HAVE_DRM
const bool hasDrmOption = hasPlugin(KWin::s_drmPlugin);
#endif
#if HAVE_LIBHYBRIS
const bool hasHwcomposerOption = hasPlugin(KWin::s_hwcomposerPlugin);
#endif
QCommandLineOption xwaylandOption(QStringLiteral("xwayland"),
i18n("Start a rootless Xwayland server."));
QCommandLineOption waylandSocketOption(QStringList{QStringLiteral("s"), QStringLiteral("socket")},
i18n("Name of the Wayland socket to listen on. If not set \"wayland-0\" is used."),
QStringLiteral("socket"));
QCommandLineOption framebufferOption(QStringLiteral("framebuffer"),
i18n("Render to framebuffer."));
QCommandLineOption framebufferDeviceOption(QStringLiteral("fb-device"),
i18n("The framebuffer device to render to."),
QStringLiteral("fbdev"));
QCommandLineOption x11DisplayOption(QStringLiteral("x11-display"),
i18n("The X11 Display to use in windowed mode on platform X11."),
QStringLiteral("display"));
QCommandLineOption waylandDisplayOption(QStringLiteral("wayland-display"),
i18n("The Wayland Display to use in windowed mode on platform Wayland."),
QStringLiteral("display"));
QCommandLineOption virtualFbOption(QStringLiteral("virtual"), i18n("Render to a virtual framebuffer."));
QCommandLineOption widthOption(QStringLiteral("width"),
i18n("The width for windowed mode. Default width is 1024."),
QStringLiteral("width"));
widthOption.setDefaultValue(QString::number(1024));
QCommandLineOption heightOption(QStringLiteral("height"),
i18n("The height for windowed mode. Default height is 768."),
QStringLiteral("height"));
heightOption.setDefaultValue(QString::number(768));
QCommandLineOption scaleOption(QStringLiteral("scale"),
i18n("The scale for windowed mode. Default value is 1."),
QStringLiteral("scale"));
scaleOption.setDefaultValue(QString::number(1));
QCommandLineOption outputCountOption(QStringLiteral("output-count"),
i18n("The number of windows to open as outputs in windowed mode. Default value is 1"),
QStringLiteral("count"));
outputCountOption.setDefaultValue(QString::number(1));
QCommandLineParser parser;
a.setupCommandLine(&parser);
parser.addOption(xwaylandOption);
parser.addOption(waylandSocketOption);
if (hasX11Option) {
parser.addOption(x11DisplayOption);
}
if (hasWaylandOption) {
parser.addOption(waylandDisplayOption);
}
if (hasFramebufferOption) {
parser.addOption(framebufferOption);
parser.addOption(framebufferDeviceOption);
}
if (hasVirtualOption) {
parser.addOption(virtualFbOption);
}
if (hasSizeOption) {
parser.addOption(widthOption);
parser.addOption(heightOption);
parser.addOption(scaleOption);
}
if (hasOutputCountOption) {
parser.addOption(outputCountOption);
}
#if HAVE_LIBHYBRIS
QCommandLineOption hwcomposerOption(QStringLiteral("hwcomposer"), i18n("Use libhybris hwcomposer"));
if (hasHwcomposerOption) {
parser.addOption(hwcomposerOption);
}
#endif
QCommandLineOption libinputOption(QStringLiteral("libinput"),
i18n("Enable libinput support for input events processing. Note: never use in a nested session."));
parser.addOption(libinputOption);
#if HAVE_DRM
QCommandLineOption drmOption(QStringLiteral("drm"), i18n("Render through drm node."));
if (hasDrmOption) {
parser.addOption(drmOption);
}
#endif
QCommandLineOption inputMethodOption(QStringLiteral("inputmethod"),
i18n("Input method that KWin starts."),
QStringLiteral("path/to/imserver"));
parser.addOption(inputMethodOption);
QCommandLineOption listBackendsOption(QStringLiteral("list-backends"),
i18n("List all available backends and quit."));
parser.addOption(listBackendsOption);
QCommandLineOption screenLockerOption(QStringLiteral("lockscreen"),
i18n("Starts the session in locked mode."));
parser.addOption(screenLockerOption);
QCommandLineOption noScreenLockerOption(QStringLiteral("no-lockscreen"),
i18n("Starts the session without lock screen support."));
parser.addOption(noScreenLockerOption);
QCommandLineOption noGlobalShortcutsOption(QStringLiteral("no-global-shortcuts"),
i18n("Starts the session without global shortcuts support."));
parser.addOption(noGlobalShortcutsOption);
QCommandLineOption exitWithSessionOption(QStringLiteral("exit-with-session"),
i18n("Exit after the session application, which is started by KWin, closed."),
QStringLiteral("/path/to/session"));
parser.addOption(exitWithSessionOption);
parser.addPositionalArgument(QStringLiteral("applications"),
