[apple/xnu.git] / bsd / kern / subr_log.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*
 * Copyright (c) 1982, 1986, 1993
 *	The Regents of the University of California.  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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 *	@(#)subr_log.c	8.3 (Berkeley) 2/14/95
 */

/*
 * Error log buffer for kernel printf's.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/ioctl.h>
#include <sys/msgbuf.h>
#include <sys/file.h>
#include <sys/errno.h>
#include <sys/select.h>
#include <kern/thread.h>
#if 0 /* [ */
#include <kern/sched_prim.h>
#include <kern/parallel.h>
#endif  /* 0 ] */

#define LOG_RDPRI	(PZERO + 1)

#define LOG_NBIO	0x02
#define LOG_ASYNC	0x04
#define LOG_RDWAIT	0x08

struct logsoftc {
	int	sc_state;		/* see above for possibilities */
	struct	selinfo sc_selp;	/* thread waiting for select */
	int	sc_pgid;		/* process/group for async I/O */
} logsoftc;

int	log_open;			/* also used in log() */
struct msgbuf temp_msgbuf;
struct msgbuf *msgbufp;
static int _logentrypend = 0;

/*
 * Serialize log access.  Note that the log can be written at interrupt level,
 * so any log manipulations that can be done from, or affect, another processor
 * at interrupt level must be guarded with a spin lock.
 */
decl_simple_lock_data(,log_lock);	/* stop races dead in their tracks */
#define	LOG_LOCK()	simple_lock(&log_lock)
#define	LOG_UNLOCK()	simple_unlock(&log_lock)
#define	LOG_LOCK_INIT()	simple_lock_init(&log_lock)

/*ARGSUSED*/
logopen(dev, flags, mode, p)
	dev_t dev;
	int flags, mode;
	struct proc *p;
{
	unix_master();			/* for pg_id, sigh */
	LOG_LOCK();
	if (log_open) {
		LOG_UNLOCK();
		unix_release();
		return (EBUSY);
	}
	log_open = 1;
	logsoftc.sc_pgid = p->p_pid;		/* signal process only */
	/*
	 * Potential race here with putchar() but since putchar should be
	 * called by autoconf, msg_magic should be initialized by the time
	 * we get here.
	 */
	if (msgbufp->msg_magic != MSG_MAGIC) {
		register int i;

		msgbufp->msg_magic = MSG_MAGIC;
		msgbufp->msg_bufx = msgbufp->msg_bufr = 0;
		for (i=0; i < MSG_BSIZE; i++)
			msgbufp->msg_bufc[i] = 0;
	}
	LOG_UNLOCK();
	unix_release();
	return (0);
}

/*ARGSUSED*/
int
logclose(dev, flag)
	dev_t dev;
{
	int oldpri;
	LOG_LOCK();
	log_open = 0;
	selwakeup(&logsoftc.sc_selp);
	oldpri = splhigh();
	selthreadclear(&logsoftc.sc_selp);
	splx(oldpri);
	LOG_UNLOCK();
	return (0);
}

/*ARGSUSED*/
int
logread(dev, uio, flag)
	dev_t dev;
	struct uio *uio;
	int flag;
{
	register long l;
	register int s;
	int error = 0;

	s = splhigh();
	while (msgbufp->msg_bufr == msgbufp->msg_bufx) {
		if (flag & IO_NDELAY) {
			splx(s);
			return (EWOULDBLOCK);
		}
		if (logsoftc.sc_state & LOG_NBIO) {
			splx(s);
			return (EWOULDBLOCK);
		}
		logsoftc.sc_state |= LOG_RDWAIT;
		if (error = tsleep((caddr_t)msgbufp, LOG_RDPRI | PCATCH,
				"klog", 0)) {
			splx(s);
			return (error);
		}
	}
	splx(s);
	logsoftc.sc_state &= ~LOG_RDWAIT;

	while (uio->uio_resid > 0) {
		l = msgbufp->msg_bufx - msgbufp->msg_bufr;
		if (l < 0)
			l = MSG_BSIZE - msgbufp->msg_bufr;
		l = min(l, uio->uio_resid);
		if (l == 0)
			break;
		error = uiomove((caddr_t)&msgbufp->msg_bufc[msgbufp->msg_bufr],
			(int)l, uio);
		if (error)
			break;
		msgbufp->msg_bufr += l;
		if (msgbufp->msg_bufr < 0 || msgbufp->msg_bufr >= MSG_BSIZE)
			msgbufp->msg_bufr = 0;
	}
	return (error);
}

