Re: [PATCH v4 13/13] random: warn when kernel uses unseeded randomness

On Tue, Jun 6, 2017 at 1:48 PM, Jason A. Donenfeld [off-list ref] wrote:

This enables an important dmesg notification about when drivers have
used the crng without it being seeded first. Prior, these errors would
occur silently, and so there hasn't been a great way of diagnosing these
types of bugs for obscure setups. By adding this as a config option, we
can leave it on by default, so that we learn where these issues happen,
in the field, will still allowing some people to turn it off, if they
really know what they're doing and do not want the log entries.

However, we don't leave it _completely_ by default. An earlier version
of this patch simply had `default y`. I'd really love that, but it turns
out, this problem with unseeded randomness being used is really quite
present and is going to take a long time to fix. Thus, as a compromise
between log-messages-for-all and nobody-knows, this is `default y`,
except it is also `depends on DEBUG_KERNEL`. This will ensure that the
curious see the messages while others don't have to.

Please forgive my ignorance... What do the last two sentence mean exactly?

If I am running a production Debian, Fedora or Ubuntu kernel, will a
messages be present if a violation occurs? A "violation" is a policy
violation, and I mean a generator is used before its operational.

Sunlight is the best disinfectant. At least one message should be
logged to ensure the issue is known. But its not clear to me if that's
what happens when trying to parse the last two sentences.

Jeff