Hi,
On 14-Nov-24 8:10 PM, Ricardo Ribalda wrote:
> Right now, we only support mappings for v4l2 controls with a max size of
> s32. This patch modifies the prototype of get/set so it can support any
> size.
>
> This is done to prepare for compound controls.
>
> Suggested-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> ---
> drivers/media/usb/uvc/uvc_ctrl.c | 183 +++++++++++++++++++++++++++------------
> drivers/media/usb/uvc/uvcvideo.h | 8 +-
> 2 files changed, 130 insertions(+), 61 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index d6afa131a5e1..6d5167eb368d 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -367,6 +367,22 @@ static const u32 uvc_control_classes[] = {
>
> static const int exposure_auto_mapping[] = { 2, 1, 4, 8 };
>
> +static s32 uvc_mapping_get_s32(struct uvc_control_mapping *mapping,
> + u8 query, const void *data_in)
> +{
> + s32 data_out;
> +
> + mapping->get(mapping, query, data_in, sizeof(data_out), &data_out);
If mapping->get() fails, e.g. hits the -EINVAL path in uvc_ctrl_get_zoom()
then this will return the uninitialized data_out.
I realize that this is supposed to never happen and adding error-handling
here would not be helpful since there is no way to return an error-code
without changing the function prototype.
But I think you should at least initialize data_out to 0 to avoid leaking
stack-memory contents to userspace if we somehow do manage to hit this.
> +
> + return data_out;
> +}
> +
> +static void uvc_mapping_set_s32(struct uvc_control_mapping *mapping,
> + s32 data_in, void *data_out)
> +{
> + mapping->set(mapping, sizeof(data_in), &data_in, data_out);
> +}
> +
> /*
> * This function translates the V4L2 menu index @idx, as exposed to userspace as
> * the V4L2 control value, to the corresponding UVC control value used by the
> @@ -405,58 +421,93 @@ uvc_mapping_get_menu_name(const struct uvc_control_mapping *mapping, u32 idx)
> return v4l2_ctrl_get_menu(mapping->id)[idx];
> }
>
> -static s32 uvc_ctrl_get_zoom(struct uvc_control_mapping *mapping,
> - u8 query, const u8 *data)
> +static int uvc_ctrl_get_zoom(struct uvc_control_mapping *mapping, u8 query,
> + const void *uvc_in, size_t v4l2_size,
> + void *v4l2_out)
> {
> - s8 zoom = (s8)data[0];
> + u8 value = ((u8 *)uvc_in)[2];
> + s8 sign = ((s8 *)uvc_in)[0];
> + s32 *out = v4l2_out;
> +
> + if (WARN_ON(v4l2_size != sizeof(s32)))
> + return -EINVAL;
>
> switch (query) {
> case UVC_GET_CUR:
> - return (zoom == 0) ? 0 : (zoom > 0 ? data[2] : -data[2]);
> + *out = (sign == 0) ? 0 : (sign > 0 ? value : -value);
> + return 0;
>
> case UVC_GET_MIN:
> case UVC_GET_MAX:
> case UVC_GET_RES:
> case UVC_GET_DEF:
> default:
> - return data[2];
> + *out = value;
> + return 0;
> }
> }
>
> -static void uvc_ctrl_set_zoom(struct uvc_control_mapping *mapping,
> - s32 value, u8 *data)
> +static int uvc_ctrl_set_zoom(struct uvc_control_mapping *mapping,
> + size_t v4l2_size, const void *v4l2_in,
> + void *uvc_out)
> {
> - data[0] = value == 0 ? 0 : (value > 0) ? 1 : 0xff;
> - data[2] = min((int)abs(value), 0xff);
> + u8 *out = uvc_out;
> + s32 value;
> +
> + if (WARN_ON(v4l2_size != sizeof(s32)))
> + return -EINVAL;
> +
> + value = *(u32 *)v4l2_in;
> + out[0] = value == 0 ? 0 : (value > 0) ? 1 : 0xff;
> + out[2] = min_t(int, abs(value), 0xff);
> +
> + return 0;
> }
>
> -static s32 uvc_ctrl_get_rel_speed(struct uvc_control_mapping *mapping,
> - u8 query, const u8 *data)
> +static int uvc_ctrl_get_rel_speed(struct uvc_control_mapping *mapping,
> + u8 query, const void *uvc_in,
> + size_t v4l2_size, void *v4l2_out)
> {
> unsigned int first = mapping->offset / 8;
> - s8 rel = (s8)data[first];
> + u8 value = ((u8 *)uvc_in)[first + 1];
> + s8 sign = ((s8 *)uvc_in)[first];
> + s32 *out = v4l2_out;
> +
> + if (WARN_ON(v4l2_size != sizeof(s32)))
> + return -EINVAL;
>
> switch (query) {
> case UVC_GET_CUR:
