Hi,
today, when testing the software watchdog, I accidentally removed the
software watchdog kernel module and got a kernel panic.
to reproduce:
- build a kernel (2.6.8.1) with softdog built as module
(and without the NOWAYOUT option)
- load the softdog module
- write something (not ending with a "V") to /dev/watchdog, e. g.
echo x >/dev/watchdog
- A message will appear that device was closed, but the watchdog is
still active (if you wait a minute now, your box will reboot...)
- remove the softdog module
- wait a minute. you will see a kernel panic.
If there is a need for the actual panic message, I'll take a piece of
paper and transcribe it (no serial console here...), but i doubt it,
since
it is quite easy to reproduce...
when you disable the watchdog by
echo "V" >/dev/watchdog
before removing the module, it will not panic.
Hmm, another thing: according to the documentation in watchdog.txt,
softdog does not honor the special "V" for closing the watchdog,
but actually it does.
Please CC me since I am not on the list,
Michael