[dpdk-stable] patch 'net/ena: fix L4 checksum Tx offload' has been queued to LTS release 18.11.3

[Kevin Traynor]

Hi,

FYI, your patch has been queued to LTS release 18.11.3

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 09/12/19. 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/kevintraynor/dpdk-stable-queue

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable-queue/commit/7b1714c76de643a43e54e76d846846d3d6e90f0e

Thanks.

Kevin Traynor

---
>From 7b1714c76de643a43e54e76d846846d3d6e90f0e Mon Sep 17 00:00:00 2001
From: Maciej Bielski <mba at semihalf.com>
Date: Thu, 1 Aug 2019 13:45:36 +0200
Subject: [PATCH] net/ena: fix L4 checksum Tx offload

[ upstream commit 40e7c02155625f18a87faf5e6a8cec2e986146e8 ]

During an if-condition evaluation, a 2-bit flag evaluates to 'true' for
'0x1', '0x2' and '0x3'. Thus, from this perspective these flags are
indistinguishable. To make them distinct, respective bits must be
extracted with a mask and then checked for strict equality.

Specifically here, even if `PKT_TX_UDP_CKSUM` (value '0x3') was set, the
expression `mbuf->ol_flags & PKT_TX_TCP` (the second flag of value
'0x1') is evaluated first and the result is 'true'. In consequence, for
UDP packets the execution flow enters an incorrect branch.

Fixes: 56b8b9b7e5d2 ("net/ena: convert to new Tx offloads API")

Reported-by: Eduard Serra <eserra at vmware.com>
Signed-off-by: Maciej Bielski <mba at semihalf.com>
Acked-by: Michal Krawczyk <mk at semihalf.com>
---
 drivers/net/ena/ena_ethdev.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ena/ena_ethdev.c b/drivers/net/ena/ena_ethdev.c
index fa7b58b7d..0779bb771 100644
--- a/drivers/net/ena/ena_ethdev.c
+++ b/drivers/net/ena/ena_ethdev.c
@@ -340,10 +340,11 @@ static inline void ena_tx_mbuf_prepare(struct rte_mbuf *mbuf,
 
 		/* check if L4 checksum is needed */
-		if ((mbuf->ol_flags & PKT_TX_TCP_CKSUM) &&
+		if (((mbuf->ol_flags & PKT_TX_L4_MASK) == PKT_TX_TCP_CKSUM) &&
 		    (queue_offloads & DEV_TX_OFFLOAD_TCP_CKSUM)) {
 			ena_tx_ctx->l4_proto = ENA_ETH_IO_L4_PROTO_TCP;
 			ena_tx_ctx->l4_csum_enable = true;
-		} else if ((mbuf->ol_flags & PKT_TX_UDP_CKSUM) &&
-			   (queue_offloads & DEV_TX_OFFLOAD_UDP_CKSUM)) {
+		} else if (((mbuf->ol_flags & PKT_TX_L4_MASK) ==
+				PKT_TX_UDP_CKSUM) &&
+				(queue_offloads & DEV_TX_OFFLOAD_UDP_CKSUM)) {
 			ena_tx_ctx->l4_proto = ENA_ETH_IO_L4_PROTO_UDP;
 			ena_tx_ctx->l4_csum_enable = true;
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2019-09-05 10:36:49.813820768 +0100
+++ 0038-net-ena-fix-L4-checksum-Tx-offload.patch	2019-09-05 10:36:47.540699804 +0100
@@ -1 +1 @@
-From 40e7c02155625f18a87faf5e6a8cec2e986146e8 Mon Sep 17 00:00:00 2001
+From 7b1714c76de643a43e54e76d846846d3d6e90f0e Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 40e7c02155625f18a87faf5e6a8cec2e986146e8 ]
+
@@ -17 +18,0 @@
-Cc: stable at dpdk.org
@@ -27 +28 @@
-index a1187851c..7d4a3b225 100644
+index fa7b58b7d..0779bb771 100644
@@ -30 +31 @@
-@@ -331,10 +331,11 @@ static inline void ena_tx_mbuf_prepare(struct rte_mbuf *mbuf,
+@@ -340,10 +340,11 @@ static inline void ena_tx_mbuf_prepare(struct rte_mbuf *mbuf,