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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 246E7C433F5 for ; Thu, 10 Mar 2022 15:11:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343723AbiCJPMd (ORCPT ); Thu, 10 Mar 2022 10:12:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344156AbiCJPMT (ORCPT ); Thu, 10 Mar 2022 10:12:19 -0500 Received: from mail-ej1-x634.google.com (mail-ej1-x634.google.com [IPv6:2a00:1450:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE61ADFD6; Thu, 10 Mar 2022 07:07:20 -0800 (PST) Received: by mail-ej1-x634.google.com with SMTP id yy13so12782216ejb.2; Thu, 10 Mar 2022 07:07:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=60uYG3ckY3WcYm8l3Wrv4qJH3dnlWFZqsAvB7+3ByW0=; b=is2XzSK4nxrutLs8h20VyMU7x3CVgv/M56eIif7Nnfl/h77xnTU4TVvx9LJTFzKN54 xbtUokAT0kbf6nUHZtgHz/6JxBbVHaLSg/9d9GyglRPJ1M8rmXT93D6Ia3I20/0uVnH1 ps7cvKs1J4WQejow2+4miwnHu6jgg1GmqAuYOg9S6VloqH9t2uZZf3VtE1cYOrcRu8hZ JREp9V1GIqrHrWRAQyEZtTJYQ9DReztp52i9TlhxQGZzkMOgWVGGI2BxEBQAaIUfDkja rWtxHH/RJEDz7foPphypKWHQ2Jc1MBc3vJ0SsOulZBRqlED9CK+f8AojLcU7sNF955TG 8Wcg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=60uYG3ckY3WcYm8l3Wrv4qJH3dnlWFZqsAvB7+3ByW0=; b=fSkWTMuTkM9ct0CA8qwvucZh+2cVhpGRTbefwEVq3j7H5PViJeDADXm13Uwsp+y4Ea hCUnoNF0VL1PMbdczFmjGHVTHpHuESZNzGmlVw0SPTUgpfN3QZRV9+NVk4Aixq37imOj Gsmug7xmw7fRfoZQ1GiWAzU5zAmED0iJBb2V4ViUt7dkapCY+QYXt2xxaNiRivmRoxIx CQ8BDT5o2bkbvYVVlhD8bpqOUv3+uwWvivK0i2C3g1zhgZKKfNmKU1ncVs+DRq9RB9oc UIH3oTPTcpjZwzjz7PLTBElIL/3Dc3bz1Sh1xSz7hUDcGTD5Vpvlvmucd5p0TGRTD1hz 72yQ== X-Gm-Message-State: AOAM531dKMqdh7N+K+8qrhHRNnF+eqTSppA6DvjhSHy71qMwtSW7ibYy ULy41pmsbfi82xOTKW8s2Jc= X-Google-Smtp-Source: ABdhPJxiCsP0sqkSn+ttfs3GtimM/042s3/C6Rgq02nQi/V1TT3l/TsZrKzhFHTcMUy/KcA8QeXpiA== X-Received: by 2002:a17:907:7b92:b0:6db:71f1:fc20 with SMTP id ne18-20020a1709077b9200b006db71f1fc20mr4619349ejc.343.1646924839382; Thu, 10 Mar 2022 07:07:19 -0800 (PST) Received: from skbuf ([188.25.231.156]) by smtp.gmail.com with ESMTPSA id t14-20020a170906608e00b006d1455acc62sm1858557ejj.74.2022.03.10.07.07.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Mar 2022 07:07:18 -0800 (PST) Date: Thu, 10 Mar 2022 17:07:17 +0200 From: Vladimir Oltean To: Hans Schultz Cc: davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org, Andrew Lunn , Vivien Didelot , Florian Fainelli , Jiri Pirko , Ivan Vecera , Roopa Prabhu , Nikolay Aleksandrov , Daniel Borkmann , Ido Schimmel , linux-kernel@vger.kernel.org, bridge@lists.linux-foundation.org Subject: Re: [PATCH net-next 3/3] net: dsa: mv88e6xxx: mac-auth/MAB implementation Message-ID: <20220310150717.h7gaxamvzv47e5zc@skbuf> References: <20220310142320.611738-1-schultz.hans+netdev@gmail.com> <20220310142320.611738-4-schultz.hans+netdev@gmail.com> <20220310142836.m5onuelv4jej5gvs@skbuf> <865yolg8d7.fsf@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <865yolg8d7.fsf@gmail.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, Mar 10, 2022 at 04:00:52PM +0100, Hans Schultz wrote: > >> + brport = dsa_port_to_bridge_port(dp); > > > > Since this is threaded interrupt context, I suppose it could race with > > dsa_port_bridge_leave(). So it is best to check whether "brport" is NULL > > or not. > > > Would something like: > if (dsa_is_unused_port(chip->ds, port)) > return -ENODATA; > > be appropriate and sufficient for that? static inline struct net_device *dsa_port_to_bridge_port(const struct dsa_port *dp) { if (!dp->bridge) return NULL; if (dp->lag) return dp->lag->dev; else if (dp->hsr_dev) return dp->hsr_dev; return dp->slave; } Notice the "dp->bridge" check. The assignments are in dsa_port_bridge_create() and in dsa_port_bridge_destroy(). These functions assume rtnl_mutex protection. The question was how do you serialize with that, and why do you assume that dsa_port_to_bridge_port() returns non-NULL. So no, dsa_is_unused_port() would do absolutely nothing to help.