From 559835ea7292e2f09304d81eda16f4209433245e Mon Sep 17 00:00:00 2001 From: Pravin B Shelar Date: Tue, 24 Sep 2013 10:25:40 -0700 Subject: vxlan: Use RCU apis to access sk_user_data. Use of RCU api makes vxlan code easier to understand. It also fixes bug due to missing ACCESS_ONCE() on sk_user_data dereference. In rare case without ACCESS_ONCE() compiler might omit vs on sk_user_data dereference. Compiler can use vs as alias for sk->sk_user_data, resulting in multiple sk_user_data dereference in rcu read context which could change. CC: Jesse Gross Signed-off-by: Pravin B Shelar Signed-off-by: David S. Miller --- include/net/sock.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/net/sock.h') diff --git a/include/net/sock.h b/include/net/sock.h index 6ba2e7b0e2b1..1d37a8086bed 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -409,6 +409,11 @@ struct sock { void (*sk_destruct)(struct sock *sk); }; +#define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data))) + +#define rcu_dereference_sk_user_data(sk) rcu_dereference(__sk_user_data((sk))) +#define rcu_assign_sk_user_data(sk, ptr) rcu_assign_pointer(__sk_user_data((sk)), ptr) + /* * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK * or not whether his port will be reused by someone else. SK_FORCE_REUSE -- cgit v1.2.1