sys_lwp.c revision 1.47 1 /* $NetBSD: sys_lwp.c,v 1.47 2009/10/22 13:12:47 rmind Exp $ */
2
3 /*-
4 * Copyright (c) 2001, 2006, 2007, 2008 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Nathan J. Williams, and Andrew Doran.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
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 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 /*
33 * Lightweight process (LWP) system calls. See kern_lwp.c for a description
34 * of LWPs.
35 */
36
37 #include <sys/cdefs.h>
38 __KERNEL_RCSID(0, "$NetBSD: sys_lwp.c,v 1.47 2009/10/22 13:12:47 rmind Exp $");
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/pool.h>
43 #include <sys/proc.h>
44 #include <sys/types.h>
45 #include <sys/syscallargs.h>
46 #include <sys/kauth.h>
47 #include <sys/kmem.h>
48 #include <sys/sleepq.h>
49 #include <sys/lwpctl.h>
50 #include <sys/cpu.h>
51
52 #include <uvm/uvm_extern.h>
53
54 #include "opt_sa.h"
55
56 #define LWP_UNPARK_MAX 1024
57
58 static syncobj_t lwp_park_sobj = {
59 SOBJ_SLEEPQ_LIFO,
60 sleepq_unsleep,
61 sleepq_changepri,
62 sleepq_lendpri,
63 syncobj_noowner,
64 };
65
66 static sleeptab_t lwp_park_tab;
67
68 void
69 lwp_sys_init(void)
70 {
71 sleeptab_init(&lwp_park_tab);
72 }
73
74 int
75 sys__lwp_create(struct lwp *l, const struct sys__lwp_create_args *uap,
76 register_t *retval)
77 {
78 /* {
79 syscallarg(const ucontext_t *) ucp;
80 syscallarg(u_long) flags;
81 syscallarg(lwpid_t *) new_lwp;
82 } */
83 struct proc *p = l->l_proc;
84 struct lwp *l2;
85 vaddr_t uaddr;
86 ucontext_t *newuc;
87 int error, lid;
88
89 #ifdef KERN_SA
90 mutex_enter(p->p_lock);
91 if ((p->p_sflag & (PS_SA | PS_WEXIT)) != 0 || p->p_sa != NULL) {
92 mutex_exit(p->p_lock);
93 return EINVAL;
94 }
95 mutex_exit(p->p_lock);
96 #endif
97
98 newuc = pool_get(&lwp_uc_pool, PR_WAITOK);
99
100 error = copyin(SCARG(uap, ucp), newuc, p->p_emul->e_ucsize);
101 if (error) {
102 pool_put(&lwp_uc_pool, newuc);
103 return error;
104 }
105
106 /* XXX check against resource limits */
107
108 uaddr = uvm_uarea_alloc();
109 if (__predict_false(uaddr == 0)) {
110 pool_put(&lwp_uc_pool, newuc);
111 return ENOMEM;
112 }
113
114 error = lwp_create(l, p, uaddr, SCARG(uap, flags) & LWP_DETACHED,
115 NULL, 0, p->p_emul->e_startlwp, newuc, &l2, l->l_class);
116 if (__predict_false(error)) {
117 uvm_uarea_free(uaddr);
118 pool_put(&lwp_uc_pool, newuc);
119 return error;
120 }
121
122 lid = l2->l_lid;
123 error = copyout(&lid, SCARG(uap, new_lwp), sizeof(lid));
124 if (error) {
125 lwp_exit(l2);
126 pool_put(&lwp_uc_pool, newuc);
127 return error;
128 }
129
130 /*
131 * Set the new LWP running, unless the caller has requested that
132 * it be created in suspended state. If the process is stopping,
133 * then the LWP is created stopped.
