I've also created a Smatch check for missing ->release() functions. It find one bug in that file. There are other bugs, but the static checker is not clever enough to find them. I expect Smatch will get smarter about this in the coming year. sound/core/control_led.c:685 snd_ctl_led_sysfs_add() warn: calling put_device() with no ->release() function So, yeay, I feel like this thread has been useful and I now understand put_device() a little better. Please review the email thread again and send a v2 patch. :) regards, dan carpenter /* * Copyright (C) 2021 Oracle. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt */ #include "smatch.h" #include "smatch_extra.h" static int my_id; static void match_put_device(struct expression *expr, const char *name, struct symbol *sym, void *data) { struct smatch_state *state; state = get_state(SMATCH_EXTRA, name, sym); if (!state || estate_min(state).value != 0 || estate_max(state).value != 0) return; sm_warning("calling put_device() with no ->release() function"); } void check_no_release(int id) { my_id = id; if (option_project != PROJ_KERNEL) return; add_function_param_key_hook("put_device", &match_put_device, 0, "$->release", NULL); add_function_param_key_hook("device_unregister", &match_put_device, 0, "$->release", NULL); }
