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rtc: max8925: 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 17:26:25 -07:00
parent a015dbc110
commit 2f5c4fe8f9
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-max8925.c
View File

@ -258,6 +258,8 @@ static int __devinit max8925_rtc_probe(struct platform_device *pdev)
}
dev_set_drvdata(&pdev->dev, info);
/* XXX - isn't this redundant? */
platform_set_drvdata(pdev, info);
info->rtc_dev = rtc_device_register("max8925-rtc", &pdev->dev,
&max8925_rtc_ops, THIS_MODULE);
@ -267,10 +269,9 @@ static int __devinit max8925_rtc_probe(struct platform_device *pdev)
goto out_rtc;
}
platform_set_drvdata(pdev, info);
return 0;
out_rtc:
platform_set_drvdata(pdev, NULL);
free_irq(chip->irq_base + MAX8925_IRQ_RTC_ALARM0, info);
out_irq:
kfree(info);