[PATCH 4.16 34/55] net/mlx5e: TX, Use correct counter in dma_map error flow

From: Greg Kroah-Hartman
Date: Fri May 18 2018 - 03:21:44 EST


4.16-stable review patch. If anyone has any objections, please let me know.

------------------

From: Tariq Toukan <tariqt@xxxxxxxxxxxx>

[ Upstream commit d9a96ec362e3da878c378854e25321c85bac52c2 ]

In case of a dma_mapping_error, do not use wi->num_dma
as a parameter for dma unmap function because it's yet
to be set, and holds an out-of-date value.
Use actual value (local variable num_dma) instead.

Fixes: 34802a42b352 ("net/mlx5e: Do not modify the TX SKB")
Fixes: e586b3b0baee ("net/mlx5: Ethernet Datapath files")
Signed-off-by: Tariq Toukan <tariqt@xxxxxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/mellanox/mlx5/core/en_tx.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
@@ -255,7 +255,7 @@ mlx5e_txwqe_build_dsegs(struct mlx5e_txq
dma_addr = dma_map_single(sq->pdev, skb_data, headlen,
DMA_TO_DEVICE);
if (unlikely(dma_mapping_error(sq->pdev, dma_addr)))
- return -ENOMEM;
+ goto dma_unmap_wqe_err;

dseg->addr = cpu_to_be64(dma_addr);
dseg->lkey = sq->mkey_be;
@@ -273,7 +273,7 @@ mlx5e_txwqe_build_dsegs(struct mlx5e_txq
dma_addr = skb_frag_dma_map(sq->pdev, frag, 0, fsz,
DMA_TO_DEVICE);
if (unlikely(dma_mapping_error(sq->pdev, dma_addr)))
- return -ENOMEM;
+ goto dma_unmap_wqe_err;

dseg->addr = cpu_to_be64(dma_addr);
dseg->lkey = sq->mkey_be;
@@ -285,6 +285,10 @@ mlx5e_txwqe_build_dsegs(struct mlx5e_txq
}

return num_dma;
+
+dma_unmap_wqe_err:
+ mlx5e_dma_unmap_wqe_err(sq, num_dma);
+ return -ENOMEM;
}

static inline void
@@ -380,17 +384,15 @@ static netdev_tx_t mlx5e_sq_xmit(struct
num_dma = mlx5e_txwqe_build_dsegs(sq, skb, skb_data, headlen,
(struct mlx5_wqe_data_seg *)cseg + ds_cnt);
if (unlikely(num_dma < 0))
- goto dma_unmap_wqe_err;
+ goto err_drop;

mlx5e_txwqe_complete(sq, skb, opcode, ds_cnt + num_dma,
num_bytes, num_dma, wi, cseg);

return NETDEV_TX_OK;

-dma_unmap_wqe_err:
+err_drop:
sq->stats.dropped++;
- mlx5e_dma_unmap_wqe_err(sq, wi->num_dma);
-
dev_kfree_skb_any(skb);

return NETDEV_TX_OK;
@@ -620,17 +622,15 @@ netdev_tx_t mlx5i_sq_xmit(struct mlx5e_t
num_dma = mlx5e_txwqe_build_dsegs(sq, skb, skb_data, headlen,
(struct mlx5_wqe_data_seg *)cseg + ds_cnt);
if (unlikely(num_dma < 0))
- goto dma_unmap_wqe_err;
+ goto err_drop;

mlx5e_txwqe_complete(sq, skb, opcode, ds_cnt + num_dma,
num_bytes, num_dma, wi, cseg);

return NETDEV_TX_OK;

-dma_unmap_wqe_err:
+err_drop:
sq->stats.dropped++;
- mlx5e_dma_unmap_wqe_err(sq, wi->num_dma);
-
dev_kfree_skb_any(skb);

return NETDEV_TX_OK;