[PATCH 0/2] v4l2-ctrls: various improvements

[PATCH 0/2] v4l2-ctrls: various improvements

[Hans Verkuil]

The first patch improves WARN_ON handling, the second adds a
generic __v4l2_ctrl_s_ctrl_compound function and replaces the
__v4l2_ctrl_s_ctrl_area functions by defines that use the new
__v4l2_ctrl_s_ctrl_compound instead.

Regards,

	Hans

Hans Verkuil (2):
  v4l2-ctrls: v4l2_ctrl_g/s_ctrl*(): don't continue when WARN_ON
  v4l2-ctrls: add __v4l2_ctrl_s_ctrl_compound()

 drivers/media/v4l2-core/v4l2-ctrls.c | 26 +++++++++------
 include/media/v4l2-ctrls.h           | 49 ++++++++++++++++------------
 2 files changed, 45 insertions(+), 30 deletions(-)

-- 
2.25.1

[PATCH 1/2] v4l2-ctrls: v4l2_ctrl_g/s_ctrl*(): don't continue when WARN_ON

[Hans Verkuil]

If the v4l2_ctrl_g_ctrl*() or __v4l2_ctrl_s_ctrl*() functions
are called for the wrong control type then they call WARN_ON
since that is a driver error. But they still continue, potentially
overwriting data. Change this to return an error (s_ctrl) or 0
(g_ctrl), just to be safe.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
---
 drivers/media/v4l2-core/v4l2-ctrls.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 2928c5e0a73d..d3bacf6b59d6 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -3794,7 +3794,8 @@ s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl)
 	struct v4l2_ext_control c;
 
 	/* It's a driver bug if this happens. */
-	WARN_ON(!ctrl->is_int);
+	if (WARN_ON(!ctrl->is_int))
+		return 0;
 	c.value = 0;
 	get_ctrl(ctrl, &c);
 	return c.value;
@@ -3806,7 +3807,8 @@ s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl)
 	struct v4l2_ext_control c;
 
 	/* It's a driver bug if this happens. */
-	WARN_ON(ctrl->is_ptr || ctrl->type != V4L2_CTRL_TYPE_INTEGER64);
+	if (WARN_ON(ctrl->is_ptr || ctrl->type != V4L2_CTRL_TYPE_INTEGER64))
+		return 0;
 	c.value64 = 0;
 	get_ctrl(ctrl, &c);
 	return c.value64;
@@ -4215,7 +4217,8 @@ int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
 	lockdep_assert_held(ctrl->handler->lock);
 
 	/* It's a driver bug if this happens. */
-	WARN_ON(!ctrl->is_int);
+	if (WARN_ON(!ctrl->is_int))
+		return -EINVAL;
 	ctrl->val = val;
 	return set_ctrl(NULL, ctrl, 0);
 }
@@ -4226,7 +4229,8 @@ int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
 	lockdep_assert_held(ctrl->handler->lock);
 
 	/* It's a driver bug if this happens. */
-	WARN_ON(ctrl->is_ptr || ctrl->type != V4L2_CTRL_TYPE_INTEGER64);
+	if (WARN_ON(ctrl->is_ptr || ctrl->type != V4L2_CTRL_TYPE_INTEGER64))
+		return -EINVAL;
 	*ctrl->p_new.p_s64 = val;
 	return set_ctrl(NULL, ctrl, 0);
 }
@@ -4237,7 +4241,8 @@ int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
 	lockdep_assert_held(ctrl->handler->lock);
 
 	/* It's a driver bug if this happens. */
-	WARN_ON(ctrl->type != V4L2_CTRL_TYPE_STRING);
+	if (WARN_ON(ctrl->type != V4L2_CTRL_TYPE_STRING))
+		return -EINVAL;
 	strscpy(ctrl->p_new.p_char, s, ctrl->maximum + 1);
 	return set_ctrl(NULL, ctrl, 0);
 }
@@ -4249,7 +4254,8 @@ int __v4l2_ctrl_s_ctrl_area(struct v4l2_ctrl *ctrl,
 	lockdep_assert_held(ctrl->handler->lock);
 
 	/* It's a driver bug if this happens. */
-	WARN_ON(ctrl->type != V4L2_CTRL_TYPE_AREA);
+	if (WARN_ON(ctrl->type != V4L2_CTRL_TYPE_AREA))
+		return -EINVAL;
 	*ctrl->p_new.p_area = *area;
 	return set_ctrl(NULL, ctrl, 0);
 }
-- 
2.25.1

[PATCH 2/2] v4l2-ctrls: add __v4l2_ctrl_s_ctrl_compound()

[Hans Verkuil]

