Re: [PATCH 12/16] arm64: prefer __section from compiler_attributes.h

From: Nick Desaulniers <ndesaulniers@google.com>
To: Will Deacon <will@kernel.org>,
	Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Sedat Dilek <sedat.dilek@gmail.com>,
	Josh Poimboeuf <jpoimboe@redhat.com>, Yonghong Song <yhs@fb.com>,
	clang-built-linux <clang-built-linux@googlegroups.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Andrey Konovalov <andreyknvl@google.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Enrico Weigelt <info@metux.net>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>,
	Shaokun Zhang <zhangshaokun@hisilicon.com>,
	Alexios Zavras <alexios.zavras@intel.com>,
	Allison Randal <allison@lohutok.net>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Network Development <netdev@vger.kernel.org>,
	bpf@vger.kernel.org
Subject: Re: [PATCH 12/16] arm64: prefer __section from compiler_attributes.h
Date: Wed, 14 Aug 2019 15:20:33 -0700	[thread overview]
Message-ID: <CAKwvOdk4hca8WzWzhcPEvxXnJVLbXGnhBdDZbeL_W_H91Ttjqw@mail.gmail.com> (raw)
In-Reply-To: <20190813170829.c3lryb6va3eopxd7@willie-the-truck>

On Tue, Aug 13, 2019 at 10:08 AM Will Deacon <will@kernel.org> wrote:
>
> On Tue, Aug 13, 2019 at 02:36:06PM +0200, Miguel Ojeda wrote:
> > On Tue, Aug 13, 2019 at 10:27 AM Will Deacon <will@kernel.org> wrote:
> > > On Mon, Aug 12, 2019 at 02:50:45PM -0700, Nick Desaulniers wrote:
> > > > GCC unescapes escaped string section names while Clang does not. Because
> > > > __section uses the `#` stringification operator for the section name, it
> > > > doesn't need to be escaped.
> > > >
> > > > This antipattern was found with:
> > > > $ grep -e __section\(\" -e __section__\(\" -r
> > > >
> > > > Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
> > > > Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
> > > > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> > > > ---
> > > >  arch/arm64/include/asm/cache.h     | 2 +-
> > > >  arch/arm64/kernel/smp_spin_table.c | 2 +-
> > > >  2 files changed, 2 insertions(+), 2 deletions(-)
> > >
> > > Does this fix a build issue, or is it just cosmetic or do we end up with
> > > duplicate sections or something else?
> >
> > This should be cosmetic -- basically we are trying to move all users
> > of current available __attribute__s in compiler_attributes.h to the
> > __attr forms. I am also adding (slowly) new attributes that are
> > already used but we don't have them yet in __attr form.

This lone patch of the series is just cosmetic, but patch 14/16 fixes
a real boot issue:
https://github.com/ClangBuiltLinux/linux/issues/619
Miguel, I'd like to get that one landed ASAP; the rest are just for consistency.

> >
> > > Happy to route it via arm64, just having trouble working out whether it's
> > > 5.3 material!

Thanks!
https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/commit/?h=for-next/core&id=80d838122643a09a9f99824adea4b4261e4451e6

> >
> > As you prefer! Those that are not taken by a maintainer I will pick up
> > and send via compiler-attributes.

Miguel, how do you want to take the rest of these patches? Will picked
up the arm64 one, I think the SuperH one got picked up.  There was
feedback to add more info to individual commits' commit messages.

I kept these tree wide changes separate to improve the likelihood that
they'd backport to stable cleanly, but could always squash if you'd
prefer to have 1 patch instead of a series.  Just let me know.
-- 
Thanks,
~Nick Desaulniers