rtc: max8998: Initialize drvdata before registering device
Commit f44f7f96a20 ("RTC: Initialize kernel state from RTC") uncovered
an issue in a number of RTC drivers, where the drivers call
rtc_device_register before initializing the device or platform drvdata.
This frequently results in null pointer dereferences when the
rtc_device_register immediately makes use of the rtc device, calling
rtc_read_alarm.
The solution is to ensure the drvdata is initialized prior to registering
the rtc device.
CC: Wolfram Sang <w.sang@pengutronix.de>
CC: Alessandro Zummo <a.zummo@towertech.it>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: rtc-linux@googlegroups.com
Signed-off-by: John Stultz <john.stultz@linaro.org>
diff --git a/drivers/rtc/rtc-max8998.c b/drivers/rtc/rtc-max8998.c
index 3f7bc6b..2e48aa6 100644
--- a/drivers/rtc/rtc-max8998.c
+++ b/drivers/rtc/rtc-max8998.c
@@ -265,6 +265,8 @@
info->rtc = max8998->rtc;
info->irq = max8998->irq_base + MAX8998_IRQ_ALARM0;
+ platform_set_drvdata(pdev, info);
+
info->rtc_dev = rtc_device_register("max8998-rtc", &pdev->dev,
&max8998_rtc_ops, THIS_MODULE);
@@ -274,8 +276,6 @@
goto out_rtc;
}
- platform_set_drvdata(pdev, info);
-
ret = request_threaded_irq(info->irq, NULL, max8998_rtc_alarm_irq, 0,
"rtc-alarm0", info);
@@ -293,6 +293,7 @@
return 0;
out_rtc:
+ platform_set_drvdata(pdev, NULL);
kfree(info);
return ret;
}