Rather than creating new compound control helpers for each new
type, create one generic function and just create defines on
top.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
---
 drivers/media/v4l2-core/v4l2-ctrls.c | 10 +++---
 include/media/v4l2-ctrls.h           | 49 ++++++++++++++++------------
 2 files changed, 34 insertions(+), 25 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index d3bacf6b59d6..68684fcbdc61 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -4248,18 +4248,18 @@ int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
 }
 EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_string);
 
-int __v4l2_ctrl_s_ctrl_area(struct v4l2_ctrl *ctrl,
-			    const struct v4l2_area *area)
+int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
+				enum v4l2_ctrl_type type, const void *p)
 {
 	lockdep_assert_held(ctrl->handler->lock);
 
 	/* It's a driver bug if this happens. */
-	if (WARN_ON(ctrl->type != V4L2_CTRL_TYPE_AREA))
+	if (WARN_ON(ctrl->type != type))
 		return -EINVAL;
-	*ctrl->p_new.p_area = *area;
+	memcpy(ctrl->p_new.p, p, ctrl->elems * ctrl->elem_size);
 	return set_ctrl(NULL, ctrl, 0);
 }
-EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_area);
+EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_compound);
 
 void v4l2_ctrl_request_complete(struct media_request *req,
 				struct v4l2_ctrl_handler *main_hdl)
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index 7db9e719a583..75a8daacb4c4 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -1113,45 +1113,54 @@ static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
 }
 
 /**
- * __v4l2_ctrl_s_ctrl_area() - Unlocked variant of v4l2_ctrl_s_ctrl_area().
+ * __v4l2_ctrl_s_ctrl_compound() - Unlocked variant to set a compound control
  *
- * @ctrl:	The control.
- * @area:	The new area.
+ * @ctrl: The control.
+ * @type: The type of the data.
+ * @p:    The new compound payload.
  *
- * This sets the control's new area safely by going through the control
- * framework. This function assumes the control's handler is already locked,
- * allowing it to be used from within the &v4l2_ctrl_ops functions.
+ * This sets the control's new compound payload safely by going through the
+ * control framework. This function assumes the control's handler is already
+ * locked, allowing it to be used from within the &v4l2_ctrl_ops functions.
  *
- * This function is for area type controls only.
+ * This function is for compound type controls only.
  */
-int __v4l2_ctrl_s_ctrl_area(struct v4l2_ctrl *ctrl,
-			    const struct v4l2_area *area);
+int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
+				enum v4l2_ctrl_type type, const void *p);
 
 /**
- * v4l2_ctrl_s_ctrl_area() - Helper function to set a control's area value
- *	 from within a driver.
+ * v4l2_ctrl_s_ctrl_compound() - Helper function to set a compound control
+ *	from within a driver.
  *
- * @ctrl:	The control.
- * @area:	The new area.
+ * @ctrl: The control.
+ * @type: The type of the data.
+ * @p:    The new compound payload.
  *
- * This sets the control's new area safely by going through the control
- * framework. This function will lock the control's handler, so it cannot be
- * used from within the &v4l2_ctrl_ops functions.
+ * This sets the control's new compound payload safely by going through the
+ * control framework. This function will lock the control's handler, so it
+ * cannot be used from within the &v4l2_ctrl_ops functions.
  *
- * This function is for area type controls only.
+ * This function is for compound type controls only.
  */
-static inline int v4l2_ctrl_s_ctrl_area(struct v4l2_ctrl *ctrl,
-					const struct v4l2_area *area)
+static inline int v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
+					    enum v4l2_ctrl_type type,
+					    const void *p)
 {
 	int rval;
 
 	v4l2_ctrl_lock(ctrl);
-	rval = __v4l2_ctrl_s_ctrl_area(ctrl, area);
+	rval = __v4l2_ctrl_s_ctrl_compound(ctrl, type, p);
 	v4l2_ctrl_unlock(ctrl);
 
 	return rval;
 }
 
+/* Helper defines for area type controls */
+#define __v4l2_ctrl_s_ctrl_area(ctrl, area) \
+	__v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
+#define v4l2_ctrl_s_ctrl_area(ctrl, area) \
+	v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
+
 /* Internal helper functions that deal with control events. */
 extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
 
-- 
2.25.1

Re: [PATCH 2/2] v4l2-ctrls: add __v4l2_ctrl_s_ctrl_compound()

[Ricardo Ribalda Delgado]

HI Hans

I have just come back from holidays. If you give me a week I can test
it in real hardware.

Thanks!