> - return (rel == 0) ? 0 : (rel > 0 ? data[first+1]
> - : -data[first+1]);
> + *out = (sign == 0) ? 0 : (sign > 0 ? value : -value);
> + return 0;
> case UVC_GET_MIN:
> - return -data[first+1];
> + *out = -value;
> + return 0;
> case UVC_GET_MAX:
> case UVC_GET_RES:
> case UVC_GET_DEF:
> default:
> - return data[first+1];
> + *out = value;
> + return 0;
> }
> }
>
> -static void uvc_ctrl_set_rel_speed(struct uvc_control_mapping *mapping,
> - s32 value, u8 *data)
> +static int uvc_ctrl_set_rel_speed(struct uvc_control_mapping *mapping,
> + size_t v4l2_size, const void *v4l2_in,
> + void *uvc_out)
> {
> unsigned int first = mapping->offset / 8;
> + u8 *out = uvc_out;
> + s32 value;
> +
> + if (WARN_ON(v4l2_size != sizeof(s32)))
> + return -EINVAL;
>
> - data[first] = value == 0 ? 0 : (value > 0) ? 1 : 0xff;
> - data[first+1] = min_t(int, abs(value), 0xff);
> + value = *(u32 *)v4l2_in;
> + out[first] = value == 0 ? 0 : (value > 0) ? 1 : 0xff;
> + out[first + 1] = min_t(int, abs(value), 0xff);
> +
> + return 0;
> }
>
> static const struct uvc_control_mapping uvc_ctrl_power_line_mapping_limited = {
> @@ -887,14 +938,20 @@ static s32 uvc_menu_to_v4l2_menu(struct uvc_control_mapping *mapping, s32 val)
> * a signed 32bit integer. Sign extension will be performed if the mapping
> * references a signed data type.
> */
> -static s32 uvc_get_le_value(struct uvc_control_mapping *mapping,
> - u8 query, const u8 *data)
> +static int uvc_get_le_value(struct uvc_control_mapping *mapping,
> + u8 query, const void *uvc_in, size_t v4l2_size,
> + void *v4l2_out)
> {
> - int bits = mapping->size;
> int offset = mapping->offset;
> + int bits = mapping->size;
> + const u8 *data = uvc_in;
> + s32 *out = v4l2_out;
> s32 value = 0;
> u8 mask;
>
> + if (WARN_ON(v4l2_size != sizeof(s32)))
> + return -EINVAL;
> +
> data += offset / 8;
> offset &= 7;
> mask = ((1LL << bits) - 1) << offset;
> @@ -916,29 +973,40 @@ static s32 uvc_get_le_value(struct uvc_control_mapping *mapping,
> value |= -(value & (1 << (mapping->size - 1)));
>
> /* If it is a menu, convert from uvc to v4l2. */
> - if (mapping->v4l2_type != V4L2_CTRL_TYPE_MENU)
> - return value;
> + if (mapping->v4l2_type != V4L2_CTRL_TYPE_MENU) {
> + *out = value;
> + return 0;
> + }
>
> switch (query) {
> case UVC_GET_CUR:
> case UVC_GET_DEF:
> - return uvc_menu_to_v4l2_menu(mapping, value);
> + *out = uvc_menu_to_v4l2_menu(mapping, value);
> + return 0;
> }
>
> - return value;
> + *out = value;
> + return 0;
> }
>
> /*
> * Set the bit string specified by mapping->offset and mapping->size
> * in the little-endian data stored at 'data' to the value 'value'.
> */
> -static void uvc_set_le_value(struct uvc_control_mapping *mapping,
> - s32 value, u8 *data)
> +static int uvc_set_le_value(struct uvc_control_mapping *mapping,
> + size_t v4l2_size, const void *v4l2_in,
> + void *uvc_out)
> {
> - int bits = mapping->size;
> int offset = mapping->offset;
> + int bits = mapping->size;
> + u8 *data = uvc_out;
> + s32 value;
> u8 mask;
>
> + if (WARN_ON(v4l2_size != sizeof(s32)))
> + return -EINVAL;
> +
> + value = *(s32 *)v4l2_in;
> if (mapping->v4l2_type == V4L2_CTRL_TYPE_MENU)
> value = uvc_mapping_get_menu_value(mapping, value);
> /*
> @@ -960,6 +1028,8 @@ static void uvc_set_le_value(struct uvc_control_mapping *mapping,
> bits -= 8 - offset;
> offset = 0;
> }
> +
> + return 0;
> }
>
> /* ------------------------------------------------------------------------
> @@ -1141,8 +1211,8 @@ static int __uvc_ctrl_get(struct uvc_video_chain *chain,
> if (ret < 0)
> return ret;
>
> - *value = mapping->get(mapping, UVC_GET_CUR,
> - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
> + *value = uvc_mapping_get_s32(mapping, UVC_GET_CUR,
> + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
>
> return 0;
> }
> @@ -1275,12 +1345,12 @@ static u32 uvc_get_ctrl_bitmap(struct uvc_control *ctrl,
> * as supported.
