Commit bfd7b2d9 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

Merge tag 'devfreq-next-for-6.8' of... 

Merge tag 'devfreq-next-for-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux into pm-devfreq

Merge devfreq updates for v6.8 from Chanwoo Choi:

"1. Fix buffer overflow of trans_stat_show sysfs node on devfreq core

    - Fix buffer overflow of trans_stat_show sysfs node to replace
      sprintf with scnprintf and then replace it with sysfs_emit
      according to the syfs guide.

 2. Fix the timer list corruption when frequent switching of governor
    by synchronizing the devfreq_moniotr_start and _stop function."

* tag 'devfreq-next-for-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux:
  PM / devfreq: Synchronize devfreq_monitor_[start/stop]
  PM / devfreq: Convert to use sysfs_emit_at() API
  PM / devfreq: Fix buffer overflow in trans_stat_show
parents ceb6a6f0 aed5ed59

Documentation/ABI/testing/sysfs-class-devfreq

+3 −0
Original line number Diff line number Diff line
@@ -52,6 +52,9 @@ Description: 


			echo 0 > /sys/class/devfreq/.../trans_stat



		If the transition table is bigger than PAGE_SIZE, reading

		this will return an -EFBIG error.



What:		/sys/class/devfreq/.../available_frequencies

Date:		October 2012

Contact:	Nishanth Menon <nm@ti.com>

drivers/devfreq/devfreq.c

+59 −21
Original line number Diff line number Diff line
@@ -461,10 +461,14 @@ static void devfreq_monitor(struct work_struct *work) 
	if (err)

		dev_err(&devfreq->dev, "dvfs failed with (%d) error\n", err);



	if (devfreq->stop_polling)

		goto out;



	queue_delayed_work(devfreq_wq, &devfreq->work,

				msecs_to_jiffies(devfreq->profile->polling_ms));

	mutex_unlock(&devfreq->lock);



out:

	mutex_unlock(&devfreq->lock);

	trace_devfreq_monitor(devfreq);

}
@@ -483,6 +487,10 @@ void devfreq_monitor_start(struct devfreq *devfreq) 
	if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))

		return;



	mutex_lock(&devfreq->lock);

	if (delayed_work_pending(&devfreq->work))

		goto out;



	switch (devfreq->profile->timer) {

	case DEVFREQ_TIMER_DEFERRABLE:

		INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor);
@@ -491,12 +499,16 @@ void devfreq_monitor_start(struct devfreq *devfreq) 
		INIT_DELAYED_WORK(&devfreq->work, devfreq_monitor);

		break;

	default:

		return;

		goto out;

	}



	if (devfreq->profile->polling_ms)

		queue_delayed_work(devfreq_wq, &devfreq->work,

			msecs_to_jiffies(devfreq->profile->polling_ms));



out:

	devfreq->stop_polling = false;

	mutex_unlock(&devfreq->lock);

}

EXPORT_SYMBOL(devfreq_monitor_start);
@@ -513,6 +525,14 @@ void devfreq_monitor_stop(struct devfreq *devfreq) 
	if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))

		return;



	mutex_lock(&devfreq->lock);

	if (devfreq->stop_polling) {

		mutex_unlock(&devfreq->lock);

		return;

	}



	devfreq->stop_polling = true;

	mutex_unlock(&devfreq->lock);

	cancel_delayed_work_sync(&devfreq->work);

}

EXPORT_SYMBOL(devfreq_monitor_stop);
@@ -1688,7 +1708,7 @@ static ssize_t trans_stat_show(struct device *dev, 
			       struct device_attribute *attr, char *buf)

{

	struct devfreq *df = to_devfreq(dev);

	ssize_t len;

	ssize_t len = 0;

	int i, j;

	unsigned int max_state;
@@ -1697,7 +1717,7 @@ static ssize_t trans_stat_show(struct device *dev, 
	max_state = df->max_state;



	if (max_state == 0)

		return sprintf(buf, "Not Supported.\n");

		return sysfs_emit(buf, "Not Supported.\n");



	mutex_lock(&df->lock);

	if (!df->stop_polling &&
@@ -1707,31 +1727,49 @@ static ssize_t trans_stat_show(struct device *dev, 
	}

	mutex_unlock(&df->lock);



	len = sprintf(buf, "     From  :   To\n");

	len += sprintf(buf + len, "           :");

	for (i = 0; i < max_state; i++)

		len += sprintf(buf + len, "%10lu",

	len += sysfs_emit_at(buf, len, "     From  :   To\n");

	len += sysfs_emit_at(buf, len, "           :");

	for (i = 0; i < max_state; i++) {

		if (len >= PAGE_SIZE - 1)

			break;

		len += sysfs_emit_at(buf, len, "%10lu",

				     df->freq_table[i]);

	}



	len += sprintf(buf + len, "   time(ms)\n");

	if (len >= PAGE_SIZE - 1)

		return PAGE_SIZE - 1;

	len += sysfs_emit_at(buf, len, "   time(ms)\n");



	for (i = 0; i < max_state; i++) {

		if (df->freq_table[i] == df->previous_freq)

			len += sprintf(buf + len, "*");

		if (len >= PAGE_SIZE - 1)

			break;

		if (df->freq_table[2] == df->previous_freq)

			len += sysfs_emit_at(buf, len, "*");

		else

			len += sprintf(buf + len, " ");



		len += sprintf(buf + len, "%10lu:", df->freq_table[i]);

		for (j = 0; j < max_state; j++)

			len += sprintf(buf + len, "%10u",

			len += sysfs_emit_at(buf, len, " ");

		if (len >= PAGE_SIZE - 1)

			break;

		len += sysfs_emit_at(buf, len, "%10lu:", df->freq_table[i]);

		for (j = 0; j < max_state; j++) {

			if (len >= PAGE_SIZE - 1)

				break;

			len += sysfs_emit_at(buf, len, "%10u",

				df->stats.trans_table[(i * max_state) + j]);



		len += sprintf(buf + len, "%10llu\n", (u64)

		}

		if (len >= PAGE_SIZE - 1)

			break;

		len += sysfs_emit_at(buf, len, "%10llu\n", (u64)

				     jiffies64_to_msecs(df->stats.time_in_state[i]));

	}



	len += sprintf(buf + len, "Total transition : %u\n",

	if (len < PAGE_SIZE - 1)

		len += sysfs_emit_at(buf, len, "Total transition : %u\n",

				     df->stats.total_trans);

	if (len >= PAGE_SIZE - 1) {

		pr_warn_once("devfreq transition table exceeds PAGE_SIZE. Disabling\n");

		return -EFBIG;

	}



	return len;

}