From a91d2bab355f3a5caa767d7316f80422bfcd2ad6 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Wed, 25 May 2011 12:56:51 +0200 Subject: [PATCH] rtc: stmp3xxx: Initialize drvdata before registering device 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 Tested-by: Shawn Guo Signed-off-by: John Stultz --- drivers/rtc/rtc-stmp3xxx.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/rtc/rtc-stmp3xxx.c b/drivers/rtc/rtc-stmp3xxx.c index ac40f971a40e..90f05fe60620 100644 --- a/drivers/rtc/rtc-stmp3xxx.c +++ b/drivers/rtc/rtc-stmp3xxx.c @@ -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);