From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754151Ab1EGBVI (ORCPT ); Fri, 6 May 2011 21:21:08 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:41423 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752695Ab1EGBVF (ORCPT ); Fri, 6 May 2011 21:21:05 -0400 From: John Stultz To: lkml Cc: Wolfram Sang , Alessandro Zummo , Thomas Gleixner , rtc-linux@googlegroups.com, John Stultz Subject: [PATCH 01/11] rtc: mxc: Initialize drvdata before registering device Date: Fri, 6 May 2011 18:20:44 -0700 Message-Id: <1304731254-3238-2-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 From: Wolfram Sang 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: Alessandro Zummo CC: Thomas Gleixner CC: rtc-linux@googlegroups.com Signed-off-by: Wolfram Sang [fixed up commit log -jstultz] Signed-off-by: John Stultz --- drivers/rtc/rtc-mxc.c | 19 +++++++++++-------- 1 files changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c index 826ab64..d814417 100644 --- a/drivers/rtc/rtc-mxc.c +++ b/drivers/rtc/rtc-mxc.c @@ -418,14 +418,6 @@ static int __init mxc_rtc_probe(struct platform_device *pdev) goto exit_put_clk; } - rtc = rtc_device_register(pdev->name, &pdev->dev, &mxc_rtc_ops, - THIS_MODULE); - if (IS_ERR(rtc)) { - ret = PTR_ERR(rtc); - goto exit_put_clk; - } - - pdata->rtc = rtc; platform_set_drvdata(pdev, pdata); /* Configure and enable the RTC */ @@ -438,8 +430,19 @@ static int __init mxc_rtc_probe(struct platform_device *pdev) pdata->irq = -1; } + rtc = rtc_device_register(pdev->name, &pdev->dev, &mxc_rtc_ops, + THIS_MODULE); + if (IS_ERR(rtc)) { + ret = PTR_ERR(rtc); + goto exit_clr_drvdata; + } + + pdata->rtc = rtc; + return 0; +exit_clr_drvdata: + platform_set_drvdata(pdev, NULL); exit_put_clk: clk_disable(pdata->clk); clk_put(pdata->clk); -- 1.7.3.2.146.gca209