[PATCH RT 03/16] genirq: Handle missing work_struct in irq_set_affinity_notifier()

[Steven Rostedt <rostedt@goodmis.org>]

4.19.59-rt24-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

[ Upstream commit bbc4d2a7d6ff54ba923640d9a42c7bef7185fe98 ]

The backported stable commit
   59c39840f5abf ("genirq: Prevent use-after-free and work list corruption")

added cancel_work_sync() on a work_struct element which is not available
in RT.

Replace cancel_work_sync() with kthread_cancel_work_sync() on RT.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/irq/manage.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 381305c48a0a..b2736d7d863b 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -385,8 +385,9 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
 	raw_spin_unlock_irqrestore(&desc->lock, flags);
 
 	if (old_notify) {
-#ifndef CONFIG_PREEMPT_RT_BASE
-		/* Need to address this for PREEMPT_RT */
+#ifdef CONFIG_PREEMPT_RT_BASE
+		kthread_cancel_work_sync(&notify->work);
+#else
 		cancel_work_sync(&old_notify->work);
 #endif
 		kref_put(&old_notify->kref, old_notify->release);
-- 
2.20.1