unity8 crashed with SIGSEGV in QTouchEvent::TouchPoint::pos()

[Paweł Stołowski]

Running latest latest image (phablet-flash ubuntu-system --channel devel-proposed --no-backup) as of 2013-10-10, upgraded with ppa:ubuntu-unity/daily-build. I got unity8 crash with the following bt:

#0 0x405d0ff4 in QTouchEvent::TouchPoint::pos() const ()
   from /usr/lib/arm-linux-gnueabihf/libQt5Gui.so.5
#1 0x45c5de6a in DirectionalDragArea::touchEvent_undecided(QTouchEvent*) ()
   from /usr/lib/arm-linux-gnueabihf/unity8/qml/Ubuntu/Gestures/libUbuntuGestureQml.so
#2 0x4041be6e in QQuickWindowPrivate::deliverMatchingPointsToItem(QQuickItem*, QTouchEvent*, QSet<int>*, QSet<int> const&, QList<QTouchEvent::TouchPoint> const&) () from /usr/lib/arm-linux-gnueabihf/libQt5Quick.so.5
#3 0x4041c3f4 in QQuickWindowPrivate::deliverTouchPoints(QQuickItem*, QTouchEvent*, QList<QTouchEvent::TouchPoint> const&, QSet<int>*, QHash<QQuickItem*, QList<QTouchEvent::TouchPoint> >*) ()
   from /usr/lib/arm-linux-gnueabihf/libQt5Quick.so.5
#4 0x4041c318 in QQuickWindowPrivate::deliverTouchPoints(QQuickItem*, QTouchEvent*, QList<QTouchEvent::TouchPoint> const&, QSet<int>*, QHash<QQuickItem*, QList<QTouchEvent::TouchPoint> >*) ()
   from /usr/lib/arm-linux-gnueabihf/libQt5Quick.so.5
#5 0x4041c318 in QQuickWindowPrivate::deliverTouchPoints(QQuickItem*, QTouchEvent*, QList<QTouchEvent::TouchPoint> const&, QSet<int>*, QHash<QQuickItem*, QList<QTouchEvent::TouchPoint> >*) ()
   from /usr/lib/arm-linux-gnueabihf/libQt5Quick.so.5
#6 0x4041c318 in QQuickWindowPrivate::deliverTouchPoints(QQuickItem*, QTouchEvent*, QList<QTouchEvent::TouchPoint> const&, QSet<int>*, QHash<QQuickItem*, QList<QTouchEvent::TouchPoint> >*) ()
   from /usr/lib/arm-linux-gnueabihf/libQt5Quick.so.5
#7 0x4041c318 in QQuickWindowPrivate::deliverTouchPoints(QQuickItem*, QTouchEvent*, QList<QTouchEvent::TouchPoint> const&, QSet<int>*, QHash<QQuickItem*, QList<QTouchEvent::TouchPoint> >*) ()
   from /usr/lib/arm-linux-gnueabihf/libQt5Quick.so.5
#8 0x4041c6f6 in QQuickWindowPrivate::deliverTouchEvent(QTouchEvent*) ()
   from /usr/lib/arm-linux-gnueabihf/libQt5Quick.so.5
#9 0x408f0b62 in QCoreApplication::notify(QObject*, QEvent*) ()
   from /usr/lib/arm-linux-gnueabihf/libQt5Core.so.5
#10 0x408f0946 in QCoreApplication::notifyInternal(QObject*, QEvent*) ()
   from /usr/lib/arm-linux-gnueabihf/libQt5Core.so.5
#11 0x405c89b4 in QGuiApplicationPrivate::processTouchEvent(QWindowSystemInterfacePrivate::TouchEvent*) () from /usr/lib/arm-linux-gnueabihf/libQt5Gui.so.5
#12 0x01b2be20 in ?? ()
Cannot access memory at address 0x0
#13 0x01b2be20 in ?? ()
Cannot access memory at address 0x0

ProblemType: Crash
DistroRelease: Ubuntu 13.10
Package: unity8 7.82+13.10.20131010-0ubuntu1
Uname: Linux 3.0.0-3-maguro armv7l
ApportVersion: 2.12.5-0ubuntu1
Architecture: armhf
Date: Thu Oct 10 11:01:42 2013
ExecutablePath: /usr/bin/unity8
InstallationDate: Installed on 2013-10-10 (0 days ago)
InstallationMedia: Ubuntu Saucy Salamander (development branch) - armhf (20131010.1)
MarkForUpload: True
ProcCmdline: unity8
Signal: 11
SourcePackage: unity8
StacktraceTop:
 QTouchEvent::TouchPoint::pos() const () from /usr/lib/arm-linux-gnueabihf/libQt5Gui.so.5
 DirectionalDragArea::touchEvent_undecided(QTouchEvent*) () from /usr/lib/arm-linux-gnueabihf/unity8/qml/Ubuntu/Gestures/libUbuntuGestureQml.so
 QQuickWindowPrivate::deliverMatchingPointsToItem(QQuickItem*, QTouchEvent*, QSet<int>*, QSet<int> const&, QList<QTouchEvent::TouchPoint> const&) () from /usr/lib/arm-linux-gnueabihf/libQt5Quick.so.5
 QQuickWindowPrivate::deliverTouchPoints(QQuickItem*, QTouchEvent*, QList<QTouchEvent::TouchPoint> const&, QSet<int>*, QHash<QQuickItem*, QList<QTouchEvent::TouchPoint> >*) () from /usr/lib/arm-linux-gnueabihf/libQt5Quick.so.5
 QQuickWindowPrivate::deliverTouchPoints(QQuickItem*, QTouchEvent*, QList<QTouchEvent::TouchPoint> const&, QSet<int>*, QHash<QQuickItem*, QList<QTouchEvent::TouchPoint> >*) () from /usr/lib/arm-linux-gnueabihf/libQt5Quick.so.5
Title: unity8 crashed with SIGSEGV in QTouchEvent::TouchPoint::pos()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm autopilot cdrom dialout dip nopasswdlogin plugdev sudo tty video

[Apport retracing service (apport)]

StacktraceTop:
 QTouchEvent::TouchPoint::pos() const () at kernel/qevent.cpp:3744
 DirectionalDragArea::touchEvent_undecided(QTouchEvent*) () at /build/buildd/unity8-7.82+13.10.20131010/plugins/Ubuntu/Gestures/DirectionalDragArea.cpp:236
 QQuickWindowPrivate::deliverMatchingPointsToItem(QQuickItem*, QTouchEvent*, QSet<int>*, QSet<int> const&, QList<QTouchEvent::TouchPoint> const&) () at items/qquickwindow.cpp:1660
 QQuickWindowPrivate::deliverTouchPoints(QQuickItem*, QTouchEvent*, QList<QTouchEvent::TouchPoint> const&, QSet<int>*, QHash<QQuickItem*, QList<QTouchEvent::TouchPoint> >*) () at items/qquickwindow.cpp:1627
 QQuickWindowPrivate::deliverTouchPoints(QQuickItem*, QTouchEvent*, QList<QTouchEvent::TouchPoint> const&, QSet<int>*, QHash<QQuickItem*, QList<QTouchEvent::TouchPoint> >*) () at items/qquickwindow.cpp:1582

[Michał Sawicz (saviq)]

Any idea about steps to reproduce? I think mzanetti was looking at this and couldn't find either real steps or an explanation from the trace...

Michael, can you confirm this was what you were looking at? Is there a bug for it?

[Paweł Stołowski (stolowski)]

No idea how to reproduce.... I don't think I was doing anything special, probably just swiping through dash...

[Michal Hruby (mhr3)]

Happened to me yesterday with image #97 as well, I also didn't do anything special, just swiping back and forth everywhere...