tipc: Fix race condition when creating socket or native port

This patch eliminates the (very remote) chance of a crash resulting
from a partially initialized socket or native port unexpectedly
receiving a message.  Now, during the creation of a socket or native
port, the underlying generic port's lock is not released until all
initialization required to handle incoming messages has been done.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/tipc/tipc_port.h

@@ -84,7 +84,8 @@ struct tipc_port {
 u32 tipc_createport_raw(void *usr_handle,
 			u32 (*dispatcher)(struct tipc_port *, struct sk_buff *),
 			void (*wakeup)(struct tipc_port *),
-			const u32 importance);
+			const u32 importance,
+			struct tipc_port **tp_ptr);
 
 int tipc_reject_msg(struct sk_buff *buf, u32 err);