Subject: [PATCH 1/1] Dynamically allocate the loopback device

From: [email-masked]
Date: Fri, 24 Aug 2007 17:36:43 +0200

From: Daniel Lezcano <[email-masked]>

Doing this makes loopback.c a better example of how to do a
simple network device, and it removes the special case
single static allocation of a struct net_device, hopefully
making maintenance easier.

Applies against net-2.6.24

Tested on i386, x86_64
Compiled on ia64, sparc

Signed-off-by: Eric W. Biederman <[email-masked]>
Signed-off-by: Daniel Lezcano <[email-masked]>
Acked-By: Kirill Korotaev <[email-masked]>
Acked-by: Benjamin Thery <[email-masked]>
---
 drivers/net/loopback.c           |   63 +++++++++++++++++++++++---------------
 include/linux/netdevice.h        |    2 +-
 net/core/dst.c                   |    8 ++--
 net/decnet/dn_dev.c              |    4 +-
 net/decnet/dn_route.c            |   14 ++++----
 net/ipv4/devinet.c               |    6 ++--
 net/ipv4/ipconfig.c              |    6 ++--
 net/ipv4/ipvs/ip_vs_core.c       |    2 +-
 net/ipv4/route.c                 |   18 +++++-----
 net/ipv4/xfrm4_policy.c          |    2 +-
 net/ipv6/addrconf.c              |   15 +++++---
 net/ipv6/ip6_input.c             |    2 +-
 net/ipv6/netfilter/ip6t_REJECT.c |    2 +-
 net/ipv6/route.c                 |   15 +++-----
 net/ipv6/xfrm6_policy.c          |    2 +-
 net/xfrm/xfrm_policy.c           |    4 +-
 16 files changed, 89 insertions(+), 76 deletions(-)

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 5106c23..3642aff 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -199,44 +199,57 @@ static const struct ethtool_ops loopback_ethtool_ops = {
 	.get_rx_csum		= always_on,
 };
 
-/*
- * The loopback device is special. There is only one instance and
- * it is statically allocated. Don't do this for other devices.
- */
-struct net_device loopback_dev = {
-	.name	 		= "lo",
-	.get_stats		= &get_stats,
-	.mtu			= (16 * 1024) + 20 + 20 + 12,
-	.hard_start_xmit	= loopback_xmit,
-	.hard_header		= eth_header,
-	.hard_header_cache	= eth_header_cache,
-	.header_cache_update	= eth_header_cache_update,
-	.hard_header_len	= ETH_HLEN,	/* 14	*/
-	.addr_len		= ETH_ALEN,	/* 6	*/
-	.tx_queue_len		= 0,
-	.type			= ARPHRD_LOOPBACK,	/* 0x0001*/
-	.rebuild_header		= eth_rebuild_header,
-	.flags			= IFF_LOOPBACK,
-	.features 		= NETIF_F_SG | NETIF_F_FRAGLIST
+static void loopback_setup(struct net_device *dev)
+{
+	dev->get_stats		= &get_stats;
+	dev->mtu		= (16 * 1024) + 20 + 20 + 12;
+	dev->hard_start_xmit	= loopback_xmit;
+	dev->hard_header	= eth_header;
+	dev->hard_header_cache	= eth_header_cache;
+	dev->header_cache_update = eth_header_cache_update;
+	dev->hard_header_len	= ETH_HLEN;	/* 14	*/
+	dev->addr_len		= ETH_ALEN;	/* 6	*/
+	dev->tx_queue_len	= 0;
+	dev->type		= ARPHRD_LOOPBACK;	/* 0x0001*/
+	dev->rebuild_header	= eth_rebuild_header;
+	dev->flags		= IFF_LOOPBACK;
+	dev->features 		= NETIF_F_SG | NETIF_F_FRAGLIST
 #ifdef LOOPBACK_TSO
 				  | NETIF_F_TSO
 #endif
 				  | NETIF_F_NO_CSUM | NETIF_F_HIGHDMA
-				  | NETIF_F_LLTX,
-	.ethtool_ops		= &loopback_ethtool_ops,
-};
+				  | NETIF_F_LLTX;
+	dev->ethtool_ops	= &loopback_ethtool_ops;
+}
 
 /* Setup and register the loopback device. */
 static int __init loopback_init(void)
 {
-	int err = register_netdev(&loopback_dev);
+	struct net_device *dev;
+	int err;
+	
+	err = -ENOMEM;
+	dev = alloc_netdev(0, "lo", loopback_setup);
+	if (!dev)
+		goto out;
+
+	err = register_netdev(dev);
+	if (err)
+		goto out_free_netdev;
 
