Bug 104993 - X server aborts when Composite extension is disabled
Summary: X server aborts when Composite extension is disabled
Status: RESOLVED FIXED
Alias: None
Product: xorg
Classification: Unclassified
Component: Server/Ext/GLX (show other bugs)
Version: git
Hardware: Other All
: medium normal
Assignee: Xorg Project Team
QA Contact: Xorg Project Team
URL:
Whiteboard:
Keywords:
: 106226 (view as bug list)
Depends on:
Blocks:
 
Reported: 2018-02-07 13:15 UTC by Michal Srb
Modified: 2018-04-25 08:26 UTC (History)
2 users (show)

See Also:
i915 platform:
i915 features:

Attachments
Backtrace of the abort. (1.46 KB, text/plain)
2018-02-07 13:15 UTC, Michal Srb 		no flags Details
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Description Michal Srb 2018-02-07 13:15:19 UTC 
Created attachment 137216 [details]
Backtrace of the abort.

Since commit f84e59a4f474d22860bac8aec2947798a86db69b "glx: Duplicate relevant fbconfigs for compositing visuals" the X server aborts if the Composite extension is disabled.

Abort message:
  X: ../include/privates.h:122: dixGetPrivateAddr: Assertion `key->initialized'
  failed.

Backtrace attached.

The `pickFBConfig` function calls `compIsAlternateVisual` which tries to get the `CompScreenPtr` of the screen using the `CompScreenPrivateKey`, but that key was never initialized because the Composite extension is disabled.

One solution that comes to mind is to wrap all the calls from GLX code to Composite code in `if (!noCompositeExtension) { ... }` blocks, but I am not sure if that is the best solution.
Comment 1 Felix Miata 2018-04-05 04:30:48 UTC 
Server 1.19.6 aborts in Debian Buster with kernel 4.15.11 if /etc/X11/xorg.conf includes:

		Option "Composite" "Disable"
Comment 2 Felix Miata 2018-04-05 08:18:03 UTC 
Comment 1 is with i915G video.

Server 1.19.6 aborts in Fedora 28 beta with HD5450 Radeon if /etc/X11/xorg.conf includes:

		Option "Composite" "Disable"
Comment 3 Michal Srb 2018-04-20 08:18:53 UTC 
The patch was merged, this bug is fixed.
Comment 4 Michel Dänzer 2018-04-25 08:26:28 UTC 
*** Bug 106226 has been marked as a duplicate of this bug. ***

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