1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2015, 2016 The FreeBSD Foundation 5 * Copyright (c) 2004, David Xu <davidxu@freebsd.org> 6 * Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org> 7 * All rights reserved. 8 * 9 * Portions of this software were developed by Konstantin Belousov 10 * under sponsorship from the FreeBSD Foundation. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice unmodified, this list of conditions, and the following 17 * disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 #include "opt_umtx_profiling.h" 36 37 #include <sys/param.h> 38 #include <sys/kernel.h> 39 #include <sys/fcntl.h> 40 #include <sys/file.h> 41 #include <sys/filedesc.h> 42 #include <sys/limits.h> 43 #include <sys/lock.h> 44 #include <sys/malloc.h> 45 #include <sys/mman.h> 46 #include <sys/mutex.h> 47 #include <sys/priv.h> 48 #include <sys/proc.h> 49 #include <sys/resource.h> 50 #include <sys/resourcevar.h> 51 #include <sys/rwlock.h> 52 #include <sys/sbuf.h> 53 #include <sys/sched.h> 54 #include <sys/smp.h> 55 #include <sys/sysctl.h> 56 #include <sys/systm.h> 57 #include <sys/sysproto.h> 58 #include <sys/syscallsubr.h> 59 #include <sys/taskqueue.h> 60 #include <sys/time.h> 61 #include <sys/eventhandler.h> 62 #include <sys/umtx.h> 63 #include <sys/umtxvar.h> 64 65 #include <security/mac/mac_framework.h> 66 67 #include <vm/vm.h> 68 #include <vm/vm_param.h> 69 #include <vm/pmap.h> 70 #include <vm/vm_map.h> 71 #include <vm/vm_object.h> 72 73 #include <machine/atomic.h> 74 #include <machine/cpu.h> 75 76 #include <compat/freebsd32/freebsd32.h> 77 #ifdef COMPAT_FREEBSD32 78 #include <compat/freebsd32/freebsd32_proto.h> 79 #endif 80 81 #define _UMUTEX_TRY 1 82 #define _UMUTEX_WAIT 2 83 84 #ifdef UMTX_PROFILING 85 #define UPROF_PERC_BIGGER(w, f, sw, sf) \ 86 (((w) > (sw)) || ((w) == (sw) && (f) > (sf))) 87 #endif 88 89 #define UMTXQ_LOCKED_ASSERT(uc) mtx_assert(&(uc)->uc_lock, MA_OWNED) 90 #ifdef INVARIANTS 91 #define UMTXQ_ASSERT_LOCKED_BUSY(key) do { \ 92 struct umtxq_chain *uc; \ 93 \ 94 uc = umtxq_getchain(key); \ 95 mtx_assert(&uc->uc_lock, MA_OWNED); \ 96 KASSERT(uc->uc_busy != 0, ("umtx chain is not busy")); \ 97 } while (0) 98 #else 99 #define UMTXQ_ASSERT_LOCKED_BUSY(key) do {} while (0) 100 #endif 101 102 /* 103 * Don't propagate time-sharing priority, there is a security reason, 104 * a user can simply introduce PI-mutex, let thread A lock the mutex, 105 * and let another thread B block on the mutex, because B is 106 * sleeping, its priority will be boosted, this causes A's priority to 107 * be boosted via priority propagating too and will never be lowered even 108 * if it is using 100%CPU, this is unfair to other processes. 109 */ 110 111 #define UPRI(td) (((td)->td_user_pri >= PRI_MIN_TIMESHARE &&\ 112 (td)->td_user_pri <= PRI_MAX_TIMESHARE) ?\ 113 PRI_MAX_TIMESHARE : (td)->td_user_pri) 114 115 #define GOLDEN_RATIO_PRIME 2654404609U 116 #ifndef UMTX_CHAINS 117 #define UMTX_CHAINS 512 118 #endif 119 #define UMTX_SHIFTS (__WORD_BIT - 9) 120 121 #define GET_SHARE(flags) \ 122 (((flags) & USYNC_PROCESS_SHARED) == 0 ? THREAD_SHARE : PROCESS_SHARE) 123 124 #define BUSY_SPINS 200 125 126 struct umtx_copyops { 127 int (*copyin_timeout)(const void *uaddr, struct timespec *tsp); 128 int (*copyin_umtx_time)(const void *uaddr, size_t size, 129 struct _umtx_time *tp); 130 int (*copyin_robust_lists)(const void *uaddr, size_t size, 131 struct umtx_robust_lists_params *rbp); 132 int (*copyout_timeout)(void *uaddr, size_t size, 133 struct timespec *tsp); 134 const size_t timespec_sz; 135 const size_t umtx_time_sz; 136 const bool compat32; 137 }; 138 139 _Static_assert(sizeof(struct umutex) == sizeof(struct umutex32), "umutex32"); 140 _Static_assert(__offsetof(struct umutex, m_spare[0]) == 141 __offsetof(struct umutex32, m_spare[0]), "m_spare32"); 142 143 int umtx_shm_vnobj_persistent = 0; 144 SYSCTL_INT(_kern_ipc, OID_AUTO, umtx_vnode_persistent, CTLFLAG_RWTUN, 145 &umtx_shm_vnobj_persistent, 0, 146 "False forces destruction of umtx attached to file, on last close"); 147 static int umtx_max_rb = 1000; 148 SYSCTL_INT(_kern_ipc, OID_AUTO, umtx_max_robust, CTLFLAG_RWTUN, 149 &umtx_max_rb, 0, 150 "Maximum number of robust mutexes allowed for each thread"); 151 152 static uma_zone_t umtx_pi_zone; 153 static struct umtxq_chain umtxq_chains[2][UMTX_CHAINS]; 154 static MALLOC_DEFINE(M_UMTX, "umtx", "UMTX queue memory"); 155 static int umtx_pi_allocated; 156 157 static SYSCTL_NODE(_debug, OID_AUTO, umtx, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 158 "umtx debug"); 159 SYSCTL_INT(_debug_umtx, OID_AUTO, umtx_pi_allocated, CTLFLAG_RD, 160 &umtx_pi_allocated, 0, "Allocated umtx_pi"); 161 static int umtx_verbose_rb = 1; 162 SYSCTL_INT(_debug_umtx, OID_AUTO, robust_faults_verbose, CTLFLAG_RWTUN, 163 &umtx_verbose_rb, 0, 164 ""); 165 166 #ifdef UMTX_PROFILING 167 static long max_length; 168 SYSCTL_LONG(_debug_umtx, OID_AUTO, max_length, CTLFLAG_RD, &max_length, 0, "max_length"); 169 static SYSCTL_NODE(_debug_umtx, OID_AUTO, chains, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 170 "umtx chain stats"); 171 #endif 172 173 static inline void umtx_abs_timeout_init2(struct umtx_abs_timeout *timo, 174 const struct _umtx_time *umtxtime); 175 176 static void umtx_shm_init(void); 177 static void umtxq_sysinit(void *); 178 static void umtxq_hash(struct umtx_key *key); 179 static int do_unlock_pp(struct thread *td, struct umutex *m, uint32_t flags, 180 bool rb); 181 static void umtx_thread_cleanup(struct thread *td); 182 SYSINIT(umtx, SI_SUB_EVENTHANDLER+1, SI_ORDER_MIDDLE, umtxq_sysinit, NULL); 183 184 #define umtxq_signal(key, nwake) umtxq_signal_queue((key), (nwake), UMTX_SHARED_QUEUE) 185 186 static struct mtx umtx_lock; 187 188 #ifdef UMTX_PROFILING 189 static void 190 umtx_init_profiling(void) 191 { 192 struct sysctl_oid *chain_oid; 193 char chain_name[10]; 194 int i; 195 196 for (i = 0; i < UMTX_CHAINS; ++i) { 197 snprintf(chain_name, sizeof(chain_name), "%d", i); 198 chain_oid = SYSCTL_ADD_NODE(NULL, 199 SYSCTL_STATIC_CHILDREN(_debug_umtx_chains), OID_AUTO, 200 chain_name, CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 201 "umtx hash stats"); 202 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO, 203 "max_length0", CTLFLAG_RD, &umtxq_chains[0][i].max_length, 0, NULL); 204 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO, 205 "max_length1", CTLFLAG_RD, &umtxq_chains[1][i].max_length, 0, NULL); 206 } 207 } 208 209 static int 210 sysctl_debug_umtx_chains_peaks(SYSCTL_HANDLER_ARGS) 211 { 212 char buf[512]; 213 struct sbuf sb; 214 struct umtxq_chain *uc; 215 u_int fract, i, j, tot, whole; 216 u_int sf0, sf1, sf2, sf3, sf4; 217 u_int si0, si1, si2, si3, si4; 218 u_int sw0, sw1, sw2, sw3, sw4; 219 220 sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN); 221 for (i = 0; i < 2; i++) { 222 tot = 0; 223 for (j = 0; j < UMTX_CHAINS; ++j) { 224 uc = &umtxq_chains[i][j]; 225 mtx_lock(&uc->uc_lock); 226 tot += uc->max_length; 227 mtx_unlock(&uc->uc_lock); 228 } 229 if (tot == 0) 230 sbuf_printf(&sb, "%u) Empty ", i); 231 else { 232 sf0 = sf1 = sf2 = sf3 = sf4 = 0; 233 si0 = si1 = si2 = si3 = si4 = 0; 234 sw0 = sw1 = sw2 = sw3 = sw4 = 0; 235 for (j = 0; j < UMTX_CHAINS; j++) { 236 uc = &umtxq_chains[i][j]; 237 mtx_lock(&uc->uc_lock); 238 whole = uc->max_length * 100; 239 mtx_unlock(&uc->uc_lock); 240 fract = (whole % tot) * 100; 241 if (UPROF_PERC_BIGGER(whole, fract, sw0, sf0)) { 242 sf0 = fract; 243 si0 = j; 244 sw0 = whole; 245 } else if (UPROF_PERC_BIGGER(whole, fract, sw1, 246 sf1)) { 247 sf1 = fract; 248 si1 = j; 249 sw1 = whole; 250 } else if (UPROF_PERC_BIGGER(whole, fract, sw2, 251 sf2)) { 252 sf2 = fract; 253 si2 = j; 254 sw2 = whole; 255 } else if (UPROF_PERC_BIGGER(whole, fract, sw3, 256 sf3)) { 257 sf3 = fract; 258 si3 = j; 259 sw3 = whole; 260 } else if (UPROF_PERC_BIGGER(whole, fract, sw4, 261 sf4)) { 262 sf4 = fract; 263 si4 = j; 264 sw4 = whole; 265 } 266 } 267 sbuf_printf(&sb, "queue %u:\n", i); 268 sbuf_printf(&sb, "1st: %u.%u%% idx: %u\n", sw0 / tot, 269 sf0 / tot, si0); 270 sbuf_printf(&sb, "2nd: %u.%u%% idx: %u\n", sw1 / tot, 271 sf1 / tot, si1); 272 sbuf_printf(&sb, "3rd: %u.%u%% idx: %u\n", sw2 / tot, 273 sf2 / tot, si2); 274 sbuf_printf(&sb, "4th: %u.%u%% idx: %u\n", sw3 / tot, 275 sf3 / tot, si3); 276 sbuf_printf(&sb, "5th: %u.%u%% idx: %u\n", sw4 / tot, 277 sf4 / tot, si4); 278 } 279 } 280 sbuf_trim(&sb); 281 sbuf_finish(&sb); 282 sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req); 283 sbuf_delete(&sb); 284 return (0); 285 } 286 287 static int 288 sysctl_debug_umtx_chains_clear(SYSCTL_HANDLER_ARGS) 289 { 290 struct umtxq_chain *uc; 291 u_int i, j; 292 int clear, error; 293 294 clear = 0; 295 error = sysctl_handle_int(oidp, &clear, 0, req); 296 if (error != 0 || req->newptr == NULL) 297 return (error); 298 299 if (clear != 0) { 300 for (i = 0; i < 2; ++i) { 301 for (j = 0; j < UMTX_CHAINS; ++j) { 302 uc = &umtxq_chains[i][j]; 303 mtx_lock(&uc->uc_lock); 304 uc->length = 0; 305 uc->max_length = 0; 306 mtx_unlock(&uc->uc_lock); 307 } 308 } 309 } 310 return (0); 311 } 312 313 SYSCTL_PROC(_debug_umtx_chains, OID_AUTO, clear, 314 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0, 315 sysctl_debug_umtx_chains_clear, "I", 316 "Clear umtx chains statistics"); 317 SYSCTL_PROC(_debug_umtx_chains, OID_AUTO, peaks, 318 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0, 319 sysctl_debug_umtx_chains_peaks, "A", 320 "Highest peaks in chains max length"); 321 #endif 322 323 static void 324 umtxq_sysinit(void *arg __unused) 325 { 326 int i, j; 327 328 umtx_pi_zone = uma_zcreate("umtx pi", sizeof(struct umtx_pi), 329 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 330 for (i = 0; i < 2; ++i) { 331 for (j = 0; j < UMTX_CHAINS; ++j) { 332 mtx_init(&umtxq_chains[i][j].uc_lock, "umtxql", NULL, 333 MTX_DEF | MTX_DUPOK); 334 LIST_INIT(&umtxq_chains[i][j].uc_queue[0]); 335 LIST_INIT(&umtxq_chains[i][j].uc_queue[1]); 336 LIST_INIT(&umtxq_chains[i][j].uc_spare_queue); 337 TAILQ_INIT(&umtxq_chains[i][j].uc_pi_list); 338 umtxq_chains[i][j].uc_busy = 0; 339 umtxq_chains[i][j].uc_waiters = 0; 340 #ifdef UMTX_PROFILING 341 umtxq_chains[i][j].length = 0; 342 umtxq_chains[i][j].max_length = 0; 343 #endif 344 } 345 } 346 #ifdef UMTX_PROFILING 347 umtx_init_profiling(); 348 #endif 349 mtx_init(&umtx_lock, "umtx lock", NULL, MTX_DEF); 350 umtx_shm_init(); 351 } 352 353 struct umtx_q * 354 umtxq_alloc(void) 355 { 356 struct umtx_q *uq; 357 358 uq = malloc(sizeof(struct umtx_q), M_UMTX, M_WAITOK | M_ZERO); 359 uq->uq_spare_queue = malloc(sizeof(struct umtxq_queue), M_UMTX, 360 M_WAITOK | M_ZERO); 361 TAILQ_INIT(&uq->uq_spare_queue->head); 362 TAILQ_INIT(&uq->uq_pi_contested); 363 uq->uq_inherited_pri = PRI_MAX; 364 return (uq); 365 } 366 367 void 368 umtxq_free(struct umtx_q *uq) 369 { 370 371 MPASS(uq->uq_spare_queue != NULL); 372 free(uq->uq_spare_queue, M_UMTX); 373 free(uq, M_UMTX); 374 } 375 376 static inline void 377 umtxq_hash(struct umtx_key *key) 378 { 379 unsigned n; 380 381 n = (uintptr_t)key->info.both.a + key->info.both.b; 382 key->hash = ((n * GOLDEN_RATIO_PRIME) >> UMTX_SHIFTS) % UMTX_CHAINS; 383 } 384 385 struct umtxq_chain * 386 umtxq_getchain(struct umtx_key *key) 387 { 388 389 if (key->type <= TYPE_SEM) 390 return (&umtxq_chains[1][key->hash]); 391 return (&umtxq_chains[0][key->hash]); 392 } 393 394 /* 395 * Set chain to busy state when following operation 396 * may be blocked (kernel mutex can not be used). 397 */ 398 void 399 umtxq_busy(struct umtx_key *key) 400 { 401 struct umtxq_chain *uc; 402 403 uc = umtxq_getchain(key); 404 mtx_assert(&uc->uc_lock, MA_OWNED); 405 if (uc->uc_busy) { 406 #ifdef SMP 407 if (smp_cpus > 1) { 408 int count = BUSY_SPINS; 409 if (count > 0) { 410 umtxq_unlock(key); 411 while (uc->uc_busy && --count > 0) 412 cpu_spinwait(); 413 umtxq_lock(key); 414 } 415 } 416 #endif 417 while (uc->uc_busy) { 418 uc->uc_waiters++; 419 msleep(uc, &uc->uc_lock, 0, "umtxqb", 0); 420 uc->uc_waiters--; 421 } 422 } 423 uc->uc_busy = 1; 424 } 425 426 /* 427 * Unbusy a chain. 428 */ 429 void 430 umtxq_unbusy(struct umtx_key *key) 431 { 432 struct umtxq_chain *uc; 433 434 uc = umtxq_getchain(key); 435 mtx_assert(&uc->uc_lock, MA_OWNED); 436 KASSERT(uc->uc_busy != 0, ("not busy")); 437 uc->uc_busy = 0; 438 if (uc->uc_waiters) 439 wakeup_one(uc); 440 } 441 442 void 443 umtxq_unbusy_unlocked(struct umtx_key *key) 444 { 445 446 umtxq_lock(key); 447 umtxq_unbusy(key); 448 umtxq_unlock(key); 449 } 450 451 static struct umtxq_queue * 452 umtxq_queue_lookup(struct umtx_key *key, int q) 453 { 454 struct umtxq_queue *uh; 455 struct umtxq_chain *uc; 456 457 uc = umtxq_getchain(key); 458 UMTXQ_LOCKED_ASSERT(uc); 459 LIST_FOREACH(uh, &uc->uc_queue[q], link) { 460 if (umtx_key_match(&uh->key, key)) 461 return (uh); 462 } 463 464 return (NULL); 465 } 466 467 void 468 umtxq_insert_queue(struct umtx_q *uq, int q) 469 { 470 struct umtxq_queue *uh; 471 struct umtxq_chain *uc; 472 473 uc = umtxq_getchain(&uq->uq_key); 474 UMTXQ_LOCKED_ASSERT(uc); 475 KASSERT((uq->uq_flags & UQF_UMTXQ) == 0, ("umtx_q is already on queue")); 476 uh = umtxq_queue_lookup(&uq->uq_key, q); 477 if (uh != NULL) { 478 LIST_INSERT_HEAD(&uc->uc_spare_queue, uq->uq_spare_queue, link); 479 } else { 480 uh = uq->uq_spare_queue; 481 uh->key = uq->uq_key; 482 LIST_INSERT_HEAD(&uc->uc_queue[q], uh, link); 483 #ifdef UMTX_PROFILING 484 uc->length++; 485 if (uc->length > uc->max_length) { 486 uc->max_length = uc->length; 487 if (uc->max_length > max_length) 488 max_length = uc->max_length; 489 } 490 #endif 491 } 492 uq->uq_spare_queue = NULL; 493 494 TAILQ_INSERT_TAIL(&uh->head, uq, uq_link); 495 uh->length++; 496 uq->uq_flags |= UQF_UMTXQ; 497 uq->uq_cur_queue = uh; 498 return; 499 } 500 501 void 502 umtxq_remove_queue(struct umtx_q *uq, int q) 503 { 504 struct umtxq_chain *uc; 505 struct umtxq_queue *uh; 506 507 uc = umtxq_getchain(&uq->uq_key); 508 UMTXQ_LOCKED_ASSERT(uc); 509 if (uq->uq_flags & UQF_UMTXQ) { 510 uh = uq->uq_cur_queue; 511 TAILQ_REMOVE(&uh->head, uq, uq_link); 512 uh->length--; 513 uq->uq_flags &= ~UQF_UMTXQ; 514 if (TAILQ_EMPTY(&uh->head)) { 515 KASSERT(uh->length == 0, 516 ("inconsistent umtxq_queue length")); 517 #ifdef UMTX_PROFILING 518 uc->length--; 519 #endif 520 LIST_REMOVE(uh, link); 521 } else { 522 uh = LIST_FIRST(&uc->uc_spare_queue); 523 KASSERT(uh != NULL, ("uc_spare_queue is empty")); 524 LIST_REMOVE(uh, link); 525 } 526 uq->uq_spare_queue = uh; 527 uq->uq_cur_queue = NULL; 528 } 529 } 530 531 /* 532 * Check if there are multiple waiters 533 */ 534 int 535 umtxq_count(struct umtx_key *key) 536 { 537 struct umtxq_queue *uh; 538 539 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key)); 540 uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE); 541 if (uh != NULL) 542 return (uh->length); 543 return (0); 544 } 545 546 /* 547 * Check if there are multiple PI waiters and returns first 548 * waiter. 549 */ 550 static int 551 umtxq_count_pi(struct umtx_key *key, struct umtx_q **first) 552 { 553 struct umtxq_queue *uh; 554 555 *first = NULL; 556 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key)); 557 uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE); 558 if (uh != NULL) { 559 *first = TAILQ_FIRST(&uh->head); 560 return (uh->length); 561 } 562 return (0); 563 } 564 565 /* 566 * Wake up threads waiting on an userland object by a bit mask. 567 */ 568 int 569 umtxq_signal_mask(struct umtx_key *key, int n_wake, u_int bitset) 570 { 571 struct umtxq_queue *uh; 572 struct umtx_q *uq, *uq_temp; 573 int ret; 574 575 ret = 0; 576 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key)); 577 uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE); 578 if (uh == NULL) 579 return (0); 580 TAILQ_FOREACH_SAFE(uq, &uh->head, uq_link, uq_temp) { 581 if ((uq->uq_bitset & bitset) == 0) 582 continue; 583 umtxq_remove_queue(uq, UMTX_SHARED_QUEUE); 584 wakeup_one(uq); 585 if (++ret >= n_wake) 586 break; 587 } 588 return (ret); 589 } 590 591 /* 592 * Wake up threads waiting on an userland object. 593 */ 594 595 static int 596 umtxq_signal_queue(struct umtx_key *key, int n_wake, int q) 597 { 598 struct umtxq_queue *uh; 599 struct umtx_q *uq; 600 int ret; 601 602 ret = 0; 603 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key)); 604 uh = umtxq_queue_lookup(key, q); 605 if (uh != NULL) { 606 while ((uq = TAILQ_FIRST(&uh->head)) != NULL) { 607 umtxq_remove_queue(uq, q); 608 wakeup(uq); 609 if (++ret >= n_wake) 610 return (ret); 611 } 612 } 613 return (ret); 614 } 615 616 /* 617 * Wake up specified thread. 618 */ 619 static inline void 620 umtxq_signal_thread(struct umtx_q *uq) 621 { 622 623 UMTXQ_LOCKED_ASSERT(umtxq_getchain(&uq->uq_key)); 624 umtxq_remove(uq); 625 wakeup(uq); 626 } 627 628 /* 629 * Wake up a maximum of n_wake threads that are waiting on an userland 630 * object identified by key. The remaining threads are removed from queue 631 * identified by key and added to the queue identified by key2 (requeued). 