Re: [PATCH] Differentiate scenarios when watchdog is closed

[Guenter Roeck <linux@roeck-us.net>]

On 8/31/26 13:05, chaithco@redhat.com wrote:
> On Thu, 2026-08-27 at 11:10 -0700, Guenter Roeck wrote:
>> Problem is that we don't know if "something bad happened". The same
>> message
>> will be seen if the watchdog daemon was killed or crashed. We can not
>> just
>> assume that closing the watchdog device was intentional.
> 
> That's the same sticking point I've come across. Differentiating
> between positive intentional closure versus malicious or buggy closure
> would somehow need to be communicated to the kernel. It makes more
> sense that users of the watchdog which intend to close the watchdog
> while still running maybe denote such. I opened a PR with systemd at
> https://github.com/systemd/systemd/pull/43552 to see if there was some
> way this could be tackled from that perspective.

I'd want to see a message even if the watchdog is closed but left running
on purpose. The best we can do is to add another message if there was an
error when trying to stop the watchdog. That should not happen too often
(well, not at all, really, unless there is a bug or hardware problem),
so it would not really add noise.

Thanks,
Guenter