[PATCH 4.4 193/312] ipv6: fix checksum annotation in udp6_csum_init

[Greg Kroah-Hartman]

From: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx>

commit c148d16369ff0095eca950d17968ba1d56a47b53 upstream.

Cc: Tom Herbert <tom@xxxxxxxxxxxxxxx>
Fixes: 4068579e1e098fa ("net: Implmement RFC 6936 (zero RX csums for UDP/IPv6")
Signed-off-by: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 net/ipv6/ip6_checksum.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/net/ipv6/ip6_checksum.c
+++ b/net/ipv6/ip6_checksum.c
@@ -84,9 +84,12 @@ int udp6_csum_init(struct sk_buff *skb,
 	 * we accept a checksum of zero here. When we find the socket
 	 * for the UDP packet we'll check if that socket allows zero checksum
 	 * for IPv6 (set by socket option).
+	 *
+	 * Note, we are only interested in != 0 or == 0, thus the
+	 * force to int.
 	 */
-	return skb_checksum_init_zero_check(skb, proto, uh->check,
-					   ip6_compute_pseudo);
+	return (__force int)skb_checksum_init_zero_check(skb, proto, uh->check,
+							 ip6_compute_pseudo);
 }
 EXPORT_SYMBOL(udp6_csum_init);