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.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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
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 $
40 * $DragonFly: src/sys/kern/kern_subr.c,v 1.20 2004/11/09 17:52:45 joerg Exp $
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
49 #include <sys/malloc.h>
51 #include <sys/resourcevar.h>
52 #include <sys/sysctl.h>
54 #include <sys/vnode.h>
55 #include <machine/limits.h>
58 #include <vm/vm_page.h>
59 #include <vm/vm_map.h>
61 SYSCTL_INT(_kern
, KERN_IOV_MAX
, iov_max
, CTLFLAG_RD
, NULL
, UIO_MAXIOV
,
62 "Maximum number of elements in an I/O vector; sysconf(_SC_IOV_MAX)");
65 * UIO_READ: copy the kernelspace cp to the user or kernelspace UIO
66 * UIO_WRITE: copy the user or kernelspace UIO to cp
68 * For userspace UIO's, uio_td must be the current thread.
71 uiomove(caddr_t cp
, int n
, struct uio
*uio
)
77 int baseticks
= ticks
;
79 KASSERT(uio
->uio_rw
== UIO_READ
|| uio
->uio_rw
== UIO_WRITE
,
81 KASSERT(uio
->uio_segflg
!= UIO_USERSPACE
|| uio
->uio_td
== curthread
,
85 save
= curproc
->p_flag
& P_DEADLKTREAT
;
86 curproc
->p_flag
|= P_DEADLKTREAT
;
89 while (n
> 0 && uio
->uio_resid
) {
100 switch (uio
->uio_segflg
) {
103 if (ticks
- baseticks
>= hogticks
) {
107 if (uio
->uio_rw
== UIO_READ
)
108 error
= copyout(cp
, iov
->iov_base
, cnt
);
110 error
= copyin(iov
->iov_base
, cp
, cnt
);
116 if (uio
->uio_rw
== UIO_READ
)
117 bcopy((caddr_t
)cp
, iov
->iov_base
, cnt
);
119 bcopy(iov
->iov_base
, (caddr_t
)cp
, cnt
);
124 iov
->iov_base
+= cnt
;
126 uio
->uio_resid
-= cnt
;
127 uio
->uio_offset
+= cnt
;
132 curproc
->p_flag
= (curproc
->p_flag
& ~P_DEADLKTREAT
) | save
;
136 * Wrapper for uiomove() that validates the arguments against a known-good
137 * kernel buffer. Currently, uiomove accepts a signed (n) argument, which
138 * is almost definitely a bad thing, so we catch that here as well. We
139 * return a runtime failure, but it might be desirable to generate a runtime
140 * assertion failure instead.
143 uiomove_frombuf(void *buf
, int buflen
, struct uio
*uio
)
145 unsigned int offset
, n
;
147 if (uio
->uio_offset
< 0 || uio
->uio_resid
< 0 ||
148 (offset
= uio
->uio_offset
) != uio
->uio_offset
)
150 if (buflen
<= 0 || offset
>= buflen
)
152 if ((n
= buflen
- offset
) > INT_MAX
)
154 return (uiomove((char *)buf
+ offset
, n
, uio
));
159 uiomoveco(cp
, n
, uio
, obj
)
163 struct vm_object
*obj
;
168 int baseticks
= ticks
;
170 KASSERT(uio
->uio_rw
== UIO_READ
|| uio
->uio_rw
== UIO_WRITE
,
171 ("uiomoveco: mode"));
172 KASSERT(uio
->uio_segflg
!= UIO_USERSPACE
|| uio
->uio_td
== curthread
,
175 while (n
> 0 && uio
->uio_resid
) {
186 switch (uio
->uio_segflg
) {
189 if (ticks
- baseticks
>= hogticks
) {
193 if (uio
->uio_rw
== UIO_READ
) {
194 error
= copyout(cp
, iov
->iov_base
, cnt
);
196 error
= copyin(iov
->iov_base
, cp
, cnt
);
203 if (uio
->uio_rw
== UIO_READ
)
204 bcopy((caddr_t
)cp
, iov
->iov_base
, cnt
);
206 bcopy(iov
->iov_base
, (caddr_t
)cp
, cnt
);
211 iov
->iov_base
+= cnt
;
213 uio
->uio_resid
-= cnt
;
214 uio
->uio_offset
+= cnt
;
222 * Give next character to user as result of read.
232 if (uio
->uio_iovcnt
== 0 || uio
->uio_resid
== 0)
235 if (iov
->iov_len
== 0) {
240 switch (uio
->uio_segflg
) {
243 if (subyte(iov
->iov_base
, c
) < 0)
262 * General routine to allocate a hash table. Make the hash table size a
263 * power of 2 greater or equal to the number of elements requested, and
264 * store the masking value in *hashmask.
267 hashinit(elements
, type
, hashmask
)
269 struct malloc_type
*type
;
273 LIST_HEAD(generic
, generic
) *hashtbl
;
277 panic("hashinit: bad elements");
278 for (hashsize
= 2; hashsize
< elements
; hashsize
<<= 1)
280 hashtbl
= malloc((u_long
)hashsize
* sizeof(*hashtbl
), type
, M_WAITOK
);
281 for (i
= 0; i
< hashsize
; i
++)
282 LIST_INIT(&hashtbl
[i
]);
283 *hashmask
= hashsize
- 1;
287 static int primes
[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531, 2039,
288 2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143, 6653,
289 7159, 7673, 8191, 12281, 16381, 24571, 32749 };
290 #define NPRIMES (sizeof(primes) / sizeof(primes[0]))
293 * General routine to allocate a prime number sized hash table.
296 phashinit(elements
, type
, nentries
)
298 struct malloc_type
*type
;
302 LIST_HEAD(generic
, generic
) *hashtbl
;
306 panic("phashinit: bad elements");
307 for (i
= 1, hashsize
= primes
[1]; hashsize
<= elements
;) {
311 hashsize
= primes
[i
];
313 hashsize
= primes
[i
- 1];
314 hashtbl
= malloc((u_long
)hashsize
* sizeof(*hashtbl
), type
, M_WAITOK
);
315 for (i
= 0; i
< hashsize
; i
++)
316 LIST_INIT(&hashtbl
[i
]);
317 *nentries
= hashsize
;
322 * Copyin an iovec. If the iovec array fits, use the preallocated small
323 * iovec structure. If it is too big, dynamically allocate an iovec array
324 * of sufficient size.
327 iovec_copyin(struct iovec
*uiov
, struct iovec
**kiov
, struct iovec
*siov
,
328 size_t iov_cnt
, size_t *iov_len
)
333 if (iov_cnt
>= UIO_MAXIOV
)
335 if (iov_cnt
>= UIO_SMALLIOV
) {
336 MALLOC(*kiov
, struct iovec
*, sizeof(struct iovec
) * iov_cnt
,
341 error
= copyin(uiov
, *kiov
, iov_cnt
* sizeof(struct iovec
));
345 for (i
= 0, iovp
= *kiov
; i
< iov_cnt
; i
++, iovp
++)
346 *iov_len
+= iovp
->iov_len
;
350 iovec_free(kiov
, siov
);