Hi Jason, Am Sat, Feb 05, 2022 at 02:17:15PM +0100 schrieb Jason A. Donenfeld: > Does this introduce a lock nesting inversion situation? > > With your patch, crng_fast_load() now does: > > lock(primary_crng) > invalidate_batched_entropy() > lock(batch_lock) > unlock(batch_lock) > unlock(primary_crng) > > While get_random_{u32,u64}() does: > > lock(batch_lock) > extract_crng() > lock(primary_crng) > unlock(primary_crng) > unlock(batch_lock) > > Is this correct? If so, we might have to defer this patch until after > <https://git.kernel.org/pub/scm/linux/kernel/git/crng/random.git/commit/?id=2dfab1b1> > or something like it lands, which attempts to get rid of the batched > entropy lock. > > If that analysis seems right to you, I could pull this patch into that > development branch for poking and prodding. Right, this makes sense -- I already "read" invalidate_batched_entropy() as being just a call to atomic_inc(). Thanks, Dominik