[apple/xnu.git] / bsd / kern / kern_subr.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, 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * 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.
 *
 *	@(#)kern_subr.c	8.3 (Berkeley) 1/21/94
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/queue.h>
#include <vm/pmap.h>

#include <kdebug.h>

#include <sys/kdebug.h>
#define DBG_UIO_COPYOUT 16
#define DBG_UIO_COPYIN  17


int
uiomove(cp, n, uio)
	register caddr_t cp;
	register int n;
	register struct uio *uio;
{
	return uiomove64((addr64_t)((unsigned int)cp), n, uio);
}

int
uiomove64(addr64_t cp, int n, struct uio *uio)
{
	register struct iovec *iov;
	u_int cnt;
	int error = 0;

#if DIAGNOSTIC
	if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE)
		panic("uiomove: mode");
	if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != current_proc())
		panic("uiomove proc");
#endif

	while (n > 0 && uio->uio_resid) {
		iov = uio->uio_iov;
		cnt = iov->iov_len;
		if (cnt == 0) {
			uio->uio_iov++;
			uio->uio_iovcnt--;
			continue;
		}
		if (cnt > n)
			cnt = n;
		switch (uio->uio_segflg) {

		case UIO_USERSPACE:
		case UIO_USERISPACE:
			if (uio->uio_rw == UIO_READ)
			  {
			        KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYOUT)) | DBG_FUNC_START,
					 (int)cp, (int)iov->iov_base, cnt, 0,0);

				error = copyout( CAST_DOWN(caddr_t, cp), iov->iov_base, cnt );

			        KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYOUT)) | DBG_FUNC_END,
					 (int)cp, (int)iov->iov_base, cnt, 0,0);
			  }
			else
			  {
			        KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYIN)) | DBG_FUNC_START,
					 (int)iov->iov_base, (int)cp, cnt, 0,0);

			        error = copyin(iov->iov_base, CAST_DOWN(caddr_t, cp), cnt);

			        KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYIN)) | DBG_FUNC_END,
					 (int)iov->iov_base, (int)cp, cnt, 0,0);
			  }
			if (error)
				return (error);
			break;

		case UIO_SYSSPACE:
			if (uio->uio_rw == UIO_READ)
				error = copywithin(CAST_DOWN(caddr_t, cp), iov->iov_base,
						   cnt);
			else
				error = copywithin(iov->iov_base, CAST_DOWN(caddr_t, cp),
						   cnt);
			break;

		case UIO_PHYS_USERSPACE:
			if (uio->uio_rw == UIO_READ)
			  {
			        KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYOUT)) | DBG_FUNC_START,
					 (int)cp, (int)iov->iov_base, cnt, 1,0);

				if (error = copypv((addr64_t)cp, (addr64_t)((unsigned int)iov->iov_base), cnt, cppvPsrc | cppvNoRefSrc)) 	/* Copy physical to virtual */
				        error = EFAULT;

			        KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYOUT)) | DBG_FUNC_END,
					 (int)cp, (int)iov->iov_base, cnt, 1,0);
			  }
			else
			  {
			        KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYIN)) | DBG_FUNC_START,
					 (int)iov->iov_base, (int)cp, cnt, 1,0);

				if (error = copypv((addr64_t)((unsigned int)iov->iov_base), (addr64_t)cp, cnt, cppvPsnk | cppvNoRefSrc | cppvNoModSnk))	/* Copy virtual to physical */
				        error = EFAULT;

			        KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYIN)) | DBG_FUNC_END,
					 (int)iov->iov_base, (int)cp, cnt, 1,0);
			  }
			if (error)
				return (error);
			break;

		case UIO_PHYS_SYSSPACE:
			if (uio->uio_rw == UIO_READ)
			  {
			        KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYOUT)) | DBG_FUNC_START,
					 (int)cp, (int)iov->iov_base, cnt, 2,0);

				if (error = copypv((addr64_t)cp, (addr64_t)((unsigned int)iov->iov_base), cnt, cppvKmap | cppvPsrc | cppvNoRefSrc)) 	/* Copy physical to virtual */
				        error = EFAULT;

