[PATCH 1/3] arm64: efistub: drop __init annotation from handle_kernel_image()

[Ard Biesheuvel]

On 29 January 2016 at 17:00, Matt Fleming <matt at 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 at 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