Re: [PATCH 3/9] mfd: pm8xxx: convert to v2 irq interfaces to support hierarchical IRQ chips

[Linus Walleij]

Hi Brian!

I found one more bug in this patch, still not the last bug but I'm still
digging around:

On Fri, Jan 25, 2019 at 5:23 PM Brian Masney <masneyb@xxxxxxxxxxxxx> wrote:

> +struct pm_irq_data {
> +       int num_irqs;
> +       struct irq_chip *irq_chip;
> +       void (*irq_handler)(struct irq_desc *desc);
> +};
> +
>  struct pm_irq_chip {
>         struct regmap           *regmap;
>         spinlock_t              pm_irq_lock;
>         struct irq_domain       *irqdomain;
> -       unsigned int            num_irqs;
>         unsigned int            num_blocks;
>         unsigned int            num_masters;
>         u8                      config[0];
> -};
> -
> -struct pm_irq_data {
> -       int num_irqs;
> -       const struct irq_domain_ops  *irq_domain_ops;
> -       void (*irq_handler)(struct irq_desc *desc);
> +       const struct pm_irq_data *pm_irq_data;
>  };

This doesn't work: the config[0] must be the tail element
of the struct since we allocate dynamically the trailing
config[] bytes.

As it looks now, the *pm_irq_data gets overwritten by
the configs and it crashes.

Yours,
Linus Walleij