632 * The n_requeue specifies an upper limit on the number of threads that 633 * are requeued to the second queue. 634 */ 635 int 636 umtxq_requeue(struct umtx_key *key, int n_wake, struct umtx_key *key2, 637 int n_requeue) 638 { 639 struct umtxq_queue *uh; 640 struct umtx_q *uq, *uq_temp; 641 int ret; 642 643 ret = 0; 644 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key)); 645 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key2)); 646 uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE); 647 if (uh == NULL) 648 return (0); 649 TAILQ_FOREACH_SAFE(uq, &uh->head, uq_link, uq_temp) { 650 if (++ret <= n_wake) { 651 umtxq_remove(uq); 652 wakeup_one(uq); 653 } else { 654 umtxq_remove(uq); 655 uq->uq_key = *key2; 656 umtxq_insert(uq); 657 if (ret - n_wake == n_requeue) 658 break; 659 } 660 } 661 return (ret); 662 } 663 664 static inline int 665 tstohz(const struct timespec *tsp) 666 { 667 struct timeval tv; 668 669 TIMESPEC_TO_TIMEVAL(&tv, tsp); 670 return tvtohz(&tv); 671 } 672 673 void 674 umtx_abs_timeout_init(struct umtx_abs_timeout *timo, int clockid, 675 int absolute, const struct timespec *timeout) 676 { 677 678 timo->clockid = clockid; 679 if (!absolute) { 680 timo->is_abs_real = false; 681 kern_clock_gettime(curthread, timo->clockid, &timo->cur); 682 timespecadd(&timo->cur, timeout, &timo->end); 683 } else { 684 timo->end = *timeout; 685 timo->is_abs_real = clockid == CLOCK_REALTIME || 686 clockid == CLOCK_REALTIME_FAST || 687 clockid == CLOCK_REALTIME_PRECISE || 688 clockid == CLOCK_SECOND; 689 } 690 } 691 692 static void 693 umtx_abs_timeout_init2(struct umtx_abs_timeout *timo, 694 const struct _umtx_time *umtxtime) 695 { 696 697 umtx_abs_timeout_init(timo, umtxtime->_clockid, 698 (umtxtime->_flags & UMTX_ABSTIME) != 0, &umtxtime->_timeout); 699 } 700 701 static void 702 umtx_abs_timeout_enforce_min(sbintime_t *sbt) 703 { 704 sbintime_t when, mint; 705 706 mint = curproc->p_umtx_min_timeout; 707 if (__predict_false(mint != 0)) { 708 when = sbinuptime() + mint; 709 if (*sbt < when) 710 *sbt = when; 711 } 712 } 713 714 static int 715 umtx_abs_timeout_getsbt(struct umtx_abs_timeout *timo, sbintime_t *sbt, 716 int *flags) 717 { 718 struct bintime bt, bbt; 719 struct timespec tts; 720 sbintime_t rem; 721 722 switch (timo->clockid) { 723 724 /* Clocks that can be converted into absolute time. */ 725 case CLOCK_REALTIME: 726 case CLOCK_REALTIME_PRECISE: 727 case CLOCK_REALTIME_FAST: 728 case CLOCK_MONOTONIC: 729 case CLOCK_MONOTONIC_PRECISE: 730 case CLOCK_MONOTONIC_FAST: 731 case CLOCK_UPTIME: 732 case CLOCK_UPTIME_PRECISE: 733 case CLOCK_UPTIME_FAST: 734 case CLOCK_SECOND: 735 timespec2bintime(&timo->end, &bt); 736 switch (timo->clockid) { 737 case CLOCK_REALTIME: 738 case CLOCK_REALTIME_PRECISE: 739 case CLOCK_REALTIME_FAST: 740 case CLOCK_SECOND: 741 getboottimebin(&bbt); 742 bintime_sub(&bt, &bbt); 743 break; 744 } 745 if (bt.sec < 0) 746 return (ETIMEDOUT); 747 if (bt.sec >= (SBT_MAX >> 32)) { 748 *sbt = 0; 749 *flags = 0; 750 return (0); 751 } 752 *sbt = bttosbt(bt); 753 umtx_abs_timeout_enforce_min(sbt); 754 755 /* 756 * Check if the absolute time should be aligned to 757 * avoid firing multiple timer events in non-periodic 758 * timer mode. 759 */ 760 switch (timo->clockid) { 761 case CLOCK_REALTIME_FAST: 762 case CLOCK_MONOTONIC_FAST: 763 case CLOCK_UPTIME_FAST: 764 rem = *sbt % tc_tick_sbt; 765 if (__predict_true(rem != 0)) 766 *sbt += tc_tick_sbt - rem; 767 break; 768 case CLOCK_SECOND: 769 rem = *sbt % SBT_1S; 770 if (__predict_true(rem != 0)) 771 *sbt += SBT_1S - rem; 772 break; 773 } 774 *flags = C_ABSOLUTE; 775 return (0); 776 777 /* Clocks that has to be periodically polled. */ 778 case CLOCK_VIRTUAL: 779 case CLOCK_PROF: 780 case CLOCK_THREAD_CPUTIME_ID: 781 case CLOCK_PROCESS_CPUTIME_ID: 782 default: 783 kern_clock_gettime(curthread, timo->clockid, &timo->cur); 784 if (timespeccmp(&timo->end, &timo->cur, <=)) 785 return (ETIMEDOUT); 786 timespecsub(&timo->end, &timo->cur, &tts); 787 *sbt = tick_sbt * tstohz(&tts); 788 *flags = C_HARDCLOCK; 789 return (0); 790 } 791 } 792 793 static uint32_t 794 umtx_unlock_val(uint32_t flags, bool rb) 795 { 796 797 if (rb) 798 return (UMUTEX_RB_OWNERDEAD); 799 else if ((flags & UMUTEX_NONCONSISTENT) != 0) 800 return (UMUTEX_RB_NOTRECOV); 801 else 802 return (UMUTEX_UNOWNED); 803 804 } 805 806 /* 807 * Put thread into sleep state, before sleeping, check if 808 * thread was removed from umtx queue. 809 */ 810 int 811 umtxq_sleep(struct umtx_q *uq, const char *wmesg, 812 struct umtx_abs_timeout *timo) 813 { 814 struct umtxq_chain *uc; 815 sbintime_t sbt = 0; 816 int error, flags = 0; 817 818 uc = umtxq_getchain(&uq->uq_key); 819 UMTXQ_LOCKED_ASSERT(uc); 820 for (;;) { 821 if (!(uq->uq_flags & UQF_UMTXQ)) { 822 error = 0; 823 break; 824 } 825 if (timo != NULL) { 826 if (timo->is_abs_real) 827 curthread->td_rtcgen = 828 atomic_load_acq_int(&rtc_generation); 829 error = umtx_abs_timeout_getsbt(timo, &sbt, &flags); 830 if (error != 0) 831 break; 832 } 833 error = msleep_sbt(uq, &uc->uc_lock, PCATCH | PDROP, wmesg, 834 sbt, 0, flags); 835 uc = umtxq_getchain(&uq->uq_key); 836 mtx_lock(&uc->uc_lock); 837 if (error == EINTR || error == ERESTART) 838 break; 839 if (error == EWOULDBLOCK && (flags & C_ABSOLUTE) != 0) { 840 error = ETIMEDOUT; 841 break; 842 } 843 } 844 845 curthread->td_rtcgen = 0; 846 return (error); 847 } 848 849 /* 850 * Convert userspace address into unique logical address. 851 */ 852 int 853 umtx_key_get(const void *addr, int type, int share, struct umtx_key *key) 854 { 855 struct thread *td = curthread; 856 vm_map_t map; 857 vm_map_entry_t entry; 858 vm_pindex_t pindex; 859 vm_prot_t prot; 860 boolean_t wired; 861 862 key->type = type; 863 if (share == THREAD_SHARE) { 864 key->shared = 0; 865 key->info.private.vs = td->td_proc->p_vmspace; 866 key->info.private.addr = (uintptr_t)addr; 867 } else { 868 MPASS(share == PROCESS_SHARE || share == AUTO_SHARE); 869 map = &td->td_proc->p_vmspace->vm_map; 870 if (vm_map_lookup(&map, (vm_offset_t)addr, VM_PROT_WRITE, 871 &entry, &key->info.shared.object, &pindex, &prot, 872 &wired) != KERN_SUCCESS) { 873 return (EFAULT); 874 } 875 876 if ((share == PROCESS_SHARE) || 877 (share == AUTO_SHARE && 878 VM_INHERIT_SHARE == entry->inheritance)) { 879 key->shared = 1; 880 key->info.shared.offset = (vm_offset_t)addr - 881 entry->start + entry->offset; 882 vm_object_reference(key->info.shared.object); 883 } else { 884 key->shared = 0; 885 key->info.private.vs = td->td_proc->p_vmspace; 886 key->info.private.addr = (uintptr_t)addr; 887 } 888 vm_map_lookup_done(map, entry); 889 } 890 891 umtxq_hash(key); 892 return (0); 893 } 894 895 /* 896 * Release key. 897 */ 898 void 899 umtx_key_release(struct umtx_key *key) 900 { 901 if (key->shared) 902 vm_object_deallocate(key->info.shared.object); 903 } 904 905 #ifdef COMPAT_FREEBSD10 906 /* 907 * Lock a umtx object. 908 */ 909 static int 910 do_lock_umtx(struct thread *td, struct umtx *umtx, u_long id, 911 const struct timespec *timeout) 912 { 913 struct umtx_abs_timeout timo; 914 struct umtx_q *uq; 915 u_long owner; 916 u_long old; 917 int error = 0; 918 919 uq = td->td_umtxq; 920 if (timeout != NULL) 921 umtx_abs_timeout_init(&timo, CLOCK_REALTIME, 0, timeout); 922 923 /* 924 * Care must be exercised when dealing with umtx structure. It 925 * can fault on any access. 926 */ 927 for (;;) { 928 /* 929 * Try the uncontested case. This should be done in userland. 930 */ 931 owner = casuword(&umtx->u_owner, UMTX_UNOWNED, id); 932 933 /* The acquire succeeded. */ 934 if (owner == UMTX_UNOWNED) 935 return (0); 936 937 /* The address was invalid. */ 938 if (owner == -1) 939 return (EFAULT); 940 941 /* If no one owns it but it is contested try to acquire it. */ 942 if (owner == UMTX_CONTESTED) { 943 owner = casuword(&umtx->u_owner, 944 UMTX_CONTESTED, id | UMTX_CONTESTED); 945 946 if (owner == UMTX_CONTESTED) 947 return (0); 948 949 /* The address was invalid. */ 950 if (owner == -1) 951 return (EFAULT); 952 953 error = thread_check_susp(td, false); 954 if (error != 0) 955 break; 956 957 /* If this failed the lock has changed, restart. */ 958 continue; 959 } 960 961 /* 962 * If we caught a signal, we have retried and now 963 * exit immediately. 964 */ 965 if (error != 0) 966 break; 967 968 if ((error = umtx_key_get(umtx, TYPE_SIMPLE_LOCK, 969 AUTO_SHARE, &uq->uq_key)) != 0) 970 return (error); 971 972 umtxq_lock(&uq->uq_key); 973 umtxq_busy(&uq->uq_key); 974 umtxq_insert(uq); 975 umtxq_unbusy(&uq->uq_key); 976 umtxq_unlock(&uq->uq_key); 977 978 /* 979 * Set the contested bit so that a release in user space 980 * knows to use the system call for unlock. If this fails 981 * either some one else has acquired the lock or it has been 982 * released. 983 */ 984 old = casuword(&umtx->u_owner, owner, owner | UMTX_CONTESTED); 985 986 /* The address was invalid. */ 987 if (old == -1) { 988 umtxq_lock(&uq->uq_key); 989 umtxq_remove(uq); 990 umtxq_unlock(&uq->uq_key); 991 umtx_key_release(&uq->uq_key); 992 return (EFAULT); 993 } 994 995 /* 996 * We set the contested bit, sleep. Otherwise the lock changed 997 * and we need to retry or we lost a race to the thread 998 * unlocking the umtx. 999 */ 1000 umtxq_lock(&uq->uq_key); 1001 if (old == owner) 1002 error = umtxq_sleep(uq, "umtx", timeout == NULL ? NULL : 1003 &timo); 1004 umtxq_remove(uq); 1005 umtxq_unlock(&uq->uq_key); 1006 umtx_key_release(&uq->uq_key); 1007 1008 if (error == 0) 1009 error = thread_check_susp(td, false); 1010 } 1011 1012 if (timeout == NULL) { 1013 /* Mutex locking is restarted if it is interrupted. */ 1014 if (error == EINTR) 1015 error = ERESTART; 1016 } else { 1017 /* Timed-locking is not restarted. */ 1018 if (error == ERESTART) 1019 error = EINTR; 1020 } 1021 return (error); 1022 } 1023 1024 /* 1025 * Unlock a umtx object. 1026 */ 1027 static int 1028 do_unlock_umtx(struct thread *td, struct umtx *umtx, u_long id) 1029 { 1030 struct umtx_key key; 1031 u_long owner; 1032 u_long old; 1033 int error; 1034 int count; 1035 1036 /* 1037 * Make sure we own this mtx. 1038 */ 1039 owner = fuword(__DEVOLATILE(u_long *, &umtx->u_owner)); 1040 if (owner == -1) 1041 return (EFAULT); 1042 1043 if ((owner & ~UMTX_CONTESTED) != id) 1044 return (EPERM); 1045 1046 /* This should be done in userland */ 1047 if ((owner & UMTX_CONTESTED) == 0) { 1048 old = casuword(&umtx->u_owner, owner, UMTX_UNOWNED); 1049 if (old == -1) 1050 return (EFAULT); 1051 if (old == owner) 1052 return (0); 1053 owner = old; 1054 } 1055 1056 /* We should only ever be in here for contested locks */ 1057 if ((error = umtx_key_get(umtx, TYPE_SIMPLE_LOCK, AUTO_SHARE, 1058 &key)) != 0) 1059 return (error); 1060 1061 umtxq_lock(&key); 1062 umtxq_busy(&key); 1063 count = umtxq_count(&key); 1064 umtxq_unlock(&key); 1065 1066 /* 1067 * When unlocking the umtx, it must be marked as unowned if 1068 * there is zero or one thread only waiting for it. 1069 * Otherwise, it must be marked as contested. 1070 */ 1071 old = casuword(&umtx->u_owner, owner, 1072 count <= 1 ? UMTX_UNOWNED : UMTX_CONTESTED); 1073 umtxq_lock(&key); 1074 umtxq_signal(&key,1); 1075 umtxq_unbusy(&key); 1076 umtxq_unlock(&key); 1077 umtx_key_release(&key); 1078 if (old == -1) 1079 return (EFAULT); 1080 if (old != owner) 1081 return (EINVAL); 1082 return (0); 1083 } 1084 1085 #ifdef COMPAT_FREEBSD32 1086 1087 /* 1088 * Lock a umtx object. 1089 */ 1090 static int 1091 do_lock_umtx32(struct thread *td, uint32_t *m, uint32_t id, 1092 const struct timespec *timeout) 1093 { 1094 struct umtx_abs_timeout timo; 1095 struct umtx_q *uq; 1096 uint32_t owner; 1097 uint32_t old; 1098 int error = 0; 1099 1100 uq = td->td_umtxq; 1101 1102 if (timeout != NULL) 1103 umtx_abs_timeout_init(&timo, CLOCK_REALTIME, 0, timeout); 1104 1105 /* 1106 * Care must be exercised when dealing with umtx structure. It 1107 * can fault on any access. 1108 */ 1109 for (;;) { 1110 /* 1111 * Try the uncontested case. This should be done in userland. 1112 */ 1113 owner = casuword32(m, UMUTEX_UNOWNED, id); 1114 1115 /* The acquire succeeded. */ 1116 if (owner == UMUTEX_UNOWNED) 1117 return (0); 1118 1119 /* The address was invalid. */ 1120 if (owner == -1) 1121 return (EFAULT); 1122 1123 /* If no one owns it but it is contested try to acquire it. */ 1124 if (owner == UMUTEX_CONTESTED) { 1125 owner = casuword32(m, 1126 UMUTEX_CONTESTED, id | UMUTEX_CONTESTED); 1127 if (owner == UMUTEX_CONTESTED) 1128 return (0); 1129 1130 /* The address was invalid. */ 1131 if (owner == -1) 1132 return (EFAULT); 1133 1134 error = thread_check_susp(td, false); 1135 if (error != 0) 1136 break; 1137 1138 /* If this failed the lock has changed, restart. */ 1139 continue; 1140 } 1141 1142 /* 1143 * If we caught a signal, we have retried and now 1144 * exit immediately. 1145 */ 1146 if (error != 0) 1147 return (error); 1148 1149 if ((error = umtx_key_get(m, TYPE_SIMPLE_LOCK, 1150 AUTO_SHARE, &uq->uq_key)) != 0) 1151 return (error); 1152 1153 umtxq_lock(&uq->uq_key); 1154 umtxq_busy(&uq->uq_key); 1155 umtxq_insert(uq); 1156 umtxq_unbusy(&uq->uq_key); 1157 umtxq_unlock(&uq->uq_key); 1158 1159 /* 1160 * Set the contested bit so that a release in user space 1161 * knows to use the system call for unlock. If this fails 1162 * either some one else has acquired the lock or it has been 1163 * released. 1164 */ 1165 old = casuword32(m, owner, owner | UMUTEX_CONTESTED); 1166 1167 /* The address was invalid. */ 1168 if (old == -1) { 1169 umtxq_lock(&uq->uq_key); 1170 umtxq_remove(uq); 1171 umtxq_unlock(&uq->uq_key); 1172 umtx_key_release(&uq->uq_key); 1173 return (EFAULT); 1174 } 1175 1176 /* 1177 * We set the contested bit, sleep. Otherwise the lock changed 1178 * and we need to retry or we lost a race to the thread 1179 * unlocking the umtx. 1180 */ 1181 umtxq_lock(&uq->uq_key); 1182 if (old == owner) 1183 error = umtxq_sleep(uq, "umtx", timeout == NULL ? 1184 NULL : &timo); 1185 umtxq_remove(uq); 1186 umtxq_unlock(&uq->uq_key); 1187 umtx_key_release(&uq->uq_key); 1188 1189 if (error == 0) 1190 error = thread_check_susp(td, false); 1191 } 1192 1193 if (timeout == NULL) { 1194 /* Mutex locking is restarted if it is interrupted. */ 1195 if (error == EINTR) 1196 error = ERESTART; 1197 } else { 1198 /* Timed-locking is not restarted. */ 1199 if (error == ERESTART) 1200 error = EINTR; 1201 } 1202 return (error); 1203 } 1204 1205 /* 1206 * Unlock a umtx object. 1207 */ 1208 static int 1209 do_unlock_umtx32(struct thread *td, uint32_t *m, uint32_t id) 1210 { 1211 struct umtx_key key; 1212 uint32_t owner; 1213 uint32_t old; 1214 int error; 1215 int count; 1216 1217 /* 1218 * Make sure we own this mtx. 1219 */ 1220 owner = fuword32(m); 1221 if (owner == -1) 1222 return (EFAULT); 1223 1224 if ((owner & ~UMUTEX_CONTESTED) != id) 1225 return (EPERM); 1226 1227 /* This should be done in userland */ 1228 if ((owner & UMUTEX_CONTESTED) == 0) { 1229 old = casuword32(m, owner, UMUTEX_UNOWNED); 1230 if (old == -1) 1231 return (EFAULT); 1232 if (old == owner) 1233 return (0); 1234 owner = old; 1235 } 1236 1237 /* We should only ever be in here for contested locks */ 1238 if ((error = umtx_key_get(m, TYPE_SIMPLE_LOCK, AUTO_SHARE, 1239 &key)) != 0) 1240 return (error); 1241 1242 umtxq_lock(&key); 1243 umtxq_busy(&key); 1244 count = umtxq_count(&key); 1245 umtxq_unlock(&key); 1246 1247 /* 1248 * When unlocking the umtx, it must be marked as unowned if 1249 * there is zero or one thread only waiting for it. 1250 * Otherwise, it must be marked as contested. 1251 */ 1252 old = casuword32(m, owner, 1253 count <= 1 ? UMUTEX_UNOWNED : UMUTEX_CONTESTED); 1254 umtxq_lock(&key); 1255 umtxq_signal(&key,1); 1256 umtxq_unbusy(&key); 1257 umtxq_unlock(&key); 1258 umtx_key_release(&key); 1259 if (old == -1) 1260 return (EFAULT); 1261 if (old != owner) 1262 return (EINVAL); 1263 return (0); 1264 } 1265 #endif /* COMPAT_FREEBSD32 */ 1266 #endif /* COMPAT_FREEBSD10 */ 1267 1268 /* 1269 * Fetch and compare value, sleep on the address if value is not changed. 1270 */ 1271 static int 1272 do_wait(struct thread *td, void *addr, u_long id, 1273 struct _umtx_time *timeout, int compat32, int is_private) 1274 { 1275 struct umtx_abs_timeout timo; 1276 struct umtx_q *uq; 1277 u_long tmp; 1278 uint32_t tmp32; 1279 int error = 0; 1280 1281 uq = td->td_umtxq; 1282 if ((error = umtx_key_get(addr, TYPE_SIMPLE_WAIT, 1283 is_private ? THREAD_SHARE : AUTO_SHARE, &uq->uq_key)) != 0) 1284 return (error); 1285 1286 if (timeout != NULL) 1287 umtx_abs_timeout_init2(&timo, timeout); 1288 1289 umtxq_lock(&uq->uq_key); 1290 umtxq_insert(uq); 1291 umtxq_unlock(&uq->uq_key); 1292 if (compat32 == 0) { 1293 error = fueword(addr, &tmp); 1294 if (error != 0) 1295 error = EFAULT; 1296 } else { 1297 error = fueword32(addr, &tmp32); 1298 if (error == 0) 1299 tmp = tmp32; 1300 else 1301 error = EFAULT; 1302 } 1303 umtxq_lock(&uq->uq_key); 1304 if (error == 0) { 1305 if (tmp == id) 1306 error = umtxq_sleep(uq, "uwait", timeout == NULL ? 