From patchwork Mon Aug 10 15:22:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 266668 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=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 76B41C433E1 for ; Mon, 10 Aug 2020 15:30:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C055207FF for ; Mon, 10 Aug 2020 15:30:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597073440; bh=yCnOv7z6QR8V//pqvrVl+elidpg/YiHVrVZ9pqUErzk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=eF3kKK7EMSIHBZDXViX6wkEFcBv63/ImAQ1pgH4PY6uEIQu2W91WaTmT6jlUMo4Bp 9wtRfg+pPQh/pfLqDacDsoHso7RLZlTw3ImDPFPqhmJrY9mj29ulzK0qdCyEbbHXap I9919MvYOvBLQqsJFtpdvo4tg0KXOMrnxZGoY2K4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728605AbgHJPaj (ORCPT ); Mon, 10 Aug 2020 11:30:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:37638 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728318AbgHJPah (ORCPT ); Mon, 10 Aug 2020 11:30:37 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 655DA20774; Mon, 10 Aug 2020 15:30:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597073436; bh=yCnOv7z6QR8V//pqvrVl+elidpg/YiHVrVZ9pqUErzk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0Eix6MotZRTq77L5XkIg+eDqmqRe63MhzXhclL4qi4X4zuon3BscF7ytxw35Te6q2 vPOEPqGLRPIaxyFyHiwbzKzBhepZ0+dveAdZh9YWrUSXtufKd9m4BRuAANNlzGIFzK OZCXQ11voLLBu2b6Jvo7gEmO5wIPWie0NFMnkFGk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Rafael P." , Dean Nelson , Xin Long , "David S. Miller" Subject: [PATCH 4.19 39/48] net: thunderx: use spin_lock_bh in nicvf_set_rx_mode_task() Date: Mon, 10 Aug 2020 17:22:01 +0200 Message-Id: <20200810151806.141225080@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200810151804.199494191@linuxfoundation.org> References: <20200810151804.199494191@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Xin Long [ Upstream commit bab9693a9a8c6dd19f670408ec1e78e12a320682 ] A dead lock was triggered on thunderx driver: CPU0 CPU1 ---- ---- [01] lock(&(&nic->rx_mode_wq_lock)->rlock); [11] lock(&(&mc->mca_lock)->rlock); [12] lock(&(&nic->rx_mode_wq_lock)->rlock); [02] lock(&(&mc->mca_lock)->rlock); The path for each is: [01] worker_thread() -> process_one_work() -> nicvf_set_rx_mode_task() [02] mld_ifc_timer_expire() [11] ipv6_add_dev() -> ipv6_dev_mc_inc() -> igmp6_group_added() -> [12] dev_mc_add() -> __dev_set_rx_mode() -> nicvf_set_rx_mode() To fix it, it needs to disable bh on [1], so that the timer on [2] wouldn't be triggered until rx_mode_wq_lock is released. So change to use spin_lock_bh() instead of spin_lock(). Thanks to Paolo for helping with this. v1->v2: - post to netdev. Reported-by: Rafael P. Tested-by: Dean Nelson Fixes: 469998c861fa ("net: thunderx: prevent concurrent data re-writing by nicvf_set_rx_mode") Signed-off-by: Xin Long Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/cavium/thunder/nicvf_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c +++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c @@ -2015,11 +2015,11 @@ static void nicvf_set_rx_mode_task(struc /* Save message data locally to prevent them from * being overwritten by next ndo_set_rx_mode call(). */ - spin_lock(&nic->rx_mode_wq_lock); + spin_lock_bh(&nic->rx_mode_wq_lock); mode = vf_work->mode; mc = vf_work->mc; vf_work->mc = NULL; - spin_unlock(&nic->rx_mode_wq_lock); + spin_unlock_bh(&nic->rx_mode_wq_lock); __nicvf_set_rx_mode_task(mode, mc, nic); }