Re: [PATCH v2 2/2] Compiler Attributes: naked can be shared

From: Greg Kroah-Hartman
Date: Wed Sep 19 2018 - 17:24:16 EST


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@xxxxxxxxxxxxxxxxxxx> 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