Re: [PATCH] powerpc: add crtsavres.o to always-y instead of extra-y

Jan Stancek
2024-02-05T13:22:11Z

On Mon, Feb 5, 2024 at 12:50 PM Michael Ellerman <mpe@ellerman.id.au> wrote:
>
> Jan Stancek <jstancek@redhat.com> writes:
> > On Tue, Nov 21, 2023 at 10:51:34AM +1000, Nicholas Piggin wrote:
> >>On Tue Nov 21, 2023 at 9:23 AM AEST, Masahiro Yamada wrote:
> >>> crtsavres.o is linked to modules. However, as explained in commit
> >>> d0e628cd817f ("kbuild: doc: clarify the difference between extra-y
> >>> and always-y"), 'make modules' does not build extra-y.
> >>>
> >>> For example, the following command fails:
> >>>
> >>> $ make ARCH=powerpc LLVM=1 KBUILD_MODPOST_WARN=1 mrproper ps3_defconfig modules
> >>> [snip]
> >>> LD [M] arch/powerpc/platforms/cell/spufs/spufs.ko
> >>> ld.lld: error: cannot open arch/powerpc/lib/crtsavres.o: No such file or directory
> >>> make[3]: *** [scripts/Makefile.modfinal:56: arch/powerpc/platforms/cell/spufs/spufs.ko] Error 1
> >>> make[2]: *** [Makefile:1844: modules] Error 2
> >>> make[1]: *** [/home/masahiro/workspace/linux-kbuild/Makefile:350: __build_one_by_one] Error 2
> >>> make: *** [Makefile:234: __sub-make] Error 2
> >>>
> >>
> >>Thanks. Is this the correct Fixes tag?
> >>
> >>Fixes: d0e628cd817f ("powerpc/64: Do not link crtsavres.o in vmlinux")
> >>
> >>Hmm, looks like LLD might just do this now automatically for us
> >>too without --save-restore-funcs (https://reviews.llvm.org/D79977).
> >>But we probably still need it for older versions, so we still need
> >>your patch.
> >
> > Hi,
> >
> > I'm still seeing the error of crtsavres.o missing when building external modules
> > after "make LLVM=1 modules_prepare". Should it be built also in archprepare?
>
> Or modules_prepare?
>
> Example patch below.

I tested your patch with my setup and that works for me as well.

>
> cheers
>
>
> diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
> index 051247027da0..82cdef40a9cd 100644
> --- a/arch/powerpc/Makefile
> +++ b/arch/powerpc/Makefile
> @@ -59,6 +59,11 @@ ifeq ($(CONFIG_PPC64)$(CONFIG_LD_IS_BFD),yy)
> KBUILD_LDFLAGS_MODULE += --save-restore-funcs
> else
> KBUILD_LDFLAGS_MODULE += arch/powerpc/lib/crtsavres.o
> +
> +crtsavres_prepare: scripts
> + $(MAKE) $(build)=arch/powerpc/lib arch/powerpc/lib/crtsavres.o
> +
> +modules_prepare: crtsavres_prepare
> endif
>
> ifdef CONFIG_CPU_LITTLE_ENDIAN
>