From owner-freebsd-current@FreeBSD.ORG Sat May 8 20:26:55 2010 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 98E7D1065672; Sat, 8 May 2010 20:26:55 +0000 (UTC) (envelope-from kaduk@mit.edu) Received: from dmz-mailsec-scanner-8.mit.edu (DMZ-MAILSEC-SCANNER-8.MIT.EDU [18.7.68.37]) by mx1.freebsd.org (Postfix) with ESMTP id 40EF68FC08; Sat, 8 May 2010 20:26:55 +0000 (UTC) X-AuditID: 12074425-b7d00ae000002295-47-4be5c5885901 Received: from mailhub-auth-3.mit.edu (MAILHUB-AUTH-3.MIT.EDU [18.9.21.43]) by dmz-mailsec-scanner-8.mit.edu (Symantec Brightmail Gateway) with SMTP id 83.1B.08853.885C5EB4; Sat, 8 May 2010 16:11:52 -0400 (EDT) Received: from outgoing.mit.edu (OUTGOING-AUTH.MIT.EDU [18.7.22.103]) by mailhub-auth-3.mit.edu (8.13.8/8.9.2) with ESMTP id o48KBqPx008510; Sat, 8 May 2010 16:11:52 -0400 Received: from multics.mit.edu (MULTICS.MIT.EDU [18.187.1.73]) (authenticated bits=56) (User authenticated as kaduk@ATHENA.MIT.EDU) by outgoing.mit.edu (8.13.6/8.12.4) with ESMTP id o48KBnBV020054 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Sat, 8 May 2010 16:11:51 -0400 (EDT) Received: (from kaduk@localhost) by multics.mit.edu (8.12.9.20060308) id o48KBndL024796; Sat, 8 May 2010 16:11:49 -0400 (EDT) Date: Sat, 8 May 2010 16:11:49 -0400 (EDT) From: Benjamin Kaduk To: Weongyo Jeong In-Reply-To: <20100508200032.GB31100@weongyo> Message-ID: References: <20100508200032.GB31100@weongyo> User-Agent: Alpine 1.10 (GSO 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Brightmail-Tracker: AAAAAA== Cc: current@freebsd.org Subject: Re: a panic on uart_z8530_class? 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, 08 May 2010 20:26:55 -0000 On Sat, 8 May 2010, Weongyo Jeong wrote: > Hello, > > Anyone encountered this panic on recent CURRENT kernel? > db> bt > Tracing pid 1795 tid 100096 td 0xffffff0003d8b390 > uart_z8530_class() at 0 > ifc_simple_create() at ifc_simple_create+0x89 > if_clone_createif() at if_clone_createif+0x64 > ifioctl() at ifioctl+0x685 > kern_ioctl() at kern_ioctl+0xc5 > ioctl() at ioctl+0xfd > syscall() at syscall+0x102 > Xfast_syscall() at Xfast_syscall+0xe1 > --- syscall (54, FreeBSD ELF64, ioctl), rip = 0x800b86d0c, rsp = 0x7fffffffe2e8, rbp = 0x7fffffffee36 --- I haven't seen that particular panic, but I have seen uart_z8530_class (or something superficially similar to it) in stack traces that I can't see touching a uart device. > [root@test ~]# kgdb /boot/kernel/kernel /var/crash/vmcore.1 > GNU gdb 6.1.1 [FreeBSD] > Copyright 2004 Free Software Foundation, Inc. > GDB is free software, covered by the GNU General Public License, and you are > welcome to change it and/or distribute copies of it under certain conditions. > Type "show copying" to see the conditions. > There is absolutely no warranty for GDB. Type "show warranty" for details. > This GDB was configured as "amd64-marcel-freebsd"... > Cannot access memory at address 0xffffff0127ffffe0 > (kgdb) bt > #0 0x0000000000000000 in ?? () > Cannot access memory at address 0x0 > (kgdb) q I have seen this behavior from kgdb --- it doesn't seem to be able to handle coredumps I've made recently. At first I thought that I managed to trash either my kernel image or kgdb binary with all the unclean shutdowns I've been having, but if you're seeing kgdb failures, maybe it's not just my local system. Yet I am assuming that this is not broken for *everyone*, or we would have heard more noise about it. I'm running a current snapshot from April 4th; maybe I will try updating to a new snapshot tonight and see if kgdb behaves better after everything is rebuilt. -Ben Kaduk