kern_umtx.c revision 164033
1/*- 2 * Copyright (c) 2004, David Xu <davidxu@freebsd.org> 3 * Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice unmodified, this list of conditions, and the following 11 * disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28#include <sys/cdefs.h> 29__FBSDID("$FreeBSD: head/sys/kern/kern_umtx.c 164033 2006-11-06 13:42:10Z rwatson $"); 30 31#include "opt_compat.h" 32#include <sys/param.h> 33#include <sys/kernel.h> 34#include <sys/limits.h> 35#include <sys/lock.h> 36#include <sys/malloc.h> 37#include <sys/mutex.h> 38#include <sys/priv.h> 39#include <sys/proc.h> 40#include <sys/sched.h> 41#include <sys/sysctl.h> 42#include <sys/sysent.h> 43#include <sys/systm.h> 44#include <sys/sysproto.h> 45#include <sys/eventhandler.h> 46#include <sys/umtx.h> 47 48#include <vm/vm.h> 49#include <vm/vm_param.h> 50#include <vm/pmap.h> 51#include <vm/vm_map.h> 52#include <vm/vm_object.h> 53 54#ifdef COMPAT_IA32 55#include <compat/freebsd32/freebsd32_proto.h> 56#endif 57 58#define TYPE_SIMPLE_LOCK 0 59#define TYPE_SIMPLE_WAIT 1 60#define TYPE_NORMAL_UMUTEX 2 61#define TYPE_PI_UMUTEX 3 62#define TYPE_PP_UMUTEX 4 63#define TYPE_CV 5 64 65/* Key to represent a unique userland synchronous object */ 66struct umtx_key { 67 int hash; 68 int type; 69 int shared; 70 union { 71 struct { 72 vm_object_t object; 73 uintptr_t offset; 74 } shared; 75 struct { 76 struct vmspace *vs; 77 uintptr_t addr; 78 } private; 79 struct { 80 void *a; 81 uintptr_t b; 82 } both; 83 } info; 84}; 85 86/* Priority inheritance mutex info. */ 87struct umtx_pi { 88 /* Owner thread */ 89 struct thread *pi_owner; 90 91 /* Reference count */ 92 int pi_refcount; 93 94 /* List entry to link umtx holding by thread */ 95 TAILQ_ENTRY(umtx_pi) pi_link; 96 97 /* List entry in hash */ 98 TAILQ_ENTRY(umtx_pi) pi_hashlink; 99 100 /* List for waiters */ 101 TAILQ_HEAD(,umtx_q) pi_blocked; 102 103 /* Identify a userland lock object */ 104 struct umtx_key pi_key; 105}; 106 107/* A userland synchronous object user. */ 108struct umtx_q { 109 /* Linked list for the hash. */ 110 TAILQ_ENTRY(umtx_q) uq_link; 111 112 /* Umtx key. */ 113 struct umtx_key uq_key; 114 115 /* Umtx flags. */ 116 int uq_flags; 117#define UQF_UMTXQ 0x0001 118 119 /* The thread waits on. */ 120 struct thread *uq_thread; 121 122 /* 123 * Blocked on PI mutex. read can use chain lock 124 * or sched_lock, write must have both chain lock and 125 * sched_lock being hold. 126 */ 127 struct umtx_pi *uq_pi_blocked; 128 129 /* On blocked list */ 130 TAILQ_ENTRY(umtx_q) uq_lockq; 131 132 /* Thread contending with us */ 133 TAILQ_HEAD(,umtx_pi) uq_pi_contested; 134 135 /* Inherited priority from PP mutex */ 136 u_char uq_inherited_pri; 137}; 138 139TAILQ_HEAD(umtxq_head, umtx_q); 140 141/* Userland lock object's wait-queue chain */ 142struct umtxq_chain { 143 /* Lock for this chain. */ 144 struct mtx uc_lock; 145 146 /* List of sleep queues. */ 147 struct umtxq_head uc_queue; 148 149 /* Busy flag */ 150 char uc_busy; 151 152 /* Chain lock waiters */ 153 int uc_waiters; 154 155 /* All PI in the list */ 156 TAILQ_HEAD(,umtx_pi) uc_pi_list; 157}; 158 159#define UMTXQ_LOCKED_ASSERT(uc) mtx_assert(&(uc)->uc_lock, MA_OWNED) 160 161/* 162 * Don't propagate time-sharing priority, there is a security reason, 163 * a user can simply introduce PI-mutex, let thread A lock the mutex, 164 * and let another thread B block on the mutex, because B is 165 * sleeping, its priority will be boosted, this causes A's priority to 166 * be boosted via priority propagating too and will never be lowered even 167 * if it is using 100%CPU, this is unfair to other processes. 168 */ 169 170#ifdef KSE 171#define UPRI(td) (((td)->td_ksegrp->kg_user_pri >= PRI_MIN_TIMESHARE &&\ 172 (td)->td_ksegrp->kg_user_pri <= PRI_MAX_TIMESHARE) ?\ 173 PRI_MAX_TIMESHARE : (td)->td_ksegrp->kg_user_pri) 174#else 175#define UPRI(td) (((td)->td_user_pri >= PRI_MIN_TIMESHARE &&\ 176 (td)->td_user_pri <= PRI_MAX_TIMESHARE) ?\ 177 PRI_MAX_TIMESHARE : (td)->td_user_pri) 178#endif 179 180#define GOLDEN_RATIO_PRIME 2654404609U 181#define UMTX_CHAINS 128 182#define UMTX_SHIFTS (__WORD_BIT - 7) 183 184#define THREAD_SHARE 0 185#define PROCESS_SHARE 1 186#define AUTO_SHARE 2 187 188#define GET_SHARE(flags) \ 189 (((flags) & USYNC_PROCESS_SHARED) == 0 ? THREAD_SHARE : PROCESS_SHARE) 190 191static uma_zone_t umtx_pi_zone; 192static struct umtxq_chain umtxq_chains[UMTX_CHAINS]; 193static MALLOC_DEFINE(M_UMTX, "umtx", "UMTX queue memory"); 194static int umtx_pi_allocated; 195 196SYSCTL_NODE(_debug, OID_AUTO, umtx, CTLFLAG_RW, 0, "umtx debug"); 197SYSCTL_INT(_debug_umtx, OID_AUTO, umtx_pi_allocated, CTLFLAG_RD, 198 &umtx_pi_allocated, 0, "Allocated umtx_pi"); 199 200static void umtxq_sysinit(void *); 201static void umtxq_hash(struct umtx_key *key); 202static struct umtxq_chain *umtxq_getchain(struct umtx_key *key); 203static void umtxq_lock(struct umtx_key *key); 204static void umtxq_unlock(struct umtx_key *key); 205static void umtxq_busy(struct umtx_key *key); 206static void umtxq_unbusy(struct umtx_key *key); 207static void umtxq_insert(struct umtx_q *uq); 208static void umtxq_remove(struct umtx_q *uq); 209static int umtxq_sleep(struct umtx_q *uq, const char *wmesg, int timo); 210static int umtxq_count(struct umtx_key *key); 211static int umtxq_signal(struct umtx_key *key, int nr_wakeup); 212static int umtx_key_match(const struct umtx_key *k1, const struct umtx_key *k2); 213static int umtx_key_get(void *addr, int type, int share, 214 struct umtx_key *key); 215static void umtx_key_release(struct umtx_key *key); 216static struct umtx_pi *umtx_pi_alloc(int); 217static void umtx_pi_free(struct umtx_pi *pi); 218static int do_unlock_pp(struct thread *td, struct umutex *m, uint32_t flags); 219static void umtx_thread_cleanup(struct thread *td); 220static void umtx_exec_hook(void *arg __unused, struct proc *p __unused, 221 struct image_params *imgp __unused); 222SYSINIT(umtx, SI_SUB_EVENTHANDLER+1, SI_ORDER_MIDDLE, umtxq_sysinit, NULL); 223 224static void 225umtxq_sysinit(void *arg __unused) 226{ 227 int i; 228 229 umtx_pi_zone = uma_zcreate("umtx pi", sizeof(struct umtx_pi), 230 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 231 for (i = 0; i < UMTX_CHAINS; ++i) { 232 mtx_init(&umtxq_chains[i].uc_lock, "umtxql", NULL, 233 MTX_DEF | MTX_DUPOK); 234 TAILQ_INIT(&umtxq_chains[i].uc_queue); 235 TAILQ_INIT(&umtxq_chains[i].uc_pi_list); 236 umtxq_chains[i].uc_busy = 0; 237 umtxq_chains[i].uc_waiters = 0; 238 } 239 EVENTHANDLER_REGISTER(process_exec, umtx_exec_hook, NULL, 240 EVENTHANDLER_PRI_ANY); 241} 242 243struct umtx_q * 244umtxq_alloc(void) 245{ 246 struct umtx_q *uq; 247 248 uq = malloc(sizeof(struct umtx_q), M_UMTX, M_WAITOK | M_ZERO); 249 TAILQ_INIT(&uq->uq_pi_contested); 250 uq->uq_inherited_pri = PRI_MAX; 251 return (uq); 252} 253 254void 255umtxq_free(struct umtx_q *uq) 256{ 257 free(uq, M_UMTX); 258} 259 260static inline void 261umtxq_hash(struct umtx_key *key) 262{ 263 unsigned n = (uintptr_t)key->info.both.a + key->info.both.b; 264 key->hash = ((n * GOLDEN_RATIO_PRIME) >> UMTX_SHIFTS) % UMTX_CHAINS; 265} 266 267static inline int 268umtx_key_match(const struct umtx_key *k1, const struct umtx_key *k2) 269{ 270 return (k1->type == k2->type && 271 k1->info.both.a == k2->info.both.a && 272 k1->info.both.b == k2->info.both.b); 273} 274 275static inline struct umtxq_chain * 276umtxq_getchain(struct umtx_key *key) 277{ 278 return (&umtxq_chains[key->hash]); 279} 280 281/* 282 * Set chain to busy state when following operation 283 * may be blocked (kernel mutex can not be used). 284 */ 285static inline void 286umtxq_busy(struct umtx_key *key) 287{ 288 struct umtxq_chain *uc; 289 290 uc = umtxq_getchain(key); 291 mtx_assert(&uc->uc_lock, MA_OWNED); 292 while (uc->uc_busy != 0) { 293 uc->uc_waiters++; 294 msleep(uc, &uc->uc_lock, 0, "umtxqb", 0); 295 uc->uc_waiters--; 296 } 297 uc->uc_busy = 1; 298} 299 300/* 301 * Unbusy a chain. 