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=-2.2 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 05E32C432C0 for ; Tue, 19 Nov 2019 01:53:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C870D208C3 for ; Tue, 19 Nov 2019 01:53:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="K5jmA2k+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727092AbfKSBxv (ORCPT ); Mon, 18 Nov 2019 20:53:51 -0500 Received: from mail-pj1-f67.google.com ([209.85.216.67]:45382 "EHLO mail-pj1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726761AbfKSBxu (ORCPT ); Mon, 18 Nov 2019 20:53:50 -0500 Received: by mail-pj1-f67.google.com with SMTP id m71so2062952pjb.12 for ; Mon, 18 Nov 2019 17:53:48 -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=Ls+aABLS0sCk5dUgoz4Wrzqiif8l3ljdf3X473J33rU=; b=K5jmA2k+cyHpoSiBFUjf7eRFPcRDq7CPzL+cckTnVgHOV33vMZrhj/T58pfccedI5E vXxFp0j2V1LssCBGLTql/AjiknbiLbQUHYfBX1Egsy1rskIg7LeCf8UYzBZjdUAl+Pln eOIicbWAffRWOYUws08kcDghWroNDrRIzRTmEk7dvSH0x+BULUezzU3hhe72EDmuSxpX BjuITwsjsBKaaPS8NdCoqXf3Q6bJ4BTYivp9JRoeooBJHZjxI3FrHZc5dY+HWiqPfd3p 16hT56mWMyzn/uyydlr7UWYKfXyVlJofVRlr+ggAjw0bvZOMmZnSs7m6wXDWvFfT9pcq XMhQ== 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=Ls+aABLS0sCk5dUgoz4Wrzqiif8l3ljdf3X473J33rU=; b=gU0RmD6qd/y/v0z2Me2vf8tBDcYwWtYOnhw/zOOpLC8xYWR69sQCyFQgtW7RQc3nCs yl2S4w5ZUDgnpJXlyk/jH4ZFL4sxhsga4qrlLnTEs0X8DRE6KnTzuM2vDZAUpLAM9m7s dt4ejoZkuhSt6amnQ7JZqWr7VvgaPvnF/o8tdWDVuvkaB3YCFXEI5WNs/eRMjVscW88H idPr0q1r0Y5MYPw9w1527BIoMELJ4aCHFAUcXqMoQ8PoG5ryVEUUh6eSQbHi8RTXtzxy 2gVg/bW/zSRuIWZ5mUGPbCoeP/ZCF55KlmHaMcMMvjfaoPsk/wtlLgrP1QQZalu33+do L06Q== X-Gm-Message-State: APjAAAX0CSg4PFmDWJxCUFwyhyKWIxrESePmc5nQkmfWFnpBhoFP/dWs 1WjVhB9oS2/5D4GxYJzBQ20= X-Google-Smtp-Source: APXvYqzVrz7poCtDfnMF+QvSBERwyHvHWF2owORdo+jcubW3zCxq0q4snBElckJLu9M6O4Aa6HiW9Q== X-Received: by 2002:a17:90a:b308:: with SMTP id d8mr2779028pjr.23.1574128428441; Mon, 18 Nov 2019 17:53:48 -0800 (PST) Received: from dhcp-12-139.nay.redhat.com ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id w62sm24450377pfb.15.2019.11.18.17.53.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Nov 2019 17:53:47 -0800 (PST) Date: Tue, 19 Nov 2019 09:53:38 +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: <20191119015338.GD18865@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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191115105455.24a4dd48@redhat.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 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? Thanks Hangbin