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Date: Tue, 2 Sep 2008 10:54:08 -0700
From: "Maksim Yevmenkin" <maksim.yevmenkin@gmail.com>
To: "Andrew Thompson" <thompsa@freebsd.org>
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Cc: current@freebsd.org
Subject: Re: m_uiotombuf alignment
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Andrew,

>  I have a patch here to removing the alignment of the align parameter. I
>  can not see why it was added as it up to the caller to specify this, it
>  breaks tap(4) on strict alignment machines as m_uiotombuf is called with
>  ETHER_ALIGN. Also 'align' isnt a great description of this field, its
>  more a padding or data offset.

hmm... strange... from cvs

===

Revision 1.53
Wed May 4 18:55:02 2005 UTC (3 years, 4 months ago) by emax
Branches: MAIN

Change m_uiotombuf so it will accept offset at which data should be copied
to the mbuf. Offset cannot exceed MHLEN bytes. This is currently used to
fix Ethernet header alignment problem on alpha and sparc64. Also change all
users of m_uiotombuf to pass proper offset.

Reviewed by:	jmg, sam
Tested by:	Sten Spans "sten AT blinkenlights DOT nl"
MFC after:	1 week

===

could you please explain how and on which platforms it breaks tap(4)?

thanks,
max