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 * $FreeBSD$ 29 */ 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/kernel.h> 34 #include <sys/lock.h> 35 #include <sys/malloc.h> 36 #include <sys/mutex.h> 37 #include <sys/proc.h> 38 #include <sys/smp.h> 39 #include <sys/sysctl.h> 40 #include <sys/sysproto.h> 41 #include <sys/filedesc.h> 42 #include <sys/sched.h> 43 #include <sys/signalvar.h> 44 #include <sys/sx.h> 45 #include <sys/tty.h> 46 #include <sys/user.h> 47 #include <sys/jail.h> 48 #include <sys/kse.h> 49 #include <sys/ktr.h> 50 #include <sys/ucontext.h> 51 52 #include <vm/vm.h> 53 #include <vm/vm_object.h> 54 #include <vm/pmap.h> 55 #include <vm/uma.h> 56 #include <vm/vm_map.h> 57 58 #include <machine/frame.h> 59 60 /* 61 * KSEGRP related storage. 62 */ 63 static uma_zone_t ksegrp_zone; 64 static uma_zone_t kse_zone; 65 static uma_zone_t thread_zone; 66 static uma_zone_t upcall_zone; 67 68 /* DEBUG ONLY */ 69 SYSCTL_NODE(_kern, OID_AUTO, threads, CTLFLAG_RW, 0, "thread allocation"); 70 static int thread_debug = 0; 71 SYSCTL_INT(_kern_threads, OID_AUTO, debug, CTLFLAG_RW, 72 &thread_debug, 0, "thread debug"); 73 74 static int max_threads_per_proc = 30; 75 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_per_proc, CTLFLAG_RW, 76 &max_threads_per_proc, 0, "Limit on threads per proc"); 77 78 static int max_groups_per_proc = 5; 79 SYSCTL_INT(_kern_threads, OID_AUTO, max_groups_per_proc, CTLFLAG_RW, 80 &max_groups_per_proc, 0, "Limit on thread groups per proc"); 81 82 static int max_threads_hits; 83 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_hits, CTLFLAG_RD, 84 &max_threads_hits, 0, ""); 85 86 static int virtual_cpu; 87 88 #define RANGEOF(type, start, end) (offsetof(type, end) - offsetof(type, start)) 89 90 TAILQ_HEAD(, thread) zombie_threads = TAILQ_HEAD_INITIALIZER(zombie_threads); 91 TAILQ_HEAD(, kse) zombie_kses = TAILQ_HEAD_INITIALIZER(zombie_kses); 92 TAILQ_HEAD(, ksegrp) zombie_ksegrps = TAILQ_HEAD_INITIALIZER(zombie_ksegrps); 93 TAILQ_HEAD(, kse_upcall) zombie_upcalls = 94 TAILQ_HEAD_INITIALIZER(zombie_upcalls); 95 struct mtx kse_zombie_lock; 96 MTX_SYSINIT(kse_zombie_lock, &kse_zombie_lock, "kse zombie lock", MTX_SPIN); 97 98 static void kse_purge(struct proc *p, struct thread *td); 99 static void kse_purge_group(struct thread *td); 100 static int thread_update_usr_ticks(struct thread *td, int user); 101 static void thread_alloc_spare(struct thread *td, struct thread *spare); 102 103 static int 104 sysctl_kse_virtual_cpu(SYSCTL_HANDLER_ARGS) 105 { 106 int error, new_val; 107 int def_val; 108 109 #ifdef SMP 110 def_val = mp_ncpus; 111 #else 112 def_val = 1; 113 #endif 114 if (virtual_cpu == 0) 115 new_val = def_val; 116 else 117 new_val = virtual_cpu; 118 error = sysctl_handle_int(oidp, &new_val, 0, req); 119 if (error != 0 || req->newptr == NULL) 120 return (error); 121 if (new_val < 0) 122 return (EINVAL); 123 virtual_cpu = new_val; 124 return (0); 125 } 126 127 /* DEBUG ONLY */ 128 SYSCTL_PROC(_kern_threads, OID_AUTO, virtual_cpu, CTLTYPE_INT|CTLFLAG_RW, 129 0, sizeof(virtual_cpu), sysctl_kse_virtual_cpu, "I", 130 "debug virtual cpus"); 131 132 /* 133 * Prepare a thread for use. 134 */ 135 static void 136 thread_ctor(void *mem, int size, void *arg) 137 { 138 struct thread *td; 139 140 td = (struct thread *)mem; 141 td->td_state = TDS_INACTIVE; 142 } 143 144 /* 145 * Reclaim a thread after use. 146 */ 147 static void 148 thread_dtor(void *mem, int size, void *arg) 149 { 150 struct thread *td; 151 152 td = (struct thread *)mem; 153 154 #ifdef INVARIANTS 155 /* Verify that this thread is in a safe state to free. */ 156 switch (td->td_state) { 157 case TDS_INHIBITED: 158 case TDS_RUNNING: 159 case TDS_CAN_RUN: 160 case TDS_RUNQ: 161 /* 162 * We must never unlink a thread that is in one of 163 * these states, because it is currently active. 164 */ 165 panic("bad state for thread unlinking"); 166 /* NOTREACHED */ 167 case TDS_INACTIVE: 168 break; 169 default: 170 panic("bad thread state"); 171 /* NOTREACHED */ 172 } 173 #endif 174 } 175 176 /* 177 * Initialize type-stable parts of a thread (when newly created). 178 */ 179 static void 180 thread_init(void *mem, int size) 181 { 182 struct thread *td; 183 184 td = (struct thread *)mem; 185 mtx_lock(&Giant); 186 pmap_new_thread(td, 0); 187 mtx_unlock(&Giant); 188 cpu_thread_setup(td); 189 td->td_sched = (struct td_sched *)&td[1]; 190 } 191 192 /* 193 * Tear down type-stable parts of a thread (just before being discarded). 194 */ 195 static void 196 thread_fini(void *mem, int size) 197 { 198 struct thread *td; 199 200 td = (struct thread *)mem; 201 pmap_dispose_thread(td); 202 } 203 204 /* 205 * Initialize type-stable parts of a kse (when newly created). 206 */ 207 static void 208 kse_init(void *mem, int size) 209 { 210 struct kse *ke; 211 212 ke = (struct kse *)mem; 213 ke->ke_sched = (struct ke_sched *)&ke[1]; 214 } 215 216 /* 217 * Initialize type-stable parts of a ksegrp (when newly created). 218 */ 219 static void 220 ksegrp_init(void *mem, int size) 221 { 222 struct ksegrp *kg; 223 224 kg = (struct ksegrp *)mem; 225 kg->kg_sched = (struct kg_sched *)&kg[1]; 226 } 227 228 /* 229 * KSE is linked into kse group. 230 */ 231 void 232 kse_link(struct kse *ke, struct ksegrp *kg) 233 { 234 struct proc *p = kg->kg_proc; 235 236 TAILQ_INSERT_HEAD(&kg->kg_kseq, ke, ke_kglist); 237 kg->kg_kses++; 238 ke->ke_state = KES_UNQUEUED; 239 ke->ke_proc = p; 240 ke->ke_ksegrp = kg; 241 ke->ke_thread = NULL; 242 ke->ke_oncpu = NOCPU; 243 ke->ke_flags = 0; 244 } 245 246 void 247 kse_unlink(struct kse *ke) 248 { 249 struct ksegrp *kg; 250 251 mtx_assert(&sched_lock, MA_OWNED); 252 kg = ke->ke_ksegrp; 253 TAILQ_REMOVE(&kg->kg_kseq, ke, ke_kglist); 254 if (ke->ke_state == KES_IDLE) { 255 TAILQ_REMOVE(&kg->kg_iq, ke, ke_kgrlist); 256 kg->kg_idle_kses--; 257 } 258 if (--kg->kg_kses == 0) 259 ksegrp_unlink(kg); 260 /* 261 * Aggregate stats from the KSE 262 */ 263 kse_stash(ke); 264 } 265 266 void 267 ksegrp_link(struct ksegrp *kg, struct proc *p) 268 { 269 270 TAILQ_INIT(&kg->kg_threads); 271 TAILQ_INIT(&kg->kg_runq); /* links with td_runq */ 272 TAILQ_INIT(&kg->kg_slpq); /* links with td_runq */ 273 TAILQ_INIT(&kg->kg_kseq); /* all kses in ksegrp */ 274 TAILQ_INIT(&kg->kg_iq); /* all idle kses in ksegrp */ 275 TAILQ_INIT(&kg->kg_upcalls); /* all upcall structure in ksegrp */ 276 kg->kg_proc = p; 277 /* 278 * the following counters are in the -zero- section 279 * and may not need clearing 280 */ 281 kg->kg_numthreads = 0; 282 kg->kg_runnable = 0; 283 kg->kg_kses = 0; 284 kg->kg_runq_kses = 0; /* XXXKSE change name */ 285 kg->kg_idle_kses = 0; 286 kg->kg_numupcalls = 0; 287 /* link it in now that it's consistent */ 288 p->p_numksegrps++; 289 TAILQ_INSERT_HEAD(&p->p_ksegrps, kg, kg_ksegrp); 290 } 291 292 void 293 ksegrp_unlink(struct ksegrp *kg) 294 { 295 struct proc *p; 