fork: use vma_pages() to simplify the code

The current code can be replaced by vma_pages().  So use it to simplify
the code.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/kernel/fork.c b/kernel/fork.c
index e5736aa98cb117b7262e869399ab75250bf0bac5..0707a2ed104ad2500df3ce5a8a727b1cfc00208e 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -390,7 +390,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
                charge = 0;
                if (mpnt->vm_flags & VM_ACCOUNT) {
                        unsigned long len;
-                       len = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
+                       len = vma_pages(mpnt);
                        if (security_vm_enough_memory_mm(oldmm, len)) /* sic */
                                goto fail_nomem;
                        charge = len;