Re: Immediate values

Arjan van de Ven
2009-09-25T06:51:34Z

On Thu, 24 Sep 2009 21:34:22 +0200
Ingo Molnar <mingo@elte.hu> wrote:

>
> * H. Peter Anvin <hpa@zytor.com> wrote:
>
> > I would like to get an official ACK or NAK for this patching
> > technique from inside Intel, and preferrably from AMD as well. If
> > it does work as described it would provide a very clean way to do
> > one-shot alternative functions, which probably would be higher
> > value than immediate data values.
>
> Sounds tempting. Things like the CONFIG_SECURITY hookery could use it?
>
> But ... since it's patched under stopmachine, is there any reason why
> this wouldnt work?
>

stopmachine is fine.

more aggressive tricks are rather dicey.

(cross modifying code that's being executed in ring 0 is ... not
something CPU designers had in mind)

--
Arjan van de Ven Intel Open Source Technology Centre
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