296 297 mtx_assert(&sched_lock, MA_OWNED); 298 KASSERT((kg->kg_numthreads == 0), ("ksegrp_unlink: residual threads")); 299 KASSERT((kg->kg_kses == 0), ("ksegrp_unlink: residual kses")); 300 KASSERT((kg->kg_numupcalls == 0), ("ksegrp_unlink: residual upcalls")); 301 302 p = kg->kg_proc; 303 TAILQ_REMOVE(&p->p_ksegrps, kg, kg_ksegrp); 304 p->p_numksegrps--; 305 /* 306 * Aggregate stats from the KSE 307 */ 308 ksegrp_stash(kg); 309 } 310 311 struct kse_upcall * 312 upcall_alloc(void) 313 { 314 struct kse_upcall *ku; 315 316 ku = uma_zalloc(upcall_zone, M_WAITOK); 317 bzero(ku, sizeof(*ku)); 318 return (ku); 319 } 320 321 void 322 upcall_free(struct kse_upcall *ku) 323 { 324 325 uma_zfree(upcall_zone, ku); 326 } 327 328 void 329 upcall_link(struct kse_upcall *ku, struct ksegrp *kg) 330 { 331 332 mtx_assert(&sched_lock, MA_OWNED); 333 TAILQ_INSERT_TAIL(&kg->kg_upcalls, ku, ku_link); 334 ku->ku_ksegrp = kg; 335 kg->kg_numupcalls++; 336 } 337 338 void 339 upcall_unlink(struct kse_upcall *ku) 340 { 341 struct ksegrp *kg = ku->ku_ksegrp; 342 343 mtx_assert(&sched_lock, MA_OWNED); 344 KASSERT(ku->ku_owner == NULL, ("%s: have owner", __func__)); 345 TAILQ_REMOVE(&kg->kg_upcalls, ku, ku_link); 346 kg->kg_numupcalls--; 347 upcall_stash(ku); 348 } 349 350 void 351 upcall_remove(struct thread *td) 352 { 353 354 if (td->td_upcall) { 355 td->td_upcall->ku_owner = NULL; 356 upcall_unlink(td->td_upcall); 357 td->td_upcall = 0; 358 } 359 } 360 361 /* 362 * For a newly created process, 363 * link up all the structures and its initial threads etc. 364 */ 365 void 366 proc_linkup(struct proc *p, struct ksegrp *kg, 367 struct kse *ke, struct thread *td) 368 { 369 370 TAILQ_INIT(&p->p_ksegrps); /* all ksegrps in proc */ 371 TAILQ_INIT(&p->p_threads); /* all threads in proc */ 372 TAILQ_INIT(&p->p_suspended); /* Threads suspended */ 373 p->p_numksegrps = 0; 374 p->p_numthreads = 0; 375 376 ksegrp_link(kg, p); 377 kse_link(ke, kg); 378 thread_link(td, kg); 379 } 380 381 /* 382 struct kse_thr_interrupt_args { 383 struct kse_thr_mailbox * tmbx; 384 }; 385 */ 386 int 387 kse_thr_interrupt(struct thread *td, struct kse_thr_interrupt_args *uap) 388 { 389 struct proc *p; 390 struct thread *td2; 391 392 p = td->td_proc; 393 if (!(p->p_flag & P_THREADED) || (uap->tmbx == NULL)) 394 return (EINVAL); 395 mtx_lock_spin(&sched_lock); 396 FOREACH_THREAD_IN_PROC(p, td2) { 397 if (td2->td_mailbox == uap->tmbx) { 398 td2->td_flags |= TDF_INTERRUPT; 399 if (TD_ON_SLEEPQ(td2) && (td2->td_flags & TDF_SINTR)) { 400 if (td2->td_flags & TDF_CVWAITQ) 401 cv_abort(td2); 402 else 403 abortsleep(td2); 404 } 405 mtx_unlock_spin(&sched_lock); 406 return (0); 407 } 408 } 409 mtx_unlock_spin(&sched_lock); 410 return (ESRCH); 411 } 412 413 /* 414 struct kse_exit_args { 415 register_t dummy; 416 }; 417 */ 418 int 419 kse_exit(struct thread *td, struct kse_exit_args *uap) 420 { 421 struct proc *p; 422 struct ksegrp *kg; 423 struct kse *ke; 424 425 p = td->td_proc; 426 /* 427 * Only UTS can call the syscall and current group 428 * should be a threaded group. 429 */ 430 if ((td->td_mailbox != NULL) || (td->td_ksegrp->kg_numupcalls == 0)) 431 return (EINVAL); 432 KASSERT((td->td_upcall != NULL), ("%s: not own an upcall", __func__)); 433 434 kg = td->td_ksegrp; 435 /* Serialize removing upcall */ 436 PROC_LOCK(p); 437 mtx_lock_spin(&sched_lock); 438 if ((kg->kg_numupcalls == 1) && (kg->kg_numthreads > 1)) { 439 mtx_unlock_spin(&sched_lock); 440 PROC_UNLOCK(p); 441 return (EDEADLK); 442 } 443 ke = td->td_kse; 444 upcall_remove(td); 445 if (p->p_numthreads == 1) { 446 kse_purge(p, td); 447 p->p_flag &= ~P_THREADED; 448 mtx_unlock_spin(&sched_lock); 449 PROC_UNLOCK(p); 450 } else { 451 if (kg->kg_numthreads == 1) { /* Shutdown a group */ 452 kse_purge_group(td); 453 ke->ke_flags |= KEF_EXIT; 454 } 455 thread_exit(); 456 /* NOTREACHED */ 457 } 458 return (0); 459 } 460 461 /* 462 * Either becomes an upcall or waits for an awakening event and 463 * then becomes an upcall. Only error cases return. 464 */ 465 /* 466 struct kse_release_args { 467 struct timespec *timeout; 468 }; 469 */ 470 int 471 kse_release(struct thread *td, struct kse_release_args *uap) 472 { 473 struct proc *p; 474 struct ksegrp *kg; 475 struct timespec ts, ts2, ts3, timeout; 476 struct timeval tv; 477 int error; 478 479 p = td->td_proc; 480 kg = td->td_ksegrp; 481 /* 482 * Only UTS can call the syscall and current group 483 * should be a threaded group. 484 */ 485 if ((td->td_mailbox != NULL) || (td->td_ksegrp->kg_numupcalls == 0)) 486 return (EINVAL); 487 KASSERT((td->td_upcall != NULL), ("%s: not own an upcall", __func__)); 488 if (uap->timeout != NULL) { 489 if ((error = copyin(uap->timeout, &timeout, sizeof(timeout)))) 490 return (error); 491 getnanouptime(&ts); 492 timespecadd(&ts, &timeout); 493 TIMESPEC_TO_TIMEVAL(&tv, &timeout); 494 } 495 mtx_lock_spin(&sched_lock); 496 /* Change OURSELF to become an upcall. */ 497 td->td_flags = TDF_UPCALLING; 498 if (p->p_sflag & PS_NEEDSIGCHK) 499 td->td_flags |= TDF_ASTPENDING; 500 mtx_unlock_spin(&sched_lock); 501 PROC_LOCK(p); 502 while ((td->td_upcall->ku_flags & KUF_DOUPCALL) == 0 && 503 (kg->kg_completed == NULL)) { 504 kg->kg_upsleeps++; 505 error = msleep(&kg->kg_completed, &p->p_mtx, PPAUSE|PCATCH, 506 "kse_rel", (uap->timeout ? tvtohz(&tv) : 0)); 507 kg->kg_upsleeps--; 508 PROC_UNLOCK(p); 509 if (uap->timeout == NULL || error != EWOULDBLOCK) 510 return (0); 511 getnanouptime(&ts2); 512 if (timespeccmp(&ts2, &ts, >=)) 513 return (0); 514 ts3 = ts; 515 timespecsub(&ts3, &ts2); 516 TIMESPEC_TO_TIMEVAL(&tv, &ts3); 517 PROC_LOCK(p); 518 } 519 PROC_UNLOCK(p); 520 return (0); 521 } 522 523 /* struct kse_wakeup_args { 524 struct kse_mailbox *mbx; 525 }; */ 526 int 527 kse_wakeup(struct thread *td, struct kse_wakeup_args *uap) 528 { 529 struct proc *p; 530 struct ksegrp *kg; 531 struct kse_upcall *ku; 532 struct thread *td2; 533 534 p = td->td_proc; 535 td2 = NULL; 536 ku = NULL; 537 /* KSE-enabled processes only, please. */ 538 if (!(p->p_flag & P_THREADED)) 539 return (EINVAL); 540 PROC_LOCK(p); 541 mtx_lock_spin(&sched_lock); 542 if (uap->mbx) { 543 FOREACH_KSEGRP_IN_PROC(p, kg) { 544 FOREACH_UPCALL_IN_GROUP(kg, ku) { 545 if (ku->ku_mailbox == uap->mbx) 546 break; 547 } 548 if (ku) 549 break; 550 } 551 } else { 552 kg = td->td_ksegrp; 553 if (kg->kg_upsleeps) { 554 wakeup_one(&kg->kg_completed); 555 mtx_unlock_spin(&sched_lock); 556 PROC_UNLOCK(p); 557 return (0); 558 } 559 ku = TAILQ_FIRST(&kg->kg_upcalls); 560 } 561 if (ku) { 562 if ((td2 = ku->ku_owner) == NULL) { 563 panic("%s: no owner", __func__); 564 } else if (TD_ON_SLEEPQ(td2) && 565 (td2->td_wchan == &kg->kg_completed)) { 566 abortsleep(td2); 567 } else { 568 ku->ku_flags |= KUF_DOUPCALL; 569 } 570 mtx_unlock_spin(&sched_lock); 571 PROC_UNLOCK(p); 572 return (0); 573 } 574 mtx_unlock_spin(&sched_lock); 575 PROC_UNLOCK(p); 576 return (ESRCH); 577 } 578 579 /* 580 * No new KSEG: first call: use current KSE, don't schedule an upcall 581 * All other situations, do allocate max new KSEs and schedule an upcall. 