[kwin] [Bug 390760] New: Wayland crashes to SDDM greeter

[Michael D]

https://bugs.kde.org/show_bug.cgi?id=390760

Bug ID: 390760
Summary: Wayland crashes to SDDM greeter
Product: kwin
Version: 5.12.1
Platform: Neon Packages
OS: Linux
Status: UNCONFIRMED
Severity: normal
Priority: NOR
Component: wayland-generic
Assignee: kwin-bugs-***@kde.org
Reporter: ***@gmail.com
Target Milestone: ---

Every couple of days or so, my wayland session crashes to the SDDM greeter.
This *never* happens in an X session. I think it's caused by xwayland, but this
is just a hunch, since I have *no* debugging info. My hunch is caused by what
I'm often doing when I get kicked out of a session, which is often something in
Firefox or Thunderbird. xlsclients lists dropbox, telegram, thunderbird, and
firefox.

I am happy to provide any information I can. This has been happening to me for
a good number of plasma versions.

Hardware: Intel i5 7200U (Kaby Lake), modesetting driver.

[Martin Flöser]

https://bugs.kde.org/show_bug.cgi?id=390760

Martin Flöser <***@kde.org> changed:

What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |BACKTRACE
Status|UNCONFIRMED |NEEDSINFO

--- Comment #1 from Martin Flöser <***@kde.org> ---
We need a backtrace of the crashing KWin.

[Michael D]

https://bugs.kde.org/show_bug.cgi?id=390760

--- Comment #2 from Michael D <***@gmail.com> ---
Created attachment 110878
--> https://bugs.kde.org/attachment.cgi?id=110878&action=edit
Attempted backtrace

[Michael D]

https://bugs.kde.org/show_bug.cgi?id=390760

--- Comment #3 from Michael D <***@gmail.com> ---
Sorry, but I'm not sure how to get a backtrace. I tried following
https://community.kde.org/KWin/Debugging by entering the following commands in
this order:

echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope
gdb --pid `pidof kwin_wayland` 2>&1 | tee kwin.gdb

and it crashed the session. Worse, I can't login anymore to wayland anymore---I
just get a black screen (though if I push the power button, it shuts down
properly).

Attached is the kwin.gdb file.

[Michael D]

https://bugs.kde.org/show_bug.cgi?id=390760

--- Comment #4 from Michael D <***@gmail.com> ---
I discovered the following in my /var/log/kern.log which may be a bit helpful.
It happened after a resume from suspend. (Still can't get a proper backtrace.)

