Commit 4e587ea7 authored by Wei Wang's avatar Wei Wang Committed by David S. Miller
Browse files

ipv6: fix sparse warning on rt6i_node 



Commit c5cff856 adds rcu grace period before freeing fib6_node. This
generates a new sparse warning on rt->rt6i_node related code:
  net/ipv6/route.c:1394:30: error: incompatible types in comparison
  expression (different address spaces)
  ./include/net/ip6_fib.h:187:14: error: incompatible types in comparison
  expression (different address spaces)

This commit adds "__rcu" tag for rt6i_node and makes sure corresponding
rcu API is used for it.
After this fix, sparse no longer generates the above warning.

Fixes: c5cff856 ("ipv6: add rcu grace period before freeing fib6_node")
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0f308686

include/net/ip6_fib.h

+1 −1
Original line number Diff line number Diff line
@@ -105,7 +105,7 @@ struct rt6_info { 
	 * the same cache line.

	 */

	struct fib6_table		*rt6i_table;

	struct fib6_node		*rt6i_node;

	struct fib6_node __rcu		*rt6i_node;



	struct in6_addr			rt6i_gateway;

net/ipv6/addrconf.c

+1 −1
Original line number Diff line number Diff line
@@ -5556,7 +5556,7 @@ static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp) 
		 * our DAD process, so we don't need

		 * to do it again

		 */

		if (!(ifp->rt->rt6i_node))

		if (!rcu_access_pointer(ifp->rt->rt6i_node))

			ip6_ins_rt(ifp->rt);

		if (ifp->idev->cnf.forwarding)

			addrconf_join_anycast(ifp);

net/ipv6/ip6_fib.c

+7 −4
Original line number Diff line number Diff line
@@ -889,7 +889,7 @@ add: 


		rt->dst.rt6_next = iter;

		*ins = rt;

		rt->rt6i_node = fn;

		rcu_assign_pointer(rt->rt6i_node, fn);

		atomic_inc(&rt->rt6i_ref);

		if (!info->skip_notify)

			inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
@@ -915,7 +915,7 @@ add: 
			return err;



		*ins = rt;

		rt->rt6i_node = fn;

		rcu_assign_pointer(rt->rt6i_node, fn);

		rt->dst.rt6_next = iter->dst.rt6_next;

		atomic_inc(&rt->rt6i_ref);

		if (!info->skip_notify)
@@ -1480,8 +1480,9 @@ static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp, 


int fib6_del(struct rt6_info *rt, struct nl_info *info)

{

	struct fib6_node *fn = rcu_dereference_protected(rt->rt6i_node,

				    lockdep_is_held(&rt->rt6i_table->tb6_lock));

	struct net *net = info->nl_net;

	struct fib6_node *fn = rt->rt6i_node;

	struct rt6_info **rtp;



#if RT6_DEBUG >= 2
@@ -1670,7 +1671,9 @@ static int fib6_clean_node(struct fib6_walker *w) 
			if (res) {

#if RT6_DEBUG >= 2

				pr_debug("%s: del failed: rt=%p@%p err=%d\n",

					 __func__, rt, rt->rt6i_node, res);

					 __func__, rt,

					 rcu_access_pointer(rt->rt6i_node),

					 res);

#endif

				continue;

			}

net/ipv6/route.c

+2 −1
Original line number Diff line number Diff line
@@ -1383,7 +1383,8 @@ static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu) 
static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)

{

	return !(rt->rt6i_flags & RTF_CACHE) &&

		(rt->rt6i_flags & RTF_PCPU || rt->rt6i_node);

		(rt->rt6i_flags & RTF_PCPU ||

		 rcu_access_pointer(rt->rt6i_node));

}



static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,

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