Re: [PATCH v2 2/2] Compiler Attributes: naked can be shared - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>,
	Eli Friedman <efriedma@codeaurora.org>,
	Christopher Li <sparse@chrisli.org>,
	Kees Cook <keescook@chromium.org>, Ingo Molnar <mingo@kernel.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Masahiro Yamada <yamada.masahiro@socionext.com>,
	Joe Perches <joe@perches.com>,
	Dominique Martinet <asmadeus@codewreck.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	linux-sparse@vger.kernel.org
Subject: Re: [PATCH v2 2/2] Compiler Attributes: naked can be shared
Date: Wed, 19 Sep 2018 23:14:58 +0200	[thread overview]
Message-ID: <20180919211458.GA8757@kroah.com> (raw)
In-Reply-To: <CANiq72=ZU61EaoWm2N4G1SZF0QUvzquULo50uEvDRU-hitOJVQ@mail.gmail.com>

On Tue, Sep 18, 2018 at 08:56:04PM +0200, Miguel Ojeda wrote:
> Hi Greg,
> 
> On Tue, Sep 18, 2018 at 7:34 PM, Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> > On Tue, Sep 18, 2018 at 06:55:42PM +0200, Miguel Ojeda wrote:
> >> The naked attribute is supported by at least gcc >= 4.6 (for ARM,
> >> which is the only current user), gcc >= 8 (for x86), clang >= 3.1
> >> and icc >= 13. See https://godbolt.org/z/350Dyc
> >>
> >> Therefore, move it out of compiler-gcc.h so that the definition
> >> is shared by all compilers.
> >>
> >> This also fixes Clang support for ARM32 --- 815f0ddb346c
> >> ("include/linux/compiler*.h: make compiler-*.h mutually exclusive").
> >
> > So, with this applied, does clang really build an arm32 kernel
> > successfully?  No other problem at all?  And this isn't really a
> > regression, arm32 never really worked with clang yet, right?
> >
> 
> To recap a bit: these two patches come from the "Compiler Attributes"
> series which is meant as a general improvement.

Ok, so that's not for regressions, that's fine.

> Since Linus/Andrew/you
> didn't comment on whether you wanted or not this for 4.19, we are
> assuming they would go in for 4.20. However, Stefan/Nick/... wanted
> this for 4.19 instead, they asked me to extract these patches two
> separately for 4.19. I let them comment further on the status of Clang
> on arm32.

If these do not fix a regression, I don't see how they would be ready
for 4.19-final.

> I am going to send a v5 of the entire series without these two
> patches, based on -rc4 (or -next, which one do you prefer? I would say
> these patches should be applied early in the -next branches, so that
> everyone is ready for the change, given it "touches" every translation
> unit).

That's up to whomever takes these into their tree for linux-next
inclusion.  If you are about to break everything, then you might
consider changing your patches so they do not do that :)

good luck!

greg k-h