kbuild: rust: keep Rust objects out of Clang LTO with inline helpersgrafted

Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit
`objtool` errors such as:

    vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a:
    can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd

The reason is that in such builds, the Clang invocation that compiles
the combined Rust plus helpers bitcode emits LLVM bitcode (again) --
the final code generation happens in the linker's LTO step, which the
`-mllvm` trap options passed to Clang do not reach.

This, in turn, means that unreachable traps are missing, and the
impossible paths do not merely fallthrough to the next symbol, but past
the end of their own section, since LTO builds place each function in
its own section.

Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always
emits machine code directly, with the traps in place.

Assisted-by: LLM
Cc: Gary Guo <gary@garyguo.net>
Cc: Boqun Feng <boqun@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Matthew Maurer <mmaurer@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust")
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

1 files changed, 640 insertions, 0 deletions

diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c
new file mode 100644
index 000000000..f4b261844
--- /dev/null
+++ b/net/ipv6/addrlabel.c
@@ -0,0 +1,640 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * IPv6 Address Label subsystem
+ * for the IPv6 "Default" Source Address Selection
+ *
+ * Copyright (C)2007 USAGI/WIDE Project
+ */
+/*
+ * Author:
+ *	YOSHIFUJI Hideaki @ USAGI/WIDE Project <yoshfuji@linux-ipv6.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/rcupdate.h>
+#include <linux/in6.h>
+#include <linux/slab.h>
+#include <net/addrconf.h>
+#include <linux/if_addrlabel.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+
+/*
+ * Policy Table
+ */
+struct ip6addrlbl_entry {
+	struct in6_addr prefix;
+	int prefixlen;
+	int ifindex;
+	int addrtype;
+	u32 label;
+	struct hlist_node list;
+	struct rcu_head rcu;
+};
+
+/*
+ * Default policy table (RFC6724 + extensions)
+ *
+ * prefix		addr_type	label
+ * -------------------------------------------------------------------------
+ * ::1/128		LOOPBACK	0
+ * ::/0			N/A		1
+ * 2002::/16		N/A		2
+ * ::/96		COMPATv4	3
+ * ::ffff:0:0/96	V4MAPPED	4
+ * fc00::/7		N/A		5		ULA (RFC 4193)
+ * 2001::/32		N/A		6		Teredo (RFC 4380)
+ * 2001:10::/28		N/A		7		ORCHID (RFC 4843)
+ * fec0::/10		N/A		11		Site-local
+ *							(deprecated by RFC3879)
+ * 3ffe::/16		N/A		12		6bone
+ *
+ * Note: 0xffffffff is used if we do not have any policies.
+ * Note: Labels for ULA and 6to4 are different from labels listed in RFC6724.
+ */
+
+#define IPV6_ADDR_LABEL_DEFAULT	0xffffffffUL
+
+static const __net_initconst struct ip6addrlbl_init_table
+{
+	const struct in6_addr *prefix;
+	int prefixlen;
+	u32 label;
+} ip6addrlbl_init_table[] = {
+	{	/* ::/0 */
+		.prefix = &in6addr_any,
+		.label = 1,
+	}, {	/* fc00::/7 */
