diff options
| author | Rainer Keller <Rainer.Keller@qt.io> | 2019-10-10 13:32:31 +0200 |
|---|---|---|
| committer | Shawn Rutledge <shawn.rutledge@qt.io> | 2020-05-26 14:27:20 +0000 |
| commit | 3315a400fcfe355f5056f65aade20454cbdd4928 (patch) | |
| tree | 5ac3e42b90fbb751263bd937b1afc966380802c3 /src | |
| parent | 232bd0a05f517c55cfe15d509697b15b90dcfe6e (diff) | |
Protect global variable g_pointIdMap with mutexes
The evdev touch handler is thread based and calls
QWindowSystemInterface::handleTouchEvent. The global variable
in qwindowsysteminterface.cpp is used without being protected by mutexes
which causes data loss and crashes when multiple touch screens are used.
Fixes: QTBUG-63584
Change-Id: I8b5bb04cc517fab96ac428b2bd2bc128b2ca1a54
Reviewed-by: Johan Helsing <johan.helsing@qt.io>
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
(cherry picked from commit 23d73208524d3ab2166121d08594da88e6b4460b)
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>
Diffstat (limited to 'src')
| -rw-r--r-- | src/gui/kernel/qwindowsysteminterface.cpp | 6 | ||||
| -rw-r--r-- | src/gui/kernel/qwindowsysteminterface_p.h | 1 |
2 files changed, 7 insertions, 0 deletions
diff --git a/src/gui/kernel/qwindowsysteminterface.cpp b/src/gui/kernel/qwindowsysteminterface.cpp index b0f2869128..8e50e5ef9e 100644 --- a/src/gui/kernel/qwindowsysteminterface.cpp +++ b/src/gui/kernel/qwindowsysteminterface.cpp @@ -619,6 +619,7 @@ bool QWindowSystemInterface::isTouchDeviceRegistered(const QTouchDevice *device) static int g_nextPointId = 1; // map from device-independent point id (arbitrary) to "Qt point" ids +QMutex QWindowSystemInterfacePrivate::pointIdMapMutex; typedef QMap<quint64, int> PointIdMap; Q_GLOBAL_STATIC(PointIdMap, g_pointIdMap) @@ -636,6 +637,8 @@ Q_GLOBAL_STATIC(PointIdMap, g_pointIdMap) */ static int acquireCombinedPointId(quint8 deviceId, int pointId) { + QMutexLocker locker(&QWindowSystemInterfacePrivate::pointIdMapMutex); + quint64 combinedId64 = (quint64(deviceId) << 32) + pointId; auto it = g_pointIdMap->constFind(combinedId64); int uid; @@ -695,6 +698,8 @@ QList<QTouchEvent::TouchPoint> } if (states == Qt::TouchPointReleased) { + QMutexLocker locker(&QWindowSystemInterfacePrivate::pointIdMapMutex); + // All points on deviceId have been released. // Remove all points associated with that device from g_pointIdMap. // (On other devices, some touchpoints might still be pressed. @@ -714,6 +719,7 @@ QList<QTouchEvent::TouchPoint> void QWindowSystemInterfacePrivate::clearPointIdMap() { + QMutexLocker locker(&QWindowSystemInterfacePrivate::pointIdMapMutex); g_pointIdMap->clear(); g_nextPointId = 1; } diff --git a/src/gui/kernel/qwindowsysteminterface_p.h b/src/gui/kernel/qwindowsysteminterface_p.h index cea02fb8b7..7b065a4a16 100644 --- a/src/gui/kernel/qwindowsysteminterface_p.h +++ b/src/gui/kernel/qwindowsysteminterface_p.h @@ -529,6 +529,7 @@ public: static QWaitCondition eventsFlushed; static QMutex flushEventMutex; + static QMutex pointIdMapMutex; static QAtomicInt eventAccepted; static QList<QTouchEvent::TouchPoint> |