syscall.c revision 86316 
1/*-
2 * Copyright (c) 1999 Assar Westerlund
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: head/share/examples/kld/syscall/module/syscall.c 86316 2001-11-13 07:42:30Z arr $
27 */
28
29#include <sys/types.h>
30#include <sys/param.h>
31#include <sys/proc.h>
32#include <sys/module.h>
33#include <sys/sysent.h>
34#include <sys/kernel.h>
35#include <sys/systm.h>
36
37/*
38 * The function for implementing the syscall.
39 */
40
41static int
42hello (struct thread *td, void *arg)
43{
44	printf ("hello kernel\n");
45	return 0;
46}
47
48/*
49 * The `sysent' for the new syscall
50 */
51
52static struct sysent hello_sysent = {
53	0,			/* sy_narg */
54	hello			/* sy_call */
55};
56
57/*
58 * The offset in sysent where the syscall is allocated.
59 */
60
61static int offset = NO_SYSCALL;
62
63/*
64 * The function called at load/unload.
65 */
66
67static int
68load (struct module *module, int cmd, void *arg)
69{
70	int error = 0;
71
72	switch (cmd) {
73	case MOD_LOAD :
74		printf ("syscall loaded at %d\n", offset);
75		break;
76	case MOD_UNLOAD :
77		printf ("syscall unloaded from %d\n", offset);
78		break;
79	default :
80		error = EINVAL;
81		break;
82	}
83	return error;
84}
85
86SYSCALL_MODULE(syscall, &offset, &hello_sysent, load, NULL);
87