From owner-freebsd-current@FreeBSD.ORG Fri Feb 6 14:13:54 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4D7DB1065670; Fri, 6 Feb 2009 14:13:54 +0000 (UTC) (envelope-from olli@lurza.secnetix.de) Received: from lurza.secnetix.de (unknown [IPv6:2a01:170:102f::2]) by mx1.freebsd.org (Postfix) with ESMTP id AC0918FC1F; Fri, 6 Feb 2009 14:13:53 +0000 (UTC) (envelope-from olli@lurza.secnetix.de) Received: from lurza.secnetix.de (localhost [127.0.0.1]) by lurza.secnetix.de (8.14.3/8.14.3) with ESMTP id n16EDgeq065858; Fri, 6 Feb 2009 15:13:43 +0100 (CET) (envelope-from oliver.fromme@secnetix.de) Received: (from olli@localhost) by lurza.secnetix.de (8.14.3/8.14.3/Submit) id n16EDgii065856; Fri, 6 Feb 2009 15:13:42 +0100 (CET) (envelope-from olli) From: Oliver Fromme Message-Id: <200902061413.n16EDgii065856@lurza.secnetix.de> To: c47g@gmx.at (Christian Gusenbauer) Date: Fri, 6 Feb 2009 15:13:42 +0100 (CET) In-Reply-To: <200902061413.53508.c47g@gmx.at> X-Mailer: ELM [version 2.5 PL8] MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.1.2 (lurza.secnetix.de [127.0.0.1]); Fri, 06 Feb 2009 15:13:43 +0100 (CET) Cc: freebsd-hackers@freebsd.org, freebsd-current@freebsd.org Subject: Re: CFT: Graphics support for /boot/loader 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: Fri, 06 Feb 2009 14:13:54 -0000 Christian Gusenbauer wrote: > Oliver Fromme wrote: > > Danny Braniss wrote: > > > just tried it via pxe: > > > > > > panic: free: guard1 @ 0x7f3a4aec from /usr/src/lib/libstand/close.c:79 > > > > > > what changes are needed in pxeboot? > > > > The panic message means that the heap memory was corruped. > > It could be caused by a buffer overflow or similar. > > I'll try to look into it. > > I got this some years ago when I played with FreeBSD 6.1. It has something to > do with reading/parsing the loader.conf file. Inserting some dummy lines > (comments etc.) into loader.conf solves it (at least that's a workaround). As > I've never seen it again since 6.1 I thought it has already been fixed :-(. I think that's unrelated. That guard panic just means that the program has written beyond the memory that was allocated. Unfortunately it is difficult to find the piece of code responsible for that behaviour (especially when I can't reproduce the problem myself because I don't have a PXE- capable machine). It could be almost anywhere. In fact, the bug doesn't even have to be in the C code: FORTH supports (and even encourages) pointer arithmetic, too. This is real fun ... Best regards Oliver -- Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing b. M. Handelsregister: Registergericht Muenchen, HRA 74606, Geschäftsfuehrung: secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht Mün- chen, HRB 125758, Geschäftsführer: Maik Bachmann, Olaf Erb, Ralf Gebhart FreeBSD-Dienstleistungen, -Produkte und mehr: http://www.secnetix.de/bsd "Unix gives you just enough rope to hang yourself -- and then a couple of more feet, just to be sure." -- Eric Allman