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From:   Ard Biesheuvel <ardb@kernel.org>
Date:   Wed, 11 Nov 2020 08:19:13 +0100
Message-ID: <CAMj1kXF_0_bu0nbJyUU-yBDCOAirRvGkX-V8kQPVh_GHO2WM-g@mail.gmail.com>
Subject: Re: [PATCH -next] treewide: Remove stringification from __alias macro definition
To:     Joe Perches <joe@perches.com>, Russell King <linux@armlinux.org.uk>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Borislav Petkov <bp@alien8.de>, X86 ML <x86@kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
        Marco Elver <elver@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-efi <linux-efi@vger.kernel.org>,
        kasan-dev <kasan-dev@googlegroups.com>,
        Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
        linux-mm <linux-mm@kvack.org>
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(+ Russell)

On Thu, 22 Oct 2020 at 18:20, Joe Perches <joe@perches.com> wrote:
>
> On Thu, 2020-10-22 at 09:33 +0200, Peter Zijlstra wrote:
> > On Wed, Oct 21, 2020 at 11:58:25AM -0700, Joe Perches wrote:
> > > Like the __section macro, the __alias macro uses
> > > macro # stringification to create quotes around
> > > the section name used in the __attribute__.
> > >
> > > Remove the stringification and add quotes or a
> > > stringification to the uses instead.
> >
> > There's a complete lack of rationale for this change.
>
> I'll eventually post V2.
> I'm waiting to see if there are more comments.
>
> As I wrote in reply to Ard:
>
> https://lore.kernel.org/lkml/1cecfbfc853b2e71a96ab58661037c28a2f9280e.camel@perches.com/
>
> Using quotes in __section caused/causes differences
> between clang and gcc.
>
> https://lkml.org/lkml/2020/9/29/2187
>
> Using common styles for details like this is good.
>

This patch is now causing problems in the ARM tree, because some new
uses of __alias() have been queued (for KASAN), and since this is a
non-backwards compatible change, we have to choose between breaking
the maintainer's tree or breaking -next (given that the change has
been pulled in there now)

I am still not convinced we need this change, as I don't see how the
concerns regarding __section apply to __alias. But if we do, can we
please use the same approach, i.e., revert the current patch, and
queue it again after v5.11-rc1 with all new occurrences covered as
well?