+		.prefix = &(struct in6_addr){ { { 0xfc } } } ,
+		.prefixlen = 7,
+		.label = 5,
+	}, {	/* fec0::/10 */
+		.prefix = &(struct in6_addr){ { { 0xfe, 0xc0 } } },
+		.prefixlen = 10,
+		.label = 11,
+	}, {	/* 2002::/16 */
+		.prefix = &(struct in6_addr){ { { 0x20, 0x02 } } },
+		.prefixlen = 16,
+		.label = 2,
+	}, {	/* 3ffe::/16 */
+		.prefix = &(struct in6_addr){ { { 0x3f, 0xfe } } },
+		.prefixlen = 16,
+		.label = 12,
+	}, {	/* 2001::/32 */
+		.prefix = &(struct in6_addr){ { { 0x20, 0x01 } } },
+		.prefixlen = 32,
+		.label = 6,
+	}, {	/* 2001:10::/28 */
+		.prefix = &(struct in6_addr){ { { 0x20, 0x01, 0x00, 0x10 } } },
+		.prefixlen = 28,
+		.label = 7,
+	}, {	/* ::ffff:0:0 */
+		.prefix = &(struct in6_addr){ { { [10] = 0xff, [11] = 0xff } } },
+		.prefixlen = 96,
+		.label = 4,
+	}, {	/* ::/96 */
+		.prefix = &in6addr_any,
+		.prefixlen = 96,
+		.label = 3,
+	}, {	/* ::1/128 */
+		.prefix = &in6addr_loopback,
+		.prefixlen = 128,
+		.label = 0,
+	}
+};
+
+/* Find label */
+static bool __ip6addrlbl_match(const struct ip6addrlbl_entry *p,
+			       const struct in6_addr *addr,
+			       int addrtype, int ifindex)
+{
+	if (p->ifindex && p->ifindex != ifindex)
+		return false;
+	if (p->addrtype && p->addrtype != addrtype)
+		return false;
+	if (!ipv6_prefix_equal(addr, &p->prefix, p->prefixlen))
+		return false;
+	return true;
+}
+
+static struct ip6addrlbl_entry *__ipv6_addr_label(struct net *net,
+						  const struct in6_addr *addr,
+						  int type, int ifindex)
+{
+	struct ip6addrlbl_entry *p;
+
+	hlist_for_each_entry_rcu(p, &net->ipv6.ip6addrlbl_table.head, list) {
+		if (__ip6addrlbl_match(p, addr, type, ifindex))
+			return p;
+	}
+	return NULL;
+}
+
+u32 ipv6_addr_label(struct net *net,
+		    const struct in6_addr *addr, int type, int ifindex)
+{
+	u32 label;
+	struct ip6addrlbl_entry *p;
+
+	type &= IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK;
+
+	rcu_read_lock();
+	p = __ipv6_addr_label(net, addr, type, ifindex);
+	label = p ? p->label : IPV6_ADDR_LABEL_DEFAULT;
+	rcu_read_unlock();
+
+	net_dbg_ratelimited("%s(addr=%pI6, type=%d, ifindex=%d) => %08x\n", __func__, addr, type,
+			    ifindex, label);
+
+	return label;
+}
+
+/* allocate one entry */
+static struct ip6addrlbl_entry *ip6addrlbl_alloc(const struct in6_addr *prefix,
+						 int prefixlen, int ifindex,
+						 u32 label)
+{
+	struct ip6addrlbl_entry *newp;
+	int addrtype;
+
+	net_dbg_ratelimited("%s(prefix=%pI6, prefixlen=%d, ifindex=%d, label=%u)\n", __func__,
+			    prefix, prefixlen, ifindex, (unsigned int)label);
+
+	addrtype = ipv6_addr_type(prefix) & (IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK);
+
+	switch (addrtype) {
+	case IPV6_ADDR_MAPPED:
+		if (prefixlen > 96)
+			return ERR_PTR(-EINVAL);
+		if (prefixlen < 96)
+			addrtype = 0;
+		break;
+	case IPV6_ADDR_COMPATv4:
+		if (prefixlen != 96)
+			addrtype = 0;
+		break;
+	case IPV6_ADDR_LOOPBACK:
+		if (prefixlen != 128)
+			addrtype = 0;
+		break;
+	}
+
+	newp = kmalloc_obj(*newp);
