From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965992AbcJZN23 (ORCPT ); Wed, 26 Oct 2016 09:28:29 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:55074 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965136AbcJZMZg (ORCPT ); Wed, 26 Oct 2016 08:25:36 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alex Estrin , Bart Van Assche , Doug Ledford Subject: [PATCH 4.8 047/140] IB/srp: Fix infinite loop when FMR sg[0].offset != 0 Date: Wed, 26 Oct 2016 14:21:47 +0200 Message-Id: <20161026122222.386599543@linuxfoundation.org> X-Mailer: git-send-email 2.10.1 In-Reply-To: <20161026122220.384323763@linuxfoundation.org> References: <20161026122220.384323763@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bart Van Assche commit 681cc3608355737c1effebc8145f95c8c3344bc3 upstream. Avoid that mapping an sg-list in which the first element has a non-zero offset triggers an infinite loop when using FMR. This patch makes the FMR mapping code similar to that of ib_sg_to_pages(). Note: older Mellanox HCAs do not support non-zero offsets for FMR. See also commit 8c4037b501ac ("IB/srp: always avoid non-zero offsets into an FMR"). Reported-by: Alex Estrin Signed-off-by: Bart Van Assche Signed-off-by: Doug Ledford Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/ulp/srp/ib_srp.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -1400,7 +1400,9 @@ static int srp_map_sg_entry(struct srp_m while (dma_len) { unsigned offset = dma_addr & ~dev->mr_page_mask; - if (state->npages == dev->max_pages_per_mr || offset != 0) { + + if (state->npages == dev->max_pages_per_mr || + (state->npages > 0 && offset != 0)) { ret = srp_map_finish_fmr(state, ch); if (ret) return ret; @@ -1417,12 +1419,12 @@ static int srp_map_sg_entry(struct srp_m } /* - * If the last entry of the MR wasn't a full page, then we need to + * If the end of the MR is not on a page boundary then we need to * close it out and start a new one -- we can only merge at page * boundaries. */ ret = 0; - if (len != dev->mr_page_size) + if ((dma_addr & ~dev->mr_page_mask) != 0) ret = srp_map_finish_fmr(state, ch); return ret; }