From: John Stultz Date: Sat, 7 May 2011 00:27:07 +0000 (-0700) Subject: rtc: max8998: Initialize drvdata before registering device X-Git-Tag: firefly_0821_release~7613^2~1427^2~1^2~4 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=03cf7c477de8cb47658ba93f33dc93242985acff;p=firefly-linux-kernel-4.4.55.git rtc: max8998: 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 --- diff --git a/drivers/rtc/rtc-max8998.c b/drivers/rtc/rtc-max8998.c index 3f7bc6b9fefa..2e48aa604273 100644 --- a/drivers/rtc/rtc-max8998.c +++ b/drivers/rtc/rtc-max8998.c @@ -265,6 +265,8 @@ static int __devinit max8998_rtc_probe(struct platform_device *pdev) info->rtc = max8998->rtc; info->irq = max8998->irq_base + MAX8998_IRQ_ALARM0; + platform_set_drvdata(pdev, info); + info->rtc_dev = rtc_device_register("max8998-rtc", &pdev->dev, &max8998_rtc_ops, THIS_MODULE); @@ -274,8 +276,6 @@ static int __devinit max8998_rtc_probe(struct platform_device *pdev) goto out_rtc; } - platform_set_drvdata(pdev, info); - ret = request_threaded_irq(info->irq, NULL, max8998_rtc_alarm_irq, 0, "rtc-alarm0", info); @@ -293,6 +293,7 @@ static int __devinit max8998_rtc_probe(struct platform_device *pdev) return 0; out_rtc: + platform_set_drvdata(pdev, NULL); kfree(info); return ret; }