Re: [PATCH v5 01/17] arm64: add pointer authentication register bits

[Will Deacon]

On Fri, Oct 12, 2018 at 09:53:54AM +0100, Mark Rutland wrote:
> On Thu, Oct 11, 2018 at 05:28:14PM +0100, Will Deacon wrote:
> > On Fri, Oct 05, 2018 at 09:47:38AM +0100, Kristina Martsenko wrote:
> 
> > > +#define ESR_ELx_EC_PAC		(0x09)
> > 
> > Really minor nit: but shouldn't this be ESR_EL2_EC_PAC, since this trap
> > can't occur at EL1 afaict?
> 
> It can also be taken to EL3 dependent on SCR_EL3.API.
> 
> We use ESR_ELx_EC_<foo> for other exceptions that can't be taken to EL1
> (e.g. ESR_ELx_EC_SMC{32,64}), so I think it would be more consistent to
> leave this as ESR_ELx_EC_PAC rather than ESR_EL2_EC_PAC.

Fair enough, but if we grow a different EC for ESR_EL1 that uses encoding
0x09, this all falls apart. At the very list, maybe we should comment those
that are EL2 or higher with /* EL2 and above */ or just fix the misnomer and
drop the useless _ELx_ part of the names completely.

Will