[PATCH net-next 09/13] ipv6: annotate data-races around devconf->proxy_ndp

[Eric Dumazet <edumazet@google.com>]

devconf->proxy_ndp can be read and written locklessly,
add appropriate annotations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv6/addrconf.c   | 3 ++-
 net/ipv6/ip6_output.c | 2 +-
 net/ipv6/ndisc.c      | 5 +++--
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 86992c1701485834662ec1a11d78576b211fdfab..f2a91bdda23f808d38640d3f3ec91140386bc640 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -561,7 +561,8 @@ static int inet6_netconf_fill_devconf(struct sk_buff *skb, int ifindex,
 		goto nla_put_failure;
 #endif
 	if ((all || type == NETCONFA_PROXY_NEIGH) &&
-	    nla_put_s32(skb, NETCONFA_PROXY_NEIGH, devconf->proxy_ndp) < 0)
+	    nla_put_s32(skb, NETCONFA_PROXY_NEIGH,
+			READ_ONCE(devconf->proxy_ndp)) < 0)
 		goto nla_put_failure;
 
 	if ((all || type == NETCONFA_IGNORE_ROUTES_WITH_LINKDOWN) &&
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 444be8c84cc579bf32b2950e0261ffe7c1d265a8..f08af3f4e54f5dcb0b8b5fb8f60463e41bd1f578 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -552,7 +552,7 @@ int ip6_forward(struct sk_buff *skb)
 	}
 
 	/* XXX: idev->cnf.proxy_ndp? */
-	if (net->ipv6.devconf_all->proxy_ndp &&
+	if (READ_ONCE(net->ipv6.devconf_all->proxy_ndp) &&
 	    pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
 		int proxied = ip6_forward_proxy_check(skb);
 		if (proxied > 0) {
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index f6430db249401b12debc0b174027af966fa71ccb..4114918f12c88f2b74e53d6d726018994feaf213 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -904,7 +904,8 @@ static enum skb_drop_reason ndisc_recv_ns(struct sk_buff *skb)
 
 		if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
 		    (READ_ONCE(idev->cnf.forwarding) &&
-		     (net->ipv6.devconf_all->proxy_ndp || idev->cnf.proxy_ndp) &&
+		     (READ_ONCE(net->ipv6.devconf_all->proxy_ndp) ||
+		      READ_ONCE(idev->cnf.proxy_ndp)) &&
 		     (is_router = pndisc_is_router(&msg->target, dev)) >= 0)) {
 			if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) &&
 			    skb->pkt_type != PACKET_HOST &&
@@ -1101,7 +1102,7 @@ static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb)
 		 */
 		if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) &&
 		    READ_ONCE(net->ipv6.devconf_all->forwarding) &&
-		    net->ipv6.devconf_all->proxy_ndp &&
+		    READ_ONCE(net->ipv6.devconf_all->proxy_ndp) &&
 		    pneigh_lookup(&nd_tbl, net, &msg->target, dev, 0)) {
 			/* XXX: idev->cnf.proxy_ndp */
 			goto out;
-- 
2.44.0.rc1.240.g4c46232300-goog