Hi Sandy,
On Sat, Apr 23, 2022 at 10:24:07AM +0800, Sandy Harris wrote:
On Sat, Apr 23, 2022 at 6:37 AM Jason A. Donenfeld <Jason@xxxxxxxxx> wrote:
All platforms are now guaranteed to provide some value for
random_get_entropy(). In case some bug leads to this not being so, we
print a warning, ...
Would it make sense to test at compile time? If there is no hardware
RNG nor a cycle counter, then the kernel should be compiled with
the gcc latent entropy plugin. Generate a warning suggesting that,
or even an error insisting on it.
Unfortunately, as a last ditch warning safeguard against bugs, I don't
think that's something we can determine at build time. A lot of this
machinery is dynamic. Fortunately a single check at init time brings
with it zero appreciable overhead.
Jason
