[NET]: Make neigh_parms setup/teardown handling symmetric.

net/core/neighbour.c

@@ -1114,9 +1114,6 @@ void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms)
 		if (*p == parms) {
 			*p = parms->next;
 			write_unlock_bh(&tbl->lock);
-#ifdef CONFIG_SYSCTL
-			neigh_sysctl_unregister(parms);
-#endif
 			kfree(parms);
 			return;
 		}
@@ -1179,9 +1176,6 @@ int neigh_table_clear(struct neigh_table *tbl)
 		}
 	}
 	write_unlock(&neigh_tbl_lock);
-#ifdef CONFIG_SYSCTL
-	neigh_sysctl_unregister(&tbl->parms);
-#endif
 	return 0;
 }
 

net/ipv4/devinet.c

@@ -197,7 +197,9 @@ static void inetdev_destroy(struct in_device *in_dev)
 	/* in_dev_put following below will kill the in_device */
 	write_unlock_bh(&inetdev_lock);
 
-
+#ifdef CONFIG_SYSCTL
+	neigh_sysctl_unregister(in_dev->arp_parms);
+#endif
 	neigh_parms_release(&arp_tbl, in_dev->arp_parms);
 	in_dev_put(in_dev);
 }

net/ipv6/addrconf.c

@@ -1893,10 +1893,11 @@ static int addrconf_ifdown(struct net_device *dev, int how)
 	/* Shot the device (if unregistered) */
 
 	if (how == 1) {
-		neigh_parms_release(&nd_tbl, idev->nd_parms);
 #ifdef CONFIG_SYSCTL
 		addrconf_sysctl_unregister(&idev->cnf);
+		neigh_sysctl_unregister(&idev->nd_parms);
 #endif
+		neigh_parms_release(&nd_tbl, idev->nd_parms);
 		in6_dev_put(idev);
 	}
 	return 0;

net/ipv6/ndisc.c

@@ -1487,6 +1487,9 @@ int __init ndisc_init(struct net_proto_family *ops)
 
 void ndisc_cleanup(void)
 {
+#ifdef CONFIG_SYSCTL
+	neigh_sysctl_unregister(&nd_tbl.parms);
+#endif
 	neigh_table_clear(&nd_tbl);
 	sock_release(ndisc_socket);
 	ndisc_socket = NULL; /* For safety. */

net/netsyms.c

@@ -190,6 +190,7 @@ EXPORT_SYMBOL(neigh_app_ns);
 #endif
 #ifdef CONFIG_SYSCTL
 EXPORT_SYMBOL(neigh_sysctl_register);
+EXPORT_SYMBOL(neigh_sysctl_unregister);
 #endif
 EXPORT_SYMBOL(pneigh_lookup);
 EXPORT_SYMBOL(pneigh_enqueue);