From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754851Ab1EGBWT (ORCPT ); Fri, 6 May 2011 21:22:19 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.145]:51964 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754402Ab1EGBWP (ORCPT ); Fri, 6 May 2011 21:22:15 -0400 From: John Stultz To: lkml Cc: John Stultz , Wolfram Sang , Alessandro Zummo , Thomas Gleixner , rtc-linux@googlegroups.com Subject: [PATCH 05/11] rtc: m41t80: Initialize clientdata before registering device Date: Fri, 6 May 2011 18:20:48 -0700 Message-Id: <1304731254-3238-6-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 clientdata. 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 clientdata 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-m41t80.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c index 69fe664..eda128f 100644 --- a/drivers/rtc/rtc-m41t80.c +++ b/drivers/rtc/rtc-m41t80.c @@ -783,6 +783,9 @@ static int m41t80_probe(struct i2c_client *client, goto exit; } + clientdata->features = id->driver_data; + i2c_set_clientdata(client, clientdata); + rtc = rtc_device_register(client->name, &client->dev, &m41t80_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) { @@ -792,8 +795,6 @@ static int m41t80_probe(struct i2c_client *client, } clientdata->rtc = rtc; - clientdata->features = id->driver_data; - i2c_set_clientdata(client, clientdata); /* Make sure HT (Halt Update) bit is cleared */ rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR); -- 1.7.3.2.146.gca209