From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 32DFAA04E0; Wed, 27 Nov 2019 10:35:15 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id A8A801B103; Wed, 27 Nov 2019 10:35:14 +0100 (CET) Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id 1771B28EE; Wed, 27 Nov 2019 10:35:11 +0100 (CET) X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Nov 2019 01:35:10 -0800 X-IronPort-AV: E=Sophos;i="5.69,248,1571727600"; d="scan'208";a="203016310" Received: from bricha3-mobl.ger.corp.intel.com ([10.237.221.46]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 27 Nov 2019 01:35:08 -0800 Date: Wed, 27 Nov 2019 09:35:05 +0000 From: Bruce Richardson To: "Yu, Jin" Cc: Maxime Coquelin , "Bie, Tiwei" , "Wang, Zhihong" , "dev@dpdk.org" , "stable@dpdk.org" Message-ID: <20191127093505.GC1158@bricha3-MOBL.ger.corp.intel.com> References: <20191126153214.7952-1-jin.yu@intel.com> <20191126102555.GA1629@bricha3-MOBL.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) Subject: Re: [dpdk-dev] [PATCH] examples/vhost_blk: fix the TOCTOU X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Wed, Nov 27, 2019 at 02:36:01AM +0000, Yu, Jin wrote: > > -----Original Message----- > > From: Bruce Richardson > > Sent: Tuesday, November 26, 2019 6:26 PM > > To: Yu, Jin > > Cc: Maxime Coquelin ; Bie, Tiwei > > ; Wang, Zhihong ; > > dev@dpdk.org; stable@dpdk.org > > Subject: Re: [dpdk-dev] [PATCH] examples/vhost_blk: fix the TOCTOU > > > > On Tue, Nov 26, 2019 at 11:32:14PM +0800, Jin Yu wrote: > > > Fix the time of check time of use warning in example code > > > > > > Coverity issue: 350589 158663 > > > Fixes: c19beb3f38cd ("examples/vhost_blk: introduce vhost storage > > > sample") > > > Cc: stable@dpdk.org > > > > > > Signed-off-by: Jin Yu > > > --- > > > examples/vhost_blk/vhost_blk.c | 9 ++------- > > > 1 file changed, 2 insertions(+), 7 deletions(-) > > > > > > diff --git a/examples/vhost_blk/vhost_blk.c > > > b/examples/vhost_blk/vhost_blk.c index 3182a488b..bcb4ebb0b 100644 > > > --- a/examples/vhost_blk/vhost_blk.c > > > +++ b/examples/vhost_blk/vhost_blk.c > > > @@ -993,11 +993,7 @@ vhost_blk_ctrlr_construct(const char *ctrlr_name) > > > } > > > snprintf(dev_pathname, sizeof(dev_pathname), "%s/%s", path, > > > ctrlr_name); > > > > > > - if (access(dev_pathname, F_OK) != -1) { > > > - if (unlink(dev_pathname) != 0) > > > - rte_exit(EXIT_FAILURE, "Cannot remove %s.\n", > > > - dev_pathname); > > > - } > > > + unlink(dev_pathname); > > > > > > > The original code did an exit if the delete failed, do you intend there to be a > > behaviour change here? You can probably get the same behaviour if you > > check the errno on an unlink failure, e.g. ENOENT means file doesn't exist. > > > > If not having the app exit on unlink failure is reasonable behaviour then > > ignore this comment. > > I considered it. I think it's ok to ignore the errno of unlink failure. This code just want > to remove the file. There are two situations. The first one is that file doesn't exist the unlink > fails and it's ok to ignore. The second one is that unlink fails to remove file but the next bind() > would fail too so I think it's ok to ignore too. > > Ok, thanks for clarifying.