Re: [PATCH v3 4/5] x86/asm: Add asm macros for static keys/jump labels

[Thomas Gleixner]

On Thu, 12 Nov 2015, Andy Lutomirski wrote:

> Unfortunately, we can only do this if HAVE_JUMP_LABEL.  In principle, we
> could do some serious surgery on the core jump label infrastructure
> to keep the patch infrastructure available on x86 on all builds, but
> that's probably not worth it.
> 
> Implementing the macros using a conditional branch as a fallback
> seems like a bad idea: we'd have to clobber flags.
> 
> This limitation can't cause silent failures -- trying to include
> asm/jump_label.h at all on a non-HAVE_JUMP_LABEL kernel will error
> out.  The macro's users are responsible for handling this issue
> themselves.
> 
> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>

Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
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