Re: [PATCH] random: Initialize vsprintf's pointer hash once the random core is ready.

From: Sebastian Andrzej Siewior
Date: Fri Jul 29 2022 - 06:21:36 EST


On 2022-07-29 12:12:08 [+0200], Jason A. Donenfeld wrote:
> Hi Sebastian,
Hi Jason,

> Gumming up random.c with these sorts of things isn't alright. vsprintf
> isn't special in any regard here.
>
> If you can't do this from ordinary context inside of vsprintf, just
> launch a workqueue to do it. This is already needed for changing
> vsprintf's static branch, so just move the get_random_bytes() call into
> there on RT (leaving it alone on non-RT, I guess).

So launching a worker to obtain the random data? That would mean that
the first %p print won't have nothing, right? I could do it as part of
an init-call but I don't know when the random pool is ready. And trying
it again every other second if the random core isn't ready looks kind of
wasteful.

> Jason

Sebastian