1 files changed, 20 insertions, 35 deletions

diff --git a/mm/mapping_dirty_helpers.c b/mm/mapping_dirty_helpers.c
index 175e424b9ab1..737c407f4081 100644
--- a/mm/mapping_dirty_helpers.c
+++ b/mm/mapping_dirty_helpers.c
@@ -35,7 +35,7 @@ static int wp_pte(pte_t *pte, unsigned long addr, unsigned long end,
 		  struct mm_walk *walk)
 {
 	struct wp_walk *wpwalk = walk->private;
-	pte_t ptent = *pte;
+	pte_t ptent = ptep_get(pte);
 
 	if (pte_write(ptent)) {
 		pte_t old_pte = ptep_modify_prot_start(walk->vma, addr, pte);
@@ -91,7 +91,7 @@ static int clean_record_pte(pte_t *pte, unsigned long addr,
 {
 	struct wp_walk *wpwalk = walk->private;
 	struct clean_walk *cwalk = to_clean_walk(wpwalk);
-	pte_t ptent = *pte;
+	pte_t ptent = ptep_get(pte);
 
 	if (pte_dirty(ptent)) {
 		pgoff_t pgoff = ((addr - walk->vma->vm_start) >> PAGE_SHIFT) +
@@ -128,19 +128,11 @@ static int wp_clean_pmd_entry(pmd_t *pmd, unsigned long addr, unsigned long end,
 {
 	pmd_t pmdval = pmdp_get_lockless(pmd);
 
-	if (!pmd_trans_unstable(&pmdval))
-		return 0;
-
-	if (pmd_none(pmdval)) {
-		walk->action = ACTION_AGAIN;
-		return 0;
-	}
-
-	/* Huge pmd, present or migrated */
-	walk->action = ACTION_CONTINUE;
-	if (pmd_trans_huge(pmdval) || pmd_devmap(pmdval))
+	/* Do not split a huge pmd, present or migrated */
+	if (pmd_trans_huge(pmdval)) {
 		WARN_ON(pmd_write(pmdval) || pmd_dirty(pmdval));
-
+		walk->action = ACTION_CONTINUE;
+	}
 	return 0;
 }
 
@@ -156,23 +148,15 @@ static int wp_clean_pmd_entry(pmd_t *pmd, unsigned long addr, unsigned long end,
 static int wp_clean_pud_entry(pud_t *pud, unsigned long addr, unsigned long end,
 			      struct mm_walk *walk)
 {
-	pud_t pudval = READ_ONCE(*pud);
-
-	if (!pud_trans_unstable(&pudval))
-		return 0;
-
-	if (pud_none(pudval)) {
-		walk->action = ACTION_AGAIN;
-		return 0;
-	}
-
 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
-	/* Huge pud */
-	walk->action = ACTION_CONTINUE;
-	if (pud_trans_huge(pudval) || pud_devmap(pudval))
+	pud_t pudval = pudp_get(pud);
+
+	/* Do not split a huge pud */
+	if (pud_trans_huge(pudval)) {
 		WARN_ON(pud_write(pudval) || pud_dirty(pudval));
+		walk->action = ACTION_CONTINUE;
+	}
 #endif
-
 	return 0;
 }
 
@@ -191,7 +175,7 @@ static int wp_clean_pre_vma(unsigned long start, unsigned long end,
 	wpwalk->tlbflush_end = start;
 
 	mmu_notifier_range_init(&wpwalk->range, MMU_NOTIFY_PROTECTION_PAGE, 0,
-				walk->vma, walk->mm, start, end);
+				walk->mm, start, end);
 	mmu_notifier_invalidate_range_start(&wpwalk->range);
 	flush_cache_range(walk->vma, start, end);
 
@@ -234,7 +218,7 @@ static void wp_clean_post_vma(struct mm_walk *walk)
 static int wp_clean_test_walk(unsigned long start, unsigned long end,
 			      struct mm_walk *walk)
 {
-	unsigned long vm_flags = READ_ONCE(walk->vma->vm_flags);
+	vm_flags_t vm_flags = READ_ONCE(walk->vma->vm_flags);
 
 	/* Skip non-applicable VMAs */
 	if ((vm_flags & (VM_SHARED | VM_MAYWRITE | VM_HUGETLB)) !=
@@ -304,13 +288,14 @@ EXPORT_SYMBOL_GPL(wp_shared_mapping_range);
  * @end: Pointer to the number of the last set bit in @bitmap.
  * none set. The value is modified as new bits are set by the function.
  *
- * Note: When this function returns there is no guarantee that a CPU has
+ * When this function returns there is no guarantee that a CPU has
  * not already dirtied new ptes. However it will not clean any ptes not
  * reported in the bitmap. The guarantees are as follows:
- * a) All ptes dirty when the function starts executing will end up recorded
- *    in the bitmap.
- * b) All ptes dirtied after that will either remain dirty, be recorded in the
- *    bitmap or both.
+ *
+ * * All ptes dirty when the function starts executing will end up recorded
+ *   in the bitmap.
+ * * All ptes dirtied after that will either remain dirty, be recorded in the
+ *   bitmap or both.
  *
  * If a caller needs to make sure all dirty ptes are picked up and none
  * additional are added, it first needs to write-protect the address-space