Re: [PATCH v8 4/9] media: uvcvideo: Use standard names for menus

From: Ricardo Ribalda
Date: Sat Jun 18 2022 - 03:50:59 EST


Hi Laurent

On Sat, 18 Jun 2022 at 01:56, Ricardo Ribalda <ribalda@xxxxxxxxxxxx> wrote:
>
> Instead of duplicating the menu info, use the one from the core.
> Also, do not use extra memory for 1:1 mappings.
>
> Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> Suggested-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/usb/uvc/uvc_ctrl.c | 116 +++++++++++++++++++++----------
> drivers/media/usb/uvc/uvc_v4l2.c | 80 ++++++++++++++++-----
> drivers/media/usb/uvc/uvcvideo.h | 3 +-
> include/uapi/linux/uvcvideo.h | 3 +-
> 4 files changed, 144 insertions(+), 58 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index a03714c3a265..1a3021a16b76 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -362,19 +362,31 @@ static const u32 uvc_control_classes[] = {
> V4L2_CID_USER_CLASS,
> };
>
> -static const struct uvc_menu_info power_line_frequency_controls[] = {
> - { 0, "Disabled" },
> - { 1, "50 Hz" },
> - { 2, "60 Hz" },
> - { 3, "Auto" },
> -};
> +static const int exposure_auto_mapping[] = { 2, 1, 4, 8 };
>
> -static const struct uvc_menu_info exposure_auto_controls[] = {
> - { 2, "Auto Mode" },
> - { 1, "Manual Mode" },
> - { 4, "Shutter Priority Mode" },
> - { 8, "Aperture Priority Mode" },
> -};
> +static u32 uvc_mapping_get_menu_value(struct uvc_control_mapping *mapping,
> + u32 idx)
> +{
> + if (!test_bit(idx, &mapping->menu_mask))
> + return 0;
> +
> + if (mapping->menu_mapping)
> + return mapping->menu_mapping[idx];
> +
> + return idx;
> +}
> +
> +static const char
> +*uvc_mapping_get_menu_name(struct uvc_control_mapping *mapping, u32 idx)
> +{
> + if (!test_bit(idx, &mapping->menu_mask))
> + return NULL;
> +
> + if (mapping->menu_names)
> + return mapping->menu_names[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)
> @@ -523,9 +535,9 @@ static const struct uvc_control_mapping uvc_ctrl_mappings[] = {
> .offset = 0,
> .v4l2_type = V4L2_CTRL_TYPE_MENU,
> .data_type = UVC_CTRL_DATA_TYPE_BITMASK,
> - .menu_info = exposure_auto_controls,
> + .menu_mapping = exposure_auto_mapping,
> .menu_mask =
> - BIT_MASK(ARRAY_SIZE(exposure_auto_controls)),
> + GENMASK(ARRAY_SIZE(exposure_auto_mapping) - 1, 0),
> .slave_ids = { V4L2_CID_EXPOSURE_ABSOLUTE, },
> },
> {
> @@ -730,9 +742,8 @@ static const struct uvc_control_mapping uvc_ctrl_mappings_uvc11[] = {
> .offset = 0,
> .v4l2_type = V4L2_CTRL_TYPE_MENU,
> .data_type = UVC_CTRL_DATA_TYPE_ENUM,
> - .menu_info = power_line_frequency_controls,
> .menu_mask =
> - BIT_MASK(ARRAY_SIZE(power_line_frequency_controls) - 1),
> + GENMASK(V4L2_CID_POWER_LINE_FREQUENCY_60HZ, 0),
> },
> };
>
> @@ -745,9 +756,8 @@ static const struct uvc_control_mapping uvc_ctrl_mappings_uvc15[] = {
> .offset = 0,
> .v4l2_type = V4L2_CTRL_TYPE_MENU,
> .data_type = UVC_CTRL_DATA_TYPE_ENUM,
> - .menu_info = power_line_frequency_controls,
> .menu_mask =
