* [PATCH] rtc: sunxi: fix possible race condition
@ 2018-06-04 12:05 ` Alexandre Belloni
0 siblings, 0 replies; 4+ messages in thread
From: Alexandre Belloni @ 2018-06-04 12:05 UTC (permalink / raw)
To: linux-rtc
Cc: linux-kernel, Maxime Ripard, Chen-Yu Tsai, linux-arm-kernel,
Alexandre Belloni
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-sunxi.c | 23 +++++++++--------------
1 file changed, 9 insertions(+), 14 deletions(-)
diff --git a/drivers/rtc/rtc-sunxi.c b/drivers/rtc/rtc-sunxi.c
index dadbf8b324ad..21865d3d8fe8 100644
--- a/drivers/rtc/rtc-sunxi.c
+++ b/drivers/rtc/rtc-sunxi.c
@@ -445,6 +445,10 @@ static int sunxi_rtc_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, chip);
chip->dev = &pdev->dev;
+ chip->rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(chip->rtc))
+ return PTR_ERR(chip->rtc);
+
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
chip->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(chip->base))
@@ -481,11 +485,12 @@ static int sunxi_rtc_probe(struct platform_device *pdev)
writel(SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND, chip->base +
SUNXI_ALRM_IRQ_STA);
- chip->rtc = rtc_device_register("rtc-sunxi", &pdev->dev,
- &sunxi_rtc_ops, THIS_MODULE);
- if (IS_ERR(chip->rtc)) {
+ chip->rtc->ops = &sunxi_rtc_ops;
+
+ ret = rtc_register_device(chip->rtc);
+ if (ret) {
dev_err(&pdev->dev, "unable to register device\n");
- return PTR_ERR(chip->rtc);
+ return ret;
}
dev_info(&pdev->dev, "RTC enabled\n");
@@ -493,18 +498,8 @@ static int sunxi_rtc_probe(struct platform_device *pdev)
return 0;
}
-static int sunxi_rtc_remove(struct platform_device *pdev)
-{
- struct sunxi_rtc_dev *chip = platform_get_drvdata(pdev);
-
- rtc_device_unregister(chip->rtc);
-
- return 0;
-}
-
static struct platform_driver sunxi_rtc_driver = {
.probe = sunxi_rtc_probe,
- .remove = sunxi_rtc_remove,
.driver = {
.name = "sunxi-rtc",
.of_match_table = sunxi_rtc_dt_ids,
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH] rtc: sunxi: fix possible race condition
@ 2018-06-04 12:05 ` Alexandre Belloni
0 siblings, 0 replies; 4+ messages in thread
From: Alexandre Belloni @ 2018-06-04 12:05 UTC (permalink / raw)
To: linux-arm-kernel
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-sunxi.c | 23 +++++++++--------------
1 file changed, 9 insertions(+), 14 deletions(-)
diff --git a/drivers/rtc/rtc-sunxi.c b/drivers/rtc/rtc-sunxi.c
index dadbf8b324ad..21865d3d8fe8 100644
--- a/drivers/rtc/rtc-sunxi.c
+++ b/drivers/rtc/rtc-sunxi.c
@@ -445,6 +445,10 @@ static int sunxi_rtc_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, chip);
chip->dev = &pdev->dev;
+ chip->rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(chip->rtc))
+ return PTR_ERR(chip->rtc);
+
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
chip->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(chip->base))
@@ -481,11 +485,12 @@ static int sunxi_rtc_probe(struct platform_device *pdev)
writel(SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND, chip->base +
SUNXI_ALRM_IRQ_STA);
- chip->rtc = rtc_device_register("rtc-sunxi", &pdev->dev,
- &sunxi_rtc_ops, THIS_MODULE);
- if (IS_ERR(chip->rtc)) {
+ chip->rtc->ops = &sunxi_rtc_ops;
+
+ ret = rtc_register_device(chip->rtc);
+ if (ret) {
dev_err(&pdev->dev, "unable to register device\n");
- return PTR_ERR(chip->rtc);
+ return ret;
}
dev_info(&pdev->dev, "RTC enabled\n");
@@ -493,18 +498,8 @@ static int sunxi_rtc_probe(struct platform_device *pdev)
return 0;
}
-static int sunxi_rtc_remove(struct platform_device *pdev)
-{
- struct sunxi_rtc_dev *chip = platform_get_drvdata(pdev);
-
- rtc_device_unregister(chip->rtc);
-
- return 0;
-}
-
static struct platform_driver sunxi_rtc_driver = {
.probe = sunxi_rtc_probe,
- .remove = sunxi_rtc_remove,
.driver = {
.name = "sunxi-rtc",
.of_match_table = sunxi_rtc_dt_ids,
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] rtc: sunxi: fix possible race condition
2018-06-04 12:05 ` Alexandre Belloni
@ 2018-06-04 12:31 ` Maxime Ripard
-1 siblings, 0 replies; 4+ messages in thread
From: Maxime Ripard @ 2018-06-04 12:31 UTC (permalink / raw)
To: Alexandre Belloni; +Cc: linux-rtc, linux-kernel, Chen-Yu Tsai, linux-arm-kernel
[-- Attachment #1: Type: text/plain, Size: 604 bytes --]
On Mon, Jun 04, 2018 at 02:05:40PM +0200, Alexandre Belloni wrote:
> 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>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Maxime
--
Maxime Ripard, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com
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^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH] rtc: sunxi: fix possible race condition
@ 2018-06-04 12:31 ` Maxime Ripard
0 siblings, 0 replies; 4+ messages in thread
From: Maxime Ripard @ 2018-06-04 12:31 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Jun 04, 2018 at 02:05:40PM +0200, Alexandre Belloni wrote:
> 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>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Maxime
--
Maxime Ripard, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com
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^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-06-04 12:31 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2018-06-04 12:05 [PATCH] rtc: sunxi: fix possible race condition Alexandre Belloni
2018-06-04 12:05 ` Alexandre Belloni
2018-06-04 12:31 ` Maxime Ripard
2018-06-04 12:31 ` Maxime Ripard
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