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/thread2.h>
56 #include <machine/limits.h>
58 #include <cpu/lwbuf.h>
61 #include <vm/vm_page.h>
62 #include <vm/vm_map.h>
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)");
68 * UIO_READ: copy the kernelspace cp to the user or kernelspace UIO
69 * UIO_WRITE: copy the user or kernelspace UIO to the kernelspace cp
71 * For userspace UIO's, uio_td must be the current thread.
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
79 uiomove(caddr_t cp, size_t n, struct uio *uio)
85 int baseticks = ticks;
87 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
89 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
93 save = curproc->p_flag & P_DEADLKTREAT;
94 curproc->p_flag |= P_DEADLKTREAT;
97 while (n > 0 && uio->uio_resid) {
108 switch (uio->uio_segflg) {
111 if (ticks - baseticks >= hogticks) {
115 if (uio->uio_rw == UIO_READ)
116 error = copyout(cp, iov->iov_base, cnt);
118 error = copyin(iov->iov_base, cp, cnt);
124 if (uio->uio_rw == UIO_READ)
125 bcopy((caddr_t)cp, iov->iov_base, cnt);
127 bcopy(iov->iov_base, (caddr_t)cp, cnt);
132 iov->iov_base = (char *)iov->iov_base + cnt;
134 uio->uio_resid -= cnt;
135 uio->uio_offset += cnt;
140 curproc->p_flag = (curproc->p_flag & ~P_DEADLKTREAT) | save;
145 * Like uiomove() but copies zero-fill. Only allowed for UIO_READ,
146 * for obvious reasons.
149 uiomovez(size_t n, struct uio *uio)
155 KASSERT(uio->uio_rw == UIO_READ, ("uiomovez: mode"));
156 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
159 while (n > 0 && uio->uio_resid) {
170 switch (uio->uio_segflg) {
172 error = copyout(ZeroPage, iov->iov_base, cnt);
177 bzero(iov->iov_base, cnt);
182 iov->iov_base = (char *)iov->iov_base + cnt;
184 uio->uio_resid -= cnt;
185 uio->uio_offset += cnt;
192 * Wrapper for uiomove() that validates the arguments against a known-good
196 uiomove_frombuf(void *buf, size_t buflen, struct uio *uio)
200 offset = (size_t)uio->uio_offset;
201 if ((off_t)offset != uio->uio_offset)
203 if (buflen == 0 || offset >= buflen)
205 return (uiomove((char *)buf + offset, buflen - offset, uio));
209 * Give next character to user as result of read.
212 ureadc(int c, struct uio *uio)
218 if (uio->uio_iovcnt == 0 || uio->uio_resid == 0)
221 if (iov->iov_len == 0) {
226 switch (uio->uio_segflg) {
229 if (subyte(iov->iov_base, c) < 0)
234 iov_base = iov->iov_base;
236 iov->iov_base = iov_base;
242 iov->iov_base = (char *)iov->iov_base + 1;
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.
255 hashinit(int elements, struct malloc_type *type, u_long *hashmask)
258 LIST_HEAD(generic, generic) *hashtbl;
262 panic("hashinit: bad elements");
263 for (hashsize = 2; hashsize < elements; hashsize <<= 1)
265 hashtbl = kmalloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
266 for (i = 0; i < hashsize; i++)
267 LIST_INIT(&hashtbl[i]);
268 *hashmask = hashsize - 1;
273 * This is a newer version which allocates a hash table of structures.
275 * The returned array will be zero'd. The caller is responsible for
276 * initializing the structures.
279 hashinit_ext(int elements, size_t size, struct malloc_type *type,
286 panic("hashinit: bad elements");
287 for (hashsize = 2; hashsize < elements; hashsize <<= 1)
289 hashtbl = kmalloc((size_t)hashsize * size, type, M_WAITOK | M_ZERO);
290 *hashmask = hashsize - 1;
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]))
300 * General routine to allocate a prime number sized hash table.
303 phashinit(int elements, struct malloc_type *type, u_long *nentries)
306 LIST_HEAD(generic, generic) *hashtbl;
310 panic("phashinit: bad elements");
311 for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
315 hashsize = primes[i];
317 hashsize = primes[i - 1];
318 hashtbl = kmalloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
319 for (i = 0; i < hashsize; i++)
320 LIST_INIT(&hashtbl[i]);
321 *nentries = hashsize;
326 * This is a newer version which allocates a hash table of structures
327 * in a prime-number size.
329 * The returned array will be zero'd. The caller is responsible for
330 * initializing the structures.
333 phashinit_ext(int elements, size_t size, struct malloc_type *type,
341 panic("phashinit: bad elements");
342 for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
346 hashsize = primes[i];
348 hashsize = primes[i - 1];
349 hashtbl = kmalloc((size_t)hashsize * size, type, M_WAITOK | M_ZERO);
350 *nentries = hashsize;
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.
362 iovec_copyin(struct iovec *uiov, struct iovec **kiov, struct iovec *siov,
363 size_t iov_cnt, size_t *iov_len)
369 if (iov_cnt > UIO_MAXIOV)
371 if (iov_cnt > UIO_SMALLIOV) {
372 MALLOC(*kiov, struct iovec *, sizeof(struct iovec) * iov_cnt,
377 error = copyin(uiov, *kiov, iov_cnt * sizeof(struct iovec));
380 for (i = 0, iovp = *kiov; i < iov_cnt; i++, iovp++) {
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.
386 * GCC4 - overflow check opt requires assign/test.
388 len = *iov_len + iovp->iov_len;
396 * From userland disallow iovec's which exceed the sized size
397 * limit as the system calls return ssize_t.
399 * NOTE: Internal kernel interfaces can handle the unsigned
402 if (error == 0 && (ssize_t)*iov_len < 0)
406 iovec_free(kiov, siov);
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.
421 * Redistribution and use in source and binary forms, with or without
422 * modification, are permitted provided that the following conditions
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.
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
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 $
450 * Implement uiomove(9) from physical memory using lwbuf's to reduce
451 * the creation and destruction of ephemeral mappings.
454 uiomove_fromphys(vm_page_t *ma, vm_offset_t offset, size_t n, struct uio *uio)
457 struct thread *td = curthread;
460 vm_offset_t page_offset;
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"));
472 save = td->td_flags & TDF_DEADLKTREAT;
473 td->td_flags |= TDF_DEADLKTREAT;
476 while (n > 0 && uio->uio_resid) {
486 page_offset = offset & PAGE_MASK;
487 cnt = min(cnt, PAGE_SIZE - page_offset);
488 m = ma[offset >> PAGE_SHIFT];
489 lwb = lwbuf_alloc(m);
490 cp = (char *)lwbuf_kva(lwb) + page_offset;
491 switch (uio->uio_segflg) {
494 * note: removed uioyield (it was the wrong place to
497 if (uio->uio_rw == UIO_READ)
498 error = copyout(cp, iov->iov_base, cnt);
500 error = copyin(iov->iov_base, cp, cnt);
507 if (uio->uio_rw == UIO_READ)
508 bcopy(cp, iov->iov_base, cnt);
510 bcopy(iov->iov_base, cp, cnt);
516 iov->iov_base = (char *)iov->iov_base + cnt;
518 uio->uio_resid -= cnt;
519 uio->uio_offset += cnt;
526 td->td_flags &= ~TDF_DEADLKTREAT;