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/uma.h>
71 #include <vm/vm_map.h>
72 #include <vm/vm_object.h>
73
74 #include <machine/atomic.h>
75 #include <machine/cpu.h>
76
77 #include <compat/freebsd32/freebsd32.h>
78 #ifdef COMPAT_FREEBSD32
79 #include <compat/freebsd32/freebsd32_proto.h>
80 #endif
81
82 #define _UMUTEX_TRY 1
83 #define _UMUTEX_WAIT 2
84
85 #ifdef UMTX_PROFILING
86 #define UPROF_PERC_BIGGER(w, f, sw, sf) \
87 (((w) > (sw)) || ((w) == (sw) && (f) > (sf)))
88 #endif
89
90 #define UMTXQ_LOCKED_ASSERT(uc) mtx_assert(&(uc)->uc_lock, MA_OWNED)
91 #ifdef INVARIANTS
92 #define UMTXQ_ASSERT_LOCKED_BUSY(key) do { \
93 struct umtxq_chain *uc; \
94 \
95 uc = umtxq_getchain(key); \
96 mtx_assert(&uc->uc_lock, MA_OWNED); \
97 KASSERT(uc->uc_busy != 0, ("umtx chain is not busy")); \
98 } while (0)
99 #else
100 #define UMTXQ_ASSERT_LOCKED_BUSY(key) do {} while (0)
101 #endif
102
103 /*
104 * Don't propagate time-sharing priority, there is a security reason,
105 * a user can simply introduce PI-mutex, let thread A lock the mutex,
106 * and let another thread B block on the mutex, because B is
107 * sleeping, its priority will be boosted, this causes A's priority to
108 * be boosted via priority propagating too and will never be lowered even
109 * if it is using 100%CPU, this is unfair to other processes.
110 */
111
112 #define UPRI(td) (((td)->td_user_pri >= PRI_MIN_TIMESHARE &&\
113 (td)->td_user_pri <= PRI_MAX_TIMESHARE) ?\
114 PRI_MAX_TIMESHARE : (td)->td_user_pri)
115
116 #define GOLDEN_RATIO_PRIME 2654404609U
117 #ifndef UMTX_CHAINS
118 #define UMTX_CHAINS 512
119 #endif
120 #define UMTX_SHIFTS (__WORD_BIT - 9)
121
122 #define GET_SHARE(flags) \
123 (((flags) & USYNC_PROCESS_SHARED) == 0 ? THREAD_SHARE : PROCESS_SHARE)
124
125 #define BUSY_SPINS 200
126
127 struct umtx_copyops {
128 int (*copyin_timeout)(const void *uaddr, struct timespec *tsp);
129 int (*copyin_umtx_time)(const void *uaddr, size_t size,
130 struct _umtx_time *tp);
131 int (*copyin_robust_lists)(const void *uaddr, size_t size,
132 struct umtx_robust_lists_params *rbp);
133 int (*copyout_timeout)(void *uaddr, size_t size,
134 struct timespec *tsp);
135 const size_t timespec_sz;
136 const size_t umtx_time_sz;
137 const bool compat32;
138 };
139
140 _Static_assert(sizeof(struct umutex) == sizeof(struct umutex32), "umutex32");
141 _Static_assert(__offsetof(struct umutex, m_spare[0]) ==
142 __offsetof(struct umutex32, m_spare[0]), "m_spare32");
143
144 int umtx_shm_vnobj_persistent = 0;
145 SYSCTL_INT(_kern_ipc, OID_AUTO, umtx_vnode_persistent, CTLFLAG_RWTUN,
146 &umtx_shm_vnobj_persistent, 0,
147 "False forces destruction of umtx attached to file, on last close");
148 static int umtx_max_rb = 1000;
149 SYSCTL_INT(_kern_ipc, OID_AUTO, umtx_max_robust, CTLFLAG_RWTUN,
150 &umtx_max_rb, 0,
151 "Maximum number of robust mutexes allowed for each thread");
152
153 static uma_zone_t umtx_pi_zone;
154 static struct umtxq_chain umtxq_chains[2][UMTX_CHAINS];
155 static MALLOC_DEFINE(M_UMTX, "umtx", "UMTX queue memory");
156 static int umtx_pi_allocated;
157
158 static SYSCTL_NODE(_debug, OID_AUTO, umtx, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
159 "umtx debug");
160 SYSCTL_INT(_debug_umtx, OID_AUTO, umtx_pi_allocated, CTLFLAG_RD,
161 &umtx_pi_allocated, 0, "Allocated umtx_pi");
162 static int umtx_verbose_rb = 1;
163 SYSCTL_INT(_debug_umtx, OID_AUTO, robust_faults_verbose, CTLFLAG_RWTUN,
164 &umtx_verbose_rb, 0,
165 "");
166
167 #ifdef UMTX_PROFILING
168 static long max_length;
169 SYSCTL_LONG(_debug_umtx, OID_AUTO, max_length, CTLFLAG_RD, &max_length, 0, "max_length");
170 static SYSCTL_NODE(_debug_umtx, OID_AUTO, chains, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
171 "umtx chain stats");
172 #endif
173
174 static inline void umtx_abs_timeout_init2(struct umtx_abs_timeout *timo,
175 const struct _umtx_time *umtxtime);
176
177 static void umtx_shm_init(void);
178 static void umtxq_sysinit(void *);
179 static void umtxq_hash(struct umtx_key *key);
180 static int do_unlock_pp(struct thread *td, struct umutex *m, uint32_t flags,
181 bool rb);
182 static void umtx_thread_cleanup(struct thread *td);
183 SYSINIT(umtx, SI_SUB_EVENTHANDLER+1, SI_ORDER_MIDDLE, umtxq_sysinit, NULL);
184
185 #define umtxq_signal(key, nwake) umtxq_signal_queue((key), (nwake), UMTX_SHARED_QUEUE)
186
187 static struct mtx umtx_lock;
188
189 #ifdef UMTX_PROFILING
190 static void
umtx_init_profiling(void)191 umtx_init_profiling(void)
192 {
193 struct sysctl_oid *chain_oid;
194 char chain_name[10];
195 int i;
196
197 for (i = 0; i < UMTX_CHAINS; ++i) {
198 snprintf(chain_name, sizeof(chain_name), "%d", i);
199 chain_oid = SYSCTL_ADD_NODE(NULL,
200 SYSCTL_STATIC_CHILDREN(_debug_umtx_chains), OID_AUTO,
201 chain_name, CTLFLAG_RD | CTLFLAG_MPSAFE, NULL,
202 "umtx hash stats");
203 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO,
204 "max_length0", CTLFLAG_RD, &umtxq_chains[0][i].max_length, 0, NULL);
205 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO,
206 "max_length1", CTLFLAG_RD, &umtxq_chains[1][i].max_length, 0, NULL);
207 }
208 }
209
210 static int
sysctl_debug_umtx_chains_peaks(SYSCTL_HANDLER_ARGS)211 sysctl_debug_umtx_chains_peaks(SYSCTL_HANDLER_ARGS)
212 {
213 char buf[512];
214 struct sbuf sb;
215 struct umtxq_chain *uc;
216 u_int fract, i, j, tot, whole;
217 u_int sf0, sf1, sf2, sf3, sf4;
218 u_int si0, si1, si2, si3, si4;
219 u_int sw0, sw1, sw2, sw3, sw4;
220
221 sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN);
222 for (i = 0; i < 2; i++) {
223 tot = 0;
224 for (j = 0; j < UMTX_CHAINS; ++j) {
225 uc = &umtxq_chains[i][j];
226 mtx_lock(&uc->uc_lock);
227 tot += uc->max_length;
228 mtx_unlock(&uc->uc_lock);
229 }
230 if (tot == 0)
231 sbuf_printf(&sb, "%u) Empty ", i);
232 else {
233 sf0 = sf1 = sf2 = sf3 = sf4 = 0;
234 si0 = si1 = si2 = si3 = si4 = 0;
235 sw0 = sw1 = sw2 = sw3 = sw4 = 0;
236 for (j = 0; j < UMTX_CHAINS; j++) {
237 uc = &umtxq_chains[i][j];
238 mtx_lock(&uc->uc_lock);
239 whole = uc->max_length * 100;
240 mtx_unlock(&uc->uc_lock);
241 fract = (whole % tot) * 100;
242 if (UPROF_PERC_BIGGER(whole, fract, sw0, sf0)) {
243 sf0 = fract;
244 si0 = j;
245 sw0 = whole;
246 } else if (UPROF_PERC_BIGGER(whole, fract, sw1,
247 sf1)) {
248 sf1 = fract;
249 si1 = j;
250 sw1 = whole;
251 } else if (UPROF_PERC_BIGGER(whole, fract, sw2,
252 sf2)) {
253 sf2 = fract;
254 si2 = j;
255 sw2 = whole;
256 } else if (UPROF_PERC_BIGGER(whole, fract, sw3,
257 sf3)) {
258 sf3 = fract;
259 si3 = j;
260 sw3 = whole;
261 } else if (UPROF_PERC_BIGGER(whole, fract, sw4,
262 sf4)) {
263 sf4 = fract;
264 si4 = j;
265 sw4 = whole;
266 }
267 }
268 sbuf_printf(&sb, "queue %u:\n", i);
269 sbuf_printf(&sb, "1st: %u.%u%% idx: %u\n", sw0 / tot,
270 sf0 / tot, si0);
271 sbuf_printf(&sb, "2nd: %u.%u%% idx: %u\n", sw1 / tot,
272 sf1 / tot, si1);
273 sbuf_printf(&sb, "3rd: %u.%u%% idx: %u\n", sw2 / tot,
274 sf2 / tot, si2);
275 sbuf_printf(&sb, "4th: %u.%u%% idx: %u\n", sw3 / tot,
276 sf3 / tot, si3);
277 sbuf_printf(&sb, "5th: %u.%u%% idx: %u\n", sw4 / tot,
278 sf4 / tot, si4);
279 }
280 }
281 sbuf_trim(&sb);
282 sbuf_finish(&sb);
283 sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
284 sbuf_delete(&sb);
285 return (0);
286 }
287
288 static int
sysctl_debug_umtx_chains_clear(SYSCTL_HANDLER_ARGS)289 sysctl_debug_umtx_chains_clear(SYSCTL_HANDLER_ARGS)
290 {
291 struct umtxq_chain *uc;
292 u_int i, j;
293 int clear, error;
294
295 clear = 0;
296 error = sysctl_handle_int(oidp, &clear, 0, req);
297 if (error != 0 || req->newptr == NULL)
298 return (error);
299
300 if (clear != 0) {
301 for (i = 0; i < 2; ++i) {
302 for (j = 0; j < UMTX_CHAINS; ++j) {
303 uc = &umtxq_chains[i][j];
304 mtx_lock(&uc->uc_lock);
305 uc->length = 0;
306 uc->max_length = 0;
307 mtx_unlock(&uc->uc_lock);
308 }
309 }
310 }
311 return (0);
312 }
313
314 SYSCTL_PROC(_debug_umtx_chains, OID_AUTO, clear,
315 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0,
316 sysctl_debug_umtx_chains_clear, "I",
317 "Clear umtx chains statistics");
318 SYSCTL_PROC(_debug_umtx_chains, OID_AUTO, peaks,
319 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0,
320 sysctl_debug_umtx_chains_peaks, "A",
321 "Highest peaks in chains max length");
322 #endif
323
324 static void
umtxq_sysinit(void * arg __unused)325 umtxq_sysinit(void *arg __unused)
326 {
327 int i, j;
328
329 umtx_pi_zone = uma_zcreate("umtx pi", sizeof(struct umtx_pi),
330 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
331 for (i = 0; i < 2; ++i) {
332 for (j = 0; j < UMTX_CHAINS; ++j) {
333 mtx_init(&umtxq_chains[i][j].uc_lock, "umtxql", NULL,
334 MTX_DEF | MTX_DUPOK);
335 LIST_INIT(&umtxq_chains[i][j].uc_queue[0]);
336 LIST_INIT(&umtxq_chains[i][j].uc_queue[1]);
337 LIST_INIT(&umtxq_chains[i][j].uc_spare_queue);
338 TAILQ_INIT(&umtxq_chains[i][j].uc_pi_list);
339 umtxq_chains[i][j].uc_busy = 0;
340 umtxq_chains[i][j].uc_waiters = 0;
341 #ifdef UMTX_PROFILING
342 umtxq_chains[i][j].length = 0;
343 umtxq_chains[i][j].max_length = 0;
344 #endif
345 }
346 }
347 #ifdef UMTX_PROFILING
348 umtx_init_profiling();
349 #endif
350 mtx_init(&umtx_lock, "umtx lock", NULL, MTX_DEF);
351 umtx_shm_init();
352 }
353
354 struct umtx_q *
umtxq_alloc(void)355 umtxq_alloc(void)
356 {
357 struct umtx_q *uq;
358
359 uq = malloc(sizeof(struct umtx_q), M_UMTX, M_WAITOK | M_ZERO);
360 uq->uq_spare_queue = malloc(sizeof(struct umtxq_queue), M_UMTX,
361 M_WAITOK | M_ZERO);
362 TAILQ_INIT(&uq->uq_spare_queue->head);
363 TAILQ_INIT(&uq->uq_pi_contested);
364 uq->uq_inherited_pri = PRI_MAX;
365 return (uq);
366 }
367
368 void
umtxq_free(struct umtx_q * uq)369 umtxq_free(struct umtx_q *uq)
370 {
371
372 MPASS(uq->uq_spare_queue != NULL);
373 free(uq->uq_spare_queue, M_UMTX);
374 free(uq, M_UMTX);
375 }
376
377 static inline void
umtxq_hash(struct umtx_key * key)378 umtxq_hash(struct umtx_key *key)
379 {
380 unsigned n;
381
382 n = (uintptr_t)key->info.both.a + key->info.both.b;
383 key->hash = ((n * GOLDEN_RATIO_PRIME) >> UMTX_SHIFTS) % UMTX_CHAINS;
384 }
385
386 struct umtxq_chain *
umtxq_getchain(struct umtx_key * key)387 umtxq_getchain(struct umtx_key *key)
388 {
389
390 if (key->type <= TYPE_SEM)
391 return (&umtxq_chains[1][key->hash]);
392 return (&umtxq_chains[0][key->hash]);
393 }
394
395 /*
396 * Set chain to busy state when following operation
397 * may be blocked (kernel mutex can not be used).
398 */
399 void
umtxq_busy(struct umtx_key * key)400 umtxq_busy(struct umtx_key *key)
401 {
402 struct umtxq_chain *uc;
403
404 uc = umtxq_getchain(key);
405 mtx_assert(&uc->uc_lock, MA_OWNED);
406 if (uc->uc_busy) {
407 #ifdef SMP
408 if (smp_cpus > 1) {
409 int count = BUSY_SPINS;
410 if (count > 0) {
411 umtxq_unlock(key);
412 while (uc->uc_busy && --count > 0)
413 cpu_spinwait();
414 umtxq_lock(key);
415 }
416 }
417 #endif
418 while (uc->uc_busy) {
419 uc->uc_waiters++;
420 msleep(uc, &uc->uc_lock, 0, "umtxqb", 0);
421 uc->uc_waiters--;
422 }
423 }
424 uc->uc_busy = 1;
425 }
426
427 /*
428 * Unbusy a chain.
429 */
430 void
umtxq_unbusy(struct umtx_key * key)431 umtxq_unbusy(struct umtx_key *key)
432 {
433 struct umtxq_chain *uc;
434
435 uc = umtxq_getchain(key);
436 mtx_assert(&uc->uc_lock, MA_OWNED);
437 KASSERT(uc->uc_busy != 0, ("not busy"));
438 uc->uc_busy = 0;
439 if (uc->uc_waiters)
440 wakeup_one(uc);
441 }
442
443 void
umtxq_unbusy_unlocked(struct umtx_key * key)444 umtxq_unbusy_unlocked(struct umtx_key *key)
445 {
446
447 umtxq_lock(key);
448 umtxq_unbusy(key);
449 umtxq_unlock(key);
450 }
451
452 static struct umtxq_queue *
umtxq_queue_lookup(struct umtx_key * key,int q)453 umtxq_queue_lookup(struct umtx_key *key, int q)
454 {
455 struct umtxq_queue *uh;
456 struct umtxq_chain *uc;
457
458 uc = umtxq_getchain(key);
459 UMTXQ_LOCKED_ASSERT(uc);
460 LIST_FOREACH(uh, &uc->uc_queue[q], link) {
461 if (umtx_key_match(&uh->key, key))
462 return (uh);
463 }
464
465 return (NULL);
466 }
467
468 void
umtxq_insert_queue(struct umtx_q * uq,int q)469 umtxq_insert_queue(struct umtx_q *uq, int q)
470 {
471 struct umtxq_queue *uh;
472 struct umtxq_chain *uc;
473
474 uc = umtxq_getchain(&uq->uq_key);
475 UMTXQ_LOCKED_ASSERT(uc);
476 KASSERT((uq->uq_flags & UQF_UMTXQ) == 0, ("umtx_q is already on queue"));
477 uh = umtxq_queue_lookup(&uq->uq_key, q);
478 if (uh != NULL) {
479 LIST_INSERT_HEAD(&uc->uc_spare_queue, uq->uq_spare_queue, link);
480 } else {
481 uh = uq->uq_spare_queue;
482 uh->key = uq->uq_key;
483 LIST_INSERT_HEAD(&uc->uc_queue[q], uh, link);
484 #ifdef UMTX_PROFILING
485 uc->length++;
486 if (uc->length > uc->max_length) {
487 uc->max_length = uc->length;
488 if (uc->max_length > max_length)
489 max_length = uc->max_length;
490 }
491 #endif
492 }
493 uq->uq_spare_queue = NULL;
494
495 TAILQ_INSERT_TAIL(&uh->head, uq, uq_link);
496 uh->length++;
497 uq->uq_flags |= UQF_UMTXQ;
498 uq->uq_cur_queue = uh;
499 return;
500 }
501
502 void
umtxq_remove_queue(struct umtx_q * uq,int q)503 umtxq_remove_queue(struct umtx_q *uq, int q)
504 {
505 struct umtxq_chain *uc;
506 struct umtxq_queue *uh;
507
508 uc = umtxq_getchain(&uq->uq_key);
509 UMTXQ_LOCKED_ASSERT(uc);
510 if (uq->uq_flags & UQF_UMTXQ) {
511 uh = uq->uq_cur_queue;
512 TAILQ_REMOVE(&uh->head, uq, uq_link);
513 uh->length--;
514 uq->uq_flags &= ~UQF_UMTXQ;
515 if (TAILQ_EMPTY(&uh->head)) {
516 KASSERT(uh->length == 0,
517 ("inconsistent umtxq_queue length"));
518 #ifdef UMTX_PROFILING
519 uc->length--;
520 #endif
521 LIST_REMOVE(uh, link);
522 } else {
523 uh = LIST_FIRST(&uc->uc_spare_queue);
524 KASSERT(uh != NULL, ("uc_spare_queue is empty"));
525 LIST_REMOVE(uh, link);
526 }
527 uq->uq_spare_queue = uh;
528 uq->uq_cur_queue = NULL;
529 }
530 }
531
532 /*
533 * Check if there are multiple waiters
534 */
535 int
umtxq_count(struct umtx_key * key)536 umtxq_count(struct umtx_key *key)
537 {
538 struct umtxq_queue *uh;
539
540 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key));
541 uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE);
542 if (uh != NULL)
543 return (uh->length);
544 return (0);
545 }
546
547 /*
548 * Check if there are multiple PI waiters and returns first
549 * waiter.
550 */
551 static int
umtxq_count_pi(struct umtx_key * key,struct umtx_q ** first)552 umtxq_count_pi(struct umtx_key *key, struct umtx_q **first)
553 {
554 struct umtxq_queue *uh;
555
556 *first = NULL;
557 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key));
558 uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE);
559 if (uh != NULL) {
560 *first = TAILQ_FIRST(&uh->head);
561 return (uh->length);
562 }
563 return (0);
564 }
565
566 /*
567 * Wake up threads waiting on an userland object by a bit mask.
568 */
569 int
umtxq_signal_mask(struct umtx_key * key,int n_wake,u_int bitset)570 umtxq_signal_mask(struct umtx_key *key, int n_wake, u_int bitset)
571 {
572 struct umtxq_queue *uh;
573 struct umtx_q *uq, *uq_temp;
574 int ret;
575
576 ret = 0;
577 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key));
578 uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE);
579 if (uh == NULL)
580 return (0);
581 TAILQ_FOREACH_SAFE(uq, &uh->head, uq_link, uq_temp) {
582 if ((uq->uq_bitset & bitset) == 0)
583 continue;
584 umtxq_remove_queue(uq, UMTX_SHARED_QUEUE);
585 wakeup_one(uq);
586 if (++ret >= n_wake)
587 break;
588 }
589 return (ret);
590 }
591
592 /*
593 * Wake up threads waiting on an userland object.
594 */
595
596 static int
umtxq_signal_queue(struct umtx_key * key,int n_wake,int q)597 umtxq_signal_queue(struct umtx_key *key, int n_wake, int q)
598 {
599 struct umtxq_queue *uh;
600 struct umtx_q *uq;
601 int ret;
602
603 ret = 0;
604 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key));
605 uh = umtxq_queue_lookup(key, q);
606 if (uh != NULL) {
607 while ((uq = TAILQ_FIRST(&uh->head)) != NULL) {
608 umtxq_remove_queue(uq, q);
609 wakeup(uq);
610 if (++ret >= n_wake)
611 return (ret);
612 }
613 }
614 return (ret);
615 }
616
617 /*
618 * Wake up specified thread.
619 */
620 static inline void
umtxq_signal_thread(struct umtx_q * uq)621 umtxq_signal_thread(struct umtx_q *uq)
622 {
623
624 UMTXQ_LOCKED_ASSERT(umtxq_getchain(&uq->uq_key));
625 umtxq_remove(uq);
626 wakeup(uq);
627 }
628
629 /*
630 * Wake up a maximum of n_wake threads that are waiting on an userland
631 * object identified by key. The remaining threads are removed from queue
632 * identified by key and added to the queue identified by key2 (requeued).
633 * The n_requeue specifies an upper limit on the number of threads that
634 * are requeued to the second queue.