134 */
135 mutex_enter(p->p_lock);
136 lwp_lock(l2);
137 if ((SCARG(uap, flags) & LWP_SUSPENDED) == 0 &&
138 (l->l_flag & (LW_WREBOOT | LW_WSUSPEND | LW_WEXIT)) == 0) {
139 if (p->p_stat == SSTOP || (p->p_sflag & PS_STOPPING) != 0)
140 l2->l_stat = LSSTOP;
141 else {
142 KASSERT(lwp_locked(l2, l2->l_cpu->ci_schedstate.spc_mutex));
143 p->p_nrlwps++;
144 l2->l_stat = LSRUN;
145 sched_enqueue(l2, false);
146 }
147 lwp_unlock(l2);
148 } else {
149 l2->l_stat = LSSUSPENDED;
150 lwp_unlock_to(l2, l2->l_cpu->ci_schedstate.spc_lwplock);
151 }
152 mutex_exit(p->p_lock);
153
154 return 0;
155 }
156
157 int
158 sys__lwp_exit(struct lwp *l, const void *v, register_t *retval)
159 {
160
161 lwp_exit(l);
162 return 0;
163 }
164
165 int
166 sys__lwp_self(struct lwp *l, const void *v, register_t *retval)
167 {
168
169 *retval = l->l_lid;
170 return 0;
171 }
172
173 int
174 sys__lwp_getprivate(struct lwp *l, const void *v, register_t *retval)
175 {
176
177 *retval = (uintptr_t)l->l_private;
178 return 0;
179 }
180
181 int
182 sys__lwp_setprivate(struct lwp *l, const struct sys__lwp_setprivate_args *uap,
183 register_t *retval)
184 {
185 /* {
186 syscallarg(void *) ptr;
187 } */
188
189 l->l_private = SCARG(uap, ptr);
190 #ifdef __HAVE_CPU_LWP_SETPRIVATE
191 cpu_lwp_setprivate(l, SCARG(uap, ptr));
192 #endif
193
194 return 0;
195 }
196
197 int
198 sys__lwp_suspend(struct lwp *l, const struct sys__lwp_suspend_args *uap,
199 register_t *retval)
200 {
201 /* {
202 syscallarg(lwpid_t) target;
203 } */
204 struct proc *p = l->l_proc;
205 struct lwp *t;
206 int error;
207
208 mutex_enter(p->p_lock);
209
210 #ifdef KERN_SA
211 if ((p->p_sflag & PS_SA) != 0 || p->p_sa != NULL) {
212 mutex_exit(p->p_lock);
213 return EINVAL;
214 }
215 #endif
216
217 if ((t = lwp_find(p, SCARG(uap, target))) == NULL) {
218 mutex_exit(p->p_lock);
219 return ESRCH;
220 }
221
222 /*
223 * Check for deadlock, which is only possible when we're suspending
224 * ourself. XXX There is a short race here, as p_nrlwps is only
225 * incremented when an LWP suspends itself on the kernel/user
226 * boundary. It's still possible to kill -9 the process so we
227 * don't bother checking further.
228 */
229 lwp_lock(t);
230 if ((t == l && p->p_nrlwps == 1) ||
231 (l->l_flag & (LW_WCORE | LW_WEXIT)) != 0) {
232 lwp_unlock(t);
233 mutex_exit(p->p_lock);
234 return EDEADLK;
235 }
236
237 /*
238 * Suspend the LWP. XXX If it's on a different CPU, we should wait
239 * for it to be preempted, where it will put itself to sleep.
240 *
241 * Suspension of the current LWP will happen on return to userspace.
242 */
243 error = lwp_suspend(l, t);
244 if (error) {
245 mutex_exit(p->p_lock);
246 return error;
247 }
248
249 /*
250 * Wait for:
251 * o process exiting
252 * o target LWP suspended
253 * o target LWP not suspended and L_WSUSPEND clear
254 * o target LWP exited
255 */
256 for (;;) {
257 error = cv_wait_sig(&p->p_lwpcv, p->p_lock);
258 if (error) {
259 error = ERESTART;
260 break;
261 }
262 if (lwp_find(p, SCARG(uap, target)) == NULL) {
263 error = ESRCH;
264 break;
265 }
266 if ((l->l_flag | t->l_flag) & (LW_WCORE | LW_WEXIT)) {
267 error = ERESTART;
268 break;
269 }
270 if (t->l_stat == LSSUSPENDED ||
271 (t->l_flag & LW_WSUSPEND) == 0)
272 break;
273 }
274 mutex_exit(p->p_lock);
275
276 return error;
277 }
278
279 int
280 sys__lwp_continue(struct lwp *l, const struct sys__lwp_continue_args *uap,
