Commit 596c4051 authored Dec 10, 2014 by Yingjoe Chen Committed by Jason Cooper Jan 07, 2015

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 <b.galvani@gmail.com>
Signed-off-by: Yingjoe Chen <yingjoe.chen@mediatek.com>
Link: https://lkml.kernel.org/r/1418205302-22531-1-git-send-email-yingjoe.chen@mediatek.com


Signed-off-by: Jason Cooper <jason@lakedaemon.net>

parent 97bf6af1

drivers/irqchip/irq-mtk-sysirq.c

+2 −2

Original line number	Original line	Diff line number	Diff line
	@@ -137,9 +137,9 @@ static int __init mtk_sysirq_of_init(struct device_node *node,
	return -ENOMEM;		return -ENOMEM;

	chip_data->intpol_base = of_io_request_and_map(node, 0, "intpol");		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");		pr_err("mtk_sysirq: unable to map sysirq register\n");
	ret = -ENOMEM;		ret = PTR_ERR(chip_data->intpol_base);
	goto out_free;		goto out_free;
	}		}