diff options
| author | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2020-03-06 04:01:44 +0300 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2020-03-16 13:12:09 +0300 |
| commit | f2997775b111c6d660c32a18d5d44d37cb7361b1 (patch) | |
| tree | 3deabb27fff17fee84aadab8dbd2bdc4d5a73efc /drivers/rtc/rtc-sa1100.c | |
| parent | 0a22bd6fe46db507b4e9d3ea2db3dc8ed480b0b3 (diff) | |
| download | linux-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.c | 18 |
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) { |