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 $
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
48 #include <sys/malloc.h>
50 #include <sys/resourcevar.h>
51 #include <sys/sysctl.h>
53 #include <sys/vnode.h>
54 #include <sys/thread2.h>
55 #include <machine/limits.h>
57 #include <cpu/lwbuf.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.
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
78 uiomove(caddr_t cp, size_t n, struct uio *uio)
80 thread_t td = curthread;
86 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
88 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == td,
92 save = td->td_flags & TDF_DEADLKTREAT;
93 td->td_flags |= TDF_DEADLKTREAT;
96 while (n > 0 && uio->uio_resid) {
107 switch (uio->uio_segflg) {
111 if (uio->uio_rw == UIO_READ)
112 error = copyout(cp, iov->iov_base, cnt);
114 error = copyin(iov->iov_base, cp, cnt);
120 if (uio->uio_rw == UIO_READ)
121 bcopy((caddr_t)cp, iov->iov_base, cnt);
123 bcopy(iov->iov_base, (caddr_t)cp, cnt);
128 iov->iov_base = (char *)iov->iov_base + cnt;
130 uio->uio_resid -= cnt;
131 uio->uio_offset += cnt;
136 td->td_flags = (td->td_flags & ~TDF_DEADLKTREAT) | save;
142 * Like uiomove() but copies zero-fill. Only allowed for UIO_READ,
143 * for obvious reasons.
146 uiomovez(size_t n, struct uio *uio)
152 KASSERT(uio->uio_rw == UIO_READ, ("uiomovez: mode"));
153 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
156 while (n > 0 && uio->uio_resid) {
167 switch (uio->uio_segflg) {
169 error = copyout(ZeroPage, iov->iov_base, cnt);
174 bzero(iov->iov_base, cnt);
179 iov->iov_base = (char *)iov->iov_base + cnt;
181 uio->uio_resid -= cnt;
182 uio->uio_offset += cnt;
189 * Wrapper for uiomove() that validates the arguments against a known-good
193 uiomove_frombuf(void *buf, size_t buflen, struct uio *uio)
197 offset = (size_t)uio->uio_offset;
198 if ((off_t)offset != uio->uio_offset)
200 if (buflen == 0 || offset >= buflen)
202 return (uiomove((char *)buf + offset, buflen - offset, uio));
206 * Give next character to user as result of read.
209 ureadc(int c, struct uio *uio)
215 if (uio->uio_iovcnt == 0 || uio->uio_resid == 0)
218 if (iov->iov_len == 0) {
223 switch (uio->uio_segflg) {
226 if (subyte(iov->iov_base, c) < 0)
231 iov_base = iov->iov_base;
233 iov->iov_base = iov_base;
239 iov->iov_base = (char *)iov->iov_base + 1;
247 * General routine to allocate a hash table. Make the hash table size a
248 * power of 2 greater or equal to the number of elements requested, and
249 * store the masking value in *hashmask.
252 hashinit(int elements, struct malloc_type *type, u_long *hashmask)
255 LIST_HEAD(generic, generic) *hashtbl;
259 panic("hashinit: bad elements");
260 for (hashsize = 2; hashsize < elements; hashsize <<= 1)
262 hashtbl = kmalloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
263 for (i = 0; i < hashsize; i++)
264 LIST_INIT(&hashtbl[i]);
265 *hashmask = hashsize - 1;
270 * This is a newer version which allocates a hash table of structures.
272 * The returned array will be zero'd. The caller is responsible for
273 * initializing the structures.
276 hashinit_ext(int elements, size_t size, struct malloc_type *type,
283 panic("hashinit: bad elements");
284 for (hashsize = 2; hashsize < elements; hashsize <<= 1)
286 hashtbl = kmalloc((size_t)hashsize * size, type, M_WAITOK | M_ZERO);
287 *hashmask = hashsize - 1;
291 static int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531, 2039,
292 2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143, 6653,
293 7159, 7673, 8191, 12281, 16381, 24571, 32749 };
294 #define NPRIMES NELEM(primes)
297 * General routine to allocate a prime number sized hash table.
300 phashinit(int elements, struct malloc_type *type, u_long *nentries)
303 LIST_HEAD(generic, generic) *hashtbl;
307 panic("phashinit: bad elements");
308 for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
312 hashsize = primes[i];
314 hashsize = primes[i - 1];
315 hashtbl = kmalloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
316 for (i = 0; i < hashsize; i++)
317 LIST_INIT(&hashtbl[i]);
318 *nentries = hashsize;
323 * This is a newer version which allocates a hash table of structures
324 * in a prime-number size.
