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Date: Mon, 23 Jun 2014 12:42:35 +0800
From: Julian Elischer <julian@freebsd.org>
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To: =?UTF-8?B?UGF3ZcWCIFR5bGw=?= <ofca@ofca.me>,
 Adrian Chadd <adrian@freebsd.org>
Subject: Re: FreeBSD 9 as PPPoE BRAS(mpd 5.7) kernel panic
References: <53A719C3.3040002@hostelnet.ru>
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Cc: FreeBSD Net <freebsd-net@freebsd.org>, noc@hostelnet.ru
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On 6/23/14, 7:16 AM, Paweł Tyll wrote:
> 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 :)

probably means we need to look at a netgraph framework based fix.

>
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