From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: [PATCH]scsi: BUG_ON() impossible condition. Date: Mon, 19 Nov 2007 11:28:48 +1100 Message-ID: <200711191128.48340.rusty@rustcorp.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from ozlabs.org ([203.10.76.45]:57325 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752718AbXKSA3L (ORCPT ); Sun, 18 Nov 2007 19:29:11 -0500 Content-Disposition: inline Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James.Bottomley@hansenpartnership.com Cc: linux-scsi@vger.kernel.org If blk_rq_map_sg wrote more than was allocated in the scatterlist, BUG_ON() is probably the right thing to do. Signed-off-by: Rusty Russell Acked-by: Jens Axboe --- drivers/scsi/scsi_tgt_lib.c | 11 +++-------- 1 files changed, 3 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1102,7 +1102,6 @@ void scsi_io_completion(struct scsi_cmnd * * Returns: 0 on success * BLKPREP_DEFER if the failure is retryable - * BLKPREP_KILL if the failure is fatal */ static int scsi_init_io(struct scsi_cmnd *cmd) { @@ -1136,17 +1135,9 @@ static int scsi_init_io(struct scsi_cmnd * each segment. */ count = blk_rq_map_sg(req->q, req, cmd->request_buffer); - if (likely(count <= cmd->use_sg)) { - cmd->use_sg = count; - return BLKPREP_OK; - } - - printk(KERN_ERR "Incorrect number of segments after building list\n"); - printk(KERN_ERR "counted %d, received %d\n", count, cmd->use_sg); - printk(KERN_ERR "req nr_sec %lu, cur_nr_sec %u\n", req->nr_sectors, - req->current_nr_sectors); - - return BLKPREP_KILL; + BUG_ON(count > cmd->use_sg); + cmd->use_sg = count; + return BLKPREP_OK; } static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev, diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c --- a/drivers/scsi/scsi_tgt_lib.c +++ b/drivers/scsi/scsi_tgt_lib.c @@ -367,14 +367,9 @@ static int scsi_tgt_init_cmd(struct scsi dprintk("cmd %p cnt %d %lu\n", cmd, cmd->use_sg, rq_data_dir(rq)); count = blk_rq_map_sg(rq->q, rq, cmd->request_buffer); - if (likely(count <= cmd->use_sg)) { - cmd->use_sg = count; - return 0; - } - - eprintk("cmd %p cnt %d\n", cmd, cmd->use_sg); - scsi_free_sgtable(cmd); - return -EINVAL; + BUG_ON(count > cmd->use_sg); + cmd->use_sg = count; + return 0; } /* TODO: test this crap and replace bio_map_user with new interface maybe */