Bug 357975

Summary:	Unrecoverable blank screen
Product:	[Unmaintained] kscreenlocker	Reporter:	Robin Green <greenrd>
Component:	general	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	critical	CC:	bshah, mgraesslin
Priority:	NOR	Keywords:	triaged
Version First Reported In:	unspecified
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Robin Green 2016-01-14 11:00:41 UTC

I have configured the top-right screen corner to lock the screen if I move my mouse into it, and also configured Meta+L to lock the screen. I was shoving my mouse pointer into the top right corner of the screen and nothing was happening, so I pressed Meta+L, but still nothing happened.

When I returned from my meeting, the screens were black, with just a mouse pointer. I could switch to VT2 with Ctrl+Alt+F2, so I did so and ran top. kwin was using 100% CPU so I killed it, and switched back to VT1. This brought my desktop back, but of course kwin was not running and also, I could not click on anything. When I tried to rerun kwin from VT2, I again experienced black screens on VT1. I then noticed on VT2 that the screen lock greeter was still running. I attempted to kill this but it respawned. I then attempted to kill its parent, which killed my KDE session. After I then logged in, my new KDE session was somehow broken, so I had to reboot, and then things worked again.

Reproducible: Didn't try

Steps to Reproduce:
Unknown



I was running toggl and by the time I returned from my meeting, it had raised a popup - that could be relevant. Also, there was an error message printed from kwin when I restarted it, mentioning KWayland - not sure if that is relevant - I am not running Wayland.

I'm guessing this is some kind of race condition because locking normally works.

Comment 1 Martin Flöser 2016-01-14 11:09:36 UTC

> I then noticed on VT2 that the screen lock greeter was still running. I attempted to kill this but it respawned.

This is expected behavior. Killing the process is not allowed. Next time just do loginctl unlock-sessions.

> I then attempted to kill its parent, which killed my KDE session

this is also expected as the parent is ksmserver - the session manager.

There is unfortunately not much we can do now. All we know is something went wrong. What it was is no longer possible to see as you killed the processes and restarted the system. If it happens again, please try to get a backtrace of badly behaving applications.

Comment 2 Andrew Crouthamel 2018-09-25 21:56:06 UTC

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!

Comment 3 Andrew Crouthamel 2018-10-27 03:32:17 UTC

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!