From patchwork Fri Apr 23 08:14:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steffen Klassert X-Patchwork-Id: 426698 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, 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 A9453C433B4 for ; Fri, 23 Apr 2021 08:14:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6DCE1613CD for ; Fri, 23 Apr 2021 08:14:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241500AbhDWIO7 (ORCPT ); Fri, 23 Apr 2021 04:14:59 -0400 Received: from mailout2.secunet.com ([62.96.220.49]:50552 "EHLO mailout2.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241147AbhDWIOy (ORCPT ); Fri, 23 Apr 2021 04:14:54 -0400 Received: from cas-essen-01.secunet.de (unknown [10.53.40.201]) by mailout2.secunet.com (Postfix) with ESMTP id C9AD680005A; Fri, 23 Apr 2021 10:14:17 +0200 (CEST) Received: from mbx-essen-01.secunet.de (10.53.40.197) by cas-essen-01.secunet.de (10.53.40.201) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 23 Apr 2021 10:14:17 +0200 Received: from gauss2.secunet.de (10.182.7.193) by mbx-essen-01.secunet.de (10.53.40.197) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 23 Apr 2021 10:14:17 +0200 Received: by gauss2.secunet.de (Postfix, from userid 1000) id 453D831805B6; Fri, 23 Apr 2021 10:14:16 +0200 (CEST) From: Steffen Klassert To: David Miller , Jakub Kicinski CC: Herbert Xu , Steffen Klassert , Subject: [PATCH 3/4] xfrm: avoid synchronize_rcu during netns destruction Date: Fri, 23 Apr 2021 10:14:08 +0200 Message-ID: <20210423081409.729557-4-steffen.klassert@secunet.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210423081409.729557-1-steffen.klassert@secunet.com> References: <20210423081409.729557-1-steffen.klassert@secunet.com> MIME-Version: 1.0 X-ClientProxiedBy: cas-essen-02.secunet.de (10.53.40.202) To mbx-essen-01.secunet.de (10.53.40.197) X-EXCLAIMER-MD-CONFIG: 2c86f778-e09b-4440-8b15-867914633a10 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Florian Westphal Use the new exit_pre hook to NULL the netlink socket. The net namespace core will do a synchronize_rcu() between the exit_pre and exit/exit_batch handlers. Signed-off-by: Florian Westphal Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_user.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index df8bc8fc724c..f0aecee4d539 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -3480,18 +3480,22 @@ static int __net_init xfrm_user_net_init(struct net *net) return 0; } +static void __net_exit xfrm_user_net_pre_exit(struct net *net) +{ + RCU_INIT_POINTER(net->xfrm.nlsk, NULL); +} + static void __net_exit xfrm_user_net_exit(struct list_head *net_exit_list) { struct net *net; - list_for_each_entry(net, net_exit_list, exit_list) - RCU_INIT_POINTER(net->xfrm.nlsk, NULL); - synchronize_net(); + list_for_each_entry(net, net_exit_list, exit_list) netlink_kernel_release(net->xfrm.nlsk_stash); } static struct pernet_operations xfrm_user_net_ops = { .init = xfrm_user_net_init, + .pre_exit = xfrm_user_net_pre_exit, .exit_batch = xfrm_user_net_exit, };