635 */
636 int
umtxq_requeue(struct umtx_key * key,int n_wake,struct umtx_key * key2,int n_requeue)637 umtxq_requeue(struct umtx_key *key, int n_wake, struct umtx_key *key2,
638 int n_requeue)
639 {
640 struct umtxq_queue *uh;
641 struct umtx_q *uq, *uq_temp;
642 int ret;
643
644 ret = 0;
645 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key));
646 UMTXQ_LOCKED_ASSERT(umtxq_getchain(key2));
647 uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE);
648 if (uh == NULL)
649 return (0);
650 TAILQ_FOREACH_SAFE(uq, &uh->head, uq_link, uq_temp) {
651 if (++ret <= n_wake) {
652 umtxq_remove(uq);
653 wakeup_one(uq);
654 } else {
655 umtxq_remove(uq);
656 uq->uq_key = *key2;
657 umtxq_insert(uq);
658 if (ret - n_wake == n_requeue)
659 break;
660 }
661 }
662 return (ret);
663 }
664
665 static inline int
tstohz(const struct timespec * tsp)666 tstohz(const struct timespec *tsp)
667 {
668 struct timeval tv;
669
670 TIMESPEC_TO_TIMEVAL(&tv, tsp);
671 return tvtohz(&tv);
672 }
673
674 void
umtx_abs_timeout_init(struct umtx_abs_timeout * timo,int clockid,int absolute,const struct timespec * timeout)675 umtx_abs_timeout_init(struct umtx_abs_timeout *timo, int clockid,
676 int absolute, const struct timespec *timeout)
677 {
678
679 timo->clockid = clockid;
680 if (!absolute) {
681 timo->is_abs_real = false;
682 kern_clock_gettime(curthread, timo->clockid, &timo->cur);
683 timespecadd(&timo->cur, timeout, &timo->end);
684 } else {
685 timo->end = *timeout;
686 timo->is_abs_real = clockid == CLOCK_REALTIME ||
687 clockid == CLOCK_REALTIME_FAST ||
688 clockid == CLOCK_REALTIME_PRECISE ||
689 clockid == CLOCK_SECOND;
690 }
691 }
692
693 static void
umtx_abs_timeout_init2(struct umtx_abs_timeout * timo,const struct _umtx_time * umtxtime)694 umtx_abs_timeout_init2(struct umtx_abs_timeout *timo,
695 const struct _umtx_time *umtxtime)
696 {
697
698 umtx_abs_timeout_init(timo, umtxtime->_clockid,
699 (umtxtime->_flags & UMTX_ABSTIME) != 0, &umtxtime->_timeout);
700 }
701
702 static void
umtx_abs_timeout_enforce_min(sbintime_t * sbt)703 umtx_abs_timeout_enforce_min(sbintime_t *sbt)
704 {
705 sbintime_t when, mint;
706
707 mint = curproc->p_umtx_min_timeout;
708 if (__predict_false(mint != 0)) {
709 when = sbinuptime() + mint;
710 if (*sbt < when)
711 *sbt = when;
712 }
713 }
714
715 static int
umtx_abs_timeout_getsbt(struct umtx_abs_timeout * timo,sbintime_t * sbt,int * flags)716 umtx_abs_timeout_getsbt(struct umtx_abs_timeout *timo, sbintime_t *sbt,
717 int *flags)
718 {
719 struct bintime bt, bbt;
720 struct timespec tts;
721 sbintime_t rem;
722
723 switch (timo->clockid) {
724
725 /* Clocks that can be converted into absolute time. */
726 case CLOCK_REALTIME:
727 case CLOCK_REALTIME_PRECISE:
728 case CLOCK_REALTIME_FAST:
729 case CLOCK_MONOTONIC:
730 case CLOCK_MONOTONIC_PRECISE:
731 case CLOCK_MONOTONIC_FAST:
732 case CLOCK_UPTIME:
733 case CLOCK_UPTIME_PRECISE:
734 case CLOCK_UPTIME_FAST:
735 case CLOCK_SECOND:
736 timespec2bintime(&timo->end, &bt);
737 switch (timo->clockid) {
738 case CLOCK_REALTIME:
739 case CLOCK_REALTIME_PRECISE:
740 case CLOCK_REALTIME_FAST:
741 case CLOCK_SECOND:
742 getboottimebin(&bbt);
743 bintime_sub(&bt, &bbt);
744 break;
745 }
746 if (bt.sec < 0)
747 return (ETIMEDOUT);
748 if (bt.sec >= (SBT_MAX >> 32)) {
749 *sbt = 0;
750 *flags = 0;
751 return (0);
752 }
753 *sbt = bttosbt(bt);
754 umtx_abs_timeout_enforce_min(sbt);
755
756 /*
757 * Check if the absolute time should be aligned to
758 * avoid firing multiple timer events in non-periodic
759 * timer mode.
760 */
761 switch (timo->clockid) {
762 case CLOCK_REALTIME_FAST:
763 case CLOCK_MONOTONIC_FAST:
764 case CLOCK_UPTIME_FAST:
765 rem = *sbt % tc_tick_sbt;
766 if (__predict_true(rem != 0))
767 *sbt += tc_tick_sbt - rem;
768 break;
769 case CLOCK_SECOND:
770 rem = *sbt % SBT_1S;
771 if (__predict_true(rem != 0))
772 *sbt += SBT_1S - rem;
773 break;
774 }
775 *flags = C_ABSOLUTE;
776 return (0);
777
778 /* Clocks that has to be periodically polled. */
779 case CLOCK_VIRTUAL:
780 case CLOCK_PROF:
781 case CLOCK_THREAD_CPUTIME_ID:
782 case CLOCK_PROCESS_CPUTIME_ID:
783 default:
784 kern_clock_gettime(curthread, timo->clockid, &timo->cur);
785 if (timespeccmp(&timo->end, &timo->cur, <=))
786 return (ETIMEDOUT);
787 timespecsub(&timo->end, &timo->cur, &tts);
788 *sbt = tick_sbt * tstohz(&tts);
789 *flags = C_HARDCLOCK;
790 return (0);
791 }
792 }
793
794 static uint32_t
umtx_unlock_val(uint32_t flags,bool rb)795 umtx_unlock_val(uint32_t flags, bool rb)
796 {
797
798 if (rb)
799 return (UMUTEX_RB_OWNERDEAD);
800 else if ((flags & UMUTEX_NONCONSISTENT) != 0)
801 return (UMUTEX_RB_NOTRECOV);
802 else
803 return (UMUTEX_UNOWNED);
804
805 }
806
807 /*
808 * Put thread into sleep state, before sleeping, check if
809 * thread was removed from umtx queue.
810 */
811 int
umtxq_sleep(struct umtx_q * uq,const char * wmesg,struct umtx_abs_timeout * timo)812 umtxq_sleep(struct umtx_q *uq, const char *wmesg,
813 struct umtx_abs_timeout *timo)
814 {
815 struct umtxq_chain *uc;
816 sbintime_t sbt = 0;
817 int error, flags = 0;
818
819 uc = umtxq_getchain(&uq->uq_key);
820 UMTXQ_LOCKED_ASSERT(uc);
821 for (;;) {
822 if (!(uq->uq_flags & UQF_UMTXQ)) {
823 error = 0;
824 break;
825 }
826 if (timo != NULL) {
827 if (timo->is_abs_real)
828 curthread->td_rtcgen =
829 atomic_load_acq_int(&rtc_generation);
830 error = umtx_abs_timeout_getsbt(timo, &sbt, &flags);
831 if (error != 0)
832 break;
833 }
834 error = msleep_sbt(uq, &uc->uc_lock, PCATCH | PDROP, wmesg,
835 sbt, 0, flags);
836 uc = umtxq_getchain(&uq->uq_key);
837 mtx_lock(&uc->uc_lock);
838 if (error == EINTR || error == ERESTART)
839 break;
840 if (error == EWOULDBLOCK && (flags & C_ABSOLUTE) != 0) {
841 error = ETIMEDOUT;
842 break;
843 }
844 }
845
846 curthread->td_rtcgen = 0;
847 return (error);
848 }
849
850 /*
851 * Convert userspace address into unique logical address.
852 */
853 int
umtx_key_get(const void * addr,int type,int share,struct umtx_key * key)854 umtx_key_get(const void *addr, int type, int share, struct umtx_key *key)
855 {
856 struct thread *td = curthread;
857 vm_map_t map;
858 vm_map_entry_t entry;
859 vm_pindex_t pindex;
860 vm_prot_t prot;
861 boolean_t wired;
862
863 key->type = type;
864 if (share == THREAD_SHARE) {
865 key->shared = 0;
866 key->info.private.vs = td->td_proc->p_vmspace;
867 key->info.private.addr = (uintptr_t)addr;
868 } else {
869 MPASS(share == PROCESS_SHARE || share == AUTO_SHARE);
870 map = &td->td_proc->p_vmspace->vm_map;
871 if (vm_map_lookup(&map, (vm_offset_t)addr, VM_PROT_WRITE,
872 &entry, &key->info.shared.object, &pindex, &prot,
873 &wired) != KERN_SUCCESS) {
874 return (EFAULT);
875 }
876
877 if ((share == PROCESS_SHARE) ||
878 (share == AUTO_SHARE &&
879 VM_INHERIT_SHARE == entry->inheritance)) {
880 key->shared = 1;
881 key->info.shared.offset = (vm_offset_t)addr -
882 entry->start + entry->offset;
883 vm_object_reference(key->info.shared.object);
884 } else {
885 key->shared = 0;
886 key->info.private.vs = td->td_proc->p_vmspace;
887 key->info.private.addr = (uintptr_t)addr;
888 }
889 vm_map_lookup_done(map, entry);
890 }
891
892 umtxq_hash(key);
893 return (0);
894 }
895
896 /*
897 * Release key.
898 */
899 void
umtx_key_release(struct umtx_key * key)900 umtx_key_release(struct umtx_key *key)
901 {
902 if (key->shared)
903 vm_object_deallocate(key->info.shared.object);
904 }
905
906 #ifdef COMPAT_FREEBSD10
907 /*
908 * Lock a umtx object.
909 */
910 static int
do_lock_umtx(struct thread * td,struct umtx * umtx,u_long id,const struct timespec * timeout)911 do_lock_umtx(struct thread *td, struct umtx *umtx, u_long id,
912 const struct timespec *timeout)
913 {
914 struct umtx_abs_timeout timo;
915 struct umtx_q *uq;
916 u_long owner;
917 u_long old;
918 int error = 0;
919
920 uq = td->td_umtxq;
921 if (timeout != NULL)
922 umtx_abs_timeout_init(&timo, CLOCK_REALTIME, 0, timeout);
923
924 /*
925 * Care must be exercised when dealing with umtx structure. It
926 * can fault on any access.
927 */
928 for (;;) {
929 /*
930 * Try the uncontested case. This should be done in userland.
931 */
932 owner = casuword(&umtx->u_owner, UMTX_UNOWNED, id);
933
934 /* The acquire succeeded. */
935 if (owner == UMTX_UNOWNED)
936 return (0);
937
938 /* The address was invalid. */
939 if (owner == -1)
940 return (EFAULT);
941
942 /* If no one owns it but it is contested try to acquire it. */
943 if (owner == UMTX_CONTESTED) {
944 owner = casuword(&umtx->u_owner,
945 UMTX_CONTESTED, id | UMTX_CONTESTED);
946
947 if (owner == UMTX_CONTESTED)
948 return (0);
949
950 /* The address was invalid. */
951 if (owner == -1)
952 return (EFAULT);
953
954 error = thread_check_susp(td, false);
955 if (error != 0)
956 break;
957
958 /* If this failed the lock has changed, restart. */
959 continue;
960 }
961
962 /*
963 * If we caught a signal, we have retried and now
964 * exit immediately.
965 */
966 if (error != 0)
967 break;
968
969 if ((error = umtx_key_get(umtx, TYPE_SIMPLE_LOCK,
970 AUTO_SHARE, &uq->uq_key)) != 0)
971 return (error);
972
973 umtxq_lock(&uq->uq_key);
974 umtxq_busy(&uq->uq_key);
975 umtxq_insert(uq);
976 umtxq_unbusy(&uq->uq_key);
977 umtxq_unlock(&uq->uq_key);
978
979 /*
980 * Set the contested bit so that a release in user space
981 * knows to use the system call for unlock. If this fails
982 * either some one else has acquired the lock or it has been
983 * released.
984 */
985 old = casuword(&umtx->u_owner, owner, owner | UMTX_CONTESTED);
986
987 /* The address was invalid. */
988 if (old == -1) {
989 umtxq_lock(&uq->uq_key);
990 umtxq_remove(uq);
991 umtxq_unlock(&uq->uq_key);
992 umtx_key_release(&uq->uq_key);
993 return (EFAULT);
994 }
995
996 /*
997 * We set the contested bit, sleep. Otherwise the lock changed
998 * and we need to retry or we lost a race to the thread
999 * unlocking the umtx.
1000 */
1001 umtxq_lock(&uq->uq_key);
1002 if (old == owner)
1003 error = umtxq_sleep(uq, "umtx", timeout == NULL ? NULL :
1004 &timo);
1005 umtxq_remove(uq);
1006 umtxq_unlock(&uq->uq_key);
1007 umtx_key_release(&uq->uq_key);
1008
1009 if (error == 0)
1010 error = thread_check_susp(td, false);
1011 }
1012
1013 if (timeout == NULL) {
1014 /* Mutex locking is restarted if it is interrupted. */
1015 if (error == EINTR)
1016 error = ERESTART;
1017 } else {
1018 /* Timed-locking is not restarted. */
1019 if (error == ERESTART)
1020 error = EINTR;
1021 }
1022 return (error);
1023 }
1024
1025 /*
1026 * Unlock a umtx object.
1027 */
1028 static int
do_unlock_umtx(struct thread * td,struct umtx * umtx,u_long id)1029 do_unlock_umtx(struct thread *td, struct umtx *umtx, u_long id)
1030 {
1031 struct umtx_key key;
1032 u_long owner;
1033 u_long old;
1034 int error;
1035 int count;
1036
1037 /*
1038 * Make sure we own this mtx.
1039 */
1040 owner = fuword(__DEVOLATILE(u_long *, &umtx->u_owner));
1041 if (owner == -1)
1042 return (EFAULT);
1043
1044 if ((owner & ~UMTX_CONTESTED) != id)
1045 return (EPERM);
1046
1047 /* This should be done in userland */
1048 if ((owner & UMTX_CONTESTED) == 0) {
1049 old = casuword(&umtx->u_owner, owner, UMTX_UNOWNED);
1050 if (old == -1)
1051 return (EFAULT);
1052 if (old == owner)
1053 return (0);
1054 owner = old;
1055 }
1056
1057 /* We should only ever be in here for contested locks */
1058 if ((error = umtx_key_get(umtx, TYPE_SIMPLE_LOCK, AUTO_SHARE,
1059 &key)) != 0)
1060 return (error);
1061
1062 umtxq_lock(&key);
1063 umtxq_busy(&key);
1064 count = umtxq_count(&key);
1065 umtxq_unlock(&key);
1066
1067 /*
1068 * When unlocking the umtx, it must be marked as unowned if
1069 * there is zero or one thread only waiting for it.
1070 * Otherwise, it must be marked as contested.
1071 */
1072 old = casuword(&umtx->u_owner, owner,
1073 count <= 1 ? UMTX_UNOWNED : UMTX_CONTESTED);
1074 umtxq_lock(&key);
1075 umtxq_signal(&key,1);
1076 umtxq_unbusy(&key);
1077 umtxq_unlock(&key);
1078 umtx_key_release(&key);
1079 if (old == -1)
1080 return (EFAULT);
1081 if (old != owner)
1082 return (EINVAL);
1083 return (0);
1084 }
1085
1086 #ifdef COMPAT_FREEBSD32
1087
1088 /*
1089 * Lock a umtx object.
1090 */
1091 static int
do_lock_umtx32(struct thread * td,uint32_t * m,uint32_t id,const struct timespec * timeout)1092 do_lock_umtx32(struct thread *td, uint32_t *m, uint32_t id,
1093 const struct timespec *timeout)
1094 {
1095 struct umtx_abs_timeout timo;
1096 struct umtx_q *uq;
1097 uint32_t owner;
1098 uint32_t old;
1099 int error = 0;
1100
1101 uq = td->td_umtxq;
1102
1103 if (timeout != NULL)
1104 umtx_abs_timeout_init(&timo, CLOCK_REALTIME, 0, timeout);
1105
1106 /*
1107 * Care must be exercised when dealing with umtx structure. It
1108 * can fault on any access.
1109 */
1110 for (;;) {
1111 /*
1112 * Try the uncontested case. This should be done in userland.
1113 */
1114 owner = casuword32(m, UMUTEX_UNOWNED, id);
1115
1116 /* The acquire succeeded. */
1117 if (owner == UMUTEX_UNOWNED)
1118 return (0);
1119
1120 /* The address was invalid. */
1121 if (owner == -1)
1122 return (EFAULT);
1123
1124 /* If no one owns it but it is contested try to acquire it. */
1125 if (owner == UMUTEX_CONTESTED) {
1126 owner = casuword32(m,
1127 UMUTEX_CONTESTED, id | UMUTEX_CONTESTED);
1128 if (owner == UMUTEX_CONTESTED)
1129 return (0);
1130
1131 /* The address was invalid. */
1132 if (owner == -1)
1133 return (EFAULT);
1134
1135 error = thread_check_susp(td, false);
1136 if (error != 0)
1137 break;
1138
1139 /* If this failed the lock has changed, restart. */
1140 continue;
1141 }
1142
1143 /*
1144 * If we caught a signal, we have retried and now
1145 * exit immediately.
1146 */
1147 if (error != 0)
1148 return (error);
1149
1150 if ((error = umtx_key_get(m, TYPE_SIMPLE_LOCK,
1151 AUTO_SHARE, &uq->uq_key)) != 0)
1152 return (error);
1153
1154 umtxq_lock(&uq->uq_key);
1155 umtxq_busy(&uq->uq_key);
1156 umtxq_insert(uq);
1157 umtxq_unbusy(&uq->uq_key);
1158 umtxq_unlock(&uq->uq_key);
1159
1160 /*
1161 * Set the contested bit so that a release in user space
1162 * knows to use the system call for unlock. If this fails
1163 * either some one else has acquired the lock or it has been
1164 * released.
1165 */
1166 old = casuword32(m, owner, owner | UMUTEX_CONTESTED);
1167
1168 /* The address was invalid. */
1169 if (old == -1) {
1170 umtxq_lock(&uq->uq_key);
1171 umtxq_remove(uq);
1172 umtxq_unlock(&uq->uq_key);
1173 umtx_key_release(&uq->uq_key);
1174 return (EFAULT);
1175 }
1176
1177 /*
1178 * We set the contested bit, sleep. Otherwise the lock changed
1179 * and we need to retry or we lost a race to the thread
1180 * unlocking the umtx.
1181 */
1182 umtxq_lock(&uq->uq_key);
1183 if (old == owner)
1184 error = umtxq_sleep(uq, "umtx", timeout == NULL ?
1185 NULL : &timo);
1186 umtxq_remove(uq);
1187 umtxq_unlock(&uq->uq_key);
1188 umtx_key_release(&uq->uq_key);
1189
1190 if (error == 0)
1191 error = thread_check_susp(td, false);
1192 }
1193
1194 if (timeout == NULL) {
1195 /* Mutex locking is restarted if it is interrupted. */
1196 if (error == EINTR)
1197 error = ERESTART;
1198 } else {
1199 /* Timed-locking is not restarted. */
1200 if (error == ERESTART)
1201 error = EINTR;
1202 }
1203 return (error);
1204 }
1205
1206 /*
1207 * Unlock a umtx object.
1208 */
1209 static int
do_unlock_umtx32(struct thread * td,uint32_t * m,uint32_t id)1210 do_unlock_umtx32(struct thread *td, uint32_t *m, uint32_t id)
1211 {
1212 struct umtx_key key;
1213 uint32_t owner;
1214 uint32_t old;
1215 int error;
1216 int count;
1217
1218 /*
1219 * Make sure we own this mtx.
1220 */
1221 owner = fuword32(m);
1222 if (owner == -1)
1223 return (EFAULT);
1224
1225 if ((owner & ~UMUTEX_CONTESTED) != id)
1226 return (EPERM);
1227
1228 /* This should be done in userland */
1229 if ((owner & UMUTEX_CONTESTED) == 0) {
1230 old = casuword32(m, owner, UMUTEX_UNOWNED);
1231 if (old == -1)
1232 return (EFAULT);
1233 if (old == owner)
1234 return (0);
1235 owner = old;
1236 }
1237
1238 /* We should only ever be in here for contested locks */
1239 if ((error = umtx_key_get(m, TYPE_SIMPLE_LOCK, AUTO_SHARE,
1240 &key)) != 0)
1241 return (error);
1242
1243 umtxq_lock(&key);
1244 umtxq_busy(&key);
1245 count = umtxq_count(&key);
1246 umtxq_unlock(&key);
1247
1248 /*
1249 * When unlocking the umtx, it must be marked as unowned if
1250 * there is zero or one thread only waiting for it.
1251 * Otherwise, it must be marked as contested.
1252 */
1253 old = casuword32(m, owner,
1254 count <= 1 ? UMUTEX_UNOWNED : UMUTEX_CONTESTED);
1255 umtxq_lock(&key);
1256 umtxq_signal(&key,1);
1257 umtxq_unbusy(&key);
1258 umtxq_unlock(&key);
1259 umtx_key_release(&key);
1260 if (old == -1)
1261 return (EFAULT);
1262 if (old != owner)
1263 return (EINVAL);
1264 return (0);
1265 }
1266 #endif /* COMPAT_FREEBSD32 */
1267 #endif /* COMPAT_FREEBSD10 */
1268
1269 /*
1270 * Fetch and compare value, sleep on the address if value is not changed.