1307 NULL : &timo); 1308 if ((uq->uq_flags & UQF_UMTXQ) == 0) 1309 error = 0; 1310 else 1311 umtxq_remove(uq); 1312 } else if ((uq->uq_flags & UQF_UMTXQ) != 0) { 1313 umtxq_remove(uq); 1314 } 1315 umtxq_unlock(&uq->uq_key); 1316 umtx_key_release(&uq->uq_key); 1317 if (error == ERESTART) 1318 error = EINTR; 1319 return (error); 1320 } 1321 1322 /* 1323 * Wake up threads sleeping on the specified address. 1324 */ 1325 int 1326 kern_umtx_wake(struct thread *td, void *uaddr, int n_wake, int is_private) 1327 { 1328 struct umtx_key key; 1329 int ret; 1330 1331 if ((ret = umtx_key_get(uaddr, TYPE_SIMPLE_WAIT, 1332 is_private ? THREAD_SHARE : AUTO_SHARE, &key)) != 0) 1333 return (ret); 1334 umtxq_lock(&key); 1335 umtxq_signal(&key, n_wake); 1336 umtxq_unlock(&key); 1337 umtx_key_release(&key); 1338 return (0); 1339 } 1340 1341 /* 1342 * Lock PTHREAD_PRIO_NONE protocol POSIX mutex. 1343 */ 1344 static int 1345 do_lock_normal(struct thread *td, struct umutex *m, uint32_t flags, 1346 struct _umtx_time *timeout, int mode) 1347 { 1348 struct umtx_abs_timeout timo; 1349 struct umtx_q *uq; 1350 uint32_t owner, old, id; 1351 int error, rv; 1352 1353 id = td->td_tid; 1354 uq = td->td_umtxq; 1355 error = 0; 1356 if (timeout != NULL) 1357 umtx_abs_timeout_init2(&timo, timeout); 1358 1359 /* 1360 * Care must be exercised when dealing with umtx structure. It 1361 * can fault on any access. 1362 */ 1363 for (;;) { 1364 rv = fueword32(&m->m_owner, &owner); 1365 if (rv == -1) 1366 return (EFAULT); 1367 if (mode == _UMUTEX_WAIT) { 1368 if (owner == UMUTEX_UNOWNED || 1369 owner == UMUTEX_CONTESTED || 1370 owner == UMUTEX_RB_OWNERDEAD || 1371 owner == UMUTEX_RB_NOTRECOV) 1372 return (0); 1373 } else { 1374 /* 1375 * Robust mutex terminated. Kernel duty is to 1376 * return EOWNERDEAD to the userspace. The 1377 * umutex.m_flags UMUTEX_NONCONSISTENT is set 1378 * by the common userspace code. 1379 */ 1380 if (owner == UMUTEX_RB_OWNERDEAD) { 1381 rv = casueword32(&m->m_owner, 1382 UMUTEX_RB_OWNERDEAD, &owner, 1383 id | UMUTEX_CONTESTED); 1384 if (rv == -1) 1385 return (EFAULT); 1386 if (rv == 0) { 1387 MPASS(owner == UMUTEX_RB_OWNERDEAD); 1388 return (EOWNERDEAD); /* success */ 1389 } 1390 MPASS(rv == 1); 1391 rv = thread_check_susp(td, false); 1392 if (rv != 0) 1393 return (rv); 1394 continue; 1395 } 1396 if (owner == UMUTEX_RB_NOTRECOV) 1397 return (ENOTRECOVERABLE); 1398 1399 /* 1400 * Try the uncontested case. This should be 1401 * done in userland. 1402 */ 1403 rv = casueword32(&m->m_owner, UMUTEX_UNOWNED, 1404 &owner, id); 1405 /* The address was invalid. */ 1406 if (rv == -1) 1407 return (EFAULT); 1408 1409 /* The acquire succeeded. */ 1410 if (rv == 0) { 1411 MPASS(owner == UMUTEX_UNOWNED); 1412 return (0); 1413 } 1414 1415 /* 1416 * If no one owns it but it is contested try 1417 * to acquire it. 1418 */ 1419 MPASS(rv == 1); 1420 if (owner == UMUTEX_CONTESTED) { 1421 rv = casueword32(&m->m_owner, 1422 UMUTEX_CONTESTED, &owner, 1423 id | UMUTEX_CONTESTED); 1424 /* The address was invalid. */ 1425 if (rv == -1) 1426 return (EFAULT); 1427 if (rv == 0) { 1428 MPASS(owner == UMUTEX_CONTESTED); 1429 return (0); 1430 } 1431 if (rv == 1) { 1432 rv = thread_check_susp(td, false); 1433 if (rv != 0) 1434 return (rv); 1435 } 1436 1437 /* 1438 * If this failed the lock has 1439 * changed, restart. 1440 */ 1441 continue; 1442 } 1443 1444 /* rv == 1 but not contested, likely store failure */ 1445 rv = thread_check_susp(td, false); 1446 if (rv != 0) 1447 return (rv); 1448 } 1449 1450 if (mode == _UMUTEX_TRY) 1451 return (EBUSY); 1452 1453 /* 1454 * If we caught a signal, we have retried and now 1455 * exit immediately. 1456 */ 1457 if (error != 0) 1458 return (error); 1459 1460 if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX, 1461 GET_SHARE(flags), &uq->uq_key)) != 0) 1462 return (error); 1463 1464 umtxq_lock(&uq->uq_key); 1465 umtxq_busy(&uq->uq_key); 1466 umtxq_insert(uq); 1467 umtxq_unlock(&uq->uq_key); 1468 1469 /* 1470 * Set the contested bit so that a release in user space 1471 * knows to use the system call for unlock. If this fails 1472 * either some one else has acquired the lock or it has been 1473 * released. 1474 */ 1475 rv = casueword32(&m->m_owner, owner, &old, 1476 owner | UMUTEX_CONTESTED); 1477 1478 /* The address was invalid or casueword failed to store. */ 1479 if (rv == -1 || rv == 1) { 1480 umtxq_lock(&uq->uq_key); 1481 umtxq_remove(uq); 1482 umtxq_unbusy(&uq->uq_key); 1483 umtxq_unlock(&uq->uq_key); 1484 umtx_key_release(&uq->uq_key); 1485 if (rv == -1) 1486 return (EFAULT); 1487 if (rv == 1) { 1488 rv = thread_check_susp(td, false); 1489 if (rv != 0) 1490 return (rv); 1491 } 1492 continue; 1493 } 1494 1495 /* 1496 * We set the contested bit, sleep. Otherwise the lock changed 1497 * and we need to retry or we lost a race to the thread 1498 * unlocking the umtx. 1499 */ 1500 umtxq_lock(&uq->uq_key); 1501 umtxq_unbusy(&uq->uq_key); 1502 MPASS(old == owner); 1503 error = umtxq_sleep(uq, "umtxn", timeout == NULL ? 1504 NULL : &timo); 1505 umtxq_remove(uq); 1506 umtxq_unlock(&uq->uq_key); 1507 umtx_key_release(&uq->uq_key); 1508 1509 if (error == 0) 1510 error = thread_check_susp(td, false); 1511 } 1512 1513 return (0); 1514 } 1515 1516 /* 1517 * Unlock PTHREAD_PRIO_NONE protocol POSIX mutex. 1518 */ 1519 static int 1520 do_unlock_normal(struct thread *td, struct umutex *m, uint32_t flags, bool rb) 1521 { 1522 struct umtx_key key; 1523 uint32_t owner, old, id, newlock; 1524 int error, count; 1525 1526 id = td->td_tid; 1527 1528 again: 1529 /* 1530 * Make sure we own this mtx. 1531 */ 1532 error = fueword32(&m->m_owner, &owner); 1533 if (error == -1) 1534 return (EFAULT); 1535 1536 if ((owner & ~UMUTEX_CONTESTED) != id) 1537 return (EPERM); 1538 1539 newlock = umtx_unlock_val(flags, rb); 1540 if ((owner & UMUTEX_CONTESTED) == 0) { 1541 error = casueword32(&m->m_owner, owner, &old, newlock); 1542 if (error == -1) 1543 return (EFAULT); 1544 if (error == 1) { 1545 error = thread_check_susp(td, false); 1546 if (error != 0) 1547 return (error); 1548 goto again; 1549 } 1550 MPASS(old == owner); 1551 return (0); 1552 } 1553 1554 /* We should only ever be in here for contested locks */ 1555 if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX, GET_SHARE(flags), 1556 &key)) != 0) 1557 return (error); 1558 1559 umtxq_lock(&key); 1560 umtxq_busy(&key); 1561 count = umtxq_count(&key); 1562 umtxq_unlock(&key); 1563 1564 /* 1565 * When unlocking the umtx, it must be marked as unowned if 1566 * there is zero or one thread only waiting for it. 1567 * Otherwise, it must be marked as contested. 1568 */ 1569 if (count > 1) 1570 newlock |= UMUTEX_CONTESTED; 1571 error = casueword32(&m->m_owner, owner, &old, newlock); 1572 umtxq_lock(&key); 1573 umtxq_signal(&key, 1); 1574 umtxq_unbusy(&key); 1575 umtxq_unlock(&key); 1576 umtx_key_release(&key); 1577 if (error == -1) 1578 return (EFAULT); 1579 if (error == 1) { 1580 if (old != owner) 1581 return (EINVAL); 1582 error = thread_check_susp(td, false); 1583 if (error != 0) 1584 return (error); 1585 goto again; 1586 } 1587 return (0); 1588 } 1589 1590 /* 1591 * Check if the mutex is available and wake up a waiter, 1592 * only for simple mutex. 1593 */ 1594 static int 1595 do_wake_umutex(struct thread *td, struct umutex *m) 1596 { 1597 struct umtx_key key; 1598 uint32_t owner; 1599 uint32_t flags; 1600 int error; 1601 int count; 1602 1603 again: 1604 error = fueword32(&m->m_owner, &owner); 1605 if (error == -1) 1606 return (EFAULT); 1607 1608 if ((owner & ~UMUTEX_CONTESTED) != 0 && owner != UMUTEX_RB_OWNERDEAD && 1609 owner != UMUTEX_RB_NOTRECOV) 1610 return (0); 1611 1612 error = fueword32(&m->m_flags, &flags); 1613 if (error == -1) 1614 return (EFAULT); 1615 1616 /* We should only ever be in here for contested locks */ 1617 if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX, GET_SHARE(flags), 1618 &key)) != 0) 1619 return (error); 1620 1621 umtxq_lock(&key); 1622 umtxq_busy(&key); 1623 count = umtxq_count(&key); 1624 umtxq_unlock(&key); 1625 1626 if (count <= 1 && owner != UMUTEX_RB_OWNERDEAD && 1627 owner != UMUTEX_RB_NOTRECOV) { 1628 error = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner, 1629 UMUTEX_UNOWNED); 1630 if (error == -1) { 1631 error = EFAULT; 1632 } else if (error == 1) { 1633 umtxq_lock(&key); 1634 umtxq_unbusy(&key); 1635 umtxq_unlock(&key); 1636 umtx_key_release(&key); 1637 error = thread_check_susp(td, false); 1638 if (error != 0) 1639 return (error); 1640 goto again; 1641 } 1642 } 1643 1644 umtxq_lock(&key); 1645 if (error == 0 && count != 0) { 1646 MPASS((owner & ~UMUTEX_CONTESTED) == 0 || 1647 owner == UMUTEX_RB_OWNERDEAD || 1648 owner == UMUTEX_RB_NOTRECOV); 1649 umtxq_signal(&key, 1); 1650 } 1651 umtxq_unbusy(&key); 1652 umtxq_unlock(&key); 1653 umtx_key_release(&key); 1654 return (error); 1655 } 1656 1657 /* 1658 * Check if the mutex has waiters and tries to fix contention bit. 1659 */ 1660 static int 1661 do_wake2_umutex(struct thread *td, struct umutex *m, uint32_t flags) 1662 { 1663 struct umtx_key key; 1664 uint32_t owner, old; 1665 int type; 1666 int error; 1667 int count; 1668 1669 switch (flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT | 1670 UMUTEX_ROBUST)) { 1671 case 0: 1672 case UMUTEX_ROBUST: 1673 type = TYPE_NORMAL_UMUTEX; 1674 break; 1675 case UMUTEX_PRIO_INHERIT: 1676 type = TYPE_PI_UMUTEX; 1677 break; 1678 case (UMUTEX_PRIO_INHERIT | UMUTEX_ROBUST): 1679 type = TYPE_PI_ROBUST_UMUTEX; 1680 break; 1681 case UMUTEX_PRIO_PROTECT: 1682 type = TYPE_PP_UMUTEX; 1683 break; 1684 case (UMUTEX_PRIO_PROTECT | UMUTEX_ROBUST): 1685 type = TYPE_PP_ROBUST_UMUTEX; 1686 break; 1687 default: 1688 return (EINVAL); 1689 } 1690 if ((error = umtx_key_get(m, type, GET_SHARE(flags), &key)) != 0) 1691 return (error); 1692 1693 owner = 0; 1694 umtxq_lock(&key); 1695 umtxq_busy(&key); 1696 count = umtxq_count(&key); 1697 umtxq_unlock(&key); 1698 1699 error = fueword32(&m->m_owner, &owner); 1700 if (error == -1) 1701 error = EFAULT; 1702 1703 /* 1704 * Only repair contention bit if there is a waiter, this means 1705 * the mutex is still being referenced by userland code, 1706 * otherwise don't update any memory. 1707 */ 1708 while (error == 0 && (owner & UMUTEX_CONTESTED) == 0 && 1709 (count > 1 || (count == 1 && (owner & ~UMUTEX_CONTESTED) != 0))) { 1710 error = casueword32(&m->m_owner, owner, &old, 1711 owner | UMUTEX_CONTESTED); 1712 if (error == -1) { 1713 error = EFAULT; 1714 break; 1715 } 1716 if (error == 0) { 1717 MPASS(old == owner); 1718 break; 1719 } 1720 owner = old; 1721 error = thread_check_susp(td, false); 1722 } 1723 1724 umtxq_lock(&key); 1725 if (error == EFAULT) { 1726 umtxq_signal(&key, INT_MAX); 1727 } else if (count != 0 && ((owner & ~UMUTEX_CONTESTED) == 0 || 1728 owner == UMUTEX_RB_OWNERDEAD || owner == UMUTEX_RB_NOTRECOV)) 1729 umtxq_signal(&key, 1); 1730 umtxq_unbusy(&key); 1731 umtxq_unlock(&key); 1732 umtx_key_release(&key); 1733 return (error); 1734 } 1735 1736 struct umtx_pi * 1737 umtx_pi_alloc(int flags) 1738 { 1739 struct umtx_pi *pi; 1740 1741 pi = uma_zalloc(umtx_pi_zone, M_ZERO | flags); 1742 TAILQ_INIT(&pi->pi_blocked); 1743 atomic_add_int(&umtx_pi_allocated, 1); 1744 return (pi); 1745 } 1746 1747 void 1748 umtx_pi_free(struct umtx_pi *pi) 1749 { 1750 uma_zfree(umtx_pi_zone, pi); 1751 atomic_add_int(&umtx_pi_allocated, -1); 1752 } 1753 1754 /* 1755 * Adjust the thread's position on a pi_state after its priority has been 1756 * changed. 1757 */ 1758 static int 1759 umtx_pi_adjust_thread(struct umtx_pi *pi, struct thread *td) 1760 { 1761 struct umtx_q *uq, *uq1, *uq2; 1762 struct thread *td1; 1763 1764 mtx_assert(&umtx_lock, MA_OWNED); 1765 if (pi == NULL) 1766 return (0); 1767 1768 uq = td->td_umtxq; 1769 1770 /* 1771 * Check if the thread needs to be moved on the blocked chain. 1772 * It needs to be moved if either its priority is lower than 1773 * the previous thread or higher than the next thread. 1774 */ 1775 uq1 = TAILQ_PREV(uq, umtxq_head, uq_lockq); 1776 uq2 = TAILQ_NEXT(uq, uq_lockq); 1777 if ((uq1 != NULL && UPRI(td) < UPRI(uq1->uq_thread)) || 1778 (uq2 != NULL && UPRI(td) > UPRI(uq2->uq_thread))) { 1779 /* 1780 * Remove thread from blocked chain and determine where 1781 * it should be moved to. 1782 */ 1783 TAILQ_REMOVE(&pi->pi_blocked, uq, uq_lockq); 1784 TAILQ_FOREACH(uq1, &pi->pi_blocked, uq_lockq) { 1785 td1 = uq1->uq_thread; 1786 MPASS(td1->td_proc->p_magic == P_MAGIC); 1787 if (UPRI(td1) > UPRI(td)) 1788 break; 1789 } 1790 1791 if (uq1 == NULL) 1792 TAILQ_INSERT_TAIL(&pi->pi_blocked, uq, uq_lockq); 1793 else 1794 TAILQ_INSERT_BEFORE(uq1, uq, uq_lockq); 1795 } 1796 return (1); 1797 } 1798 1799 static struct umtx_pi * 1800 umtx_pi_next(struct umtx_pi *pi) 1801 { 1802 struct umtx_q *uq_owner; 1803 1804 if (pi->pi_owner == NULL) 1805 return (NULL); 1806 uq_owner = pi->pi_owner->td_umtxq; 1807 if (uq_owner == NULL) 1808 return (NULL); 1809 return (uq_owner->uq_pi_blocked); 1810 } 1811 1812 /* 1813 * Floyd's Cycle-Finding Algorithm. 1814 */ 1815 static bool 1816 umtx_pi_check_loop(struct umtx_pi *pi) 1817 { 1818 struct umtx_pi *pi1; /* fast iterator */ 1819 1820 mtx_assert(&umtx_lock, MA_OWNED); 1821 if (pi == NULL) 1822 return (false); 1823 pi1 = pi; 1824 for (;;) { 1825 pi = umtx_pi_next(pi); 1826 if (pi == NULL) 1827 break; 1828 pi1 = umtx_pi_next(pi1); 1829 if (pi1 == NULL) 1830 break; 1831 pi1 = umtx_pi_next(pi1); 1832 if (pi1 == NULL) 1833 break; 1834 if (pi == pi1) 1835 return (true); 1836 } 1837 return (false); 1838 } 1839 1840 /* 1841 * Propagate priority when a thread is blocked on POSIX 1842 * PI mutex. 1843 */ 1844 static void 1845 umtx_propagate_priority(struct thread *td) 1846 { 1847 struct umtx_q *uq; 1848 struct umtx_pi *pi; 1849 int pri; 1850 1851 mtx_assert(&umtx_lock, MA_OWNED); 1852 pri = UPRI(td); 1853 uq = td->td_umtxq; 1854 pi = uq->uq_pi_blocked; 1855 if (pi == NULL) 1856 return; 1857 if (umtx_pi_check_loop(pi)) 1858 return; 1859 1860 for (;;) { 1861 td = pi->pi_owner; 1862 if (td == NULL || td == curthread) 1863 return; 1864 1865 MPASS(td->td_proc != NULL); 1866 MPASS(td->td_proc->p_magic == P_MAGIC); 1867 1868 thread_lock(td); 1869 if (td->td_lend_user_pri > pri) 1870 sched_lend_user_prio(td, pri); 1871 else { 1872 thread_unlock(td); 1873 break; 1874 } 1875 thread_unlock(td); 1876 1877 /* 1878 * Pick up the lock that td is blocked on. 1879 */ 1880 uq = td->td_umtxq; 1881 pi = uq->uq_pi_blocked; 1882 if (pi == NULL) 1883 break; 1884 /* Resort td on the list if needed. */ 1885 umtx_pi_adjust_thread(pi, td); 1886 } 1887 } 1888 1889 /* 1890 * Unpropagate priority for a PI mutex when a thread blocked on 1891 * it is interrupted by signal or resumed by others. 1892 */ 1893 static void 1894 umtx_repropagate_priority(struct umtx_pi *pi) 1895 { 1896 struct umtx_q *uq, *uq_owner; 1897 struct umtx_pi *pi2; 1898 int pri; 1899 1900 mtx_assert(&umtx_lock, MA_OWNED); 1901 1902 if (umtx_pi_check_loop(pi)) 1903 return; 1904 while (pi != NULL && pi->pi_owner != NULL) { 1905 pri = PRI_MAX; 1906 uq_owner = pi->pi_owner->td_umtxq; 1907 1908 TAILQ_FOREACH(pi2, &uq_owner->uq_pi_contested, pi_link) { 1909 uq = TAILQ_FIRST(&pi2->pi_blocked); 1910 if (uq != NULL) { 1911 if (pri > UPRI(uq->uq_thread)) 1912 pri = UPRI(uq->uq_thread); 1913 } 1914 } 1915 1916 if (pri > uq_owner->uq_inherited_pri) 1917 pri = uq_owner->uq_inherited_pri; 1918 thread_lock(pi->pi_owner); 1919 sched_lend_user_prio(pi->pi_owner, pri); 1920 thread_unlock(pi->pi_owner); 1921 if ((pi = uq_owner->uq_pi_blocked) != NULL) 1922 umtx_pi_adjust_thread(pi, uq_owner->uq_thread); 1923 } 1924 } 1925 1926 /* 1927 * Insert a PI mutex into owned list. 1928 */ 1929 static void 1930 umtx_pi_setowner(struct umtx_pi *pi, struct thread *owner) 1931 { 1932 struct umtx_q *uq_owner; 1933 1934 uq_owner = owner->td_umtxq; 1935 mtx_assert(&umtx_lock, MA_OWNED); 1936 MPASS(pi->pi_owner == NULL); 1937 pi->pi_owner = owner; 1938 TAILQ_INSERT_TAIL(&uq_owner->uq_pi_contested, pi, pi_link); 1939 } 1940 1941 /* 1942 * Disown a PI mutex, and remove it from the owned list. 1943 */ 1944 static void 1945 umtx_pi_disown(struct umtx_pi *pi) 1946 { 1947 1948 mtx_assert(&umtx_lock, MA_OWNED); 1949 TAILQ_REMOVE(&pi->pi_owner->td_umtxq->uq_pi_contested, pi, pi_link); 1950 pi->pi_owner = NULL; 1951 } 1952 1953 /* 1954 * Claim ownership of a PI mutex. 1955 */ 1956 int 1957 umtx_pi_claim(struct umtx_pi *pi, struct thread *owner) 1958 { 1959 struct umtx_q *uq; 1960 int pri; 1961 1962 mtx_lock(&umtx_lock); 1963 if (pi->pi_owner == owner) { 1964 mtx_unlock(&umtx_lock); 1965 return (0); 1966 } 1967 1968 if (pi->pi_owner != NULL) { 1969 /* 1970 * userland may have already messed the mutex, sigh. 1971 */ 1972 mtx_unlock(&umtx_lock); 1973 return (EPERM); 1974 } 1975 umtx_pi_setowner(pi, owner); 1976 uq = TAILQ_FIRST(&pi->pi_blocked); 1977 if (uq != NULL) { 1978 pri = UPRI(uq->uq_thread); 1979 thread_lock(owner); 1980 if (pri < UPRI(owner)) 1981 sched_lend_user_prio(owner, pri); 1982 thread_unlock(owner); 1983 } 1984 mtx_unlock(&umtx_lock); 1985 return (0); 1986 } 1987 1988 /* 1989 * Adjust a thread's order position in its blocked PI mutex, 1990 * this may result new priority propagating process. 