[v5] RE: [RFC PATCH v5 0/2] sysret_rip update for the Intel FRED architecture

RE: [RFC PATCH v5 0/2] sysret_rip update for the Intel FRED architecture

Posted by Li, Xin3 2 years, 6 months ago

> > > > Would it be better to get this patch set merged first?
> > > >
> > > > Otherwise surely I will include it in the FRED patch set.
> > >
> > > If the maintainers are ok with it, it would be better to merge it
> > > sooner: once we have agreed on the semantics, which I believe we
> > > have, we should be testing those semantics and nothing else.
> >
> > OK, let's keep this patchset separated from the FRED support patchset.
> 
> Thanks!
> 
> This patch set first makes the R11/RCX semantics clearer, and it BTW fixes FRED
> tests.
> 
> To me it's more of an improvement to the existing code.

Hi Faizi,

Any update on this patch set?

Thanks!
Xin

Re: [RFC PATCH v5 0/2] sysret_rip update for the Intel FRED architecture

Posted by Ammar Faizi 2 years, 6 months ago

On Wed, Feb 15, 2023 at 07:42:47AM +0000, Li, Xin3 wrote:
> Hi Faizi,
> 
> Any update on this patch set?

No comment from HPA. But after the recent discussion with Andrew, I
think at least it's now clear that we are not going to use "+r"(rsp) to
avoid the red zone problem.

I am on leave today. Will send revision v8 on Monday.

Thanks,

-- 
Ammar Faizi

Re: [RFC PATCH v5 0/2] sysret_rip update for the Intel FRED architecture

Posted by H. Peter Anvin 2 years, 6 months ago

On February 17, 2023 8:27:40 PM PST, Ammar Faizi <ammarfaizi2@gnuweeb.org> wrote:
>On Wed, Feb 15, 2023 at 07:42:47AM +0000, Li, Xin3 wrote:
>> Hi Faizi,
>> 
>> Any update on this patch set?
>
>No comment from HPA. But after the recent discussion with Andrew, I
>think at least it's now clear that we are not going to use "+r"(rsp) to
>avoid the red zone problem.
>
>I am on leave today. Will send revision v8 on Monday.
>
>Thanks,
>

My apologies, I missed your latest response in the torrent of email. The redzone issue is weird; it ought to be breaking all over the place, not just this.

Let me take a quick look at it...

Re: [RFC PATCH v5 0/2] sysret_rip update for the Intel FRED architecture

Posted by Ammar Faizi 2 years, 6 months ago

On Wed, Feb 15, 2023 at 07:42:47AM +0000, Li, Xin3 wrote:
> Hi Faizi,
> 
> Any update on this patch set?

Xin,

Before I send the next version, I need an answer for this one:
https://lore.kernel.org/lkml/Y9LfmQ%2Fr1%2FpEP+uv@biznet-home.integral.gnuweeb.org/

I don't think the redzone problem is handled correctly here. Using
"+r" (rsp) constraint doesn't solve the redzone problem.

HPA, Andrew, anybody?

-- 
Ammar Faizi