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 X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 8E30DC10F0E for ; Mon, 15 Apr 2019 19:28:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5B3C220651 for ; Mon, 15 Apr 2019 19:28:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555356515; bh=Neicr4jzu4/wVe1gtmAsi1K8Q5U6p3on/Zrf3CdEg8s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lGF6OxJ8QxSNMX6N6scmVB08tdQUqdAt3tp8EMqrBYf4E/QMHXZnjtgw0nNxvkPjY RWYCZZJFiHYaoHSz9luBjlUkl28a/CKsKIsDPb3LR9Q59jYhGPPueHvbK2c1rZlDDz oYMETN+dHmN/jeDxXSVn1hO9RXHu+SzxoSRW0UhA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729110AbfDOTDG (ORCPT ); Mon, 15 Apr 2019 15:03:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:34544 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729083AbfDOTDD (ORCPT ); Mon, 15 Apr 2019 15:03:03 -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 E597D20880; Mon, 15 Apr 2019 19:03:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555354982; bh=Neicr4jzu4/wVe1gtmAsi1K8Q5U6p3on/Zrf3CdEg8s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=irl2SJjmyrmEae0DI4IckLouMU4VIoeEImB70drxf80UGxWigWg47SN+e1cWDl1Lx w28RsQ06sOEeVySTYHZGbH4mbbZW7DnlpjLaDOACXI0MLGDxxnvGTvMIDxYBijIouK /Zzj5T11/yo+ZNkrbOo0yAIuL+0Bhq4fwZOrrR9s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mohammed Gamal , Haiyang Zhang , "David S. Miller" Subject: [PATCH 4.14 38/69] hv_netvsc: Fix unwanted wakeup after tx_disable Date: Mon, 15 Apr 2019 20:58:56 +0200 Message-Id: <20190415183732.366513910@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190415183726.036654568@linuxfoundation.org> References: <20190415183726.036654568@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Haiyang Zhang [ Upstream commit 1b704c4a1ba95574832e730f23817b651db2aa59 ] After queue stopped, the wakeup mechanism may wake it up again when ring buffer usage is lower than a threshold. This may cause send path panic on NULL pointer when we stopped all tx queues in netvsc_detach and start removing the netvsc device. This patch fix it by adding a tx_disable flag to prevent unwanted queue wakeup. Fixes: 7b2ee50c0cd5 ("hv_netvsc: common detach logic") Reported-by: Mohammed Gamal Signed-off-by: Haiyang Zhang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/hyperv/hyperv_net.h | 1 + drivers/net/hyperv/netvsc.c | 6 ++++-- drivers/net/hyperv/netvsc_drv.c | 32 ++++++++++++++++++++++++++------ 3 files changed, 31 insertions(+), 8 deletions(-) --- a/drivers/net/hyperv/hyperv_net.h +++ b/drivers/net/hyperv/hyperv_net.h @@ -779,6 +779,7 @@ struct netvsc_device { wait_queue_head_t wait_drain; bool destroy; + bool tx_disable; /* if true, do not wake up queue again */ /* Receive buffer allocated by us but manages by NetVSP */ void *recv_buf; --- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c @@ -107,6 +107,7 @@ static struct netvsc_device *alloc_net_d init_waitqueue_head(&net_device->wait_drain); net_device->destroy = false; + net_device->tx_disable = false; atomic_set(&net_device->open_cnt, 0); net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT; net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT; @@ -712,7 +713,7 @@ static void netvsc_send_tx_complete(stru } else { struct netdev_queue *txq = netdev_get_tx_queue(ndev, q_idx); - if (netif_tx_queue_stopped(txq) && + if (netif_tx_queue_stopped(txq) && !net_device->tx_disable && (hv_ringbuf_avail_percent(&channel->outbound) > RING_AVAIL_PERCENT_HIWATER || queue_sends < 1)) { netif_tx_wake_queue(txq); @@ -865,7 +866,8 @@ static inline int netvsc_send_pkt( netif_tx_stop_queue(txq); } else if (ret == -EAGAIN) { netif_tx_stop_queue(txq); - if (atomic_read(&nvchan->queue_sends) < 1) { + if (atomic_read(&nvchan->queue_sends) < 1 && + !net_device->tx_disable) { netif_tx_wake_queue(txq); ret = -ENOSPC; } --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -108,6 +108,15 @@ static void netvsc_set_rx_mode(struct ne rcu_read_unlock(); } +static void netvsc_tx_enable(struct netvsc_device *nvscdev, + struct net_device *ndev) +{ + nvscdev->tx_disable = false; + virt_wmb(); /* ensure queue wake up mechanism is on */ + + netif_tx_wake_all_queues(ndev); +} + static int netvsc_open(struct net_device *net) { struct net_device_context *ndev_ctx = netdev_priv(net); @@ -128,7 +137,7 @@ static int netvsc_open(struct net_device rdev = nvdev->extension; if (!rdev->link_state) { netif_carrier_on(net); - netif_tx_wake_all_queues(net); + netvsc_tx_enable(nvdev, net); } if (vf_netdev) { @@ -183,6 +192,17 @@ static int netvsc_wait_until_empty(struc } } +static void netvsc_tx_disable(struct netvsc_device *nvscdev, + struct net_device *ndev) +{ + if (nvscdev) { + nvscdev->tx_disable = true; + virt_wmb(); /* ensure txq will not wake up after stop */ + } + + netif_tx_disable(ndev); +} + static int netvsc_close(struct net_device *net) { struct net_device_context *net_device_ctx = netdev_priv(net); @@ -191,7 +211,7 @@ static int netvsc_close(struct net_devic struct netvsc_device *nvdev = rtnl_dereference(net_device_ctx->nvdev); int ret; - netif_tx_disable(net); + netvsc_tx_disable(nvdev, net); /* No need to close rndis filter if it is removed already */ if (!nvdev) @@ -893,7 +913,7 @@ static int netvsc_detach(struct net_devi /* If device was up (receiving) then shutdown */ if (netif_running(ndev)) { - netif_tx_disable(ndev); + netvsc_tx_disable(nvdev, ndev); ret = rndis_filter_close(nvdev); if (ret) { @@ -1720,7 +1740,7 @@ static void netvsc_link_change(struct wo if (rdev->link_state) { rdev->link_state = false; netif_carrier_on(net); - netif_tx_wake_all_queues(net); + netvsc_tx_enable(net_device, net); } else { notify = true; } @@ -1730,7 +1750,7 @@ static void netvsc_link_change(struct wo if (!rdev->link_state) { rdev->link_state = true; netif_carrier_off(net); - netif_tx_stop_all_queues(net); + netvsc_tx_disable(net_device, net); } kfree(event); break; @@ -1739,7 +1759,7 @@ static void netvsc_link_change(struct wo if (!rdev->link_state) { rdev->link_state = true; netif_carrier_off(net); - netif_tx_stop_all_queues(net); + netvsc_tx_disable(net_device, net); event->event = RNDIS_STATUS_MEDIA_CONNECT; spin_lock_irqsave(&ndev_ctx->lock, flags); list_add(&event->list, &ndev_ctx->reconfig_events);