drm: Check mode object lease status in all master ioctl paths [v4]

Attempts to modify un-leased objects are rejected with an error.
Information returned about unleased objects is modified to make them
appear unusable and/or disconnected.

Changes for v2 as suggested by Daniel Vetter <daniel.vetter@ffwll.ch>:

 * With the change in the __drm_mode_object_find API to pass the
   file_priv along, we can now centralize most of the lease-based
   access checks in that function.

 * A few places skip that API and require in-line checks.

Changes for v3 provided by Dave Airlie <airlied@redhat.com>

 * remove support for leasing encoders.
 * add support for leasing planes.

Changes for v4

 * Only call drm_lease_held if DRIVER_MODESET.

Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_auth.c

@@ -310,7 +310,7 @@ void drm_master_release(struct drm_file *file_priv)
  */
 bool drm_is_current_master(struct drm_file *fpriv)
 {
-	return fpriv->is_master && fpriv->master == fpriv->minor->dev->master;
+	return fpriv->is_master && drm_lease_owner(fpriv->master) == fpriv->minor->dev->master;
 }
 EXPORT_SYMBOL(drm_is_current_master);
 

drivers/gpu/drm/drm_encoder.c

@@ -226,15 +226,16 @@ int drm_mode_getencoder(struct drm_device *dev, void *data,
 
 	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
 	crtc = drm_encoder_get_crtc(encoder);
-	if (crtc)
+	if (crtc && drm_lease_held(file_priv, crtc->base.id))
 		enc_resp->crtc_id = crtc->base.id;
 	else
 		enc_resp->crtc_id = 0;
 	drm_modeset_unlock(&dev->mode_config.connection_mutex);
 
 	enc_resp->encoder_type = encoder->encoder_type;
 	enc_resp->encoder_id = encoder->base.id;
-	enc_resp->possible_crtcs = encoder->possible_crtcs;
+	enc_resp->possible_crtcs = drm_lease_filter_crtcs(file_priv,
+							  encoder->possible_crtcs);
 	enc_resp->possible_clones = encoder->possible_clones;
 
 	return 0;

drivers/gpu/drm/drm_mode_config.c

@@ -122,10 +122,12 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
 	count = 0;
 	crtc_id = u64_to_user_ptr(card_res->crtc_id_ptr);
 	drm_for_each_crtc(crtc, dev) {
-		if (count < card_res->count_crtcs &&
-		    put_user(crtc->base.id, crtc_id + count))
-			return -EFAULT;
-		count++;
+		if (drm_lease_held(file_priv, crtc->base.id)) {
+			if (count < card_res->count_crtcs &&
+			    put_user(crtc->base.id, crtc_id + count))
+				return -EFAULT;
+			count++;
+		}
 	}
 	card_res->count_crtcs = count;
 
@@ -143,12 +145,14 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
 	count = 0;
 	connector_id = u64_to_user_ptr(card_res->connector_id_ptr);
 	drm_for_each_connector_iter(connector, &conn_iter) {
-		if (count < card_res->count_connectors &&
-		    put_user(connector->base.id, connector_id + count)) {
-			drm_connector_list_iter_end(&conn_iter);
-			return -EFAULT;
+		if (drm_lease_held(file_priv, connector->base.id)) {
+			if (count < card_res->count_connectors &&
+			    put_user(connector->base.id, connector_id + count)) {
+				drm_connector_list_iter_end(&conn_iter);
+				return -EFAULT;
+			}
+			count++;
 		}
-		count++;
 	}
 	card_res->count_connectors = count;
 	drm_connector_list_iter_end(&conn_iter);

drivers/gpu/drm/drm_mode_object.c

@@ -104,6 +104,25 @@ void drm_mode_object_unregister(struct drm_device *dev,
 	mutex_unlock(&dev->mode_config.idr_mutex);
 }
 
+/**
+ * drm_lease_required - check types which must be leased to be used
+ * @type: type of object
+ *
+ * Returns whether the provided type of drm_mode_object must
+ * be owned or leased to be used by a process.
+ */
+static bool drm_lease_required(uint32_t type)
+{
+	switch(type) {
+	case DRM_MODE_OBJECT_CRTC:
+	case DRM_MODE_OBJECT_CONNECTOR:
+	case DRM_MODE_OBJECT_PLANE:
+		return true;
+	default:
+		return false;
+	}
+}
+
 struct drm_mode_object *__drm_mode_object_find(struct drm_device *dev,
 					       struct drm_file *file_priv,
 					       uint32_t id, uint32_t type)
@@ -117,6 +136,9 @@ struct drm_mode_object *__drm_mode_object_find(struct drm_device *dev,
 	if (obj && obj->id != id)
 		obj = NULL;
 
