[PATCH] ipv6: sit: Replace rcu_assign_pointer() with RCU_INIT_POINTER()

From: Andreea-Cristina Bernat
Date: Tue Aug 26 2014 - 09:46:46 EST


According to RCU_INIT_POINTER()'s block comment 3.a, it can be used if
"3. The referenced data structure has already been exposed to readers either
at compile time or via rcu_assign_pointer() -and-
a. You have not made -any- reader-visible changes to this structure since
then".

This case fulfills the conditions above because between the rtnl_dereference()
call and the rcu_assign_pointer() call there is no update of that value.
Therefore, this patch makes the replacement.

The following Coccinelle semantic patch was used:
@@
@@

- rcu_assign_pointer
+ RCU_INIT_POINTER
(...,
(
rtnl_dereference(...)
|
rcu_dereference_protected(...)
) )

Signed-off-by: Andreea-Cristina Bernat <bernat.ada@xxxxxxxxx>
---
net/ipv6/sit.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 4f40817..24c2dba 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -167,7 +167,7 @@ static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
{
struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);

- rcu_assign_pointer(t->next, rtnl_dereference(*tp));
+ RCU_INIT_POINTER(t->next, rtnl_dereference(*tp));
rcu_assign_pointer(*tp, t);
}

--
1.9.1

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