[PATCH] fbdev: Pan display fixes

- Fix fb_pan_display rejecting yoffsets that are valid if panning mode
  is ywrap.

- Add more robust error checking in fb_pan_display specially since this
  function is accessible by userland apps.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Antonino A. Daplas 2005-12-12 22:17:17 -08:00 committed by Linus Torvalds
parent 4743484718
commit 1207069f6f

View file

@ -722,14 +722,30 @@ static void try_to_load(int fb)
int
fb_pan_display(struct fb_info *info, struct fb_var_screeninfo *var)
{
struct fb_fix_screeninfo *fix = &info->fix;
int xoffset = var->xoffset;
int yoffset = var->yoffset;
int err;
int err = 0, yres = info->var.yres;
if (var->yoffset > 0) {
if (var->vmode & FB_VMODE_YWRAP) {
if (!fix->ywrapstep || (var->yoffset % fix->ywrapstep))
err = -EINVAL;
else
yres = 0;
} else if (!fix->ypanstep || (var->yoffset % fix->ypanstep))
err = -EINVAL;
}
if (var->xoffset > 0 && (!fix->xpanstep ||
(var->xoffset % fix->xpanstep)))
err = -EINVAL;
if (err || !info->fbops->fb_pan_display || xoffset < 0 ||
yoffset < 0 || var->yoffset + yres > info->var.yres_virtual ||
var->xoffset + info->var.xres > info->var.xres_virtual)
return -EINVAL;
if (xoffset < 0 || yoffset < 0 || !info->fbops->fb_pan_display ||
xoffset + info->var.xres > info->var.xres_virtual ||
yoffset + info->var.yres > info->var.yres_virtual)
return -EINVAL;
if ((err = info->fbops->fb_pan_display(var, info)))
return err;
info->var.xoffset = var->xoffset;