[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/thread2.h>
#include <machine/limits.h>

#include <cpu/lwbuf.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);
}

/*
 * Like uiomove() but copies zero-fill.  Only allowed for UIO_READ,
 * for obvious reasons.
 */
int
uiomovez(size_t n, struct uio *uio)
{
	struct iovec *iov;
	size_t cnt;
	int error = 0;

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

	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:
			error = copyout(ZeroPage, iov->iov_base, cnt);
			if (error)
				break;
			break;
		case UIO_SYSSPACE:
			bzero(iov->iov_base, 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;
		n -= cnt;
	}
	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);
}

/*
 * This is a newer version which allocates a hash table of structures.
 *
 * The returned array will be zero'd.  The caller is responsible for
 * initializing the structures.
 */
void *
hashinit_ext(int elements, size_t size, struct malloc_type *type,
	     u_long *hashmask)
{
	long hashsize;
	void *hashtbl;

	if (elements <= 0)
		panic("hashinit: bad elements");
	for (hashsize = 2; hashsize < elements; hashsize <<= 1)
		continue;
	hashtbl = kmalloc((size_t)hashsize * size, type, M_WAITOK | M_ZERO);
	*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);
}

/*
 * This is a newer version which allocates a hash table of structures
 * in a prime-number size.
 *
 * The returned array will be zero'd.  The caller is responsible for
 * initializing the structures.
 */
void *
phashinit_ext(int elements, size_t size, struct malloc_type *type,
	      u_long *nentries)
{
	long hashsize;
	void *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((size_t)hashsize * size, type, M_WAITOK | M_ZERO);
	*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 lwbuf's 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 lwbuf *lwb;
	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];
		lwb = lwbuf_alloc(m);
		cp = (char *)lwbuf_kva(lwb) + 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) {
				lwbuf_free(lwb);
				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;
		}
		lwbuf_free(lwb);
		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	55	#include <sys/thread2.h>
25e80b06	56	#include <machine/limits.h>
984263bc	57
5c5185ae SG	58	#include <cpu/lwbuf.h>
5c5185ae SG	59
984263bc MD	60	#include <vm/vm.h>
	61	#include <vm/vm_page.h>
	62	#include <vm/vm_map.h>
	63
cbd0496d JS	64	SYSCTL_INT(_kern, KERN_IOV_MAX, iov_max, CTLFLAG_RD, NULL, UIO_MAXIOV,
	65	"Maximum number of elements in an I/O vector; sysconf(_SC_IOV_MAX)");
	66
1301b4d8 MD	67	/*
1301b4d8 MD	68	* UIO_READ: copy the kernelspace cp to the user or kernelspace UIO
8ddc6004	69	* UIO_WRITE: copy the user or kernelspace UIO to the kernelspace cp
1301b4d8 MD	70	*
1301b4d8 MD	71	* For userspace UIO's, uio_td must be the current thread.
e54488bb MD	72	*
	73	* The syscall interface is responsible for limiting the length to
	74	* ssize_t for things like read() or write() which return the bytes
	75	* read or written as ssize_t. These functions work with unsigned
	76	* lengths.
