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Commit 4b3687f9 authored by John Stultz's avatar John Stultz
Browse files

rtc: pcap: Initialize drvdata before registering device 



Commit f44f7f96 ("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: default avatarJohn Stultz <john.stultz@linaro.org>
parent 93015236

drivers/rtc/rtc-pcap.c

+3 −1
Original line number Diff line number Diff line
@@ -151,6 +151,8 @@ static int __devinit pcap_rtc_probe(struct platform_device *pdev) 


	pcap_rtc->pcap = dev_get_drvdata(pdev->dev.parent);



	platform_set_drvdata(pdev, pcap_rtc);



	pcap_rtc->rtc = rtc_device_register("pcap", &pdev->dev,

				  &pcap_rtc_ops, THIS_MODULE);

	if (IS_ERR(pcap_rtc->rtc)) {
@@ -158,7 +160,6 @@ static int __devinit pcap_rtc_probe(struct platform_device *pdev) 
		goto fail_rtc;

	}



	platform_set_drvdata(pdev, pcap_rtc);



	timer_irq = pcap_to_irq(pcap_rtc->pcap, PCAP_IRQ_1HZ);

	alarm_irq = pcap_to_irq(pcap_rtc->pcap, PCAP_IRQ_TODA);
@@ -177,6 +178,7 @@ static int __devinit pcap_rtc_probe(struct platform_device *pdev) 
fail_timer:

	rtc_device_unregister(pcap_rtc->rtc);

fail_rtc:

	platform_set_drvdata(pdev, NULL);

	kfree(pcap_rtc);

	return err;

}