[merged mm-stable] mm-huge_memory-preserve-pmd_swp_uffd_wp-on-device-private-pmd-downgrade.patch removed from -mm tree

[merged mm-stable] mm-huge_memory-preserve-pmd_swp_uffd_wp-on-device-private-pmd-downgrade.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/huge_memory: preserve pmd_swp_uffd_wp on device-private PMD downgrade
has been removed from the -mm tree.  Its filename was
     mm-huge_memory-preserve-pmd_swp_uffd_wp-on-device-private-pmd-downgrade.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: "Kiryl Shutsemau (Meta)" <kas@kernel.org>
Subject: mm/huge_memory: preserve pmd_swp_uffd_wp on device-private PMD downgrade
Date: Fri, 29 May 2026 18:23:28 +0100

change_non_present_huge_pmd() rewrites a writable device-private PMD swap
entry into a readable one without carrying pmd_swp_uffd_wp() across.  The
PTE-level change_softleaf_pte() does this correctly; mirror that here,
matching what copy_huge_pmd() does for the fork path.  Without the carry,
a plain mprotect() over a UFFD_WP-marked device-private THP strips the bit
and the trap is bypassed on swap-in.

Link: https://lore.kernel.org/20260529172331.356655-5-kas@kernel.org
Fixes: 368076f52ebe ("mm/huge_memory: add device-private THP support to PMD operations")
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Reported-by: Sashiko AI review <sashiko-bot@kernel.org>
Reviewed-by: Balbir Singh <balbirs@nvidia.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/huge_memory.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/mm/huge_memory.c~mm-huge_memory-preserve-pmd_swp_uffd_wp-on-device-private-pmd-downgrade
+++ a/mm/huge_memory.c
@@ -2565,6 +2565,8 @@ static void change_non_present_huge_pmd(
 	} else if (softleaf_is_device_private_write(entry)) {
 		entry = make_readable_device_private_entry(swp_offset(entry));
 		newpmd = swp_entry_to_pmd(entry);
+		if (pmd_swp_uffd_wp(*pmd))
+			newpmd = pmd_swp_mkuffd_wp(newpmd);
 	} else {
 		newpmd = *pmd;
 	}
_

Patches currently in -mm which might be from kas@kernel.org are