1301b4d8	77	*/
984263bc	78	int
e54488bb	79	uiomove(caddr_t cp, size_t n, struct uio *uio)
984263bc	80	{
1fd87d54	81	struct iovec *iov;
e54488bb	82	size_t cnt;
984263bc MD	83	int error = 0;
984263bc MD	84	int save = 0;
d16a8831	85	int baseticks = ticks;
984263bc MD	86
	87	KASSERT(uio->uio_rw == UIO_READ \|\| uio->uio_rw == UIO_WRITE,
	88	("uiomove: mode"));
dadab5e9	89	KASSERT(uio->uio_segflg != UIO_USERSPACE \|\| uio->uio_td == curthread,
984263bc MD	90	("uiomove proc"));
	91
	92	if (curproc) {
	93	save = curproc->p_flag & P_DEADLKTREAT;
	94	curproc->p_flag \|= P_DEADLKTREAT;
	95	}
	96
	97	while (n > 0 && uio->uio_resid) {
	98	iov = uio->uio_iov;
	99	cnt = iov->iov_len;
	100	if (cnt == 0) {
	101	uio->uio_iov++;
	102	uio->uio_iovcnt--;
	103	continue;
	104	}
	105	if (cnt > n)
	106	cnt = n;
	107
	108	switch (uio->uio_segflg) {
	109
	110	case UIO_USERSPACE:
d16a8831	111	if (ticks - baseticks >= hogticks) {
984263bc	112	uio_yield();
d16a8831 MD	113	baseticks = ticks;
d16a8831 MD	114	}
984263bc MD	115	if (uio->uio_rw == UIO_READ)
	116	error = copyout(cp, iov->iov_base, cnt);
	117	else
	118	error = copyin(iov->iov_base, cp, cnt);
	119	if (error)
	120	break;
	121	break;
	122
	123	case UIO_SYSSPACE:
	124	if (uio->uio_rw == UIO_READ)
	125	bcopy((caddr_t)cp, iov->iov_base, cnt);
	126	else
	127	bcopy(iov->iov_base, (caddr_t)cp, cnt);
	128	break;
	129	case UIO_NOCOPY:
	130	break;
	131	}
656849c6	132	iov->iov_base = (char *)iov->iov_base + cnt;
984263bc MD	133	iov->iov_len -= cnt;
	134	uio->uio_resid -= cnt;
	135	uio->uio_offset += cnt;
	136	cp += cnt;
	137	n -= cnt;
	138	}
	139	if (curproc)
	140	curproc->p_flag = (curproc->p_flag & ~P_DEADLKTREAT) \| save;
	141	return (error);
	142	}
c7841cbe MD	143
	144	/*
	145	* Like uiomove() but copies zero-fill. Only allowed for UIO_READ,
	146	* for obvious reasons.
	147	*/
	148	int
	149	uiomovez(size_t n, struct uio *uio)
	150	{
	151	struct iovec *iov;
	152	size_t cnt;
	153	int error = 0;
	154
	155	KASSERT(uio->uio_rw == UIO_READ, ("uiomovez: mode"));
	156	KASSERT(uio->uio_segflg != UIO_USERSPACE \|\| uio->uio_td == curthread,
	157	("uiomove proc"));
	158
	159	while (n > 0 && uio->uio_resid) {
	160	iov = uio->uio_iov;
	161	cnt = iov->iov_len;
	162	if (cnt == 0) {
	163	uio->uio_iov++;
	164	uio->uio_iovcnt--;
	165	continue;
	166	}
	167	if (cnt > n)
	168	cnt = n;
	169
	170	switch (uio->uio_segflg) {
	171	case UIO_USERSPACE:
	172	error = copyout(ZeroPage, iov->iov_base, cnt);
	173	if (error)
	174	break;
	175	break;
	176	case UIO_SYSSPACE:
	177	bzero(iov->iov_base, cnt);
	178	break;
	179	case UIO_NOCOPY:
	180	break;
	181	}
	182	iov->iov_base = (char *)iov->iov_base + cnt;
	183	iov->iov_len -= cnt;
	184	uio->uio_resid -= cnt;
	185	uio->uio_offset += cnt;
	186	n -= cnt;
	187	}
	188	return (error);
	189	}
	190
25e80b06 DR	191	/*
25e80b06 DR	192	* Wrapper for uiomove() that validates the arguments against a known-good
e54488bb	193	* kernel buffer.
25e80b06 DR	194	*/
25e80b06 DR	195	int
e54488bb	196	uiomove_frombuf(void buf, size_t buflen, struct uio uio)
25e80b06	197	{
e54488bb	198	size_t offset;
25e80b06	199
e54488bb MD	200	offset = (size_t)uio->uio_offset;
e54488bb MD	201	if ((off_t)offset != uio->uio_offset)
25e80b06	202	return (EINVAL);
e54488bb	203	if (buflen == 0 \|\| offset >= buflen)
25e80b06	204	return (0);
e54488bb	205	return (uiomove((char *)buf + offset, buflen - offset, uio));
984263bc MD	206	}
984263bc MD	207
984263bc MD	208	/*
	209	* Give next character to user as result of read.