281 register_t *retval)
282 {
283 /* {
284 syscallarg(lwpid_t) target;
285 } */
286 int error;
287 struct proc *p = l->l_proc;
288 struct lwp *t;
289
290 error = 0;
291
292 mutex_enter(p->p_lock);
293 if ((t = lwp_find(p, SCARG(uap, target))) == NULL) {
294 mutex_exit(p->p_lock);
295 return ESRCH;
296 }
297
298 lwp_lock(t);
299 lwp_continue(t);
300 mutex_exit(p->p_lock);
301
302 return error;
303 }
304
305 int
306 sys__lwp_wakeup(struct lwp *l, const struct sys__lwp_wakeup_args *uap,
307 register_t *retval)
308 {
309 /* {
310 syscallarg(lwpid_t) target;
311 } */
312 struct lwp *t;
313 struct proc *p;
314 int error;
315
316 p = l->l_proc;
317 mutex_enter(p->p_lock);
318
319 if ((t = lwp_find(p, SCARG(uap, target))) == NULL) {
320 mutex_exit(p->p_lock);
321 return ESRCH;
322 }
323
324 lwp_lock(t);
325 t->l_flag |= (LW_CANCELLED | LW_UNPARKED);
326
327 if (t->l_stat != LSSLEEP) {
328 lwp_unlock(t);
329 error = ENODEV;
330 } else if ((t->l_flag & LW_SINTR) == 0) {
331 lwp_unlock(t);
332 error = EBUSY;
333 } else {
334 /* Wake it up. lwp_unsleep() will release the LWP lock. */
335 lwp_unsleep(t, true);
336 error = 0;
337 }
338
339 mutex_exit(p->p_lock);
340
341 return error;
342 }
343
344 int
345 sys__lwp_wait(struct lwp *l, const struct sys__lwp_wait_args *uap,
346 register_t *retval)
347 {
348 /* {
349 syscallarg(lwpid_t) wait_for;
350 syscallarg(lwpid_t *) departed;
351 } */
352 struct proc *p = l->l_proc;
353 int error;
354 lwpid_t dep;
355
356 mutex_enter(p->p_lock);
357 error = lwp_wait1(l, SCARG(uap, wait_for), &dep, 0);
358 mutex_exit(p->p_lock);
359
360 if (error)
361 return error;
362
363 if (SCARG(uap, departed)) {
364 error = copyout(&dep, SCARG(uap, departed), sizeof(dep));
365 if (error)
366 return error;
367 }
368
369 return 0;
370 }
371
372 int
373 sys__lwp_kill(struct lwp *l, const struct sys__lwp_kill_args *uap,
374 register_t *retval)
375 {
376 /* {
377 syscallarg(lwpid_t) target;
378 syscallarg(int) signo;
379 } */
380 struct proc *p = l->l_proc;
381 struct lwp *t;
382 ksiginfo_t ksi;
383 int signo = SCARG(uap, signo);
384 int error = 0;
385
386 if ((u_int)signo >= NSIG)
387 return EINVAL;
388
389 KSI_INIT(&ksi);
390 ksi.ksi_signo = signo;
391 ksi.ksi_code = SI_LWP;
392 ksi.ksi_pid = p->p_pid;
393 ksi.ksi_uid = kauth_cred_geteuid(l->l_cred);
394 ksi.ksi_lid = SCARG(uap, target);
395
396 mutex_enter(proc_lock);
397 mutex_enter(p->p_lock);
398 if ((t = lwp_find(p, ksi.ksi_lid)) == NULL)
399 error = ESRCH;
400 else if (signo != 0)
401 kpsignal2(p, &ksi);
402 mutex_exit(p->p_lock);
403 mutex_exit(proc_lock);
404
405 return error;
406 }
407
408 int
409 sys__lwp_detach(struct lwp *l, const struct sys__lwp_detach_args *uap,
410 register_t *retval)
411 {
412 /* {
413 syscallarg(lwpid_t) target;
414 } */
415 struct proc *p;
416 struct lwp *t;
417 lwpid_t target;
418 int error;
419
420 target = SCARG(uap, target);
421 p = l->l_proc;
422
423 mutex_enter(p->p_lock);
424
425 if (l->l_lid == target)
426 t = l;
427 else {
428 /*
429 * We can't use lwp_find() here because the target might
430 * be a zombie.
431 */
432 LIST_FOREACH(t, &p->p_lwps, l_sibling)
433 if (t->l_lid == target)
434 break;
435 }
436
437 /*
438 * If the LWP is already detached, there's nothing to do.
439 * If it's a zombie, we need to clean up after it. LSZOMB
440 * is visible with the proc mutex held.
