[dragonfly.git] / sys / kern / kern_subr.c

/*
 * 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
 * $FreeBSD: src/sys/kern/kern_subr.c,v 1.31.2.2 2002/04/21 08:09:37 bde Exp $
 * $DragonFly: src/sys/kern/kern_subr.c,v 1.27 2007/01/29 20:44:02 tgen Exp $
 */

#include "opt_ddb.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/resourcevar.h>
#include <sys/sysctl.h>
#include <sys/uio.h>
#include <sys/vnode.h>
#include <sys/sfbuf.h>
#include <sys/thread2.h>
#include <machine/limits.h>

#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>

SYSCTL_INT(_kern, KERN_IOV_MAX, iov_max, CTLFLAG_RD, NULL, UIO_MAXIOV,
	"Maximum number of elements in an I/O vector; sysconf(_SC_IOV_MAX)");

/*
 * UIO_READ:	copy the kernelspace cp to the user or kernelspace UIO
 * UIO_WRITE:	copy the user or kernelspace UIO to the kernelspace cp
 *
 * For userspace UIO's, uio_td must be the current thread.
 *
 * The syscall interface is responsible for limiting the length to
 * ssize_t for things like read() or write() which return the bytes
 * read or written as ssize_t.  These functions work with unsigned
 * lengths.
 */
int
uiomove(caddr_t cp, size_t n, struct uio *uio)
{
	struct iovec *iov;
	size_t cnt;
	int error = 0;
	int save = 0;
	int baseticks = ticks;

	KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
	    ("uiomove: mode"));
	KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
	    ("uiomove proc"));

	if (curproc) {
		save = curproc->p_flag & P_DEADLKTREAT;
		curproc->p_flag |= P_DEADLKTREAT;
	}

	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:
			if (ticks - baseticks >= hogticks) {
				uio_yield();
				baseticks = ticks;
			}
			if (uio->uio_rw == UIO_READ)
				error = copyout(cp, iov->iov_base, cnt);
			else
				error = copyin(iov->iov_base, cp, cnt);
			if (error)
				break;
			break;

		case UIO_SYSSPACE:
			if (uio->uio_rw == UIO_READ)
				bcopy((caddr_t)cp, iov->iov_base, cnt);
			else
				bcopy(iov->iov_base, (caddr_t)cp, cnt);
			break;
		case UIO_NOCOPY:
			break;
		}
		iov->iov_base = (char *)iov->iov_base + cnt;
		iov->iov_len -= cnt;
		uio->uio_resid -= cnt;
		uio->uio_offset += cnt;
		cp += cnt;
		n -= cnt;
	}
	if (curproc)
		curproc->p_flag = (curproc->p_flag & ~P_DEADLKTREAT) | save;
	return (error);
}
/*
 * Wrapper for uiomove() that validates the arguments against a known-good
 * kernel buffer.
 */
int
uiomove_frombuf(void *buf, size_t buflen, struct uio *uio)
{
	size_t offset;

	offset = (size_t)uio->uio_offset;
	if ((off_t)offset != uio->uio_offset)
		return (EINVAL);
	if (buflen == 0 || offset >= buflen)
		return (0);
	return (uiomove((char *)buf + offset, buflen - offset, uio));
}

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

again:
	if (uio->uio_iovcnt == 0 || uio->uio_resid == 0)
		panic("ureadc");
	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_base = iov->iov_base;
		*iov_base = c;
		iov->iov_base = iov_base;
		break;

	case UIO_NOCOPY:
		break;
	}
	iov->iov_base = (char *)iov->iov_base + 1;
	iov->iov_len--;
	uio->uio_resid--;
	uio->uio_offset++;
	return (0);
}

/*
 * General routine to allocate a hash table.  Make the hash table size a
 * power of 2 greater or equal to the number of elements requested, and 
 * store the masking value in *hashmask.
 */
void *
hashinit(int elements, struct malloc_type *type, u_long *hashmask)
{
	long hashsize;
	LIST_HEAD(generic, generic) *hashtbl;
	int i;

	if (elements <= 0)
		panic("hashinit: bad elements");
	for (hashsize = 2; hashsize < elements; hashsize <<= 1)
		continue;
	hashtbl = kmalloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
	for (i = 0; i < hashsize; i++)
		LIST_INIT(&hashtbl[i]);
	*hashmask = hashsize - 1;
	return (hashtbl);
}

static int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531, 2039,
			2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143, 6653,
			7159, 7673, 8191, 12281, 16381, 24571, 32749 };
#define NPRIMES (sizeof(primes) / sizeof(primes[0]))