			        KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYOUT)) | DBG_FUNC_END,
					 (int)cp, (int)iov->iov_base, cnt, 2,0);
			  }
			else
			  {
			        KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYIN)) | DBG_FUNC_START,
					 (int)iov->iov_base, (int)cp, cnt, 2,0);

				if (error = copypv((addr64_t)((unsigned int)iov->iov_base), (addr64_t)cp, cnt, cppvKmap | cppvPsnk | cppvNoRefSrc | cppvNoModSnk))	/* Copy virtual to physical */
				        error = EFAULT;

			        KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYIN)) | DBG_FUNC_END,
					 (int)iov->iov_base, (int)cp, cnt, 2,0);
			  }
			if (error)
				return (error);
			break;
		}
		iov->iov_base += cnt;
		iov->iov_len -= cnt;
		uio->uio_resid -= cnt;
		uio->uio_offset += cnt;
		cp += cnt;
		n -= cnt;
	}
	return (error);
}

/*
 * Give next character to user as result of read.
 */
int
ureadc(c, uio)
	register int c;
	register struct uio *uio;
{
	register struct iovec *iov;

	if (uio->uio_resid <= 0)
		panic("ureadc: non-positive resid");
again:
	if (uio->uio_iovcnt == 0)
		panic("ureadc: non-positive iovcnt");
	iov = uio->uio_iov;
	if (iov->iov_len <= 0) {
		uio->uio_iovcnt--;
		uio->uio_iov++;
		goto again;
	}
	switch (uio->uio_segflg) {

	case UIO_USERSPACE:
		if (subyte(iov->iov_base, c) < 0)
			return (EFAULT);
		break;

	case UIO_SYSSPACE:
		*iov->iov_base = c;
		break;

	case UIO_USERISPACE:
		if (suibyte(iov->iov_base, c) < 0)
			return (EFAULT);
		break;
	}
	iov->iov_base++;
	iov->iov_len--;
	uio->uio_resid--;
	uio->uio_offset++;
	return (0);
}

#if defined(vax) || defined(ppc)
/* unused except by ct.c, other oddities XXX */
/*
 * Get next character written in by user from uio.
 */
uwritec(uio)
	struct uio *uio;
{
	register struct iovec *iov;
	register int c;

	if (uio->uio_resid <= 0)
		return (-1);
again:
	if (uio->uio_iovcnt <= 0)
		panic("uwritec: non-positive iovcnt");
	iov = uio->uio_iov;
	if (iov->iov_len == 0) {
		uio->uio_iov++;
		if (--uio->uio_iovcnt == 0)
			return (-1);
		goto again;
	}
	switch (uio->uio_segflg) {

	case UIO_USERSPACE:
		c = fubyte(iov->iov_base);
		break;

	case UIO_SYSSPACE:
		c = *iov->iov_base & 0377;
		break;

	case UIO_USERISPACE:
		c = fuibyte(iov->iov_base);
		break;

	default:
		c = 0;	/* avoid uninitialized variable warning */
		panic("uwritec: bogus uio_segflg");
		break;
	}
	if (c < 0)
		return (-1);
	iov->iov_base++;
	iov->iov_len--;
	uio->uio_resid--;
	uio->uio_offset++;
	return (c);
}
#endif /* vax || ppc */

