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Subject: Re: page fault in tcp_do_segment (r287759 suspected)
To: freebsd-net <freebsd-net@FreeBSD.org>,
 "George V. Neville-Neil" <gnn@FreeBSD.org>
References: <56011276.4060206@FreeBSD.org>
From: Andriy Gapon <avg@FreeBSD.org>
Message-ID: <560250B9.3080002@FreeBSD.org>
Date: Wed, 23 Sep 2015 10:11:53 +0300
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On 22/09/2015 11:33, Andriy Gapon wrote:
> That code actually looks like the following DTrace probe a few lines below:
> 
> TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));
> 
> So, it seems like 'm' could be NULL here.
> I see two places in tcp_do_segment() where m gets assigned with NULL followed by
> goto drop.  If I had to guess then my guess would be that one of those code
> paths was taken.
> Since those NULL assignments were there for more than a year, then I would guess
> that the addition of the probe is to blame:
> https://svnweb.freebsd.org/base?view=revision&revision=287759

Should I file a bug report about this?
Does anyone has suggestion for a simple fix?

-- 
Andriy Gapon