FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_kse.c
1 /*-
2 * Copyright (C) 2001 Julian Elischer <julian@freebsd.org>.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice(s), this list of conditions and the following disclaimer as
10 * the first lines of this file unmodified other than the possible
11 * addition of one or more copyright notices.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice(s), 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 COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
17 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
20 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
23 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
26 * DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD: releng/6.0/sys/kern/kern_kse.c 151012 2005-10-06 18:24:24Z delphij $");
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/imgact.h>
36 #include <sys/lock.h>
37 #include <sys/mutex.h>
38 #include <sys/proc.h>
39 #include <sys/ptrace.h>
40 #include <sys/smp.h>
41 #include <sys/syscallsubr.h>
42 #include <sys/sysproto.h>
43 #include <sys/sched.h>
44 #include <sys/signalvar.h>
45 #include <sys/sleepqueue.h>
46 #include <sys/kse.h>
47 #include <sys/ktr.h>
48 #include <vm/uma.h>
49
50 /*
51 * KSEGRP related storage.
52 */
53 static uma_zone_t upcall_zone;
54
55 /* DEBUG ONLY */
56 extern int virtual_cpu;
57 extern int thread_debug;
58
59 extern int max_threads_per_proc;
60 extern int max_groups_per_proc;
61 extern int max_threads_hits;
62 extern struct mtx kse_zombie_lock;
63
64
65 TAILQ_HEAD(, kse_upcall) zombie_upcalls =
66 TAILQ_HEAD_INITIALIZER(zombie_upcalls);
67
68 static int thread_update_usr_ticks(struct thread *td);
69 static void thread_alloc_spare(struct thread *td);
70
71 struct kse_upcall *
72 upcall_alloc(void)
73 {
74 struct kse_upcall *ku;
75
76 ku = uma_zalloc(upcall_zone, M_WAITOK | M_ZERO);
77 return (ku);
78 }
79
80 void
81 upcall_free(struct kse_upcall *ku)
82 {
83
84 uma_zfree(upcall_zone, ku);
85 }
86
87 void
88 upcall_link(struct kse_upcall *ku, struct ksegrp *kg)
89 {
90
91 mtx_assert(&sched_lock, MA_OWNED);
92 TAILQ_INSERT_TAIL(&kg->kg_upcalls, ku, ku_link);
93 ku->ku_ksegrp = kg;
94 kg->kg_numupcalls++;
95 }
96
97 void
98 upcall_unlink(struct kse_upcall *ku)
99 {
100 struct ksegrp *kg = ku->ku_ksegrp;
101
102 mtx_assert(&sched_lock, MA_OWNED);
103 KASSERT(ku->ku_owner == NULL, ("%s: have owner", __func__));
104 TAILQ_REMOVE(&kg->kg_upcalls, ku, ku_link);
105 kg->kg_numupcalls--;
106 upcall_stash(ku);
107 }
108
109 void
110 upcall_remove(struct thread *td)
111 {
112
113 mtx_assert(&sched_lock, MA_OWNED);
114 if (td->td_upcall != NULL) {
115 td->td_upcall->ku_owner = NULL;
116 upcall_unlink(td->td_upcall);
117 td->td_upcall = NULL;
118 }
119 }
120
121 #ifndef _SYS_SYSPROTO_H_
122 struct kse_switchin_args {
123 struct kse_thr_mailbox *tmbx;
124 int flags;
125 };
126 #endif
127
128 int
129 kse_switchin(struct thread *td, struct kse_switchin_args *uap)
130 {
131 struct kse_thr_mailbox tmbx;
132 struct kse_upcall *ku;
133 int error;
134
135 if ((ku = td->td_upcall) == NULL || TD_CAN_UNBIND(td))
136 return (EINVAL);
137 error = (uap->tmbx == NULL) ? EINVAL : 0;
138 if (!error)
139 error = copyin(uap->tmbx, &tmbx, sizeof(tmbx));
140 if (!error && (uap->flags & KSE_SWITCHIN_SETTMBX))
141 error = (suword(&ku->ku_mailbox->km_curthread,
142 (long)uap->tmbx) != 0 ? EINVAL : 0);
143 if (!error)
144 error = set_mcontext(td, &tmbx.tm_context.uc_mcontext);
145 if (!error) {
146 suword32(&uap->tmbx->tm_lwp, td->td_tid);
147 if (uap->flags & KSE_SWITCHIN_SETTMBX) {
148 td->td_mailbox = uap->tmbx;
149 td->td_pflags |= TDP_CAN_UNBIND;
150 }
151 if (td->td_proc->p_flag & P_TRACED) {
152 if (tmbx.tm_dflags & TMDF_SSTEP)
153 ptrace_single_step(td);
154 else
155 ptrace_clear_single_step(td);
156 if (tmbx.tm_dflags & TMDF_SUSPEND) {
157 mtx_lock_spin(&sched_lock);
158 /* fuword can block, check again */
159 if (td->td_upcall)
160 ku->ku_flags |= KUF_DOUPCALL;
161 mtx_unlock_spin(&sched_lock);
162 }
163 }
164 }
165 return ((error == 0) ? EJUSTRETURN : error);
166 }
167
168 /*
169 struct kse_thr_interrupt_args {
170 struct kse_thr_mailbox * tmbx;
171 int cmd;
172 long data;
173 };
174 */
175 int
176 kse_thr_interrupt(struct thread *td, struct kse_thr_interrupt_args *uap)
177 {
178 struct kse_execve_args args;
179 struct image_args iargs;
180 struct proc *p;
181 struct thread *td2;
182 struct kse_upcall *ku;
183 struct kse_thr_mailbox *tmbx;
184 uint32_t flags;
185 int error;
186
187 p = td->td_proc;
188
189 if (!(p->p_flag & P_SA))
190 return (EINVAL);
191
192 switch (uap->cmd) {
193 case KSE_INTR_SENDSIG:
194 if (uap->data < 0 || uap->data > _SIG_MAXSIG)
195 return (EINVAL);
196 case KSE_INTR_INTERRUPT:
197 case KSE_INTR_RESTART:
198 PROC_LOCK(p);
199 mtx_lock_spin(&sched_lock);
200 FOREACH_THREAD_IN_PROC(p, td2) {
201 if (td2->td_mailbox == uap->tmbx)
202 break;
203 }
204 if (td2 == NULL) {
205 mtx_unlock_spin(&sched_lock);
206 PROC_UNLOCK(p);
207 return (ESRCH);
208 }
