Re: [PATCH v2 1/1] x86/ia32: Normalize any null selector value to 0

[Xin Li]

On 11/20/2024 11:34 AM, Andrew Cooper wrote:
> On 20/11/2024 7:09 pm, Xin Li wrote:
> > On 11/20/2024 1:33 AM, Andrew Cooper wrote:
> > > Right now, this change is codifying the problem behaviour we were trying
> > > to fix out under FRED.
> > >
> > > Under FRED, if userspace loads e.g. 2 into a selector, it should remain
> > > 2 until userspace changes it to something else.
> >
> > Okay, I will fix it by:
> > 1) For null selector values, do nothing.
> > 2) For non-null selector values, set RPL bits.
> >
> > sounds okay?
>
> Yeah, that sounds okay.

Actually this is what v1 does:

https://lore.kernel.org/lkml/20230706052231.2183-1-xin3.li@xxxxxxxxx/

But obviously I need to rewrite the change log.

> The selftest ought to work under FRED, but it was speculative coding.  I
> can't rule out that tweaks might be needed.

The v1 makes the test happy with both IDT and FRED.

Thanks!
    Xin