[PATCH] getrandom: new applet

[Denys Vlasenko]

On Fri, Jul 8, 2016 at 5:25 PM, Etienne Champetier
<champetier.etienne at gmail.com> wrote:
>> B) To accomplish _what_? You seem to want to use the new API because it
>> exists.
>
> unblock (2 times) faster, nothing more

I think for now the applet should not be accepted.

It uses an API which is so new many build environments would not have it.
Which means it should be set to "not selected by default"
in defconfig, which is not typical; or it should be worked around
with using hardcoded syscall numbers (ugly).

The resulting binary will not work on many deployed kernels
(this is a nuisance: you have your stuff work on your
well-updated desktop distro, but on your router it does not. Grrrr).

The above could be ignored if the applet would be a really useful
addition. But it is not: dd from /dev/random works almost as well
for the stated purpose.

Yes, blocking for 3 minutes rather than 6 minutes is an improvement,
but would 3 minute pause on boot be acceptable for many? I suspect
it's still bad; and if I would have that system at hand, I'd experiment
with making it initialize random pool faster. Basically,
I'd look into kernel source, find what makes it feed entropy pool,
and do that activity a lot in a separate process, while dd is blocked.