rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER

When assigning a NULL value to an RCU protected pointer, no barrier
is needed. The rcu_assign_pointer, used to handle that but will soon
change to not handle the special case.

Convert all rcu_assign_pointer of NULL value.

//smpl
@@ expression P; @@

- rcu_assign_pointer(P, NULL)
+ RCU_INIT_POINTER(P, NULL)

// </smpl>

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/802/garp.c

@@ -553,7 +553,7 @@ static void garp_release_port(struct net_device *dev)
 		if (rtnl_dereference(port->applicants[i]))
 			return;
 	}
-	rcu_assign_pointer(dev->garp_port, NULL);
+	RCU_INIT_POINTER(dev->garp_port, NULL);
 	kfree_rcu(port, rcu);
 }
 
@@ -605,7 +605,7 @@ void garp_uninit_applicant(struct net_device *dev, struct garp_application *appl
 
 	ASSERT_RTNL();
 
-	rcu_assign_pointer(port->applicants[appl->type], NULL);
+	RCU_INIT_POINTER(port->applicants[appl->type], NULL);
 
 	/* Delete timer and generate a final TRANSMIT_PDU event to flush out
 	 * all pending messages before the applicant is gone. */

net/802/stp.c

@@ -88,9 +88,9 @@ void stp_proto_unregister(const struct stp_proto *proto)
 {
 	mutex_lock(&stp_proto_mutex);
 	if (is_zero_ether_addr(proto->group_address))
-		rcu_assign_pointer(stp_proto, NULL);
+		RCU_INIT_POINTER(stp_proto, NULL);
 	else
-		rcu_assign_pointer(garp_protos[proto->group_address[5] -
+		RCU_INIT_POINTER(garp_protos[proto->group_address[5] -
 					       GARP_ADDR_MIN], NULL);
 	synchronize_rcu();
 

net/8021q/vlan.c

@@ -133,7 +133,7 @@ void unregister_vlan_dev(struct net_device *dev, struct list_head *head)
 	if (grp->nr_vlans == 0) {
 		vlan_gvrp_uninit_applicant(real_dev);
 
-		rcu_assign_pointer(real_dev->vlgrp, NULL);
+		RCU_INIT_POINTER(real_dev->vlgrp, NULL);
 
 		/* Free the group, after all cpu's are done. */
 		call_rcu(&grp->rcu, vlan_rcu_free);

net/bridge/netfilter/ebtable_broute.c

@@ -87,14 +87,14 @@ static int __init ebtable_broute_init(void)
 	if (ret < 0)
 		return ret;
 	/* see br_input.c */
-	rcu_assign_pointer(br_should_route_hook,
+	RCU_INIT_POINTER(br_should_route_hook,
 			   (br_should_route_hook_t *)ebt_broute);
 	return 0;
 }
 
 static void __exit ebtable_broute_fini(void)
 {
-	rcu_assign_pointer(br_should_route_hook, NULL);
+	RCU_INIT_POINTER(br_should_route_hook, NULL);
 	synchronize_net();
 	unregister_pernet_subsys(&broute_net_ops);
 }

net/caif/cfmuxl.c

@@ -108,7 +108,7 @@ struct cflayer *cfmuxl_remove_dnlayer(struct cflayer *layr, u8 phyid)
 	int idx = phyid % DN_CACHE_SIZE;
 
 	spin_lock_bh(&muxl->transmit_lock);
-	rcu_assign_pointer(muxl->dn_cache[idx], NULL);
+	RCU_INIT_POINTER(muxl->dn_cache[idx], NULL);
 	dn = get_from_id(&muxl->frml_list, phyid);
 	if (dn == NULL)
 		goto out;
@@ -164,7 +164,7 @@ struct cflayer *cfmuxl_remove_uplayer(struct cflayer *layr, u8 id)
 	if (up == NULL)
 		goto out;
 