1271 */
1272 static int
do_wait(struct thread * td,void * addr,u_long id,struct _umtx_time * timeout,int compat32,int is_private)1273 do_wait(struct thread *td, void *addr, u_long id,
1274 struct _umtx_time *timeout, int compat32, int is_private)
1275 {
1276 struct umtx_abs_timeout timo;
1277 struct umtx_q *uq;
1278 u_long tmp;
1279 uint32_t tmp32;
1280 int error = 0;
1281
1282 uq = td->td_umtxq;
1283 if ((error = umtx_key_get(addr, TYPE_SIMPLE_WAIT,
1284 is_private ? THREAD_SHARE : AUTO_SHARE, &uq->uq_key)) != 0)
1285 return (error);
1286
1287 if (timeout != NULL)
1288 umtx_abs_timeout_init2(&timo, timeout);
1289
1290 umtxq_lock(&uq->uq_key);
1291 umtxq_insert(uq);
1292 umtxq_unlock(&uq->uq_key);
1293 if (compat32 == 0) {
1294 error = fueword(addr, &tmp);
1295 if (error != 0)
1296 error = EFAULT;
1297 } else {
1298 error = fueword32(addr, &tmp32);
1299 if (error == 0)
1300 tmp = tmp32;
1301 else
1302 error = EFAULT;
1303 }
1304 umtxq_lock(&uq->uq_key);
1305 if (error == 0) {
1306 if (tmp == id)
1307 error = umtxq_sleep(uq, "uwait", timeout == NULL ?
1308 NULL : &timo);
1309 if ((uq->uq_flags & UQF_UMTXQ) == 0)
1310 error = 0;
1311 else
1312 umtxq_remove(uq);
1313 } else if ((uq->uq_flags & UQF_UMTXQ) != 0) {
1314 umtxq_remove(uq);
1315 }
1316 umtxq_unlock(&uq->uq_key);
1317 umtx_key_release(&uq->uq_key);
1318 if (error == ERESTART)
1319 error = EINTR;
1320 return (error);
1321 }
1322
1323 /*
1324 * Wake up threads sleeping on the specified address.
1325 */
1326 int
kern_umtx_wake(struct thread * td,void * uaddr,int n_wake,int is_private)1327 kern_umtx_wake(struct thread *td, void *uaddr, int n_wake, int is_private)
1328 {
1329 struct umtx_key key;
1330 int ret;
1331
1332 if ((ret = umtx_key_get(uaddr, TYPE_SIMPLE_WAIT,
1333 is_private ? THREAD_SHARE : AUTO_SHARE, &key)) != 0)
1334 return (ret);
1335 umtxq_lock(&key);
1336 umtxq_signal(&key, n_wake);
1337 umtxq_unlock(&key);
1338 umtx_key_release(&key);
1339 return (0);
1340 }
1341
1342 /*
1343 * Lock PTHREAD_PRIO_NONE protocol POSIX mutex.
1344 */
1345 static int
do_lock_normal(struct thread * td,struct umutex * m,uint32_t flags,struct _umtx_time * timeout,int mode)1346 do_lock_normal(struct thread *td, struct umutex *m, uint32_t flags,
1347 struct _umtx_time *timeout, int mode)
1348 {
1349 struct umtx_abs_timeout timo;
1350 struct umtx_q *uq;
1351 uint32_t owner, old, id;
1352 int error, rv;
1353
1354 id = td->td_tid;
1355 uq = td->td_umtxq;
1356 error = 0;
1357 if (timeout != NULL)
1358 umtx_abs_timeout_init2(&timo, timeout);
1359
1360 /*
1361 * Care must be exercised when dealing with umtx structure. It
1362 * can fault on any access.
1363 */
1364 for (;;) {
1365 rv = fueword32(&m->m_owner, &owner);
1366 if (rv == -1)
1367 return (EFAULT);
1368 if (mode == _UMUTEX_WAIT) {
1369 if (owner == UMUTEX_UNOWNED ||
1370 owner == UMUTEX_CONTESTED ||
1371 owner == UMUTEX_RB_OWNERDEAD ||
1372 owner == UMUTEX_RB_NOTRECOV)
1373 return (0);
1374 } else {
1375 /*
1376 * Robust mutex terminated. Kernel duty is to
1377 * return EOWNERDEAD to the userspace. The
1378 * umutex.m_flags UMUTEX_NONCONSISTENT is set
1379 * by the common userspace code.
1380 */
1381 if (owner == UMUTEX_RB_OWNERDEAD) {
1382 rv = casueword32(&m->m_owner,
1383 UMUTEX_RB_OWNERDEAD, &owner,
1384 id | UMUTEX_CONTESTED);
1385 if (rv == -1)
1386 return (EFAULT);
1387 if (rv == 0) {
1388 MPASS(owner == UMUTEX_RB_OWNERDEAD);
1389 return (EOWNERDEAD); /* success */
1390 }
1391 MPASS(rv == 1);
1392 rv = thread_check_susp(td, false);
1393 if (rv != 0)
1394 return (rv);
1395 continue;
1396 }
1397 if (owner == UMUTEX_RB_NOTRECOV)
1398 return (ENOTRECOVERABLE);
1399
1400 /*
1401 * Try the uncontested case. This should be
1402 * done in userland.
1403 */
1404 rv = casueword32(&m->m_owner, UMUTEX_UNOWNED,
1405 &owner, id);
1406 /* The address was invalid. */
1407 if (rv == -1)
1408 return (EFAULT);
1409
1410 /* The acquire succeeded. */
1411 if (rv == 0) {
1412 MPASS(owner == UMUTEX_UNOWNED);
1413 return (0);
1414 }
1415
1416 /*
1417 * If no one owns it but it is contested try
1418 * to acquire it.
1419 */
1420 MPASS(rv == 1);
1421 if (owner == UMUTEX_CONTESTED) {
1422 rv = casueword32(&m->m_owner,
1423 UMUTEX_CONTESTED, &owner,
1424 id | UMUTEX_CONTESTED);
1425 /* The address was invalid. */
1426 if (rv == -1)
1427 return (EFAULT);
1428 if (rv == 0) {
1429 MPASS(owner == UMUTEX_CONTESTED);
1430 return (0);
1431 }
1432 if (rv == 1) {
1433 rv = thread_check_susp(td, false);
1434 if (rv != 0)
1435 return (rv);
1436 }
1437
1438 /*
1439 * If this failed the lock has
1440 * changed, restart.
1441 */
1442 continue;
1443 }
1444
1445 /* rv == 1 but not contested, likely store failure */
1446 rv = thread_check_susp(td, false);
1447 if (rv != 0)
1448 return (rv);
1449 }
1450
1451 if (mode == _UMUTEX_TRY)
1452 return (EBUSY);
1453
1454 /*
1455 * If we caught a signal, we have retried and now
1456 * exit immediately.
1457 */
1458 if (error != 0)
1459 return (error);
1460
1461 if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX,
1462 GET_SHARE(flags), &uq->uq_key)) != 0)
1463 return (error);
1464
1465 umtxq_lock(&uq->uq_key);
1466 umtxq_busy(&uq->uq_key);
1467 umtxq_insert(uq);
1468 umtxq_unlock(&uq->uq_key);
1469
1470 /*
1471 * Set the contested bit so that a release in user space
1472 * knows to use the system call for unlock. If this fails
1473 * either some one else has acquired the lock or it has been
1474 * released.
1475 */
1476 rv = casueword32(&m->m_owner, owner, &old,
1477 owner | UMUTEX_CONTESTED);
1478
1479 /* The address was invalid or casueword failed to store. */
1480 if (rv == -1 || rv == 1) {
1481 umtxq_lock(&uq->uq_key);
1482 umtxq_remove(uq);
1483 umtxq_unbusy(&uq->uq_key);
1484 umtxq_unlock(&uq->uq_key);
1485 umtx_key_release(&uq->uq_key);
1486 if (rv == -1)
1487 return (EFAULT);
1488 if (rv == 1) {
1489 rv = thread_check_susp(td, false);
1490 if (rv != 0)
1491 return (rv);
1492 }
1493 continue;
1494 }
1495
1496 /*
1497 * We set the contested bit, sleep. Otherwise the lock changed
1498 * and we need to retry or we lost a race to the thread
1499 * unlocking the umtx.
1500 */
1501 umtxq_lock(&uq->uq_key);
1502 umtxq_unbusy(&uq->uq_key);
1503 MPASS(old == owner);
1504 error = umtxq_sleep(uq, "umtxn", timeout == NULL ?
1505 NULL : &timo);
1506 umtxq_remove(uq);
1507 umtxq_unlock(&uq->uq_key);
1508 umtx_key_release(&uq->uq_key);
1509
1510 if (error == 0)
1511 error = thread_check_susp(td, false);
1512 }
1513
1514 return (0);
1515 }
1516
1517 /*
1518 * Unlock PTHREAD_PRIO_NONE protocol POSIX mutex.
1519 */
1520 static int
do_unlock_normal(struct thread * td,struct umutex * m,uint32_t flags,bool rb)1521 do_unlock_normal(struct thread *td, struct umutex *m, uint32_t flags, bool rb)
1522 {
1523 struct umtx_key key;
1524 uint32_t owner, old, id, newlock;
1525 int error, count;
1526
1527 id = td->td_tid;
1528
1529 again:
1530 /*
1531 * Make sure we own this mtx.
1532 */
1533 error = fueword32(&m->m_owner, &owner);
1534 if (error == -1)
1535 return (EFAULT);
1536
1537 if ((owner & ~UMUTEX_CONTESTED) != id)
1538 return (EPERM);
1539
1540 newlock = umtx_unlock_val(flags, rb);
1541 if ((owner & UMUTEX_CONTESTED) == 0) {
1542 error = casueword32(&m->m_owner, owner, &old, newlock);
1543 if (error == -1)
1544 return (EFAULT);
1545 if (error == 1) {
1546 error = thread_check_susp(td, false);
1547 if (error != 0)
1548 return (error);
1549 goto again;
1550 }
1551 MPASS(old == owner);
1552 return (0);
1553 }
1554
1555 /* We should only ever be in here for contested locks */
1556 if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX, GET_SHARE(flags),
1557 &key)) != 0)
1558 return (error);
1559
1560 umtxq_lock(&key);
1561 umtxq_busy(&key);
1562 count = umtxq_count(&key);
1563 umtxq_unlock(&key);
1564
1565 /*
1566 * When unlocking the umtx, it must be marked as unowned if
1567 * there is zero or one thread only waiting for it.
1568 * Otherwise, it must be marked as contested.
1569 */
1570 if (count > 1)
1571 newlock |= UMUTEX_CONTESTED;
1572 error = casueword32(&m->m_owner, owner, &old, newlock);
1573 umtxq_lock(&key);
1574 umtxq_signal(&key, 1);
1575 umtxq_unbusy(&key);
1576 umtxq_unlock(&key);
1577 umtx_key_release(&key);
1578 if (error == -1)
1579 return (EFAULT);
1580 if (error == 1) {
1581 if (old != owner)
1582 return (EINVAL);
1583 error = thread_check_susp(td, false);
1584 if (error != 0)
1585 return (error);
1586 goto again;
1587 }
1588 return (0);
1589 }
1590
1591 /*
1592 * Check if the mutex is available and wake up a waiter,
1593 * only for simple mutex.
1594 */
1595 static int
do_wake_umutex(struct thread * td,struct umutex * m)1596 do_wake_umutex(struct thread *td, struct umutex *m)
1597 {
1598 struct umtx_key key;
1599 uint32_t owner;
1600 uint32_t flags;
1601 int error;
1602 int count;
1603
1604 again:
1605 error = fueword32(&m->m_owner, &owner);
1606 if (error == -1)
1607 return (EFAULT);
1608
1609 if ((owner & ~UMUTEX_CONTESTED) != 0 && owner != UMUTEX_RB_OWNERDEAD &&
1610 owner != UMUTEX_RB_NOTRECOV)
1611 return (0);
1612
1613 error = fueword32(&m->m_flags, &flags);
1614 if (error == -1)
1615 return (EFAULT);
1616
1617 /* We should only ever be in here for contested locks */
1618 if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX, GET_SHARE(flags),
1619 &key)) != 0)
1620 return (error);
1621
1622 umtxq_lock(&key);
1623 umtxq_busy(&key);
1624 count = umtxq_count(&key);
1625 umtxq_unlock(&key);
1626
1627 if (count <= 1 && owner != UMUTEX_RB_OWNERDEAD &&
1628 owner != UMUTEX_RB_NOTRECOV) {
1629 error = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner,
1630 UMUTEX_UNOWNED);
1631 if (error == -1) {
1632 error = EFAULT;
1633 } else if (error == 1) {
1634 umtxq_lock(&key);
1635 umtxq_unbusy(&key);
1636 umtxq_unlock(&key);
1637 umtx_key_release(&key);
1638 error = thread_check_susp(td, false);
1639 if (error != 0)
1640 return (error);
1641 goto again;
1642 }
1643 }
1644
1645 umtxq_lock(&key);
1646 if (error == 0 && count != 0) {
1647 MPASS((owner & ~UMUTEX_CONTESTED) == 0 ||
1648 owner == UMUTEX_RB_OWNERDEAD ||
1649 owner == UMUTEX_RB_NOTRECOV);
1650 umtxq_signal(&key, 1);
1651 }
1652 umtxq_unbusy(&key);
1653 umtxq_unlock(&key);
1654 umtx_key_release(&key);
1655 return (error);
1656 }
1657
1658 /*
1659 * Check if the mutex has waiters and tries to fix contention bit.
1660 */
1661 static int
do_wake2_umutex(struct thread * td,struct umutex * m,uint32_t flags)1662 do_wake2_umutex(struct thread *td, struct umutex *m, uint32_t flags)
1663 {
1664 struct umtx_key key;
1665 uint32_t owner, old;
1666 int type;
1667 int error;
1668 int count;
1669
1670 switch (flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT |
1671 UMUTEX_ROBUST)) {
1672 case 0:
1673 case UMUTEX_ROBUST:
1674 type = TYPE_NORMAL_UMUTEX;
1675 break;
1676 case UMUTEX_PRIO_INHERIT:
1677 type = TYPE_PI_UMUTEX;
1678 break;
1679 case (UMUTEX_PRIO_INHERIT | UMUTEX_ROBUST):
1680 type = TYPE_PI_ROBUST_UMUTEX;
1681 break;
1682 case UMUTEX_PRIO_PROTECT:
1683 type = TYPE_PP_UMUTEX;
1684 break;
1685 case (UMUTEX_PRIO_PROTECT | UMUTEX_ROBUST):
1686 type = TYPE_PP_ROBUST_UMUTEX;
1687 break;
1688 default:
1689 return (EINVAL);
1690 }
1691 if ((error = umtx_key_get(m, type, GET_SHARE(flags), &key)) != 0)
1692 return (error);
1693
1694 owner = 0;
1695 umtxq_lock(&key);
1696 umtxq_busy(&key);
1697 count = umtxq_count(&key);
1698 umtxq_unlock(&key);
1699
1700 error = fueword32(&m->m_owner, &owner);
1701 if (error == -1)
1702 error = EFAULT;
1703
1704 /*
1705 * Only repair contention bit if there is a waiter, this means
1706 * the mutex is still being referenced by userland code,
1707 * otherwise don't update any memory.
1708 */
1709 while (error == 0 && (owner & UMUTEX_CONTESTED) == 0 &&
1710 (count > 1 || (count == 1 && (owner & ~UMUTEX_CONTESTED) != 0))) {
1711 error = casueword32(&m->m_owner, owner, &old,
1712 owner | UMUTEX_CONTESTED);
1713 if (error == -1) {
1714 error = EFAULT;
1715 break;
1716 }
1717 if (error == 0) {
1718 MPASS(old == owner);
1719 break;
1720 }
1721 owner = old;
1722 error = thread_check_susp(td, false);
1723 }
1724
1725 umtxq_lock(&key);
1726 if (error == EFAULT) {
1727 umtxq_signal(&key, INT_MAX);
1728 } else if (count != 0 && ((owner & ~UMUTEX_CONTESTED) == 0 ||
1729 owner == UMUTEX_RB_OWNERDEAD || owner == UMUTEX_RB_NOTRECOV))
1730 umtxq_signal(&key, 1);
1731 umtxq_unbusy(&key);
1732 umtxq_unlock(&key);
1733 umtx_key_release(&key);
1734 return (error);
1735 }
1736
1737 struct umtx_pi *
umtx_pi_alloc(int flags)1738 umtx_pi_alloc(int flags)
1739 {
1740 struct umtx_pi *pi;
1741
1742 pi = uma_zalloc(umtx_pi_zone, M_ZERO | flags);
1743 if (pi == NULL)
1744 return (NULL);
1745
1746 TAILQ_INIT(&pi->pi_blocked);
1747 atomic_add_int(&umtx_pi_allocated, 1);
1748 return (pi);
1749 }
1750
1751 void
umtx_pi_free(struct umtx_pi * pi)1752 umtx_pi_free(struct umtx_pi *pi)
1753 {
1754 uma_zfree(umtx_pi_zone, pi);
1755 atomic_add_int(&umtx_pi_allocated, -1);
1756 }
1757
1758 /*
1759 * Adjust the thread's position on a pi_state after its priority has been
1760 * changed.
1761 */
1762 static int
umtx_pi_adjust_thread(struct umtx_pi * pi,struct thread * td)1763 umtx_pi_adjust_thread(struct umtx_pi *pi, struct thread *td)
1764 {
1765 struct umtx_q *uq, *uq1, *uq2;
1766 struct thread *td1;
1767
1768 mtx_assert(&umtx_lock, MA_OWNED);
1769 if (pi == NULL)
1770 return (0);
1771
1772 uq = td->td_umtxq;
1773
1774 /*
1775 * Check if the thread needs to be moved on the blocked chain.
1776 * It needs to be moved if either its priority is lower than
1777 * the previous thread or higher than the next thread.
1778 */
1779 uq1 = TAILQ_PREV(uq, umtxq_head, uq_lockq);
1780 uq2 = TAILQ_NEXT(uq, uq_lockq);
1781 if ((uq1 != NULL && UPRI(td) < UPRI(uq1->uq_thread)) ||
1782 (uq2 != NULL && UPRI(td) > UPRI(uq2->uq_thread))) {
1783 /*
1784 * Remove thread from blocked chain and determine where
1785 * it should be moved to.
1786 */
1787 TAILQ_REMOVE(&pi->pi_blocked, uq, uq_lockq);
1788 TAILQ_FOREACH(uq1, &pi->pi_blocked, uq_lockq) {
1789 td1 = uq1->uq_thread;
1790 MPASS(td1->td_proc->p_magic == P_MAGIC);
1791 if (UPRI(td1) > UPRI(td))
1792 break;
1793 }
1794
1795 if (uq1 == NULL)
1796 TAILQ_INSERT_TAIL(&pi->pi_blocked, uq, uq_lockq);
1797 else
1798 TAILQ_INSERT_BEFORE(uq1, uq, uq_lockq);
1799 }
1800 return (1);
1801 }
1802
1803 static struct umtx_pi *
umtx_pi_next(struct umtx_pi * pi)1804 umtx_pi_next(struct umtx_pi *pi)
1805 {
1806 struct umtx_q *uq_owner;
1807
1808 if (pi->pi_owner == NULL)
1809 return (NULL);
1810 uq_owner = pi->pi_owner->td_umtxq;
1811 if (uq_owner == NULL)
1812 return (NULL);
1813 return (uq_owner->uq_pi_blocked);
1814 }
1815
1816 /*
1817 * Floyd's Cycle-Finding Algorithm.
1818 */
1819 static bool
umtx_pi_check_loop(struct umtx_pi * pi)1820 umtx_pi_check_loop(struct umtx_pi *pi)
1821 {
1822 struct umtx_pi *pi1; /* fast iterator */
1823
1824 mtx_assert(&umtx_lock, MA_OWNED);
1825 if (pi == NULL)
1826 return (false);
1827 pi1 = pi;
1828 for (;;) {
1829 pi = umtx_pi_next(pi);
1830 if (pi == NULL)
1831 break;
1832 pi1 = umtx_pi_next(pi1);
1833 if (pi1 == NULL)
1834 break;
1835 pi1 = umtx_pi_next(pi1);
1836 if (pi1 == NULL)
1837 break;
1838 if (pi == pi1)
1839 return (true);
1840 }
1841 return (false);
1842 }
1843
1844 /*
1845 * Propagate priority when a thread is blocked on POSIX
1846 * PI mutex.
1847 */
1848 static void
umtx_propagate_priority(struct thread * td)1849 umtx_propagate_priority(struct thread *td)
1850 {
1851 struct umtx_q *uq;
1852 struct umtx_pi *pi;
1853 int pri;
1854
1855 mtx_assert(&umtx_lock, MA_OWNED);
1856 pri = UPRI(td);
1857 uq = td->td_umtxq;
1858 pi = uq->uq_pi_blocked;
1859 if (pi == NULL)
1860 return;
1861 if (umtx_pi_check_loop(pi))
1862 return;
1863
1864 for (;;) {
1865 td = pi->pi_owner;
1866 if (td == NULL || td == curthread)
1867 return;
1868
1869 MPASS(td->td_proc != NULL);
1870 MPASS(td->td_proc->p_magic == P_MAGIC);
1871
1872 thread_lock(td);
1873 if (td->td_lend_user_pri > pri)
1874 sched_lend_user_prio(td, pri);
1875 else {
1876 thread_unlock(td);
1877 break;
1878 }
1879 thread_unlock(td);
1880
1881 /*
1882 * Pick up the lock that td is blocked on.
1883 */
1884 uq = td->td_umtxq;
1885 pi = uq->uq_pi_blocked;
1886 if (pi == NULL)
1887 break;
1888 /* Resort td on the list if needed. */
1889 umtx_pi_adjust_thread(pi, td);
1890 }
1891 }
1892
1893 /*
1894 * Unpropagate priority for a PI mutex when a thread blocked on
1895 * it is interrupted by signal or resumed by others.
