From patchwork Wed Mar 31 08:18:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steffen Klassert X-Patchwork-Id: 12174685 X-Patchwork-Delegate: kuba@kernel.org 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 D555BC433EB for ; Wed, 31 Mar 2021 08:19:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C14CE61957 for ; Wed, 31 Mar 2021 08:19:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234459AbhCaITl (ORCPT ); Wed, 31 Mar 2021 04:19:41 -0400 Received: from a.mx.secunet.com ([62.96.220.36]:48072 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234389AbhCaIS5 (ORCPT ); Wed, 31 Mar 2021 04:18:57 -0400 Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id 4ACFC205A6; Wed, 31 Mar 2021 10:18:56 +0200 (CEST) X-Virus-Scanned: by secunet Received: from a.mx.secunet.com ([127.0.0.1]) by localhost (a.mx.secunet.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Vm161SePqO9g; Wed, 31 Mar 2021 10:18:55 +0200 (CEST) Received: from cas-essen-02.secunet.de (unknown [10.53.40.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by a.mx.secunet.com (Postfix) with ESMTPS id AC75D2057A; Wed, 31 Mar 2021 10:18:54 +0200 (CEST) Received: from mbx-essen-01.secunet.de (10.53.40.197) by cas-essen-02.secunet.de (10.53.40.202) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 31 Mar 2021 10:18:54 +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; Wed, 31 Mar 2021 10:18:53 +0200 Received: by gauss2.secunet.de (Postfix, from userid 1000) id 98E8331805F1; Wed, 31 Mar 2021 10:18:52 +0200 (CEST) From: Steffen Klassert To: David Miller , Jakub Kicinski CC: Herbert Xu , Steffen Klassert , Subject: [PATCH 06/11] net: xfrm: Use sequence counter with associated spinlock Date: Wed, 31 Mar 2021 10:18:42 +0200 Message-ID: <20210331081847.3547641-7-steffen.klassert@secunet.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210331081847.3547641-1-steffen.klassert@secunet.com> References: <20210331081847.3547641-1-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 X-Patchwork-Delegate: kuba@kernel.org From: "Ahmed S. Darwish" A sequence counter write section must be serialized or its internal state can get corrupted. A plain seqcount_t does not contain the information of which lock must be held to guaranteee write side serialization. For xfrm_state_hash_generation, use seqcount_spinlock_t instead of plain seqcount_t. This allows to associate the spinlock used for write serialization with the sequence counter. It thus enables lockdep to verify that the write serialization lock is indeed held before entering the sequence counter write section. If lockdep is disabled, this lock association is compiled out and has neither storage size nor runtime overhead. Signed-off-by: Ahmed S. Darwish Signed-off-by: Steffen Klassert --- include/net/netns/xfrm.h | 2 +- net/xfrm/xfrm_state.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/include/net/netns/xfrm.h b/include/net/netns/xfrm.h index b59d73d529ba..e816b6a3ef2b 100644 --- a/include/net/netns/xfrm.h +++ b/include/net/netns/xfrm.h @@ -73,7 +73,7 @@ struct netns_xfrm { struct dst_ops xfrm6_dst_ops; #endif spinlock_t xfrm_state_lock; - seqcount_t xfrm_state_hash_generation; + seqcount_spinlock_t xfrm_state_hash_generation; spinlock_t xfrm_policy_lock; struct mutex xfrm_cfg_mutex; diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index ffd315cff984..4496f7efa220 100644 --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -2665,7 +2665,8 @@ int __net_init xfrm_state_init(struct net *net) net->xfrm.state_num = 0; INIT_WORK(&net->xfrm.state_hash_work, xfrm_hash_resize); spin_lock_init(&net->xfrm.xfrm_state_lock); - seqcount_init(&net->xfrm.xfrm_state_hash_generation); + seqcount_spinlock_init(&net->xfrm.xfrm_state_hash_generation, + &net->xfrm.xfrm_state_lock); return 0; out_byspi: