[PATCH 15/21] arm64: KVM: Add panic handling

[Mark Rutland]

> >> +	/* Call panic for real */
> >> +	while (1) {
> >> +		unsigned long str_va = (unsigned long)__hyp_panic_string;
> >> +
> >> +		str_va -= HYP_PAGE_OFFSET;
> >> +		str_va += PAGE_OFFSET;
> >> +		__hyp_do_panic(str_va,
> >> +			       spsr,  elr,
> >> +			       read_sysreg(esr_el2),   read_sysreg(far_el2),
> >> +			       read_sysreg(hpfar_el2), par,
> >> +			       read_sysreg(tpidr_el2));
> >> +	}
> >> +}
> > 
> > I think the while (1) here is confusing.
> > 
> > Can we not jsut declare str_va at the start of the function and get rid
> > of the loop?
> 
> The while(1) is to prevent GCC from screaming (it otherwise believes
> that the function actually returns, despite the __noreturn attribute).

Aha!

Perhaps a comment to that effect...?

> Or were you thinking of something else?

I just failed to derive the __noreturn problem from first principles.

Perhaps follow the __hyp_do_panic() call with an unreachable(), with the
comment as to GCC failing to reason about the __noreturn? That would be
less confusing than the loop, assuming that it works.

Mark.