Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030411AbXFHOMd (ORCPT ); Fri, 8 Jun 2007 10:12:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S968685AbXFHOMZ (ORCPT ); Fri, 8 Jun 2007 10:12:25 -0400 Received: from adsl-70-250-156-241.dsl.austtx.swbell.net ([70.250.156.241]:57978 "EHLO gw.microgate.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S968350AbXFHOMY (ORCPT ); Fri, 8 Jun 2007 10:12:24 -0400 Subject: Re: [Bug 8473] New: Oops: 0010 [1] SMP From: Paul Fulghum To: Andrew Morton Cc: =?ISO-8859-1?Q?Bj=F6rn?= Steinbrink , Arnd Bergmann , Alan Cox , Nicolas Mailhot , Randy Dunlap , "bugme-daemon@kernel-bugs.osdl.org" , linux-kernel@vger.kernel.org, Mel Gorman , Christoph Lameter In-Reply-To: <20070607201604.726094fc.akpm@linux-foundation.org> References: <200705132102.l4DL2onF003014@fire-2.osdl.org> <20070513154718.bb338ceb.akpm@linux-foundation.org> <1179098742.7322.5.camel@rousalka.dyndns.org> <1179396003.31796.4.camel@rousalka.dyndns.org> <20070517094557.c96f7e54.randy.dunlap@oracle.com> <1179421196.5000.5.camel@rousalka.dyndns.org> <1180206615.3430.8.camel@rousalka.dyndns.org> <20070608030629.GA18493@atjola.homenet> <20070607201604.726094fc.akpm@linux-foundation.org> Content-Type: text/plain; charset=utf-8 Date: Fri, 08 Jun 2007 09:10:57 -0500 Message-Id: <1181311857.3985.7.camel@amdx2.microgate.com> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-4.fc4) Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1462 Lines: 39 On Thu, 2007-06-07 at 20:16 -0700, Andrew Morton wrote: > On Fri, 8 Jun 2007 05:06:29 +0200 Björn Steinbrink wrote: > > This is do_tty_hangup() exchanging the fops while we're waiting for the > > lock. The new fops (hung_up_tty_fops) only have the unlocked variant and > > thus we Oops our way. > > ah, yes, that explains it, thanks. Culprit: > > commit e10cc1df1d2014f68a4bdcf73f6dd122c4561f94 > Author: Paul Fulghum > Date: Thu May 10 22:22:50 2007 -0700 > > tty: add compat_ioctl > > Add compat_ioctl method for tty code to allow processing of 32 bit ioctl > calls on 64 bit systems by tty core, tty drivers, and line disciplines. OK, the change of hung_up_tty_ioctl() from locked to unlocked is not necessary for this patch. On the surface it seemed a clever way of not needing two different functions to do the same simple: return cmd == TIOCSPGRP ? -ENOTTY : -EIO; which does not need any locking for its own sake. But clearly the hangup behavior requires the locked version. I'll redo the patch with hung_up_tty_ioctl remaining locked. That will separate the compat ioctl stuff from this issue. -- Paul Fulghum Microgate Systems, Ltd - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/