+	if (!newp)
+		return ERR_PTR(-ENOMEM);
+
+	ipv6_addr_prefix(&newp->prefix, prefix, prefixlen);
+	newp->prefixlen = prefixlen;
+	newp->ifindex = ifindex;
+	newp->addrtype = addrtype;
+	newp->label = label;
+	INIT_HLIST_NODE(&newp->list);
+	return newp;
+}
+
+/* add a label */
+static int __ip6addrlbl_add(struct net *net, struct ip6addrlbl_entry *newp,
+			    int replace)
+{
+	struct ip6addrlbl_entry *last = NULL, *p = NULL;
+	struct hlist_node *n;
+	int ret = 0;
+
+	net_dbg_ratelimited("%s(newp=%p, replace=%d)\n", __func__, newp, replace);
+
+	hlist_for_each_entry_safe(p, n,	&net->ipv6.ip6addrlbl_table.head, list) {
+		if (p->prefixlen == newp->prefixlen &&
+		    p->ifindex == newp->ifindex &&
+		    ipv6_addr_equal(&p->prefix, &newp->prefix)) {
+			if (!replace) {
+				ret = -EEXIST;
+				goto out;
+			}
+			hlist_replace_rcu(&p->list, &newp->list);
+			kfree_rcu(p, rcu);
+			goto out;
+		} else if ((p->prefixlen == newp->prefixlen && !p->ifindex) ||
+			   (p->prefixlen < newp->prefixlen)) {
+			hlist_add_before_rcu(&newp->list, &p->list);
+			goto out;
+		}
+		last = p;
+	}
+	if (last)
+		hlist_add_behind_rcu(&newp->list, &last->list);
+	else
+		hlist_add_head_rcu(&newp->list, &net->ipv6.ip6addrlbl_table.head);
+out:
+	if (!ret)
+		WRITE_ONCE(net->ipv6.ip6addrlbl_table.seq,
+			   net->ipv6.ip6addrlbl_table.seq + 1);
+	return ret;
+}
+
+/* add a label */
+static int ip6addrlbl_add(struct net *net,
+			  const struct in6_addr *prefix, int prefixlen,
+			  int ifindex, u32 label, int replace)
+{
+	struct ip6addrlbl_entry *newp;
+	int ret = 0;
+
+	net_dbg_ratelimited("%s(prefix=%pI6, prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
+			    __func__, prefix, prefixlen, ifindex, (unsigned int)label, replace);
+
+	newp = ip6addrlbl_alloc(prefix, prefixlen, ifindex, label);
+	if (IS_ERR(newp))
+		return PTR_ERR(newp);
+	spin_lock(&net->ipv6.ip6addrlbl_table.lock);
+	ret = __ip6addrlbl_add(net, newp, replace);
+	spin_unlock(&net->ipv6.ip6addrlbl_table.lock);
+	if (ret)
+		kfree(newp);
+	return ret;
+}
+
+/* remove a label */
+static int __ip6addrlbl_del(struct net *net,
+			    const struct in6_addr *prefix, int prefixlen,
+			    int ifindex)
+{
+	struct ip6addrlbl_entry *p = NULL;
+	struct hlist_node *n;
+	int ret = -ESRCH;
+
+	net_dbg_ratelimited("%s(prefix=%pI6, prefixlen=%d, ifindex=%d)\n", __func__, prefix,
+			    prefixlen, ifindex);
+
+	hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
+		if (p->prefixlen == prefixlen &&
+		    p->ifindex == ifindex &&
+		    ipv6_addr_equal(&p->prefix, prefix)) {
+			hlist_del_rcu(&p->list);
+			kfree_rcu(p, rcu);
+			ret = 0;
+			break;
+		}
+	}
+	return ret;
+}
+
+static int ip6addrlbl_del(struct net *net,
+			  const struct in6_addr *prefix, int prefixlen,
+			  int ifindex)
+{
+	struct in6_addr prefix_buf;
+	int ret;
+
+	net_dbg_ratelimited("%s(prefix=%pI6, prefixlen=%d, ifindex=%d)\n", __func__, prefix,
+			    prefixlen, ifindex);
+
