2019-03-04 20:04:27

by Arnd Bergmann

Subject: [PATCH] irqchip/imx-irqsteer: fix of_property_read_u32() error handling

gcc points out that irqs_num is not initialized when of_property_read_u32()
is an empty stub function:

Included from drivers/irqchip/irq-imx-irqsteer.c:7:
drivers/irqchip/irq-imx-irqsteer.c: In function 'imx_irqsteer_probe':
include/uapi/linux/kernel.h:13:49: error: 'irqs_num' may be used uninitialized in this function [-Werror=maybe-uninitialized]

The same can actually happen with CONFIG_OF=y as well, though we don't
get a warning then.

Add error checking here that lets the code deal with missing or
invalid properties as well as avoid the warning.

Fixes: 28528fca4908 ("irqchip/imx-irqsteer: Add multi output interrupts support")
Signed-off-by: Arnd Bergmann <[email protected]>
---
drivers/irqchip/irq-imx-irqsteer.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-imx-irqsteer.c b/drivers/irqchip/irq-imx-irqsteer.c
index d1098f4da6a4..88df3d00052c 100644
--- a/drivers/irqchip/irq-imx-irqsteer.c
+++ b/drivers/irqchip/irq-imx-irqsteer.c
@@ -169,8 +169,12 @@ static int imx_irqsteer_probe(struct platform_device *pdev)

raw_spin_lock_init(&data->lock);

- of_property_read_u32(np, "fsl,num-irqs", &irqs_num);
- of_property_read_u32(np, "fsl,channel", &data->channel);
+ ret = of_property_read_u32(np, "fsl,num-irqs", &irqs_num);
+ if (ret)
+ return ret;
+ ret = of_property_read_u32(np, "fsl,channel", &data->channel);
+ if (ret)
+ return ret;

/*
* There is one output irq for each group of 64 inputs.
--
2.20.0

2019-03-04 21:15:37

by Marc Zyngier

Subject: Re: [PATCH] irqchip/imx-irqsteer: fix of_property_read_u32() error handling

On Mon, 04 Mar 2019 20:02:18 +0000,
Arnd Bergmann <[email protected]> wrote:
>
> gcc points out that irqs_num is not initialized when of_property_read_u32()
> is an empty stub function:
>
> Included from drivers/irqchip/irq-imx-irqsteer.c:7:
> drivers/irqchip/irq-imx-irqsteer.c: In function 'imx_irqsteer_probe':
> include/uapi/linux/kernel.h:13:49: error: 'irqs_num' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>
> The same can actually happen with CONFIG_OF=y as well, though we don't
> get a warning then.
>
> Add error checking here that lets the code deal with missing or
> invalid properties as well as avoid the warning.
>
> Fixes: 28528fca4908 ("irqchip/imx-irqsteer: Add multi output interrupts support")
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
> drivers/irqchip/irq-imx-irqsteer.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)

Applied, thanks Arnd.

M.

--
Jazz is not dead, it just smell funny.