mm/memory-failure: hold PTL in hwpoison_hugetlb_range

Hold PTL in hwpoison_hugetlb_range() to avoid operating on stale page, as
hwpoison_pte_range() have done.

This change is not known to address any issues which users have
experienced.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jinjiang Tu <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Andrei Vagin <[email protected]>
Cc: Andrii Nakryiko <[email protected]>
Cc: Baolin Wang <[email protected]>
Cc: Brahmajit Das <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Dev Jain <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Joern Engel <[email protected]>
Cc: Kefeng Wang <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Thiago Jung Bauermann <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

1 files changed, 9 insertions, 3 deletions

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 9e2cff199934..f0f0b23dcf2d 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -837,11 +837,17 @@ static int hwpoison_hugetlb_range(pte_t *ptep, unsigned long hmask,
 			    struct mm_walk *walk)
 {
 	struct hwpoison_walk *hwp = walk->private;
-	pte_t pte = huge_ptep_get(walk->mm, addr, ptep);
 	struct hstate *h = hstate_vma(walk->vma);
+	spinlock_t *ptl;
+	pte_t pte;
+	int ret;
 
-	return check_hwpoisoned_entry(pte, addr, huge_page_shift(h),
-				      hwp->pfn, &hwp->tk);
+	ptl = huge_pte_lock(h, walk->mm, ptep);
+	pte = huge_ptep_get(walk->mm, addr, ptep);
+	ret = check_hwpoisoned_entry(pte, addr, huge_page_shift(h),
+					hwp->pfn, &hwp->tk);
+	spin_unlock(ptl);
+	return ret;
 }
 #else
 #define hwpoison_hugetlb_range	NULL