Re: Console client, signal handeling patch

[Niels Möller]

Marcus Brinkmann <Marcus.Brinkmann@ruhr-uni-bochum.de> writes:

> However, for a production system, I don't want those unexpected
> signals to happen, so I don't think I want to catch me, too. We
> don't do in any other part of the system either.

And *if* a crashing vga console client is a real problem, then the
right way to deal with it (besides just fixing the client; perhaps we
want a non-root user to be able to use his own buggy vga client,
whatever), is to implement a vga device/translator.

The device should be smaller and simpler than the console client, and
therefore less likely to crash [1]. Then the console client will just
open the device, and if it crashes, the device close code will notice
and it can restore the hardware to a sane state.

If you think that you need to install a signal handler for SIGSEGV in
order to do reasonable cleanup of resources if a process terminates
unexpectedly, then you should really think about improving the
resource tracking features of the operating system. If your process
gets a SIGSEGV, then you most likely have some corrupted state in the
process' address space, so you better have some other, un-corrupted,
process clean up the mess.

[1] Ok, this is in theory, perhaps the device turns out to be as
complex as the console server, and then there's not much point in
introducing it.

Regards,
/Niels