]> git.saurik.com Git - apple/xnu.git/blame - bsd/kern/subr_log.c
xnu-792.18.15.tar.gz
[apple/xnu.git] / bsd / kern / subr_log.c
CommitLineData
1c79356b 1/*
5d5c5d0d
A
2 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
3 *
8f6c56a5 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b 5 *
8f6c56a5
A
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
8ad349bb 24 * limitations under the License.
8f6c56a5
A
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b
A
27 */
28/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
29/*
30 * Copyright (c) 1982, 1986, 1993
31 * The Regents of the University of California. All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 * 1. Redistributions of source code must retain the above copyright
37 * notice, this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 * notice, this list of conditions and the following disclaimer in the
40 * documentation and/or other materials provided with the distribution.
41 * 3. All advertising materials mentioning features or use of this software
42 * must display the following acknowledgement:
43 * This product includes software developed by the University of
44 * California, Berkeley and its contributors.
45 * 4. Neither the name of the University nor the names of its contributors
46 * may be used to endorse or promote products derived from this software
47 * without specific prior written permission.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 * SUCH DAMAGE.
60 *
61 * @(#)subr_log.c 8.3 (Berkeley) 2/14/95
62 */
63
64/*
65 * Error log buffer for kernel printf's.
66 */
67
68#include <sys/param.h>
69#include <sys/systm.h>
91447636 70#include <sys/proc_internal.h>
1c79356b
A
71#include <sys/vnode.h>
72#include <sys/ioctl.h>
73#include <sys/msgbuf.h>
91447636 74#include <sys/file_internal.h>
1c79356b
A
75#include <sys/errno.h>
76#include <sys/select.h>
91447636 77#include <sys/kernel.h>
1c79356b 78#include <kern/thread.h>
91447636 79#include <sys/lock.h>
1c79356b
A
80
81#define LOG_RDPRI (PZERO + 1)
82
83#define LOG_NBIO 0x02
84#define LOG_ASYNC 0x04
85#define LOG_RDWAIT 0x08
86
87struct logsoftc {
88 int sc_state; /* see above for possibilities */
89 struct selinfo sc_selp; /* thread waiting for select */
90 int sc_pgid; /* process/group for async I/O */
91} logsoftc;
92
93int log_open; /* also used in log() */
94struct msgbuf temp_msgbuf;
95struct msgbuf *msgbufp;
96static int _logentrypend = 0;
91447636
A
97static int log_inited = 0;
98void bsd_log_lock(void);
99/* the following two are implemented in osfmk/kern/printf.c */
100extern void bsd_log_unlock(void);
101extern void bsd_log_init(void);
1c79356b
A
102
103/*
104 * Serialize log access. Note that the log can be written at interrupt level,
105 * so any log manipulations that can be done from, or affect, another processor
106 * at interrupt level must be guarded with a spin lock.
107 */
91447636
A
108
109#define LOG_LOCK() bsd_log_lock()
110#define LOG_UNLOCK() bsd_log_unlock()
111
1c79356b
A
112
113/*ARGSUSED*/
114logopen(dev, flags, mode, p)
115 dev_t dev;
116 int flags, mode;
117 struct proc *p;
118{
1c79356b
A
119 LOG_LOCK();
120 if (log_open) {
121 LOG_UNLOCK();
1c79356b
A
122 return (EBUSY);
123 }
124 log_open = 1;
125 logsoftc.sc_pgid = p->p_pid; /* signal process only */
126 /*
127 * Potential race here with putchar() but since putchar should be
128 * called by autoconf, msg_magic should be initialized by the time
129 * we get here.