1991 */ 1992 void 1993 umtx_pi_adjust(struct thread *td, u_char oldpri) 1994 { 1995 struct umtx_q *uq; 1996 struct umtx_pi *pi; 1997 1998 uq = td->td_umtxq; 1999 mtx_lock(&umtx_lock); 2000 /* 2001 * Pick up the lock that td is blocked on. 2002 */ 2003 pi = uq->uq_pi_blocked; 2004 if (pi != NULL) { 2005 umtx_pi_adjust_thread(pi, td); 2006 umtx_repropagate_priority(pi); 2007 } 2008 mtx_unlock(&umtx_lock); 2009 } 2010 2011 /* 2012 * Sleep on a PI mutex. 2013 */ 2014 int 2015 umtxq_sleep_pi(struct umtx_q *uq, struct umtx_pi *pi, uint32_t owner, 2016 const char *wmesg, struct umtx_abs_timeout *timo, bool shared) 2017 { 2018 struct thread *td, *td1; 2019 struct umtx_q *uq1; 2020 int error, pri; 2021 #ifdef INVARIANTS 2022 struct umtxq_chain *uc; 2023 2024 uc = umtxq_getchain(&pi->pi_key); 2025 #endif 2026 error = 0; 2027 td = uq->uq_thread; 2028 KASSERT(td == curthread, ("inconsistent uq_thread")); 2029 UMTXQ_LOCKED_ASSERT(umtxq_getchain(&uq->uq_key)); 2030 KASSERT(uc->uc_busy != 0, ("umtx chain is not busy")); 2031 umtxq_insert(uq); 2032 mtx_lock(&umtx_lock); 2033 if (pi->pi_owner == NULL) { 2034 mtx_unlock(&umtx_lock); 2035 td1 = tdfind(owner, shared ? -1 : td->td_proc->p_pid); 2036 mtx_lock(&umtx_lock); 2037 if (td1 != NULL) { 2038 if (pi->pi_owner == NULL) 2039 umtx_pi_setowner(pi, td1); 2040 PROC_UNLOCK(td1->td_proc); 2041 } 2042 } 2043 2044 TAILQ_FOREACH(uq1, &pi->pi_blocked, uq_lockq) { 2045 pri = UPRI(uq1->uq_thread); 2046 if (pri > UPRI(td)) 2047 break; 2048 } 2049 2050 if (uq1 != NULL) 2051 TAILQ_INSERT_BEFORE(uq1, uq, uq_lockq); 2052 else 2053 TAILQ_INSERT_TAIL(&pi->pi_blocked, uq, uq_lockq); 2054 2055 uq->uq_pi_blocked = pi; 2056 thread_lock(td); 2057 td->td_flags |= TDF_UPIBLOCKED; 2058 thread_unlock(td); 2059 umtx_propagate_priority(td); 2060 mtx_unlock(&umtx_lock); 2061 umtxq_unbusy(&uq->uq_key); 2062 2063 error = umtxq_sleep(uq, wmesg, timo); 2064 umtxq_remove(uq); 2065 2066 mtx_lock(&umtx_lock); 2067 uq->uq_pi_blocked = NULL; 2068 thread_lock(td); 2069 td->td_flags &= ~TDF_UPIBLOCKED; 2070 thread_unlock(td); 2071 TAILQ_REMOVE(&pi->pi_blocked, uq, uq_lockq); 2072 umtx_repropagate_priority(pi); 2073 mtx_unlock(&umtx_lock); 2074 umtxq_unlock(&uq->uq_key); 2075 2076 return (error); 2077 } 2078 2079 /* 2080 * Add reference count for a PI mutex. 2081 */ 2082 void 2083 umtx_pi_ref(struct umtx_pi *pi) 2084 { 2085 2086 UMTXQ_LOCKED_ASSERT(umtxq_getchain(&pi->pi_key)); 2087 pi->pi_refcount++; 2088 } 2089 2090 /* 2091 * Decrease reference count for a PI mutex, if the counter 2092 * is decreased to zero, its memory space is freed. 2093 */ 2094 void 2095 umtx_pi_unref(struct umtx_pi *pi) 2096 { 2097 struct umtxq_chain *uc; 2098 2099 uc = umtxq_getchain(&pi->pi_key); 2100 UMTXQ_LOCKED_ASSERT(uc); 2101 KASSERT(pi->pi_refcount > 0, ("invalid reference count")); 2102 if (--pi->pi_refcount == 0) { 2103 mtx_lock(&umtx_lock); 2104 if (pi->pi_owner != NULL) 2105 umtx_pi_disown(pi); 2106 KASSERT(TAILQ_EMPTY(&pi->pi_blocked), 2107 ("blocked queue not empty")); 2108 mtx_unlock(&umtx_lock); 2109 TAILQ_REMOVE(&uc->uc_pi_list, pi, pi_hashlink); 2110 umtx_pi_free(pi); 2111 } 2112 } 2113 2114 /* 2115 * Find a PI mutex in hash table. 2116 */ 2117 struct umtx_pi * 2118 umtx_pi_lookup(struct umtx_key *key) 2119 { 2120 struct umtxq_chain *uc; 2121 struct umtx_pi *pi; 2122 2123 uc = umtxq_getchain(key); 2124 UMTXQ_LOCKED_ASSERT(uc); 2125 2126 TAILQ_FOREACH(pi, &uc->uc_pi_list, pi_hashlink) { 2127 if (umtx_key_match(&pi->pi_key, key)) { 2128 return (pi); 2129 } 2130 } 2131 return (NULL); 2132 } 2133 2134 /* 2135 * Insert a PI mutex into hash table. 2136 */ 2137 void 2138 umtx_pi_insert(struct umtx_pi *pi) 2139 { 2140 struct umtxq_chain *uc; 2141 2142 uc = umtxq_getchain(&pi->pi_key); 2143 UMTXQ_LOCKED_ASSERT(uc); 2144 TAILQ_INSERT_TAIL(&uc->uc_pi_list, pi, pi_hashlink); 2145 } 2146 2147 /* 2148 * Drop a PI mutex and wakeup a top waiter. 2149 */ 2150 int 2151 umtx_pi_drop(struct thread *td, struct umtx_key *key, bool rb, int *count) 2152 { 2153 struct umtx_q *uq_first, *uq_first2, *uq_me; 2154 struct umtx_pi *pi, *pi2; 2155 int pri; 2156 2157 UMTXQ_ASSERT_LOCKED_BUSY(key); 2158 *count = umtxq_count_pi(key, &uq_first); 2159 if (uq_first != NULL) { 2160 mtx_lock(&umtx_lock); 2161 pi = uq_first->uq_pi_blocked; 2162 KASSERT(pi != NULL, ("pi == NULL?")); 2163 if (pi->pi_owner != td && !(rb && pi->pi_owner == NULL)) { 2164 mtx_unlock(&umtx_lock); 2165 /* userland messed the mutex */ 2166 return (EPERM); 2167 } 2168 uq_me = td->td_umtxq; 2169 if (pi->pi_owner == td) 2170 umtx_pi_disown(pi); 2171 /* get highest priority thread which is still sleeping. */ 2172 uq_first = TAILQ_FIRST(&pi->pi_blocked); 2173 while (uq_first != NULL && 2174 (uq_first->uq_flags & UQF_UMTXQ) == 0) { 2175 uq_first = TAILQ_NEXT(uq_first, uq_lockq); 2176 } 2177 pri = PRI_MAX; 2178 TAILQ_FOREACH(pi2, &uq_me->uq_pi_contested, pi_link) { 2179 uq_first2 = TAILQ_FIRST(&pi2->pi_blocked); 2180 if (uq_first2 != NULL) { 2181 if (pri > UPRI(uq_first2->uq_thread)) 2182 pri = UPRI(uq_first2->uq_thread); 2183 } 2184 } 2185 thread_lock(td); 2186 sched_lend_user_prio(td, pri); 2187 thread_unlock(td); 2188 mtx_unlock(&umtx_lock); 2189 if (uq_first) 2190 umtxq_signal_thread(uq_first); 2191 } else { 2192 pi = umtx_pi_lookup(key); 2193 /* 2194 * A umtx_pi can exist if a signal or timeout removed the 2195 * last waiter from the umtxq, but there is still 2196 * a thread in do_lock_pi() holding the umtx_pi. 2197 */ 2198 if (pi != NULL) { 2199 /* 2200 * The umtx_pi can be unowned, such as when a thread 2201 * has just entered do_lock_pi(), allocated the 2202 * umtx_pi, and unlocked the umtxq. 2203 * If the current thread owns it, it must disown it. 2204 */ 2205 mtx_lock(&umtx_lock); 2206 if (pi->pi_owner == td) 2207 umtx_pi_disown(pi); 2208 mtx_unlock(&umtx_lock); 2209 } 2210 } 2211 return (0); 2212 } 2213 2214 /* 2215 * Lock a PI mutex. 2216 */ 2217 static int 2218 do_lock_pi(struct thread *td, struct umutex *m, uint32_t flags, 2219 struct _umtx_time *timeout, int try) 2220 { 2221 struct umtx_abs_timeout timo; 2222 struct umtx_q *uq; 2223 struct umtx_pi *pi, *new_pi; 2224 uint32_t id, old_owner, owner, old; 2225 int error, rv; 2226 2227 id = td->td_tid; 2228 uq = td->td_umtxq; 2229 2230 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ? 2231 TYPE_PI_ROBUST_UMUTEX : TYPE_PI_UMUTEX, GET_SHARE(flags), 2232 &uq->uq_key)) != 0) 2233 return (error); 2234 2235 if (timeout != NULL) 2236 umtx_abs_timeout_init2(&timo, timeout); 2237 2238 umtxq_lock(&uq->uq_key); 2239 pi = umtx_pi_lookup(&uq->uq_key); 2240 if (pi == NULL) { 2241 new_pi = umtx_pi_alloc(M_NOWAIT); 2242 if (new_pi == NULL) { 2243 umtxq_unlock(&uq->uq_key); 2244 new_pi = umtx_pi_alloc(M_WAITOK); 2245 umtxq_lock(&uq->uq_key); 2246 pi = umtx_pi_lookup(&uq->uq_key); 2247 if (pi != NULL) { 2248 umtx_pi_free(new_pi); 2249 new_pi = NULL; 2250 } 2251 } 2252 if (new_pi != NULL) { 2253 new_pi->pi_key = uq->uq_key; 2254 umtx_pi_insert(new_pi); 2255 pi = new_pi; 2256 } 2257 } 2258 umtx_pi_ref(pi); 2259 umtxq_unlock(&uq->uq_key); 2260 2261 /* 2262 * Care must be exercised when dealing with umtx structure. It 2263 * can fault on any access. 2264 */ 2265 for (;;) { 2266 /* 2267 * Try the uncontested case. This should be done in userland. 2268 */ 2269 rv = casueword32(&m->m_owner, UMUTEX_UNOWNED, &owner, id); 2270 /* The address was invalid. */ 2271 if (rv == -1) { 2272 error = EFAULT; 2273 break; 2274 } 2275 /* The acquire succeeded. */ 2276 if (rv == 0) { 2277 MPASS(owner == UMUTEX_UNOWNED); 2278 error = 0; 2279 break; 2280 } 2281 2282 if (owner == UMUTEX_RB_NOTRECOV) { 2283 error = ENOTRECOVERABLE; 2284 break; 2285 } 2286 2287 /* 2288 * Nobody owns it, but the acquire failed. This can happen 2289 * with ll/sc atomics. 2290 */ 2291 if (owner == UMUTEX_UNOWNED) { 2292 error = thread_check_susp(td, true); 2293 if (error != 0) 2294 break; 2295 continue; 2296 } 2297 2298 /* 2299 * Avoid overwriting a possible error from sleep due 2300 * to the pending signal with suspension check result. 2301 */ 2302 if (error == 0) { 2303 error = thread_check_susp(td, true); 2304 if (error != 0) 2305 break; 2306 } 2307 2308 /* If no one owns it but it is contested try to acquire it. */ 2309 if (owner == UMUTEX_CONTESTED || owner == UMUTEX_RB_OWNERDEAD) { 2310 old_owner = owner; 2311 rv = casueword32(&m->m_owner, owner, &owner, 2312 id | UMUTEX_CONTESTED); 2313 /* The address was invalid. */ 2314 if (rv == -1) { 2315 error = EFAULT; 2316 break; 2317 } 2318 if (rv == 1) { 2319 if (error == 0) { 2320 error = thread_check_susp(td, true); 2321 if (error != 0) 2322 break; 2323 } 2324 2325 /* 2326 * If this failed the lock could 2327 * changed, restart. 2328 */ 2329 continue; 2330 } 2331 2332 MPASS(rv == 0); 2333 MPASS(owner == old_owner); 2334 umtxq_lock(&uq->uq_key); 2335 umtxq_busy(&uq->uq_key); 2336 error = umtx_pi_claim(pi, td); 2337 umtxq_unbusy(&uq->uq_key); 2338 umtxq_unlock(&uq->uq_key); 2339 if (error != 0) { 2340 /* 2341 * Since we're going to return an 2342 * error, restore the m_owner to its 2343 * previous, unowned state to avoid 2344 * compounding the problem. 2345 */ 2346 (void)casuword32(&m->m_owner, 2347 id | UMUTEX_CONTESTED, old_owner); 2348 } 2349 if (error == 0 && old_owner == UMUTEX_RB_OWNERDEAD) 2350 error = EOWNERDEAD; 2351 break; 2352 } 2353 2354 if ((owner & ~UMUTEX_CONTESTED) == id) { 2355 error = EDEADLK; 2356 break; 2357 } 2358 2359 if (try != 0) { 2360 error = EBUSY; 2361 break; 2362 } 2363 2364 /* 2365 * If we caught a signal, we have retried and now 2366 * exit immediately. 2367 */ 2368 if (error != 0) 2369 break; 2370 2371 umtxq_lock(&uq->uq_key); 2372 umtxq_busy(&uq->uq_key); 2373 umtxq_unlock(&uq->uq_key); 2374 2375 /* 2376 * Set the contested bit so that a release in user space 2377 * knows to use the system call for unlock. If this fails 2378 * either some one else has acquired the lock or it has been 2379 * released. 2380 */ 2381 rv = casueword32(&m->m_owner, owner, &old, owner | 2382 UMUTEX_CONTESTED); 2383 2384 /* The address was invalid. */ 2385 if (rv == -1) { 2386 umtxq_unbusy_unlocked(&uq->uq_key); 2387 error = EFAULT; 2388 break; 2389 } 2390 if (rv == 1) { 2391 umtxq_unbusy_unlocked(&uq->uq_key); 2392 error = thread_check_susp(td, true); 2393 if (error != 0) 2394 break; 2395 2396 /* 2397 * The lock changed and we need to retry or we 2398 * lost a race to the thread unlocking the 2399 * umtx. Note that the UMUTEX_RB_OWNERDEAD 2400 * value for owner is impossible there. 2401 */ 2402 continue; 2403 } 2404 2405 umtxq_lock(&uq->uq_key); 2406 2407 /* We set the contested bit, sleep. */ 2408 MPASS(old == owner); 2409 error = umtxq_sleep_pi(uq, pi, owner & ~UMUTEX_CONTESTED, 2410 "umtxpi", timeout == NULL ? NULL : &timo, 2411 (flags & USYNC_PROCESS_SHARED) != 0); 2412 if (error != 0) 2413 continue; 2414 2415 error = thread_check_susp(td, false); 2416 if (error != 0) 2417 break; 2418 } 2419 2420 umtxq_lock(&uq->uq_key); 2421 umtx_pi_unref(pi); 2422 umtxq_unlock(&uq->uq_key); 2423 2424 umtx_key_release(&uq->uq_key); 2425 return (error); 2426 } 2427 2428 /* 2429 * Unlock a PI mutex. 2430 */ 2431 static int 2432 do_unlock_pi(struct thread *td, struct umutex *m, uint32_t flags, bool rb) 2433 { 2434 struct umtx_key key; 2435 uint32_t id, new_owner, old, owner; 2436 int count, error; 2437 2438 id = td->td_tid; 2439 2440 usrloop: 2441 /* 2442 * Make sure we own this mtx. 2443 */ 2444 error = fueword32(&m->m_owner, &owner); 2445 if (error == -1) 2446 return (EFAULT); 2447 2448 if ((owner & ~UMUTEX_CONTESTED) != id) 2449 return (EPERM); 2450 2451 new_owner = umtx_unlock_val(flags, rb); 2452 2453 /* This should be done in userland */ 2454 if ((owner & UMUTEX_CONTESTED) == 0) { 2455 error = casueword32(&m->m_owner, owner, &old, new_owner); 2456 if (error == -1) 2457 return (EFAULT); 2458 if (error == 1) { 2459 error = thread_check_susp(td, true); 2460 if (error != 0) 2461 return (error); 2462 goto usrloop; 2463 } 2464 if (old == owner) 2465 return (0); 2466 owner = old; 2467 } 2468 2469 /* We should only ever be in here for contested locks */ 2470 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ? 2471 TYPE_PI_ROBUST_UMUTEX : TYPE_PI_UMUTEX, GET_SHARE(flags), 2472 &key)) != 0) 2473 return (error); 2474 2475 umtxq_lock(&key); 2476 umtxq_busy(&key); 2477 error = umtx_pi_drop(td, &key, rb, &count); 2478 if (error != 0) { 2479 umtxq_unbusy(&key); 2480 umtxq_unlock(&key); 2481 umtx_key_release(&key); 2482 /* userland messed the mutex */ 2483 return (error); 2484 } 2485 umtxq_unlock(&key); 2486 2487 /* 2488 * When unlocking the umtx, it must be marked as unowned if 2489 * there is zero or one thread only waiting for it. 2490 * Otherwise, it must be marked as contested. 2491 */ 2492 2493 if (count > 1) 2494 new_owner |= UMUTEX_CONTESTED; 2495 again: 2496 error = casueword32(&m->m_owner, owner, &old, new_owner); 2497 if (error == 1) { 2498 error = thread_check_susp(td, false); 2499 if (error == 0) 2500 goto again; 2501 } 2502 umtxq_unbusy_unlocked(&key); 2503 umtx_key_release(&key); 2504 if (error == -1) 2505 return (EFAULT); 2506 if (error == 0 && old != owner) 2507 return (EINVAL); 2508 return (error); 2509 } 2510 2511 /* 2512 * Lock a PP mutex. 2513 */ 2514 static int 2515 do_lock_pp(struct thread *td, struct umutex *m, uint32_t flags, 2516 struct _umtx_time *timeout, int try) 2517 { 2518 struct umtx_abs_timeout timo; 2519 struct umtx_q *uq, *uq2; 2520 struct umtx_pi *pi; 2521 uint32_t ceiling; 2522 uint32_t owner, id; 2523 int error, pri, old_inherited_pri, su, rv; 2524 2525 id = td->td_tid; 2526 uq = td->td_umtxq; 2527 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ? 2528 TYPE_PP_ROBUST_UMUTEX : TYPE_PP_UMUTEX, GET_SHARE(flags), 2529 &uq->uq_key)) != 0) 2530 return (error); 2531 2532 if (timeout != NULL) 2533 umtx_abs_timeout_init2(&timo, timeout); 2534 2535 su = (priv_check(td, PRIV_SCHED_RTPRIO) == 0); 2536 for (;;) { 2537 old_inherited_pri = uq->uq_inherited_pri; 2538 umtxq_lock(&uq->uq_key); 2539 umtxq_busy(&uq->uq_key); 2540 umtxq_unlock(&uq->uq_key); 2541 2542 rv = fueword32(&m->m_ceilings[0], &ceiling); 2543 if (rv == -1) { 2544 error = EFAULT; 2545 goto out; 2546 } 2547 ceiling = RTP_PRIO_MAX - ceiling; 2548 if (ceiling > RTP_PRIO_MAX) { 2549 error = EINVAL; 2550 goto out; 2551 } 2552 2553 mtx_lock(&umtx_lock); 2554 if (UPRI(td) < PRI_MIN_REALTIME + ceiling) { 2555 mtx_unlock(&umtx_lock); 2556 error = EINVAL; 2557 goto out; 2558 } 2559 if (su && PRI_MIN_REALTIME + ceiling < uq->uq_inherited_pri) { 2560 uq->uq_inherited_pri = PRI_MIN_REALTIME + ceiling; 2561 thread_lock(td); 2562 if (uq->uq_inherited_pri < UPRI(td)) 2563 sched_lend_user_prio(td, uq->uq_inherited_pri); 2564 thread_unlock(td); 2565 } 2566 mtx_unlock(&umtx_lock); 2567 2568 rv = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner, 2569 id | UMUTEX_CONTESTED); 2570 /* The address was invalid. */ 2571 if (rv == -1) { 2572 error = EFAULT; 2573 break; 2574 } 2575 if (rv == 0) { 2576 MPASS(owner == UMUTEX_CONTESTED); 2577 error = 0; 2578 break; 2579 } 2580 /* rv == 1 */ 2581 if (owner == UMUTEX_RB_OWNERDEAD) { 2582 rv = casueword32(&m->m_owner, UMUTEX_RB_OWNERDEAD, 2583 &owner, id | UMUTEX_CONTESTED); 2584 if (rv == -1) { 2585 error = EFAULT; 2586 break; 2587 } 2588 if (rv == 0) { 2589 MPASS(owner == UMUTEX_RB_OWNERDEAD); 2590 error = EOWNERDEAD; /* success */ 2591 break; 2592 } 2593 2594 /* 2595 * rv == 1, only check for suspension if we 2596 * did not already catched a signal. If we 2597 * get an error from the check, the same 2598 * condition is checked by the umtxq_sleep() 2599 * call below, so we should obliterate the 2600 * error to not skip the last loop iteration. 2601 */ 2602 if (error == 0) { 2603 error = thread_check_susp(td, false); 2604 if (error == 0) { 2605 if (try != 0) 2606 error = EBUSY; 2607 else 2608 continue; 2609 } 2610 error = 0; 2611 } 2612 } else if (owner == UMUTEX_RB_NOTRECOV) { 2613 error = ENOTRECOVERABLE; 2614 } 2615 2616 if (try != 0) 2617 error = EBUSY; 2618 2619 /* 2620 * If we caught a signal, we have retried and now 2621 * exit immediately. 2622 */ 2623 if (error != 0) 2624 break; 2625 2626 umtxq_lock(&uq->uq_key); 2627 umtxq_insert(uq); 2628 umtxq_unbusy(&uq->uq_key); 2629 error = umtxq_sleep(uq, "umtxpp", timeout == NULL ? 2630 NULL : &timo); 2631 umtxq_remove(uq); 2632 umtxq_unlock(&uq->uq_key); 2633 2634 mtx_lock(&umtx_lock); 2635 uq->uq_inherited_pri = old_inherited_pri; 2636 pri = PRI_MAX; 2637 TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) { 2638 uq2 = TAILQ_FIRST(&pi->pi_blocked); 2639 if (uq2 != NULL) { 2640 if (pri > UPRI(uq2->uq_thread)) 2641 pri = UPRI(uq2->uq_thread); 2642 } 2643 } 2644 if (pri > uq->uq_inherited_pri) 2645 pri = uq->uq_inherited_pri; 2646 thread_lock(td); 2647 sched_lend_user_prio(td, pri); 2648 thread_unlock(td); 2649 mtx_unlock(&umtx_lock); 2650 } 2651 2652 if (error != 0 && error != EOWNERDEAD) { 2653 mtx_lock(&umtx_lock); 2654 uq->uq_inherited_pri = old_inherited_pri; 2655 pri = PRI_MAX; 2656 TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) { 2657 uq2 = TAILQ_FIRST(&pi->pi_blocked); 2658 if (uq2 != NULL) { 2659 if (pri > UPRI(uq2->uq_thread)) 2660 pri = UPRI(uq2->uq_thread); 2661 } 2662 } 2663 if (pri > uq->uq_inherited_pri) 2664 pri = uq->uq_inherited_pri; 2665 thread_lock(td); 2666 sched_lend_user_prio(td, pri); 2667 thread_unlock(td); 2668 mtx_unlock(&umtx_lock); 2669 } 2670 2671 out: 2672 umtxq_unbusy_unlocked(&uq->uq_key); 2673 umtx_key_release(&uq->uq_key); 2674 return (error); 2675 } 2676 2677 /* 2678 * Unlock a PP mutex. 