Re: [tip:x86/mm] x86, mm: Use a bitfield to mask nuisance get_user() warnings

From: H.J. Lu
Date: Tue Feb 12 2013 - 11:38:41 EST


On Mon, Feb 11, 2013 at 8:21 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
> On 02/11/2013 07:33 PM, Linus Torvalds wrote:
>> On Mon, Feb 11, 2013 at 5:37 PM, tip-bot for H. Peter Anvin
>> <hpa@xxxxxxxxx> wrote:
>>>
>>> However, we can declare a bitfield using sizeof(), which is legal
>>> because sizeof() is a constant expression. This quiets the warning,
>>> although the code generated isn't 100% identical from the baseline
>>> before 96477b4 x86-32: Add support for 64bit get_user():
>>
>> Christ. This is so ugly that it's almost a work of art.
>
> :)
>
>> Has anybody run this past any gcc developers? And if so, did they run
>> away screaming?
>
> I haven't no... H.J., any comments on this patch?
>

Can you do something similar to what we did in glibc:

http://sourceware.org/git/?p=glibc.git;a=patch;h=c515fb5148f1d81d5f7736825e14c7502c15432a

--
H.J.
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