/*
 * General routine to allocate a prime number sized hash table.
 */
void *
phashinit(int elements, struct malloc_type *type, u_long *nentries)
{
	long hashsize;
	LIST_HEAD(generic, generic) *hashtbl;
	int i;

	if (elements <= 0)
		panic("phashinit: bad elements");
	for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
		i++;
		if (i == NPRIMES)
			break;
		hashsize = primes[i];
	}
	hashsize = primes[i - 1];
	hashtbl = kmalloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
	for (i = 0; i < hashsize; i++)
		LIST_INIT(&hashtbl[i]);
	*nentries = hashsize;
	return (hashtbl);
}

/*
 * Copyin an iovec.  If the iovec array fits, use the preallocated small
 * iovec structure.  If it is too big, dynamically allocate an iovec array
 * of sufficient size.
 *
 * MPSAFE
 */
int
iovec_copyin(struct iovec *uiov, struct iovec **kiov, struct iovec *siov,
	     size_t iov_cnt, size_t *iov_len)
{
	struct iovec *iovp;
	int error, i;
	size_t len;

	if (iov_cnt > UIO_MAXIOV)
		return EMSGSIZE;
	if (iov_cnt > UIO_SMALLIOV) {
		MALLOC(*kiov, struct iovec *, sizeof(struct iovec) * iov_cnt,
		    M_IOV, M_WAITOK);
	} else {
		*kiov = siov;
	}
	error = copyin(uiov, *kiov, iov_cnt * sizeof(struct iovec));
	if (error == 0) {
		*iov_len = 0;
		for (i = 0, iovp = *kiov; i < iov_cnt; i++, iovp++) {
			/*
			 * Check for both *iov_len overflows and out of
			 * range iovp->iov_len's.  We limit to the
			 * capabilities of signed integers.
			 *
			 * GCC4 - overflow check opt requires assign/test.
			 */
			len = *iov_len + iovp->iov_len;
			if (len < *iov_len)
				error = EINVAL;
			*iov_len = len;
		}
	}

	/*
	 * From userland disallow iovec's which exceed the sized size
	 * limit as the system calls return ssize_t.
	 *
	 * NOTE: Internal kernel interfaces can handle the unsigned
	 *	 limit.
	 */
	if (error == 0 && (ssize_t)*iov_len < 0)
		error = EINVAL;

	if (error)
		iovec_free(kiov, siov);
	return (error);
}


/*
 * Copyright (c) 2004 Alan L. Cox <alc@cs.rice.edu>
 * 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.
 * 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
 * $FreeBSD: src/sys/i386/i386/uio_machdep.c,v 1.1 2004/03/21 20:28:36 alc Exp $
 */

/*
 * Implement uiomove(9) from physical memory using sf_bufs to reduce
 * the creation and destruction of ephemeral mappings.
 */
int
uiomove_fromphys(vm_page_t *ma, vm_offset_t offset, size_t n, struct uio *uio)
{
	struct sf_buf *sf;
	struct thread *td = curthread;
	struct iovec *iov;
	void *cp;
	vm_offset_t page_offset;
	vm_page_t m;
	size_t cnt;
	int error = 0;
	int save = 0;

	KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
	    ("uiomove_fromphys: mode"));
	KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
	    ("uiomove_fromphys proc"));

	crit_enter();
	save = td->td_flags & TDF_DEADLKTREAT;
	td->td_flags |= TDF_DEADLKTREAT;
	crit_exit();

