kern_umtx.c revision 140102
1/*-
2 * Copyright (c) 2004, David Xu <davidxu@freebsd.org>
3 * Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice unmodified, this list of conditions, and the following
11 *    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 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: head/sys/kern/kern_umtx.c 140102 2005-01-12 05:55:52Z davidxu $");
30
31#include <sys/param.h>
32#include <sys/kernel.h>
33#include <sys/limits.h>
34#include <sys/lock.h>
35#include <sys/malloc.h>
36#include <sys/mutex.h>
37#include <sys/proc.h>
38#include <sys/sysent.h>
39#include <sys/systm.h>
40#include <sys/sysproto.h>
41#include <sys/eventhandler.h>
42#include <sys/thr.h>
43#include <sys/umtx.h>
44
45#include <vm/vm.h>
46#include <vm/vm_param.h>
47#include <vm/pmap.h>
48#include <vm/vm_map.h>
49#include <vm/vm_object.h>
50
51#define UMTX_PRIVATE	0
52#define UMTX_SHARED	1
53
54#define UMTX_STATIC_SHARED
55
56struct umtx_key {
57	int	type;
58	union {
59		struct {
60			vm_object_t	object;
61			long		offset;
62		} shared;
63		struct {
64			struct umtx	*umtx;
65			long		pid;
66		} private;
67		struct {
68			void		*ptr;
69			long		word;
70		} both;
71	} info;
72};
73
74struct umtx_q {
75	LIST_ENTRY(umtx_q)	uq_next;	/* Linked list for the hash. */
76	struct umtx_key		uq_key;		/* Umtx key. */
77	struct thread		*uq_thread;	/* The thread waits on. */
78	LIST_ENTRY(umtx_q)	uq_rqnext;	/* Linked list for requeuing. */
79	vm_offset_t		uq_addr;	/* Umtx's virtual address. */
80};
81
82LIST_HEAD(umtx_head, umtx_q);
83struct umtxq_chain {
84	struct mtx		uc_lock;	/* Lock for this chain. */
85	struct umtx_head	uc_queue;	/* List of sleep queues. */
86#define	UCF_BUSY		0x01
87#define	UCF_WANT		0x02
88	int			uc_flags;
89};
90
91#define	GOLDEN_RATIO_PRIME	2654404609U
92#define	UMTX_CHAINS		128
93#define	UMTX_SHIFTS		(__WORD_BIT - 7)
94
95static struct umtxq_chain umtxq_chains[UMTX_CHAINS];
96static MALLOC_DEFINE(M_UMTX, "umtx", "UMTX queue memory");
97
98static void umtxq_init_chains(void *);
99static int umtxq_hash(struct umtx_key *key);
100static struct mtx *umtxq_mtx(int chain);
101static void umtxq_lock(struct umtx_key *key);
102static void umtxq_unlock(struct umtx_key *key);
103static void umtxq_busy(struct umtx_key *key);
104static void umtxq_unbusy(struct umtx_key *key);
105static void umtxq_insert(struct umtx_q *uq);
106static void umtxq_remove(struct umtx_q *uq);
107static int umtxq_sleep(struct thread *td, struct umtx_key *key,
108	int prio, const char *wmesg, int timo);
109static int umtxq_count(struct umtx_key *key);
110static int umtxq_signal(struct umtx_key *key, int nr_wakeup);
111#ifdef UMTX_DYNAMIC_SHARED
112static void fork_handler(void *arg, struct proc *p1, struct proc *p2,
113	int flags);
114#endif
115static int umtx_key_match(const struct umtx_key *k1, const struct umtx_key *k2);
