[systemd-devel] Triggering the HW Watchdog

[D.S. Ljungmark]

On 27/02/18 15:21, Lennart Poettering wrote:
> On Di, 27.02.18 15:12, D.S. Ljungmark (ljungmark at modio.se) wrote:
> 
>>> I figure you can send SIGSTOP to PID 1, no? (there are some signals
>>> the kernel blocks for PID 1, but I think SIGSTOP is not among them,
>>> please try)
>>
>> It seems that SIGSTOP is being filtered, because nothing appears to
>> happen, and the system certainly isn't rebooting.
> 
> You should be able to trigger an abort in PID 1 by sending it SIGABRT
> or SIGQUIT or so. If PID 1 aborts it will actually enter a freeze loop
> in which it stops pinging the hw watchdog.
> 
> Lennart


ABRT works,  or well..

systemd[1]: Caught <ABRT>, core dump failed (child 3844, code=killed,
status=6/ABRT).

And then a broadcast, freezing execution


And after that, what I was afraid of:

[25417.186351] watchdog: watchdog0: watchdog did not stop!


Well, that gives me a tool to debug this with, Thank you!


//D.S

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