/*
 * General routine to allocate a hash table.
 */
void *
hashinit(elements, type, hashmask)
	int elements, type;
	u_long *hashmask;
{
	long hashsize;
	LIST_HEAD(generic, generic) *hashtbl;
	int i;

	if (elements <= 0)
		panic("hashinit: bad cnt");
	for (hashsize = 1; hashsize <= elements; hashsize <<= 1)
		continue;
	hashsize >>= 1;
	MALLOC(hashtbl, struct generic *, 
			(u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
	bzero(hashtbl, (u_long)hashsize * sizeof(*hashtbl));
	for (i = 0; i < hashsize; i++)
		LIST_INIT(&hashtbl[i]);
	*hashmask = hashsize - 1;
	return (hashtbl);
}
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, 1991, 1993
	28	* The Regents of the University of California. All rights reserved.
	29	* (c) UNIX System Laboratories, Inc.
	30	* All or some portions of this file are derived from material licensed
	31	* to the University of California by American Telephone and Telegraph
	32	* Co. or Unix System Laboratories, Inc. and are reproduced herein with
	33	* the permission of UNIX System Laboratories, Inc.
	34	*
	35	* Redistribution and use in source and binary forms, with or without
	36	* modification, are permitted provided that the following conditions
	37	* are met:
	38	* 1. Redistributions of source code must retain the above copyright
	39	* notice, this list of conditions and the following disclaimer.
	40	* 2. Redistributions in binary form must reproduce the above copyright
	41	* notice, this list of conditions and the following disclaimer in the
	42	* documentation and/or other materials provided with the distribution.
	43	* 3. All advertising materials mentioning features or use of this software
	44	* must display the following acknowledgement:
	45	* This product includes software developed by the University of
	46	* California, Berkeley and its contributors.
	47	* 4. Neither the name of the University nor the names of its contributors
	48	* may be used to endorse or promote products derived from this software
	49	* without specific prior written permission.
	50	*
	51	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	52	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	53	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	54	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	55	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	56	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	57	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	58	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	59	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	60	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	61	* SUCH DAMAGE.
	62	*
	63	* @(#)kern_subr.c 8.3 (Berkeley) 1/21/94
	64	*/
	65
	66	#include <sys/param.h>
	67	#include <sys/systm.h>
	68	#include <sys/proc.h>
	69	#include <sys/malloc.h>
	70	#include <sys/queue.h>
55e303ae	71	#include <vm/pmap.h>
1c79356b A	72
	73	#include <kdebug.h>
	74
	75	#include <sys/kdebug.h>
	76	#define DBG_UIO_COPYOUT 16
	77	#define DBG_UIO_COPYIN 17
	78
de355530	79
1c79356b A	80	int
	81	uiomove(cp, n, uio)
	82	register caddr_t cp;
	83	register int n;
	84	register struct uio *uio;
55e303ae A	85	{
	86	return uiomove64((addr64_t)((unsigned int)cp), n, uio);
	87	}
	88
	89	int
	90	uiomove64(addr64_t cp, int n, struct uio *uio)
1c79356b A	91	{
	92	register struct iovec *iov;
	93	u_int cnt;
	94	int error = 0;
	95
	96	#if DIAGNOSTIC
	97	if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE)
