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

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Submitter John Stultz
Date May 7, 2011, 1:20 a.m.
Message ID <1304731254-3238-5-git-send-email-john.stultz@linaro.org>
Download mbox | patch
Permalink /patch/94449/
State New
Headers show

Comments

John Stultz - May 7, 2011, 1:20 a.m.
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@pengutronix.de>
CC: Alessandro Zummo <a.zummo@towertech.it>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: rtc-linux@googlegroups.com
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 drivers/rtc/rtc-ds1286.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

Patch

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: