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;
MIME-Version: 1.0
References: <20181209032715.3466040-1-liuxiaozhou@bytedance.com>
 <CANiq72nqFuJm5f69G-Pc_9QHz+anwaon-WfVsPrkZWah1OP7Fg@mail.gmail.com> <CANiq72=Sim1rmTBqWx6+t4GpRmZoNAhTppvbhEjOo-T2_g0N2A@mail.gmail.com>
In-Reply-To: <CANiq72=Sim1rmTBqWx6+t4GpRmZoNAhTppvbhEjOo-T2_g0N2A@mail.gmail.com>
From:   =?UTF-8?B?5YiY5pmT6Iif?= <liuxiaozhou@bytedance.com>
Date:   Fri, 14 Dec 2018 18:17:14 +0800
Message-ID: <CAEEtttUT4D8z9XeUyZdh4LGnNgUP4cXUdLF=Pk1RWVk43C4jHA@mail.gmail.com>
Subject: Re: [PATCH v2] Compiler Attributes: don't pollute userspace with
 macro definitions
To:     Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc:     Greg KH <gregkh@linuxfoundation.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Masahiro Yamada <yamada.masahiro@socionext.com>,
        Luc Van Oostenryck <luc.vanoostenryck@gmail.com>,
        Paul Burton <paul.burton@mips.com>,
        Arnd Bergmann <arnd@arndb.de>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi Miguel,

On Thu, Dec 13, 2018 at 10:59:10PM +0100, Miguel Ojeda wrote:

> I wonder if we can/should simply move them into the __KERNEL__ &&
> !__ASSEMBLY__ block that is above, instead. It would be simpler to
> read, and there aren't apparently dependencies to those outside it
> that go after the block.

Yes, this is also more accurate. I will send a v3.

> I took a look at where the macros were at each "step", and, on one
> hand, compiler-gcc.h was (and is) included entirely inside it, which
> is from where most of the macros come originally from. On the other
> hand, not all do: __must_check (the generic version, not the one in
> -gcc.h) and noinline_for_stack were defined in __KERNEL__ (only)
> before commit 815f0ddb346c ("include/linux/compiler*.h: make
> compiler-*.h mutually exclusive"). But anyway using those two in
> assembly does not make sense, right?
>
> What do you think?

A simple grep shows no assembly are using those macros. Pretty sure
it is safe to do it this way.


Thanks,
Xiaozhou