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 1.27 2007/01/29 20:44:02 tgen 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 <sys/sfbuf.h>
56 #include <sys/thread2.h>
57 #include <machine/limits.h>
60 #include <vm/vm_page.h>
61 #include <vm/vm_map.h>
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)");
67 * UIO_READ: copy the kernelspace cp to the user or kernelspace UIO
68 * UIO_WRITE: copy the user or kernelspace UIO to the kernelspace cp
70 * For userspace UIO's, uio_td must be the current thread.
73 uiomove(caddr_t cp, int n, struct uio *uio)
79 int baseticks = ticks;
81 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
83 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
87 save = curproc->p_flag & P_DEADLKTREAT;
88 curproc->p_flag |= P_DEADLKTREAT;
91 while (n > 0 && uio->uio_resid) {
102 switch (uio->uio_segflg) {
105 if (ticks - baseticks >= hogticks) {
109 if (uio->uio_rw == UIO_READ)
110 error = copyout(cp, iov->iov_base, cnt);
112 error = copyin(iov->iov_base, cp, cnt);
118 if (uio->uio_rw == UIO_READ)
119 bcopy((caddr_t)cp, iov->iov_base, cnt);
121 bcopy(iov->iov_base, (caddr_t)cp, cnt);
126 iov->iov_base += cnt;
128 uio->uio_resid -= cnt;
129 uio->uio_offset += cnt;
134 curproc->p_flag = (curproc->p_flag & ~P_DEADLKTREAT) | save;
138 * Wrapper for uiomove() that validates the arguments against a known-good
139 * kernel buffer. Currently, uiomove accepts a signed (n) argument, which
140 * is almost definitely a bad thing, so we catch that here as well. We
141 * return a runtime failure, but it might be desirable to generate a runtime
142 * assertion failure instead.
145 uiomove_frombuf(void *buf, int buflen, struct uio *uio)
147 unsigned int offset, n;
149 if (uio->uio_offset < 0 || uio->uio_resid < 0 ||
150 (offset = uio->uio_offset) != uio->uio_offset)
152 if (buflen <= 0 || offset >= buflen)
154 if ((n = buflen - offset) > INT_MAX)
156 return (uiomove((char *)buf + offset, n, uio));
161 uiomoveco(caddr_t cp, int n, struct uio *uio, struct vm_object *obj)
166 int baseticks = ticks;
168 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
169 ("uiomoveco: mode"));
170 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
173 while (n > 0 && uio->uio_resid) {
184 switch (uio->uio_segflg) {
187 if (ticks - baseticks >= hogticks) {
191 if (uio->uio_rw == UIO_READ) {
192 error = copyout(cp, iov->iov_base, cnt);
194 error = copyin(iov->iov_base, cp, cnt);
201 if (uio->uio_rw == UIO_READ)
202 bcopy((caddr_t)cp, iov->iov_base, cnt);
204 bcopy(iov->iov_base, (caddr_t)cp, cnt);
209 iov->iov_base += cnt;
211 uio->uio_resid -= cnt;
212 uio->uio_offset += cnt;
220 * Give next character to user as result of read.
223 ureadc(int c, struct uio *uio)
228 if (uio->uio_iovcnt == 0 || uio->uio_resid == 0)
231 if (iov->iov_len == 0) {
236 switch (uio->uio_segflg) {
239 if (subyte(iov->iov_base, c) < 0)
258 * General routine to allocate a hash table. Make the hash table size a
259 * power of 2 greater or equal to the number of elements requested, and
260 * store the masking value in *hashmask.
263 hashinit(int elements, struct malloc_type *type, u_long *hashmask)
266 LIST_HEAD(generic, generic) *hashtbl;
270 panic("hashinit: bad elements");
271 for (hashsize = 2; hashsize < elements; hashsize <<= 1)
273 hashtbl = kmalloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
274 for (i = 0; i < hashsize; i++)
275 LIST_INIT(&hashtbl[i]);
276 *hashmask = hashsize - 1;
280 static int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531, 2039,
281 2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143, 6653,
282 7159, 7673, 8191, 12281, 16381, 24571, 32749 };
283 #define NPRIMES (sizeof(primes) / sizeof(primes[0]))
286 * General routine to allocate a prime number sized hash table.
