From: "Paul E. McKenney" <paulmck@linux.ibm.com>
Date: Wed, 19 Jun 2019 15:42:51 -0700
Subject: rcu: Add destroy_work_on_stack() to match INIT_WORK_ONSTACK()
Git-commit: fbad01af8c3bb9618848abde8054ab7e0c2330fe
Patch-mainline: 5.4-rc1
References: bnc#1151927 5.3.4
The synchronize_rcu_expedited() function has an INIT_WORK_ONSTACK(),
but lacks the corresponding destroy_work_on_stack(). This commit
therefore adds destroy_work_on_stack().
Reported-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Acked-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
kernel/rcu/tree_exp.h | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -792,6 +792,7 @@ static int rcu_print_task_exp_stall(stru
*/
void synchronize_rcu_expedited(void)
{
+ bool boottime = (rcu_scheduler_active == RCU_SCHEDULER_INIT);
struct rcu_exp_work rew;
struct rcu_node *rnp;
unsigned long s;
@@ -817,7 +818,7 @@ void synchronize_rcu_expedited(void)
return; /* Someone else did our work for us. */
/* Ensure that load happens before action based on it. */
- if (unlikely(rcu_scheduler_active == RCU_SCHEDULER_INIT)) {
+ if (unlikely(boottime)) {
/* Direct call during scheduler init and early_initcalls(). */
rcu_exp_sel_wait_wake(s);
} else {
@@ -835,5 +836,8 @@ void synchronize_rcu_expedited(void)
/* Let the next expedited grace period start. */
mutex_unlock(&rcu_state.exp_mutex);
+
+ if (likely(!boottime))
+ destroy_work_on_stack(&rew.rew_work);
}
EXPORT_SYMBOL_GPL(synchronize_rcu_expedited);