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authorAlexandre Belloni <alexandre.belloni@bootlin.com>2020-03-06 04:01:44 +0300
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2020-03-16 13:12:09 +0300
commitf2997775b111c6d660c32a18d5d44d37cb7361b1 (patch)
tree3deabb27fff17fee84aadab8dbd2bdc4d5a73efc /drivers/rtc/rtc-sa1100.c
parent0a22bd6fe46db507b4e9d3ea2db3dc8ed480b0b3 (diff)
downloadlinux-f2997775b111c6d660c32a18d5d44d37cb7361b1.tar.xz
rtc: sa1100: fix possible race condition
Both RTC IRQs are requested before the struct rtc_device is allocated, this may lead to a NULL pointer dereference in the IRQ handler. To fix this issue, allocating the rtc_device struct before requesting the IRQs using devm_rtc_allocate_device, and use rtc_register_device to register the RTC device. Link: https://lore.kernel.org/r/20200306010146.39762-1-alexandre.belloni@bootlin.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/rtc/rtc-sa1100.c')
-rw-r--r--drivers/rtc/rtc-sa1100.c18
1 files changed, 10 insertions, 8 deletions
diff --git a/drivers/rtc/rtc-sa1100.c b/drivers/rtc/rtc-sa1100.c
index d37893f6eaee..97c352594033 100644
--- a/drivers/rtc/rtc-sa1100.c
+++ b/drivers/rtc/rtc-sa1100.c
@@ -182,7 +182,6 @@ static const struct rtc_class_ops sa1100_rtc_ops = {
int sa1100_rtc_init(struct platform_device *pdev, struct sa1100_rtc *info)
{
- struct rtc_device *rtc;
int ret;
spin_lock_init(&info->lock);
@@ -211,15 +210,14 @@ int sa1100_rtc_init(struct platform_device *pdev, struct sa1100_rtc *info)
writel_relaxed(0, info->rcnr);
}
- rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &sa1100_rtc_ops,
- THIS_MODULE);
- if (IS_ERR(rtc)) {
+ info->rtc->ops = &sa1100_rtc_ops;
+ info->rtc->max_user_freq = RTC_FREQ;
+
+ ret = rtc_register_device(info->rtc);
+ if (ret) {
clk_disable_unprepare(info->clk);
- return PTR_ERR(rtc);
+ return ret;
}
- info->rtc = rtc;
-
- rtc->max_user_freq = RTC_FREQ;
/* Fix for a nasty initialization problem the in SA11xx RTSR register.
* See also the comments in sa1100_rtc_interrupt().
@@ -267,6 +265,10 @@ static int sa1100_rtc_probe(struct platform_device *pdev)
info->irq_1hz = irq_1hz;
info->irq_alarm = irq_alarm;
+ info->rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(info->rtc))
+ return PTR_ERR(info->rtc);
+
ret = devm_request_irq(&pdev->dev, irq_1hz, sa1100_rtc_interrupt, 0,
"rtc 1Hz", &pdev->dev);
if (ret) {