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

Thomas Gleixner
2015-11-13T14:23:45Z

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@kernel.org>

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>