[PATCH 2/5] rcu: Add missing annotation for exit_tasks_rcu_start()

[Jules Irenge]

Sparse reports a warning at exit_tasks_rcu_start(void)

|warning: context imbalance in exit_tasks_rcu_start() - wrong count at exit

To fix this, an __acquires(&tasks_rcu_exit_srcu) is added.
Given that exit_tasks_rcu_start() does actually call __srcu_read_lock().
This not only fixes the warning
but also improves on the readability of the code.

Signed-off-by: Jules Irenge <jbi.octave@xxxxxxxxx>
---
 kernel/rcu/update.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index 1861103662db..99f4e617116b 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -801,7 +801,7 @@ static int __init rcu_spawn_tasks_kthread(void)
 core_initcall(rcu_spawn_tasks_kthread);
 
 /* Do the srcu_read_lock() for the above synchronize_srcu().  */
-void exit_tasks_rcu_start(void)
+void exit_tasks_rcu_start(void) __acquires(&tasks_rcu_exit_srcu)
 {
 	preempt_disable();
 	current->rcu_tasks_idx = __srcu_read_lock(&tasks_rcu_exit_srcu);
-- 
2.24.1