116static int umtx_key_get(struct thread *td, struct umtx *umtx,
117	struct umtx_key *key);
118static void umtx_key_release(struct umtx_key *key);
119
120SYSINIT(umtx, SI_SUB_EVENTHANDLER+1, SI_ORDER_MIDDLE, umtxq_init_chains, NULL);
121
122static void
123umtxq_init_chains(void *arg __unused)
124{
125	int i;
126
127	for (i = 0; i < UMTX_CHAINS; ++i) {
128		mtx_init(&umtxq_chains[i].uc_lock, "umtxq_lock", NULL,
129			 MTX_DEF | MTX_DUPOK);
130		LIST_INIT(&umtxq_chains[i].uc_queue);
131		umtxq_chains[i].uc_flags = 0;
132	}
133#ifdef UMTX_DYNAMIC_SHARED
134	EVENTHANDLER_REGISTER(process_fork, fork_handler, 0, 10000);
135#endif
136}
137
138static inline int
139umtxq_hash(struct umtx_key *key)
140{
141	unsigned n = (uintptr_t)key->info.both.ptr + key->info.both.word;
142	return (((n * GOLDEN_RATIO_PRIME) >> UMTX_SHIFTS) % UMTX_CHAINS);
143}
144
145static inline int
146umtx_key_match(const struct umtx_key *k1, const struct umtx_key *k2)
147{
148	return (k1->type == k2->type &&
149		k1->info.both.ptr == k2->info.both.ptr &&
150	        k1->info.both.word == k2->info.both.word);
151}
152
153static inline struct mtx *
154umtxq_mtx(int chain)
155{
156	return (&umtxq_chains[chain].uc_lock);
157}
158
159static inline void
160umtxq_busy(struct umtx_key *key)
161{
162	int chain = umtxq_hash(key);
163
164	mtx_assert(umtxq_mtx(chain), MA_OWNED);
165	while (umtxq_chains[chain].uc_flags & UCF_BUSY) {
166		umtxq_chains[chain].uc_flags |= UCF_WANT;
167		msleep(&umtxq_chains[chain], umtxq_mtx(chain),
168		       curthread->td_priority, "umtxq_busy", 0);
169	}
170	umtxq_chains[chain].uc_flags |= UCF_BUSY;
171}
172
173static inline void
174umtxq_unbusy(struct umtx_key *key)
175{
176	int chain = umtxq_hash(key);
177
178	mtx_assert(umtxq_mtx(chain), MA_OWNED);
179	KASSERT(umtxq_chains[chain].uc_flags & UCF_BUSY, ("not busy"));
180	umtxq_chains[chain].uc_flags &= ~UCF_BUSY;
181	if (umtxq_chains[chain].uc_flags & UCF_WANT) {
182		umtxq_chains[chain].uc_flags &= ~UCF_WANT;
183		wakeup(&umtxq_chains[chain]);
184	}
185}
186
187static inline void
188umtxq_lock(struct umtx_key *key)
189{
190	int chain = umtxq_hash(key);
191	mtx_lock(umtxq_mtx(chain));
192}
193
194static inline void
195umtxq_unlock(struct umtx_key *key)
196{
197	int chain = umtxq_hash(key);
198	mtx_unlock(umtxq_mtx(chain));
199}
200
201/*
202 * Insert a thread onto the umtx queue.
203 */
204static inline void
205umtxq_insert(struct umtx_q *uq)
206{
207	struct umtx_head *head;
208	int chain = umtxq_hash(&uq->uq_key);
209
210	mtx_assert(umtxq_mtx(chain), MA_OWNED);
211	head = &umtxq_chains[chain].uc_queue;
212	LIST_INSERT_HEAD(head, uq, uq_next);
213	uq->uq_thread->td_umtxq = uq;
214	mtx_lock_spin(&sched_lock);
215	uq->uq_thread->td_flags |= TDF_UMTXQ;
216	mtx_unlock_spin(&sched_lock);
217}
218
219/*
220 * Remove thread from the umtx queue.
