viafb: use display information in info not in var for panning

commit d933990c57b498c092ceef591c7c5d69dbfe9f30 upstream.

As Laurent pointed out we must not use any information in the passed
var besides xoffset, yoffset and vmode as otherwise applications
might abuse it. Also use the aligned fix.line_length and not the
(possible) unaligned xres_virtual.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/video/via/viafbdev.c b/drivers/video/via/viafbdev.c
index 53aa4430d86ea74cb525a1adc37484ee60c07b07..e19dc43d2bcbb558fe45db7811e2731fc969a602 100644 (file)
--- a/drivers/video/via/viafbdev.c
+++ b/drivers/video/via/viafbdev.c
@@ -348,8 +348,9 @@ static int viafb_pan_display(struct fb_var_screeninfo *var,
        struct fb_info *info)
 {
        struct viafb_par *viapar = info->par;
-       u32 vram_addr = (var->yoffset * var->xres_virtual + var->xoffset)
-               * (var->bits_per_pixel / 8) + viapar->vram_addr;
+       u32 vram_addr = viapar->vram_addr
+               + var->yoffset * info->fix.line_length
+               + var->xoffset * info->var.bits_per_pixel / 8;
 
        DEBUG_MSG(KERN_DEBUG "viafb_pan_display, address = %d\n", vram_addr);
        if (!viafb_dual_fb) {