+	ipv6_addr_prefix(&prefix_buf, prefix, prefixlen);
+	spin_lock(&net->ipv6.ip6addrlbl_table.lock);
+	ret = __ip6addrlbl_del(net, &prefix_buf, prefixlen, ifindex);
+	spin_unlock(&net->ipv6.ip6addrlbl_table.lock);
+	return ret;
+}
+
+/* add default label */
+static int __net_init ip6addrlbl_net_init(struct net *net)
+{
+	struct ip6addrlbl_entry *p = NULL;
+	struct hlist_node *n;
+	int err;
+	int i;
+
+	spin_lock_init(&net->ipv6.ip6addrlbl_table.lock);
+	INIT_HLIST_HEAD(&net->ipv6.ip6addrlbl_table.head);
+
+	for (i = 0; i < ARRAY_SIZE(ip6addrlbl_init_table); i++) {
+		err = ip6addrlbl_add(net,
+				     ip6addrlbl_init_table[i].prefix,
+				     ip6addrlbl_init_table[i].prefixlen,
+				     0,
+				     ip6addrlbl_init_table[i].label, 0);
+		if (err)
+			goto err_ip6addrlbl_add;
+	}
+	return 0;
+
+err_ip6addrlbl_add:
+	hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
+		hlist_del_rcu(&p->list);
+		kfree_rcu(p, rcu);
+	}
+	return err;
+}
+
+static void __net_exit ip6addrlbl_net_exit(struct net *net)
+{
+	struct ip6addrlbl_entry *p = NULL;
+	struct hlist_node *n;
+
+	/* Remove all labels belonging to the exiting net */
+	spin_lock(&net->ipv6.ip6addrlbl_table.lock);
+	hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
+		hlist_del_rcu(&p->list);
+		kfree_rcu(p, rcu);
+	}
+	spin_unlock(&net->ipv6.ip6addrlbl_table.lock);
+}
+
+static struct pernet_operations ipv6_addr_label_ops = {
+	.init = ip6addrlbl_net_init,
+	.exit = ip6addrlbl_net_exit,
+};
+
+int __init ipv6_addr_label_init(void)
+{
+	return register_pernet_subsys(&ipv6_addr_label_ops);
+}
+
+void ipv6_addr_label_cleanup(void)
+{
+	unregister_pernet_subsys(&ipv6_addr_label_ops);
+}
+
+static const struct nla_policy ifal_policy[IFAL_MAX+1] = {
+	[IFAL_ADDRESS]		= { .len = sizeof(struct in6_addr), },
+	[IFAL_LABEL]		= { .len = sizeof(u32), },
+};
+
+static bool addrlbl_ifindex_exists(struct net *net, int ifindex)
+{
+
+	struct net_device *dev;
+
+	rcu_read_lock();
+	dev = dev_get_by_index_rcu(net, ifindex);
+	rcu_read_unlock();
+
+	return dev != NULL;
+}
+
+static int ip6addrlbl_newdel(struct sk_buff *skb, struct nlmsghdr *nlh,
+			     struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(skb->sk);
+	struct ifaddrlblmsg *ifal;
+	struct nlattr *tb[IFAL_MAX+1];
+	struct in6_addr *pfx;
+	u32 label;
+	int err = 0;
+
+	err = nlmsg_parse_deprecated(nlh, sizeof(*ifal), tb, IFAL_MAX,
+				     ifal_policy, extack);
+	if (err < 0)
+		return err;
+
+	ifal = nlmsg_data(nlh);
+
+	if (ifal->ifal_family != AF_INET6 ||
+	    ifal->ifal_prefixlen > 128)
+		return -EINVAL;
+
+	if (!tb[IFAL_ADDRESS])
+		return -EINVAL;
+	pfx = nla_data(tb[IFAL_ADDRESS]);
+
+	if (!tb[IFAL_LABEL])
+		return -EINVAL;
+	label = nla_get_u32(tb[IFAL_LABEL]);
+	if (label == IPV6_ADDR_LABEL_DEFAULT)
+		return -EINVAL;
+
+	switch (nlh->nlmsg_type) {
+	case RTM_NEWADDRLABEL:
+		if (ifal->ifal_index &&
+		    !addrlbl_ifindex_exists(net, ifal->ifal_index))
+			return -EINVAL;
+
+		err = ip6addrlbl_add(net, pfx, ifal->ifal_prefixlen,
