[PATCH 15/21] arm64: KVM: Add panic handling
Marc Zyngier
marc.zyngier at arm.com
Mon Nov 16 06:44:17 PST 2015
On 16/11/15 14:32, Mark Rutland wrote:
>>>> + /* 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.
Worth giving it a try.
M.
--
Jazz is not dead. It just smells funny...
More information about the linux-arm-kernel
mailing list