From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1139CC28CF6 for ; Fri, 3 Aug 2018 06:19:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C33FB21711 for ; Fri, 3 Aug 2018 06:19:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C33FB21711 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728574AbeHCIOF (ORCPT ); Fri, 3 Aug 2018 04:14:05 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:10618 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727226AbeHCIOF (ORCPT ); Fri, 3 Aug 2018 04:14:05 -0400 Received: from DGGEMS413-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 3FAC6620A7B4; Fri, 3 Aug 2018 14:19:19 +0800 (CST) Received: from [10.177.253.249] (10.177.253.249) by smtp.huawei.com (10.3.19.213) with Microsoft SMTP Server id 14.3.399.0; Fri, 3 Aug 2018 14:19:14 +0800 Subject: Re: [V9fs-developer] [PATCH] net/9p: Modify the problem of BUG_ON judgment To: jiangyiwen , Eric Van Hensbergen , Ron Minnich , Latchesar Ionkov , Dominique Martinet References: <5B63D5F6.6080109@huawei.com> CC: , Linux Kernel Mailing List , From: piaojun Message-ID: <5B63F3D1.3020408@huawei.com> Date: Fri, 3 Aug 2018 14:18:57 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <5B63D5F6.6080109@huawei.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.253.249] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org LGTM On 2018/8/3 12:11, jiangyiwen wrote: > Because the value of limit is VIRTQUEUE_NUM, if index is equal to > limit, it will cause sg array out of bounds, so correct the judgement > of BUG_ON. > > Signed-off-by: Yiwen Jiang Acked-by: Jun Piao > --- > net/9p/trans_virtio.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c > index 6265d1d..08264ba 100644 > --- a/net/9p/trans_virtio.c > +++ b/net/9p/trans_virtio.c > @@ -191,7 +191,7 @@ static int pack_sg_list(struct scatterlist *sg, int start, > s = rest_of_page(data); > if (s > count) > s = count; > - BUG_ON(index > limit); > + BUG_ON(index >= limit); > /* Make sure we don't terminate early. */ > sg_unmark_end(&sg[index]); > sg_set_buf(&sg[index++], data, s); > @@ -236,6 +236,7 @@ static int p9_virtio_cancel(struct p9_client *client, struct p9_req_t *req) > s = PAGE_SIZE - data_off; > if (s > count) > s = count; > + BUG_ON(index >= limit); > /* Make sure we don't terminate early. */ > sg_unmark_end(&sg[index]); > sg_set_page(&sg[index++], pdata[i++], s, data_off); >