Re: [PATCH] vt: fix broken display when running aptitude

[Nicolas Pitre]

On Tue, 23 Oct 2018, Mikulas Patocka wrote:

> If you run aptitude on framebuffer console, the display is corrupted. The 
> corruption is caused by the commit d8ae7242. The patch adds "offset" to 
> "start" when calling scr_memsetw, but it forgets to do the same addition 
> on a subsequent call to do_update_region.
> 
> Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
> Fixes: d8ae72427187 ("vt: preserve unicode values corresponding to screen characters")
> Cc: stable@xxxxxxxxxxxxxxx	# 4.19

Good catch.

Reviewed-by: Nicolas Pitre <nico@xxxxxxxxxx>

> ---
>  drivers/tty/vt/vt.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Index: linux-2.6/drivers/tty/vt/vt.c
> ===================================================================
> --- linux-2.6.orig/drivers/tty/vt/vt.c	2018-10-23 16:15:08.000000000 +0200
> +++ linux-2.6/drivers/tty/vt/vt.c	2018-10-23 16:29:20.000000000 +0200
> @@ -1551,7 +1551,7 @@ static void csi_K(struct vc_data *vc, in
>  	scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
>  	vc->vc_need_wrap = 0;
>  	if (con_should_update(vc))
> -		do_update_region(vc, (unsigned long) start, count);
> +		do_update_region(vc, (unsigned long)(start + offset), count);
>  }
>  
>  static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */
>