Re: [PATCH v5] printk: hash addresses printed with %p

[Kees Cook]

On Wed, Oct 18, 2017 at 10:49 PM, Jason A. Donenfeld <Jason@xxxxxxxxx> wrote:
> static void fill_random_ptr_key(struct random_ready_callback *rdy)
> {
>     get_random_bytes(&ptr_secret, sizeof(ptr_secret));
>     static_branch_disable(&no_ptr_secret);
> }
>
> static struct random_ready_callback random_ready = {
>     .func = fill_random_ptr_key
> };
>
> static int __init initialize_ptr_random(void)
> {
>     int ret = add_random_ready_callback(&random_ready);
>
>     if (!ret)
>         return 0;
>     else if (ret == -EALREADY) {
>         fill_random_ptr_key(&random_ready);
>         return 0;
>     }
>
>     return ret;
> }
> early_initcall(initialize_ptr_random);

Tangent: why is the random_ready API designed with -EALREADY? Couldn't
add_random_ready_callback() just perform the call itself and avoid
needing all the callers to check for -EALREADY?

-Kees

-- 
Kees Cook
Pixel Security