From: Madhuparna Bhowmik <madhuparnabhowmik04@xxxxxxxxx> This patch adds the macro list_tail_rcu() and documents it. Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik04@xxxxxxxxx> [ paulmck: Reword a bit. ] Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx> --- include/linux/rculist.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/include/linux/rculist.h b/include/linux/rculist.h index 4b7ae1b..9f313e4 100644 --- a/include/linux/rculist.h +++ b/include/linux/rculist.h @@ -40,6 +40,16 @@ static inline void INIT_LIST_HEAD_RCU(struct list_head *list) */ #define list_next_rcu(list) (*((struct list_head __rcu **)(&(list)->next))) +/** + * list_tail_rcu - returns the prev pointer of the head of the list + * @head: the head of the list + * + * Note: This should only be used with the list header, and even then + * only if list_del() and similar primitives are not also used on the + * list header. + */ +#define list_tail_rcu(head) (*((struct list_head __rcu **)(&(head)->prev))) + /* * Check during list traversal that we are within an RCU reader */ -- 2.9.5
