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| author |   Maxim Mikityanskiy <maximmi@mellanox.com> | 2019-09-16 14:54:20 +0300 |
|---|---|---|
| committer |   Saeed Mahameed <saeedm@mellanox.com> | 2019-10-29 16:27:19 -0700 |
| commit | 9df86bdb6746d7fcfc2fda715f7a7c3d0ddb2654 (patch) | |
| tree | 4c2f65e512991a8f987027fb150074301d0b4251 /drivers | |
| parent | net/mlx5e: Don't store direct pointer to action's tunnel info (diff) | |
| download | linux-dev-9df86bdb6746d7fcfc2fda715f7a7c3d0ddb2654.tar.xz linux-dev-9df86bdb6746d7fcfc2fda715f7a7c3d0ddb2654.zip | |
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: 7219ab34f184 ("net/mlx5e: CQE compression")
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Diffstat (limited to 'drivers')
| -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 d6a547238de0..82cffb3a9964 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c @@ -1386,8 +1386,11 @@ 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) { |