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| author | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2018-05-20 14:33:36 +0200 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2018-05-23 09:25:27 +0200 |
| commit | d482510fee9957ffaca3a0357c655628f3e3870b (patch) | |
| tree | 74185f8d03ec53dfba3343c132a7f8d116dd817a /drivers/rtc | |
| parent | b72252b6580c9c7ad74644642378e2a9a86b2283 (diff) | |
| download | linux-d482510fee9957ffaca3a0357c655628f3e3870b.tar.gz linux-d482510fee9957ffaca3a0357c655628f3e3870b.tar.bz2 linux-d482510fee9957ffaca3a0357c655628f3e3870b.zip | |
rtc: st-lpc: 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.
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-st-lpc.c | 24 |
1 files changed, 9 insertions, 15 deletions
diff --git a/drivers/rtc/rtc-st-lpc.c b/drivers/rtc/rtc-st-lpc.c index d5222667f892..2f1ef2c28740 100644 --- a/drivers/rtc/rtc-st-lpc.c +++ b/drivers/rtc/rtc-st-lpc.c @@ -212,6 +212,10 @@ static int st_rtc_probe(struct platform_device *pdev) if (!rtc) return -ENOMEM; + rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc->rtc_dev)) + return PTR_ERR(rtc->rtc_dev); + spin_lock_init(&rtc->lock); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); @@ -253,26 +257,17 @@ static int st_rtc_probe(struct platform_device *pdev) platform_set_drvdata(pdev, rtc); - rtc->rtc_dev = rtc_device_register("st-lpc-rtc", &pdev->dev, - &st_rtc_ops, THIS_MODULE); - if (IS_ERR(rtc->rtc_dev)) { + rtc->rtc_dev->ops = &st_rtc_ops; + + ret = rtc_register_device(rtc->rtc_dev); + if (ret) { clk_disable_unprepare(rtc->clk); - return PTR_ERR(rtc->rtc_dev); + return ret; } return 0; } -static int st_rtc_remove(struct platform_device *pdev) -{ - struct st_rtc *rtc = platform_get_drvdata(pdev); - - if (likely(rtc->rtc_dev)) - rtc_device_unregister(rtc->rtc_dev); - - return 0; -} - #ifdef CONFIG_PM_SLEEP static int st_rtc_suspend(struct device *dev) { @@ -325,7 +320,6 @@ static struct platform_driver st_rtc_platform_driver = { .of_match_table = st_rtc_match, }, .probe = st_rtc_probe, - .remove = st_rtc_remove, }; module_platform_driver(st_rtc_platform_driver); |