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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 1.18 2004/07/27 13:50:15 hmp 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/vnode.h>
53 #include <machine/limits.h>
56 #include <vm/vm_page.h>
57 #include <vm/vm_map.h>
60 * UIO_READ: copy the kernelspace cp to the user or kernelspace UIO
61 * UIO_WRITE: copy the user or kernelspace UIO to cp
63 * For userspace UIO's, uio_td must be the current thread.
66 uiomove(caddr_t cp, int n, struct uio *uio)
72 int baseticks = ticks;
74 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
76 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
80 save = curproc->p_flag & P_DEADLKTREAT;
81 curproc->p_flag |= P_DEADLKTREAT;
84 while (n > 0 && uio->uio_resid) {
95 switch (uio->uio_segflg) {
98 if (ticks - baseticks >= hogticks) {
102 if (uio->uio_rw == UIO_READ)
103 error = copyout(cp, iov->iov_base, cnt);
105 error = copyin(iov->iov_base, cp, cnt);
111 if (uio->uio_rw == UIO_READ)
112 bcopy((caddr_t)cp, iov->iov_base, cnt);
114 bcopy(iov->iov_base, (caddr_t)cp, cnt);
119 iov->iov_base += cnt;
121 uio->uio_resid -= cnt;
122 uio->uio_offset += cnt;
127 curproc->p_flag = (curproc->p_flag & ~P_DEADLKTREAT) | save;
131 * Wrapper for uiomove() that validates the arguments against a known-good
132 * kernel buffer. Currently, uiomove accepts a signed (n) argument, which
133 * is almost definitely a bad thing, so we catch that here as well. We
134 * return a runtime failure, but it might be desirable to generate a runtime
135 * assertion failure instead.
138 uiomove_frombuf(void *buf, int buflen, struct uio *uio)
140 unsigned int offset, n;
142 if (uio->uio_offset < 0 || uio->uio_resid < 0 ||
143 (offset = uio->uio_offset) != uio->uio_offset)
145 if (buflen <= 0 || offset >= buflen)
147 if ((n = buflen - offset) > INT_MAX)
149 return (uiomove((char *)buf + offset, n, uio));
154 uiomoveco(cp, n, uio, obj)
158 struct vm_object *obj;
163 int baseticks = ticks;
165 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
166 ("uiomoveco: mode"));
167 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
170 while (n > 0 && uio->uio_resid) {
181 switch (uio->uio_segflg) {
184 if (ticks - baseticks >= hogticks) {
188 if (uio->uio_rw == UIO_READ) {
189 #ifdef ENABLE_VFS_IOOPT
190 if (vfs_ioopt && ((cnt & PAGE_MASK) == 0) &&
191 ((((intptr_t) iov->iov_base) & PAGE_MASK) == 0) &&
192 ((uio->uio_offset & PAGE_MASK) == 0) &&
193 ((((intptr_t) cp) & PAGE_MASK) == 0)) {
194 error = vm_uiomove(&curproc->p_vmspace->vm_map, obj,
195 uio->uio_offset, cnt,
196 (vm_offset_t) iov->iov_base, NULL);
200 error = copyout(cp, iov->iov_base, cnt);
203 error = copyin(iov->iov_base, cp, cnt);
210 if (uio->uio_rw == UIO_READ)
211 bcopy((caddr_t)cp, iov->iov_base, cnt);
213 bcopy(iov->iov_base, (caddr_t)cp, cnt);
218 iov->iov_base += cnt;
220 uio->uio_resid -= cnt;
221 uio->uio_offset += cnt;
228 #ifdef ENABLE_VFS_IOOPT
231 uioread(n, uio, obj, nread)
234 struct vm_object *obj;
241 int baseticks = ticks;
249 while (n > 0 && uio->uio_resid) {
260 if ((uio->uio_segflg == UIO_USERSPACE) &&
261 ((((intptr_t) iov->iov_base) & PAGE_MASK) == 0) &&
262 ((uio->uio_offset & PAGE_MASK) == 0) ) {
269 if (ticks - baseticks >= hogticks) {
273 error = vm_uiomove(&curproc->p_vmspace->vm_map, obj,
274 uio->uio_offset, cnt,
275 (vm_offset_t) iov->iov_base, &npagesmoved);
277 if (npagesmoved == 0)
280 tcnt = npagesmoved * PAGE_SIZE;
286 iov->iov_base += cnt;
288 uio->uio_resid -= cnt;
289 uio->uio_offset += cnt;
302 * Give next character to user as result of read.
312 if (uio->uio_iovcnt == 0 || uio->uio_resid == 0)
315 if (iov->iov_len == 0) {
320 switch (uio->uio_segflg) {
323 if (subyte(iov->iov_base, c) < 0)
342 * General routine to allocate a hash table. Make the hash table size a
343 * power of 2 greater or equal to the number of elements requested, and
344 * store the masking value in *hashmask.
347 hashinit(elements, type, hashmask)
349 struct malloc_type *type;
353 LIST_HEAD(generic, generic) *hashtbl;
357 panic("hashinit: bad elements");
358 for (hashsize = 2; hashsize < elements; hashsize <<= 1)
360 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
361 for (i = 0; i < hashsize; i++)
362 LIST_INIT(&hashtbl[i]);
363 *hashmask = hashsize - 1;
367 static int primes[] = { 1, 13, 31, 61, 127, 251, 509, 761, 1021, 1531, 2039,
368 2557, 3067, 3583, 4093, 4603, 5119, 5623, 6143, 6653,
369 7159, 7673, 8191, 12281, 16381, 24571, 32749 };
370 #define NPRIMES (sizeof(primes) / sizeof(primes[0]))
373 * General routine to allocate a prime number sized hash table.
376 phashinit(elements, type, nentries)
378 struct malloc_type *type;
382 LIST_HEAD(generic, generic) *hashtbl;
386 panic("phashinit: bad elements");
387 for (i = 1, hashsize = primes[1]; hashsize <= elements;) {
391 hashsize = primes[i];
393 hashsize = primes[i - 1];
394 hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
395 for (i = 0; i < hashsize; i++)
396 LIST_INIT(&hashtbl[i]);
397 *nentries = hashsize;
402 * Copyin an iovec. If the iovec array fits, use the preallocated small
403 * iovec structure. If it is too big, dynamically allocate an iovec array
404 * of sufficient size.
407 iovec_copyin(struct iovec *uiov, struct iovec **kiov, struct iovec *siov,
408 size_t iov_cnt, size_t *iov_len)
413 if (iov_cnt >= UIO_MAXIOV)
415 if (iov_cnt >= UIO_SMALLIOV) {
416 MALLOC(*kiov, struct iovec *, sizeof(struct iovec) * iov_cnt,
421 error = copyin(uiov, *kiov, iov_cnt * sizeof(struct iovec));
425 for (i = 0, iovp = *kiov; i < iov_cnt; i++, iovp++)
426 *iov_len += iovp->iov_len;
430 iovec_free(kiov, siov);