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authorAlexandre Belloni <alexandre.belloni@bootlin.com>2018-06-04 14:05:40 +0200
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2018-06-04 14:36:14 +0200
commit29615d03ccc0f8f01b45178737600810d8bf971f (patch)
tree5eeb0fd992473e03dc6a711c8b8e1bf30a9d543c /drivers/rtc
parent696fa1d043ecd605166cc97b24c0b7a59dd5a135 (diff)
downloadlinux-29615d03ccc0f8f01b45178737600810d8bf971f.tar.bz2
rtc: sunxi: fix possible race condition
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> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/rtc-sunxi.c23
1 files 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,