Re: [PATCH] lib: fix kconfig dependency on ARCH_WANT_FRAME_POINTERS

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Julian,

On Sat, Mar 20, 2021 at 1:17 AM Julian Braha <julianbraha@gmail.com> wrote:
> When LATENCYTOP is enabled and ARCH_WANT_FRAME_POINTERS
> is disabled, Kbuild gives the following warning:
>
> WARNING: unmet direct dependencies detected for FRAME_POINTER
>   Depends on [n]: DEBUG_KERNEL [=y] && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS [=n] || MCOUNT [=n]
>   Selected by [y]:
>   - LATENCYTOP [=y] && DEBUG_KERNEL [=y] && STACKTRACE_SUPPORT [=y] && PROC_FS [=y] && !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
>
> This is because LATENCYTOP selects FRAME_POINTER,
> without selecting or depending on ARCH_WANT_FRAME_POINTERS,
> despite FRAME_POINTER depending on ARCH_WANT_FRAME_POINTERS.
>
> Signed-off-by: Julian Braha <julianbraha@gmail.com>

Thanks for your patch!

> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -1675,6 +1675,7 @@ config LATENCYTOP
>         depends on DEBUG_KERNEL
>         depends on STACKTRACE_SUPPORT
>         depends on PROC_FS
> +       select ARCH_WANT_FRAME_POINTERS if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86

ARCH_WANT_FRAME_POINTERS is a symbol that is only to be selected by
architecture-specific configuration, and must not be overridden:

    # Select this config option from the architecture Kconfig, if it
    # is preferred to always offer frame pointers as a config
    # option on the architecture (regardless of KERNEL_DEBUG):

Probably this should be turned into a depends instead?

>         select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
>         select KALLSYMS
>         select KALLSYMS_ALL
> --
> 2.25.1
>


-- 
Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds