Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 30 Dec 2019 11:41:44 -0800
From:   Kees Cook <keescook@chromium.org>
To:     Masahiro Yamada <masahiroy@kernel.org>
Cc:     Arnd Bergmann <arnd@arndb.de>, Emese Revfy <re.emese@gmail.com>,
        Ard Biesheuvel <ardb@kernel.org>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Kernel Hardening <kernel-hardening@lists.openwall.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        clang-built-linux <clang-built-linux@googlegroups.com>,
        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] gcc-plugins: make it possible to disable
 CONFIG_GCC_PLUGINS again
Message-ID: <201912301141.38C6F7E0@keescook>
References: <20191211133951.401933-1-arnd@arndb.de>
 <CAK7LNASeyPxgQczSvEN4S3Ae7fRtYyynhU9kJ=96VX34S4TECA@mail.gmail.com>
 <CAK8P3a1dH+msCgxU-=w4gp30Bw+x3=6Cj473DuFzxun+3dfOcA@mail.gmail.com>
 <201912120943.486E507@keescook>
 <CAK7LNAQKuyyC-bjSZ=8bhkd1PHjRa-LDEsZra_tFdYbL7X-Azw@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAK7LNAQKuyyC-bjSZ=8bhkd1PHjRa-LDEsZra_tFdYbL7X-Azw@mail.gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Sat, Dec 14, 2019 at 05:56:34PM +0900, Masahiro Yamada wrote:
> On Fri, Dec 13, 2019 at 2:44 AM Kees Cook <keescook@chromium.org> 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@kernel.org> wrote:
> > > >
> > > > On Wed, Dec 11, 2019 at 10:40 PM Arnd Bergmann <arnd@arndb.de> 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@arndb.de>
> > > >
> > > > Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
> > >
> > > On Wed, Dec 11, 2019 at 2:59 PM Ard Biesheuvel
> > > <ard.biesheuvel@linaro.org> wrote:
> > > >Acked-by: Ard Biesheuvel <ardb@kernel.org>
> > >
> > > Thanks! Who would be the best person to pick up the patch?
> > > Should I send it to Andrew?
> >
> > Acked-by: Kees Cook <keescook@chromium.org>
> >
> > 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, applied!

-- 
Kees Cook