[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>

#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;
{
	LOG_LOCK();
	if (log_open) {
		LOG_UNLOCK();
		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();

	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, wql, p)
	dev_t dev;
	int rw;
	void * wql;
	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, wql);
		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) {
		LOG_LOCK();
		pgid = logsoftc.sc_pgid;
		LOG_UNLOCK();
		if (pgid < 0)
			gsignal(-pgid, SIGIO); 
		else if (p = pfind(pgid))
			psignal(p, SIGIO);
	}
	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(dev, 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	*
e5568f75 A	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.
1c79356b	11	*
e5568f75 A	12	* This Original Code and all software distributed under the License are
e5568f75 A	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
1c79356b A	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
1c79356b A	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
e5568f75 A	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.
1c79356b A	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>
1c79356b A	72
	73	#define LOG_RDPRI (PZERO + 1)
	74
	75	#define LOG_NBIO 0x02
	76	#define LOG_ASYNC 0x04
	77	#define LOG_RDWAIT 0x08
	78
	79	struct logsoftc {
	80	int sc_state; /* see above for possibilities */
	81	struct selinfo sc_selp; /* thread waiting for select */
	82	int sc_pgid; /* process/group for async I/O */
	83	} logsoftc;
	84
	85	int log_open; /* also used in log() */
	86	struct msgbuf temp_msgbuf;
	87	struct msgbuf *msgbufp;
	88	static int _logentrypend = 0;
	89
	90	/*
	91	* Serialize log access. Note that the log can be written at interrupt level,
	92	* so any log manipulations that can be done from, or affect, another processor
	93	* at interrupt level must be guarded with a spin lock.
	94	*/
	95	decl_simple_lock_data(,log_lock); /* stop races dead in their tracks */
	96	#define LOG_LOCK() simple_lock(&log_lock)
	97	#define LOG_UNLOCK() simple_unlock(&log_lock)
	98	#define LOG_LOCK_INIT() simple_lock_init(&log_lock)
	99
	100	/ARGSUSED/
	101	logopen(dev, flags, mode, p)
	102	dev_t dev;
	103	int flags, mode;
	104	struct proc *p;
	105	{
1c79356b A	106	LOG_LOCK();
	107	if (log_open) {
	108	LOG_UNLOCK();
1c79356b A	109	return (EBUSY);
	110	}
	111	log_open = 1;
	112	logsoftc.sc_pgid = p->p_pid; /* signal process only */
	113	/*
	114	* Potential race here with putchar() but since putchar should be
	115	* called by autoconf, msg_magic should be initialized by the time
	116	* we get here.
	117	*/
	118	if (msgbufp->msg_magic != MSG_MAGIC) {
	119	register int i;
	120
	121	msgbufp->msg_magic = MSG_MAGIC;
	122	msgbufp->msg_bufx = msgbufp->msg_bufr = 0;
	123	for (i=0; i < MSG_BSIZE; i++)
	124	msgbufp->msg_bufc[i] = 0;
	125	}
	126	LOG_UNLOCK();
9bccf70c	127
1c79356b A	128	return (0);
	129	}
	130
	131	/ARGSUSED/
	132	int
	133	logclose(dev, flag)
	134	dev_t dev;
	135	{
	136	int oldpri;
	137	LOG_LOCK();
	138	log_open = 0;
	139	selwakeup(&logsoftc.sc_selp);
	140	oldpri = splhigh();
	141	selthreadclear(&logsoftc.sc_selp);
	142	splx(oldpri);
	143	LOG_UNLOCK();
	144	return (0);
	145	}
	146
	147	/ARGSUSED/
	148	int
	149	logread(dev, uio, flag)
	150	dev_t dev;
	151	struct uio *uio;
	152	int flag;
	153	{
	154	register long l;
	155	register int s;
	156	int error = 0;
	157
	158	s = splhigh();
	159	while (msgbufp->msg_bufr == msgbufp->msg_bufx) {
	160	if (flag & IO_NDELAY) {
	161	splx(s);
	162	return (EWOULDBLOCK);
	163	}
	164	if (logsoftc.sc_state & LOG_NBIO) {
