Commit 303c07db487be59ae9fda10600ea65ca11c21497
Committed by
David S. Miller
David S. Miller
1 parent
7cb08d7f3a
Exists in
master
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20 other branches
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>
Showing 1 changed file with 8 additions and 0 deletions Side-by-side Diff
drivers/net/ppp/ppp_generic.c
| ... | ... | @@ -1058,7 +1058,15 @@ |
| 1058 | 1058 | return stats64; |
| 1059 | 1059 | } |
| 1060 | 1060 | |
| 1061 | +static struct lock_class_key ppp_tx_busylock; | |
| 1062 | +static int ppp_dev_init(struct net_device *dev) | |
| 1063 | +{ | |
| 1064 | + dev->qdisc_tx_busylock = &ppp_tx_busylock; | |
| 1065 | + return 0; | |
| 1066 | +} | |
| 1067 | + | |
| 1061 | 1068 | static const struct net_device_ops ppp_netdev_ops = { |
| 1069 | + .ndo_init = ppp_dev_init, | |
| 1062 | 1070 | .ndo_start_xmit = ppp_start_xmit, |
| 1063 | 1071 | .ndo_do_ioctl = ppp_net_ioctl, |
| 1064 | 1072 | .ndo_get_stats64 = ppp_get_stats64, |