Fix a minor bug that prevented compilation.
[dragonfly.git] / sys / kern / subr_log.c
CommitLineData
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1/*
2 * Copyright (c) 1982, 1986, 1993
3 * The Regents of the University of California. 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 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)subr_log.c 8.1 (Berkeley) 6/10/93
34 * $FreeBSD: src/sys/kern/subr_log.c,v 1.39.2.2 2001/06/02 08:11:25 phk Exp $
9ba76b73 35 * $DragonFly: src/sys/kern/subr_log.c,v 1.9 2006/06/13 08:12:03 dillon Exp $
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36 */
37
38/*
39 * Error log buffer for kernel printf's.
40 */
41
42#include <sys/param.h>
43#include <sys/systm.h>
44#include <sys/conf.h>
45#include <sys/proc.h>
46#include <sys/vnode.h>
47#include <sys/filio.h>
48#include <sys/ttycom.h>
49#include <sys/msgbuf.h>
50#include <sys/signalvar.h>
51#include <sys/kernel.h>
52#include <sys/poll.h>
53#include <sys/filedesc.h>
54#include <sys/sysctl.h>
e43a034f 55#include <sys/thread2.h>
984263bc 56
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57#define LOG_ASYNC 0x04
58#define LOG_RDWAIT 0x08
59
60static d_open_t logopen;
61static d_close_t logclose;
62static d_read_t logread;
63static d_ioctl_t logioctl;
64static d_poll_t logpoll;
65
66static void logtimeout(void *arg);
67
68#define CDEV_MAJOR 7
69static struct cdevsw log_cdevsw = {
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70 /* name */ "log",
71 /* maj */ CDEV_MAJOR,
72 /* flags */ 0,
73 /* port */ NULL,
455fcd7e 74 /* clone */ NULL,
fabb8ceb 75
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76 /* open */ logopen,
77 /* close */ logclose,
78 /* read */ logread,
79 /* write */ nowrite,
80 /* ioctl */ logioctl,
81 /* poll */ logpoll,
82 /* mmap */ nommap,
83 /* strategy */ nostrategy,
984263bc 84 /* dump */ nodump,
fabb8ceb 85 /* psize */ nopsize
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86};
87
88static struct logsoftc {
89 int sc_state; /* see above for possibilities */
90 struct selinfo sc_selp; /* process waiting on select call */
91 struct sigio *sc_sigio; /* information for async I/O */
92 struct callout sc_callout; /* callout to wakeup syslog */
93} logsoftc;
94
95int log_open; /* also used in log() */
96
97/* Times per second to check for a pending syslog wakeup. */
98static int log_wakeups_per_second = 5;
99SYSCTL_INT(_kern, OID_AUTO, log_wakeups_per_second, CTLFLAG_RW,
100 &log_wakeups_per_second, 0, "");
101
102/*ARGSUSED*/
103static int
41c20dac 104logopen(dev_t dev, int flags, int mode, struct thread *td)
984263bc 105{
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106 struct proc *p = td->td_proc;
107
108 KKASSERT(p != NULL);
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109 if (log_open)
110 return (EBUSY);
111 log_open = 1;
112 callout_init(&logsoftc.sc_callout);
113 fsetown(p->p_pid, &logsoftc.sc_sigio); /* signal process only */
114 callout_reset(&logsoftc.sc_callout, hz / log_wakeups_per_second,
115 logtimeout, NULL);
116 return (0);
117}
118
119/*ARGSUSED*/
120static int
41c20dac 121logclose(dev_t dev, int flag, int mode, struct thread *td)
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122{
123
124 log_open = 0;
125 callout_stop(&logsoftc.sc_callout);
126 logsoftc.sc_state = 0;
127 funsetown(logsoftc.sc_sigio);
128 return (0);
129}
130
131/*ARGSUSED*/
132static int
133logread(dev_t dev, struct uio *uio, int flag)
134{
135 struct msgbuf *mbp = msgbufp;
136 long l;
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137 int error = 0;
138
e43a034f 139 crit_enter();
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140 while (mbp->msg_bufr == mbp->msg_bufx) {
