Re: [PATCH 0/4] LD_DEAD_CODE_DATA_ELIMINATION fixes and enabling for powerpc

Mathieu Malaterre
2018-04-20T10:00:17Z

On Fri, Apr 20, 2018 at 9:34 AM, Nicholas Piggin <npiggin@gmail.com> wrote:
> A few people have been interested in this again. And I promised
> if it remains dead code it should be removed, so I would like to
> have another try.
>
> I think I got snagged on the modules problem last time and did
> not take the time to work it out, this time I just turned off the
> compile options for modules (the linker option was never set anyway
> so no loss).
>
> This includes some linker script catches and ideas from others, I
> didn't documnt them all, but thanks for looking.

This series works for me. v2 from Christophe was triggering a kernel
panic (call stack mentioned set_pte_at...).

So if needed:

Tested-by: Mathieu Malaterre <malat@debian.org>

Env: Mac Mini G4, with custom config.

> I would be interested to help other archs get this working too, if
> anybody needs some help.
>
> Thanks,
> Nick
>
> Nicholas Piggin (4):
> kbuild: Fix asm-generic/vmlinux.lds.h for
> LD_DEAD_CODE_DATA_ELIMINATION
> kbuild: LD_DEAD_CODE_DATA_ELIMINATION no
> -ffunction-sections/-fdata-sections for module build
> kbuild: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selectable if
> enabled
> powerpc: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selected
>
> Makefile | 4 +--
> arch/Kconfig | 15 ----------
> arch/powerpc/Kconfig | 1 +
> arch/powerpc/kernel/vmlinux.lds.S | 22 +++++++-------
> include/asm-generic/vmlinux.lds.h | 49 ++++++++++++++++++-------------
> init/Kconfig | 27 +++++++++++++++++
> 6 files changed, 70 insertions(+), 48 deletions(-)
>
> --
> 2.17.0
>