289 phashinit(int elements, struct malloc_type *type, u_long *nentries)
292 LIST_HEAD(generic, generic) *hashtbl;
296 panic("phashinit: bad elements");
297 for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
301 hashsize = primes[i];
303 hashsize = primes[i - 1];
304 hashtbl = kmalloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
305 for (i = 0; i < hashsize; i++)
306 LIST_INIT(&hashtbl[i]);
307 *nentries = hashsize;
312 * Copyin an iovec. If the iovec array fits, use the preallocated small
313 * iovec structure. If it is too big, dynamically allocate an iovec array
314 * of sufficient size.
319 iovec_copyin(struct iovec *uiov, struct iovec **kiov, struct iovec *siov,
320 size_t iov_cnt, int *iov_len)
325 if (iov_cnt > UIO_MAXIOV)
327 if (iov_cnt > UIO_SMALLIOV) {
328 MALLOC(*kiov, struct iovec *, sizeof(struct iovec) * iov_cnt,
333 error = copyin(uiov, *kiov, iov_cnt * sizeof(struct iovec));
336 for (i = 0, iovp = *kiov; i < iov_cnt; i++, iovp++) {
338 * Check for both *iov_len overflows and out of
339 * range iovp->iov_len's. We limit to the
340 * capabilities of signed integers.
342 if (*iov_len + (int)iovp->iov_len < *iov_len)
344 *iov_len += (int)iovp->iov_len;
348 iovec_free(kiov, siov);
354 * Copyright (c) 2004 Alan L. Cox <alc@cs.rice.edu>
355 * Copyright (c) 1982, 1986, 1991, 1993
356 * The Regents of the University of California. All rights reserved.
357 * (c) UNIX System Laboratories, Inc.
358 * All or some portions of this file are derived from material licensed
359 * to the University of California by American Telephone and Telegraph
360 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
361 * the permission of UNIX System Laboratories, Inc.
363 * Redistribution and use in source and binary forms, with or without
364 * modification, are permitted provided that the following conditions
366 * 1. Redistributions of source code must retain the above copyright
367 * notice, this list of conditions and the following disclaimer.
368 * 2. Redistributions in binary form must reproduce the above copyright
369 * notice, this list of conditions and the following disclaimer in the
370 * documentation and/or other materials provided with the distribution.
371 * 4. Neither the name of the University nor the names of its contributors
372 * may be used to endorse or promote products derived from this software
373 * without specific prior written permission.
375 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
376 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
377 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
378 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
379 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
380 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
381 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
382 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
383 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
384 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
387 * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94
388 * $FreeBSD: src/sys/i386/i386/uio_machdep.c,v 1.1 2004/03/21 20:28:36 alc Exp $
392 * Implement uiomove(9) from physical memory using sf_bufs to reduce
393 * the creation and destruction of ephemeral mappings.
396 uiomove_fromphys(vm_page_t *ma, vm_offset_t offset, int n, struct uio *uio)
399 struct thread *td = curthread;
402 vm_offset_t page_offset;
408 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
409 ("uiomove_fromphys: mode"));
410 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
411 ("uiomove_fromphys proc"));
414 save = td->td_flags & TDF_DEADLKTREAT;
415 td->td_flags |= TDF_DEADLKTREAT;
418 while (n > 0 && uio->uio_resid) {
428 page_offset = offset & PAGE_MASK;
429 cnt = min(cnt, PAGE_SIZE - page_offset);
430 m = ma[offset >> PAGE_SHIFT];
431 sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
432 cp = (char *)sf_buf_kva(sf) + page_offset;
433 switch (uio->uio_segflg) {
436 * note: removed uioyield (it was the wrong place to
439 if (uio->uio_rw == UIO_READ)
440 error = copyout(cp, iov->iov_base, cnt);
442 error = copyin(iov->iov_base, cp, cnt);
449 if (uio->uio_rw == UIO_READ)
450 bcopy(cp, iov->iov_base, cnt);
452 bcopy(iov->iov_base, cp, cnt);
458 iov->iov_base = (char *)iov->iov_base + cnt;
460 uio->uio_resid -= cnt;
461 uio->uio_offset += cnt;
468 td->td_flags &= ~TDF_DEADLKTREAT;