From owner-freebsd-bugs  Mon Apr 21 21:55:46 1997
Return-Path: <owner-bugs>
Received: (from root@localhost)
          by freefall.freebsd.org (8.8.5/8.8.5) id VAA13678
          for bugs-outgoing; Mon, 21 Apr 1997 21:55:46 -0700 (PDT)
Received: from sendero.i-connect.net (sendero-ppp.i-Connect.Net [206.190.143.100])
          by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id VAA13666
          for <freebsd-bugs@freebsd.org>; Mon, 21 Apr 1997 21:55:43 -0700 (PDT)
Received: (from shimon@localhost)
	by sendero.i-connect.net (8.8.5/8.8.5) id VAA00363;
	Mon, 21 Apr 1997 21:55:28 -0700 (PDT)
Message-ID: <XFMail.970421215527.Shimon@i-Connect.Net>
X-Mailer: XFMail 1.1-alpha [p0] on FreeBSD
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 8bit
MIME-Version: 1.0
In-Reply-To: <19970421152036.AM09487@uriah.heep.sax.de>
Date: Mon, 21 Apr 1997 18:20:48 -0700 (PDT)
Organization: iConnect Corp.
From: Simon Shapiro <Shimon@i-Connect.Net>
To: (Joerg Wunsch) <joerg_wunsch@uriah.heep.sax.de>
Subject: Re: Mystery of the X11 Panic...
Cc: freebsd-bugs@freebsd.org, (J Wunsch) <j@uriah.heep.sax.de>
Sender: owner-bugs@freebsd.org
X-Loop: FreeBSD.org
Precedence: bulk


Hi J Wunsch;  On 21-Apr-97 you wrote: 
> As David Greenman wrote:
> 
> > >This means that cdevsw[maj]->d_open is bad (probably null) although
> > >cdevsw[maj] != NULL.  This might be caused by a buggy or stale LKM.
> 
> Nope, Bruce:
> 
>                 if ( (cdevsw[maj] == NULL) || (cdevsw[maj]->d_open ==
> NULL))
>                                                ^^^^^^^^^^^^^^^^^^^
>                         return ENXIO;
> 
> This case is tested, and it's actually this test itself that causes
> the panic.
> 
> >    ...or it could be caused by the bug in kern_exec.c, which could have
> > mangled adjacent buffers or possibly random kernel memory. It seems
> > to involve bash and the kern_exec.c bug was triggered when running
> small
> > shell scripts.
> 
> This seems more reasonable after reading that piece of code.
> 
> Simon didn't tell us the faulting VA, but i bet it's not right NULL.

No, i did not, but AFAICR it was not null.  These are easier to spot.  Even
i can track these down ;-)

Simon