	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;
		page_offset = offset & PAGE_MASK;
		cnt = min(cnt, PAGE_SIZE - page_offset);
		m = ma[offset >> PAGE_SHIFT];
		sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
		cp = (char *)sf_buf_kva(sf) + page_offset;
		switch (uio->uio_segflg) {
		case UIO_USERSPACE:
			/*
			 * note: removed uioyield (it was the wrong place to
			 * put it).
			 */
			if (uio->uio_rw == UIO_READ)
				error = copyout(cp, iov->iov_base, cnt);
			else
				error = copyin(iov->iov_base, cp, cnt);
			if (error) {
				sf_buf_free(sf);
				goto out;
			}
			break;
		case UIO_SYSSPACE:
			if (uio->uio_rw == UIO_READ)
				bcopy(cp, iov->iov_base, cnt);
			else
				bcopy(iov->iov_base, cp, cnt);
			break;
		case UIO_NOCOPY:
			break;
		}
		sf_buf_free(sf);
		iov->iov_base = (char *)iov->iov_base + cnt;
		iov->iov_len -= cnt;
		uio->uio_resid -= cnt;
		uio->uio_offset += cnt;
		offset += cnt;
		n -= cnt;
	}
out:
	if (save == 0) {
		crit_enter();
		td->td_flags &= ~TDF_DEADLKTREAT;
		crit_exit();
	}
	return (error);
}
Commit	Line	Data
984263bc MD	1	/*
	2	* Copyright (c) 1982, 1986, 1991, 1993
	3	* The Regents of the University of California. All rights reserved.
	4	* (c) UNIX System Laboratories, Inc.
	5	* All or some portions of this file are derived from material licensed
	6	* to the University of California by American Telephone and Telegraph
	7	* Co. or Unix System Laboratories, Inc. and are reproduced herein with
	8	* the permission of UNIX System Laboratories, Inc.
	9	*
	10	* Redistribution and use in source and binary forms, with or without
	11	* modification, are permitted provided that the following conditions
	12	* are met:
	13	* 1. Redistributions of source code must retain the above copyright
	14	* notice, this list of conditions and the following disclaimer.
	15	* 2. Redistributions in binary form must reproduce the above copyright
	16	* notice, this list of conditions and the following disclaimer in the
	17	* documentation and/or other materials provided with the distribution.
	18	* 3. All advertising materials mentioning features or use of this software
	19	* must display the following acknowledgement:
	20	* This product includes software developed by the University of
	21	* California, Berkeley and its contributors.
	22	* 4. Neither the name of the University nor the names of its contributors
	23	* may be used to endorse or promote products derived from this software
	24	* without specific prior written permission.
	25	*
	26	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	27	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	28	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	29	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	30	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	31	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	32	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	33	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	34	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	35	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	36	* SUCH DAMAGE.
	37	*
	38	* @(#)kern_subr.c 8.3 (Berkeley) 1/21/94
	39	* $FreeBSD: src/sys/kern/kern_subr.c,v 1.31.2.2 2002/04/21 08:09:37 bde Exp $
fe57a30b	40	* $DragonFly: src/sys/kern/kern_subr.c,v 1.27 2007/01/29 20:44:02 tgen Exp $
984263bc MD	41	*/
984263bc MD	42
6bd9bbba HP	43	#include "opt_ddb.h"
6bd9bbba HP	44
984263bc MD	45	#include <sys/param.h>
	46	#include <sys/systm.h>
	47	#include <sys/kernel.h>
	48	#include <sys/proc.h>
	49	#include <sys/malloc.h>
	50	#include <sys/lock.h>
	51	#include <sys/resourcevar.h>
cbd0496d JS	52	#include <sys/sysctl.h>
cbd0496d JS	53	#include <sys/uio.h>
984263bc	54	#include <sys/vnode.h>
a358fd45 MD	55	#include <sys/sfbuf.h>
a358fd45 MD	56	#include <sys/thread2.h>
25e80b06	57	#include <machine/limits.h>
984263bc MD	58
	59	#include <vm/vm.h>
	60	#include <vm/vm_page.h>
