[PATCH net] net: fix sparse warning in sk_dst_set()

[PATCH net] net: fix sparse warning in sk_dst_set()

[Eric Dumazet]

From: Eric Dumazet <edumazet@google.com>

sk_dst_cache has __rcu annotation, so we need a cast to avoid
following sparse error :

include/net/sock.h:1774:19: warning: incorrect type in initializer (different address spaces)
include/net/sock.h:1774:19:    expected struct dst_entry [noderef] <asn:4>*__ret
include/net/sock.h:1774:19:    got struct dst_entry *dst

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Fixes: 7f502361531e ("ipv4: irq safe sk_dst_[re]set() and ipv4_sk_update_pmtu() fix")
---
 include/net/sock.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index c556fd9b05ac..156350745700 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1771,7 +1771,7 @@ sk_dst_set(struct sock *sk, struct dst_entry *dst)
 	struct dst_entry *old_dst;
 
 	sk_tx_queue_clear(sk);
-	old_dst = xchg(&sk->sk_dst_cache, dst);
+	old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
 	dst_release(old_dst);
 }
 

Re: [PATCH net] net: fix sparse warning in sk_dst_set()

[David Miller]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 02 Jul 2014 02:39:38 -0700

> From: Eric Dumazet <edumazet@google.com>
> 
> sk_dst_cache has __rcu annotation, so we need a cast to avoid
> following sparse error :
> 
> include/net/sock.h:1774:19: warning: incorrect type in initializer (different address spaces)
> include/net/sock.h:1774:19:    expected struct dst_entry [noderef] <asn:4>*__ret
> include/net/sock.h:1774:19:    got struct dst_entry *dst
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Reported-by: kbuild test robot <fengguang.wu@intel.com>
> Fixes: 7f502361531e ("ipv4: irq safe sk_dst_[re]set() and ipv4_sk_update_pmtu() fix")

Applied and I'll make sure this gets passed along with I send 7f502361531e to -stable.

Thanks.