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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,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 26953C742B9 for ; Fri, 12 Jul 2019 12:21:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EC6012166E for ; Fri, 12 Jul 2019 12:21:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562934104; bh=VsZms4Ebu41p9h8mUbbIv4O/kyaymEWAYms16wI9iH4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=CZ0hFbiI97s6mMOYyA0ab5WgdM6Y72YM0fNv9BQlHBARDSYkpqCwRJ0Wr7+Z2BXHb U77/ywgfyOEXeEq24K5TX1DZCXtgj6ul8Eap6zVVe+dkMvEIW9p8Lvdgxu524+4oyG u0KcdNRDFcJlZZ11EGZ/MF9LxRYuGTdejsUmlX80= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727615AbfGLMVj (ORCPT ); Fri, 12 Jul 2019 08:21:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:55920 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727627AbfGLMVi (ORCPT ); Fri, 12 Jul 2019 08:21:38 -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 DE5DF20863; Fri, 12 Jul 2019 12:21:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562934098; bh=VsZms4Ebu41p9h8mUbbIv4O/kyaymEWAYms16wI9iH4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j+VT5OGJUmPX7DvTXe9alYqGFSpl6/btBkEj4rCM2kIwOuL2MZgwuK7orDi3C/yLH btIcEzZ50W2+AzmOEXJFCzWTDOlCgWqx5vBpf+E2b9WbnUJ8jgEhtOuk0NARt7VAvW lSqjQSjgZxNN1CMQ1RKT/06ZnHFGriGDpffOQfWY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniele Palmas , Reinhard Speyerer , "David S. Miller" , Sasha Levin Subject: [PATCH 4.19 43/91] qmi_wwan: avoid RCU stalls on device disconnect when in QMAP mode Date: Fri, 12 Jul 2019 14:18:46 +0200 Message-Id: <20190712121623.814315766@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190712121621.422224300@linuxfoundation.org> References: <20190712121621.422224300@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 [ Upstream commit a8fdde1cb830e560208af42b6c10750137f53eb3 ] Switch qmimux_unregister_device() and qmi_wwan_disconnect() to use unregister_netdevice_queue() and unregister_netdevice_many() instead of unregister_netdevice(). This avoids RCU stalls which have been observed on device disconnect in certain setups otherwise. Fixes: c6adf77953bc ("net: usb: qmi_wwan: add qmap mux protocol support") Cc: Daniele Palmas Signed-off-by: Reinhard Speyerer Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/usb/qmi_wwan.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c index 090227118d3d..44ada5c38756 100644 --- a/drivers/net/usb/qmi_wwan.c +++ b/drivers/net/usb/qmi_wwan.c @@ -247,13 +247,14 @@ static int qmimux_register_device(struct net_device *real_dev, u8 mux_id) return err; } -static void qmimux_unregister_device(struct net_device *dev) +static void qmimux_unregister_device(struct net_device *dev, + struct list_head *head) { struct qmimux_priv *priv = netdev_priv(dev); struct net_device *real_dev = priv->real_dev; netdev_upper_dev_unlink(real_dev, dev); - unregister_netdevice(dev); + unregister_netdevice_queue(dev, head); /* Get rid of the reference to real_dev */ dev_put(real_dev); @@ -424,7 +425,7 @@ static ssize_t del_mux_store(struct device *d, struct device_attribute *attr, c ret = -EINVAL; goto err; } - qmimux_unregister_device(del_dev); + qmimux_unregister_device(del_dev, NULL); if (!qmimux_has_slaves(dev)) info->flags &= ~QMI_WWAN_FLAG_MUX; @@ -1434,6 +1435,7 @@ static void qmi_wwan_disconnect(struct usb_interface *intf) struct qmi_wwan_state *info; struct list_head *iter; struct net_device *ldev; + LIST_HEAD(list); /* called twice if separate control and data intf */ if (!dev) @@ -1446,8 +1448,9 @@ static void qmi_wwan_disconnect(struct usb_interface *intf) } rcu_read_lock(); netdev_for_each_upper_dev_rcu(dev->net, ldev, iter) - qmimux_unregister_device(ldev); + qmimux_unregister_device(ldev, &list); rcu_read_unlock(); + unregister_netdevice_many(&list); rtnl_unlock(); info->flags &= ~QMI_WWAN_FLAG_MUX; } -- 2.20.1