	98	panic("uiomove: mode");
	99	if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != current_proc())
	100	panic("uiomove proc");
	101	#endif
	102
	103	while (n > 0 && uio->uio_resid) {
	104	iov = uio->uio_iov;
	105	cnt = iov->iov_len;
	106	if (cnt == 0) {
	107	uio->uio_iov++;
	108	uio->uio_iovcnt--;
	109	continue;
	110	}
	111	if (cnt > n)
	112	cnt = n;
	113	switch (uio->uio_segflg) {
	114
	115	case UIO_USERSPACE:
	116	case UIO_USERISPACE:
	117	if (uio->uio_rw == UIO_READ)
	118	{
	119	KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYOUT)) \| DBG_FUNC_START,
55e303ae	120	(int)cp, (int)iov->iov_base, cnt, 0,0);
1c79356b	121
55e303ae	122	error = copyout( CAST_DOWN(caddr_t, cp), iov->iov_base, cnt );
1c79356b A	123
1c79356b A	124	KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYOUT)) \| DBG_FUNC_END,
55e303ae	125	(int)cp, (int)iov->iov_base, cnt, 0,0);
1c79356b A	126	}
	127	else
	128	{
	129	KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYIN)) \| DBG_FUNC_START,
55e303ae	130	(int)iov->iov_base, (int)cp, cnt, 0,0);
1c79356b	131
55e303ae	132	error = copyin(iov->iov_base, CAST_DOWN(caddr_t, cp), cnt);
1c79356b A	133
1c79356b A	134	KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYIN)) \| DBG_FUNC_END,
55e303ae	135	(int)iov->iov_base, (int)cp, cnt, 0,0);
1c79356b A	136	}
	137	if (error)
	138	return (error);
	139	break;
	140
	141	case UIO_SYSSPACE:
	142	if (uio->uio_rw == UIO_READ)
55e303ae	143	error = copywithin(CAST_DOWN(caddr_t, cp), iov->iov_base,
1c79356b A	144	cnt);
1c79356b A	145	else
55e303ae	146	error = copywithin(iov->iov_base, CAST_DOWN(caddr_t, cp),
1c79356b A	147	cnt);
1c79356b A	148	break;
9bccf70c	149
1c79356b A	150	case UIO_PHYS_USERSPACE:
	151	if (uio->uio_rw == UIO_READ)
	152	{
	153	KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYOUT)) \| DBG_FUNC_START,
55e303ae A	154	(int)cp, (int)iov->iov_base, cnt, 1,0);
	155
	156	if (error = copypv((addr64_t)cp, (addr64_t)((unsigned int)iov->iov_base), cnt, cppvPsrc \| cppvNoRefSrc)) /* Copy physical to virtual */
	157	error = EFAULT;
	158
	159	KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYOUT)) \| DBG_FUNC_END,
	160	(int)cp, (int)iov->iov_base, cnt, 1,0);
	161	}
	162	else
	163	{
	164	KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYIN)) \| DBG_FUNC_START,
	165	(int)iov->iov_base, (int)cp, cnt, 1,0);
1c79356b	166
55e303ae A	167	if (error = copypv((addr64_t)((unsigned int)iov->iov_base), (addr64_t)cp, cnt, cppvPsnk \| cppvNoRefSrc \| cppvNoModSnk)) /* Copy virtual to physical */
	168	error = EFAULT;
	169
	170	KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYIN)) \| DBG_FUNC_END,
	171	(int)iov->iov_base, (int)cp, cnt, 1,0);
	172	}
	173	if (error)
	174	return (error);
	175	break;
	176
	177	case UIO_PHYS_SYSSPACE:
	178	if (uio->uio_rw == UIO_READ)
	179	{
	180	KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYOUT)) \| DBG_FUNC_START,
	181	(int)cp, (int)iov->iov_base, cnt, 2,0);
de355530	182
55e303ae A	183	if (error = copypv((addr64_t)cp, (addr64_t)((unsigned int)iov->iov_base), cnt, cppvKmap \| cppvPsrc \| cppvNoRefSrc)) /* Copy physical to virtual */
55e303ae A	184	error = EFAULT;
1c79356b A	185
1c79356b A	186	KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYOUT)) \| DBG_FUNC_END,
55e303ae	187	(int)cp, (int)iov->iov_base, cnt, 2,0);
1c79356b A	188	}
	189	else
	190	{
	191	KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYIN)) \| DBG_FUNC_START,
