Re: [PATCH v6 01/17] media: v4l2-ioctl: check_ext_ctrls: Fix multiclass V4L2_CTRL_WHICH_DEF_VAL

From: Hans Verkuil
Date: Thu Mar 18 2021 - 03:48:57 EST


On 18/03/2021 08:17, Ricardo Ribalda wrote:
> Hi Hans
>
> Can I merge 1-3, but leave 4 as a separate one? It helps to tell a
> story for 5 and 6.

I really prefer it as a single patch. All four patches are basically a single big fix
for v4l2-ioctl.c where the code for drivers that do not use the control framework had
become very outdated. Fixing it in a single patch helps backporting to stable, and
it is easier to review and see everything that had to be done to fix this.

In this case I wondered when I was reviewing patch 1 why V4L2_CTRL_WHICH_DEF_VAL was
just accepted without checking for S/TRY_EXT_CTRLS. Basically patch 1 is a broken fix
w.r.t. DEF_VAL until patch 4, which really fixes it.

Just do it all in a single patch, splitting it up doesn't work in this particular case.

Regards,

Hans

>
> Thanks
>
> On Thu, Mar 18, 2021 at 8:14 AM Hans Verkuil <hverkuil-cisco@xxxxxxxxx> wrote:
>>
>> Hi Ricardo,
>>
>> On 17/03/2021 17:44, Ricardo Ribalda wrote:
>>> Drivers that do not use the ctrl-framework use this function instead.
>>>
>>> - Do not check for multiple classes when getting the DEF_VAL.
>>>
>>> Fixes v4l2-compliance:
>>> Control ioctls (Input 0):
>>> fail: v4l2-test-controls.cpp(813): doioctl(node, VIDIOC_G_EXT_CTRLS, &ctrls)
>>> test VIDIOC_G/S/TRY_EXT_CTRLS: FAIL
>>
>> Can you merge patches 1-4 into a single patch? It's really one big fix since
>> this code was never updated when new 'which' values were added. So keeping it
>> together is, for once, actually preferred.
>>
>> You can add my:
>>
>> Reviewed-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
>>
>> after these 4 patches are merged. It looks much nicer now.
>>
>> Regards,
>>
>> Hans
>>
>>>
>>> Cc: stable@xxxxxxxxxxxxxxx
>>> Fixes: 6fa6f831f095 ("media: v4l2-ctrls: add core request support")
>>> Suggested-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
>>> Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
>>> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
>>> ---
>>> drivers/media/v4l2-core/v4l2-ioctl.c | 47 ++++++++++++++++------------
>>> 1 file changed, 27 insertions(+), 20 deletions(-)
>>>
>>> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
>>> index 31d1342e61e8..403f957a1012 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 +917,30 @@ 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_CROP)
>>> + return false;
>>> + break;
>>> + case V4L2_CTRL_WHICH_DEF_VAL:
>>> + case V4L2_CTRL_WHICH_CUR_VAL:
>>> + return true;
>>> + }
>>> +
>>> /* 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;
>>> + return false;
>>> }
>>> }
>>> - return 1;
>>> + return true;
>>> }
>>>
>>> static int check_fmt(struct file *file, enum v4l2_buf_type type)
>>> @@ -2229,7 +2236,7 @@ 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 +2270,7 @@ 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 +2292,8 @@ 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 +2313,8 @@ 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 +2334,8 @@ 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;
>>> }
>>>
>>> /*
>>>
>>
>
>