On Tue, Mar 3, 2020 at 12:03 PM Hans Verkuil <hverkuil-cisco@xs4all.nl> wrote:
>
> Rather than creating new compound control helpers for each new
> type, create one generic function and just create defines on
> top.
>
> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
> ---
>  drivers/media/v4l2-core/v4l2-ctrls.c | 10 +++---
>  include/media/v4l2-ctrls.h           | 49 ++++++++++++++++------------
>  2 files changed, 34 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
> index d3bacf6b59d6..68684fcbdc61 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> @@ -4248,18 +4248,18 @@ int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
>  }
>  EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_string);
>
> -int __v4l2_ctrl_s_ctrl_area(struct v4l2_ctrl *ctrl,
> -                           const struct v4l2_area *area)
> +int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
> +                               enum v4l2_ctrl_type type, const void *p)
>  {
>         lockdep_assert_held(ctrl->handler->lock);
>
>         /* It's a driver bug if this happens. */
> -       if (WARN_ON(ctrl->type != V4L2_CTRL_TYPE_AREA))
> +       if (WARN_ON(ctrl->type != type))
>                 return -EINVAL;
> -       *ctrl->p_new.p_area = *area;
> +       memcpy(ctrl->p_new.p, p, ctrl->elems * ctrl->elem_size);
>         return set_ctrl(NULL, ctrl, 0);
>  }
> -EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_area);
> +EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_compound);
>
>  void v4l2_ctrl_request_complete(struct media_request *req,
>                                 struct v4l2_ctrl_handler *main_hdl)
> diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
> index 7db9e719a583..75a8daacb4c4 100644
> --- a/include/media/v4l2-ctrls.h
> +++ b/include/media/v4l2-ctrls.h
> @@ -1113,45 +1113,54 @@ static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
>  }
>
>  /**
> - * __v4l2_ctrl_s_ctrl_area() - Unlocked variant of v4l2_ctrl_s_ctrl_area().
> + * __v4l2_ctrl_s_ctrl_compound() - Unlocked variant to set a compound control
>   *
> - * @ctrl:      The control.
> - * @area:      The new area.
> + * @ctrl: The control.
> + * @type: The type of the data.
> + * @p:    The new compound payload.
>   *
> - * This sets the control's new area safely by going through the control
> - * framework. This function assumes the control's handler is already locked,
> - * allowing it to be used from within the &v4l2_ctrl_ops functions.
> + * This sets the control's new compound payload safely by going through the
> + * control framework. This function assumes the control's handler is already
> + * locked, allowing it to be used from within the &v4l2_ctrl_ops functions.
>   *
> - * This function is for area type controls only.
> + * This function is for compound type controls only.
>   */
> -int __v4l2_ctrl_s_ctrl_area(struct v4l2_ctrl *ctrl,
> -                           const struct v4l2_area *area);
> +int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
> +                               enum v4l2_ctrl_type type, const void *p);
>
>  /**
> - * v4l2_ctrl_s_ctrl_area() - Helper function to set a control's area value
> - *      from within a driver.
> + * v4l2_ctrl_s_ctrl_compound() - Helper function to set a compound control
> + *     from within a driver.
>   *
> - * @ctrl:      The control.
> - * @area:      The new area.
> + * @ctrl: The control.
> + * @type: The type of the data.
> + * @p:    The new compound payload.
>   *
> - * This sets the control's new area safely by going through the control
> - * framework. This function will lock the control's handler, so it cannot be
> - * used from within the &v4l2_ctrl_ops functions.
> + * This sets the control's new compound payload safely by going through the
> + * control framework. This function will lock the control's handler, so it
> + * cannot be used from within the &v4l2_ctrl_ops functions.
>   *
> - * This function is for area type controls only.
> + * This function is for compound type controls only.
>   */
> -static inline int v4l2_ctrl_s_ctrl_area(struct v4l2_ctrl *ctrl,
> -                                       const struct v4l2_area *area)
> +static inline int v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
> +                                           enum v4l2_ctrl_type type,
> +                                           const void *p)
>  {
>         int rval;
>
>         v4l2_ctrl_lock(ctrl);
> -       rval = __v4l2_ctrl_s_ctrl_area(ctrl, area);
> +       rval = __v4l2_ctrl_s_ctrl_compound(ctrl, type, p);
>         v4l2_ctrl_unlock(ctrl);
>
>         return rval;
>  }
>
> +/* Helper defines for area type controls */
> +#define __v4l2_ctrl_s_ctrl_area(ctrl, area) \
> +       __v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
> +#define v4l2_ctrl_s_ctrl_area(ctrl, area) \
> +       v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
> +
>  /* Internal helper functions that deal with control events. */
>  extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
>
> --
> 2.25.1
>

Re: [PATCH 2/2] v4l2-ctrls: add __v4l2_ctrl_s_ctrl_compound()

[Paul Kocialkowski]

[-- Attachment #1: Type: text/plain, Size: 5149 bytes --]

Hi Hans,

On Tue 03 Mar 20, 12:02, Hans Verkuil wrote:
> Rather than creating new compound control helpers for each new
> type, create one generic function and just create defines on
> top.

