From ee2875566868687a95b8ec23913c0d6bce220efd Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 5 May 2020 19:22:14 +0200
Subject: net: bareudp: avoid uninitialized variable warning

clang points out that building without IPv6 would lead to returning
an uninitialized variable if a packet with family!=AF_INET is
passed into bareudp_udp_encap_recv():

drivers/net/bareudp.c:139:6: error: variable 'err' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
        if (family == AF_INET)
            ^~~~~~~~~~~~~~~~~
drivers/net/bareudp.c:146:15: note: uninitialized use occurs here
        if (unlikely(err)) {
                     ^~~
include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
 # define unlikely(x)    __builtin_expect(!!(x), 0)
                                            ^
drivers/net/bareudp.c:139:2: note: remove the 'if' if its condition is always true
        if (family == AF_INET)
        ^~~~~~~~~~~~~~~~~~~~~~

This cannot happen in practice, so change the condition in a way that
gcc sees the IPv4 case as unconditionally true here.
For consistency, change all the similar constructs in this file the
same way, using "if(IS_ENABLED())" instead of #if IS_ENABLED()".

Fixes: 571912c69f0e ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/udp_tunnel.h | 2 --
 1 file changed, 2 deletions(-)

(limited to 'include/net/udp_tunnel.h')

diff --git a/include/net/udp_tunnel.h b/include/net/udp_tunnel.h
index 4b1f95e08307..e7312ceb2794 100644
--- a/include/net/udp_tunnel.h
+++ b/include/net/udp_tunnel.h
@@ -143,14 +143,12 @@ void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb
 			 __be16 df, __be16 src_port, __be16 dst_port,
 			 bool xnet, bool nocheck);
 
-#if IS_ENABLED(CONFIG_IPV6)
 int udp_tunnel6_xmit_skb(struct dst_entry *dst, struct sock *sk,
 			 struct sk_buff *skb,
 			 struct net_device *dev, struct in6_addr *saddr,
 			 struct in6_addr *daddr,
 			 __u8 prio, __u8 ttl, __be32 label,
 			 __be16 src_port, __be16 dst_port, bool nocheck);
-#endif
 
 void udp_tunnel_sock_release(struct socket *sock);
 
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