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 38417ECAAD5 for ; Fri, 2 Sep 2022 12:29:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236634AbiIBM34 (ORCPT ); Fri, 2 Sep 2022 08:29:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236520AbiIBM2c (ORCPT ); Fri, 2 Sep 2022 08:28:32 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA7095FE7; Fri, 2 Sep 2022 05:24:47 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E86986210A; Fri, 2 Sep 2022 12:23:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AB6B6C433D7; Fri, 2 Sep 2022 12:23:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1662121415; bh=HCozxiwfuRdOkCThfE6MAv65G6TqAXwpnaKlKnXiZpM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ovw0sxi5piyST3asPeFV0HJpuSicyaLZwi6QrD4IbdtHIiaYStLaQQFKEZ+dw3smI rJZ5c7E7gn4J6TEUGmDkAnGnq6S1GlX5+ylR/25G/HTQuCjSZm9Lij1MqDRTDMcp4y AXP4NWuk4BYNp7UwBOJmoXLiXJf+0G7wf4KifkgQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kuniyuki Iwashima , "David S. Miller" , Sasha Levin Subject: [PATCH 4.14 12/42] net: Fix data-races around weight_p and dev_weight_[rt]x_bias. Date: Fri, 2 Sep 2022 14:18:36 +0200 Message-Id: <20220902121359.234283065@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220902121358.773776406@linuxfoundation.org> References: <20220902121358.773776406@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kuniyuki Iwashima [ Upstream commit bf955b5ab8f6f7b0632cdef8e36b14e4f6e77829 ] While reading weight_p, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Also, dev_[rt]x_weight can be read/written at the same time. So, we need to use READ_ONCE() and WRITE_ONCE() for its access. Moreover, to use the same weight_p while changing dev_[rt]x_weight, we add a mutex in proc_do_dev_weight(). Fixes: 3d48b53fb2ae ("net: dev_weight: TX/RX orthogonality") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/core/dev.c | 2 +- net/core/sysctl_net_core.c | 15 +++++++++------ net/sched/sch_generic.c | 2 +- 3 files changed, 11 insertions(+), 8 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index ea09e0809c122..51721fb2e30cf 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5186,7 +5186,7 @@ static int process_backlog(struct napi_struct *napi, int quota) net_rps_action_and_irq_enable(sd); } - napi->weight = dev_rx_weight; + napi->weight = READ_ONCE(dev_rx_weight); while (again) { struct sk_buff *skb; diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index ac1a32d5cad3c..1b5749f2ef9c0 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -229,14 +229,17 @@ static int set_default_qdisc(struct ctl_table *table, int write, static int proc_do_dev_weight(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - int ret; + static DEFINE_MUTEX(dev_weight_mutex); + int ret, weight; + mutex_lock(&dev_weight_mutex); ret = proc_dointvec(table, write, buffer, lenp, ppos); - if (ret != 0) - return ret; - - dev_rx_weight = weight_p * dev_weight_rx_bias; - dev_tx_weight = weight_p * dev_weight_tx_bias; + if (!ret && write) { + weight = READ_ONCE(weight_p); + WRITE_ONCE(dev_rx_weight, weight * dev_weight_rx_bias); + WRITE_ONCE(dev_tx_weight, weight * dev_weight_tx_bias); + } + mutex_unlock(&dev_weight_mutex); return ret; } diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 82752dcbf2a2c..4a76ceeca6fdd 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -251,7 +251,7 @@ static inline int qdisc_restart(struct Qdisc *q, int *packets) void __qdisc_run(struct Qdisc *q) { - int quota = dev_tx_weight; + int quota = READ_ONCE(dev_tx_weight); int packets; while (qdisc_restart(q, &packets)) { -- 2.35.1