+	if (obj && drm_lease_required(obj->type) && !_drm_lease_held(file_priv, obj->id))
+		obj = NULL;
+
 	if (obj && obj->free_cb) {
 		if (!kref_get_unless_zero(&obj->refcount))
 			obj = NULL;

drivers/gpu/drm/drm_plane.c

@@ -479,10 +479,12 @@ int drm_mode_getplane_res(struct drm_device *dev, void *data,
 		    !file_priv->universal_planes)
 			continue;
 
-		if (count < plane_resp->count_planes &&
-		    put_user(plane->base.id, plane_ptr + count))
-			return -EFAULT;
-		count++;
+		if (drm_lease_held(file_priv, plane->base.id)) {
+			if (count < plane_resp->count_planes &&
+			    put_user(plane->base.id, plane_ptr + count))
+				return -EFAULT;
+			count++;
+		}
 	}
 	plane_resp->count_planes = count;
 
@@ -504,9 +506,9 @@ int drm_mode_getplane(struct drm_device *dev, void *data,
 		return -ENOENT;
 
 	drm_modeset_lock(&plane->mutex, NULL);
-	if (plane->state && plane->state->crtc)
+	if (plane->state && plane->state->crtc && drm_lease_held(file_priv, plane->state->crtc->base.id))
 		plane_resp->crtc_id = plane->state->crtc->base.id;
-	else if (!plane->state && plane->crtc)
+	else if (!plane->state && plane->crtc && drm_lease_held(file_priv, plane->crtc->base.id))
 		plane_resp->crtc_id = plane->crtc->base.id;
 	else
 		plane_resp->crtc_id = 0;
@@ -520,7 +522,9 @@ int drm_mode_getplane(struct drm_device *dev, void *data,
 	drm_modeset_unlock(&plane->mutex);
 
 	plane_resp->plane_id = plane->base.id;
-	plane_resp->possible_crtcs = plane->possible_crtcs;
+	plane_resp->possible_crtcs = drm_lease_filter_crtcs(file_priv,
+							    plane->possible_crtcs);
+
 	plane_resp->gamma_size = 0;
 
 	/*

drivers/gpu/drm/drm_vblank.c

@@ -1447,10 +1447,12 @@ static void drm_wait_vblank_reply(struct drm_device *dev, unsigned int pipe,
 int drm_wait_vblank_ioctl(struct drm_device *dev, void *data,
 			  struct drm_file *file_priv)
 {
+	struct drm_crtc *crtc;
 	struct drm_vblank_crtc *vblank;
 	union drm_wait_vblank *vblwait = data;
 	int ret;
 	u64 req_seq, seq;
+	unsigned int pipe_index;
 	unsigned int flags, pipe, high_pipe;
 
 	if (!dev->irq_enabled)
@@ -1472,9 +1474,25 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, void *data,
 	flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
 	high_pipe = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
 	if (high_pipe)
-		pipe = high_pipe >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
+		pipe_index = high_pipe >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
 	else
-		pipe = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
+		pipe_index = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
+
+	/* Convert lease-relative crtc index into global crtc index */
+	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+		pipe = 0;
+		drm_for_each_crtc(crtc, dev) {
+			if (drm_lease_held(file_priv, crtc->base.id)) {
+				if (pipe_index == 0)
+					break;
+				pipe_index--;
+			}
+			pipe++;
+		}
+	} else {
+		pipe = pipe_index;
+	}
+
 	if (pipe >= dev->num_crtcs)
 		return -EINVAL;
 

include/drm/drm_lease.h

@@ -31,6 +31,4 @@ void drm_lease_revoke(struct drm_master *master);
 
 uint32_t drm_lease_filter_crtcs(struct drm_file *file_priv, uint32_t crtcs);
 
-uint32_t drm_lease_filter_encoders(struct drm_file *file_priv, uint32_t encoders);
-
 #endif /* _DRM_LEASE_H_ */