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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,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 117E4C43381 for ; Thu, 28 Mar 2019 17:50:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E08792183F for ; Thu, 28 Mar 2019 17:50:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727416AbfC1RuL (ORCPT ); Thu, 28 Mar 2019 13:50:11 -0400 Received: from a2nlsmtp01-02.prod.iad2.secureserver.net ([198.71.225.36]:59536 "EHLO a2nlsmtp01-02.prod.iad2.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726034AbfC1RuL (ORCPT ); Thu, 28 Mar 2019 13:50:11 -0400 Received: from linuxonhyperv2.linuxonhyperv.com ([107.180.71.197]) by : HOSTING RELAY : with ESMTP id 9Z9JhVvWdO5E59Z9JhQc8T; Thu, 28 Mar 2019 10:49:09 -0700 x-originating-ip: 107.180.71.197 Received: from haiyangz by linuxonhyperv2.linuxonhyperv.com with local (Exim 4.91) (envelope-from ) id 1h9Z9J-0001GA-2c; Thu, 28 Mar 2019 10:49:09 -0700 From: Haiyang Zhang To: sashal@kernel.org, linux-hyperv@vger.kernel.org Cc: haiyangz@microsoft.com, kys@microsoft.com, sthemmin@microsoft.com, olaf@aepfle.de, vkuznets@redhat.com, davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH hyperv-fixes] hv_netvsc: Fix unwanted wakeup after tx_disable Date: Thu, 28 Mar 2019 17:48:45 +0000 Message-Id: <20190328174845.4799-1-haiyangz@linuxonhyperv.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CMAE-Envelope: MS4wfMZltb/sB/e4UFgHZssbiqMVSxMBg9AEbr636/S1oQ8KsXQsBgkLBRKZ/UGFHIUHnpqPbg8WYWhK0FjV7KYU1om1AERIXUCiQL+IC388fmc83N88XzIz K7lVMgJLkBQnBSRsOJX3ixnNvn21rJVRT14hwWEZh9TymyHp3W8TMWjblycauAJ5t11F1bvzBJewElSGeXtKnSpIBkjuAdP5+XlY9707Zu+Ks1a/+VtUYANb hIkIla+gc7BqMoqo8tc5ZlGHxS5lq8djKsUDyIFo/rC0L+A1aztSQq4J/x+Qs43XRM8jdjB5a1myyC46lNaAAzhsZdqeKYchN6CBTAifdZyk4fF+kKuRhLAH nlZxYA9ileifSvTJXCnUeV5MzRl2gtyYmNgNJpfflR8wvzzgoc/7crh7AhsQYxMALXs5olUMWVPbLD2DWEn7x+GrDLCHb8NwSGJcqo2Ma5BYqlpcxmKdFz2X x6HKPxmftdVpexfuDQG/zezAmGMMOV/jM0LgATFT1WoFEfKUpClO45VGB5Q= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Haiyang Zhang 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 --- 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(-) diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h index e859ae2..49f41b6 100644 --- a/drivers/net/hyperv/hyperv_net.h +++ b/drivers/net/hyperv/hyperv_net.h @@ -987,6 +987,7 @@ 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; diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index 813d195..e0dce37 100644 --- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c @@ -110,6 +110,7 @@ static struct netvsc_device *alloc_net_device(void) init_waitqueue_head(&net_device->wait_drain); net_device->destroy = false; + net_device->tx_disable = false; net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT; net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT; @@ -719,7 +720,7 @@ static void netvsc_send_tx_complete(struct net_device *ndev, } 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_get_avail_to_write_percent(&channel->outbound) > RING_AVAIL_PERCENT_HIWATER || queue_sends < 1)) { netif_tx_wake_queue(txq); @@ -874,7 +875,8 @@ static inline int netvsc_send_pkt( } else if (ret == -EAGAIN) { netif_tx_stop_queue(txq); ndev_ctx->eth_stats.stop_queue++; - if (atomic_read(&nvchan->queue_sends) < 1) { + if (atomic_read(&nvchan->queue_sends) < 1 && + !net_device->tx_disable) { netif_tx_wake_queue(txq); ndev_ctx->eth_stats.wake_queue++; ret = -ENOSPC; diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 1a08679..0824155 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -109,6 +109,15 @@ static void netvsc_set_rx_mode(struct net_device *net) rcu_read_unlock(); } +static inline void netvsc_tx_enable(struct netvsc_device *nvscdev, + struct net_device *ndev) +{ + nvscdev->tx_disable = false; + mb(); /* 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); @@ -129,7 +138,7 @@ static int netvsc_open(struct net_device *net) 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) { @@ -184,6 +193,17 @@ static int netvsc_wait_until_empty(struct netvsc_device *nvdev) } } +static inline void netvsc_tx_disable(struct netvsc_device *nvscdev, + struct net_device *ndev) +{ + if (nvscdev) { + nvscdev->tx_disable = true; + mb(); /* 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); @@ -192,7 +212,7 @@ static int netvsc_close(struct net_device *net) 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) @@ -918,7 +938,7 @@ static int netvsc_detach(struct net_device *ndev, /* 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) { @@ -1906,7 +1926,7 @@ static void netvsc_link_change(struct work_struct *w) 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; } @@ -1916,7 +1936,7 @@ static void netvsc_link_change(struct work_struct *w) 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; @@ -1925,7 +1945,7 @@ static void netvsc_link_change(struct work_struct *w) 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); -- 1.8.3.1