From: Sinclair Yeh <syeh@vmware.com>
Date: Thu, 21 Apr 2016 18:29:31 +0000 (-0700)
Subject: drm/vmwgfx: Fix order of operation
X-Git-Tag: firefly_0821_release~176^2~4^2~42^2~24
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=55d851a914b51e79b33e52dabef18fe22ea80a46;p=firefly-linux-kernel-4.4.55.git

drm/vmwgfx: Fix order of operation

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>
---

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
index 3b1faf7862a5..679a4cb98ee3 100644
--- 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;
 	}