2679 */ 2680 static int 2681 do_unlock_pp(struct thread *td, struct umutex *m, uint32_t flags, bool rb) 2682 { 2683 struct umtx_key key; 2684 struct umtx_q *uq, *uq2; 2685 struct umtx_pi *pi; 2686 uint32_t id, owner, rceiling; 2687 int error, pri, new_inherited_pri, su; 2688 2689 id = td->td_tid; 2690 uq = td->td_umtxq; 2691 su = (priv_check(td, PRIV_SCHED_RTPRIO) == 0); 2692 2693 /* 2694 * Make sure we own this mtx. 2695 */ 2696 error = fueword32(&m->m_owner, &owner); 2697 if (error == -1) 2698 return (EFAULT); 2699 2700 if ((owner & ~UMUTEX_CONTESTED) != id) 2701 return (EPERM); 2702 2703 error = copyin(&m->m_ceilings[1], &rceiling, sizeof(uint32_t)); 2704 if (error != 0) 2705 return (error); 2706 2707 if (rceiling == -1) 2708 new_inherited_pri = PRI_MAX; 2709 else { 2710 rceiling = RTP_PRIO_MAX - rceiling; 2711 if (rceiling > RTP_PRIO_MAX) 2712 return (EINVAL); 2713 new_inherited_pri = PRI_MIN_REALTIME + rceiling; 2714 } 2715 2716 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ? 2717 TYPE_PP_ROBUST_UMUTEX : TYPE_PP_UMUTEX, GET_SHARE(flags), 2718 &key)) != 0) 2719 return (error); 2720 umtxq_lock(&key); 2721 umtxq_busy(&key); 2722 umtxq_unlock(&key); 2723 /* 2724 * For priority protected mutex, always set unlocked state 2725 * to UMUTEX_CONTESTED, so that userland always enters kernel 2726 * to lock the mutex, it is necessary because thread priority 2727 * has to be adjusted for such mutex. 2728 */ 2729 error = suword32(&m->m_owner, umtx_unlock_val(flags, rb) | 2730 UMUTEX_CONTESTED); 2731 2732 umtxq_lock(&key); 2733 if (error == 0) 2734 umtxq_signal(&key, 1); 2735 umtxq_unbusy(&key); 2736 umtxq_unlock(&key); 2737 2738 if (error == -1) 2739 error = EFAULT; 2740 else { 2741 mtx_lock(&umtx_lock); 2742 if (su != 0) 2743 uq->uq_inherited_pri = new_inherited_pri; 2744 pri = PRI_MAX; 2745 TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) { 2746 uq2 = TAILQ_FIRST(&pi->pi_blocked); 2747 if (uq2 != NULL) { 2748 if (pri > UPRI(uq2->uq_thread)) 2749 pri = UPRI(uq2->uq_thread); 2750 } 2751 } 2752 if (pri > uq->uq_inherited_pri) 2753 pri = uq->uq_inherited_pri; 2754 thread_lock(td); 2755 sched_lend_user_prio(td, pri); 2756 thread_unlock(td); 2757 mtx_unlock(&umtx_lock); 2758 } 2759 umtx_key_release(&key); 2760 return (error); 2761 } 2762 2763 static int 2764 do_set_ceiling(struct thread *td, struct umutex *m, uint32_t ceiling, 2765 uint32_t *old_ceiling) 2766 { 2767 struct umtx_q *uq; 2768 uint32_t flags, id, owner, save_ceiling; 2769 int error, rv, rv1; 2770 2771 error = fueword32(&m->m_flags, &flags); 2772 if (error == -1) 2773 return (EFAULT); 2774 if ((flags & UMUTEX_PRIO_PROTECT) == 0) 2775 return (EINVAL); 2776 if (ceiling > RTP_PRIO_MAX) 2777 return (EINVAL); 2778 id = td->td_tid; 2779 uq = td->td_umtxq; 2780 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ? 2781 TYPE_PP_ROBUST_UMUTEX : TYPE_PP_UMUTEX, GET_SHARE(flags), 2782 &uq->uq_key)) != 0) 2783 return (error); 2784 for (;;) { 2785 umtxq_lock(&uq->uq_key); 2786 umtxq_busy(&uq->uq_key); 2787 umtxq_unlock(&uq->uq_key); 2788 2789 rv = fueword32(&m->m_ceilings[0], &save_ceiling); 2790 if (rv == -1) { 2791 error = EFAULT; 2792 break; 2793 } 2794 2795 rv = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner, 2796 id | UMUTEX_CONTESTED); 2797 if (rv == -1) { 2798 error = EFAULT; 2799 break; 2800 } 2801 2802 if (rv == 0) { 2803 MPASS(owner == UMUTEX_CONTESTED); 2804 rv = suword32(&m->m_ceilings[0], ceiling); 2805 rv1 = suword32(&m->m_owner, UMUTEX_CONTESTED); 2806 error = (rv == 0 && rv1 == 0) ? 0: EFAULT; 2807 break; 2808 } 2809 2810 if ((owner & ~UMUTEX_CONTESTED) == id) { 2811 rv = suword32(&m->m_ceilings[0], ceiling); 2812 error = rv == 0 ? 0 : EFAULT; 2813 break; 2814 } 2815 2816 if (owner == UMUTEX_RB_OWNERDEAD) { 2817 error = EOWNERDEAD; 2818 break; 2819 } else if (owner == UMUTEX_RB_NOTRECOV) { 2820 error = ENOTRECOVERABLE; 2821 break; 2822 } 2823 2824 /* 2825 * If we caught a signal, we have retried and now 2826 * exit immediately. 2827 */ 2828 if (error != 0) 2829 break; 2830 2831 /* 2832 * We set the contested bit, sleep. Otherwise the lock changed 2833 * and we need to retry or we lost a race to the thread 2834 * unlocking the umtx. 2835 */ 2836 umtxq_lock(&uq->uq_key); 2837 umtxq_insert(uq); 2838 umtxq_unbusy(&uq->uq_key); 2839 error = umtxq_sleep(uq, "umtxpp", NULL); 2840 umtxq_remove(uq); 2841 umtxq_unlock(&uq->uq_key); 2842 } 2843 umtxq_lock(&uq->uq_key); 2844 if (error == 0) 2845 umtxq_signal(&uq->uq_key, INT_MAX); 2846 umtxq_unbusy(&uq->uq_key); 2847 umtxq_unlock(&uq->uq_key); 2848 umtx_key_release(&uq->uq_key); 2849 if (error == 0 && old_ceiling != NULL) { 2850 rv = suword32(old_ceiling, save_ceiling); 2851 error = rv == 0 ? 0 : EFAULT; 2852 } 2853 return (error); 2854 } 2855 2856 /* 2857 * Lock a userland POSIX mutex. 2858 */ 2859 static int 2860 do_lock_umutex(struct thread *td, struct umutex *m, 2861 struct _umtx_time *timeout, int mode) 2862 { 2863 uint32_t flags; 2864 int error; 2865 2866 error = fueword32(&m->m_flags, &flags); 2867 if (error == -1) 2868 return (EFAULT); 2869 2870 switch (flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT)) { 2871 case 0: 2872 error = do_lock_normal(td, m, flags, timeout, mode); 2873 break; 2874 case UMUTEX_PRIO_INHERIT: 2875 error = do_lock_pi(td, m, flags, timeout, mode); 2876 break; 2877 case UMUTEX_PRIO_PROTECT: 2878 error = do_lock_pp(td, m, flags, timeout, mode); 2879 break; 2880 default: 2881 return (EINVAL); 2882 } 2883 if (timeout == NULL) { 2884 if (error == EINTR && mode != _UMUTEX_WAIT) 2885 error = ERESTART; 2886 } else { 2887 /* Timed-locking is not restarted. */ 2888 if (error == ERESTART) 2889 error = EINTR; 2890 } 2891 return (error); 2892 } 2893 2894 /* 2895 * Unlock a userland POSIX mutex. 2896 */ 2897 static int 2898 do_unlock_umutex(struct thread *td, struct umutex *m, bool rb) 2899 { 2900 uint32_t flags; 2901 int error; 2902 2903 error = fueword32(&m->m_flags, &flags); 2904 if (error == -1) 2905 return (EFAULT); 2906 2907 switch (flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT)) { 2908 case 0: 2909 return (do_unlock_normal(td, m, flags, rb)); 2910 case UMUTEX_PRIO_INHERIT: 2911 return (do_unlock_pi(td, m, flags, rb)); 2912 case UMUTEX_PRIO_PROTECT: 2913 return (do_unlock_pp(td, m, flags, rb)); 2914 } 2915 2916 return (EINVAL); 2917 } 2918 2919 static int 2920 do_cv_wait(struct thread *td, struct ucond *cv, struct umutex *m, 2921 struct timespec *timeout, u_long wflags) 2922 { 2923 struct umtx_abs_timeout timo; 2924 struct umtx_q *uq; 2925 uint32_t flags, clockid, hasw; 2926 int error; 2927 2928 uq = td->td_umtxq; 2929 error = fueword32(&cv->c_flags, &flags); 2930 if (error == -1) 2931 return (EFAULT); 2932 error = umtx_key_get(cv, TYPE_CV, GET_SHARE(flags), &uq->uq_key); 2933 if (error != 0) 2934 return (error); 2935 2936 if ((wflags & CVWAIT_CLOCKID) != 0) { 2937 error = fueword32(&cv->c_clockid, &clockid); 2938 if (error == -1) { 2939 umtx_key_release(&uq->uq_key); 2940 return (EFAULT); 2941 } 2942 if (clockid < CLOCK_REALTIME || 2943 clockid >= CLOCK_THREAD_CPUTIME_ID) { 2944 /* hmm, only HW clock id will work. */ 2945 umtx_key_release(&uq->uq_key); 2946 return (EINVAL); 2947 } 2948 } else { 2949 clockid = CLOCK_REALTIME; 2950 } 2951 2952 umtxq_lock(&uq->uq_key); 2953 umtxq_busy(&uq->uq_key); 2954 umtxq_insert(uq); 2955 umtxq_unlock(&uq->uq_key); 2956 2957 /* 2958 * Set c_has_waiters to 1 before releasing user mutex, also 2959 * don't modify cache line when unnecessary. 2960 */ 2961 error = fueword32(&cv->c_has_waiters, &hasw); 2962 if (error == 0 && hasw == 0) 2963 suword32(&cv->c_has_waiters, 1); 2964 2965 umtxq_unbusy_unlocked(&uq->uq_key); 2966 2967 error = do_unlock_umutex(td, m, false); 2968 2969 if (timeout != NULL) 2970 umtx_abs_timeout_init(&timo, clockid, 2971 (wflags & CVWAIT_ABSTIME) != 0, timeout); 2972 2973 umtxq_lock(&uq->uq_key); 2974 if (error == 0) { 2975 error = umtxq_sleep(uq, "ucond", timeout == NULL ? 2976 NULL : &timo); 2977 } 2978 2979 if ((uq->uq_flags & UQF_UMTXQ) == 0) 2980 error = 0; 2981 else { 2982 /* 2983 * This must be timeout,interrupted by signal or 2984 * surprious wakeup, clear c_has_waiter flag when 2985 * necessary. 2986 */ 2987 umtxq_busy(&uq->uq_key); 2988 if ((uq->uq_flags & UQF_UMTXQ) != 0) { 2989 int oldlen = uq->uq_cur_queue->length; 2990 umtxq_remove(uq); 2991 if (oldlen == 1) { 2992 umtxq_unlock(&uq->uq_key); 2993 suword32(&cv->c_has_waiters, 0); 2994 umtxq_lock(&uq->uq_key); 2995 } 2996 } 2997 umtxq_unbusy(&uq->uq_key); 2998 if (error == ERESTART) 2999 error = EINTR; 3000 } 3001 3002 umtxq_unlock(&uq->uq_key); 3003 umtx_key_release(&uq->uq_key); 3004 return (error); 3005 } 3006 3007 /* 3008 * Signal a userland condition variable. 3009 */ 3010 static int 3011 do_cv_signal(struct thread *td, struct ucond *cv) 3012 { 3013 struct umtx_key key; 3014 int error, cnt, nwake; 3015 uint32_t flags; 3016 3017 error = fueword32(&cv->c_flags, &flags); 3018 if (error == -1) 3019 return (EFAULT); 3020 if ((error = umtx_key_get(cv, TYPE_CV, GET_SHARE(flags), &key)) != 0) 3021 return (error); 3022 umtxq_lock(&key); 3023 umtxq_busy(&key); 3024 cnt = umtxq_count(&key); 3025 nwake = umtxq_signal(&key, 1); 3026 if (cnt <= nwake) { 3027 umtxq_unlock(&key); 3028 error = suword32(&cv->c_has_waiters, 0); 3029 if (error == -1) 3030 error = EFAULT; 3031 umtxq_lock(&key); 3032 } 3033 umtxq_unbusy(&key); 3034 umtxq_unlock(&key); 3035 umtx_key_release(&key); 3036 return (error); 3037 } 3038 3039 static int 3040 do_cv_broadcast(struct thread *td, struct ucond *cv) 3041 { 3042 struct umtx_key key; 3043 int error; 3044 uint32_t flags; 3045 3046 error = fueword32(&cv->c_flags, &flags); 3047 if (error == -1) 3048 return (EFAULT); 3049 if ((error = umtx_key_get(cv, TYPE_CV, GET_SHARE(flags), &key)) != 0) 3050 return (error); 3051 3052 umtxq_lock(&key); 3053 umtxq_busy(&key); 3054 umtxq_signal(&key, INT_MAX); 3055 umtxq_unlock(&key); 3056 3057 error = suword32(&cv->c_has_waiters, 0); 3058 if (error == -1) 3059 error = EFAULT; 3060 3061 umtxq_unbusy_unlocked(&key); 3062 3063 umtx_key_release(&key); 3064 return (error); 3065 } 3066 3067 static int 3068 do_rw_rdlock(struct thread *td, struct urwlock *rwlock, long fflag, 3069 struct _umtx_time *timeout) 3070 { 3071 struct umtx_abs_timeout timo; 3072 struct umtx_q *uq; 3073 uint32_t flags, wrflags; 3074 int32_t state, oldstate; 3075 int32_t blocked_readers; 3076 int error, error1, rv; 3077 3078 uq = td->td_umtxq; 3079 error = fueword32(&rwlock->rw_flags, &flags); 3080 if (error == -1) 3081 return (EFAULT); 3082 error = umtx_key_get(rwlock, TYPE_RWLOCK, GET_SHARE(flags), &uq->uq_key); 3083 if (error != 0) 3084 return (error); 3085 3086 if (timeout != NULL) 3087 umtx_abs_timeout_init2(&timo, timeout); 3088 3089 wrflags = URWLOCK_WRITE_OWNER; 3090 if (!(fflag & URWLOCK_PREFER_READER) && !(flags & URWLOCK_PREFER_READER)) 3091 wrflags |= URWLOCK_WRITE_WAITERS; 3092 3093 for (;;) { 3094 rv = fueword32(&rwlock->rw_state, &state); 3095 if (rv == -1) { 3096 umtx_key_release(&uq->uq_key); 3097 return (EFAULT); 3098 } 3099 3100 /* try to lock it */ 3101 while (!(state & wrflags)) { 3102 if (__predict_false(URWLOCK_READER_COUNT(state) == 3103 URWLOCK_MAX_READERS)) { 3104 umtx_key_release(&uq->uq_key); 3105 return (EAGAIN); 3106 } 3107 rv = casueword32(&rwlock->rw_state, state, 3108 &oldstate, state + 1); 3109 if (rv == -1) { 3110 umtx_key_release(&uq->uq_key); 3111 return (EFAULT); 3112 } 3113 if (rv == 0) { 3114 MPASS(oldstate == state); 3115 umtx_key_release(&uq->uq_key); 3116 return (0); 3117 } 3118 error = thread_check_susp(td, true); 3119 if (error != 0) 3120 break; 3121 state = oldstate; 3122 } 3123 3124 if (error) 3125 break; 3126 3127 /* grab monitor lock */ 3128 umtxq_lock(&uq->uq_key); 3129 umtxq_busy(&uq->uq_key); 3130 umtxq_unlock(&uq->uq_key); 3131 3132 /* 3133 * re-read the state, in case it changed between the try-lock above 3134 * and the check below 3135 */ 3136 rv = fueword32(&rwlock->rw_state, &state); 3137 if (rv == -1) 3138 error = EFAULT; 3139 3140 /* set read contention bit */ 3141 while (error == 0 && (state & wrflags) && 3142 !(state & URWLOCK_READ_WAITERS)) { 3143 rv = casueword32(&rwlock->rw_state, state, 3144 &oldstate, state | URWLOCK_READ_WAITERS); 3145 if (rv == -1) { 3146 error = EFAULT; 3147 break; 3148 } 3149 if (rv == 0) { 3150 MPASS(oldstate == state); 3151 goto sleep; 3152 } 3153 state = oldstate; 3154 error = thread_check_susp(td, false); 3155 if (error != 0) 3156 break; 3157 } 3158 if (error != 0) { 3159 umtxq_unbusy_unlocked(&uq->uq_key); 3160 break; 3161 } 3162 3163 /* state is changed while setting flags, restart */ 3164 if (!(state & wrflags)) { 3165 umtxq_unbusy_unlocked(&uq->uq_key); 3166 error = thread_check_susp(td, true); 3167 if (error != 0) 3168 break; 3169 continue; 3170 } 3171 3172 sleep: 3173 /* 3174 * Contention bit is set, before sleeping, increase 3175 * read waiter count. 3176 */ 3177 rv = fueword32(&rwlock->rw_blocked_readers, 3178 &blocked_readers); 3179 if (rv == -1) { 3180 umtxq_unbusy_unlocked(&uq->uq_key); 3181 error = EFAULT; 3182 break; 3183 } 3184 suword32(&rwlock->rw_blocked_readers, blocked_readers+1); 3185 3186 while (state & wrflags) { 3187 umtxq_lock(&uq->uq_key); 3188 umtxq_insert(uq); 3189 umtxq_unbusy(&uq->uq_key); 3190 3191 error = umtxq_sleep(uq, "urdlck", timeout == NULL ? 3192 NULL : &timo); 3193 3194 umtxq_busy(&uq->uq_key); 3195 umtxq_remove(uq); 3196 umtxq_unlock(&uq->uq_key); 3197 if (error) 3198 break; 3199 rv = fueword32(&rwlock->rw_state, &state); 3200 if (rv == -1) { 3201 error = EFAULT; 3202 break; 3203 } 3204 } 3205 3206 /* decrease read waiter count, and may clear read contention bit */ 3207 rv = fueword32(&rwlock->rw_blocked_readers, 3208 &blocked_readers); 3209 if (rv == -1) { 3210 umtxq_unbusy_unlocked(&uq->uq_key); 3211 error = EFAULT; 3212 break; 3213 } 3214 suword32(&rwlock->rw_blocked_readers, blocked_readers-1); 3215 if (blocked_readers == 1) { 3216 rv = fueword32(&rwlock->rw_state, &state); 3217 if (rv == -1) { 3218 umtxq_unbusy_unlocked(&uq->uq_key); 3219 error = EFAULT; 3220 break; 3221 } 3222 for (;;) { 3223 rv = casueword32(&rwlock->rw_state, state, 3224 &oldstate, state & ~URWLOCK_READ_WAITERS); 3225 if (rv == -1) { 3226 error = EFAULT; 3227 break; 3228 } 3229 if (rv == 0) { 3230 MPASS(oldstate == state); 3231 break; 3232 } 3233 state = oldstate; 3234 error1 = thread_check_susp(td, false); 3235 if (error1 != 0) { 3236 if (error == 0) 3237 error = error1; 3238 break; 3239 } 3240 } 3241 } 3242 3243 umtxq_unbusy_unlocked(&uq->uq_key); 3244 if (error != 0) 3245 break; 3246 } 3247 umtx_key_release(&uq->uq_key); 3248 if (error == ERESTART) 3249 error = EINTR; 3250 return (error); 3251 } 3252 3253 static int 3254 do_rw_wrlock(struct thread *td, struct urwlock *rwlock, struct _umtx_time *timeout) 3255 { 3256 struct umtx_abs_timeout timo; 3257 struct umtx_q *uq; 3258 uint32_t flags; 3259 int32_t state, oldstate; 3260 int32_t blocked_writers; 3261 int32_t blocked_readers; 3262 int error, error1, rv; 3263 3264 uq = td->td_umtxq; 3265 error = fueword32(&rwlock->rw_flags, &flags); 3266 if (error == -1) 3267 return (EFAULT); 3268 error = umtx_key_get(rwlock, TYPE_RWLOCK, GET_SHARE(flags), &uq->uq_key); 3269 if (error != 0) 3270 return (error); 3271 3272 if (timeout != NULL) 3273 umtx_abs_timeout_init2(&timo, timeout); 3274 3275 blocked_readers = 0; 3276 for (;;) { 3277 rv = fueword32(&rwlock->rw_state, &state); 3278 if (rv == -1) { 3279 umtx_key_release(&uq->uq_key); 3280 return (EFAULT); 3281 } 3282 while ((state & URWLOCK_WRITE_OWNER) == 0 && 3283 URWLOCK_READER_COUNT(state) == 0) { 3284 rv = casueword32(&rwlock->rw_state, state, 3285 &oldstate, state | URWLOCK_WRITE_OWNER); 3286 if (rv == -1) { 3287 umtx_key_release(&uq->uq_key); 3288 return (EFAULT); 3289 } 3290 if (rv == 0) { 3291 MPASS(oldstate == state); 3292 umtx_key_release(&uq->uq_key); 3293 return (0); 3294 } 3295 state = oldstate; 3296 error = thread_check_susp(td, true); 3297 if (error != 0) 3298 break; 3299 } 3300 3301 if (error) { 3302 if ((state & (URWLOCK_WRITE_OWNER | 3303 URWLOCK_WRITE_WAITERS)) == 0 && 3304 blocked_readers != 0) { 3305 umtxq_lock(&uq->uq_key); 3306 umtxq_busy(&uq->uq_key); 3307 umtxq_signal_queue(&uq->uq_key, INT_MAX, 3308 UMTX_SHARED_QUEUE); 3309 umtxq_unbusy(&uq->uq_key); 3310 umtxq_unlock(&uq->uq_key); 3311 } 3312 3313 break; 3314 } 3315 3316 /* grab monitor lock */ 3317 umtxq_lock(&uq->uq_key); 3318 umtxq_busy(&uq->uq_key); 3319 umtxq_unlock(&uq->uq_key); 3320 3321 /* 3322 * Re-read the state, in case it changed between the 3323 * try-lock above and the check below. 