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Date: Mon, 23 Jun 2014 01:16:20 +0200
From: =?windows-1250?Q?Pawe=B3_Tyll?= <ofca@ofca.me>
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Message-ID: <2510165566.20140623011620@ofca.me>
To: Adrian Chadd <adrian@freebsd.org>
Subject: Re: FreeBSD 9 as PPPoE BRAS(mpd 5.7) kernel panic
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References: <53A719C3.3040002@hostelnet.ru>
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Hello Adrian,

Sunday, June 22, 2014, 8:14:22 PM, you wrote:
> They're NULL pointer derferences, so it's likely a race condition with
> some other thread destroying something and setting the pointer value
> to NULL somewhere.

> I thought this was a reasonably well known problem? Was it ever fixed
> in 10/head?
It  probably  wasn't, since I had similar issues on 10-STABLE r266523.
It's  caused  (most  often)  by  packet returning from traffic shaping
queues, when in the meantime ng interface got destroyed by mpd. That's
why the sleep hack works; mpd destroys interface 1s later that usual.

Curious  though,  that  hostelnet uses ng_car for traffic shaping, yet
things  still panic, even though whole ordeal happens inside netgraph.

Lots of entry-points for a fix :)