From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965739AbXDBT3n (ORCPT ); Mon, 2 Apr 2007 15:29:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965738AbXDBT3n (ORCPT ); Mon, 2 Apr 2007 15:29:43 -0400 Received: from verein.lst.de ([213.95.11.210]:57593 "EHLO mail.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965730AbXDBT3m (ORCPT ); Mon, 2 Apr 2007 15:29:42 -0400 Date: Mon, 2 Apr 2007 21:29:40 +0200 From: Christoph Hellwig To: David Miller Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, hch@lst.de, tcallawa@redhat.com Subject: Re: [PATCH]: Fix scsi_send_eh_cmnd scatterlist handling Message-ID: <20070402192940.GA6644@lst.de> References: <20070402.122439.71098419.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070402.122439.71098419.davem@davemloft.net> User-Agent: Mutt/1.3.28i X-Spam-Score: -0.001 () BAYES_44 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 02, 2007 at 12:24:39PM -0700, David Miller wrote: > > This fixes a regression caused by commit: > > 2dc611de5a3fd955cd0298c50691d4c05046db97 > > The sense buffer code in scsi_send_eh_cmnd was changed to use > alloc_page() and a scatter list, but the sense data copy was not > updated to match so what we actually get in the sense buffer is total > grabage starting with the kernel address of the struct page we got. > Basically the stack frame of scsi_send_eh_cmd() is what ends up > in the sense buffer. > > Depending upon how pointers look on a given platform, you can > end up getting sr_ioctl.c errors when you mount a cdrom. If > the CDROM gives a check condition for GPCMD_GET_CONFIGURATION issued > by drivers/cdrom/cdrom.c:cdrom_mmc_profile(), sr_ioctl will > spit out this error message in sr_do_ioctl() with the way pointers > are on sparc64: > > default: > printk(KERN_ERR "%s: CDROM (ioctl) error, command: ", cd->cdi.name); > __scsi_print_command(cgc->cmd); > scsi_print_sense_hdr("sr", &sshdr); > err = -EIO; > > This is the error Tom Callaway reported in: > > http://marc.info/?l=linux-sparc&m=117407453208101&w=2 > > Anyways, fix this by using page_address(sgl.page) which is OK > because we know this is low-mem due to GFP_ATOMIC. The patch looks correct to me and thanks for spotting this stupid bug!