Don't crash if the cursor theme fails to create

Summary:
If the cursor theme failed to create KWin crashed due to an endless
recursion. There are two reasons for this fault:
1) When the physical size does not exist we perform a division by 0
which results in an invalid size going into wl_cursor_theme_load
2) We emit the signal that the cursor theme changed even if it didn't
change thus creating an endless recursion

This change addresses both problems: it checks that the size is not 0
and changes the handling for theme update to only destroy the previous
theme if the new theme could be created and only emits the signal if
things change.

BUG: 390314
FIXED-IN: 5.12.3

Test Plan: Added a new test case which crashed with old code

Reviewers: #kwin, #plasma

Subscribers: plasma-devel, kwin

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D10549
This commit is contained in:
Martin Flöser 2018-02-15 18:04:12 +01:00
parent b554e54e87
commit 2ea5153e1c
3 changed files with 142 additions and 9 deletions

View file

@ -55,6 +55,7 @@ integrationTest(WAYLAND_ONLY NAME testVirtualDesktop SRCS virtual_desktop_test.c
integrationTest(WAYLAND_ONLY NAME testShellClientRules SRCS shell_client_rules_test.cpp)
integrationTest(WAYLAND_ONLY NAME testIdleInhibition SRCS idle_inhibition_test.cpp)
integrationTest(WAYLAND_ONLY NAME testColorCorrectNightColor SRCS colorcorrect_nightcolor_test.cpp)
integrationTest(WAYLAND_ONLY NAME testDontCrashCursorPhysicalSizeEmpty SRCS dont_crash_cursor_physical_size_empty.cpp)
if (XCB_ICCCM_FOUND)
integrationTest(NAME testMoveResize SRCS move_resize_window_test.cpp LIBS XCB::ICCCM)

View file

@ -0,0 +1,124 @@
/********************************************************************
KWin - the KDE window manager
This file is part of the KDE project.
Copyright (C) 2018 Martin Flöser <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 "kwin_wayland_test.h"
#include "composite.h"
#include "effectloader.h"
#include "client.h"
#include "cursor.h"
#include "effects.h"
#include "platform.h"
#include "shell_client.h"
#include "screens.h"
#include "wayland_server.h"
#include "workspace.h"
#include <KConfigGroup>
#include <KWayland/Client/seat.h>
#include <KWayland/Client/server_decoration.h>
#include <KWayland/Client/xdgshell.h>
#include <KWayland/Client/surface.h>
#include <KWayland/Server/display.h>
#include <KWayland/Server/output_interface.h>
using namespace KWin;
using namespace KWayland::Client;
static const QString s_socketName = QStringLiteral("wayland_test_kwin_crash_cursor_physical_size_empty-0");
class DontCrashCursorPhysicalSizeEmpty : public QObject
{
Q_OBJECT
private Q_SLOTS:
void init();
void initTestCase();
void cleanup();
void testMoveCursorOverDeco_data();
void testMoveCursorOverDeco();
};
void DontCrashCursorPhysicalSizeEmpty::init()
{
QVERIFY(Test::setupWaylandConnection(Test::AdditionalWaylandInterface::Decoration));
screens()->setCurrent(0);
KWin::Cursor::setPos(QPoint(640, 512));
}
void DontCrashCursorPhysicalSizeEmpty::cleanup()
{
Test::destroyWaylandConnection();
}
void DontCrashCursorPhysicalSizeEmpty::initTestCase()
{
qRegisterMetaType<KWin::ShellClient*>();
qRegisterMetaType<KWin::AbstractClient*>();
QSignalSpy workspaceCreatedSpy(kwinApp(), &Application::workspaceCreated);
QVERIFY(workspaceCreatedSpy.isValid());
kwinApp()->platform()->setInitialWindowSize(QSize(1280, 1024));
QVERIFY(waylandServer()->init(s_socketName.toLocal8Bit()));
if (!QStandardPaths::locateAll(QStandardPaths::GenericDataLocation, QStringLiteral("icons/DMZ-White/index.theme")).isEmpty()) {
qputenv("XCURSOR_THEME", QByteArrayLiteral("DMZ-White"));
} else {
// might be vanilla-dmz (e.g. Arch, FreeBSD)
qputenv("XCURSOR_THEME", QByteArrayLiteral("Vanilla-DMZ"));
}
qputenv("XCURSOR_SIZE", QByteArrayLiteral("0"));
kwinApp()->start();
QVERIFY(workspaceCreatedSpy.wait());
}
void DontCrashCursorPhysicalSizeEmpty::testMoveCursorOverDeco_data()
{
QTest::addColumn<Test::ShellSurfaceType>("type");
QTest::newRow("wlShell") << Test::ShellSurfaceType::WlShell;
QTest::newRow("xdgShellV5") << Test::ShellSurfaceType::XdgShellV5;
QTest::newRow("xdgShellV6") << Test::ShellSurfaceType::XdgShellV6;
}
void DontCrashCursorPhysicalSizeEmpty::testMoveCursorOverDeco()
{
// This test ensures that there is no endless recursion if the cursor theme cannot be created
// a reason for creation failure could be physical size not existing
// see BUG: 390314
QScopedPointer<Surface> surface(Test::createSurface());
QFETCH(Test::ShellSurfaceType, type);
Test::waylandServerSideDecoration()->create(surface.data(), surface.data());
QScopedPointer<QObject> shellSurface(Test::createShellSurface(type, surface.data()));
auto c = Test::renderAndWaitForShown(surface.data(), QSize(100, 50), Qt::blue);
QVERIFY(c);
QVERIFY(c->isDecorated());
// destroy physical size
KWayland::Server::Display *display = waylandServer()->display();
auto output = display->outputs().first();
output->setPhysicalSize(QSize(0, 0));
// and fake a cursor theme change, so that the theme gets recreated
emit KWin::Cursor::self()->themeChanged();
KWin::Cursor::setPos(QPoint(c->geometry().center().x(), c->clientPos().y() / 2));
}
WAYLANDTEST_MAIN(DontCrashCursorPhysicalSizeEmpty)
#include "dont_crash_cursor_physical_size_empty.moc"

View file

@ -50,12 +50,6 @@ void WaylandCursorTheme::loadTheme()
return;
}
Cursor *c = Cursor::self();
if (!m_theme) {
// so far the theme had not been created, this means we need to start tracking theme changes
connect(c, &Cursor::themeChanged, this, &WaylandCursorTheme::loadTheme);
} else {
destroyTheme();
}
int size = c->themeSize();
if (size == 0) {
// resolution depended
@ -63,11 +57,25 @@ void WaylandCursorTheme::loadTheme()
KWayland::Server::Display *display = waylandServer()->display();
auto output = display->outputs().first();
// calculate dots per inch, multiplied with magic constants from Cursor::loadThemeSettings()
if (output->physicalSize().height()) {
size = qreal(output->pixelSize().height()) / (qreal(output->physicalSize().height()) * 0.0393701) * 16.0 / 72.0;
} else {
// use sensible default
size = 24;
}
m_theme = wl_cursor_theme_load(c->themeName().toUtf8().constData(),
}
auto theme = wl_cursor_theme_load(c->themeName().toUtf8().constData(),
size, m_shm->shm());
if (theme) {
if (!m_theme) {
// so far the theme had not been created, this means we need to start tracking theme changes
connect(c, &Cursor::themeChanged, this, &WaylandCursorTheme::loadTheme);
} else {
destroyTheme();
}
m_theme = theme;
emit themeChanged();
}
}
void WaylandCursorTheme::destroyTheme()