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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 B01E7C3F2D1 for ; Mon, 2 Mar 2020 12:37:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8EE1521739 for ; Mon, 2 Mar 2020 12:37:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727644AbgCBMhG (ORCPT ); Mon, 2 Mar 2020 07:37:06 -0500 Received: from correo.us.es ([193.147.175.20]:40004 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727612AbgCBMhG (ORCPT ); Mon, 2 Mar 2020 07:37:06 -0500 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id E48C81C4397 for ; Mon, 2 Mar 2020 13:36:51 +0100 (CET) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id D7696DA3A4 for ; Mon, 2 Mar 2020 13:36:51 +0100 (CET) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id CEB97DA3C2; Mon, 2 Mar 2020 13:36:51 +0100 (CET) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id D78A8FC5E8; Mon, 2 Mar 2020 13:36:49 +0100 (CET) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Mon, 02 Mar 2020 13:36:49 +0100 (CET) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from us.es (unknown [90.77.255.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: 1984lsi) by entrada.int (Postfix) with ESMTPSA id 9E2A44251480; Mon, 2 Mar 2020 13:36:49 +0100 (CET) Date: Mon, 2 Mar 2020 13:37:01 +0100 X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: Amol Grover Cc: Jozsef Kadlecsik , Florian Westphal , "David S . Miller" , Alexey Kuznetsov , Hideaki YOSHIFUJI , Jakub Kicinski , linux-kernel@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, Joel Fernandes , Madhuparna Bhowmik , "Paul E . McKenney" , netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org Subject: Re: [PATCH] netfilter: ipt_CLUSTERIP: Pass lockdep expression to RCU lists Message-ID: <20200302123701.qnjmnmyoxycaixs6@salvia> References: <20200219101626.31943-1-frextrite@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200219101626.31943-1-frextrite@gmail.com> User-Agent: NeoMutt/20170113 (1.7.2) X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 19, 2020 at 03:46:27PM +0530, Amol Grover wrote: > cn->configs is traversed using list_for_each_entry_rcu > outside an RCU read-side critical section but under the protection > of cn->lock. > > Hence, add corresponding lockdep expression to silence false-positive > warnings, and harden RCU lists. > > Signed-off-by: Amol Grover > --- > net/ipv4/netfilter/ipt_CLUSTERIP.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c > index 6bdb1ab8af61..df856ff835b7 100644 > --- a/net/ipv4/netfilter/ipt_CLUSTERIP.c > +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c > @@ -139,7 +139,8 @@ __clusterip_config_find(struct net *net, __be32 clusterip) > struct clusterip_config *c; > struct clusterip_net *cn = clusterip_pernet(net); > > - list_for_each_entry_rcu(c, &cn->configs, list) { > + list_for_each_entry_rcu(c, &cn->configs, list, > + lockdep_is_held(&cn->lock)) { bh is disabled before calling __clusterip_config_find(), then rcu_read_lock_any_held() evaluates true. Are you sure this really results in a WARN_ON splat?