[Patch] media: v4l2-ctrls: Fix 64bit support in get_ctrl()

[Patch] media: v4l2-ctrls: Fix 64bit support in get_ctrl()

[Benoit Parrot]

When trying to use v4l2_ctrl_g_ctrl_int64() to retrieve a
V4L2_CTRL_TYPE_INTEGER64 type value the internal helper function
get_ctrl() would prematurely exits because for this control type
the 'is_int' flag is not set. This would result in v4l2_ctrl_g_ctrl_int64
always returning 0.

This patch extend the condition check to allow V4L2_CTRL_TYPE_INTEGER64
type to continue processing instead of exiting.

Signed-off-by: Benoit Parrot <bparrot@ti.com>
---
 drivers/media/v4l2-core/v4l2-ctrls.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index b6b7dcc1b77d..989919c44c2f 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -2884,7 +2884,7 @@ static int get_ctrl(struct v4l2_ctrl *ctrl, struct v4l2_ext_control *c)
 	 * cur_to_user() calls below would need to be modified not to access
 	 * userspace memory when called from get_ctrl().
 	 */
-	if (!ctrl->is_int)
+	if (!ctrl->is_int && ctrl->type != V4L2_CTRL_TYPE_INTEGER64)
 		return -EINVAL;
 
 	if (ctrl->flags & V4L2_CTRL_FLAG_WRITE_ONLY)
-- 
1.8.5.1

Re: [Patch] media: v4l2-ctrls: Fix 64bit support in get_ctrl()

[Sakari Ailus]

Hi Benoit,

On Wed, Sep 16, 2015 at 05:58:19PM -0500, Benoit Parrot wrote:
> When trying to use v4l2_ctrl_g_ctrl_int64() to retrieve a
> V4L2_CTRL_TYPE_INTEGER64 type value the internal helper function
> get_ctrl() would prematurely exits because for this control type
> the 'is_int' flag is not set. This would result in v4l2_ctrl_g_ctrl_int64
> always returning 0.
> 
> This patch extend the condition check to allow V4L2_CTRL_TYPE_INTEGER64
> type to continue processing instead of exiting.
> 
> Signed-off-by: Benoit Parrot <bparrot@ti.com>
> ---
>  drivers/media/v4l2-core/v4l2-ctrls.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
> index b6b7dcc1b77d..989919c44c2f 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> @@ -2884,7 +2884,7 @@ static int get_ctrl(struct v4l2_ctrl *ctrl, struct v4l2_ext_control *c)
>  	 * cur_to_user() calls below would need to be modified not to access
>  	 * userspace memory when called from get_ctrl().
>  	 */
> -	if (!ctrl->is_int)
> +	if (!ctrl->is_int && ctrl->type != V4L2_CTRL_TYPE_INTEGER64)
>  		return -EINVAL;
>  
>  	if (ctrl->flags & V4L2_CTRL_FLAG_WRITE_ONLY)

Well spotted.

However, this does not appear to be the only problem with
v4l2_ctrl_g_ctrl_int64(). It accesses the 32-bit value field instead of
value64. While at it, could you fix that one as well?

I wonder how this could have happened. :-o

-- 
Regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi	XMPP: sailus@retiisi.org.uk