[tip: core/rcu] rcu: Add missing annotation for exit_tasks_rcu_finish()

[tip-bot2 for Jules Irenge]

The following commit has been merged into the core/rcu branch of tip:

Commit-ID:     90ba11ba99e0a4cc75302335d10a225b27a44918
Gitweb:        https://git.kernel.org/tip/90ba11ba99e0a4cc75302335d10a225b27a44918
Author:        Jules Irenge <jbi.octave@xxxxxxxxx>
AuthorDate:    Mon, 20 Jan 2020 22:41:54 
Committer:     Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Thu, 20 Feb 2020 16:00:45 -08:00

rcu: Add missing annotation for exit_tasks_rcu_finish()

Sparse reports a warning at exit_tasks_rcu_finish(void)

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

To fix this, this commit adds a __releases(&tasks_rcu_exit_srcu).
Given that exit_tasks_rcu_finish() 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>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Reviewed-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
---
 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 a04fe54..ede656c 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -809,7 +809,7 @@ void exit_tasks_rcu_start(void) __acquires(&tasks_rcu_exit_srcu)
 }
 
 /* Do the srcu_read_unlock() for the above synchronize_srcu().  */
-void exit_tasks_rcu_finish(void)
+void exit_tasks_rcu_finish(void) __releases(&tasks_rcu_exit_srcu)
 {
 	preempt_disable();
 	__srcu_read_unlock(&tasks_rcu_exit_srcu, current->rcu_tasks_idx);