We can figure out if reading/writing a set of controls can fail without
accessing them by checking their flags.
This way we can honor the API closer:
If an error is found when validating the list of controls passed with
VIDIOC_G_EXT_CTRLS, then error_idx shall be set to ctrls->count to
indicate to userspace that no actual hardware was touched.
Fixes v4l2-compliance:
Control ioctls (Input 0):
warn: v4l2-test-controls.cpp(765): g_ext_ctrls(0) invalid error_idx 0
fail: v4l2-test-controls.cpp(645): invalid error index write only control
test VIDIOC_G/S/TRY_EXT_CTRLS: FAIL
Reviewed-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
drivers/media/usb/uvc/uvc_ctrl.c | 22 ++++++++++++++++++
drivers/media/usb/uvc/uvc_v4l2.c | 39 ++++++++++++++++++++++++++++----
drivers/media/usb/uvc/uvcvideo.h | 2 ++
3 files changed, 58 insertions(+), 5 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 929e70dff11a..24fd5afc4e4f 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1046,6 +1046,28 @@ static int uvc_query_v4l2_class(struct uvc_video_chain *chain, u32 req_id,
return 0;
}
+int uvc_ctrl_is_accessible(struct uvc_video_chain *chain, u32 v4l2_id,
+ bool read)
+{
+ struct uvc_control_mapping *mapping;
+ struct uvc_control *ctrl;
+
+ if (__uvc_query_v4l2_class(chain, v4l2_id, 0) >= 0)
+ return -EACCES;
+
+ ctrl = uvc_find_control(chain, v4l2_id, &mapping);
+ if (!ctrl)
+ return -EINVAL;
+
+ if (!(ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) && read)
+ return -EACCES;
+
+ if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR) && !read)
+ return -EACCES;
+
+ return 0;
+}
+
static const char *uvc_map_get_name(const struct uvc_control_mapping *map)
{
const char *name;
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index ed262f61e6a6..fbb99f3c2fb4 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -1045,6 +1045,26 @@ static int uvc_ioctl_s_ctrl(struct file *file, void *fh,
return 0;
}
+static int uvc_ctrl_check_access(struct uvc_video_chain *chain,
+ struct v4l2_ext_controls *ctrls,
+ unsigned long ioctl)
+{
+ struct v4l2_ext_control *ctrl = ctrls->controls;
+ unsigned int i;
+ int ret = 0;
+
+ for (i = 0; i < ctrls->count; ++ctrl, ++i) {
+ ret = uvc_ctrl_is_accessible(chain, ctrl->id,
+ ioctl == VIDIOC_G_EXT_CTRLS);
+ if (ret)
+ break;
+ }
+
+ ctrls->error_idx = ioctl == VIDIOC_TRY_EXT_CTRLS ? i : ctrls->count;
+
+ return ret;
+}
+
static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
struct v4l2_ext_controls *ctrls)
{
@@ -1054,6 +1074,10 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
unsigned int i;
int ret;
+ ret = uvc_ctrl_check_access(chain, ctrls, VIDIOC_G_EXT_CTRLS);
+ if (ret < 0)
+ return ret;
+
if (ctrls->which == V4L2_CTRL_WHICH_DEF_VAL) {
for (i = 0; i < ctrls->count; ++ctrl, ++i) {
struct v4l2_queryctrl qc = { .id = ctrl->id };
@@ -1090,13 +1114,17 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
struct v4l2_ext_controls *ctrls,
- bool commit)
+ unsigned long ioctl)
{
struct v4l2_ext_control *ctrl = ctrls->controls;
struct uvc_video_chain *chain = handle->chain;
unsigned int i;
int ret;
+ ret = uvc_ctrl_check_access(chain, ctrls, ioctl);
+ if (ret < 0)
+ return ret;
+
ret = uvc_ctrl_begin(chain);
if (ret < 0)
return ret;
@@ -1105,14 +1133,15 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
ret = uvc_ctrl_set(handle, ctrl);
if (ret < 0) {
uvc_ctrl_rollback(handle);
- ctrls->error_idx = commit ? ctrls->count : i;
+ ctrls->error_idx = ioctl == VIDIOC_S_EXT_CTRLS ?
+ ctrls->count : i;
return ret;
}
}
ctrls->error_idx = 0;
- if (commit)
+ if (ioctl == VIDIOC_S_EXT_CTRLS)
return uvc_ctrl_commit(handle, ctrls->controls, ctrls->count);
else
return uvc_ctrl_rollback(handle);
@@ -1123,7 +1152,7 @@ static int uvc_ioctl_s_ext_ctrls(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
- return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, true);
+ return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_S_EXT_CTRLS);
}
static int uvc_ioctl_try_ext_ctrls(struct file *file, void *fh,
@@ -1131,7 +1160,7 @@ static int uvc_ioctl_try_ext_ctrls(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
- return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, false);
+ return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, VIDIOC_TRY_EXT_CTRLS);
}
static int uvc_ioctl_querymenu(struct file *file, void *fh,
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index dc20021f7ee0..9471c342a310 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -902,6 +902,8 @@ static inline int uvc_ctrl_rollback(struct uvc_fh *handle)
int uvc_ctrl_get(struct uvc_video_chain *chain, struct v4l2_ext_control *xctrl);
int uvc_ctrl_set(struct uvc_fh *handle, struct v4l2_ext_control *xctrl);
+int uvc_ctrl_is_accessible(struct uvc_video_chain *chain, u32 v4l2_id,
+ bool read);
int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
struct uvc_xu_control_query *xqry);
--
2.31.0.rc2.261.g7f71774620-goog
