Bug 623513 - GDM fails to log in if ck-history is too slow
Summary: GDM fails to log in if ck-history is too slow
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Red Hat Enterprise Linux 6
Classification: Red Hat
Component: gdm
Version: 6.0
Hardware: All
OS: Linux
urgent
urgent
Target Milestone: rc
: ---
Assignee: Ray Strode [halfline]
QA Contact: desktop-bugs@redhat.com
URL:
Whiteboard:
Keywords:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2010-08-12 01:39 UTC by Ray Strode [halfline]
Modified: 2010-11-10 20:28 UTC (History)
3 users (show)

(edit)
Clone Of:
(edit)
Last Closed: 2010-11-10 20:28:21 UTC


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External Trackers
Tracker ID Priority Status Summary Last Updated
GNOME Bugzilla 626564 None None None Never

Description Ray Strode [halfline] 2010-08-12 01:39:04 UTC
We got an report upstream from Canonical about GDM not working properly for some of their users.  It would never show a login screen for those users.

I spent a few hours debugging the issue with them and determined GDMs "watchdog" handling code (which kills ck-history after a timeout) is missing a line of code to zero out its process id after killing the process.  This missing line prevents GDM from working properly.

This is probably a blocker issue because it means that after months of accumulated use (when the history file gets big) GDM will just stop working.

I've fixed this upstream here:

http://git.gnome.org/browse/gdm/commit/?h=gnome-2-30&id=285d6dda3ee0439349cca22346efef3392d66d48

and got confirmation from several Ubuntu users hit by the issue that the fix works for them.

Artificially reproducing the problem is fairly straight forward:


1) Replace ck-history with a thin shell script wrapper that adds an artificial delay
# mv /usr/bin/ck-history /usr/bin/ck-history.binary

cat > /usr/bin/ck-history << EOF
#!/bin/sh
sleep 5
exec /usr/bin/ck-history.binary "$@"
EOF
chmod +x /usr/bin/ck-history

2) Reboot

At this point the GDM greeter will never load

Comment 1 Ray Strode [halfline] 2010-08-12 17:08:15 UTC
This is building now.

Comment 2 Vladimir Benes 2010-08-16 14:39:49 UTC
tested using instructions above .. gdm shows user list even after 5 second delay
-> VERIFIED

Comment 3 Vladimir Benes 2010-08-16 14:40:58 UTC
gdm-2.30.4-21.el6 tested from latest build

Comment 4 releng-rhel@redhat.com 2010-11-10 20:28:21 UTC
Red Hat Enterprise Linux 6.0 is now available and should resolve
the problem described in this bug report. This report is therefore being closed
with a resolution of CURRENTRELEASE. You may reopen this bug report if the
solution does not work for you.


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