drm/vmwgfx: Fix order of operation

BugLink: http://bugs.launchpad.net/bugs/1590455
commit 7851496a32319237456919575e5f4ba62f74cc7d upstream.

mode->hdisplay * (var->bits_per_pixel + 7) gets evaluated before
the division, potentially making the pitch larger than it should
be.

Since the original intention is to do a div-round-up, just use
the macro instead.

Signed-off-by: Sinclair Yeh <syeh@vmware.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
index 3b1faf7862a55f2d400ce7f80444a7388bdb2310..679a4cb98ee306bb47c5c0097f1aa829c17a7fc8 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
@@ -573,9 +573,9 @@ static int vmw_fb_set_par(struct fb_info *info)
                mode = old_mode;
                old_mode = NULL;
        } else if (!vmw_kms_validate_mode_vram(vmw_priv,
-                                              mode->hdisplay *
-                                              (var->bits_per_pixel + 7) / 8,
-                                              mode->vdisplay)) {
+                                       mode->hdisplay *
+                                       DIV_ROUND_UP(var->bits_per_pixel, 8),
+                                       mode->vdisplay)) {
                drm_mode_destroy(vmw_priv->dev, mode);
                return -EINVAL;
        }