582 */ 583 /* struct kse_create_args { 584 struct kse_mailbox *mbx; 585 int newgroup; 586 }; */ 587 int 588 kse_create(struct thread *td, struct kse_create_args *uap) 589 { 590 struct kse *newke; 591 struct ksegrp *newkg; 592 struct ksegrp *kg; 593 struct proc *p; 594 struct kse_mailbox mbx; 595 struct kse_upcall *newku; 596 int err, ncpus; 597 598 p = td->td_proc; 599 if ((err = copyin(uap->mbx, &mbx, sizeof(mbx)))) 600 return (err); 601 602 /* Too bad, why hasn't kernel always a cpu counter !? */ 603 #ifdef SMP 604 ncpus = mp_ncpus; 605 #else 606 ncpus = 1; 607 #endif 608 if (thread_debug && virtual_cpu != 0) 609 ncpus = virtual_cpu; 610 611 /* Easier to just set it than to test and set */ 612 p->p_flag |= P_THREADED; 613 kg = td->td_ksegrp; 614 if (uap->newgroup) { 615 /* Have race condition but it is cheap */ 616 if (p->p_numksegrps >= max_groups_per_proc) 617 return (EPROCLIM); 618 /* 619 * If we want a new KSEGRP it doesn't matter whether 620 * we have already fired up KSE mode before or not. 621 * We put the process in KSE mode and create a new KSEGRP. 622 */ 623 newkg = ksegrp_alloc(); 624 bzero(&newkg->kg_startzero, RANGEOF(struct ksegrp, 625 kg_startzero, kg_endzero)); 626 bcopy(&kg->kg_startcopy, &newkg->kg_startcopy, 627 RANGEOF(struct ksegrp, kg_startcopy, kg_endcopy)); 628 mtx_lock_spin(&sched_lock); 629 if (p->p_numksegrps >= max_groups_per_proc) { 630 mtx_unlock_spin(&sched_lock); 631 ksegrp_free(newkg); 632 return (EPROCLIM); 633 } 634 ksegrp_link(newkg, p); 635 mtx_unlock_spin(&sched_lock); 636 } else { 637 newkg = kg; 638 } 639 640 /* 641 * Creating upcalls more than number of physical cpu does 642 * not help performance. 643 */ 644 if (newkg->kg_numupcalls >= ncpus) 645 return (EPROCLIM); 646 647 if (newkg->kg_numupcalls == 0) { 648 /* 649 * Initialize KSE group, optimized for MP. 650 * Create KSEs as many as physical cpus, this increases 651 * concurrent even if userland is not MP safe and can only run 652 * on single CPU (for early version of libpthread, it is true). 653 * In ideal world, every physical cpu should execute a thread. 654 * If there is enough KSEs, threads in kernel can be 655 * executed parallel on different cpus with full speed, 656 * Concurrent in kernel shouldn't be restricted by number of 657 * upcalls userland provides. 658 * Adding more upcall structures only increases concurrent 659 * in userland. 660 * Highest performance configuration is: 661 * N kses = N upcalls = N phyiscal cpus 662 */ 663 while (newkg->kg_kses < ncpus) { 664 newke = kse_alloc(); 665 bzero(&newke->ke_startzero, RANGEOF(struct kse, 666 ke_startzero, ke_endzero)); 667 #if 0 668 mtx_lock_spin(&sched_lock); 669 bcopy(&ke->ke_startcopy, &newke->ke_startcopy, 670 RANGEOF(struct kse, ke_startcopy, ke_endcopy)); 671 mtx_unlock_spin(&sched_lock); 672 #endif 673 mtx_lock_spin(&sched_lock); 674 kse_link(newke, newkg); 675 /* Add engine */ 676 kse_reassign(newke); 677 mtx_unlock_spin(&sched_lock); 678 } 679 } 680 newku = upcall_alloc(); 681 newku->ku_mailbox = uap->mbx; 682 newku->ku_func = mbx.km_func; 683 bcopy(&mbx.km_stack, &newku->ku_stack, sizeof(stack_t)); 684 685 /* For the first call this may not have been set */ 686 if (td->td_standin == NULL) 687 thread_alloc_spare(td, NULL); 688 689 mtx_lock_spin(&sched_lock); 690 if (newkg->kg_numupcalls >= ncpus) { 691 mtx_unlock_spin(&sched_lock); 692 upcall_free(newku); 693 return (EPROCLIM); 694 } 695 upcall_link(newku, newkg); 696 697 /* 698 * Each upcall structure has an owner thread, find which 699 * one owns it. 700 */ 701 if (uap->newgroup) { 702 /* 703 * Because new ksegrp hasn't thread, 704 * create an initial upcall thread to own it. 705 */ 706 thread_schedule_upcall(td, newku); 707 } else { 708 /* 709 * If current thread hasn't an upcall structure, 710 * just assign the upcall to it. 711 */ 712 if (td->td_upcall == NULL) { 713 newku->ku_owner = td; 714 td->td_upcall = newku; 715 } else { 716 /* 717 * Create a new upcall thread to own it. 718 */ 719 thread_schedule_upcall(td, newku); 720 } 721 } 722 mtx_unlock_spin(&sched_lock); 723 return (0); 724 } 725 726 /* 727 * Fill a ucontext_t with a thread's context information. 728 * 729 * This is an analogue to getcontext(3). 730 */ 731 void 732 thread_getcontext(struct thread *td, ucontext_t *uc) 733 { 734 735 /* 736 * XXX this is declared in a MD include file, i386/include/ucontext.h but 737 * is used in MI code. 738 */ 739 #ifdef __i386__ 740 get_mcontext(td, &uc->uc_mcontext); 741 #endif 742 uc->uc_sigmask = td->td_proc->p_sigmask; 743 } 744 745 /* 746 * Set a thread's context from a ucontext_t. 747 * 748 * This is an analogue to setcontext(3). 749 */ 750 int 751 thread_setcontext(struct thread *td, ucontext_t *uc) 752 { 753 int ret; 754 755 /* 756 * XXX this is declared in a MD include file, i386/include/ucontext.h but 757 * is used in MI code. 758 */ 759 #ifdef __i386__ 760 ret = set_mcontext(td, &uc->uc_mcontext); 761 #else 762 ret = ENOSYS; 763 #endif 764 if (ret == 0) { 765 SIG_CANTMASK(uc->uc_sigmask); 766 PROC_LOCK(td->td_proc); 767 td->td_proc->p_sigmask = uc->uc_sigmask; 768 PROC_UNLOCK(td->td_proc); 769 } 770 return (ret); 771 } 772 773 /* 774 * Initialize global thread allocation resources. 775 */ 776 void 777 threadinit(void) 778 { 779 780 #ifndef __ia64__ 781 thread_zone = uma_zcreate("THREAD", sched_sizeof_thread(), 782 thread_ctor, thread_dtor, thread_init, thread_fini, 783 UMA_ALIGN_CACHE, 0); 784 #else 785 /* 786 * XXX the ia64 kstack allocator is really lame and is at the mercy 787 * of contigmallloc(). This hackery is to pre-construct a whole 788 * pile of thread structures with associated kernel stacks early 789 * in the system startup while contigmalloc() still works. Once we 790 * have them, keep them. Sigh. 791 */ 792 thread_zone = uma_zcreate("THREAD", sched_sizeof_thread(), 793 thread_ctor, thread_dtor, thread_init, thread_fini, 794 UMA_ALIGN_CACHE, UMA_ZONE_NOFREE); 795 uma_prealloc(thread_zone, 512); /* XXX arbitary */ 796 #endif 797 ksegrp_zone = uma_zcreate("KSEGRP", sched_sizeof_ksegrp(), 798 NULL, NULL, ksegrp_init, NULL, 799 UMA_ALIGN_CACHE, 0); 800 kse_zone = uma_zcreate("KSE", sched_sizeof_kse(), 801 NULL, NULL, kse_init, NULL, 802 UMA_ALIGN_CACHE, 0); 803 upcall_zone = uma_zcreate("UPCALL", sizeof(struct kse_upcall), 804 NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0); 805 } 806 807 /* 808 * Stash an embarasingly extra thread into the zombie thread queue. 809 */ 810 void 811 thread_stash(struct thread *td) 812 { 813 mtx_lock_spin(&kse_zombie_lock); 814 TAILQ_INSERT_HEAD(&zombie_threads, td, td_runq); 815 mtx_unlock_spin(&kse_zombie_lock); 816 } 817 818 /* 819 * Stash an embarasingly extra kse into the zombie kse queue. 