[PATCH REVIEW 1/2] watchdog: extend the mutex-protected section in watchdog_cdev_unregister()
From: Alexey Klimov
Date: Wed Aug 17 2022 - 22:06:37 EST
watchdog_stop() should be called with wd_data->lock mutex locked.
Updates to wdd->status also occur under this look throughout the
watchdog_dev.c as well as functions that deal with pretimeout hrtimer
like watchdog_hrtimer_pretimeout_stop() here.
Signed-off-by: Alexey Klimov <aklimov@xxxxxxxxxx>
---
drivers/watchdog/watchdog_dev.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 54903f3c851e..804236a094f6 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -1095,6 +1095,8 @@ static void watchdog_cdev_unregister(struct watchdog_device *wdd)
old_wd_data = NULL;
}
+ mutex_lock(&wd_data->lock);
+
if (watchdog_active(wdd) &&
test_bit(WDOG_STOP_ON_UNREGISTER, &wdd->status)) {
watchdog_stop(wdd);
@@ -1102,7 +1104,6 @@ static void watchdog_cdev_unregister(struct watchdog_device *wdd)
watchdog_hrtimer_pretimeout_stop(wdd);
- mutex_lock(&wd_data->lock);
wd_data->wdd = NULL;
wdd->wd_data = NULL;
mutex_unlock(&wd_data->lock);
--
2.37.2