On Fri, May 27, 2022 at 11:10:35PM +0200, Jason A. Donenfeld wrote:
> Hi Guenter,
>
> On Fri, May 27, 2022 at 09:59:14AM -0700, Guenter Roeck wrote:
> > Given that we (ChromeOS) have been hit by rng related
> > issues before (specifically boot stalls on some hardware), I am quite
> > concerned about the possible impact of this series for stable releases.
>
> The urandom try_to_generate_entropy() change from 5.18 wasn't backported.
>
Was it not backported on purpose or is it missing ?
Thanks,
Guenter
> zx2c4@thinkpad ~/Projects/random-linux $ git diff linux-5.10.y:drivers/char/random.c master:drivers/char/random.c
> [...snip...]
> @@ -1292,6 +1311,13 @@ static ssize_t urandom_read_iter(struct kiocb *kiocb, struct iov_iter *iter)
> {
> static int maxwarn = 10;
>
> + /*
> + * Opportunistically attempt to initialize the RNG on platforms that
> + * have fast cycle counters, but don't (for now) require it to succeed.
> + */
> + if (!crng_ready())
> + try_to_generate_entropy();
> +
> if (!crng_ready()) {
> if (!ratelimit_disable && maxwarn <= 0)
> ++urandom_warning.missed;
>
>
>
> Jason
