xref: /freebsd/lib/libthr/thread/thr_attr.c (revision a03411e84728e9b267056fd31c7d1d9d1dc1b01e)
1 /*-
2  * SPDX-License-Identifier: BSD-4-Clause
3  *
4  * Copyright (c) 2003 Craig Rodrigues <rodrigc@attbi.com>.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by Craig Rodrigues.
18  * 4. Neither the name of the author nor the names of any co-contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY CRAIG RODRIGUES AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  */
35 
36 /*
37  * Copyright (c) 1998 Daniel Eischen <eischen@vigrid.com>.
38  * Copyright (C) 2001 Jason Evans <jasone@freebsd.org>.
39  * Copyright (c) 2002,2003 Alexey Zelkin <phantom@FreeBSD.org>
40  * All rights reserved.
41  *
42  * Redistribution and use in source and binary forms, with or without
43  * modification, are permitted provided that the following conditions
44  * are met:
45  * 1. Redistributions of source code must retain the above copyright
46  *    notice(s), this list of conditions and the following disclaimer
47  *    unmodified other than the allowable addition of one or more
48  *    copyright notices.
49  * 2. Redistributions in binary form must reproduce the above copyright
50  *    notice(s), this list of conditions and the following disclaimer in
51  *    the documentation and/or other materials provided with the
52  *    distribution.
53  *
54  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
55  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
57  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
58  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
59  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
60  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
61  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
62  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
63  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
64  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
65  */
66 
67 /*
68  * Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
69  * All rights reserved.
70  *
71  * Redistribution and use in source and binary forms, with or without
72  * modification, are permitted provided that the following conditions
73  * are met:
74  * 1. Redistributions of source code must retain the above copyright
75  *    notice, this list of conditions and the following disclaimer.
76  * 2. Redistributions in binary form must reproduce the above copyright
77  *    notice, this list of conditions and the following disclaimer in the
78  *    documentation and/or other materials provided with the distribution.
79  * 3. Neither the name of the author nor the names of any co-contributors
80  *    may be used to endorse or promote products derived from this software
81  *    without specific prior written permission.
82  *
83  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
84  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
85  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
86  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
87  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
88  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
89  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
90  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
91  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
92  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
93  * SUCH DAMAGE.
94  */
95 
96 #include <sys/cdefs.h>
97 #include "namespace.h"
98 #include <errno.h>
99 #include <pthread.h>
100 #include <stdlib.h>
101 #include <string.h>
102 #include <pthread_np.h>
103 #include <sys/sysctl.h>
104 #include "un-namespace.h"
105 
106 #include "thr_private.h"
107 
108 static size_t	_get_kern_cpuset_size(void);
109 
110 __weak_reference(_thr_attr_destroy, _pthread_attr_destroy);
111 __weak_reference(_thr_attr_destroy, pthread_attr_destroy);
112 
113 int
114 _thr_attr_destroy(pthread_attr_t *attr)
115 {
116 
117 	if (attr == NULL || *attr == NULL)
118 		return (EINVAL);
119 
120 	free((*attr)->cpuset);
121 	free(*attr);
122 	*attr = NULL;
123 	return (0);
124 }
125 
126 __weak_reference(_thr_attr_get_np, pthread_attr_get_np);
127 __weak_reference(_thr_attr_get_np, _pthread_attr_get_np);
128 
129 int
130 _thr_attr_get_np(pthread_t pthread, pthread_attr_t *dstattr)
131 {
132 	struct pthread_attr *dst;
133 	struct pthread *curthread;
134 	cpuset_t *cpuset;
135 	size_t kern_size;
136 	int error;
137 
138 	if (pthread == NULL || dstattr == NULL || (dst = *dstattr) == NULL)
139 		return (EINVAL);
140 
141 	kern_size = _get_kern_cpuset_size();
142 	if (dst->cpuset == NULL) {
143 		if ((cpuset = malloc(kern_size)) == NULL)
144 			return (ENOMEM);
145 	} else
146 		cpuset = dst->cpuset;
147 
148 	curthread = _get_curthread();
149 	/* Arg 0 is to include dead threads. */
150 	if ((error = _thr_find_thread(curthread, pthread, 0)) != 0)
151 		goto free_and_exit;
152 
153 	error = cpuset_getaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TID, TID(pthread),
154 	    kern_size, cpuset);
155 	if (error == -1) {
156 		THR_THREAD_UNLOCK(curthread, pthread);
157 		error = errno;
158 		goto free_and_exit;
159 	}
160 
161 	/*
162 	 * From this point on, we can't fail, so we can start modifying 'dst'.