820 */ 821 void 822 kse_stash(struct kse *ke) 823 { 824 mtx_lock_spin(&kse_zombie_lock); 825 TAILQ_INSERT_HEAD(&zombie_kses, ke, ke_procq); 826 mtx_unlock_spin(&kse_zombie_lock); 827 } 828 829 /* 830 * Stash an embarasingly extra upcall into the zombie upcall queue. 831 */ 832 833 void 834 upcall_stash(struct kse_upcall *ku) 835 { 836 mtx_lock_spin(&kse_zombie_lock); 837 TAILQ_INSERT_HEAD(&zombie_upcalls, ku, ku_link); 838 mtx_unlock_spin(&kse_zombie_lock); 839 } 840 841 /* 842 * Stash an embarasingly extra ksegrp into the zombie ksegrp queue. 843 */ 844 void 845 ksegrp_stash(struct ksegrp *kg) 846 { 847 mtx_lock_spin(&kse_zombie_lock); 848 TAILQ_INSERT_HEAD(&zombie_ksegrps, kg, kg_ksegrp); 849 mtx_unlock_spin(&kse_zombie_lock); 850 } 851 852 /* 853 * Reap zombie kse resource. 854 */ 855 void 856 thread_reap(void) 857 { 858 struct thread *td_first, *td_next; 859 struct kse *ke_first, *ke_next; 860 struct ksegrp *kg_first, * kg_next; 861 struct kse_upcall *ku_first, *ku_next; 862 863 /* 864 * Don't even bother to lock if none at this instant, 865 * we really don't care about the next instant.. 866 */ 867 if ((!TAILQ_EMPTY(&zombie_threads)) 868 || (!TAILQ_EMPTY(&zombie_kses)) 869 || (!TAILQ_EMPTY(&zombie_ksegrps)) 870 || (!TAILQ_EMPTY(&zombie_upcalls))) { 871 mtx_lock_spin(&kse_zombie_lock); 872 td_first = TAILQ_FIRST(&zombie_threads); 873 ke_first = TAILQ_FIRST(&zombie_kses); 874 kg_first = TAILQ_FIRST(&zombie_ksegrps); 875 ku_first = TAILQ_FIRST(&zombie_upcalls); 876 if (td_first) 877 TAILQ_INIT(&zombie_threads); 878 if (ke_first) 879 TAILQ_INIT(&zombie_kses); 880 if (kg_first) 881 TAILQ_INIT(&zombie_ksegrps); 882 if (ku_first) 883 TAILQ_INIT(&zombie_upcalls); 884 mtx_unlock_spin(&kse_zombie_lock); 885 while (td_first) { 886 td_next = TAILQ_NEXT(td_first, td_runq); 887 if (td_first->td_ucred) 888 crfree(td_first->td_ucred); 889 thread_free(td_first); 890 td_first = td_next; 891 } 892 while (ke_first) { 893 ke_next = TAILQ_NEXT(ke_first, ke_procq); 894 kse_free(ke_first); 895 ke_first = ke_next; 896 } 897 while (kg_first) { 898 kg_next = TAILQ_NEXT(kg_first, kg_ksegrp); 899 ksegrp_free(kg_first); 900 kg_first = kg_next; 901 } 902 while (ku_first) { 903 ku_next = TAILQ_NEXT(ku_first, ku_link); 904 upcall_free(ku_first); 905 ku_first = ku_next; 906 } 907 } 908 } 909 910 /* 911 * Allocate a ksegrp. 912 */ 913 struct ksegrp * 914 ksegrp_alloc(void) 915 { 916 return (uma_zalloc(ksegrp_zone, M_WAITOK)); 917 } 918 919 /* 920 * Allocate a kse. 921 */ 922 struct kse * 923 kse_alloc(void) 924 { 925 return (uma_zalloc(kse_zone, M_WAITOK)); 926 } 927 928 /* 929 * Allocate a thread. 930 */ 931 struct thread * 932 thread_alloc(void) 933 { 934 thread_reap(); /* check if any zombies to get */ 935 return (uma_zalloc(thread_zone, M_WAITOK)); 936 } 937 938 /* 939 * Deallocate a ksegrp. 940 */ 941 void 942 ksegrp_free(struct ksegrp *td) 943 { 944 uma_zfree(ksegrp_zone, td); 945 } 946 947 /* 948 * Deallocate a kse. 949 */ 950 void 951 kse_free(struct kse *td) 952 { 953 uma_zfree(kse_zone, td); 954 } 955 956 /* 957 * Deallocate a thread. 958 */ 959 void 960 thread_free(struct thread *td) 961 { 962 963 cpu_thread_clean(td); 964 uma_zfree(thread_zone, td); 965 } 966 967 /* 968 * Store the thread context in the UTS's mailbox. 969 * then add the mailbox at the head of a list we are building in user space. 970 * The list is anchored in the ksegrp structure. 971 */ 972 int 973 thread_export_context(struct thread *td) 974 { 975 struct proc *p; 976 struct ksegrp *kg; 977 uintptr_t mbx; 978 void *addr; 979 int error,temp; 980 ucontext_t uc; 981 982 p = td->td_proc; 983 kg = td->td_ksegrp; 984 985 /* Export the user/machine context. */ 986 addr = (void *)(&td->td_mailbox->tm_context); 987 error = copyin(addr, &uc, sizeof(ucontext_t)); 988 if (error) 989 goto bad; 990 991 thread_getcontext(td, &uc); 992 error = copyout(&uc, addr, sizeof(ucontext_t)); 993 if (error) 994 goto bad; 995 996 /* Exports clock ticks in kernel mode */ 997 addr = (caddr_t)(&td->td_mailbox->tm_sticks); 998 temp = fuword(addr) + td->td_usticks; 999 if (suword(addr, temp)) 1000 goto bad; 1001 1002 addr = (caddr_t)(&td->td_mailbox->tm_slices); 1003 temp = fuword(addr) - td->td_usticks; 1004 if (suword(addr, temp)) 1005 goto bad; 1006 1007 /* Get address in latest mbox of list pointer */ 1008 addr = (void *)(&td->td_mailbox->tm_next); 1009 /* 1010 * Put the saved address of the previous first 1011 * entry into this one 1012 */ 1013 for (;;) { 1014 mbx = (uintptr_t)kg->kg_completed; 1015 if (suword(addr, mbx)) { 1016 error = EFAULT; 1017 goto bad; 1018 } 1019 PROC_LOCK(p); 1020 if (mbx == (uintptr_t)kg->kg_completed) { 1021 kg->kg_completed = td->td_mailbox; 1022 /* 1023 * The thread context may be taken away by 1024 * other upcall threads when we unlock 1025 * process lock. it's no longer valid to 1026 * use it again in any other places. 1027 */ 1028 td->td_mailbox = NULL; 1029 PROC_UNLOCK(p); 1030 break; 1031 } 1032 PROC_UNLOCK(p); 1033 } 1034 td->td_usticks = 0; 1035 return (0); 1036 1037 bad: 1038 PROC_LOCK(p); 1039 psignal(p, SIGSEGV); 1040 PROC_UNLOCK(p); 1041 /* The mailbox is bad, don't use it */ 1042 td->td_mailbox = NULL; 1043 td->td_usticks = 0; 1044 return (error); 1045 } 1046 1047 /* 1048 * Take the list of completed mailboxes for this KSEGRP and put them on this 1049 * upcall's mailbox as it's the next one going up. 1050 */ 1051 static int 1052 thread_link_mboxes(struct ksegrp *kg, struct kse_upcall *ku) 1053 { 1054 struct proc *p = kg->kg_proc; 1055 void *addr; 1056 uintptr_t mbx; 1057 1058 addr = (void *)(&ku->ku_mailbox->km_completed); 1059 for (;;) { 1060 mbx = (uintptr_t)kg->kg_completed; 1061 if (suword(addr, mbx)) { 1062 PROC_LOCK(p); 1063 psignal(p, SIGSEGV); 1064 PROC_UNLOCK(p); 1065 return (EFAULT); 1066 } 1067 PROC_LOCK(p); 1068 if (mbx == (uintptr_t)kg->kg_completed) { 1069 kg->kg_completed = NULL; 1070 PROC_UNLOCK(p); 1071 break; 1072 } 1073 PROC_UNLOCK(p); 1074 } 1075 return (0); 1076 } 1077 1078 /* 1079 * This function should be called at statclock interrupt time 1080 */ 1081 int 1082 thread_statclock(int user) 1083 { 1084 struct thread *td = curthread; 1085 1086 if (td->td_ksegrp->kg_numupcalls == 0) 1087 return (-1); 1088 if (user) { 1089 /* Current always do via ast() */ 1090 td->td_flags |= (TDF_USTATCLOCK|TDF_ASTPENDING); 1091 td->td_uuticks++; 1092 } else { 1093 if (td->td_mailbox != NULL) 1094 td->td_usticks++; 1095 else { 1096 /* XXXKSE 1097 * We will call thread_user_enter() for every 1098 * kernel entry in future, so if the thread mailbox 1099 * is NULL, it must be a UTS kernel, don't account 1100 * clock ticks for it. 1101 */ 1102 } 1103 } 1104 return (0); 1105 } 1106 1107 /* 1108 * Export state clock ticks for userland 1109 */ 1110 static int 1111 thread_update_usr_ticks(struct thread *td, int user) 1112 { 1113 struct