+	err = 0;
+	loopback_dev = dev;
+
+out:
 	if (err)
 		panic("loopback: Failed to register netdevice: %d\n", err);
-
 	return err;
+out_free_netdev:
+	free_netdev(dev);
+	goto out;
 };
 
-module_init(loopback_init);
+fs_initcall(loopback_init);
 
+struct net_device *loopback_dev;
 EXPORT_SYMBOL(loopback_dev);
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 8d12f02..7cd0641 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -680,7 +680,7 @@ struct packet_type {
 #include <linux/interrupt.h>
 #include <linux/notifier.h>
 
-extern struct net_device		loopback_dev;		/* The loopback */
+extern struct net_device		*loopback_dev;		/* The loopback */
 extern struct list_head			dev_base_head;		/* All devices */
 extern rwlock_t				dev_base_lock;		/* Device list lock */
 
diff --git a/net/core/dst.c b/net/core/dst.c
index c6a0587..ad8549e 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -236,13 +236,13 @@ static inline void dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 	if (!unregister) {
 		dst->input = dst->output = dst_discard;
 	} else {
-		dst->dev = &loopback_dev;
-		dev_hold(&loopback_dev);
+		dst->dev = loopback_dev;
+		dev_hold(dst->dev);
 		dev_put(dev);
 		if (dst->neighbour && dst->neighbour->dev == dev) {
-			dst->neighbour->dev = &loopback_dev;
+			dst->neighbour->dev = loopback_dev;
 			dev_put(dev);
-			dev_hold(&loopback_dev);
+			dev_hold(dst->neighbour->dev);
 		}
 	}
 }
diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index fa6604f..9fea83e 100644
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -868,10 +868,10 @@ last_chance:
 		rv = dn_dev_get_first(dev, addr);
 		read_unlock(&dev_base_lock);
 		dev_put(dev);
-		if (rv == 0 || dev == &loopback_dev)
+		if (rv == 0 || dev == loopback_dev)
 			return rv;
 	}
-	dev = &loopback_dev;
+	dev = loopback_dev;
 	dev_hold(dev);
 	goto last_chance;
 }
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index a4a6209..8c04ebc 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -883,7 +883,7 @@ static int dn_route_output_slow(struct dst_entry **pprt, const struct flowi *old
 					.scope = RT_SCOPE_UNIVERSE,
 				     } },
 			    .mark = oldflp->mark,
-			    .iif = loopback_dev.ifindex,
+			    .iif = loopback_dev->ifindex,
 			    .oif = oldflp->oif };
 	struct dn_route *rt = NULL;
 	struct net_device *dev_out = NULL, *dev;
@@ -900,7 +900,7 @@ static int dn_route_output_slow(struct dst_entry **pprt, const struct flowi *old
 		       "dn_route_output_slow: dst=%04x src=%04x mark=%d"
 		       " iif=%d oif=%d\n", dn_ntohs(oldflp->fld_dst),
 		       dn_ntohs(oldflp->fld_src),
-		       oldflp->mark, loopback_dev.ifindex, oldflp->oif);
+		       oldflp->mark, loopback_dev->ifindex, oldflp->oif);
 
 	/* If we have an output interface, verify its a DECnet device */
 	if (oldflp->oif) {
@@ -953,7 +953,7 @@ source_ok:
 		err = -EADDRNOTAVAIL;
 		if (dev_out)
 			dev_put(dev_out);
-		dev_out = &loopback_dev;
+		dev_out = loopback_dev;
 		dev_hold(dev_out);
 		if (!fl.fld_dst) {
 			fl.fld_dst =
@@ -962,7 +962,7 @@ source_ok:
 			if (!fl.fld_dst)
 				goto out;
 		}
-		fl.oif = loopback_dev.ifindex;
+		fl.oif = loopback_dev->ifindex;
 		res.type = RTN_LOCAL;
 		goto make_route;
 	}
@@ -1008,7 +1008,7 @@ source_ok:
 					if (dev_out)
 						dev_put(dev_out);
 					if (dn_dev_islocal(neigh->dev, fl.fld_dst)) {
-						dev_out = &loopback_dev;
+						dev_out = loopback_dev;
 						res.type = RTN_LOCAL;
 					} else {
 						dev_out = neigh->dev;
@@ -1029,7 +1029,7 @@ source_ok:
 		/* Possible improvement - check all devices for local addr */
 		if (dn_dev_islocal(dev_out, fl.fld_dst)) {
 			dev_put(dev_out);
-			dev_out = &loopback_dev;
+			dev_out = loopback_dev;
 			dev_hold(dev_out);
 			res.type = RTN_LOCAL;
 			goto select_source;
@@ -1065,7 +1065,7 @@ select_source:
 			fl.fld_src = fl.fld_dst;
 		if (dev_out)
 			dev_put(dev_out);
-		dev_out = &loopback_dev;
+		dev_out = loopback_dev;
 		dev_hold(dev_out);
 		fl.oif = dev_out->ifindex;
 		if (res.fi)
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 5b77bda..808f529 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -203,7 +203,7 @@ static void inetdev_destroy(struct in_device *in_dev)
 	ASSERT_RTNL();
 