i18n("Applications to start once Wayland and Xwayland server are started"),
QStringLiteral("[/path/to/application...]"));
parser.process(a);
a.processCommandLine(&parser);
#ifdef KWIN_BUILD_ACTIVITIES
a.setUseKActivities(false);
#endif
if (parser.isSet(listBackendsOption)) {
for (const auto &plugin: availablePlugins) {
std::cout << std::setw(40) << std::left << qPrintable(plugin.name()) << qPrintable(plugin.description()) << std::endl;
}
return 0;
}
if (parser.isSet(exitWithSessionOption)) {
a.setSessionArgument(parser.value(exitWithSessionOption));
}
KWin::Application::setUseLibinput(parser.isSet(libinputOption));
QString pluginName;
QSize initialWindowSize;
QByteArray deviceIdentifier;
int outputCount = 1;
qreal outputScale = 1;
#if HAVE_DRM
if (hasDrmOption && parser.isSet(drmOption)) {
pluginName = KWin::s_drmPlugin;
}
#endif
if (hasSizeOption) {
bool ok = false;
const int width = parser.value(widthOption).toInt(&ok);
if (!ok) {
std::cerr << "FATAL ERROR incorrect value for width" << std::endl;
return 1;
}
const int height = parser.value(heightOption).toInt(&ok);
if (!ok) {
std::cerr << "FATAL ERROR incorrect value for height" << std::endl;
return 1;
}
const qreal scale = parser.value(scaleOption).toDouble(&ok);
if (!ok || scale < 1) {
std::cerr << "FATAL ERROR incorrect value for scale" << std::endl;
return 1;
}
outputScale = scale;
initialWindowSize = QSize(width, height);
}
if (hasOutputCountOption) {
bool ok = false;
const int count = parser.value(outputCountOption).toInt(&ok);
if (ok) {
outputCount = qMax(1, count);
}
}
if (hasX11Option && parser.isSet(x11DisplayOption)) {
deviceIdentifier = parser.value(x11DisplayOption).toUtf8();
pluginName = KWin::s_x11Plugin;
} else if (hasWaylandOption && parser.isSet(waylandDisplayOption)) {
deviceIdentifier = parser.value(waylandDisplayOption).toUtf8();
pluginName = KWin::s_waylandPlugin;
}
if (hasFramebufferOption && parser.isSet(framebufferOption)) {
pluginName = KWin::s_fbdevPlugin;
deviceIdentifier = parser.value(framebufferDeviceOption).toUtf8();
}
#if HAVE_LIBHYBRIS
if (hasHwcomposerOption && parser.isSet(hwcomposerOption)) {
pluginName = KWin::s_hwcomposerPlugin;
}
#endif
if (hasVirtualOption && parser.isSet(virtualFbOption)) {
pluginName = KWin::s_virtualPlugin;
}
if (pluginName.isEmpty()) {
std::cerr << "No backend specified through command line argument, trying auto resolution" << std::endl;
pluginName = KWin::automaticBackendSelection();
}
auto pluginIt = std::find_if(availablePlugins.begin(), availablePlugins.end(),
[&pluginName] (const KPluginMetaData &plugin) {
return plugin.pluginId() == pluginName;
}
);
if (pluginIt == availablePlugins.end()) {
std::cerr << "FATAL ERROR: could not find a backend" << std::endl;
return 1;
}
// TODO: create backend without having the server running
KWin::WaylandServer *server = KWin::WaylandServer::create(&a);
KWin::WaylandServer::InitalizationFlags flags;
if (parser.isSet(screenLockerOption)) {
flags = KWin::WaylandServer::InitalizationFlag::LockScreen;
} else if (parser.isSet(noScreenLockerOption)) {
flags = KWin::WaylandServer::InitalizationFlag::NoLockScreenIntegration;
}
if (parser.isSet(noGlobalShortcutsOption)) {
flags |= KWin::WaylandServer::InitalizationFlag::NoGlobalShortcuts;
}
if (!server->init(parser.value(waylandSocketOption).toUtf8(), flags)) {
std::cerr << "FATAL ERROR: could not create Wayland server" << std::endl;
return 1;
}
a.initPlatform(*pluginIt);
if (!a.platform()) {
std::cerr << "FATAL ERROR: could not instantiate a backend" << std::endl;
return 1;
}
if (!deviceIdentifier.isEmpty()) {
a.platform()->setDeviceIdentifier(deviceIdentifier);
}
if (initialWindowSize.isValid()) {
a.platform()->setInitialWindowSize(initialWindowSize);
}
a.platform()->setInitialOutputScale(outputScale);
a.platform()->setInitialOutputCount(outputCount);
QObject::connect(&a, &KWin::Application::workspaceCreated, server, &KWin::WaylandServer::initWorkspace);
environment.insert(QStringLiteral("WAYLAND_DISPLAY"), server->display()->socketName());
a.setProcessStartupEnvironment(environment);
a.setStartXwayland(parser.isSet(xwaylandOption));
a.setApplicationsToStart(parser.positionalArguments());
a.setInputMethodServerToStart(parser.value(inputMethodOption));
a.start();
return a.exec();
}