rtc: 88pm860x: fix possible race condition

The RTC IRQ is requested before the struct rtc_device is allocated,
this may lead to a NULL pointer dereference in the IRQ handler.

To fix this issue, allocating the rtc_device struct before requesting
the RTC IRQ using devm_rtc_allocate_device, and use rtc_register_device
to register the RTC device.

Also remove the unnecessary error message as the core already prints the
info.

Link: https://lore.kernel.org/r/20200311223956.51352-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Alexandre Belloni 2020-03-11 23:39:51 +01:00
parent 7863bd076b
commit 9cf4789e6e

View file

@ -336,6 +336,10 @@ static int pm860x_rtc_probe(struct platform_device *pdev)
info->dev = &pdev->dev;
dev_set_drvdata(&pdev->dev, info);
info->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(info->rtc_dev))
return PTR_ERR(info->rtc_dev);
ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
rtc_update_handler, IRQF_ONESHOT, "rtc",
info);
@ -377,13 +381,11 @@ static int pm860x_rtc_probe(struct platform_device *pdev)
}
}
info->rtc_dev = devm_rtc_device_register(&pdev->dev, "88pm860x-rtc",
&pm860x_rtc_ops, THIS_MODULE);
ret = PTR_ERR(info->rtc_dev);
if (IS_ERR(info->rtc_dev)) {
dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
info->rtc_dev->ops = &pm860x_rtc_ops;
ret = rtc_register_device(info->rtc_dev);
if (ret)
return ret;
}
/*
* enable internal XO instead of internal 3.25MHz clock since it can