char: Use vma_pages() to replace (vm_end - vm_start) >> PAGE_SHIFT

(*->vm_end - *->vm_start) >> PAGE_SHIFT operation is implemented
as a inline funcion vma_pages() in linux/mm.h, so using it.

Signed-off-by: Libin <huawei.libin@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/char/mspec.c b/drivers/char/mspec.c
index e1f60f968fddc8e55b932f4d2ac185835871dfb3..f1d7fa45c2759b0ed97d9a54669d705f2547040c 100644 (file)
--- a/drivers/char/mspec.c
+++ b/drivers/char/mspec.c
@@ -267,7 +267,7 @@ mspec_mmap(struct file *file, struct vm_area_struct *vma,
        if ((vma->vm_flags & VM_WRITE) == 0)
                return -EPERM;
 
-       pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+       pages = vma_pages(vma);
        vdata_size = sizeof(struct vma_data) + pages * sizeof(long);
        if (vdata_size <= PAGE_SIZE)
                vdata = kzalloc(vdata_size, GFP_KERNEL);