Re: [v6 PATCH 12/21] x86/insn: Support both signed 32-bit and 64-bit effective addresses

Ricardo Neri
2017-05-12T01:55:54Z

On Mon, 2017-05-08 at 13:42 +0200, Borislav Petkov wrote:
> On Wed, Apr 26, 2017 at 08:33:46PM -0700, Ricardo Neri wrote:
> > This is the reason I check the value of long_bytes. If long_bytes is not
> > 4, being the only other possible value 8 (perhaps I need to issue an
> > error when the value is not any of these values),
>
> Well, maybe I'm a bit too paranoid. Bottom line is, we should do the
> address computations exactly like the hardware does them so that there
> are no surprises. Doing them with longs looks ok to me.

Using long is exactly what I intend to do. The problem that I am trying
to resolve is to sign-extend signed memory offsets of 32-bit programs
running on 64-bit kernels. For 64-bit programs running on 64-bit kernels
I can simply use longs. I added error checking in my v7 of this series
[1].

Thanks and BR,
Ricardo

[1]. https://lkml.org/lkml/2017/5/5/407