Re: [PATCH v10 3/4] random: introduce generic vDSO getrandom() implementation

[Florian Weimer <fweimer@redhat.com>]

* Jason A. Donenfeld:

> diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h
> index 73eb622e7663..9ae4d76b36c7 100644
> --- a/include/vdso/datapage.h
> +++ b/include/vdso/datapage.h
> @@ -109,6 +109,16 @@ struct vdso_data {
>  	struct arch_vdso_data	arch_data;
>  };
>  
> +/**
> + * struct vdso_rng_data - vdso RNG state information
> + * @generation:	a counter representing the number of RNG reseeds
> + * @is_ready:	whether the RNG is initialized
> + */
> +struct vdso_rng_data {
> +	unsigned long	generation;
> +	bool		is_ready;
> +};
> +

I don't think you can use a type like long here.  The header says this:

 * vdso_data will be accessed by 64 bit and compat code at the same time
 * so we should be careful before modifying this structure.

So the ABI must be same for 32-bit and 64-bit mode, and long isn't.

Thanks,
Florian