Re: [PATCH 7/8] Windows gdb: Implement XState (Intel AVX) support

 Am Freitag, 17. Juli 2026 um 16:16:31 MESZ hat Schimpe, Christina <[email protected]> Folgendes geschrieben:

> > -----Original Message-----
> > From: Hannes Domani <[email protected]>
> > Sent: Freitag, 17. Juli 2026 15:47
> > To: [email protected]; Schimpe, Christina
> > <[email protected]>
> > Subject: Re: [PATCH 7/8] Windows gdb: Implement XState (Intel AVX) support
> >
> >  Am Freitag, 17. Juli 2026 um 14:54:59 MESZ hat Schimpe, Christina
> > <[email protected]> Folgendes geschrieben:
> >
> > > Hi Hannes,
> > >
> > > Thank you for working on this.
> > > It appears that this patch uses the same commit message header as
> > > patch #8. Is it intentional that these are separate commits?
> >
> > This one is the gdb part, and #8 is the gdbserver part, that is stated in the
> > title.
> 
> Oups, I wonder how I came to that conclusion.  Sorry for that.
> 
> >
> > > In any case, IMO, commit messages should not have identical headers.
> > > Also, this patch seems big enough for a commit message which is not
> > > header only. :)
> 
> This part still stands for the commit message. Since it's not only avx registers,
> I believe it makes sense to share more details here.

Yes, I will do that.


> > > Do any AVX-* specific tests pass on Windows now? If so, it would be
> > > helpful to mention that in the commit message as well.
> >
> > I actually planned to add that info, but forgot.
> >
> > These tests then pass on Windows:
> > gdb.arch/i386-avx.exp
> > gdb.arch/i386-avx512.exp
> 
> What's the state for SSE  (gdb.arch/i386-sse.exp) ?

i386-sse.exp works since patch #1, it was only a compile issue of the test itself.
I will mention this in the patch as well.


> I also saw you introduced some code for PKRU and the shadow stack pointer.
> We have GDB tests for those registers, too:
> - gdb.arch/i386-pkru.exp
> - gdb.arch/amd64-shadow-stack*.exp

For these I just added the equivalent code as is done on Linux, without really
knowing what they are for.

i386-pkru.exp tells me:

(gdb) print have_pkru()
$1 = 0
(gdb) PASS: gdb.arch/i386-pkru.exp: probe PKRU support
UNSUPPORTED: gdb.arch/i386-pkru.exp: processor does not support protection key feature.

Do only certain CPU's have this register?

And amd64-shadow-stack.exp:

(gdb) print $pl3_ssp
$1 = (void *) 0x0
(gdb) FAIL: gdb.arch/amd64-shadow-stack.exp: test shadow stack support

No idea if that should work, since Windows is supplying data for the $pl3_ssp register.


Hannes