Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 29615d03 authored by Alexandre Belloni's avatar Alexandre Belloni
Browse files

rtc: sunxi: fix possible race condition 



The IRQ is requested before the struct rtc is allocated and registered, but
this struct is used in the IRQ handler. This may lead to a NULL pointer
dereference.

Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc
before requesting the IRQ.

Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: default avatarMaxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent 696fa1d0

drivers/rtc/rtc-sunxi.c

+9 −14
Original line number Diff line number Diff line
@@ -445,6 +445,10 @@ static int sunxi_rtc_probe(struct platform_device *pdev) 
	platform_set_drvdata(pdev, chip);

	chip->dev = &pdev->dev;



	chip->rtc = devm_rtc_allocate_device(&pdev->dev);

	if (IS_ERR(chip->rtc))

		return PTR_ERR(chip->rtc);



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	chip->base = devm_ioremap_resource(&pdev->dev, res);

	if (IS_ERR(chip->base))
@@ -481,11 +485,12 @@ static int sunxi_rtc_probe(struct platform_device *pdev) 
	writel(SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND, chip->base +

			SUNXI_ALRM_IRQ_STA);



	chip->rtc = rtc_device_register("rtc-sunxi", &pdev->dev,

			&sunxi_rtc_ops, THIS_MODULE);

	if (IS_ERR(chip->rtc)) {

	chip->rtc->ops = &sunxi_rtc_ops;



	ret = rtc_register_device(chip->rtc);

	if (ret) {

		dev_err(&pdev->dev, "unable to register device\n");

		return PTR_ERR(chip->rtc);

		return ret;

	}



	dev_info(&pdev->dev, "RTC enabled\n");
@@ -493,18 +498,8 @@ static int sunxi_rtc_probe(struct platform_device *pdev) 
	return 0;

}



static int sunxi_rtc_remove(struct platform_device *pdev)

{

	struct sunxi_rtc_dev *chip = platform_get_drvdata(pdev);



	rtc_device_unregister(chip->rtc);



	return 0;

}



static struct platform_driver sunxi_rtc_driver = {

	.probe		= sunxi_rtc_probe,

	.remove		= sunxi_rtc_remove,

	.driver		= {

		.name		= "sunxi-rtc",

		.of_match_table = sunxi_rtc_dt_ids,