mm/pagewalk.c: fix walk_page_range() access of wrong PTEs

[sfrench/cifs-2.6.git] / mm / mlock.c

diff --git a/mm/mlock.c b/mm/mlock.c
index 67ba6da7d0e311b1b45007bbd0e37bd78db0f3a8..d480cd6fc475854259bdd51021d5125dbdfbe479 100644 (file)
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -379,10 +379,14 @@ static unsigned long __munlock_pagevec_fill(struct pagevec *pvec,
 
        /*
         * Initialize pte walk starting at the already pinned page where we
-        * are sure that there is a pte.
+        * are sure that there is a pte, as it was pinned under the same
+        * mmap_sem write op.
         */
        pte = get_locked_pte(vma->vm_mm, start, &ptl);
-       end = min(end, pmd_addr_end(start, end));
+       /* Make sure we do not cross the page table boundary */
+       end = pgd_addr_end(start, end);
+       end = pud_addr_end(start, end);
+       end = pmd_addr_end(start, end);
 
        /* The page next to the pinned page is the first we will try to get */
        start += PAGE_SIZE;