209 if (uap->cmd == KSE_INTR_SENDSIG) {
210 if (uap->data > 0) {
211 td2->td_flags &= ~TDF_INTERRUPT;
212 mtx_unlock_spin(&sched_lock);
213 tdsignal(td2, (int)uap->data, SIGTARGET_TD);
214 } else {
215 mtx_unlock_spin(&sched_lock);
216 }
217 } else {
218 td2->td_flags |= TDF_INTERRUPT | TDF_ASTPENDING;
219 if (TD_CAN_UNBIND(td2))
220 td2->td_upcall->ku_flags |= KUF_DOUPCALL;
221 if (uap->cmd == KSE_INTR_INTERRUPT)
222 td2->td_intrval = EINTR;
223 else
224 td2->td_intrval = ERESTART;
225 if (TD_ON_SLEEPQ(td2) && (td2->td_flags & TDF_SINTR))
226 sleepq_abort(td2);
227 mtx_unlock_spin(&sched_lock);
228 }
229 PROC_UNLOCK(p);
230 break;
231 case KSE_INTR_SIGEXIT:
232 if (uap->data < 1 || uap->data > _SIG_MAXSIG)
233 return (EINVAL);
234 PROC_LOCK(p);
235 sigexit(td, (int)uap->data);
236 break;
237
238 case KSE_INTR_DBSUSPEND:
239 /* this sub-function is only for bound thread */
240 if (td->td_pflags & TDP_SA)
241 return (EINVAL);
242 ku = td->td_upcall;
243 tmbx = (void *)fuword((void *)&ku->ku_mailbox->km_curthread);
244 if (tmbx == NULL || tmbx == (void *)-1)
245 return (EINVAL);
246 flags = 0;
247 while ((p->p_flag & P_TRACED) && !(p->p_flag & P_SINGLE_EXIT)) {
248 flags = fuword32(&tmbx->tm_dflags);
249 if (!(flags & TMDF_SUSPEND))
250 break;
251 PROC_LOCK(p);
252 mtx_lock_spin(&sched_lock);
253 thread_stopped(p);
254 thread_suspend_one(td);
255 PROC_UNLOCK(p);
256 mi_switch(SW_VOL, NULL);
257 mtx_unlock_spin(&sched_lock);
258 }
259 return (0);
260
261 case KSE_INTR_EXECVE:
262 error = copyin((void *)uap->data, &args, sizeof(args));
263 if (error)
264 return (error);
265 error = exec_copyin_args(&iargs, args.path, UIO_USERSPACE,
266 args.argv, args.envp);
267 if (error == 0)
268 error = kern_execve(td, &iargs, NULL);
269 exec_free_args(&iargs);
270 if (error == 0) {
271 PROC_LOCK(p);
272 SIGSETOR(td->td_siglist, args.sigpend);
273 PROC_UNLOCK(p);
274 kern_sigprocmask(td, SIG_SETMASK, &args.sigmask, NULL,
275 0);
276 }
277 return (error);
278
279 default:
280 return (EINVAL);
281 }
282 return (0);
283 }
284
285 /*
286 struct kse_exit_args {
287 register_t dummy;
288 };
289 */
290 int
291 kse_exit(struct thread *td, struct kse_exit_args *uap)
292 {
293 struct proc *p;
294 struct ksegrp *kg;
295 struct kse_upcall *ku, *ku2;
296 int error, count;
297
298 p = td->td_proc;
299 /*
300 * Ensure that this is only called from the UTS
301 */
302 if ((ku = td->td_upcall) == NULL || TD_CAN_UNBIND(td))
303 return (EINVAL);
304
305 kg = td->td_ksegrp;
306 count = 0;
307
308 /*
309 * Calculate the existing non-exiting upcalls in this ksegroup.
310 * If we are the last upcall but there are still other threads,
311 * then do not exit. We need the other threads to be able to
312 * complete whatever they are doing.
313 * XXX This relies on the userland knowing what to do if we return.
314 * It may be a better choice to convert ourselves into a kse_release
315 * ( or similar) and wait in the kernel to be needed.
316 */
317 PROC_LOCK(p);
318 mtx_lock_spin(&sched_lock);
319 FOREACH_UPCALL_IN_GROUP(kg, ku2) {
320 if (ku2->ku_flags & KUF_EXITING)
321 count++;
322 }
323 if ((kg->kg_numupcalls - count) == 1 &&
324 (kg->kg_numthreads > 1)) {
325 mtx_unlock_spin(&sched_lock);
326 PROC_UNLOCK(p);
327 return (EDEADLK);
328 }
329 ku->ku_flags |= KUF_EXITING;
330 mtx_unlock_spin(&sched_lock);
331 PROC_UNLOCK(p);
332
333 /*
334 * Mark the UTS mailbox as having been finished with.
335 * If that fails then just go for a segfault.
336 * XXX need to check it that can be deliverred without a mailbox.
337 */
338 error = suword32(&ku->ku_mailbox->km_flags, ku->ku_mflags|KMF_DONE);
339 if (!(td->td_pflags & TDP_SA))
340 if (suword32(&td->td_mailbox->tm_lwp, 0))
341 error = EFAULT;
342 PROC_LOCK(p);
343 if (error)
344 psignal(p, SIGSEGV);
345 mtx_lock_spin(&sched_lock);
346 upcall_remove(td);
347 if (p->p_numthreads != 1) {
348 /*
349 * If we are not the last thread, but we are the last
350 * thread in this ksegrp, then by definition this is not
351 * the last group and we need to clean it up as well.
352 * thread_exit will clean up the kseg as needed.
353 */
354 thread_stopped(p);
355 thread_exit();
356 /* NOTREACHED */
357 }
358 /*
359 * This is the last thread. Just return to the user.
360 * We know that there is only one ksegrp too, as any others
361 * would have been discarded in previous calls to thread_exit().
362 * Effectively we have left threading mode..
363 * The only real thing left to do is ensure that the
364 * scheduler sets out concurrency back to 1 as that may be a
365 * resource leak otherwise.
366 * This is an A[PB]I issue.. what SHOULD we do?
367 * One possibility is to return to the user. It may not cope well.
368 * The other possibility would be to let the process exit.
369 */
370 thread_unthread(td);
371 mtx_unlock_spin(&sched_lock);
372 PROC_UNLOCK(p);
373 #if 1
374 return (0);
375 #else
376 exit1(td, 0);
377 #endif
378 }
379
380 /*
381 * Either becomes an upcall or waits for an awakening event and
382 * then becomes an upcall. Only error cases return.