141 if (flag & IO_NDELAY) {
e43a034f 142 crit_exit();
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143 return (EWOULDBLOCK);
144 }
145 logsoftc.sc_state |= LOG_RDWAIT;
377d4740 146 if ((error = tsleep((caddr_t)mbp, PCATCH, "klog", 0))) {
e43a034f 147 crit_exit();
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148 return (error);
149 }
150 }
e43a034f 151 crit_exit();
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152 logsoftc.sc_state &= ~LOG_RDWAIT;
153
154 while (uio->uio_resid > 0) {
155 l = mbp->msg_bufx - mbp->msg_bufr;
156 if (l < 0)
157 l = mbp->msg_size - mbp->msg_bufr;
158 l = min(l, uio->uio_resid);
159 if (l == 0)
160 break;
161 error = uiomove((caddr_t)msgbufp->msg_ptr + mbp->msg_bufr,
162 (int)l, uio);
163 if (error)
164 break;
165 mbp->msg_bufr += l;
166 if (mbp->msg_bufr >= mbp->msg_size)
167 mbp->msg_bufr = 0;
168 }
169 return (error);
170}
171
172/*ARGSUSED*/
173static int
41c20dac 174logpoll(dev_t dev, int events, struct thread *td)
984263bc 175{
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176 int revents = 0;
177
e43a034f 178 crit_enter();
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179 if (events & (POLLIN | POLLRDNORM)) {
180 if (msgbufp->msg_bufr != msgbufp->msg_bufx)
181 revents |= events & (POLLIN | POLLRDNORM);
182 else
41c20dac 183 selrecord(td, &logsoftc.sc_selp);
984263bc 184 }
e43a034f 185 crit_exit();
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186 return (revents);
187}
188
189static void
190logtimeout(void *arg)
191{
192
193 if (!log_open)
194 return;
195 if (msgbuftrigger == 0) {
196 callout_reset(&logsoftc.sc_callout,
197 hz / log_wakeups_per_second, logtimeout, NULL);
198 return;
199 }
200 msgbuftrigger = 0;
201 selwakeup(&logsoftc.sc_selp);
202 if ((logsoftc.sc_state & LOG_ASYNC) && logsoftc.sc_sigio != NULL)
203 pgsigio(logsoftc.sc_sigio, SIGIO, 0);
204 if (logsoftc.sc_state & LOG_RDWAIT) {
205 wakeup((caddr_t)msgbufp);
206 logsoftc.sc_state &= ~LOG_RDWAIT;
207 }
208 callout_reset(&logsoftc.sc_callout, hz / log_wakeups_per_second,
209 logtimeout, NULL);
210}
211
212/*ARGSUSED*/
213static int
41c20dac 214logioctl(dev_t dev, u_long com, caddr_t data, int flag, struct thread *td)
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215{
216 long l;
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217
218 switch (com) {
219
220 /* return number of characters immediately available */
221 case FIONREAD:
e43a034f 222 crit_enter();
984263bc 223 l = msgbufp->msg_bufx - msgbufp->msg_bufr;
e43a034f 224 crit_exit();
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225 if (l < 0)
226 l += msgbufp->msg_size;
227 *(int *)data = l;
228 break;
229
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230 case FIOASYNC:
231 if (*(int *)data)
232 logsoftc.sc_state |= LOG_ASYNC;
233 else
234 logsoftc.sc_state &= ~LOG_ASYNC;
235 break;
236
237 case FIOSETOWN:
238 return (fsetown(*(int *)data, &logsoftc.sc_sigio));
239
240 case FIOGETOWN:
241 *(int *)data = fgetown(logsoftc.sc_sigio);
242 break;
243
244 /* This is deprecated, FIOSETOWN should be used instead. */
245 case TIOCSPGRP:
246 return (fsetown(-(*(int *)data), &logsoftc.sc_sigio));
247
248 /* This is deprecated, FIOGETOWN should be used instead */
249 case TIOCGPGRP:
250 *(int *)data = -fgetown(logsoftc.sc_sigio);
251 break;
252
253 default:
254 return (ENOTTY);
255 }
256 return (0);
257}
258
259static void
260log_drvinit(void *unused)
261{
e4c9c0c8 262 cdevsw_add(&log_cdevsw, 0, 0);
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263 make_dev(&log_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "klog");
264}
265
266SYSINIT(logdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,log_drvinit,NULL)