{
        struct nsim_bpf_bound_prog *state;
        char name[16];
-       int err;
 
        state = kzalloc(sizeof(*state), GFP_KERNEL);
        if (!state)
        /* Program id is not populated yet when we create the state. */
        sprintf(name, "%u", ns->prog_id_gen++);
        state->ddir = debugfs_create_dir(name, ns->ddir_bpf_bound_progs);
-       if (IS_ERR(state->ddir)) {
-               err = PTR_ERR(state->ddir);
+       if (IS_ERR_OR_NULL(state->ddir)) {
                kfree(state);
-               return err;
+               return -ENOMEM;
        }
 
        debugfs_create_u32("id", 0400, state->ddir, &prog->aux->id);
                           &ns->bpf_bind_verifier_delay);
        ns->ddir_bpf_bound_progs =
                debugfs_create_dir("bpf_bound_progs", ns->ddir);
+       if (IS_ERR_OR_NULL(ns->ddir_bpf_bound_progs))
+               return -ENOMEM;
 
        ns->bpf_tc_accept = true;
        debugfs_create_bool("bpf_tc_accept", 0600, ns->ddir,
 
 
        ns->netdev = dev;
        ns->ddir = debugfs_create_dir(netdev_name(dev), nsim_ddir);
+       if (IS_ERR_OR_NULL(ns->ddir))
+               return -ENOMEM;
 
        err = nsim_bpf_init(ns);
        if (err)
        int err;
 
        nsim_ddir = debugfs_create_dir(DRV_NAME, NULL);
-       if (IS_ERR(nsim_ddir))
-               return PTR_ERR(nsim_ddir);
+       if (IS_ERR_OR_NULL(nsim_ddir))
+               return -ENOMEM;
 
        err = bus_register(&nsim_bus);
        if (err)