[PATCH 04/11] rtc: ds1286: Initialize drvdata before registering device

From: John Stultz
Date: Fri May 06 2011 - 21:21:57 EST


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.

CC: Wolfram Sang <w.sang@xxxxxxxxxxxxxx>
CC: Alessandro Zummo <a.zummo@xxxxxxxxxxxx>
CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CC: rtc-linux@xxxxxxxxxxxxxxxx
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
drivers/rtc/rtc-ds1286.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/rtc/rtc-ds1286.c b/drivers/rtc/rtc-ds1286.c
index 60ce696..47e681d 100644
--- a/drivers/rtc/rtc-ds1286.c
+++ b/drivers/rtc/rtc-ds1286.c
@@ -355,6 +355,7 @@ static int __devinit ds1286_probe(struct platform_device *pdev)
goto out;
}
spin_lock_init(&priv->lock);
+ platform_set_drvdata(pdev, priv);
rtc = rtc_device_register("ds1286", &pdev->dev,
&ds1286_ops, THIS_MODULE);
if (IS_ERR(rtc)) {
@@ -362,7 +363,6 @@ static int __devinit ds1286_probe(struct platform_device *pdev)
goto out;
}
priv->rtc = rtc;
- platform_set_drvdata(pdev, priv);
return 0;

out:
--
1.7.3.2.146.gca209

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