From owner-freebsd-current@FreeBSD.ORG Wed Dec 10 10:58:31 2003 Return-Path: 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 9E26916A4CE for ; Wed, 10 Dec 2003 10:58:31 -0800 (PST) Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.86.163]) by mx1.FreeBSD.org (Postfix) with ESMTP id B1C1843D1F for ; Wed, 10 Dec 2003 10:58:27 -0800 (PST) (envelope-from phk@phk.freebsd.dk) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.12.10/8.12.10) with ESMTP id hBAIwPV8058734 for ; Wed, 10 Dec 2003 19:58:26 +0100 (CET) (envelope-from phk@phk.freebsd.dk) To: current@freebsd.org From: Poul-Henning Kamp Date: Wed, 10 Dec 2003 19:58:25 +0100 Message-ID: <58733.1071082705@critter.freebsd.dk> Subject: kernel pointer polka, possibly by mount_nfs X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 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: Wed, 10 Dec 2003 18:58:31 -0000 I have a 100% reproducible case here where it looks like mount_nfs tramples on the softc of a led(4) device. Stock -current kernel, HZ=1000, I've added a couple of sanity-checks in the timeout routine of led(4) and they trigger reliably on a byte which should not have been zero. In all cases so far, the currently running program is mount_nfs run from /etc/rc.mumble somewhere. The machine is a Soekris 4501 booting diskless. I have also seen a reproducible page fault panic in in_pcbremlist() if I put "set -x" as the second line in /etc/rc on the same machine, it smells the same to me. This problem likely affects 5.2-WHATEVER as well, and could be responsible for other Heisenbugs, and could be considered a showstopper. If anybody is interested in working on this, I'll be happy to test patches or provide tracebacks etc from DDB (sorry, no GDB spoken). -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.