302 */ 303static inline void 304umtxq_unbusy(struct umtx_key *key) 305{ 306 struct umtxq_chain *uc; 307 308 uc = umtxq_getchain(key); 309 mtx_assert(&uc->uc_lock, MA_OWNED); 310 KASSERT(uc->uc_busy != 0, ("not busy")); 311 uc->uc_busy = 0; 312 if (uc->uc_waiters) 313 wakeup_one(uc); 314} 315 316/* 317 * Lock a chain. 318 */ 319static inline void 320umtxq_lock(struct umtx_key *key) 321{ 322 struct umtxq_chain *uc; 323 324 uc = umtxq_getchain(key); 325 mtx_lock(&uc->uc_lock); 326} 327 328/* 329 * Unlock a chain. 330 */ 331static inline void 332umtxq_unlock(struct umtx_key *key) 333{ 334 struct umtxq_chain *uc; 335 336 uc = umtxq_getchain(key); 337 mtx_unlock(&uc->uc_lock); 338} 339 340/* 341 * Insert a thread onto the umtx queue. 342 */ 343static inline void 344umtxq_insert(struct umtx_q *uq) 345{ 346 struct umtxq_chain *uc; 347 348 uc = umtxq_getchain(&uq->uq_key); 349 UMTXQ_LOCKED_ASSERT(uc); 350 TAILQ_INSERT_TAIL(&uc->uc_queue, uq, uq_link); 351 uq->uq_flags |= UQF_UMTXQ; 352} 353 354/* 355 * Remove thread from the umtx queue. 356 */ 357static inline void 358umtxq_remove(struct umtx_q *uq) 359{ 360 struct umtxq_chain *uc; 361 362 uc = umtxq_getchain(&uq->uq_key); 363 UMTXQ_LOCKED_ASSERT(uc); 364 if (uq->uq_flags & UQF_UMTXQ) { 365 TAILQ_REMOVE(&uc->uc_queue, uq, uq_link); 366 uq->uq_flags &= ~UQF_UMTXQ; 367 } 368} 369 370/* 371 * Check if there are multiple waiters 372 */ 373static int 374umtxq_count(struct umtx_key *key) 375{ 376 struct umtxq_chain *uc; 377 struct umtx_q *uq; 378 int count = 0; 379 380 uc = umtxq_getchain(key); 381 UMTXQ_LOCKED_ASSERT(uc); 382 TAILQ_FOREACH(uq, &uc->uc_queue, uq_link) { 383 if (umtx_key_match(&uq->uq_key, key)) { 384 if (++count > 1) 385 break; 386 } 387 } 388 return (count); 389} 390 391/* 392 * Check if there are multiple PI waiters and returns first 393 * waiter. 394 */ 395static int 396umtxq_count_pi(struct umtx_key *key, struct umtx_q **first) 397{ 398 struct umtxq_chain *uc; 399 struct umtx_q *uq; 400 int count = 0; 401 402 *first = NULL; 403 uc = umtxq_getchain(key); 404 UMTXQ_LOCKED_ASSERT(uc); 405 TAILQ_FOREACH(uq, &uc->uc_queue, uq_link) { 406 if (umtx_key_match(&uq->uq_key, key)) { 407 if (++count > 1) 408 break; 409 *first = uq; 410 } 411 } 412 return (count); 413} 414 415/* 416 * Wake up threads waiting on an userland object. 417 */ 418static int 419umtxq_signal(struct umtx_key *key, int n_wake) 420{ 421 struct umtxq_chain *uc; 422 struct umtx_q *uq, *next; 423 int ret; 424 425 ret = 0; 426 uc = umtxq_getchain(key); 427 UMTXQ_LOCKED_ASSERT(uc); 428 TAILQ_FOREACH_SAFE(uq, &uc->uc_queue, uq_link, next) { 429 if (umtx_key_match(&uq->uq_key, key)) { 430 umtxq_remove(uq); 431 wakeup(uq); 432 if (++ret >= n_wake) 433 break; 434 } 435 } 436 return (ret); 437} 438 439/* 440 * Wake up specified thread. 441 */ 442static inline void 443umtxq_signal_thread(struct umtx_q *uq) 444{ 445 struct umtxq_chain *uc; 446 447 uc = umtxq_getchain(&uq->uq_key); 448 UMTXQ_LOCKED_ASSERT(uc); 449 umtxq_remove(uq); 450 wakeup(uq); 451} 452 453/* 454 * Put thread into sleep state, before sleeping, check if 455 * thread was removed from umtx queue. 456 */ 457static inline int 458umtxq_sleep(struct umtx_q *uq, const char *wmesg, int timo) 459{ 460 struct umtxq_chain *uc; 461 int error; 462 463 uc = umtxq_getchain(&uq->uq_key); 464 UMTXQ_LOCKED_ASSERT(uc); 465 if (!(uq->uq_flags & UQF_UMTXQ)) 466 return (0); 467 error = msleep(uq, &uc->uc_lock, PCATCH, wmesg, timo); 468 if (error == EWOULDBLOCK) 469 error = ETIMEDOUT; 470 return (error); 471} 472 473/* 474 * Convert userspace address into unique logical address. 475 */ 476static int 477umtx_key_get(void *addr, int type, int share, struct umtx_key *key) 478{ 479 struct thread *td = curthread; 480 vm_map_t map; 481 vm_map_entry_t entry; 482 vm_pindex_t pindex; 483 vm_prot_t prot; 484 boolean_t wired; 485 486 key->type = type; 487 if (share == THREAD_SHARE) { 488 key->shared = 0; 489 key->info.private.vs = td->td_proc->p_vmspace; 490 key->info.private.addr = (uintptr_t)addr; 491 } else { 492 MPASS(share == PROCESS_SHARE || share == AUTO_SHARE); 493 map = &td->td_proc->p_vmspace->vm_map; 494 if (vm_map_lookup(&map, (vm_offset_t)addr, VM_PROT_WRITE, 495 &entry, &key->info.shared.object, &pindex, &prot, 496 &wired) != KERN_SUCCESS) { 497 return EFAULT; 498 } 499 500 if ((share == PROCESS_SHARE) || 501 (share == AUTO_SHARE && 502 VM_INHERIT_SHARE == entry->inheritance)) { 503 key->shared = 1; 504 key->info.shared.offset = entry->offset + entry->start - 505 (vm_offset_t)addr; 506 vm_object_reference(key->info.shared.object); 507 } else { 508 key->shared = 0; 509 key->info.private.vs = td->td_proc->p_vmspace; 510 key->info.private.addr = (uintptr_t)addr; 511 } 512 vm_map_lookup_done(map, entry); 513 } 514 515 umtxq_hash(key); 516 return (0); 517} 518 519/* 520 * Release key. 521 */ 522static inline void 523umtx_key_release(struct umtx_key *key) 524{ 525 if (key->shared) 526 vm_object_deallocate(key->info.shared.object); 527} 528 529/* 530 * Lock a umtx object. 531 */ 532static int 533_do_lock_umtx(struct thread *td, struct umtx *umtx, u_long id, int timo) 534{ 535 struct umtx_q *uq; 536 u_long owner; 537 u_long old; 538 int error = 0; 539 540 uq = td->td_umtxq; 541 542 /* 543 * Care must be exercised when dealing with umtx structure. It 544 * can fault on any access. 545 */ 546 for (;;) { 547 /* 548 * Try the uncontested case. This should be done in userland. 549 */ 550 owner = casuword(&umtx->u_owner, UMTX_UNOWNED, id); 551 552 /* The acquire succeeded. */ 553 if (owner == UMTX_UNOWNED) 554 return (0); 555 556 /* The address was invalid. */ 557 if (owner == -1) 558 return (EFAULT); 559 560 /* If no one owns it but it is contested try to acquire it. */ 561 if (owner == UMTX_CONTESTED) { 562 owner = casuword(&umtx->u_owner, 563 UMTX_CONTESTED, id | UMTX_CONTESTED); 564 565 if (owner == UMTX_CONTESTED) 566 return (0); 567 568 /* The address was invalid. */ 569 if (owner == -1) 570 return (EFAULT); 571 572 /* If this failed the lock has changed, restart. */ 573 continue; 574 } 575 576 /* 577 * If we caught a signal, we have retried and now 578 * exit immediately. 579 */ 580 if (error != 0) 581 return (error); 582 583 if ((error = umtx_key_get(umtx, TYPE_SIMPLE_LOCK, 584 AUTO_SHARE, &uq->uq_key)) != 0) 585 return (error); 586 587 umtxq_lock(&uq->uq_key); 588 umtxq_busy(&uq->uq_key); 589 umtxq_insert(uq); 590 umtxq_unbusy(&uq->uq_key); 591 umtxq_unlock(&uq->uq_key); 592 593 /* 594 * Set the contested bit so that a release in user space 595 * knows to use the system call for unlock. If this fails 596 * either some one else has acquired the lock or it has been 597 * released. 598 */ 599 old = casuword(&umtx->u_owner, owner, owner | UMTX_CONTESTED); 600 601 /* The address was invalid. */ 602 if (old == -1) { 603 umtxq_lock(&uq->uq_key); 604 umtxq_remove(uq); 605 umtxq_unlock(&uq->uq_key); 606 umtx_key_release(&uq->uq_key); 607 return (EFAULT); 608 } 609 610 /* 611 * We set the contested bit, sleep. Otherwise the lock changed 612 * and we need to retry or we lost a race to the thread 613 * unlocking the umtx. 614 */ 615 umtxq_lock(&uq->uq_key); 616 if (old == owner) 617 error = umtxq_sleep(uq, "umtx", timo); 618 umtxq_remove(uq); 619 umtxq_unlock(&uq->uq_key); 620 umtx_key_release(&uq->uq_key); 621 } 622 623 return (0); 624} 625 626/* 627 * Lock a umtx object. 