	210	*/
	211	int
c972a82f	212	ureadc(int c, struct uio *uio)
984263bc	213	{
1fd87d54	214	struct iovec *iov;
656849c6	215	char *iov_base;
984263bc MD	216
	217	again:
	218	if (uio->uio_iovcnt == 0 \|\| uio->uio_resid == 0)
	219	panic("ureadc");
	220	iov = uio->uio_iov;
	221	if (iov->iov_len == 0) {
	222	uio->uio_iovcnt--;
	223	uio->uio_iov++;
	224	goto again;
	225	}
	226	switch (uio->uio_segflg) {
	227
	228	case UIO_USERSPACE:
	229	if (subyte(iov->iov_base, c) < 0)
	230	return (EFAULT);
	231	break;
	232
	233	case UIO_SYSSPACE:
656849c6 SW	234	iov_base = iov->iov_base;
	235	*iov_base = c;
	236	iov->iov_base = iov_base;
984263bc MD	237	break;
984263bc MD	238
984263bc MD	239	case UIO_NOCOPY:
	240	break;
	241	}
656849c6	242	iov->iov_base = (char *)iov->iov_base + 1;
984263bc MD	243	iov->iov_len--;
	244	uio->uio_resid--;
	245	uio->uio_offset++;
	246	return (0);
	247	}
	248
984263bc	249	/*
1c86b25b MD	250	* General routine to allocate a hash table. Make the hash table size a
	251	* power of 2 greater or equal to the number of elements requested, and
	252	* store the masking value in *hashmask.
984263bc MD	253	*/
984263bc MD	254	void *
c972a82f	255	hashinit(int elements, struct malloc_type type, u_long hashmask)
984263bc MD	256	{
	257	long hashsize;
	258	LIST_HEAD(generic, generic) *hashtbl;
	259	int i;
	260
	261	if (elements <= 0)
	262	panic("hashinit: bad elements");
8f17cbc6	263	for (hashsize = 2; hashsize < elements; hashsize <<= 1)
984263bc	264	continue;
efda3bd0	265	hashtbl = kmalloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
984263bc MD	266	for (i = 0; i < hashsize; i++)
	267	LIST_INIT(&hashtbl[i]);
	268	*hashmask = hashsize - 1;
	269	return (hashtbl);
	270	}
	271
c02197ac MD	272	/*
	273	* This is a newer version which allocates a hash table of structures.
	274	*
	275	* The returned array will be zero'd. The caller is responsible for
	276	* initializing the structures.
	277	*/
	278	void *
	279	hashinit_ext(int elements, size_t size, struct malloc_type *type,
	280	u_long *hashmask)
	281	{
	282	long hashsize;
	283	void *hashtbl;
	284
	285	if (elements <= 0)
	286	panic("hashinit: bad elements");
	287	for (hashsize = 2; hashsize < elements; hashsize <<= 1)
	288	continue;
	289	hashtbl = kmalloc((size_t)hashsize * size, type, M_WAITOK \| M_ZERO);
	290	*hashmask = hashsize - 1;
	291	return (hashtbl);
	292	}
	293
984263bc MD	294	static int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531, 2039,
	295	2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143, 6653,
	296	7159, 7673, 8191, 12281, 16381, 24571, 32749 };
	297	#define NPRIMES (sizeof(primes) / sizeof(primes[0]))
	298
	299	/*
	300	* General routine to allocate a prime number sized hash table.
	301	*/
	302	void *
c972a82f	303	phashinit(int elements, struct malloc_type type, u_long nentries)
984263bc MD	304	{
	305	long hashsize;
	306	LIST_HEAD(generic, generic) *hashtbl;
	307	int i;
	308
	309	if (elements <= 0)
	310	panic("phashinit: bad elements");
	311	for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
	312	i++;
	313	if (i == NPRIMES)
	314	break;
	315	hashsize = primes[i];
	316	}
	317	hashsize = primes[i - 1];
efda3bd0	318	hashtbl = kmalloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
984263bc MD	319	for (i = 0; i < hashsize; i++)
	320	LIST_INIT(&hashtbl[i]);
	321	*nentries = hashsize;
	322	return (hashtbl);
	323	}
75a872f8 DRJ	324
75a872f8 DRJ	325	/*
c02197ac MD	326	* This is a newer version which allocates a hash table of structures
	327	* in a prime-number size.
