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