xref: /freebsd/sys/kern/kern_kthread.c (revision 9c8b8baa38c9a8135d7602f127cb0c735010837d)
1 /*
2  * Copyright (c) 1999 Peter Wemm <peter@FreeBSD.org>
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  * $FreeBSD$
27  */
28 
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/kernel.h>
32 #include <sys/proc.h>
33 #include <sys/kthread.h>
34 #include <sys/unistd.h>
35 #include <sys/wait.h>
36 
37 #include <machine/cpu.h>
38 #include <machine/stdarg.h>
39 
40 /*
41  * Start a kernel process.  This is called after a fork() call in
42  * mi_startup() in the file kern/init_main.c.
43  *
44  * This function is used to start "internal" daemons and intended
45  * to be called from SYSINIT().
46  */
47 void
48 kproc_start(udata)
49 	const void *udata;
50 {
51 	const struct kproc_desc	*kp = udata;
52 	int error;
53 
54 	error = kthread_create((void (*)(void *))kp->func, NULL,
55 		    kp->global_procpp, kp->arg0);
56 	if (error)
57 		panic("kproc_start: %s: error %d", kp->arg0, error);
58 }
59 
60 /*
61  * Create a kernel process/thread/whatever.  It shares it's address space
62  * with proc0 - ie: kernel only.
63  */
64 int
65 kthread_create(void (*func)(void *), void *arg,
66     struct proc **newpp, const char *fmt, ...)
67 {
68 	int error;
69 	va_list ap;
70 	struct proc *p2;
71 
72 	error = fork1(&proc0, RFMEM | RFFDG | RFPROC, &p2);
73 	if (error)
74 		return error;
75 
76 	/* save a global descriptor, if desired */
77 	if (newpp != NULL)
78 		*newpp = p2;
79 
80 	/* this is a non-swapped system process */
81 	p2->p_flag |= P_INMEM | P_SYSTEM | P_NOCLDWAIT;
82 	PHOLD(p2);
83 
84 	/* set up arg0 for 'ps', et al */
85 	va_start(ap, fmt);
86 	vsnprintf(p2->p_comm, sizeof(p2->p_comm), fmt, ap);
87 	va_end(ap);
88 
89 	/* call the processes' main()... */
90 	cpu_set_fork_handler(p2, func, arg);
91 
92 	return 0;
93 }
94 
95 void
96 kthread_exit(int ecode)
97 {
98 	exit1(curproc, W_EXITCODE(ecode, 0));
99 }
100 
101