> From: Anson.Huang@xxxxxxx <Anson.Huang@xxxxxxx>
> Sent: Tuesday, July 16, 2019 3:19 PM
>
> The RTC IRQ is requested before the struct rtc_device is allocated, this may
> lead to a NULL pointer dereference in 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.
>
I saw other rtc drivers did the same way as us, so this looks like a common problem.
My question is if we can clear interrupt status before register to avoid this issue as
other rtc drivers?
Regards
Aisheng
> Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
> ---
> drivers/rtc/rtc-snvs.c | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c index
> 7ee673a2..4f9a107 100644
> --- a/drivers/rtc/rtc-snvs.c
> +++ b/drivers/rtc/rtc-snvs.c
> @@ -279,6 +279,10 @@ static int snvs_rtc_probe(struct platform_device
> *pdev)
> if (!data)
> return -ENOMEM;
>
> + data->rtc = devm_rtc_allocate_device(&pdev->dev);
> + if (IS_ERR(data->rtc))
> + return PTR_ERR(data->rtc);
> +
> data->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
> "regmap");
>
> if (IS_ERR(data->regmap)) {
> @@ -343,10 +347,9 @@ static int snvs_rtc_probe(struct platform_device
> *pdev)
> goto error_rtc_device_register;
> }
>
> - data->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
> - &snvs_rtc_ops, THIS_MODULE);
> - if (IS_ERR(data->rtc)) {
> - ret = PTR_ERR(data->rtc);
> + data->rtc->ops = &snvs_rtc_ops;
> + ret = rtc_register_device(data->rtc);
> + if (ret) {
> dev_err(&pdev->dev, "failed to register rtc: %d\n", ret);
> goto error_rtc_device_register;
> }
> --
> 2.7.4
