rtc: xgene: fix possible race condition

[ Upstream commit a652e00ee1233e251a337c28e18a1da59224e5ce ]

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.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Alexandre Belloni 2019-03-20 13:32:27 +01:00 committed by Greg Kroah-Hartman
parent 4775e99e29
commit ae087a4a56

View File

@ -163,6 +163,10 @@ static int xgene_rtc_probe(struct platform_device *pdev)
if (IS_ERR(pdata->csr_base))
return PTR_ERR(pdata->csr_base);
pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(pdata->rtc))
return PTR_ERR(pdata->rtc);
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "No IRQ resource\n");
@ -187,15 +191,15 @@ static int xgene_rtc_probe(struct platform_device *pdev)
device_init_wakeup(&pdev->dev, 1);
pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
&xgene_rtc_ops, THIS_MODULE);
if (IS_ERR(pdata->rtc)) {
clk_disable_unprepare(pdata->clk);
return PTR_ERR(pdata->rtc);
}
/* HW does not support update faster than 1 seconds */
pdata->rtc->uie_unsupported = 1;
pdata->rtc->ops = &xgene_rtc_ops;
ret = rtc_register_device(pdata->rtc);
if (ret) {
clk_disable_unprepare(pdata->clk);
return ret;
}
return 0;
}