Re: [PATCH] MIPS: VDSO: Conditionally export __vdso_gettimeofday()

[Fangrui Song <maskray@google.com>]

On Wed, Aug 16, 2023 at 2:59 PM Nathan Chancellor <nathan@kernel.org> wrote:
>
> ld.lld 16.0.0 and newer defaults to '--no-undefined-version', which
> causes the following error when CONFIG_MIPS_CLOCK_VSYSCALL is not set:
>
>   ld.lld: error: version script assignment of 'LINUX_2.6' to symbol '__vdso_gettimeofday' failed: symbol not defined
>
> Only export __vdso_gettimeofday() when it will be present in the final
> object file, which clears up the error.
>
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202308170532.zxFFv25c-lkp@intel.com/
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> ---
>  arch/mips/vdso/vdso.lds.S | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/arch/mips/vdso/vdso.lds.S b/arch/mips/vdso/vdso.lds.S
> index d90b65724d78..836465e3bcb8 100644
> --- a/arch/mips/vdso/vdso.lds.S
> +++ b/arch/mips/vdso/vdso.lds.S
> @@ -94,7 +94,9 @@ VERSION
>  #ifndef CONFIG_MIPS_DISABLE_VDSO
>         global:
>                 __vdso_clock_gettime;
> +#ifdef CONFIG_MIPS_CLOCK_VSYSCALL
>                 __vdso_gettimeofday;
> +#endif
>                 __vdso_clock_getres;
>  #if _MIPS_SIM != _MIPS_SIM_ABI64
>                 __vdso_clock_gettime64;
>
> ---
> base-commit: 2ccdd1b13c591d306f0401d98dedc4bdcd02b421
> change-id: 20230816-mips-vdso-cond-export-__vdso_gettimeofday-30ab92c716d4
>
> Best regards,
> --
> Nathan Chancellor <nathan@kernel.org>
>
>

LGTM as a maintainer of lld/ELF who has fixed some user-space packages
(https://github.com/gentoo/gentoo/pull/29097#issuecomment-1383304538).

Reviewed-by: Fangrui Song <maskray@google.com>


-- 
宋方睿