Subject: [PATCH] viafb: use display information in info not in var for panning

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 <[email protected]>
Reported-by: Laurent Pinchart <[email protected]>
Cc: [email protected]
---
drivers/video/via/viafbdev.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/video/via/viafbdev.c b/drivers/video/via/viafbdev.c
index 3114a87..aa87529 100644
--- 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) {
--
1.6.3.2


2011-05-25 09:41:49

by Laurent Pinchart

[permalink] [raw]
Subject: Re: [PATCH] viafb: use display information in info not in var for panning

Hi Florian,

On Tuesday 24 May 2011 00:07:26 Florian Tobias Schandinat wrote:
> 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 <[email protected]>
> Reported-by: Laurent Pinchart <[email protected]>
> Cc: [email protected]

Acked-by: Laurent Pinchart <[email protected]>

> ---
> drivers/video/via/viafbdev.c | 5 +++--
> 1 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/video/via/viafbdev.c b/drivers/video/via/viafbdev.c
> index 3114a87..aa87529 100644
> --- 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) {

--
Regards,

Laurent Pinchart