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authorRaghavendra Ganiga <ravi23ganiga@gmail.com>2014-06-06 14:36:01 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-06-06 16:08:08 -0700
commit10b06b87b77e9fcd7d1282f8cacf9736fb5143b3 (patch)
treedce63ae7ddb4aa4439c64e5c82f6403ba082d39d /drivers/rtc/rtc-ds1343.c
parent0dd449b1626c3db6b40fc2c7685bf9b0ac79ce00 (diff)
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 <ravi23ganiga@gmail.com> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/rtc/rtc-ds1343.c')
-rw-r--r--drivers/rtc/rtc-ds1343.c38
1 files 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 @@ 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);
@@ -593,18 +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);