1896 */
1897 static void
umtx_repropagate_priority(struct umtx_pi * pi)1898 umtx_repropagate_priority(struct umtx_pi *pi)
1899 {
1900 struct umtx_q *uq, *uq_owner;
1901 struct umtx_pi *pi2;
1902 int pri;
1903
1904 mtx_assert(&umtx_lock, MA_OWNED);
1905
1906 if (umtx_pi_check_loop(pi))
1907 return;
1908 while (pi != NULL && pi->pi_owner != NULL) {
1909 pri = PRI_MAX;
1910 uq_owner = pi->pi_owner->td_umtxq;
1911
1912 TAILQ_FOREACH(pi2, &uq_owner->uq_pi_contested, pi_link) {
1913 uq = TAILQ_FIRST(&pi2->pi_blocked);
1914 if (uq != NULL) {
1915 if (pri > UPRI(uq->uq_thread))
1916 pri = UPRI(uq->uq_thread);
1917 }
1918 }
1919
1920 if (pri > uq_owner->uq_inherited_pri)
1921 pri = uq_owner->uq_inherited_pri;
1922 thread_lock(pi->pi_owner);
1923 sched_lend_user_prio(pi->pi_owner, pri);
1924 thread_unlock(pi->pi_owner);
1925 if ((pi = uq_owner->uq_pi_blocked) != NULL)
1926 umtx_pi_adjust_thread(pi, uq_owner->uq_thread);
1927 }
1928 }
1929
1930 /*
1931 * Insert a PI mutex into owned list.
1932 */
1933 static void
umtx_pi_setowner(struct umtx_pi * pi,struct thread * owner)1934 umtx_pi_setowner(struct umtx_pi *pi, struct thread *owner)
1935 {
1936 struct umtx_q *uq_owner;
1937
1938 uq_owner = owner->td_umtxq;
1939 mtx_assert(&umtx_lock, MA_OWNED);
1940 MPASS(pi->pi_owner == NULL);
1941 pi->pi_owner = owner;
1942 TAILQ_INSERT_TAIL(&uq_owner->uq_pi_contested, pi, pi_link);
1943 }
1944
1945 /*
1946 * Disown a PI mutex, and remove it from the owned list.
1947 */
1948 static void
umtx_pi_disown(struct umtx_pi * pi)1949 umtx_pi_disown(struct umtx_pi *pi)
1950 {
1951
1952 mtx_assert(&umtx_lock, MA_OWNED);
1953 TAILQ_REMOVE(&pi->pi_owner->td_umtxq->uq_pi_contested, pi, pi_link);
1954 pi->pi_owner = NULL;
1955 }
1956
1957 /*
1958 * Claim ownership of a PI mutex.
1959 */
1960 int
umtx_pi_claim(struct umtx_pi * pi,struct thread * owner)1961 umtx_pi_claim(struct umtx_pi *pi, struct thread *owner)
1962 {
1963 struct umtx_q *uq;
1964 int pri;
1965
1966 mtx_lock(&umtx_lock);
1967 if (pi->pi_owner == owner) {
1968 mtx_unlock(&umtx_lock);
1969 return (0);
1970 }
1971
1972 if (pi->pi_owner != NULL) {
1973 /*
1974 * userland may have already messed the mutex, sigh.
1975 */
1976 mtx_unlock(&umtx_lock);
1977 return (EPERM);
1978 }
1979 umtx_pi_setowner(pi, owner);
1980 uq = TAILQ_FIRST(&pi->pi_blocked);
1981 if (uq != NULL) {
1982 pri = UPRI(uq->uq_thread);
1983 thread_lock(owner);
1984 if (pri < UPRI(owner))
1985 sched_lend_user_prio(owner, pri);
1986 thread_unlock(owner);
1987 }
1988 mtx_unlock(&umtx_lock);
1989 return (0);
1990 }
1991
1992 /*
1993 * Adjust a thread's order position in its blocked PI mutex,
1994 * this may result new priority propagating process.
1995 */
1996 void
umtx_pi_adjust(struct thread * td,u_char oldpri)1997 umtx_pi_adjust(struct thread *td, u_char oldpri)
1998 {
1999 struct umtx_q *uq;
2000 struct umtx_pi *pi;
2001
2002 uq = td->td_umtxq;
2003 mtx_lock(&umtx_lock);
2004 /*
2005 * Pick up the lock that td is blocked on.
2006 */
2007 pi = uq->uq_pi_blocked;
2008 if (pi != NULL) {
2009 umtx_pi_adjust_thread(pi, td);
2010 umtx_repropagate_priority(pi);
2011 }
2012 mtx_unlock(&umtx_lock);
2013 }
2014
2015 /*
2016 * Sleep on a PI mutex.
2017 */
2018 int
umtxq_sleep_pi(struct umtx_q * uq,struct umtx_pi * pi,uint32_t owner,const char * wmesg,struct umtx_abs_timeout * timo,bool shared)2019 umtxq_sleep_pi(struct umtx_q *uq, struct umtx_pi *pi, uint32_t owner,
2020 const char *wmesg, struct umtx_abs_timeout *timo, bool shared)
2021 {
2022 struct thread *td, *td1;
2023 struct umtx_q *uq1;
2024 int error, pri;
2025 #ifdef INVARIANTS
2026 struct umtxq_chain *uc;
2027
2028 uc = umtxq_getchain(&pi->pi_key);
2029 #endif
2030 error = 0;
2031 td = uq->uq_thread;
2032 KASSERT(td == curthread, ("inconsistent uq_thread"));
2033 UMTXQ_LOCKED_ASSERT(umtxq_getchain(&uq->uq_key));
2034 KASSERT(uc->uc_busy != 0, ("umtx chain is not busy"));
2035 umtxq_insert(uq);
2036 mtx_lock(&umtx_lock);
2037 if (pi->pi_owner == NULL) {
2038 mtx_unlock(&umtx_lock);
2039 td1 = tdfind(owner, shared ? -1 : td->td_proc->p_pid);
2040 mtx_lock(&umtx_lock);
2041 if (td1 != NULL) {
2042 if (pi->pi_owner == NULL)
2043 umtx_pi_setowner(pi, td1);
2044 PROC_UNLOCK(td1->td_proc);
2045 }
2046 }
2047
2048 TAILQ_FOREACH(uq1, &pi->pi_blocked, uq_lockq) {
2049 pri = UPRI(uq1->uq_thread);
2050 if (pri > UPRI(td))
2051 break;
2052 }
2053
2054 if (uq1 != NULL)
2055 TAILQ_INSERT_BEFORE(uq1, uq, uq_lockq);
2056 else
2057 TAILQ_INSERT_TAIL(&pi->pi_blocked, uq, uq_lockq);
2058
2059 uq->uq_pi_blocked = pi;
2060 thread_lock(td);
2061 td->td_flags |= TDF_UPIBLOCKED;
2062 thread_unlock(td);
2063 umtx_propagate_priority(td);
2064 mtx_unlock(&umtx_lock);
2065 umtxq_unbusy(&uq->uq_key);
2066
2067 error = umtxq_sleep(uq, wmesg, timo);
2068 umtxq_remove(uq);
2069
2070 mtx_lock(&umtx_lock);
2071 uq->uq_pi_blocked = NULL;
2072 thread_lock(td);
2073 td->td_flags &= ~TDF_UPIBLOCKED;
2074 thread_unlock(td);
2075 TAILQ_REMOVE(&pi->pi_blocked, uq, uq_lockq);
2076 umtx_repropagate_priority(pi);
2077 mtx_unlock(&umtx_lock);
2078 umtxq_unlock(&uq->uq_key);
2079
2080 return (error);
2081 }
2082
2083 /*
2084 * Add reference count for a PI mutex.
2085 */
2086 void
umtx_pi_ref(struct umtx_pi * pi)2087 umtx_pi_ref(struct umtx_pi *pi)
2088 {
2089
2090 UMTXQ_LOCKED_ASSERT(umtxq_getchain(&pi->pi_key));
2091 pi->pi_refcount++;
2092 }
2093
2094 /*
2095 * Decrease reference count for a PI mutex, if the counter
2096 * is decreased to zero, its memory space is freed.
2097 */
2098 void
umtx_pi_unref(struct umtx_pi * pi)2099 umtx_pi_unref(struct umtx_pi *pi)
2100 {
2101 struct umtxq_chain *uc;
2102
2103 uc = umtxq_getchain(&pi->pi_key);
2104 UMTXQ_LOCKED_ASSERT(uc);
2105 KASSERT(pi->pi_refcount > 0, ("invalid reference count"));
2106 if (--pi->pi_refcount == 0) {
2107 mtx_lock(&umtx_lock);
2108 if (pi->pi_owner != NULL)
2109 umtx_pi_disown(pi);
2110 KASSERT(TAILQ_EMPTY(&pi->pi_blocked),
2111 ("blocked queue not empty"));
2112 mtx_unlock(&umtx_lock);
2113 TAILQ_REMOVE(&uc->uc_pi_list, pi, pi_hashlink);
2114 umtx_pi_free(pi);
2115 }
2116 }
2117
2118 /*
2119 * Find a PI mutex in hash table.
2120 */
2121 struct umtx_pi *
umtx_pi_lookup(struct umtx_key * key)2122 umtx_pi_lookup(struct umtx_key *key)
2123 {
2124 struct umtxq_chain *uc;
2125 struct umtx_pi *pi;
2126
2127 uc = umtxq_getchain(key);
2128 UMTXQ_LOCKED_ASSERT(uc);
2129
2130 TAILQ_FOREACH(pi, &uc->uc_pi_list, pi_hashlink) {
2131 if (umtx_key_match(&pi->pi_key, key)) {
2132 return (pi);
2133 }
2134 }
2135 return (NULL);
2136 }
2137
2138 /*
2139 * Insert a PI mutex into hash table.
2140 */
2141 void
umtx_pi_insert(struct umtx_pi * pi)2142 umtx_pi_insert(struct umtx_pi *pi)
2143 {
2144 struct umtxq_chain *uc;
2145
2146 uc = umtxq_getchain(&pi->pi_key);
2147 UMTXQ_LOCKED_ASSERT(uc);
2148 TAILQ_INSERT_TAIL(&uc->uc_pi_list, pi, pi_hashlink);
2149 }
2150
2151 /*
2152 * Drop a PI mutex and wakeup a top waiter.
2153 */
2154 int
umtx_pi_drop(struct thread * td,struct umtx_key * key,bool rb,int * count)2155 umtx_pi_drop(struct thread *td, struct umtx_key *key, bool rb, int *count)
2156 {
2157 struct umtx_q *uq_first, *uq_first2, *uq_me;
2158 struct umtx_pi *pi, *pi2;
2159 int pri;
2160
2161 UMTXQ_ASSERT_LOCKED_BUSY(key);
2162 *count = umtxq_count_pi(key, &uq_first);
2163 if (uq_first != NULL) {
2164 mtx_lock(&umtx_lock);
2165 pi = uq_first->uq_pi_blocked;
2166 KASSERT(pi != NULL, ("pi == NULL?"));
2167 if (pi->pi_owner != td && !(rb && pi->pi_owner == NULL)) {
2168 mtx_unlock(&umtx_lock);
2169 /* userland messed the mutex */
2170 return (EPERM);
2171 }
2172 uq_me = td->td_umtxq;
2173 if (pi->pi_owner == td)
2174 umtx_pi_disown(pi);
2175 /* get highest priority thread which is still sleeping. */
2176 uq_first = TAILQ_FIRST(&pi->pi_blocked);
2177 while (uq_first != NULL &&
2178 (uq_first->uq_flags & UQF_UMTXQ) == 0) {
2179 uq_first = TAILQ_NEXT(uq_first, uq_lockq);
2180 }
2181 pri = PRI_MAX;
2182 TAILQ_FOREACH(pi2, &uq_me->uq_pi_contested, pi_link) {
2183 uq_first2 = TAILQ_FIRST(&pi2->pi_blocked);
2184 if (uq_first2 != NULL) {
2185 if (pri > UPRI(uq_first2->uq_thread))
2186 pri = UPRI(uq_first2->uq_thread);
2187 }
2188 }
2189 thread_lock(td);
2190 sched_lend_user_prio(td, pri);
2191 thread_unlock(td);
2192 mtx_unlock(&umtx_lock);
2193 if (uq_first)
2194 umtxq_signal_thread(uq_first);
2195 } else {
2196 pi = umtx_pi_lookup(key);
2197 /*
2198 * A umtx_pi can exist if a signal or timeout removed the
2199 * last waiter from the umtxq, but there is still
2200 * a thread in do_lock_pi() holding the umtx_pi.
2201 */
2202 if (pi != NULL) {
2203 /*
2204 * The umtx_pi can be unowned, such as when a thread
2205 * has just entered do_lock_pi(), allocated the
2206 * umtx_pi, and unlocked the umtxq.
2207 * If the current thread owns it, it must disown it.
2208 */
2209 mtx_lock(&umtx_lock);
2210 if (pi->pi_owner == td)
2211 umtx_pi_disown(pi);
2212 mtx_unlock(&umtx_lock);
2213 }
2214 }
2215 return (0);
2216 }
2217
2218 /*
2219 * Lock a PI mutex.
2220 */
2221 static int
do_lock_pi(struct thread * td,struct umutex * m,uint32_t flags,struct _umtx_time * timeout,int try)2222 do_lock_pi(struct thread *td, struct umutex *m, uint32_t flags,
2223 struct _umtx_time *timeout, int try)
2224 {
2225 struct umtx_abs_timeout timo;
2226 struct umtx_q *uq;
2227 struct umtx_pi *pi, *new_pi;
2228 uint32_t id, old_owner, owner, old;
2229 int error, rv;
2230
2231 id = td->td_tid;
2232 uq = td->td_umtxq;
2233
2234 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
2235 TYPE_PI_ROBUST_UMUTEX : TYPE_PI_UMUTEX, GET_SHARE(flags),
2236 &uq->uq_key)) != 0)
2237 return (error);
2238
2239 if (timeout != NULL)
2240 umtx_abs_timeout_init2(&timo, timeout);
2241
2242 umtxq_lock(&uq->uq_key);
2243 pi = umtx_pi_lookup(&uq->uq_key);
2244 if (pi == NULL) {
2245 new_pi = umtx_pi_alloc(M_NOWAIT);
2246 if (new_pi == NULL) {
2247 umtxq_unlock(&uq->uq_key);
2248 new_pi = umtx_pi_alloc(M_WAITOK);
2249 umtxq_lock(&uq->uq_key);
2250 pi = umtx_pi_lookup(&uq->uq_key);
2251 if (pi != NULL) {
2252 umtx_pi_free(new_pi);
2253 new_pi = NULL;
2254 }
2255 }
2256 if (new_pi != NULL) {
2257 new_pi->pi_key = uq->uq_key;
2258 umtx_pi_insert(new_pi);
2259 pi = new_pi;
2260 }
2261 }
2262 umtx_pi_ref(pi);
2263 umtxq_unlock(&uq->uq_key);
2264
2265 /*
2266 * Care must be exercised when dealing with umtx structure. It
2267 * can fault on any access.
2268 */
2269 for (;;) {
2270 /*
2271 * Try the uncontested case. This should be done in userland.
2272 */
2273 rv = casueword32(&m->m_owner, UMUTEX_UNOWNED, &owner, id);
2274 /* The address was invalid. */
2275 if (rv == -1) {
2276 error = EFAULT;
2277 break;
2278 }
2279 /* The acquire succeeded. */
2280 if (rv == 0) {
2281 MPASS(owner == UMUTEX_UNOWNED);
2282 error = 0;
2283 break;
2284 }
2285
2286 if (owner == UMUTEX_RB_NOTRECOV) {
2287 error = ENOTRECOVERABLE;
2288 break;
2289 }
2290
2291 /*
2292 * Nobody owns it, but the acquire failed. This can happen
2293 * with ll/sc atomics.
2294 */
2295 if (owner == UMUTEX_UNOWNED) {
2296 error = thread_check_susp(td, true);
2297 if (error != 0)
2298 break;
2299 continue;
2300 }
2301
2302 /*
2303 * Avoid overwriting a possible error from sleep due
2304 * to the pending signal with suspension check result.
2305 */
2306 if (error == 0) {
2307 error = thread_check_susp(td, true);
2308 if (error != 0)
2309 break;
2310 }
2311
2312 /* If no one owns it but it is contested try to acquire it. */
2313 if (owner == UMUTEX_CONTESTED || owner == UMUTEX_RB_OWNERDEAD) {
2314 old_owner = owner;
2315 rv = casueword32(&m->m_owner, owner, &owner,
2316 id | UMUTEX_CONTESTED);
2317 /* The address was invalid. */
2318 if (rv == -1) {
2319 error = EFAULT;
2320 break;
2321 }
2322 if (rv == 1) {
2323 if (error == 0) {
2324 error = thread_check_susp(td, true);
2325 if (error != 0)
2326 break;
2327 }
2328
2329 /*
2330 * If this failed the lock could
2331 * changed, restart.
2332 */
2333 continue;
2334 }
2335
2336 MPASS(rv == 0);
2337 MPASS(owner == old_owner);
2338 umtxq_lock(&uq->uq_key);
2339 umtxq_busy(&uq->uq_key);
2340 error = umtx_pi_claim(pi, td);
2341 umtxq_unbusy(&uq->uq_key);
2342 umtxq_unlock(&uq->uq_key);
2343 if (error != 0) {
2344 /*
2345 * Since we're going to return an
2346 * error, restore the m_owner to its
2347 * previous, unowned state to avoid
2348 * compounding the problem.
2349 */
2350 (void)casuword32(&m->m_owner,
2351 id | UMUTEX_CONTESTED, old_owner);
2352 }
2353 if (error == 0 && old_owner == UMUTEX_RB_OWNERDEAD)
2354 error = EOWNERDEAD;
2355 break;
2356 }
2357
2358 if ((owner & ~UMUTEX_CONTESTED) == id) {
2359 error = EDEADLK;
2360 break;
2361 }
2362
2363 if (try != 0) {
2364 error = EBUSY;
2365 break;
2366 }
2367
2368 /*
2369 * If we caught a signal, we have retried and now
2370 * exit immediately.
2371 */
2372 if (error != 0)
2373 break;
2374
2375 umtxq_lock(&uq->uq_key);
2376 umtxq_busy(&uq->uq_key);
2377 umtxq_unlock(&uq->uq_key);
2378
2379 /*
2380 * Set the contested bit so that a release in user space
2381 * knows to use the system call for unlock. If this fails
2382 * either some one else has acquired the lock or it has been
2383 * released.
2384 */
2385 rv = casueword32(&m->m_owner, owner, &old, owner |
2386 UMUTEX_CONTESTED);
2387
2388 /* The address was invalid. */
2389 if (rv == -1) {
2390 umtxq_unbusy_unlocked(&uq->uq_key);
2391 error = EFAULT;
2392 break;
2393 }
2394 if (rv == 1) {
2395 umtxq_unbusy_unlocked(&uq->uq_key);
2396 error = thread_check_susp(td, true);
2397 if (error != 0)
2398 break;
2399
2400 /*
2401 * The lock changed and we need to retry or we
2402 * lost a race to the thread unlocking the
2403 * umtx. Note that the UMUTEX_RB_OWNERDEAD
2404 * value for owner is impossible there.
2405 */
2406 continue;
2407 }
2408
2409 umtxq_lock(&uq->uq_key);
2410
2411 /* We set the contested bit, sleep. */
2412 MPASS(old == owner);
2413 error = umtxq_sleep_pi(uq, pi, owner & ~UMUTEX_CONTESTED,
2414 "umtxpi", timeout == NULL ? NULL : &timo,
2415 (flags & USYNC_PROCESS_SHARED) != 0);
2416 if (error != 0)
2417 continue;
2418
2419 error = thread_check_susp(td, false);
2420 if (error != 0)
2421 break;
2422 }
2423
2424 umtxq_lock(&uq->uq_key);
2425 umtx_pi_unref(pi);
2426 umtxq_unlock(&uq->uq_key);
2427
2428 umtx_key_release(&uq->uq_key);
2429 return (error);
2430 }
2431
2432 /*
2433 * Unlock a PI mutex.
2434 */
2435 static int
do_unlock_pi(struct thread * td,struct umutex * m,uint32_t flags,bool rb)2436 do_unlock_pi(struct thread *td, struct umutex *m, uint32_t flags, bool rb)
2437 {
2438 struct umtx_key key;
2439 uint32_t id, new_owner, old, owner;
2440 int count, error;
2441
2442 id = td->td_tid;
2443
2444 usrloop:
2445 /*
2446 * Make sure we own this mtx.
2447 */
2448 error = fueword32(&m->m_owner, &owner);
2449 if (error == -1)
2450 return (EFAULT);
2451
2452 if ((owner & ~UMUTEX_CONTESTED) != id)
2453 return (EPERM);
2454
2455 new_owner = umtx_unlock_val(flags, rb);
2456
2457 /* This should be done in userland */
2458 if ((owner & UMUTEX_CONTESTED) == 0) {
2459 error = casueword32(&m->m_owner, owner, &old, new_owner);
2460 if (error == -1)
2461 return (EFAULT);
2462 if (error == 1) {
2463 error = thread_check_susp(td, true);
2464 if (error != 0)
2465 return (error);
2466 goto usrloop;
2467 }
2468 if (old == owner)
2469 return (0);
2470 owner = old;
2471 }
2472
2473 /* We should only ever be in here for contested locks */
2474 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
2475 TYPE_PI_ROBUST_UMUTEX : TYPE_PI_UMUTEX, GET_SHARE(flags),
2476 &key)) != 0)
2477 return (error);
2478
2479 umtxq_lock(&key);
2480 umtxq_busy(&key);
2481 error = umtx_pi_drop(td, &key, rb, &count);
2482 if (error != 0) {
2483 umtxq_unbusy(&key);
2484 umtxq_unlock(&key);
2485 umtx_key_release(&key);
2486 /* userland messed the mutex */
2487 return (error);
2488 }
2489 umtxq_unlock(&key);
2490
2491 /*
2492 * When unlocking the umtx, it must be marked as unowned if
2493 * there is zero or one thread only waiting for it.
2494 * Otherwise, it must be marked as contested.
2495 */
2496
2497 if (count > 1)
2498 new_owner |= UMUTEX_CONTESTED;
2499 again:
2500 error = casueword32(&m->m_owner, owner, &old, new_owner);
2501 if (error == 1) {
2502 error = thread_check_susp(td, false);
2503 if (error == 0)
2504 goto again;
2505 }
2506 umtxq_unbusy_unlocked(&key);
2507 umtx_key_release(&key);
2508 if (error == -1)
2509 return (EFAULT);
2510 if (error == 0 && old != owner)
2511 return (EINVAL);
2512 return (error);
2513 }
2514
2515 /*
2516 * Lock a PP mutex.
