linux-stable/net/xdp
Maciej Fijalkowski d678cbd2f8 xsk: Fix handling of invalid descriptors in XSK TX batching API
xdpxceiver run on a AF_XDP ZC enabled driver revealed a problem with XSK
Tx batching API. There is a test that checks how invalid Tx descriptors
are handled by AF_XDP. Each valid descriptor is followed by invalid one
on Tx side whereas the Rx side expects only to receive a set of valid
descriptors.

In current xsk_tx_peek_release_desc_batch() function, the amount of
available descriptors is hidden inside xskq_cons_peek_desc_batch(). This
can be problematic in cases where invalid descriptors are present due to
the fact that xskq_cons_peek_desc_batch() returns only a count of valid
descriptors. This means that it is impossible to properly update XSK
ring state when calling xskq_cons_release_n().

To address this issue, pull out the contents of
xskq_cons_peek_desc_batch() so that callers (currently only
xsk_tx_peek_release_desc_batch()) will always be able to update the
state of ring properly, as total count of entries is now available and
use this value as an argument in xskq_cons_release_n(). By
doing so, xskq_cons_peek_desc_batch() can be dropped altogether.

Fixes: 9349eb3a9d ("xsk: Introduce batched Tx descriptor interfaces")
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20220607142200.576735-1-maciej.fijalkowski@intel.com
2022-06-08 16:20:07 +02:00
..
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile xsk: Introduce AF_XDP buffer allocation API 2020-05-21 17:31:26 -07:00
xdp_umem.c xsk: Use kvcalloc to support large umems 2021-05-25 13:11:50 +02:00
xdp_umem.h xsk: Fix umem cleanup bug at socket destruct 2020-11-20 15:52:39 +01:00
xsk.c xsk: Fix handling of invalid descriptors in XSK TX batching API 2022-06-08 16:20:07 +02:00
xsk.h xdp: Add proper __rcu annotations to redirect map entries 2021-06-24 19:41:15 +02:00
xsk_buff_pool.c xsk: Fix possible crash when multiple sockets are created 2022-04-26 16:19:54 +02:00
xsk_diag.c xsk: Fix possible segfault in xsk umem diagnostics 2020-09-02 16:49:40 +02:00
xsk_queue.c xsk: Remove MEM_TYPE_ZERO_COPY and corresponding code 2020-05-21 17:31:27 -07:00
xsk_queue.h xsk: Fix handling of invalid descriptors in XSK TX batching API 2022-06-08 16:20:07 +02:00
xskmap.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00