Bug 4947 - Xv byteswap
Summary: Xv byteswap
Alias: None
Product: xorg
Classification: Unclassified
Component: Server/General (show other bugs)
Version: unspecified
Hardware: x86 (IA32) Linux (All)
: high major
Assignee: Alan Coopersmith
QA Contact: Xorg Project Team
Depends on:
Reported: 2005-11-02 17:27 UTC by Scott Arnold
Modified: 2008-01-02 19:36 UTC (History)
0 users

See Also:
i915 platform:
i915 features:


Description Scott Arnold 2005-11-02 17:27:38 UTC
FYI Byteswap routines are broken in xvdisp.c. SWriteQueryExtensionReply for 
instance is calling WriteToClient with (char *)&rep (pointer to nothing) as 
last arg. I believe it should be (char *)rep. In my situation the client is 
running on SGI (Irix 6.5) server is running on linux / X86. Apparently these 
routines were never tested. I am working on a fix. Fixed return args but 
server is now aborting elsewere. Works fine with same-sex platform. Using 
xvinfo to test.

Comment 1 Erik Andren 2006-05-03 06:06:47 UTC
So how is that fix going?
Comment 2 Scott Arnold 2006-05-03 08:23:30 UTC
(In reply to comment #1)
> So how is that fix going?

I have it fixed, Server is working fine now. 
I will check to see if I can send the code.
Comment 3 Erik Andren 2006-05-21 18:56:38 UTC
Please attach to the code to this bug and keyword it as a patch.
Comment 4 Daniel Stone 2007-02-27 01:28:38 UTC
Sorry about the phenomenal bug spam, guys.  Adding xorg-team@ to the QA contact so bugs don't get lost in future.
Comment 5 Alan Coopersmith 2008-01-02 16:19:14 UTC
I don't see a proposed patch ever got attached, but hit this today, and confirmed
the diagnosis in comment #0, as well as additional errors from using variables
like length fields or number of items in a list after swapping them.    Will 
commit patch to Xorg git master shortly.
Comment 6 Alan Coopersmith 2008-01-02 19:36:43 UTC
Fix committed to git master:

commit dfd682b582636a36345144bcf835e3ee46718d90
Author: Alan Coopersmith <alan.coopersmith@sun.com>
Date:   Wed Jan 2 19:27:22 2008 -0800

    X.Org bug 4947/Sun bug 6646626: Xv extension not byte-swapping properly
    X.Org Bugzilla #4947 <https://bugs.freedesktop.org/show_bug.cgi?id=4947>
    Sun bug 6646626 <http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6646626>
    Don't use swapped data after swapping it.   When done swapping data,
    send the swapped data, not the address of the pointer to it, to the client.

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