Re: [PATCH RFC 33/35] kfence: drop nth_page() usage

David Hildenbrand
2025-08-21T23:17:09Z

On 21.08.25 22:32, David Hildenbrand wrote:
> On 21.08.25 22:06, David Hildenbrand wrote:
>> We want to get rid of nth_page(), and kfence init code is the last user.
>>
>> Unfortunately, we might actually walk a PFN range where the pages are
>> not contiguous, because we might be allocating an area from memblock
>> that could span memory sections in problematic kernel configs (SPARSEMEM
>> without SPARSEMEM_VMEMMAP).
>>
>> We could check whether the page range is contiguous
>> using page_range_contiguous() and failing kfence init, or making kfence
>> incompatible these problemtic kernel configs.
>>
>> Let's keep it simple and simply use pfn_to_page() by iterating PFNs.
>>
>
> Fortunately this series is RFC due to lack of detailed testing :P
>
> Something gives me a NULL-pointer pointer here (maybe the virt_to_phys()).
>
> Will look into that tomorrow.

Okay, easy: relying on i but not updating it /me facepalm

--
Cheers

David / dhildenb