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To: Heikki Suonsivu <hsu@mail.clinet.fi>
cc: Brian Somers <brian@FreeBSD.ORG>, hsu@clinet.fi, freebsd-bugs@FreeBSD.ORG
Subject: Re: kern/1293 
In-reply-to: Your message of "Tue, 09 Sep 1997 17:19:13 +0300."
             <199709091419.RAA18239@katiska.clinet.fi> 
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Date: Tue, 09 Sep 1997 23:37:07 +0100
From: Brian Somers <brian@awfulhak.org>
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> 
> Brian Somers writes:
>  > Synopsis: Fatal trap 12: page fault while in kernel mode (PPP/modems/cyclades?)
>  > 
>  > State-Changed-From-To: feedback-closed
>  > State-Changed-By: brian
>  > State-Changed-When: Mon Sep 8 14:00:11 PDT 1997
>  > State-Changed-Why: 
>  > I suspect this was the vjcompression thing.  I sent mail to
>  > the bug submitter, but never got a reply.
> 
> I must have missed it.  Aug 31 kernel (2.2-stable) has still crashed couple
> of times.  What kind of symptoms "vjcompression thing" fixed and when ?

This is the fix I was talking about, but it was committed back in 
June, so it looks like it didn't solve your problem:

revision 1.10
date: 1997/06/22 02:19:53;  author: brian;  state: Exp;  lines: +5 -1
Fix this damn mbuf with a negative m_len.  It turns
out to be a problem with VJ header compression.
davidg spotted this in usr.sbin/ppp/slcompress.c
a while ago, but I believe gave the wrong reasons -
it's too easy to reproduce !  The only scenario that
I've been able to reproduce the problem under is when
m_len is *exactly* 40 !  So go figure !

PR:             3749
Submitted elsewhere by: davidg
Obtained from: usr.sbin/ppp/slcompress.c


Have you tried disabling vj and predictor compression ?  It may make 
a difference.  Also, have you tried using user-mode ppp.  If this 
didn't work, we'd have access to a far more flexible logging system.

> -- 
> Heikki Suonsivu, T{ysikuu 10 C 83/02210 Espoo/FINLAND, hsu@clinet.fi
> mobile +358-40-5519679 work +358-9-43542270 fax -4555276

-- 
Brian <brian@awfulhak.org>, <brian@freebsd.org>
      <http://www.awfulhak.org>
Don't _EVER_ lose your sense of humour....