2517 */
2518 static int
do_lock_pp(struct thread * td,struct umutex * m,uint32_t flags,struct _umtx_time * timeout,int try)2519 do_lock_pp(struct thread *td, struct umutex *m, uint32_t flags,
2520 struct _umtx_time *timeout, int try)
2521 {
2522 struct umtx_abs_timeout timo;
2523 struct umtx_q *uq, *uq2;
2524 struct umtx_pi *pi;
2525 uint32_t ceiling;
2526 uint32_t owner, id;
2527 int error, pri, old_inherited_pri, new_pri, rv;
2528 bool su;
2529
2530 id = td->td_tid;
2531 uq = td->td_umtxq;
2532 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
2533 TYPE_PP_ROBUST_UMUTEX : TYPE_PP_UMUTEX, GET_SHARE(flags),
2534 &uq->uq_key)) != 0)
2535 return (error);
2536
2537 if (timeout != NULL)
2538 umtx_abs_timeout_init2(&timo, timeout);
2539
2540 su = (priv_check(td, PRIV_SCHED_RTPRIO) == 0);
2541 for (;;) {
2542 old_inherited_pri = uq->uq_inherited_pri;
2543 umtxq_lock(&uq->uq_key);
2544 umtxq_busy(&uq->uq_key);
2545 umtxq_unlock(&uq->uq_key);
2546
2547 rv = fueword32(&m->m_ceilings[0], &ceiling);
2548 if (rv == -1) {
2549 error = EFAULT;
2550 goto out;
2551 }
2552 ceiling = RTP_PRIO_MAX - ceiling;
2553 if (ceiling > RTP_PRIO_MAX) {
2554 error = EINVAL;
2555 goto out;
2556 }
2557 new_pri = PRI_MIN_REALTIME + ceiling;
2558
2559 if (td->td_base_user_pri < new_pri) {
2560 error = EINVAL;
2561 goto out;
2562 }
2563 if (su) {
2564 mtx_lock(&umtx_lock);
2565 if (new_pri < uq->uq_inherited_pri) {
2566 uq->uq_inherited_pri = new_pri;
2567 thread_lock(td);
2568 if (new_pri < UPRI(td))
2569 sched_lend_user_prio(td, new_pri);
2570 thread_unlock(td);
2571 }
2572 mtx_unlock(&umtx_lock);
2573 }
2574
2575 rv = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner,
2576 id | UMUTEX_CONTESTED);
2577 /* The address was invalid. */
2578 if (rv == -1) {
2579 error = EFAULT;
2580 break;
2581 }
2582 if (rv == 0) {
2583 MPASS(owner == UMUTEX_CONTESTED);
2584 error = 0;
2585 break;
2586 }
2587 /* rv == 1 */
2588 if (owner == UMUTEX_RB_OWNERDEAD) {
2589 rv = casueword32(&m->m_owner, UMUTEX_RB_OWNERDEAD,
2590 &owner, id | UMUTEX_CONTESTED);
2591 if (rv == -1) {
2592 error = EFAULT;
2593 break;
2594 }
2595 if (rv == 0) {
2596 MPASS(owner == UMUTEX_RB_OWNERDEAD);
2597 error = EOWNERDEAD; /* success */
2598 break;
2599 }
2600
2601 /*
2602 * rv == 1, only check for suspension if we
2603 * did not already catched a signal. If we
2604 * get an error from the check, the same
2605 * condition is checked by the umtxq_sleep()
2606 * call below, so we should obliterate the
2607 * error to not skip the last loop iteration.
2608 */
2609 if (error == 0) {
2610 error = thread_check_susp(td, false);
2611 if (error == 0 && try == 0) {
2612 umtxq_unbusy_unlocked(&uq->uq_key);
2613 continue;
2614 }
2615 error = 0;
2616 }
2617 } else if (owner == UMUTEX_RB_NOTRECOV) {
2618 error = ENOTRECOVERABLE;
2619 }
2620
2621 if (try != 0)
2622 error = EBUSY;
2623
2624 /*
2625 * If we caught a signal, we have retried and now
2626 * exit immediately.
2627 */
2628 if (error != 0)
2629 break;
2630
2631 umtxq_lock(&uq->uq_key);
2632 umtxq_insert(uq);
2633 umtxq_unbusy(&uq->uq_key);
2634 error = umtxq_sleep(uq, "umtxpp", timeout == NULL ?
2635 NULL : &timo);
2636 umtxq_remove(uq);
2637 umtxq_unlock(&uq->uq_key);
2638
2639 mtx_lock(&umtx_lock);
2640 uq->uq_inherited_pri = old_inherited_pri;
2641 pri = PRI_MAX;
2642 TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) {
2643 uq2 = TAILQ_FIRST(&pi->pi_blocked);
2644 if (uq2 != NULL) {
2645 if (pri > UPRI(uq2->uq_thread))
2646 pri = UPRI(uq2->uq_thread);
2647 }
2648 }
2649 if (pri > uq->uq_inherited_pri)
2650 pri = uq->uq_inherited_pri;
2651 thread_lock(td);
2652 sched_lend_user_prio(td, pri);
2653 thread_unlock(td);
2654 mtx_unlock(&umtx_lock);
2655 }
2656
2657 if (error != 0 && error != EOWNERDEAD) {
2658 mtx_lock(&umtx_lock);
2659 uq->uq_inherited_pri = old_inherited_pri;
2660 pri = PRI_MAX;
2661 TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) {
2662 uq2 = TAILQ_FIRST(&pi->pi_blocked);
2663 if (uq2 != NULL) {
2664 if (pri > UPRI(uq2->uq_thread))
2665 pri = UPRI(uq2->uq_thread);
2666 }
2667 }
2668 if (pri > uq->uq_inherited_pri)
2669 pri = uq->uq_inherited_pri;
2670 thread_lock(td);
2671 sched_lend_user_prio(td, pri);
2672 thread_unlock(td);
2673 mtx_unlock(&umtx_lock);
2674 }
2675
2676 out:
2677 umtxq_unbusy_unlocked(&uq->uq_key);
2678 umtx_key_release(&uq->uq_key);
2679 return (error);
2680 }
2681
2682 /*
2683 * Unlock a PP mutex.
2684 */
2685 static int
do_unlock_pp(struct thread * td,struct umutex * m,uint32_t flags,bool rb)2686 do_unlock_pp(struct thread *td, struct umutex *m, uint32_t flags, bool rb)
2687 {
2688 struct umtx_key key;
2689 struct umtx_q *uq, *uq2;
2690 struct umtx_pi *pi;
2691 uint32_t id, owner, rceiling;
2692 int error, pri, new_inherited_pri;
2693 bool su;
2694
2695 id = td->td_tid;
2696 uq = td->td_umtxq;
2697 su = (priv_check(td, PRIV_SCHED_RTPRIO) == 0);
2698
2699 /*
2700 * Make sure we own this mtx.
2701 */
2702 error = fueword32(&m->m_owner, &owner);
2703 if (error == -1)
2704 return (EFAULT);
2705
2706 if ((owner & ~UMUTEX_CONTESTED) != id)
2707 return (EPERM);
2708
2709 error = copyin(&m->m_ceilings[1], &rceiling, sizeof(uint32_t));
2710 if (error != 0)
2711 return (error);
2712
2713 if (rceiling == -1)
2714 new_inherited_pri = PRI_MAX;
2715 else {
2716 rceiling = RTP_PRIO_MAX - rceiling;
2717 if (rceiling > RTP_PRIO_MAX)
2718 return (EINVAL);
2719 new_inherited_pri = PRI_MIN_REALTIME + rceiling;
2720 }
2721
2722 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
2723 TYPE_PP_ROBUST_UMUTEX : TYPE_PP_UMUTEX, GET_SHARE(flags),
2724 &key)) != 0)
2725 return (error);
2726 umtxq_lock(&key);
2727 umtxq_busy(&key);
2728 umtxq_unlock(&key);
2729 /*
2730 * For priority protected mutex, always set unlocked state
2731 * to UMUTEX_CONTESTED, so that userland always enters kernel
2732 * to lock the mutex, it is necessary because thread priority
2733 * has to be adjusted for such mutex.
2734 */
2735 error = suword32(&m->m_owner, umtx_unlock_val(flags, rb) |
2736 UMUTEX_CONTESTED);
2737
2738 umtxq_lock(&key);
2739 if (error == 0)
2740 umtxq_signal(&key, 1);
2741 umtxq_unbusy(&key);
2742 umtxq_unlock(&key);
2743
2744 if (error == -1)
2745 error = EFAULT;
2746 else {
2747 mtx_lock(&umtx_lock);
2748 if (su || new_inherited_pri == PRI_MAX)
2749 uq->uq_inherited_pri = new_inherited_pri;
2750 pri = PRI_MAX;
2751 TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) {
2752 uq2 = TAILQ_FIRST(&pi->pi_blocked);
2753 if (uq2 != NULL) {
2754 if (pri > UPRI(uq2->uq_thread))
2755 pri = UPRI(uq2->uq_thread);
2756 }
2757 }
2758 if (pri > uq->uq_inherited_pri)
2759 pri = uq->uq_inherited_pri;
2760 thread_lock(td);
2761 sched_lend_user_prio(td, pri);
2762 thread_unlock(td);
2763 mtx_unlock(&umtx_lock);
2764 }
2765 umtx_key_release(&key);
2766 return (error);
2767 }
2768
2769 static int
do_set_ceiling(struct thread * td,struct umutex * m,uint32_t ceiling,uint32_t * old_ceiling)2770 do_set_ceiling(struct thread *td, struct umutex *m, uint32_t ceiling,
2771 uint32_t *old_ceiling)
2772 {
2773 struct umtx_q *uq;
2774 uint32_t flags, id, owner, save_ceiling;
2775 int error, rv, rv1;
2776
2777 error = fueword32(&m->m_flags, &flags);
2778 if (error == -1)
2779 return (EFAULT);
2780 if ((flags & UMUTEX_PRIO_PROTECT) == 0)
2781 return (EINVAL);
2782 if (ceiling > RTP_PRIO_MAX)
2783 return (EINVAL);
2784 id = td->td_tid;
2785 uq = td->td_umtxq;
2786 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
2787 TYPE_PP_ROBUST_UMUTEX : TYPE_PP_UMUTEX, GET_SHARE(flags),
2788 &uq->uq_key)) != 0)
2789 return (error);
2790 for (;;) {
2791 umtxq_lock(&uq->uq_key);
2792 umtxq_busy(&uq->uq_key);
2793 umtxq_unlock(&uq->uq_key);
2794
2795 rv = fueword32(&m->m_ceilings[0], &save_ceiling);
2796 if (rv == -1) {
2797 error = EFAULT;
2798 break;
2799 }
2800
2801 rv = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner,
2802 id | UMUTEX_CONTESTED);
2803 if (rv == -1) {
2804 error = EFAULT;
2805 break;
2806 }
2807
2808 if (rv == 0) {
2809 MPASS(owner == UMUTEX_CONTESTED);
2810 rv = suword32(&m->m_ceilings[0], ceiling);
2811 rv1 = suword32(&m->m_owner, UMUTEX_CONTESTED);
2812 error = (rv == 0 && rv1 == 0) ? 0: EFAULT;
2813 break;
2814 }
2815
2816 if ((owner & ~UMUTEX_CONTESTED) == id) {
2817 rv = suword32(&m->m_ceilings[0], ceiling);
2818 error = rv == 0 ? 0 : EFAULT;
2819 break;
2820 }
2821
2822 if (owner == UMUTEX_RB_OWNERDEAD) {
2823 error = EOWNERDEAD;
2824 break;
2825 } else if (owner == UMUTEX_RB_NOTRECOV) {
2826 error = ENOTRECOVERABLE;
2827 break;
2828 }
2829
2830 /*
2831 * If we caught a signal, we have retried and now
2832 * exit immediately.
2833 */
2834 if (error != 0)
2835 break;
2836
2837 /*
2838 * We set the contested bit, sleep. Otherwise the lock changed
2839 * and we need to retry or we lost a race to the thread
2840 * unlocking the umtx.
2841 */
2842 umtxq_lock(&uq->uq_key);
2843 umtxq_insert(uq);
2844 umtxq_unbusy(&uq->uq_key);
2845 error = umtxq_sleep(uq, "umtxpp", NULL);
2846 umtxq_remove(uq);
2847 umtxq_unlock(&uq->uq_key);
2848 }
2849 umtxq_lock(&uq->uq_key);
2850 if (error == 0)
2851 umtxq_signal(&uq->uq_key, INT_MAX);
2852 umtxq_unbusy(&uq->uq_key);
2853 umtxq_unlock(&uq->uq_key);
2854 umtx_key_release(&uq->uq_key);
2855 if (error == 0 && old_ceiling != NULL) {
2856 rv = suword32(old_ceiling, save_ceiling);
2857 error = rv == 0 ? 0 : EFAULT;
2858 }
2859 return (error);
2860 }
2861
2862 /*
2863 * Lock a userland POSIX mutex.
2864 */
2865 static int
do_lock_umutex(struct thread * td,struct umutex * m,struct _umtx_time * timeout,int mode)2866 do_lock_umutex(struct thread *td, struct umutex *m,
2867 struct _umtx_time *timeout, int mode)
2868 {
2869 uint32_t flags;
2870 int error;
2871
2872 error = fueword32(&m->m_flags, &flags);
2873 if (error == -1)
2874 return (EFAULT);
2875
2876 switch (flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT)) {
2877 case 0:
2878 error = do_lock_normal(td, m, flags, timeout, mode);
2879 break;
2880 case UMUTEX_PRIO_INHERIT:
2881 error = do_lock_pi(td, m, flags, timeout, mode);
2882 break;
2883 case UMUTEX_PRIO_PROTECT:
2884 error = do_lock_pp(td, m, flags, timeout, mode);
2885 break;
2886 default:
2887 return (EINVAL);
2888 }
2889 if (timeout == NULL) {
2890 if (error == EINTR && mode != _UMUTEX_WAIT)
2891 error = ERESTART;
2892 } else {
2893 /* Timed-locking is not restarted. */
2894 if (error == ERESTART)
2895 error = EINTR;
2896 }
2897 return (error);
2898 }
2899
2900 /*
2901 * Unlock a userland POSIX mutex.
2902 */
2903 static int
do_unlock_umutex(struct thread * td,struct umutex * m,bool rb)2904 do_unlock_umutex(struct thread *td, struct umutex *m, bool rb)
2905 {
2906 uint32_t flags;
2907 int error;
2908
2909 error = fueword32(&m->m_flags, &flags);
2910 if (error == -1)
2911 return (EFAULT);
2912
2913 switch (flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT)) {
2914 case 0:
2915 return (do_unlock_normal(td, m, flags, rb));
2916 case UMUTEX_PRIO_INHERIT:
2917 return (do_unlock_pi(td, m, flags, rb));
2918 case UMUTEX_PRIO_PROTECT:
2919 return (do_unlock_pp(td, m, flags, rb));
2920 }
2921
2922 return (EINVAL);
2923 }
2924
2925 static int
do_cv_wait(struct thread * td,struct ucond * cv,struct umutex * m,struct timespec * timeout,u_long wflags)2926 do_cv_wait(struct thread *td, struct ucond *cv, struct umutex *m,
2927 struct timespec *timeout, u_long wflags)
2928 {
2929 struct umtx_abs_timeout timo;
2930 struct umtx_q *uq;
2931 uint32_t flags, clockid, hasw;
2932 int error;
2933
2934 uq = td->td_umtxq;
2935 error = fueword32(&cv->c_flags, &flags);
2936 if (error == -1)
2937 return (EFAULT);
2938 error = umtx_key_get(cv, TYPE_CV, GET_SHARE(flags), &uq->uq_key);
2939 if (error != 0)
2940 return (error);
2941
2942 if ((wflags & CVWAIT_CLOCKID) != 0) {
2943 error = fueword32(&cv->c_clockid, &clockid);
2944 if (error == -1) {
2945 umtx_key_release(&uq->uq_key);
2946 return (EFAULT);
2947 }
2948 if (clockid < CLOCK_REALTIME ||
2949 clockid >= CLOCK_THREAD_CPUTIME_ID) {
2950 /* hmm, only HW clock id will work. */
2951 umtx_key_release(&uq->uq_key);
2952 return (EINVAL);
2953 }
2954 } else {
2955 clockid = CLOCK_REALTIME;
2956 }
2957
2958 umtxq_lock(&uq->uq_key);
2959 umtxq_busy(&uq->uq_key);
2960 umtxq_insert(uq);
2961 umtxq_unlock(&uq->uq_key);
2962
2963 /*
2964 * Set c_has_waiters to 1 before releasing user mutex, also
2965 * don't modify cache line when unnecessary.
2966 */
2967 error = fueword32(&cv->c_has_waiters, &hasw);
2968 if (error == 0 && hasw == 0)
2969 error = suword32(&cv->c_has_waiters, 1);
2970 if (error != 0) {
2971 umtxq_lock(&uq->uq_key);
2972 umtxq_remove(uq);
2973 umtxq_unbusy(&uq->uq_key);
2974 error = EFAULT;
2975 goto out;
2976 }
2977
2978 umtxq_unbusy_unlocked(&uq->uq_key);
2979
2980 error = do_unlock_umutex(td, m, false);
2981
2982 if (timeout != NULL)
2983 umtx_abs_timeout_init(&timo, clockid,
2984 (wflags & CVWAIT_ABSTIME) != 0, timeout);
2985
2986 umtxq_lock(&uq->uq_key);
2987 if (error == 0) {
2988 error = umtxq_sleep(uq, "ucond", timeout == NULL ?
2989 NULL : &timo);
2990 }
2991
2992 if ((uq->uq_flags & UQF_UMTXQ) == 0)
2993 error = 0;
2994 else {
2995 /*
2996 * This must be timeout,interrupted by signal or
2997 * surprious wakeup, clear c_has_waiter flag when
2998 * necessary.
2999 */
3000 umtxq_busy(&uq->uq_key);
3001 if ((uq->uq_flags & UQF_UMTXQ) != 0) {
3002 int oldlen = uq->uq_cur_queue->length;
3003 umtxq_remove(uq);
3004 if (oldlen == 1) {
3005 umtxq_unlock(&uq->uq_key);
3006 if (suword32(&cv->c_has_waiters, 0) != 0 &&
3007 error == 0)
3008 error = EFAULT;
3009 umtxq_lock(&uq->uq_key);
3010 }
3011 }
3012 umtxq_unbusy(&uq->uq_key);
3013 if (error == ERESTART)
3014 error = EINTR;
3015 }
3016 out:
3017 umtxq_unlock(&uq->uq_key);
3018 umtx_key_release(&uq->uq_key);
3019 return (error);
3020 }
3021
3022 /*
3023 * Signal a userland condition variable.
3024 */
3025 static int
do_cv_signal(struct thread * td,struct ucond * cv)3026 do_cv_signal(struct thread *td, struct ucond *cv)
3027 {
3028 struct umtx_key key;
3029 int error, cnt, nwake;
3030 uint32_t flags;
3031
3032 error = fueword32(&cv->c_flags, &flags);
3033 if (error == -1)
3034 return (EFAULT);
3035 if ((error = umtx_key_get(cv, TYPE_CV, GET_SHARE(flags), &key)) != 0)
3036 return (error);
3037 umtxq_lock(&key);
3038 umtxq_busy(&key);
3039 cnt = umtxq_count(&key);
3040 nwake = umtxq_signal(&key, 1);
3041 if (cnt <= nwake) {
3042 umtxq_unlock(&key);
3043 error = suword32(&cv->c_has_waiters, 0);
3044 if (error == -1)
3045 error = EFAULT;
3046 umtxq_lock(&key);
3047 }
3048 umtxq_unbusy(&key);
3049 umtxq_unlock(&key);
3050 umtx_key_release(&key);
3051 return (error);
3052 }
3053
3054 static int
do_cv_broadcast(struct thread * td,struct ucond * cv)3055 do_cv_broadcast(struct thread *td, struct ucond *cv)
3056 {
3057 struct umtx_key key;
3058 int error;
3059 uint32_t flags;
3060
3061 error = fueword32(&cv->c_flags, &flags);
3062 if (error == -1)
3063 return (EFAULT);
3064 if ((error = umtx_key_get(cv, TYPE_CV, GET_SHARE(flags), &key)) != 0)
3065 return (error);
3066
3067 umtxq_lock(&key);
3068 umtxq_busy(&key);
3069 umtxq_signal(&key, INT_MAX);
3070 umtxq_unlock(&key);
3071
3072 error = suword32(&cv->c_has_waiters, 0);
3073 if (error == -1)
3074 error = EFAULT;
3075
3076 umtxq_unbusy_unlocked(&key);
3077
3078 umtx_key_release(&key);
3079 return (error);
3080 }
3081
3082 static int
do_rw_rdlock(struct thread * td,struct urwlock * rwlock,long fflag,struct _umtx_time * timeout)3083 do_rw_rdlock(struct thread *td, struct urwlock *rwlock, long fflag,
3084 struct _umtx_time *timeout)
3085 {
3086 struct umtx_abs_timeout timo;
3087 struct umtx_q *uq;
3088 uint32_t flags, wrflags;
3089 int32_t state, oldstate;
3090 int32_t blocked_readers;
3091 int error, error1, rv;
3092
3093 uq = td->td_umtxq;
3094 error = fueword32(&rwlock->rw_flags, &flags);
3095 if (error == -1)
3096 return (EFAULT);
3097 error = umtx_key_get(rwlock, TYPE_RWLOCK, GET_SHARE(flags), &uq->uq_key);
3098 if (error != 0)
3099 return (error);
3100
3101 if (timeout != NULL)
3102 umtx_abs_timeout_init2(&timo, timeout);
3103
3104 wrflags = URWLOCK_WRITE_OWNER;
3105 if (!(fflag & URWLOCK_PREFER_READER) && !(flags & URWLOCK_PREFER_READER))
3106 wrflags |= URWLOCK_WRITE_WAITERS;
3107
3108 for (;;) {
3109 rv = fueword32(&rwlock->rw_state, &state);
3110 if (rv == -1) {
3111 umtx_key_release(&uq->uq_key);
3112 return (EFAULT);
3113 }
3114
3115 /* try to lock it */
3116 while (!(state & wrflags)) {
3117 if (__predict_false(URWLOCK_READER_COUNT(state) ==
3118 URWLOCK_MAX_READERS)) {
3119 umtx_key_release(&uq->uq_key);
3120 return (EAGAIN);
3121 }
3122 rv = casueword32(&rwlock->rw_state, state,
3123 &oldstate, state + 1);
3124 if (rv == -1) {
3125 umtx_key_release(&uq->uq_key);
3126 return (EFAULT);
3127 }
3128 if (rv == 0) {
3129 MPASS(oldstate == state);
3130 umtx_key_release(&uq->uq_key);
3131 return (0);
3132 }
3133 error = thread_check_susp(td, true);
3134 if (error != 0)
3135 break;
3136 state = oldstate;
3137 }
3138
3139 if (error)
3140 break;
3141
3142 /* grab monitor lock */
3143 umtxq_lock(&uq->uq_key);
3144 umtxq_busy(&uq->uq_key);
3145 umtxq_unlock(&uq->uq_key);
3146
3147 /*
3148 * re-read the state, in case it changed between the try-lock above
3149 * and the check below
3150 */
3151 rv = fueword32(&rwlock->rw_state, &state);
3152 if (rv == -1)
3153 error = EFAULT;
3154
3155 /* set read contention bit */
3156 while (error == 0 && (state & wrflags) &&
3157 !(state & URWLOCK_READ_WAITERS)) {
3158 rv = casueword32(&rwlock->rw_state, state,
3159 &oldstate, state | URWLOCK_READ_WAITERS);
3160 if (rv == -1) {
3161 error = EFAULT;
3162 break;
3163 }
3164 if (rv == 0) {
3165 MPASS(oldstate == state);
3166 goto sleep;
3167 }
3168 state = oldstate;
3169 error = thread_check_susp(td, false);
3170 if (error != 0)
3171 break;
3172 }
3173 if (error != 0) {
3174 umtxq_unbusy_unlocked(&uq->uq_key);
3175 break;
3176 }
3177
3178 /* state is changed while setting flags, restart */
3179 if (!(state & wrflags)) {
3180 umtxq_unbusy_unlocked(&uq->uq_key);
3181 error = thread_check_susp(td, true);
3182 if (error != 0)
3183 break;
3184 continue;
3185 }
3186
3187 sleep:
3188 /*
3189 * Contention bit is set, before sleeping, increase
3190 * read waiter count.
