Re: [PATCH] bpf: merge two CONFIG_BPF entries

[Yonghong Song]

On 2/4/24 3:37 PM, Masahiro Yamada wrote:
> On Mon, Feb 5, 2024 at 3:11 AM Yonghong Song <yonghong.song@xxxxxxxxx> wrote:
> > On 2/3/24 11:56 PM, Masahiro Yamada wrote:
> > > 'config BPF' exists in both init/Kconfig and kernel/bpf/Kconfig.
> > >
> > > Commit b24abcff918a ("bpf, kconfig: Add consolidated menu entry for bpf
> > > with core options") added the second one to kernel/bpf/Kconfig instead
> > > of moving the existing one.
> > >
> > > Merge them together.
> > >
> > > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> > > ---
> > >
> > >    init/Kconfig       | 5 -----
> > >    kernel/bpf/Kconfig | 1 +
> > >    2 files changed, 1 insertion(+), 5 deletions(-)
> > >
> > > diff --git a/init/Kconfig b/init/Kconfig
> > > index 8d4e836e1b6b..46ccad83a664 100644
> > > --- a/init/Kconfig
> > > +++ b/init/Kconfig
> > > @@ -1457,11 +1457,6 @@ config SYSCTL_ARCH_UNALIGN_ALLOW
> > >    config HAVE_PCSPKR_PLATFORM
> > >        bool
> > >
> > > -# interpreter that classic socket filters depend on
> > > -config BPF
> > > -     bool
> > > -     select CRYPTO_LIB_SHA1
> > > -
> > >    menuconfig EXPERT
> > >        bool "Configure standard kernel features (expert users)"
> > >        # Unhide debug options, to make the on-by-default options visible
> > > diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig
> > > index 6a906ff93006..bc25f5098a25 100644
> > > --- a/kernel/bpf/Kconfig
> > > +++ b/kernel/bpf/Kconfig
> > > @@ -3,6 +3,7 @@
> > >    # BPF interpreter that, for example, classic socket filters depend on.
> > >    config BPF
> > >        bool
> > > +     select CRYPTO_LIB_SHA1
> > Currently, the kernel/bpf directory is guarded with CONFIG_BPF
> >     obj-$(CONFIG_BPF) += bpf/
> > in kernel/bpf/Makefile.
>
> Wrong.
>
> "in kernel/Makefile".
>
>
> Why is it related to this patch?

Sorry, my obvious mistake.

> > Your patch probably works since there are lots of some other BPF related
> > configurations which requires CONFIG_BPF. But maybe we sould
> > keep 'config BPF' in init/Kconfig and remove 'config BPF'
> > in kernel/bpf/Kconfig. This will be less confusing?
>
> Why?

The 'less confusing' part is just my initial feeling. I found
some CGROUP related configs are defined in init/Kconfig but not
under kernel/cgroup directory. So I thought 'config BPF' could
stay in init/Kconfig as well.

But I just did some other checking. For example, 'config NET'
is actually under 'net' directory. So probably you are right,
let us remove the one in init/Kconfig and use the one
in kernel/bpf/Kconfig.

So

Acked-by: Yonghong Song <yonghong.song@xxxxxxxxx>

> > >    # Used by archs to tell that they support BPF JIT compiler plus which
> > >    # flavour. Only one of the two can be selected for a specific arch since