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

[Julian Braha <julianbraha@gmail.com>]

On Sunday, March 21, 2021 2:28:43 PM EDT you wrote:
> 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
> >
> 
> 
> 

Hi Geert,

Making this a 'depends' causes a recursive dependency error. 
Any other ideas?

- Julian Braha