QT Wayland client crash

[vpanchal]

Hi,

I am using a QT version of 5.9.7 on an embedded linux platform. Occasionally, I have been observing some strange crashes with our QT application, and the issue seems to be related to the QT wayland client.

Sep 27 10:51:45 my-controller gui_app[4302]: The Wayland connection experienced a fatal error (No child processes)

The application crashes after this printout. I've collected a GDB backtrace from the gui_app QT application after the crash - the backtrace is always the same each time it crashes. Here it is below:

(gdb) bt
#0  0xb62fe65c in QQmlData::isSignalConnected(QAbstractDeclarativeData*, QObject const*, int) ()
   from /usr/lib/libQt5Qml.so.5
#1  0xb5d3c0bc in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQt5Core.so.5
#2  0xb5c84dbc in QProcess::finished(int, QProcess::ExitStatus) () from /usr/lib/libQt5Core.so.5
#3  0xb5c8d124 in ?? () from /usr/lib/libQt5Core.so.5
#4  0xb5c8d270 in ?? () from /usr/lib/libQt5Core.so.5
#5  0xb5d3c5b8 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/libQt5Core.so.5
#6  0xb5d48e7c in QSocketNotifier::activated(int, QSocketNotifier::QPrivateSignal) ()
   from /usr/lib/libQt5Core.so.5
#7  0xb5d49210 in QSocketNotifier::event(QEvent*) () from /usr/lib/libQt5Core.so.5
#8  0xb5d0c488 in QCoreApplication::notify(QObject*, QEvent*) () from /usr/lib/libQt5Core.so.5
#9  0xb5d0c600 in QCoreApplication::notifyInternal2(QObject*, QEvent*) ()
   from /usr/lib/libQt5Core.so.5
#10 0xb5d65e5c in QEventDispatcherUNIXPrivate::activateSocketNotifiers() ()
   from /usr/lib/libQt5Core.so.5
#11 0xb5d661bc in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from /usr/lib/libQt5Core.so.5
Cannot access memory at address 0x24
#12 0xb39043a4 in ?? () from /usr/lib/libQt5WaylandClient.so.5
Cannot access memory at address 0x24
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

There is also no backtrace to any specific call to my application code so it is hard to track down. Do you have any suggestions as to what this issue may be or how I can resolve it?

Thank you,

[ivd0]

Have you somehow solved this issue may be? We're experiencing exactly same error every two weeks of uptime. Qt version is 5.6.2, platform i.MX6DL.

[vpanchal]

No, I have not solved this issue. I have not seen it recently, but I think it will still happen under some circumstances.

Please update this thread if you come across a solution.