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 81012C28CF6 for ; Wed, 1 Aug 2018 08:25:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 42C742083E for ; Wed, 1 Aug 2018 08:25:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 42C742083E 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 S2388662AbeHAKJy (ORCPT ); Wed, 1 Aug 2018 06:09:54 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:60782 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2387699AbeHAKJx (ORCPT ); Wed, 1 Aug 2018 06:09:53 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id C9F94D586D2F1; Wed, 1 Aug 2018 16:25:11 +0800 (CST) Received: from [10.177.253.249] (10.177.253.249) by smtp.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.399.0; Wed, 1 Aug 2018 16:25:07 +0800 Subject: Re: [PATCH] net/9p/trans_virtio.c: add a terminal char for mount tag To: Dominique Martinet References: <5B6164F6.60004@huawei.com> <20180801081157.GA20127@nautica> CC: "akpm@linux-foundation.org" , "Linux Kernel Mailing List" , , Greg Kurz From: piaojun Message-ID: <5B616E3B.4050205@huawei.com> Date: Wed, 1 Aug 2018 16:24:27 +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: <20180801081157.GA20127@nautica> Content-Type: text/plain; charset="utf-8" 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 Hi Dominique, On 2018/8/1 16:11, Dominique Martinet wrote: > piaojun wrote on Wed, Aug 01, 2018: >> chan->tag has no terminal char at last which will result in printing messy >> code when debugging code. So we should add '\0' for tag. > > 9p is full of non null-terminated string so I'm not sure how I feel > about it, is there anything wrong with how this is used or was this just > when you tried to printf it? There is nothing wrong at the places using tag, as they calculated the tag_len carefully. Adding '\0' for it will make the code more robust. And I'm glad to hear others' opinions. Thanks, Jun > > If it's just for debugging I'd suggest using the printf format "%.*s" > with "chan->tag_len, chan->tag" arguments, > > > That said it's not like this is costly, so I'll take it if someone else > thinks this is helpful > >> >> Signed-off-by: Jun Piao >> --- >> net/9p/trans_virtio.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c >> index d422bfc..49d71d6 100644 >> --- a/net/9p/trans_virtio.c >> +++ b/net/9p/trans_virtio.c >> @@ -585,7 +585,7 @@ static int p9_virtio_probe(struct virtio_device *vdev) >> err = -EINVAL; >> goto out_free_vq; >> } >> - tag = kmalloc(tag_len, GFP_KERNEL); >> + tag = kzalloc(tag_len + 1, GFP_KERNEL); >> if (!tag) { >> err = -ENOMEM; >> goto out_free_vq; >> --