1 files changed, 47 insertions, 23 deletions

diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index 90dfa0df747..0a870b7e5c3 100644
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -13,6 +13,7 @@
 
 #include <linux/module.h>
 #include <linux/rtc.h>
+#include <linux/smp_lock.h>
 #include "rtc-core.h"
 
 static dev_t rtc_devt;
@@ -26,8 +27,11 @@ static int rtc_dev_open(struct inode *inode, struct file *file)
 					struct rtc_device, char_dev);
 	const struct rtc_class_ops *ops = rtc->ops;
 
-	if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
-		return -EBUSY;
+	lock_kernel();
+	if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags)) {
+		err = -EBUSY;
+		goto out;
+	}
 
 	file->private_data = rtc;
 
@@ -37,11 +41,13 @@ static int rtc_dev_open(struct inode *inode, struct file *file)
 		rtc->irq_data = 0;
 		spin_unlock_irq(&rtc->irq_lock);
 
-		return 0;
+		goto out;
 	}
 
 	/* something has gone wrong */
 	clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
+out:
+	unlock_kernel();
 	return err;
 }
 
@@ -203,7 +209,7 @@ static unsigned int rtc_dev_poll(struct file *file, poll_table *wait)
 	return (data != 0) ? (POLLIN | POLLRDNORM) : 0;
 }
 
-static int rtc_dev_ioctl(struct inode *inode, struct file *file,
+static long rtc_dev_ioctl(struct file *file,
 		unsigned int cmd, unsigned long arg)
 {
 	int err = 0;
@@ -213,6 +219,10 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file,
 	struct rtc_wkalrm alarm;
 	void __user *uarg = (void __user *) arg;
 
+	err = mutex_lock_interruptible(&rtc->ops_lock);
+	if (err)
+		return -EBUSY;
+
 	/* check that the calling task has appropriate permissions
 	 * for certain ioctls. doing this check here is useful
 	 * to avoid duplicate code in each driver.
@@ -221,26 +231,31 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file,
 	case RTC_EPOCH_SET:
 	case RTC_SET_TIME:
 		if (!capable(CAP_SYS_TIME))
-			return -EACCES;
+			err = -EACCES;
 		break;
 
 	case RTC_IRQP_SET:
 		if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE))
-			return -EACCES;
+			err = -EACCES;
 		break;
 
 	case RTC_PIE_ON:
 		if (rtc->irq_freq > rtc->max_user_freq &&
 				!capable(CAP_SYS_RESOURCE))
-			return -EACCES;
+			err = -EACCES;
 		break;
 	}
 
+	if (err)
+		goto done;
+
 	/* try the driver's ioctl interface */
 	if (ops->ioctl) {
 		err = ops->ioctl(rtc->dev.parent, cmd, arg);
-		if (err != -ENOIOCTLCMD)
+		if (err != -ENOIOCTLCMD) {
+			mutex_unlock(&rtc->ops_lock);
 			return err;
+		}
 	}
 
 	/* if the driver does not provide the ioctl interface
@@ -259,15 +274,19 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file,
 
 	switch (cmd) {
 	case RTC_ALM_READ:
+		mutex_unlock(&rtc->ops_lock);
+
 		err = rtc_read_alarm(rtc, &alarm);
 		if (err < 0)
 			return err;
 
 		if (copy_to_user(uarg, &alarm.time, sizeof(tm)))
-			return -EFAULT;
-		break;
+			err = -EFAULT;
+		return err;
 
 	case RTC_ALM_SET:
+		mutex_unlock(&rtc->ops_lock);
+
 		if (copy_from_user(&alarm.time, uarg, sizeof(tm)))
 			return -EFAULT;
 
@@ -315,24 +334,26 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file,
 			}
 		}
 
-		err = rtc_set_alarm(rtc, &alarm);
-		break;
+		return rtc_set_alarm(rtc, &alarm);
 
 	case RTC_RD_TIME:
+		mutex_unlock(&rtc->ops_lock);
+
 		err = rtc_read_time(rtc, &tm);
 		if (err < 0)
 			return err;
 
 		if (copy_to_user(uarg, &tm, sizeof(tm)))
-			return -EFAULT;
-		break;
+			err = -EFAULT;
+		return err;
 
 	case RTC_SET_TIME:
+		mutex_unlock(&rtc->ops_lock);
+
 		if (copy_from_user(&tm, uarg, sizeof(tm)))
 			return -EFAULT;
 
-		err = rtc_set_time(rtc, &tm);
-		break;
+		return rtc_set_time(rtc, &tm);
 
 	case RTC_PIE_ON:
 		err = rtc_irq_set_state(rtc, NULL, 1);
@@ -370,34 +391,37 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file,
 		break;
 #endif
 	case RTC_WKALM_SET:
+		mutex_unlock(&rtc->ops_lock);
 		if (copy_from_user(&alarm, uarg, sizeof(alarm)))
 			return -EFAULT;
 
-		err = rtc_set_alarm(rtc, &alarm);
-		break;
+		return rtc_set_alarm(rtc, &alarm);
 
 	case RTC_WKALM_RD:
+		mutex_unlock(&rtc->ops_lock);
 		err = rtc_read_alarm(rtc, &alarm);
 		if (err < 0)
 			return err;
 
 		if (copy_to_user(uarg, &alarm, sizeof(alarm)))
-			return -EFAULT;
-		break;
+			err = -EFAULT;
+		return err;
 
 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
 	case RTC_UIE_OFF:
 		clear_uie(rtc);
-		return 0;
+		break;
 
 	case RTC_UIE_ON:
-		return set_uie(rtc);
+		err = set_uie(rtc);
 #endif
 	default:
 		err = -ENOTTY;
 		break;
 	}
 
+done:
+	mutex_unlock(&rtc->ops_lock);
 	return err;
 }
 
@@ -426,7 +450,7 @@ static const struct file_operations rtc_dev_fops = {
 	.llseek		= no_llseek,
 	.read		= rtc_dev_read,
 	.poll		= rtc_dev_poll,
-	.ioctl		= rtc_dev_ioctl,
+	.unlocked_ioctl	= rtc_dev_ioctl,
 	.open		= rtc_dev_open,
 	.release	= rtc_dev_release,
 	.fasync		= rtc_dev_fasync,