[merged mm-stable] mm-page_vma_mapped_walk-use-ptep_get_lockless-for-lockless-access.patch removed from -mm tree

[merged mm-stable] mm-page_vma_mapped_walk-use-ptep_get_lockless-for-lockless-access.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/page_vma_mapped_walk: use ptep_get_lockless() for lockless access
has been removed from the -mm tree.  Its filename was
     mm-page_vma_mapped_walk-use-ptep_get_lockless-for-lockless-access.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: Alexander Gordeev <agordeev@linux.ibm.com>
Subject: mm/page_vma_mapped_walk: use ptep_get_lockless() for lockless access
Date: Thu, 28 May 2026 09:55:07 +0200

When not holding the lock, there is a chance that the pte gets modified
under our feet, so we need to use the lockless API to make sure that the
entries remain consistent during the read."

Switch from ptep_get() to ptep_get_lockless() accessor for PTE reads when
no lock is taken.

[osalvador@suse.de: changelog addition]
  Link: https://lore.kernel.org/ahhNq0pFKvSKZQbR@localhost.localdomain
Link: https://lore.kernel.org/20260528075507.1821939-1-agordeev@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Oscar Salvador (SUSE) <osalvador@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Harry Yoo <harry@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_vma_mapped.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

--- a/mm/page_vma_mapped.c~mm-page_vma_mapped_walk-use-ptep_get_lockless-for-lockless-access
+++ a/mm/page_vma_mapped.c
@@ -41,7 +41,7 @@ again:
 	if (!pvmw->pte)
 		return false;
 
-	ptent = ptep_get(pvmw->pte);
+	ptent = ptep_get_lockless(pvmw->pte);
 
 	if (pte_none(ptent)) {
 		return false;
@@ -183,6 +183,7 @@ bool page_vma_mapped_walk(struct page_vm
 	struct mm_struct *mm = vma->vm_mm;
 	unsigned long end;
 	spinlock_t *ptl;
+	pte_t pteval;
 	pgd_t *pgd;
 	p4d_t *p4d;
 	pud_t *pud;
@@ -310,7 +311,11 @@ next_pte:
 				goto restart;
 			}
 			pvmw->pte++;
-		} while (pte_none(ptep_get(pvmw->pte)));
+			if (!pvmw->ptl)
+				pteval = ptep_get_lockless(pvmw->pte);
+			else
+				pteval = ptep_get(pvmw->pte);
+		} while (pte_none(pteval));
 
 		if (!pvmw->ptl) {
 			spin_lock(ptl);
_

Patches currently in -mm which might be from agordeev@linux.ibm.com are