>
> On Sat, 24 Jul 1999, Alexander Viro wrote:
>
> > BTW, for x86 gurus: what will happen if in ring 0 you change %cr3
> > (register, that is), leave the value in TSS unmodified and then return to
> > ring 3? Is there any chance that processor will reload the old value
> > (undefined/some processors are buggy and know to do that/it's documented
> > behaviour/never happens on known processors)?
>
> the TSS is only ever consulted when we switch from ring3 into ring0, to
> get esp and ss registers. (plus the io bitmaps if using ioperm()) It's not
> supposed to reload %cr3 except when we do an explicit TSS switch.
Which excludes the "documented behaviour" variant. Could you try to modify
activate_context() (add assignment to init_tss[smp_processor_id()].cr3)
and see if it will change the behaviour on your processor? I can see how
somebody might decide to reuse the microcode...
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/