[dpdk-stable] patch 'net/mlx4: fix buffer leakage on device close' has been queued to stable release 20.11.2

[Xueming Li]

Hi,

FYI, your patch has been queued to stable release 20.11.2

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 06/14/21. 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/steevenlee/dpdk

This queued commit can be viewed at:
https://github.com/steevenlee/dpdk/commit/1c43f69982f8ca627c4ccb5bbac68b980ef85a3e

Thanks.

Xueming Li <xuemingl at nvidia.com>

---
>From 1c43f69982f8ca627c4ccb5bbac68b980ef85a3e Mon Sep 17 00:00:00 2001
From: Viacheslav Ovsiienko <viacheslavo at nvidia.com>
Date: Sat, 17 Apr 2021 20:14:14 +0300
Subject: [PATCH] net/mlx4: fix buffer leakage on device close
Cc: Luca Boccassi <bluca at debian.org>

[ upstream commit b014c6b7b595277860308468c4c12a9337bf132e ]

The mlx4 PMD tracks the buffers (mbufs) for the packets being
transmitted in the dedicated array named as "elts". The tx_burst
routine frees the mbufs from this array once it needs to rearm
the hardware descriptor and store the new mbuf, so it looks
like as replacement mbuf pointer in the elts array.

On the device stop mlx4 PMD freed only the part of elts according
tail and head pointers, leaking the rest of buffers, remained in
the elts array.

Fixes: a2ce2121c01c ("net/mlx4: separate Tx configuration functions")

Signed-off-by: Viacheslav Ovsiienko <viacheslavo at nvidia.com>
---
 drivers/net/mlx4/mlx4_rxtx.c |  4 ----
 drivers/net/mlx4/mlx4_txq.c  | 19 +++++++++----------
 2 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/net/mlx4/mlx4_rxtx.c b/drivers/net/mlx4/mlx4_rxtx.c
index adc1c9bf81..ecf08f53cf 100644
--- a/drivers/net/mlx4/mlx4_rxtx.c
+++ b/drivers/net/mlx4/mlx4_rxtx.c
@@ -921,10 +921,6 @@ mlx4_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 		if (likely(elt->buf != NULL)) {
 			struct rte_mbuf *tmp = elt->buf;
 
-#ifdef RTE_LIBRTE_MLX4_DEBUG
-			/* Poisoning. */
-			memset(&elt->buf, 0x66, sizeof(struct rte_mbuf *));
-#endif
 			/* Faster than rte_pktmbuf_free(). */
 			do {
 				struct rte_mbuf *next = tmp->next;
diff --git a/drivers/net/mlx4/mlx4_txq.c b/drivers/net/mlx4/mlx4_txq.c
index 60560d9545..cc5200a1e1 100644
--- a/drivers/net/mlx4/mlx4_txq.c
+++ b/drivers/net/mlx4/mlx4_txq.c
@@ -206,19 +206,18 @@ mlx4_tx_uar_uninit_secondary(struct rte_eth_dev *dev __rte_unused)
 static void
 mlx4_txq_free_elts(struct txq *txq)
 {
-	unsigned int elts_head = txq->elts_head;
-	unsigned int elts_tail = txq->elts_tail;
 	struct txq_elt (*elts)[txq->elts_n] = txq->elts;
-	unsigned int elts_m = txq->elts_n - 1;
+	unsigned int n = txq->elts_n;
 
-	DEBUG("%p: freeing WRs", (void *)txq);
-	while (elts_tail != elts_head) {
-		struct txq_elt *elt = &(*elts)[elts_tail++ & elts_m];
+	DEBUG("%p: freeing WRs, %u", (void *)txq, n);
+	while (n--) {
+		struct txq_elt *elt = &(*elts)[n];
 
-		MLX4_ASSERT(elt->buf != NULL);
-		rte_pktmbuf_free(elt->buf);
-		elt->buf = NULL;
-		elt->wqe = NULL;
+		if (elt->buf) {
+			rte_pktmbuf_free(elt->buf);
+			elt->buf = NULL;
+			elt->wqe = NULL;
+		}
 	}
 	txq->elts_tail = txq->elts_head;
 }
-- 
2.25.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2021-06-12 06:53:57.771358900 +0800
+++ 0043-net-mlx4-fix-buffer-leakage-on-device-close.patch	2021-06-12 06:53:56.210000000 +0800
@@ -1 +1 @@
-From b014c6b7b595277860308468c4c12a9337bf132e Mon Sep 17 00:00:00 2001
+From 1c43f69982f8ca627c4ccb5bbac68b980ef85a3e Mon Sep 17 00:00:00 2001
@@ -4,0 +5,3 @@
+Cc: Luca Boccassi <bluca at debian.org>
+
+[ upstream commit b014c6b7b595277860308468c4c12a9337bf132e ]
@@ -17 +19,0 @@
-Cc: stable at dpdk.org
@@ -41 +43 @@
-index 31ab308050..2df26842fb 100644
+index 60560d9545..cc5200a1e1 100644