-	rcu_assign_pointer(muxl->up_cache[idx], NULL);
+	RCU_INIT_POINTER(muxl->up_cache[idx], NULL);
 	list_del_rcu(&up->node);
 out:
 	spin_unlock_bh(&muxl->receive_lock);
@@ -261,7 +261,7 @@ static void cfmuxl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
 
 				idx = layer->id % UP_CACHE_SIZE;
 				spin_lock_bh(&muxl->receive_lock);
-				rcu_assign_pointer(muxl->up_cache[idx], NULL);
+				RCU_INIT_POINTER(muxl->up_cache[idx], NULL);
 				list_del_rcu(&layer->node);
 				spin_unlock_bh(&muxl->receive_lock);
 			}

net/can/af_can.c

@@ -719,7 +719,7 @@ int can_proto_register(const struct can_proto *cp)
 		       proto);
 		err = -EBUSY;
 	} else
-		rcu_assign_pointer(proto_tab[proto], cp);
+		RCU_INIT_POINTER(proto_tab[proto], cp);
 
 	mutex_unlock(&proto_tab_lock);
 
@@ -740,7 +740,7 @@ void can_proto_unregister(const struct can_proto *cp)
 
 	mutex_lock(&proto_tab_lock);
 	BUG_ON(proto_tab[proto] != cp);
-	rcu_assign_pointer(proto_tab[proto], NULL);
+	RCU_INIT_POINTER(proto_tab[proto], NULL);
 	mutex_unlock(&proto_tab_lock);
 
 	synchronize_rcu();

net/core/dev.c

@@ -3094,8 +3094,8 @@ void netdev_rx_handler_unregister(struct net_device *dev)
 {
 
 	ASSERT_RTNL();
-	rcu_assign_pointer(dev->rx_handler, NULL);
+	RCU_INIT_POINTER(dev->rx_handler, NULL);
-	rcu_assign_pointer(dev->rx_handler_data, NULL);
+	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
 }
 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
 

net/core/fib_rules.c

@@ -487,7 +487,7 @@ static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 		if (ops->nr_goto_rules > 0) {
 			list_for_each_entry(tmp, &ops->rules_list, list) {
 				if (rtnl_dereference(tmp->ctarget) == rule) {
-					rcu_assign_pointer(tmp->ctarget, NULL);
+					RCU_INIT_POINTER(tmp->ctarget, NULL);
 					ops->unresolved_rules++;
 				}
 			}

net/core/filter.c

@@ -645,7 +645,7 @@ int sk_detach_filter(struct sock *sk)
 	filter = rcu_dereference_protected(sk->sk_filter,
 					   sock_owned_by_user(sk));
 	if (filter) {
-		rcu_assign_pointer(sk->sk_filter, NULL);
+		RCU_INIT_POINTER(sk->sk_filter, NULL);
 		sk_filter_uncharge(sk, filter);
 		ret = 0;
 	}

net/core/net-sysfs.c

@@ -987,10 +987,10 @@ static ssize_t store_xps_map(struct netdev_queue *queue,
 	}
 
 	if (nonempty)
-		rcu_assign_pointer(dev->xps_maps, new_dev_maps);
+		RCU_INIT_POINTER(dev->xps_maps, new_dev_maps);
 	else {
 		kfree(new_dev_maps);
-		rcu_assign_pointer(dev->xps_maps, NULL);
+		RCU_INIT_POINTER(dev->xps_maps, NULL);
 	}
 
 	if (dev_maps)

net/core/netpoll.c

@@ -760,7 +760,7 @@ int __netpoll_setup(struct netpoll *np)
 	}
 
 	/* last thing to do is link it to the net device structure */
-	rcu_assign_pointer(ndev->npinfo, npinfo);
+	RCU_INIT_POINTER(ndev->npinfo, npinfo);
 
 	return 0;
 
@@ -901,7 +901,7 @@ void __netpoll_cleanup(struct netpoll *np)
 		if (ops->ndo_netpoll_cleanup)
 			ops->ndo_netpoll_cleanup(np->dev);
 
-		rcu_assign_pointer(np->dev->npinfo, NULL);
+		RCU_INIT_POINTER(np->dev->npinfo, NULL);
 
