Subject: [PATCH 1/2] arm64: Refactor vDSO time functions

From: [email-masked] (Will Deacon)
Date: Mon, 11 Jul 2016 18:42:25 +0100

On Mon, Jul 11, 2016 at 06:31:16PM +0100, Kevin Brodsky wrote:
> On 08/07/16 15:11, Will Deacon wrote:
> >Fixup patch below. If you fold it in, then:
> >
> >Acked-by: Will Deacon <[email-masked]>
> >
> >for the series.
> 
> I just have one small concern with your fixup patch: the ALIGN macro from
> linkage.h (not the one from kernel.h, which is for C, not assembly) uses
> 0x90 as padding, which apparently is NOP on x86 but does not make much sense
> on ARM64 (or ARM for that matter). It is not currently used in arm{,64}. I
> am not sure if it could decode to a valid instruction on ARM64, but maybe
> using simply 0x0 as a padding byte would be less arbitrary. I also don't
> like this ALIGN macro too much, because the "4" argument means something
> different depending on the architecture (4 bytes on x86, 2^4 on arm*:
> https://sourceware.org/binutils/docs/as/Align.html).

ALIGN expands to __ALIGN which is defined in
arch/arm64/include/asm/linkage.h as .align 4.

You're 4 years late ;)

http://git.kernel.org/linus/aeed41a9371e

Will