net: sched: cls_u32 add missing rcu_assign_pointer and annotation

Add missing rcu_assign_pointer and missing  annotation for ht_up
in cls_u32.c

Caught by kbuild bot,

>> net/sched/cls_u32.c:378:36: sparse: incorrect type in initializer (different address spaces)
   net/sched/cls_u32.c:378:36:    expected struct tc_u_hnode *ht
   net/sched/cls_u32.c:378:36:    got struct tc_u_hnode [noderef] <asn:4>*ht_up
>> net/sched/cls_u32.c:610:54: sparse: incorrect type in argument 4 (different address spaces)
   net/sched/cls_u32.c:610:54:    expected struct tc_u_hnode *ht
   net/sched/cls_u32.c:610:54:    got struct tc_u_hnode [noderef] <asn:4>*ht_up
>> net/sched/cls_u32.c:684:18: sparse: incorrect type in assignment (different address spaces)
   net/sched/cls_u32.c:684:18:    expected struct tc_u_hnode [noderef] <asn:4>*ht_up
   net/sched/cls_u32.c:684:18:    got struct tc_u_hnode *[assigned] ht
>> net/sched/cls_u32.c:359:18: sparse: dereference of noderef expression
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/cls_u32.c

@@ -375,7 +375,7 @@ static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
 {
 	struct tc_u_knode __rcu **kp;
 	struct tc_u_knode *pkp;
-	struct tc_u_hnode *ht = key->ht_up;
+	struct tc_u_hnode *ht = rtnl_dereference(key->ht_up);
 
 	if (ht) {
 		kp = &ht->ht[TC_U32_HASH(key->handle)];
@@ -607,7 +607,8 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 		if (TC_U32_KEY(n->handle) == 0)
 			return -EINVAL;
 
-		return u32_set_parms(net, tp, base, n->ht_up, n, tb,
+		return u32_set_parms(net, tp, base,
+				     rtnl_dereference(n->ht_up), n, tb,
 				     tca[TCA_RATE], ovr);
 	}
 
@@ -681,7 +682,7 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 #endif
 
 	memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
-	n->ht_up = ht;
+	RCU_INIT_POINTER(n->ht_up, ht);
 	n->handle = handle;
 	n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
 	tcf_exts_init(&n->exts, TCA_U32_ACT, TCA_U32_POLICE);