Re: [PATCH v3] kbuild: Show marked Kconfig fragments in "help"

From: Kees Cook <keescook@chromium.org>
To: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Christophe Leroy <christophe.leroy@csgroup.eu>,
	Randy Dunlap <rdunlap@infradead.org>,
	linux-kernel@vger.kernel.org, x86@kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org,
	linux-s390@vger.kernel.org, linux-kbuild@vger.kernel.org,
	linux-hardening@vger.kernel.org
Subject: Re: [PATCH v3] kbuild: Show marked Kconfig fragments in "help"
Date: Fri, 1 Sep 2023 12:50:29 -0700	[thread overview]
Message-ID: <202309011250.AB0DAA03@keescook> (raw)
In-Reply-To: <CAK7LNATENQQy6LrWS10S-EXsyAvTraSj2WA=O7rFsS9Ht6a+3g@mail.gmail.com>

On Fri, Sep 01, 2023 at 04:58:37PM +0900, Masahiro Yamada wrote:
> On Fri, Sep 1, 2023 at 4:13 AM Kees Cook <keescook@chromium.org> wrote:
> >
> > Currently the Kconfig fragments in kernel/configs and arch/*/configs
> > that aren't used internally aren't discoverable through "make help",
> > which consists of hard-coded lists of config fragments. Instead, list
> > all the fragment targets that have a "# Help: " comment prefix so the
> > targets can be generated dynamically.
> >
> > Add logic to the Makefile to search for and display the fragment and
> > comment. Add comments to fragments that are intended to be direct targets.
> >
> > Cc: Nicolas Schier <nicolas@fjasle.eu>
> > Cc: Michael Ellerman <mpe@ellerman.id.au>
> > Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
> > Cc: Randy Dunlap <rdunlap@infradead.org>
> > Cc: linux-kernel@vger.kernel.org
> > Cc: x86@kernel.org
> > Cc: linux-arm-kernel@lists.infradead.org
> > Cc: linuxppc-dev@lists.ozlabs.org
> > Cc: linux-riscv@lists.infradead.org
> > Cc: linux-s390@vger.kernel.org
> > Cc: linux-kbuild@vger.kernel.org
> > Cc: linux-hardening@vger.kernel.org
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > Co-developed-by: Masahiro Yamada <masahiroy@kernel.org>
> > ---
> > v3:
> > - Use Makefile logic from Masahiro Yamada
> > - Use "# Help: " prefix, but only on desired fragment targets
> > v2: https://lore.kernel.org/all/20230825194329.gonna.911-kees@kernel.org
> > v1: https://lore.kernel.org/all/20230824223606.never.762-kees@kernel.org
> > ---
> >  Makefile                                   |  1 -
> >  arch/arm/configs/dram_0x00000000.config    |  1 +
> >  arch/arm/configs/dram_0xc0000000.config    |  1 +
> >  arch/arm/configs/dram_0xd0000000.config    |  1 +
> >  arch/arm/configs/lpae.config               |  1 +
> >  arch/arm64/configs/virt.config             |  1 +
> >  arch/powerpc/configs/disable-werror.config |  1 +
> >  arch/powerpc/configs/security.config       |  4 +++-
> >  arch/riscv/configs/32-bit.config           |  1 +
> >  arch/riscv/configs/64-bit.config           |  1 +
> >  arch/s390/configs/btf.config               |  1 +
> >  arch/s390/configs/kasan.config             |  1 +
> >  arch/x86/Makefile                          |  4 ----
> >  kernel/configs/debug.config                |  2 ++
> >  kernel/configs/kvm_guest.config            |  1 +
> >  kernel/configs/nopm.config                 |  2 ++
> >  kernel/configs/rust.config                 |  1 +
> >  kernel/configs/tiny.config                 |  2 ++
> >  kernel/configs/x86_debug.config            |  1 +
> >  kernel/configs/xen.config                  |  2 ++
> >  scripts/kconfig/Makefile                   | 15 ++++++++++++---
> >  21 files changed, 36 insertions(+), 9 deletions(-)
> >
> 
> 
> Just one thing.
> 
> 
> 
> 
> 
> > diff --git a/kernel/configs/tiny.config b/kernel/configs/tiny.config
> > index 00009f7d0835..60a4b6d80b36 100644
> > --- a/kernel/configs/tiny.config
> > +++ b/kernel/configs/tiny.config
> > @@ -1,3 +1,5 @@
> > +# Help: Size-optimized kernel image
> 
> 
> I will drop this.
> 
> 
> We already have a hard-coded help message.
> 
>   tinyconfig   - Configure the tiniest possible kernel
> 
> 
> 
> 
> Then, some lines below, again.
> 
>   tiny.config               - Size-optimized kernel image
> 
> 
> 
> tiny.config is for internal use for tinyconfig.

Shall I send a v4, or did you fix this up already?

-- 
Kees Cook