From mboxrd@z Thu Jan  1 00:00:00 1970
From: matt@codeblueprint.co.uk (Matt Fleming)
Date: Tue, 2 Feb 2016 11:08:21 +0000
Subject: [PATCH 1/3] arm64: efistub: drop __init annotation from
 handle_kernel_image()
In-Reply-To: <CAKv+Gu96tdf8ZrGHDi_YKacsRF_b336Nu4Anh61j4u3Lg18BHg@mail.gmail.com>
References: <1453979254-25374-1-git-send-email-ard.biesheuvel@linaro.org>
 <1453979254-25374-2-git-send-email-ard.biesheuvel@linaro.org>
 <20160128225809.GF2571@codeblueprint.co.uk>
 <CAKv+Gu9sE4oJrFmSK8sEjTrU8A7k53Hj1S1pTyCqyA5Gsba2Kw@mail.gmail.com>
 <20160129160006.GD2611@codeblueprint.co.uk>
 <CAKv+Gu96tdf8ZrGHDi_YKacsRF_b336Nu4Anh61j4u3Lg18BHg@mail.gmail.com>
Message-ID: <20160202110821.GB2642@codeblueprint.co.uk>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Fri, 29 Jan, at 05:03:16PM, Ard Biesheuvel wrote:
> On 29 January 2016 at 17:00, Matt Fleming <matt@codeblueprint.co.uk> wrote:
> > On Fri, 29 Jan, at 10:36:03AM, Ard Biesheuvel wrote:
> >> On 28 January 2016 at 23:58, Matt Fleming <matt@codeblueprint.co.uk> wrote:
> >> >
> >> > Would it make more sense to #undef __init in one of the arm64 efistub
> >> > header files? I'm thinking of the case where some poor unsuspecting
> >> > developer writes a new function and marks it as __init, and we miss it
> >> > during review.
> >> >
> >>
> >> Yes, I can add it to efistub.h, and make sure it gets included in all the files
> >>
> >> Should we #undef it and #define it to a string that is easily grep'ed
> >> for, so it is easy to find the explanatory comment that goes along
> >> with it?
> >> E.g.,
> >>
> >> #define __init __init_not_supported_in_efi_stub
> >
> > This would produce a compilation failure if someone tags something as
> > __init right? Looks fine to me.
> 
> Yes, but it makes the error message difficult to decipher, since
> __init is printed and not what it resolves to. Locally, I tried this,
> which seems to work:
> 
> #undef __init
> #define __init __attribute__((__init_not_supported_in_efi_stub))
> #pragma GCC diagnostic error "-Wattributes"
> 
> which produces
> 
>   CC      drivers/firmware/efi/libstub/arm-stub.o
> /home/ard/linux-2.6/drivers/firmware/efi/libstub/arm-stub.c:24:1:
> error: ?__init_not_supported_in_efi_stub? attribute directive ignored
> [-Werror=attributes]
>  {
>  ^
> cc1: some warnings being treated as errors
> 
> which is slightly dodgy, but at least puts the string right in the error message

What about,

#define __init __compiletime_error("__init not supported in EFI boot stub")

?