3191 */
3192 rv = fueword32(&rwlock->rw_blocked_readers,
3193 &blocked_readers);
3194 if (rv == 0)
3195 rv = suword32(&rwlock->rw_blocked_readers,
3196 blocked_readers + 1);
3197 if (rv == -1) {
3198 umtxq_unbusy_unlocked(&uq->uq_key);
3199 error = EFAULT;
3200 break;
3201 }
3202
3203 while (state & wrflags) {
3204 umtxq_lock(&uq->uq_key);
3205 umtxq_insert(uq);
3206 umtxq_unbusy(&uq->uq_key);
3207
3208 error = umtxq_sleep(uq, "urdlck", timeout == NULL ?
3209 NULL : &timo);
3210
3211 umtxq_busy(&uq->uq_key);
3212 umtxq_remove(uq);
3213 umtxq_unlock(&uq->uq_key);
3214 if (error)
3215 break;
3216 rv = fueword32(&rwlock->rw_state, &state);
3217 if (rv == -1) {
3218 error = EFAULT;
3219 break;
3220 }
3221 }
3222
3223 /* decrease read waiter count, and may clear read contention bit */
3224 rv = fueword32(&rwlock->rw_blocked_readers,
3225 &blocked_readers);
3226 if (rv == 0)
3227 rv = suword32(&rwlock->rw_blocked_readers,
3228 blocked_readers - 1);
3229 if (rv == -1) {
3230 umtxq_unbusy_unlocked(&uq->uq_key);
3231 error = EFAULT;
3232 break;
3233 }
3234 if (blocked_readers == 1) {
3235 rv = fueword32(&rwlock->rw_state, &state);
3236 if (rv == -1) {
3237 umtxq_unbusy_unlocked(&uq->uq_key);
3238 error = EFAULT;
3239 break;
3240 }
3241 for (;;) {
3242 rv = casueword32(&rwlock->rw_state, state,
3243 &oldstate, state & ~URWLOCK_READ_WAITERS);
3244 if (rv == -1) {
3245 error = EFAULT;
3246 break;
3247 }
3248 if (rv == 0) {
3249 MPASS(oldstate == state);
3250 break;
3251 }
3252 state = oldstate;
3253 error1 = thread_check_susp(td, false);
3254 if (error1 != 0) {
3255 if (error == 0)
3256 error = error1;
3257 break;
3258 }
3259 }
3260 }
3261
3262 umtxq_unbusy_unlocked(&uq->uq_key);
3263 if (error != 0)
3264 break;
3265 }
3266 umtx_key_release(&uq->uq_key);
3267 if (error == ERESTART)
3268 error = EINTR;
3269 return (error);
3270 }
3271
3272 static int
do_rw_wrlock(struct thread * td,struct urwlock * rwlock,struct _umtx_time * timeout)3273 do_rw_wrlock(struct thread *td, struct urwlock *rwlock, struct _umtx_time *timeout)
3274 {
3275 struct umtx_abs_timeout timo;
3276 struct umtx_q *uq;
3277 uint32_t flags;
3278 int32_t state, oldstate;
3279 int32_t blocked_writers;
3280 int32_t blocked_readers;
3281 int error, error1, rv;
3282
3283 uq = td->td_umtxq;
3284 error = fueword32(&rwlock->rw_flags, &flags);
3285 if (error == -1)
3286 return (EFAULT);
3287 error = umtx_key_get(rwlock, TYPE_RWLOCK, GET_SHARE(flags), &uq->uq_key);
3288 if (error != 0)
3289 return (error);
3290
3291 if (timeout != NULL)
3292 umtx_abs_timeout_init2(&timo, timeout);
3293
3294 blocked_readers = 0;
3295 for (;;) {
3296 rv = fueword32(&rwlock->rw_state, &state);
3297 if (rv == -1) {
3298 umtx_key_release(&uq->uq_key);
3299 return (EFAULT);
3300 }
3301 while ((state & URWLOCK_WRITE_OWNER) == 0 &&
3302 URWLOCK_READER_COUNT(state) == 0) {
3303 rv = casueword32(&rwlock->rw_state, state,
3304 &oldstate, state | URWLOCK_WRITE_OWNER);
3305 if (rv == -1) {
3306 umtx_key_release(&uq->uq_key);
3307 return (EFAULT);
3308 }
3309 if (rv == 0) {
3310 MPASS(oldstate == state);
3311 umtx_key_release(&uq->uq_key);
3312 return (0);
3313 }
3314 state = oldstate;
3315 error = thread_check_susp(td, true);
3316 if (error != 0)
3317 break;
3318 }
3319
3320 if (error) {
3321 if ((state & (URWLOCK_WRITE_OWNER |
3322 URWLOCK_WRITE_WAITERS)) == 0 &&
3323 blocked_readers != 0) {
3324 umtxq_lock(&uq->uq_key);
3325 umtxq_busy(&uq->uq_key);
3326 umtxq_signal_queue(&uq->uq_key, INT_MAX,
3327 UMTX_SHARED_QUEUE);
3328 umtxq_unbusy(&uq->uq_key);
3329 umtxq_unlock(&uq->uq_key);
3330 }
3331
3332 break;
3333 }
3334
3335 /* grab monitor lock */
3336 umtxq_lock(&uq->uq_key);
3337 umtxq_busy(&uq->uq_key);
3338 umtxq_unlock(&uq->uq_key);
3339
3340 /*
3341 * Re-read the state, in case it changed between the
3342 * try-lock above and the check below.
3343 */
3344 rv = fueword32(&rwlock->rw_state, &state);
3345 if (rv == -1)
3346 error = EFAULT;
3347
3348 while (error == 0 && ((state & URWLOCK_WRITE_OWNER) ||
3349 URWLOCK_READER_COUNT(state) != 0) &&
3350 (state & URWLOCK_WRITE_WAITERS) == 0) {
3351 rv = casueword32(&rwlock->rw_state, state,
3352 &oldstate, state | URWLOCK_WRITE_WAITERS);
3353 if (rv == -1) {
3354 error = EFAULT;
3355 break;
3356 }
3357 if (rv == 0) {
3358 MPASS(oldstate == state);
3359 goto sleep;
3360 }
3361 state = oldstate;
3362 error = thread_check_susp(td, false);
3363 if (error != 0)
3364 break;
3365 }
3366 if (error != 0) {
3367 umtxq_unbusy_unlocked(&uq->uq_key);
3368 break;
3369 }
3370
3371 if ((state & URWLOCK_WRITE_OWNER) == 0 &&
3372 URWLOCK_READER_COUNT(state) == 0) {
3373 umtxq_unbusy_unlocked(&uq->uq_key);
3374 error = thread_check_susp(td, false);
3375 if (error != 0)
3376 break;
3377 continue;
3378 }
3379 sleep:
3380 rv = fueword32(&rwlock->rw_blocked_writers,
3381 &blocked_writers);
3382 if (rv == 0)
3383 rv = suword32(&rwlock->rw_blocked_writers,
3384 blocked_writers + 1);
3385 if (rv == -1) {
3386 umtxq_unbusy_unlocked(&uq->uq_key);
3387 error = EFAULT;
3388 break;
3389 }
3390
3391 while ((state & URWLOCK_WRITE_OWNER) ||
3392 URWLOCK_READER_COUNT(state) != 0) {
3393 umtxq_lock(&uq->uq_key);
3394 umtxq_insert_queue(uq, UMTX_EXCLUSIVE_QUEUE);
3395 umtxq_unbusy(&uq->uq_key);
3396
3397 error = umtxq_sleep(uq, "uwrlck", timeout == NULL ?
3398 NULL : &timo);
3399
3400 umtxq_busy(&uq->uq_key);
3401 umtxq_remove_queue(uq, UMTX_EXCLUSIVE_QUEUE);
3402 umtxq_unlock(&uq->uq_key);
3403 if (error)
3404 break;
3405 rv = fueword32(&rwlock->rw_state, &state);
3406 if (rv == -1) {
3407 error = EFAULT;
3408 break;
3409 }
3410 }
3411
3412 rv = fueword32(&rwlock->rw_blocked_writers,
3413 &blocked_writers);
3414 if (rv == 0)
3415 rv = suword32(&rwlock->rw_blocked_writers,
3416 blocked_writers - 1);
3417 if (rv == -1) {
3418 umtxq_unbusy_unlocked(&uq->uq_key);
3419 error = EFAULT;
3420 break;
3421 }
3422 if (blocked_writers == 1) {
3423 rv = fueword32(&rwlock->rw_state, &state);
3424 if (rv == -1) {
3425 umtxq_unbusy_unlocked(&uq->uq_key);
3426 error = EFAULT;
3427 break;
3428 }
3429 for (;;) {
3430 rv = casueword32(&rwlock->rw_state, state,
3431 &oldstate, state & ~URWLOCK_WRITE_WAITERS);
3432 if (rv == -1) {
3433 error = EFAULT;
3434 break;
3435 }
3436 if (rv == 0) {
3437 MPASS(oldstate == state);
3438 break;
3439 }
3440 state = oldstate;
3441 error1 = thread_check_susp(td, false);
3442 /*
3443 * We are leaving the URWLOCK_WRITE_WAITERS
3444 * behind, but this should not harm the
3445 * correctness.
3446 */
3447 if (error1 != 0) {
3448 if (error == 0)
3449 error = error1;
3450 break;
3451 }
3452 }
3453 rv = fueword32(&rwlock->rw_blocked_readers,
3454 &blocked_readers);
3455 if (rv == -1) {
3456 umtxq_unbusy_unlocked(&uq->uq_key);
3457 error = EFAULT;
3458 break;
3459 }
3460 } else
3461 blocked_readers = 0;
3462
3463 umtxq_unbusy_unlocked(&uq->uq_key);
3464 }
3465
3466 umtx_key_release(&uq->uq_key);
3467 if (error == ERESTART)
3468 error = EINTR;
3469 return (error);
3470 }
3471
3472 static int
do_rw_unlock(struct thread * td,struct urwlock * rwlock)3473 do_rw_unlock(struct thread *td, struct urwlock *rwlock)
3474 {
3475 struct umtx_q *uq;
3476 uint32_t flags;
3477 int32_t state, oldstate;
3478 int error, rv, q, count;
3479
3480 uq = td->td_umtxq;
3481 error = fueword32(&rwlock->rw_flags, &flags);
3482 if (error == -1)
3483 return (EFAULT);
3484 error = umtx_key_get(rwlock, TYPE_RWLOCK, GET_SHARE(flags), &uq->uq_key);
3485 if (error != 0)
3486 return (error);
3487
3488 error = fueword32(&rwlock->rw_state, &state);
3489 if (error == -1) {
3490 error = EFAULT;
3491 goto out;
3492 }
3493 if (state & URWLOCK_WRITE_OWNER) {
3494 for (;;) {
3495 rv = casueword32(&rwlock->rw_state, state,
3496 &oldstate, state & ~URWLOCK_WRITE_OWNER);
3497 if (rv == -1) {
3498 error = EFAULT;
3499 goto out;
3500 }
3501 if (rv == 1) {
3502 state = oldstate;
3503 if (!(oldstate & URWLOCK_WRITE_OWNER)) {
3504 error = EPERM;
3505 goto out;
3506 }
3507 error = thread_check_susp(td, true);
3508 if (error != 0)
3509 goto out;
3510 } else
3511 break;
3512 }
3513 } else if (URWLOCK_READER_COUNT(state) != 0) {
3514 for (;;) {
3515 rv = casueword32(&rwlock->rw_state, state,
3516 &oldstate, state - 1);
3517 if (rv == -1) {
3518 error = EFAULT;
3519 goto out;
3520 }
3521 if (rv == 1) {
3522 state = oldstate;
3523 if (URWLOCK_READER_COUNT(oldstate) == 0) {
3524 error = EPERM;
3525 goto out;
3526 }
3527 error = thread_check_susp(td, true);
3528 if (error != 0)
3529 goto out;
3530 } else
3531 break;
3532 }
3533 } else {
3534 error = EPERM;
3535 goto out;
3536 }
3537
3538 count = 0;
3539
3540 if (!(flags & URWLOCK_PREFER_READER)) {
3541 if (state & URWLOCK_WRITE_WAITERS) {
3542 count = 1;
3543 q = UMTX_EXCLUSIVE_QUEUE;
3544 } else if (state & URWLOCK_READ_WAITERS) {
3545 count = INT_MAX;
3546 q = UMTX_SHARED_QUEUE;
3547 }
3548 } else {
3549 if (state & URWLOCK_READ_WAITERS) {
3550 count = INT_MAX;
3551 q = UMTX_SHARED_QUEUE;
3552 } else if (state & URWLOCK_WRITE_WAITERS) {
3553 count = 1;
3554 q = UMTX_EXCLUSIVE_QUEUE;
3555 }
3556 }
3557
3558 if (count) {
3559 umtxq_lock(&uq->uq_key);
3560 umtxq_busy(&uq->uq_key);
3561 umtxq_signal_queue(&uq->uq_key, count, q);
3562 umtxq_unbusy(&uq->uq_key);
3563 umtxq_unlock(&uq->uq_key);
3564 }
3565 out:
3566 umtx_key_release(&uq->uq_key);
3567 return (error);
3568 }
3569
3570 #if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
3571 static int
do_sem_wait(struct thread * td,struct _usem * sem,struct _umtx_time * timeout)3572 do_sem_wait(struct thread *td, struct _usem *sem, struct _umtx_time *timeout)
3573 {
3574 struct umtx_abs_timeout timo;
3575 struct umtx_q *uq;
3576 uint32_t flags, count, count1;
3577 int error, rv, rv1;
3578
3579 uq = td->td_umtxq;
3580 error = fueword32(&sem->_flags, &flags);
3581 if (error == -1)
3582 return (EFAULT);
3583 error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &uq->uq_key);
3584 if (error != 0)
3585 return (error);
3586
3587 if (timeout != NULL)
3588 umtx_abs_timeout_init2(&timo, timeout);
3589
3590 again:
3591 umtxq_lock(&uq->uq_key);
3592 umtxq_busy(&uq->uq_key);
3593 umtxq_insert(uq);
3594 umtxq_unlock(&uq->uq_key);
3595 rv = casueword32(&sem->_has_waiters, 0, &count1, 1);
3596 if (rv != -1)
3597 rv1 = fueword32(&sem->_count, &count);
3598 if (rv == -1 || rv1 == -1 || count != 0 || (rv == 1 && count1 == 0)) {
3599 if (rv == 0)
3600 rv = suword32(&sem->_has_waiters, 0);
3601 umtxq_lock(&uq->uq_key);
3602 umtxq_unbusy(&uq->uq_key);
3603 umtxq_remove(uq);
3604 umtxq_unlock(&uq->uq_key);
3605 if (rv == -1 || rv1 == -1) {
3606 error = EFAULT;
3607 goto out;
3608 }
3609 if (count != 0) {
3610 error = 0;
3611 goto out;
3612 }
3613 MPASS(rv == 1 && count1 == 0);
3614 rv = thread_check_susp(td, true);
3615 if (rv == 0)
3616 goto again;
3617 error = rv;
3618 goto out;
3619 }
3620 umtxq_lock(&uq->uq_key);
3621 umtxq_unbusy(&uq->uq_key);
3622
3623 error = umtxq_sleep(uq, "usem", timeout == NULL ? NULL : &timo);
3624
3625 if ((uq->uq_flags & UQF_UMTXQ) == 0)
3626 error = 0;
3627 else {
3628 umtxq_remove(uq);
3629 /* A relative timeout cannot be restarted. */
3630 if (error == ERESTART && timeout != NULL &&
3631 (timeout->_flags & UMTX_ABSTIME) == 0)
3632 error = EINTR;
3633 }
3634 umtxq_unlock(&uq->uq_key);
3635 out:
3636 umtx_key_release(&uq->uq_key);
3637 return (error);
3638 }
3639
3640 /*
3641 * Signal a userland semaphore.
3642 */
3643 static int
do_sem_wake(struct thread * td,struct _usem * sem)3644 do_sem_wake(struct thread *td, struct _usem *sem)
3645 {
3646 struct umtx_key key;
3647 int error, cnt;
3648 uint32_t flags;
3649
3650 error = fueword32(&sem->_flags, &flags);
3651 if (error == -1)
3652 return (EFAULT);
3653 if ((error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &key)) != 0)
3654 return (error);
3655 umtxq_lock(&key);
3656 umtxq_busy(&key);
3657 cnt = umtxq_count(&key);
3658 if (cnt > 0) {
3659 /*
3660 * Check if count is greater than 0, this means the memory is
3661 * still being referenced by user code, so we can safely
3662 * update _has_waiters flag.
3663 */
3664 if (cnt == 1) {
3665 umtxq_unlock(&key);
3666 error = suword32(&sem->_has_waiters, 0);
3667 umtxq_lock(&key);
3668 if (error == -1)
3669 error = EFAULT;
3670 }
3671 umtxq_signal(&key, 1);
3672 }
3673 umtxq_unbusy(&key);
3674 umtxq_unlock(&key);
3675 umtx_key_release(&key);
3676 return (error);
3677 }
3678 #endif
3679
3680 static int
do_sem2_wait(struct thread * td,struct _usem2 * sem,struct _umtx_time * timeout)3681 do_sem2_wait(struct thread *td, struct _usem2 *sem, struct _umtx_time *timeout)
3682 {
3683 struct umtx_abs_timeout timo;
3684 struct umtx_q *uq;
3685 uint32_t count, flags;
3686 int error, rv;
3687
3688 uq = td->td_umtxq;
3689 flags = fuword32(&sem->_flags);
3690 if (timeout != NULL)
3691 umtx_abs_timeout_init2(&timo, timeout);
3692
3693 again:
3694 error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &uq->uq_key);
3695 if (error != 0)
3696 return (error);
3697 umtxq_lock(&uq->uq_key);
3698 umtxq_busy(&uq->uq_key);
3699 umtxq_insert(uq);
3700 umtxq_unlock(&uq->uq_key);
3701 rv = fueword32(&sem->_count, &count);
3702 if (rv == -1) {
3703 umtxq_lock(&uq->uq_key);
3704 umtxq_unbusy(&uq->uq_key);
3705 umtxq_remove(uq);
3706 umtxq_unlock(&uq->uq_key);
3707 umtx_key_release(&uq->uq_key);
3708 return (EFAULT);
3709 }
3710 for (;;) {
3711 if (USEM_COUNT(count) != 0) {
3712 umtxq_lock(&uq->uq_key);
3713 umtxq_unbusy(&uq->uq_key);
3714 umtxq_remove(uq);
3715 umtxq_unlock(&uq->uq_key);
3716 umtx_key_release(&uq->uq_key);
3717 return (0);
3718 }
3719 if (count == USEM_HAS_WAITERS)
3720 break;
3721 rv = casueword32(&sem->_count, 0, &count, USEM_HAS_WAITERS);
3722 if (rv == 0)
3723 break;
3724 umtxq_lock(&uq->uq_key);
3725 umtxq_unbusy(&uq->uq_key);
3726 umtxq_remove(uq);
3727 umtxq_unlock(&uq->uq_key);
3728 umtx_key_release(&uq->uq_key);
3729 if (rv == -1)
3730 return (EFAULT);
3731 rv = thread_check_susp(td, true);
3732 if (rv != 0)
3733 return (rv);
3734 goto again;
3735 }
3736 umtxq_lock(&uq->uq_key);
3737 umtxq_unbusy(&uq->uq_key);
3738
3739 error = umtxq_sleep(uq, "usem", timeout == NULL ? NULL : &timo);
3740
3741 if ((uq->uq_flags & UQF_UMTXQ) == 0)
3742 error = 0;
3743 else {
3744 umtxq_remove(uq);
3745 if (timeout != NULL && (timeout->_flags & UMTX_ABSTIME) == 0) {
3746 /* A relative timeout cannot be restarted. */
3747 if (error == ERESTART)
3748 error = EINTR;
3749 if (error == EINTR) {
3750 kern_clock_gettime(curthread, timo.clockid,
3751 &timo.cur);
3752 timespecsub(&timo.end, &timo.cur,
3753 &timeout->_timeout);
3754 }
3755 }
3756 }
3757 umtxq_unlock(&uq->uq_key);
3758 umtx_key_release(&uq->uq_key);
3759 return (error);
3760 }
3761
3762 /*
3763 * Signal a userland semaphore.