	328	*
	329	* The returned array will be zero'd. The caller is responsible for
	330	* initializing the structures.
	331	*/
	332	void *
	333	phashinit_ext(int elements, size_t size, struct malloc_type *type,
	334	u_long *nentries)
	335	{
	336	long hashsize;
	337	void *hashtbl;
	338	int i;
	339
	340	if (elements <= 0)
	341	panic("phashinit: bad elements");
	342	for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
	343	i++;
	344	if (i == NPRIMES)
	345	break;
	346	hashsize = primes[i];
	347	}
	348	hashsize = primes[i - 1];
	349	hashtbl = kmalloc((size_t)hashsize * size, type, M_WAITOK \| M_ZERO);
	350	*nentries = hashsize;
	351	return (hashtbl);
	352	}
	353
	354	/*
75a872f8 DRJ	355	* Copyin an iovec. If the iovec array fits, use the preallocated small
	356	* iovec structure. If it is too big, dynamically allocate an iovec array
	357	* of sufficient size.
f832287e MD	358	*
f832287e MD	359	* MPSAFE
75a872f8 DRJ	360	*/
	361	int
	362	iovec_copyin(struct iovec uiov, struct iovec kiov, struct iovec siov,
e54488bb	363	size_t iov_cnt, size_t *iov_len)
75a872f8 DRJ	364	{
	365	struct iovec *iovp;
	366	int error, i;
e54488bb	367	size_t len;
75a872f8	368
fe57a30b	369	if (iov_cnt > UIO_MAXIOV)
75a872f8	370	return EMSGSIZE;
fe57a30b	371	if (iov_cnt > UIO_SMALLIOV) {
75a872f8 DRJ	372	MALLOC(kiov, struct iovec , sizeof(struct iovec) * iov_cnt,
	373	M_IOV, M_WAITOK);
	374	} else {
	375	*kiov = siov;
	376	}
	377	error = copyin(uiov, kiov, iov_cnt sizeof(struct iovec));
ef5c76d7 MD	378	if (error == 0) {
	379	*iov_len = 0;
	380	for (i = 0, iovp = *kiov; i < iov_cnt; i++, iovp++) {
	381	/*
	382	* Check for both *iov_len overflows and out of
	383	* range iovp->iov_len's. We limit to the
	384	* capabilities of signed integers.
e54488bb MD	385	*
e54488bb MD	386	* GCC4 - overflow check opt requires assign/test.
ef5c76d7	387	*/
e54488bb MD	388	len = *iov_len + iovp->iov_len;
e54488bb MD	389	if (len < *iov_len)
ef5c76d7	390	error = EINVAL;
e54488bb	391	*iov_len = len;
ef5c76d7 MD	392	}
ef5c76d7 MD	393	}
e54488bb MD	394
	395	/*
	396	* From userland disallow iovec's which exceed the sized size
	397	* limit as the system calls return ssize_t.
	398	*
	399	* NOTE: Internal kernel interfaces can handle the unsigned
	400	* limit.
	401	*/
	402	if (error == 0 && (ssize_t)*iov_len < 0)
	403	error = EINVAL;
	404
75a872f8 DRJ	405	if (error)
	406	iovec_free(kiov, siov);
	407	return (error);
	408	}
a358fd45 MD	409
	410
	411	/*
	412	* Copyright (c) 2004 Alan L. Cox <alc@cs.rice.edu>
	413	* Copyright (c) 1982, 1986, 1991, 1993
	414	* The Regents of the University of California. All rights reserved.
	415	* (c) UNIX System Laboratories, Inc.
	416	* All or some portions of this file are derived from material licensed
	417	* to the University of California by American Telephone and Telegraph
	418	* Co. or Unix System Laboratories, Inc. and are reproduced herein with
	419	* the permission of UNIX System Laboratories, Inc.
	420	*
	421	* Redistribution and use in source and binary forms, with or without
	422	* modification, are permitted provided that the following conditions
	423	* are met:
	424	* 1. Redistributions of source code must retain the above copyright
	425	* notice, this list of conditions and the following disclaimer.
