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Bug 690270

Summary: Xserver segfaults in miwindow.c when backing store is enabled
Product: Red Hat Enterprise Linux 5 Reporter: RHEL Program Management <pm-rhel>
Component: xorg-x11-serverAssignee: Adam Jackson <ajax>
Status: CLOSED ERRATA QA Contact: desktop-bugs <desktop-bugs>
Severity: urgent Docs Contact:
Priority: urgent    
Version: 5.6CC: ajax, cww, ofourdan, plyons, pm-eus, vbenes, vsharapo
Target Milestone: rcKeywords: Patch, Triaged, ZStream
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Prior to this update, running the X.Org server with the support for backing store enabled (the "backingstore" option) caused the server to occasionally terminate with a segmentation fault. With this update, the underlying source code has been modified to address this issue, and enabling the "backingstore" option in the server's configuration no longer leads to unexpected crashes.
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-04-20 06:57:06 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 676270    
Bug Blocks:    

Description RHEL Program Management 2011-03-23 18:29:41 UTC
This bug has been copied from bug #676270 and has been proposed
to be backported to 5.6 z-stream (EUS).

Comment 4 Adam Jackson 2011-03-28 19:39:45 UTC
3210529 build (RHEL-5.6-Z-candidate, /cvs/dist:rpms/xorg-x11-server/RHEL-5:xorg-x11-server-1_1_1-48_76_el5_6_3) completed successfully

MODIFIED

Comment 6 Vasiliy Sharapov 2011-04-13 19:57:36 UTC
I'm unable to verify the existence of the bug. I tried to exercise the backingstore by running firefox windows and glxgears with other windows moving and resizing over them. Backingstore was enabled the whole time but there was no occurrence of the crash after over 24 hours, there were approximately 2,592,000 runs through the codepath that has the race condition in it. I can make a more intense test if necessary, but it looks like the customer is doing something we're not.

If someone comes up with a reliable reproducer, I can verify the bug, until then I can only test for regressions. =\ So this bug is staying ON_QA until something changes.

Comment 7 Jaromir Hradilek 2011-04-19 15:33:41 UTC
    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
Prior to this update, running the X.Org server with the support for backing store enabled (the "backingstore" option) caused the server to occasionally terminate with a segmentation fault. With this update, the underlying source code has been modified to address this issue, and enabling the "backingstore" option in the server's configuration no longer leads to unexpected crashes.

Comment 8 errata-xmlrpc 2011-04-20 06:57:06 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHBA-2011-0456.html