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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 C9873C432C0 for ; Tue, 19 Nov 2019 13:41:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9DB5820409 for ; Tue, 19 Nov 2019 13:41:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="BHEP+Xeq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727791AbfKSNlE (ORCPT ); Tue, 19 Nov 2019 08:41:04 -0500 Received: from mail-pf1-f193.google.com ([209.85.210.193]:39691 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725798AbfKSNlE (ORCPT ); Tue, 19 Nov 2019 08:41:04 -0500 Received: by mail-pf1-f193.google.com with SMTP id x28so12202334pfo.6 for ; Tue, 19 Nov 2019 05:41:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=4OoxzfinYAPlGdTVivW4kv+plojwt++H5CBPTA6EerQ=; b=BHEP+XeqNUcztgaikMDVp7r+L7HYPdLNOgXSOMzLbxv56UJC0BH0Y4i45+qBY0X9W4 m+YWbVczWYlsfNoQKVeLl1ssSauxifKehxk+/KzMT+37J6sOEc/oc87Jv69Jdi4jOSXu TbisArqFgWpaYmZdjbhHGvoVfV6HONHdWdXZNfnqy7B+Ybon1I9Y9IB1+1lMtQOxMfm1 0jPf1GBePnudkwL2hYjIT8EHPX9XVSHGehXOqIaLanzVj3uxPwuVllzhXL15poTlT6MK lOG63paXAb0Y9WD82qQ7fay/aKouBxShxcX91ua8E14C+R1cWE8xwm74AfIjht2k6YB+ IPNw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=4OoxzfinYAPlGdTVivW4kv+plojwt++H5CBPTA6EerQ=; b=Q3FCpII/gQ5WsFB8atZmfyyBopJmbzZKXJa2u5Cv13aVUP015SlmwcUuNCrgb2Yw/3 2IfwzOJ0z1qIYOsGQwkzVAnIq70WZXJH45cm+815SqTRTXtysW+uTWHTxGaiiTTm9jxR H/g4a1xJTgq766QvVH/wrf4gw4rAl66xSEhej0i1nEfRwXUUER1CiW2xm6Tt7HFuPD21 VNuy5TyNgrFW9ipDlS5P0/lWWTh0w3/3jmzIxVVYtl12oOKhsqyLea3rUQNWsLIj3xJF CdRcx8iynE2Yb1r6cV5lu6W5tcFGx2XU92h8kcq06BDULwvt3hB5IsmVB2Jn7vLq9uJy eDhQ== X-Gm-Message-State: APjAAAVgmIeyfxt/c6poVJ7LwkrQdDqT5PAytMsy+o8KhkcnP/R1u3/T X1iv9hl934T/+YfHZHBVuvb3aIiVWfAxng== X-Google-Smtp-Source: APXvYqxfsiIf5Z2aTI1KPrF8C+ixgsLbLi2LnHUGyYi8JTpRaxJb8RJPigQvwbUr8K1AMrTYFUulFg== X-Received: by 2002:a63:381b:: with SMTP id f27mr5485597pga.291.1574170862031; Tue, 19 Nov 2019 05:41:02 -0800 (PST) Received: from dhcp-12-139.nay.redhat.com ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id a16sm24592697pgb.7.2019.11.19.05.40.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 Nov 2019 05:41:01 -0800 (PST) Date: Tue, 19 Nov 2019 21:40:51 +0800 From: Hangbin Liu To: Eric Dumazet Cc: Jiri Benc , netdev@vger.kernel.org, Eric Dumazet , "David S . Miller" Subject: Re: [PATCH net] tcp: switch snprintf to scnprintf Message-ID: <20191119134051.GE18865@dhcp-12-139.nay.redhat.com> References: <20191114102831.23753-1-liuhangbin@gmail.com> <557b2545-3b3c-63a9-580c-270a0a103b2e@gmail.com> <20191115024106.GB18865@dhcp-12-139.nay.redhat.com> <20191115105455.24a4dd48@redhat.com> <20191119015338.GD18865@dhcp-12-139.nay.redhat.com> <22361732-351e-4768-0974-bd4050eb9f2e@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <22361732-351e-4768-0974-bd4050eb9f2e@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Nov 18, 2019 at 07:48:32PM -0800, Eric Dumazet wrote: > > > On 11/18/19 5:53 PM, Hangbin Liu wrote: > > On Fri, Nov 15, 2019 at 10:54:55AM +0100, Jiri Benc wrote: > >> On Fri, 15 Nov 2019 10:41:06 +0800, Hangbin Liu wrote: > >>>> We need to properly size the output buffers before using them, > >>>> we can not afford truncating silently the output. > >>> > >>> Yes, I agree. Just as I said, the buffer is still enough, while scnprintf > >>> is just a safer usage compired with snprintf. > >> > >> So maybe keep snprintf but add WARN_ON and bail out of the loop if the > >> buffer size was reached? > >> > >> if (WARN_ON(offs >= maxlen)) > >> break; > >> > > > > Hi Eric, > > > > What do you think? > > > > WARN_ON_ONCE() please... > OK, I will post a v2 update. Should it target to net or net-next? Thanks Hangbin