proc *p = td->td_proc; 1114 struct kse_thr_mailbox *tmbx; 1115 struct kse_upcall *ku; 1116 caddr_t addr; 1117 uint uticks; 1118 int slices; 1119 1120 if ((ku = td->td_upcall) == NULL) 1121 return (-1); 1122 1123 tmbx = (void *)fuword((void *)&ku->ku_mailbox->km_curthread); 1124 if ((tmbx == NULL) || (tmbx == (void *)-1)) 1125 return (-1); 1126 if (user) { 1127 uticks = td->td_uuticks; 1128 td->td_uuticks = 0; 1129 addr = (caddr_t)&tmbx->tm_uticks; 1130 } else { 1131 uticks = td->td_usticks; 1132 td->td_usticks = 0; 1133 addr = (caddr_t)&tmbx->tm_sticks; 1134 } 1135 if (uticks) { 1136 if (suword(addr, uticks+fuword(addr))) { 1137 PROC_LOCK(p); 1138 psignal(p, SIGSEGV); 1139 PROC_UNLOCK(p); 1140 return (-2); 1141 } 1142 addr = (caddr_t)&tmbx->tm_slices; 1143 slices = (int)fuword(addr); 1144 if (slices > 0) { 1145 slices -= (int)uticks; 1146 if (suword(addr, slices)) { 1147 PROC_LOCK(p); 1148 psignal(p, SIGSEGV); 1149 PROC_UNLOCK(p); 1150 return (-2); 1151 } 1152 if (slices <= 0) { 1153 mtx_lock_spin(&sched_lock); 1154 td->td_upcall->ku_flags |= KUF_DOUPCALL; 1155 mtx_unlock_spin(&sched_lock); 1156 } 1157 } 1158 } 1159 return (0); 1160 } 1161 1162 /* 1163 * Discard the current thread and exit from its context. 1164 * 1165 * Because we can't free a thread while we're operating under its context, 1166 * push the current thread into our CPU's deadthread holder. This means 1167 * we needn't worry about someone else grabbing our context before we 1168 * do a cpu_throw(). 1169 */ 1170 void 1171 thread_exit(void) 1172 { 1173 struct thread *td; 1174 struct kse *ke; 1175 struct proc *p; 1176 struct ksegrp *kg; 1177 1178 td = curthread; 1179 kg = td->td_ksegrp; 1180 p = td->td_proc; 1181 ke = td->td_kse; 1182 1183 mtx_assert(&sched_lock, MA_OWNED); 1184 KASSERT(p != NULL, ("thread exiting without a process")); 1185 KASSERT(ke != NULL, ("thread exiting without a kse")); 1186 KASSERT(kg != NULL, ("thread exiting without a kse group")); 1187 PROC_LOCK_ASSERT(p, MA_OWNED); 1188 CTR1(KTR_PROC, "thread_exit: thread %p", td); 1189 KASSERT(!mtx_owned(&Giant), ("dying thread owns giant")); 1190 1191 if (td->td_standin != NULL) { 1192 thread_stash(td->td_standin); 1193 td->td_standin = NULL; 1194 } 1195 1196 cpu_thread_exit(td); /* XXXSMP */ 1197 1198 /* 1199 * The last thread is left attached to the process 1200 * So that the whole bundle gets recycled. Skip 1201 * all this stuff. 1202 */ 1203 if (p->p_numthreads > 1) { 1204 /* 1205 * Unlink this thread from its proc and the kseg. 1206 * In keeping with the other structs we probably should 1207 * have a thread_unlink() that does some of this but it 1208 * would only be called from here (I think) so it would 1209 * be a waste. (might be useful for proc_fini() as well.) 1210 */ 1211 TAILQ_REMOVE(&p->p_threads, td, td_plist); 1212 p->p_numthreads--; 1213 TAILQ_REMOVE(&kg->kg_threads, td, td_kglist); 1214 kg->kg_numthreads--; 1215 if (p->p_maxthrwaits) 1216 wakeup(&p->p_numthreads); 1217 /* 1218 * The test below is NOT true if we are the 1219 * sole exiting thread. P_STOPPED_SNGL is unset 1220 * in exit1() after it is the only survivor. 1221 */ 1222 if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) { 1223 if (p->p_numthreads == p->p_suspcount) { 1224 thread_unsuspend_one(p->p_singlethread); 1225 } 1226 } 1227 1228 /* 1229 * Because each upcall structure has an owner thread, 1230 * owner thread exits only when process is in exiting 1231 * state, so upcall to userland is no longer needed, 1232 * deleting upcall structure is safe here. 1233 * So when all threads in a group is exited, all upcalls 1234 * in the group should be automatically freed. 1235 */ 1236 if (td->td_upcall) 1237 upcall_remove(td); 1238 1239 ke->ke_state = KES_UNQUEUED; 1240 ke->ke_thread = NULL; 1241 /* 1242 * Decide what to do with the KSE attached to this thread. 1243 */ 1244 if (ke->ke_flags & KEF_EXIT) 1245 kse_unlink(ke); 1246 else 1247 kse_reassign(ke); 1248 PROC_UNLOCK(p); 1249 td->td_kse = NULL; 1250 td->td_state = TDS_INACTIVE; 1251 td->td_proc = NULL; 1252 td->td_ksegrp = NULL; 1253 td->td_last_kse = NULL; 1254 PCPU_SET(deadthread, td); 1255 } else { 1256 PROC_UNLOCK(p); 1257 } 1258 cpu_throw(); 1259 /* NOTREACHED */ 1260 } 1261 1262 /* 1263 * Do any thread specific cleanups that may be needed in wait() 1264 * called with Giant held, proc and schedlock not held. 1265 */ 1266 void 1267 thread_wait(struct proc *p) 1268 { 1269 struct thread *td; 1270 1271 KASSERT((p->p_numthreads == 1), ("Muliple threads in wait1()")); 1272 KASSERT((p->p_numksegrps == 1), ("Muliple ksegrps in wait1()")); 1273 FOREACH_THREAD_IN_PROC(p, td) { 1274 if (td->td_standin != NULL) { 1275 thread_free(td->td_standin); 1276 td->td_standin = NULL; 1277 } 1278 cpu_thread_clean(td); 1279 } 1280 thread_reap(); /* check for zombie threads etc. */ 1281 } 1282 1283 /* 1284 * Link a thread to a process. 1285 * set up anything that needs to be initialized for it to 1286 * be used by the process. 1287 * 1288 * Note that we do not link to the proc's ucred here. 1289 * The thread is linked as if running but no KSE assigned. 1290 */ 1291 void 1292 thread_link(struct thread *td, struct ksegrp *kg) 1293 { 1294 struct proc *p; 1295 1296 p = kg->kg_proc; 1297 td->td_state = TDS_INACTIVE; 1298 td->td_proc = p; 1299 td->td_ksegrp = kg; 1300 td->td_last_kse = NULL; 1301 td->td_flags = 0; 1302 td->td_kse = NULL; 1303 1304 LIST_INIT(&td->td_contested); 1305 callout_init(&td->td_slpcallout, 1); 1306 TAILQ_INSERT_HEAD(&p->p_threads, td, td_plist); 1307 TAILQ_INSERT_HEAD(&kg->kg_threads, td, td_kglist); 1308 p->p_numthreads++; 1309 kg->kg_numthreads++; 1310 } 1311 1312 /* 1313 * Purge a ksegrp resource. When a ksegrp is preparing to 1314 * exit, it calls this function. 1315 */ 1316 void 1317 kse_purge_group(struct thread *td) 1318 { 1319 struct ksegrp *kg; 1320 struct kse *ke; 1321 1322 kg = td->td_ksegrp; 1323 KASSERT(kg->kg_numthreads == 1, ("%s: bad thread number", __func__)); 1324 while ((ke = TAILQ_FIRST(&kg->kg_iq)) != NULL) { 1325 KASSERT(ke->ke_state == KES_IDLE, 1326 ("%s: wrong idle KSE state", __func__)); 1327 kse_unlink(ke); 1328 } 1329 KASSERT((kg->kg_kses == 1), 1330 ("%s: ksegrp still has %d KSEs", __func__, kg->kg_kses)); 1331 KASSERT((kg->kg_numupcalls == 0), 1332 ("%s: ksegrp still has %d upcall datas", 1333 __func__, kg->kg_numupcalls)); 1334 } 1335 1336 /* 1337 * Purge a process's KSE resource. When a process is preparing to 1338 * exit, it calls kse_purge to release any extra KSE resources in 1339 * the process. 