Subject: bug#36380: service urandom-seed takes too long on boot

From: Leo Famulari <[email-masked]>
Date: Sun, 22 Mar 2020 16:19:19 -0400

On Sun, Mar 22, 2020 at 08:43:33AM +0000, Brice Waegeneire wrote:
> This article has been updated since then with a section[0] about a fix
> authored by Linus[1][2] and merged in Linux 5.4. The gist of it that now
> `getrandom()' will actively try to collect entropy in early boot, if it
> is missing, by using the CPU jitter. The Debian wiki is saying the same[3].

The issue here is not related to getrandom() or our kernel. I think the
bug is still relevant.

The Guix system unconditionally reads from /dev/hwrng if it exists, and
there is no reason for that to take a noticeable amount of time.

But this bug report revealed that some VPS providers have a broken
deployment that does cause delays. Who knows how they are feeding
/dev/hwrng... they would not reply to my questions.

It doesn't really matter though, the problem is ours to fix.

We need to make this read time out after a second, but in the past I
could not figure out how to do this without crashing the system (I'm not
a strong Schemer).

Help is still wanted!