163 	 */
164 
165 	*dst = pthread->attr;
166 	if ((pthread->flags & THR_FLAGS_DETACHED) != 0)
167 		dst->flags |= PTHREAD_DETACHED;
168 
169 	THR_THREAD_UNLOCK(curthread, pthread);
170 
171 	dst->cpuset = cpuset;
172 	dst->cpusetsize = kern_size;
173 	return (0);
174 
175 free_and_exit:
176 	if (dst->cpuset == NULL)
177 		free(cpuset);
178 	return (error);
179 }
180 
181 __weak_reference(_thr_attr_getdetachstate, pthread_attr_getdetachstate);
182 __weak_reference(_thr_attr_getdetachstate, _pthread_attr_getdetachstate);
183 
184 int
185 _thr_attr_getdetachstate(const pthread_attr_t *attr, int *detachstate)
186 {
187 
188 	if (attr == NULL || *attr == NULL || detachstate == NULL)
189 		return (EINVAL);
190 
191 	if (((*attr)->flags & PTHREAD_DETACHED) != 0)
192 		*detachstate = PTHREAD_CREATE_DETACHED;
193 	else
194 		*detachstate = PTHREAD_CREATE_JOINABLE;
195 	return (0);
196 }
197 
198 __weak_reference(_thr_attr_getguardsize, pthread_attr_getguardsize);
199 __weak_reference(_thr_attr_getguardsize, _pthread_attr_getguardsize);
200 
201 int
202 _thr_attr_getguardsize(const pthread_attr_t * __restrict attr,
203     size_t * __restrict guardsize)
204 {
205 
206 	if (attr == NULL || *attr == NULL || guardsize == NULL)
207 		return (EINVAL);
208 
209 	*guardsize = (*attr)->guardsize_attr;
210 	return (0);
211 }
212 
213 __weak_reference(_thr_attr_getinheritsched, pthread_attr_getinheritsched);
214 __weak_reference(_thr_attr_getinheritsched, _pthread_attr_getinheritsched);
215 
216 int
217 _thr_attr_getinheritsched(const pthread_attr_t * __restrict attr,
218     int * __restrict sched_inherit)
219 {
220 
221 	if (attr == NULL || *attr == NULL)
222 		return (EINVAL);
223 
224 	*sched_inherit = (*attr)->sched_inherit;
225 	return (0);
226 }
227 
228 __weak_reference(_thr_attr_getschedparam, pthread_attr_getschedparam);
229 __weak_reference(_thr_attr_getschedparam, _pthread_attr_getschedparam);
230 
231 int
232 _thr_attr_getschedparam(const pthread_attr_t * __restrict attr,
233     struct sched_param * __restrict param)
234 {
235 
236 	if (attr == NULL || *attr == NULL || param == NULL)
237 		return (EINVAL);
238 
239 	param->sched_priority = (*attr)->prio;
240 	return (0);
241 }
242 
243 __weak_reference(_thr_attr_getschedpolicy, pthread_attr_getschedpolicy);
244 __weak_reference(_thr_attr_getschedpolicy, _pthread_attr_getschedpolicy);
245 
246 int
247 _thr_attr_getschedpolicy(const pthread_attr_t * __restrict attr,
248     int * __restrict policy)
249 {
250 
251 	if (attr == NULL || *attr == NULL || policy == NULL)
252 		return (EINVAL);
253 
254 	*policy = (*attr)->sched_policy;
255 	return (0);
256 }
257 
258 __weak_reference(_thr_attr_getscope, pthread_attr_getscope);
259 __weak_reference(_thr_attr_getscope, _pthread_attr_getscope);
260 
261 int
262 _thr_attr_getscope(const pthread_attr_t * __restrict attr,
263     int * __restrict contentionscope)
264 {
265 
266 	if (attr == NULL || *attr == NULL || contentionscope == NULL)
267 		return (EINVAL);
268 
269 	*contentionscope = ((*attr)->flags & PTHREAD_SCOPE_SYSTEM) != 0 ?
