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=-6.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_GIT autolearn=unavailable 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 8EE13C28EBD for ; Sun, 9 Jun 2019 17:15:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6896A20652 for ; Sun, 9 Jun 2019 17:15:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560100515; bh=/ek4AUce4ipkcqRnQIfzGZ375DYFAzQTb61jjPHljYk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=WqAqV1KdOzF7pz0DpQnQaB9KD3KNZj4HdUdJy7UBXKQdkSNz0q/D0KziS8R+AF9fA XV2X1K3oD7gsbuqWpOkYNrRMClXobBojojkF63Dkop5tbRV2csFtKEqUaZbl2wjjq0 HixBn55IRdL2XV1TBeAbkiHbs8VAsTCFMLSoIck0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732748AbfFIQzW (ORCPT ); Sun, 9 Jun 2019 12:55:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:57450 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732773AbfFIQzW (ORCPT ); Sun, 9 Jun 2019 12:55:22 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 39585204EC; Sun, 9 Jun 2019 16:55:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560099321; bh=/ek4AUce4ipkcqRnQIfzGZ375DYFAzQTb61jjPHljYk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Dkfmb8fiMOr2NfUi2BodHruR2gDZFaYqdPaTdDugvPveu3kGeGp3TdcwUIKYRhQNu ZpQ+l7OT6ypaUzMzrni23Zmh/ydpg42BbLlXmzlYmXXc0zwEoL577sRNJoSHrKmBNM LkwuQlYSFzlEqrr3tn8I9W7L862fdHXwii+v9kdo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alan Maguire , David Ahern , "David S. Miller" Subject: [PATCH 4.9 63/83] neighbor: Call __ipv4_neigh_lookup_noref in neigh_xmit Date: Sun, 9 Jun 2019 18:42:33 +0200 Message-Id: <20190609164133.192575221@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190609164127.843327870@linuxfoundation.org> References: <20190609164127.843327870@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: David Ahern [ Upstream commit 4b2a2bfeb3f056461a90bd621e8bd7d03fa47f60 ] Commit cd9ff4de0107 changed the key for IFF_POINTOPOINT devices to INADDR_ANY but neigh_xmit which is used for MPLS encapsulations was not updated to use the altered key. The result is that every packet Tx does a lookup on the gateway address which does not find an entry, a new one is created only to find the existing one in the table right before the insert since arp_constructor was updated to reset the primary key. This is seen in the allocs and destroys counters: ip -s -4 ntable show | head -10 | grep alloc which increase for each packet showing the unnecessary overhread. Fix by having neigh_xmit use __ipv4_neigh_lookup_noref for NEIGH_ARP_TABLE. Fixes: cd9ff4de0107 ("ipv4: Make neigh lookup keys for loopback/point-to-point devices be INADDR_ANY") Reported-by: Alan Maguire Signed-off-by: David Ahern Tested-by: Alan Maguire Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/neighbour.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include #include @@ -2489,7 +2490,13 @@ int neigh_xmit(int index, struct net_dev if (!tbl) goto out; rcu_read_lock_bh(); - neigh = __neigh_lookup_noref(tbl, addr, dev); + if (index == NEIGH_ARP_TABLE) { + u32 key = *((u32 *)addr); + + neigh = __ipv4_neigh_lookup_noref(dev, key); + } else { + neigh = __neigh_lookup_noref(tbl, addr, dev); + } if (!neigh) neigh = __neigh_create(tbl, addr, dev, false); err = PTR_ERR(neigh);