From owner-freebsd-hackers@FreeBSD.ORG  Thu Apr  3 20:17:14 2014
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115])
 (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id 7F28E416
 for <freebsd-hackers@freebsd.org>; Thu,  3 Apr 2014 20:17:14 +0000 (UTC)
Received: from bigwig.baldwin.cx (bigwig.baldwin.cx [IPv6:2001:470:1f11:75::1])
 (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id 56FC5A46
 for <freebsd-hackers@freebsd.org>; Thu,  3 Apr 2014 20:17:14 +0000 (UTC)
Received: from jhbbsd.localnet (unknown [209.249.190.124])
 by bigwig.baldwin.cx (Postfix) with ESMTPSA id 3D332B97F;
 Thu,  3 Apr 2014 16:17:13 -0400 (EDT)
From: John Baldwin <jhb@freebsd.org>
To: Karl Pielorz <kpielorz_lst@tdx.co.uk>
Subject: Re: Stuck CLOSED sockets / sshd / zombies...
Date: Thu, 3 Apr 2014 16:14:40 -0400
User-Agent: KMail/1.13.5 (FreeBSD/8.4-CBSD-20130906; KDE/4.5.5; amd64; ; )
References: <3FE645E9723756F22EF901AE@Mail-PC.tdx.co.uk>
 <201404031232.16465.jhb@freebsd.org>
 <4B53DEF2407E2EC90A8DDF9D@study64.tdx.co.uk>
In-Reply-To: <4B53DEF2407E2EC90A8DDF9D@study64.tdx.co.uk>
MIME-Version: 1.0
Content-Type: Text/Plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Message-Id: <201404031614.40951.jhb@freebsd.org>
X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7
 (bigwig.baldwin.cx); Thu, 03 Apr 2014 16:17:13 -0400 (EDT)
Cc: freebsd-hackers@freebsd.org
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
 <freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-hackers>, 
 <mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers/>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
 <mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 03 Apr 2014 20:17:14 -0000

On Thursday, April 03, 2014 3:38:39 pm Karl Pielorz wrote:
> 
> --On 3 April 2014 12:32:16 -0400 John Baldwin <jhb@freebsd.org> wrote:
> 
> >> "
> >> USER   CMD     PID  FD MOUNT  INUM MODE         SZ|DV R/W
> >> root   sshd   4346   8* local stream fffff80002e55c30 <->
> >> fffff80002e552d0 ...
> >> root   sshd   4344   4* local stream fffff80002e552d0 <->
> >> fffff80002e55c30 "
> >
> > Right, so it's just blocked on a UNIX domain socket from the parent
> > waiting for the parent to tell it to do something.  The root issue is the
> > parent (as I feared).  Is 4344 threaded (procstat -t?)
> 
> "
> # procstat -t 4344
>   PID    TID COMM             TDNAME           CPU  PRI STATE   WCHAN
>  4344 100068 sshd             -                  0  120 sleep   urdlck
> "

That's really odd.  A single threaded program has no business even trying
to grab a lock.  Is your sshd even linked against libthr via ldd?

-- 
John Baldwin