383 */
384 /*
385 struct kse_release_args {
386 struct timespec *timeout;
387 };
388 */
389 int
390 kse_release(struct thread *td, struct kse_release_args *uap)
391 {
392 struct proc *p;
393 struct ksegrp *kg;
394 struct kse_upcall *ku;
395 struct timespec timeout;
396 struct timeval tv;
397 sigset_t sigset;
398 int error;
399
400 p = td->td_proc;
401 kg = td->td_ksegrp;
402 if ((ku = td->td_upcall) == NULL || TD_CAN_UNBIND(td))
403 return (EINVAL);
404 if (uap->timeout != NULL) {
405 if ((error = copyin(uap->timeout, &timeout, sizeof(timeout))))
406 return (error);
407 TIMESPEC_TO_TIMEVAL(&tv, &timeout);
408 }
409 if (td->td_pflags & TDP_SA)
410 td->td_pflags |= TDP_UPCALLING;
411 else {
412 ku->ku_mflags = fuword32(&ku->ku_mailbox->km_flags);
413 if (ku->ku_mflags == -1) {
414 PROC_LOCK(p);
415 sigexit(td, SIGSEGV);
416 }
417 }
418 PROC_LOCK(p);
419 if (ku->ku_mflags & KMF_WAITSIGEVENT) {
420 /* UTS wants to wait for signal event */
421 if (!(p->p_flag & P_SIGEVENT) &&
422 !(ku->ku_flags & KUF_DOUPCALL)) {
423 td->td_kflags |= TDK_KSERELSIG;
424 error = msleep(&p->p_siglist, &p->p_mtx, PPAUSE|PCATCH,
425 "ksesigwait", (uap->timeout ? tvtohz(&tv) : 0));
426 td->td_kflags &= ~(TDK_KSERELSIG | TDK_WAKEUP);
427 }
428 p->p_flag &= ~P_SIGEVENT;
429 sigset = p->p_siglist;
430 PROC_UNLOCK(p);
431 error = copyout(&sigset, &ku->ku_mailbox->km_sigscaught,
432 sizeof(sigset));
433 } else {
434 if ((ku->ku_flags & KUF_DOUPCALL) == 0 &&
435 ((ku->ku_mflags & KMF_NOCOMPLETED) ||
436 (kg->kg_completed == NULL))) {
437 kg->kg_upsleeps++;
438 td->td_kflags |= TDK_KSEREL;
439 error = msleep(&kg->kg_completed, &p->p_mtx,
440 PPAUSE|PCATCH, "kserel",
441 (uap->timeout ? tvtohz(&tv) : 0));
442 td->td_kflags &= ~(TDK_KSEREL | TDK_WAKEUP);
443 kg->kg_upsleeps--;
444 }
445 PROC_UNLOCK(p);
446 }
447 if (ku->ku_flags & KUF_DOUPCALL) {
448 mtx_lock_spin(&sched_lock);
449 ku->ku_flags &= ~KUF_DOUPCALL;
450 mtx_unlock_spin(&sched_lock);
451 }
452 return (0);
453 }
454
455 /* struct kse_wakeup_args {
456 struct kse_mailbox *mbx;
457 }; */
458 int
459 kse_wakeup(struct thread *td, struct kse_wakeup_args *uap)
460 {
461 struct proc *p;
462 struct ksegrp *kg;
463 struct kse_upcall *ku;
464 struct thread *td2;
465
466 p = td->td_proc;
467 td2 = NULL;
468 ku = NULL;
469 /* KSE-enabled processes only, please. */
470 if (!(p->p_flag & P_SA))
471 return (EINVAL);
472 PROC_LOCK(p);
473 mtx_lock_spin(&sched_lock);
474 if (uap->mbx) {
475 FOREACH_KSEGRP_IN_PROC(p, kg) {
476 FOREACH_UPCALL_IN_GROUP(kg, ku) {
477 if (ku->ku_mailbox == uap->mbx)
478 break;
479 }
480 if (ku)
481 break;
482 }
483 } else {
484 kg = td->td_ksegrp;
485 if (kg->kg_upsleeps) {
486 mtx_unlock_spin(&sched_lock);
487 wakeup(&kg->kg_completed);
488 PROC_UNLOCK(p);
489 return (0);
490 }
491 ku = TAILQ_FIRST(&kg->kg_upcalls);
492 }
493 if (ku == NULL) {
494 mtx_unlock_spin(&sched_lock);
495 PROC_UNLOCK(p);
496 return (ESRCH);
497 }
498 if ((td2 = ku->ku_owner) == NULL) {
499 mtx_unlock_spin(&sched_lock);
500 panic("%s: no owner", __func__);
501 } else if (td2->td_kflags & (TDK_KSEREL | TDK_KSERELSIG)) {
502 mtx_unlock_spin(&sched_lock);
503 if (!(td2->td_kflags & TDK_WAKEUP)) {
504 td2->td_kflags |= TDK_WAKEUP;
505 if (td2->td_kflags & TDK_KSEREL)
506 sleepq_remove(td2, &kg->kg_completed);
507 else
508 sleepq_remove(td2, &p->p_siglist);
509 }
510 } else {
511 ku->ku_flags |= KUF_DOUPCALL;
512 mtx_unlock_spin(&sched_lock);
513 }
514 PROC_UNLOCK(p);
515 return (0);
516 }
517
518 /*
519 * No new KSEG: first call: use current KSE, don't schedule an upcall
520 * All other situations, do allocate max new KSEs and schedule an upcall.
521 *
522 * XXX should be changed so that 'first' behaviour lasts for as long
523 * as you have not made a kse in this ksegrp. i.e. as long as we do not have
524 * a mailbox..
525 */
526 /* struct kse_create_args {
527 struct kse_mailbox *mbx;
528 int newgroup;
529 }; */
530 int
531 kse_create(struct thread *td, struct kse_create_args *uap)
532 {
533 struct ksegrp *newkg;
534 struct ksegrp *kg;
535 struct proc *p;
536 struct kse_mailbox mbx;
537 struct kse_upcall *newku;
538 int err, ncpus, sa = 0, first = 0;
539 struct thread *newtd;
540
541 p = td->td_proc;
542 kg = td->td_ksegrp;
543 if ((err = copyin(uap->mbx, &mbx, sizeof(mbx))))
544 return (err);
545
546 ncpus = mp_ncpus;
547 if (virtual_cpu != 0)
548 ncpus = virtual_cpu;
549 /*
550 * If the new UTS mailbox says that this
551 * will be a BOUND lwp, then it had better
552 * have its thread mailbox already there.
553 * In addition, this ksegrp will be limited to
554 * a concurrency of 1. There is more on this later.
