From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755550AbaGVO67 (ORCPT ); Tue, 22 Jul 2014 10:58:59 -0400 Received: from e28smtp06.in.ibm.com ([122.248.162.6]:49601 "EHLO e28smtp06.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755197AbaGVO64 (ORCPT ); Tue, 22 Jul 2014 10:58:56 -0400 Message-ID: <53CE7C29.6050908@linux.vnet.ibm.com> Date: Tue, 22 Jul 2014 22:58:49 +0800 From: Mike Qiu User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130805 Thunderbird/17.0.8 MIME-Version: 1.0 To: Mike Qiu CC: linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, tj@kernel.org, wenxiong@linux.vnet.ibm.com, brking@linux.vnet.ibm.com, zhenghch@cn.ibm.com, haokexin@gmail.com Subject: Re: [PATCH 2/2] libata: Fix NULL pointer of scsi_host in ata_port References: <1406040688-1762-1-git-send-email-qiudayu@linux.vnet.ibm.com> In-Reply-To: <1406040688-1762-1-git-send-email-qiudayu@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14072214-9574-0000-0000-0000002A3F00 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [+cc Wendy, Brian King, Stephen] On 07/22/2014 10:51 PM, Mike Qiu wrote: > In ata_sas_port_alloc(), it haven't initialized scsi_host field in > ata_port, although scsi_host is in parameters list and unused in this > function. > > With commit 1871ee134b73 ("libata: support the ata host which implements a queue depth less than 32") > ata_qc_new() try to use scsi_host, while it > is a NULL pointer for ipr IOA and error message shows below: > > Unable to handle kernel paging request for data at address 0x00000114 > Faulting instruction address: 0xc0000000005c2580 > Oops: Kernel access of bad area, sig: 11 [#1] > ... > NIP [c0000000005c2580] .ata_qc_new_init+0x30/0x1f0 > LR [c0000000005c9384] .ata_scsi_translate+0x44/0x230 > Call Trace: > 0xc0000003ad332280 (unreliable) > .ata_scsi_translate+0x44/0x230 > .ipr_queuecommand+0x2e0/0x780 [ipr] > .scsi_dispatch_cmd+0xec/0x400 > .scsi_request_fn+0x52c/0x670 > .__blk_run_queue+0x5c/0x80 > .blk_execute_rq_nowait+0xf8/0x1c0 > .blk_execute_rq+0x88/0x150 > .scsi_execute+0xf0/0x1f0 > .scsi_execute_req_flags+0xc4/0x170 > .scsi_probe_and_add_lun+0x2d4/0xe00 > .__scsi_scan_target+0x1a4/0x790 > .scsi_scan_channel.part.3+0x80/0xc0 > .scsi_scan_host_selected+0x1a0/0x240 > .do_scan_async+0x30/0x210 > .async_run_entry_fn+0x78/0x1c0 > .process_one_work+0x1c4/0x4a0 > .worker_thread+0x184/0x600 > .kthread+0x10c/0x130 > .ret_from_kernel_thread+0x58/0x7c > > While scsi_host is unused in ata_sas_port_alloc(), better to set it > in ata_sas_port_alloc() instead of in driver. > > Signed-off-by: Mike Qiu > --- > drivers/ata/libata-scsi.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c > index 0586f66..a472b6f 100644 > --- a/drivers/ata/libata-scsi.c > +++ b/drivers/ata/libata-scsi.c > @@ -4070,6 +4070,7 @@ struct ata_port *ata_sas_port_alloc(struct ata_host *host, > ap->flags |= port_info->flags; > ap->ops = port_info->port_ops; > ap->cbl = ATA_CBL_SATA; > + ap->scsi_host = shost; > > return ap; > }