| From 4ead5e2075773c4d8b789044f55c0dd293448713 Mon Sep 17 00:00:00 2001 |
| From: Eric Dumazet <edumazet@google.com> |
| Date: Tue, 19 Feb 2013 10:42:03 -0800 |
| Subject: ppp: set qdisc_tx_busylock to avoid LOCKDEP splat |
| |
| |
| From: Eric Dumazet <edumazet@google.com> |
| |
| [ Upstream commit 303c07db487be59ae9fda10600ea65ca11c21497 ] |
| |
| 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> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/net/ppp/ppp_generic.c | 8 ++++++++ |
| 1 file changed, 8 insertions(+) |
| |
| --- 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, |
| 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, |
