jitterentropy vs. simulation

[Johannes Berg]

[I guess we should keep the CCs so other see it]

> Looking at the stuck check it will be bogus in simulations.

True.

> You might as well ifdef that instead.
> 
> If a simulation is running insert the entropy regardless and do not compute the derivatives used in the check.

Actually you mostly don't want anything inserted in that case, so it's
not bad to skip it.

I was mostly thinking this might be better than adding a completely
unrelated ifdef. Also I guess in real systems with a bad implementation
of random_get_entropy(), the second/third derivates might be
constant/zero for quite a while, so may be better to abort?

In any case, I couldn't figure out any way to not configure this into
the kernel when any kind of crypto is also in ...

johannes