From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Aring , Eric Dumazet , "David S. Miller" Subject: [PATCH 3.10 20/97] 6lowpan: fix lockdep splats Date: Tue, 4 Mar 2014 12:03:33 -0800 Message-Id: <20140304200346.740968301@linuxfoundation.org> In-Reply-To: <20140304200345.895517495@linuxfoundation.org> References: <20140304200345.895517495@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 20e7c4e80dcd01dad5e6c8b32455228b8fe9c619 ] When a device ndo_start_xmit() calls again dev_queue_xmit(), lockdep can complain because dev_queue_xmit() is re-entered and the spinlocks protecting tx queues share a common lockdep class. Same issue was fixed for bonding/l2tp/ppp in commits 0daa2303028a6 ("[PATCH] bonding: lockdep annotation") 49ee49202b4ac ("bonding: set qdisc_tx_busylock to avoid LOCKDEP splat") 23d3b8bfb8eb2 ("net: qdisc busylock needs lockdep annotations ") 303c07db487be ("ppp: set qdisc_tx_busylock to avoid LOCKDEP splat ") Reported-by: Alexander Aring Signed-off-by: Eric Dumazet Tested-by: Alexander Aring Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ieee802154/6lowpan.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) --- a/net/ieee802154/6lowpan.c +++ b/net/ieee802154/6lowpan.c @@ -1173,7 +1173,27 @@ static struct header_ops lowpan_header_o .create = lowpan_header_create, }; +static struct lock_class_key lowpan_tx_busylock; +static struct lock_class_key lowpan_netdev_xmit_lock_key; + +static void lowpan_set_lockdep_class_one(struct net_device *dev, + struct netdev_queue *txq, + void *_unused) +{ + lockdep_set_class(&txq->_xmit_lock, + &lowpan_netdev_xmit_lock_key); +} + + +static int lowpan_dev_init(struct net_device *dev) +{ + netdev_for_each_tx_queue(dev, lowpan_set_lockdep_class_one, NULL); + dev->qdisc_tx_busylock = &lowpan_tx_busylock; + return 0; +} + static const struct net_device_ops lowpan_netdev_ops = { + .ndo_init = lowpan_dev_init, .ndo_start_xmit = lowpan_xmit, .ndo_set_mac_address = lowpan_set_address, };