441 *
442 * After we have detached or released the LWP, kick any
443 * other LWPs that may be sitting in _lwp_wait(), waiting
444 * for the target LWP to exit.
445 */
446 if (t != NULL && t->l_stat != LSIDL) {
447 if ((t->l_prflag & LPR_DETACHED) == 0) {
448 p->p_ndlwps++;
449 t->l_prflag |= LPR_DETACHED;
450 if (t->l_stat == LSZOMB) {
451 /* Releases proc mutex. */
452 lwp_free(t, false, false);
453 return 0;
454 }
455 error = 0;
456
457 /*
458 * Have any LWPs sleeping in lwp_wait() recheck
459 * for deadlock.
460 */
461 cv_broadcast(&p->p_lwpcv);
462 } else
463 error = EINVAL;
464 } else
465 error = ESRCH;
466
467 mutex_exit(p->p_lock);
468
469 return error;
470 }
471
472 static inline wchan_t
473 lwp_park_wchan(struct proc *p, const void *hint)
474 {
475
476 return (wchan_t)((uintptr_t)p ^ (uintptr_t)hint);
477 }
478
479 int
480 lwp_unpark(lwpid_t target, const void *hint)
481 {
482 sleepq_t *sq;
483 wchan_t wchan;
484 kmutex_t *mp;
485 proc_t *p;
486 lwp_t *t;
487
488 /*
489 * Easy case: search for the LWP on the sleep queue. If
490 * it's parked, remove it from the queue and set running.
491 */
492 p = curproc;
493 wchan = lwp_park_wchan(p, hint);
494 sq = sleeptab_lookup(&lwp_park_tab, wchan, &mp);
495
496 TAILQ_FOREACH(t, sq, l_sleepchain)
497 if (t->l_proc == p && t->l_lid == target)
498 break;
499
500 if (__predict_true(t != NULL)) {
501 sleepq_remove(sq, t);
502 mutex_spin_exit(mp);
503 return 0;
504 }
505
506 /*
507 * The LWP hasn't parked yet. Take the hit and mark the
508 * operation as pending.
509 */
510 mutex_spin_exit(mp);
511
512 mutex_enter(p->p_lock);
513 if ((t = lwp_find(p, target)) == NULL) {
514 mutex_exit(p->p_lock);
515 return ESRCH;
516 }
517
518 /*
519 * It may not have parked yet, we may have raced, or it
520 * is parked on a different user sync object.
521 */
522 lwp_lock(t);
523 if (t->l_syncobj == &lwp_park_sobj) {
524 /* Releases the LWP lock. */
525 lwp_unsleep(t, true);
526 } else {
527 /*
528 * Set the operation pending. The next call to _lwp_park
529 * will return early.
530 */
531 t->l_flag |= LW_UNPARKED;
532 lwp_unlock(t);
533 }
534
535 mutex_exit(p->p_lock);
536 return 0;
537 }
538
539 int
540 lwp_park(struct timespec *ts, const void *hint)
541 {
542 struct timespec tsx;
543 sleepq_t *sq;
544 kmutex_t *mp;
545 wchan_t wchan;
546 int timo, error;
547 lwp_t *l;
548
549 /* Fix up the given timeout value. */
550 if (ts != NULL) {
551 getnanotime(&tsx);
552 timespecsub(ts, &tsx, &tsx);
553 if (tsx.tv_sec < 0 || (tsx.tv_sec == 0 && tsx.tv_nsec <= 0))
554 return ETIMEDOUT;
555 if ((error = itimespecfix(&tsx)) != 0)
556 return error;
557 timo = tstohz(&tsx);
558 KASSERT(timo != 0);
559 } else
560 timo = 0;
561
562 /* Find and lock the sleep queue. */
563 l = curlwp;
564 wchan = lwp_park_wchan(l->l_proc, hint);
565 sq = sleeptab_lookup(&lwp_park_tab, wchan, &mp);
566
567 /*
568 * Before going the full route and blocking, check to see if an
569 * unpark op is pending.
