Initial import from FreeBSD RELENG_4:
[dragonfly.git] / sys / kern / kern_kthread.c
CommitLineData
984263bc
MD
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: src/sys/kern/kern_kthread.c,v 1.5.2.3 2001/12/25 01:51:14 dillon Exp $
27 */
28
29#include <sys/param.h>
30#include <sys/systm.h>
31#include <sys/proc.h>
32#include <sys/kthread.h>
33#include <sys/ptrace.h>
34#include <sys/resourcevar.h>
35#include <sys/signalvar.h>
36#include <sys/unistd.h>
37#include <sys/wait.h>
38
39#include <machine/stdarg.h>
40
41/*
42 * Start a kernel process. This is called after a fork() call in
43 * mi_startup() in the file kern/init_main.c.
44 *
45 * This function is used to start "internal" daemons and intended
46 * to be called from SYSINIT().
47 */
48void
49kproc_start(udata)
50 const void *udata;
51{
52 const struct kproc_desc *kp = udata;
53 int error;
54
55 error = kthread_create((void (*)(void *))kp->func, NULL,
56 kp->global_procpp, kp->arg0);
57 if (error)
58 panic("kproc_start: %s: error %d", kp->arg0, error);
59}
60
61/*
62 * Create a kernel process/thread/whatever. It shares it's address space
63 * with proc0 - ie: kernel only.
64 */
65int
66kthread_create(void (*func)(void *), void *arg,
67 struct proc **newpp, const char *fmt, ...)
68{
69 int error;
70 va_list ap;
71 struct proc *p2;
72
73 if (!proc0.p_stats /* || proc0.p_stats->p_start.tv_sec == 0 */) {
74 panic("kthread_create called too soon");
75 }
76
77 error = fork1(&proc0, RFMEM | RFFDG | RFPROC, &p2);
78 if (error)
79 return error;
80
81 /* save a global descriptor, if desired */
82 if (newpp != NULL)
83 *newpp = p2;
84
85 /* this is a non-swapped system process */
86 p2->p_flag |= P_INMEM | P_SYSTEM;
87 p2->p_procsig->ps_flag |= PS_NOCLDWAIT;
88 PHOLD(p2);
89
90 /* set up arg0 for 'ps', et al */
91 va_start(ap, fmt);
92 vsnprintf(p2->p_comm, sizeof(p2->p_comm), fmt, ap);
93 va_end(ap);
94
95 /* call the processes' main()... */
96 cpu_set_fork_handler(p2, func, arg);
97
98 return 0;
99}
100
101void
102kthread_exit(int ecode)
103{
104 proc_reparent(curproc, initproc);
105 exit1(curproc, W_EXITCODE(ecode, 0));
106}
107
108/*
109 * Advise a kernel process to suspend (or resume) in its main loop.
110 * Participation is voluntary.
111 */
112int
113suspend_kproc(struct proc *p, int timo)
114{
115 /*
116 * Make sure this is indeed a system process and we can safely
117 * use the p_siglist field.
118 */
119 if ((p->p_flag & P_SYSTEM) == 0)
120 return (EINVAL);
121 SIGADDSET(p->p_siglist, SIGSTOP);
122 wakeup(p);
123 return tsleep((caddr_t)&p->p_siglist, PPAUSE, "suspkp", timo);
124}
125
126int
127resume_kproc(struct proc *p)
128{
129 /*
130 * Make sure this is indeed a system process and we can safely
131 * use the p_siglist field.
132 */
133 if ((p->p_flag & P_SYSTEM) == 0)
134 return (EINVAL);
135 SIGDELSET(p->p_siglist, SIGSTOP);
136 wakeup((caddr_t)&p->p_siglist);
137 return (0);
138}
139
140void
141kproc_suspend_loop(struct proc *p)
142{
143 while (SIGISMEMBER(p->p_siglist, SIGSTOP)) {
144 wakeup((caddr_t)&p->p_siglist);
145 tsleep((caddr_t)&p->p_siglist, PPAUSE, "kpsusp", 0);
146 }
147}