628 */ 629static int 630do_lock_umtx(struct thread *td, struct umtx *umtx, u_long id, 631 struct timespec *timeout) 632{ 633 struct timespec ts, ts2, ts3; 634 struct timeval tv; 635 int error; 636 637 if (timeout == NULL) { 638 error = _do_lock_umtx(td, umtx, id, 0); 639 /* Mutex locking is restarted if it is interrupted. */ 640 if (error == EINTR) 641 error = ERESTART; 642 } else { 643 getnanouptime(&ts); 644 timespecadd(&ts, timeout); 645 TIMESPEC_TO_TIMEVAL(&tv, timeout); 646 for (;;) { 647 error = _do_lock_umtx(td, umtx, id, tvtohz(&tv)); 648 if (error != ETIMEDOUT) 649 break; 650 getnanouptime(&ts2); 651 if (timespeccmp(&ts2, &ts, >=)) { 652 error = ETIMEDOUT; 653 break; 654 } 655 ts3 = ts; 656 timespecsub(&ts3, &ts2); 657 TIMESPEC_TO_TIMEVAL(&tv, &ts3); 658 } 659 /* Timed-locking is not restarted. */ 660 if (error == ERESTART) 661 error = EINTR; 662 } 663 return (error); 664} 665 666/* 667 * Unlock a umtx object. 668 */ 669static int 670do_unlock_umtx(struct thread *td, struct umtx *umtx, u_long id) 671{ 672 struct umtx_key key; 673 u_long owner; 674 u_long old; 675 int error; 676 int count; 677 678 /* 679 * Make sure we own this mtx. 680 */ 681 owner = fuword(__DEVOLATILE(u_long *, &umtx->u_owner)); 682 if (owner == -1) 683 return (EFAULT); 684 685 if ((owner & ~UMTX_CONTESTED) != id) 686 return (EPERM); 687 688 /* This should be done in userland */ 689 if ((owner & UMTX_CONTESTED) == 0) { 690 old = casuword(&umtx->u_owner, owner, UMTX_UNOWNED); 691 if (old == -1) 692 return (EFAULT); 693 if (old == owner) 694 return (0); 695 owner = old; 696 } 697 698 /* We should only ever be in here for contested locks */ 699 if ((error = umtx_key_get(umtx, TYPE_SIMPLE_LOCK, AUTO_SHARE, 700 &key)) != 0) 701 return (error); 702 703 umtxq_lock(&key); 704 umtxq_busy(&key); 705 count = umtxq_count(&key); 706 umtxq_unlock(&key); 707 708 /* 709 * When unlocking the umtx, it must be marked as unowned if 710 * there is zero or one thread only waiting for it. 711 * Otherwise, it must be marked as contested. 712 */ 713 old = casuword(&umtx->u_owner, owner, 714 count <= 1 ? UMTX_UNOWNED : UMTX_CONTESTED); 715 umtxq_lock(&key); 716 umtxq_signal(&key,1); 717 umtxq_unbusy(&key); 718 umtxq_unlock(&key); 719 umtx_key_release(&key); 720 if (old == -1) 721 return (EFAULT); 722 if (old != owner) 723 return (EINVAL); 724 return (0); 725} 726 727#ifdef COMPAT_IA32 728 729/* 730 * Lock a umtx object. 731 */ 732static int 733_do_lock_umtx32(struct thread *td, uint32_t *m, uint32_t id, int timo) 734{ 735 struct umtx_q *uq; 736 uint32_t owner; 737 uint32_t old; 738 int error = 0; 739 740 uq = td->td_umtxq; 741 742 /* 743 * Care must be exercised when dealing with umtx structure. It 744 * can fault on any access. 745 */ 746 for (;;) { 747 /* 748 * Try the uncontested case. This should be done in userland. 749 */ 750 owner = casuword32(m, UMUTEX_UNOWNED, id); 751 752 /* The acquire succeeded. */ 753 if (owner == UMUTEX_UNOWNED) 754 return (0); 755 756 /* The address was invalid. */ 757 if (owner == -1) 758 return (EFAULT); 759 760 /* If no one owns it but it is contested try to acquire it. */ 761 if (owner == UMUTEX_CONTESTED) { 762 owner = casuword32(m, 763 UMUTEX_CONTESTED, id | UMUTEX_CONTESTED); 764 if (owner == UMUTEX_CONTESTED) 765 return (0); 766 767 /* The address was invalid. */ 768 if (owner == -1) 769 return (EFAULT); 770 771 /* If this failed the lock has changed, restart. */ 772 continue; 773 } 774 775 /* 776 * If we caught a signal, we have retried and now 777 * exit immediately. 778 */ 779 if (error != 0) 780 return (error); 781 782 if ((error = umtx_key_get(m, TYPE_SIMPLE_LOCK, 783 AUTO_SHARE, &uq->uq_key)) != 0) 784 return (error); 785 786 umtxq_lock(&uq->uq_key); 787 umtxq_busy(&uq->uq_key); 788 umtxq_insert(uq); 789 umtxq_unbusy(&uq->uq_key); 790 umtxq_unlock(&uq->uq_key); 791 792 /* 793 * Set the contested bit so that a release in user space 794 * knows to use the system call for unlock. If this fails 795 * either some one else has acquired the lock or it has been 796 * released. 797 */ 798 old = casuword32(m, owner, owner | UMUTEX_CONTESTED); 799 800 /* The address was invalid. */ 801 if (old == -1) { 802 umtxq_lock(&uq->uq_key); 803 umtxq_remove(uq); 804 umtxq_unlock(&uq->uq_key); 805 umtx_key_release(&uq->uq_key); 806 return (EFAULT); 807 } 808 809 /* 810 * We set the contested bit, sleep. Otherwise the lock changed 811 * and we need to retry or we lost a race to the thread 812 * unlocking the umtx. 813 */ 814 umtxq_lock(&uq->uq_key); 815 if (old == owner) 816 error = umtxq_sleep(uq, "umtx", timo); 817 umtxq_remove(uq); 818 umtxq_unlock(&uq->uq_key); 819 umtx_key_release(&uq->uq_key); 820 } 821 822 return (0); 823} 824 825/* 826 * Lock a umtx object. 827 */ 828static int 829do_lock_umtx32(struct thread *td, void *m, uint32_t id, 830 struct timespec *timeout) 831{ 832 struct timespec ts, ts2, ts3; 833 struct timeval tv; 834 int error; 835 836 if (timeout == NULL) { 837 error = _do_lock_umtx32(td, m, id, 0); 838 /* Mutex locking is restarted if it is interrupted. */ 839 if (error == EINTR) 840 error = ERESTART; 841 } else { 842 getnanouptime(&ts); 843 timespecadd(&ts, timeout); 844 TIMESPEC_TO_TIMEVAL(&tv, timeout); 845 for (;;) { 846 error = _do_lock_umtx32(td, m, id, tvtohz(&tv)); 847 if (error != ETIMEDOUT) 848 break; 849 getnanouptime(&ts2); 850 if (timespeccmp(&ts2, &ts, >=)) { 851 error = ETIMEDOUT; 852 break; 853 } 854 ts3 = ts; 855 timespecsub(&ts3, &ts2); 856 TIMESPEC_TO_TIMEVAL(&tv, &ts3); 857 } 858 /* Timed-locking is not restarted. */ 859 if (error == ERESTART) 860 error = EINTR; 861 } 862 return (error); 863} 864 865/* 866 * Unlock a umtx object. 867 */ 868static int 869do_unlock_umtx32(struct thread *td, uint32_t *m, uint32_t id) 870{ 871 struct umtx_key key; 872 uint32_t owner; 873 uint32_t old; 874 int error; 875 int count; 876 877 /* 878 * Make sure we own this mtx. 879 */ 880 owner = fuword32(m); 881 if (owner == -1) 882 return (EFAULT); 883 884 if ((owner & ~UMUTEX_CONTESTED) != id) 885 return (EPERM); 886 887 /* This should be done in userland */ 888 if ((owner & UMUTEX_CONTESTED) == 0) { 889 old = casuword32(m, owner, UMUTEX_UNOWNED); 890 if (old == -1) 891 return (EFAULT); 892 if (old == owner) 893 return (0); 894 owner = old; 895 } 896 897 /* We should only ever be in here for contested locks */ 898 if ((error = umtx_key_get(m, TYPE_SIMPLE_LOCK, AUTO_SHARE, 899 &key)) != 0) 900 return (error); 901 902 umtxq_lock(&key); 903 umtxq_busy(&key); 904 count = umtxq_count(&key); 905 umtxq_unlock(&key); 906 907 /* 908 * When unlocking the umtx, it must be marked as unowned if 909 * there is zero or one thread only waiting for it. 910 * Otherwise, it must be marked as contested. 911 */ 912 old = casuword32(m, owner, 913 count <= 1 ? UMUTEX_UNOWNED : UMUTEX_CONTESTED); 914 umtxq_lock(&key); 915 umtxq_signal(&key,1); 916 umtxq_unbusy(&key); 917 umtxq_unlock(&key); 918 umtx_key_release(&key); 919 if (old == -1) 920 return (EFAULT); 921 if (old != owner) 922 return (EINVAL); 923 return (0); 924} 925#endif 926 927/* 928 * Fetch and compare value, sleep on the address if value is not changed. 929 */ 930static int 931do_wait(struct thread *td, void *addr, u_long id, 932 struct timespec *timeout, int compat32) 933{ 934 struct umtx_q *uq; 935 struct timespec ts, ts2, ts3; 936 struct timeval tv; 937 u_long tmp; 938 int error = 0; 939 940 uq = td->td_umtxq; 941 if ((error = umtx_key_get(addr, TYPE_SIMPLE_WAIT, AUTO_SHARE, 942 &uq->uq_key)) != 0) 943 return (error); 944 945 umtxq_lock(&uq->uq_key); 946 umtxq_insert(uq); 947 umtxq_unlock(&uq->uq_key); 948 if (compat32 == 0) 949 tmp = fuword(addr); 950 else 951 tmp = fuword32(addr); 952 if (tmp != id) { 953 umtxq_lock(&uq->uq_key); 954 umtxq_remove(uq); 955 umtxq_unlock(&uq->uq_key); 956 } else if (timeout == NULL) { 957 umtxq_lock(&uq->uq_key); 958 error = umtxq_sleep(uq, "ucond", 0); 959 umtxq_remove(uq); 960 umtxq_unlock(&uq->uq_key); 961 } else { 962 getnanouptime(&ts); 963 timespecadd(&ts, timeout); 964 TIMESPEC_TO_TIMEVAL(&tv, timeout); 965 umtxq_lock(&uq->uq_key); 966 for (;;) { 967 error = umtxq_sleep(uq, "ucond", tvtohz(&tv)); 968 if (!