1 files changed, 22 insertions, 11 deletions

diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 9b3db11a4d1d..2ff3a5bebceb 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -110,7 +110,7 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
 	do {
 again:
 		next = pmd_addr_end(addr, end);
-		if (pmd_none(*pmd) || (!walk->vma && !walk->no_vma)) {
+		if (pmd_none(*pmd)) {
 			if (ops->pte_hole)
 				err = ops->pte_hole(addr, next, depth, walk);
 			if (err)
@@ -171,7 +171,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
 	do {
  again:
 		next = pud_addr_end(addr, end);
-		if (pud_none(*pud) || (!walk->vma && !walk->no_vma)) {
+		if (pud_none(*pud)) {
 			if (ops->pte_hole)
 				err = ops->pte_hole(addr, next, depth, walk);
 			if (err)
@@ -366,19 +366,19 @@ static int __walk_page_range(unsigned long start, unsigned long end,
 	struct vm_area_struct *vma = walk->vma;
 	const struct mm_walk_ops *ops = walk->ops;
 
-	if (vma && ops->pre_vma) {
+	if (ops->pre_vma) {
 		err = ops->pre_vma(start, end, walk);
 		if (err)
 			return err;
 	}
 
-	if (vma && is_vm_hugetlb_page(vma)) {
+	if (is_vm_hugetlb_page(vma)) {
 		if (ops->hugetlb_entry)
 			err = walk_hugetlb_range(start, end, walk);
 	} else
 		err = walk_pgd_range(start, end, walk);
 
-	if (vma && ops->post_vma)
+	if (ops->post_vma)
 		ops->post_vma(walk);
 
 	return err;
@@ -450,13 +450,17 @@ int walk_page_range(struct mm_struct *mm, unsigned long start,
 		if (!vma) { /* after the last vma */
 			walk.vma = NULL;
 			next = end;
+			if (ops->pte_hole)
+				err = ops->pte_hole(start, next, -1, &walk);
 		} else if (start < vma->vm_start) { /* outside vma */
 			walk.vma = NULL;
 			next = min(end, vma->vm_start);
+			if (ops->pte_hole)
+				err = ops->pte_hole(start, next, -1, &walk);
 		} else { /* inside vma */
 			walk.vma = vma;
 			next = min(end, vma->vm_end);
-			vma = vma->vm_next;
+			vma = find_vma(mm, vma->vm_end);
 
 			err = walk_page_test(start, next, &walk);
 			if (err > 0) {
@@ -470,16 +474,23 @@ int walk_page_range(struct mm_struct *mm, unsigned long start,
 			}
 			if (err < 0)
 				break;
-		}
-		if (walk.vma || walk.ops->pte_hole)
 			err = __walk_page_range(start, next, &walk);
+		}
 		if (err)
 			break;
 	} while (start = next, start < end);
 	return err;
 }
 
-/*
+/**
+ * walk_page_range_novma - walk a range of pagetables not backed by a vma
+ * @mm:		mm_struct representing the target process of page table walk
+ * @start:	start address of the virtual address range
+ * @end:	end address of the virtual address range
+ * @ops:	operation to call during the walk
+ * @pgd:	pgd to walk if different from mm->pgd
+ * @private:	private data for callbacks' usage
+ *
  * Similar to walk_page_range() but can walk any page tables even if they are
  * not backed by VMAs. Because 'unusual' entries may be walked this function
  * will also not lock the PTEs for the pte_entry() callback. This is useful for
@@ -501,9 +512,9 @@ int walk_page_range_novma(struct mm_struct *mm, unsigned long start,
 	if (start >= end || !walk.mm)
 		return -EINVAL;
 
-	mmap_assert_locked(walk.mm);
+	mmap_assert_write_locked(walk.mm);
 
-	return __walk_page_range(start, end, &walk);
+	return walk_pgd_range(start, end, &walk);
 }
 
 int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops,