Re: [PATCH] selftests/nolibc: fix sparc32 tests with -mcpu=v9

["Thomas Weißschuh" <linux@weissschuh.net>]

Hi Geert,

On 2026-01-06 14:36:23+0100, Geert Uytterhoeven wrote:
> On Tue, 6 Jan 2026 at 12:47, Thomas Weißschuh <linux@weissschuh.net> wrote:
> > On 2026-01-06 12:40:12+0100, Geert Uytterhoeven wrote:
> > > On Sun, 4 Jan 2026 at 23:14, Thomas Weißschuh <linux@weissschuh.net> wrote:
> >
> > (...)
> >
> > > > --- a/tools/testing/selftests/nolibc/Makefile.nolibc
> > > > +++ b/tools/testing/selftests/nolibc/Makefile.nolibc
> > > > @@ -117,7 +117,7 @@ DEFCONFIG_riscv32    = rv32_defconfig
> > > >  DEFCONFIG_riscv64    = defconfig
> > > >  DEFCONFIG_s390x      = defconfig
> > > >  DEFCONFIG_loongarch  = defconfig
> > > > -DEFCONFIG_sparc32    = sparc32_defconfig
> > > > +DEFCONFIG_sparc32    = sparc64_defconfig
> > >
> > > How can we test sparc32 using a 64-bit kernel?
> >
> > CONFIG_COMPAT=y
> 
> FWIW, testing 32-bit userland on a 64-bit kernel is something completely
> different...

I can't really follow. We are testing the userspace nolibc here and
assume that the kernel component already works correctly. Whether that
is a native 32-bit kernel, 64-bit kernel with CONFIG_COMPAT=y or even
qemu-user-sparc doesn't really matter in my opinion. What am I missing?

> > Please note that this changed in (the now committed) v2 anyways:
> > https://lore.kernel.org/lkml/20260106-nolibc-sparc32-fix-v2-1-7c5cd6b175c2@weissschuh.net/
> 
> Sorry, I hadn't noticed the newer version, as the latter does not
> include some keywords to trigger my interest ;-)

Now I am left wondering about the specific keyword that triggered on v1
but not v2 :-)


Thomas