(uq->uq_flags & UQF_UMTXQ)) 969 break; 970 if (error != ETIMEDOUT) 971 break; 972 umtxq_unlock(&uq->uq_key); 973 getnanouptime(&ts2); 974 if (timespeccmp(&ts2, &ts, >=)) { 975 error = ETIMEDOUT; 976 umtxq_lock(&uq->uq_key); 977 break; 978 } 979 ts3 = ts; 980 timespecsub(&ts3, &ts2); 981 TIMESPEC_TO_TIMEVAL(&tv, &ts3); 982 umtxq_lock(&uq->uq_key); 983 } 984 umtxq_remove(uq); 985 umtxq_unlock(&uq->uq_key); 986 } 987 umtx_key_release(&uq->uq_key); 988 if (error == ERESTART) 989 error = EINTR; 990 return (error); 991} 992 993/* 994 * Wake up threads sleeping on the specified address. 995 */ 996int 997kern_umtx_wake(struct thread *td, void *uaddr, int n_wake) 998{ 999 struct umtx_key key; 1000 int ret; 1001 1002 if ((ret = umtx_key_get(uaddr, TYPE_SIMPLE_WAIT, AUTO_SHARE, 1003 &key)) != 0) 1004 return (ret); 1005 umtxq_lock(&key); 1006 ret = umtxq_signal(&key, n_wake); 1007 umtxq_unlock(&key); 1008 umtx_key_release(&key); 1009 return (0); 1010} 1011 1012/* 1013 * Lock PTHREAD_PRIO_NONE protocol POSIX mutex. 1014 */ 1015static int 1016_do_lock_normal(struct thread *td, struct umutex *m, uint32_t flags, int timo, 1017 int try) 1018{ 1019 struct umtx_q *uq; 1020 uint32_t owner, old, id; 1021 int error = 0; 1022 1023 id = td->td_tid; 1024 uq = td->td_umtxq; 1025 1026 /* 1027 * Care must be exercised when dealing with umtx structure. It 1028 * can fault on any access. 1029 */ 1030 for (;;) { 1031 /* 1032 * Try the uncontested case. This should be done in userland. 1033 */ 1034 owner = casuword32(&m->m_owner, UMUTEX_UNOWNED, id); 1035 1036 /* The acquire succeeded. */ 1037 if (owner == UMUTEX_UNOWNED) 1038 return (0); 1039 1040 /* The address was invalid. */ 1041 if (owner == -1) 1042 return (EFAULT); 1043 1044 /* If no one owns it but it is contested try to acquire it. */ 1045 if (owner == UMUTEX_CONTESTED) { 1046 owner = casuword32(&m->m_owner, 1047 UMUTEX_CONTESTED, id | UMUTEX_CONTESTED); 1048 1049 if (owner == UMUTEX_CONTESTED) 1050 return (0); 1051 1052 /* The address was invalid. */ 1053 if (owner == -1) 1054 return (EFAULT); 1055 1056 /* If this failed the lock has changed, restart. */ 1057 continue; 1058 } 1059 1060 if ((flags & UMUTEX_ERROR_CHECK) != 0 && 1061 (owner & ~UMUTEX_CONTESTED) == id) 1062 return (EDEADLK); 1063 1064 if (try != 0) 1065 return (EBUSY); 1066 1067 /* 1068 * If we caught a signal, we have retried and now 1069 * exit immediately. 1070 */ 1071 if (error != 0) 1072 return (error); 1073 1074 if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX, 1075 GET_SHARE(flags), &uq->uq_key)) != 0) 1076 return (error); 1077 1078 umtxq_lock(&uq->uq_key); 1079 umtxq_busy(&uq->uq_key); 1080 umtxq_insert(uq); 1081 umtxq_unbusy(&uq->uq_key); 1082 umtxq_unlock(&uq->uq_key); 1083 1084 /* 1085 * Set the contested bit so that a release in user space 1086 * knows to use the system call for unlock. If this fails 1087 * either some one else has acquired the lock or it has been 1088 * released. 1089 */ 1090 old = casuword32(&m->m_owner, owner, owner | UMUTEX_CONTESTED); 1091 1092 /* The address was invalid. */ 1093 if (old == -1) { 1094 umtxq_lock(&uq->uq_key); 1095 umtxq_remove(uq); 1096 umtxq_unlock(&uq->uq_key); 1097 umtx_key_release(&uq->uq_key); 1098 return (EFAULT); 1099 } 1100 1101 /* 1102 * We set the contested bit, sleep. Otherwise the lock changed 1103 * and we need to retry or we lost a race to the thread 1104 * unlocking the umtx. 1105 */ 1106 umtxq_lock(&uq->uq_key); 1107 if (old == owner) 1108 error = umtxq_sleep(uq, "umtxn", timo); 1109 umtxq_remove(uq); 1110 umtxq_unlock(&uq->uq_key); 1111 umtx_key_release(&uq->uq_key); 1112 } 1113 1114 return (0); 1115} 1116 1117/* 1118 * Lock PTHREAD_PRIO_NONE protocol POSIX mutex. 1119 */ 1120/* 1121 * Unlock PTHREAD_PRIO_NONE protocol POSIX mutex. 1122 */ 1123static int 1124do_unlock_normal(struct thread *td, struct umutex *m, uint32_t flags) 1125{ 1126 struct umtx_key key; 1127 uint32_t owner, old, id; 1128 int error; 1129 int count; 1130 1131 id = td->td_tid; 1132 /* 1133 * Make sure we own this mtx. 1134 */ 1135 owner = fuword32(__DEVOLATILE(uint32_t *, &m->m_owner)); 1136 if (owner == -1) 1137 return (EFAULT); 1138 1139 if ((owner & ~UMUTEX_CONTESTED) != id) 1140 return (EPERM); 1141 1142 /* This should be done in userland */ 1143 if ((owner & UMUTEX_CONTESTED) == 0) { 1144 old = casuword32(&m->m_owner, owner, UMUTEX_UNOWNED); 1145 if (old == -1) 1146 return (EFAULT); 1147 if (old == owner) 1148 return (0); 1149 owner = old; 1150 } 1151 1152 /* We should only ever be in here for contested locks */ 1153 if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX, GET_SHARE(flags), 1154 &key)) != 0) 1155 return (error); 1156 1157 umtxq_lock(&key); 1158 umtxq_busy(&key); 1159 count = umtxq_count(&key); 1160 umtxq_unlock(&key); 1161 1162 /* 1163 * When unlocking the umtx, it must be marked as unowned if 1164 * there is zero or one thread only waiting for it. 1165 * Otherwise, it must be marked as contested. 1166 */ 1167 old = casuword32(&m->m_owner, owner, 1168 count <= 1 ? UMUTEX_UNOWNED : UMUTEX_CONTESTED); 1169 umtxq_lock(&key); 1170 umtxq_signal(&key,1); 1171 umtxq_unbusy(&key); 1172 umtxq_unlock(&key); 1173 umtx_key_release(&key); 1174 if (old == -1) 1175 return (EFAULT); 1176 if (old != owner) 1177 return (EINVAL); 1178 return (0); 1179} 1180 1181static inline struct umtx_pi * 1182umtx_pi_alloc(int flags) 1183{ 1184 struct umtx_pi *pi; 1185 1186 pi = uma_zalloc(umtx_pi_zone, M_ZERO | flags); 1187 TAILQ_INIT(&pi->pi_blocked); 1188 atomic_add_int(&umtx_pi_allocated, 1); 1189 return (pi); 1190} 1191 1192static inline void 1193umtx_pi_free(struct umtx_pi *pi) 1194{ 1195 uma_zfree(umtx_pi_zone, pi); 1196 atomic_add_int(&umtx_pi_allocated, -1); 1197} 1198 1199/* 1200 * Adjust the thread's position on a pi_state after its priority has been 1201 * changed. 1202 */ 1203static int 1204umtx_pi_adjust_thread(struct umtx_pi *pi, struct thread *td) 1205{ 1206 struct umtx_q *uq, *uq1, *uq2; 1207 struct thread *td1; 1208 1209 mtx_assert(&sched_lock, MA_OWNED); 1210 if (pi == NULL) 1211 return (0); 1212 1213 uq = td->td_umtxq; 1214 1215 /* 1216 * Check if the thread needs to be moved on the blocked chain. 1217 * It needs to be moved if either its priority is lower than 1218 * the previous thread or higher than the next thread. 1219 */ 1220 uq1 = TAILQ_PREV(uq, umtxq_head, uq_lockq); 1221 uq2 = TAILQ_NEXT(uq, uq_lockq); 1222 if ((uq1 != NULL && UPRI(td) < UPRI(uq1->uq_thread)) || 1223 (uq2 != NULL && UPRI(td) > UPRI(uq2->uq_thread))) { 1224 /* 1225 * Remove thread from blocked chain and determine where 1226 * it should be moved to. 1227 */ 1228 TAILQ_REMOVE(&pi->pi_blocked, uq, uq_lockq); 1229 TAILQ_FOREACH(uq1, &pi->pi_blocked, uq_lockq) { 1230 td1 = uq1->uq_thread; 1231 MPASS(td1->td_proc->p_magic == P_MAGIC); 1232 if (UPRI(td1) > UPRI(td)) 1233 break; 1234 } 1235 1236 if (uq1 == NULL) 1237 TAILQ_INSERT_TAIL(&pi->pi_blocked, uq, uq_lockq); 1238 else 1239 TAILQ_INSERT_BEFORE(uq1, uq, uq_lockq); 1240 } 1241 return (1); 1242} 1243 1244/* 1245 * Propagate priority when a thread is blocked on POSIX 1246 * PI mutex. 1247 */ 1248static void 1249umtx_propagate_priority(struct thread *td) 1250{ 1251 struct umtx_q *uq; 1252 struct umtx_pi *pi; 1253 int pri; 1254 1255 mtx_assert(&sched_lock, MA_OWNED); 1256 pri = UPRI(td); 1257 uq = td->td_umtxq; 1258 pi = uq->uq_pi_blocked; 1259 if (pi == NULL) 1260 return; 1261 1262 for (;;) { 1263 td = pi->pi_owner; 1264 if (td == NULL) 1265 return; 1266 1267 MPASS(td->td_proc != NULL); 1268 MPASS(td->td_proc->p_magic == P_MAGIC); 1269 1270 if (UPRI(td) <= pri) 1271 return; 1272 1273 sched_lend_user_prio(td, pri); 1274 1275 /* 1276 * Pick up the lock that td is blocked on. 1277 */ 1278 uq = td->td_umtxq; 1279 pi = uq->uq_pi_blocked; 1280 /* Resort td on the list if needed. */ 1281 if (!umtx_pi_adjust_thread(pi, td)) 1282 break; 1283 } 1284} 1285 1286/* 1287 * Unpropagate priority for a PI mutex when a thread blocked on 1288 * it is interrupted by signal or resumed by others. 