	61	#include <vm/vm_map.h>
	62
cbd0496d JS	63	SYSCTL_INT(_kern, KERN_IOV_MAX, iov_max, CTLFLAG_RD, NULL, UIO_MAXIOV,
	64	"Maximum number of elements in an I/O vector; sysconf(_SC_IOV_MAX)");
	65
1301b4d8 MD	66	/*
1301b4d8 MD	67	* UIO_READ: copy the kernelspace cp to the user or kernelspace UIO
8ddc6004	68	* UIO_WRITE: copy the user or kernelspace UIO to the kernelspace cp
1301b4d8 MD	69	*
1301b4d8 MD	70	* For userspace UIO's, uio_td must be the current thread.
e54488bb MD	71	*
	72	* The syscall interface is responsible for limiting the length to
	73	* ssize_t for things like read() or write() which return the bytes
	74	* read or written as ssize_t. These functions work with unsigned
	75	* lengths.
1301b4d8	76	*/
984263bc	77	int
e54488bb	78	uiomove(caddr_t cp, size_t n, struct uio *uio)
984263bc	79	{
1fd87d54	80	struct iovec *iov;
e54488bb	81	size_t cnt;
984263bc MD	82	int error = 0;
984263bc MD	83	int save = 0;
d16a8831	84	int baseticks = ticks;
984263bc MD	85
	86	KASSERT(uio->uio_rw == UIO_READ \|\| uio->uio_rw == UIO_WRITE,
	87	("uiomove: mode"));
dadab5e9	88	KASSERT(uio->uio_segflg != UIO_USERSPACE \|\| uio->uio_td == curthread,
984263bc MD	89	("uiomove proc"));
	90
	91	if (curproc) {
	92	save = curproc->p_flag & P_DEADLKTREAT;
	93	curproc->p_flag \|= P_DEADLKTREAT;
	94	}
	95
	96	while (n > 0 && uio->uio_resid) {
	97	iov = uio->uio_iov;
	98	cnt = iov->iov_len;
	99	if (cnt == 0) {
	100	uio->uio_iov++;
	101	uio->uio_iovcnt--;
	102	continue;
	103	}
	104	if (cnt > n)
	105	cnt = n;
	106
	107	switch (uio->uio_segflg) {
	108
	109	case UIO_USERSPACE:
d16a8831	110	if (ticks - baseticks >= hogticks) {
984263bc	111	uio_yield();
d16a8831 MD	112	baseticks = ticks;
d16a8831 MD	113	}
984263bc MD	114	if (uio->uio_rw == UIO_READ)
	115	error = copyout(cp, iov->iov_base, cnt);
	116	else
	117	error = copyin(iov->iov_base, cp, cnt);
	118	if (error)
	119	break;
	120	break;
	121
	122	case UIO_SYSSPACE:
	123	if (uio->uio_rw == UIO_READ)
	124	bcopy((caddr_t)cp, iov->iov_base, cnt);
	125	else
	126	bcopy(iov->iov_base, (caddr_t)cp, cnt);
	127	break;
	128	case UIO_NOCOPY:
	129	break;
	130	}
656849c6	131	iov->iov_base = (char *)iov->iov_base + cnt;
984263bc MD	132	iov->iov_len -= cnt;
	133	uio->uio_resid -= cnt;
	134	uio->uio_offset += cnt;
	135	cp += cnt;
	136	n -= cnt;
	137	}
	138	if (curproc)
	139	curproc->p_flag = (curproc->p_flag & ~P_DEADLKTREAT) \| save;
	140	return (error);
	141	}
25e80b06 DR	142	/*
25e80b06 DR	143	* Wrapper for uiomove() that validates the arguments against a known-good
e54488bb	144	* kernel buffer.
25e80b06 DR	145	*/
25e80b06 DR	146	int
e54488bb	147	uiomove_frombuf(void buf, size_t buflen, struct uio uio)
25e80b06	148	{
e54488bb	149	size_t offset;
25e80b06	150
e54488bb MD	151	offset = (size_t)uio->uio_offset;
e54488bb MD	152	if ((off_t)offset != uio->uio_offset)
25e80b06	153	return (EINVAL);
e54488bb	154	if (buflen == 0 \|\| offset >= buflen)
25e80b06	155	return (0);
e54488bb	156	return (uiomove((char *)buf + offset, buflen - offset, uio));
984263bc MD	157	}
984263bc MD	158
984263bc MD	159	/*
	160	* Give next character to user as result of read.
	161	*/
	162	int
c972a82f	163	ureadc(int c, struct uio *uio)
984263bc	164	{
1fd87d54	165	struct iovec *iov;
656849c6	166	char *iov_base;
984263bc MD	167
	168	again:
	169	if (uio->uio_iovcnt == 0 \|\| uio->uio_resid == 0)
	170	panic("ureadc");
	171	iov = uio->uio_iov;
	172	if (iov->iov_len == 0) {
	173	uio->uio_iovcnt--;
	174	uio->uio_iov++;
	175	goto again;
	176	}
	177	switch (uio->uio_segflg) {
	178
	179	case UIO_USERSPACE:
	180	if (subyte(iov->iov_base, c) < 0)
	181	return (EFAULT);
	182	break;
	183
	184	case UIO_SYSSPACE:
656849c6 SW	185	iov_base = iov->iov_base;
	186	*iov_base = c;
	187	iov->iov_base = iov_base;
984263bc MD	188	break;
984263bc MD	189
984263bc MD	190	case UIO_NOCOPY:
	191	break;
	192	}
656849c6	193	iov->iov_base = (char *)iov->iov_base + 1;
984263bc MD	194	iov->iov_len--;
