Re: Invalid Opcode on ia32, Pistachio 0.4

[Alexander Wieder]
> This looks to me like any invalid opcode in the user area (except
> the sequence lock; nop;) will execute enter_kdebug() and thus
> basicly crash.  By this, the exception-IPC will only be sent if the
> invalid opcode was executed _not_ in user area.

> Does this make sense? Wouldn't it make more sense to skip the
> enter_kdebug() in L.238 (comment out) to sent the exception-IPC if
> the exception was not caused by the KIP-syscall?

Your observation is correct.  The kernel will indeed enter kdebug upon
invalid opcode exceptions.  As I mentioned in another mail some time
ago (can't remember exactly when, must have been a month or two ago)
we currently don't always send an exception IPC upon unhandled
user-level exceptions.  This is purely due to "laziness" and
implement-whenever-needed-syndorme on the developer side (and also to
ease debugging when, e.g., doing paravirtualized Linux).  As the spec
says, the kernel is supposed to send exception IPCs when it does not
handle the exception internally.

	eSk