Re: [PATCH v3 2/3] kbuild: remove PROVIDE() for kallsyms symbols

[Nicolas Schier]

On Mon, Jun 10, 2024 at 08:25:17PM +0900, Masahiro Yamada wrote:
> This reimplements commit 951bcae6c5a0 ("kallsyms: Avoid weak references
> for kallsyms symbols") because I am not a big fan of PROVIDE().
> 
> As an alternative solution, this commit prepends one more kallsyms step.
> 
>     KSYMS   .tmp_vmlinux.kallsyms0.S          # added
>     AS      .tmp_vmlinux.kallsyms0.o          # added
>     LD      .tmp_vmlinux.btf
>     BTF     .btf.vmlinux.bin.o
>     LD      .tmp_vmlinux.kallsyms1
>     NM      .tmp_vmlinux.kallsyms1.syms
>     KSYMS   .tmp_vmlinux.kallsyms1.S
>     AS      .tmp_vmlinux.kallsyms1.o
>     LD      .tmp_vmlinux.kallsyms2
>     NM      .tmp_vmlinux.kallsyms2.syms
>     KSYMS   .tmp_vmlinux.kallsyms2.S
>     AS      .tmp_vmlinux.kallsyms2.o
>     LD      vmlinux
> 
> Step 0 takes /dev/null as input, and generates .tmp_vmlinux.kallsyms0.o,
> which has a valid kallsyms format with the empty symbol list, and can be
> linked to vmlinux. Since it is really small, the added compile-time cost
> is negligible.
> 
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
> ---

Reviewed-by: Nicolas Schier <nicolas@xxxxxxxxx>