arp: fixed -Wuninitialized compiler warning

Commit 6340eecdaa0c20e68c6ba226eaa15b102bffaf0f ("arp: always override
existing neigh entries with gratuitous ARP") introduced a compiler
warning:

net/ipv4/arp.c:880:35: warning: 'addr_type' may be used uninitialized in
this function [-Wmaybe-uninitialized]

While the code logic seems to be correct and doesn't allow the variable
to be used uninitialized, and the warning is not consistently
reproducible, it's still worth fixing it for other people not to waste
time looking at the warning in case it pops up in the build environment.
Yes, compiler is probably at fault, but we will need to accommodate.

Fixes: 6340eecdaa0c ("arp: always override existing neigh entries with gratuitous ARP")
Signed-off-by: Ihar Hrachyshka <ihrachys@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index ae96e6f3e0cb048e6a9273421343daf3582e9463..e9f3386a528b4a792839d5e50894a68d3097eb42 100644 (file)
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -863,8 +863,8 @@ static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb)
 
        n = __neigh_lookup(&arp_tbl, &sip, dev, 0);
 
+       addr_type = -1;
        if (n || IN_DEV_ARP_ACCEPT(in_dev)) {
-               addr_type = -1;
                is_garp = arp_is_garp(net, dev, &addr_type, arp->ar_op,
                                      sip, tip, sha, tha);
        }