Commit b1b102bf authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
Browse files

Merge tag 'counter-fixes-for-6.15' of... 

Merge tag 'counter-fixes-for-6.15' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wbg/counter into char-misc-next

William writes:

Counter fixes for 6.15

A fix to prevent a race condition when accessing the Count enable
component in interrupt-cnt.

* tag 'counter-fixes-for-6.15' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wbg/counter:
  counter: interrupt-cnt: Protect enable/disable OPs with mutex
parents 81e9edc1 73513126

drivers/counter/interrupt-cnt.c

+9 −0
Original line number Diff line number Diff line
@@ -3,12 +3,14 @@ 
 * Copyright (c) 2021 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>

 */



#include <linux/cleanup.h>

#include <linux/counter.h>

#include <linux/gpio/consumer.h>

#include <linux/interrupt.h>

#include <linux/irq.h>

#include <linux/mod_devicetable.h>

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/platform_device.h>

#include <linux/types.h>
@@ -19,6 +21,7 @@ struct interrupt_cnt_priv { 
	struct gpio_desc *gpio;

	int irq;

	bool enabled;

	struct mutex lock;

	struct counter_signal signals;

	struct counter_synapse synapses;

	struct counter_count cnts;
@@ -41,6 +44,8 @@ static int interrupt_cnt_enable_read(struct counter_device *counter, 
{

	struct interrupt_cnt_priv *priv = counter_priv(counter);



	guard(mutex)(&priv->lock);



	*enable = priv->enabled;



	return 0;
@@ -51,6 +56,8 @@ static int interrupt_cnt_enable_write(struct counter_device *counter, 
{

	struct interrupt_cnt_priv *priv = counter_priv(counter);



	guard(mutex)(&priv->lock);



	if (priv->enabled == enable)

		return 0;
@@ -227,6 +234,8 @@ static int interrupt_cnt_probe(struct platform_device *pdev) 
	if (ret)

		return ret;



	mutex_init(&priv->lock);



	ret = devm_counter_add(dev, counter);

	if (ret < 0)

		return dev_err_probe(dev, ret, "Failed to add counter\n");