221 */
222static inline void
223umtxq_remove(struct umtx_q *uq)
224{
225	mtx_assert(umtxq_mtx(umtxq_hash(&uq->uq_key)), MA_OWNED);
226	if (uq->uq_thread->td_flags & TDF_UMTXQ) {
227		LIST_REMOVE(uq, uq_next);
228		uq->uq_thread->td_umtxq = NULL;
229		/* turning off TDF_UMTXQ should be the last thing. */
230		mtx_lock_spin(&sched_lock);
231		uq->uq_thread->td_flags &= ~TDF_UMTXQ;
232		mtx_unlock_spin(&sched_lock);
233	}
234}
235
236static int
237umtxq_count(struct umtx_key *key)
238{
239	struct umtx_q *uq;
240	struct umtx_head *head;
241	int chain, count = 0;
242
243	chain = umtxq_hash(key);
244	mtx_assert(umtxq_mtx(chain), MA_OWNED);
245	head = &umtxq_chains[chain].uc_queue;
246	LIST_FOREACH(uq, head, uq_next) {
247		if (umtx_key_match(&uq->uq_key, key)) {
248			if (++count > 1)
249				break;
250		}
251	}
252	return (count);
253}
254
255static int
256umtxq_signal(struct umtx_key *key, int n_wake)
257{
258	struct umtx_q *uq, *next;
259	struct umtx_head *head;
260	struct thread *blocked = NULL;
261	int chain, ret;
262
263	ret = 0;
264	chain = umtxq_hash(key);
265	mtx_assert(umtxq_mtx(chain), MA_OWNED);
266	head = &umtxq_chains[chain].uc_queue;
267	for (uq = LIST_FIRST(head); uq; uq = next) {
268		next = LIST_NEXT(uq, uq_next);
269		if (umtx_key_match(&uq->uq_key, key)) {
270			blocked = uq->uq_thread;
271			umtxq_remove(uq);
272			wakeup(blocked);
273			if (++ret >= n_wake)
274				break;
275		}
276	}
277	return (ret);
278}
279
280static inline int
281umtxq_sleep(struct thread *td, struct umtx_key *key, int priority,
282	    const char *wmesg, int timo)
283{
284	int chain = umtxq_hash(key);
285	int error = msleep(td, umtxq_mtx(chain), priority, wmesg, timo);
286	if (error == EWOULDBLOCK)
287		error = ETIMEDOUT;
288	return (error);
289}
290
291static int
292umtx_key_get(struct thread *td, struct umtx *umtx, struct umtx_key *key)
293{
294#if defined(UMTX_DYNAMIC_SHARED) || defined(UMTX_STATIC_SHARED)
295	vm_map_t map;
296	vm_map_entry_t entry;
297	vm_pindex_t pindex;
298	vm_prot_t prot;
299	boolean_t wired;
300
301	map = &td->td_proc->p_vmspace->vm_map;
302	if (vm_map_lookup(&map, (vm_offset_t)umtx, VM_PROT_WRITE,
303	    &entry, &key->info.shared.object, &pindex, &prot,
304	    &wired) != KERN_SUCCESS) {
305		return EFAULT;
306	}
307#endif
308
309#if defined(UMTX_DYNAMIC_SHARED)
310	key->type = UMTX_SHARED;
311	key->info.shared.offset = entry->offset + entry->start -
312		(vm_offset_t)umtx;
313	/*
314	 * Add object reference, if we don't do this, a buggy application
315	 * deallocates the object, the object will be reused by other
316	 * applications, then unlock will wake wrong thread.
317	 */
318	vm_object_reference(key->info.shared.object);
319	vm_map_lookup_done(map, entry);
320#elif defined(UMTX_STATIC_SHARED)
321	if (VM_INHERIT_SHARE == entry->inheritance) {
322		key->type = UMTX_SHARED;
323		key->info.shared.offset = entry->offset + entry->start -
324			(vm_offset_t)umtx;
325		vm_object_reference(key->info.shared.object);
326	} else {
327		key->type = UMTX_PRIVATE;
328		key->info.private.umtx = umtx;
329		key->info.private.pid  = td->td_proc->p_pid;
330	}
331	vm_map_lookup_done(map, entry);
332#else
333	key->type = UMTX_PRIVATE;
334	key->info.private.umtx = umtx;
335	key->info.private.pid  = td->td_proc->p_pid;
336#endif
337	return (0);
338}
339
340static inline void
341umtx_key_release(struct umtx_key *key)
342{
343	if (key->type == UMTX_SHARED)
344		vm_object_deallocate(key->info.shared.object);
345}
346
347static inline int
348umtxq_queue_me(struct thread *td, struct umtx *umtx, struct umtx_q *uq)
349{
350	int error;
351