570 */
571 lwp_lock(l);
572 if ((l->l_flag & (LW_CANCELLED | LW_UNPARKED)) != 0) {
573 l->l_flag &= ~(LW_CANCELLED | LW_UNPARKED);
574 lwp_unlock(l);
575 mutex_spin_exit(mp);
576 return EALREADY;
577 }
578 lwp_unlock_to(l, mp);
579 l->l_biglocks = 0;
580 sleepq_enqueue(sq, wchan, "parked", &lwp_park_sobj);
581 error = sleepq_block(timo, true);
582 switch (error) {
583 case EWOULDBLOCK:
584 error = ETIMEDOUT;
585 break;
586 case ERESTART:
587 error = EINTR;
588 break;
589 default:
590 /* nothing */
591 break;
592 }
593 return error;
594 }
595
596 /*
597 * 'park' an LWP waiting on a user-level synchronisation object. The LWP
598 * will remain parked until another LWP in the same process calls in and
599 * requests that it be unparked.
600 */
601 int
602 sys____lwp_park50(struct lwp *l, const struct sys____lwp_park50_args *uap,
603 register_t *retval)
604 {
605 /* {
606 syscallarg(const struct timespec *) ts;
607 syscallarg(lwpid_t) unpark;
608 syscallarg(const void *) hint;
609 syscallarg(const void *) unparkhint;
610 } */
611 struct timespec ts, *tsp;
612 int error;
613
614 if (SCARG(uap, ts) == NULL)
615 tsp = NULL;
616 else {
617 error = copyin(SCARG(uap, ts), &ts, sizeof(ts));
618 if (error != 0)
619 return error;
620 tsp = &ts;
621 }
622
623 if (SCARG(uap, unpark) != 0) {
624 error = lwp_unpark(SCARG(uap, unpark), SCARG(uap, unparkhint));
625 if (error != 0)
626 return error;
627 }
628
629 return lwp_park(tsp, SCARG(uap, hint));
630 }
631
632 int
633 sys__lwp_unpark(struct lwp *l, const struct sys__lwp_unpark_args *uap,
634 register_t *retval)
635 {
636 /* {
637 syscallarg(lwpid_t) target;
638 syscallarg(const void *) hint;
639 } */
640
641 return lwp_unpark(SCARG(uap, target), SCARG(uap, hint));
642 }
643
644 int
645 sys__lwp_unpark_all(struct lwp *l, const struct sys__lwp_unpark_all_args *uap,
646 register_t *retval)
647 {
648 /* {
649 syscallarg(const lwpid_t *) targets;
650 syscallarg(size_t) ntargets;
651 syscallarg(const void *) hint;
652 } */
653 struct proc *p;
654 struct lwp *t;
655 sleepq_t *sq;
656 wchan_t wchan;
657 lwpid_t targets[32], *tp, *tpp, *tmax, target;
658 int error;
659 kmutex_t *mp;
660 u_int ntargets;
661 size_t sz;
662
663 p = l->l_proc;
664 ntargets = SCARG(uap, ntargets);
665
666 if (SCARG(uap, targets) == NULL) {
667 /*
668 * Let the caller know how much we are willing to do, and
669 * let it unpark the LWPs in blocks.
670 */
671 *retval = LWP_UNPARK_MAX;
672 return 0;
673 }
674 if (ntargets > LWP_UNPARK_MAX || ntargets == 0)
675 return EINVAL;
676
677 /*
678 * Copy in the target array. If it's a small number of LWPs, then
679 * place the numbers on the stack.
680 */
681 sz = sizeof(target) * ntargets;
682 if (sz <= sizeof(targets))
683 tp = targets;
684 else {
685 tp = kmem_alloc(sz, KM_SLEEP);
686 if (tp == NULL)
687 return ENOMEM;
688 }
689 error = copyin(SCARG(uap, targets), tp, sz);
690 if (error != 0) {
691 if (tp != targets) {
692 kmem_free(tp, sz);
693 }
694 return error;
695 }
696
697 wchan = lwp_park_wchan(p, SCARG(uap, hint));
698 sq = sleeptab_lookup(&lwp_park_tab, wchan, &mp);
699
700 for (tmax = tp + ntargets, tpp = tp; tpp < tmax; tpp++) {
701 target = *tpp;
702
703 /*
704 * Easy case: search for the LWP on the sleep queue. If
705 * it's parked, remove it from the queue and set running.
706 */
707 TAILQ_FOREACH(t, sq, l_sleepchain)
708 if (t->l_proc == p && t->l_lid == target)
709 break;
710
711 if (t != NULL) {
712 sleepq_remove(sq, t);
713 continue;
714 }
715
716 /*
717 * The LWP hasn't parked yet. Take the hit and
718 * mark the operation as pending.
