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Commit a91d2bab authored by Wolfram Sang's avatar Wolfram Sang Committed by John Stultz
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rtc: stmp3xxx: 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.

Signed-off-by: default avatarWolfram Sang <w.sang@pengutronix.de>
Tested-by: default avatarShawn Guo <shawn.guo@freescale.com>
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
parent 46b21218

drivers/rtc/rtc-stmp3xxx.c

+5 −2
Original line number Diff line number Diff line
@@ -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);