On Mon, Feb 5, 2024 at 10:22 PM Jan Stancek [off-list ref] wrote:

On Mon, Feb 5, 2024 at 12:50 PM Michael Ellerman [off-list ref] wrote:

quoted

Jan Stancek [off-list ref] writes:

quoted

On Tue, Nov 21, 2023 at 10:51:34AM +1000, Nicholas Piggin wrote:

quoted

On Tue Nov 21, 2023 at 9:23 AM AEST, Masahiro Yamada wrote:

quoted

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.

Please note 'make ARCH=powerpc clean' will remove  '*.o'
files globally.


Kbuild promised you would still be able to compile external modules
after 'make clean' (until you run 'make mrproper'), but
that would not work in this case.

So, the external module support for powerpc
is broken in another way, already.


Perhaps, an easy workaround might be to change
the suffix, but I did not test it at all.

mv arch/powerpc/lib/crtsavres.o arch/powerpc/lib/crtsavres.o.do_not_remove_me




-- 
Best Regards
Masahiro Yamada