From owner-freebsd-current@FreeBSD.ORG Sat Aug 19 07:08:09 2006 Return-Path: X-Original-To: current@FreeBSD.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3233216A4DE; Sat, 19 Aug 2006 07:08:09 +0000 (UTC) (envelope-from yar@comp.chem.msu.su) Received: from comp.chem.msu.su (comp.chem.msu.su [158.250.32.97]) by mx1.FreeBSD.org (Postfix) with ESMTP id 53B7E43D45; Sat, 19 Aug 2006 07:08:08 +0000 (GMT) (envelope-from yar@comp.chem.msu.su) Received: from comp.chem.msu.su (localhost [127.0.0.1]) by comp.chem.msu.su (8.13.4/8.13.3) with ESMTP id k7J785EY023136; Sat, 19 Aug 2006 11:08:05 +0400 (MSD) (envelope-from yar@comp.chem.msu.su) Received: (from yar@localhost) by comp.chem.msu.su (8.13.4/8.13.3/Submit) id k7J785Hv023135; Sat, 19 Aug 2006 11:08:05 +0400 (MSD) (envelope-from yar) Date: Sat, 19 Aug 2006 11:08:05 +0400 From: Yar Tikhiy To: Pawel Jakub Dawidek Message-ID: <20060819070804.GA23066@comp.chem.msu.su> References: <20060818184656.GB16008@comp.chem.msu.su> <20060818191457.GA78998@xor.obsecurity.org> <20060818202508.GA88159@garage.freebsd.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060818202508.GA88159@garage.freebsd.pl> User-Agent: Mutt/1.5.9i Cc: current@FreeBSD.org, Kris Kennaway Subject: Re: mount * 2 + umount + lookup = GEOM panic X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 19 Aug 2006 07:08:09 -0000 On Fri, Aug 18, 2006 at 10:25:08PM +0200, Pawel Jakub Dawidek wrote: > On Fri, Aug 18, 2006 at 03:14:57PM -0400, Kris Kennaway wrote: > > On Fri, Aug 18, 2006 at 10:46:57PM +0400, Yar Tikhiy wrote: > > > Hi all, > > > > > > Here is a recipe how to panic CURRENT's GENERIC kernel from the > > > command line: > > > > > > (enter single-user mode) > > > > > > # mount -r /usr > > > # mount -r /usr > > > # umount /usr > > > # cat > > > [panic!] > > > > > > As shown below, the panic happens in GEOM when /bin/sh searches > > > $PATH for cat(1). The recipe works in 6-STABLE, too. Is anybody > > > interested? Thanks! > > > > This has been reported a number of times before, apparently it's > > difficult to solve. > > No, it's difficult to solve in a architectural clean way, but IMHO this > bug should be fixed. I've a fix for this (which allows for multiple > read-only mounts). It's hackish, but works. > > Unfortunately phk@ didn't agree on committing it, so next time, please > CC him:) Just to satisfy my curiosity: Do you have references to a discussion of the problem? When such a simple script triggers an architectural issue, the latter is definitely worth taking a glance at. :-) Thanks! -- Yar