Re: [PATCH v1 09/10] gdb/linux-tdep: parse ProtectionKey in /proc/PID/smaps

Yury Khrustalev <[email protected]> writes:

> On Sat, Jul 25, 2026 at 06:40:33AM +0000, Thiago Jung Bauermann wrote:
>> Yury Khrustalev <[email protected]> writes:
>> 
>> ...
>>
>> >> > The look-up of those overlay permissions is platform-specific).
>> >> 
>> >> Considering that there are differences in how protection keys are
>> >> implemented in different architectures (e.g., IIUC only Arm has overlay
>> >> permissions), the whole "effective: r-- overlay: r--" part of the line
>> >> should be printed by a gdbarch hook.
>> >> 
>> >> > If no protection key support exists on the target, the PKey column would not be
>> >> > printed.
>> >> > Same for the threads' permissions (effective and overlay).
>> >> 
>> >> Also even if protection key support is available, if there's no
>> >> protection key set for any mapping then the column shouldn't be printed
>> >> either. Or is there always a key associated with every mapping?
>> >
>> > I think the column should be just empty or have some placeholder like a
>> > hyphen when mapping is not associated with a pkey.
>> 
>> I don't see much use for an empty column (or one containing only
>> placeholder values), but I also don't feel strongly about it.
>
> The point of the empty column (that is only shown when pkeys are
> supported) is that it would show that none of your mappings use any
> pkeys. I think this is useful piece of information. E.g. if I expect to
> see a key but due to a bug it's not used, I don't want to not see this
> column at all because I would think that my version of GDB does not
> support it or something.

Ah, indeed it makes sense. Thanks for clarifying.

-- 
Thiago
(he/him)