3324 */ 3325 rv = fueword32(&rwlock->rw_state, &state); 3326 if (rv == -1) 3327 error = EFAULT; 3328 3329 while (error == 0 && ((state & URWLOCK_WRITE_OWNER) || 3330 URWLOCK_READER_COUNT(state) != 0) && 3331 (state & URWLOCK_WRITE_WAITERS) == 0) { 3332 rv = casueword32(&rwlock->rw_state, state, 3333 &oldstate, state | URWLOCK_WRITE_WAITERS); 3334 if (rv == -1) { 3335 error = EFAULT; 3336 break; 3337 } 3338 if (rv == 0) { 3339 MPASS(oldstate == state); 3340 goto sleep; 3341 } 3342 state = oldstate; 3343 error = thread_check_susp(td, false); 3344 if (error != 0) 3345 break; 3346 } 3347 if (error != 0) { 3348 umtxq_unbusy_unlocked(&uq->uq_key); 3349 break; 3350 } 3351 3352 if ((state & URWLOCK_WRITE_OWNER) == 0 && 3353 URWLOCK_READER_COUNT(state) == 0) { 3354 umtxq_unbusy_unlocked(&uq->uq_key); 3355 error = thread_check_susp(td, false); 3356 if (error != 0) 3357 break; 3358 continue; 3359 } 3360 sleep: 3361 rv = fueword32(&rwlock->rw_blocked_writers, 3362 &blocked_writers); 3363 if (rv == -1) { 3364 umtxq_unbusy_unlocked(&uq->uq_key); 3365 error = EFAULT; 3366 break; 3367 } 3368 suword32(&rwlock->rw_blocked_writers, blocked_writers + 1); 3369 3370 while ((state & URWLOCK_WRITE_OWNER) || 3371 URWLOCK_READER_COUNT(state) != 0) { 3372 umtxq_lock(&uq->uq_key); 3373 umtxq_insert_queue(uq, UMTX_EXCLUSIVE_QUEUE); 3374 umtxq_unbusy(&uq->uq_key); 3375 3376 error = umtxq_sleep(uq, "uwrlck", timeout == NULL ? 3377 NULL : &timo); 3378 3379 umtxq_busy(&uq->uq_key); 3380 umtxq_remove_queue(uq, UMTX_EXCLUSIVE_QUEUE); 3381 umtxq_unlock(&uq->uq_key); 3382 if (error) 3383 break; 3384 rv = fueword32(&rwlock->rw_state, &state); 3385 if (rv == -1) { 3386 error = EFAULT; 3387 break; 3388 } 3389 } 3390 3391 rv = fueword32(&rwlock->rw_blocked_writers, 3392 &blocked_writers); 3393 if (rv == -1) { 3394 umtxq_unbusy_unlocked(&uq->uq_key); 3395 error = EFAULT; 3396 break; 3397 } 3398 suword32(&rwlock->rw_blocked_writers, blocked_writers-1); 3399 if (blocked_writers == 1) { 3400 rv = fueword32(&rwlock->rw_state, &state); 3401 if (rv == -1) { 3402 umtxq_unbusy_unlocked(&uq->uq_key); 3403 error = EFAULT; 3404 break; 3405 } 3406 for (;;) { 3407 rv = casueword32(&rwlock->rw_state, state, 3408 &oldstate, state & ~URWLOCK_WRITE_WAITERS); 3409 if (rv == -1) { 3410 error = EFAULT; 3411 break; 3412 } 3413 if (rv == 0) { 3414 MPASS(oldstate == state); 3415 break; 3416 } 3417 state = oldstate; 3418 error1 = thread_check_susp(td, false); 3419 /* 3420 * We are leaving the URWLOCK_WRITE_WAITERS 3421 * behind, but this should not harm the 3422 * correctness. 3423 */ 3424 if (error1 != 0) { 3425 if (error == 0) 3426 error = error1; 3427 break; 3428 } 3429 } 3430 rv = fueword32(&rwlock->rw_blocked_readers, 3431 &blocked_readers); 3432 if (rv == -1) { 3433 umtxq_unbusy_unlocked(&uq->uq_key); 3434 error = EFAULT; 3435 break; 3436 } 3437 } else 3438 blocked_readers = 0; 3439 3440 umtxq_unbusy_unlocked(&uq->uq_key); 3441 } 3442 3443 umtx_key_release(&uq->uq_key); 3444 if (error == ERESTART) 3445 error = EINTR; 3446 return (error); 3447 } 3448 3449 static int 3450 do_rw_unlock(struct thread *td, struct urwlock *rwlock) 3451 { 3452 struct umtx_q *uq; 3453 uint32_t flags; 3454 int32_t state, oldstate; 3455 int error, rv, q, count; 3456 3457 uq = td->td_umtxq; 3458 error = fueword32(&rwlock->rw_flags, &flags); 3459 if (error == -1) 3460 return (EFAULT); 3461 error = umtx_key_get(rwlock, TYPE_RWLOCK, GET_SHARE(flags), &uq->uq_key); 3462 if (error != 0) 3463 return (error); 3464 3465 error = fueword32(&rwlock->rw_state, &state); 3466 if (error == -1) { 3467 error = EFAULT; 3468 goto out; 3469 } 3470 if (state & URWLOCK_WRITE_OWNER) { 3471 for (;;) { 3472 rv = casueword32(&rwlock->rw_state, state, 3473 &oldstate, state & ~URWLOCK_WRITE_OWNER); 3474 if (rv == -1) { 3475 error = EFAULT; 3476 goto out; 3477 } 3478 if (rv == 1) { 3479 state = oldstate; 3480 if (!(oldstate & URWLOCK_WRITE_OWNER)) { 3481 error = EPERM; 3482 goto out; 3483 } 3484 error = thread_check_susp(td, true); 3485 if (error != 0) 3486 goto out; 3487 } else 3488 break; 3489 } 3490 } else if (URWLOCK_READER_COUNT(state) != 0) { 3491 for (;;) { 3492 rv = casueword32(&rwlock->rw_state, state, 3493 &oldstate, state - 1); 3494 if (rv == -1) { 3495 error = EFAULT; 3496 goto out; 3497 } 3498 if (rv == 1) { 3499 state = oldstate; 3500 if (URWLOCK_READER_COUNT(oldstate) == 0) { 3501 error = EPERM; 3502 goto out; 3503 } 3504 error = thread_check_susp(td, true); 3505 if (error != 0) 3506 goto out; 3507 } else 3508 break; 3509 } 3510 } else { 3511 error = EPERM; 3512 goto out; 3513 } 3514 3515 count = 0; 3516 3517 if (!(flags & URWLOCK_PREFER_READER)) { 3518 if (state & URWLOCK_WRITE_WAITERS) { 3519 count = 1; 3520 q = UMTX_EXCLUSIVE_QUEUE; 3521 } else if (state & URWLOCK_READ_WAITERS) { 3522 count = INT_MAX; 3523 q = UMTX_SHARED_QUEUE; 3524 } 3525 } else { 3526 if (state & URWLOCK_READ_WAITERS) { 3527 count = INT_MAX; 3528 q = UMTX_SHARED_QUEUE; 3529 } else if (state & URWLOCK_WRITE_WAITERS) { 3530 count = 1; 3531 q = UMTX_EXCLUSIVE_QUEUE; 3532 } 3533 } 3534 3535 if (count) { 3536 umtxq_lock(&uq->uq_key); 3537 umtxq_busy(&uq->uq_key); 3538 umtxq_signal_queue(&uq->uq_key, count, q); 3539 umtxq_unbusy(&uq->uq_key); 3540 umtxq_unlock(&uq->uq_key); 3541 } 3542 out: 3543 umtx_key_release(&uq->uq_key); 3544 return (error); 3545 } 3546 3547 #if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10) 3548 static int 3549 do_sem_wait(struct thread *td, struct _usem *sem, struct _umtx_time *timeout) 3550 { 3551 struct umtx_abs_timeout timo; 3552 struct umtx_q *uq; 3553 uint32_t flags, count, count1; 3554 int error, rv, rv1; 3555 3556 uq = td->td_umtxq; 3557 error = fueword32(&sem->_flags, &flags); 3558 if (error == -1) 3559 return (EFAULT); 3560 error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &uq->uq_key); 3561 if (error != 0) 3562 return (error); 3563 3564 if (timeout != NULL) 3565 umtx_abs_timeout_init2(&timo, timeout); 3566 3567 again: 3568 umtxq_lock(&uq->uq_key); 3569 umtxq_busy(&uq->uq_key); 3570 umtxq_insert(uq); 3571 umtxq_unlock(&uq->uq_key); 3572 rv = casueword32(&sem->_has_waiters, 0, &count1, 1); 3573 if (rv != -1) 3574 rv1 = fueword32(&sem->_count, &count); 3575 if (rv == -1 || rv1 == -1 || count != 0 || (rv == 1 && count1 == 0)) { 3576 if (rv == 0) 3577 suword32(&sem->_has_waiters, 0); 3578 umtxq_lock(&uq->uq_key); 3579 umtxq_unbusy(&uq->uq_key); 3580 umtxq_remove(uq); 3581 umtxq_unlock(&uq->uq_key); 3582 if (rv == -1 || rv1 == -1) { 3583 error = EFAULT; 3584 goto out; 3585 } 3586 if (count != 0) { 3587 error = 0; 3588 goto out; 3589 } 3590 MPASS(rv == 1 && count1 == 0); 3591 rv = thread_check_susp(td, true); 3592 if (rv == 0) 3593 goto again; 3594 error = rv; 3595 goto out; 3596 } 3597 umtxq_lock(&uq->uq_key); 3598 umtxq_unbusy(&uq->uq_key); 3599 3600 error = umtxq_sleep(uq, "usem", timeout == NULL ? NULL : &timo); 3601 3602 if ((uq->uq_flags & UQF_UMTXQ) == 0) 3603 error = 0; 3604 else { 3605 umtxq_remove(uq); 3606 /* A relative timeout cannot be restarted. */ 3607 if (error == ERESTART && timeout != NULL && 3608 (timeout->_flags & UMTX_ABSTIME) == 0) 3609 error = EINTR; 3610 } 3611 umtxq_unlock(&uq->uq_key); 3612 out: 3613 umtx_key_release(&uq->uq_key); 3614 return (error); 3615 } 3616 3617 /* 3618 * Signal a userland semaphore. 3619 */ 3620 static int 3621 do_sem_wake(struct thread *td, struct _usem *sem) 3622 { 3623 struct umtx_key key; 3624 int error, cnt; 3625 uint32_t flags; 3626 3627 error = fueword32(&sem->_flags, &flags); 3628 if (error == -1) 3629 return (EFAULT); 3630 if ((error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &key)) != 0) 3631 return (error); 3632 umtxq_lock(&key); 3633 umtxq_busy(&key); 3634 cnt = umtxq_count(&key); 3635 if (cnt > 0) { 3636 /* 3637 * Check if count is greater than 0, this means the memory is 3638 * still being referenced by user code, so we can safely 3639 * update _has_waiters flag. 3640 */ 3641 if (cnt == 1) { 3642 umtxq_unlock(&key); 3643 error = suword32(&sem->_has_waiters, 0); 3644 umtxq_lock(&key); 3645 if (error == -1) 3646 error = EFAULT; 3647 } 3648 umtxq_signal(&key, 1); 3649 } 3650 umtxq_unbusy(&key); 3651 umtxq_unlock(&key); 3652 umtx_key_release(&key); 3653 return (error); 3654 } 3655 #endif 3656 3657 static int 3658 do_sem2_wait(struct thread *td, struct _usem2 *sem, struct _umtx_time *timeout) 3659 { 3660 struct umtx_abs_timeout timo; 3661 struct umtx_q *uq; 3662 uint32_t count, flags; 3663 int error, rv; 3664 3665 uq = td->td_umtxq; 3666 flags = fuword32(&sem->_flags); 3667 if (timeout != NULL) 3668 umtx_abs_timeout_init2(&timo, timeout); 3669 3670 again: 3671 error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &uq->uq_key); 3672 if (error != 0) 3673 return (error); 3674 umtxq_lock(&uq->uq_key); 3675 umtxq_busy(&uq->uq_key); 3676 umtxq_insert(uq); 3677 umtxq_unlock(&uq->uq_key); 3678 rv = fueword32(&sem->_count, &count); 3679 if (rv == -1) { 3680 umtxq_lock(&uq->uq_key); 3681 umtxq_unbusy(&uq->uq_key); 3682 umtxq_remove(uq); 3683 umtxq_unlock(&uq->uq_key); 3684 umtx_key_release(&uq->uq_key); 3685 return (EFAULT); 3686 } 3687 for (;;) { 3688 if (USEM_COUNT(count) != 0) { 3689 umtxq_lock(&uq->uq_key); 3690 umtxq_unbusy(&uq->uq_key); 3691 umtxq_remove(uq); 3692 umtxq_unlock(&uq->uq_key); 3693 umtx_key_release(&uq->uq_key); 3694 return (0); 3695 } 3696 if (count == USEM_HAS_WAITERS) 3697 break; 3698 rv = casueword32(&sem->_count, 0, &count, USEM_HAS_WAITERS); 3699 if (rv == 0) 3700 break; 3701 umtxq_lock(&uq->uq_key); 3702 umtxq_unbusy(&uq->uq_key); 3703 umtxq_remove(uq); 3704 umtxq_unlock(&uq->uq_key); 3705 umtx_key_release(&uq->uq_key); 3706 if (rv == -1) 3707 return (EFAULT); 3708 rv = thread_check_susp(td, true); 3709 if (rv != 0) 3710 return (rv); 3711 goto again; 3712 } 3713 umtxq_lock(&uq->uq_key); 3714 umtxq_unbusy(&uq->uq_key); 3715 3716 error = umtxq_sleep(uq, "usem", timeout == NULL ? NULL : &timo); 3717 3718 if ((uq->uq_flags & UQF_UMTXQ) == 0) 3719 error = 0; 3720 else { 3721 umtxq_remove(uq); 3722 if (timeout != NULL && (timeout->_flags & UMTX_ABSTIME) == 0) { 3723 /* A relative timeout cannot be restarted. */ 3724 if (error == ERESTART) 3725 error = EINTR; 3726 if (error == EINTR) { 3727 kern_clock_gettime(curthread, timo.clockid, 3728 &timo.cur); 3729 timespecsub(&timo.end, &timo.cur, 3730 &timeout->_timeout); 3731 } 3732 } 3733 } 3734 umtxq_unlock(&uq->uq_key); 3735 umtx_key_release(&uq->uq_key); 3736 return (error); 3737 } 3738 3739 /* 3740 * Signal a userland semaphore. 3741 */ 3742 static int 3743 do_sem2_wake(struct thread *td, struct _usem2 *sem) 3744 { 3745 struct umtx_key key; 3746 int error, cnt, rv; 3747 uint32_t count, flags; 3748 3749 rv = fueword32(&sem->_flags, &flags); 3750 if (rv == -1) 3751 return (EFAULT); 3752 if ((error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &key)) != 0) 3753 return (error); 3754 umtxq_lock(&key); 3755 umtxq_busy(&key); 3756 cnt = umtxq_count(&key); 3757 if (cnt > 0) { 3758 /* 3759 * If this was the last sleeping thread, clear the waiters 3760 * flag in _count. 3761 */ 3762 if (cnt == 1) { 3763 umtxq_unlock(&key); 3764 rv = fueword32(&sem->_count, &count); 3765 while (rv != -1 && count & USEM_HAS_WAITERS) { 3766 rv = casueword32(&sem->_count, count, &count, 3767 count & ~USEM_HAS_WAITERS); 3768 if (rv == 1) { 3769 rv = thread_check_susp(td, true); 3770 if (rv != 0) 3771 break; 3772 } 3773 } 3774 if (rv == -1) 3775 error = EFAULT; 3776 else if (rv > 0) { 3777 error = rv; 3778 } 3779 umtxq_lock(&key); 3780 } 3781 3782 umtxq_signal(&key, 1); 3783 } 3784 umtxq_unbusy(&key); 3785 umtxq_unlock(&key); 3786 umtx_key_release(&key); 3787 return (error); 3788 } 3789 3790 #ifdef COMPAT_FREEBSD10 3791 int 3792 freebsd10__umtx_lock(struct thread *td, struct freebsd10__umtx_lock_args *uap) 3793 { 3794 return (do_lock_umtx(td, uap->umtx, td->td_tid, 0)); 3795 } 3796 3797 int 3798 freebsd10__umtx_unlock(struct thread *td, 3799 struct freebsd10__umtx_unlock_args *uap) 3800 { 3801 return (do_unlock_umtx(td, uap->umtx, td->td_tid)); 3802 } 3803 #endif 3804 3805 inline int 3806 umtx_copyin_timeout(const void *uaddr, struct timespec *tsp) 3807 { 3808 int error; 3809 3810 error = copyin(uaddr, tsp, sizeof(*tsp)); 3811 if (error == 0) { 3812 if (!timespecvalid_interval(tsp)) 3813 error = EINVAL; 3814 } 3815 return (error); 3816 } 3817 3818 static inline int 3819 umtx_copyin_umtx_time(const void *uaddr, size_t size, struct _umtx_time *tp) 3820 { 3821 int error; 3822 3823 if (size <= sizeof(tp->_timeout)) { 3824 tp->_clockid = CLOCK_REALTIME; 3825 tp->_flags = 0; 3826 error = copyin(uaddr, &tp->_timeout, sizeof(tp->_timeout)); 3827 } else 3828 error = copyin(uaddr, tp, sizeof(*tp)); 3829 if (error != 0) 3830 return (error); 3831 if (!timespecvalid_interval(&tp->_timeout)) 3832 return (EINVAL); 3833 return (0); 3834 } 3835 3836 static int 3837 umtx_copyin_robust_lists(const void *uaddr, size_t size, 3838 struct umtx_robust_lists_params *rb) 3839 { 3840 3841 if (size > sizeof(*rb)) 3842 return (EINVAL); 3843 return (copyin(uaddr, rb, size)); 3844 } 3845 3846 static int 3847 umtx_copyout_timeout(void *uaddr, size_t sz, struct timespec *tsp) 3848 { 3849 3850 /* 3851 * Should be guaranteed by the caller, sz == uaddr1 - sizeof(_umtx_time) 3852 * and we're only called if sz >= sizeof(timespec) as supplied in the 3853 * copyops. 3854 */ 3855 KASSERT(sz >= sizeof(*tsp), 3856 ("umtx_copyops specifies incorrect sizes")); 3857 3858 return (copyout(tsp, uaddr, sizeof(*tsp))); 3859 } 3860 3861 #ifdef COMPAT_FREEBSD10 3862 static int 3863 __umtx_op_lock_umtx(struct thread *td, struct _umtx_op_args *uap, 3864 const struct umtx_copyops *ops) 3865 { 3866 struct timespec *ts, timeout; 3867 int error; 3868 3869 /* Allow a null timespec (wait forever). */ 3870 if (uap->uaddr2 == NULL) 3871 ts = NULL; 3872 else { 3873 error = ops->copyin_timeout(uap->uaddr2, &timeout); 3874 if (error != 0) 3875 return (error); 3876 ts = &timeout; 3877 } 3878 #ifdef COMPAT_FREEBSD32 3879 if (ops->compat32) 3880 return (do_lock_umtx32(td, uap->obj, uap->val, ts)); 3881 #endif 3882 return (do_lock_umtx(td, uap->obj, uap->val, ts)); 3883 } 3884 3885 static int 3886 __umtx_op_unlock_umtx(struct thread *td, struct _umtx_op_args *uap, 3887 const struct umtx_copyops *ops) 3888 { 3889 #ifdef COMPAT_FREEBSD32 3890 if (ops->compat32) 3891 return (do_unlock_umtx32(td, uap->obj, uap->val)); 3892 #endif 3893 return (do_unlock_umtx(td, uap->obj, uap->val)); 3894 } 3895 #endif /* COMPAT_FREEBSD10 */ 3896 3897 #if !defined(COMPAT_FREEBSD10) 3898 static int 3899 __umtx_op_unimpl(struct thread *td __unused, struct _umtx_op_args *uap __unused, 3900 const struct umtx_copyops *ops __unused) 3901 { 3902 return (EOPNOTSUPP); 3903 } 3904 #endif /* COMPAT_FREEBSD10 */ 3905 3906 static int 3907 __umtx_op_wait(struct thread *td, struct _umtx_op_args *uap, 3908 const struct umtx_copyops *ops) 3909 { 3910 struct _umtx_time timeout, *tm_p; 3911 int error; 3912 3913 if (uap->uaddr2 == NULL) 3914 tm_p = NULL; 3915 else { 3916 error = ops->copyin_umtx_time( 3917 uap->uaddr2, (size_t)uap->uaddr1, &timeout); 3918 if (error != 0) 3919 return (error); 3920 tm_p = &timeout; 3921 } 3922 return (do_wait(td, uap->obj, uap->val, tm_p, ops->compat32, 0)); 3923 } 3924 3925 static int 3926 __umtx_op_wait_uint(struct thread *td, struct _umtx_op_args *uap, 3927 const struct umtx_copyops *ops) 3928 { 3929 struct _umtx_time timeout, *tm_p; 3930 int error; 3931 3932 if (uap->uaddr2 == NULL) 3933 tm_p = NULL; 3934 else { 3935 error = ops->copyin_umtx_time( 3936 uap->uaddr2, (size_t)uap->uaddr1, &timeout); 3937 if (error != 0) 3938 return (error); 3939 tm_p = &timeout; 3940 } 3941 return (do_wait(td, uap->obj, uap->val, tm_p, 1, 0)); 3942 } 3943 3944 static int 3945 __umtx_op_wait_uint_private(struct thread *td, struct _umtx_op_args *uap, 3946 const struct umtx_copyops *ops) 3947 { 3948 struct _umtx_time *tm_p, timeout; 3949 int error; 3950 3951 if (uap->uaddr2 == NULL) 3952 tm_p = NULL; 3953 else { 3954 error = ops->copyin_umtx_time( 3955 uap->uaddr2, (size_t)uap->uaddr1, &timeout); 3956 if (error != 0) 3957 return (error); 3958 tm_p = &timeout; 3959 } 3960 return (do_wait(td, uap->obj, uap->val, tm_p, 1, 1)); 3961 } 3962 3963 static int 3964 __umtx_op_wake(struct thread *td, struct _umtx_op_args *uap, 3965 const struct umtx_copyops *ops __unused) 3966 { 3967 3968 return (kern_umtx_wake(td, uap->obj, uap->val, 0)); 3969 } 3970 3971 #define BATCH_SIZE 128 3972 static int 3973 __umtx_op_nwake_private_native(struct thread *td, struct _umtx_op_args *uap) 3974 { 3975 char *uaddrs[BATCH_SIZE], **upp; 3976 int count, error, i, pos, tocopy; 3977 3978 upp = (char **)uap->obj; 3979 error = 0; 3980 for (count = uap->val, pos = 0; count > 0; count -= tocopy, 3981 pos += tocopy) { 3982 tocopy = MIN(count, BATCH_SIZE); 3983 error = copyin(upp + pos, uaddrs, tocopy * sizeof(char *)); 3984 if (error != 0) 3985 