From 303c07db487be59ae9fda10600ea65ca11c21497 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 19 Feb 2013 10:42:03 -0800 Subject: [PATCH] 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 Tested-by: Yanko Kaneti Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- drivers/net/ppp/ppp_generic.c | 8 ++++++++ 1 file changed, 8 insertions(+) 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, -- 2.39.5