/*ARGSUSED*/
int
logselect(dev, rw, p)
	dev_t dev;
	int rw;
	struct proc *p;
{
	int s = splhigh();

	switch (rw) {

	case FREAD:
		if (msgbufp->msg_bufr != msgbufp->msg_bufx) {
			splx(s);
			return (1);
		}
		selrecord(p, &logsoftc.sc_selp);
		break;
	}
	splx(s);
	return (0);
}

void
logwakeup()
{
	struct proc *p;
	int pgid;
	boolean_t funnel_state;

	if (!log_open)
		return;
	funnel_state = thread_funnel_set(kernel_flock, TRUE);
	selwakeup(&logsoftc.sc_selp);
	if (logsoftc.sc_state & LOG_ASYNC) {
		unix_master();
		LOG_LOCK();
		pgid = logsoftc.sc_pgid;
		LOG_UNLOCK();
		if (pgid < 0)
			gsignal(-pgid, SIGIO); 
		else if (p = pfind(pgid))
			psignal(p, SIGIO);
		unix_release();
	}
	if (logsoftc.sc_state & LOG_RDWAIT) {
		wakeup((caddr_t)msgbufp);
		logsoftc.sc_state &= ~LOG_RDWAIT;
	}
	(void) thread_funnel_set(kernel_flock, funnel_state);
}

void
klogwakeup()
{

	if (_logentrypend) {
		_logentrypend = 0;
		logwakeup();
	}
}

/*ARGSUSED*/
int
logioctl(com, data, flag)
	caddr_t data;
{
	long l;
	int s;

	switch (com) {

	/* return number of characters immediately available */
	case FIONREAD:
		s = splhigh();
		l = msgbufp->msg_bufx - msgbufp->msg_bufr;
		splx(s);
		if (l < 0)
			l += MSG_BSIZE;
		*(off_t *)data = l;
		break;

	case FIONBIO:
		if (*(int *)data)
			logsoftc.sc_state |= LOG_NBIO;
		else
			logsoftc.sc_state &= ~LOG_NBIO;
		break;

	case FIOASYNC:
		if (*(int *)data)
			logsoftc.sc_state |= LOG_ASYNC;
		else
			logsoftc.sc_state &= ~LOG_ASYNC;
		break;

	case TIOCSPGRP:
		LOG_LOCK();
		logsoftc.sc_pgid = *(int *)data;
		LOG_UNLOCK();
		break;

	case TIOCGPGRP:
		LOG_LOCK();
		*(int *)data = logsoftc.sc_pgid;
		LOG_UNLOCK();
		break;

	default:
		return (-1);
	}
	return (0);
}

void
log_init()
{
	msgbufp = &temp_msgbuf;
	LOG_LOCK_INIT();
}

void
log_putc(char c)
{
	register struct msgbuf *mbp;

	if (msgbufp == NULL)
		msgbufp =&temp_msgbuf;

	mbp = msgbufp; 
	if (mbp-> msg_magic != MSG_MAGIC) { 
		register int i;