 	dev = in_dev->dev;
-	if (dev == &loopback_dev)
+	if (dev == loopback_dev)
 		return;
 
 	in_dev->dead = 1;
@@ -1058,7 +1058,7 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
 			in_dev = inetdev_init(dev);
 			if (!in_dev)
 				return notifier_from_errno(-ENOMEM);
-			if (dev == &loopback_dev) {
+			if (dev == loopback_dev) {
 				IN_DEV_CONF_SET(in_dev, NOXFRM, 1);
 				IN_DEV_CONF_SET(in_dev, NOPOLICY, 1);
 			}
@@ -1074,7 +1074,7 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
 	case NETDEV_UP:
 		if (dev->mtu < 68)
 			break;
-		if (dev == &loopback_dev) {
+		if (dev == loopback_dev) {
 			struct in_ifaddr *ifa;
 			if ((ifa = inet_alloc_ifa()) != NULL) {
 				ifa->ifa_local =
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
index c5b2470..3ec7690 100644
--- a/net/ipv4/ipconfig.c
+++ b/net/ipv4/ipconfig.c
@@ -189,11 +189,11 @@ static int __init ic_open_devs(void)
 	rtnl_lock();
 
 	/* bring loopback device up first */
-	if (dev_change_flags(&loopback_dev, loopback_dev.flags | IFF_UP) < 0)
-		printk(KERN_ERR "IP-Config: Failed to open %s\n", loopback_dev.name);
+	if (dev_change_flags(loopback_dev, loopback_dev->flags | IFF_UP) < 0)
+		printk(KERN_ERR "IP-Config: Failed to open %s\n", loopback_dev->name);
 
 	for_each_netdev(dev) {
-		if (dev == &loopback_dev)
+		if (dev == loopback_dev)
 			continue;
 		if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
 		    (!(dev->flags & IFF_LOOPBACK) &&
diff --git a/net/ipv4/ipvs/ip_vs_core.c b/net/ipv4/ipvs/ip_vs_core.c
index f005a2f..7450326 100644
--- a/net/ipv4/ipvs/ip_vs_core.c
+++ b/net/ipv4/ipvs/ip_vs_core.c
@@ -961,7 +961,7 @@ ip_vs_in(unsigned int hooknum, struct sk_buff **pskb,
 	 *	... don't know why 1st test DOES NOT include 2nd (?)
 	 */
 	if (unlikely(skb->pkt_type != PACKET_HOST
-		     || skb->dev == &loopback_dev || skb->sk)) {
+		     || skb->dev == loopback_dev || skb->sk)) {
 		IP_VS_DBG(12, "packet type=%d proto=%d daddr=%d.%d.%d.%d ignored\n",
 			  skb->pkt_type,
 			  ip_hdr(skb)->protocol,
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index c7ca94b..4f13385 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1404,8 +1404,8 @@ static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 {
 	struct rtable *rt = (struct rtable *) dst;
 	struct in_device *idev = rt->idev;
-	if (dev != &loopback_dev && idev && idev->dev == dev) {
-		struct in_device *loopback_idev = in_dev_get(&loopback_dev);
+	if (dev != loopback_dev && idev && idev->dev == dev) {
+		struct in_device *loopback_idev = in_dev_get(loopback_dev);
 		if (loopback_idev) {
 			rt->idev = loopback_idev;
 			in_dev_put(idev);
@@ -1557,7 +1557,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 #endif
 	rth->rt_iif	=
 	rth->fl.iif	= dev->ifindex;
-	rth->u.dst.dev	= &loopback_dev;
+	rth->u.dst.dev	= loopback_dev;
 	dev_hold(rth->u.dst.dev);
 	rth->idev	= in_dev_get(rth->u.dst.dev);
 	rth->fl.oif	= 0;
@@ -1814,7 +1814,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 	if (res.type == RTN_LOCAL) {
 		int result;
 		result = fib_validate_source(saddr, daddr, tos,
-					     loopback_dev.ifindex,
+					     loopback_dev->ifindex,
 					     dev, &spec_dst, &itag);
 		if (result < 0)
 			goto martian_source;
@@ -1881,7 +1881,7 @@ local_input:
 #endif
 	rth->rt_iif	=
 	rth->fl.iif	= dev->ifindex;
-	rth->u.dst.dev	= &loopback_dev;
+	rth->u.dst.dev	= loopback_dev;
 	dev_hold(rth->u.dst.dev);
 	rth->idev	= in_dev_get(rth->u.dst.dev);
 	rth->rt_gateway	= daddr;
@@ -2151,7 +2151,7 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
 						  RT_SCOPE_UNIVERSE),
 				      } },
 			    .mark = oldflp->mark,
-			    .iif = loopback_dev.ifindex,
+			    .iif = loopback_dev->ifindex,
 			    .oif = oldflp->oif };
 	struct fib_result res;
 	unsigned flags = 0;
@@ -2245,9 +2245,9 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
 			fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
 		if (dev_out)
 			dev_put(dev_out);
-		dev_out = &loopback_dev;
+		dev_out = loopback_dev;
 		dev_hold(dev_out);
-		fl.oif = loopback_dev.ifindex;
+		fl.oif = loopback_dev->ifindex;
 		res.type = RTN_LOCAL;
 		flags |= RTCF_LOCAL;
 		goto make_route;
@@ -2292,7 +2292,7 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
 			fl.fl4_src = fl.fl4_dst;
 		if (dev_out)
 			dev_put(dev_out);
-		dev_out = &loopback_dev;
+		dev_out = loopback_dev;
 		dev_hold(dev_out);
 		fl.oif = dev_out->ifindex;
 		if (res.fi)
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 4ff8ed3..29ab3de 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -306,7 +306,7 @@ static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 
 	xdst = (struct xfrm_dst *)dst;
 	if (xdst->u.rt.idev->dev == dev) {
-		struct in_device *loopback_idev = in_dev_get(&loopback_dev);
+		struct in_device *loopback_idev = in_dev_get(loopback_dev);
 		BUG_ON(!loopback_idev);
 