270 	    PTHREAD_SCOPE_SYSTEM : PTHREAD_SCOPE_PROCESS;
271 	return (0);
272 }
273 
274 __weak_reference(_pthread_attr_getstack, pthread_attr_getstack);
275 
276 int
277 _pthread_attr_getstack(const pthread_attr_t * __restrict attr,
278     void ** __restrict stackaddr, size_t * __restrict stacksize)
279 {
280 
281 	if (attr == NULL || *attr == NULL || stackaddr == NULL ||
282 	    stacksize == NULL)
283 		return (EINVAL);
284 
285 	*stackaddr = (*attr)->stackaddr_attr;
286 	*stacksize = (*attr)->stacksize_attr;
287 	return (0);
288 }
289 
290 __weak_reference(_thr_attr_getstackaddr, pthread_attr_getstackaddr);
291 __weak_reference(_thr_attr_getstackaddr, _pthread_attr_getstackaddr);
292 
293 int
294 _thr_attr_getstackaddr(const pthread_attr_t *attr, void **stackaddr)
295 {
296 
297 	if (attr == NULL || *attr == NULL || stackaddr == NULL)
298 		return (EINVAL);
299 
300 	*stackaddr = (*attr)->stackaddr_attr;
301 	return (0);
302 }
303 
304 __weak_reference(_thr_attr_getstacksize, pthread_attr_getstacksize);
305 __weak_reference(_thr_attr_getstacksize, _pthread_attr_getstacksize);
306 
307 int
308 _thr_attr_getstacksize(const pthread_attr_t * __restrict attr,
309     size_t * __restrict stacksize)
310 {
311 
312 	if (attr == NULL || *attr == NULL || stacksize == NULL)
313 		return (EINVAL);
314 
315 	*stacksize = (*attr)->stacksize_attr;
316 	return (0);
317 }
318 
319 __weak_reference(_thr_attr_init, pthread_attr_init);
320 __weak_reference(_thr_attr_init, _pthread_attr_init);
321 
322 int
323 _thr_attr_init(pthread_attr_t *attr)
324 {
325 	pthread_attr_t pattr;
326 
327 	_thr_check_init();
328 
329 	if ((pattr = malloc(sizeof(*pattr))) == NULL)
330 		return (ENOMEM);
331 
332 	memcpy(pattr, &_pthread_attr_default, sizeof(*pattr));
333 	*attr = pattr;
334 	return (0);
335 }
336 
337 __weak_reference(_pthread_attr_setcreatesuspend_np,			\
338     pthread_attr_setcreatesuspend_np);
339 
340 int
341 _pthread_attr_setcreatesuspend_np(pthread_attr_t *attr)
342 {
343 
344 	if (attr == NULL || *attr == NULL)
345 		return (EINVAL);
346 
347 	(*attr)->suspend = THR_CREATE_SUSPENDED;
348 	return (0);
349 }
350 
351 __weak_reference(_thr_attr_setdetachstate, pthread_attr_setdetachstate);
352 __weak_reference(_thr_attr_setdetachstate, _pthread_attr_setdetachstate);
353 
354 int
355 _thr_attr_setdetachstate(pthread_attr_t *attr, int detachstate)
356 {
357 
358 	if (attr == NULL || *attr == NULL ||
359 	    (detachstate != PTHREAD_CREATE_DETACHED &&
360 	    detachstate != PTHREAD_CREATE_JOINABLE))
361 		return (EINVAL);
362 
363 	if (detachstate == PTHREAD_CREATE_DETACHED)
364 		(*attr)->flags |= PTHREAD_DETACHED;
365 	else
366 		(*attr)->flags &= ~PTHREAD_DETACHED;
367 	return (0);
368 }
369 
370 __weak_reference(_thr_attr_setguardsize, pthread_attr_setguardsize);
371 __weak_reference(_thr_attr_setguardsize, _pthread_attr_setguardsize);
372 
373 int
374 _thr_attr_setguardsize(pthread_attr_t *attr, size_t guardsize)
375 {
376 
377 	if (attr == NULL || *attr == NULL)
378 		return (EINVAL);
379 
380 	(*attr)->guardsize_attr = guardsize;
381 	return (0);
382 }
383 
