Kubuntu 9.04 live CD: "shutdown" doesn't

[Alan Jenkins]

Shutdown or restart from Kubuntu live CD doesn't work. It logs you out, but doesn't get any further.

I have to switch to a text console and press ctrl+alt+delete. I see the following message:

kdm not responding to TERM signal

[Alan Jenkins (aj504)]

Aha! This only happens if I enable desktop effects before trying to shut down. I have Intel 965 graphics. So this may be related to the other Intel issues, e.g. Bug 359392.

[Alan Jenkins (aj504)]

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 9.04
Release: 9.04
Codename: jaunty

$ apt-cache policy kdm
kdm:
  Installed: 4:4.2.2-0ubuntu2
  Candidate: 4:4.2.2-0ubuntu2
  Version table:
 *** 4:4.2.2-0ubuntu2 0
        500 http://archive.ubuntu.com jaunty/main Packages
        100 /var/lib/dpkg/status
$ apt-cache policy xorg
xorg:
  Installed: 1:7.4~5ubuntu18
  Candidate: 1:7.4~5ubuntu18
  Version table:
 *** 1:7.4~5ubuntu18 0
        500 http://archive.ubuntu.com jaunty/main Packages
        100 /var/lib/dpkg/status

$ lspci -nn | grep VGA
00:02.0 VGA compatible controller [0300]: Intel Corporation 82946GZ/GL Integrated Graphics Controller [8086:2972] (rev 02)

[Alan Jenkins (aj504)]

Xorg.log, prior to enabling desktop effects

[Alan Jenkins (aj504)]

Damn, I can't reproduce it now. I'll leave it for the time being; I have a load of other issues to sort through and report.

I have some ideas as to what I can try when (if) it happens again. I think X has actually exited at this point, and it's just kdm which is hanging. Because it gets as far as logging me out, and switching to a text console (but doesn't actually restart/shutdown). So I'll try to confirm that with "ps", to see that X is no longer running, and see what process state kdm is in (D-state?). And obviously I'll check Xorg.log and kdm.log for errors.

[Alan Jenkins (aj504)]

Gotcha! Ok, this does _not_ depend on me enabling desktop effects. I'm not sure what causes it :-). It could be it's just random.

[Alan Jenkins (aj504)]

Xorg.log after trying to reboot. Probably not interesting.

[Alan Jenkins (aj504)]

kdm.log after trying to reboot. Nothing obvious here, at least to my eye.

[Alan Jenkins (aj504)]

Output of "ps -ax" after trying to reboot.

There is no X process. There is a "-:0" process, I'm not sure what that means exactly, except that it's related to ":0", my X display / session.

Both kdm and kdm_greet are still running, in state "S" (interuptable sleep). As described before "killall kdm" does nothing; either the TERM signal is blocked or the signal handler isn't able to do it's job.

I checked with "strace -p" just in case it showed anything interesting about kdm, but it just showed a select() call with a number of fds, just as you would expect in a standard event loop.

[Alan Jenkins (aj504)]

It happened again and I gathered some more data, this will probably make more sense if you have the source code in front of you.

This was after maybe another 5 reboots, so it doesn't seem to happen too often.

select(12, [4 6 7 9 11], NULL, NULL, NULL) = ? ERESTARTNOHAND (To be restarted)
--- SIGTERM (Terminated) @ 0 (0) ---
write(5, "\17"..., 1) = 1
rt_sigreturn(0x5) = -1 EINTR (Interrupted system call)
kill(4123, SIGTERM) = 0
kill(4123, SIGCONT) = 0
select(12, [4 6 7 9 11], NULL, NULL, NULL) = 1 (in [4])
read(4, "\17"..., 1) = 1
kill(4123, SIGTERM) = 0
kill(4123, SIGCONT) = 0
kill(4123, SIGTERM) = 0
kill(4123, SIGCONT) = 0
select(12, [4 6 7 9 11], NULL, NULL, NULL

$ ps -ax | grep 4123
 4123 ? S 0:00 -:0

So "-:0" _is_ significant. Rats, I should have used strace on that as well. I'll just have to wait for next time again.

[Alan Jenkins (aj504)]

Here's the strace for "-:0", which is actually an instance of kdm (according to /proc/exe)

Process 4129 attached - interrupt to quit
rt_sigsuspend([]) = ? ERESTARTNOHAND (To be restarted)
--- SIGTERM (Terminated) @ 0 (0) ---
rt_sigsuspend([]

I.e. it's waiting in sigsuspend() and hasn't blocked TERM, but it refuses to die.

[Jonathan Thomas (echidnaman)]

Is this still an issue with 9.10?

[Jonathan Thomas (echidnaman)]

Hi there!

Thanks for reporting this bug! Your bug seems to be a problem with the KDE program itself, and not with our KDE packages. While we appreciate your issue, it would be better if it was tracked at https://bugs.kde.org, so that the KDE developers can deal with this speedily and have direct communication with you as the reporter for more effective debugging.

Thanks!