Bug 465877 - After plasma 5.26=>5.27 update, most KDE apps often crash when monitors enter powersaving mode.
Summary: After plasma 5.26=>5.27 update, most KDE apps often crash when monitors enter...
Status: RESOLVED FIXED
Alias: None
Product: kscreenlocker
Classification: Plasma
Component: general (show other bugs)
Version: 5.27.0
Platform: openSUSE Linux
: NOR crash
Target Milestone: ---
Assignee: Plasma Bugs List
URL:
Keywords: regression
Depends on:
Blocks:
 
Reported: 2023-02-16 22:28 UTC by Tomas Mecir
Modified: 2023-02-27 15:16 UTC (History)
6 users (show)

See Also:
Latest Commit:
Version Fixed In: 5.27.1
Sentry Crash Report:


Attachments
journalctl log (45.18 KB, text/x-log)
2023-02-16 22:28 UTC, Tomas Mecir
Details
For comparison, log when the crashes do not happen (61.54 KB, text/x-log)
2023-02-16 22:58 UTC, Tomas Mecir
Details
log (saved from KSystemLog) (7.26 KB, text/x-log)
2023-02-17 22:46 UTC, Daniel Ellis
Details

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Description Tomas Mecir 2023-02-16 22:28:11 UTC
Created attachment 156331 [details]
journalctl log

I'm probably reporting this against the wrong component, but who knows, it looks like a tricky one. Logs indicate that it could be related to the new multiscreen support. Anyway - ever since upgrading from plasma 5.26 to 5.27.0 on a dual-monitor setup, I have started getting a really strange issue in about 1/3 of cases. It goes like this:

* First, you need to leave the machine idle long enough for the powersaver to kick in and turn off the monitors
* Then, mouse/keyboard events enable the monitors correctly, but "enter password" dialog doesn't appear, the lock screen behaves as if it were frozen. You can still enter the password blindly and press enter, however
* When you do this, you are greeted by a long list of dr konqi reports about crashed applications. In every single case, the backtrace looks like this:

[KCrash Handler]
#4  0x00007f90efef506d in  () at /lib64/libQt5XcbQpa.so.5
#5  0x00007f90efef90ff in  () at /lib64/libQt5XcbQpa.so.5
#6  0x00007f90efef8400 in  () at /lib64/libQt5XcbQpa.so.5
#7  0x00007f90efed4524 in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) () at /lib64/libQt5XcbQpa.so.5
#8  0x00007f90efed54b6 in QXcbConnection::processXcbEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5XcbQpa.so.5
#9  0x00007f90efefb143 in  () at /lib64/libQt5XcbQpa.so.5
#10 0x00007f90f7f27a90 in g_main_context_dispatch () at /lib64/libglib-2.0.so.0
#11 0x00007f90f7f27e48 in  () at /lib64/libglib-2.0.so.0
#12 0x00007f90f7f27edc in g_main_context_iteration () at /lib64/libglib-2.0.so.0
#13 0x00007f90fbf33c16 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#14 0x00007f90fbedac5b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQt5Core.so.5
#15 0x00007f90fbee2dc6 in QCoreApplication::exec() () at /lib64/libQt5Core.so.5
#16 0x000055d2152ef701 in  ()
#17 0x00007f90fb62caf0 in __libc_start_call_main () at /lib64/libc.so.6
#18 0x00007f90fb62cbb9 in __libc_start_main_impl () at /lib64/libc.so.6
#19 0x000055d2152f0065 in  ()
[Inferior 1 (process 2930) detached]

Non-KDE apps like firefox survive. What further complicates matters is that this doesn't seem to happen every time, only about 1/3.

There's a lot of seemingly relevant messages in the systemd journal, I'm attaching these in a separate file.

OBSERVED RESULT
Many crashes, as described above.

EXPECTED RESULT
No crashes.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 5.27.0 (X11)
KDE Plasma Version: 
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8
Comment 1 Tomas Mecir 2023-02-16 22:58:10 UTC
Created attachment 156332 [details]
For comparison, log when the  crashes do not happen
Comment 2 Nate Graham 2023-02-17 20:57:16 UTC
No idea how to even begin debugging this one. Looks like a head-scratcher indeed. Starting with kscreenlocker since that's the first system component that starts to go wrong.
Comment 3 Daniel Ellis 2023-02-17 22:46:00 UTC Comment hidden (spam)
Comment 4 David Edmundson 2023-02-19 13:06:38 UTC Comment hidden (spam)
Comment 5 Daniel Ellis 2023-02-21 21:42:46 UTC Comment hidden (spam)
Comment 6 Daniel Ellis 2023-02-24 06:11:13 UTC Comment hidden (spam)
Comment 7 Nate Graham 2023-02-24 17:37:05 UTC
Please let us know if it stops happening after you upgrade the system to Plasma 5.27.1 (already released) or 5.27.2 (will be released in a few days).
Comment 8 Tomas Mecir 2023-02-25 08:15:45 UTC
Aye, will test once the distro updates. For what it's worth, if I (still on 5.27.0) try to use powersaving without the screenlocker, I get the same backtrace as in 464590, so chances are good that my issue will be fixed. Will report back.
Comment 9 Tomas Mecir 2023-02-26 19:59:53 UTC
After 2 days with 5.27.1, there have been no more crashes. A bit early to be entirely sure, but I'd say it's probably good now.
Comment 10 Nate Graham 2023-02-27 15:16:09 UTC
Yay! Thanks for following up.