	195	uio->uio_resid--;
	196	uio->uio_offset++;
	197	return (0);
	198	}
	199
984263bc	200	/*
1c86b25b MD	201	* General routine to allocate a hash table. Make the hash table size a
	202	* power of 2 greater or equal to the number of elements requested, and
	203	* store the masking value in *hashmask.
984263bc MD	204	*/
984263bc MD	205	void *
c972a82f	206	hashinit(int elements, struct malloc_type type, u_long hashmask)
984263bc MD	207	{
	208	long hashsize;
	209	LIST_HEAD(generic, generic) *hashtbl;
	210	int i;
	211
	212	if (elements <= 0)
	213	panic("hashinit: bad elements");
8f17cbc6	214	for (hashsize = 2; hashsize < elements; hashsize <<= 1)
984263bc	215	continue;
efda3bd0	216	hashtbl = kmalloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
984263bc MD	217	for (i = 0; i < hashsize; i++)
	218	LIST_INIT(&hashtbl[i]);
	219	*hashmask = hashsize - 1;
	220	return (hashtbl);
	221	}
	222
	223	static int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531, 2039,
	224	2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143, 6653,
	225	7159, 7673, 8191, 12281, 16381, 24571, 32749 };
	226	#define NPRIMES (sizeof(primes) / sizeof(primes[0]))
	227
	228	/*
	229	* General routine to allocate a prime number sized hash table.
	230	*/
	231	void *
c972a82f	232	phashinit(int elements, struct malloc_type type, u_long nentries)
984263bc MD	233	{
	234	long hashsize;
	235	LIST_HEAD(generic, generic) *hashtbl;
	236	int i;
	237
	238	if (elements <= 0)
	239	panic("phashinit: bad elements");
	240	for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
	241	i++;
	242	if (i == NPRIMES)
	243	break;
	244	hashsize = primes[i];
	245	}
	246	hashsize = primes[i - 1];
efda3bd0	247	hashtbl = kmalloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
984263bc MD	248	for (i = 0; i < hashsize; i++)
	249	LIST_INIT(&hashtbl[i]);
	250	*nentries = hashsize;
	251	return (hashtbl);
	252	}
75a872f8 DRJ	253
	254	/*
	255	* Copyin an iovec. If the iovec array fits, use the preallocated small
	256	* iovec structure. If it is too big, dynamically allocate an iovec array
	257	* of sufficient size.
f832287e MD	258	*
f832287e MD	259	* MPSAFE
75a872f8 DRJ	260	*/
	261	int
	262	iovec_copyin(struct iovec uiov, struct iovec kiov, struct iovec siov,
e54488bb	263	size_t iov_cnt, size_t *iov_len)
75a872f8 DRJ	264	{
	265	struct iovec *iovp;
	266	int error, i;
e54488bb	267	size_t len;
75a872f8	268
fe57a30b	269	if (iov_cnt > UIO_MAXIOV)
75a872f8	270	return EMSGSIZE;
fe57a30b	271	if (iov_cnt > UIO_SMALLIOV) {
75a872f8 DRJ	272	MALLOC(kiov, struct iovec , sizeof(struct iovec) * iov_cnt,
	273	M_IOV, M_WAITOK);
	274	} else {
	275	*kiov = siov;
	276	}
	277	error = copyin(uiov, kiov, iov_cnt sizeof(struct iovec));
ef5c76d7 MD	278	if (error == 0) {
	279	*iov_len = 0;
	280	for (i = 0, iovp = *kiov; i < iov_cnt; i++, iovp++) {
	281	/*
	282	* Check for both *iov_len overflows and out of
	283	* range iovp->iov_len's. We limit to the
	284	* capabilities of signed integers.
e54488bb MD	285	*
e54488bb MD	286	* GCC4 - overflow check opt requires assign/test.
ef5c76d7	287	*/
e54488bb MD	288	len = *iov_len + iovp->iov_len;
e54488bb MD	289	if (len < *iov_len)
ef5c76d7	290	error = EINVAL;
e54488bb	291	*iov_len = len;
ef5c76d7 MD	292	}
ef5c76d7 MD	293	}
e54488bb MD	294
	295	/*
	296	* From userland disallow iovec's which exceed the sized size
	297	* limit as the system calls return ssize_t.
	298	*
	299	* NOTE: Internal kernel interfaces can handle the unsigned
	300	* limit.
	301	*/
	302	if (error == 0 && (ssize_t)*iov_len < 0)
	303	error = EINVAL;
	304
75a872f8 DRJ	305	if (error)
	306	iovec_free(kiov, siov);
	307	return (error);
	308	}
a358fd45 MD	309
	310
	311	/*
	312	* Copyright (c) 2004 Alan L. Cox <alc@cs.rice.edu>
	313	* Copyright (c) 1982, 1986, 1991, 1993
	314	* The Regents of the University of California. All rights reserved.
	315	* (c) UNIX System Laboratories, Inc.