 		do {
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 91ef3be..d806f89 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2399,7 +2399,7 @@ static int addrconf_ifdown(struct net_device *dev, int how)
 
 	ASSERT_RTNL();
 
-	if (dev == &loopback_dev && how == 1)
+	if (dev == loopback_dev && how == 1)
 		how = 0;
 
 	rt6_ifdown(dev);
@@ -4203,16 +4203,19 @@ int __init addrconf_init(void)
 	 * device and it being up should be removed.
 	 */
 	rtnl_lock();
-	if (!ipv6_add_dev(&loopback_dev))
+	if (!ipv6_add_dev(loopback_dev))
 		err = -ENOMEM;
 	rtnl_unlock();
 	if (err)
 		return err;
 
-	ip6_null_entry.rt6i_idev = in6_dev_get(&loopback_dev);
+	ip6_null_entry.u.dst.dev = loopback_dev;
+	ip6_null_entry.rt6i_idev = in6_dev_get(loopback_dev);
 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
-	ip6_prohibit_entry.rt6i_idev = in6_dev_get(&loopback_dev);
-	ip6_blk_hole_entry.rt6i_idev = in6_dev_get(&loopback_dev);
+	ip6_prohibit_entry.u.dst.dev = loopback_dev;
+	ip6_prohibit_entry.rt6i_idev = in6_dev_get(loopback_dev);
+	ip6_blk_hole_entry.u.dst.dev = loopback_dev;
+	ip6_blk_hole_entry.rt6i_idev = in6_dev_get(loopback_dev);
 #endif
 
 	register_netdevice_notifier(&ipv6_dev_notf);
@@ -4267,7 +4270,7 @@ void __exit addrconf_cleanup(void)
 			continue;
 		addrconf_ifdown(dev, 1);
 	}
-	addrconf_ifdown(&loopback_dev, 2);
+	addrconf_ifdown(loopback_dev, 2);
 
 	/*
 	 *	Check hash table.
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 30a5cb1..15d7910 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -86,7 +86,7 @@ int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt
 	 *
 	 * BTW, when we send a packet for our own local address on a
 	 * non-loopback interface (e.g. ethX), it is being delivered
-	 * via the loopback interface (lo) here; skb->dev = &loopback_dev.
+	 * via the loopback interface (lo) here; skb->dev = loopback_dev.
 	 * It, however, should be considered as if it is being
 	 * arrived via the sending interface (ethX), because of the
 	 * nature of scoping architecture. --yoshfuji
diff --git a/net/ipv6/netfilter/ip6t_REJECT.c b/net/ipv6/netfilter/ip6t_REJECT.c
index 2f487cd..5086053 100644
--- a/net/ipv6/netfilter/ip6t_REJECT.c
+++ b/net/ipv6/netfilter/ip6t_REJECT.c
@@ -167,7 +167,7 @@ static inline void
 send_unreach(struct sk_buff *skb_in, unsigned char code, unsigned int hooknum)
 {
 	if (hooknum == NF_IP6_LOCAL_OUT && skb_in->dev == NULL)
-		skb_in->dev = &loopback_dev;
+		skb_in->dev = loopback_dev;
 