384 __weak_reference(_thr_attr_setinheritsched, pthread_attr_setinheritsched);
385 __weak_reference(_thr_attr_setinheritsched, _pthread_attr_setinheritsched);
386 
387 int
388 _thr_attr_setinheritsched(pthread_attr_t *attr, int sched_inherit)
389 {
390 
391 	if (attr == NULL || *attr == NULL ||
392 	    (sched_inherit != PTHREAD_INHERIT_SCHED &&
393 	    sched_inherit != PTHREAD_EXPLICIT_SCHED))
394 		return (EINVAL);
395 
396 	(*attr)->sched_inherit = sched_inherit;
397 	return (0);
398 }
399 
400 __weak_reference(_thr_attr_setschedparam, pthread_attr_setschedparam);
401 __weak_reference(_thr_attr_setschedparam, _pthread_attr_setschedparam);
402 
403 int
404 _thr_attr_setschedparam(pthread_attr_t * __restrict attr,
405     const struct sched_param * __restrict param)
406 {
407 	int policy;
408 
409 	if (attr == NULL || *attr == NULL || param == NULL)
410 		return (EINVAL);
411 
412 	policy = (*attr)->sched_policy;
413 
414 	if (policy == SCHED_FIFO || policy == SCHED_RR) {
415 		if (param->sched_priority < _thr_priorities[policy-1].pri_min ||
416 		    param->sched_priority > _thr_priorities[policy-1].pri_max)
417 			return (EINVAL);
418 	} else {
419 		/*
420 		 * Ignore it for SCHED_OTHER now, patches for glib ports
421 		 * are wrongly using M:N thread library's internal macro
422 		 * THR_MIN_PRIORITY and THR_MAX_PRIORITY.
423 		 */
424 	}
425 
426 	(*attr)->prio = param->sched_priority;
427 
428 	return (0);
429 }
430 
431 __weak_reference(_thr_attr_setschedpolicy, pthread_attr_setschedpolicy);
432 __weak_reference(_thr_attr_setschedpolicy, _pthread_attr_setschedpolicy);
433 
434 int
435 _thr_attr_setschedpolicy(pthread_attr_t *attr, int policy)
436 {
437 
438 	if (attr == NULL || *attr == NULL ||
439 	    policy < SCHED_FIFO || policy > SCHED_RR)
440 		return (EINVAL);
441 
442 	(*attr)->sched_policy = policy;
443 	(*attr)->prio = _thr_priorities[policy-1].pri_default;
444 	return (0);
445 }
446 
447 __weak_reference(_thr_attr_setscope, pthread_attr_setscope);
448 __weak_reference(_thr_attr_setscope, _pthread_attr_setscope);
449 
450 int
451 _thr_attr_setscope(pthread_attr_t *attr, int contentionscope)
452 {
453 
454 	if (attr == NULL || *attr == NULL ||
455 	    (contentionscope != PTHREAD_SCOPE_PROCESS &&
456 	    contentionscope != PTHREAD_SCOPE_SYSTEM))
457 		return (EINVAL);
458 
459 	if (contentionscope == PTHREAD_SCOPE_SYSTEM)
460 		(*attr)->flags |= PTHREAD_SCOPE_SYSTEM;
461 	else
462 		(*attr)->flags &= ~PTHREAD_SCOPE_SYSTEM;
463 	return (0);
464 }
465 
466 __weak_reference(_pthread_attr_setstack, pthread_attr_setstack);
467 
468 int
469 _pthread_attr_setstack(pthread_attr_t *attr, void *stackaddr,
470     size_t stacksize)
471 {
472 
473 	if (attr == NULL || *attr == NULL || stackaddr == NULL ||
474 	    stacksize < PTHREAD_STACK_MIN)
475 		return (EINVAL);
476 
477 	(*attr)->stackaddr_attr = stackaddr;
478 	(*attr)->stacksize_attr = stacksize;
479 	return (0);
480 }
481 
482 __weak_reference(_thr_attr_setstackaddr, pthread_attr_setstackaddr);
483 __weak_reference(_thr_attr_setstackaddr, _pthread_attr_setstackaddr);
484 
485 int
