1 files changed, 10 insertions, 1 deletions

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index adc395481813..c3fdbcb17658 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -636,6 +636,7 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,
         struct vm_area_struct *prev;
         struct vm_area_struct *vma;
         int err = 0;
+        pgoff_t pgoff;
         unsigned long vmstart;
         unsigned long vmend;
 
@@ -643,13 +644,21 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,
         if (!vma || vma->vm_start > start)
                 return -EFAULT;
 
+        if (start > vma->vm_start)
+                prev = vma;
+
         for (; vma && vma->vm_start < end; prev = vma, vma = next) {
                 next = vma->vm_next;
                 vmstart = max(start, vma->vm_start);
                 vmend   = min(end, vma->vm_end);
 
+                if (mpol_equal(vma_policy(vma), new_pol))
+                        continue;
+
+                pgoff = vma->vm_pgoff +
+                        ((vmstart - vma->vm_start) >> PAGE_SHIFT);
                 prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
-                                  vma->anon_vma, vma->vm_file, vma->vm_pgoff,
+                                  vma->anon_vma, vma->vm_file, pgoff,
                                   new_pol);
                 if (prev) {
                         vma = prev;