[PATCH 3/3] drm/vmwgfx: Fix order of operation

Sinclair Yeh syeh at vmware.com
Wed Apr 27 16:43:35 UTC 2016


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 at vmware.com>
Reviewed-by: Thomas Hellstrom <thellstrom at vmware.com>
---
 drivers/gpu/drm/vmwgfx/vmwgfx_fb.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fb.c
index 3b1faf7..679a4cb 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;
 	}
-- 
1.9.1



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