	165	splx(s);
	166	return (EWOULDBLOCK);
	167	}
	168	logsoftc.sc_state \|= LOG_RDWAIT;
	169	if (error = tsleep((caddr_t)msgbufp, LOG_RDPRI \| PCATCH,
	170	"klog", 0)) {
	171	splx(s);
	172	return (error);
	173	}
	174	}
	175	splx(s);
	176	logsoftc.sc_state &= ~LOG_RDWAIT;
	177
	178	while (uio->uio_resid > 0) {
	179	l = msgbufp->msg_bufx - msgbufp->msg_bufr;
	180	if (l < 0)
	181	l = MSG_BSIZE - msgbufp->msg_bufr;
	182	l = min(l, uio->uio_resid);
	183	if (l == 0)
	184	break;
	185	error = uiomove((caddr_t)&msgbufp->msg_bufc[msgbufp->msg_bufr],
	186	(int)l, uio);
	187	if (error)
	188	break;
	189	msgbufp->msg_bufr += l;
	190	if (msgbufp->msg_bufr < 0 \|\| msgbufp->msg_bufr >= MSG_BSIZE)
	191	msgbufp->msg_bufr = 0;
192	}
193	return (error);
194	}
195
196	/ARGSUSED/
197	int
0b4e3aa0	198	logselect(dev, rw, wql, p)
1c79356b A	199	dev_t dev;
1c79356b A	200	int rw;
0b4e3aa0	201	void * wql;
1c79356b A	202	struct proc *p;
	203	{
	204	int s = splhigh();
	205
	206	switch (rw) {
	207
	208	case FREAD:
	209	if (msgbufp->msg_bufr != msgbufp->msg_bufx) {
	210	splx(s);
	211	return (1);
	212	}
0b4e3aa0	213	selrecord(p, &logsoftc.sc_selp, wql);
1c79356b A	214	break;
	215	}
	216	splx(s);
	217	return (0);
	218	}
	219
	220	void
	221	logwakeup()
	222	{
	223	struct proc *p;
	224	int pgid;
	225	boolean_t funnel_state;
	226
	227	if (!log_open)
	228	return;
	229	funnel_state = thread_funnel_set(kernel_flock, TRUE);
	230	selwakeup(&logsoftc.sc_selp);
	231	if (logsoftc.sc_state & LOG_ASYNC) {
1c79356b A	232	LOG_LOCK();
	233	pgid = logsoftc.sc_pgid;
	234	LOG_UNLOCK();
	235	if (pgid < 0)
	236	gsignal(-pgid, SIGIO);
	237	else if (p = pfind(pgid))
	238	psignal(p, SIGIO);
1c79356b A	239	}
	240	if (logsoftc.sc_state & LOG_RDWAIT) {
	241	wakeup((caddr_t)msgbufp);
	242	logsoftc.sc_state &= ~LOG_RDWAIT;
	243	}
	244	(void) thread_funnel_set(kernel_flock, funnel_state);
	245	}
	246
	247	void
	248	klogwakeup()
	249	{
	250
	251	if (_logentrypend) {
	252	_logentrypend = 0;
	253	logwakeup();
	254	}
	255	}
	256
	257	/ARGSUSED/
	258	int
55e303ae	259	logioctl(dev, com, data, flag)
1c79356b A	260	caddr_t data;
	261	{
	262	long l;
	263	int s;
	264
	265	switch (com) {
	266
	267	/* return number of characters immediately available */
	268	case FIONREAD:
	269	s = splhigh();
	270	l = msgbufp->msg_bufx - msgbufp->msg_bufr;
	271	splx(s);
	272	if (l < 0)
	273	l += MSG_BSIZE;
	274	(off_t )data = l;
	275	break;
	276
	277	case FIONBIO:
	278	if ((int )data)
	279	logsoftc.sc_state \|= LOG_NBIO;
	280	else
	281	logsoftc.sc_state &= ~LOG_NBIO;
	282	break;
	283
	284	case FIOASYNC:
	285	if ((int )data)
	286	logsoftc.sc_state \|= LOG_ASYNC;
	287	else
	288	logsoftc.sc_state &= ~LOG_ASYNC;
	289	break;
	290
	291	case TIOCSPGRP:
	292	LOG_LOCK();
	293	logsoftc.sc_pgid = (int )data;
	294	LOG_UNLOCK();
	295	break;
	296
	297	case TIOCGPGRP:
	298	LOG_LOCK();
	299	(int )data = logsoftc.sc_pgid;
	300	LOG_UNLOCK();
	301	break;
	302
	303	default:
	304	return (-1);
	305	}
	306	return (0);
	307	}
	308
	309	void
	310	log_init()
	311	{
	312	msgbufp = &temp_msgbuf;
	313	LOG_LOCK_INIT();
	314	}
	315
	316	void
	317	log_putc(char c)
	318	{
	319	register struct msgbuf *mbp;
	320
	321	if (msgbufp == NULL)
	322	msgbufp =&temp_msgbuf;
	323
324	mbp = msgbufp;
325	if (mbp-> msg_magic != MSG_MAGIC) {
326	register int i;
327
328	mbp->msg_magic = MSG_MAGIC;
329	mbp->msg_bufx = mbp->msg_bufr = 0;
330	for (i=0; i < MSG_BSIZE; i++)
331	mbp->msg_bufc[i] = 0;
332	}
333	mbp->msg_bufc[mbp->msg_bufx++] = c;
334	_logentrypend = 1;
335	if (mbp->msg_bufx < 0 \|\| mbp->msg_bufx >= MSG_BSIZE)
336	mbp->msg_bufx = 0;
337	}