rmap: resurrect page_address_in_vma anon_vma check

With root anon-vma it's trivial to keep doing the usual check as in
old-anon-vma code.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/rmap.c b/mm/rmap.c
index f5d6799b8a744356873c4e20b67ee492b06c6dc3..2f855babfd060a52943b40a728a3c9e4c1278b3c 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -364,9 +364,10 @@ vma_address(struct page *page, struct vm_area_struct *vma)
  */
 unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
 {
-       if (PageAnon(page))
-               ;
-       else if (page->mapping && !(vma->vm_flags & VM_NONLINEAR)) {
+       if (PageAnon(page)) {
+               if (vma->anon_vma->root != page_anon_vma(page)->root)
+                       return -EFAULT;
+       } else if (page->mapping && !(vma->vm_flags & VM_NONLINEAR)) {
                if (!vma->vm_file ||
                    vma->vm_file->f_mapping != page->mapping)
                        return -EFAULT;