Re: [PATCH 1/1] mm/huge_memory: disallow raw PMD mappings of the huge zero page

[David Hildenbrand (Arm)]

On 9/17/26 16:32, Kiryl Shutsemau wrote:
> On Thu, Sep 17, 2026 at 08:10:10PM +0800, Lance Yang wrote:
>> vm_mixed_zeropage_allowed() validates zeropage insertion into
>> VM_MIXEDMAP VMAs. No in-tree user needs to insert the huge zero page
>> through vmf_insert_pfn_pmd().
>>
>> Return VM_FAULT_SIGBUS if vmf_insert_pfn_pmd() is asked to map it.
>>
>> Link: https://lore.kernel.org/linux-mm/f76beaf8-351a-4b22-b362-a945a5e1af6a@xxxxxxxxxx/
>> Suggested-by: Kiryl Shutsemau <kas@xxxxxxxxxx>
>> Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
>> Signed-off-by: Lance Yang <lance.yang@xxxxxxxxx>
> 
> The patch looks fine, but don't we want to cover the same for non-huge
> zero page in vmf_insert_pfn_prot()?

Why would the zeropage be a problem in PFNMAP mapping?

-- 
Cheers,

David