 		/* avoid racing with NAPI reading npinfo */
 		synchronize_rcu_bh();

net/core/sock.c

@@ -387,7 +387,7 @@ struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
 
 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
 		sk_tx_queue_clear(sk);
-		rcu_assign_pointer(sk->sk_dst_cache, NULL);
+		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
 		dst_release(dst);
 		return NULL;
 	}
@@ -1158,7 +1158,7 @@ static void __sk_free(struct sock *sk)
 				       atomic_read(&sk->sk_wmem_alloc) == 0);
 	if (filter) {
 		sk_filter_uncharge(sk, filter);
-		rcu_assign_pointer(sk->sk_filter, NULL);
+		RCU_INIT_POINTER(sk->sk_filter, NULL);
 	}
 
 	sock_disable_timestamp(sk, SOCK_TIMESTAMP);

net/decnet/dn_dev.c

@@ -388,7 +388,7 @@ static int dn_dev_insert_ifa(struct dn_dev *dn_db, struct dn_ifaddr *ifa)
 	}
 
 	ifa->ifa_next = dn_db->ifa_list;
-	rcu_assign_pointer(dn_db->ifa_list, ifa);
+	RCU_INIT_POINTER(dn_db->ifa_list, ifa);
 
 	dn_ifaddr_notify(RTM_NEWADDR, ifa);
 	blocking_notifier_call_chain(&dnaddr_chain, NETDEV_UP, ifa);
@@ -1093,7 +1093,7 @@ static struct dn_dev *dn_dev_create(struct net_device *dev, int *err)
 
 	memcpy(&dn_db->parms, p, sizeof(struct dn_dev_parms));
 
-	rcu_assign_pointer(dev->dn_ptr, dn_db);
+	RCU_INIT_POINTER(dev->dn_ptr, dn_db);
 	dn_db->dev = dev;
 	init_timer(&dn_db->timer);
 
@@ -1101,7 +1101,7 @@ static struct dn_dev *dn_dev_create(struct net_device *dev, int *err)
 
 	dn_db->neigh_parms = neigh_parms_alloc(dev, &dn_neigh_table);
 	if (!dn_db->neigh_parms) {
-		rcu_assign_pointer(dev->dn_ptr, NULL);
+		RCU_INIT_POINTER(dev->dn_ptr, NULL);
 		kfree(dn_db);
 		return NULL;
 	}

net/ipv4/devinet.c

@@ -258,7 +258,7 @@ static struct in_device *inetdev_init(struct net_device *dev)
 		ip_mc_up(in_dev);
 
 	/* we can receive as soon as ip_ptr is set -- do this last */
-	rcu_assign_pointer(dev->ip_ptr, in_dev);
+	RCU_INIT_POINTER(dev->ip_ptr, in_dev);
 out:
 	return in_dev;
 out_kfree:
@@ -291,7 +291,7 @@ static void inetdev_destroy(struct in_device *in_dev)
 		inet_free_ifa(ifa);
 	}
 
-	rcu_assign_pointer(dev->ip_ptr, NULL);
+	RCU_INIT_POINTER(dev->ip_ptr, NULL);
 
 	devinet_sysctl_unregister(in_dev);
 	neigh_parms_release(&arp_tbl, in_dev->arp_parms);
@@ -1175,7 +1175,7 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
 	switch (event) {
 	case NETDEV_REGISTER:
 		printk(KERN_DEBUG "inetdev_event: bug\n");
-		rcu_assign_pointer(dev->ip_ptr, NULL);
+		RCU_INIT_POINTER(dev->ip_ptr, NULL);
 		break;
 	case NETDEV_UP:
 		if (!inetdev_valid_mtu(dev->mtu))

net/ipv4/fib_trie.c

@@ -204,7 +204,7 @@ static inline struct tnode *node_parent_rcu(const struct rt_trie_node *node)
 	return (struct tnode *)(parent & ~NODE_TYPE_MASK);
 }
 
-/* Same as rcu_assign_pointer
+/* Same as RCU_INIT_POINTER
  * but that macro() assumes that value is a pointer.
  */
 static inline void node_set_parent(struct rt_trie_node *node, struct tnode *ptr)
@@ -528,7 +528,7 @@ static void tnode_put_child_reorg(struct tnode *tn, int i, struct rt_trie_node *
 	if (n)
 		node_set_parent(n, tn);
 
