From patchwork Wed Dec 23 21:23:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antoine Tenart X-Patchwork-Id: 352234 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, 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 4C33CC433E0 for ; Wed, 23 Dec 2020 21:24:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0FDBD2246B for ; Wed, 23 Dec 2020 21:24:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729243AbgLWVYS (ORCPT ); Wed, 23 Dec 2020 16:24:18 -0500 Received: from mail.kernel.org ([198.145.29.99]:51050 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729228AbgLWVYS (ORCPT ); Wed, 23 Dec 2020 16:24:18 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 05E3D224B1; Wed, 23 Dec 2020 21:23:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1608758617; bh=Wdrg+jwVO0FO5FqBU61dcu5tztCz+oq+TGHKbkJ1DvE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=t/WNylpaJKqBR4XKehAoIv0FYmAlrM7UwfWtj/9d5Vn/TlEXDTGRUpm/9WAk48oZO IVlxspHN1Tw9/Co1CHfEDKMhE5C+dHYcYrkYGRcdcf0m+KTnkl+bxorLKYfebrC+cD xUWQ0CqX0umC+fuwZTtSsDcrzgJyrhiFKdtCIfsySwAs7n1gxQ49UYwclG4ue00V+Z +LlKUsXmgi6eBwWXErZVlFSti2/VO/v8lgXFc3esw2R0dPJwN5fJRlmL0a5hn8pjo0 IKcdlSnXEVdoYMqrWG8HM1spBEy6x1+ia6ctxDplZOpXdf1RRArL+E2INM4O1jDCZL d/KGwV7D/LO7w== From: Antoine Tenart To: davem@davemloft.net, kuba@kernel.org, alexander.duyck@gmail.com Cc: Antoine Tenart , netdev@vger.kernel.org, pabeni@redhat.com Subject: [PATCH net v3 4/4] net-sysfs: take the rtnl lock when accessing xps_rxqs_map and num_tc Date: Wed, 23 Dec 2020 22:23:23 +0100 Message-Id: <20201223212323.3603139-5-atenart@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201223212323.3603139-1-atenart@kernel.org> References: <20201223212323.3603139-1-atenart@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Accesses to dev->xps_rxqs_map (when using dev->num_tc) should be protected by the rtnl lock, like we do for netif_set_xps_queue. I didn't see an actual bug being triggered, but let's be safe here and take the rtnl lock while accessing the map in sysfs. Fixes: 8af2c06ff4b1 ("net-sysfs: Add interface for Rx queue(s) map per Tx queue") Signed-off-by: Antoine Tenart --- net/core/net-sysfs.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 62ca2f2c0ee6..daf502c13d6d 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -1429,22 +1429,29 @@ static struct netdev_queue_attribute xps_cpus_attribute __ro_after_init static ssize_t xps_rxqs_show(struct netdev_queue *queue, char *buf) { + int j, len, ret, num_tc = 1, tc = 0; struct net_device *dev = queue->dev; struct xps_dev_maps *dev_maps; unsigned long *mask, index; - int j, len, num_tc = 1, tc = 0; index = get_netdev_queue_index(queue); + if (!rtnl_trylock()) + return restart_syscall(); + if (dev->num_tc) { num_tc = dev->num_tc; tc = netdev_txq_to_tc(dev, index); - if (tc < 0) - return -EINVAL; + if (tc < 0) { + ret = -EINVAL; + goto err_rtnl_unlock; + } } mask = bitmap_zalloc(dev->num_rx_queues, GFP_KERNEL); - if (!mask) - return -ENOMEM; + if (!mask) { + ret = -ENOMEM; + goto err_rtnl_unlock; + } rcu_read_lock(); dev_maps = rcu_dereference(dev->xps_rxqs_map); @@ -1470,10 +1477,16 @@ static ssize_t xps_rxqs_show(struct netdev_queue *queue, char *buf) out_no_maps: rcu_read_unlock(); + rtnl_unlock(); + len = bitmap_print_to_pagebuf(false, buf, mask, dev->num_rx_queues); bitmap_free(mask); return len < PAGE_SIZE ? len : -EINVAL; + +err_rtnl_unlock: + rtnl_unlock(); + return ret; } static ssize_t xps_rxqs_store(struct netdev_queue *queue, const char *buf,