linux-kernel - [PATCH 20/23] ipmi:ssif: Fix a shutdown race

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Message-ID: <20250424165020.627193-21-corey@minyard.net>
Date: Thu, 24 Apr 2025 11:49:57 -0500
From: Corey Minyard <corey@...yard.net>
To: linux-kernel@...r.kernel.org,
	openipmi-developer@...ts.sourceforge.net,
	Rik van Riel <riel@...riel.com>
Cc: "Paul E . McKenney" <paulmck@...nel.org>,
	Breno Leitao <leitao@...ian.org>,
	Corey Minyard <corey@...yard.net>,
	Corey Minyard <cminyard@...sta.com>
Subject: [PATCH 20/23] ipmi:ssif: Fix a shutdown race

It was possible for the SSIF thread to stop and quit before the
kthread_stop() call because ssif->stopping was set before the
stop.  So only exit the SSIF thread is kthread_should_stop()
returns true.

There is no need to wake the thread, as the wait will be interrupted
by kthread_stop().

Signed-off-by: Corey Minyard <cminyard@...sta.com>
---
 drivers/char/ipmi/ipmi_ssif.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c
index 506d9988721e..b016fabaac68 100644
--- a/drivers/char/ipmi/ipmi_ssif.c
+++ b/drivers/char/ipmi/ipmi_ssif.c
@@ -481,8 +481,6 @@ static int ipmi_ssif_thread(void *data)
 		/* Wait for something to do */
 		result = wait_for_completion_interruptible(
 						&ssif_info->wake_thread);
-		if (ssif_info->stopping)
-			break;
 		if (result == -ERESTARTSYS)
 			continue;
 		init_completion(&ssif_info->wake_thread);
@@ -1270,10 +1268,8 @@ static void shutdown_ssif(void *send_info)
 	ssif_info->stopping = true;
 	del_timer_sync(&ssif_info->watch_timer);
 	del_timer_sync(&ssif_info->retry_timer);
-	if (ssif_info->thread) {
-		complete(&ssif_info->wake_thread);
+	if (ssif_info->thread)
 		kthread_stop(ssif_info->thread);
-	}
 }
 
 static void ssif_remove(struct i2c_client *client)
-- 
2.43.0