1289 */ 1290static void 1291umtx_unpropagate_priority(struct umtx_pi *pi) 1292{ 1293 struct umtx_q *uq, *uq_owner; 1294 struct umtx_pi *pi2; 1295 int pri; 1296 1297 mtx_assert(&sched_lock, MA_OWNED); 1298 1299 while (pi != NULL && pi->pi_owner != NULL) { 1300 pri = PRI_MAX; 1301 uq_owner = pi->pi_owner->td_umtxq; 1302 1303 TAILQ_FOREACH(pi2, &uq_owner->uq_pi_contested, pi_link) { 1304 uq = TAILQ_FIRST(&pi2->pi_blocked); 1305 if (uq != NULL) { 1306 if (pri > UPRI(uq->uq_thread)) 1307 pri = UPRI(uq->uq_thread); 1308 } 1309 } 1310 1311 if (pri > uq_owner->uq_inherited_pri) 1312 pri = uq_owner->uq_inherited_pri; 1313 sched_unlend_user_prio(pi->pi_owner, pri); 1314 pi = uq_owner->uq_pi_blocked; 1315 } 1316} 1317 1318/* 1319 * Insert a PI mutex into owned list. 1320 */ 1321static void 1322umtx_pi_setowner(struct umtx_pi *pi, struct thread *owner) 1323{ 1324 struct umtx_q *uq_owner; 1325 1326 uq_owner = owner->td_umtxq; 1327 mtx_assert(&sched_lock, MA_OWNED); 1328 if (pi->pi_owner != NULL) 1329 panic("pi_ower != NULL"); 1330 pi->pi_owner = owner; 1331 TAILQ_INSERT_TAIL(&uq_owner->uq_pi_contested, pi, pi_link); 1332} 1333 1334/* 1335 * Claim ownership of a PI mutex. 1336 */ 1337static int 1338umtx_pi_claim(struct umtx_pi *pi, struct thread *owner) 1339{ 1340 struct umtx_q *uq, *uq_owner; 1341 1342 uq_owner = owner->td_umtxq; 1343 mtx_lock_spin(&sched_lock); 1344 if (pi->pi_owner == owner) { 1345 mtx_unlock_spin(&sched_lock); 1346 return (0); 1347 } 1348 1349 if (pi->pi_owner != NULL) { 1350 /* 1351 * userland may have already messed the mutex, sigh. 1352 */ 1353 mtx_unlock_spin(&sched_lock); 1354 return (EPERM); 1355 } 1356 umtx_pi_setowner(pi, owner); 1357 uq = TAILQ_FIRST(&pi->pi_blocked); 1358 if (uq != NULL) { 1359 int pri; 1360 1361 pri = UPRI(uq->uq_thread); 1362 if (pri < UPRI(owner)) 1363 sched_lend_user_prio(owner, pri); 1364 } 1365 mtx_unlock_spin(&sched_lock); 1366 return (0); 1367} 1368 1369/* 1370 * Adjust a thread's order position in its blocked PI mutex, 1371 * this may result new priority propagating process. 1372 */ 1373void 1374umtx_pi_adjust(struct thread *td, u_char oldpri) 1375{ 1376 struct umtx_q *uq; 1377 struct umtx_pi *pi; 1378 1379 uq = td->td_umtxq; 1380 1381 mtx_assert(&sched_lock, MA_OWNED); 1382 MPASS(TD_ON_UPILOCK(td)); 1383 1384 /* 1385 * Pick up the lock that td is blocked on. 1386 */ 1387 pi = uq->uq_pi_blocked; 1388 MPASS(pi != NULL); 1389 1390 /* Resort the turnstile on the list. */ 1391 if (!umtx_pi_adjust_thread(pi, td)) 1392 return; 1393 1394 /* 1395 * If our priority was lowered and we are at the head of the 1396 * turnstile, then propagate our new priority up the chain. 1397 */ 1398 if (uq == TAILQ_FIRST(&pi->pi_blocked) && UPRI(td) < oldpri) 1399 umtx_propagate_priority(td); 1400} 1401 1402/* 1403 * Sleep on a PI mutex. 1404 */ 1405static int 1406umtxq_sleep_pi(struct umtx_q *uq, struct umtx_pi *pi, 1407 uint32_t owner, const char *wmesg, int timo) 1408{ 1409 struct umtxq_chain *uc; 1410 struct thread *td, *td1; 1411 struct umtx_q *uq1; 1412 int pri; 1413 int error = 0; 1414 1415 td = uq->uq_thread; 1416 KASSERT(td == curthread, ("inconsistent uq_thread")); 1417 uc = umtxq_getchain(&uq->uq_key); 1418 UMTXQ_LOCKED_ASSERT(uc); 1419 umtxq_insert(uq); 1420 if (pi->pi_owner == NULL) { 1421 /* XXX 1422 * Current, We only support process private PI-mutex, 1423 * non-contended PI-mutexes are locked in userland. 1424 * Process shared PI-mutex should always be initialized 1425 * by kernel and be registered in kernel, locking should 1426 * always be done by kernel to avoid security problems. 1427 * For process private PI-mutex, we can find owner 1428 * thread and boost its priority safely. 1429 */ 1430 PROC_LOCK(curproc); 1431 td1 = thread_find(curproc, owner); 1432 mtx_lock_spin(&sched_lock); 1433 if (td1 != NULL && pi->pi_owner == NULL) { 1434 uq1 = td1->td_umtxq; 1435 umtx_pi_setowner(pi, td1); 1436 } 1437 PROC_UNLOCK(curproc); 1438 } else { 1439 mtx_lock_spin(&sched_lock); 1440 } 1441 1442 TAILQ_FOREACH(uq1, &pi->pi_blocked, uq_lockq) { 1443 pri = UPRI(uq1->uq_thread); 1444 if (pri > UPRI(td)) 1445 break; 1446 } 1447 1448 if (uq1 != NULL) 1449 TAILQ_INSERT_BEFORE(uq1, uq, uq_lockq); 1450 else 1451 TAILQ_INSERT_TAIL(&pi->pi_blocked, uq, uq_lockq); 1452 1453 uq->uq_pi_blocked = pi; 1454 td->td_flags |= TDF_UPIBLOCKED; 1455 mtx_unlock_spin(&sched_lock); 1456 umtxq_unlock(&uq->uq_key); 1457 1458 mtx_lock_spin(&sched_lock); 1459 umtx_propagate_priority(td); 1460 mtx_unlock_spin(&sched_lock); 1461 1462 umtxq_lock(&uq->uq_key); 1463 if (uq->uq_flags & UQF_UMTXQ) { 1464 error = msleep(uq, &uc->uc_lock, PCATCH, wmesg, timo); 1465 if (error == EWOULDBLOCK) 1466 error = ETIMEDOUT; 1467 if (uq->uq_flags & UQF_UMTXQ) { 1468 umtxq_busy(&uq->uq_key); 1469 umtxq_remove(uq); 1470 umtxq_unbusy(&uq->uq_key); 1471 } 1472 } 1473 umtxq_unlock(&uq->uq_key); 1474 1475 mtx_lock_spin(&sched_lock); 1476 uq->uq_pi_blocked = NULL; 1477 td->td_flags &= ~TDF_UPIBLOCKED; 1478 TAILQ_REMOVE(&pi->pi_blocked, uq, uq_lockq); 1479 umtx_unpropagate_priority(pi); 1480 mtx_unlock_spin(&sched_lock); 1481 1482 umtxq_lock(&uq->uq_key); 1483 1484 return (error); 1485} 1486 1487/* 1488 * Add reference count for a PI mutex. 1489 */ 1490static void 1491umtx_pi_ref(struct umtx_pi *pi) 1492{ 1493 struct umtxq_chain *uc; 1494 1495 uc = umtxq_getchain(&pi->pi_key); 1496 UMTXQ_LOCKED_ASSERT(uc); 1497 pi->pi_refcount++; 1498} 1499 1500/* 1501 * Decrease reference count for a PI mutex, if the counter 1502 * is decreased to zero, its memory space is freed. 1503 */ 1504static void 1505umtx_pi_unref(struct umtx_pi *pi) 1506{ 1507 struct umtxq_chain *uc; 1508 int free = 0; 1509 1510 uc = umtxq_getchain(&pi->pi_key); 1511 UMTXQ_LOCKED_ASSERT(uc); 1512 KASSERT(pi->pi_refcount > 0, ("invalid reference count")); 1513 if (--pi->pi_refcount == 0) { 1514 mtx_lock_spin(&sched_lock); 1515 if (pi->pi_owner != NULL) { 1516 TAILQ_REMOVE(&pi->pi_owner->td_umtxq->uq_pi_contested, 1517 pi, pi_link); 1518 pi->pi_owner = NULL; 1519 } 1520 KASSERT(TAILQ_EMPTY(&pi->pi_blocked), 1521 ("blocked queue not empty")); 1522 mtx_unlock_spin(&sched_lock); 1523 TAILQ_REMOVE(&uc->uc_pi_list, pi, pi_hashlink); 1524 free = 1; 1525 } 1526 if (free) 1527 umtx_pi_free(pi); 1528} 1529 1530/* 1531 * Find a PI mutex in hash table. 1532 */ 1533static struct umtx_pi * 1534umtx_pi_lookup(struct umtx_key *key) 1535{ 1536 struct umtxq_chain *uc; 1537 struct umtx_pi *pi; 1538 1539 uc = umtxq_getchain(key); 1540 UMTXQ_LOCKED_ASSERT(uc); 1541 1542 TAILQ_FOREACH(pi, &uc->uc_pi_list, pi_hashlink) { 1543 if (umtx_key_match(&pi->pi_key, key)) { 1544 return (pi); 1545 } 1546 } 1547 return (NULL); 1548} 1549 1550/* 1551 * Insert a PI mutex into hash table. 1552 */ 1553static inline void 1554umtx_pi_insert(struct umtx_pi *pi) 1555{ 1556 struct umtxq_chain *uc; 1557 1558 uc = umtxq_getchain(&pi->pi_key); 1559 UMTXQ_LOCKED_ASSERT(uc); 1560 TAILQ_INSERT_TAIL(&uc->uc_pi_list, pi, pi_hashlink); 1561} 1562 1563/* 1564 * Lock a PI mutex. 1565 */ 1566static int 1567_do_lock_pi(struct thread *td, struct umutex *m, uint32_t flags, int timo, 1568 int try) 1569{ 1570 struct umtx_q *uq; 1571 struct umtx_pi *pi, *new_pi; 1572 uint32_t id, owner, old; 1573 int error; 1574 1575 id = td->td_tid; 1576 uq = td->td_umtxq; 1577 1578 if ((error = umtx_key_get(m, TYPE_PI_UMUTEX, GET_SHARE(flags), 1579 &uq->uq_key)) != 0) 1580 return (error); 1581 umtxq_lock(&uq->uq_key); 1582 pi = umtx_pi_lookup(&uq->uq_key); 1583 if (pi == NULL) { 1584 new_pi = umtx_pi_alloc(M_NOWAIT); 1585 if (new_pi == NULL) { 1586 umtxq_unlock(&uq->uq_key); 1587 new_pi = umtx_pi_alloc(M_WAITOK); 1588 new_pi->pi_key = uq->uq_key; 1589 umtxq_lock(&uq->uq_key); 1590 pi = umtx_pi_lookup(&uq->uq_key); 1591 if (pi != NULL) { 1592 umtx_pi_free(new_pi); 1593 new_pi = NULL; 1594 } 1595 } 1596 if (new_pi != NULL) { 1597 new_pi->pi_key = uq->uq_key; 1598 umtx_pi_insert(new_pi); 1599 pi = new_pi; 1600 } 1601 } 1602 umtx_pi_ref(pi); 1603 umtxq_unlock(&uq->uq_key); 1604 1605 /* 1606 * Care must be exercised when dealing with umtx structure. It 1607 * can fault on any access. 