Writing a program that cannot be killed except by reboot

[Jonathan I. Kamens]

In article <1991Apr14.200931.17551 at aplcen.apl.jhu.edu>, akbloom at aplcen.apl.jhu.edu (Keith Bloom) writes:
|> mcgough at wrdis01.af.mil (Jeffrey B. McGough) writes:
|> >Is there anyway to block ALL signals to a program so that it
|> >may not be killed by kill???
|> 
|> I've seen situations in which the program is trying to write to some
|> device like a network socket or parallel or serial port, and there's
|> something wrong with the connection.  In this case, it frequently
|> happens that even kill -9 won't work; rebooting is the only thing *I*
|> can think of to do when this happens.  I suppose a program could do this
|> deliberately.

  While the program is hung in the device driver, it is running in the kernel,
not in the user code, which means it can't do any work at all.  I don't see
much use for a process that can't be killed but can't do any work either.  The
second the device driver exits and the program is able to work again, it can
be killed.

-- 
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