[merged mm-stable] mm-migrate-use-huge_ptep_get-in-remove_migration_pte.patch removed from -mm tree

The quilt patch titled
     Subject: mm/migrate: use huge_ptep_get() in remove_migration_pte()
has been removed from the -mm tree.  Its filename was
     mm-migrate-use-huge_ptep_get-in-remove_migration_pte.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: Dev Jain <[email protected]>
Subject: mm/migrate: use huge_ptep_get() in remove_migration_pte()
Date: Fri, 3 Jul 2026 11:41:57 +0000

remove_migration_pte() converts migration entries back to present PTEs
after folio migration completes.  For hugetlb folios,
page_vma_mapped_walk() returns the pte pointer to the hugetlb folio in
pvmw.pte, but the code reads it with ptep_get().

On arches which provide their own huge_ptep_get() to dereference a huge
pte pointer, accessing via ptep_get() would cause pte_pfn(),
pte_present() etc to misbehave.

It is not clear whether this has a trivially visible effect to userspace.

Use huge_ptep_get() to dereference a huge pte pointer.

Link: https://lore.kernel.org/[email protected]
Fixes: 290408d4a250 ("hugetlb: hugepage migration core")
Signed-off-by: Dev Jain <[email protected]>
Acked-by: Muchun Song <[email protected]>
Acked-by: David Hildenbrand (Arm) <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Byungchul Park <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Gregory Price <[email protected]>
Cc: Harry Yoo <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Joshua Hahn <[email protected]>
Cc: Jun'ichi "Nick" Nomura <[email protected]>
Cc: Kiryl Shutsemau <[email protected]>
Cc: Lance Yang <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Matthew Brost <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Pedro Falcato <[email protected]>
Cc: Rakie Kim <[email protected]>
Cc: Ralph Campbell <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Zi Yan <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

 mm/migrate.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/mm/migrate.c~mm-migrate-use-huge_ptep_get-in-remove_migration_pte
+++ a/mm/migrate.c
@@ -372,7 +372,11 @@ static bool remove_migration_pte(struct
 			continue;
 		}
 #endif
-		old_pte = ptep_get(pvmw.pte);
+		if (folio_test_hugetlb(folio))
+			old_pte = huge_ptep_get(vma->vm_mm, pvmw.address,
+						pvmw.pte);
+		else
+			old_pte = ptep_get(pvmw.pte);
 		if (rmap_walk_arg->map_unused_to_zeropage &&
 		    try_to_map_unused_to_zeropage(&pvmw, folio, old_pte, idx))
 			continue;
_

Patches currently in -mm which might be from [email protected] are

mm-rmap-convert-page-folio-for-hwpoison-checks.patch
mm-rmap-add-try_to_unmap_poisoned_hugetlb_one.patch
mm-rmap-refactor-some-code-around-lazyfree-folio-unmapping.patch
mm-rmap-refactor-anon-folio-unmap-in-try_to_unmap_one.patch
mm-rmap-add-anon-folio-unmap-dispatcher.patch
mm-memory-move-pte_install_uffd_wp_if_needed-into-memoryc.patch
mm-memory-batch-set-uffd-wp-markers-during-zapping.patch
mm-rmap-batch-unmap-file-folios-belonging-to-uffd-wp-vmas.patch