[PATCH 06/16] drm: cleanup render node ioctls

[Ilija Hadzic]

Fix a few bugs in render node create and destroy ioctl
(mostly handling of error cases). Also separate some
common code into a new function for destroying
the render node.

Signed-off-by: Ilija Hadzic <ihadzic at research.bell-labs.com>
---
 drivers/gpu/drm/drm_stub.c |   80 +++++++++++++++++++++++++++----------------
 1 files changed, 50 insertions(+), 30 deletions(-)

diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index ba6cb52..12260f0 100644
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -420,17 +420,30 @@ int drm_create_render_node(struct drm_device *dev, struct drm_minor **minor_p)
 	return 0;
 }
 
-int drm_destroy_all_render_nodes(struct drm_device *dev)
+int drm_destroy_render_node(struct drm_device *dev, int index)
 {
-	struct drm_render_node *render_node, *tmp;
+	struct drm_render_node *node, *tmp;
+
+	list_for_each_entry_safe(node, tmp, &dev->render_node_list, list) {
+		if (node->minor->index == index) {
+			list_del(&node->list);
+			drm_put_minor(&node->minor);
+			kfree(node);
+			return 0;
+		}
+	}
+	return -ENODEV;
+}
 
-	list_for_each_entry_safe(render_node, tmp,
-				 &dev->render_node_list, list) {
-		list_del(&render_node->list);
-		drm_put_minor(&render_node->minor);
-		kfree(render_node);
+void drm_destroy_all_render_nodes(struct drm_device *dev)
+{
+	struct drm_render_node *node, *tmp;
+
+	list_for_each_entry_safe(node, tmp, &dev->render_node_list, list) {
+		list_del(&node->list);
+		drm_put_minor(&node->minor);
+		kfree(node);
 	}
-	return 0;
 }
 
 /**
@@ -538,38 +551,48 @@ int drm_render_node_create_ioctl(struct drm_device *dev, void *data,
 	struct drm_minor *new_minor;
 	int total_ids, i;
 	uint32_t __user *ids_ptr;
-	ret = drm_create_render_node(dev, &new_minor);
-	if (ret)
-		goto out;
-
-	args->node_minor_id = new_minor->index;
 
+	/* trivial case: render node with no display resources */
 	if (args->num_crtc == 0 &&
 	    args->num_encoder == 0 &&
-	    args->num_connector == 0)
-		goto out;
-	if (args->num_crtc == 0 ||
-	    args->num_encoder == 0 ||
 	    args->num_connector == 0) {
-		ret = -EINVAL;
-		goto out;
+		ret = drm_create_render_node(dev, &new_minor);
+		if (!ret)
+			args->node_minor_id = new_minor->index;
+		return ret;
 	}
 
+	/* if we have display resources, then we need at least
+	 * one CRTC, one encoder and one connector */
+	if (args->num_crtc == 0 ||
+	    args->num_encoder == 0 ||
+	    args->num_connector == 0)
+		return -EINVAL;
+
+	ret = drm_create_render_node(dev, &new_minor);
+	if (ret)
+		return ret;
+
 	ret = drm_mode_group_init(dev, &new_minor->mode_group);
 	if (ret)
-		goto out;
+		goto out_del;
 
 	ids_ptr = (uint32_t __user *)(unsigned long)args->id_list_ptr;
 	total_ids = args->num_crtc + args->num_encoder + args->num_connector;
 	for (i = 0; i < total_ids; i++) {
 		if (get_user(new_minor->mode_group.id_list[i], &ids_ptr[i])) {
 			ret = -EFAULT;
-			goto out_put;
+			goto out_del;
 		}
 	}
-out_put:
-	drm_put_minor(&new_minor);
-out:
+	new_minor->mode_group.num_crtcs = args->num_crtc;
+	new_minor->mode_group.num_encoders = args->num_encoder;
+	new_minor->mode_group.num_connectors = args->num_connector;
+
+	args->node_minor_id = new_minor->index;
+	return 0;
+out_del:
+	drm_destroy_render_node(dev, new_minor->index);
 	return ret;
 }
 
@@ -577,11 +600,8 @@ int drm_render_node_remove_ioctl(struct drm_device *dev, void *data,
 				 struct drm_file *file_priv)
 {
 	struct drm_render_node_remove *args = data;
-	struct drm_render_node *del_node, *tmp;
+	int ret;
 
-	list_for_each_entry_safe(del_node, tmp, &dev->render_node_list, list) {
-		if (del_node->minor->index == args->node_minor_id)
-			drm_put_minor(&del_node->minor);
-	}
-	return 0;
+	ret = drm_destroy_render_node(dev, args->node_minor_id);
+	return ret;
 }
-- 
1.7.8.5