rtc: allow validated RTC_PIE_ON for non-root

drivers/char/rtc.c allowed RTC_PIE_ON ioctls for non-root users, as long as
the current interval (set via RTC_IRQP_SET) is <= max_user_freq.  Allow
RTC_PIE_ON under the same conditions when /dev/rtc* is handled by the rtc
subsystem.

Signed-off-by: Bryan Kadzban <bryan@kdzbn.homelinux.net>
Acked-by: Alessandro Zummo <alessandro.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index 87d4add6b7f6..814583bd2fe7 100644
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -233,7 +233,8 @@ static int rtc_dev_ioctl(struct inode *inode, struct file *file,
                 break;
 
         case RTC_PIE_ON:
-                if (!capable(CAP_SYS_RESOURCE))
+                if (rtc->irq_freq > rtc->max_user_freq &&
+                                !capable(CAP_SYS_RESOURCE))
                         return -EACCES;
                 break;
         }