rtc: sh: 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
struct before requesting the IRQ.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Alexandre Belloni 2019-03-20 12:30:09 +01:00
parent 9852023d20
commit 1097998d27

View File

@ -530,6 +530,10 @@ static int __init sh_rtc_probe(struct platform_device *pdev)
rtc->clk = NULL;
}
rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(rtc->rtc_dev))
return PTR_ERR(rtc->rtc_dev);
clk_enable(rtc->clk);
rtc->capabilities = RTC_DEF_CAPABILITIES;
@ -593,15 +597,13 @@ static int __init sh_rtc_probe(struct platform_device *pdev)
sh_rtc_setaie(&pdev->dev, 0);
sh_rtc_setcie(&pdev->dev, 0);
rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "sh",
&sh_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc->rtc_dev)) {
ret = PTR_ERR(rtc->rtc_dev);
goto err_unmap;
}
rtc->rtc_dev->ops = &sh_rtc_ops;
rtc->rtc_dev->max_user_freq = 256;
ret = rtc_register_device(rtc->rtc_dev);
if (ret)
goto err_unmap;
device_init_wakeup(&pdev->dev, 1);
return 0;