Re: [PATCH] gcc-plugins: make it possible to disable CONFIG_GCC_PLUGINS again

From: Masahiro Yamada
Date: Sat Dec 14 2019 - 03:57:25 EST


On Fri, Dec 13, 2019 at 2:44 AM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>
> On Thu, Dec 12, 2019 at 10:59:40AM +0100, Arnd Bergmann wrote:
> > On Thu, Dec 12, 2019 at 5:52 AM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote:
> > >
> > > On Wed, Dec 11, 2019 at 10:40 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
> > > >
> > > > I noticed that randconfig builds with gcc no longer produce a lot of
> > > > ccache hits, unlike with clang, and traced this back to plugins
> > > > now being enabled unconditionally if they are supported.
> > > >
> > > > I am now working around this by adding
> > > >
> > > > export CCACHE_COMPILERCHECK=/usr/bin/size -A %compiler%
> > > >
> > > > to my top-level Makefile. This changes the heuristic that ccache uses
> > > > to determine whether the plugins are the same after a 'make clean'.
> > > >
> > > > However, it also seems that being able to just turn off the plugins is
> > > > generally useful, at least for build testing it adds noticeable overhead
> > > > but does not find a lot of bugs additional bugs, and may be easier for
> > > > ccache users than my workaround.
> > > >
> > > > Fixes: 9f671e58159a ("security: Create "kernel hardening" config area")
> > > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> > >
> > > Reviewed-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> >
> > On Wed, Dec 11, 2019 at 2:59 PM Ard Biesheuvel
> > <ard.biesheuvel@xxxxxxxxxx> wrote:
> > >Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
> >
> > Thanks! Who would be the best person to pick up the patch?
> > Should I send it to Andrew?
>
> Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
>
> I can take it in my tree, or I'm happy to have Masahiro take it.
>
> --
> Kees Cook

Kees,
Please apply it to your tree.

Thanks.


--
Best Regards
Masahiro Yamada