3764 */
3765 static int
do_sem2_wake(struct thread * td,struct _usem2 * sem)3766 do_sem2_wake(struct thread *td, struct _usem2 *sem)
3767 {
3768 struct umtx_key key;
3769 int error, cnt, rv;
3770 uint32_t count, flags;
3771
3772 rv = fueword32(&sem->_flags, &flags);
3773 if (rv == -1)
3774 return (EFAULT);
3775 if ((error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &key)) != 0)
3776 return (error);
3777 umtxq_lock(&key);
3778 umtxq_busy(&key);
3779 cnt = umtxq_count(&key);
3780 if (cnt > 0) {
3781 /*
3782 * If this was the last sleeping thread, clear the waiters
3783 * flag in _count.
3784 */
3785 if (cnt == 1) {
3786 umtxq_unlock(&key);
3787 rv = fueword32(&sem->_count, &count);
3788 while (rv != -1 && count & USEM_HAS_WAITERS) {
3789 rv = casueword32(&sem->_count, count, &count,
3790 count & ~USEM_HAS_WAITERS);
3791 if (rv == 1) {
3792 rv = thread_check_susp(td, true);
3793 if (rv != 0)
3794 break;
3795 }
3796 }
3797 if (rv == -1)
3798 error = EFAULT;
3799 else if (rv > 0) {
3800 error = rv;
3801 }
3802 umtxq_lock(&key);
3803 }
3804
3805 umtxq_signal(&key, 1);
3806 }
3807 umtxq_unbusy(&key);
3808 umtxq_unlock(&key);
3809 umtx_key_release(&key);
3810 return (error);
3811 }
3812
3813 #ifdef COMPAT_FREEBSD10
3814 int
freebsd10__umtx_lock(struct thread * td,struct freebsd10__umtx_lock_args * uap)3815 freebsd10__umtx_lock(struct thread *td, struct freebsd10__umtx_lock_args *uap)
3816 {
3817 return (do_lock_umtx(td, uap->umtx, td->td_tid, 0));
3818 }
3819
3820 int
freebsd10__umtx_unlock(struct thread * td,struct freebsd10__umtx_unlock_args * uap)3821 freebsd10__umtx_unlock(struct thread *td,
3822 struct freebsd10__umtx_unlock_args *uap)
3823 {
3824 return (do_unlock_umtx(td, uap->umtx, td->td_tid));
3825 }
3826 #endif
3827
3828 inline int
umtx_copyin_timeout(const void * uaddr,struct timespec * tsp)3829 umtx_copyin_timeout(const void *uaddr, struct timespec *tsp)
3830 {
3831 int error;
3832
3833 error = copyin(uaddr, tsp, sizeof(*tsp));
3834 if (error == 0) {
3835 if (!timespecvalid_interval(tsp))
3836 error = EINVAL;
3837 }
3838 return (error);
3839 }
3840
3841 static inline int
umtx_copyin_umtx_time(const void * uaddr,size_t size,struct _umtx_time * tp)3842 umtx_copyin_umtx_time(const void *uaddr, size_t size, struct _umtx_time *tp)
3843 {
3844 int error;
3845
3846 if (size <= sizeof(tp->_timeout)) {
3847 tp->_clockid = CLOCK_REALTIME;
3848 tp->_flags = 0;
3849 error = copyin(uaddr, &tp->_timeout, sizeof(tp->_timeout));
3850 } else
3851 error = copyin(uaddr, tp, sizeof(*tp));
3852 if (error != 0)
3853 return (error);
3854 if (!timespecvalid_interval(&tp->_timeout))
3855 return (EINVAL);
3856 return (0);
3857 }
3858
3859 static int
umtx_copyin_robust_lists(const void * uaddr,size_t size,struct umtx_robust_lists_params * rb)3860 umtx_copyin_robust_lists(const void *uaddr, size_t size,
3861 struct umtx_robust_lists_params *rb)
3862 {
3863
3864 if (size > sizeof(*rb))
3865 return (EINVAL);
3866 return (copyin(uaddr, rb, size));
3867 }
3868
3869 static int
umtx_copyout_timeout(void * uaddr,size_t sz,struct timespec * tsp)3870 umtx_copyout_timeout(void *uaddr, size_t sz, struct timespec *tsp)
3871 {
3872
3873 /*
3874 * Should be guaranteed by the caller, sz == uaddr1 - sizeof(_umtx_time)
3875 * and we're only called if sz >= sizeof(timespec) as supplied in the
3876 * copyops.
3877 */
3878 KASSERT(sz >= sizeof(*tsp),
3879 ("umtx_copyops specifies incorrect sizes"));
3880
3881 return (copyout(tsp, uaddr, sizeof(*tsp)));
3882 }
3883
3884 #ifdef COMPAT_FREEBSD10
3885 static int
__umtx_op_lock_umtx(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)3886 __umtx_op_lock_umtx(struct thread *td, struct _umtx_op_args *uap,
3887 const struct umtx_copyops *ops)
3888 {
3889 struct timespec *ts, timeout;
3890 int error;
3891
3892 /* Allow a null timespec (wait forever). */
3893 if (uap->uaddr2 == NULL)
3894 ts = NULL;
3895 else {
3896 error = ops->copyin_timeout(uap->uaddr2, &timeout);
3897 if (error != 0)
3898 return (error);
3899 ts = &timeout;
3900 }
3901 #ifdef COMPAT_FREEBSD32
3902 if (ops->compat32)
3903 return (do_lock_umtx32(td, uap->obj, uap->val, ts));
3904 #endif
3905 return (do_lock_umtx(td, uap->obj, uap->val, ts));
3906 }
3907
3908 static int
__umtx_op_unlock_umtx(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)3909 __umtx_op_unlock_umtx(struct thread *td, struct _umtx_op_args *uap,
3910 const struct umtx_copyops *ops)
3911 {
3912 #ifdef COMPAT_FREEBSD32
3913 if (ops->compat32)
3914 return (do_unlock_umtx32(td, uap->obj, uap->val));
3915 #endif
3916 return (do_unlock_umtx(td, uap->obj, uap->val));
3917 }
3918 #endif /* COMPAT_FREEBSD10 */
3919
3920 #if !defined(COMPAT_FREEBSD10)
3921 static int
__umtx_op_unimpl(struct thread * td __unused,struct _umtx_op_args * uap __unused,const struct umtx_copyops * ops __unused)3922 __umtx_op_unimpl(struct thread *td __unused, struct _umtx_op_args *uap __unused,
3923 const struct umtx_copyops *ops __unused)
3924 {
3925 return (EOPNOTSUPP);
3926 }
3927 #endif /* COMPAT_FREEBSD10 */
3928
3929 static int
__umtx_op_wait(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)3930 __umtx_op_wait(struct thread *td, struct _umtx_op_args *uap,
3931 const struct umtx_copyops *ops)
3932 {
3933 struct _umtx_time timeout, *tm_p;
3934 int error;
3935
3936 if (uap->uaddr2 == NULL)
3937 tm_p = NULL;
3938 else {
3939 error = ops->copyin_umtx_time(
3940 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
3941 if (error != 0)
3942 return (error);
3943 tm_p = &timeout;
3944 }
3945 return (do_wait(td, uap->obj, uap->val, tm_p, ops->compat32, 0));
3946 }
3947
3948 static int
__umtx_op_wait_uint(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)3949 __umtx_op_wait_uint(struct thread *td, struct _umtx_op_args *uap,
3950 const struct umtx_copyops *ops)
3951 {
3952 struct _umtx_time timeout, *tm_p;
3953 int error;
3954
3955 if (uap->uaddr2 == NULL)
3956 tm_p = NULL;
3957 else {
3958 error = ops->copyin_umtx_time(
3959 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
3960 if (error != 0)
3961 return (error);
3962 tm_p = &timeout;
3963 }
3964 return (do_wait(td, uap->obj, uap->val, tm_p, 1, 0));
3965 }
3966
3967 static int
__umtx_op_wait_uint_private(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)3968 __umtx_op_wait_uint_private(struct thread *td, struct _umtx_op_args *uap,
3969 const struct umtx_copyops *ops)
3970 {
3971 struct _umtx_time *tm_p, timeout;
3972 int error;
3973
3974 if (uap->uaddr2 == NULL)
3975 tm_p = NULL;
3976 else {
3977 error = ops->copyin_umtx_time(
3978 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
3979 if (error != 0)
3980 return (error);
3981 tm_p = &timeout;
3982 }
3983 return (do_wait(td, uap->obj, uap->val, tm_p, 1, 1));
3984 }
3985
3986 static int
__umtx_op_wake(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)3987 __umtx_op_wake(struct thread *td, struct _umtx_op_args *uap,
3988 const struct umtx_copyops *ops __unused)
3989 {
3990
3991 return (kern_umtx_wake(td, uap->obj, uap->val, 0));
3992 }
3993
3994 #define BATCH_SIZE 128
3995 static int
__umtx_op_nwake_private_native(struct thread * td,struct _umtx_op_args * uap)3996 __umtx_op_nwake_private_native(struct thread *td, struct _umtx_op_args *uap)
3997 {
3998 char *uaddrs[BATCH_SIZE], **upp;
3999 int count, error, i, pos, tocopy;
4000
4001 upp = (char **)uap->obj;
4002 error = 0;
4003 for (count = uap->val, pos = 0; count > 0; count -= tocopy,
4004 pos += tocopy) {
4005 tocopy = MIN(count, BATCH_SIZE);
4006 error = copyin(upp + pos, uaddrs, tocopy * sizeof(char *));
4007 if (error != 0)
4008 break;
4009 for (i = 0; i < tocopy; ++i) {
4010 kern_umtx_wake(td, uaddrs[i], INT_MAX, 1);
4011 }
4012 maybe_yield();
4013 }
4014 return (error);
4015 }
4016
4017 static int
__umtx_op_nwake_private_compat32(struct thread * td,struct _umtx_op_args * uap)4018 __umtx_op_nwake_private_compat32(struct thread *td, struct _umtx_op_args *uap)
4019 {
4020 uint32_t uaddrs[BATCH_SIZE], *upp;
4021 int count, error, i, pos, tocopy;
4022
4023 upp = (uint32_t *)uap->obj;
4024 error = 0;
4025 for (count = uap->val, pos = 0; count > 0; count -= tocopy,
4026 pos += tocopy) {
4027 tocopy = MIN(count, BATCH_SIZE);
4028 error = copyin(upp + pos, uaddrs, tocopy * sizeof(uint32_t));
4029 if (error != 0)
4030 break;
4031 for (i = 0; i < tocopy; ++i) {
4032 kern_umtx_wake(td, (void *)(uintptr_t)uaddrs[i],
4033 INT_MAX, 1);
4034 }
4035 maybe_yield();
4036 }
4037 return (error);
4038 }
4039
4040 static int
__umtx_op_nwake_private(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4041 __umtx_op_nwake_private(struct thread *td, struct _umtx_op_args *uap,
4042 const struct umtx_copyops *ops)
4043 {
4044
4045 if (ops->compat32)
4046 return (__umtx_op_nwake_private_compat32(td, uap));
4047 return (__umtx_op_nwake_private_native(td, uap));
4048 }
4049
4050 static int
__umtx_op_wake_private(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4051 __umtx_op_wake_private(struct thread *td, struct _umtx_op_args *uap,
4052 const struct umtx_copyops *ops __unused)
4053 {
4054
4055 return (kern_umtx_wake(td, uap->obj, uap->val, 1));
4056 }
4057
4058 static int
__umtx_op_lock_umutex(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4059 __umtx_op_lock_umutex(struct thread *td, struct _umtx_op_args *uap,
4060 const struct umtx_copyops *ops)
4061 {
4062 struct _umtx_time *tm_p, timeout;
4063 int error;
4064
4065 /* Allow a null timespec (wait forever). */
4066 if (uap->uaddr2 == NULL)
4067 tm_p = NULL;
4068 else {
4069 error = ops->copyin_umtx_time(
4070 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
4071 if (error != 0)
4072 return (error);
4073 tm_p = &timeout;
4074 }
4075 return (do_lock_umutex(td, uap->obj, tm_p, 0));
4076 }
4077
4078 static int
__umtx_op_trylock_umutex(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4079 __umtx_op_trylock_umutex(struct thread *td, struct _umtx_op_args *uap,
4080 const struct umtx_copyops *ops __unused)
4081 {
4082
4083 return (do_lock_umutex(td, uap->obj, NULL, _UMUTEX_TRY));
4084 }
4085
4086 static int
__umtx_op_wait_umutex(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4087 __umtx_op_wait_umutex(struct thread *td, struct _umtx_op_args *uap,
4088 const struct umtx_copyops *ops)
4089 {
4090 struct _umtx_time *tm_p, timeout;
4091 int error;
4092
4093 /* Allow a null timespec (wait forever). */
4094 if (uap->uaddr2 == NULL)
4095 tm_p = NULL;
4096 else {
4097 error = ops->copyin_umtx_time(
4098 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
4099 if (error != 0)
4100 return (error);
4101 tm_p = &timeout;
4102 }
4103 return (do_lock_umutex(td, uap->obj, tm_p, _UMUTEX_WAIT));
4104 }
4105
4106 static int
__umtx_op_wake_umutex(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4107 __umtx_op_wake_umutex(struct thread *td, struct _umtx_op_args *uap,
4108 const struct umtx_copyops *ops __unused)
4109 {
4110
4111 return (do_wake_umutex(td, uap->obj));
4112 }
4113
4114 static int
__umtx_op_unlock_umutex(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4115 __umtx_op_unlock_umutex(struct thread *td, struct _umtx_op_args *uap,
4116 const struct umtx_copyops *ops __unused)
4117 {
4118
4119 return (do_unlock_umutex(td, uap->obj, false));
4120 }
4121
4122 static int
__umtx_op_set_ceiling(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4123 __umtx_op_set_ceiling(struct thread *td, struct _umtx_op_args *uap,
4124 const struct umtx_copyops *ops __unused)
4125 {
4126
4127 return (do_set_ceiling(td, uap->obj, uap->val, uap->uaddr1));
4128 }
4129
4130 static int
__umtx_op_cv_wait(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4131 __umtx_op_cv_wait(struct thread *td, struct _umtx_op_args *uap,
4132 const struct umtx_copyops *ops)
4133 {
4134 struct timespec *ts, timeout;
4135 int error;
4136
4137 /* Allow a null timespec (wait forever). */
4138 if (uap->uaddr2 == NULL)
4139 ts = NULL;
4140 else {
4141 error = ops->copyin_timeout(uap->uaddr2, &timeout);
4142 if (error != 0)
4143 return (error);
4144 ts = &timeout;
4145 }
4146 return (do_cv_wait(td, uap->obj, uap->uaddr1, ts, uap->val));
4147 }
4148
4149 static int
__umtx_op_cv_signal(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4150 __umtx_op_cv_signal(struct thread *td, struct _umtx_op_args *uap,
4151 const struct umtx_copyops *ops __unused)
4152 {
4153
4154 return (do_cv_signal(td, uap->obj));
4155 }
4156
4157 static int
__umtx_op_cv_broadcast(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4158 __umtx_op_cv_broadcast(struct thread *td, struct _umtx_op_args *uap,
4159 const struct umtx_copyops *ops __unused)
4160 {
4161
4162 return (do_cv_broadcast(td, uap->obj));
4163 }
4164
4165 static int
__umtx_op_rw_rdlock(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4166 __umtx_op_rw_rdlock(struct thread *td, struct _umtx_op_args *uap,
4167 const struct umtx_copyops *ops)
4168 {
4169 struct _umtx_time timeout;
4170 int error;
4171
4172 /* Allow a null timespec (wait forever). */
4173 if (uap->uaddr2 == NULL) {
4174 error = do_rw_rdlock(td, uap->obj, uap->val, 0);
4175 } else {
4176 error = ops->copyin_umtx_time(uap->uaddr2,
4177 (size_t)uap->uaddr1, &timeout);
4178 if (error != 0)
4179 return (error);
4180 error = do_rw_rdlock(td, uap->obj, uap->val, &timeout);
4181 }
4182 return (error);
4183 }
4184
4185 static int
__umtx_op_rw_wrlock(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4186 __umtx_op_rw_wrlock(struct thread *td, struct _umtx_op_args *uap,
4187 const struct umtx_copyops *ops)
4188 {
4189 struct _umtx_time timeout;
4190 int error;
4191
4192 /* Allow a null timespec (wait forever). */
4193 if (uap->uaddr2 == NULL) {
4194 error = do_rw_wrlock(td, uap->obj, 0);
4195 } else {
4196 error = ops->copyin_umtx_time(uap->uaddr2,
4197 (size_t)uap->uaddr1, &timeout);
4198 if (error != 0)
4199 return (error);
4200
4201 error = do_rw_wrlock(td, uap->obj, &timeout);
4202 }
4203 return (error);
4204 }
4205
4206 static int
__umtx_op_rw_unlock(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4207 __umtx_op_rw_unlock(struct thread *td, struct _umtx_op_args *uap,
4208 const struct umtx_copyops *ops __unused)
4209 {
4210
4211 return (do_rw_unlock(td, uap->obj));
4212 }
4213
4214 #if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
4215 static int
__umtx_op_sem_wait(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4216 __umtx_op_sem_wait(struct thread *td, struct _umtx_op_args *uap,
4217 const struct umtx_copyops *ops)
4218 {
4219 struct _umtx_time *tm_p, timeout;
4220 int error;
4221
4222 /* Allow a null timespec (wait forever). */
4223 if (uap->uaddr2 == NULL)
4224 tm_p = NULL;
4225 else {
4226 error = ops->copyin_umtx_time(
4227 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
4228 if (error != 0)
4229 return (error);
4230 tm_p = &timeout;
4231 }
4232 return (do_sem_wait(td, uap->obj, tm_p));
4233 }
4234
4235 static int
__umtx_op_sem_wake(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4236 __umtx_op_sem_wake(struct thread *td, struct _umtx_op_args *uap,
4237 const struct umtx_copyops *ops __unused)
4238 {
4239
4240 return (do_sem_wake(td, uap->obj));
4241 }
4242 #endif
4243
4244 static int
__umtx_op_wake2_umutex(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4245 __umtx_op_wake2_umutex(struct thread *td, struct _umtx_op_args *uap,
4246 const struct umtx_copyops *ops __unused)
4247 {
4248
4249 return (do_wake2_umutex(td, uap->obj, uap->val));
4250 }
4251
4252 static int
__umtx_op_sem2_wait(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4253 __umtx_op_sem2_wait(struct thread *td, struct _umtx_op_args *uap,
4254 const struct umtx_copyops *ops)
4255 {
4256 struct _umtx_time *tm_p, timeout;
4257 size_t uasize;
4258 int error;
4259
4260 /* Allow a null timespec (wait forever). */
4261 if (uap->uaddr2 == NULL) {
4262 uasize = 0;
4263 tm_p = NULL;
4264 } else {
4265 uasize = (size_t)uap->uaddr1;
4266 error = ops->copyin_umtx_time(uap->uaddr2, uasize, &timeout);
4267 if (error != 0)
4268 return (error);
4269 tm_p = &timeout;
4270 }
4271 error = do_sem2_wait(td, uap->obj, tm_p);
4272 if (error == EINTR && uap->uaddr2 != NULL &&
4273 (timeout._flags & UMTX_ABSTIME) == 0 &&
4274 uasize >= ops->umtx_time_sz + ops->timespec_sz) {
4275 error = ops->copyout_timeout(
4276 (void *)((uintptr_t)uap->uaddr2 + ops->umtx_time_sz),
4277 uasize - ops->umtx_time_sz, &timeout._timeout);
4278 if (error == 0) {
4279 error = EINTR;
4280 }
4281 }
4282
4283 return (error);
4284 }
4285
4286 static int
__umtx_op_sem2_wake(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4287 __umtx_op_sem2_wake(struct thread *td, struct _umtx_op_args *uap,
4288 const struct umtx_copyops *ops __unused)
4289 {
4290
4291 return (do_sem2_wake(td, uap->obj));
4292 }
4293
4294 #define USHM_OBJ_UMTX(o) \
4295 ((struct umtx_shm_obj_list *)(&(o)->umtx_data))
4296
4297 #define USHMF_LINKED 0x0001
4298 struct umtx_shm_reg {
4299 TAILQ_ENTRY(umtx_shm_reg) ushm_reg_link;
4300 LIST_ENTRY(umtx_shm_reg) ushm_obj_link;
4301 struct umtx_key ushm_key;
4302 struct ucred *ushm_cred;
4303 struct shmfd *ushm_obj;
4304 u_int ushm_refcnt;
4305 u_int ushm_flags;
4306 };
4307
4308 LIST_HEAD(umtx_shm_obj_list, umtx_shm_reg);
4309 TAILQ_HEAD(umtx_shm_reg_head, umtx_shm_reg);
4310
4311 static uma_zone_t umtx_shm_reg_zone;
4312 static struct umtx_shm_reg_head umtx_shm_registry[UMTX_CHAINS];
4313 static struct mtx umtx_shm_lock;
4314 static struct umtx_shm_reg_head umtx_shm_reg_delfree =
4315 TAILQ_HEAD_INITIALIZER(umtx_shm_reg_delfree);
4316
4317 static void umtx_shm_free_reg(struct umtx_shm_reg *reg);
4318
4319 static void
umtx_shm_reg_delfree_tq(void * context __unused,int pending __unused)4320 umtx_shm_reg_delfree_tq(void *context __unused, int pending __unused)
4321 {
4322 struct umtx_shm_reg_head d;
4323 struct umtx_shm_reg *reg, *reg1;
4324
4325 TAILQ_INIT(&d);
4326 mtx_lock(&umtx_shm_lock);
4327 TAILQ_CONCAT(&d, &umtx_shm_reg_delfree, ushm_reg_link);
4328 mtx_unlock(&umtx_shm_lock);
4329 TAILQ_FOREACH_SAFE(reg, &d, ushm_reg_link, reg1) {
4330 TAILQ_REMOVE(&d, reg, ushm_reg_link);
4331 umtx_shm_free_reg(reg);
4332 }
4333 }
4334
4335 static struct task umtx_shm_reg_delfree_task =
4336 TASK_INITIALIZER(0, umtx_shm_reg_delfree_tq, NULL);
4337
4338 /*
4339 * Returns 0 if a SHM with the passed key is found in the registry, in which
4340 * case it is returned through 'oreg'. Otherwise, returns an error among ESRCH
4341 * (no corresponding SHM; ESRCH was chosen for compatibility, ENOENT would have
4342 * been preferable) or EOVERFLOW (there is a corresponding SHM, but reference
4343 * count would overflow, so can't return it), in which case '*oreg' is left
4344 * unchanged.