1340 */ 1341 void 1342 kse_purge(struct proc *p, struct thread *td) 1343 { 1344 struct ksegrp *kg; 1345 struct kse *ke; 1346 1347 KASSERT(p->p_numthreads == 1, ("bad thread number")); 1348 mtx_lock_spin(&sched_lock); 1349 while ((kg = TAILQ_FIRST(&p->p_ksegrps)) != NULL) { 1350 TAILQ_REMOVE(&p->p_ksegrps, kg, kg_ksegrp); 1351 p->p_numksegrps--; 1352 /* 1353 * There is no ownership for KSE, after all threads 1354 * in the group exited, it is possible that some KSEs 1355 * were left in idle queue, gc them now. 1356 */ 1357 while ((ke = TAILQ_FIRST(&kg->kg_iq)) != NULL) { 1358 KASSERT(ke->ke_state == KES_IDLE, 1359 ("%s: wrong idle KSE state", __func__)); 1360 TAILQ_REMOVE(&kg->kg_iq, ke, ke_kgrlist); 1361 kg->kg_idle_kses--; 1362 TAILQ_REMOVE(&kg->kg_kseq, ke, ke_kglist); 1363 kg->kg_kses--; 1364 kse_stash(ke); 1365 } 1366 KASSERT(((kg->kg_kses == 0) && (kg != td->td_ksegrp)) || 1367 ((kg->kg_kses == 1) && (kg == td->td_ksegrp)), 1368 ("ksegrp has wrong kg_kses: %d", kg->kg_kses)); 1369 KASSERT((kg->kg_numupcalls == 0), 1370 ("%s: ksegrp still has %d upcall datas", 1371 __func__, kg->kg_numupcalls)); 1372 1373 if (kg != td->td_ksegrp) 1374 ksegrp_stash(kg); 1375 } 1376 TAILQ_INSERT_HEAD(&p->p_ksegrps, td->td_ksegrp, kg_ksegrp); 1377 p->p_numksegrps++; 1378 mtx_unlock_spin(&sched_lock); 1379 } 1380 1381 /* 1382 * This function is intended to be used to initialize a spare thread 1383 * for upcall. Initialize thread's large data area outside sched_lock 1384 * for thread_schedule_upcall(). 1385 */ 1386 void 1387 thread_alloc_spare(struct thread *td, struct thread *spare) 1388 { 1389 if (td->td_standin) 1390 return; 1391 if (spare == NULL) 1392 spare = thread_alloc(); 1393 td->td_standin = spare; 1394 bzero(&spare->td_startzero, 1395 (unsigned)RANGEOF(struct thread, td_startzero, td_endzero)); 1396 spare->td_proc = td->td_proc; 1397 /* Setup PCB and fork address */ 1398 cpu_set_upcall(spare, td->td_pcb); 1399 /* 1400 * XXXKSE do we really need this? (default values for the 1401 * frame). 1402 */ 1403 bcopy(td->td_frame, spare->td_frame, sizeof(struct trapframe)); 1404 spare->td_ucred = crhold(td->td_ucred); 1405 } 1406 1407 /* 1408 * Create a thread and schedule it for upcall on the KSE given. 1409 * Use our thread's standin so that we don't have to allocate one. 1410 */ 1411 struct thread * 1412 thread_schedule_upcall(struct thread *td, struct kse_upcall *ku) 1413 { 1414 struct thread *td2; 1415 1416 mtx_assert(&sched_lock, MA_OWNED); 1417 1418 /* 1419 * Schedule an upcall thread on specified kse_upcall, 1420 * the kse_upcall must be free. 1421 * td must have a spare thread. 1422 */ 1423 KASSERT(ku->ku_owner == NULL, ("%s: upcall has owner", __func__)); 1424 if ((td2 = td->td_standin) != NULL) { 1425 td->td_standin = NULL; 1426 } else { 1427 panic("no reserve thread when scheduling an upcall"); 1428 return (NULL); 1429 } 1430 CTR3(KTR_PROC, "thread_schedule_upcall: thread %p (pid %d, %s)", 1431 td2, td->td_proc->p_pid, td->td_proc->p_comm); 1432 bcopy(&td->td_startcopy, &td2->td_startcopy, 1433 (unsigned) RANGEOF(struct thread, td_startcopy, td_endcopy)); 1434 thread_link(td2, ku->ku_ksegrp); 1435 /* Let the new thread become owner of the upcall */ 1436 ku->ku_owner = td2; 1437 td2->td_upcall = ku; 1438 td2->td_flags = TDF_UPCALLING; 1439 if (td->td_proc->p_sflag & PS_NEEDSIGCHK) 1440 td2->td_flags |= TDF_ASTPENDING; 1441 td2->td_kse = NULL; 1442 td2->td_state = TDS_CAN_RUN; 1443 td2->td_inhibitors = 0; 1444 setrunqueue(td2); 1445 return (td2); /* bogus.. should be a void function */ 1446 } 1447 1448 void 1449 thread_signal_add(struct thread *td, int sig) 1450 { 1451 struct kse_upcall *ku; 1452 struct proc *p; 1453 sigset_t ss; 1454 int error; 1455 1456 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 1457 td = curthread; 1458 ku = td->td_upcall; 1459 p = td->td_proc; 1460 1461 PROC_UNLOCK(p); 1462 error = copyin(&ku->ku_mailbox->km_sigscaught, &ss, sizeof(sigset_t)); 1463 if (error) 1464 goto error; 1465 1466 SIGADDSET(ss, sig); 1467 1468 error = copyout(&ss, &ku->ku_mailbox->km_sigscaught, sizeof(sigset_t)); 1469 if (error) 1470 goto error; 1471 1472 PROC_LOCK(p); 1473 return; 1474 error: 1475 PROC_LOCK(p); 1476 sigexit(td, SIGILL); 1477 } 1478 1479 1480 /* 1481 * Schedule an upcall to notify a KSE process recieved signals. 1482 * 1483 */ 1484 void 1485 thread_signal_upcall(struct thread *td) 1486 { 1487 mtx_lock_spin(&sched_lock); 1488 td->td_flags |= TDF_UPCALLING; 1489 mtx_unlock_spin(&sched_lock); 1490 1491 return; 1492 } 1493 1494 /* 1495 * Setup done on the thread when it enters the kernel. 1496 * XXXKSE Presently only for syscalls but eventually all kernel entries. 1497 */ 1498 void 1499 thread_user_enter(struct proc *p, struct thread *td) 1500 { 1501 struct ksegrp *kg; 1502 struct kse_upcall *ku; 1503 1504 kg = td->td_ksegrp; 1505 /* 1506 * First check that we shouldn't just abort. 1507 * But check if we are the single thread first! 1508 * XXX p_singlethread not locked, but should be safe. 1509 */ 1510 if ((p->p_flag & P_SINGLE_EXIT) && (p->p_singlethread != td)) { 1511 PROC_LOCK(p); 1512 mtx_lock_spin(&sched_lock); 1513 thread_exit(); 1514 /* NOTREACHED */ 1515 } 1516 1517 /* 1518 * If we are doing a syscall in a KSE environment, 1519 * note where our mailbox is. There is always the 1520 * possibility that we could do this lazily (in kse_reassign()), 1521 * but for now do it every time. 1522 */ 1523 kg = td->td_ksegrp; 1524 if (kg->kg_numupcalls) { 1525 ku = td->td_upcall; 1526 KASSERT(ku, ("%s: no upcall owned", __func__)); 1527 KASSERT((ku->ku_owner == td), ("%s: wrong owner", __func__)); 1528 td->td_mailbox = 1529 (void *)fuword((void *)&ku->ku_mailbox->km_curthread); 1530 if ((td->td_mailbox == NULL) || 1531 (td->td_mailbox == (void *)-1)) { 1532 /* Don't schedule upcall when blocked */ 1533 td->td_mailbox = NULL; 1534 mtx_lock_spin(&sched_lock); 1535 td->td_flags &= ~TDF_CAN_UNBIND; 1536 mtx_unlock_spin(&sched_lock); 1537 } else { 1538 if (td->td_standin == NULL) 1539 thread_alloc_spare(td, NULL); 1540 mtx_lock_spin(&sched_lock); 1541 td->td_flags |= TDF_CAN_UNBIND; 1542 mtx_unlock_spin(&sched_lock); 1543 } 1544 } 1545 } 1546 1547 /* 1548 * The extra work we go through if we are a threaded process when we 1549 * return to userland. 1550 * 1551 * If we are a KSE process and returning to user mode, check for 1552 * extra work to do before we return (e.g. for more syscalls 1553 * to complete first). If we were in a critical section, we should 1554 * just return to let it finish. Same if we were in the UTS (in 1555 * which case the mailbox's context's busy indicator will be set). 1556 * The only traps we suport will have set the mailbox. 1557 * We will clear it here. 1558 */ 1559 int 1560 thread_userret(struct thread *td, struct trapframe *frame) 1561 { 1562 int error = 0, upcalls; 1563 struct kse_upcall *ku; 1564 struct ksegrp *kg, *kg2; 1565 struct proc *p; 1566 struct timespec ts; 1567 1568 p = td->td_proc; 1569 kg = td->td_ksegrp; 1570 1571 /* Nothing to do with non-threaded group/process */ 1572 if (td->td_ksegrp->kg_numupcalls == 0) 1573 return (0); 1574 1575 /* 1576 * Stat clock interrupt hit in userland, it 1577 * is returning from interrupt, charge thread's 1578 * userland time for UTS. 1579 */ 1580 if (td->td_flags & TDF_USTATCLOCK) { 1581 thread_update_usr_ticks(td, 1); 1582 mtx_lock_spin(&sched_lock); 1583 td->td_flags &= ~TDF_USTATCLOCK; 1584 mtx_unlock_spin(&sched_lock); 1585 if (kg->kg_completed || 1586 (td->td_upcall->ku_flags & KUF_DOUPCALL)) 1587 thread_user_enter(p, td); 1588 } 1589 1590 /* 1591 * Optimisation: 1592 * This thread has not started any upcall. 