Hi Michal,
> On 15 Jul 2025, at 09:45, Orzel, Michal <michal.or...@amd.com> wrote:
>
>
>
> On 15/07/2025 10:36, Hari Limaye wrote:
>> Hi Michal,
>>
>>>> +int mpumap_contains_region(pr_t *table, uint8_t nr_regions, paddr_t base,
>>>> + paddr_t limit, uint8_t *index)
>>>> +{
>>>> + ASSERT(index);
>>>> + *index = INVALID_REGION_IDX;
>>>> +
>>>> + /*
>>>> + * The caller supplies a half-open interval [base, limit), i.e. limit
>>>> is the
>>>> + * first byte *after* the region. Require limit strictly greater than
>>>> base,
>>>> + * which is necessarily a non-empty region.
>>>> + */
>>>> + ASSERT(base < limit);
>>> Well, that does not guarantee a non-empty region.
>>> Consider passing [x, x+1). The assert will pass, even though the region is
>>> empty.
>>>
>>> ~Michal
>>>
>>
>> Apologies, I may well be missing something here! Please could you suggest a
>> code snippet to understand your expectation here / what you would prefer the
>> assert to be?
>>
>> As I understand it, with a half-open interval [base, limit) as is passed to
>> this function, the size is `limit - base` and so the region [x, x+1) will
>> have size 1. The empty region starting at the same address would be [x, x).
>> But perhaps I am making the off-by-one error here.
> Hmm, I think I made a mistake here. Region of size 1B would have base == limit
> in registers. All good then.
>
> ~Michal
>
Thanks for double checking. I notice you did not add your tag here, I wanted to
check if you think this patch is reviewed from your perspective?
Many thanks,
Hari
