[    1.940588] ip (244) used greatest stack depth: 12320 bytes left
[  950.730296] blackhole_netdev_xmit(): Dropping skb.
[  950.730367] blackhole_netdev_xmit(): Dropping skb.
[  950.730398] blackhole_netdev_xmit(): Dropping skb.
[  950.730432] blackhole_netdev_xmit(): Dropping skb.