2020-01-20 22:43:36

by Jules Irenge

[permalink] [raw]
Subject: [PATCH 3/5] 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, an __releases(&tasks_rcu_exit_srcu) is added.
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 <[email protected]>
---
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 99f4e617116b..5853f19f0cb5 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);
--
2.24.1