[PATCH,v3] [aarch64] Fix removal of non-address bits for PAuth

[Lancelot SIX]

> 
> If either one of the register reads fail, then we assign the default MASK. Otherwise we
> continue with using the mask that's been read from the register.
> 
> Does that make sense?
> 

Yes of curse, I have no idea how I read this wrong.  My bad.  Sorry for
the noise.

> 
> Although this is only used on Linux systems at the moment, it is not technically Linux-specific.
> 
> When we say kernel-space, it means the other half of the VA space (non-user).
> 
> I have an upcoming patch (relying on this one) to use this function for bare metal pointer authentication
> support (with user QEMU). So I think it makes sense to have this function in arch-specific code
> and not in Linux-specific code.
> 

Thanks, for the clarification.

As far as I can tell, this looks reasonable, I’ll leave it to a
maintainer to approve.

Best,
Lanelot.