[PATCH 1/2] fbconsole: check cursor position before moving

[Bastian Stender]

On 02/24/2017 12:18 PM, Ian Abbott wrote:
> On 24/02/17 07:32, Sascha Hauer wrote:
>> On Thu, Feb 23, 2017 at 06:20:21PM +0100, Bastian Stender wrote:
>>> Moving the cursor to x=2, y=2 with "\e[3;3H" on a 12x2 framebuffer
>>> console lead to a barebox crash while drawing the cursor. The cursor can
>>> only be moved to a valid position between (0,0) and (priv->cols,
>>> priv->rows) now.
>>>
>>> Signed-off-by: Bastian Stender <bst at pengutronix.de>
>>> ---
>>>  drivers/video/fbconsole.c | 7 +++++--
>>>  1 file changed, 5 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/video/fbconsole.c b/drivers/video/fbconsole.c
>>> index 64f7d7364e..3879741b2a 100644
>>> --- a/drivers/video/fbconsole.c
>>> +++ b/drivers/video/fbconsole.c
>>> @@ -264,10 +264,13 @@ static void fbc_parse_csi(struct fbc_priv *priv)
>>>          return;
>>>      case 'H':
>>>          video_invertchar(priv, priv->x, priv->y);
>>> +
>>>          pos = simple_strtoul(priv->csi, &end, 10);
>>> -        priv->y = pos ? pos - 1 : 0;
>>> +        priv->y = (pos && pos <= priv->rows + 1) ? pos - 1 : 0;
>>> +
>>>          pos = simple_strtoul(end + 1, NULL, 10);
>>> -        priv->x = pos ? pos - 1 : 0;
>>> +        priv->x = (pos && pos <= priv->cols + 1) ? pos - 1 : 0;
>>> +
>>
>> When moving out of the screen shouldn't we place the cursor on the
>> bottom right corner of the screen? With this patch we move it to the top
>> left corner.
>
> Or clip to each edge, something like:
>
>  priv->y = !pos ? 0 : pos < priv->rows ? pos - 1 : priv->rows - 1;
>
> Same for priv->x and priv->cols?

Sounds good to me, I'll send a new version of this patch.

Regards,
Bastian

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