linux_dsm_epyc7002/drivers/net/ethernet/mellanox
Maxim Mikityanskiy 9df86bdb67 net/mlx5e: Fix handling of compressed CQEs in case of low NAPI budget
When CQE compression is enabled, compressed CQEs use the following
structure: a title is followed by one or many blocks, each containing 8
mini CQEs (except the last, which may contain fewer mini CQEs).

Due to NAPI budget restriction, a complete structure is not always
parsed in one NAPI run, and some blocks with mini CQEs may be deferred
to the next NAPI poll call - we have the mlx5e_decompress_cqes_cont call
in the beginning of mlx5e_poll_rx_cq. However, if the budget is
extremely low, some blocks may be left even after that, but the code
that follows the mlx5e_decompress_cqes_cont call doesn't check it and
assumes that a new CQE begins, which may not be the case. In such cases,
random memory corruptions occur.

An extremely low NAPI budget of 8 is used when busy_poll or busy_read is
active.

This commit adds a check to make sure that the previous compressed CQE
has been completely parsed after mlx5e_decompress_cqes_cont, otherwise
it prevents a new CQE from being fetched in the middle of a compressed
CQE.

This commit fixes random crashes in __build_skb, __page_pool_put_page
and other not-related-directly places, that used to happen when both CQE
compression and busy_poll/busy_read were enabled.

Fixes: 7219ab34f1 ("net/mlx5e: CQE compression")
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
2019-10-29 16:27:19 -07:00
..
mlx4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-09-15 14:17:27 +02:00
mlx5/core net/mlx5e: Fix handling of compressed CQEs in case of low NAPI budget 2019-10-29 16:27:19 -07:00
mlxfw mlxfw: Introduce status_notify op and call it to notify about the status 2019-06-04 14:21:40 -07:00
mlxsw mlxsw: spectrum_trap: Push Ethernet header before reporting trap 2019-10-18 10:15:09 -07:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00