FAILED: patch "[PATCH] mm/migrate: use huge_ptep_get() in remove_migration_pte()" failed to apply to 5.10-stable tree

The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x ac1ec50d71b953524100ddc09057ee61a3dfaff3
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026090334-negligee-subzero-e539@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From ac1ec50d71b953524100ddc09057ee61a3dfaff3 Mon Sep 17 00:00:00 2001
From: Dev Jain <[email protected]>
Date: Fri, 3 Jul 2026 11:41:57 +0000
Subject: [PATCH] mm/migrate: use huge_ptep_get() in remove_migration_pte()

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.

index 1977905ce12c..b6f56b67e367 100644
@@ -372,7 +372,11 @@ static bool remove_migration_pte(struct folio *folio,
 			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;