Random Segmentation Fault v200

[voltlog]

Because I was having a bunch of random segmentation fault crashes with the precompiled release, I grabbed QT 5.14.2 and compiled the latest version of SavvyCAN (v200) on Ubuntu 20.04. It still crashes randomly (and often) while using it to send custom frames. I am a noob regarding QT but I ran SavvyCAN in a debug session with QT Creator and this is the info it shows when it crashes. If there is anything else I can provide for identifying the issue here, please let me know.

[collin80]

That's really odd. The line it is faulting on is not the sort of line I'd expect to be able to cause a segfault. The only way I could see that happening is if the pointer to the object ("this" implicit pointer for the object) was simultaneously not null but also not within legitimate memory space. That sounds like the object reference is being set in a faulty manner. It might help to see what is farther down in the stack trace. I can only see the first 10 in your screenshot. It might also help if I saw the exact settings you're using in your custom senders so I could reproduce it the same way you are. Also, this crash seems to be within code that processes multiplexed frames so it probably requires that the custom sent message be within a multiplexed message.

I'm going to try to create some custom CAN frames myself with guesses to see if I can get it to do it. I have DBC files with multiplexed messages so I can load one of those then try to send custom messages on that ID. Truth be told, I never use the custom sender so it might have long standing bugs that I never caught. I'll try to make it crash for me.

[voltlog]

I've managed to isolate a scenario where it happens, this one is related to DBC interpreting of received signals(no sending during this scenario). I have a couple of incoming messages, "Overwrite mode" selected and a DBC filter file that I created myself(test_dbc.txt). The moment I activate the option "Interpret Frames" it crashes, full stack trace below.

1 DBC_SIGNAL::processAsInt dbc_classes.cpp 144 0x555555713763 2 DBC_SIGNAL::processAsText dbc_classes.cpp 64 0x555555713112 3 CANFrameModel::data canframemodel.cpp 485 0x5555555ccafc 4 QSortFilterProxyModel::data(QModelIndex const&, int) const 0x7ffff58093f9 5 QStyledItemDelegate::initStyleOption(QStyleOptionViewItem , QModelIndex const&) const 0x7ffff78c0500 6 QStyledItemDelegate::paint(QPainter , QStyleOptionViewItem const&, QModelIndex const&) const 0x7ffff78bf739 7 QTableViewPrivate::drawCell(QPainter , QStyleOptionViewItem const&, QModelIndex const&) 0x7ffff78e6b8a 8 QTableView::paintEvent(QPaintEvent ) 0x7ffff78ef350 9 QWidget::event(QEvent ) 0x7ffff7699670 10 QFrame::event(QEvent ) 0x7ffff774179e 11 QAbstractItemView::viewportEvent(QEvent ) 0x7ffff78a3fbc 12 QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject , QEvent ) 0x7ffff583d9dd 13 QApplicationPrivate::notify_helper(QObject , QEvent ) 0x7ffff765aae2 14 QApplication::notify(QObject , QEvent ) 0x7ffff7661a90 15 QCoreApplication::notifyInternal2(QObject , QEvent ) 0x7ffff583dc48 16 QWidgetPrivate::sendPaintEvent(QRegion const&) 0x7ffff76920c5 17 QWidgetPrivate::drawWidget(QPaintDevice , QRegion const&, QPoint const&, QFlags, QPainter , QWidgetRepaintManager ) 0x7ffff7692bc7 18 QWidgetRepaintManager::paintAndFlush() 0x7ffff766af03 19 QWidgetRepaintManager::sync() 0x7ffff766b648 20 QWidgetPrivate::syncBackingStore() 0x7ffff769374f 21 QWidget::event(QEvent ) 0x7ffff76997f0 22 QMainWindow::event(QEvent ) 0x7ffff77a0791 23 QApplicationPrivate::notify_helper(QObject , QEvent ) 0x7ffff765ab0c 24 QApplication::notify(QObject , QEvent ) 0x7ffff7661a90 25 QCoreApplication::notifyInternal2(QObject , QEvent ) 0x7ffff583dc48 26 QWidgetRepaintManager::sendUpdateRequest(QWidget , QWidgetRepaintManager::UpdateTime) [clone .part.94] [clone .constprop.96] 0x7ffff766c4b6 27 void QWidgetRepaintManager::markDirty(QRect const&, QWidget , QWidgetRepaintManager::UpdateTime, QWidgetRepaintManager::BufferState) 0x7ffff766fb9e 28 QWidget::repaint(QRect const&) 0x7ffff768370d 29 QWidget::repaint() 0x7ffff7683753 30 QAbstractButtonPrivate::click() 0x7ffff7747e8d 31 QAbstractButton::mouseReleaseEvent(QMouseEvent ) 0x7ffff7748025 32 QWidget::event(QEvent ) 0x7ffff7699670 33 QApplicationPrivate::notify_helper(QObject , QEvent ) 0x7ffff765ab0c 34 QApplication::notify(QObject , QEvent ) 0x7ffff76626f8 35 QCoreApplication::notifyInternal2(QObject , QEvent ) 0x7ffff583dc48 36 QApplicationPrivate::sendMouseEvent(QWidget , QMouseEvent , QWidget , QWidget , QWidget , QPointer&, bool, bool) 0x7ffff7660fda 37 QWidgetWindow::handleMouseEvent(QMouseEvent ) 0x7ffff76b2dd1 38 QWidgetWindow::event(QEvent ) 0x7ffff76b5a1b 39 QApplicationPrivate::notify_helper(QObject , QEvent ) 0x7ffff765ab0c 40 QApplication::notify(QObject , QEvent ) 0x7ffff7661a90 41 QCoreApplication::notifyInternal2(QObject , QEvent ) 0x7ffff583dc48 42 QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::MouseEvent ) 0x7ffff6d49738 43 QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent ) 0x7ffff6d4ac15 44 QWindowSystemInterface::sendWindowSystemEvents(QFlags) 0x7ffff6d26f4b 45 xcbSourceDispatch(_GSource , int ( )(void ), void ) 0x7ffff1a3533a 46 g_main_context_dispatch 0x7ffff2c1ffbd 47 ?? 0x7ffff2c20240 48 g_main_context_iteration 0x7ffff2c202e3 49 QEventDispatcherGlib::processEvents(QFlags) 0x7ffff589673c 50 QEventLoop::exec(QFlags) 0x7ffff583c662 51 QCoreApplication::exec() 0x7ffff5845590 52 main main.cpp 24 0x55555559a598

[collin80]

I've finally gotten some time to look at this. While I'm looking at the current version and not v200 I see a potential problem with your DBC file. You have RPM defined as a multiplexed signal but there is no multiplexor to use with it. This actually immediately crashes the current version when you try to load it. I'm going to fix loading of such files to at least not crash. Basically, if there is no multiplexor it'll have to revert to non-multiplexed mode which is perhaps what you wanted anyway. I think the previous version was allowing the DBC to load but if a signal was marked multiplexed but there was no multiplexor to check for value it would crash.