1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2019 Eric van Gyzen 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * $FreeBSD$ 28 */ 29 30 /* 31 * Free a pending callout. This was useful for testing the 32 * "show callout_last" ddb command. 33 */ 34 35 #include <sys/param.h> 36 #include <sys/conf.h> 37 #include <sys/kernel.h> 38 #include <sys/lock.h> 39 #include <sys/module.h> 40 #include <sys/mutex.h> 41 #include <sys/systm.h> 42 43 static struct callout callout_free; 44 static struct mtx callout_free_mutex; 45 static int callout_free_arg; 46 47 static void 48 callout_free_func(void *arg) 49 { 50 printf("squirrel!\n"); 51 mtx_destroy(&callout_free_mutex); 52 memset(&callout_free, 'C', sizeof(callout_free)); 53 } 54 55 static int 56 callout_free_load(module_t mod, int cmd, void *arg) 57 { 58 int error; 59 60 switch (cmd) { 61 case MOD_LOAD: 62 mtx_init(&callout_free_mutex, "callout_free", NULL, MTX_DEF); 63 /* 64 * Do not pass CALLOUT_RETURNUNLOCKED so the callout 65 * subsystem will unlock the "destroyed" mutex. 66 */ 67 callout_init_mtx(&callout_free, &callout_free_mutex, 0); 68 printf("callout_free_func = %p\n", callout_free_func); 69 printf("callout_free_arg = %p\n", &callout_free_arg); 70 callout_reset(&callout_free, hz/10, callout_free_func, 71 &callout_free_arg); 72 error = 0; 73 break; 74 75 case MOD_UNLOAD: 76 error = 0; 77 break; 78 79 default: 80 error = EOPNOTSUPP; 81 break; 82 } 83 84 return (error); 85 } 86 87 DEV_MODULE(callout_free, callout_free_load, NULL); 88