55e303ae	192	(int)iov->iov_base, (int)cp, cnt, 2,0);
1c79356b	193
55e303ae A	194	if (error = copypv((addr64_t)((unsigned int)iov->iov_base), (addr64_t)cp, cnt, cppvKmap \| cppvPsnk \| cppvNoRefSrc \| cppvNoModSnk)) /* Copy virtual to physical */
55e303ae A	195	error = EFAULT;
1c79356b A	196
1c79356b A	197	KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, DBG_UIO_COPYIN)) \| DBG_FUNC_END,
55e303ae	198	(int)iov->iov_base, (int)cp, cnt, 2,0);
1c79356b A	199	}
	200	if (error)
	201	return (error);
	202	break;
1c79356b A	203	}
	204	iov->iov_base += cnt;
	205	iov->iov_len -= cnt;
	206	uio->uio_resid -= cnt;
	207	uio->uio_offset += cnt;
	208	cp += cnt;
	209	n -= cnt;
	210	}
	211	return (error);
	212	}
	213
	214	/*
	215	* Give next character to user as result of read.
	216	*/
	217	int
	218	ureadc(c, uio)
	219	register int c;
	220	register struct uio *uio;
	221	{
	222	register struct iovec *iov;
	223
	224	if (uio->uio_resid <= 0)
	225	panic("ureadc: non-positive resid");
	226	again:
	227	if (uio->uio_iovcnt == 0)
	228	panic("ureadc: non-positive iovcnt");
	229	iov = uio->uio_iov;
	230	if (iov->iov_len <= 0) {
	231	uio->uio_iovcnt--;
	232	uio->uio_iov++;
	233	goto again;
	234	}
	235	switch (uio->uio_segflg) {
	236
	237	case UIO_USERSPACE:
	238	if (subyte(iov->iov_base, c) < 0)
	239	return (EFAULT);
	240	break;
	241
	242	case UIO_SYSSPACE:
	243	*iov->iov_base = c;
	244	break;
	245
	246	case UIO_USERISPACE:
	247	if (suibyte(iov->iov_base, c) < 0)
	248	return (EFAULT);
	249	break;
	250	}
	251	iov->iov_base++;
	252	iov->iov_len--;
	253	uio->uio_resid--;
	254	uio->uio_offset++;
	255	return (0);
	256	}
	257
	258	#if defined(vax) \|\| defined(ppc)
	259	/* unused except by ct.c, other oddities XXX */
	260	/*
	261	* Get next character written in by user from uio.
	262	*/
	263	uwritec(uio)
	264	struct uio *uio;
	265	{
	266	register struct iovec *iov;
267	register int c;
268
269	if (uio->uio_resid <= 0)
270	return (-1);
271	again:
272	if (uio->uio_iovcnt <= 0)
273	panic("uwritec: non-positive iovcnt");
274	iov = uio->uio_iov;
275	if (iov->iov_len == 0) {
276	uio->uio_iov++;
277	if (--uio->uio_iovcnt == 0)
278	return (-1);
279	goto again;
280	}
281	switch (uio->uio_segflg) {
282
283	case UIO_USERSPACE:
284	c = fubyte(iov->iov_base);
285	break;
286
287	case UIO_SYSSPACE:
288	c = *iov->iov_base & 0377;
289	break;
290
291	case UIO_USERISPACE:
292	c = fuibyte(iov->iov_base);
293	break;
294
295	default:
296	c = 0; /* avoid uninitialized variable warning */
297	panic("uwritec: bogus uio_segflg");
298	break;
299	}
300	if (c < 0)
301	return (-1);
302	iov->iov_base++;
303	iov->iov_len--;
304	uio->uio_resid--;
305	uio->uio_offset++;
306	return (c);
307	}
308	#endif /* vax \|\| ppc */
309
310	/*
311	* General routine to allocate a hash table.
312	*/
313	void *
314	hashinit(elements, type, hashmask)
315	int elements, type;
316	u_long *hashmask;
317	{
318	long hashsize;
319	LIST_HEAD(generic, generic) *hashtbl;
320	int i;
321
322	if (elements <= 0)
323	panic("hashinit: bad cnt");
324	for (hashsize = 1; hashsize <= elements; hashsize <<= 1)
325	continue;
326	hashsize >>= 1;
327	MALLOC(hashtbl, struct generic *,
328	(u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
329	bzero(hashtbl, (u_long)hashsize * sizeof(*hashtbl));
330	for (i = 0; i < hashsize; i++)
331	LIST_INIT(&hashtbl[i]);
332	*hashmask = hashsize - 1;
333	return (hashtbl);
334	}