Messages in this thread | | | Date | Thu, 24 Apr 2008 23:05:55 +0200 (CEST) | From | Geert Uytterhoeven <> | Subject | Re: [Linux-fbdev-devel] [PATCH] atafb: test virtual screen range before subtraction on unsigned |
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On Wed, 23 Apr 2008, Roel Kluin wrote: > a bit similar to vga16fb, > --- > dx and dy are u32's, so the test should occur before the subtraction
Note that fb_copyarea.d[xy] are also u32, while there are many tests that check for these fields being negative.
> Signed-off-by: Roel Kluin <12o3l@tiscali.nl> > --- > diff --git a/drivers/video/atafb.c b/drivers/video/atafb.c > index 5d4fbaa..8f60a8f 100644 > --- a/drivers/video/atafb.c > +++ b/drivers/video/atafb.c > @@ -2593,13 +2593,16 @@ static void atafb_copyarea(struct fb_info *info, const struct fb_copyarea *area) > width = x2 - dx; > height = y2 - dy; > > + if (area->sx + dx < area->dx || area->sy + dy < area->dy) > + return; > + > /* update sx,sy */ > sx = area->sx + (dx - area->dx); > sy = area->sy + (dy - area->dy); > > /* the source must be completely inside the virtual screen */ > - if (sx < 0 || sy < 0 || (sx + width) > info->var.xres_virtual || > - (sy + height) > info->var.yres_virtual) > + if (sx + width > info->var.xres_virtual || > + sy + height > info->var.yres_virtual) > return; > > if (dy > sy || (dy == sy && dx > sx)) { >
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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