-	rcu_assign_pointer(tn->child[i], n);
+	RCU_INIT_POINTER(tn->child[i], n);
 }
 
 #define MAX_WORK 10
@@ -1014,7 +1014,7 @@ static void trie_rebalance(struct trie *t, struct tnode *tn)
 
 		tp = node_parent((struct rt_trie_node *) tn);
 		if (!tp)
-			rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
+			RCU_INIT_POINTER(t->trie, (struct rt_trie_node *)tn);
 
 		tnode_free_flush();
 		if (!tp)
@@ -1026,7 +1026,7 @@ static void trie_rebalance(struct trie *t, struct tnode *tn)
 	if (IS_TNODE(tn))
 		tn = (struct tnode *)resize(t, (struct tnode *)tn);
 
-	rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
+	RCU_INIT_POINTER(t->trie, (struct rt_trie_node *)tn);
 	tnode_free_flush();
 }
 
@@ -1163,7 +1163,7 @@ static struct list_head *fib_insert_node(struct trie *t, u32 key, int plen)
 			put_child(t, (struct tnode *)tp, cindex,
 				  (struct rt_trie_node *)tn);
 		} else {
-			rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
+			RCU_INIT_POINTER(t->trie, (struct rt_trie_node *)tn);
 			tp = tn;
 		}
 	}
@@ -1621,7 +1621,7 @@ static void trie_leaf_remove(struct trie *t, struct leaf *l)
 		put_child(t, (struct tnode *)tp, cindex, NULL);
 		trie_rebalance(t, tp);
 	} else
-		rcu_assign_pointer(t->trie, NULL);
+		RCU_INIT_POINTER(t->trie, NULL);
 
 	free_leaf(l);
 }

net/ipv4/gre.c

@@ -34,7 +34,7 @@ int gre_add_protocol(const struct gre_protocol *proto, u8 version)
 	if (gre_proto[version])
 		goto err_out_unlock;
 
-	rcu_assign_pointer(gre_proto[version], proto);
+	RCU_INIT_POINTER(gre_proto[version], proto);
 	spin_unlock(&gre_proto_lock);
 	return 0;
 
@@ -54,7 +54,7 @@ int gre_del_protocol(const struct gre_protocol *proto, u8 version)
 	if (rcu_dereference_protected(gre_proto[version],
 			lockdep_is_held(&gre_proto_lock)) != proto)
 		goto err_out_unlock;
-	rcu_assign_pointer(gre_proto[version], NULL);
+	RCU_INIT_POINTER(gre_proto[version], NULL);
 	spin_unlock(&gre_proto_lock);
 	synchronize_rcu();
 	return 0;

net/ipv4/igmp.c

@@ -1242,7 +1242,7 @@ void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
 
 	im->next_rcu = in_dev->mc_list;
 	in_dev->mc_count++;
-	rcu_assign_pointer(in_dev->mc_list, im);
+	RCU_INIT_POINTER(in_dev->mc_list, im);
 
 #ifdef CONFIG_IP_MULTICAST
 	igmpv3_del_delrec(in_dev, im->multiaddr);
@@ -1813,7 +1813,7 @@ int ip_mc_join_group(struct sock *sk , struct ip_mreqn *imr)
 	iml->next_rcu = inet->mc_list;
 	iml->sflist = NULL;
 	iml->sfmode = MCAST_EXCLUDE;
-	rcu_assign_pointer(inet->mc_list, iml);
+	RCU_INIT_POINTER(inet->mc_list, iml);
 	ip_mc_inc_group(in_dev, addr);
 	err = 0;
 done:
@@ -1835,7 +1835,7 @@ static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
 	}
 	err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
 			iml->sfmode, psf->sl_count, psf->sl_addr, 0);
-	rcu_assign_pointer(iml->sflist, NULL);
+	RCU_INIT_POINTER(iml->sflist, NULL);
 	/* decrease mem now to avoid the memleak warning */
 	atomic_sub(IP_SFLSIZE(psf->sl_max), &sk->sk_omem_alloc);
 	kfree_rcu(psf, rcu);
@@ -2000,7 +2000,7 @@ int ip_mc_source(int add, int omode, struct sock *sk, struct
 			atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
 			kfree_rcu(psl, rcu);
 		}
-		rcu_assign_pointer(pmc->sflist, newpsl);
+		RCU_INIT_POINTER(pmc->sflist, newpsl);
 		psl = newpsl;
 	}
 	rv = 1;	/* > 0 for insert logic below if sl_count is 0 */
@@ -2103,7 +2103,7 @@ int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
 	} else
 		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
 			0, NULL, 0);
-	rcu_assign_pointer(pmc->sflist, newpsl);
+	RCU_INIT_POINTER(pmc->sflist, newpsl);
 	pmc->sfmode = msf->imsf_fmode;
 	err = 0;
 done:

