On Sat, 2011-12-03 at 04:22 +0100, Segher Boessenkool wrote:
> > +static inline int page_is_rtas_user_buf(unsigned long pfn)
> > +{
> > + unsigned long paddr = (pfn << PAGE_SHIFT);
> > + if (paddr >= rtas_rmo_buf && paddr < (rtas_rmo_buf +
> > RTAS_RMOBUF_MAX))
>
> It probably cannot overflow with actual values of rtas_rmo_buf
> and RTAS_RMOBUF_MAX, but otherwise it is an incorrect test;
> please write
>
> if (paddr >= rtas_rmo_buf && paddr - rtas_rmo_buf < RTAS_RMOBUF_MAX)
>
> (and, _MAX? Shouldn't it be the actual size here? Or is _MAX
> just a confusing name :-) )
The original code is a lot more readable and perfectly correct for all
possible values of rtas_rmo_buf :-)
Cheers,
Ben.
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