Re: Super Lint (was: Unexecutable Stack / Buffer Overflow Exploits...)

Martin Dalecki (dalecki@cs.net.pl)
Tue, 04 Jan 2000 11:34:24 +0100


Joern Rennecke wrote:
>
> > Goedel tells you about axiomatic systems which encompass both ARITHMETIC
> > and RECURSION.
> > And dman there is still the inifity requirement it needs... (int is
> > usually at best 64
> > bit!)
>
> But you might have access to a virtually infinite virtual paper tape.

No you don't have it, at least in C on a real world computer.
Tough the theoretical limit of access may be well *very* huge...

> Virtually infite being defined as whenever you'd run out of space, the
> system stalls till you have added sufficient extra space.
>
> Besides, if you want to argue about finite resources, there is this little
> problem about NP-completeness of deciding if an if-statement containing ands
> and ors of some variables can yield true for some set of values of these
> variables.

What you are talking about is as well as the whole complexity
theory just based on the assumption N!=NP, which still isn't proven...
BTW. I wanted just to point out some utterly wrong argument (Goedels
theorem).
I didn't intend to provide anyone myself.

> > int main(int argc, char *argv[] )
> > {
> > return 0;
> > }
>
> But from rice's theorem follows that for any given super-lint, there is a
> variant of this program (or any other program, for that matter) with the
> same behaviour, but which cannot be analyzed correctly.

--
	Marcin Dalecki

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