555 */
556 if (mbx.km_flags & KMF_BOUND) {
557 if (mbx.km_curthread == NULL)
558 return (EINVAL);
559 ncpus = 1;
560 } else {
561 sa = TDP_SA;
562 }
563
564 PROC_LOCK(p);
565 /*
566 * Processes using the other threading model can't
567 * suddenly start calling this one
568 */
569 if ((p->p_flag & (P_SA|P_HADTHREADS)) == P_HADTHREADS) {
570 PROC_UNLOCK(p);
571 return (EINVAL);
572 }
573
574 /*
575 * Limit it to NCPU upcall contexts per ksegrp in any case.
576 * There is a small race here as we don't hold proclock
577 * until we inc the ksegrp count, but it's not really a big problem
578 * if we get one too many, but we save a proc lock.
579 */
580 if ((!uap->newgroup) && (kg->kg_numupcalls >= ncpus)) {
581 PROC_UNLOCK(p);
582 return (EPROCLIM);
583 }
584
585 if (!(p->p_flag & P_SA)) {
586 first = 1;
587 p->p_flag |= P_SA|P_HADTHREADS;
588 }
589
590 PROC_UNLOCK(p);
591 /*
592 * Now pay attention!
593 * If we are going to be bound, then we need to be either
594 * a new group, or the first call ever. In either
595 * case we will be creating (or be) the only thread in a group.
596 * and the concurrency will be set to 1.
597 * This is not quite right, as we may still make ourself
598 * bound after making other ksegrps but it will do for now.
599 * The library will only try do this much.
600 */
601 if (!sa && !(uap->newgroup || first))
602 return (EINVAL);
603
604 if (uap->newgroup) {
605 newkg = ksegrp_alloc();
606 bzero(&newkg->kg_startzero,
607 __rangeof(struct ksegrp, kg_startzero, kg_endzero));
608 bcopy(&kg->kg_startcopy, &newkg->kg_startcopy,
609 __rangeof(struct ksegrp, kg_startcopy, kg_endcopy));
610 sched_init_concurrency(newkg);
611 PROC_LOCK(p);
612 if (p->p_numksegrps >= max_groups_per_proc) {
613 PROC_UNLOCK(p);
614 ksegrp_free(newkg);
615 return (EPROCLIM);
616 }
617 ksegrp_link(newkg, p);
618 mtx_lock_spin(&sched_lock);
619 sched_fork_ksegrp(td, newkg);
620 mtx_unlock_spin(&sched_lock);
621 PROC_UNLOCK(p);
622 } else {
623 /*
624 * We want to make a thread in our own ksegrp.
625 * If we are just the first call, either kind
626 * is ok, but if not then either we must be
627 * already an upcallable thread to make another,
628 * or a bound thread to make one of those.
629 * Once again, not quite right but good enough for now.. XXXKSE
630 */
631 if (!first && ((td->td_pflags & TDP_SA) != sa))
632 return (EINVAL);
633
634 newkg = kg;
635 }
636
637 /*
638 * This test is a bit "indirect".
639 * It might simplify things if we made a direct way of testing
640 * if a ksegrp has been worked on before.
641 * In the case of a bound request and the concurrency being set to
642 * one, the concurrency will already be 1 so it's just inefficient
643 * but not dangerous to call this again. XXX
644 */
645 if (newkg->kg_numupcalls == 0) {
646 /*
647 * Initialize KSE group with the appropriate
648 * concurrency.
649 *
650 * For a multiplexed group, create as as much concurrency
651 * as the number of physical cpus.
652 * This increases concurrency in the kernel even if the
653 * userland is not MP safe and can only run on a single CPU.
654 * In an ideal world, every physical cpu should execute a
655 * thread. If there is enough concurrency, threads in the
656 * kernel can be executed parallel on different cpus at
657 * full speed without being restricted by the number of
658 * upcalls the userland provides.
659 * Adding more upcall structures only increases concurrency
660 * in userland.
661 *
662 * For a bound thread group, because there is only one thread
663 * in the group, we only set the concurrency for the group
664 * to 1. A thread in this kind of group will never schedule
665 * an upcall when blocked. This simulates pthread system
666 * scope thread behaviour.
667 */
668 sched_set_concurrency(newkg, ncpus);
669 }
670 /*
671 * Even bound LWPs get a mailbox and an upcall to hold it.
672 */
673 newku = upcall_alloc();
674 newku->ku_mailbox = uap->mbx;
675 newku->ku_func = mbx.km_func;
676 bcopy(&mbx.km_stack, &newku->ku_stack, sizeof(stack_t));
677
678 /*
679 * For the first call this may not have been set.
680 * Of course nor may it actually be needed.
681 */
682 if (td->td_standin == NULL)
683 thread_alloc_spare(td);
684
685 PROC_LOCK(p);
686 mtx_lock_spin(&sched_lock);
687 if (newkg->kg_numupcalls >= ncpus) {
688 mtx_unlock_spin(&sched_lock);
689 PROC_UNLOCK(p);
690 upcall_free(newku);
691 return (EPROCLIM);
692 }
693
694 /*
695 * If we are the first time, and a normal thread,
696 * then transfer all the signals back to the 'process'.
697 * SA threading will make a special thread to handle them.
698 */
699 if (first && sa) {
700 SIGSETOR(p->p_siglist, td->td_siglist);
701 SIGEMPTYSET(td->td_siglist);
702 SIGFILLSET(td->td_sigmask);
703 SIG_CANTMASK(td->td_sigmask);
704 }
705
706 /*
707 * Make the new upcall available to the ksegrp.
708 * It may or may not use it, but it's available.
709 */
710 upcall_link(newku, newkg);
711 PROC_UNLOCK(p);
712 if (mbx.km_quantum)
713 newkg->kg_upquantum = max(1, mbx.km_quantum / tick);
714
715 /*
716 * Each upcall structure has an owner thread, find which
717 * one owns it.
718 */
719 if (uap->newgroup) {
720 /*
721 * Because the new ksegrp hasn't a thread,
722 * create an initial upcall thread to own it.
723 */
724 newtd = thread_schedule_upcall(td, newku);
725 } else {
726 /*
727 * If the current thread hasn't an upcall structure,
728 * just assign the upcall to it.
729 * It'll just return.
730 */
731 if (td->td_upcall == NULL) {
732 newku->ku_owner = td;
733 td->td_upcall = newku;
734 newtd = td;
735 } else {
736 /*
737 * Create a new upcall thread to own it.
738 */
739 newtd = thread_schedule_upcall(td, newku);
740 }
741 }
742 mtx_unlock_spin(&sched_lock);
743
744 /*
745 * Let the UTS instance know its LWPID.
