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 2F81EC28CF6 for ; Fri, 3 Aug 2018 09:23:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8823B21717 for ; Fri, 3 Aug 2018 09:22:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8823B21717 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 S1732305AbeHCLSX (ORCPT ); Fri, 3 Aug 2018 07:18:23 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:45217 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728122AbeHCLSX (ORCPT ); Fri, 3 Aug 2018 07:18:23 -0400 Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id B4C14AE70EA69; Fri, 3 Aug 2018 17:22:52 +0800 (CST) Received: from [10.177.253.249] (10.177.253.249) by smtp.huawei.com (10.3.19.205) with Microsoft SMTP Server id 14.3.399.0; Fri, 3 Aug 2018 17:22:50 +0800 To: Dominique Martinet CC: "akpm@linux-foundation.org" , Greg Kurz , Eric Van Hensbergen , Ron Minnich , Latchesar Ionkov , "Linux Kernel Mailing List" , From: piaojun Subject: [PATCH v3] net/9p/trans_virtio.c: add null terminal for mount tag Message-ID: <5B641ECC.5030401@huawei.com> Date: Fri, 3 Aug 2018 17:22:20 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 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 chan->tag is Non-null terminated which will result in printing messy code when debugging code. So we should add '\0' for tag to make the code more convenient and robust. In addition, I drop char->tag_len to simplify the code. Signed-off-by: Jun Piao --- net/9p/trans_virtio.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index d422bfc..46a5ab2 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -89,10 +89,8 @@ struct virtio_chan { unsigned long p9_max_pages; /* Scatterlist: can be too big for stack. */ struct scatterlist sg[VIRTQUEUE_NUM]; - - int tag_len; /* - * tag name to identify a mount Non-null terminated + * tag name to identify a mount null terminated */ char *tag; @@ -525,14 +523,15 @@ static ssize_t p9_mount_tag_show(struct device *dev, { struct virtio_chan *chan; struct virtio_device *vdev; + int tag_len; vdev = dev_to_virtio(dev); chan = vdev->priv; + tag_len = strlen(chan->tag); - memcpy(buf, chan->tag, chan->tag_len); - buf[chan->tag_len] = 0; + memcpy(buf, chan->tag, tag_len + 1); - return chan->tag_len + 1; + return tag_len + 1; } static DEVICE_ATTR(mount_tag, 0444, p9_mount_tag_show, NULL); @@ -585,7 +584,7 @@ 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; @@ -594,7 +593,6 @@ static int p9_virtio_probe(struct virtio_device *vdev) virtio_cread_bytes(vdev, offsetof(struct virtio_9p_config, tag), tag, tag_len); chan->tag = tag; - chan->tag_len = tag_len; err = sysfs_create_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr); if (err) { goto out_free_tag; @@ -654,8 +652,7 @@ static int p9_virtio_probe(struct virtio_device *vdev) mutex_lock(&virtio_9p_lock); list_for_each_entry(chan, &virtio_chan_list, chan_list) { - if (!strncmp(devname, chan->tag, chan->tag_len) && - strlen(devname) == chan->tag_len) { + if (!strcmp(devname, chan->tag)) { if (!chan->inuse) { chan->inuse = true; found = 1; --