Re: mtd: kernel BUG at arch/x86/mm/pat.c:279!

[H. Peter Anvin]

On 09/09/2012 12:04 PM, David Woodhouse wrote:
> On Sun, 2012-09-09 at 09:56 -0700, H. Peter Anvin wrote:
> > > So it should either be start=0xfffffffffffff000 end=0xffffffffffffffff
> > > or it should be start=0xfffffffffffff000 len=0x1000.
> >
> > I would strongly object to the former; that kind of inclusive ranges
> > breed a whole class of bugs by themselves.
>
> Another alternative that avoids overflow issues is to use a PFN rather
> than a byte address.

Except as a result of that logic have a bunch of places which either 
have rounding errors in how they calculate PFNs, or they think they can 
stick PFNs into 32-bit numbers.  :(

	-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

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