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authorWolfram Sang <w.sang@pengutronix.de>2011-05-25 14:56:51 +0400
committerJohn Stultz <john.stultz@linaro.org>2011-07-02 05:09:55 +0400
commita91d2bab355f3a5caa767d7316f80422bfcd2ad6 (patch)
treed195bca36a8b606c58280011ef06cd6c5ec616bc /drivers/rtc/rtc-stmp3xxx.c
parent46b21218145ecef0936eb4338a9e0ffef84f00cf (diff)
downloadlinux-a91d2bab355f3a5caa767d7316f80422bfcd2ad6.tar.xz
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 <w.sang@pengutronix.de> Tested-by: Shawn Guo <shawn.guo@freescale.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
Diffstat (limited to 'drivers/rtc/rtc-stmp3xxx.c')
-rw-r--r--drivers/rtc/rtc-stmp3xxx.c7
1 files 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 @@ 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);