+				     ifal->ifal_index, label,
+				     nlh->nlmsg_flags & NLM_F_REPLACE);
+		break;
+	case RTM_DELADDRLABEL:
+		err = ip6addrlbl_del(net, pfx, ifal->ifal_prefixlen,
+				     ifal->ifal_index);
+		break;
+	default:
+		err = -EOPNOTSUPP;
+	}
+	return err;
+}
+
+static void ip6addrlbl_putmsg(struct nlmsghdr *nlh,
+			      int prefixlen, int ifindex, u32 lseq)
+{
+	struct ifaddrlblmsg *ifal = nlmsg_data(nlh);
+	ifal->ifal_family = AF_INET6;
+	ifal->__ifal_reserved = 0;
+	ifal->ifal_prefixlen = prefixlen;
+	ifal->ifal_flags = 0;
+	ifal->ifal_index = ifindex;
+	ifal->ifal_seq = lseq;
+};
+
+static int ip6addrlbl_fill(struct sk_buff *skb,
+			   const struct ip6addrlbl_entry *p,
+			   u32 lseq,
+			   u32 portid, u32 seq, int event,
+			   unsigned int flags)
+{
+	struct nlmsghdr *nlh = nlmsg_put(skb, portid, seq, event,
+					 sizeof(struct ifaddrlblmsg), flags);
+	if (!nlh)
+		return -EMSGSIZE;
+
+	ip6addrlbl_putmsg(nlh, p->prefixlen, p->ifindex, lseq);
+
+	if (nla_put_in6_addr(skb, IFAL_ADDRESS, &p->prefix) < 0 ||
+	    nla_put_u32(skb, IFAL_LABEL, p->label) < 0) {
+		nlmsg_cancel(skb, nlh);
+		return -EMSGSIZE;
+	}
+
+	nlmsg_end(skb, nlh);
+	return 0;
+}
+
+static int ip6addrlbl_valid_dump_req(const struct nlmsghdr *nlh,
+				     struct netlink_ext_ack *extack)
+{
+	struct ifaddrlblmsg *ifal;
+
+	ifal = nlmsg_payload(nlh, sizeof(*ifal));
+	if (!ifal) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid header for address label dump request");
+		return -EINVAL;
+	}
+
+	if (ifal->__ifal_reserved || ifal->ifal_prefixlen ||
+	    ifal->ifal_flags || ifal->ifal_index || ifal->ifal_seq) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for address label dump request");
+		return -EINVAL;
+	}
+
+	if (nlmsg_attrlen(nlh, sizeof(*ifal))) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid data after header for address label dump request");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	const struct nlmsghdr *nlh = cb->nlh;
+	struct net *net = sock_net(skb->sk);
+	struct ip6addrlbl_entry *p;
+	int idx = 0, s_idx = cb->args[0];
+	int err = 0;
+	u32 lseq;
+
+	if (cb->strict_check) {
+		err = ip6addrlbl_valid_dump_req(nlh, cb->extack);
+		if (err < 0)
+			return err;
+	}
+
+	rcu_read_lock();
+	lseq = READ_ONCE(net->ipv6.ip6addrlbl_table.seq);
+	hlist_for_each_entry_rcu(p, &net->ipv6.ip6addrlbl_table.head, list) {
+		if (idx >= s_idx) {
+			err = ip6addrlbl_fill(skb, p,
+					      lseq,
+					      NETLINK_CB(cb->skb).portid,
+					      nlh->nlmsg_seq,
+					      RTM_NEWADDRLABEL,
+					      NLM_F_MULTI);
+			if (err < 0)
+				break;
+		}
+		idx++;
+	}
+	rcu_read_unlock();
+	cb->args[0] = idx;
+	return err;
+}
+
+static inline int ip6addrlbl_msgsize(void)
+{
+	return NLMSG_ALIGN(sizeof(struct ifaddrlblmsg))
+		+ nla_total_size(16)	/* IFAL_ADDRESS */
+		+ nla_total_size(4);	/* IFAL_LABEL */
+}
+
+static int ip6addrlbl_valid_get_req(struct sk_buff *skb,
+				    const struct nlmsghdr *nlh,
+				    struct nlattr **tb,
