From patchwork Sat May 7 01:20:48 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 94452 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from mail-gx0-f184.google.com (mail-gx0-f184.google.com [209.85.161.184]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 4B498B712D for ; Sat, 7 May 2011 11:21:12 +1000 (EST) Received: by gxk20 with SMTP id 20sf4891774gxk.11 for ; Fri, 06 May 2011 18:21:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlegroups.com; s=beta; h=domainkey-signature:mime-version:x-beenthere:received-spf:from:to :cc:subject:date:message-id:x-mailer:in-reply-to:references :x-original-sender:x-original-authentication-results:reply-to :precedence:mailing-list:list-id:x-google-group-id:list-post :list-help:list-archive:sender:list-subscribe:list-unsubscribe :content-type; bh=ORNa+YixsmBMLoZcCkJJnaNxi9NYGKz9srkX+GdKC/8=; b=jGiNlPypxIKR3sfkXReJvuNtvA7NL1mJE+0dRhxnI1BQ4ymfXJMH9PNDX7Kst6O8AU oYIB7v68o6pY+x1QSbw/Sh+g8AH8h4GUCTch7c6IqfELmG3q+um9SjadpIcOOUgVM52N bmgTY6jo907SY/CHydjseGeTMucE448XzK6gY= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlegroups.com; s=beta; h=mime-version:x-beenthere:received-spf:from:to:cc:subject:date :message-id:x-mailer:in-reply-to:references:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:x-google-group-id:list-post:list-help:list-archive:sender :list-subscribe:list-unsubscribe:content-type; b=P6Q4Q7fEbdtgWNjBJ5VrptFKGit3QBuCOyZb05kexBMoQ8HhW6XcwNU3xLwReNwa3X S+Gy/OKklRFk49MAr3NOJCLOFTWybBPkUrImoNCi7KjEYC+5cx5mH1Walq1qKVJxqDrU aB8HfAfRLqU5bJur/p3aatp/dZYDrxOQntq4w= Received: by 10.146.115.1 with SMTP id n1mr458479yac.8.1304731267515; Fri, 06 May 2011 18:21:07 -0700 (PDT) MIME-Version: 1.0 X-BeenThere: rtc-linux@googlegroups.com Received: by 10.101.29.30 with SMTP id g30ls491093anj.1.gmail; Fri, 06 May 2011 18:21:07 -0700 (PDT) Received: by 10.100.56.20 with SMTP id e20mr575962ana.7.1304731267091; Fri, 06 May 2011 18:21:07 -0700 (PDT) Received: by 10.100.56.20 with SMTP id e20mr575961ana.7.1304731267069; Fri, 06 May 2011 18:21:07 -0700 (PDT) Received: from e5.ny.us.ibm.com (e5.ny.us.ibm.com [32.97.182.145]) by gmr-mx.google.com with ESMTPS id c20si1104705ana.3.2011.05.06.18.21.05 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 06 May 2011 18:21:06 -0700 (PDT) Received-SPF: pass (google.com: domain of jstultz@us.ibm.com designates 32.97.182.145 as permitted sender) client-ip=32.97.182.145; Received: from d01relay05.pok.ibm.com (d01relay05.pok.ibm.com [9.56.227.237]) by e5.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p470sO7W010143 for ; Fri, 6 May 2011 20:54:24 -0400 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay05.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p471L2n1077764 for ; Fri, 6 May 2011 21:21:02 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p46LKpg8027444 for ; Fri, 6 May 2011 18:20:51 -0300 Received: from kernel.beaverton.ibm.com (kernel.beaverton.ibm.com [9.47.67.96]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p46LKo9b027440; Fri, 6 May 2011 18:20:50 -0300 Received: by kernel.beaverton.ibm.com (Postfix, from userid 1056) id 863521E7513; Fri, 6 May 2011 18:21:01 -0700 (PDT) From: John Stultz To: lkml Cc: John Stultz , Wolfram Sang , Alessandro Zummo , Thomas Gleixner , rtc-linux@googlegroups.com Subject: [rtc-linux] [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> X-Original-Sender: john.stultz@linaro.org X-Original-Authentication-Results: gmr-mx.google.com; spf=pass (google.com: domain of jstultz@us.ibm.com designates 32.97.182.145 as permitted sender) smtp.mail=jstultz@us.ibm.com Reply-To: rtc-linux@googlegroups.com Precedence: list Mailing-list: list rtc-linux@googlegroups.com; contact rtc-linux+owners@googlegroups.com List-ID: X-Google-Group-Id: 712029733259 List-Post: , List-Help: , List-Archive: Sender: rtc-linux@googlegroups.com List-Subscribe: , List-Unsubscribe: , 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);