static ssize_t mbox_test_message_write()

in mailbox-test.c [93:148]

• 42 lines of code
• 9 McCabe index (conditional complexity)

static ssize_t mbox_test_message_write(struct file *filp,
				       const char __user *userbuf,
				       size_t count, loff_t *ppos)
{
	struct mbox_test_device *tdev = filp->private_data;
	void *data;
	int ret;

	if (!tdev->tx_channel) {
		dev_err(tdev->dev, "Channel cannot do Tx\n");
		return -EINVAL;
	}

	if (count > MBOX_MAX_MSG_LEN) {
		dev_err(tdev->dev,
			"Message length %zd greater than max allowed %d\n",
			count, MBOX_MAX_MSG_LEN);
		return -EINVAL;
	}

	tdev->message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL);
	if (!tdev->message)
		return -ENOMEM;

	ret = copy_from_user(tdev->message, userbuf, count);
	if (ret) {
		ret = -EFAULT;
		goto out;
	}

	/*
	 * A separate signal is only of use if there is
	 * MMIO to subsequently pass the message through
	 */
	if (tdev->tx_mmio && tdev->signal) {
		print_hex_dump_bytes("Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS,
				     tdev->signal, MBOX_MAX_SIG_LEN);

		data = tdev->signal;
	} else
		data = tdev->message;

	print_hex_dump_bytes("Client: Sending: Message: ", DUMP_PREFIX_ADDRESS,
			     tdev->message, MBOX_MAX_MSG_LEN);

	ret = mbox_send_message(tdev->tx_channel, data);
	if (ret < 0)
		dev_err(tdev->dev, "Failed to send message via mailbox\n");

out:
	kfree(tdev->signal);
	kfree(tdev->message);
	tdev->signal = NULL;

	return ret < 0 ? ret : count;
}