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Date: Mon, 2 May 2005 21:20:01 +0200 (CEST)
From: Sten Spans <sten@blinkenlights.nl>
To: Maksim Yevmenkin <maksim.yevmenkin@savvis.net>
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cc: John-Mark Gurney <gurney_j@resnet.uoregon.edu>
cc: glebius@FreeBSD.org
cc: Julian Elischer <julian@elischer.org>
cc: net@freebsd.org
Subject: Re: if_tap unaligned access problem
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On Mon, 2 May 2005, Maksim Yevmenkin wrote:

> Hello,
>
>>>>>>> i think we have few options here:
>>>>>>> 
>>>>>>> 1) revert back original tapwrite function that was changed in v. 1.48 
>>>>>>> and set offset to 2 bytes in top mbuf
>>>>>>> 
>>>>>>> 2) change current version of tapwrite so it would m_prepend and 
>>>>>>> m_pullup mbuf after m_uiotombuf
>>>>>>> 
>>>>>>> 3) change m_uiotombuf to accept one more parameter - mbuf offset at 
>>>>>>> which data should be copied. there are not that many users of 
>>>>>>> m_uiotombuf
>>> 
>>> please find and review the attached patch (untested) that implements 
>>> option (3) above.
>
> any objections to the attached (revised) patch? can i commit it?


I've tested the code on fbsd-current alpha and it fixes
the crash. I was kinda waiting for somebody to test it on
sparc, but that's taking a few days longer than expected.
I may run a test on one of my own sparcs to verify
the results.

That said, the issue seems pretty clear-cut, as is the solution.

-- 
Sten Spans

"There is a crack in everything, that's how the light gets in."
Leonard Cohen - Anthem