Re: [PATCH v5 08/11] um: use fallback for random_get_entropy() instead of zero

Johannes Berg
2022-04-19T11:34:14Z

On Tue, 2022-04-19 at 13:16 +0200, Jason A. Donenfeld wrote:
> In the event that random_get_entropy() can't access a cycle counter or
> similar, falling back to returning 0 is really not the best we can do.
> Instead, at least calling random_get_entropy_fallback() would be
> preferable, because that always needs to return _something_, even
> falling back to jiffies eventually. It's not as though
> random_get_entropy_fallback() is super high precision or guaranteed to
> be entropic, but basically anything that's not zero all the time is
> better than returning zero all the time.
>
> This is accomplished by just including the asm-generic code like on
> other architectures, which means we can get rid of the empty stub
> function here.

LGTM, actually better than before, though not even sure any drivers in
ARCH=um have interrupts that say they can be used for this.

Acked-by: Johannes Berg <johannes@sipsolutions.net>

I assume you're going to take this through the random tree?

johannes