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rtc: stmp3xxx: 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.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Tested-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
This commit is contained in:
Wolfram Sang 2011-05-25 12:56:51 +02:00 committed by John Stultz
parent 46b2121814
commit a91d2bab35
1 changed files with 5 additions and 2 deletions
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7
drivers/rtc/rtc-stmp3xxx.c
View File

@ -176,6 +176,7 @@ static int stmp3xxx_rtc_remove(struct platform_device *pdev)
free_irq(rtc_data->irq_alarm, &pdev->dev);
free_irq(rtc_data->irq_1msec, &pdev->dev);
rtc_device_unregister(rtc_data->rtc);
platform_set_drvdata(pdev, NULL);
iounmap(rtc_data->io);
kfree(rtc_data);
@ -216,11 +217,14 @@ static int stmp3xxx_rtc_probe(struct platform_device *pdev)
goto out_remap;
}
platform_set_drvdata(pdev, rtc_data);
mxs_reset_block(rtc_data->io);
__mxs_clrl(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE,
rtc_data->io + STMP3XXX_RTC_PERSISTENT0);
rtc_data->rtc = rtc_device_register(pdev->name, &pdev->dev,
&stmp3xxx_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc_data->rtc)) {
@ -244,8 +248,6 @@ static int stmp3xxx_rtc_probe(struct platform_device *pdev)
goto out_irq1;
}
platform_set_drvdata(pdev, rtc_data);
return 0;
out_irq1:
@ -256,6 +258,7 @@ static int stmp3xxx_rtc_probe(struct platform_device *pdev)
rtc_data->io + STMP3XXX_RTC_CTRL);
rtc_device_unregister(rtc_data->rtc);
out_remap:
platform_set_drvdata(pdev, NULL);
iounmap(rtc_data->io);
out_free:
kfree(rtc_data);