drm: Use drmm_ for drm_dev_init cleanup

Well for the simple stuff at least, vblank, gem and minor cleanup I
want to further split up as a demonstration.

v2: We need to clear drm_device->dev otherwise the debug drm printing
after our cleanup hook (e.g. in drm_manged_release) will chase
released memory and result in a use-after-free. Not really pretty, but
oh well.

Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200323144950.3018436-22-daniel.vetter@ffwll.ch

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 7e01e8c1804145008e55c14892ba80af8b568a5d..d1e930a1fc62d4e6d3985846bbd0a6570ce4d149 100644 (file)
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -580,6 +580,23 @@ static void drm_fs_inode_free(struct inode *inode)
  *    used.
  */
 
+static void drm_dev_init_release(struct drm_device *dev, void *res)
+{
+       drm_legacy_ctxbitmap_cleanup(dev);
+       drm_legacy_remove_map_hash(dev);
+       drm_fs_inode_free(dev->anon_inode);
+
+       put_device(dev->dev);
+       /* Prevent use-after-free in drm_managed_release when debugging is
+        * enabled. Slightly awkward, but can't really be helped. */
+       dev->dev = NULL;
+       mutex_destroy(&dev->master_mutex);
+       mutex_destroy(&dev->clientlist_mutex);
+       mutex_destroy(&dev->filelist_mutex);
+       mutex_destroy(&dev->struct_mutex);
+       drm_legacy_destroy_members(dev);
+}
+
 /**
  * drm_dev_init - Initialise new DRM device
  * @dev: DRM device
@@ -647,11 +664,15 @@ int drm_dev_init(struct drm_device *dev,
        mutex_init(&dev->clientlist_mutex);
        mutex_init(&dev->master_mutex);
 
+       ret = drmm_add_action(dev, drm_dev_init_release, NULL);
+       if (ret)
+               return ret;
+
        dev->anon_inode = drm_fs_inode_new();
        if (IS_ERR(dev->anon_inode)) {
                ret = PTR_ERR(dev->anon_inode);
                DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
-               goto err_free;
+               goto err;
        }
 
        if (drm_core_check_feature(dev, DRIVER_RENDER)) {
@@ -688,19 +709,12 @@ err_setunique:
        if (drm_core_check_feature(dev, DRIVER_GEM))
                drm_gem_destroy(dev);
 err_ctxbitmap:
-       drm_legacy_ctxbitmap_cleanup(dev);
-       drm_legacy_remove_map_hash(dev);
 err_minors:
        drm_minor_free(dev, DRM_MINOR_PRIMARY);
        drm_minor_free(dev, DRM_MINOR_RENDER);
-       drm_fs_inode_free(dev->anon_inode);
-err_free:
-       put_device(dev->dev);
-       mutex_destroy(&dev->master_mutex);
-       mutex_destroy(&dev->clientlist_mutex);
-       mutex_destroy(&dev->filelist_mutex);
-       mutex_destroy(&dev->struct_mutex);
-       drm_legacy_destroy_members(dev);
+err:
+       drm_managed_release(dev);
+
        return ret;
 }
 EXPORT_SYMBOL(drm_dev_init);
@@ -763,20 +777,8 @@ void drm_dev_fini(struct drm_device *dev)
        if (drm_core_check_feature(dev, DRIVER_GEM))
                drm_gem_destroy(dev);
 
-       drm_legacy_ctxbitmap_cleanup(dev);
-       drm_legacy_remove_map_hash(dev);
-       drm_fs_inode_free(dev->anon_inode);
-
        drm_minor_free(dev, DRM_MINOR_PRIMARY);
        drm_minor_free(dev, DRM_MINOR_RENDER);
-
-       put_device(dev->dev);
-
-       mutex_destroy(&dev->master_mutex);
-       mutex_destroy(&dev->clientlist_mutex);
-       mutex_destroy(&dev->filelist_mutex);
-       mutex_destroy(&dev->struct_mutex);
-       drm_legacy_destroy_members(dev);
 }
 EXPORT_SYMBOL(drm_dev_fini);