 	icmpv6_send(skb_in, ICMPV6_DEST_UNREACH, code, 0, NULL);
 }
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 55ea80f..3f5c65f 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -137,7 +137,6 @@ struct rt6_info ip6_null_entry = {
 		.dst = {
 			.__refcnt	= ATOMIC_INIT(1),
 			.__use		= 1,
-			.dev		= &loopback_dev,
 			.obsolete	= -1,
 			.error		= -ENETUNREACH,
 			.metrics	= { [RTAX_HOPLIMIT - 1] = 255, },
@@ -163,7 +162,6 @@ struct rt6_info ip6_prohibit_entry = {
 		.dst = {
 			.__refcnt	= ATOMIC_INIT(1),
 			.__use		= 1,
-			.dev		= &loopback_dev,
 			.obsolete	= -1,
 			.error		= -EACCES,
 			.metrics	= { [RTAX_HOPLIMIT - 1] = 255, },
@@ -183,7 +181,6 @@ struct rt6_info ip6_blk_hole_entry = {
 		.dst = {
 			.__refcnt	= ATOMIC_INIT(1),
 			.__use		= 1,
-			.dev		= &loopback_dev,
 			.obsolete	= -1,
 			.error		= -EINVAL,
 			.metrics	= { [RTAX_HOPLIMIT - 1] = 255, },
@@ -223,8 +220,8 @@ static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 	struct rt6_info *rt = (struct rt6_info *)dst;
 	struct inet6_dev *idev = rt->rt6i_idev;
 
-	if (dev != &loopback_dev && idev != NULL && idev->dev == dev) {
-		struct inet6_dev *loopback_idev = in6_dev_get(&loopback_dev);
+	if (dev != loopback_dev && idev != NULL && idev->dev == dev) {
+		struct inet6_dev *loopback_idev = in6_dev_get(loopback_dev);
 		if (loopback_idev != NULL) {
 			rt->rt6i_idev = loopback_idev;
 			in6_dev_put(idev);
@@ -1187,12 +1184,12 @@ int ip6_route_add(struct fib6_config *cfg)
 	if ((cfg->fc_flags & RTF_REJECT) ||
 	    (dev && (dev->flags&IFF_LOOPBACK) && !(addr_type&IPV6_ADDR_LOOPBACK))) {
 		/* hold loopback dev/idev if we haven't done so. */
-		if (dev != &loopback_dev) {
+		if (dev != loopback_dev) {
 			if (dev) {
 				dev_put(dev);
 				in6_dev_put(idev);
 			}
-			dev = &loopback_dev;
+			dev = loopback_dev;
 			dev_hold(dev);
 			idev = in6_dev_get(dev);
 			if (!idev) {
@@ -1896,13 +1893,13 @@ struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
 	if (rt == NULL)
 		return ERR_PTR(-ENOMEM);
 
-	dev_hold(&loopback_dev);
+	dev_hold(loopback_dev);
 	in6_dev_hold(idev);
 
 	rt->u.dst.flags = DST_HOST;
 	rt->u.dst.input = ip6_input;
 	rt->u.dst.output = ip6_output;
-	rt->rt6i_dev = &loopback_dev;
+	rt->rt6i_dev = loopback_dev;
 	rt->rt6i_idev = idev;
 	rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev);
 	rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst));
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 3ec0c47..cc07216 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -375,7 +375,7 @@ static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 
 	xdst = (struct xfrm_dst *)dst;
 	if (xdst->u.rt6.rt6i_idev->dev == dev) {
-		struct inet6_dev *loopback_idev = in6_dev_get(&loopback_dev);
+		struct inet6_dev *loopback_idev = in6_dev_get(loopback_dev);
 		BUG_ON(!loopback_idev);
 
 		do {
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index c7b2503..ca37eec 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1947,8 +1947,8 @@ static int stale_bundle(struct dst_entry *dst)
 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
 {
 	while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
-		dst->dev = &loopback_dev;
-		dev_hold(&loopback_dev);
+		dst->dev = loopback_dev;
+		dev_hold(dst->dev);
 		dev_put(dev);
 	}
 }
-- 
1.5.2.4