746 * It doesn't really care. But the debugger will.
747 */
748 suword32(&newku->ku_mailbox->km_lwp, newtd->td_tid);
749
750 /*
751 * In the same manner, if the UTS has a current user thread,
752 * then it is also running on this LWP so set it as well.
753 * The library could do that of course.. but why not..
754 */
755 if (mbx.km_curthread)
756 suword32(&mbx.km_curthread->tm_lwp, newtd->td_tid);
757
758
759 if (sa) {
760 newtd->td_pflags |= TDP_SA;
761 } else {
762 newtd->td_pflags &= ~TDP_SA;
763
764 /*
765 * Since a library will use the mailbox pointer to
766 * identify even a bound thread, and the mailbox pointer
767 * will never be allowed to change after this syscall
768 * for a bound thread, set it here so the library can
769 * find the thread after the syscall returns.
770 */
771 newtd->td_mailbox = mbx.km_curthread;
772
773 if (newtd != td) {
774 /*
775 * If we did create a new thread then
776 * make sure it goes to the right place
777 * when it starts up, and make sure that it runs
778 * at full speed when it gets there.
779 * thread_schedule_upcall() copies all cpu state
780 * to the new thread, so we should clear single step
781 * flag here.
782 */
783 cpu_set_upcall_kse(newtd, newku->ku_func,
784 newku->ku_mailbox, &newku->ku_stack);
785 if (p->p_flag & P_TRACED)
786 ptrace_clear_single_step(newtd);
787 }
788 }
789
790 /*
791 * If we are starting a new thread, kick it off.
792 */
793 if (newtd != td) {
794 mtx_lock_spin(&sched_lock);
795 setrunqueue(newtd, SRQ_BORING);
796 mtx_unlock_spin(&sched_lock);
797 }
798 return (0);
799 }
800
801 /*
802 * Initialize global thread allocation resources.
803 */
804 void
805 kseinit(void)
806 {
807
808 upcall_zone = uma_zcreate("UPCALL", sizeof(struct kse_upcall),
809 NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
810 }
811
812 /*
813 * Stash an embarasingly extra upcall into the zombie upcall queue.
814 */
815
816 void
817 upcall_stash(struct kse_upcall *ku)
818 {
819 mtx_lock_spin(&kse_zombie_lock);
820 TAILQ_INSERT_HEAD(&zombie_upcalls, ku, ku_link);
821 mtx_unlock_spin(&kse_zombie_lock);
822 }
823
824 /*
825 * Reap zombie kse resource.
826 */
827 void
828 kse_GC(void)
829 {
830 struct kse_upcall *ku_first, *ku_next;
831
832 /*
833 * Don't even bother to lock if none at this instant,
834 * we really don't care about the next instant..
835 */
836 if (!TAILQ_EMPTY(&zombie_upcalls)) {
837 mtx_lock_spin(&kse_zombie_lock);
838 ku_first = TAILQ_FIRST(&zombie_upcalls);
839 if (ku_first)
840 TAILQ_INIT(&zombie_upcalls);
841 mtx_unlock_spin(&kse_zombie_lock);
842 while (ku_first) {
843 ku_next = TAILQ_NEXT(ku_first, ku_link);
844 upcall_free(ku_first);
845 ku_first = ku_next;
846 }
847 }
848 }
849
850 /*
851 * Store the thread context in the UTS's mailbox.
852 * then add the mailbox at the head of a list we are building in user space.
853 * The list is anchored in the ksegrp structure.
854 */
855 int
856 thread_export_context(struct thread *td, int willexit)
857 {
858 struct proc *p;
859 struct ksegrp *kg;
860 uintptr_t mbx;
861 void *addr;
862 int error = 0, sig;
863 mcontext_t mc;
864
865 p = td->td_proc;
866 kg = td->td_ksegrp;
867
868 /*
869 * Post sync signal, or process SIGKILL and SIGSTOP.
870 * For sync signal, it is only possible when the signal is not
871 * caught by userland or process is being debugged.
872 */
873 PROC_LOCK(p);
874 if (td->td_flags & TDF_NEEDSIGCHK) {
875 mtx_lock_spin(&sched_lock);
876 td->td_flags &= ~TDF_NEEDSIGCHK;
877 mtx_unlock_spin(&sched_lock);
878 mtx_lock(&p->p_sigacts->ps_mtx);
879 while ((sig = cursig(td)) != 0)
880 postsig(sig);
881 mtx_unlock(&p->p_sigacts->ps_mtx);
882 }
883 if (willexit)
884 SIGFILLSET(td->td_sigmask);
885 PROC_UNLOCK(p);
886
887 /* Export the user/machine context. */
888 get_mcontext(td, &mc, 0);
889 addr = (void *)(&td->td_mailbox->tm_context.uc_mcontext);
890 error = copyout(&mc, addr, sizeof(mcontext_t));
891 if (error)
892 goto bad;
893
894 addr = (caddr_t)(&td->td_mailbox->tm_lwp);
895 if (suword32(addr, 0)) {
896 error = EFAULT;
897 goto bad;
898 }
899
900 /* Get address in latest mbox of list pointer */
901 addr = (void *)(&td->td_mailbox->tm_next);
902 /*
903 * Put the saved address of the previous first
904 * entry into this one
905 */
906 for (;;) {
907 mbx = (uintptr_t)kg->kg_completed;
908 if (suword(addr, mbx)) {
909 error = EFAULT;
910 goto bad;
911 }
912 PROC_LOCK(p);
913 if (mbx == (uintptr_t)kg->kg_completed) {
914 kg->kg_completed = td->td_mailbox;
915 /*
916 * The thread context may be taken away by
917 * other upcall threads when we unlock
918 * process lock. it's no longer valid to
919 * use it again in any other places.
920 */
921 td->td_mailbox = NULL;
922 PROC_UNLOCK(p);
923 break;
924 }
925 PROC_UNLOCK(p);
926 }
927 td->td_usticks = 0;
928 return (0);
929
930 bad:
931 PROC_LOCK(p);
932 sigexit(td, SIGILL);
933 return (error);
934 }
935
936 /*
937 * Take the list of completed mailboxes for this KSEGRP and put them on this
938 * upcall's mailbox as it's the next one going up.
