[$] The BPF panic function

One of the key selling points of the BPF subsystem is that loading a BPFprogram is safe: the BPF verifier ensures that the program cannot hurt thekernel before allowing the load to occur. That guarantee is perhapslosing some of its force as more capabilities are made available to BPF programs but, even so, it may be abit surprising to see thisproposal from Artem Savkov adding a BPF helper that is explicitly designed tocrash the system. If this patch set is merged in something resembling itscurrent form, it will be the harbinger of a new era where BPF programs are,in some situations at least, allowed to be overtly destructive.