From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: linux-rtc@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org,
Alexandre Belloni <alexandre.belloni@bootlin.com>
Subject: [PATCH 2/3] rtc: pl030: fix possible race condition
Date: Sun, 9 Sep 2018 22:38:47 +0200 [thread overview]
Message-ID: <20180909203848.3470-2-alexandre.belloni@bootlin.com> (raw)
In-Reply-To: <20180909203848.3470-1-alexandre.belloni@bootlin.com>
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
before requesting the IRQ.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
drivers/rtc/rtc-pl030.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/rtc/rtc-pl030.c b/drivers/rtc/rtc-pl030.c
index f85a1a93e669..343bb6ed1783 100644
--- a/drivers/rtc/rtc-pl030.c
+++ b/drivers/rtc/rtc-pl030.c
@@ -112,6 +112,13 @@ static int pl030_probe(struct amba_device *dev, const struct amba_id *id)
goto err_rtc;
}
+ rtc->rtc = devm_rtc_allocate_device(&dev->dev);
+ if (IS_ERR(rtc->rtc)) {
+ ret = PTR_ERR(rtc->rtc);
+ goto err_rtc;
+ }
+
+ rtc->rtc->ops = &pl030_ops;
rtc->base = ioremap(dev->res.start, resource_size(&dev->res));
if (!rtc->base) {
ret = -ENOMEM;
@@ -128,12 +135,9 @@ static int pl030_probe(struct amba_device *dev, const struct amba_id *id)
if (ret)
goto err_irq;
- rtc->rtc = rtc_device_register("pl030", &dev->dev, &pl030_ops,
- THIS_MODULE);
- if (IS_ERR(rtc->rtc)) {
- ret = PTR_ERR(rtc->rtc);
+ ret = rtc_register_device(rtc->rtc);
+ if (ret)
goto err_reg;
- }
return 0;
@@ -154,7 +158,6 @@ static int pl030_remove(struct amba_device *dev)
writel(0, rtc->base + RTC_CR);
free_irq(dev->irq[0], rtc);
- rtc_device_unregister(rtc->rtc);
iounmap(rtc->base);
amba_release_regions(dev);
--
2.19.0.rc2
next prev parent reply other threads:[~2018-09-10 1:29 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-09 20:38 [PATCH 1/3] rtc: mt6397: fix possible race condition Alexandre Belloni
2018-09-09 20:38 ` Alexandre Belloni [this message]
2018-09-09 20:38 ` [PATCH 3/3] rtc: pl031: switch to devm_rtc_allocate_device/rtc_register_device Alexandre Belloni
2018-09-10 6:44 ` Linus Walleij
2018-09-11 11:32 ` [PATCH 1/3] rtc: mt6397: fix possible race condition Eddie Huang
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