> - BIT_MASK(ARRAY_SIZE(power_line_frequency_controls)),
> + GENMASK(V4L2_CID_POWER_LINE_FREQUENCY_AUTO, 0),
> },
> };
>
> @@ -970,13 +980,17 @@ static s32 __uvc_ctrl_get_value(struct uvc_control_mapping *mapping,
> s32 value = mapping->get(mapping, UVC_GET_CUR, data);
>
> if (mapping->v4l2_type == V4L2_CTRL_TYPE_MENU) {
> - const struct uvc_menu_info *menu = mapping->menu_info;
> unsigned int i;
>
> - for (i = 1; BIT(i) <= mapping->menu_mask; ++i, ++menu) {
> + for (i = 1; BIT(i) <= mapping->menu_mask; ++i) {
> + u32 menu_value;
> +
> if (!test_bit(i, &mapping->menu_mask))
> continue;
> - if (menu->value == value) {
> +
> + menu_value = uvc_mapping_get_menu_value(mapping, i);
> +
> + if (menu_value == value) {
> value = i;
> break;
> }
> @@ -1108,7 +1122,6 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
> {
> struct uvc_control_mapping *master_map = NULL;
> struct uvc_control *master_ctrl = NULL;
> - const struct uvc_menu_info *menu;
> unsigned int i;
>
> memset(v4l2_ctrl, 0, sizeof(*v4l2_ctrl));
> @@ -1153,11 +1166,15 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
> v4l2_ctrl->maximum = fls(mapping->menu_mask) - 1;
> v4l2_ctrl->step = 1;
>
> - menu = mapping->menu_info;
> - for (i = 1; BIT(i) <= mapping->menu_mask; ++i, ++menu) {
> + for (i = 1; BIT(i) <= mapping->menu_mask; ++i) {
> + u32 menu_value;
> +
> if (!test_bit(i, &mapping->menu_mask))
> continue;
> - if (menu->value == v4l2_ctrl->default_value) {
> +
> + menu_value = uvc_mapping_get_menu_value(mapping, i);
> +
> + if (menu_value == v4l2_ctrl->default_value) {
> v4l2_ctrl->default_value = i;
> break;
> }
> @@ -1250,11 +1267,11 @@ int uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
> int uvc_query_v4l2_menu(struct uvc_video_chain *chain,
> struct v4l2_querymenu *query_menu)
> {
> - const struct uvc_menu_info *menu_info;
> struct uvc_control_mapping *mapping;
> struct uvc_control *ctrl;
> u32 index = query_menu->index;
> u32 id = query_menu->id;
> + const char *name;
> int ret;
>
> memset(query_menu, 0, sizeof(*query_menu));
> @@ -1276,11 +1293,10 @@ int uvc_query_v4l2_menu(struct uvc_video_chain *chain,
> goto done;
> }
>
> - menu_info = &mapping->menu_info[query_menu->index];
> -
> if (mapping->data_type == UVC_CTRL_DATA_TYPE_BITMASK &&
> (ctrl->info.flags & UVC_CTRL_FLAG_GET_RES)) {
> s32 bitmap;
> + u32 menu_value;
>
> if (!ctrl->cached) {
> ret = uvc_ctrl_populate_cache(chain, ctrl);
> @@ -1288,15 +1304,22 @@ int uvc_query_v4l2_menu(struct uvc_video_chain *chain,
> goto done;
> }
>
> + menu_value = uvc_mapping_get_menu_value(mapping,
> + query_menu->index);
> +
> bitmap = mapping->get(mapping, UVC_GET_RES,
> uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
> - if (!(bitmap & menu_info->value)) {
> + if (!(bitmap & menu_value)) {
> ret = -EINVAL;
> goto done;
> }
> }
>
> - strscpy(query_menu->name, menu_info->name, sizeof(query_menu->name));
> + name = uvc_mapping_get_menu_name(mapping, query_menu->index);
> + if (name)
