Brendan Gregg talks about it in the talk in the link at 17:50.
Here is a short transcription (not verbatim):
> People have asked if BPF is Turing Complete. Is is possible to have a BPF program that can run BPF programs? We have had some serious discussions, as are we there yet. And the answer is no. The answer is no because the verifier rejects unbounded loops and so that there is some things that are not possible. There are bounded loops in BPF now.
Here is a short transcription (not verbatim):
> People have asked if BPF is Turing Complete. Is is possible to have a BPF program that can run BPF programs? We have had some serious discussions, as are we there yet. And the answer is no. The answer is no because the verifier rejects unbounded loops and so that there is some things that are not possible. There are bounded loops in BPF now.