1608 */ 1609 for (;;) { 1610 /* 1611 * Try the uncontested case. This should be done in userland. 1612 */ 1613 owner = casuword32(&m->m_owner, UMUTEX_UNOWNED, id); 1614 1615 /* The acquire succeeded. */ 1616 if (owner == UMUTEX_UNOWNED) { 1617 error = 0; 1618 break; 1619 } 1620 1621 /* The address was invalid. */ 1622 if (owner == -1) { 1623 error = EFAULT; 1624 break; 1625 } 1626 1627 /* If no one owns it but it is contested try to acquire it. */ 1628 if (owner == UMUTEX_CONTESTED) { 1629 owner = casuword32(&m->m_owner, 1630 UMUTEX_CONTESTED, id | UMUTEX_CONTESTED); 1631 1632 if (owner == UMUTEX_CONTESTED) { 1633 umtxq_lock(&uq->uq_key); 1634 error = umtx_pi_claim(pi, td); 1635 umtxq_unlock(&uq->uq_key); 1636 break; 1637 } 1638 1639 /* The address was invalid. */ 1640 if (owner == -1) { 1641 error = EFAULT; 1642 break; 1643 } 1644 1645 /* If this failed the lock has changed, restart. */ 1646 continue; 1647 } 1648 1649 if ((flags & UMUTEX_ERROR_CHECK) != 0 && 1650 (owner & ~UMUTEX_CONTESTED) == id) { 1651 error = EDEADLK; 1652 break; 1653 } 1654 1655 if (try != 0) { 1656 error = EBUSY; 1657 break; 1658 } 1659 1660 /* 1661 * If we caught a signal, we have retried and now 1662 * exit immediately. 1663 */ 1664 if (error != 0) 1665 break; 1666 1667 umtxq_lock(&uq->uq_key); 1668 umtxq_busy(&uq->uq_key); 1669 umtxq_unlock(&uq->uq_key); 1670 1671 /* 1672 * Set the contested bit so that a release in user space 1673 * knows to use the system call for unlock. If this fails 1674 * either some one else has acquired the lock or it has been 1675 * released. 1676 */ 1677 old = casuword32(&m->m_owner, owner, owner | UMUTEX_CONTESTED); 1678 1679 /* The address was invalid. */ 1680 if (old == -1) { 1681 umtxq_lock(&uq->uq_key); 1682 umtxq_unbusy(&uq->uq_key); 1683 umtxq_unlock(&uq->uq_key); 1684 error = EFAULT; 1685 break; 1686 } 1687 1688 umtxq_lock(&uq->uq_key); 1689 umtxq_unbusy(&uq->uq_key); 1690 /* 1691 * We set the contested bit, sleep. Otherwise the lock changed 1692 * and we need to retry or we lost a race to the thread 1693 * unlocking the umtx. 1694 */ 1695 if (old == owner) 1696 error = umtxq_sleep_pi(uq, pi, owner & ~UMUTEX_CONTESTED, 1697 "umtxpi", timo); 1698 umtxq_unlock(&uq->uq_key); 1699 } 1700 1701 umtxq_lock(&uq->uq_key); 1702 umtx_pi_unref(pi); 1703 umtxq_unlock(&uq->uq_key); 1704 1705 umtx_key_release(&uq->uq_key); 1706 return (error); 1707} 1708 1709/* 1710 * Unlock a PI mutex. 1711 */ 1712static int 1713do_unlock_pi(struct thread *td, struct umutex *m, uint32_t flags) 1714{ 1715 struct umtx_key key; 1716 struct umtx_q *uq_first, *uq_first2, *uq_me; 1717 struct umtx_pi *pi, *pi2; 1718 uint32_t owner, old, id; 1719 int error; 1720 int count; 1721 int pri; 1722 1723 id = td->td_tid; 1724 /* 1725 * Make sure we own this mtx. 1726 */ 1727 owner = fuword32(__DEVOLATILE(uint32_t *, &m->m_owner)); 1728 if (owner == -1) 1729 return (EFAULT); 1730 1731 if ((owner & ~UMUTEX_CONTESTED) != id) 1732 return (EPERM); 1733 1734 /* This should be done in userland */ 1735 if ((owner & UMUTEX_CONTESTED) == 0) { 1736 old = casuword32(&m->m_owner, owner, UMUTEX_UNOWNED); 1737 if (old == -1) 1738 return (EFAULT); 1739 if (old == owner) 1740 return (0); 1741 owner = old; 1742 } 1743 1744 /* We should only ever be in here for contested locks */ 1745 if ((error = umtx_key_get(m, TYPE_PI_UMUTEX, GET_SHARE(flags), 1746 &key)) != 0) 1747 return (error); 1748 1749 umtxq_lock(&key); 1750 umtxq_busy(&key); 1751 count = umtxq_count_pi(&key, &uq_first); 1752 if (uq_first != NULL) { 1753 pi = uq_first->uq_pi_blocked; 1754 if (pi->pi_owner != curthread) { 1755 umtxq_unbusy(&key); 1756 umtxq_unlock(&key); 1757 /* userland messed the mutex */ 1758 return (EPERM); 1759 } 1760 uq_me = curthread->td_umtxq; 1761 mtx_lock_spin(&sched_lock); 1762 pi->pi_owner = NULL; 1763 TAILQ_REMOVE(&uq_me->uq_pi_contested, pi, pi_link); 1764 uq_first = TAILQ_FIRST(&pi->pi_blocked); 1765 pri = PRI_MAX; 1766 TAILQ_FOREACH(pi2, &uq_me->uq_pi_contested, pi_link) { 1767 uq_first2 = TAILQ_FIRST(&pi2->pi_blocked); 1768 if (uq_first2 != NULL) { 1769 if (pri > UPRI(uq_first2->uq_thread)) 1770 pri = UPRI(uq_first2->uq_thread); 1771 } 1772 } 1773 sched_unlend_user_prio(curthread, pri); 1774 mtx_unlock_spin(&sched_lock); 1775 } 1776 umtxq_unlock(&key); 1777 1778 /* 1779 * When unlocking the umtx, it must be marked as unowned if 1780 * there is zero or one thread only waiting for it. 1781 * Otherwise, it must be marked as contested. 1782 */ 1783 old = casuword32(&m->m_owner, owner, 1784 count <= 1 ? UMUTEX_UNOWNED : UMUTEX_CONTESTED); 1785 1786 umtxq_lock(&key); 1787 if (uq_first != NULL) 1788 umtxq_signal_thread(uq_first); 1789 umtxq_unbusy(&key); 1790 umtxq_unlock(&key); 1791 umtx_key_release(&key); 1792 if (old == -1) 1793 return (EFAULT); 1794 if (old != owner) 1795 return (EINVAL); 1796 return (0); 1797} 1798 1799/* 1800 * Lock a PP mutex. 1801 */ 1802static int 1803_do_lock_pp(struct thread *td, struct umutex *m, uint32_t flags, int timo, 1804 int try) 1805{ 1806 struct umtx_q *uq, *uq2; 1807 struct umtx_pi *pi; 1808 uint32_t ceiling; 1809 uint32_t owner, id; 1810 int error, pri, old_inherited_pri, su; 1811 1812 id = td->td_tid; 1813 uq = td->td_umtxq; 1814 if ((error = umtx_key_get(m, TYPE_PP_UMUTEX, GET_SHARE(flags), 1815 &uq->uq_key)) != 0) 1816 return (error); 1817 su = (priv_check(td, PRIV_SCHED_RTPRIO) == 0); 1818 for (;;) { 1819 old_inherited_pri = uq->uq_inherited_pri; 1820 umtxq_lock(&uq->uq_key); 1821 umtxq_busy(&uq->uq_key); 1822 umtxq_unlock(&uq->uq_key); 1823 1824 ceiling = RTP_PRIO_MAX - fuword32(&m->m_ceilings[0]); 1825 if (ceiling > RTP_PRIO_MAX) { 1826 error = EINVAL; 1827 goto out; 1828 } 1829 1830 mtx_lock_spin(&sched_lock); 1831 if (UPRI(td) < PRI_MIN_REALTIME + ceiling) { 1832 mtx_unlock_spin(&sched_lock); 1833 error = EINVAL; 1834 goto out; 1835 } 1836 if (su && PRI_MIN_REALTIME + ceiling < uq->uq_inherited_pri) { 1837 uq->uq_inherited_pri = PRI_MIN_REALTIME + ceiling; 1838 if (uq->uq_inherited_pri < UPRI(td)) 1839 sched_lend_user_prio(td, uq->uq_inherited_pri); 1840 } 1841 mtx_unlock_spin(&sched_lock); 1842 1843 owner = casuword32(&m->m_owner, 1844 UMUTEX_CONTESTED, id | UMUTEX_CONTESTED); 1845 1846 if (owner == UMUTEX_CONTESTED) { 1847 error = 0; 1848 break; 1849 } 1850 1851 /* The address was invalid. */ 1852 if (owner == -1) { 1853 error = EFAULT; 1854 break; 1855 } 1856 1857 if ((flags & UMUTEX_ERROR_CHECK) != 0 && 1858 (owner & ~UMUTEX_CONTESTED) == id) { 1859 error = EDEADLK; 1860 break; 1861 } 1862 1863 if (try != 0) { 1864 error = EBUSY; 1865 break; 1866 } 1867 1868 /* 1869 * If we caught a signal, we have retried and now 1870 * exit immediately. 