From patchwork Sat May 7 01:20:44 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 1400 Return-Path: Delivered-To: unknown Received: from imap.gmail.com (74.125.159.109) by localhost6.localdomain6 with IMAP4-SSL; 08 Jun 2011 14:51:41 -0000 Delivered-To: patches@linaro.org Received: by 10.224.184.145 with SMTP id ck17cs162024qab; Fri, 6 May 2011 18:21:11 -0700 (PDT) Received: by 10.150.68.40 with SMTP id q40mr4271538yba.68.1304731271138; Fri, 06 May 2011 18:21:11 -0700 (PDT) Received: from e33.co.us.ibm.com (e33.co.us.ibm.com [32.97.110.151]) by mx.google.com with ESMTPS id g7si304346ybn.74.2011.05.06.18.21.09 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 06 May 2011 18:21:10 -0700 (PDT) Received-SPF: pass (google.com: domain of jstultz@us.ibm.com designates 32.97.110.151 as permitted sender) client-ip=32.97.110.151; Authentication-Results: mx.google.com; spf=pass (google.com: domain of jstultz@us.ibm.com designates 32.97.110.151 as permitted sender) smtp.mail=jstultz@us.ibm.com Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e33.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id p471E2kq025788; Fri, 6 May 2011 19:14:02 -0600 Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p471MB2Y095886; Fri, 6 May 2011 19:22:11 -0600 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p46JL28j026431; Fri, 6 May 2011 13:21:02 -0600 Received: from kernel.beaverton.ibm.com (kernel.beaverton.ibm.com [9.47.67.96]) by d03av04.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p46JL1WR026415; Fri, 6 May 2011 13:21:01 -0600 Received: by kernel.beaverton.ibm.com (Postfix, from userid 1056) id 5B4321E750D; Fri, 6 May 2011 18:21:01 -0700 (PDT) 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> 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);