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rtc: max8998: Initialize drvdata before registering device 

Commit f44f7f96a2 ("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>
This commit is contained in:
John Stultz 2011-05-06 17:27:07 -07:00
parent 2f5c4fe8f9
commit 03cf7c477d
1 changed files with 3 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/rtc/rtc-max8998.c
View File

@ -265,6 +265,8 @@ static int __devinit max8998_rtc_probe(struct platform_device *pdev)
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 @@ static int __devinit max8998_rtc_probe(struct platform_device *pdev)
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 @@ static int __devinit max8998_rtc_probe(struct platform_device *pdev)
return 0;
out_rtc:
platform_set_drvdata(pdev, NULL);
kfree(info);
return ret;
}