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
