| Message ID | 1418050989-21411-1-git-send-email-yingjoe.chen@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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@mediatek.com> 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@gmail.com> Signed-off-by: Yingjoe Chen <yingjoe.chen@mediatek.com> Can you see the difference? Thanks, tglx
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@mediatek.com> > > 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@gmail.com> > Signed-off-by: Yingjoe Chen <yingjoe.chen@mediatek.com> > > 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
==================== 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@mediatek.com> --- 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; }