break; 3986 for (i = 0; i < tocopy; ++i) { 3987 kern_umtx_wake(td, uaddrs[i], INT_MAX, 1); 3988 } 3989 maybe_yield(); 3990 } 3991 return (error); 3992 } 3993 3994 static int 3995 __umtx_op_nwake_private_compat32(struct thread *td, struct _umtx_op_args *uap) 3996 { 3997 uint32_t uaddrs[BATCH_SIZE], *upp; 3998 int count, error, i, pos, tocopy; 3999 4000 upp = (uint32_t *)uap->obj; 4001 error = 0; 4002 for (count = uap->val, pos = 0; count > 0; count -= tocopy, 4003 pos += tocopy) { 4004 tocopy = MIN(count, BATCH_SIZE); 4005 error = copyin(upp + pos, uaddrs, tocopy * sizeof(uint32_t)); 4006 if (error != 0) 4007 break; 4008 for (i = 0; i < tocopy; ++i) { 4009 kern_umtx_wake(td, (void *)(uintptr_t)uaddrs[i], 4010 INT_MAX, 1); 4011 } 4012 maybe_yield(); 4013 } 4014 return (error); 4015 } 4016 4017 static int 4018 __umtx_op_nwake_private(struct thread *td, struct _umtx_op_args *uap, 4019 const struct umtx_copyops *ops) 4020 { 4021 4022 if (ops->compat32) 4023 return (__umtx_op_nwake_private_compat32(td, uap)); 4024 return (__umtx_op_nwake_private_native(td, uap)); 4025 } 4026 4027 static int 4028 __umtx_op_wake_private(struct thread *td, struct _umtx_op_args *uap, 4029 const struct umtx_copyops *ops __unused) 4030 { 4031 4032 return (kern_umtx_wake(td, uap->obj, uap->val, 1)); 4033 } 4034 4035 static int 4036 __umtx_op_lock_umutex(struct thread *td, struct _umtx_op_args *uap, 4037 const struct umtx_copyops *ops) 4038 { 4039 struct _umtx_time *tm_p, timeout; 4040 int error; 4041 4042 /* Allow a null timespec (wait forever). */ 4043 if (uap->uaddr2 == NULL) 4044 tm_p = NULL; 4045 else { 4046 error = ops->copyin_umtx_time( 4047 uap->uaddr2, (size_t)uap->uaddr1, &timeout); 4048 if (error != 0) 4049 return (error); 4050 tm_p = &timeout; 4051 } 4052 return (do_lock_umutex(td, uap->obj, tm_p, 0)); 4053 } 4054 4055 static int 4056 __umtx_op_trylock_umutex(struct thread *td, struct _umtx_op_args *uap, 4057 const struct umtx_copyops *ops __unused) 4058 { 4059 4060 return (do_lock_umutex(td, uap->obj, NULL, _UMUTEX_TRY)); 4061 } 4062 4063 static int 4064 __umtx_op_wait_umutex(struct thread *td, struct _umtx_op_args *uap, 4065 const struct umtx_copyops *ops) 4066 { 4067 struct _umtx_time *tm_p, timeout; 4068 int error; 4069 4070 /* Allow a null timespec (wait forever). */ 4071 if (uap->uaddr2 == NULL) 4072 tm_p = NULL; 4073 else { 4074 error = ops->copyin_umtx_time( 4075 uap->uaddr2, (size_t)uap->uaddr1, &timeout); 4076 if (error != 0) 4077 return (error); 4078 tm_p = &timeout; 4079 } 4080 return (do_lock_umutex(td, uap->obj, tm_p, _UMUTEX_WAIT)); 4081 } 4082 4083 static int 4084 __umtx_op_wake_umutex(struct thread *td, struct _umtx_op_args *uap, 4085 const struct umtx_copyops *ops __unused) 4086 { 4087 4088 return (do_wake_umutex(td, uap->obj)); 4089 } 4090 4091 static int 4092 __umtx_op_unlock_umutex(struct thread *td, struct _umtx_op_args *uap, 4093 const struct umtx_copyops *ops __unused) 4094 { 4095 4096 return (do_unlock_umutex(td, uap->obj, false)); 4097 } 4098 4099 static int 4100 __umtx_op_set_ceiling(struct thread *td, struct _umtx_op_args *uap, 4101 const struct umtx_copyops *ops __unused) 4102 { 4103 4104 return (do_set_ceiling(td, uap->obj, uap->val, uap->uaddr1)); 4105 } 4106 4107 static int 4108 __umtx_op_cv_wait(struct thread *td, struct _umtx_op_args *uap, 4109 const struct umtx_copyops *ops) 4110 { 4111 struct timespec *ts, timeout; 4112 int error; 4113 4114 /* Allow a null timespec (wait forever). */ 4115 if (uap->uaddr2 == NULL) 4116 ts = NULL; 4117 else { 4118 error = ops->copyin_timeout(uap->uaddr2, &timeout); 4119 if (error != 0) 4120 return (error); 4121 ts = &timeout; 4122 } 4123 return (do_cv_wait(td, uap->obj, uap->uaddr1, ts, uap->val)); 4124 } 4125 4126 static int 4127 __umtx_op_cv_signal(struct thread *td, struct _umtx_op_args *uap, 4128 const struct umtx_copyops *ops __unused) 4129 { 4130 4131 return (do_cv_signal(td, uap->obj)); 4132 } 4133 4134 static int 4135 __umtx_op_cv_broadcast(struct thread *td, struct _umtx_op_args *uap, 4136 const struct umtx_copyops *ops __unused) 4137 { 4138 4139 return (do_cv_broadcast(td, uap->obj)); 4140 } 4141 4142 static int 4143 __umtx_op_rw_rdlock(struct thread *td, struct _umtx_op_args *uap, 4144 const struct umtx_copyops *ops) 4145 { 4146 struct _umtx_time timeout; 4147 int error; 4148 4149 /* Allow a null timespec (wait forever). */ 4150 if (uap->uaddr2 == NULL) { 4151 error = do_rw_rdlock(td, uap->obj, uap->val, 0); 4152 } else { 4153 error = ops->copyin_umtx_time(uap->uaddr2, 4154 (size_t)uap->uaddr1, &timeout); 4155 if (error != 0) 4156 return (error); 4157 error = do_rw_rdlock(td, uap->obj, uap->val, &timeout); 4158 } 4159 return (error); 4160 } 4161 4162 static int 4163 __umtx_op_rw_wrlock(struct thread *td, struct _umtx_op_args *uap, 4164 const struct umtx_copyops *ops) 4165 { 4166 struct _umtx_time timeout; 4167 int error; 4168 4169 /* Allow a null timespec (wait forever). */ 4170 if (uap->uaddr2 == NULL) { 4171 error = do_rw_wrlock(td, uap->obj, 0); 4172 } else { 4173 error = ops->copyin_umtx_time(uap->uaddr2, 4174 (size_t)uap->uaddr1, &timeout); 4175 if (error != 0) 4176 return (error); 4177 4178 error = do_rw_wrlock(td, uap->obj, &timeout); 4179 } 4180 return (error); 4181 } 4182 4183 static int 4184 __umtx_op_rw_unlock(struct thread *td, struct _umtx_op_args *uap, 4185 const struct umtx_copyops *ops __unused) 4186 { 4187 4188 return (do_rw_unlock(td, uap->obj)); 4189 } 4190 4191 #if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10) 4192 static int 4193 __umtx_op_sem_wait(struct thread *td, struct _umtx_op_args *uap, 4194 const struct umtx_copyops *ops) 4195 { 4196 struct _umtx_time *tm_p, timeout; 4197 int error; 4198 4199 /* Allow a null timespec (wait forever). */ 4200 if (uap->uaddr2 == NULL) 4201 tm_p = NULL; 4202 else { 4203 error = ops->copyin_umtx_time( 4204 uap->uaddr2, (size_t)uap->uaddr1, &timeout); 4205 if (error != 0) 4206 return (error); 4207 tm_p = &timeout; 4208 } 4209 return (do_sem_wait(td, uap->obj, tm_p)); 4210 } 4211 4212 static int 4213 __umtx_op_sem_wake(struct thread *td, struct _umtx_op_args *uap, 4214 const struct umtx_copyops *ops __unused) 4215 { 4216 4217 return (do_sem_wake(td, uap->obj)); 4218 } 4219 #endif 4220 4221 static int 4222 __umtx_op_wake2_umutex(struct thread *td, struct _umtx_op_args *uap, 4223 const struct umtx_copyops *ops __unused) 4224 { 4225 4226 return (do_wake2_umutex(td, uap->obj, uap->val)); 4227 } 4228 4229 static int 4230 __umtx_op_sem2_wait(struct thread *td, struct _umtx_op_args *uap, 4231 const struct umtx_copyops *ops) 4232 { 4233 struct _umtx_time *tm_p, timeout; 4234 size_t uasize; 4235 int error; 4236 4237 /* Allow a null timespec (wait forever). */ 4238 if (uap->uaddr2 == NULL) { 4239 uasize = 0; 4240 tm_p = NULL; 4241 } else { 4242 uasize = (size_t)uap->uaddr1; 4243 error = ops->copyin_umtx_time(uap->uaddr2, uasize, &timeout); 4244 if (error != 0) 4245 return (error); 4246 tm_p = &timeout; 4247 } 4248 error = do_sem2_wait(td, uap->obj, tm_p); 4249 if (error == EINTR && uap->uaddr2 != NULL && 4250 (timeout._flags & UMTX_ABSTIME) == 0 && 4251 uasize >= ops->umtx_time_sz + ops->timespec_sz) { 4252 error = ops->copyout_timeout( 4253 (void *)((uintptr_t)uap->uaddr2 + ops->umtx_time_sz), 4254 uasize - ops->umtx_time_sz, &timeout._timeout); 4255 if (error == 0) { 4256 error = EINTR; 4257 } 4258 } 4259 4260 return (error); 4261 } 4262 4263 static int 4264 __umtx_op_sem2_wake(struct thread *td, struct _umtx_op_args *uap, 4265 const struct umtx_copyops *ops __unused) 4266 { 4267 4268 return (do_sem2_wake(td, uap->obj)); 4269 } 4270 4271 #define USHM_OBJ_UMTX(o) \ 4272 ((struct umtx_shm_obj_list *)(&(o)->umtx_data)) 4273 4274 #define USHMF_REG_LINKED 0x0001 4275 #define USHMF_OBJ_LINKED 0x0002 4276 struct umtx_shm_reg { 4277 TAILQ_ENTRY(umtx_shm_reg) ushm_reg_link; 4278 LIST_ENTRY(umtx_shm_reg) ushm_obj_link; 4279 struct umtx_key ushm_key; 4280 struct ucred *ushm_cred; 4281 struct shmfd *ushm_obj; 4282 u_int ushm_refcnt; 4283 u_int ushm_flags; 4284 }; 4285 4286 LIST_HEAD(umtx_shm_obj_list, umtx_shm_reg); 4287 TAILQ_HEAD(umtx_shm_reg_head, umtx_shm_reg); 4288 4289 static uma_zone_t umtx_shm_reg_zone; 4290 static struct umtx_shm_reg_head umtx_shm_registry[UMTX_CHAINS]; 4291 static struct mtx umtx_shm_lock; 4292 static struct umtx_shm_reg_head umtx_shm_reg_delfree = 4293 TAILQ_HEAD_INITIALIZER(umtx_shm_reg_delfree); 4294 4295 static void umtx_shm_free_reg(struct umtx_shm_reg *reg); 4296 4297 static void 4298 umtx_shm_reg_delfree_tq(void *context __unused, int pending __unused) 4299 { 4300 struct umtx_shm_reg_head d; 4301 struct umtx_shm_reg *reg, *reg1; 4302 4303 TAILQ_INIT(&d); 4304 mtx_lock(&umtx_shm_lock); 4305 TAILQ_CONCAT(&d, &umtx_shm_reg_delfree, ushm_reg_link); 4306 mtx_unlock(&umtx_shm_lock); 4307 TAILQ_FOREACH_SAFE(reg, &d, ushm_reg_link, reg1) { 4308 TAILQ_REMOVE(&d, reg, ushm_reg_link); 4309 umtx_shm_free_reg(reg); 4310 } 4311 } 4312 4313 static struct task umtx_shm_reg_delfree_task = 4314 TASK_INITIALIZER(0, umtx_shm_reg_delfree_tq, NULL); 4315 4316 static struct umtx_shm_reg * 4317 umtx_shm_find_reg_locked(const struct umtx_key *key) 4318 { 4319 struct umtx_shm_reg *reg; 4320 struct umtx_shm_reg_head *reg_head; 4321 4322 KASSERT(key->shared, ("umtx_p_find_rg: private key")); 4323 mtx_assert(&umtx_shm_lock, MA_OWNED); 4324 reg_head = &umtx_shm_registry[key->hash]; 4325 TAILQ_FOREACH(reg, reg_head, ushm_reg_link) { 4326 KASSERT(reg->ushm_key.shared, 4327 ("non-shared key on reg %p %d", reg, reg->ushm_key.shared)); 4328 if (reg->ushm_key.info.shared.object == 4329 key->info.shared.object && 4330 reg->ushm_key.info.shared.offset == 4331 key->info.shared.offset) { 4332 KASSERT(reg->ushm_key.type == TYPE_SHM, ("TYPE_USHM")); 4333 KASSERT(reg->ushm_refcnt > 0, 4334 ("reg %p refcnt 0 onlist", reg)); 4335 KASSERT((reg->ushm_flags & USHMF_REG_LINKED) != 0, 4336 ("reg %p not linked", reg)); 4337 reg->ushm_refcnt++; 4338 return (reg); 4339 } 4340 } 4341 return (NULL); 4342 } 4343 4344 static struct umtx_shm_reg * 4345 umtx_shm_find_reg(const struct umtx_key *key) 4346 { 4347 struct umtx_shm_reg *reg; 4348 4349 mtx_lock(&umtx_shm_lock); 4350 reg = umtx_shm_find_reg_locked(key); 4351 mtx_unlock(&umtx_shm_lock); 4352 return (reg); 4353 } 4354 4355 static void 4356 umtx_shm_free_reg(struct umtx_shm_reg *reg) 4357 { 4358 4359 chgumtxcnt(reg->ushm_cred->cr_ruidinfo, -1, 0); 4360 crfree(reg->ushm_cred); 4361 shm_drop(reg->ushm_obj); 4362 uma_zfree(umtx_shm_reg_zone, reg); 4363 } 4364 4365 static bool 4366 umtx_shm_unref_reg_locked(struct umtx_shm_reg *reg, bool force) 4367 { 4368 bool res; 4369 4370 mtx_assert(&umtx_shm_lock, MA_OWNED); 4371 KASSERT(reg->ushm_refcnt > 0, ("ushm_reg %p refcnt 0", reg)); 4372 reg->ushm_refcnt--; 4373 res = reg->ushm_refcnt == 0; 4374 if (res || force) { 4375 if ((reg->ushm_flags & USHMF_REG_LINKED) != 0) { 4376 TAILQ_REMOVE(&umtx_shm_registry[reg->ushm_key.hash], 4377 reg, ushm_reg_link); 4378 reg->ushm_flags &= ~USHMF_REG_LINKED; 4379 } 4380 if ((reg->ushm_flags & USHMF_OBJ_LINKED) != 0) { 4381 LIST_REMOVE(reg, ushm_obj_link); 4382 reg->ushm_flags &= ~USHMF_OBJ_LINKED; 4383 } 4384 } 4385 return (res); 4386 } 4387 4388 static void 4389 umtx_shm_unref_reg(struct umtx_shm_reg *reg, bool force) 4390 { 4391 vm_object_t object; 4392 bool dofree; 4393 4394 if (force) { 4395 object = reg->ushm_obj->shm_object; 4396 VM_OBJECT_WLOCK(object); 4397 vm_object_set_flag(object, OBJ_UMTXDEAD); 4398 VM_OBJECT_WUNLOCK(object); 4399 } 4400 mtx_lock(&umtx_shm_lock); 4401 dofree = umtx_shm_unref_reg_locked(reg, force); 4402 mtx_unlock(&umtx_shm_lock); 4403 if (dofree) 4404 umtx_shm_free_reg(reg); 4405 } 4406 4407 void 4408 umtx_shm_object_init(vm_object_t object) 4409 { 4410 4411 LIST_INIT(USHM_OBJ_UMTX(object)); 4412 } 4413 4414 void 4415 umtx_shm_object_terminated(vm_object_t object) 4416 { 4417 struct umtx_shm_reg *reg, *reg1; 4418 bool dofree; 4419 4420 if (LIST_EMPTY(USHM_OBJ_UMTX(object))) 4421 return; 4422 4423 dofree = false; 4424 mtx_lock(&umtx_shm_lock); 4425 LIST_FOREACH_SAFE(reg, USHM_OBJ_UMTX(object), ushm_obj_link, reg1) { 4426 if (umtx_shm_unref_reg_locked(reg, true)) { 4427 TAILQ_INSERT_TAIL(&umtx_shm_reg_delfree, reg, 4428 ushm_reg_link); 4429 dofree = true; 4430 } 4431 } 4432 mtx_unlock(&umtx_shm_lock); 4433 if (dofree) 4434 taskqueue_enqueue(taskqueue_thread, &umtx_shm_reg_delfree_task); 4435 } 4436 4437 static int 4438 umtx_shm_create_reg(struct thread *td, const struct umtx_key *key, 4439 struct umtx_shm_reg **res) 4440 { 4441 struct umtx_shm_reg *reg, *reg1; 4442 struct ucred *cred; 4443 int error; 4444 4445 reg = umtx_shm_find_reg(key); 4446 if (reg != NULL) { 4447 *res = reg; 4448 return (0); 4449 } 4450 cred = td->td_ucred; 4451 if (!chgumtxcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_UMTXP))) 4452 return (ENOMEM); 4453 reg = uma_zalloc(umtx_shm_reg_zone, M_WAITOK | M_ZERO); 4454 reg->ushm_refcnt = 1; 4455 bcopy(key, ®->ushm_key, sizeof(*key)); 4456 reg->ushm_obj = shm_alloc(td->td_ucred, O_RDWR, false); 4457 reg->ushm_cred = crhold(cred); 4458 error = shm_dotruncate(reg->ushm_obj, PAGE_SIZE); 4459 if (error != 0) { 4460 umtx_shm_free_reg(reg); 4461 return (error); 4462 } 4463 mtx_lock(&umtx_shm_lock); 4464 reg1 = umtx_shm_find_reg_locked(key); 4465 if (reg1 != NULL) { 4466 mtx_unlock(&umtx_shm_lock); 4467 umtx_shm_free_reg(reg); 4468 *res = reg1; 4469 return (0); 4470 } 4471 reg->ushm_refcnt++; 4472 TAILQ_INSERT_TAIL(&umtx_shm_registry[key->hash], reg, ushm_reg_link); 4473 LIST_INSERT_HEAD(USHM_OBJ_UMTX(key->info.shared.object), reg, 4474 ushm_obj_link); 4475 reg->ushm_flags = USHMF_REG_LINKED | USHMF_OBJ_LINKED; 4476 mtx_unlock(&umtx_shm_lock); 4477 *res = reg; 4478 return (0); 4479 } 4480 4481 static int 4482 umtx_shm_alive(struct thread *td, void *addr) 4483 { 4484 vm_map_t map; 4485 vm_map_entry_t entry; 4486 vm_object_t object; 4487 vm_pindex_t pindex; 4488 vm_prot_t prot; 4489 int res, ret; 4490 boolean_t wired; 4491 4492 map = &td->td_proc->p_vmspace->vm_map; 4493 res = vm_map_lookup(&map, (uintptr_t)addr, VM_PROT_READ, &entry, 4494 &object, &pindex, &prot, &wired); 4495 if (res != KERN_SUCCESS) 4496 return (EFAULT); 4497 if (object == NULL) 4498 ret = EINVAL; 4499 else 4500 ret = (object->flags & OBJ_UMTXDEAD) != 0 ? ENOTTY : 0; 4501 vm_map_lookup_done(map, entry); 4502 return (ret); 4503 } 4504 4505 static void 4506 umtx_shm_init(void) 4507 { 4508 int i; 4509 4510 umtx_shm_reg_zone = uma_zcreate("umtx_shm", sizeof(struct umtx_shm_reg), 4511 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 4512 mtx_init(&umtx_shm_lock, "umtxshm", NULL, MTX_DEF); 4513 for (i = 0; i < nitems(umtx_shm_registry); i++) 4514 TAILQ_INIT(&umtx_shm_registry[i]); 4515 } 4516 4517 static int 4518 umtx_shm(struct thread *td, void *addr, u_int flags) 4519 { 4520 struct umtx_key key; 4521 struct umtx_shm_reg *reg; 4522 struct file *fp; 4523 int error, fd; 4524 4525 if (__bitcount(flags & (UMTX_SHM_CREAT | UMTX_SHM_LOOKUP | 4526 UMTX_SHM_DESTROY| UMTX_SHM_ALIVE)) != 1) 4527 return (EINVAL); 4528 if ((flags & UMTX_SHM_ALIVE) != 0) 4529 return (umtx_shm_alive(td, addr)); 4530 error = umtx_key_get(addr, TYPE_SHM, PROCESS_SHARE, &key); 4531 if (error != 0) 4532 return (error); 4533 KASSERT(key.shared == 1, ("non-shared key")); 4534 if ((flags & UMTX_SHM_CREAT) != 0) { 4535 error = umtx_shm_create_reg(td, &key, ®); 4536 } else { 4537 reg = umtx_shm_find_reg(&key); 4538 if (reg == NULL) 4539 error = ESRCH; 4540 } 4541 umtx_key_release(&key); 4542 if (error != 0) 4543 return (error); 4544 KASSERT(reg != NULL, ("no reg")); 4545 if ((flags & UMTX_SHM_DESTROY) != 0) { 4546 umtx_shm_unref_reg(reg, true); 4547 } else { 4548 #if 0 4549 #ifdef MAC 4550 error = mac_posixshm_check_open(td->td_ucred, 4551 reg->ushm_obj, FFLAGS(O_RDWR)); 4552 if (error == 0) 4553 #endif 4554 error = shm_access(reg->ushm_obj, td->td_ucred, 4555 FFLAGS(O_RDWR)); 4556 if (error == 0) 4557 #endif 4558 error = falloc_caps(td, &fp, &fd, O_CLOEXEC, NULL); 4559 if (error == 0) { 4560 shm_hold(reg->ushm_obj); 4561 finit(fp, FFLAGS(O_RDWR), DTYPE_SHM, reg->ushm_obj, 4562 &shm_ops); 4563 td->td_retval[0] = fd; 4564 fdrop(fp, td); 4565 } 4566 } 4567 umtx_shm_unref_reg(reg, false); 4568 return (error); 4569 } 4570 4571 static int 4572 __umtx_op_shm(struct thread *td, struct _umtx_op_args *uap, 4573 const struct umtx_copyops *ops __unused) 4574 { 4575 4576 return (umtx_shm(td, uap->uaddr1, uap->val)); 4577 } 4578 4579 static int 4580 __umtx_op_robust_lists(struct thread *td, struct _umtx_op_args *uap, 4581 const struct umtx_copyops *ops) 4582 { 4583 struct umtx_robust_lists_params rb; 4584 int error; 4585 4586 if (ops->compat32) { 4587 if ((td->td_pflags2 & TDP2_COMPAT32RB) == 0 && 4588 (td->td_rb_list != 0 || td->td_rbp_list != 0 || 4589 td->td_rb_inact != 0)) 4590 return (EBUSY); 4591 } else if ((td->td_pflags2 & TDP2_COMPAT32RB) != 0) { 4592 return (EBUSY); 4593 } 4594 4595 bzero(&rb, sizeof(rb)); 4596 error = ops->copyin_robust_lists(uap->uaddr1, uap->val, &rb); 4597 if (error != 0) 4598 return (error); 4599 4600 if (ops->compat32) 4601 td->td_pflags2 |= TDP2_COMPAT32RB; 4602 4603 td->td_rb_list = rb.robust_list_offset; 4604 td->td_rbp_list = rb.robust_priv_list_offset; 4605 td->td_rb_inact = rb.robust_inact_offset; 4606 return (0); 4607 } 4608 4609 static int 4610 __umtx_op_get_min_timeout(struct thread *td, struct _umtx_op_args *uap, 4611 const struct umtx_copyops *ops) 4612 { 4613 long val; 4614 int error, val1; 4615 4616 val = sbttons(td->td_proc->p_umtx_min_timeout); 4617 if (ops->compat32) { 4618 val1 = (int)val; 4619 error = copyout(&val1, uap->uaddr1, sizeof(val1)); 4620 } else { 4621 error = copyout(&val, uap->uaddr1, sizeof(val)); 4622 } 4623 return (error); 4624 } 4625 4626 static int 4627 __umtx_op_set_min_timeout(struct thread *td, struct _umtx_op_args *uap, 4628 const struct umtx_copyops *ops) 4629 { 4630 if (uap->val < 0) 4631 return (EINVAL); 4632 td->td_proc->p_umtx_min_timeout = nstosbt(uap->val); 4633 return (0); 4634 } 4635 4636 #if defined(__i386__) || defined(__amd64__) 4637 /* 4638 * Provide the standard 32-bit definitions for x86, since native/compat32 use a 4639 * 32-bit time_t there. Other architectures just need the i386 definitions 4640 * along with their standard compat32. 