Re: [PATCH 4/5] x86/uapi: Stop leaking kconfig references to userspace

[Arnd Bergmann]

On Tue, Dec 30, 2025, at 08:10, Thomas Weißschuh wrote:
> 
>  /* entries in ARCH_DLINFO: */
> -#if defined(CONFIG_IA32_EMULATION) || !defined(CONFIG_X86_64)
> +#if defined(__KERNEL__) && (defined(CONFIG_IA32_EMULATION) || 
> !defined(CONFIG_X86_64))
>  # define AT_VECTOR_SIZE_ARCH 3
>  #else /* else it's non-compat x86-64 */
>  # define AT_VECTOR_SIZE_ARCH 2

While this patch clearly keeps the current behavior, I think it's
wrong, and 32-bit userspace should see a '3' instead of '2' here.

It can probably just be '3' unconditionally, or we can
make it more complex and have a userspace definition based
on __x86_64__ being defined.

I also wonder if there is a problem with the third
x86-64 entry being zero rather than AT_IGNORE. I see that
some architectures do it like this, to keep the number constant
even if some entries are missing:

        if (likely(signal_minsigstksz))                          \
                NEW_AUX_ENT(AT_MINSIGSTKSZ, signal_minsigstksz); \
        else                                                     \
                NEW_AUX_ENT(AT_IGNORE, 0);                       \

     Arnd