Hi Lee, On Fri, Jun 16, 2017 at 11:58 PM, Lee Duncan <lduncan@xxxxxxxx> wrote: > It seems like what you are doing is basically "good", i.e. if there is > not enough random data, don't use it. But what happens in that case? The > authentication fails? How does the user know to wait and try again? The process just remains in interruptible (kill-able) sleep until there is enough entropy, so the process doesn't need to do anything. If the waiting is interrupted by a signal, it returns -ESYSRESTART, which follows the usual semantics of restartable syscalls. Jason