Commit 10b06b87 authored by Raghavendra Ganiga's avatar Raghavendra Ganiga Committed by Linus Torvalds
Browse files

drivers/rtc/rtc-ds1343.c: fix potential race condition 



Avoid the potential race condition by avoiding bailing out of driver in
probe after registering with rtc subsystem

Also the set_alarm , read_alarm and alarm_irq_enable returns error if irq
registration fails in probe.

Also the sysfs will not create entry for alarm if irq registration fails
in probe.

Signed-off-by: default avatarRaghavendra Chandra Ganiga <ravi23ganiga@gmail.com>
Acked-by: default avatarAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0dd449b1

drivers/rtc/rtc-ds1343.c

+24 −14
Original line number Diff line number Diff line
@@ -80,6 +80,7 @@ struct ds1343_priv { 
	struct regmap *map;

	struct mutex mutex;

	unsigned int irqen;

	int irq;

	int alarm_sec;

	int alarm_min;

	int alarm_hour;
@@ -262,28 +263,32 @@ static DEVICE_ATTR(trickle_charger, S_IRUGO, ds1343_show_tricklecharger, NULL); 


static int ds1343_sysfs_register(struct device *dev)

{

	struct ds1343_priv *priv = dev_get_drvdata(dev);

	int err;



	err = device_create_file(dev, &dev_attr_glitch_filter);

	if (err)

		return err;



	err = device_create_file(dev, &dev_attr_alarm_status);

	err = device_create_file(dev, &dev_attr_trickle_charger);

	if (err)

		goto error1;



	if (priv->irq <= 0)

		return err;



	err = device_create_file(dev, &dev_attr_alarm_mode);

	if (err)

		goto error2;



	err = device_create_file(dev, &dev_attr_trickle_charger);

	err = device_create_file(dev, &dev_attr_alarm_status);

	if (!err)

		return err;



	device_remove_file(dev, &dev_attr_alarm_mode);



error2:

	device_remove_file(dev, &dev_attr_alarm_status);

	device_remove_file(dev, &dev_attr_trickle_charger);



error1:

	device_remove_file(dev, &dev_attr_glitch_filter);
@@ -293,10 +298,16 @@ error1: 


static void ds1343_sysfs_unregister(struct device *dev)

{

	struct ds1343_priv *priv = dev_get_drvdata(dev);



	device_remove_file(dev, &dev_attr_glitch_filter);

	device_remove_file(dev, &dev_attr_trickle_charger);



	if (priv->irq <= 0)

		return;



	device_remove_file(dev, &dev_attr_alarm_status);

	device_remove_file(dev, &dev_attr_alarm_mode);

	device_remove_file(dev, &dev_attr_trickle_charger);

}



static int ds1343_read_time(struct device *dev, struct rtc_time *dt)
@@ -415,11 +426,10 @@ static int ds1343_update_alarm(struct device *dev) 
static int ds1343_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)

{

	struct ds1343_priv *priv = dev_get_drvdata(dev);

	struct spi_device *spi = priv->spi;

	int res = 0;

	unsigned int stat;



	if (spi->irq <= 0)

	if (priv->irq <= 0)

		return -EINVAL;



	mutex_lock(&priv->mutex);
@@ -450,10 +460,9 @@ out: 
static int ds1343_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)

{

	struct ds1343_priv *priv = dev_get_drvdata(dev);

	struct spi_device *spi = priv->spi;

	int res = 0;



	if (spi->irq <= 0)

	if (priv->irq <= 0)

		return -EINVAL;



	mutex_lock(&priv->mutex);
@@ -476,10 +485,9 @@ static int ds1343_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 
static int ds1343_alarm_irq_enable(struct device *dev, unsigned int enabled)

{

	struct ds1343_priv *priv = dev_get_drvdata(dev);

	struct spi_device *spi = priv->spi;

	int res = 0;



	if (spi->irq <= 0)

	if (priv->irq <= 0)

		return -EINVAL;



	mutex_lock(&priv->mutex);
@@ -593,19 +601,21 @@ static int ds1343_probe(struct spi_device *spi) 
		return PTR_ERR(priv->rtc);

	}



	if (spi->irq >= 0) {

	priv->irq = spi->irq;



	if (priv->irq >= 0) {

		res = devm_request_threaded_irq(&spi->dev, spi->irq, NULL,

						ds1343_thread,

						IRQF_NO_SUSPEND | IRQF_ONESHOT,

						"ds1343", priv);

		if (res) {

			priv->irq = -1;

			dev_err(&spi->dev,

				"unable to request irq for rtc ds1343\n");

			return res;

		}



		} else {

			device_set_wakeup_capable(&spi->dev, 1);

		}

	}



	res = ds1343_sysfs_register(&spi->dev);

	if (res)

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