1593 * If there is no work to report other than ourself, 1594 * then it can return direct to userland. 1595 */ 1596 if (TD_CAN_UNBIND(td)) { 1597 mtx_lock_spin(&sched_lock); 1598 td->td_flags &= ~TDF_CAN_UNBIND; 1599 mtx_unlock_spin(&sched_lock); 1600 if ((kg->kg_completed == NULL) && 1601 (td->td_upcall->ku_flags & KUF_DOUPCALL) == 0) { 1602 thread_update_usr_ticks(td, 0); 1603 if (!(kg->kg_completed || 1604 (td->td_upcall->ku_flags & KUF_DOUPCALL))) { 1605 td->td_mailbox = NULL; 1606 return (0); 1607 } 1608 } 1609 error = thread_export_context(td); 1610 if (error) { 1611 /* 1612 * Failing to do the KSE operation just defaults 1613 * back to synchonous operation, so just return from 1614 * the syscall. 1615 */ 1616 return (0); 1617 } 1618 /* 1619 * There is something to report, and we own an upcall 1620 * strucuture, we can go to userland. 1621 * Turn ourself into an upcall thread. 1622 */ 1623 mtx_lock_spin(&sched_lock); 1624 td->td_flags |= TDF_UPCALLING; 1625 mtx_unlock_spin(&sched_lock); 1626 } else if (td->td_mailbox) { 1627 error = thread_export_context(td); 1628 if (error) { 1629 PROC_LOCK(td->td_proc); 1630 mtx_lock_spin(&sched_lock); 1631 /* possibly upcall with error? */ 1632 } else { 1633 PROC_LOCK(td->td_proc); 1634 mtx_lock_spin(&sched_lock); 1635 /* 1636 * There are upcall threads waiting for 1637 * work to do, wake one of them up. 1638 * XXXKSE Maybe wake all of them up. 1639 */ 1640 if (kg->kg_upsleeps) 1641 wakeup_one(&kg->kg_completed); 1642 } 1643 thread_exit(); 1644 /* NOTREACHED */ 1645 } 1646 1647 KASSERT(TD_CAN_UNBIND(td) == 0, ("can unbind")); 1648 1649 if (p->p_numthreads > max_threads_per_proc) { 1650 max_threads_hits++; 1651 PROC_LOCK(p); 1652 while (p->p_numthreads > max_threads_per_proc) { 1653 if (P_SHOULDSTOP(p)) 1654 break; 1655 upcalls = 0; 1656 mtx_lock_spin(&sched_lock); 1657 FOREACH_KSEGRP_IN_PROC(p, kg2) { 1658 if (kg2->kg_numupcalls == 0) 1659 upcalls++; 1660 else 1661 upcalls += kg2->kg_numupcalls; 1662 } 1663 mtx_unlock_spin(&sched_lock); 1664 if (upcalls >= max_threads_per_proc) 1665 break; 1666 p->p_maxthrwaits++; 1667 msleep(&p->p_numthreads, &p->p_mtx, PPAUSE|PCATCH, 1668 "maxthreads", NULL); 1669 p->p_maxthrwaits--; 1670 } 1671 PROC_UNLOCK(p); 1672 } 1673 1674 if (td->td_flags & TDF_UPCALLING) { 1675 ku = td->td_upcall; 1676 /* 1677 * There is no more work to do and we are going to ride 1678 * this thread up to userland as an upcall. 1679 * Do the last parts of the setup needed for the upcall. 1680 */ 1681 CTR3(KTR_PROC, "userret: upcall thread %p (pid %d, %s)", 1682 td, td->td_proc->p_pid, td->td_proc->p_comm); 1683 1684 /* 1685 * Set user context to the UTS. 1686 * Will use Giant in cpu_thread_clean() because it uses 1687 * kmem_free(kernel_map, ...) 1688 */ 1689 cpu_set_upcall_kse(td, ku); 1690 mtx_lock_spin(&sched_lock); 1691 td->td_flags &= ~TDF_UPCALLING; 1692 if (ku->ku_flags & KUF_DOUPCALL) 1693 ku->ku_flags &= ~KUF_DOUPCALL; 1694 mtx_unlock_spin(&sched_lock); 1695 1696 /* 1697 * Unhook the list of completed threads. 1698 * anything that completes after this gets to 1699 * come in next time. 1700 * Put the list of completed thread mailboxes on 1701 * this KSE's mailbox. 1702 */ 1703 error = thread_link_mboxes(kg, ku); 1704 if (error) 1705 goto out; 1706 1707 /* 1708 * Set state and clear the thread mailbox pointer. 1709 * From now on we are just a bound outgoing process. 1710 * **Problem** userret is often called several times. 1711 * it would be nice if this all happenned only on the first 1712 * time through. (the scan for extra work etc.) 1713 */ 1714 error = suword((caddr_t)&ku->ku_mailbox->km_curthread, 0); 1715 if (error) 1716 goto out; 1717 1718 /* Export current system time */ 1719 nanotime(&ts); 1720 error = copyout(&ts, (caddr_t)&ku->ku_mailbox->km_timeofday, 1721 sizeof(ts)); 1722 } 1723 1724 out: 1725 if (error) { 1726 /* 1727 * Things are going to be so screwed we should just kill 1728 * the process. 1729 * how do we do that? 1730 */ 1731 PROC_LOCK(td->td_proc); 1732 psignal(td->td_proc, SIGSEGV); 1733 PROC_UNLOCK(td->td_proc); 1734 } else { 1735 /* 1736 * Optimisation: 1737 * Ensure that we have a spare thread available, 1738 * for when we re-enter the kernel. 1739 */ 1740 if (td->td_standin == NULL) 1741 thread_alloc_spare(td, NULL); 1742 } 1743 1744 /* 1745 * Clear thread mailbox first, then clear system tick count. 1746 * The order is important because thread_statclock() use 1747 * mailbox pointer to see if it is an userland thread or 1748 * an UTS kernel thread. 1749 */ 1750 td->td_mailbox = NULL; 1751 td->td_usticks = 0; 1752 return (error); /* go sync */ 1753 } 1754 1755 /* 1756 * Enforce single-threading. 1757 * 1758 * Returns 1 if the caller must abort (another thread is waiting to 1759 * exit the process or similar). Process is locked! 1760 * Returns 0 when you are successfully the only thread running. 1761 * A process has successfully single threaded in the suspend mode when 1762 * There are no threads in user mode. Threads in the kernel must be 1763 * allowed to continue until they get to the user boundary. They may even 1764 * copy out their return values and data before suspending. They may however be 1765 * accellerated in reaching the user boundary as we will wake up 1766 * any sleeping threads that are interruptable. (PCATCH). 1767 */ 1768 int 1769 thread_single(int force_exit) 1770 { 1771 struct thread *td; 1772 struct thread *td2; 1773 struct proc *p; 1774 1775 td = curthread; 1776 p = td->td_proc; 1777 mtx_assert(&Giant, MA_OWNED); 1778 PROC_LOCK_ASSERT(p, MA_OWNED); 1779 KASSERT((td != NULL), ("curthread is NULL")); 1780 1781 if ((p->p_flag & P_THREADED) == 0) 1782 return (0); 1783 1784 /* Is someone already single threading? */ 1785 if (p->p_singlethread) 1786 return (1); 1787 1788 if (force_exit == SINGLE_EXIT) { 1789 p->p_flag |= P_SINGLE_EXIT; 1790 } else 1791 p->p_flag &= ~P_SINGLE_EXIT; 1792 p->p_flag |= P_STOPPED_SINGLE; 1793 p->p_singlethread = td; 1794 /* XXXKSE Which lock protects the below values? */ 1795 while ((p->p_numthreads - p->p_suspcount) != 1) { 1796 mtx_lock_spin(&sched_lock); 1797 FOREACH_THREAD_IN_PROC(p, td2) { 1798 if (td2 == td) 1799 continue; 1800 td->td_flags |= TDF_ASTPENDING; 1801 if (TD_IS_INHIBITED(td2)) { 1802 if (force_exit == SINGLE_EXIT) { 1803 if (TD_IS_SUSPENDED(td2)) { 1804 thread_unsuspend_one(td2); 1805 } 1806 if (TD_ON_SLEEPQ(td2) && 1807 (td2->td_flags & TDF_SINTR)) { 1808 if (td2->td_flags & TDF_CVWAITQ) 1809 cv_abort(td2); 1810 else 1811 abortsleep(td2); 1812 } 1813 } else { 1814 if (TD_IS_SUSPENDED(td2)) 1815 continue; 1816 /* 1817 * maybe other inhibitted states too? 1818 * XXXKSE Is it totally safe to 1819 * suspend a non-interruptable thread? 