Lennert Buytenhek 4e2fd55519 gianfar: fix BUG under load after introduction of skb recycling
Since commit 0fd56bb5be6455d0d42241e65aed057244665e5e ("gianfar:
Add support for skb recycling"), gianfar puts skbuffs that are in
the rx ring back onto the recycle list as-is in case there was a
receive error, but this breaks the following invariant: that all
skbuffs on the recycle list have skb->data = skb->head + NET_SKB_PAD.

The RXBUF_ALIGNMENT realignment done in gfar_new_skb() will be done
twice on skbuffs recycled in this way, causing there not to be enough
room in the skb anymore to receive a full packet, eventually leading
to an skb_over_panic from gfar_clean_rx_ring() -> skb_put().

Resetting the skb->data pointer to skb->head + NET_SKB_PAD before
putting the skb back onto the recycle list restores the mentioned
invariant, and should fix this issue.

Reported-by: Michael Guntsche <mike@it-loops.com>
Tested-by: Michael Guntsche <mike@it-loops.com>
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-05-25 00:42:34 -07:00
..
2009-04-28 20:24:20 +02:00
2009-04-21 13:41:51 -07:00
2009-04-05 00:32:25 +02:00
2009-05-06 16:36:10 -07:00
2009-04-14 19:46:19 -07:00
2009-05-09 10:49:42 -04:00
2009-04-05 00:32:22 +02:00