@@ -172,6 +172,7 @@ 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);
@@ -212,11 +213,14 @@ 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)) {
@@ -240,8 +244,6 @@ static int stmp3xxx_rtc_probe(struct platform_device *pdev)
goto out_irq1;
}
- platform_set_drvdata(pdev, rtc_data);
-
return 0;
out_irq1:
@@ -251,6 +253,7 @@ out_irq_alarm:
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);
Commit f44f7f96a20 ("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> --- Thanks to John for the commit-msg ;) drivers/rtc/rtc-stmp3xxx.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-)