> + strscpy(query_menu->name, name, sizeof(query_menu->name));
> + else
> + ret = -EINVAL;
>
> done:
> mutex_unlock(&chain->ctrl_mutex);
> @@ -1783,7 +1806,7 @@ int uvc_ctrl_set(struct uvc_fh *handle,
> if (!test_bit(xctrl->value, &mapping->menu_mask))
> return -EINVAL;
>
> - value = mapping->menu_info[xctrl->value].value;
> + value = uvc_mapping_get_menu_value(mapping, xctrl->value);
>
> /* Valid menu indices are reported by the GET_RES request for
> * UVC controls that support it.
> @@ -2229,12 +2252,28 @@ static int __uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
>
> INIT_LIST_HEAD(&map->ev_subs);
>
> - size = sizeof(*mapping->menu_info) * fls(mapping->menu_mask);
> - map->menu_info = kmemdup(mapping->menu_info, size, GFP_KERNEL);
> - if (map->menu_info == NULL) {
> - kfree(map->name);
> - kfree(map);
> - return -ENOMEM;
> + if (mapping->menu_mapping && mapping->menu_mask) {
> + size = sizeof(mapping->menu_mapping[0]) *
> + fls(mapping->menu_mask);
> + map->menu_mapping = kmemdup(mapping->menu_mapping, size,
> + GFP_KERNEL);
> + if (!map->menu_mapping) {
> + kfree(map->name);
> + kfree(map);
> + return -ENOMEM;
> + }
> + }
> + if (mapping->menu_names && mapping->menu_mask) {
> + size = sizeof(mapping->menu_names[0]) *
> + fls(mapping->menu_mask);
> + map->menu_names = kmemdup(mapping->menu_names, size,
> + GFP_KERNEL);
> + if (!map->menu_names) {
> + kfree(map->menu_mapping);
> + kfree(map->name);
> + kfree(map);
> + return -ENOMEM;
> + }
> }
>
> if (map->get == NULL)
> @@ -2577,7 +2616,8 @@ static void uvc_ctrl_cleanup_mappings(struct uvc_device *dev,
>
> list_for_each_entry_safe(mapping, nm, &ctrl->info.mappings, list) {
> list_del(&mapping->list);
> - kfree(mapping->menu_info);
> + kfree(mapping->menu_names);
> + kfree(mapping->menu_mapping);
> kfree(mapping->name);
> kfree(mapping);
> }
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> index 85aced173daa..0ba1eb92df8e 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -25,6 +25,64 @@
>
> #include "uvcvideo.h"
>
> +static int uvc_control_xu_2_mapping(struct uvc_control_mapping *map,
> + struct uvc_xu_control_mapping *xmap)
> +{
> + char (*names)[UVC_MENU_NAME_LEN];
> + unsigned int i;
> + u32 *mapping;
> + size_t size;
> +
> + /* Prevent excessive memory consumption, as well as integer
> + * overflows.
> + */
> + if (xmap->menu_count == 0 ||
> + xmap->menu_count > UVC_MAX_CONTROL_MENU_ENTRIES)
> + return -EINVAL;
> +
> + map->menu_mask = BIT_MASK(xmap->menu_count);
> +
> + size = xmap->menu_count * sizeof(*map->menu_mapping);
> + mapping = kzalloc(size, GFP_KERNEL);
> + if (!mapping)
> + return -ENOMEM;
> +
> + for (i = 0; i < xmap->menu_count ; i++)
> + if (copy_from_user(&mapping[i], &xmap->menu_info[i].value,
> + sizeof(mapping[i]))) {
> + kfree(mapping);
> + return -ENOMEM;
> + }
> +
> + map->menu_mapping = mapping;
> +
> + /*
> + * Always use the standard naming if available.
> + */
> + if (v4l2_ctrl_get_menu(map->id))
> + return 0;

