See summary of the Linux change https://firstname.lastname@example.org/ :
> It adds getentropy(..., GRND_INSECURE). This causes getentropy to
> always return *something*. There is no guarantee whatsoever that
> the result will be cryptographically random or even unique, but the
> kernel will give the best quality random output it can. The name is
> a big hint: the resulting output is INSECURE.
> The purpose of this is to allow programs that genuinely want
> best-effort entropy to get it without resorting to /dev/urandom.
> Plenty of programs do this because they need to do *something*
> during boot and they can't afford to wait. Calling it "INSECURE" is
> probably the best we can do to discourage using this API for things
> that need security.
GRND_INSECURE patch: https://email@example.com/ ,
GRND_INSECURE accepted by tytso: https://lwn.net/ml/linux-kernel/20200107204400.GH3619@mit.edu/