From mboxrd@z Thu Jan 1 00:00:00 1970 From: b.galvani@gmail.com (Beniamino Galvani) Date: Wed, 10 Dec 2014 13:14:43 +0100 Subject: [PATCH v2] irqchip: mediatek: Use IS_ERR() instead of NULL pointer check In-Reply-To: <1418205302-22531-1-git-send-email-yingjoe.chen@mediatek.com> References: <1418050989-21411-1-git-send-email-yingjoe.chen@mediatek.com> <1418205302-22531-1-git-send-email-yingjoe.chen@mediatek.com> Message-ID: <20141210121442.GA14485@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.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 >