Re: "Exception at ..." with 2.1.9 and 2.1.10 kernels

Janos Farkas (chexum@bankinf.banki.hu)
Wed, 20 Nov 1996 10:14:17 +0100 (MET)


On Tue, 19 Nov 1996, Richard Henderson wrote:
> ..
> > It was a null pointer being passed. This does bring up a minor question of
> > whether a null pointer should be handled here or higher up.

> Well, that's sort of the whole point of the exceptions in 2.1.

> Anyway, the message that pops up is for debugging the mechanism that
> was put in place for this wonderful new feature. And since it is also
> useful as a clue that userland software needs to be fixed, it may very
> well stay around for a while.

And furthermore, if a user program does open(NULL,..), it of course seems
to be broken, but it MAY do "useful" things in some a.out format, or
where page zero is mapped... So it would be probably incorrect to check
early for zero. It's handled well by the exceptions, and it's useful for
programmers to know about problems in their code, but I can well
imagine how it disturbs "users". :) [Probably to the same amount that the
dreaded "Socket destroy delayed" message, which is now back.. :)]

Janos