130 */
131 if (msgbufp->msg_magic != MSG_MAGIC) {
132 register int i;
133
134 msgbufp->msg_magic = MSG_MAGIC;
135 msgbufp->msg_bufx = msgbufp->msg_bufr = 0;
136 for (i=0; i < MSG_BSIZE; i++)
137 msgbufp->msg_bufc[i] = 0;
138 }
139 LOG_UNLOCK();
9bccf70c 140
1c79356b
A
141 return (0);
142}
143
144/*ARGSUSED*/
145int
146logclose(dev, flag)
147 dev_t dev;
148{
149 int oldpri;
150 LOG_LOCK();
151 log_open = 0;
152 selwakeup(&logsoftc.sc_selp);
1c79356b 153 selthreadclear(&logsoftc.sc_selp);
1c79356b
A
154 LOG_UNLOCK();
155 return (0);
156}
157
158/*ARGSUSED*/
159int
160logread(dev, uio, flag)
161 dev_t dev;
162 struct uio *uio;
163 int flag;
164{
165 register long l;
166 register int s;
167 int error = 0;
91447636
A
168 char localbuff[MSG_BSIZE];
169 int copybytes;
1c79356b 170
91447636 171 LOG_LOCK();
1c79356b
A
172 while (msgbufp->msg_bufr == msgbufp->msg_bufx) {
173 if (flag & IO_NDELAY) {
91447636
A
174 error = EWOULDBLOCK;
175 goto out;
1c79356b
A
176 }
177 if (logsoftc.sc_state & LOG_NBIO) {
91447636
A
178 error = EWOULDBLOCK;
179 goto out;
1c79356b
A
180 }
181 logsoftc.sc_state |= LOG_RDWAIT;
91447636
A
182 LOG_UNLOCK();
183 /*
184 * If the wakeup is missed the ligtening bolt will wake this up
185 * if there are any new characters. If that doesn't do it
186 * then wait for 5 sec and reevaluate
187 */
1c79356b 188 if (error = tsleep((caddr_t)msgbufp, LOG_RDPRI | PCATCH,
91447636
A
189 "klog", 5 * hz)) {
190 /* if it times out; ignore */
191 if (error != EWOULDBLOCK)
192 return (error);
1c79356b 193 }
91447636 194 LOG_LOCK();
1c79356b 195 }
1c79356b
A
196 logsoftc.sc_state &= ~LOG_RDWAIT;
197
91447636
A
198
199 while (uio_resid(uio) > 0) {
1c79356b
A
200 l = msgbufp->msg_bufx - msgbufp->msg_bufr;
201 if (l < 0)
202 l = MSG_BSIZE - msgbufp->msg_bufr;
91447636 203 l = min(l, uio_resid(uio));
1c79356b
A
204 if (l == 0)
205 break;
91447636
A
206 bcopy(&msgbufp->msg_bufc[msgbufp->msg_bufr], &localbuff[0], l);
207 LOG_UNLOCK();
208 error = uiomove((caddr_t)&localbuff[0],
1c79356b 209 (int)l, uio);
91447636 210 LOG_LOCK();
1c79356b
A
211 if (error)
212 break;
213 msgbufp->msg_bufr += l;
214 if (msgbufp->msg_bufr < 0 || msgbufp->msg_bufr >= MSG_BSIZE)
215 msgbufp->msg_bufr = 0;
216 }
91447636
A
217out:
218 LOG_UNLOCK();
1c79356b
A
219 return (error);
220}
221
222/*ARGSUSED*/
223int
0b4e3aa0 224logselect(dev, rw, wql, p)
1c79356b
A
225 dev_t dev;
226 int rw;
0b4e3aa0 227 void * wql;
1c79356b
A
228 struct proc *p;
229{
1c79356b
A
230
231 switch (rw) {
232
233 case FREAD:
91447636 234 LOG_LOCK();
1c79356b 235 if (msgbufp->msg_bufr != msgbufp->msg_bufx) {
91447636 236 LOG_UNLOCK();
1c79356b
A
237 return (1);
238 }
