From patchwork Wed May 25 10:56:51 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 815642 Received: from bombadil.infradead.org (bombadil.infradead.org [18.85.46.34]) by demeter2.kernel.org (8.14.4/8.14.3) with ESMTP id p4PAxG76014706 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 25 May 2011 10:59:38 GMT Received: from canuck.infradead.org ([2001:4978:20e::1]) by bombadil.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QPBmV-0006h7-Sn; Wed, 25 May 2011 10:57:40 +0000 Received: from localhost ([127.0.0.1] helo=canuck.infradead.org) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QPBmU-0000pU-Ct; Wed, 25 May 2011 10:57:38 +0000 Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by canuck.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QPBm5-0000mc-5Z for linux-arm-kernel@lists.infradead.org; Wed, 25 May 2011 10:57:15 +0000 Received: from katana.hi.pengutronix.de ([2001:6f8:1178:2:221:70ff:fe71:1890] helo=pengutronix.de) by metis.ext.pengutronix.de with esmtp (Exim 4.72) (envelope-from ) id 1QPBm3-00085T-LC; Wed, 25 May 2011 12:57:11 +0200 From: Wolfram Sang To: rtc-linux@googlegroups.com Subject: [PATCH V2 3/5] rtc: stmp3xxx: Initialize drvdata before registering device Date: Wed, 25 May 2011 12:56:51 +0200 Message-Id: <1306321013-28364-4-git-send-email-w.sang@pengutronix.de> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1306321013-28364-1-git-send-email-w.sang@pengutronix.de> References: <1306321013-28364-1-git-send-email-w.sang@pengutronix.de> X-SA-Exim-Connect-IP: 2001:6f8:1178:2:221:70ff:fe71:1890 X-SA-Exim-Mail-From: w.sang@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110525_065713_497072_76C29D2F X-CRM114-Status: GOOD ( 14.86 ) X-Spam-Score: -0.0 (/) X-Spam-Report: SpamAssassin version 3.3.1 on canuck.infradead.org summary: Content analysis details: (-0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain Cc: John Stultz , Andrew Morton , Wolfram Sang , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Wed, 25 May 2011 10:59:38 +0000 (UTC) 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. Signed-off-by: Wolfram Sang Tested-by: Shawn Guo --- Thanks to John for the commit-msg ;) drivers/rtc/rtc-stmp3xxx.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/rtc/rtc-stmp3xxx.c b/drivers/rtc/rtc-stmp3xxx.c index 44e2202..fae563a 100644 --- a/drivers/rtc/rtc-stmp3xxx.c +++ b/drivers/rtc/rtc-stmp3xxx.c @@ -172,6 +172,7 @@ static int stmp3xxx_rtc_remove(struct platform_device *pdev) free_irq(rtc_data->irq_alarm, &pdev->dev); free_irq(rtc_data->irq_1msec, &pdev->dev); rtc_device_unregister(rtc_data->rtc); + platform_set_drvdata(pdev, NULL); iounmap(rtc_data->io); kfree(rtc_data); @@ -212,11 +213,14 @@ static int stmp3xxx_rtc_probe(struct platform_device *pdev) goto out_remap; } + platform_set_drvdata(pdev, rtc_data); + mxs_reset_block(rtc_data->io); __mxs_clrl(STMP3XXX_RTC_PERSISTENT0_ALARM_EN | STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN | STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE, rtc_data->io + STMP3XXX_RTC_PERSISTENT0); + rtc_data->rtc = rtc_device_register(pdev->name, &pdev->dev, &stmp3xxx_rtc_ops, THIS_MODULE); if (IS_ERR(rtc_data->rtc)) { @@ -240,8 +244,6 @@ static int stmp3xxx_rtc_probe(struct platform_device *pdev) goto out_irq1; } - platform_set_drvdata(pdev, rtc_data); - return 0; out_irq1: @@ -251,6 +253,7 @@ out_irq_alarm: rtc_data->io + STMP3XXX_RTC_CTRL); rtc_device_unregister(rtc_data->rtc); out_remap: + platform_set_drvdata(pdev, NULL); iounmap(rtc_data->io); out_free: kfree(rtc_data);