352	if ((error = umtx_key_get(td, umtx, &uq->uq_key)) != 0)
353		return (error);
354
355	uq->uq_addr = (vm_offset_t)umtx;
356	uq->uq_thread = td;
357	umtxq_lock(&uq->uq_key);
358	/* hmm, for condition variable, we don't need busy flag. */
359	umtxq_busy(&uq->uq_key);
360	umtxq_insert(uq);
361	umtxq_unbusy(&uq->uq_key);
362	umtxq_unlock(&uq->uq_key);
363	return (0);
364}
365
366#if defined(UMTX_DYNAMIC_SHARED)
367static void
368fork_handler(void *arg, struct proc *p1, struct proc *p2, int flags)
369{
370	vm_map_t map;
371	vm_map_entry_t entry;
372	vm_object_t object;
373	vm_pindex_t pindex;
374	vm_prot_t prot;
375	boolean_t wired;
376	struct umtx_key key;
377	LIST_HEAD(, umtx_q) workq;
378	struct umtx_q *uq;
379	struct thread *td;
380	int onq;
381
382	LIST_INIT(&workq);
383
384	/* Collect threads waiting on umtxq */
385	PROC_LOCK(p1);
386	FOREACH_THREAD_IN_PROC(p1, td) {
387		if (td->td_flags & TDF_UMTXQ) {
388			uq = td->td_umtxq;
389			if (uq)
390				LIST_INSERT_HEAD(&workq, uq, uq_rqnext);
391		}
392	}
393	PROC_UNLOCK(p1);
394
395	LIST_FOREACH(uq, &workq, uq_rqnext) {
396		map = &p1->p_vmspace->vm_map;
397		if (vm_map_lookup(&map, uq->uq_addr, VM_PROT_WRITE,
398		    &entry, &object, &pindex, &prot, &wired) != KERN_SUCCESS) {
399			continue;
400		}
401		key.type = UMTX_SHARED;
402		key.info.shared.object = object;
403		key.info.shared.offset = entry->offset + entry->start -
404			uq->uq_addr;
405		if (umtx_key_match(&key, &uq->uq_key)) {
406			vm_map_lookup_done(map, entry);
407			continue;
408		}
409
410		umtxq_lock(&uq->uq_key);
411		umtxq_busy(&uq->uq_key);
412		if (uq->uq_thread->td_flags & TDF_UMTXQ) {
413			umtxq_remove(uq);
414			onq = 1;
415		} else
416			onq = 0;
417		umtxq_unbusy(&uq->uq_key);
418		umtxq_unlock(&uq->uq_key);
419		if (onq) {
420			vm_object_deallocate(uq->uq_key.info.shared.object);
421			uq->uq_key = key;
422			umtxq_lock(&uq->uq_key);
423			umtxq_busy(&uq->uq_key);
424			umtxq_insert(uq);
425			umtxq_unbusy(&uq->uq_key);
426			umtxq_unlock(&uq->uq_key);
427			vm_object_reference(uq->uq_key.info.shared.object);
428		}
429		vm_map_lookup_done(map, entry);
430	}
431}
432#endif
433
434static int
435_do_lock(struct thread *td, struct umtx *umtx, long id, int timo)
436{
437	struct umtx_q uq;
438	intptr_t owner;
439	intptr_t old;
440	int error = 0;
441
442	/*
443	 * Care must be exercised when dealing with umtx structure.  It
444	 * can fault on any access.
445	 */
446
447	for (;;) {
448		/*
449		 * Try the uncontested case.  This should be done in userland.
450		 */
451		owner = casuptr((intptr_t *)&umtx->u_owner,
452		    UMTX_UNOWNED, id);
453
454		/* The acquire succeeded. */
455		if (owner == UMTX_UNOWNED)
456			return (0);
457
458		/* The address was invalid. */
459		if (owner == -1)
460			return (EFAULT);
461
462		/* If no one owns it but it is contested try to acquire it. */
463		if (owner == UMTX_CONTESTED) {
464			owner = casuptr((intptr_t *)&umtx->u_owner,
465			    UMTX_CONTESTED, id | UMTX_CONTESTED);
466
467			if (owner == UMTX_CONTESTED)
468				return (0);
469
470			/* The address was invalid. */
471			if (owner == -1)
472				return (EFAULT);
473
474			/* If this failed the lock has changed, restart. */
475			continue;
476		}
477
478		/*
479		 * If we caught a signal, we have retried and now
480		 * exit immediately.
481		 */
482		if (error || (error = umtxq_queue_me(td, umtx, &uq)) != 0)
483			return (error);
484
485		/*
486		 * Set the contested bit so that a release in user space
487		 * knows to use the system call for unlock.  If this fails
488		 * either some one else has acquired the lock or it has been
489		 * released.
