On 9/5/21 3:22 PM, Klein, Curtis wrote:
On 9/4/21, 1:19AM, Jiri Slaby wrote:
On 04. 09. 21, 10:16, Jiri Slaby wrote:
On 02. 09. 21, 16:05, Guenter Roeck wrote:
On 9/1/21 11:55 PM, Jiri Slaby wrote:
On 03. 02. 21, 21:11, Curtis Klein wrote:
This adds the option to use a hrtimer to generate a watchdog pretimeout
event for hardware watchdogs that do not natively support watchdog
pretimeouts.
With this enabled, all watchdogs will appear to have pretimeout support
in userspace. If no pretimeout value is set, there will be no change in
the watchdog's behavior.
Hi,
on my Dell Latitude 7280, CONFIG_WATCHDOG_HRTIMER_PRETIMEOUT=y causes
all reboot, kexec, suspend to panic. Disabling that option makes it
all work again. Provided it happens very late in the process, I don't
know how to grab some logs...
Any ideas?
AFAICS the timer does not stop on reboot. I think we'll need to
augment the code
to do that.
No, it is stopped via device unregister -> watchdog_dev_unregister ->
watchdog_cdev_unregister -> watchdog_hrtimer_pretimeout_stop.
But look:
watchdog_cdev_unregister
-> wdd->wd_data = NULL;
-> watchdog_hrtimer_pretimeout_stop
-> hrtimer_cancel(&wdd->wd_data->pretimeout_timer);
The diff below obviously fixes the issue,
Which is exactly a -next commit:
commit c7b178dae139f8857edc50888cfbf251cd974a38
Author: Curtis Klein <curtis.klein@xxxxxxx>
Date: Tue Jun 22 23:26:23 2021 -0700
watchdog: Fix NULL pointer dereference when releasing cdev
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -1096,6 +1096,8 @@ static void watchdog_cdev_unregister(struct
watchdog_device *wdd)
watchdog_stop(wdd);
}
+ watchdog_hrtimer_pretimeout_stop(wdd);
+
mutex_lock(&wd_data->lock);
wd_data->wdd = NULL;
wdd->wd_data = NULL;
@@ -1103,7 +1105,6 @@ static void watchdog_cdev_unregister(struct
watchdog_device *wdd)
hrtimer_cancel(&wd_data->timer);
kthread_cancel_work_sync(&wd_data->work);
- watchdog_hrtimer_pretimeout_stop(wdd);
put_device(&wd_data->dev);
}
thanks,
--
js
suse labs
Does it still make sense to stop the timer on reboot or suspend?
I haven't had any problems with rebooting but I haven't been able to test
suspending.
Only if it is really a problem.
Guenter
