| From foo@baz Thu Feb 27 20:11:26 PST 2014 |
| From: Eric Dumazet <edumazet@google.com> |
| Date: Mon, 10 Feb 2014 11:42:35 -0800 |
| Subject: 6lowpan: fix lockdep splats |
| |
| From: Eric Dumazet <edumazet@google.com> |
| |
| [ 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 <alex.aring@gmail.com> |
| Signed-off-by: Eric Dumazet <edumazet@google.com> |
| Tested-by: Alexander Aring <alex.aring@gmail.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| net/ieee802154/6lowpan.c | 20 ++++++++++++++++++++ |
| 1 file changed, 20 insertions(+) |
| |
| --- a/net/ieee802154/6lowpan.c |
| +++ b/net/ieee802154/6lowpan.c |
| @@ -1249,7 +1249,27 @@ 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, |
| }; |