Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Tue, 22 Jun 2021 10:29:37 +0100
From:   Mark Rutland <mark.rutland@arm.com>
To:     Catalin Marinas <catalin.marinas@arm.com>
Cc:     Nick Desaulniers <ndesaulniers@google.com>,
        Bill Wendling <morbo@google.com>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Will Deacon <will@kernel.org>,
        Ard Biesheuvel <ardb@kernel.org>,
        Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Christian Borntraeger <borntraeger@de.ibm.com>,
        Peter Oberparleiter <oberpar@linux.ibm.com>,
        Kees Cook <keescook@chromium.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Bill Wendling <wcw@google.com>,
        Sami Tolvanen <samitolvanen@google.com>,
        Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
        Nathan Chancellor <nathan@kernel.org>,
        Luc Van Oostenryck <luc.vanoostenryck@gmail.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Andrew Morton <akpm@linux-foundation.org>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        LKML <linux-kernel@vger.kernel.org>,
        clang-built-linux <clang-built-linux@googlegroups.com>,
        "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@kernel.org>,
        Borislav Petkov <bp@alien8.de>, Martin Liska <mliska@suse.cz>,
        Jonathan Corbet <corbet@lwn.net>,
        Fangrui Song <maskray@google.com>,
        Linux Doc Mailing List <linux-doc@vger.kernel.org>,
        Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        Dmitry Vyukov <dvyukov@google.com>,
        Johannes Berg <johannes.berg@intel.com>,
        linux-toolchains@vger.kernel.org, Marco Elver <elver@google.com>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        linux-s390 <linux-s390@vger.kernel.org>
Subject: Re: [PATCH 2/2] Kconfig: CC_HAS_NO_PROFILE_FN_ATTR, depend on for
 GCOV and PGO
Message-ID: <20210622092937.GB67232@C02TD0UTHF1T.local>
References: <20210618233023.1360185-1-ndesaulniers@google.com>
 <20210618233023.1360185-3-ndesaulniers@google.com>
 <CANpmjNNK-iYXucjz7Degh1kJPF_Z_=8+2vNLtUW17x0UnfgtPg@mail.gmail.com>
 <CAKwvOdmxGt6nAj+dDZEPdQtXNbYb8N6y3XwoCvCD+Qazskh7zw@mail.gmail.com>
 <CAGG=3QXeAxaf0AhKsg8P1-j2uHOoXne2KCOCEhq9SKa-e2dnag@mail.gmail.com>
 <CAKwvOd=9oAGPeuQmWnAMOxZn2ii_CRmyWnheoyXGcd09-U_CwA@mail.gmail.com>
 <20210622092533.GB3555@arm.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20210622092533.GB3555@arm.com>
Precedence: bulk

On Tue, Jun 22, 2021 at 10:25:34AM +0100, Catalin Marinas wrote:
> On Mon, Jun 21, 2021 at 01:43:54PM -0700, Nick Desaulniers wrote:
> > We need to be able to express via Kconfig "GCOV should not be enabled
> > for architectures that use noinstr when the toolchain does not support
> > __attribute__((no_profile_instrument_function))."
> > 
> > Where "architectures that use noinstr" are currently arm64, s390, and
> > x86.  So I guess we could do:
> > 
> > + depends on !ARM64 || !S390 || !X86 || CC_HAS_NO_PROFILE_FN_ATTR
> 
> I think you want:
> 
>   depends on !(ARM64 || S390 || X86) || CC_HAS_NO_PROFILE_FN_ATTR
> 
> > (We could add a Kconfig for ARCH_WANTS_NO_INSTR, which might be more
> > informative than listed out architectures which might be non-obvious
> > to passers-by).
> 
> That would probably look better.

It does; see:

https://lore.kernel.org/r/20210621231822.2848305-1-ndesaulniers@google.com

:)

Thanks,
Mark.