1 files changed, 39 insertions, 13 deletions

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 290fb5bf0440..44dd9d1521ec 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -563,24 +563,50 @@ static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new)
 }
 
 /* Step 2: apply policy to a range and do splits. */
-static int mbind_range(struct vm_area_struct *vma, unsigned long start,
-		       unsigned long end, struct mempolicy *new)
+static int mbind_range(struct mm_struct *mm, unsigned long start,
+		       unsigned long end, struct mempolicy *new_pol)
 {
 	struct vm_area_struct *next;
-	int err;
+	struct vm_area_struct *prev;
+	struct vm_area_struct *vma;
+	int err = 0;
+	pgoff_t pgoff;
+	unsigned long vmstart;
+	unsigned long vmend;
 
-	err = 0;
-	for (; vma && vma->vm_start < end; vma = next) {
+	vma = find_vma_prev(mm, start, &prev);
+	if (!vma || vma->vm_start > start)
+		return -EFAULT;
+
+	for (; vma && vma->vm_start < end; prev = vma, vma = next) {
 		next = vma->vm_next;
-		if (vma->vm_start < start)
-			err = split_vma(vma->vm_mm, vma, start, 1);
-		if (!err && vma->vm_end > end)
-			err = split_vma(vma->vm_mm, vma, end, 0);
-		if (!err)
-			err = policy_vma(vma, new);
+		vmstart = max(start, vma->vm_start);
+		vmend   = min(end, vma->vm_end);
+
+		pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
+		prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
+				  vma->anon_vma, vma->vm_file, pgoff, new_pol);
+		if (prev) {
+			vma = prev;
+			next = vma->vm_next;
+			continue;
+		}
+		if (vma->vm_start != vmstart) {
+			err = split_vma(vma->vm_mm, vma, vmstart, 1);
+			if (err)
+				goto out;
+		}
+		if (vma->vm_end != vmend) {
+			err = split_vma(vma->vm_mm, vma, vmend, 0);
+			if (err)
+				goto out;
+		}
+		err = policy_vma(vma, new_pol);
 		if (err)
-			break;
+			goto out;
 	}
+
+ out:
 	return err;
 }
 
@@ -1047,7 +1073,7 @@ static long do_mbind(unsigned long start, unsigned long len,
 	if (!IS_ERR(vma)) {
 		int nr_failed = 0;
 
-		err = mbind_range(vma, start, end, new);
+		err = mbind_range(mm, start, end, new);
 
 		if (!list_empty(&pagelist))
 			nr_failed = migrate_pages(&pagelist, new_vma_page,