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
callout_free_func(void * arg)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
callout_free_load(module_t mod,int cmd,void * arg)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