net: ipv6: sit: fix rcu annotations

Fix minor __rcu annotations and remove sparse warnings

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 10 deletions

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 8ce38f10a547..b1599a345c10 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -412,7 +412,7 @@ static void prl_list_destroy_rcu(struct rcu_head *head)
 
         p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
         do {
-                n = p->next;
+                n = rcu_dereference_protected(p->next, 1);
                 kfree(p);
                 p = n;
         } while (p);
@@ -421,15 +421,17 @@ static void prl_list_destroy_rcu(struct rcu_head *head)
 static int
 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
 {
-        struct ip_tunnel_prl_entry *x, **p;
+        struct ip_tunnel_prl_entry *x;
+        struct ip_tunnel_prl_entry __rcu **p;
         int err = 0;
 
         ASSERT_RTNL();
 
         if (a && a->addr != htonl(INADDR_ANY)) {
-                for (p = &t->prl; *p; p = &(*p)->next) {
-                        if ((*p)->addr == a->addr) {
-                                x = *p;
+                for (p = &t->prl;
+                     (x = rtnl_dereference(*p)) != NULL;
+                     p = &x->next) {
+                        if (x->addr == a->addr) {
                                 *p = x->next;
                                 call_rcu(&x->rcu_head, prl_entry_destroy_rcu);
                                 t->prl_count--;
@@ -438,9 +440,9 @@ ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
                 }
                 err = -ENXIO;
         } else {
-                if (t->prl) {
+                x = rtnl_dereference(t->prl);
+                if (x) {
                         t->prl_count = 0;
-                        x = t->prl;
                         call_rcu(&x->rcu_head, prl_list_destroy_rcu);
                         t->prl = NULL;
                 }
@@ -1179,7 +1181,7 @@ static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
         if (!dev->tstats)
                 return -ENOMEM;
         dev_hold(dev);
-        sitn->tunnels_wc[0]     = tunnel;
+        rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
         return 0;
 }
 
@@ -1196,11 +1198,12 @@ static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_hea
         for (prio = 1; prio < 4; prio++) {
                 int h;
                 for (h = 0; h < HASH_SIZE; h++) {
-                        struct ip_tunnel *t = sitn->tunnels[prio][h];
+                        struct ip_tunnel *t;
 
+                        t = rtnl_dereference(sitn->tunnels[prio][h]);
                         while (t != NULL) {
                                 unregister_netdevice_queue(t->dev, head);
-                                t = t->next;
+                                t = rtnl_dereference(t->next);
                         }
                 }
         }