RTC: Prevents a division by zero in kernel code.
This patch prevents a user space program from calling the RTC_IRQP_SET
ioctl with a negative value of frequency. Also, if this call is make
with a zero value of frequency, there would be a division by zero in the
kernel code.
[jstultz: Also initialize irq_freq to 1 to catch other divbyzero issues]
CC: Alessandro Zummo <a.zummo@towertech.it>
CC: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>
Signed-off-by: John Stultz <john.stultz@linaro.org>
diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index 9583cbc..c404b61 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -143,6 +143,7 @@
rtc->id = id;
rtc->ops = ops;
rtc->owner = owner;
+ rtc->irq_freq = 1;
rtc->max_user_freq = 64;
rtc->dev.parent = dev;
rtc->dev.class = rtc_class;