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
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34 * $Id: subr_log.c,v 1.5 1994/10/02 17:35:22 phk Exp $
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| 34 * $Id: subr_log.c,v 1.6 1995/04/29 05:09:19 jkh Exp $ |
35 */
36
37/*
38 * Error log buffer for kernel printf's.
39 */
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/proc.h>
44#include <sys/vnode.h>
45#include <sys/ioctl.h>
46#include <sys/msgbuf.h>
47#include <sys/file.h>
48#include <sys/signalvar.h>
49
50#define LOG_RDPRI (PZERO + 1)
51
52#define LOG_ASYNC 0x04
53#define LOG_RDWAIT 0x08
54
55struct logsoftc {
56 int sc_state; /* see above for possibilities */
57 struct selinfo sc_selp; /* process waiting on select call */
58 int sc_pgid; /* process/group for async I/O */
59} logsoftc;
60
61int log_open; /* also used in log() */
62
63/*ARGSUSED*/
64int
65logopen(dev, flags, mode, p)
66 dev_t dev;
67 int flags, mode;
68 struct proc *p;
69{
70 register struct msgbuf *mbp = msgbufp;
71
72 if (log_open)
73 return (EBUSY);
74 log_open = 1;
75 logsoftc.sc_pgid = p->p_pid; /* signal process only */
76 /*
77 * Potential race here with putchar() but since putchar should be
78 * called by autoconf, msg_magic should be initialized by the time
79 * we get here.
80 */
81 if (mbp->msg_magic != MSG_MAGIC) {
82 register int i;
83
84 mbp->msg_magic = MSG_MAGIC;
85 mbp->msg_bufx = mbp->msg_bufr = 0;
86 for (i=0; i < MSG_BSIZE; i++)
87 mbp->msg_bufc[i] = 0;
88 }
89 return (0);
90}
91
92/*ARGSUSED*/
93int
94logclose(dev, flag, mode, p)
95 dev_t dev;
96 int flag, mode;
97 struct proc *p;
98{
99
100 log_open = 0;
101 logsoftc.sc_state = 0;
102 return (0);
103}
104
105/*ARGSUSED*/
106int
107logread(dev, uio, flag)
108 dev_t dev;
109 struct uio *uio;
110 int flag;
111{
112 register struct msgbuf *mbp = msgbufp;
113 register long l;
114 register int s;
115 int error = 0;
116
117 s = splhigh();
118 while (mbp->msg_bufr == mbp->msg_bufx) {
119 if (flag & IO_NDELAY) {
120 splx(s);
121 return (EWOULDBLOCK);
122 }
123 logsoftc.sc_state |= LOG_RDWAIT;
124 if ((error = tsleep((caddr_t)mbp, LOG_RDPRI | PCATCH,
125 "klog", 0))) {
126 splx(s);
127 return (error);
128 }
129 }
130 splx(s);
131 logsoftc.sc_state &= ~LOG_RDWAIT;
132
133 while (uio->uio_resid > 0) {
134 l = mbp->msg_bufx - mbp->msg_bufr;
135 if (l < 0)
136 l = MSG_BSIZE - mbp->msg_bufr;
137 l = min(l, uio->uio_resid);
138 if (l == 0)
139 break;
140 error = uiomove((caddr_t)&mbp->msg_bufc[mbp->msg_bufr],
141 (int)l, uio);
142 if (error)
143 break;
144 mbp->msg_bufr += l;
145 if (mbp->msg_bufr < 0 || mbp->msg_bufr >= MSG_BSIZE)
146 mbp->msg_bufr = 0;
147 }
148 return (error);
149}
150
151/*ARGSUSED*/
152int
153logselect(dev, rw, p)
154 dev_t dev;
155 int rw;
156 struct proc *p;
157{
158 int s = splhigh();
159
160 switch (rw) {
161
162 case FREAD:
163 if (msgbufp->msg_bufr != msgbufp->msg_bufx) {
164 splx(s);
165 return (1);
166 }
167 selrecord(p, &logsoftc.sc_selp);
168 break;
169 }
170 splx(s);
171 return (0);
172}
173
174void
175logwakeup()
176{
177 struct proc *p;
178
179 if (!log_open)
180 return;
181 selwakeup(&logsoftc.sc_selp);
182 if (logsoftc.sc_state & LOG_ASYNC) {
183 if (logsoftc.sc_pgid < 0)
184 gsignal(-logsoftc.sc_pgid, SIGIO);
185 else if ((p = pfind(logsoftc.sc_pgid)))
186 psignal(p, SIGIO);
187 }
188 if (logsoftc.sc_state & LOG_RDWAIT) {
189 wakeup((caddr_t)msgbufp);
190 logsoftc.sc_state &= ~LOG_RDWAIT;
191 }
192}
193
194/*ARGSUSED*/
195int
196logioctl(dev, com, data, flag, p)
197 dev_t dev;
198 int com;
199 caddr_t data;
200 int flag;
201 struct proc *p;
202{
203 long l;
204 int s;
205
206 switch (com) {
207
208 /* return number of characters immediately available */
209 case FIONREAD:
210 s = splhigh();
211 l = msgbufp->msg_bufx - msgbufp->msg_bufr;
212 splx(s);
213 if (l < 0)
214 l += MSG_BSIZE;
215 *(int *)data = l;
216 break;
217
218 case FIONBIO:
219 break;
220
221 case FIOASYNC:
222 if (*(int *)data)
223 logsoftc.sc_state |= LOG_ASYNC;
224 else
225 logsoftc.sc_state &= ~LOG_ASYNC;
226 break;
227
228 case TIOCSPGRP:
229 logsoftc.sc_pgid = *(int *)data;
230 break;
231
232 case TIOCGPGRP:
233 *(int *)data = logsoftc.sc_pgid;
234 break;
235
236 default:
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237 return (EINVAL);
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| 237 return (ENOTTY); |
238 }
239 return (0);
240}
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