0b4e3aa0 239 selrecord(p, &logsoftc.sc_selp, wql);
91447636 240 LOG_UNLOCK();
1c79356b
A
241 break;
242 }
1c79356b
A
243 return (0);
244}
245
246void
247logwakeup()
248{
249 struct proc *p;
250 int pgid;
251 boolean_t funnel_state;
252
91447636
A
253 LOG_LOCK();
254 if (!log_open) {
255 LOG_UNLOCK();
1c79356b 256 return;
91447636 257 }
1c79356b
A
258 selwakeup(&logsoftc.sc_selp);
259 if (logsoftc.sc_state & LOG_ASYNC) {
1c79356b
A
260 pgid = logsoftc.sc_pgid;
261 LOG_UNLOCK();
262 if (pgid < 0)
263 gsignal(-pgid, SIGIO);
264 else if (p = pfind(pgid))
265 psignal(p, SIGIO);
91447636 266 LOG_LOCK();
1c79356b
A
267 }
268 if (logsoftc.sc_state & LOG_RDWAIT) {
269 wakeup((caddr_t)msgbufp);
270 logsoftc.sc_state &= ~LOG_RDWAIT;
271 }
91447636 272 LOG_UNLOCK();
1c79356b
A
273}
274
275void
276klogwakeup()
277{
278
279 if (_logentrypend) {
280 _logentrypend = 0;
281 logwakeup();
282 }
283}
284
285/*ARGSUSED*/
286int
55e303ae 287logioctl(dev, com, data, flag)
1c79356b
A
288 caddr_t data;
289{
290 long l;
291 int s;
292
91447636 293 LOG_LOCK();
1c79356b
A
294 switch (com) {
295
296 /* return number of characters immediately available */
297 case FIONREAD:
1c79356b 298 l = msgbufp->msg_bufx - msgbufp->msg_bufr;
1c79356b
A
299 if (l < 0)
300 l += MSG_BSIZE;
301 *(off_t *)data = l;
302 break;
303
304 case FIONBIO:
305 if (*(int *)data)
306 logsoftc.sc_state |= LOG_NBIO;
307 else
308 logsoftc.sc_state &= ~LOG_NBIO;
309 break;
310
311 case FIOASYNC:
312 if (*(int *)data)
313 logsoftc.sc_state |= LOG_ASYNC;
314 else
315 logsoftc.sc_state &= ~LOG_ASYNC;
316 break;
317
318 case TIOCSPGRP:
1c79356b 319 logsoftc.sc_pgid = *(int *)data;
1c79356b
A
320 break;
321
322 case TIOCGPGRP:
1c79356b 323 *(int *)data = logsoftc.sc_pgid;
1c79356b
A
324 break;
325
326 default:
91447636 327 LOG_UNLOCK();
1c79356b
A
328 return (-1);
329 }
91447636 330 LOG_UNLOCK();
1c79356b
A
331 return (0);
332}
333
334void
91447636 335bsd_log_init()
1c79356b 336{
91447636
A
337 if (!log_inited) {
338 msgbufp = &temp_msgbuf;
339 log_inited = 1;
340 }
1c79356b
A
341}
342
343void
344log_putc(char c)
345{
346 register struct msgbuf *mbp;
347
91447636
A
348 if (!log_inited) {
349 panic("bsd log is not inited");
350 }
351 LOG_LOCK();
1c79356b
A
352
353 mbp = msgbufp;
354 if (mbp-> msg_magic != MSG_MAGIC) {
355 register int i;
356
357 mbp->msg_magic = MSG_MAGIC;
358 mbp->msg_bufx = mbp->msg_bufr = 0;
359 for (i=0; i < MSG_BSIZE; i++)
360 mbp->msg_bufc[i] = 0;
361 }
362 mbp->msg_bufc[mbp->msg_bufx++] = c;
363 _logentrypend = 1;
364 if (mbp->msg_bufx < 0 || mbp->msg_bufx >= MSG_BSIZE)
365 mbp->msg_bufx = 0;
91447636 366 LOG_UNLOCK();
1c79356b 367}
91447636 368