+				    struct netlink_ext_ack *extack)
+{
+	struct ifaddrlblmsg *ifal;
+	int i, err;
+
+	ifal = nlmsg_payload(nlh, sizeof(*ifal));
+	if (!ifal) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid header for addrlabel get request");
+		return -EINVAL;
+	}
+
+	if (!netlink_strict_get_check(skb))
+		return nlmsg_parse_deprecated(nlh, sizeof(*ifal), tb,
+					      IFAL_MAX, ifal_policy, extack);
+
+	if (ifal->__ifal_reserved || ifal->ifal_flags || ifal->ifal_seq) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for addrlabel get request");
+		return -EINVAL;
+	}
+
+	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*ifal), tb, IFAL_MAX,
+					    ifal_policy, extack);
+	if (err)
+		return err;
+
+	for (i = 0; i <= IFAL_MAX; i++) {
+		if (!tb[i])
+			continue;
+
+		switch (i) {
+		case IFAL_ADDRESS:
+			break;
+		default:
+			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in addrlabel get request");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int ip6addrlbl_get(struct sk_buff *in_skb, struct nlmsghdr *nlh,
+			  struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(in_skb->sk);
+	struct ifaddrlblmsg *ifal;
+	struct nlattr *tb[IFAL_MAX+1];
+	struct in6_addr *addr;
+	u32 lseq;
+	int err = 0;
+	struct ip6addrlbl_entry *p;
+	struct sk_buff *skb;
+
+	err = ip6addrlbl_valid_get_req(in_skb, nlh, tb, extack);
+	if (err < 0)
+		return err;
+
+	ifal = nlmsg_data(nlh);
+
+	if (ifal->ifal_family != AF_INET6 ||
+	    ifal->ifal_prefixlen != 128)
+		return -EINVAL;
+
+	if (ifal->ifal_index &&
+	    !addrlbl_ifindex_exists(net, ifal->ifal_index))
+		return -EINVAL;
+
+	if (!tb[IFAL_ADDRESS])
+		return -EINVAL;
+	addr = nla_data(tb[IFAL_ADDRESS]);
+
+	skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL);
+	if (!skb)
+		return -ENOBUFS;
+
+	err = -ESRCH;
+
+	rcu_read_lock();
+	p = __ipv6_addr_label(net, addr, ipv6_addr_type(addr), ifal->ifal_index);
+	lseq = READ_ONCE(net->ipv6.ip6addrlbl_table.seq);
+	if (p)
+		err = ip6addrlbl_fill(skb, p, lseq,
+				      NETLINK_CB(in_skb).portid,
+				      nlh->nlmsg_seq,
+				      RTM_NEWADDRLABEL, 0);
+	rcu_read_unlock();
+
+	if (err < 0) {
+		WARN_ON(err == -EMSGSIZE);
+		kfree_skb(skb);
+	} else {
+		err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
+	}
+	return err;
+}
+
+static const struct rtnl_msg_handler ipv6_adddr_label_rtnl_msg_handlers[] __initconst_or_module = {
+	{.owner = THIS_MODULE, .protocol = PF_INET6, .msgtype = RTM_NEWADDRLABEL,
+	 .doit = ip6addrlbl_newdel, .flags = RTNL_FLAG_DOIT_UNLOCKED},
+	{.owner = THIS_MODULE, .protocol = PF_INET6, .msgtype = RTM_DELADDRLABEL,
+	 .doit = ip6addrlbl_newdel, .flags = RTNL_FLAG_DOIT_UNLOCKED},
+	{.owner = THIS_MODULE, .protocol = PF_INET6, .msgtype = RTM_GETADDRLABEL,
+	 .doit = ip6addrlbl_get, .dumpit = ip6addrlbl_dump,
+	 .flags = RTNL_FLAG_DOIT_UNLOCKED | RTNL_FLAG_DUMP_UNLOCKED},
+};
+
+int __init ipv6_addr_label_rtnl_register(void)
+{
+	return rtnl_register_many(ipv6_adddr_label_rtnl_msg_handlers);
+}