diff options
| author | Maxim Mikityanskiy <maximmi@mellanox.com> | 2019-09-16 14:54:20 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-10 11:34:50 +0100 |
| commit | 372a4ffae4c3ea164a0ef57ca02b7e75b5b24011 (patch) | |
| tree | bb4e9f427658e53afeb8a1f09753a5dece3801d0 | |
| parent | 8135afc2cecc434c0fc3eee0d85446def2389d71 (diff) | |
net/mlx5e: Fix handling of compressed CQEs in case of low NAPI budget
[ Upstream commit 9df86bdb6746d7fcfc2fda715f7a7c3d0ddb2654 ]
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: 7219ab34f184 ("net/mlx5e: CQE compression")
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c index ac6e586d403d..fb139f8b9acf 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c @@ -1367,8 +1367,11 @@ int mlx5e_poll_rx_cq(struct mlx5e_cq *cq, int budget) if (unlikely(!test_bit(MLX5E_RQ_STATE_ENABLED, &rq->state))) return 0; - if (rq->cqd.left) + if (rq->cqd.left) { work_done += mlx5e_decompress_cqes_cont(rq, cqwq, 0, budget); + if (rq->cqd.left || work_done >= budget) + goto out; + } cqe = mlx5_cqwq_get_cqe(cqwq); if (!cqe) { |