From: Yingjoe Chen Date: Wed, 10 Dec 2014 09:55:02 +0000 (+0800) Subject: irqchip: mtk-sysirq: Use IS_ERR() instead of NULL pointer check X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=596c4051eb6b0c7f5fc5437c2269b7191b59ff3b;p=deliverable%2Flinux.git irqchip: mtk-sysirq: Use IS_ERR() instead of NULL pointer check Beniamino noticed a bug that an invalid DT file for the mediatek interrupt polarity extension will cause kernel oops. 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(). [ jac: took V2 over V3 for diff formatting, hand-added V3 changes, tweaked subject line. ] Reported-by: Beniamino Galvani Signed-off-by: Yingjoe Chen Link: https://lkml.kernel.org/r/1418205302-22531-1-git-send-email-yingjoe.chen@mediatek.com Signed-off-by: Jason Cooper --- diff --git a/drivers/irqchip/irq-mtk-sysirq.c b/drivers/irqchip/irq-mtk-sysirq.c index 7e342df6a62f..0b0d2c00a2df 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; }