On Thu, May 02, 2024 at 09:55:23AM +0200, Christoph Fritz wrote:
> This patch adds a LIN (local interconnect network) bus abstraction on
> top of CAN. It is a glue driver adapting CAN on one side while offering
> LIN abstraction on the other side. So that upcoming LIN device drivers
> can make use of it.
>
> Tested-by: Andreas Lauser <andreas.lauser@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Christoph Fritz <christoph.fritz@xxxxxxxxx>
...
> diff --git a/drivers/net/can/lin.c b/drivers/net/can/lin.c
...
> +struct lin_device *register_lin(struct device *dev,
> + const struct lin_device_ops *ldops)
> +{
> + struct net_device *ndev;
> + struct lin_device *ldev;
> + int ret;
> +
> + if (!ldops || !ldops->ldo_tx || !ldops->update_bitrate ||
> + !ldops->ldo_open || !ldops->ldo_stop) {
> + netdev_err(ndev, "missing mandatory lin_device_ops\n");
Hi Christoph,
The line above uses ndev, but ndev is not initialised
until a few lines further down.
Flagged by Smatch.
> + return ERR_PTR(-EINVAL);
> + }
> +
> + ndev = alloc_candev(sizeof(struct lin_device), 1);
> + if (!ndev)
> + return ERR_PTR(-ENOMEM);
> +
> + ldev = netdev_priv(ndev);
> +
> + ldev->ldev_ops = ldops;
> + ndev->netdev_ops = &lin_netdev_ops;
> + ndev->flags |= IFF_ECHO;
> + ndev->mtu = CANFD_MTU;
> + ldev->can.bittiming.bitrate = LIN_DEFAULT_BAUDRATE;
> + ldev->can.ctrlmode = CAN_CTRLMODE_LIN;
> + ldev->can.ctrlmode_supported = 0;
> + ldev->can.bitrate_const = lin_bitrate;
> + ldev->can.bitrate_const_cnt = ARRAY_SIZE(lin_bitrate);
> + ldev->can.do_set_bittiming = lin_set_bittiming;
> + ldev->ndev = ndev;
> + ldev->dev = dev;
> +
> + SET_NETDEV_DEV(ndev, dev);
> +
> + ret = lin_set_bittiming(ndev);
> + if (ret) {
> + netdev_err(ndev, "set bittiming failed\n");
> + goto exit_candev;
> + }
> +
> + ret = register_candev(ndev);
> + if (ret)
> + goto exit_candev;
> +
> + ldev->lin_ids_kobj = kobject_create_and_add("lin_ids", &ndev->dev.kobj);
> + if (!ldev->lin_ids_kobj) {
> + netdev_err(ndev, "Failed to create sysfs directory\n");
> + ret = -ENOMEM;
> + goto exit_unreg;
> + }
> +
> + ret = lin_create_sysfs_id_files(ndev);
> + if (ret) {
> + netdev_err(ndev, "Failed to create sysfs entry: %d\n", ret);
> + goto exit_kobj_put;
> + }
> +
> + /* Using workqueue as tx over USB/SPI/... may sleep */
> + ldev->wq = alloc_workqueue(dev_name(dev), WQ_FREEZABLE | WQ_MEM_RECLAIM,
> + 0);
> + if (!ldev->wq)
> + goto exit_rm_files;
The goto above will result in: return ERR_PTR(ret)
But ret is 0 here. Should it be set to a negative error value?
Also flagged by Smatch.
> +
> + INIT_WORK(&ldev->tx_work, lin_tx_work_handler);
> +
> + netdev_info(ndev, "LIN initialized.\n");
> +
> + return ldev;
> +
> +exit_rm_files:
> + lin_remove_sysfs_id_files(ndev);
> +exit_kobj_put:
> + kobject_put(ldev->lin_ids_kobj);
> +exit_unreg:
> + unregister_candev(ndev);
> +exit_candev:
> + free_candev(ndev);
> + return ERR_PTR(ret);
> +}
> +EXPORT_SYMBOL_GPL(register_lin);
...
