Re: [PATCH v9 01/22] media: v4l2-ioctl: Fix check_ext_ctrls

Hi Ricardo,

Thank you for the patch.

On Fri, Mar 26, 2021 at 10:58:19AM +0100, Ricardo Ribalda wrote:

Drivers that do not use the ctrl-framework use this function instead.

Fix the following issues:

• Do not check for multiple classes when getting the DEF_VAL.
• Return -EINVAL for request_api calls
• Default value cannot be changed, return EINVAL as soon as possible.
• Return the right error_idx

[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. It would have been much nicer of course if error_idx could point to the control index that failed the validation, but sadly that's not how the API was designed.]

Fixes v4l2-compliance: Control ioctls (Input 0): warn: v4l2-test-controls.cpp(834): error_idx should be equal to count warn: v4l2-test-controls.cpp(855): error_idx should be equal to count fail: v4l2-test-controls.cpp(813): doioctl(node, VIDIOC_G_EXT_CTRLS, &ctrls) test VIDIOC_G/S/TRY_EXT_CTRLS: FAIL Buffer ioctls (Input 0): fail: v4l2-test-buffers.cpp(1994): ret != EINVAL && ret != EBADR && ret != ENOTTY test Requests: FAIL

Cc: stable@vger.kernel.org Fixes: 6fa6f831f095 ("media: v4l2-ctrls: add core request support") Suggested-by: Hans Verkuil hverkuil-cisco@xs4all.nl Reviewed-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Ricardo Ribalda ribalda@chromium.org

Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com

---

drivers/media/v4l2-core/v4l2-ioctl.c | 60 ++++++++++++++++++---------- 1 file changed, 39 insertions(+), 21 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index 31d1342e61e8..7b5ebdd329e8 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -908,7 +908,7 @@ static void v4l_print_default(const void *arg, bool write_only) pr_cont("driver-specific ioctl\n"); } -static int check_ext_ctrls(struct v4l2_ext_controls *c, int allow_priv) +static bool check_ext_ctrls(struct v4l2_ext_controls *c, unsigned long ioctl) { __u32 i; @@ -917,23 +917,41 @@ static int check_ext_ctrls(struct v4l2_ext_controls *c, int allow_priv) for (i = 0; i < c->count; i++) c->controls[i].reserved2[0] = 0;

• /* V4L2_CID_PRIVATE_BASE cannot be used as control class

•   when using extended controls.
  

•   Only when passed in through VIDIOC_G_CTRL and VIDIOC_S_CTRL
  

•   is it allowed for backwards compatibility.
  

• */
  

• if (!allow_priv && c->which == V4L2_CID_PRIVATE_BASE)

• return 0;
  

• if (!c->which)

• return 1;
  

• switch (c->which) {
• case V4L2_CID_PRIVATE_BASE:

• /*
  

•  * V4L2_CID_PRIVATE_BASE cannot be used as control class
  

•  * when using extended controls.
  

•  * Only when passed in through VIDIOC_G_CTRL and VIDIOC_S_CTRL
  

•  * is it allowed for backwards compatibility.
  

•  */
  

• if (ioctl == VIDIOC_G_CTRL || ioctl == VIDIOC_S_CTRL)
  

• 	return false;
  

• break;
  

• case V4L2_CTRL_WHICH_DEF_VAL:

• /* Default value cannot be changed */
  

• if (ioctl == VIDIOC_S_EXT_CTRLS ||
  

•     ioctl == VIDIOC_TRY_EXT_CTRLS) {
  

• 	c->error_idx = c->count;
  

• 	return false;
  

• }
  

• return true;
  

• case V4L2_CTRL_WHICH_CUR_VAL:

• return true;
  

• case V4L2_CTRL_WHICH_REQUEST_VAL:

• c->error_idx = c->count;
  

• return false;
  

• }
• /* Check that all controls are from the same control class. */ for (i = 0; i < c->count; i++) { if (V4L2_CTRL_ID2WHICH(c->controls[i].id) != c->which) {

• 	c->error_idx = i;
  

• 	return 0;
  

• 	c->error_idx = ioctl == VIDIOC_TRY_EXT_CTRLS ? i :
  

• 						      c->count;
  

• 	return false;
  

  } }

• return 1;

• return true;

} static int check_fmt(struct file *file, enum v4l2_buf_type type) @@ -2229,7 +2247,7 @@ static int v4l_g_ctrl(const struct v4l2_ioctl_ops *ops, ctrls.controls = &ctrl; ctrl.id = p->id; ctrl.value = p->value;

• if (check_ext_ctrls(&ctrls, 1)) {

• if (check_ext_ctrls(&ctrls, VIDIOC_G_CTRL)) { int ret = ops->vidioc_g_ext_ctrls(file, fh, &ctrls);

if (ret == 0) @@ -2263,7 +2281,7 @@ static int v4l_s_ctrl(const struct v4l2_ioctl_ops *ops, ctrls.controls = &ctrl; ctrl.id = p->id; ctrl.value = p->value;

• if (check_ext_ctrls(&ctrls, 1))

• if (check_ext_ctrls(&ctrls, VIDIOC_S_CTRL)) return ops->vidioc_s_ext_ctrls(file, fh, &ctrls); return -EINVAL;

} @@ -2285,8 +2303,8 @@ static int v4l_g_ext_ctrls(const struct v4l2_ioctl_ops *ops, vfd, vfd->v4l2_dev->mdev, p); if (ops->vidioc_g_ext_ctrls == NULL) return -ENOTTY;

• return check_ext_ctrls(p, 0) ? ops->vidioc_g_ext_ctrls(file, fh, p) :

• 			-EINVAL;
  

• return check_ext_ctrls(p, VIDIOC_G_EXT_CTRLS) ?

• 		ops->vidioc_g_ext_ctrls(file, fh, p) : -EINVAL;
  

} static int v4l_s_ext_ctrls(const struct v4l2_ioctl_ops *ops, @@ -2306,8 +2324,8 @@ static int v4l_s_ext_ctrls(const struct v4l2_ioctl_ops *ops, vfd, vfd->v4l2_dev->mdev, p); if (ops->vidioc_s_ext_ctrls == NULL) return -ENOTTY;

• return check_ext_ctrls(p, 0) ? ops->vidioc_s_ext_ctrls(file, fh, p) :

• 			-EINVAL;
  

• return check_ext_ctrls(p, VIDIOC_S_EXT_CTRLS) ?

• 		ops->vidioc_s_ext_ctrls(file, fh, p) : -EINVAL;
  

} static int v4l_try_ext_ctrls(const struct v4l2_ioctl_ops *ops, @@ -2327,8 +2345,8 @@ static int v4l_try_ext_ctrls(const struct v4l2_ioctl_ops *ops, vfd, vfd->v4l2_dev->mdev, p); if (ops->vidioc_try_ext_ctrls == NULL) return -ENOTTY;

• return check_ext_ctrls(p, 0) ? ops->vidioc_try_ext_ctrls(file, fh, p) :

• 			-EINVAL;
  

• return check_ext_ctrls(p, VIDIOC_TRY_EXT_CTRLS) ?

• 	ops->vidioc_try_ext_ctrls(file, fh, p) : -EINVAL;
  

} /*