Re: [PATCH] docs: proc: document ProtectionKey in smaps

Kevin Brodsky
2026-04-08T07:15:16Z

On 08/04/2026 09:05, David Hildenbrand (Arm) wrote:
>>>> To me "system" is a bit ambiguous here but _can_ refer to the whole
>>>> hardware/software system as a whole. To avoid redundancy, I'd say either:
>>>>
>>>> If both the kernel and the processor support protection keys...
>>>>
>>>> or
>>>>
>>>> If the system supports protection keys...
>>> I see your point. By "system" I essentially mean the hardware (the SoC).
>>> In general I would tend to avoid "processor" because not all CPUs in a
>>> system necessarily have the same features, and some features require
>>> hardware support beyond the CPU itself. Terminology is hard...
>>>
>>> Happy to replace "system" with "hardware" if that's clearer 🙂
>> I think that "system" is too nebulous there, so I would prefer to see
>> "hardware" instead.
> What if you're running in a VM where the feature is hidden ... ?

Of course that's also possible, "hardware" has to be interpreted in the
context of virtualisation... But granted it is possible to hide features
even on the host with the right kernel parameter, on arm64 at least.

"If the kernel supports protection keys (pkeys) and the hardware feature
is detected"? Still vague but a little more accurate.

- Kevin