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.

diff --git a/linux-core/drm_gem.c b/linux-core/drm_gem.c
index 607c8b6..0078929 100644 (file)
--- 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);