From 10b06b87b77e9fcd7d1282f8cacf9736fb5143b3 Mon Sep 17 00:00:00 2001 From: Raghavendra Ganiga Date: Fri, 6 Jun 2014 14:36:01 -0700 Subject: [PATCH] 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: Raghavendra Chandra Ganiga Acked-by: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-ds1343.c | 38 ++++++++++++++++++++++++-------------- 1 file changed, 24 insertions(+), 14 deletions(-) diff --git a/drivers/rtc/rtc-ds1343.c b/drivers/rtc/rtc-ds1343.c index 8ccc75021175..c3719189dd96 100644 --- a/drivers/rtc/rtc-ds1343.c +++ b/drivers/rtc/rtc-ds1343.c @@ -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 @@ static int ds1343_sysfs_register(struct device *dev) 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 @@ static int ds1343_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 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); @@ -593,18 +601,20 @@ 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); } - - device_set_wakeup_capable(&spi->dev, 1); } res = ds1343_sysfs_register(&spi->dev); -- GitLab