From patchwork Thu Sep 15 01:08:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Ziyang Xuan (William)" X-Patchwork-Id: 12976740 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5871BC6FA82 for ; Thu, 15 Sep 2022 01:12:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229702AbiIOBIq (ORCPT ); Wed, 14 Sep 2022 21:08:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229479AbiIOBIq (ORCPT ); Wed, 14 Sep 2022 21:08:46 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4812A8052E; Wed, 14 Sep 2022 18:08:41 -0700 (PDT) Received: from canpemm500006.china.huawei.com (unknown [172.30.72.57]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4MSfB04wcsz14QWd; Thu, 15 Sep 2022 09:04:40 +0800 (CST) Received: from localhost.localdomain (10.175.104.82) by canpemm500006.china.huawei.com (7.192.105.130) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 15 Sep 2022 09:08:38 +0800 From: Ziyang Xuan To: , , , CC: Subject: [PATCH net-next] net/af_packet: registration process optimization in packet_init() Date: Thu, 15 Sep 2022 09:08:35 +0800 Message-ID: <20220915010835.1761211-1-william.xuanziyang@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.175.104.82] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To canpemm500006.china.huawei.com (7.192.105.130) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Now, register_pernet_subsys() and register_netdevice_notifier() are both after sock_register(). It can create PF_PACKET socket and process socket once sock_register() successfully. It is possible PF_PACKET socket is creating but register_pernet_subsys() and register_netdevice_notifier() are not registered yet. Thus net->packet.sklist_lock and net->packet.sklist will be accessed without initialization that is done in packet_net_init(). Although this is a low probability scenario. Move register_pernet_subsys() and register_netdevice_notifier() to the front in packet_init(). Correspondingly, adjust the unregister process in packet_exit(). Signed-off-by: Ziyang Xuan --- net/packet/af_packet.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 5cbe07116e04..52cc9931b367 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -4725,37 +4725,37 @@ static struct pernet_operations packet_net_ops = { static void __exit packet_exit(void) { - unregister_netdevice_notifier(&packet_netdev_notifier); - unregister_pernet_subsys(&packet_net_ops); sock_unregister(PF_PACKET); proto_unregister(&packet_proto); + unregister_netdevice_notifier(&packet_netdev_notifier); + unregister_pernet_subsys(&packet_net_ops); } static int __init packet_init(void) { int rc; - rc = proto_register(&packet_proto, 0); - if (rc) - goto out; - rc = sock_register(&packet_family_ops); - if (rc) - goto out_proto; rc = register_pernet_subsys(&packet_net_ops); if (rc) - goto out_sock; + goto out; rc = register_netdevice_notifier(&packet_netdev_notifier); if (rc) goto out_pernet; + rc = proto_register(&packet_proto, 0); + if (rc) + goto out_notifier; + rc = sock_register(&packet_family_ops); + if (rc) + goto out_proto; return 0; -out_pernet: - unregister_pernet_subsys(&packet_net_ops); -out_sock: - sock_unregister(PF_PACKET); out_proto: proto_unregister(&packet_proto); +out_notifier: + unregister_netdevice_notifier(&packet_netdev_notifier); +out_pernet: + unregister_pernet_subsys(&packet_net_ops); out: return rc; }