netdevsim: move devlink registration under the instance lock

To prevent races with netdev code accessing free devlink instances
move the registration under the devlink instance lock.
Core now waits for the instance to be registered before accessing it.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/netdevsim/dev.c

@@ -1556,10 +1556,14 @@ int nsim_drv_probe(struct nsim_bus_dev *nsim_bus_dev)
 		goto err_devlink_unlock;
 	}
 
-	err = nsim_dev_resources_register(devlink);
+	err = devl_register(devlink);
 	if (err)
 		goto err_vfc_free;
 
+	err = nsim_dev_resources_register(devlink);
+	if (err)
+		goto err_dl_unregister;
+
 	err = devlink_params_register(devlink, nsim_devlink_params,
 				      ARRAY_SIZE(nsim_devlink_params));
 	if (err)
@@ -1607,7 +1611,6 @@ int nsim_drv_probe(struct nsim_bus_dev *nsim_bus_dev)
 	nsim_dev->esw_mode = DEVLINK_ESWITCH_MODE_LEGACY;
 	devlink_set_features(devlink, DEVLINK_F_RELOAD);
 	devl_unlock(devlink);
-	devlink_register(devlink);
 	return 0;
 
 err_hwstats_exit:
@@ -1631,6 +1634,8 @@ int nsim_drv_probe(struct nsim_bus_dev *nsim_bus_dev)
 				  ARRAY_SIZE(nsim_devlink_params));
 err_resource_unregister:
 	devl_resources_unregister(devlink);
+err_dl_unregister:
+	devl_unregister(devlink);
 err_vfc_free:
 	kfree(nsim_dev->vfconfigs);
 err_devlink_unlock:
@@ -1668,7 +1673,6 @@ void nsim_drv_remove(struct nsim_bus_dev *nsim_bus_dev)
 	struct nsim_dev *nsim_dev = dev_get_drvdata(&nsim_bus_dev->dev);
 	struct devlink *devlink = priv_to_devlink(nsim_dev);
 
-	devlink_unregister(devlink);
 	devl_lock(devlink);
 	nsim_dev_reload_destroy(nsim_dev);
 
@@ -1677,6 +1681,7 @@ void nsim_drv_remove(struct nsim_bus_dev *nsim_bus_dev)
 	devlink_params_unregister(devlink, nsim_devlink_params,
 				  ARRAY_SIZE(nsim_devlink_params));
 	devl_resources_unregister(devlink);
+	devl_unregister(devlink);
 	kfree(nsim_dev->vfconfigs);
 	kfree(nsim_dev->fa_cookie);
 	devl_unlock(devlink);