mirror of
https://github.com/torvalds/linux.git
synced 2024-11-26 22:21:42 +00:00
9d0a67b9d4
Currently, xsk_build_skb() is a function that builds skb in two possible
ways and then is ended with common error handling.
We can distinguish four possible error paths and handling in xsk_build_skb():
1. sock_alloc_send_skb fails: Retry (skb is NULL).
2. skb_store_bits fails : Free skb and retry.
3. MAX_SKB_FRAGS exceeded: Free skb, cleanup and drop packet.
4. alloc_page fails for frag: Retry page allocation w/o freeing skb
1] and 3] can happen in xsk_build_skb_zerocopy(), which is one of the
two code paths responsible for building skb. Common error path in
xsk_build_skb() assumes that in case errno != -EAGAIN, skb is a valid
pointer, which is wrong as kernel test robot reports that in
xsk_build_skb_zerocopy() other errno values are returned for skb being
NULL.
To fix this, set -EOVERFLOW as error when MAX_SKB_FRAGS are exceeded
and packet needs to be dropped in both xsk_build_skb() and
xsk_build_skb_zerocopy() and use this to distinguish against all other
error cases. Also, add explicit kfree_skb() for 3] so that handling
of 1], 2], and 3] becomes identical where allocation needs to be retried.
Fixes:
|
||
|---|---|---|
| .. | ||
| Kconfig | ||
| Makefile | ||
| xdp_umem.c | ||
| xdp_umem.h | ||
| xsk_buff_pool.c | ||
| xsk_diag.c | ||
| xsk_queue.c | ||
| xsk_queue.h | ||
| xsk.c | ||
| xsk.h | ||
| xskmap.c | ||