939 */
940 static int
941 thread_link_mboxes(struct ksegrp *kg, struct kse_upcall *ku)
942 {
943 struct proc *p = kg->kg_proc;
944 void *addr;
945 uintptr_t mbx;
946
947 addr = (void *)(&ku->ku_mailbox->km_completed);
948 for (;;) {
949 mbx = (uintptr_t)kg->kg_completed;
950 if (suword(addr, mbx)) {
951 PROC_LOCK(p);
952 psignal(p, SIGSEGV);
953 PROC_UNLOCK(p);
954 return (EFAULT);
955 }
956 PROC_LOCK(p);
957 if (mbx == (uintptr_t)kg->kg_completed) {
958 kg->kg_completed = NULL;
959 PROC_UNLOCK(p);
960 break;
961 }
962 PROC_UNLOCK(p);
963 }
964 return (0);
965 }
966
967 /*
968 * This function should be called at statclock interrupt time
969 */
970 int
971 thread_statclock(int user)
972 {
973 struct thread *td = curthread;
974
975 if (!(td->td_pflags & TDP_SA))
976 return (0);
977 if (user) {
978 /* Current always do via ast() */
979 mtx_lock_spin(&sched_lock);
980 td->td_flags |= TDF_ASTPENDING;
981 mtx_unlock_spin(&sched_lock);
982 td->td_uuticks++;
983 } else if (td->td_mailbox != NULL)
984 td->td_usticks++;
985 return (0);
986 }
987
988 /*
989 * Export state clock ticks for userland
990 */
991 static int
992 thread_update_usr_ticks(struct thread *td)
993 {
994 struct proc *p = td->td_proc;
995 caddr_t addr;
996 u_int uticks;
997
998 if (td->td_mailbox == NULL)
999 return (-1);
1000
1001 if ((uticks = td->td_uuticks) != 0) {
1002 td->td_uuticks = 0;
1003 addr = (caddr_t)&td->td_mailbox->tm_uticks;
1004 if (suword32(addr, uticks+fuword32(addr)))
1005 goto error;
1006 }
1007 if ((uticks = td->td_usticks) != 0) {
1008 td->td_usticks = 0;
1009 addr = (caddr_t)&td->td_mailbox->tm_sticks;
1010 if (suword32(addr, uticks+fuword32(addr)))
1011 goto error;
1012 }
1013 return (0);
1014
1015 error:
1016 PROC_LOCK(p);
1017 psignal(p, SIGSEGV);
1018 PROC_UNLOCK(p);
1019 return (-2);
1020 }
1021
1022 /*
1023 * This function is intended to be used to initialize a spare thread
1024 * for upcall. Initialize thread's large data area outside sched_lock
1025 * for thread_schedule_upcall(). The crhold is also here to get it out
1026 * from the schedlock as it has a mutex op itself.
1027 * XXX BUG.. we need to get the cr ref after the thread has
1028 * checked and chenged its own, not 6 months before...
1029 */
1030 void
1031 thread_alloc_spare(struct thread *td)
1032 {
1033 struct thread *spare;
1034
1035 if (td->td_standin)
1036 return;
1037 spare = thread_alloc();
1038 td->td_standin = spare;
1039 bzero(&spare->td_startzero,
1040 __rangeof(struct thread, td_startzero, td_endzero));
1041 spare->td_proc = td->td_proc;
1042 spare->td_ucred = crhold(td->td_ucred);
1043 }
1044
1045 /*
1046 * Create a thread and schedule it for upcall on the KSE given.
1047 * Use our thread's standin so that we don't have to allocate one.
1048 */
1049 struct thread *
1050 thread_schedule_upcall(struct thread *td, struct kse_upcall *ku)
1051 {
1052 struct thread *td2;
1053
1054 mtx_assert(&sched_lock, MA_OWNED);
1055
1056 /*
1057 * Schedule an upcall thread on specified kse_upcall,
1058 * the kse_upcall must be free.
1059 * td must have a spare thread.
1060 */
1061 KASSERT(ku->ku_owner == NULL, ("%s: upcall has owner", __func__));
1062 if ((td2 = td->td_standin) != NULL) {
1063 td->td_standin = NULL;
1064 } else {
1065 panic("no reserve thread when scheduling an upcall");
1066 return (NULL);
1067 }
1068 CTR3(KTR_PROC, "thread_schedule_upcall: thread %p (pid %d, %s)",
1069 td2, td->td_proc->p_pid, td->td_proc->p_comm);
1070 /*
1071 * Bzero already done in thread_alloc_spare() because we can't
1072 * do the crhold here because we are in schedlock already.
1073 */
1074 bcopy(&td->td_startcopy, &td2->td_startcopy,
1075 __rangeof(struct thread, td_startcopy, td_endcopy));
1076 thread_link(td2, ku->ku_ksegrp);
1077 /* inherit parts of blocked thread's context as a good template */
1078 cpu_set_upcall(td2, td);
1079 /* Let the new thread become owner of the upcall */
1080 ku->ku_owner = td2;
1081 td2->td_upcall = ku;
1082 td2->td_flags = 0;
1083 td2->td_pflags = TDP_SA|TDP_UPCALLING;
1084 td2->td_state = TDS_CAN_RUN;
1085 td2->td_inhibitors = 0;
1086 SIGFILLSET(td2->td_sigmask);
1087 SIG_CANTMASK(td2->td_sigmask);
1088 sched_fork_thread(td, td2);
1089 return (td2); /* bogus.. should be a void function */
1090 }
1091
1092 /*
1093 * It is only used when thread generated a trap and process is being
1094 * debugged.
1095 */
1096 void
1097 thread_signal_add(struct thread *td, int sig)
1098 {
1099 struct proc *p;
1100 siginfo_t siginfo;
1101 struct sigacts *ps;
1102 int error;
1103
1104 p = td->td_proc;
1105 PROC_LOCK_ASSERT(p, MA_OWNED);
1106 ps = p->p_sigacts;
1107 mtx_assert(&ps->ps_mtx, MA_OWNED);
1108
1109 cpu_thread_siginfo(sig, 0, &siginfo);
1110 mtx_unlock(&ps->ps_mtx);
1111 SIGADDSET(td->td_sigmask, sig);
1112 PROC_UNLOCK(p);
1113 error = copyout(&siginfo, &td->td_mailbox->tm_syncsig, sizeof(siginfo));
1114 if (error) {
1115 PROC_LOCK(p);
1116 sigexit(td, SIGSEGV);
1117 }
1118 PROC_LOCK(p);
1119 mtx_lock(&ps->ps_mtx);
1120 }
1121 #include "opt_sched.h"
1122 struct thread *
1123 thread_switchout(struct thread *td, int flags, struct thread *nextthread)
1124 {
1125 struct kse_upcall *ku;
1126 struct thread *td2;
1127
1128 mtx_assert(&sched_lock, MA_OWNED);
1129
1130 /*
1131 * If the outgoing thread is in threaded group and has never
1132 * scheduled an upcall, decide whether this is a short
1133 * or long term event and thus whether or not to schedule
1134 * an upcall.
