Ubuntu
bug-buddy package

bug-buddy can block 'x-session-manager', preventing new X processes

Bug #70368 reported by Paul Sladen
4
Affects Status Importance Assigned to Milestone
Bug Buddy
Fix Released
Medium
bug-buddy (Ubuntu)
Fix Released
High
Ubuntu Desktop Bugs

Bug Description

[Unfortunately, 1.5hours worth of debugging to the cause of this problem was lost after 'kill -9 `pidof bug-buddy...gnome-session-manager`, which then took down the X server].

Bug-buddy can block 'x-session-manager'; the following is what the straces/gdb dumps showed from 5minutes ago:

New processes attempt to connect to the Session Manager using:

  /tmp/.ICE-unix/NNNN

New processes start by writing a request to this socket and then blocking, awaiting the Session Manager to respond. However, the SM is locked:

  waitpid(`pidof gnome-session-manager`, <unfinished>

and the GNOME Session Manager instance blocked:

  waitpid(`pidof bug-buddy`, <unfinished>

This instance of 'bug-buddy' was the one watching 'gnome-session-manager' was blocking on:

  read(24, <unfinished>

I do not know what Socket 24 was supposed, or was, connected to.

So there seems to be some cyclic relationship between the g-s-m and an instance of bug-buddy watching over 'g-s-m'; the end result of which is a race-condition where 'x-session-manager' is left completely blocked.

Revision history for this message
Daniel Holbach (dholbach) wrote :

Thanks for the report, Paul.

Somebody of the team should forward this upstream.

Changed in bug-buddy:
importance: Undecided → Medium
Dan Winship (danw-gnome)
Changed in bug-buddy:
status: Unconfirmed → Unknown
Sebastien Bacher (seb128)
Changed in bug-buddy:
assignee: nobody → desktop-bugs
importance: Medium → High
status: Unconfirmed → Confirmed
Revision history for this message
Allison Karlitskaya (desrt) wrote :

I had this problem too and just filed directly upstream.

Dan Winship has proposed a fix to bug buddy to make it avoid registering for session management (thus breaking the loop).

Bug Watch Updater (bug-watch-updater)
Changed in bug-buddy:
status: Unknown → Unconfirmed
Revision history for this message
Sebastien Bacher (seb128) wrote :

fixed upstream

Changed in bug-buddy:
status: Confirmed → Fix Committed
Bug Watch Updater (bug-watch-updater)
Changed in bug-buddy:
status: Unconfirmed → Fix Released
Revision history for this message
Sebastien Bacher (seb128) wrote :

That upload fixes the bug:

 bug-buddy (2.17.4-0ubuntu1) feisty; urgency=low
 .
   * New upstream version:
     - Don't register with the session manager (Ubuntu: #70368)
     - Fix invalid read in the gmenu code
     - Search for desktop files in the autostart dir too
     - Compiler warning fixes
     - String fixes
     - Fix "looks for non-existing Desktop when saving" (Ubuntu: #55131)
     - Fix "Doesn't display crashed program name" (Ubuntu: #62592)
   * debian/control.in:
     - package maintained by the Ubuntu Desktop Team

Changed in bug-buddy:
status: Fix Committed → Fix Released
Bug Watch Updater (bug-watch-updater)
Changed in bug-buddy:
importance: Unknown → Medium
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