Thanks for the patch, works fine here!

Tested-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>

Cheers,

Paul

> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
> ---
>  drivers/media/v4l2-core/v4l2-ctrls.c | 10 +++---
>  include/media/v4l2-ctrls.h           | 49 ++++++++++++++++------------
>  2 files changed, 34 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
> index d3bacf6b59d6..68684fcbdc61 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> @@ -4248,18 +4248,18 @@ int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
>  }
>  EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_string);
>  
> -int __v4l2_ctrl_s_ctrl_area(struct v4l2_ctrl *ctrl,
> -			    const struct v4l2_area *area)
> +int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
> +				enum v4l2_ctrl_type type, const void *p)
>  {
>  	lockdep_assert_held(ctrl->handler->lock);
>  
>  	/* It's a driver bug if this happens. */
> -	if (WARN_ON(ctrl->type != V4L2_CTRL_TYPE_AREA))
> +	if (WARN_ON(ctrl->type != type))
>  		return -EINVAL;
> -	*ctrl->p_new.p_area = *area;
> +	memcpy(ctrl->p_new.p, p, ctrl->elems * ctrl->elem_size);
>  	return set_ctrl(NULL, ctrl, 0);
>  }
> -EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_area);
> +EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_compound);
>  
>  void v4l2_ctrl_request_complete(struct media_request *req,
>  				struct v4l2_ctrl_handler *main_hdl)
> diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
> index 7db9e719a583..75a8daacb4c4 100644
> --- a/include/media/v4l2-ctrls.h
> +++ b/include/media/v4l2-ctrls.h
> @@ -1113,45 +1113,54 @@ static inline int v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
>  }
>  
>  /**
> - * __v4l2_ctrl_s_ctrl_area() - Unlocked variant of v4l2_ctrl_s_ctrl_area().
> + * __v4l2_ctrl_s_ctrl_compound() - Unlocked variant to set a compound control
>   *
> - * @ctrl:	The control.
> - * @area:	The new area.
> + * @ctrl: The control.
> + * @type: The type of the data.
> + * @p:    The new compound payload.
>   *
> - * This sets the control's new area safely by going through the control
> - * framework. This function assumes the control's handler is already locked,
> - * allowing it to be used from within the &v4l2_ctrl_ops functions.
> + * This sets the control's new compound payload safely by going through the
> + * control framework. This function assumes the control's handler is already
> + * locked, allowing it to be used from within the &v4l2_ctrl_ops functions.
>   *
> - * This function is for area type controls only.
> + * This function is for compound type controls only.
>   */
> -int __v4l2_ctrl_s_ctrl_area(struct v4l2_ctrl *ctrl,
> -			    const struct v4l2_area *area);
> +int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
> +				enum v4l2_ctrl_type type, const void *p);
>  
>  /**
> - * v4l2_ctrl_s_ctrl_area() - Helper function to set a control's area value
> - *	 from within a driver.
> + * v4l2_ctrl_s_ctrl_compound() - Helper function to set a compound control
> + *	from within a driver.
>   *
> - * @ctrl:	The control.
> - * @area:	The new area.
> + * @ctrl: The control.
> + * @type: The type of the data.
> + * @p:    The new compound payload.
>   *
> - * This sets the control's new area safely by going through the control
> - * framework. This function will lock the control's handler, so it cannot be
> - * used from within the &v4l2_ctrl_ops functions.
> + * This sets the control's new compound payload safely by going through the
> + * control framework. This function will lock the control's handler, so it
> + * cannot be used from within the &v4l2_ctrl_ops functions.
>   *
> - * This function is for area type controls only.
> + * This function is for compound type controls only.
>   */
> -static inline int v4l2_ctrl_s_ctrl_area(struct v4l2_ctrl *ctrl,
> -					const struct v4l2_area *area)
> +static inline int v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
> +					    enum v4l2_ctrl_type type,
> +					    const void *p)
>  {
>  	int rval;
>  
>  	v4l2_ctrl_lock(ctrl);
> -	rval = __v4l2_ctrl_s_ctrl_area(ctrl, area);
> +	rval = __v4l2_ctrl_s_ctrl_compound(ctrl, type, p);
>  	v4l2_ctrl_unlock(ctrl);
>  
>  	return rval;
>  }
>  
> +/* Helper defines for area type controls */
> +#define __v4l2_ctrl_s_ctrl_area(ctrl, area) \
> +	__v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
> +#define v4l2_ctrl_s_ctrl_area(ctrl, area) \
> +	v4l2_ctrl_s_ctrl_compound((ctrl), V4L2_CTRL_TYPE_AREA, (area))
> +
>  /* Internal helper functions that deal with control events. */
>  extern const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops;
>  
> -- 
> 2.25.1
> 

-- 
Paul Kocialkowski, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com

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