From patchwork Mon Sep 28 21:46:06 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steve Wise X-Patchwork-Id: 7281121 Return-Path: X-Original-To: patchwork-linux-rdma@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 8AA86BF90C for ; Mon, 28 Sep 2015 21:46:12 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id BE369206AD for ; Mon, 28 Sep 2015 21:46:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D19C2206C5 for ; Mon, 28 Sep 2015 21:46:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752982AbbI1VqI (ORCPT ); Mon, 28 Sep 2015 17:46:08 -0400 Received: from smtp.opengridcomputing.com ([72.48.136.20]:50741 "EHLO smtp.opengridcomputing.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752013AbbI1VqH (ORCPT ); Mon, 28 Sep 2015 17:46:07 -0400 Received: from build2.ogc.int (build2.ogc.int [10.10.0.32]) by smtp.opengridcomputing.com (Postfix) with ESMTP id C8F9A29E61; Mon, 28 Sep 2015 16:46:06 -0500 (CDT) From: Steve Wise Subject: [PATCH RESEND] svcrdma: handle rdma read with a non-zero initial page offset To: bfields@fieldses.org Cc: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org Date: Mon, 28 Sep 2015 16:46:06 -0500 Message-ID: <20150928214605.17900.50257.stgit@build2.ogc.int> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The server rdma_read_chunk_lcl() and rdma_read_chunk_frmr() functions were not taking into account the initial page_offset when determining the rdma read length. This resulted in a read who's starting address and length exceeded the base/bounds of the frmr. Most work loads don't tickle this bug apparently, but one test hit it every time: building the linux kernel on a 16 core node with 'make -j 16 O=/mnt/0' where /mnt/0 is a ramdisk mounted via NFSRDMA. This bug seems to only be tripped with devices having small fastreg page list depths. I didn't see it with mlx4, for instance. Fixes: 0bf4828983df ('svcrdma: refactor marshalling logic') Signed-off-by: Steve Wise Tested-by: Chuck Lever --- net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c index cb51742..5f6ca47 100644 --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c @@ -136,7 +136,8 @@ int rdma_read_chunk_lcl(struct svcxprt_rdma *xprt, ctxt->direction = DMA_FROM_DEVICE; ctxt->read_hdr = head; pages_needed = min_t(int, pages_needed, xprt->sc_max_sge_rd); - read = min_t(int, pages_needed << PAGE_SHIFT, rs_length); + read = min_t(int, (pages_needed << PAGE_SHIFT) - *page_offset, + rs_length); for (pno = 0; pno < pages_needed; pno++) { int len = min_t(int, rs_length, PAGE_SIZE - pg_off); @@ -235,7 +236,8 @@ int rdma_read_chunk_frmr(struct svcxprt_rdma *xprt, ctxt->direction = DMA_FROM_DEVICE; ctxt->frmr = frmr; pages_needed = min_t(int, pages_needed, xprt->sc_frmr_pg_list_len); - read = min_t(int, pages_needed << PAGE_SHIFT, rs_length); + read = min_t(int, (pages_needed << PAGE_SHIFT) - *page_offset, + rs_length); frmr->kva = page_address(rqstp->rq_arg.pages[pg_no]); frmr->direction = DMA_FROM_DEVICE;