path: root/drivers/net/ppp/ppp_generic.c
diff options
authorEric Dumazet <edumazet@google.com>2013-02-19 10:42:03 -0800
committerDavid S. Miller <davem@davemloft.net>2013-02-19 14:33:55 -0500
commit303c07db487be59ae9fda10600ea65ca11c21497 (patch)
tree23a66e53bed3b6f8093d815890388b9057760bd9 /drivers/net/ppp/ppp_generic.c
parentatl1c: restore buffer state (diff)
ppp: set qdisc_tx_busylock to avoid LOCKDEP splat
If a qdisc is installed on a ppp device, its possible to get a lockdep splat under stress, because nested dev_queue_xmit() can lock busylock a second time (on a different device, so its a false positive) Avoid this problem using a distinct lock_class_key for ppp devices. Reported-by: Yanko Kaneti <yaneti@declera.com> Tested-by: Yanko Kaneti <yaneti@declera.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ppp/ppp_generic.c')
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 4fd754e74eb2..3db9131e9229 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -1058,7 +1058,15 @@ ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64)
return stats64;
+static struct lock_class_key ppp_tx_busylock;
+static int ppp_dev_init(struct net_device *dev)
+ dev->qdisc_tx_busylock = &ppp_tx_busylock;
+ return 0;
static const struct net_device_ops ppp_netdev_ops = {
+ .ndo_init = ppp_dev_init,
.ndo_start_xmit = ppp_start_xmit,
.ndo_do_ioctl = ppp_net_ioctl,
.ndo_get_stats64 = ppp_get_stats64,