486 _thr_attr_setstackaddr(pthread_attr_t *attr, void *stackaddr)
487 {
488 
489 	if (attr == NULL || *attr == NULL || stackaddr == NULL)
490 		return (EINVAL);
491 
492 	(*attr)->stackaddr_attr = stackaddr;
493 	return (0);
494 }
495 
496 __weak_reference(_thr_attr_setstacksize, pthread_attr_setstacksize);
497 __weak_reference(_thr_attr_setstacksize, _pthread_attr_setstacksize);
498 
499 int
500 _thr_attr_setstacksize(pthread_attr_t *attr, size_t stacksize)
501 {
502 
503 	if (attr == NULL || *attr == NULL || stacksize < PTHREAD_STACK_MIN)
504 		return (EINVAL);
505 
506 	(*attr)->stacksize_attr = stacksize;
507 	return (0);
508 }
509 
510 static size_t
511 _get_kern_cpuset_size(void)
512 {
513 	static int kern_cpuset_size = 0;
514 
515 	if (kern_cpuset_size == 0) {
516 		size_t len;
517 
518 		len = sizeof(kern_cpuset_size);
519 		if (sysctlbyname("kern.sched.cpusetsizemin", &kern_cpuset_size,
520 		    &len, NULL, 0) != 0 &&
521 		    sysctlbyname("kern.sched.cpusetsize", &kern_cpuset_size,
522 		    &len, NULL, 0) != 0)
523 			PANIC("failed to get sysctl kern.sched.cpusetsize");
524 	}
525 
526 	return (kern_cpuset_size);
527 }
528 
529 __weak_reference(_pthread_attr_setaffinity_np, pthread_attr_setaffinity_np);
530 
531 int
532 _pthread_attr_setaffinity_np(pthread_attr_t *pattr, size_t cpusetsize,
533     const cpuset_t *cpusetp)
534 {
535 	pthread_attr_t attr;
536 	size_t kern_size;
537 
538 	if (pattr == NULL || (attr = (*pattr)) == NULL)
539 		return (EINVAL);
540 
541 	if (cpusetsize == 0 || cpusetp == NULL) {
542 		if (attr->cpuset != NULL) {
543 			free(attr->cpuset);
544 			attr->cpuset = NULL;
545 			attr->cpusetsize = 0;
546 		}
547 		return (0);
548 	}
549 
550 	kern_size = _get_kern_cpuset_size();
551 	/* Kernel rejects small set, we check it here too. */
552 	if (cpusetsize < kern_size)
553 		return (ERANGE);
554 	if (cpusetsize > kern_size) {
555 		/* Kernel checks invalid bits, we check it here too. */
556 		size_t i;
557 
558 		for (i = kern_size; i < cpusetsize; ++i)
559 			if (((const char *)cpusetp)[i] != 0)
560 				return (EINVAL);
561 	}
562 	if (attr->cpuset == NULL) {
563 		attr->cpuset = malloc(kern_size);
564 		if (attr->cpuset == NULL)
565 			return (errno);
566 		attr->cpusetsize = kern_size;
567 	}
568 	memcpy(attr->cpuset, cpusetp, kern_size);
569 	return (0);
570 }
571 
572 __weak_reference(_pthread_attr_getaffinity_np, pthread_attr_getaffinity_np);
573 
574 int
575 _pthread_attr_getaffinity_np(const pthread_attr_t *pattr, size_t cpusetsize,
576     cpuset_t *cpusetp)
577 {
578 	pthread_attr_t attr;
579 
580 	if (pattr == NULL || (attr = (*pattr)) == NULL)
581 		return (EINVAL);
582 
583 	/* Kernel rejects small set, we check it here too. */
584 	size_t kern_size = _get_kern_cpuset_size();
585 	if (cpusetsize < kern_size)
586 		return (ERANGE);
587 	if (attr->cpuset != NULL)
588 		memcpy(cpusetp, attr->cpuset, MIN(cpusetsize,
589 		    attr->cpusetsize));
590 	else
591 		memset(cpusetp, -1, kern_size);
592 	if (cpusetsize > kern_size)
593 		memset(((char *)cpusetp) + kern_size, 0,
594 		    cpusetsize - kern_size);
595 	return (0);
596 }
597