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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 7B6F4C48BD9 for ; Thu, 27 Jun 2019 00:45:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 539F6214DA for ; Thu, 27 Jun 2019 00:45:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561596344; bh=7/1DSFg69VhOmR5parl9oVNvXdxXXvIKGHrdgROtRvA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VWQ41NgyHOTDYT0ffV5XzrqbW6om90lQ7kCzJF/IE4kzEZyU1ub9Y+fcH5BcRO97z RzhiSEiqIVbBW6w0NIVME+II+BcuPBB2VzriNKyTeC6cmkHI1N2nu/qSb36v5L03mg 6hf5fhmb1Eua9F97WyPCsWRZ0zxN4B58uHfpWqsI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729384AbfF0Apn (ORCPT ); Wed, 26 Jun 2019 20:45:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:44768 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728661AbfF0Akz (ORCPT ); Wed, 26 Jun 2019 20:40:55 -0400 Received: from sasha-vm.mshome.net (unknown [107.242.116.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AD127205ED; Thu, 27 Jun 2019 00:40:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561596054; bh=7/1DSFg69VhOmR5parl9oVNvXdxXXvIKGHrdgROtRvA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0qFEmI5aa9W0XBLWl2sNq5cOxgSXlJGcdyh9xf4S+dF5DZ3oOnFEbJM121OURDZWJ GFMbu9yd43Bfh+C68F+z5/Bjz9ZGuX88eHVIpC67lM2Tm6AgnaNdFpyE94Y60wMFet JwVgbDw/d0uJCNGxvbvV5qiIenqUS3CPwux0xxfs= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Reinhard Speyerer , Daniele Palmas , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org, linux-usb@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 26/35] qmi_wwan: avoid RCU stalls on device disconnect when in QMAP mode Date: Wed, 26 Jun 2019 20:39:14 -0400 Message-Id: <20190627003925.21330-26-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190627003925.21330-1-sashal@kernel.org> References: <20190627003925.21330-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Reinhard Speyerer [ 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 023bb2daa72f..a77223887022 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; @@ -1423,6 +1424,7 @@ 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) @@ -1435,8 +1437,9 @@ 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