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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 4EE23C4360F for ; Thu, 4 Apr 2019 14:46:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 27867206B7 for ; Thu, 4 Apr 2019 14:46:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729202AbfDDOqM (ORCPT ); Thu, 4 Apr 2019 10:46:12 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:57674 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728027AbfDDOqL (ORCPT ); Thu, 4 Apr 2019 10:46:11 -0400 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1hC3cx-0002JK-H6; Thu, 04 Apr 2019 14:46:03 +0000 From: Colin King To: Eric Dumazet , "David S . Miller" , Alexey Kuznetsov , Hideaki YOSHIFUJI , netdev@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] tcp: remove redundant check on tskb Date: Thu, 4 Apr 2019 15:46:03 +0100 Message-Id: <20190404144603.27682-1-colin.king@canonical.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- net/ipv4/tcp_output.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index e265d1aeeb66..32061928b054 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3088,7 +3088,6 @@ void tcp_send_fin(struct sock *sk) tskb = skb_rb_last(&sk->tcp_rtx_queue); if (tskb) { -coalesce: TCP_SKB_CB(tskb)->tcp_flags |= TCPHDR_FIN; TCP_SKB_CB(tskb)->end_seq++; tp->write_seq++; @@ -3104,11 +3103,9 @@ void tcp_send_fin(struct sock *sk) } } else { skb = alloc_skb_fclone(MAX_TCP_HEADER, sk->sk_allocation); - if (unlikely(!skb)) { - if (tskb) - goto coalesce; + if (unlikely(!skb)) return; - } + INIT_LIST_HEAD(&skb->tcp_tsorted_anchor); skb_reserve(skb, MAX_TCP_HEADER); sk_forced_mem_schedule(sk, skb->truesize); -- 2.20.1