326 * The returned array will be zero'd. The caller is responsible for
327 * initializing the structures.
330 phashinit_ext(int elements, size_t size, struct malloc_type *type,
338 panic("phashinit: bad elements");
339 for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
343 hashsize = primes[i];
345 hashsize = primes[i - 1];
346 hashtbl = kmalloc((size_t)hashsize * size, type, M_WAITOK | M_ZERO);
347 *nentries = hashsize;
352 * Copyin an iovec. If the iovec array fits, use the preallocated small
353 * iovec structure. If it is too big, dynamically allocate an iovec array
354 * of sufficient size.
359 iovec_copyin(struct iovec *uiov, struct iovec **kiov, struct iovec *siov,
360 size_t iov_cnt, size_t *iov_len)
366 if (iov_cnt > UIO_MAXIOV)
368 if (iov_cnt > UIO_SMALLIOV) {
369 MALLOC(*kiov, struct iovec *, sizeof(struct iovec) * iov_cnt,
374 error = copyin(uiov, *kiov, iov_cnt * sizeof(struct iovec));
377 for (i = 0, iovp = *kiov; i < iov_cnt; i++, iovp++) {
379 * Check for both *iov_len overflows and out of
380 * range iovp->iov_len's. We limit to the
381 * capabilities of signed integers.
383 * GCC4 - overflow check opt requires assign/test.
385 len = *iov_len + iovp->iov_len;
393 * From userland disallow iovec's which exceed the sized size
394 * limit as the system calls return ssize_t.
396 * NOTE: Internal kernel interfaces can handle the unsigned
399 if (error == 0 && (ssize_t)*iov_len < 0)
403 iovec_free(kiov, siov);
409 * Copyright (c) 2004 Alan L. Cox <alc@cs.rice.edu>
410 * Copyright (c) 1982, 1986, 1991, 1993
411 * The Regents of the University of California. All rights reserved.
412 * (c) UNIX System Laboratories, Inc.
413 * All or some portions of this file are derived from material licensed
414 * to the University of California by American Telephone and Telegraph
415 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
416 * the permission of UNIX System Laboratories, Inc.
418 * Redistribution and use in source and binary forms, with or without
419 * modification, are permitted provided that the following conditions
421 * 1. Redistributions of source code must retain the above copyright
422 * notice, this list of conditions and the following disclaimer.
423 * 2. Redistributions in binary form must reproduce the above copyright
424 * notice, this list of conditions and the following disclaimer in the
425 * documentation and/or other materials provided with the distribution.
426 * 4. Neither the name of the University nor the names of its contributors
427 * may be used to endorse or promote products derived from this software
428 * without specific prior written permission.
430 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
431 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
432 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
433 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
434 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
435 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
436 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
437 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
438 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
439 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
442 * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94
443 * $FreeBSD: src/sys/i386/i386/uio_machdep.c,v 1.1 2004/03/21 20:28:36 alc Exp $
447 * Implement uiomove(9) from physical memory using lwbuf's to reduce
448 * the creation and destruction of ephemeral mappings.
451 uiomove_fromphys(vm_page_t *ma, vm_offset_t offset, size_t n, struct uio *uio)
453 struct lwbuf lwb_cache;
455 struct thread *td = curthread;
458 vm_offset_t page_offset;
464 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
465 ("uiomove_fromphys: mode"));
466 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
467 ("uiomove_fromphys proc"));
470 save = td->td_flags & TDF_DEADLKTREAT;
471 td->td_flags |= TDF_DEADLKTREAT;
474 while (n > 0 && uio->uio_resid) {
484 page_offset = offset & PAGE_MASK;
485 cnt = min(cnt, PAGE_SIZE - page_offset);
486 m = ma[offset >> PAGE_SHIFT];
487 lwb = lwbuf_alloc(m, &lwb_cache);
488 cp = (char *)lwbuf_kva(lwb) + page_offset;
489 switch (uio->uio_segflg) {
492 * note: removed uioyield (it was the wrong place to
495 if (uio->uio_rw == UIO_READ)
496 error = copyout(cp, iov->iov_base, cnt);
498 error = copyin(iov->iov_base, cp, cnt);
505 if (uio->uio_rw == UIO_READ)
506 bcopy(cp, iov->iov_base, cnt);
508 bcopy(iov->iov_base, cp, cnt);
514 iov->iov_base = (char *)iov->iov_base + cnt;
516 uio->uio_resid -= cnt;
517 uio->uio_offset += cnt;
524 td->td_flags &= ~TDF_DEADLKTREAT;