rtc: snvs: 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 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.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Link: https://lore.kernel.org/r/20190716071858.36750-1-Anson.Huang@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Anson Huang 2019-07-16 15:18:58 +08:00 committed by Alexandre Belloni
parent 28abbba36a
commit 6fd4fe9b49
1 changed files with 7 additions and 4 deletions

View File

@ -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;
}