From f945a3d9600633de589ce698233b34ff6ad57e55 Mon Sep 17 00:00:00 2001 From: Zhangfei Gao Date: Wed, 27 Apr 2011 11:44:29 -0700 Subject: rtc: max8925: Call dev_set_drvdata before rtc_device_register We call rtc_read_alarm from rtc_device_register, so it is important that the rtc device is fully initialized prior to registration. rtc-max8925 sets drvdata after register, so the rtc_read_alarm code dereferences a NULL pointer. Call dev_set_drvdata before rtc_device_register. [ jstultz/tglx: Massaged commit message ] Signed-off-by: Zhangfei Gao Cc: Alessandro Zummo Link: http://lkml.kernel.org/r/%3C1303929869-25249-1-git-send-email-john.stultz%40linaro.org%3E Signed-off-by: John Stultz Signed-off-by: Thomas Gleixner --- drivers/rtc/rtc-max8925.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/rtc/rtc-max8925.c') diff --git a/drivers/rtc/rtc-max8925.c b/drivers/rtc/rtc-max8925.c index 174036dda786..20494b5edc3c 100644 --- a/drivers/rtc/rtc-max8925.c +++ b/drivers/rtc/rtc-max8925.c @@ -257,6 +257,8 @@ static int __devinit max8925_rtc_probe(struct platform_device *pdev) goto out_irq; } + dev_set_drvdata(&pdev->dev, info); + info->rtc_dev = rtc_device_register("max8925-rtc", &pdev->dev, &max8925_rtc_ops, THIS_MODULE); ret = PTR_ERR(info->rtc_dev); @@ -265,7 +267,6 @@ static int __devinit max8925_rtc_probe(struct platform_device *pdev) goto out_rtc; } - dev_set_drvdata(&pdev->dev, info); platform_set_drvdata(pdev, info); return 0; -- cgit v1.2.3 From 2f5c4fe8f9811152d69ef5cd020e095a1f84ca65 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Fri, 6 May 2011 17:26:25 -0700 Subject: rtc: max8925: Initialize drvdata before registering device Commit f44f7f96a20 ("RTC: Initialize kernel state from RTC") uncovered an issue in a number of RTC drivers, where the drivers call rtc_device_register before initializing the device or platform drvdata. This frequently results in null pointer dereferences when the rtc_device_register immediately makes use of the rtc device, calling rtc_read_alarm. The solution is to ensure the drvdata is initialized prior to registering the rtc device. CC: Wolfram Sang CC: Alessandro Zummo CC: Thomas Gleixner CC: rtc-linux@googlegroups.com Signed-off-by: John Stultz --- drivers/rtc/rtc-max8925.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/rtc/rtc-max8925.c') diff --git a/drivers/rtc/rtc-max8925.c b/drivers/rtc/rtc-max8925.c index 20494b5edc3c..3bc046f427e0 100644 --- a/drivers/rtc/rtc-max8925.c +++ b/drivers/rtc/rtc-max8925.c @@ -258,6 +258,8 @@ static int __devinit max8925_rtc_probe(struct platform_device *pdev) } dev_set_drvdata(&pdev->dev, info); + /* XXX - isn't this redundant? */ + platform_set_drvdata(pdev, info); info->rtc_dev = rtc_device_register("max8925-rtc", &pdev->dev, &max8925_rtc_ops, THIS_MODULE); @@ -267,10 +269,9 @@ static int __devinit max8925_rtc_probe(struct platform_device *pdev) goto out_rtc; } - platform_set_drvdata(pdev, info); - return 0; out_rtc: + platform_set_drvdata(pdev, NULL); free_irq(chip->irq_base + MAX8925_IRQ_RTC_ALARM0, info); out_irq: kfree(info); -- cgit v1.2.3