From 6ba8bcd457d9fc793ac9435aa2e4138f571d4ec5 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Mon, 24 May 2010 14:33:49 -0700 Subject: [PATCH] rtc-cmos: do dev_set_drvdata() earlier in the initialization The bug is an oops when dev_get_drvdata() returned null in cmos_update_irq_enable(). The call tree looks like this: rtc_dev_ioctl() => rtc_update_irq_enable() => cmos_update_irq_enable() It's caused by a race condition in the module initialization. It is rtc_device_register() which makes the ioctl operations live so I moved the call to dev_set_drvdata() before the call to rtc_device_register(). Addresses https://bugzilla.kernel.org/show_bug.cgi?id=15963 Reported-by: Randy Dunlap Signed-off-by: Dan Carpenter Tested-by: Randy Dunlap Cc: Alessandro Zummo Cc: Paul Gortmaker Cc: Malte Schroder Cc: Ralf Baechle Cc: Herton Ronaldo Krzesinski Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-cmos.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c index 96e8e70fbf1e..11b8ea29d2b7 100644 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@ -719,6 +719,9 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq) } } + cmos_rtc.dev = dev; + dev_set_drvdata(dev, &cmos_rtc); + cmos_rtc.rtc = rtc_device_register(driver_name, dev, &cmos_rtc_ops, THIS_MODULE); if (IS_ERR(cmos_rtc.rtc)) { @@ -726,8 +729,6 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq) goto cleanup0; } - cmos_rtc.dev = dev; - dev_set_drvdata(dev, &cmos_rtc); rename_region(ports, dev_name(&cmos_rtc.rtc->dev)); spin_lock_irq(&rtc_lock);