4641 */ 4642 struct timespecx32 { 4643 int64_t tv_sec; 4644 int32_t tv_nsec; 4645 }; 4646 4647 struct umtx_timex32 { 4648 struct timespecx32 _timeout; 4649 uint32_t _flags; 4650 uint32_t _clockid; 4651 }; 4652 4653 #ifndef __i386__ 4654 #define timespeci386 timespec32 4655 #define umtx_timei386 umtx_time32 4656 #endif 4657 #else /* !__i386__ && !__amd64__ */ 4658 /* 32-bit architectures can emulate i386, so define these almost everywhere. */ 4659 struct timespeci386 { 4660 int32_t tv_sec; 4661 int32_t tv_nsec; 4662 }; 4663 4664 struct umtx_timei386 { 4665 struct timespeci386 _timeout; 4666 uint32_t _flags; 4667 uint32_t _clockid; 4668 }; 4669 4670 #if defined(__LP64__) 4671 #define timespecx32 timespec32 4672 #define umtx_timex32 umtx_time32 4673 #endif 4674 #endif 4675 4676 static int 4677 umtx_copyin_robust_lists32(const void *uaddr, size_t size, 4678 struct umtx_robust_lists_params *rbp) 4679 { 4680 struct umtx_robust_lists_params_compat32 rb32; 4681 int error; 4682 4683 if (size > sizeof(rb32)) 4684 return (EINVAL); 4685 bzero(&rb32, sizeof(rb32)); 4686 error = copyin(uaddr, &rb32, size); 4687 if (error != 0) 4688 return (error); 4689 CP(rb32, *rbp, robust_list_offset); 4690 CP(rb32, *rbp, robust_priv_list_offset); 4691 CP(rb32, *rbp, robust_inact_offset); 4692 return (0); 4693 } 4694 4695 #ifndef __i386__ 4696 static inline int 4697 umtx_copyin_timeouti386(const void *uaddr, struct timespec *tsp) 4698 { 4699 struct timespeci386 ts32; 4700 int error; 4701 4702 error = copyin(uaddr, &ts32, sizeof(ts32)); 4703 if (error == 0) { 4704 if (!timespecvalid_interval(&ts32)) 4705 error = EINVAL; 4706 else { 4707 CP(ts32, *tsp, tv_sec); 4708 CP(ts32, *tsp, tv_nsec); 4709 } 4710 } 4711 return (error); 4712 } 4713 4714 static inline int 4715 umtx_copyin_umtx_timei386(const void *uaddr, size_t size, struct _umtx_time *tp) 4716 { 4717 struct umtx_timei386 t32; 4718 int error; 4719 4720 t32._clockid = CLOCK_REALTIME; 4721 t32._flags = 0; 4722 if (size <= sizeof(t32._timeout)) 4723 error = copyin(uaddr, &t32._timeout, sizeof(t32._timeout)); 4724 else 4725 error = copyin(uaddr, &t32, sizeof(t32)); 4726 if (error != 0) 4727 return (error); 4728 if (!timespecvalid_interval(&t32._timeout)) 4729 return (EINVAL); 4730 TS_CP(t32, *tp, _timeout); 4731 CP(t32, *tp, _flags); 4732 CP(t32, *tp, _clockid); 4733 return (0); 4734 } 4735 4736 static int 4737 umtx_copyout_timeouti386(void *uaddr, size_t sz, struct timespec *tsp) 4738 { 4739 struct timespeci386 remain32 = { 4740 .tv_sec = tsp->tv_sec, 4741 .tv_nsec = tsp->tv_nsec, 4742 }; 4743 4744 /* 4745 * Should be guaranteed by the caller, sz == uaddr1 - sizeof(_umtx_time) 4746 * and we're only called if sz >= sizeof(timespec) as supplied in the 4747 * copyops. 4748 */ 4749 KASSERT(sz >= sizeof(remain32), 4750 ("umtx_copyops specifies incorrect sizes")); 4751 4752 return (copyout(&remain32, uaddr, sizeof(remain32))); 4753 } 4754 #endif /* !__i386__ */ 4755 4756 #if defined(__i386__) || defined(__LP64__) 4757 static inline int 4758 umtx_copyin_timeoutx32(const void *uaddr, struct timespec *tsp) 4759 { 4760 struct timespecx32 ts32; 4761 int error; 4762 4763 error = copyin(uaddr, &ts32, sizeof(ts32)); 4764 if (error == 0) { 4765 if (!timespecvalid_interval(&ts32)) 4766 error = EINVAL; 4767 else { 4768 CP(ts32, *tsp, tv_sec); 4769 CP(ts32, *tsp, tv_nsec); 4770 } 4771 } 4772 return (error); 4773 } 4774 4775 static inline int 4776 umtx_copyin_umtx_timex32(const void *uaddr, size_t size, struct _umtx_time *tp) 4777 { 4778 struct umtx_timex32 t32; 4779 int error; 4780 4781 t32._clockid = CLOCK_REALTIME; 4782 t32._flags = 0; 4783 if (size <= sizeof(t32._timeout)) 4784 error = copyin(uaddr, &t32._timeout, sizeof(t32._timeout)); 4785 else 4786 error = copyin(uaddr, &t32, sizeof(t32)); 4787 if (error != 0) 4788 return (error); 4789 if (!timespecvalid_interval(&t32._timeout)) 4790 return (EINVAL); 4791 TS_CP(t32, *tp, _timeout); 4792 CP(t32, *tp, _flags); 4793 CP(t32, *tp, _clockid); 4794 return (0); 4795 } 4796 4797 static int 4798 umtx_copyout_timeoutx32(void *uaddr, size_t sz, struct timespec *tsp) 4799 { 4800 struct timespecx32 remain32 = { 4801 .tv_sec = tsp->tv_sec, 4802 .tv_nsec = tsp->tv_nsec, 4803 }; 4804 4805 /* 4806 * Should be guaranteed by the caller, sz == uaddr1 - sizeof(_umtx_time) 4807 * and we're only called if sz >= sizeof(timespec) as supplied in the 4808 * copyops. 4809 */ 4810 KASSERT(sz >= sizeof(remain32), 4811 ("umtx_copyops specifies incorrect sizes")); 4812 4813 return (copyout(&remain32, uaddr, sizeof(remain32))); 4814 } 4815 #endif /* __i386__ || __LP64__ */ 4816 4817 typedef int (*_umtx_op_func)(struct thread *td, struct _umtx_op_args *uap, 4818 const struct umtx_copyops *umtx_ops); 4819 4820 static const _umtx_op_func op_table[] = { 4821 #ifdef COMPAT_FREEBSD10 4822 [UMTX_OP_LOCK] = __umtx_op_lock_umtx, 4823 [UMTX_OP_UNLOCK] = __umtx_op_unlock_umtx, 4824 #else 4825 [UMTX_OP_LOCK] = __umtx_op_unimpl, 4826 [UMTX_OP_UNLOCK] = __umtx_op_unimpl, 4827 #endif 4828 [UMTX_OP_WAIT] = __umtx_op_wait, 4829 [UMTX_OP_WAKE] = __umtx_op_wake, 4830 [UMTX_OP_MUTEX_TRYLOCK] = __umtx_op_trylock_umutex, 4831 [UMTX_OP_MUTEX_LOCK] = __umtx_op_lock_umutex, 4832 [UMTX_OP_MUTEX_UNLOCK] = __umtx_op_unlock_umutex, 4833 [UMTX_OP_SET_CEILING] = __umtx_op_set_ceiling, 4834 [UMTX_OP_CV_WAIT] = __umtx_op_cv_wait, 4835 [UMTX_OP_CV_SIGNAL] = __umtx_op_cv_signal, 4836 [UMTX_OP_CV_BROADCAST] = __umtx_op_cv_broadcast, 4837 [UMTX_OP_WAIT_UINT] = __umtx_op_wait_uint, 4838 [UMTX_OP_RW_RDLOCK] = __umtx_op_rw_rdlock, 4839 [UMTX_OP_RW_WRLOCK] = __umtx_op_rw_wrlock, 4840 [UMTX_OP_RW_UNLOCK] = __umtx_op_rw_unlock, 4841 [UMTX_OP_WAIT_UINT_PRIVATE] = __umtx_op_wait_uint_private, 4842 [UMTX_OP_WAKE_PRIVATE] = __umtx_op_wake_private, 4843 [UMTX_OP_MUTEX_WAIT] = __umtx_op_wait_umutex, 4844 [UMTX_OP_MUTEX_WAKE] = __umtx_op_wake_umutex, 4845 #if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10) 4846 [UMTX_OP_SEM_WAIT] = __umtx_op_sem_wait, 4847 [UMTX_OP_SEM_WAKE] = __umtx_op_sem_wake, 4848 #else 4849 [UMTX_OP_SEM_WAIT] = __umtx_op_unimpl, 4850 [UMTX_OP_SEM_WAKE] = __umtx_op_unimpl, 4851 #endif 4852 [UMTX_OP_NWAKE_PRIVATE] = __umtx_op_nwake_private, 4853 [UMTX_OP_MUTEX_WAKE2] = __umtx_op_wake2_umutex, 4854 [UMTX_OP_SEM2_WAIT] = __umtx_op_sem2_wait, 4855 [UMTX_OP_SEM2_WAKE] = __umtx_op_sem2_wake, 4856 [UMTX_OP_SHM] = __umtx_op_shm, 4857 [UMTX_OP_ROBUST_LISTS] = __umtx_op_robust_lists, 4858 [UMTX_OP_GET_MIN_TIMEOUT] = __umtx_op_get_min_timeout, 4859 [UMTX_OP_SET_MIN_TIMEOUT] = __umtx_op_set_min_timeout, 4860 }; 4861 4862 static const struct umtx_copyops umtx_native_ops = { 4863 .copyin_timeout = umtx_copyin_timeout, 4864 .copyin_umtx_time = umtx_copyin_umtx_time, 4865 .copyin_robust_lists = umtx_copyin_robust_lists, 4866 .copyout_timeout = umtx_copyout_timeout, 4867 .timespec_sz = sizeof(struct timespec), 4868 .umtx_time_sz = sizeof(struct _umtx_time), 4869 }; 4870 4871 #ifndef __i386__ 4872 static const struct umtx_copyops umtx_native_opsi386 = { 4873 .copyin_timeout = umtx_copyin_timeouti386, 4874 .copyin_umtx_time = umtx_copyin_umtx_timei386, 4875 .copyin_robust_lists = umtx_copyin_robust_lists32, 4876 .copyout_timeout = umtx_copyout_timeouti386, 4877 .timespec_sz = sizeof(struct timespeci386), 4878 .umtx_time_sz = sizeof(struct umtx_timei386), 4879 .compat32 = true, 4880 }; 4881 #endif 4882 4883 #if defined(__i386__) || defined(__LP64__) 4884 /* i386 can emulate other 32-bit archs, too! */ 4885 static const struct umtx_copyops umtx_native_opsx32 = { 4886 .copyin_timeout = umtx_copyin_timeoutx32, 4887 .copyin_umtx_time = umtx_copyin_umtx_timex32, 4888 .copyin_robust_lists = umtx_copyin_robust_lists32, 4889 .copyout_timeout = umtx_copyout_timeoutx32, 4890 .timespec_sz = sizeof(struct timespecx32), 4891 .umtx_time_sz = sizeof(struct umtx_timex32), 4892 .compat32 = true, 4893 }; 4894 4895 #ifdef COMPAT_FREEBSD32 4896 #ifdef __amd64__ 4897 #define umtx_native_ops32 umtx_native_opsi386 4898 #else 4899 #define umtx_native_ops32 umtx_native_opsx32 4900 #endif 4901 #endif /* COMPAT_FREEBSD32 */ 4902 #endif /* __i386__ || __LP64__ */ 4903 4904 #define UMTX_OP__FLAGS (UMTX_OP__32BIT | UMTX_OP__I386) 4905 4906 static int 4907 kern__umtx_op(struct thread *td, void *obj, int op, unsigned long val, 4908 void *uaddr1, void *uaddr2, const struct umtx_copyops *ops) 4909 { 4910 struct _umtx_op_args uap = { 4911 .obj = obj, 4912 .op = op & ~UMTX_OP__FLAGS, 4913 .val = val, 4914 .uaddr1 = uaddr1, 4915 .uaddr2 = uaddr2 4916 }; 4917 4918 if ((uap.op >= nitems(op_table))) 4919 return (EINVAL); 4920 return ((*op_table[uap.op])(td, &uap, ops)); 4921 } 4922 4923 int 4924 sys__umtx_op(struct thread *td, struct _umtx_op_args *uap) 4925 { 4926 static const struct umtx_copyops *umtx_ops; 4927 4928 umtx_ops = &umtx_native_ops; 4929 #ifdef __LP64__ 4930 if ((uap->op & (UMTX_OP__32BIT | UMTX_OP__I386)) != 0) { 4931 if ((uap->op & UMTX_OP__I386) != 0) 4932 umtx_ops = &umtx_native_opsi386; 4933 else 4934 umtx_ops = &umtx_native_opsx32; 4935 } 4936 #elif !defined(__i386__) 4937 /* We consider UMTX_OP__32BIT a nop on !i386 ILP32. */ 4938 if ((uap->op & UMTX_OP__I386) != 0) 4939 umtx_ops = &umtx_native_opsi386; 4940 #else 4941 /* Likewise, UMTX_OP__I386 is a nop on i386. */ 4942 if ((uap->op & UMTX_OP__32BIT) != 0) 4943 umtx_ops = &umtx_native_opsx32; 4944 #endif 4945 return (kern__umtx_op(td, uap->obj, uap->op, uap->val, uap->uaddr1, 4946 uap->uaddr2, umtx_ops)); 4947 } 4948 4949 #ifdef COMPAT_FREEBSD32 4950 #ifdef COMPAT_FREEBSD10 4951 int 4952 freebsd10_freebsd32__umtx_lock(struct thread *td, 4953 struct freebsd10_freebsd32__umtx_lock_args *uap) 4954 { 4955 return (do_lock_umtx32(td, (uint32_t *)uap->umtx, td->td_tid, NULL)); 4956 } 4957 4958 int 4959 freebsd10_freebsd32__umtx_unlock(struct thread *td, 4960 struct freebsd10_freebsd32__umtx_unlock_args *uap) 4961 { 4962 return (do_unlock_umtx32(td, (uint32_t *)uap->umtx, td->td_tid)); 4963 } 4964 #endif /* COMPAT_FREEBSD10 */ 4965 4966 int 4967 freebsd32__umtx_op(struct thread *td, struct freebsd32__umtx_op_args *uap) 4968 { 4969 4970 return (kern__umtx_op(td, uap->obj, uap->op, uap->val, uap->uaddr1, 4971 uap->uaddr2, &umtx_native_ops32)); 4972 } 4973 #endif /* COMPAT_FREEBSD32 */ 4974 4975 void 4976 umtx_thread_init(struct thread *td) 4977 { 4978 4979 td->td_umtxq = umtxq_alloc(); 4980 td->td_umtxq->uq_thread = td; 4981 } 4982 4983 void 4984 umtx_thread_fini(struct thread *td) 4985 { 4986 4987 umtxq_free(td->td_umtxq); 4988 } 4989 4990 /* 4991 * It will be called when new thread is created, e.g fork(). 4992 */ 4993 void 4994 umtx_thread_alloc(struct thread *td) 4995 { 4996 struct umtx_q *uq; 4997 4998 uq = td->td_umtxq; 4999 uq->uq_inherited_pri = PRI_MAX; 5000 5001 KASSERT(uq->uq_flags == 0, ("uq_flags != 0")); 5002 KASSERT(uq->uq_thread == td, ("uq_thread != td")); 5003 KASSERT(uq->uq_pi_blocked == NULL, ("uq_pi_blocked != NULL")); 5004 KASSERT(TAILQ_EMPTY(&uq->uq_pi_contested), ("uq_pi_contested is not empty")); 5005 } 5006 5007 /* 5008 * exec() hook. 5009 * 5010 * Clear robust lists for all process' threads, not delaying the 5011 * cleanup to thread exit, since the relevant address space is 5012 * destroyed right now. 5013 */ 5014 void 5015 umtx_exec(struct proc *p) 5016 { 5017 struct thread *td; 5018 5019 KASSERT(p == curproc, ("need curproc")); 5020 KASSERT((p->p_flag & P_HADTHREADS) == 0 || 5021 (p->p_flag & P_STOPPED_SINGLE) != 0, 5022 ("curproc must be single-threaded")); 5023 /* 5024 * There is no need to lock the list as only this thread can be 5025 * running. 5026 */ 5027 FOREACH_THREAD_IN_PROC(p, td) { 5028 KASSERT(td == curthread || 5029 ((td->td_flags & TDF_BOUNDARY) != 0 && TD_IS_SUSPENDED(td)), 5030 ("running thread %p %p", p, td)); 5031 umtx_thread_cleanup(td); 5032 td->td_rb_list = td->td_rbp_list = td->td_rb_inact = 0; 5033 } 5034 5035 p->p_umtx_min_timeout = 0; 5036 } 5037 5038 /* 5039 * thread exit hook. 5040 */ 5041 void 5042 umtx_thread_exit(struct thread *td) 5043 { 5044 5045 umtx_thread_cleanup(td); 5046 } 5047 5048 static int 5049 umtx_read_uptr(struct thread *td, uintptr_t ptr, uintptr_t *res, bool compat32) 5050 { 5051 u_long res1; 5052 uint32_t res32; 5053 int error; 5054 5055 if (compat32) { 5056 error = fueword32((void *)ptr, &res32); 5057 if (error == 0) 5058 res1 = res32; 5059 } else { 5060 error = fueword((void *)ptr, &res1); 5061 } 5062 if (error == 0) 5063 *res = res1; 5064 else 5065 error = EFAULT; 5066 return (error); 5067 } 5068 5069 static void 5070 umtx_read_rb_list(struct thread *td, struct umutex *m, uintptr_t *rb_list, 5071 bool compat32) 5072 { 5073 struct umutex32 m32; 5074 5075 if (compat32) { 5076 memcpy(&m32, m, sizeof(m32)); 5077 *rb_list = m32.m_rb_lnk; 5078 } else { 5079 *rb_list = m->m_rb_lnk; 5080 } 5081 } 5082 5083 static int 5084 umtx_handle_rb(struct thread *td, uintptr_t rbp, uintptr_t *rb_list, bool inact, 5085 bool compat32) 5086 { 5087 struct umutex m; 5088 int error; 5089 5090 KASSERT(td->td_proc == curproc, ("need current vmspace")); 5091 error = copyin((void *)rbp, &m, sizeof(m)); 5092 if (error != 0) 5093 return (error); 5094 if (rb_list != NULL) 5095 umtx_read_rb_list(td, &m, rb_list, compat32); 5096 if ((m.m_flags & UMUTEX_ROBUST) == 0) 5097 return (EINVAL); 5098 if ((m.m_owner & ~UMUTEX_CONTESTED) != td->td_tid) 5099 /* inact is cleared after unlock, allow the inconsistency */ 5100 return (inact ? 0 : EINVAL); 5101 return (do_unlock_umutex(td, (struct umutex *)rbp, true)); 5102 } 5103 5104 static void 5105 umtx_cleanup_rb_list(struct thread *td, uintptr_t rb_list, uintptr_t *rb_inact, 5106 const char *name, bool compat32) 5107 { 5108 int error, i; 5109 uintptr_t rbp; 5110 bool inact; 5111 5112 if (rb_list == 0) 5113 return; 5114 error = umtx_read_uptr(td, rb_list, &rbp, compat32); 5115 for (i = 0; error == 0 && rbp != 0 && i < umtx_max_rb; i++) { 5116 if (rbp == *rb_inact) { 5117 inact = true; 5118 *rb_inact = 0; 5119 } else 5120 inact = false; 5121 error = umtx_handle_rb(td, rbp, &rbp, inact, compat32); 5122 } 5123 if (i == umtx_max_rb && umtx_verbose_rb) { 5124 uprintf("comm %s pid %d: reached umtx %smax rb %d\n", 5125 td->td_proc->p_comm, td->td_proc->p_pid, name, umtx_max_rb); 5126 } 5127 if (error != 0 && umtx_verbose_rb) { 5128 uprintf("comm %s pid %d: handling %srb error %d\n", 5129 td->td_proc->p_comm, td->td_proc->p_pid, name, error); 5130 } 5131 } 5132 5133 /* 5134 * Clean up umtx data. 5135 */ 5136 static void 5137 umtx_thread_cleanup(struct thread *td) 5138 { 5139 struct umtx_q *uq; 5140 struct umtx_pi *pi; 5141 uintptr_t rb_inact; 5142 bool compat32; 5143 5144 /* 5145 * Disown pi mutexes. 5146 */ 5147 uq = td->td_umtxq; 5148 if (uq != NULL) { 5149 if (uq->uq_inherited_pri != PRI_MAX || 5150 !TAILQ_EMPTY(&uq->uq_pi_contested)) { 5151 mtx_lock(&umtx_lock); 5152 uq->uq_inherited_pri = PRI_MAX; 5153 while ((pi = TAILQ_FIRST(&uq->uq_pi_contested)) != NULL) { 5154 pi->pi_owner = NULL; 5155 TAILQ_REMOVE(&uq->uq_pi_contested, pi, pi_link); 5156 } 5157 mtx_unlock(&umtx_lock); 5158 } 5159 sched_lend_user_prio_cond(td, PRI_MAX); 5160 } 5161 5162 compat32 = (td->td_pflags2 & TDP2_COMPAT32RB) != 0; 5163 td->td_pflags2 &= ~TDP2_COMPAT32RB; 5164 5165 if (td->td_rb_inact == 0 && td->td_rb_list == 0 && td->td_rbp_list == 0) 5166 return; 5167 5168 /* 5169 * Handle terminated robust mutexes. Must be done after 5170 * robust pi disown, otherwise unlock could see unowned 5171 * entries. 5172 */ 5173 rb_inact = td->td_rb_inact; 5174 if (rb_inact != 0) 5175 (void)umtx_read_uptr(td, rb_inact, &rb_inact, compat32); 5176 umtx_cleanup_rb_list(td, td->td_rb_list, &rb_inact, "", compat32); 5177 umtx_cleanup_rb_list(td, td->td_rbp_list, &rb_inact, "priv ", compat32); 5178 if (rb_inact != 0) 5179 (void)umtx_handle_rb(td, rb_inact, NULL, true, compat32); 5180 } 5181