Re: [PATCH v2 03/14] mm: rename uffd-wp PTE accessors to uffd

[SeongJae Park <sj@kernel.org>]

On Fri,  8 May 2026 16:55:15 +0100 "Kiryl Shutsemau (Meta)" <kas@kernel.org> wrote:

> Userfaultfd RWP will reuse the uffd-wp PTE bit to mark access-tracking
> PTEs, alongside the write-protected ones it already marks. The bit's
> meaning now depends on the VMA flag (WP or RWP), not on its name.
> 
> Rename the kernel-internal names that describe the bit:
> 
>   - pte/pmd/huge_pte accessors (and swap variants)
>   - pgtable_supports_uffd() capability query
>   - SCAN_PTE_UFFD khugepaged enum
> 
> The ftrace string emitted by mm_khugepaged_scan_pmd for this enum is
> kept as "pte_uffd_wp" so existing trace-based tooling keeps matching.
> 
> Pure mechanical rename -- no behavior change.
> 
> Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
> Assisted-by: Claude:claude-opus-4-6
> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

Reviewed-by: SeongJae Park <sj@kernel.org>

[...]
> @@ -4934,10 +4934,10 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
>  		softleaf = softleaf_from_pte(entry);
>  		if (unlikely(softleaf_is_hwpoison(softleaf))) {
>  			if (!userfaultfd_wp(dst_vma))
> -				entry = huge_pte_clear_uffd_wp(entry);
> +				entry = huge_pte_clear_uffd(entry);
>  			set_huge_pte_at(dst, addr, dst_pte, entry, sz);
>  		} else if (unlikely(softleaf_is_migration(softleaf))) {
> -			bool uffd_wp = pte_swp_uffd_wp(entry);
> +			bool uffd_wp = pte_swp_uffd(entry);

Just curious.  Is the variable name intentionally kept to avoid unnecessary
change?


Thanks,
SJ

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