From 7cf76420f5420f91c64a2d7aff02fb34676eecea Mon Sep 17 00:00:00 2001
From: Zhang Qiang <qiang.zhang@windriver.com>
Date: Wed, 27 May 2020 15:57:15 +0800
Subject: [PATCH] workqueue: Remove unnecessary kfree() call in rcu_free_wq()

commit 342ed2400b78072cc01c0130ce41240dec60d56d upstream.

The data structure member "wq->rescuer" was reset to a null pointer
in one if branch. It was passed to a call of the function "kfree"
in the callback function "rcu_free_wq" (which was eventually executed).
The function "kfree" does not perform more meaningful data processing
for a passed null pointer (besides immediately returning from such a call).
Thus delete this function call which became unnecessary with the referenced
software update.

Fixes: def98c84b6cd ("workqueue: Fix spurious sanity check failures in destroy_workqueue()")

Suggested-by: Markus Elfring <Markus.Elfring@web.de>
Signed-off-by: Zhang Qiang <qiang.zhang@windriver.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index cc98bd34d925..6bf536113bc1 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3496,7 +3496,6 @@ static void rcu_free_wq(struct rcu_head *rcu)
 	else
 		free_workqueue_attrs(wq->unbound_attrs);
 
-	kfree(wq->rescuer);
 	kfree(wq);
 }
 
-- 
2.7.4