diff options
| author | Rainer Keller <Rainer.Keller@qt.io> | 2019-10-10 13:32:31 +0200 |
|---|---|---|
| committer | Rainer Keller <Rainer.Keller@qt.io> | 2019-10-11 12:51:23 +0200 |
| commit | 23d73208524d3ab2166121d08594da88e6b4460b (patch) | |
| tree | 6d76b3120b03d8455c865134c9082132e64a2b4e /src | |
| parent | c54083ff933830a28f43551b9c3b132bfb11492d (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>
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 03be72ca30..5f61853a6d 100644 --- a/src/gui/kernel/qwindowsysteminterface.cpp +++ b/src/gui/kernel/qwindowsysteminterface.cpp @@ -617,6 +617,7 @@ 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) @@ -634,6 +635,8 @@ 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; @@ -693,6 +696,8 @@ 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. @@ -712,6 +717,7 @@ 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 540170f733..55fd181ef0 100644 --- a/src/gui/kernel/qwindowsysteminterface_p.h +++ b/src/gui/kernel/qwindowsysteminterface_p.h @@ -528,6 +528,7 @@ public: static QWaitCondition eventsFlushed; static QMutex flushEventMutex; + static QMutex pointIdMapMutex; static QAtomicInt eventAccepted; static QList<QTouchEvent::TouchPoint> |