Re: [PATCH v11] leds: trigger: implement a tty trigger

From: Pavel Machek
Date: Thu Feb 18 2021 - 11:25:59 EST


Hi!

Close, but see below:

> +static ssize_t ttyname_store(struct device *dev,
> + struct device_attribute *attr, const char *buf,
> + size_t size)
> +{
> + struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev);
> + char *ttyname;
> + ssize_t ret = size;
> + bool running;
> +
> + if (size > 0 && buf[size - 1] == '\n')
> + size -= 1;
> +
> + if (size) {
> + ttyname = kmemdup_nul(buf, size, GFP_KERNEL);
> + if (!ttyname) {
> + ret = -ENOMEM;
> + goto out_unlock;

Unlock without a lock:

> +out_unlock:
> + mutex_unlock(&trigger_data->mutex);
> +
> + if (ttyname && !running)
> + ledtrig_tty_restart(trigger_data);
> +
> + return ret;
> +}

> +
> + tty = tty_kopen_shared(devno);
> + if (IS_ERR(tty) || !tty)
> + /* What to do? retry or abort */
> + goto out;

Abort would make sense to me.

> + if (icount.rx != trigger_data->rx ||
> + icount.tx != trigger_data->tx) {
> + led_set_brightness(trigger_data->led_cdev, LED_ON);

Please use _sync version.

Best regards,
Pavel
--
http://www.livejournal.com/~pavelmachek

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