1135 * If it is a short term event, just suspend it in
1136 * a way that takes its KSE with it.
1137 * Select the events for which we want to schedule upcalls.
1138 * For now it's just sleep or if thread is suspended but
1139 * process wide suspending flag is not set (debugger
1140 * suspends thread).
1141 * XXXKSE eventually almost any inhibition could do.
1142 */
1143 if (TD_CAN_UNBIND(td) && (td->td_standin) &&
1144 (TD_ON_SLEEPQ(td) || (TD_IS_SUSPENDED(td) &&
1145 !P_SHOULDSTOP(td->td_proc)))) {
1146 /*
1147 * Release ownership of upcall, and schedule an upcall
1148 * thread, this new upcall thread becomes the owner of
1149 * the upcall structure. It will be ahead of us in the
1150 * run queue, so as we are stopping, it should either
1151 * start up immediatly, or at least before us if
1152 * we release our slot.
1153 */
1154 ku = td->td_upcall;
1155 ku->ku_owner = NULL;
1156 td->td_upcall = NULL;
1157 td->td_pflags &= ~TDP_CAN_UNBIND;
1158 td2 = thread_schedule_upcall(td, ku);
1159 if (flags & SW_INVOL || nextthread) {
1160 setrunqueue(td2, SRQ_YIELDING);
1161 } else {
1162 /* Keep up with reality.. we have one extra thread
1163 * in the picture.. and it's 'running'.
1164 */
1165 return td2;
1166 }
1167 }
1168 return (nextthread);
1169 }
1170
1171 /*
1172 * Setup done on the thread when it enters the kernel.
1173 */
1174 void
1175 thread_user_enter(struct thread *td)
1176 {
1177 struct proc *p = td->td_proc;
1178 struct ksegrp *kg;
1179 struct kse_upcall *ku;
1180 struct kse_thr_mailbox *tmbx;
1181 uint32_t flags;
1182
1183 /*
1184 * First check that we shouldn't just abort. we
1185 * can suspend it here or just exit.
1186 */
1187 if (__predict_false(P_SHOULDSTOP(p))) {
1188 PROC_LOCK(p);
1189 thread_suspend_check(0);
1190 PROC_UNLOCK(p);
1191 }
1192
1193 if (!(td->td_pflags & TDP_SA))
1194 return;
1195
1196 /*
1197 * If we are doing a syscall in a KSE environment,
1198 * note where our mailbox is.
1199 */
1200
1201 kg = td->td_ksegrp;
1202 ku = td->td_upcall;
1203
1204 KASSERT(ku != NULL, ("no upcall owned"));
1205 KASSERT(ku->ku_owner == td, ("wrong owner"));
1206 KASSERT(!TD_CAN_UNBIND(td), ("can unbind"));
1207
1208 if (td->td_standin == NULL)
1209 thread_alloc_spare(td);
1210 ku->ku_mflags = fuword32((void *)&ku->ku_mailbox->km_flags);
1211 tmbx = (void *)fuword((void *)&ku->ku_mailbox->km_curthread);
1212 if ((tmbx == NULL) || (tmbx == (void *)-1L) ||
1213 (ku->ku_mflags & KMF_NOUPCALL)) {
1214 td->td_mailbox = NULL;
1215 } else {
1216 flags = fuword32(&tmbx->tm_flags);
1217 /*
1218 * On some architectures, TP register points to thread
1219 * mailbox but not points to kse mailbox, and userland
1220 * can not atomically clear km_curthread, but can
1221 * use TP register, and set TMF_NOUPCALL in thread
1222 * flag to indicate a critical region.
1223 */
1224 if (flags & TMF_NOUPCALL) {
1225 td->td_mailbox = NULL;
1226 } else {
1227 td->td_mailbox = tmbx;
1228 td->td_pflags |= TDP_CAN_UNBIND;
1229 if (__predict_false(p->p_flag & P_TRACED)) {
1230 flags = fuword32(&tmbx->tm_dflags);
1231 if (flags & TMDF_SUSPEND) {
1232 mtx_lock_spin(&sched_lock);
1233 /* fuword can block, check again */
1234 if (td->td_upcall)
1235 ku->ku_flags |= KUF_DOUPCALL;
1236 mtx_unlock_spin(&sched_lock);
1237 }
1238 }
1239 }
1240 }
1241 }
1242
1243 /*
1244 * The extra work we go through if we are a threaded process when we
1245 * return to userland.
1246 *
1247 * If we are a KSE process and returning to user mode, check for
1248 * extra work to do before we return (e.g. for more syscalls
1249 * to complete first). If we were in a critical section, we should
1250 * just return to let it finish. Same if we were in the UTS (in
1251 * which case the mailbox's context's busy indicator will be set).
1252 * The only traps we suport will have set the mailbox.
1253 * We will clear it here.
1254 */
1255 int
1256 thread_userret(struct thread *td, struct trapframe *frame)
1257 {
1258 struct kse_upcall *ku;
1259 struct ksegrp *kg, *kg2;
1260 struct proc *p;
1261 struct timespec ts;
1262 int error = 0, upcalls, uts_crit;
1263
1264 /* Nothing to do with bound thread */
1265 if (!(td->td_pflags & TDP_SA))
1266 return (0);
1267
1268 /*
1269 * Update stat clock count for userland
1270 */
1271 if (td->td_mailbox != NULL) {
1272 thread_update_usr_ticks(td);
1273 uts_crit = 0;
1274 } else {
1275 uts_crit = 1;
1276 }
1277
1278 p = td->td_proc;
1279 kg = td->td_ksegrp;
1280 ku = td->td_upcall;
1281
1282 /*
1283 * Optimisation:
1284 * This thread has not started any upcall.
1285 * If there is no work to report other than ourself,
1286 * then it can return direct to userland.
1287 */
1288 if (TD_CAN_UNBIND(td)) {
1289 td->td_pflags &= ~TDP_CAN_UNBIND;
1290 if ((td->td_flags & TDF_NEEDSIGCHK) == 0 &&
1291 (kg->kg_completed == NULL) &&
1292 (ku->ku_flags & KUF_DOUPCALL) == 0 &&
1293 (kg->kg_upquantum && ticks < kg->kg_nextupcall)) {
1294 nanotime(&ts);
1295 error = copyout(&ts,
1296 (caddr_t)&ku->ku_mailbox->km_timeofday,
1297 sizeof(ts));
1298 td->td_mailbox = 0;
1299 ku->ku_mflags = 0;
1300 if (error)
1301 goto out;
1302 return (0);
1303 }
1304 thread_export_context(td, 0);
1305 /*
1306 * There is something to report, and we own an upcall
1307 * structure, we can go to userland.
