Commit 92d921c5 authored May 05, 2011 by Wolfram Sang Committed by John Stultz May 06, 2011

rtc: ep93xx: Initialize drvdata before registering device



Commit f44f7f96 ("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: Alessandro Zummo <a.zummo@towertech.it>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: rtc-linux@googlegroups.com
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
[Fixed up commit log -jstultz]
Signed-off-by: John Stultz <john.stultz@linaro.org>

parent f4e708ae

drivers/rtc/rtc-ep93xx.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -151,6 +151,7 @@ static int __init ep93xx_rtc_probe(struct platform_device *pdev)
		return -ENXIO;

		pdev->dev.platform_data = ep93xx_rtc;
		platform_set_drvdata(pdev, rtc);

		rtc = rtc_device_register(pdev->name,
		&pdev->dev, &ep93xx_rtc_ops, THIS_MODULE);
		@@ -159,8 +160,6 @@ static int __init ep93xx_rtc_probe(struct platform_device *pdev)
		goto exit;
		}

		platform_set_drvdata(pdev, rtc);

		err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_rtc_sysfs_files);
		if (err)
		goto fail;
		@@ -168,9 +167,9 @@ static int __init ep93xx_rtc_probe(struct platform_device *pdev)
		return 0;

		fail:
		platform_set_drvdata(pdev, NULL);
		rtc_device_unregister(rtc);
		exit:
		platform_set_drvdata(pdev, NULL);
		pdev->dev.platform_data = NULL;
		return err;
		}