net/ipv4/ipip.c

@@ -231,7 +231,7 @@ static void ipip_tunnel_unlink(struct ipip_net *ipn, struct ip_tunnel *t)
 	     (iter = rtnl_dereference(*tp)) != NULL;
 	     tp = &iter->next) {
 		if (t == iter) {
-			rcu_assign_pointer(*tp, t->next);
+			RCU_INIT_POINTER(*tp, t->next);
 			break;
 		}
 	}
@@ -241,8 +241,8 @@ static void ipip_tunnel_link(struct ipip_net *ipn, struct ip_tunnel *t)
 {
 	struct ip_tunnel __rcu **tp = ipip_bucket(ipn, t);
 
-	rcu_assign_pointer(t->next, rtnl_dereference(*tp));
+	RCU_INIT_POINTER(t->next, rtnl_dereference(*tp));
-	rcu_assign_pointer(*tp, t);
+	RCU_INIT_POINTER(*tp, t);
 }
 
 static struct ip_tunnel * ipip_tunnel_locate(struct net *net,
@@ -301,7 +301,7 @@ static void ipip_tunnel_uninit(struct net_device *dev)
 	struct ipip_net *ipn = net_generic(net, ipip_net_id);
 
 	if (dev == ipn->fb_tunnel_dev)
-		rcu_assign_pointer(ipn->tunnels_wc[0], NULL);
+		RCU_INIT_POINTER(ipn->tunnels_wc[0], NULL);
 	else
 		ipip_tunnel_unlink(ipn, netdev_priv(dev));
 	dev_put(dev);
@@ -791,7 +791,7 @@ static int __net_init ipip_fb_tunnel_init(struct net_device *dev)
 		return -ENOMEM;
 
 	dev_hold(dev);
-	rcu_assign_pointer(ipn->tunnels_wc[0], tunnel);
+	RCU_INIT_POINTER(ipn->tunnels_wc[0], tunnel);
 	return 0;
 }
 

net/ipv4/ipmr.c

@@ -1176,7 +1176,7 @@ static void mrtsock_destruct(struct sock *sk)
 	ipmr_for_each_table(mrt, net) {
 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
-			rcu_assign_pointer(mrt->mroute_sk, NULL);
+			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
 			mroute_clean_tables(mrt);
 		}
 	}
@@ -1224,7 +1224,7 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsi
 
 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
 		if (ret == 0) {
-			rcu_assign_pointer(mrt->mroute_sk, sk);
+			RCU_INIT_POINTER(mrt->mroute_sk, sk);
 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
 		}
 		rtnl_unlock();

net/ipv4/netfilter/nf_nat_amanda.c

@@ -70,14 +70,14 @@ static unsigned int help(struct sk_buff *skb,
 
 static void __exit nf_nat_amanda_fini(void)
 {
-	rcu_assign_pointer(nf_nat_amanda_hook, NULL);
+	RCU_INIT_POINTER(nf_nat_amanda_hook, NULL);
 	synchronize_rcu();
 }
 
 static int __init nf_nat_amanda_init(void)
 {
 	BUG_ON(nf_nat_amanda_hook != NULL);
-	rcu_assign_pointer(nf_nat_amanda_hook, help);
+	RCU_INIT_POINTER(nf_nat_amanda_hook, help);
 	return 0;
 }