1871 */ 1872 if (error != 0) 1873 break; 1874 1875 umtxq_lock(&uq->uq_key); 1876 umtxq_insert(uq); 1877 umtxq_unbusy(&uq->uq_key); 1878 error = umtxq_sleep(uq, "umtxpp", timo); 1879 umtxq_remove(uq); 1880 umtxq_unlock(&uq->uq_key); 1881 1882 mtx_lock_spin(&sched_lock); 1883 uq->uq_inherited_pri = old_inherited_pri; 1884 pri = PRI_MAX; 1885 TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) { 1886 uq2 = TAILQ_FIRST(&pi->pi_blocked); 1887 if (uq2 != NULL) { 1888 if (pri > UPRI(uq2->uq_thread)) 1889 pri = UPRI(uq2->uq_thread); 1890 } 1891 } 1892 if (pri > uq->uq_inherited_pri) 1893 pri = uq->uq_inherited_pri; 1894 sched_unlend_user_prio(td, pri); 1895 mtx_unlock_spin(&sched_lock); 1896 } 1897 1898 if (error != 0) { 1899 mtx_lock_spin(&sched_lock); 1900 uq->uq_inherited_pri = old_inherited_pri; 1901 pri = PRI_MAX; 1902 TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) { 1903 uq2 = TAILQ_FIRST(&pi->pi_blocked); 1904 if (uq2 != NULL) { 1905 if (pri > UPRI(uq2->uq_thread)) 1906 pri = UPRI(uq2->uq_thread); 1907 } 1908 } 1909 if (pri > uq->uq_inherited_pri) 1910 pri = uq->uq_inherited_pri; 1911 sched_unlend_user_prio(td, pri); 1912 mtx_unlock_spin(&sched_lock); 1913 } 1914 1915out: 1916 umtxq_lock(&uq->uq_key); 1917 umtxq_unbusy(&uq->uq_key); 1918 umtxq_unlock(&uq->uq_key); 1919 umtx_key_release(&uq->uq_key); 1920 return (error); 1921} 1922 1923/* 1924 * Unlock a PP mutex. 1925 */ 1926static int 1927do_unlock_pp(struct thread *td, struct umutex *m, uint32_t flags) 1928{ 1929 struct umtx_key key; 1930 struct umtx_q *uq, *uq2; 1931 struct umtx_pi *pi; 1932 uint32_t owner, id; 1933 uint32_t rceiling; 1934 int error, pri, new_inherited_pri, su; 1935 1936 id = td->td_tid; 1937 uq = td->td_umtxq; 1938 su = (priv_check(td, PRIV_SCHED_RTPRIO) == 0); 1939 1940 /* 1941 * Make sure we own this mtx. 1942 */ 1943 owner = fuword32(__DEVOLATILE(uint32_t *, &m->m_owner)); 1944 if (owner == -1) 1945 return (EFAULT); 1946 1947 if ((owner & ~UMUTEX_CONTESTED) != id) 1948 return (EPERM); 1949 1950 error = copyin(&m->m_ceilings[1], &rceiling, sizeof(uint32_t)); 1951 if (error != 0) 1952 return (error); 1953 1954 if (rceiling == -1) 1955 new_inherited_pri = PRI_MAX; 1956 else { 1957 rceiling = RTP_PRIO_MAX - rceiling; 1958 if (rceiling > RTP_PRIO_MAX) 1959 return (EINVAL); 1960 new_inherited_pri = PRI_MIN_REALTIME + rceiling; 1961 } 1962 1963 if ((error = umtx_key_get(m, TYPE_PP_UMUTEX, GET_SHARE(flags), 1964 &key)) != 0) 1965 return (error); 1966 umtxq_lock(&key); 1967 umtxq_busy(&key); 1968 umtxq_unlock(&key); 1969 /* 1970 * For priority protected mutex, always set unlocked state 1971 * to UMUTEX_CONTESTED, so that userland always enters kernel 1972 * to lock the mutex, it is necessary because thread priority 1973 * has to be adjusted for such mutex. 1974 */ 1975 error = suword32(__DEVOLATILE(uint32_t *, &m->m_owner), 1976 UMUTEX_CONTESTED); 1977 1978 umtxq_lock(&key); 1979 if (error == 0) 1980 umtxq_signal(&key, 1); 1981 umtxq_unbusy(&key); 1982 umtxq_unlock(&key); 1983 1984 if (error == -1) 1985 error = EFAULT; 1986 else { 1987 mtx_lock_spin(&sched_lock); 1988 if (su != 0) 1989 uq->uq_inherited_pri = new_inherited_pri; 1990 pri = PRI_MAX; 1991 TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) { 1992 uq2 = TAILQ_FIRST(&pi->pi_blocked); 1993 if (uq2 != NULL) { 1994 if (pri > UPRI(uq2->uq_thread)) 1995 pri = UPRI(uq2->uq_thread); 1996 } 1997 } 1998 if (pri > uq->uq_inherited_pri) 1999 pri = uq->uq_inherited_pri; 2000 sched_unlend_user_prio(td, pri); 2001 mtx_unlock_spin(&sched_lock); 2002 } 2003 umtx_key_release(&key); 2004 return (error); 2005} 2006 2007static int 2008do_set_ceiling(struct thread *td, struct umutex *m, uint32_t ceiling, 2009 uint32_t *old_ceiling) 2010{ 2011 struct umtx_q *uq; 2012 uint32_t save_ceiling; 2013 uint32_t owner, id; 2014 uint32_t flags; 2015 int error; 2016 2017 flags = fuword32(&m->m_flags); 2018 if ((flags & UMUTEX_PRIO_PROTECT) == 0) 2019 return (EINVAL); 2020 if (ceiling > RTP_PRIO_MAX) 2021 return (EINVAL); 2022 id = td->td_tid; 2023 uq = td->td_umtxq; 2024 if ((error = umtx_key_get(m, TYPE_PP_UMUTEX, GET_SHARE(flags), 2025 &uq->uq_key)) != 0) 2026 return (error); 2027 for (;;) { 2028 umtxq_lock(&uq->uq_key); 2029 umtxq_busy(&uq->uq_key); 2030 umtxq_unlock(&uq->uq_key); 2031 2032 save_ceiling = fuword32(&m->m_ceilings[0]); 2033 2034 owner = casuword32(&m->m_owner, 2035 UMUTEX_CONTESTED, id | UMUTEX_CONTESTED); 2036 2037 if (owner == UMUTEX_CONTESTED) { 2038 suword32(&m->m_ceilings[0], ceiling); 2039 suword32(__DEVOLATILE(uint32_t *, &m->m_owner), 2040 UMUTEX_CONTESTED); 2041 error = 0; 2042 break; 2043 } 2044 2045 /* The address was invalid. */ 2046 if (owner == -1) { 2047 error = EFAULT; 2048 break; 2049 } 2050 2051 if ((owner & ~UMUTEX_CONTESTED) == id) { 2052 suword32(&m->m_ceilings[0], ceiling); 2053 error = 0; 2054 break; 2055 } 2056 2057 /* 2058 * If we caught a signal, we have retried and now 2059 * exit immediately. 2060 */ 2061 if (error != 0) 2062 break; 2063 2064 /* 2065 * We set the contested bit, sleep. Otherwise the lock changed 2066 * and we need to retry or we lost a race to the thread 2067 * unlocking the umtx. 2068 */ 2069 umtxq_lock(&uq->uq_key); 2070 umtxq_insert(uq); 2071 umtxq_unbusy(&uq->uq_key); 2072 error = umtxq_sleep(uq, "umtxpp", 0); 2073 umtxq_remove(uq); 2074 umtxq_unlock(&uq->uq_key); 2075 } 2076 umtxq_lock(&uq->uq_key); 2077 if (error == 0) 2078 umtxq_signal(&uq->uq_key, INT_MAX); 2079 umtxq_unbusy(&uq->uq_key); 2080 umtxq_unlock(&uq->uq_key); 2081 umtx_key_release(&uq->uq_key); 2082 if (error == 0 && old_ceiling != NULL) 2083 suword32(old_ceiling, save_ceiling); 2084 return (error); 2085} 2086 2087static int 2088_do_lock_umutex(struct thread *td, struct umutex *m, int flags, int timo, 2089 int try) 2090{ 2091 switch(flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT)) { 2092 case 0: 2093 return (_do_lock_normal(td, m, flags, timo, try)); 2094 case UMUTEX_PRIO_INHERIT: 2095 return (_do_lock_pi(td, m, flags, timo, try)); 2096 case UMUTEX_PRIO_PROTECT: 2097 return (_do_lock_pp(td, m, flags, timo, try)); 2098 } 2099 return (EINVAL); 2100} 2101 2102/* 2103 * Lock a userland POSIX mutex. 2104 */ 2105static int 2106do_lock_umutex(struct thread *td, struct umutex *m, 2107 struct timespec *timeout, int try) 2108{ 2109 struct timespec ts, ts2, ts3; 2110 struct timeval tv; 2111 uint32_t flags; 2112 int error; 2113 2114 flags = fuword32(&m->m_flags); 2115 if (flags == -1) 2116 return (EFAULT); 2117 2118 if (timeout == NULL) { 2119 error = _do_lock_umutex(td, m, flags, 0, try); 2120 /* Mutex locking is restarted if it is interrupted. */ 2121 if (error == EINTR) 2122 error = ERESTART; 2123 } else { 2124 getnanouptime(&ts); 2125 timespecadd(&ts, timeout); 2126 TIMESPEC_TO_TIMEVAL(&tv, timeout); 2127 for (;;) { 2128 error = _do_lock_umutex(td, m, flags, tvtohz(&tv), try); 2129 if (error != ETIMEDOUT) 2130 break; 2131 getnanouptime(&ts2); 2132 if (timespeccmp(&ts2, &ts, >=)) { 2133 error = ETIMEDOUT; 2134 break; 2135 } 2136 ts3 = ts; 2137 timespecsub(&ts3, &ts2); 2138 TIMESPEC_TO_TIMEVAL(&tv, &ts3); 2139 } 2140 /* Timed-locking is not restarted. */ 2141 if (error == ERESTART) 2142 error = EINTR; 2143 } 2144 return (error); 2145} 2146 2147/* 2148 * Unlock a userland POSIX mutex. 