1 files changed, 8 insertions, 13 deletions

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 638edabaff71..367b7f6c0637 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -123,8 +123,6 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
         unsigned long oldflags = vma->vm_flags;
         long nrpages = (end - start) >> PAGE_SHIFT;
         unsigned long charged = 0;
-        unsigned int mask;
-        pgprot_t newprot;
         pgoff_t pgoff;
         int error;
 
@@ -176,24 +174,21 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
         }
 
 success:
-        /* Don't make the VMA automatically writable if it's shared, but the
-         * backer wishes to know when pages are first written to */
-        mask = VM_READ|VM_WRITE|VM_EXEC|VM_SHARED;
-        if (vma->vm_ops && vma->vm_ops->page_mkwrite)
-                mask &= ~VM_SHARED;
-
-        newprot = protection_map[newflags & mask];
-
         /*
          * vm_flags and vm_page_prot are protected by the mmap_sem
          * held in write mode.
          */
         vma->vm_flags = newflags;
-        vma->vm_page_prot = newprot;
+        vma->vm_page_prot = protection_map[newflags &
+                (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)];
+        if (vma_wants_writenotify(vma))
+                vma->vm_page_prot = protection_map[newflags &
+                        (VM_READ|VM_WRITE|VM_EXEC)];
+
         if (is_vm_hugetlb_page(vma))
-                hugetlb_change_protection(vma, start, end, newprot);
+                hugetlb_change_protection(vma, start, end, vma->vm_page_prot);
         else
-                change_protection(vma, start, end, newprot);
+                change_protection(vma, start, end, vma->vm_page_prot);
         vm_stat_account(mm, oldflags, vma->vm_file, -nrpages);
         vm_stat_account(mm, newflags, vma->vm_file, nrpages);
         return 0;