[PATCH] xdr_array and calloc security fix

[Jakub Jelinek]

On Fri, Aug 02, 2002 at 02:50:40AM -0700, Ulrich Drepper wrote:
> Ulrich Drepper wrote:
> 
> > It should be possible to have something like
> > 
> >   ((a | b) > (a * b))
> > 
> > for unsigned values.  I'm not 100% sure, though.
> 
> I mean, this is an approximation which lets us avoid the division in 
> many (most?) cases.

Many. a=1 b=2 -> is this overflow?
a=0x6000000 b=64 -> this would signal no overflow, while in fact
it overflowed. Etc.
I think the only way is to put the multiply + check for overflow into some
macro and optimize it per-architecture...

	Jakub