490		 */
491		old = casuptr((intptr_t *)&umtx->u_owner, owner,
492		    owner | UMTX_CONTESTED);
493
494		/* The address was invalid. */
495		if (old == -1) {
496			umtxq_lock(&uq.uq_key);
497			umtxq_busy(&uq.uq_key);
498			umtxq_remove(&uq);
499			umtxq_unbusy(&uq.uq_key);
500			umtxq_unlock(&uq.uq_key);
501			umtx_key_release(&uq.uq_key);
502			return (EFAULT);
503		}
504
505		/*
506		 * We set the contested bit, sleep. Otherwise the lock changed
507		 * and we need to retry or we lost a race to the thread
508		 * unlocking the umtx.
509		 */
510		umtxq_lock(&uq.uq_key);
511		if (old == owner && (td->td_flags & TDF_UMTXQ)) {
512			error = umtxq_sleep(td, &uq.uq_key,
513				       td->td_priority | PCATCH,
514				       "umtx", timo);
515		}
516		umtxq_busy(&uq.uq_key);
517		umtxq_remove(&uq);
518		umtxq_unbusy(&uq.uq_key);
519		umtxq_unlock(&uq.uq_key);
520		umtx_key_release(&uq.uq_key);
521	}
522
523	return (0);
524}
525
526static int
527do_lock(struct thread *td, struct umtx *umtx, long id,
528	struct timespec *abstime)
529{
530	struct timespec ts1, ts2;
531	struct timeval tv;
532	int timo, error;
533
534	if (abstime == NULL) {
535		error = _do_lock(td, umtx, id, 0);
536	} else {
537		for (;;) {
538			ts1 = *abstime;
539			getnanotime(&ts2);
540			timespecsub(&ts1, &ts2);
541			TIMESPEC_TO_TIMEVAL(&tv, &ts1);
542			if (tv.tv_sec < 0) {
543				error = ETIMEDOUT;
544				break;
545			}
546			timo = tvtohz(&tv);
547			error = _do_lock(td, umtx, id, timo);
548			if (error != ETIMEDOUT)
549				break;
550		}
551	}
552	/*
553	 * This lets userland back off critical region if needed.
554	 */
555	if (error == ERESTART)
556		error = EINTR;
557	return (error);
558}
559
560static int
561do_unlock(struct thread *td, struct umtx *umtx, long id)
562{
563	struct umtx_key key;
564	intptr_t owner;
565	intptr_t old;
566	int error;
567	int count;
568
569	/*
570	 * Make sure we own this mtx.
571	 *
572	 * XXX Need a {fu,su}ptr this is not correct on arch where
573	 * sizeof(intptr_t) != sizeof(long).
574	 */
575	if ((owner = fuword(&umtx->u_owner)) == -1)
576		return (EFAULT);
577
578	if ((owner & ~UMTX_CONTESTED) != id)
579		return (EPERM);
580
581	/* We should only ever be in here for contested locks */
582	if ((owner & UMTX_CONTESTED) == 0)
583		return (EINVAL);
584
585	if ((error = umtx_key_get(td, umtx, &key)) != 0)
586		return (error);
587
588	umtxq_lock(&key);
589	umtxq_busy(&key);
590	count = umtxq_count(&key);
591	umtxq_unlock(&key);
592
593	/*
594	 * When unlocking the umtx, it must be marked as unowned if
595	 * there is zero or one thread only waiting for it.
596	 * Otherwise, it must be marked as contested.
