On Wed, Nov 12, 2025 at 09:03:23PM +0100, Nicolas Schier wrote:
> On Tue, Oct 14, 2025 at 03:05:15PM +0200, Thomas Weißschuh wrote:
> > The current logic to inherit -m32/-m64 from the kernel build only works
> > for a few architectures. It does not handle byte order differences,
> > architectures using different compiler flags or different kinds of ABIs.
> >
> > Introduce a per-architecture override mechanism to set CC_CAN_LINK and
> > the flags used for userprogs.
> >
> > Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> > ---
> > Changes in v2:
> > - Rebase and drop already applied patch
> > - Disable CC_CAN_LINK if the test program generates warnings
> > - Move to architecture-specific logic
> > - Link to v1: https://lore.kernel.org/r/20250813-kbuild-userprogs-bits-v1-0-2d9f7f411083@linutronix.de
> >
> > ---
> > Thomas Weißschuh (10):
> > kbuild: don't enable CC_CAN_LINK if the dummy program generates warnings
> > init: deduplicate cc-can-link.sh invocations
> > kbuild: allow architectures to override CC_CAN_LINK
> > riscv: Implement custom CC_CAN_LINK
> > s390: Implement custom CC_CAN_LINK
> > powerpc: Implement custom CC_CAN_LINK
> > MIPS: Implement custom CC_CAN_LINK
> > x86/Kconfig: Implement custom CC_CAN_LINK
> > sparc: Implement custom CC_CAN_LINK
> > kbuild: simplify CC_CAN_LINK
> >
> > Makefile | 8 ++++++--
> > arch/mips/Kconfig | 15 +++++++++++++++
> > arch/powerpc/Kconfig | 15 +++++++++++++++
> > arch/riscv/Kconfig | 11 +++++++++++
> > arch/s390/Kconfig | 11 +++++++++++
> > arch/sparc/Kconfig | 11 +++++++++++
> > arch/x86/Kconfig | 11 +++++++++++
> > init/Kconfig | 7 +++++--
> > scripts/Kconfig.include | 3 +++
> > scripts/cc-can-link.sh | 2 +-
> > 10 files changed, 89 insertions(+), 5 deletions(-)
> > ---
> > base-commit: 10f8210c7a7098897fcee5ca70236167b39eb797
> > change-id: 20250813-kbuild-userprogs-bits-03c117da4d50
> >
> > Best regards,
> > --
> > Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> >
>
> Thanks for the patch set and all the work behind! I found only one
> issue in patch 3, the rest looks good to me as they are.
>
> I haven't reviewed the compiler flags for the archs, but from the formal
> point of view they look good to me, too.
>
> How shall we proceed with here? I think, easiest would be if we get
> appropriate acks from the architecture maintainers, so we could take
> this via kbuild.
That would surely be the best option. Unfortunately quite frequently it is hard
to get architecture maintainer's feedback on a cross-architecture series.
> Other opinions?
It would also work to only take the first three patches through the kbuild tree
and push the other ones through the architecture trees.
I don't really have a clear preference.
Thomas