Received: by 2002:a25:4158:0:0:0:0:0 with SMTP id o85csp1624644yba; Sat, 6 Apr 2019 18:19:38 -0700 (PDT) X-Google-Smtp-Source: APXvYqwIuy3tJNma2kqej9Vguk4I6P6VllhQgFok768QsFnrAYx024rSr2CUhCM8P4mm/5aF550M X-Received: by 2002:a17:902:168:: with SMTP id 95mr21336921plb.212.1554599978093; Sat, 06 Apr 2019 18:19:38 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1554599978; cv=none; d=google.com; s=arc-20160816; b=l/G1+SHgJHb05S9fAMJYff3dCmq8KkQ7CxwJk2LRWH7gIP7mkepve9g9TmchHl1LGJ EBTFnrcbbLg/TSQwXGY9Q0RTDeT89FpGV6tX9pFYnLYWPTKZd6hOzI2SufdZszERPBVC 0G2TVJB1nbSTRhFEfW6eydDkN/6jdeRdiahHsPG8rdx7KjNwIV8OFFMvc2TMQ19+H/BZ lxcsEHDJcTqr/vY4zLB3SmhBSAuj6uJrQTgTBKRAOxWTCH+2l4ODbS1ELYN+Iv6fulRs 9oNvuQ3GZP4QUbNXHAFmSWFalApj3EndA4E/Arl4C8U49jtZQ/NwBTexDJ6cJ8YUBlz3 3dGQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:from:subject:cc:to:message-id:date; bh=cwJar7FgshVo/BxGXi7os9pWjYxMmAdd1UlYK/l9MPI=; b=Ni9f/NHgcSpNqi8GwoMaMc7LvC1DZncaEQ2+8M3xxneCpskuZYJJNuqiT5NDcnBQk5 b3fqcGKvLYgsnB2I9GbWL8k/k/jmSkBlXp+xhwE0FNitDOcrdAKdKibb2jjtW2eoFlAH 4r3wjg4aMBpAN1tZe97iPPDMTHqy7jiqhUJOWPdNY3IZexBqJ5fABht1gfbwUWJ50MlL rryerJWW+1VyHhQAEpLhwJEqS1T6TQ0zP+bflkvZ1zw/giDJXm2DmrTxpNYe5aihH29c U8cpGBdmYHGvfmOF8N5ma5/dCHL4uMiUv1tDhYxU/kuXxePMHK07GiuP+mPUoMbmLFTl J2QA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id k132si4862123pgc.131.2019.04.06.18.19.22; Sat, 06 Apr 2019 18:19:38 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726624AbfDGBSg (ORCPT + 99 others); Sat, 6 Apr 2019 21:18:36 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:39612 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726144AbfDGBSg (ORCPT ); Sat, 6 Apr 2019 21:18:36 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::d71]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 5F82114BC08AC; Sat, 6 Apr 2019 18:18:35 -0700 (PDT) Date: Sat, 06 Apr 2019 18:18:34 -0700 (PDT) Message-Id: <20190406.181834.995998216821289412.davem@davemloft.net> To: colin.king@canonical.com Cc: edumazet@google.com, kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org, netdev@vger.kernel.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tcp: remove redundant check on tskb From: David Miller In-Reply-To: <20190404144603.27682-1-colin.king@canonical.com> References: <20190404144603.27682-1-colin.king@canonical.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Sat, 06 Apr 2019 18:18:35 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Colin King Date: Thu, 4 Apr 2019 15:46:03 +0100 > From: Colin Ian King > > The non-null check on tskb is always false because it is in an else > path of a check on tskb and hence tskb is null in this code block. > This is check is therefore redundant and can be removed as well > as the label coalesc. > > if (tsbk) { > ... > } else { > ... > if (unlikely(!skb)) { > if (tskb) /* can never be true, redundant code */ > goto coalesc; > return; > } > } > > Addresses-Coverity: ("Logically dead code") > Signed-off-by: Colin Ian King Applied to net-next.