[PATCH 5/9] rv: Ensure all pending probes terminate on per-obj monitor destroy

[Gabriele Monaco <gmonaco@redhat.com>]

The monitor disable/destroy sequence detaches all probes and resets the
monitor's data, however it doesn't wait for pending probes. This is an
issue with per-object monitors, which free the monitor storage.

Call tracepoint_synchronize_unregister() to make sure to wait for all
pending probes before destroying the monitor storage.

Fixes: 4a24127bd6cb ("rv: Add support for per-object monitors in DA/HA")
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
---
 include/rv/da_monitor.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/rv/da_monitor.h b/include/rv/da_monitor.h
index a9fd284195ee..a4a13b62d1a4 100644
--- a/include/rv/da_monitor.h
+++ b/include/rv/da_monitor.h
@@ -515,9 +515,10 @@ static inline void da_monitor_destroy(void)
 	struct hlist_node *tmp;
 	int bkt;
 
+	tracepoint_synchronize_unregister();
 	/*
-	 * This function is called after all probes are disabled, we need only
-	 * worry about concurrency against old events.
+	 * This function is called after all probes are disabled and no longer
+	 * pending, we can safely assume no concurrent user.
 	 */
 	synchronize_rcu();
 	hash_for_each_safe(da_monitor_ht, bkt, tmp, mon_storage, node) {
-- 
2.54.0