2149 */ 2150static int 2151do_unlock_umutex(struct thread *td, struct umutex *m) 2152{ 2153 uint32_t flags; 2154 2155 flags = fuword32(&m->m_flags); 2156 if (flags == -1) 2157 return (EFAULT); 2158 2159 switch(flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT)) { 2160 case 0: 2161 return (do_unlock_normal(td, m, flags)); 2162 case UMUTEX_PRIO_INHERIT: 2163 return (do_unlock_pi(td, m, flags)); 2164 case UMUTEX_PRIO_PROTECT: 2165 return (do_unlock_pp(td, m, flags)); 2166 } 2167 2168 return (EINVAL); 2169} 2170 2171int 2172_umtx_lock(struct thread *td, struct _umtx_lock_args *uap) 2173 /* struct umtx *umtx */ 2174{ 2175 return _do_lock_umtx(td, uap->umtx, td->td_tid, 0); 2176} 2177 2178int 2179_umtx_unlock(struct thread *td, struct _umtx_unlock_args *uap) 2180 /* struct umtx *umtx */ 2181{ 2182 return do_unlock_umtx(td, uap->umtx, td->td_tid); 2183} 2184 2185static int 2186__umtx_op_lock_umtx(struct thread *td, struct _umtx_op_args *uap) 2187{ 2188 struct timespec *ts, timeout; 2189 int error; 2190 2191 /* Allow a null timespec (wait forever). */ 2192 if (uap->uaddr2 == NULL) 2193 ts = NULL; 2194 else { 2195 error = copyin(uap->uaddr2, &timeout, sizeof(timeout)); 2196 if (error != 0) 2197 return (error); 2198 if (timeout.tv_nsec >= 1000000000 || 2199 timeout.tv_nsec < 0) { 2200 return (EINVAL); 2201 } 2202 ts = &timeout; 2203 } 2204 return (do_lock_umtx(td, uap->obj, uap->val, ts)); 2205} 2206 2207static int 2208__umtx_op_unlock_umtx(struct thread *td, struct _umtx_op_args *uap) 2209{ 2210 return (do_unlock_umtx(td, uap->obj, uap->val)); 2211} 2212 2213static int 2214__umtx_op_wait(struct thread *td, struct _umtx_op_args *uap) 2215{ 2216 struct timespec *ts, timeout; 2217 int error; 2218 2219 if (uap->uaddr2 == NULL) 2220 ts = NULL; 2221 else { 2222 error = copyin(uap->uaddr2, &timeout, sizeof(timeout)); 2223 if (error != 0) 2224 return (error); 2225 if (timeout.tv_nsec >= 1000000000 || 2226 timeout.tv_nsec < 0) 2227 return (EINVAL); 2228 ts = &timeout; 2229 } 2230 return do_wait(td, uap->obj, uap->val, ts, 0); 2231} 2232 2233static int 2234__umtx_op_wake(struct thread *td, struct _umtx_op_args *uap) 2235{ 2236 return (kern_umtx_wake(td, uap->obj, uap->val)); 2237} 2238 2239static int 2240__umtx_op_lock_umutex(struct thread *td, struct _umtx_op_args *uap) 2241{ 2242 struct timespec *ts, timeout; 2243 int error; 2244 2245 /* Allow a null timespec (wait forever). */ 2246 if (uap->uaddr2 == NULL) 2247 ts = NULL; 2248 else { 2249 error = copyin(uap->uaddr2, &timeout, 2250 sizeof(timeout)); 2251 if (error != 0) 2252 return (error); 2253 if (timeout.tv_nsec >= 1000000000 || 2254 timeout.tv_nsec < 0) { 2255 return (EINVAL); 2256 } 2257 ts = &timeout; 2258 } 2259 return do_lock_umutex(td, uap->obj, ts, 0); 2260} 2261 2262static int 2263__umtx_op_trylock_umutex(struct thread *td, struct _umtx_op_args *uap) 2264{ 2265 return do_lock_umutex(td, uap->obj, NULL, 1); 2266} 2267 2268static int 2269__umtx_op_unlock_umutex(struct thread *td, struct _umtx_op_args *uap) 2270{ 2271 return do_unlock_umutex(td, uap->obj); 2272} 2273 2274static int 2275__umtx_op_set_ceiling(struct thread *td, struct _umtx_op_args *uap) 2276{ 2277 return do_set_ceiling(td, uap->obj, uap->val, uap->uaddr1); 2278} 2279 2280typedef int (*_umtx_op_func)(struct thread *td, struct _umtx_op_args *uap); 2281 2282static _umtx_op_func op_table[] = { 2283 __umtx_op_lock_umtx, /* UMTX_OP_LOCK */ 2284 __umtx_op_unlock_umtx, /* UMTX_OP_UNLOCK */ 2285 __umtx_op_wait, /* UMTX_OP_WAIT */ 2286 __umtx_op_wake, /* UMTX_OP_WAKE */ 2287 __umtx_op_trylock_umutex, /* UMTX_OP_MUTEX_TRYLOCK */ 2288 __umtx_op_lock_umutex, /* UMTX_OP_MUTEX_LOCK */ 2289 __umtx_op_unlock_umutex, /* UMTX_OP_MUTEX_UNLOCK */ 2290 __umtx_op_set_ceiling /* UMTX_OP_SET_CEILING */ 2291}; 2292 2293int 2294_umtx_op(struct thread *td, struct _umtx_op_args *uap) 2295{ 2296 if ((unsigned)uap->op < UMTX_OP_MAX) 2297 return (*op_table[uap->op])(td, uap); 2298 return (EINVAL); 2299} 2300 2301#ifdef COMPAT_IA32 2302 2303int 2304freebsd32_umtx_lock(struct thread *td, struct freebsd32_umtx_lock_args *uap) 2305 /* struct umtx *umtx */ 2306{ 2307 return (do_lock_umtx32(td, (uint32_t *)uap->umtx, td->td_tid, NULL)); 2308} 2309 2310int 2311freebsd32_umtx_unlock(struct thread *td, struct freebsd32_umtx_unlock_args *uap) 2312 /* struct umtx *umtx */ 2313{ 2314 return (do_unlock_umtx32(td, (uint32_t *)uap->umtx, td->td_tid)); 2315} 2316 2317struct timespec32 { 2318 u_int32_t tv_sec; 2319 u_int32_t tv_nsec; 2320}; 2321 2322static inline int 2323copyin_timeout32(void *addr, struct timespec *tsp) 2324{ 2325 struct timespec32 ts32; 2326 int error; 2327 2328 error = copyin(addr, &ts32, sizeof(struct timespec32)); 2329 if (error == 0) { 2330 tsp->tv_sec = ts32.tv_sec; 2331 tsp->tv_nsec = ts32.tv_nsec; 2332 } 2333 return (error); 2334} 2335 2336static int 2337__umtx_op_lock_umtx_compat32(struct thread *td, struct _umtx_op_args *uap) 2338{ 2339 struct timespec *ts, timeout; 2340 int error; 2341 2342 /* Allow a null timespec (wait forever). */ 2343 if (uap->uaddr2 == NULL) 2344 ts = NULL; 2345 else { 2346 error = copyin_timeout32(uap->uaddr2, &timeout); 2347 if (error != 0) 2348 return (error); 2349 if (timeout.tv_nsec >= 1000000000 || 2350 timeout.tv_nsec < 0) { 2351 return (EINVAL); 2352 } 2353 ts = &timeout; 2354 } 2355 return (do_lock_umtx32(td, uap->obj, uap->val, ts)); 2356} 2357 2358static int 2359__umtx_op_unlock_umtx_compat32(struct thread *td, struct _umtx_op_args *uap) 2360{ 2361 return (do_unlock_umtx32(td, uap->obj, (uint32_t)uap->val)); 2362} 2363 2364static int 2365__umtx_op_wait_compat32(struct thread *td, struct _umtx_op_args *uap) 2366{ 2367 struct timespec *ts, timeout; 2368 int error; 2369 2370 if (uap->uaddr2 == NULL) 2371 ts = NULL; 2372 else { 2373 error = copyin_timeout32(uap->uaddr2, &timeout); 2374 if (error != 0) 2375 return (error); 2376 if (timeout.tv_nsec >= 1000000000 || 2377 timeout.tv_nsec < 0) 2378 return (EINVAL); 2379 ts = &timeout; 2380 } 2381 return do_wait(td, uap->obj, uap->val, ts, 1); 2382} 2383 2384static int 2385__umtx_op_lock_umutex_compat32(struct thread *td, struct _umtx_op_args *uap) 2386{ 2387 struct timespec *ts, timeout; 2388 int error; 2389 2390 /* Allow a null timespec (wait forever). */ 2391 if (uap->uaddr2 == NULL) 2392 ts = NULL; 2393 else { 2394 error = copyin_timeout32(uap->uaddr2, &timeout); 2395 if (error != 0) 2396 return (error); 2397 if (timeout.tv_nsec >= 1000000000 || 2398 timeout.tv_nsec < 0) 2399 return (EINVAL); 2400 ts = &timeout; 2401 } 2402 return do_lock_umutex(td, uap->obj, ts, 0); 2403} 2404 2405static _umtx_op_func op_table_compat32[] = { 2406 __umtx_op_lock_umtx_compat32, /* UMTX_OP_LOCK */ 2407 __umtx_op_unlock_umtx_compat32, /* UMTX_OP_UNLOCK */ 2408 __umtx_op_wait_compat32, /* UMTX_OP_WAIT */ 2409 __umtx_op_wake, /* UMTX_OP_WAKE */ 2410 __umtx_op_trylock_umutex, /* UMTX_OP_MUTEX_LOCK */ 2411 __umtx_op_lock_umutex_compat32, /* UMTX_OP_MUTEX_TRYLOCK */ 2412 __umtx_op_unlock_umutex, /* UMTX_OP_MUTEX_UNLOCK */ 2413 __umtx_op_set_ceiling /* UMTX_OP_SET_CEILING */ 2414}; 2415 2416int 2417freebsd32_umtx_op(struct thread *td, struct freebsd32_umtx_op_args *uap) 2418{ 2419 if ((unsigned)uap->op < UMTX_OP_MAX) 2420 return (*op_table_compat32[uap->op])(td, 2421 (struct _umtx_op_args *)uap); 2422 return (EINVAL); 2423} 2424#endif 2425 2426void 2427umtx_thread_init(struct thread *td) 2428{ 2429 td->td_umtxq = umtxq_alloc(); 2430 td->td_umtxq->uq_thread = td; 2431} 2432 2433void 2434umtx_thread_fini(struct thread *td) 2435{ 2436 umtxq_free(td->td_umtxq); 2437} 2438 2439/* 2440 * It will be called when new thread is created, e.g fork(). 2441 */ 2442void 2443umtx_thread_alloc(struct thread *td) 2444{ 2445 struct umtx_q *uq; 2446 2447 uq = td->td_umtxq; 2448 uq->uq_inherited_pri = PRI_MAX; 2449 2450 KASSERT(uq->uq_flags == 0, ("uq_flags != 0")); 2451 KASSERT(uq->uq_thread == td, ("uq_thread != td")); 2452 KASSERT(uq->uq_pi_blocked == NULL, ("uq_pi_blocked != NULL")); 2453 KASSERT(TAILQ_EMPTY(&uq->uq_pi_contested), ("uq_pi_contested is not empty")); 2454} 2455 2456/* 2457 * exec() hook. 2458 */ 2459static void 2460umtx_exec_hook(void *arg __unused, struct proc *p __unused, 2461 struct image_params *imgp __unused) 2462{ 2463 umtx_thread_cleanup(curthread); 2464} 2465 2466/* 2467 * thread_exit() hook. 2468 */ 2469void 2470umtx_thread_exit(struct thread *td) 2471{ 2472 umtx_thread_cleanup(td); 2473} 2474 2475/* 2476 * clean up umtx data. 2477 */ 2478static void 2479umtx_thread_cleanup(struct thread *td) 2480{ 2481 struct umtx_q *uq; 2482 struct umtx_pi *pi; 2483 2484 if ((uq = td->td_umtxq) == NULL) 2485 return; 2486 2487 mtx_lock_spin(&sched_lock); 2488 uq->uq_inherited_pri = PRI_MAX; 2489 while ((pi = TAILQ_FIRST(&uq->uq_pi_contested)) != NULL) { 2490 pi->pi_owner = NULL; 2491 TAILQ_REMOVE(&uq->uq_pi_contested, pi, pi_link); 2492 } 2493 td->td_flags &= ~TDF_UBORROWING; 2494 mtx_unlock_spin(&sched_lock); 2495} 2496