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

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The 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, QUIET ENJOYMENT 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	*
43866e37	6	* Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
1c79356b	7	*
43866e37 A	8	* This file contains Original Code and/or Modifications of Original Code
	9	* as defined in and that are subject to the Apple Public Source License
	10	* Version 2.0 (the 'License'). You may not use this file except in
	11	* compliance with the License. Please obtain a copy of the License at
	12	* http://www.opensource.apple.com/apsl/ and read it before using this
	13	* file.
	14	*
	15	* The Original Code and all software distributed under the License are
	16	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
1c79356b A	17	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
1c79356b A	18	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
43866e37 A	19	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	20	* Please see the License for the specific language governing rights and
	21	* limitations under the License.
1c79356b A	22	*
	23	* @APPLE_LICENSE_HEADER_END@
	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>
1c79356b A	75
	76	#define LOG_RDPRI (PZERO + 1)
	77
	78	#define LOG_NBIO 0x02
	79	#define LOG_ASYNC 0x04
	80	#define LOG_RDWAIT 0x08
	81
	82	struct logsoftc {
	83	int sc_state; /* see above for possibilities */
	84	struct selinfo sc_selp; /* thread waiting for select */
	85	int sc_pgid; /* process/group for async I/O */
	86	} logsoftc;
	87
	88	int log_open; /* also used in log() */
	89	struct msgbuf temp_msgbuf;
	90	struct msgbuf *msgbufp;
	91	static int _logentrypend = 0;
	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	{
1c79356b A	109	LOG_LOCK();
	110	if (log_open) {
	111	LOG_UNLOCK();
1c79356b A	112	return (EBUSY);
	113	}
	114	log_open = 1;
	115	logsoftc.sc_pgid = p->p_pid; /* signal process only */
	116	/*
	117	* Potential race here with putchar() but since putchar should be
	118	* called by autoconf, msg_magic should be initialized by the time
	119	* we get here.
	120	*/
	121	if (msgbufp->msg_magic != MSG_MAGIC) {
	122	register int i;
	123
	124	msgbufp->msg_magic = MSG_MAGIC;
	125	msgbufp->msg_bufx = msgbufp->msg_bufr = 0;
	126	for (i=0; i < MSG_BSIZE; i++)
	127	msgbufp->msg_bufc[i] = 0;
	128	}
	129	LOG_UNLOCK();
9bccf70c	130
1c79356b A	131	return (0);
	132	}
	133
	134	/ARGSUSED/
	135	int
	136	logclose(dev, flag)
	137	dev_t dev;
	138	{
	139	int oldpri;
	140	LOG_LOCK();
	141	log_open = 0;
	142	selwakeup(&logsoftc.sc_selp);
	143	oldpri = splhigh();
	144	selthreadclear(&logsoftc.sc_selp);
	145	splx(oldpri);
	146	LOG_UNLOCK();
	147	return (0);
	148	}
	149
	150	/ARGSUSED/
	151	int
	152	logread(dev, uio, flag)
	153	dev_t dev;
	154	struct uio *uio;
	155	int flag;
	156	{
	157	register long l;
	158	register int s;
	159	int error = 0;
	160
	161	s = splhigh();
	162	while (msgbufp->msg_bufr == msgbufp->msg_bufx) {
	163	if (flag & IO_NDELAY) {
	164	splx(s);
	165	return (EWOULDBLOCK);
	166	}
	167	if (logsoftc.sc_state & LOG_NBIO) {
	168	splx(s);
	169	return (EWOULDBLOCK);
	170	}
	171	logsoftc.sc_state \|= LOG_RDWAIT;
	172	if (error = tsleep((caddr_t)msgbufp, LOG_RDPRI \| PCATCH,