1308 * Turn ourself into an upcall thread.
1309 */
1310 td->td_pflags |= TDP_UPCALLING;
1311 } else if (td->td_mailbox && (ku == NULL)) {
1312 thread_export_context(td, 1);
1313 PROC_LOCK(p);
1314 if (kg->kg_upsleeps)
1315 wakeup(&kg->kg_completed);
1316 WITNESS_WARN(WARN_PANIC, &p->p_mtx.mtx_object,
1317 "thread exiting in userret");
1318 mtx_lock_spin(&sched_lock);
1319 thread_stopped(p);
1320 thread_exit();
1321 /* NOTREACHED */
1322 }
1323
1324 KASSERT(ku != NULL, ("upcall is NULL"));
1325 KASSERT(TD_CAN_UNBIND(td) == 0, ("can unbind"));
1326
1327 if (p->p_numthreads > max_threads_per_proc) {
1328 max_threads_hits++;
1329 PROC_LOCK(p);
1330 mtx_lock_spin(&sched_lock);
1331 p->p_maxthrwaits++;
1332 while (p->p_numthreads > max_threads_per_proc) {
1333 upcalls = 0;
1334 FOREACH_KSEGRP_IN_PROC(p, kg2) {
1335 if (kg2->kg_numupcalls == 0)
1336 upcalls++;
1337 else
1338 upcalls += kg2->kg_numupcalls;
1339 }
1340 if (upcalls >= max_threads_per_proc)
1341 break;
1342 mtx_unlock_spin(&sched_lock);
1343 if (msleep(&p->p_numthreads, &p->p_mtx, PPAUSE|PCATCH,
1344 "maxthreads", hz/10) != EWOULDBLOCK) {
1345 mtx_lock_spin(&sched_lock);
1346 break;
1347 } else {
1348 mtx_lock_spin(&sched_lock);
1349 }
1350 }
1351 p->p_maxthrwaits--;
1352 mtx_unlock_spin(&sched_lock);
1353 PROC_UNLOCK(p);
1354 }
1355
1356 if (td->td_pflags & TDP_UPCALLING) {
1357 uts_crit = 0;
1358 kg->kg_nextupcall = ticks + kg->kg_upquantum;
1359 /*
1360 * There is no more work to do and we are going to ride
1361 * this thread up to userland as an upcall.
1362 * Do the last parts of the setup needed for the upcall.
1363 */
1364 CTR3(KTR_PROC, "userret: upcall thread %p (pid %d, %s)",
1365 td, td->td_proc->p_pid, td->td_proc->p_comm);
1366
1367 td->td_pflags &= ~TDP_UPCALLING;
1368 if (ku->ku_flags & KUF_DOUPCALL) {
1369 mtx_lock_spin(&sched_lock);
1370 ku->ku_flags &= ~KUF_DOUPCALL;
1371 mtx_unlock_spin(&sched_lock);
1372 }
1373 /*
1374 * Set user context to the UTS
1375 */
1376 if (!(ku->ku_mflags & KMF_NOUPCALL)) {
1377 cpu_set_upcall_kse(td, ku->ku_func, ku->ku_mailbox,
1378 &ku->ku_stack);
1379 if (p->p_flag & P_TRACED)
1380 ptrace_clear_single_step(td);
1381 error = suword32(&ku->ku_mailbox->km_lwp,
1382 td->td_tid);
1383 if (error)
1384 goto out;
1385 error = suword(&ku->ku_mailbox->km_curthread, 0);
1386 if (error)
1387 goto out;
1388 }
1389
1390 /*
1391 * Unhook the list of completed threads.
1392 * anything that completes after this gets to
1393 * come in next time.
1394 * Put the list of completed thread mailboxes on
1395 * this KSE's mailbox.
1396 */
1397 if (!(ku->ku_mflags & KMF_NOCOMPLETED) &&
1398 (error = thread_link_mboxes(kg, ku)) != 0)
1399 goto out;
1400 }
1401 if (!uts_crit) {
1402 nanotime(&ts);
1403 error = copyout(&ts, &ku->ku_mailbox->km_timeofday, sizeof(ts));
1404 }
1405
1406 out:
1407 if (error) {
1408 /*
1409 * Things are going to be so screwed we should just kill
1410 * the process.
1411 * how do we do that?
1412 */
1413 PROC_LOCK(p);
1414 psignal(p, SIGSEGV);
1415 PROC_UNLOCK(p);
1416 } else {
1417 /*
1418 * Optimisation:
1419 * Ensure that we have a spare thread available,
1420 * for when we re-enter the kernel.
1421 */
1422 if (td->td_standin == NULL)
1423 thread_alloc_spare(td);
1424 }
1425
1426 ku->ku_mflags = 0;
1427 td->td_mailbox = NULL;
1428 td->td_usticks = 0;
1429 return (error); /* go sync */
1430 }
1431
1432 /*
1433 * called after ptrace resumed a process, force all
1434 * virtual CPUs to schedule upcall for SA process,
1435 * because debugger may have changed something in userland,
1436 * we should notice UTS as soon as possible.
1437 */
1438 void
1439 thread_continued(struct proc *p)
1440 {
1441 struct ksegrp *kg;
1442 struct kse_upcall *ku;
1443 struct thread *td;
1444
1445 PROC_LOCK_ASSERT(p, MA_OWNED);
1446 KASSERT(P_SHOULDSTOP(p), ("process not stopped"));
1447
1448 if (!(p->p_flag & P_SA))
1449 return;
1450
1451 if (p->p_flag & P_TRACED) {
1452 FOREACH_KSEGRP_IN_PROC(p, kg) {
1453 td = TAILQ_FIRST(&kg->kg_threads);
1454 if (td == NULL)
1455 continue;
1456 /* not a SA group, nothing to do */
1457 if (!(td->td_pflags & TDP_SA))
1458 continue;
1459 FOREACH_UPCALL_IN_GROUP(kg, ku) {
1460 mtx_lock_spin(&sched_lock);
1461 ku->ku_flags |= KUF_DOUPCALL;
1462 mtx_unlock_spin(&sched_lock);
1463 wakeup(&kg->kg_completed);
1464 }
1465 }
1466 }
1467 }
Cache object: 4aa3b68f87417ded174f0d84e3c6dcf2
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