gem: protect idr_pre with the spinlock

There seems to be an issue if we don't protect idr_pre with
the spinlock we use for idr operations.

1 files changed, 3 insertions, 5 deletions

diff --git a/linux-core/drm_gem.c b/linux-core/drm_gem.c
index 607c8b67..0078929a 100644
--- a/linux-core/drm_gem.c
+++ b/linux-core/drm_gem.c
@@ -175,12 +175,11 @@ drm_gem_handle_create(struct drm_file *file_priv,
 	 * Get the user-visible handle using idr.
 	 */
 again:
+	/* do the allocation under our spinlock */
+	spin_lock(&file_priv->table_lock);
 	/* ensure there is space available to allocate a handle */
 	if (idr_pre_get(&file_priv->object_idr, GFP_KERNEL) == 0)
 		return -ENOMEM;
-
-	/* do the allocation under our spinlock */
-	spin_lock(&file_priv->table_lock);
 	ret = idr_get_new_above(&file_priv->object_idr, obj, 1, handlep);
 	spin_unlock(&file_priv->table_lock);
 	if (ret == -EAGAIN)
@@ -258,10 +257,9 @@ drm_gem_flink_ioctl(struct drm_device *dev, void *data,
 		return -EINVAL;
 
 again:
+	spin_lock(&dev->object_name_lock);
 	if (idr_pre_get(&dev->object_name_idr, GFP_KERNEL) == 0)
 		return -ENOMEM;
-
-	spin_lock(&dev->object_name_lock);
 	if (obj->name) {
 		args->name = (uint64_t) obj->name;
 		spin_unlock(&dev->object_name_lock);