From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754751Ab1EGBVy (ORCPT ); Fri, 6 May 2011 21:21:54 -0400 Received: from e37.co.us.ibm.com ([32.97.110.158]:36718 "EHLO e37.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754031Ab1EGBVH (ORCPT ); Fri, 6 May 2011 21:21:07 -0400 From: John Stultz To: lkml Cc: John Stultz , Wolfram Sang , Alessandro Zummo , Thomas Gleixner , rtc-linux@googlegroups.com Subject: [PATCH 06/11] rtc: max8925: Initialize drvdata before registering device Date: Fri, 6 May 2011 18:20:49 -0700 Message-Id: <1304731254-3238-7-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 1.7.3.2.146.gca209 In-Reply-To: <1304731254-3238-1-git-send-email-john.stultz@linaro.org> References: <1304731254-3238-1-git-send-email-john.stultz@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 files changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/rtc/rtc-max8925.c b/drivers/rtc/rtc-max8925.c index 20494b5..3bc046f 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); -- 1.7.3.2.146.gca209