		mbp->msg_magic = MSG_MAGIC;
		mbp->msg_bufx = mbp->msg_bufr = 0;
		for (i=0; i < MSG_BSIZE; i++)
			mbp->msg_bufc[i] = 0;
	}
	mbp->msg_bufc[mbp->msg_bufx++] = c;
	_logentrypend = 1;
	if (mbp->msg_bufx < 0 || mbp->msg_bufx >= MSG_BSIZE)
		mbp->msg_bufx = 0;
}
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
	11	*
	12	* This Original Code and all software distributed under the License are
	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
	23	/*
	24	* Copyright (c) 1982, 1986, 1993
	25	* The Regents of the University of California. All rights reserved.
	26	*
	27	* Redistribution and use in source and binary forms, with or without
	28	* modification, are permitted provided that the following conditions
	29	* are met:
	30	* 1. Redistributions of source code must retain the above copyright
	31	* notice, this list of conditions and the following disclaimer.
	32	* 2. Redistributions in binary form must reproduce the above copyright
	33	* notice, this list of conditions and the following disclaimer in the
	34	* documentation and/or other materials provided with the distribution.
	35	* 3. All advertising materials mentioning features or use of this software
	36	* must display the following acknowledgement:
	37	* This product includes software developed by the University of
	38	* California, Berkeley and its contributors.
	39	* 4. Neither the name of the University nor the names of its contributors
	40	* may be used to endorse or promote products derived from this software
	41	* without specific prior written permission.
	42	*
	43	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	44	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	45	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	46	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	47	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	48	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	49	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	50	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	51	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	52	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	53	* SUCH DAMAGE.
	54	*
	55	* @(#)subr_log.c 8.3 (Berkeley) 2/14/95
	56	*/
	57
	58	/*
	59	* Error log buffer for kernel printf's.
	60	*/
	61
	62	#include <sys/param.h>
	63	#include <sys/systm.h>
	64	#include <sys/proc.h>
65	#include <sys/vnode.h>
66	#include <sys/ioctl.h>
67	#include <sys/msgbuf.h>
68	#include <sys/file.h>
69	#include <sys/errno.h>
70	#include <sys/select.h>
71	#include <kern/thread.h>
72	#if 0 /* [ */
73	#include <kern/sched_prim.h>
74	#include <kern/parallel.h>
75	#endif /* 0 ] */
76
77	#define LOG_RDPRI (PZERO + 1)
78
79	#define LOG_NBIO 0x02
80	#define LOG_ASYNC 0x04
81	#define LOG_RDWAIT 0x08
82
83	struct logsoftc {
84	int sc_state; /* see above for possibilities */
85	struct selinfo sc_selp; /* thread waiting for select */
86	int sc_pgid; /* process/group for async I/O */
87	} logsoftc;
88
89	int log_open; /* also used in log() */
90	struct msgbuf temp_msgbuf;
91	struct msgbuf *msgbufp;
92	static int _logentrypend = 0;
93
94	/*
95	* Serialize log access. Note that the log can be written at interrupt level,
96	* so any log manipulations that can be done from, or affect, another processor
97	* at interrupt level must be guarded with a spin lock.
98	*/
99	decl_simple_lock_data(,log_lock); /* stop races dead in their tracks */
100	#define LOG_LOCK() simple_lock(&log_lock)
101	#define LOG_UNLOCK() simple_unlock(&log_lock)
102	#define LOG_LOCK_INIT() simple_lock_init(&log_lock)
103
104	/ARGSUSED/
105	logopen(dev, flags, mode, p)
106	dev_t dev;
107	int flags, mode;
108	struct proc *p;
109	{
110	unix_master(); /* for pg_id, sigh */
111	LOG_LOCK();
112	if (log_open) {
113	LOG_UNLOCK();
114	unix_release();
115	return (EBUSY);
116	}
117	log_open = 1;
118	logsoftc.sc_pgid = p->p_pid; /* signal process only */
119	/*
120	* Potential race here with putchar() but since putchar should be
121	* called by autoconf, msg_magic should be initialized by the time
122	* we get here.
123	*/
124	if (msgbufp->msg_magic != MSG_MAGIC) {
125	register int i;
126
127	msgbufp->msg_magic = MSG_MAGIC;
