On Wed, 2024-02-21 at 17:25 +0100, Benjamin Tissoires wrote: [...] > @@ -12120,6 +12137,16 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, > } > } > > + if (is_async_callback_calling_kfunc(meta.func_id)) { I think that it's better to check specific kfunc id here: meta.func_id == special_kfunc_list[KF_bpf_timer_set_sleepable_cb_impl] In case if some new async callback calling kfunc would be added, for which set_timer_callback_state() won't be correct. > + err = push_callback_call(env, insn, insn_idx, meta.subprogno, > + set_timer_callback_state); > + if (err) { > + verbose(env, "kfunc %s#%d failed callback verification\n", > + func_name, meta.func_id); > + return err; > + } > + } > + > rcu_lock = is_kfunc_bpf_rcu_read_lock(&meta); > rcu_unlock = is_kfunc_bpf_rcu_read_unlock(&meta); > >