Re: [PATCH] irqchip: mediatek: Fix error return code detection

From: Yingjoe Chen
Date: Tue Dec 09 2014 - 01:11:39 EST


On Mon, 2014-12-08 at 21:30 +0100, Thomas Gleixner wrote:
> On Mon, 8 Dec 2014, Yingjoe Chen wrote:
>
> > This fix an error handling bug reported by Beniamino, this is based on
> > mtk intpol patches [1]
> >
> > Joe.C
> >
> > http://lists.infradead.org/pipermail/linux-arm-kernel/2014-November/305808.html
> >
> > ====================
> > of_io_request_and_map() return ERR_PTR wrapped error code instead of
> > NULL when fail, fix code in mtk_sysirq_of_init() to correctly handle
> > this.
> >
> > Signed-off-by: Yingjoe Chen <yingjoe.chen@xxxxxxxxxxxx>
>
> This is not a proper changelog. Let me write up a proper one:
>
> Subject: irqchip: mediatek: Use IS_ERR() instead of NULL pointer check
>
> 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
> merily checks for at 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 <b.galvani@xxxxxxxxx>
> Signed-off-by: Yingjoe Chen <yingjoe.chen@xxxxxxxxxxxx>
>
> Can you see the difference?
>
> Thanks,
>
> tglx

Thanks for the review.

This changelog describe issue and why we need this change more clearly.
I'll prepare a new patch with this changelog, Thanks.

Joe.C


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