[dpdk-stable] patch 'mbuf: avoid implicit demotion in 64-bit arithmetic' has been queued to LTS release 17.11.5

[Yongseok Koh <yskoh@mellanox.com>]

Hi,

FYI, your patch has been queued to LTS release 17.11.5

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 01/04/19. 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. If the code is different (ie: not only metadata diffs), due for example to
a change in context or macro names, please double check it.

Thanks.

Yongseok

---
>From cf80647272d6586f2032059361162f0ad2f9f14f Mon Sep 17 00:00:00 2001
From: Andy Green <andy@warmcat.com>
Date: Tue, 22 May 2018 09:24:32 +0800
Subject: [PATCH] mbuf: avoid implicit demotion in 64-bit arithmetic

[ upstream commit ef5092e16b137fd5e23d19b4b17b32f330d4a4ad ]

GCC 8.1 warned:

In function 'rte_validate_tx_offload':
rte_mbuf.h:2112:19: warning: conversion to 'uint64_t'
{aka 'long unsigned int'} from 'int' may change the
sign of the result [-Wsign-conversion]
  inner_l3_offset += m->outer_l2_len + m->outer_l3_len;
                   ^~

  uint64_t inner_l3_offset...

  /* fields for TX offloading of tunnels */
  uint64_t outer_l3_len:9; /**< Outer L3 (IP) Hdr Length. */
  uint64_t outer_l2_len:7; /**< Outer L2 (MAC) Hdr Length. */

We want to do the arithmetic entirely in uint64_t
space, but with the +=, the rhs type becomes int since the
bitfields will fit in int.

Elaborate the artithmetic to be u64 = u64 + int + int, so
the type of the result is correct to be stored in the u64.

Fixes: 4fb7e803eb ("ethdev: add Tx preparation")

Signed-off-by: Andy Green <andy@warmcat.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
---
 lib/librte_mbuf/rte_mbuf.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index ee94ec6b2..8c63a9fdb 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -1870,7 +1870,11 @@ rte_validate_tx_offload(const struct rte_mbuf *m)
 		return 0;
 
 	if (ol_flags & PKT_TX_OUTER_IP_CKSUM)
-		inner_l3_offset += m->outer_l2_len + m->outer_l3_len;
+		/* NB: elaborating the addition like this instead of using
+		 *     += gives the result uint64_t type instead of int,
+		 *     avoiding compiler warnings on gcc 8.1 at least */
+		inner_l3_offset = inner_l3_offset + m->outer_l2_len +
+				  m->outer_l3_len;
 
 	/* Headers are fragmented */
 	if (rte_pktmbuf_data_len(m) < inner_l3_offset + m->l3_len + m->l4_len)
-- 
2.11.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2019-01-02 23:59:13.923877201 -0800
+++ 0035-mbuf-avoid-implicit-demotion-in-64-bit-arithmetic.patch	2019-01-02 23:59:12.103815000 -0800
@@ -1,8 +1,10 @@
-From ef5092e16b137fd5e23d19b4b17b32f330d4a4ad Mon Sep 17 00:00:00 2001
+From cf80647272d6586f2032059361162f0ad2f9f14f Mon Sep 17 00:00:00 2001
 From: Andy Green <andy@warmcat.com>
 Date: Tue, 22 May 2018 09:24:32 +0800
 Subject: [PATCH] mbuf: avoid implicit demotion in 64-bit arithmetic
 
+[ upstream commit ef5092e16b137fd5e23d19b4b17b32f330d4a4ad ]
+
 GCC 8.1 warned:
 
 In function 'rte_validate_tx_offload':
@@ -26,7 +28,6 @@
 the type of the result is correct to be stored in the u64.
 
 Fixes: 4fb7e803eb ("ethdev: add Tx preparation")
-Cc: stable@dpdk.org
 
 Signed-off-by: Andy Green <andy@warmcat.com>
 Acked-by: Bruce Richardson <bruce.richardson@intel.com>
@@ -35,10 +36,10 @@
  1 file changed, 5 insertions(+), 1 deletion(-)
 
 diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
-index 715f90ea0..0e89a6927 100644
+index ee94ec6b2..8c63a9fdb 100644
 --- a/lib/librte_mbuf/rte_mbuf.h
 +++ b/lib/librte_mbuf/rte_mbuf.h
-@@ -2112,7 +2112,11 @@ rte_validate_tx_offload(const struct rte_mbuf *m)
+@@ -1870,7 +1870,11 @@ rte_validate_tx_offload(const struct rte_mbuf *m)
  		return 0;
  
  	if (ol_flags & PKT_TX_OUTER_IP_CKSUM)