[dpdk-stable] patch 'net/mlx5: fix mbuf freeing in vectorized MPRQ' has been queued to stable release 20.11.1

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 20.11.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 02/07/21. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/bluca/dpdk-stable

This queued commit can be viewed at:
https://github.com/bluca/dpdk-stable/commit/3d5ab0eacb07440b78317e8b09c12fde83bb3954

Thanks.

Luca Boccassi

---
>From 3d5ab0eacb07440b78317e8b09c12fde83bb3954 Mon Sep 17 00:00:00 2001
From: Alexander Kozyrev <akozyrev at nvidia.com>
Date: Thu, 10 Dec 2020 15:14:23 +0000
Subject: [PATCH] net/mlx5: fix mbuf freeing in vectorized MPRQ

[ upstream commit ac340e1fe5fdaa6cd3ed90feaf5443a3c906e2ff ]

Wrong index is used to find mbufs belonging to an application in
the rxq_free_elts_sprq() function in the case of vectorized MPRQ.
elts_ci points to the last allocated mbuf in this case, not rq_ci.
Use this field to avoid double free of mbuf and segmentation fault.

Fixes: 0f20acbf5eda ("net/mlx5: implement vectorized MPRQ burst")

Signed-off-by: Alexander Kozyrev <akozyrev at nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo at nvidia.com>
---
 drivers/net/mlx5/mlx5_rxq.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
index da7a8b3cd7..114f75b42b 100644
--- a/drivers/net/mlx5/mlx5_rxq.c
+++ b/drivers/net/mlx5/mlx5_rxq.c
@@ -346,7 +346,9 @@ rxq_free_elts_sprq(struct mlx5_rxq_ctrl *rxq_ctrl)
 		(1 << rxq->elts_n) * (1 << rxq->strd_num_n) :
 		(1 << rxq->elts_n);
 	const uint16_t q_mask = q_n - 1;
-	uint16_t used = q_n - (rxq->rq_ci - rxq->rq_pi);
+	uint16_t elts_ci = mlx5_rxq_mprq_enabled(&rxq_ctrl->rxq) ?
+		rxq->elts_ci : rxq->rq_ci;
+	uint16_t used = q_n - (elts_ci - rxq->rq_pi);
 	uint16_t i;
 
 	DRV_LOG(DEBUG, "port %u Rx queue %u freeing %d WRs",
@@ -359,8 +361,8 @@ rxq_free_elts_sprq(struct mlx5_rxq_ctrl *rxq_ctrl)
 	 */
 	if (mlx5_rxq_check_vec_support(rxq) > 0) {
 		for (i = 0; i < used; ++i)
-			(*rxq->elts)[(rxq->rq_ci + i) & q_mask] = NULL;
-		rxq->rq_pi = rxq->rq_ci;
+			(*rxq->elts)[(elts_ci + i) & q_mask] = NULL;
+		rxq->rq_pi = elts_ci;
 	}
 	for (i = 0; i != q_n; ++i) {
 		if ((*rxq->elts)[i] != NULL)
-- 
2.29.2

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2021-02-05 11:18:31.756034873 +0000
+++ 0055-net-mlx5-fix-mbuf-freeing-in-vectorized-MPRQ.patch	2021-02-05 11:18:28.790690807 +0000
@@ -1 +1 @@
-From ac340e1fe5fdaa6cd3ed90feaf5443a3c906e2ff Mon Sep 17 00:00:00 2001
+From 3d5ab0eacb07440b78317e8b09c12fde83bb3954 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit ac340e1fe5fdaa6cd3ed90feaf5443a3c906e2ff ]
+
@@ -12 +13,0 @@
-Cc: stable at dpdk.org