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1.1 root 1: /*
2: * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
3: *
4: * @APPLE_LICENSE_HEADER_START@
5: *
6: * Portions Copyright (c) 1999 Apple Computer, Inc. All Rights
7: * Reserved. This file contains Original Code and/or Modifications of
8: * Original Code as defined in and that are subject to the Apple Public
9: * Source License Version 1.1 (the "License"). You may not use this file
10: * except in compliance with the License. Please obtain a copy of the
11: * License at http://www.apple.com/publicsource and read it before using
12: * this file.
13: *
14: * The Original Code and all software distributed under the License are
15: * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
16: * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
17: * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
18: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
19: * License for the specific language governing rights and limitations
20: * under the License.
21: *
22: * @APPLE_LICENSE_HEADER_END@
23: */
24:
25: /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
26: /*
27: * Copyright (c) 1982, 1986, 1993
28: * The Regents of the University of California. All rights reserved.
29: *
30: * Redistribution and use in source and binary forms, with or without
31: * modification, are permitted provided that the following conditions
32: * are met:
33: * 1. Redistributions of source code must retain the above copyright
34: * notice, this list of conditions and the following disclaimer.
35: * 2. Redistributions in binary form must reproduce the above copyright
36: * notice, this list of conditions and the following disclaimer in the
37: * documentation and/or other materials provided with the distribution.
38: * 3. All advertising materials mentioning features or use of this software
39: * must display the following acknowledgement:
40: * This product includes software developed by the University of
41: * California, Berkeley and its contributors.
42: * 4. Neither the name of the University nor the names of its contributors
43: * may be used to endorse or promote products derived from this software
44: * without specific prior written permission.
45: *
46: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
47: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
48: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
49: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
50: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
51: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
52: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
53: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
54: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
55: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
56: * SUCH DAMAGE.
57: *
58: * @(#)subr_log.c 8.3 (Berkeley) 2/14/95
59: */
60:
61: /*
62: * Error log buffer for kernel printf's.
63: */
64:
65: #include <sys/param.h>
66: #include <sys/systm.h>
67: #include <sys/proc.h>
68: #include <sys/vnode.h>
69: #include <sys/ioctl.h>
70: #include <sys/msgbuf.h>
71: #include <sys/file.h>
72: #include <sys/errno.h>
73: #include <sys/select.h>
74: #include <kern/thread.h>
75: #include <kern/sched_prim.h>
76: #include <kern/parallel.h>
77:
78: #define LOG_RDPRI (PZERO + 1)
79:
80: #define LOG_NBIO 0x02
81: #define LOG_ASYNC 0x04
82: #define LOG_RDWAIT 0x08
83:
84: struct logsoftc {
85: int sc_state; /* see above for possibilities */
86: struct selinfo sc_selp; /* thread waiting for select */
87: int sc_pgid; /* process/group for async I/O */
88: } logsoftc;
89:
90: int log_open; /* also used in log() */
91: struct msgbuf *msgbufp;
92:
93: /*
94: * Serialize log access. Note that the log can be written at interrupt level,
95: * so any log manipulations that can be done from, or affect, another processor
96: * at interrupt level must be guarded with a spin lock.
97: */
98: decl_simple_lock_data(,log_lock); /* stop races dead in their tracks */
99: #define LOG_LOCK() simple_lock(&log_lock)
100: #define LOG_UNLOCK() simple_unlock(&log_lock)
101: #define LOG_LOCK_INIT() simple_lock_init(&log_lock)
102:
103: /*ARGSUSED*/
104: logopen(dev, flags, mode, p)
105: dev_t dev;
106: int flags, mode;
107: struct proc *p;
108: {
109: unix_master(); /* for pg_id, sigh */
110: LOG_LOCK();
111: if (log_open) {
112: LOG_UNLOCK();
113: return (EBUSY);
114: }
115: log_open = 1;
116: logsoftc.sc_pgid = p->p_pid; /* signal process only */
117: /*
118: * Potential race here with putchar() but since putchar should be
119: * called by autoconf, msg_magic should be initialized by the time
120: * we get here.
