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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_MUTT 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 512C1C10F0E for ; Fri, 15 Feb 2019 09:43:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E2B1221B1A for ; Fri, 15 Feb 2019 09:35:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="mkTw7k1I" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392931AbfBOJfa (ORCPT ); Fri, 15 Feb 2019 04:35:30 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:39476 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726146AbfBOJf3 (ORCPT ); Fri, 15 Feb 2019 04:35:29 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x1F9XlTf089418; Fri, 15 Feb 2019 09:35:16 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2018-07-02; bh=+RB02ueo5EzSN1SvadwA/3sS1Xx5cCyLiZbxDRhnnUo=; b=mkTw7k1I7L6u93e3/EcS4e0lAr2hZAdg2nni5o/MyFMZJ718xFtWmcTrXHQCQoNDdvie 4BeULQ1LCUrzLWagmGDwtRA9QNlX0CkLunNV9IxH9vMtZQnH6Fvw43mEjFBX8IhRVXyJ vTPQmEmzZkoQGKxd5MnUvRo2YJObLtu6BEwFv7e6nYKvVG4yJDKr6yviVb2ykFRsOIMe uWYcJkaWxCb0f76o+JMxVL8qzZn5idA6jjq1HvUle+7Qso72tgkOuBRIEHliXGaqVTq6 eMTiBacCEgymHhKHuhQKi26Wah4bZvRcuEARNm1OuprOOgbBJAAT9cmrIHvAwIgVnghn Bg== Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by userp2120.oracle.com with ESMTP id 2qhreectrj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 15 Feb 2019 09:35:16 +0000 Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserv0021.oracle.com (8.14.4/8.14.4) with ESMTP id x1F9ZFEE022622 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 15 Feb 2019 09:35:15 GMT Received: from abhmp0007.oracle.com (abhmp0007.oracle.com [141.146.116.13]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x1F9ZENP010706; Fri, 15 Feb 2019 09:35:14 GMT Received: from kadam (/197.157.0.55) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 15 Feb 2019 09:35:13 +0000 Date: Fri, 15 Feb 2019 12:35:03 +0300 From: Dan Carpenter To: Chao Yu Cc: devel@driverdev.osuosl.org, Greg Kroah-Hartman , Miao Xie , Chao Yu , LKML , stable@vger.kernel.org, weidu.du@huawei.com, Al Viro , linux-erofs@lists.ozlabs.org, Fang Wei Subject: Re: [PATCH v2] staging: erofs: keep corrupted fs from crashing kernel in erofs_namei() Message-ID: <20190215093503.GH2326@kadam> References: <20190201121631.15179-1-gaoxiang25@huawei.com> <20190215075757.GG2326@kadam> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9167 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=656 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1902150070 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 15, 2019 at 05:32:33PM +0800, Chao Yu wrote: > On 2019/2/15 15:57, Dan Carpenter wrote: > > On Fri, Feb 15, 2019 at 03:02:25PM +0800, Chao Yu wrote: > >> On 2019/2/1 20:16, Gao Xiang wrote: > >>> + /* > >>> + * on-disk error, let's only BUG_ON in the debugging mode. > >>> + * otherwise, it will return 1 to just skip the invalid name > >>> + * and go on (in consideration of the lookup performance). > >>> + */ > >>> + DBG_BUGON(qd->name > qd->end); > >> > >> qd->name == qd->end is not allowed as well? > >> > >> So will it be better to return directly here? > >> > >> if (unlikely(qd->name >= qd->end)) { > >> DBG_BUGON(1); > >> return 1; > >> } > > > > Please don't add likely/unlikely() annotations unless you have > > benchmarked it and it makes a difference. > > Well, it only occur for corrupted image, since the image is readonly, so it > is really rare. The likely/unlikely() annotations make the code harder to read. It's only worth it if it's is a speedup on a fast path. regards, dan carpenter