1820 */ 1821 if (td2->td_inhibitors & 1822 (TDI_SLEEPING | TDI_SWAPPED)) 1823 thread_suspend_one(td2); 1824 } 1825 } 1826 } 1827 /* 1828 * Maybe we suspended some threads.. was it enough? 1829 */ 1830 if ((p->p_numthreads - p->p_suspcount) == 1) { 1831 mtx_unlock_spin(&sched_lock); 1832 break; 1833 } 1834 1835 /* 1836 * Wake us up when everyone else has suspended. 1837 * In the mean time we suspend as well. 1838 */ 1839 thread_suspend_one(td); 1840 mtx_unlock(&Giant); 1841 PROC_UNLOCK(p); 1842 p->p_stats->p_ru.ru_nvcsw++; 1843 mi_switch(); 1844 mtx_unlock_spin(&sched_lock); 1845 mtx_lock(&Giant); 1846 PROC_LOCK(p); 1847 } 1848 if (force_exit == SINGLE_EXIT) { 1849 if (td->td_upcall) { 1850 mtx_lock_spin(&sched_lock); 1851 upcall_remove(td); 1852 mtx_unlock_spin(&sched_lock); 1853 } 1854 kse_purge(p, td); 1855 } 1856 return (0); 1857 } 1858 1859 /* 1860 * Called in from locations that can safely check to see 1861 * whether we have to suspend or at least throttle for a 1862 * single-thread event (e.g. fork). 1863 * 1864 * Such locations include userret(). 1865 * If the "return_instead" argument is non zero, the thread must be able to 1866 * accept 0 (caller may continue), or 1 (caller must abort) as a result. 1867 * 1868 * The 'return_instead' argument tells the function if it may do a 1869 * thread_exit() or suspend, or whether the caller must abort and back 1870 * out instead. 1871 * 1872 * If the thread that set the single_threading request has set the 1873 * P_SINGLE_EXIT bit in the process flags then this call will never return 1874 * if 'return_instead' is false, but will exit. 1875 * 1876 * P_SINGLE_EXIT | return_instead == 0| return_instead != 0 1877 *---------------+--------------------+--------------------- 1878 * 0 | returns 0 | returns 0 or 1 1879 * | when ST ends | immediatly 1880 *---------------+--------------------+--------------------- 1881 * 1 | thread exits | returns 1 1882 * | | immediatly 1883 * 0 = thread_exit() or suspension ok, 1884 * other = return error instead of stopping the thread. 1885 * 1886 * While a full suspension is under effect, even a single threading 1887 * thread would be suspended if it made this call (but it shouldn't). 1888 * This call should only be made from places where 1889 * thread_exit() would be safe as that may be the outcome unless 1890 * return_instead is set. 1891 */ 1892 int 1893 thread_suspend_check(int return_instead) 1894 { 1895 struct thread *td; 1896 struct proc *p; 1897 struct ksegrp *kg; 1898 1899 td = curthread; 1900 p = td->td_proc; 1901 kg = td->td_ksegrp; 1902 PROC_LOCK_ASSERT(p, MA_OWNED); 1903 while (P_SHOULDSTOP(p)) { 1904 if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) { 1905 KASSERT(p->p_singlethread != NULL, 1906 ("singlethread not set")); 1907 /* 1908 * The only suspension in action is a 1909 * single-threading. Single threader need not stop. 1910 * XXX Should be safe to access unlocked 1911 * as it can only be set to be true by us. 1912 */ 1913 if (p->p_singlethread == td) 1914 return (0); /* Exempt from stopping. */ 1915 } 1916 if (return_instead) 1917 return (1); 1918 1919 /* 1920 * If the process is waiting for us to exit, 1921 * this thread should just suicide. 1922 * Assumes that P_SINGLE_EXIT implies P_STOPPED_SINGLE. 1923 */ 1924 if ((p->p_flag & P_SINGLE_EXIT) && (p->p_singlethread != td)) { 1925 mtx_lock_spin(&sched_lock); 1926 while (mtx_owned(&Giant)) 1927 mtx_unlock(&Giant); 1928 thread_exit(); 1929 } 1930 1931 /* 1932 * When a thread suspends, it just 1933 * moves to the processes's suspend queue 1934 * and stays there. 1935 */ 1936 mtx_lock_spin(&sched_lock); 1937 if ((p->p_flag & P_STOPPED_SIG) && 1938 (p->p_suspcount+1 == p->p_numthreads)) { 1939 mtx_unlock_spin(&sched_lock); 1940 PROC_LOCK(p->p_pptr); 1941 if ((p->p_pptr->p_procsig->ps_flag & 1942 PS_NOCLDSTOP) == 0) { 1943 psignal(p->p_pptr, SIGCHLD); 1944 } 1945 PROC_UNLOCK(p->p_pptr); 1946 mtx_lock_spin(&sched_lock); 1947 } 1948 mtx_assert(&Giant, MA_NOTOWNED); 1949 thread_suspend_one(td); 1950 PROC_UNLOCK(p); 1951 if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) { 1952 if (p->p_numthreads == p->p_suspcount) { 1953 thread_unsuspend_one(p->p_singlethread); 1954 } 1955 } 1956 p->p_stats->p_ru.ru_nivcsw++; 1957 mi_switch(); 1958 mtx_unlock_spin(&sched_lock); 1959 PROC_LOCK(p); 1960 } 1961 return (0); 1962 } 1963 1964 void 1965 thread_suspend_one(struct thread *td) 1966 { 1967 struct proc *p = td->td_proc; 1968 1969 mtx_assert(&sched_lock, MA_OWNED); 1970 p->p_suspcount++; 1971 TD_SET_SUSPENDED(td); 1972 TAILQ_INSERT_TAIL(&p->p_suspended, td, td_runq); 1973 /* 1974 * Hack: If we are suspending but are on the sleep queue 1975 * then we are in msleep or the cv equivalent. We 1976 * want to look like we have two Inhibitors. 1977 * May already be set.. doesn't matter. 1978 */ 1979 if (TD_ON_SLEEPQ(td)) 1980 TD_SET_SLEEPING(td); 1981 } 1982 1983 void 1984 thread_unsuspend_one(struct thread *td) 1985 { 1986 struct proc *p = td->td_proc; 1987 1988 mtx_assert(&sched_lock, MA_OWNED); 1989 TAILQ_REMOVE(&p->p_suspended, td, td_runq); 1990 TD_CLR_SUSPENDED(td); 1991 p->p_suspcount--; 1992 setrunnable(td); 1993 } 1994 1995 /* 1996 * Allow all threads blocked by single threading to continue running. 1997 */ 1998 void 1999 thread_unsuspend(struct proc *p) 2000 { 2001 struct thread *td; 2002 2003 mtx_assert(&sched_lock, MA_OWNED); 2004 PROC_LOCK_ASSERT(p, MA_OWNED); 2005 if (!P_SHOULDSTOP(p)) { 2006 while (( td = TAILQ_FIRST(&p->p_suspended))) { 2007 thread_unsuspend_one(td); 2008 } 2009 } else if ((P_SHOULDSTOP(p) == P_STOPPED_SINGLE) && 2010 (p->p_numthreads == p->p_suspcount)) { 2011 /* 2012 * Stopping everything also did the job for the single 2013 * threading request. Now we've downgraded to single-threaded, 2014 * let it continue. 2015 */ 2016 thread_unsuspend_one(p->p_singlethread); 2017 } 2018 } 2019 2020 void 2021 thread_single_end(void) 2022 { 2023 struct thread *td; 2024 struct proc *p; 2025 2026 td = curthread; 2027 p = td->td_proc; 2028 PROC_LOCK_ASSERT(p, MA_OWNED); 2029 p->p_flag &= ~P_STOPPED_SINGLE; 2030 p->p_singlethread = NULL; 2031 /* 2032 * If there are other threads they mey now run, 2033 * unless of course there is a blanket 'stop order' 2034 * on the process. The single threader must be allowed 2035 * to continue however as this is a bad place to stop. 2036 */ 2037 if ((p->p_numthreads != 1) && (!P_SHOULDSTOP(p))) { 2038 mtx_lock_spin(&sched_lock); 2039 while (( td = TAILQ_FIRST(&p->p_suspended))) { 2040 thread_unsuspend_one(td); 2041 } 2042 mtx_unlock_spin(&sched_lock); 2043 } 2044 } 2045 2046 2047