1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
/*
* Copyright (c) 1999 Peter Wemm <peter@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/kthread.h>
#include <sys/resourcevar.h>
#include <sys/signalvar.h>
#include <sys/unistd.h>
#include <sys/wait.h>
#include <machine/stdarg.h>
/*
* Start a kernel process. This is called after a fork() call in
* mi_startup() in the file kern/init_main.c.
*
* This function is used to start "internal" daemons and intended
* to be called from SYSINIT().
*/
void
kproc_start(udata)
const void *udata;
{
const struct kproc_desc *kp = udata;
int error;
error = kthread_create((void (*)(void *))kp->func, NULL,
kp->global_procpp, kp->arg0);
if (error)
panic("kproc_start: %s: error %d", kp->arg0, error);
}
/*
* Create a kernel process/thread/whatever. It shares it's address space
* with proc0 - ie: kernel only.
*/
int
kthread_create(void (*func)(void *), void *arg,
struct proc **newpp, const char *fmt, ...)
{
int error;
va_list ap;
struct proc *p2;
error = fork1(&proc0, RFMEM | RFFDG | RFPROC, &p2);
if (error)
return error;
/* save a global descriptor, if desired */
if (newpp != NULL)
*newpp = p2;
/* this is a non-swapped system process */
p2->p_flag |= P_INMEM | P_SYSTEM;
p2->p_procsig->ps_flag |= PS_NOCLDWAIT;
PHOLD(p2);
/* set up arg0 for 'ps', et al */
va_start(ap, fmt);
vsnprintf(p2->p_comm, sizeof(p2->p_comm), fmt, ap);
va_end(ap);
/* call the processes' main()... */
cpu_set_fork_handler(p2, func, arg);
return 0;
}
void
kthread_exit(int ecode)
{
exit1(curproc, W_EXITCODE(ecode, 0));
}
/*
* Advise a kernel process to suspend (or resume) in its main loop.
* Participation is voluntary.
*/
int
suspend_kproc(struct proc *p, int timo)
{
/*
* Make sure this is indeed a system process and we can safely
* use the p_siglist field.
*/
if ((p->p_flag & P_SYSTEM) == 0)
return (EINVAL);
SIGADDSET(p->p_siglist, SIGSTOP);
return tsleep((caddr_t)&p->p_siglist, PPAUSE, "suspkp", timo);
}
int
resume_kproc(struct proc *p)
{
/*
* Make sure this is indeed a system process and we can safely
* use the p_siglist field.
*/
if ((p->p_flag & P_SYSTEM) == 0)
return (EINVAL);
SIGDELSET(p->p_siglist, SIGSTOP);
wakeup((caddr_t)&p->p_siglist);
return (0);
}
void
kproc_suspend_loop(struct proc *p)
{
while (SIGISMEMBER(p->p_siglist, SIGSTOP)) {
wakeup((caddr_t)&p->p_siglist);
tsleep((caddr_t)&p->p_siglist, PPAUSE, "kpsusp", 0);
}
}
|
