bpf: print full verifier states on infinite loop detection

Additional logging in is_state_visited(): if infinite loop is detected
print full verifier state for both current and equivalent states.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231024000917.12153-8-eddyz87@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

kernel/bpf/verifier.c

@@ -16928,6 +16928,10 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
 			    !iter_active_depths_differ(&sl->state, cur)) {
 				verbose_linfo(env, insn_idx, "; ");
 				verbose(env, "infinite loop detected at insn %d\n", insn_idx);
+				verbose(env, "cur state:");
+				print_verifier_state(env, cur->frame[cur->curframe], true);
+				verbose(env, "old state:");
+				print_verifier_state(env, sl->state.frame[cur->curframe], true);
 				return -EINVAL;
 			}
 			/* if the verifier is processing a loop, avoid adding new state