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 28 /* 29 * Free a pending callout. This was useful for testing the 30 * "show callout_last" ddb command. 31 */ 32 33 #include <sys/param.h> 34 #include <sys/conf.h> 35 #include <sys/kernel.h> 36 #include <sys/lock.h> 37 #include <sys/module.h> 38 #include <sys/mutex.h> 39 #include <sys/systm.h> 40 41 static struct callout callout_free; 42 static struct mtx callout_free_mutex; 43 static int callout_free_arg; 44 45 static void 46 callout_free_func(void *arg) 47 { 48 printf("squirrel!\n"); 49 mtx_destroy(&callout_free_mutex); 50 memset(&callout_free, 'C', sizeof(callout_free)); 51 } 52 53 static int 54 callout_free_load(module_t mod, int cmd, void *arg) 55 { 56 int error; 57 58 switch (cmd) { 59 case MOD_LOAD: 60 mtx_init(&callout_free_mutex, "callout_free", NULL, MTX_DEF); 61 /* 62 * Do not pass CALLOUT_RETURNUNLOCKED so the callout 63 * subsystem will unlock the "destroyed" mutex. 64 */ 65 callout_init_mtx(&callout_free, &callout_free_mutex, 0); 66 printf("callout_free_func = %p\n", callout_free_func); 67 printf("callout_free_arg = %p\n", &callout_free_arg); 68 callout_reset(&callout_free, hz/10, callout_free_func, 69 &callout_free_arg); 70 error = 0; 71 break; 72 73 case MOD_UNLOAD: 74 error = 0; 75 break; 76 77 default: 78 error = EOPNOTSUPP; 79 break; 80 } 81 82 return (error); 83 } 84 85 DEV_MODULE(callout_free, callout_free_load, NULL); 86