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ipv6: fix sparse warning on rt6i_node 

Commit c5cff8561d 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: c5cff8561d ("ipv6: add rcu grace period before freeing fib6_node")
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Wei Wang 2017-08-25 15:03:10 -07:00 committed by David S. Miller
parent 0f3086868e
commit 4e587ea71b
4 changed files with 11 additions and 7 deletions
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2
include/net/ip6_fib.h
View File

@ -105,7 +105,7 @@ struct rt6_info {
* the same cache line. * the same cache line.
*/ */
struct fib6_table *rt6i_table; struct fib6_table *rt6i_table;
struct fib6_node *rt6i_node; struct fib6_node __rcu *rt6i_node;
struct in6_addr rt6i_gateway; struct in6_addr rt6i_gateway;

2
net/ipv6/addrconf.c
View File

@ -5556,7 +5556,7 @@ static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
* our DAD process, so we don't need * our DAD process, so we don't need
* to do it again * to do it again
*/ */
if (!(ifp->rt->rt6i_node)) if (!rcu_access_pointer(ifp->rt->rt6i_node))
ip6_ins_rt(ifp->rt); ip6_ins_rt(ifp->rt);
if (ifp->idev->cnf.forwarding) if (ifp->idev->cnf.forwarding)
addrconf_join_anycast(ifp); addrconf_join_anycast(ifp);

11
net/ipv6/ip6_fib.c
View File

@ -889,7 +889,7 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
rt->dst.rt6_next = iter; rt->dst.rt6_next = iter;
*ins = rt; *ins = rt;
rt->rt6i_node = fn; rcu_assign_pointer(rt->rt6i_node, fn);
atomic_inc(&rt->rt6i_ref); atomic_inc(&rt->rt6i_ref);
if (!info->skip_notify) if (!info->skip_notify)
inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
@ -915,7 +915,7 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
return err; return err;
*ins = rt; *ins = rt;
rt->rt6i_node = fn; rcu_assign_pointer(rt->rt6i_node, fn);
rt->dst.rt6_next = iter->dst.rt6_next; rt->dst.rt6_next = iter->dst.rt6_next;
atomic_inc(&rt->rt6i_ref); atomic_inc(&rt->rt6i_ref);
if (!info->skip_notify) 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) 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 net *net = info->nl_net;
struct fib6_node *fn = rt->rt6i_node;
struct rt6_info **rtp; struct rt6_info **rtp;
#if RT6_DEBUG >= 2 #if RT6_DEBUG >= 2
@ -1670,7 +1671,9 @@ static int fib6_clean_node(struct fib6_walker *w)
if (res) { if (res) {
#if RT6_DEBUG >= 2 #if RT6_DEBUG >= 2
pr_debug("%s: del failed: rt=%p@%p err=%d\n", 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 #endif
continue; continue;
} }

3
net/ipv6/route.c
View File

@ -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) static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
{ {
return !(rt->rt6i_flags & RTF_CACHE) && 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, static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,