	316	* All or some portions of this file are derived from material licensed
	317	* to the University of California by American Telephone and Telegraph
	318	* Co. or Unix System Laboratories, Inc. and are reproduced herein with
	319	* the permission of UNIX System Laboratories, Inc.
	320	*
	321	* Redistribution and use in source and binary forms, with or without
	322	* modification, are permitted provided that the following conditions
	323	* are met:
	324	* 1. Redistributions of source code must retain the above copyright
	325	* notice, this list of conditions and the following disclaimer.
	326	* 2. Redistributions in binary form must reproduce the above copyright
	327	* notice, this list of conditions and the following disclaimer in the
	328	* documentation and/or other materials provided with the distribution.
	329	* 4. Neither the name of the University nor the names of its contributors
	330	* may be used to endorse or promote products derived from this software
	331	* without specific prior written permission.
	332	*
	333	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	334	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	335	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	336	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	337	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	338	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	339	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	340	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	341	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	342	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	343	* SUCH DAMAGE.
	344	*
	345	* @(#)kern_subr.c 8.3 (Berkeley) 1/21/94
	346	* $FreeBSD: src/sys/i386/i386/uio_machdep.c,v 1.1 2004/03/21 20:28:36 alc Exp $
	347	*/
	348
	349	/*
	350	* Implement uiomove(9) from physical memory using sf_bufs to reduce
	351	* the creation and destruction of ephemeral mappings.
	352	*/
	353	int
e54488bb	354	uiomove_fromphys(vm_page_t ma, vm_offset_t offset, size_t n, struct uio uio)
a358fd45 MD	355	{
	356	struct sf_buf *sf;
	357	struct thread *td = curthread;
	358	struct iovec *iov;
	359	void *cp;
	360	vm_offset_t page_offset;
	361	vm_page_t m;
	362	size_t cnt;
	363	int error = 0;
	364	int save = 0;
	365
	366	KASSERT(uio->uio_rw == UIO_READ \|\| uio->uio_rw == UIO_WRITE,
	367	("uiomove_fromphys: mode"));
	368	KASSERT(uio->uio_segflg != UIO_USERSPACE \|\| uio->uio_td == curthread,
	369	("uiomove_fromphys proc"));
	370
	371	crit_enter();
	372	save = td->td_flags & TDF_DEADLKTREAT;
	373	td->td_flags \|= TDF_DEADLKTREAT;
	374	crit_exit();
	375
	376	while (n > 0 && uio->uio_resid) {
	377	iov = uio->uio_iov;
	378	cnt = iov->iov_len;
	379	if (cnt == 0) {
	380	uio->uio_iov++;
	381	uio->uio_iovcnt--;
	382	continue;
	383	}
	384	if (cnt > n)
	385	cnt = n;
	386	page_offset = offset & PAGE_MASK;
	387	cnt = min(cnt, PAGE_SIZE - page_offset);
	388	m = ma[offset >> PAGE_SHIFT];
	389	sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
	390	cp = (char *)sf_buf_kva(sf) + page_offset;
	391	switch (uio->uio_segflg) {
	392	case UIO_USERSPACE:
	393	/*
	394	* note: removed uioyield (it was the wrong place to
	395	* put it).
	396	*/
	397	if (uio->uio_rw == UIO_READ)
	398	error = copyout(cp, iov->iov_base, cnt);
	399	else
	400	error = copyin(iov->iov_base, cp, cnt);
	401	if (error) {
	402	sf_buf_free(sf);
	403	goto out;
	404	}
	405	break;
	406	case UIO_SYSSPACE:
	407	if (uio->uio_rw == UIO_READ)
	408	bcopy(cp, iov->iov_base, cnt);
	409	else
	410	bcopy(iov->iov_base, cp, cnt);
	411	break;
	412	case UIO_NOCOPY:
	413	break;
	414	}
	415	sf_buf_free(sf);
	416	iov->iov_base = (char *)iov->iov_base + cnt;
	417	iov->iov_len -= cnt;
	418	uio->uio_resid -= cnt;
419	uio->uio_offset += cnt;
420	offset += cnt;
421	n -= cnt;
422	}
423	out:
424	if (save == 0) {
425	crit_enter();
426	td->td_flags &= ~TDF_DEADLKTREAT;
427	crit_exit();
428	}
429	return (error);
430	}
431