drm/exynos: release resources properly when fb creation is failed.

This patch releases allocated resources properly when
exynos_user_fb_create() is failed.
Signed-off-by: YoungJun Cho <yj44.cho@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_fb.c

@@ -221,23 +221,25 @@ exynos_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
 		      struct drm_mode_fb_cmd2 *mode_cmd)
 {
 	struct drm_gem_object *obj;
+	struct exynos_drm_gem_obj *exynos_gem_obj;
 	struct exynos_drm_fb *exynos_fb;
 	int i, ret;
 
 	DRM_DEBUG_KMS("%s\n", __FILE__);
 
-	obj = drm_gem_object_lookup(dev, file_priv, mode_cmd->handles[0]);
-	if (!obj) {
-		DRM_ERROR("failed to lookup gem object\n");
-		return ERR_PTR(-ENOENT);
-	}
-
 	exynos_fb = kzalloc(sizeof(*exynos_fb), GFP_KERNEL);
 	if (!exynos_fb) {
 		DRM_ERROR("failed to allocate exynos drm framebuffer\n");
 		return ERR_PTR(-ENOMEM);
 	}
 
+	obj = drm_gem_object_lookup(dev, file_priv, mode_cmd->handles[0]);
+	if (!obj) {
+		DRM_ERROR("failed to lookup gem object\n");
+		ret = -ENOENT;
+		goto err_free;
+	}
+
 	drm_helper_mode_fill_fb_struct(&exynos_fb->fb, mode_cmd);
 	exynos_fb->exynos_gem_obj[0] = to_exynos_gem_obj(obj);
 	exynos_fb->buf_cnt = exynos_drm_format_num_buffers(mode_cmd);
@@ -245,43 +247,44 @@ exynos_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
 	DRM_DEBUG_KMS("buf_cnt = %d\n", exynos_fb->buf_cnt);
 
 	for (i = 1; i < exynos_fb->buf_cnt; i++) {
-		struct exynos_drm_gem_obj *exynos_gem_obj;
-		int ret;
-
 		obj = drm_gem_object_lookup(dev, file_priv,
 				mode_cmd->handles[i]);
 		if (!obj) {
 			DRM_ERROR("failed to lookup gem object\n");
-			kfree(exynos_fb);
-			return ERR_PTR(-ENOENT);
+			ret = -ENOENT;
+			exynos_fb->buf_cnt = i;
+			goto err_unreference;
 		}
 
 		exynos_gem_obj = to_exynos_gem_obj(obj);
+		exynos_fb->exynos_gem_obj[i] = exynos_gem_obj;
 
 		ret = check_fb_gem_memory_type(dev, exynos_gem_obj);
 		if (ret < 0) {
 			DRM_ERROR("cannot use this gem memory type for fb.\n");
-			kfree(exynos_fb);
-			return ERR_PTR(ret);
+			goto err_unreference;
 		}
-
-		exynos_fb->exynos_gem_obj[i] = to_exynos_gem_obj(obj);
 	}
 
 	ret = drm_framebuffer_init(dev, &exynos_fb->fb, &exynos_drm_fb_funcs);
 	if (ret) {
+		DRM_ERROR("failed to init framebuffer.\n");
+		goto err_unreference;
+	}
+
+	return &exynos_fb->fb;
+
+err_unreference:
 	for (i = 0; i < exynos_fb->buf_cnt; i++) {
-			struct exynos_drm_gem_obj *gem_obj;
+		struct drm_gem_object *obj;
 
-			gem_obj = exynos_fb->exynos_gem_obj[i];
-			drm_gem_object_unreference_unlocked(&gem_obj->base);
+		obj = &exynos_fb->exynos_gem_obj[i]->base;
+		if (obj)
+			drm_gem_object_unreference_unlocked(obj);
 	}
-
+err_free:
 	kfree(exynos_fb);
 	return ERR_PTR(ret);
-	}
-
-	return &exynos_fb->fb;
 }
 
 struct exynos_drm_gem_buf *exynos_drm_fb_buffer(struct drm_framebuffer *fb,