128	msgbufp->msg_bufx = msgbufp->msg_bufr = 0;
129	for (i=0; i < MSG_BSIZE; i++)
130	msgbufp->msg_bufc[i] = 0;
131	}
132	LOG_UNLOCK();
133	unix_release();
134	return (0);
135	}
136
137	/ARGSUSED/
138	int
139	logclose(dev, flag)
140	dev_t dev;
141	{
142	int oldpri;
143	LOG_LOCK();
144	log_open = 0;
145	selwakeup(&logsoftc.sc_selp);
146	oldpri = splhigh();
147	selthreadclear(&logsoftc.sc_selp);
148	splx(oldpri);
149	LOG_UNLOCK();
150	return (0);
151	}
152
153	/ARGSUSED/
154	int
155	logread(dev, uio, flag)
156	dev_t dev;
157	struct uio *uio;
158	int flag;
159	{
160	register long l;
161	register int s;
162	int error = 0;
163
164	s = splhigh();
165	while (msgbufp->msg_bufr == msgbufp->msg_bufx) {
166	if (flag & IO_NDELAY) {
167	splx(s);
168	return (EWOULDBLOCK);
169	}
170	if (logsoftc.sc_state & LOG_NBIO) {
171	splx(s);
172	return (EWOULDBLOCK);
173	}
174	logsoftc.sc_state \|= LOG_RDWAIT;
175	if (error = tsleep((caddr_t)msgbufp, LOG_RDPRI \| PCATCH,
176	"klog", 0)) {
177	splx(s);
178	return (error);
179	}
180	}
181	splx(s);
182	logsoftc.sc_state &= ~LOG_RDWAIT;
183
184	while (uio->uio_resid > 0) {
185	l = msgbufp->msg_bufx - msgbufp->msg_bufr;
186	if (l < 0)
187	l = MSG_BSIZE - msgbufp->msg_bufr;
188	l = min(l, uio->uio_resid);
189	if (l == 0)
190	break;
191	error = uiomove((caddr_t)&msgbufp->msg_bufc[msgbufp->msg_bufr],
192	(int)l, uio);
193	if (error)
194	break;
195	msgbufp->msg_bufr += l;
196	if (msgbufp->msg_bufr < 0 \|\| msgbufp->msg_bufr >= MSG_BSIZE)
197	msgbufp->msg_bufr = 0;
198	}
199	return (error);
200	}
201
202	/ARGSUSED/
203	int
204	logselect(dev, rw, p)
205	dev_t dev;
206	int rw;
207	struct proc *p;
208	{
209	int s = splhigh();
210
211	switch (rw) {
212
213	case FREAD:
214	if (msgbufp->msg_bufr != msgbufp->msg_bufx) {
215	splx(s);
216	return (1);
217	}
218	selrecord(p, &logsoftc.sc_selp);
219	break;
220	}
221	splx(s);
222	return (0);
223	}
224
225	void
226	logwakeup()
227	{
228	struct proc *p;
229	int pgid;
230	boolean_t funnel_state;
231
232	if (!log_open)
233	return;
234	funnel_state = thread_funnel_set(kernel_flock, TRUE);
235	selwakeup(&logsoftc.sc_selp);
236	if (logsoftc.sc_state & LOG_ASYNC) {
237	unix_master();
238	LOG_LOCK();
239	pgid = logsoftc.sc_pgid;
240	LOG_UNLOCK();
241	if (pgid < 0)
242	gsignal(-pgid, SIGIO);
243	else if (p = pfind(pgid))
244	psignal(p, SIGIO);
245	unix_release();
246	}
247	if (logsoftc.sc_state & LOG_RDWAIT) {
248	wakeup((caddr_t)msgbufp);
249	logsoftc.sc_state &= ~LOG_RDWAIT;
250	}
251	(void) thread_funnel_set(kernel_flock, funnel_state);
252	}
253
254	void
255	klogwakeup()
256	{
257
258	if (_logentrypend) {
259	_logentrypend = 0;
260	logwakeup();
261	}
262	}
263
264	/ARGSUSED/
265	int
266	logioctl(com, data, flag)
267	caddr_t data;
268	{
269	long l;
270	int s;
271
272	switch (com) {
273
274	/* return number of characters immediately available */
275	case FIONREAD:
276	s = splhigh();
277	l = msgbufp->msg_bufx - msgbufp->msg_bufr;
278	splx(s);
279	if (l < 0)
280	l += MSG_BSIZE;
281	(off_t )data = l;
282	break;
283
284	case FIONBIO:
285	if ((int )data)
286	logsoftc.sc_state \|= LOG_NBIO;
287	else
288	logsoftc.sc_state &= ~LOG_NBIO;
289	break;
290
291	case FIOASYNC:
292	if ((int )data)
293	logsoftc.sc_state \|= LOG_ASYNC;
294	else
295	logsoftc.sc_state &= ~LOG_ASYNC;
296	break;
297
298	case TIOCSPGRP:
299	LOG_LOCK();
300	logsoftc.sc_pgid = (int )data;
301	LOG_UNLOCK();
302	break;
303
304	case TIOCGPGRP:
305	LOG_LOCK();
306	(int )data = logsoftc.sc_pgid;
307	LOG_UNLOCK();
308	break;
309
310	default:
311	return (-1);
312	}
313	return (0);
314	}
315
316	void
317	log_init()
318	{
319	msgbufp = &temp_msgbuf;
320	LOG_LOCK_INIT();
321	}
322
323	void
324	log_putc(char c)
325	{
326	register struct msgbuf *mbp;
327
328	if (msgbufp == NULL)
329	msgbufp =&temp_msgbuf;
330
331	mbp = msgbufp;
332	if (mbp-> msg_magic != MSG_MAGIC) {
333	register int i;
334
335	mbp->msg_magic = MSG_MAGIC;
336	mbp->msg_bufx = mbp->msg_bufr = 0;
337	for (i=0; i < MSG_BSIZE; i++)
338	mbp->msg_bufc[i] = 0;
339	}
340	mbp->msg_bufc[mbp->msg_bufx++] = c;
341	_logentrypend = 1;
342	if (mbp->msg_bufx < 0 \|\| mbp->msg_bufx >= MSG_BSIZE)
343	mbp->msg_bufx = 0;
344	}