Re: klp: remove superfluous errors in asm/livepatch.h

[Jessica Yu]

+++ Jiri Kosina [06/03/16 22:13 +0100]:
> On Fri, 4 Mar 2016, Josh Poimboeuf wrote:
>
> > > There is an #error in asm/livepatch.h for both x86 and s390 in
> > > !CONFIG_LIVEPATCH cases. It does not make much sense as pointed out by
> > > Michael Ellerman. One can happily include asm/livepatch.h with
> > > CONFIG_LIVEPATCH. Remove it as useless.
> > >
> > > Suggested-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> > > Signed-off-by: Miroslav Benes <mbenes@xxxxxxx>
> >
> > Looks fine to me.
>
> Thanks. I consider this to be your Ack then :) (if you disagree, please
> shout loudly).
>
> > While we're at it, do we even need the '#ifdef CONFIG_LIVEPATCH' in
> > these files?  And in include/linux/livepatch.h?
>
> You are right, this seems indeed completely unnecessary. I'll remove it
> for 4.6 as well, if noone has any objections.

Hm, I should've caught this earlier, but the notifier cleanup patch
that removes the livepatch module notifier had kernel/module.c include
livepatch.h for the klp_module_{coming,going} function stubs in the
!CONFIG_LIVEPATCH case. See here: https://lkml.org/lkml/2016/2/8/1182

Looking back, I now don't think it makes sense for module.c to include
all those livepatch definitions in the first place, since all it
needed was the klp_module_{coming,going} declarations. I guess my
question is, since we've removed the #ifdef CONFIG_LIVEPATCH blocks
from livepatch.h, where might be a better place for the
klp_module_{coming,going} stubs? Perhaps they could go in module.h
instead?

Jessica