There is a potential invalid memory access here if we use the standard
naming for custom controls.
let's say that the user says that there are 32 values, but picks a
CTRL_ID that only has 3 values.

Simply removing the previous 2 lines should be enough to take care of that.

I will send a new version once there is more feedback on the series.

[did I said that I hate user defined controls :P, is anyone using it? ]

> +
> + size = xmap->menu_count * sizeof(map->menu_names[0]);
> + names = kzalloc(size, GFP_KERNEL);
> + if (!names) {
> + kfree(mapping);
> + return -ENOMEM;
> + }
> +
> + for (i = 0; i < xmap->menu_count ; i++) {
> + /* sizeof(names[i]) - 1: to take care of \0 */
> + if (copy_from_user(&names[i], &xmap->menu_info[i].name,
> + sizeof(names[i]) - 1)) {
> + kfree(names);
> + kfree(mapping);
> + return -ENOMEM;
> + }
> + }
> + map->menu_names = names;
> +
> + return 0;
> +}
> +
> /* ------------------------------------------------------------------------
> * UVC ioctls
> */
> @@ -32,7 +90,6 @@ static int uvc_ioctl_ctrl_map(struct uvc_video_chain *chain,
> struct uvc_xu_control_mapping *xmap)
> {
> struct uvc_control_mapping *map;
> - unsigned int size;
> int ret;
>
> map = kzalloc(sizeof(*map), GFP_KERNEL);
> @@ -63,23 +120,9 @@ static int uvc_ioctl_ctrl_map(struct uvc_video_chain *chain,
> break;
>
> case V4L2_CTRL_TYPE_MENU:
> - /* Prevent excessive memory consumption, as well as integer
> - * overflows.
> - */
> - if (xmap->menu_count == 0 ||
> - xmap->menu_count > UVC_MAX_CONTROL_MENU_ENTRIES) {
> - ret = -EINVAL;
> - goto free_map;
> - }
> -
> - size = xmap->menu_count * sizeof(*map->menu_info);
> - map->menu_info = memdup_user(xmap->menu_info, size);
> - if (IS_ERR(map->menu_info)) {
> - ret = PTR_ERR(map->menu_info);
> + ret = uvc_control_xu_2_mapping(map, xmap);
> + if (ret)
> goto free_map;
> - }
> -
> - map->menu_mask = BIT_MASK(xmap->menu_count);
> break;
>
> default:
> @@ -91,7 +134,8 @@ static int uvc_ioctl_ctrl_map(struct uvc_video_chain *chain,
>
> ret = uvc_ctrl_add_mapping(chain, map);
>
> - kfree(map->menu_info);
> + kfree(map->menu_names);
> + kfree(map->menu_mapping);
> free_map:
> kfree(map);
>
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index 0736b8815d79..b702f1c8547b 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -253,7 +253,8 @@ struct uvc_control_mapping {
> enum v4l2_ctrl_type v4l2_type;
> u32 data_type;
>
> - const struct uvc_menu_info *menu_info;
> + const u32 *menu_mapping;
> + const char (*menu_names)[UVC_MENU_NAME_LEN];
> unsigned long menu_mask;
>
> u32 master_id;
> diff --git a/include/uapi/linux/uvcvideo.h b/include/uapi/linux/uvcvideo.h
> index 8288137387c0..1b64b6aa40b5 100644
> --- a/include/uapi/linux/uvcvideo.h
> +++ b/include/uapi/linux/uvcvideo.h
> @@ -36,9 +36,10 @@
> UVC_CTRL_FLAG_GET_MAX | UVC_CTRL_FLAG_GET_RES | \
> UVC_CTRL_FLAG_GET_DEF)
>
> +#define UVC_MENU_NAME_LEN 32
> struct uvc_menu_info {
> __u32 value;
> - __u8 name[32];
> + __u8 name[UVC_MENU_NAME_LEN];
> };
>
> struct uvc_xu_control_mapping {
> --
> 2.37.0.rc0.104.g0611611a94-goog
>


--
Ricardo Ribalda