	426	* 2. Redistributions in binary form must reproduce the above copyright
	427	* notice, this list of conditions and the following disclaimer in the
	428	* documentation and/or other materials provided with the distribution.
	429	* 4. Neither the name of the University nor the names of its contributors
	430	* may be used to endorse or promote products derived from this software
	431	* without specific prior written permission.
	432	*
	433	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	434	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	435	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	436	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	437	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	438	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	439	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	440	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	441	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	442	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	443	* SUCH DAMAGE.
	444	*
	445	* @(#)kern_subr.c 8.3 (Berkeley) 1/21/94
	446	* $FreeBSD: src/sys/i386/i386/uio_machdep.c,v 1.1 2004/03/21 20:28:36 alc Exp $
	447	*/
	448
	449	/*
5c5185ae	450	* Implement uiomove(9) from physical memory using lwbuf's to reduce
a358fd45 MD	451	* the creation and destruction of ephemeral mappings.
	452	*/
	453	int
e54488bb	454	uiomove_fromphys(vm_page_t ma, vm_offset_t offset, size_t n, struct uio uio)
a358fd45	455	{
5c5185ae	456	struct lwbuf *lwb;
a358fd45 MD	457	struct thread *td = curthread;
	458	struct iovec *iov;
	459	void *cp;
	460	vm_offset_t page_offset;
	461	vm_page_t m;
	462	size_t cnt;
	463	int error = 0;
	464	int save = 0;
	465
	466	KASSERT(uio->uio_rw == UIO_READ \|\| uio->uio_rw == UIO_WRITE,
	467	("uiomove_fromphys: mode"));
	468	KASSERT(uio->uio_segflg != UIO_USERSPACE \|\| uio->uio_td == curthread,
	469	("uiomove_fromphys proc"));
	470
	471	crit_enter();
	472	save = td->td_flags & TDF_DEADLKTREAT;
	473	td->td_flags \|= TDF_DEADLKTREAT;
	474	crit_exit();
	475
	476	while (n > 0 && uio->uio_resid) {
	477	iov = uio->uio_iov;
	478	cnt = iov->iov_len;
	479	if (cnt == 0) {
	480	uio->uio_iov++;
	481	uio->uio_iovcnt--;
	482	continue;
	483	}
	484	if (cnt > n)
	485	cnt = n;
	486	page_offset = offset & PAGE_MASK;
	487	cnt = min(cnt, PAGE_SIZE - page_offset);
	488	m = ma[offset >> PAGE_SHIFT];
5c5185ae SG	489	lwb = lwbuf_alloc(m);
5c5185ae SG	490	cp = (char *)lwbuf_kva(lwb) + page_offset;
a358fd45 MD	491	switch (uio->uio_segflg) {
	492	case UIO_USERSPACE:
	493	/*
	494	* note: removed uioyield (it was the wrong place to
	495	* put it).
	496	*/
	497	if (uio->uio_rw == UIO_READ)
	498	error = copyout(cp, iov->iov_base, cnt);
	499	else
	500	error = copyin(iov->iov_base, cp, cnt);
	501	if (error) {
5c5185ae	502	lwbuf_free(lwb);
a358fd45 MD	503	goto out;
	504	}
	505	break;
	506	case UIO_SYSSPACE:
	507	if (uio->uio_rw == UIO_READ)
	508	bcopy(cp, iov->iov_base, cnt);
	509	else
	510	bcopy(iov->iov_base, cp, cnt);
	511	break;
	512	case UIO_NOCOPY:
	513	break;
	514	}
5c5185ae	515	lwbuf_free(lwb);
a358fd45 MD	516	iov->iov_base = (char *)iov->iov_base + cnt;
	517	iov->iov_len -= cnt;
	518	uio->uio_resid -= cnt;
	519	uio->uio_offset += cnt;
	520	offset += cnt;
	521	n -= cnt;
	522	}
	523	out:
	524	if (save == 0) {
	525	crit_enter();
	526	td->td_flags &= ~TDF_DEADLKTREAT;
	527	crit_exit();
	528	}
	529	return (error);
	530	}
	531