	173	"klog", 0)) {
	174	splx(s);
	175	return (error);
	176	}
	177	}
	178	splx(s);
	179	logsoftc.sc_state &= ~LOG_RDWAIT;
	180
	181	while (uio->uio_resid > 0) {
	182	l = msgbufp->msg_bufx - msgbufp->msg_bufr;
	183	if (l < 0)
	184	l = MSG_BSIZE - msgbufp->msg_bufr;
	185	l = min(l, uio->uio_resid);
	186	if (l == 0)
	187	break;
	188	error = uiomove((caddr_t)&msgbufp->msg_bufc[msgbufp->msg_bufr],
	189	(int)l, uio);
	190	if (error)
	191	break;
	192	msgbufp->msg_bufr += l;
	193	if (msgbufp->msg_bufr < 0 \|\| msgbufp->msg_bufr >= MSG_BSIZE)
	194	msgbufp->msg_bufr = 0;
195	}
196	return (error);
197	}
198
199	/ARGSUSED/
200	int
0b4e3aa0	201	logselect(dev, rw, wql, p)
1c79356b A	202	dev_t dev;
1c79356b A	203	int rw;
0b4e3aa0	204	void * wql;
1c79356b A	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	}
0b4e3aa0	216	selrecord(p, &logsoftc.sc_selp, wql);
1c79356b A	217	break;
	218	}
	219	splx(s);
	220	return (0);
	221	}
	222
	223	void
	224	logwakeup()
	225	{
	226	struct proc *p;
	227	int pgid;
	228	boolean_t funnel_state;
	229
	230	if (!log_open)
	231	return;
	232	funnel_state = thread_funnel_set(kernel_flock, TRUE);
	233	selwakeup(&logsoftc.sc_selp);
	234	if (logsoftc.sc_state & LOG_ASYNC) {
1c79356b A	235	LOG_LOCK();
	236	pgid = logsoftc.sc_pgid;
	237	LOG_UNLOCK();
	238	if (pgid < 0)
	239	gsignal(-pgid, SIGIO);
	240	else if (p = pfind(pgid))
	241	psignal(p, SIGIO);
1c79356b A	242	}
	243	if (logsoftc.sc_state & LOG_RDWAIT) {
	244	wakeup((caddr_t)msgbufp);
	245	logsoftc.sc_state &= ~LOG_RDWAIT;
	246	}
	247	(void) thread_funnel_set(kernel_flock, funnel_state);
	248	}
	249
	250	void
	251	klogwakeup()
	252	{
	253
	254	if (_logentrypend) {
	255	_logentrypend = 0;
	256	logwakeup();
	257	}
	258	}
	259
	260	/ARGSUSED/
	261	int
55e303ae	262	logioctl(dev, com, data, flag)
1c79356b A	263	caddr_t data;
	264	{
	265	long l;
	266	int s;
	267
	268	switch (com) {
	269
	270	/* return number of characters immediately available */
	271	case FIONREAD:
	272	s = splhigh();
	273	l = msgbufp->msg_bufx - msgbufp->msg_bufr;
	274	splx(s);
	275	if (l < 0)
	276	l += MSG_BSIZE;
	277	(off_t )data = l;
	278	break;
	279
	280	case FIONBIO:
	281	if ((int )data)
	282	logsoftc.sc_state \|= LOG_NBIO;
	283	else
	284	logsoftc.sc_state &= ~LOG_NBIO;
	285	break;
	286
	287	case FIOASYNC:
	288	if ((int )data)
	289	logsoftc.sc_state \|= LOG_ASYNC;
	290	else
	291	logsoftc.sc_state &= ~LOG_ASYNC;
	292	break;
	293
	294	case TIOCSPGRP:
	295	LOG_LOCK();
	296	logsoftc.sc_pgid = (int )data;
	297	LOG_UNLOCK();
	298	break;
	299
	300	case TIOCGPGRP:
	301	LOG_LOCK();
	302	(int )data = logsoftc.sc_pgid;
	303	LOG_UNLOCK();
	304	break;
	305
	306	default:
	307	return (-1);
	308	}
	309	return (0);
	310	}
	311
	312	void
	313	log_init()
	314	{
	315	msgbufp = &temp_msgbuf;
	316	LOG_LOCK_INIT();
	317	}
	318
	319	void
	320	log_putc(char c)
	321	{
	322	register struct msgbuf *mbp;
	323
	324	if (msgbufp == NULL)
	325	msgbufp =&temp_msgbuf;
	326
327	mbp = msgbufp;
328	if (mbp-> msg_magic != MSG_MAGIC) {
329	register int i;
330
331	mbp->msg_magic = MSG_MAGIC;
332	mbp->msg_bufx = mbp->msg_bufr = 0;
333	for (i=0; i < MSG_BSIZE; i++)
334	mbp->msg_bufc[i] = 0;
335	}
336	mbp->msg_bufc[mbp->msg_bufx++] = c;
337	_logentrypend = 1;
338	if (mbp->msg_bufx < 0 \|\| mbp->msg_bufx >= MSG_BSIZE)
339	mbp->msg_bufx = 0;
340	}