[PATCH 1/5] powerpc/64s: Kernel Hypervisor Restricted Access Prevention

[Russell Currey]

On Wed, 2018-10-17 at 22:30 +1100, Michael Ellerman wrote:
> Russell Currey <ruscur at russell.cc> writes:
> > diff --git a/arch/powerpc/kernel/entry_64.S
> > b/arch/powerpc/kernel/entry_64.S
> > index 7b1693adff2a..090f72cbb02d 100644
> > --- a/arch/powerpc/kernel/entry_64.S
> > +++ b/arch/powerpc/kernel/entry_64.S
> > @@ -286,6 +286,9 @@ BEGIN_FTR_SECTION
> >  	HMT_MEDIUM_LOW
> >  END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
> >  
> > +	/* headed back to userspace, so unlock the AMR */
> > +	UNLOCK_AMR(r2)
> > +
> 
> This one needs an ifdef, or preferable an empty version in a header
> for
> non-book3s 64, otherwise we get:
> 
>   arch/powerpc/kernel/entry_64.S: Assembler messages:
>   arch/powerpc/kernel/entry_64.S:290: Error: unrecognized opcode:
> `unlock_amr(%r2)'
>   scripts/Makefile.build:405: recipe for target
> 'arch/powerpc/kernel/entry_64.o' failed
> 
> That's a corenet64-ish defconfig.

Yep, sorry.  I knew it wouldn't build on non-64s but I just wanted to
get the main part out there so people could start looking at it.  Will
fix.

- Russell

> 
> cheers