Closed star-buck closed 9 years ago
still there as of kci 20150327, I tested with having firefox window still open, then logout, screen goes black for a second, then shows firefox window content without any other plasma components like panel, etc. only mouse cursor visible which can move, otherwise desktop seems frozen (no ALT-SPACE possible).
still happening kci20150403
yeah, it's not just Kubuntu. I've got some other reports here https://github.com/sddm/sddm/issues/385. I've been on it for the past 2 days but I'm rather stumped.
After 3 solid days, I've found it! And for the 5th time in a row, the bug is caused by Kubuntu's replacement PAM files. Though in fairness, this time is probably the fault of someone else moving something in Vivid, and in a super surprise twist the fault of Gnome.
Kubuntu people packaged the sddm PAM file to include pam_gnome_keyring. common_password already included pam_gnome_keyring. sddm's pam file includes common_password.
The end result is session pam_gnome_keyring is included twice.
The first one sets up a signal handler, starts gnome-keyring and all is well. The second one sets up a signal handler, does nothing, then intercepts all of my SIGCHLD signals that I need in sddm-helper to know when our session ends. Our QProcess object never gets told the child exited so never wakes up and the session (startkde, openbox whatever) is in a defunct state waiting for us to read the exit state.
In upstream SDDM our sddm pam file doesn't include gnome-keyring, we just source system-login so it's not a problem there.
Fix: remove both lines referencing gnome_keyring in the sddm.pam file in the packaging patches. sddm-autologin should be left as-is.
does it also fix these upstream cases: https://bugs.launchpad.net/ubuntu/+source/casper/+bug/1436715
I don't think so. That message is long after SDDM has finished doing anything useful. Also it appears in that report to affect vanilla Ubuntu which wouldn't by running SDDM at all.
okay, i just thought I sometimes experienced the freeze not only with logout, but also when shutdown or reboot.
Heh. I just patched gnome-keyring to make sure it didn't leakily leave signal handlers on error. It's been fixed already will be in 3.15.92
upstream report, it broke mdm too https://bugzilla.gnome.org/show_bug.cgi?id=745673
IMHO waiting for that patch to hit Vivid is probably the better fix.
https://launchpad.net/ubuntu/+source/gnome-keyring 3.16 packaged and in with the fix
works.
possible upstream report: https://bugs.launchpad.net/ubuntu/+source/sddm/+bug/1407152 https://bugs.launchpad.net/ubuntu/+source/casper/+bug/1436715