From: Willy Tarreau <w@1wt.eu>
Date: Wed, 22 Jul 2020 12:33:53 +0000 (+0200)
Subject: MINOR: tasks/debug: add a BUG_ON() check to detect requeued task on free
X-Git-Tag: v2.3-dev2~38
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f2452b3c70762ee0917a95dc1634770f5611e2e3;p=thirdparty%2Fhaproxy.git

MINOR: tasks/debug: add a BUG_ON() check to detect requeued task on free

__task_free() cannot be called with a task still in the queue. This
test adds a check which confirms there is no concurrency issue on such
a case where a thread could requeue nor wakeup a task being freed.
---

diff --git a/include/haproxy/task.h b/include/haproxy/task.h
index 820c2f1dd2..24be2b6ed4 100644
--- a/include/haproxy/task.h
+++ b/include/haproxy/task.h
@@ -473,6 +473,7 @@ static inline void __task_free(struct task *t)
 		sched->current = NULL;
 		__ha_barrier_store();
 	}
+	BUG_ON(task_in_wq(t) || task_in_rq(t));
 	pool_free(pool_head_task, t);
 	if (unlikely(stopping))
 		pool_flush(pool_head_task);