From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752570AbaLJMRc (ORCPT ); Wed, 10 Dec 2014 07:17:32 -0500 Received: from mail-wi0-f169.google.com ([209.85.212.169]:41089 "EHLO mail-wi0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750777AbaLJMRb (ORCPT ); Wed, 10 Dec 2014 07:17:31 -0500 Date: Wed, 10 Dec 2014 13:14:43 +0100 From: Beniamino Galvani To: Yingjoe Chen Cc: Thomas Gleixner , Jason Cooper , Marc Zyngier , srv_heupstream@mediatek.com, hc.yen@mediatek.com, yh.chen@mediatek.com, linux-kernel@vger.kernel.org, Matthias Brugger , nathan.chung@mediatek.com, Sascha Hauer , eddie.huang@mediatek.com, yingjoe.chen@gmail.com, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2] irqchip: mediatek: Use IS_ERR() instead of NULL pointer check Message-ID: <20141210121442.GA14485@gmail.com> References: <1418050989-21411-1-git-send-email-yingjoe.chen@mediatek.com> <1418205302-22531-1-git-send-email-yingjoe.chen@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1418205302-22531-1-git-send-email-yingjoe.chen@mediatek.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 10, 2014 at 05:55:02PM +0800, Yingjoe Chen wrote: > Beniamino reported a kernel oops caused by an invalid DT file for the > mediatek interrupt polarity extension. > > The reason is that the interrupt polarity support for mediatek chips > merely checks for NULL pointer instead of a casted error return > value in mtk_sysirq_of_init() so any other casted error value passes > the NULL pointer check and causes a kernel panic when dereferenced. > > Use IS_ERR() and return the error value via PTR_ERR(). > > Reported-and-tested-by: Beniamino Galvani Well, actually I only reported the bug and didn't do any test. Can the "-and-tested" portion of the tag be dropped while applying the patch? Beniamino > Signed-off-by: Yingjoe Chen > --- > drivers/irqchip/irq-mtk-sysirq.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/irqchip/irq-mtk-sysirq.c b/drivers/irqchip/irq-mtk-sysirq.c > index 7e342df..0b0d2c0 100644 > --- a/drivers/irqchip/irq-mtk-sysirq.c > +++ b/drivers/irqchip/irq-mtk-sysirq.c > @@ -137,9 +137,9 @@ static int __init mtk_sysirq_of_init(struct device_node *node, > return -ENOMEM; > > chip_data->intpol_base = of_io_request_and_map(node, 0, "intpol"); > - if (!chip_data->intpol_base) { > + if (IS_ERR(chip_data->intpol_base)) { > pr_err("mtk_sysirq: unable to map sysirq register\n"); > - ret = -ENOMEM; > + ret = PTR_ERR(chip_data->intpol_base); > goto out_free; > } > > -- > 1.8.1.1.dirty >