> */
> if (ctrl->info.flags & UVC_CTRL_FLAG_GET_RES)
> - return mapping->get(mapping, UVC_GET_RES,
> - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
> + return uvc_mapping_get_s32(mapping, UVC_GET_RES,
> + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
>
> if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MAX)
> - return mapping->get(mapping, UVC_GET_MAX,
> - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX));
> + return uvc_mapping_get_s32(mapping, UVC_GET_MAX,
> + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX));
>
> return ~0;
> }
> @@ -1324,10 +1394,9 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
> return ret;
> }
>
> - if (ctrl->info.flags & UVC_CTRL_FLAG_GET_DEF) {
> - v4l2_ctrl->default_value = mapping->get(mapping, UVC_GET_DEF,
> - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_DEF));
> - }
> + if (ctrl->info.flags & UVC_CTRL_FLAG_GET_DEF)
> + v4l2_ctrl->default_value = uvc_mapping_get_s32(mapping,
> + UVC_GET_DEF, uvc_ctrl_data(ctrl, UVC_CTRL_DATA_DEF));
>
> switch (mapping->v4l2_type) {
> case V4L2_CTRL_TYPE_MENU:
The dropping of the { } here seems to be an unrelated code style change, please
drop this.
> @@ -1359,16 +1428,16 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
> }
>
> if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MIN)
> - v4l2_ctrl->minimum = mapping->get(mapping, UVC_GET_MIN,
> - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN));
> + v4l2_ctrl->minimum = uvc_mapping_get_s32(mapping, UVC_GET_MIN,
> + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN));
>
> if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MAX)
> - v4l2_ctrl->maximum = mapping->get(mapping, UVC_GET_MAX,
> - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX));
> + v4l2_ctrl->maximum = uvc_mapping_get_s32(mapping, UVC_GET_MAX,
> + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX));
>
> if (ctrl->info.flags & UVC_CTRL_FLAG_GET_RES)
> - v4l2_ctrl->step = mapping->get(mapping, UVC_GET_RES,
> - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
> + v4l2_ctrl->step = uvc_mapping_get_s32(mapping, UVC_GET_RES,
> + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
>
> return 0;
> }
> @@ -1581,7 +1650,7 @@ void uvc_ctrl_status_event(struct uvc_video_chain *chain,
> ctrl->handle = NULL;
>
> list_for_each_entry(mapping, &ctrl->info.mappings, list) {
> - s32 value = mapping->get(mapping, UVC_GET_CUR, data);
> + s32 value = uvc_mapping_get_s32(mapping, UVC_GET_CUR, data);
>
> /*
> * handle may be NULL here if the device sends auto-update
> @@ -1925,8 +1994,8 @@ int uvc_ctrl_get(struct uvc_video_chain *chain, u32 which,
> if (ret < 0)
> return ret;
> }
> - xctrl->value = mapping->get(mapping, UVC_GET_DEF,
> - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_DEF));
> + xctrl->value = uvc_mapping_get_s32(mapping, UVC_GET_DEF,
> + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_DEF));
> return 0;
> }
>
> @@ -1963,12 +2032,12 @@ int uvc_ctrl_set(struct uvc_fh *handle,
> return ret;
> }
>
> - min = mapping->get(mapping, UVC_GET_MIN,
> - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN));
> - max = mapping->get(mapping, UVC_GET_MAX,
> - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX));
> - step = mapping->get(mapping, UVC_GET_RES,
> - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
> + min = uvc_mapping_get_s32(mapping, UVC_GET_MIN,
> + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN));
> + max = uvc_mapping_get_s32(mapping, UVC_GET_MAX,
> + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX));
> + step = uvc_mapping_get_s32(mapping, UVC_GET_RES,
> + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
> if (step == 0)
> step = 1;
>
> @@ -2047,8 +2116,8 @@ int uvc_ctrl_set(struct uvc_fh *handle,
> ctrl->info.size);
> }
>
> - mapping->set(mapping, value,
> - uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
> + uvc_mapping_set_s32(mapping, value,
> + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
>
> if (ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
> ctrl->handle = handle;
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index 6ebaabd11443..3d32a56c5ff8 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -131,10 +131,10 @@ struct uvc_control_mapping {
> const struct uvc_control_mapping *(*filter_mapping)
> (struct uvc_video_chain *chain,
> struct uvc_control *ctrl);
> - s32 (*get)(struct uvc_control_mapping *mapping, u8 query,
> - const u8 *data);
> - void (*set)(struct uvc_control_mapping *mapping, s32 value,
> - u8 *data);
> + int (*get)(struct uvc_control_mapping *mapping, u8 query,
> + const void *uvc_in, size_t v4l2_size, void *v4l2_out);
> + int (*set)(struct uvc_control_mapping *mapping, size_t v4l2_size,
> + const void *v4l2_in, void *uvc_out);
> };
>
> struct uvc_control {
>
Exceot for my 2 small remarks this patch looks good to me:
Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Regards,
Hans