Feb 25 21:17:26 michael-yoga kernel: [ 8139.547367] kwin_wayland[1251]:
segfault at 10 ip 00007efc0caf6fd0 sp 00007fffd40b88c8 error 4 in
libKF5WaylandServer.so.5.43.0[7efc0ca72000+d2000]
Feb 25 21:17:26 michael-yoga sddm-helper[1201]: [PAM] Closing session
Feb 25 21:17:28 michael-yoga sddm-helper[1201]: [PAM] Ended.
Feb 25 21:17:28 michael-yoga sddm[917]: Auth: sddm-helper exited successfully
Feb 25 21:17:28 michael-yoga sddm[917]: Greeter stopping...
Feb 25 21:17:28 michael-yoga sddm[917]: Socket server stopping...
Feb 25 21:17:28 michael-yoga sddm[917]: Socket server stopped.
Feb 25 21:17:28 michael-yoga sddm[917]: Display server stopping...
Feb 25 21:17:28 michael-yoga sddm-greeter[1144]: The X11 connection broke: I/O
error (code 1)
Feb 25 21:17:28 michael-yoga sddm-helper[1135]: [PAM] Closing session
Feb 25 21:17:28 michael-yoga sddm-helper[1135]: [PAM] Ended.
Feb 25 21:17:33 michael-yoga sddm[917]: Removing display ":0" ...
Feb 25 21:17:33 michael-yoga sddm[917]: Adding new display on vt 7 ...
Feb 25 21:17:33 michael-yoga sddm[917]: Loading theme configuration from ""
Feb 25 21:17:33 michael-yoga sddm[917]: Display server starting...
Feb 25 21:17:33 michael-yoga sddm[917]: Running: /usr/bin/X -nolisten tcp -auth
/var/run/sddm/{163cc817-3a33-4f8e-9d51-60915bb77926} -background none -noreset
-displayfd 22 -seat seat0 vt7
Feb 25 21:17:33 michael-yoga sddm[917]: Setting default cursor
Feb 25 21:17:33 michael-yoga sddm[917]: Running display setup script
"/usr/share/sddm/scripts/Xsetup"
Feb 25 21:17:33 michael-yoga sddm[917]: Display server started.
Feb 25 21:17:33 michael-yoga sddm[917]: Socket server starting...
Feb 25 21:17:33 michael-yoga sddm[917]: Socket server started.
Feb 25 21:17:33 michael-yoga sddm[917]: Loading theme configuration from
"/usr/share/sddm/themes/breeze/theme.conf"
Feb 25 21:17:33 michael-yoga sddm[917]: Greeter starting...
Feb 25 21:17:33 michael-yoga sddm[917]: Adding cookie to
"/var/run/sddm/{163cc817-3a33-4f8e-9d51-60915bb77926}"
Feb 25 21:17:33 michael-yoga sddm[917]: Display server stopping...
Feb 25 21:17:33 michael-yoga sddm[917]: Display server stopped.
Feb 25 21:17:33 michael-yoga sddm[917]: Running display stop script
"/usr/share/sddm/scripts/Xstop"
Feb 25 21:17:33 michael-yoga sddm[917]: Greeter stopping...
Feb 25 21:17:33 michael-yoga sddm[917]: QProcess: Destroyed while process
("/usr/lib/x86_64-linux-gnu/sddm/sddm-helper") is still running.
Feb 25 21:17:33 michael-yoga sddm-helper[8718]: [PAM] Starting...
Feb 25 21:17:33 michael-yoga sddm-helper[8718]: [PAM] Authenticating...
Feb 25 21:17:33 michael-yoga sddm-helper[8718]: [PAM] returning.
Feb 25 21:17:33 michael-yoga sddm[917]: Greeter session started successfully

On earlier dates, kern.log shows:

Feb 22 20:34:13 michael-yoga kernel: [32110.623142] kwin_wayland[10959]:
segfault at 30 ip 00007fda8c0572a0 sp 00007ffcaf4a52c0 error 4 in
libQt5Core.so.5.9.3[7fda8bdda000+52e000]

Feb 24 14:14:47 michael-yoga kernel: [15097.989608] kwin_wayland[1245]:
segfault at 7f2256b17ec0 ip 00007f2278069eb0 sp 00007ffd8c8701a0 error 4 in
libEGL.so.1.0.0[7f2278054000+39000]

[David Murray]

https://bugs.kde.org/show_bug.cgi?id=390760

David Murray <***@davidmurray.name> changed:

What |Removed |Added
----------------------------------------------------------------------------
CC| |***@davidmurray.name

[Martin Flöser]

https://bugs.kde.org/show_bug.cgi?id=390760

--- Comment #5 from Martin Flöser <***@kde.org> ---
After resume might mean that we fixed it. We had a bug if screens are removed
and that could happen while suspend/resume.

[Andrew Crouthamel]

https://bugs.kde.org/show_bug.cgi?id=390760

Andrew Crouthamel <***@kdemail.net> changed:

What |Removed |Added
----------------------------------------------------------------------------
Keywords| |triaged

--- Comment #6 from Andrew Crouthamel <***@kdemail.net> ---
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least 15 days.
Please provide the requested information as soon as possible and set the bug
status as REPORTED. Due to regular bug tracker maintenance, if the bug is still
in NEEDSINFO status with no change in 30 days, the bug will be closed as
RESOLVED > WORKSFORME due to lack of needed information.

For more information about our bug triaging procedures please read the wiki
located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please set the bug
status as REPORTED so that the KDE team knows that the bug is ready to be
confirmed.

Thank you for helping us make KDE software even better for everyone!

[Andrew Crouthamel]

https://bugs.kde.org/show_bug.cgi?id=390760

Andrew Crouthamel <***@kdemail.net> changed:

What |Removed |Added
----------------------------------------------------------------------------
Resolution|BACKTRACE |WORKSFORME
Status|NEEDSINFO |RESOLVED

--- Comment #7 from Andrew Crouthamel <***@kdemail.net> ---
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least 30 days. The
bug is now closed as RESOLVED > WORKSFORME due to lack of needed information.

For more information about our bug triaging procedures please read the wiki
located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

Thank you for helping us make KDE software even better for everyone!