int ipc_rcu_getref(struct kern_ipc_perm *ptr);
void ipc_rcu_putref(struct kern_ipc_perm *ptr,
void (*func)(struct rcu_head *head));
-void ipc_rcu_free(struct rcu_head *h);
struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int);
struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id);