From: Alexander Duyck <alexander.h.duyck@intel.com>
Date: Mon, 7 May 2018 11:08:28 -0700
Subject: udp: Do not pass MSS as parameter to GSO segmentation
Patch-mainline: v4.18-rc1
Git-commit: b21c034b3df833b5d9db1cfdc3938dbb0d7995c6
References: bsc#1109837

There is no point in passing MSS as a parameter for for the GSO
segmentation call as it is already available via the shared info for the
skb itself.

Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 include/net/udp.h      |    2 +-
 net/ipv4/udp_offload.c |    6 ++++--
 net/ipv6/udp_offload.c |    2 +-
 3 files changed, 6 insertions(+), 4 deletions(-)

--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -176,7 +176,7 @@ int udp_gro_complete(struct sk_buff *skb
 
 struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
 				  netdev_features_t features,
-				  unsigned int mss, __sum16 check);
+				  __sum16 check);
 
 static inline struct udphdr *udp_gro_udphdr(struct sk_buff *skb)
 {
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -189,14 +189,16 @@ EXPORT_SYMBOL(skb_udp_tunnel_segment);
 
 struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
 				  netdev_features_t features,
-				  unsigned int mss, __sum16 check)
+				  __sum16 check)
 {
 	struct sock *sk = gso_skb->sk;
 	unsigned int sum_truesize = 0;
 	struct sk_buff *segs, *seg;
 	unsigned int hdrlen;
 	struct udphdr *uh;
+	unsigned int mss;
 
+	mss = skb_shinfo(gso_skb)->gso_size;
 	if (gso_skb->len <= sizeof(*uh) + mss)
 		return ERR_PTR(-EINVAL);
 
@@ -244,7 +246,7 @@ static struct sk_buff *__udp4_gso_segmen
 	if (!can_checksum_protocol(features, htons(ETH_P_IP)))
 		return ERR_PTR(-EIO);
 
-	return __udp_gso_segment(gso_skb, features, mss,
+	return __udp_gso_segment(gso_skb, features,
 				 udp_v4_check(sizeof(struct udphdr) + mss,
 					      iph->saddr, iph->daddr, 0));
 }
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -26,7 +26,7 @@ static struct sk_buff *__udp6_gso_segmen
 	if (!can_checksum_protocol(features, htons(ETH_P_IPV6)))
 		return ERR_PTR(-EIO);
 
-	return __udp_gso_segment(gso_skb, features, mss,
+	return __udp_gso_segment(gso_skb, features,
 				 udp_v6_check(sizeof(struct udphdr) + mss,
 					      &ip6h->saddr, &ip6h->daddr, 0));
 }