Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3843e71f authored by Rob Clark's avatar Rob Clark Committed by Daniel Vetter
Browse files

drm: allow property validation for refcnted props 



We can already have object properties, which technically can be fb's.
Switch the property validation logic over to a get/put style interface
so it can take a ref to refcnt'd objects, and then drop that ref after
the driver has a chance to take it's own ref.

Signed-off-by: default avatarRob Clark <robdclark@gmail.com>
Reviewed-by: default avatarSean Paul <seanpaul@chromium.org>
Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 07cc0ef6

drivers/gpu/drm/drm_crtc.c

+43 −15
Original line number Diff line number Diff line
@@ -4193,12 +4193,22 @@ int drm_mode_connector_update_edid_property(struct drm_connector *connector, 
}

EXPORT_SYMBOL(drm_mode_connector_update_edid_property);



static bool drm_property_change_is_valid(struct drm_property *property,

					 uint64_t value)

/* Some properties could refer to dynamic refcnt'd objects, or things that

 * need special locking to handle lifetime issues (ie. to ensure the prop

 * value doesn't become invalid part way through the property update due to

 * race).  The value returned by reference via 'obj' should be passed back

 * to drm_property_change_valid_put() after the property is set (and the

 * object to which the property is attached has a chance to take it's own

 * reference).

 */

static bool drm_property_change_valid_get(struct drm_property *property,

					 uint64_t value, struct drm_mode_object **ref)

{

	if (property->flags & DRM_MODE_PROP_IMMUTABLE)

		return false;



	*ref = NULL;



	if (drm_property_type_is(property, DRM_MODE_PROP_RANGE)) {

		if (value < property->values[0] || value > property->values[1])

			return false;
@@ -4219,19 +4229,23 @@ static bool drm_property_change_is_valid(struct drm_property *property, 
		/* Only the driver knows */

		return true;

	} else if (drm_property_type_is(property, DRM_MODE_PROP_OBJECT)) {

		struct drm_mode_object *obj;

		/* a zero value for an object property translates to null: */

		if (value == 0)

			return true;

		/*

		 * NOTE: use _object_find() directly to bypass restriction on

		 * looking up refcnt'd objects (ie. fb's).  For a refcnt'd

		 * object this could race against object finalization, so it

		 * simply tells us that the object *was* valid.  Which is good

		 * enough.

		 */

		obj = _object_find(property->dev, value, property->values[0]);

		return obj != NULL;



		/* handle refcnt'd objects specially: */

		if (property->values[0] == DRM_MODE_OBJECT_FB) {

			struct drm_framebuffer *fb;

			fb = drm_framebuffer_lookup(property->dev, value);

			if (fb) {

				*ref = &fb->base;

				return true;

			} else {

				return false;

			}

		} else {

			return _object_find(property->dev, value, property->values[0]) != NULL;

		}

	} else {

		int i;

		for (i = 0; i < property->num_values; i++)
@@ -4241,6 +4255,18 @@ static bool drm_property_change_is_valid(struct drm_property *property, 
	}

}



static void drm_property_change_valid_put(struct drm_property *property,

		struct drm_mode_object *ref)

{

	if (!ref)

		return;



	if (drm_property_type_is(property, DRM_MODE_PROP_OBJECT)) {

		if (property->values[0] == DRM_MODE_OBJECT_FB)

			drm_framebuffer_unreference(obj_to_fb(ref));

	}

}



/**

 * drm_mode_connector_property_set_ioctl - set the current value of a connector property

 * @dev: DRM device
@@ -4429,8 +4455,8 @@ int drm_mode_obj_set_property_ioctl(struct drm_device *dev, void *data, 
	struct drm_mode_object *arg_obj;

	struct drm_mode_object *prop_obj;

	struct drm_property *property;

	int ret = -EINVAL;

	int i;

	int i, ret = -EINVAL;

	struct drm_mode_object *ref;



	if (!drm_core_check_feature(dev, DRIVER_MODESET))

		return -EINVAL;
@@ -4460,7 +4486,7 @@ int drm_mode_obj_set_property_ioctl(struct drm_device *dev, void *data, 
	}

	property = obj_to_property(prop_obj);



	if (!drm_property_change_is_valid(property, arg->value))

	if (!drm_property_change_valid_get(property, arg->value, &ref))

		goto out;



	switch (arg_obj->type) {
@@ -4477,6 +4503,8 @@ int drm_mode_obj_set_property_ioctl(struct drm_device *dev, void *data, 
		break;

	}



	drm_property_change_valid_put(property, ref);



out:

	drm_modeset_unlock_all(dev);

	return ret;