int optee_open_session()

in optee/call.c [140:218]
62 lines of code
8 McCabe index (conditional complexity)

int optee_open_session(struct tee_context *ctx,
		       struct tee_ioctl_open_session_arg *arg,
		       struct tee_param *param)
{
	struct optee *optee = tee_get_drvdata(ctx->teedev);
	struct optee_context_data *ctxdata = ctx->data;
	int rc;
	struct tee_shm *shm;
	struct optee_msg_arg *msg_arg;
	struct optee_session *sess = NULL;
	uuid_t client_uuid;

	/* +2 for the meta parameters added below */
	shm = optee_get_msg_arg(ctx, arg->num_params + 2, &msg_arg);
	if (IS_ERR(shm))
		return PTR_ERR(shm);

	msg_arg->cmd = OPTEE_MSG_CMD_OPEN_SESSION;
	msg_arg->cancel_id = arg->cancel_id;

	/*
	 * Initialize and add the meta parameters needed when opening a
	 * session.
	 */
	msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT |
				  OPTEE_MSG_ATTR_META;
	msg_arg->params[1].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT |
				  OPTEE_MSG_ATTR_META;
	memcpy(&msg_arg->params[0].u.value, arg->uuid, sizeof(arg->uuid));
	msg_arg->params[1].u.value.c = arg->clnt_login;

	rc = tee_session_calc_client_uuid(&client_uuid, arg->clnt_login,
					  arg->clnt_uuid);
	if (rc)
		goto out;
	export_uuid(msg_arg->params[1].u.octets, &client_uuid);

	rc = optee->ops->to_msg_param(optee, msg_arg->params + 2,
				      arg->num_params, param);
	if (rc)
		goto out;

	sess = kzalloc(sizeof(*sess), GFP_KERNEL);
	if (!sess) {
		rc = -ENOMEM;
		goto out;
	}

	if (optee->ops->do_call_with_arg(ctx, shm)) {
		msg_arg->ret = TEEC_ERROR_COMMUNICATION;
		msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
	}

	if (msg_arg->ret == TEEC_SUCCESS) {
		/* A new session has been created, add it to the list. */
		sess->session_id = msg_arg->session;
		mutex_lock(&ctxdata->mutex);
		list_add(&sess->list_node, &ctxdata->sess_list);
		mutex_unlock(&ctxdata->mutex);
	} else {
		kfree(sess);
	}

	if (optee->ops->from_msg_param(optee, param, arg->num_params,
				       msg_arg->params + 2)) {
		arg->ret = TEEC_ERROR_COMMUNICATION;
		arg->ret_origin = TEEC_ORIGIN_COMMS;
		/* Close session again to avoid leakage */
		optee_close_session(ctx, msg_arg->session);
	} else {
		arg->session = msg_arg->session;
		arg->ret = msg_arg->ret;
		arg->ret_origin = msg_arg->ret_origin;
	}
out:
	tee_shm_free(shm);

	return rc;
}