Subject: Re: linux-next: build failure after merge of the kspp tree (in pinctrl-npcm7xx)

From: Jonathan Neuschäfer <[email-masked]>
Date: Wed, 16 Mar 2022 13:00:17 +0100

Hello Stephen, Tomer, and others,

On Wed, Mar 16, 2022 at 06:32:27PM +1100, Stephen Rothwell wrote:
> Hi all,
> 
> After merging the kspp tree, today's linux-next build (x86_64
> allmodconfig) failed like this:
> 
[...]
> drivers/pinctrl/nuvoton/pinctrl-npcm7xx.c: In function 'npcmgpio_irq_handler':
> include/linux/find.h:40:23: error: array subscript 'long unsigned int[0]' is partly outside array bounds of 'u32[1]' {aka 'unsigned int[1]'} [-Werror=array-bounds]
>    40 |                 val = *addr & GENMASK(size - 1, offset);
>       |                       ^~~~~
> drivers/pinctrl/nuvoton/pinctrl-npcm7xx.c:219:13: note: while referencing 'sts'
>   219 |         u32 sts, en, bit;
>       |             ^~~

Quoting the code in pinctrl-npcm7xx:

	for_each_set_bit(bit, (const void *)&sts, NPCM7XX_GPIO_PER_BANK)
		generic_handle_domain_irq(gc->irq.domain, bit);

The cast is indeed already a bit suspicious, because such casts can hide
type mismatch bugs.

The pinctrl-npcm7xx driver probably won't actually *run* on a 64-bit
platform (I guess there will be a separate pinctrl-npcm8xx driver for
the upcoming 64-bit platform from Nuvoton) but it's better not to have
unnecessary 32bit-isms.

> 
> Caused by commit
> 
>   3b588e43ee5c ("pinctrl: nuvoton: add NPCM7xx pinctrl and GPIO driver")
> 
> probably exposed by commit
> 
>   a1d1e0e3d80a ("pinctrl: nuvoton: Add driver for WPCM450")
> 
> from the pinctrl tree and enabling -Werror=array-bounds.
> 
> I have applied the following hack patch for today.
> 
> From: Stephen Rothwell <[email-masked]>
> Date: Wed, 16 Mar 2022 18:12:14 +1100
> Subject: [PATCH] fixup for "pinctrl: nuvoton: add NPCM7xx pinctrl and GPIO driver"
> 
> Signed-off-by: Stephen Rothwell <[email-masked]>
> ---
>  drivers/pinctrl/nuvoton/pinctrl-npcm7xx.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pinctrl/nuvoton/pinctrl-npcm7xx.c b/drivers/pinctrl/nuvoton/pinctrl-npcm7xx.c
> index 41136f63014a..fddcb7d6bdf4 100644
> --- a/drivers/pinctrl/nuvoton/pinctrl-npcm7xx.c
> +++ b/drivers/pinctrl/nuvoton/pinctrl-npcm7xx.c
> @@ -216,7 +216,8 @@ static void npcmgpio_irq_handler(struct irq_desc *desc)
>  	struct gpio_chip *gc;
>  	struct irq_chip *chip;
>  	struct npcm7xx_gpio *bank;
> -	u32 sts, en, bit;
> +	unsigned long sts, bit;
> +	u32 en;
>  
>  	gc = irq_desc_get_handler_data(desc);
>  	bank = gpiochip_get_data(gc);
> @@ -225,7 +226,7 @@ static void npcmgpio_irq_handler(struct irq_desc *desc)
>  	chained_irq_enter(chip, desc);
>  	sts = ioread32(bank->base + NPCM7XX_GP_N_EVST);
>  	en  = ioread32(bank->base + NPCM7XX_GP_N_EVEN);
> -	dev_dbg(bank->gc.parent, "==> got irq sts %.8x %.8x\n", sts,
> +	dev_dbg(bank->gc.parent, "==> got irq sts %.8lx %.8x\n", sts,
>  		en);

This fix looks reasonable to me.

Thanks,
Jonathan