597	 */
598	old = casuptr((intptr_t *)&umtx->u_owner, owner,
599			count <= 1 ? UMTX_UNOWNED : UMTX_CONTESTED);
600	umtxq_lock(&key);
601	umtxq_signal(&key, 0);
602	umtxq_unbusy(&key);
603	umtxq_unlock(&key);
604	umtx_key_release(&key);
605	if (old == -1)
606		return (EFAULT);
607	if (old != owner)
608		return (EINVAL);
609	return (0);
610}
611
612static int
613do_wait(struct thread *td, struct umtx *umtx, long id, struct timespec *abstime)
614{
615	struct umtx_q uq;
616	struct timespec ts1, ts2;
617	struct timeval tv;
618	long tmp;
619	int timo, error = 0;
620
621	if ((error = umtxq_queue_me(td, umtx, &uq)) != 0)
622		return (error);
623	tmp = fuword(&umtx->u_owner);
624	if (tmp != id) {
625		umtxq_lock(&uq.uq_key);
626		umtxq_remove(&uq);
627		umtxq_unlock(&uq.uq_key);
628	} else if (abstime == NULL) {
629		umtxq_lock(&uq.uq_key);
630		if (td->td_flags & TDF_UMTXQ)
631			error = umtxq_sleep(td, &uq.uq_key,
632			       td->td_priority | PCATCH, "ucond", 0);
633		if (!(td->td_flags & TDF_UMTXQ))
634			error = 0;
635		else
636			umtxq_remove(&uq);
637		umtxq_unlock(&uq.uq_key);
638	} else {
639		for (;;) {
640			ts1 = *abstime;
641			getnanotime(&ts2);
642			timespecsub(&ts1, &ts2);
643			TIMESPEC_TO_TIMEVAL(&tv, &ts1);
644			umtxq_lock(&uq.uq_key);
645			if (tv.tv_sec < 0) {
646				error = ETIMEDOUT;
647				break;
648			}
649			timo = tvtohz(&tv);
650			if (td->td_flags & TDF_UMTXQ)
651				error = umtxq_sleep(td, &uq.uq_key,
652					    td->td_priority | PCATCH,
653					    "ucond", timo);
654			if (error != ETIMEDOUT || !(td->td_flags & TDF_UMTXQ))
655				break;
656			umtxq_unlock(&uq.uq_key);
657		}
658		if (!(td->td_flags & TDF_UMTXQ))
659			error = 0;
660		else
661			umtxq_remove(&uq);
662		umtxq_unlock(&uq.uq_key);
663	}
664	umtx_key_release(&uq.uq_key);
665	if (error == ERESTART)
666		error = EINTR;
667	return (error);
668}
669
670static int
671do_wake(struct thread *td, void *uaddr, int n_wake)
672{
673	struct umtx_key key;
674	int ret;
675
676	if ((ret = umtx_key_get(td, uaddr, &key)) != 0)
677		return (ret);
678	umtxq_lock(&key);
679	ret = umtxq_signal(&key, n_wake);
680	umtxq_unlock(&key);
681	umtx_key_release(&key);
682	return (0);
683}
684
685int
686_umtx_lock(struct thread *td, struct _umtx_lock_args *uap)
687    /* struct umtx *umtx */
688{
689	return _do_lock(td, uap->umtx, td->td_tid, 0);
690}
691
692int
693_umtx_unlock(struct thread *td, struct _umtx_unlock_args *uap)
694    /* struct umtx *umtx */
695{
696	return do_unlock(td, uap->umtx, td->td_tid);
697}
698
699int
700_umtx_op(struct thread *td, struct _umtx_op_args *uap)
701{
702	struct timespec abstime;
703	struct timespec *ts;
704	int error;
705
706	switch(uap->op) {
707	case UMTX_OP_LOCK:
708		/* Allow a null timespec (wait forever). */
709		if (uap->uaddr2 == NULL)
710			ts = NULL;
711		else {
712			error = copyin(uap->uaddr2, &abstime, sizeof(abstime));
713			if (error != 0)
714				break;
715			printf("uap->abstime: %d.%ld\n", abstime.tv_sec, abstime.tv_nsec);
716			if (abstime.tv_nsec >= 1000000000 ||
717			    abstime.tv_nsec < 0) {
718				error = EINVAL;
719				break;
720			}
721			ts = &abstime;
722		}
723		error = do_lock(td, uap->umtx, uap->id, ts);
724		break;
725	case UMTX_OP_UNLOCK:
726		error = do_unlock(td, uap->umtx, uap->id);
727		break;
728	case UMTX_OP_WAIT:
729		/* Allow a null timespec (wait forever). */
730		if (uap->uaddr2 == NULL)
731			ts = NULL;
732		else {
733			error = copyin(uap->uaddr2, &abstime, sizeof(abstime));
734			if (error != 0)
735				break;
736			if (abstime.tv_nsec >= 1000000000 ||
737			    abstime.tv_nsec < 0) {
738				error = EINVAL;
739				break;
740			}
741			ts = &abstime;
742		}
743		error = do_wait(td, uap->umtx, uap->id, ts);
744		break;
745	case UMTX_OP_WAKE:
746		error = do_wake(td, uap->umtx, uap->id);
747		break;
748	default:
749		error = EINVAL;
750		break;
751	}
752	td->td_retval[0] = -error;
753	return (0);
754}
755