diff options
| author | Sven Eckelmann <sven@narfation.org> | 2012-08-20 09:03:59 +0200 |
|---|---|---|
| committer | Antonio Quartulli <ordex@autistici.org> | 2012-10-29 09:42:32 +0100 |
| commit | 36c1d1531130dcfadf845419fd15735b9b4c004f (patch) | |
| tree | 7bb3d3253eed07d3d32cb51c00ad3a17e496543e /net/batman-adv | |
| parent | c10dba051a3e287a4f023aaaeffa53fd642cf8c5 (diff) | |
batman-adv: Set special lockdep classes to avoid lockdep warning
Transmissions over batman-adv devices always start another nested transmission
over devices attached to the batman-adv interface. These devices usually use
the ethernet lockdep class for the tx_queue lock which is also set by default
for all batman-adv devices. Lockdep will detect a nested locking attempt of two
locks with the same class and warn about a possible deadlock.
This is the default and expected behavior and should not alarm the locking
correctness prove mechanism. Therefore, the locks for all netdevice specific tx
queues get a special batman-adv lock class to avoid a false positive for each
transmission.
Reported-by: Linus Luessing <linus.luessing@web.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Diffstat (limited to 'net/batman-adv')
| -rw-r--r-- | net/batman-adv/soft-interface.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index b9a28d2dd3e..948860a2a57 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -347,7 +347,51 @@ out: return; } +/* batman-adv network devices have devices nesting below it and are a special + * "super class" of normal network devices; split their locks off into a + * separate class since they always nest. + */ +static struct lock_class_key batadv_netdev_xmit_lock_key; +static struct lock_class_key batadv_netdev_addr_lock_key; + +/** + * batadv_set_lockdep_class_one - Set lockdep class for a single tx queue + * @dev: device which owns the tx queue + * @txq: tx queue to modify + * @_unused: always NULL + */ +static void batadv_set_lockdep_class_one(struct net_device *dev, + struct netdev_queue *txq, + void *_unused) +{ + lockdep_set_class(&txq->_xmit_lock, &batadv_netdev_xmit_lock_key); +} + +/** + * batadv_set_lockdep_class - Set txq and addr_list lockdep class + * @dev: network device to modify + */ +static void batadv_set_lockdep_class(struct net_device *dev) +{ + lockdep_set_class(&dev->addr_list_lock, &batadv_netdev_addr_lock_key); + netdev_for_each_tx_queue(dev, batadv_set_lockdep_class_one, NULL); +} + +/** + * batadv_softif_init - Late stage initialization of soft interface + * @dev: registered network device to modify + * + * Returns error code on failures + */ +static int batadv_softif_init(struct net_device *dev) +{ + batadv_set_lockdep_class(dev); + + return 0; +} + static const struct net_device_ops batadv_netdev_ops = { + .ndo_init = batadv_softif_init, .ndo_open = batadv_interface_open, .ndo_stop = batadv_interface_release, .ndo_get_stats = batadv_interface_stats, |