121: */
122: if (msgbufp->msg_magic != MSG_MAGIC) {
123: register int i;
124:
125: msgbufp->msg_magic = MSG_MAGIC;
126: msgbufp->msg_bufx = msgbufp->msg_bufr = 0;
127: for (i=0; i < MSG_BSIZE; i++)
128: msgbufp->msg_bufc[i] = 0;
129: }
130: LOG_UNLOCK();
131: unix_release();
132: return (0);
133: }
134:
135: /*ARGSUSED*/
136: int
137: logclose(dev, flag)
138: dev_t dev;
139: {
140: int oldpri;
141: LOG_LOCK();
142: log_open = 0;
143: selwakeup(&logsoftc.sc_selp);
144: oldpri = splhigh();
145: selthreadclear(&logsoftc.sc_selp);
146: splx(oldpri);
147: LOG_UNLOCK();
148: return (0);
149: }
150:
151: /*ARGSUSED*/
152: int
153: logread(dev, uio, flag)
154: dev_t dev;
155: struct uio *uio;
156: int flag;
157: {
158: register long l;
159: register int s;
160: int error = 0;
161:
162: s = splhigh();
163: while (msgbufp->msg_bufr == msgbufp->msg_bufx) {
164: if (flag & IO_NDELAY) {
165: splx(s);
166: return (EWOULDBLOCK);
167: }
168: if (logsoftc.sc_state & LOG_NBIO) {
169: splx(s);
170: return (EWOULDBLOCK);
171: }
172: logsoftc.sc_state |= LOG_RDWAIT;
173: if (error = tsleep((caddr_t)msgbufp, LOG_RDPRI | PCATCH,
174: "klog", 0)) {
175: splx(s);
176: return (error);
177: }
178: }
179: splx(s);
180: logsoftc.sc_state &= ~LOG_RDWAIT;
181:
182: while (uio->uio_resid > 0) {
183: l = msgbufp->msg_bufx - msgbufp->msg_bufr;
184: if (l < 0)
185: l = MSG_BSIZE - msgbufp->msg_bufr;
186: l = min(l, uio->uio_resid);
187: if (l == 0)
188: break;
189: error = uiomove((caddr_t)&msgbufp->msg_bufc[msgbufp->msg_bufr],
190: (int)l, uio);
191: if (error)
192: break;
193: msgbufp->msg_bufr += l;
194: if (msgbufp->msg_bufr < 0 || msgbufp->msg_bufr >= MSG_BSIZE)
195: msgbufp->msg_bufr = 0;
196: }
197: return (error);
198: }
199:
200: /*ARGSUSED*/
201: int
202: logselect(dev, rw, p)
203: dev_t dev;
204: int rw;
205: struct proc *p;
206: {
207: int s = splhigh();
208:
209: switch (rw) {
210:
211: case FREAD:
212: if (msgbufp->msg_bufr != msgbufp->msg_bufx) {
213: splx(s);
214: return (1);
215: }
216: selrecord(p, &logsoftc.sc_selp);
217: break;
218: }
219: splx(s);
220: return (0);
221: }
222:
223: void
224: logwakeup()
225: {
226: struct proc *p;
227: int pgid;
228:
229: if (!log_open)
230: return;
231: selwakeup(&logsoftc.sc_selp);
232: if (logsoftc.sc_state & LOG_ASYNC) {
233: unix_master();
234: LOG_LOCK();
235: pgid = logsoftc.sc_pgid;
236: LOG_UNLOCK();
237: if (pgid < 0)
238: gsignal(-pgid, SIGIO);
239: else if (p = pfind(pgid))
240: psignal(p, SIGIO);
241: unix_release();
242: }
243: if (logsoftc.sc_state & LOG_RDWAIT) {
244: wakeup((caddr_t)msgbufp);
245: logsoftc.sc_state &= ~LOG_RDWAIT;
246: }
247: }
248:
249: /*ARGSUSED*/
250: int
251: logioctl(com, data, flag)
252: caddr_t data;
253: {
254: long l;
255: int s;
256:
257: switch (com) {
258:
259: /* return number of characters immediately available */
260: case FIONREAD:
261: s = splhigh();
262: l = msgbufp->msg_bufx - msgbufp->msg_bufr;
263: splx(s);
264: if (l < 0)
265: l += MSG_BSIZE;
266: *(off_t *)data = l;
267: break;
268:
269: case FIONBIO:
270: if (*(int *)data)
271: logsoftc.sc_state |= LOG_NBIO;
272: else
273: logsoftc.sc_state &= ~LOG_NBIO;
274: break;
275:
276: case FIOASYNC:
277: if (*(int *)data)
278: logsoftc.sc_state |= LOG_ASYNC;
279: else
280: logsoftc.sc_state &= ~LOG_ASYNC;
281: break;
282:
283: case TIOCSPGRP:
284: LOG_LOCK();
285: logsoftc.sc_pgid = *(int *)data;
286: LOG_UNLOCK();
287: break;
288:
289: case TIOCGPGRP:
290: LOG_LOCK();
291: *(int *)data = logsoftc.sc_pgid;
292: LOG_UNLOCK();
293: break;
294:
295: default:
296: return (-1);
297: }
298: return (0);
299: }
300:
301: void
302: log_init()
303: {
304: LOG_LOCK_INIT();
305: }
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