719 */
720 mutex_spin_exit(mp);
721 mutex_enter(p->p_lock);
722 if ((t = lwp_find(p, target)) == NULL) {
723 mutex_exit(p->p_lock);
724 mutex_spin_enter(mp);
725 continue;
726 }
727 lwp_lock(t);
728
729 /*
730 * It may not have parked yet, we may have raced, or
731 * it is parked on a different user sync object.
732 */
733 if (t->l_syncobj == &lwp_park_sobj) {
734 /* Releases the LWP lock. */
735 lwp_unsleep(t, true);
736 } else {
737 /*
738 * Set the operation pending. The next call to
739 * _lwp_park will return early.
740 */
741 t->l_flag |= LW_UNPARKED;
742 lwp_unlock(t);
743 }
744
745 mutex_exit(p->p_lock);
746 mutex_spin_enter(mp);
747 }
748
749 mutex_spin_exit(mp);
750 if (tp != targets)
751 kmem_free(tp, sz);
752
753 return 0;
754 }
755
756 int
757 sys__lwp_setname(struct lwp *l, const struct sys__lwp_setname_args *uap,
758 register_t *retval)
759 {
760 /* {
761 syscallarg(lwpid_t) target;
762 syscallarg(const char *) name;
763 } */
764 char *name, *oname;
765 lwpid_t target;
766 proc_t *p;
767 lwp_t *t;
768 int error;
769
770 if ((target = SCARG(uap, target)) == 0)
771 target = l->l_lid;
772
773 name = kmem_alloc(MAXCOMLEN, KM_SLEEP);
774 if (name == NULL)
775 return ENOMEM;
776 error = copyinstr(SCARG(uap, name), name, MAXCOMLEN, NULL);
777 switch (error) {
778 case ENAMETOOLONG:
779 case 0:
780 name[MAXCOMLEN - 1] = '\0';
781 break;
782 default:
783 kmem_free(name, MAXCOMLEN);
784 return error;
785 }
786
787 p = curproc;
788 mutex_enter(p->p_lock);
789 if ((t = lwp_find(p, target)) == NULL) {
790 mutex_exit(p->p_lock);
791 kmem_free(name, MAXCOMLEN);
792 return ESRCH;
793 }
794 lwp_lock(t);
795 oname = t->l_name;
796 t->l_name = name;
797 lwp_unlock(t);
798 mutex_exit(p->p_lock);
799
800 if (oname != NULL)
801 kmem_free(oname, MAXCOMLEN);
802
803 return 0;
804 }
805
806 int
807 sys__lwp_getname(struct lwp *l, const struct sys__lwp_getname_args *uap,
808 register_t *retval)
809 {
810 /* {
811 syscallarg(lwpid_t) target;
812 syscallarg(char *) name;
813 syscallarg(size_t) len;
814 } */
815 char name[MAXCOMLEN];
816 lwpid_t target;
817 proc_t *p;
818 lwp_t *t;
819
820 if ((target = SCARG(uap, target)) == 0)
821 target = l->l_lid;
822
823 p = curproc;
824 mutex_enter(p->p_lock);
825 if ((t = lwp_find(p, target)) == NULL) {
826 mutex_exit(p->p_lock);
827 return ESRCH;
828 }
829 lwp_lock(t);
830 if (t->l_name == NULL)
831 name[0] = '\0';
832 else
833 strcpy(name, t->l_name);
834 lwp_unlock(t);
835 mutex_exit(p->p_lock);
836
837 return copyoutstr(name, SCARG(uap, name), SCARG(uap, len), NULL);
838 }
839
840 int
841 sys__lwp_ctl(struct lwp *l, const struct sys__lwp_ctl_args *uap,
842 register_t *retval)
843 {
844 /* {
845 syscallarg(int) features;
846 syscallarg(struct lwpctl **) address;
847 } */
848 int error, features;
849 vaddr_t vaddr;
850
851 features = SCARG(uap, features);
852 features &= ~(LWPCTL_FEATURE_CURCPU | LWPCTL_FEATURE_PCTR);
853 if (features != 0)
854 return ENODEV;
855 if ((error = lwp_ctl_alloc(&vaddr)) != 0)
856 return error;
857 return copyout(&vaddr, SCARG(uap, address), sizeof(void *));
858 }
859