lkml.org 
[lkml]   [2017]   [Sep]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.12 03/52] ipv6: fix sparse warning on rt6i_node
Date
4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Wei Wang <weiwan@google.com>


[ Upstream commit 4e587ea71bf924f7dac621f1351653bd41e446cb ]

Commit c5cff8561d2d 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: c5cff8561d2d ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/net/ip6_fib.h | 2 +-
net/ipv6/addrconf.c | 2 +-
net/ipv6/ip6_fib.c | 11 +++++++----
net/ipv6/route.c | 3 ++-
4 files changed, 11 insertions(+), 7 deletions(-)

--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -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;

--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -5541,7 +5541,7 @@ static void __ipv6_ifa_notify(int event,
* 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);
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -887,7 +887,7 @@ 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);
@@ -913,7 +913,7 @@ 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)
@@ -1475,8 +1475,9 @@ static void fib6_del_route(struct fib6_n

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
@@ -1665,7 +1666,9 @@ static int fib6_clean_node(struct fib6_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;
}
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1383,7 +1383,8 @@ static void rt6_do_update_pmtu(struct rt
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,

\
 
 \ /
  Last update: 2017-09-18 11:51    [W:0.272 / U:1.792 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site