4345 */
4346 static int
umtx_shm_find_reg_locked(const struct umtx_key * key,struct umtx_shm_reg ** const oreg)4347 umtx_shm_find_reg_locked(const struct umtx_key *key,
4348 struct umtx_shm_reg **const oreg)
4349 {
4350 struct umtx_shm_reg *reg;
4351 struct umtx_shm_reg_head *reg_head;
4352
4353 KASSERT(key->shared, ("umtx_p_find_rg: private key"));
4354 mtx_assert(&umtx_shm_lock, MA_OWNED);
4355 reg_head = &umtx_shm_registry[key->hash];
4356 TAILQ_FOREACH(reg, reg_head, ushm_reg_link) {
4357 KASSERT(reg->ushm_key.shared,
4358 ("non-shared key on reg %p %d", reg, reg->ushm_key.shared));
4359 if (reg->ushm_key.info.shared.object ==
4360 key->info.shared.object &&
4361 reg->ushm_key.info.shared.offset ==
4362 key->info.shared.offset) {
4363 KASSERT(reg->ushm_key.type == TYPE_SHM, ("TYPE_USHM"));
4364 KASSERT(reg->ushm_refcnt != 0,
4365 ("reg %p refcnt 0 onlist", reg));
4366 KASSERT((reg->ushm_flags & USHMF_LINKED) != 0,
4367 ("reg %p not linked", reg));
4368 /*
4369 * Don't let overflow happen, just deny a new reference
4370 * (this is additional protection against some reference
4371 * count leak, which is known not to be the case at the
4372 * time of this writing).
4373 */
4374 if (__predict_false(reg->ushm_refcnt == UINT_MAX))
4375 return (EOVERFLOW);
4376 reg->ushm_refcnt++;
4377 *oreg = reg;
4378 return (0);
4379 }
4380 }
4381 return (ESRCH);
4382 }
4383
4384 /*
4385 * Calls umtx_shm_find_reg_unlocked() under the 'umtx_shm_lock'.
4386 */
4387 static int
umtx_shm_find_reg(const struct umtx_key * key,struct umtx_shm_reg ** const oreg)4388 umtx_shm_find_reg(const struct umtx_key *key, struct umtx_shm_reg **const oreg)
4389 {
4390 int error;
4391
4392 mtx_lock(&umtx_shm_lock);
4393 error = umtx_shm_find_reg_locked(key, oreg);
4394 mtx_unlock(&umtx_shm_lock);
4395 return (error);
4396 }
4397
4398 static void
umtx_shm_free_reg(struct umtx_shm_reg * reg)4399 umtx_shm_free_reg(struct umtx_shm_reg *reg)
4400 {
4401
4402 chgumtxcnt(reg->ushm_cred->cr_ruidinfo, -1, 0);
4403 crfree(reg->ushm_cred);
4404 shm_drop(reg->ushm_obj);
4405 uma_zfree(umtx_shm_reg_zone, reg);
4406 }
4407
4408 static bool
umtx_shm_unref_reg_locked(struct umtx_shm_reg * reg,bool linked_ref)4409 umtx_shm_unref_reg_locked(struct umtx_shm_reg *reg, bool linked_ref)
4410 {
4411 mtx_assert(&umtx_shm_lock, MA_OWNED);
4412 KASSERT(reg->ushm_refcnt != 0, ("ushm_reg %p refcnt 0", reg));
4413
4414 if (linked_ref) {
4415 if ((reg->ushm_flags & USHMF_LINKED) == 0)
4416 /*
4417 * The reference tied to USHMF_LINKED has already been
4418 * released concurrently.
4419 */
4420 return (false);
4421
4422 TAILQ_REMOVE(&umtx_shm_registry[reg->ushm_key.hash], reg,
4423 ushm_reg_link);
4424 LIST_REMOVE(reg, ushm_obj_link);
4425 reg->ushm_flags &= ~USHMF_LINKED;
4426 }
4427
4428 reg->ushm_refcnt--;
4429 return (reg->ushm_refcnt == 0);
4430 }
4431
4432 static void
umtx_shm_unref_reg(struct umtx_shm_reg * reg,bool linked_ref)4433 umtx_shm_unref_reg(struct umtx_shm_reg *reg, bool linked_ref)
4434 {
4435 vm_object_t object;
4436 bool dofree;
4437
4438 if (linked_ref) {
4439 /*
4440 * Note: This may be executed multiple times on the same
4441 * shared-memory VM object in presence of concurrent callers
4442 * because 'umtx_shm_lock' is not held all along in umtx_shm()
4443 * and here.
4444 */
4445 object = reg->ushm_obj->shm_object;
4446 VM_OBJECT_WLOCK(object);
4447 vm_object_set_flag(object, OBJ_UMTXDEAD);
4448 VM_OBJECT_WUNLOCK(object);
4449 }
4450 mtx_lock(&umtx_shm_lock);
4451 dofree = umtx_shm_unref_reg_locked(reg, linked_ref);
4452 mtx_unlock(&umtx_shm_lock);
4453 if (dofree)
4454 umtx_shm_free_reg(reg);
4455 }
4456
4457 void
umtx_shm_object_init(vm_object_t object)4458 umtx_shm_object_init(vm_object_t object)
4459 {
4460
4461 LIST_INIT(USHM_OBJ_UMTX(object));
4462 }
4463
4464 void
umtx_shm_object_terminated(vm_object_t object)4465 umtx_shm_object_terminated(vm_object_t object)
4466 {
4467 struct umtx_shm_reg *reg, *reg1;
4468 bool dofree;
4469
4470 if (LIST_EMPTY(USHM_OBJ_UMTX(object)))
4471 return;
4472
4473 dofree = false;
4474 mtx_lock(&umtx_shm_lock);
4475 LIST_FOREACH_SAFE(reg, USHM_OBJ_UMTX(object), ushm_obj_link, reg1) {
4476 if (umtx_shm_unref_reg_locked(reg, true)) {
4477 TAILQ_INSERT_TAIL(&umtx_shm_reg_delfree, reg,
4478 ushm_reg_link);
4479 dofree = true;
4480 }
4481 }
4482 mtx_unlock(&umtx_shm_lock);
4483 if (dofree)
4484 taskqueue_enqueue(taskqueue_thread, &umtx_shm_reg_delfree_task);
4485 }
4486
4487 static int
umtx_shm_create_reg(struct thread * td,const struct umtx_key * key,struct umtx_shm_reg ** res)4488 umtx_shm_create_reg(struct thread *td, const struct umtx_key *key,
4489 struct umtx_shm_reg **res)
4490 {
4491 struct shmfd *shm;
4492 struct umtx_shm_reg *reg, *reg1;
4493 struct ucred *cred;
4494 int error;
4495
4496 error = umtx_shm_find_reg(key, res);
4497 if (error != ESRCH) {
4498 /*
4499 * Either no error occured, and '*res' was filled, or EOVERFLOW
4500 * was returned, indicating a reference count limit, and we
4501 * won't create a duplicate registration. In both cases, we are
4502 * done.
4503 */
4504 return (error);
4505 }
4506 /* No entry, we will create one. */
4507
4508 cred = td->td_ucred;
4509 if (!chgumtxcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_UMTXP)))
4510 return (ENOMEM);
4511 shm = shm_alloc(td->td_ucred, O_RDWR, false);
4512 if (shm == NULL) {
4513 chgumtxcnt(cred->cr_ruidinfo, -1, 0);
4514 return (ENOMEM);
4515 }
4516 reg = uma_zalloc(umtx_shm_reg_zone, M_WAITOK | M_ZERO);
4517 bcopy(key, ®->ushm_key, sizeof(*key));
4518 reg->ushm_obj = shm;
4519 reg->ushm_cred = crhold(cred);
4520 error = shm_dotruncate(reg->ushm_obj, PAGE_SIZE);
4521 if (error != 0) {
4522 umtx_shm_free_reg(reg);
4523 return (error);
4524 }
4525 mtx_lock(&umtx_shm_lock);
4526 /* Re-lookup as 'umtx_shm_lock' has been temporarily released. */
4527 error = umtx_shm_find_reg_locked(key, ®1);
4528 switch (error) {
4529 case 0:
4530 mtx_unlock(&umtx_shm_lock);
4531 umtx_shm_free_reg(reg);
4532 *res = reg1;
4533 return (0);
4534 case ESRCH:
4535 break;
4536 default:
4537 mtx_unlock(&umtx_shm_lock);
4538 umtx_shm_free_reg(reg);
4539 return (error);
4540 }
4541 TAILQ_INSERT_TAIL(&umtx_shm_registry[key->hash], reg, ushm_reg_link);
4542 LIST_INSERT_HEAD(USHM_OBJ_UMTX(key->info.shared.object), reg,
4543 ushm_obj_link);
4544 reg->ushm_flags = USHMF_LINKED;
4545 /*
4546 * This is one reference for the registry and the list of shared
4547 * mutexes referenced by the VM object containing the lock pointer, and
4548 * another for the caller, which it will free after use. So, one of
4549 * these is tied to the presence of USHMF_LINKED.
4550 */
4551 reg->ushm_refcnt = 2;
4552 mtx_unlock(&umtx_shm_lock);
4553 *res = reg;
4554 return (0);
4555 }
4556
4557 static int
umtx_shm_alive(struct thread * td,void * addr)4558 umtx_shm_alive(struct thread *td, void *addr)
4559 {
4560 vm_map_t map;
4561 vm_map_entry_t entry;
4562 vm_object_t object;
4563 vm_pindex_t pindex;
4564 vm_prot_t prot;
4565 int res, ret;
4566 boolean_t wired;
4567
4568 map = &td->td_proc->p_vmspace->vm_map;
4569 res = vm_map_lookup(&map, (uintptr_t)addr, VM_PROT_READ, &entry,
4570 &object, &pindex, &prot, &wired);
4571 if (res != KERN_SUCCESS)
4572 return (EFAULT);
4573 if (object == NULL)
4574 ret = EINVAL;
4575 else
4576 ret = (object->flags & OBJ_UMTXDEAD) != 0 ? ENOTTY : 0;
4577 vm_map_lookup_done(map, entry);
4578 return (ret);
4579 }
4580
4581 static void
umtx_shm_init(void)4582 umtx_shm_init(void)
4583 {
4584 int i;
4585
4586 umtx_shm_reg_zone = uma_zcreate("umtx_shm", sizeof(struct umtx_shm_reg),
4587 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
4588 mtx_init(&umtx_shm_lock, "umtxshm", NULL, MTX_DEF);
4589 for (i = 0; i < nitems(umtx_shm_registry); i++)
4590 TAILQ_INIT(&umtx_shm_registry[i]);
4591 }
4592
4593 static int
umtx_shm(struct thread * td,void * addr,u_int flags)4594 umtx_shm(struct thread *td, void *addr, u_int flags)
4595 {
4596 struct umtx_key key;
4597 struct umtx_shm_reg *reg;
4598 struct file *fp;
4599 int error, fd;
4600
4601 if (__bitcount(flags & (UMTX_SHM_CREAT | UMTX_SHM_LOOKUP |
4602 UMTX_SHM_DESTROY| UMTX_SHM_ALIVE)) != 1)
4603 return (EINVAL);
4604 if ((flags & UMTX_SHM_ALIVE) != 0)
4605 return (umtx_shm_alive(td, addr));
4606 error = umtx_key_get(addr, TYPE_SHM, PROCESS_SHARE, &key);
4607 if (error != 0)
4608 return (error);
4609 KASSERT(key.shared == 1, ("non-shared key"));
4610 error = (flags & UMTX_SHM_CREAT) != 0 ?
4611 umtx_shm_create_reg(td, &key, ®) :
4612 umtx_shm_find_reg(&key, ®);
4613 umtx_key_release(&key);
4614 if (error != 0)
4615 return (error);
4616 KASSERT(reg != NULL, ("no reg"));
4617 if ((flags & UMTX_SHM_DESTROY) != 0) {
4618 umtx_shm_unref_reg(reg, true);
4619 } else {
4620 #if 0
4621 #ifdef MAC
4622 error = mac_posixshm_check_open(td->td_ucred,
4623 reg->ushm_obj, FFLAGS(O_RDWR));
4624 if (error == 0)
4625 #endif
4626 error = shm_access(reg->ushm_obj, td->td_ucred,
4627 FFLAGS(O_RDWR));
4628 if (error == 0)
4629 #endif
4630 error = falloc_caps(td, &fp, &fd, O_CLOEXEC, NULL);
4631 if (error == 0) {
4632 shm_hold(reg->ushm_obj);
4633 finit(fp, FFLAGS(O_RDWR), DTYPE_SHM, reg->ushm_obj,
4634 &shm_ops);
4635 td->td_retval[0] = fd;
4636 fdrop(fp, td);
4637 }
4638 }
4639 umtx_shm_unref_reg(reg, false);
4640 return (error);
4641 }
4642
4643 static int
__umtx_op_shm(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops __unused)4644 __umtx_op_shm(struct thread *td, struct _umtx_op_args *uap,
4645 const struct umtx_copyops *ops __unused)
4646 {
4647
4648 return (umtx_shm(td, uap->uaddr1, uap->val));
4649 }
4650
4651 static int
__umtx_op_robust_lists(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4652 __umtx_op_robust_lists(struct thread *td, struct _umtx_op_args *uap,
4653 const struct umtx_copyops *ops)
4654 {
4655 struct umtx_robust_lists_params rb;
4656 int error;
4657
4658 if (ops->compat32) {
4659 if ((td->td_pflags2 & TDP2_COMPAT32RB) == 0 &&
4660 (td->td_rb_list != 0 || td->td_rbp_list != 0 ||
4661 td->td_rb_inact != 0))
4662 return (EBUSY);
4663 } else if ((td->td_pflags2 & TDP2_COMPAT32RB) != 0) {
4664 return (EBUSY);
4665 }
4666
4667 bzero(&rb, sizeof(rb));
4668 error = ops->copyin_robust_lists(uap->uaddr1, uap->val, &rb);
4669 if (error != 0)
4670 return (error);
4671
4672 if (ops->compat32)
4673 td->td_pflags2 |= TDP2_COMPAT32RB;
4674
4675 td->td_rb_list = rb.robust_list_offset;
4676 td->td_rbp_list = rb.robust_priv_list_offset;
4677 td->td_rb_inact = rb.robust_inact_offset;
4678 return (0);
4679 }
4680
4681 static int
__umtx_op_get_min_timeout(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4682 __umtx_op_get_min_timeout(struct thread *td, struct _umtx_op_args *uap,
4683 const struct umtx_copyops *ops)
4684 {
4685 long val;
4686 int error, val1;
4687
4688 val = sbttons(td->td_proc->p_umtx_min_timeout);
4689 if (ops->compat32) {
4690 val1 = (int)val;
4691 error = copyout(&val1, uap->uaddr1, sizeof(val1));
4692 } else {
4693 error = copyout(&val, uap->uaddr1, sizeof(val));
4694 }
4695 return (error);
4696 }
4697
4698 static int
__umtx_op_set_min_timeout(struct thread * td,struct _umtx_op_args * uap,const struct umtx_copyops * ops)4699 __umtx_op_set_min_timeout(struct thread *td, struct _umtx_op_args *uap,
4700 const struct umtx_copyops *ops)
4701 {
4702 if (uap->val < 0)
4703 return (EINVAL);
4704 td->td_proc->p_umtx_min_timeout = nstosbt(uap->val);
4705 return (0);
4706 }
4707
4708 #if defined(__i386__) || defined(__amd64__)
4709 /*
4710 * Provide the standard 32-bit definitions for x86, since native/compat32 use a
4711 * 32-bit time_t there. Other architectures just need the i386 definitions
4712 * along with their standard compat32.
4713 */
4714 struct timespecx32 {
4715 int64_t tv_sec;
4716 int32_t tv_nsec;
4717 };
4718
4719 struct umtx_timex32 {
4720 struct timespecx32 _timeout;
4721 uint32_t _flags;
4722 uint32_t _clockid;
4723 };
4724
4725 #ifndef __i386__
4726 #define timespeci386 timespec32
4727 #define umtx_timei386 umtx_time32
4728 #endif
4729 #else /* !__i386__ && !__amd64__ */
4730 /* 32-bit architectures can emulate i386, so define these almost everywhere. */
4731 struct timespeci386 {
4732 int32_t tv_sec;
4733 int32_t tv_nsec;
4734 };
4735
4736 struct umtx_timei386 {
4737 struct timespeci386 _timeout;
4738 uint32_t _flags;
4739 uint32_t _clockid;
4740 };
4741
4742 #if defined(__LP64__)
4743 #define timespecx32 timespec32
4744 #define umtx_timex32 umtx_time32
4745 #endif
4746 #endif
4747
4748 static int
umtx_copyin_robust_lists32(const void * uaddr,size_t size,struct umtx_robust_lists_params * rbp)4749 umtx_copyin_robust_lists32(const void *uaddr, size_t size,
4750 struct umtx_robust_lists_params *rbp)
4751 {
4752 struct umtx_robust_lists_params_compat32 rb32;
4753 int error;
4754
4755 if (size > sizeof(rb32))
4756 return (EINVAL);
4757 bzero(&rb32, sizeof(rb32));
4758 error = copyin(uaddr, &rb32, size);
4759 if (error != 0)
4760 return (error);
4761 CP(rb32, *rbp, robust_list_offset);
4762 CP(rb32, *rbp, robust_priv_list_offset);
4763 CP(rb32, *rbp, robust_inact_offset);
4764 return (0);
4765 }
4766
4767 #ifndef __i386__
4768 static inline int
umtx_copyin_timeouti386(const void * uaddr,struct timespec * tsp)4769 umtx_copyin_timeouti386(const void *uaddr, struct timespec *tsp)
4770 {
4771 struct timespeci386 ts32;
4772 int error;
4773
4774 error = copyin(uaddr, &ts32, sizeof(ts32));
4775 if (error == 0) {
4776 if (!timespecvalid_interval(&ts32))
4777 error = EINVAL;
4778 else {
4779 CP(ts32, *tsp, tv_sec);
4780 CP(ts32, *tsp, tv_nsec);
4781 }
4782 }
4783 return (error);
4784 }
4785
4786 static inline int
umtx_copyin_umtx_timei386(const void * uaddr,size_t size,struct _umtx_time * tp)4787 umtx_copyin_umtx_timei386(const void *uaddr, size_t size, struct _umtx_time *tp)
4788 {
4789 struct umtx_timei386 t32;
4790 int error;
4791
4792 t32._clockid = CLOCK_REALTIME;
4793 t32._flags = 0;
4794 if (size <= sizeof(t32._timeout))
4795 error = copyin(uaddr, &t32._timeout, sizeof(t32._timeout));
4796 else
4797 error = copyin(uaddr, &t32, sizeof(t32));
4798 if (error != 0)
4799 return (error);
4800 if (!timespecvalid_interval(&t32._timeout))
4801 return (EINVAL);
4802 TS_CP(t32, *tp, _timeout);
4803 CP(t32, *tp, _flags);
4804 CP(t32, *tp, _clockid);
4805 return (0);
4806 }
4807
4808 static int
umtx_copyout_timeouti386(void * uaddr,size_t sz,struct timespec * tsp)4809 umtx_copyout_timeouti386(void *uaddr, size_t sz, struct timespec *tsp)
4810 {
4811 struct timespeci386 remain32 = {
4812 .tv_sec = tsp->tv_sec,
4813 .tv_nsec = tsp->tv_nsec,
4814 };
4815
4816 /*
4817 * Should be guaranteed by the caller, sz == uaddr1 - sizeof(_umtx_time)
4818 * and we're only called if sz >= sizeof(timespec) as supplied in the
4819 * copyops.
4820 */
4821 KASSERT(sz >= sizeof(remain32),
4822 ("umtx_copyops specifies incorrect sizes"));
4823
4824 return (copyout(&remain32, uaddr, sizeof(remain32)));
4825 }
4826 #endif /* !__i386__ */
4827
4828 #if defined(__i386__) || defined(__LP64__)
4829 static inline int
umtx_copyin_timeoutx32(const void * uaddr,struct timespec * tsp)4830 umtx_copyin_timeoutx32(const void *uaddr, struct timespec *tsp)
4831 {
4832 struct timespecx32 ts32;
4833 int error;
4834
4835 error = copyin(uaddr, &ts32, sizeof(ts32));
4836 if (error == 0) {
4837 if (!timespecvalid_interval(&ts32))
4838 error = EINVAL;
4839 else {
4840 CP(ts32, *tsp, tv_sec);
4841 CP(ts32, *tsp, tv_nsec);
4842 }
4843 }
4844 return (error);
4845 }
4846
4847 static inline int
umtx_copyin_umtx_timex32(const void * uaddr,size_t size,struct _umtx_time * tp)4848 umtx_copyin_umtx_timex32(const void *uaddr, size_t size, struct _umtx_time *tp)
4849 {
4850 struct umtx_timex32 t32;
4851 int error;
4852
4853 t32._clockid = CLOCK_REALTIME;
4854 t32._flags = 0;
4855 if (size <= sizeof(t32._timeout))
4856 error = copyin(uaddr, &t32._timeout, sizeof(t32._timeout));
4857 else
4858 error = copyin(uaddr, &t32, sizeof(t32));
4859 if (error != 0)
4860 return (error);
4861 if (!timespecvalid_interval(&t32._timeout))
4862 return (EINVAL);
4863 TS_CP(t32, *tp, _timeout);
4864 CP(t32, *tp, _flags);
4865 CP(t32, *tp, _clockid);
4866 return (0);
4867 }
4868
4869 static int
umtx_copyout_timeoutx32(void * uaddr,size_t sz,struct timespec * tsp)4870 umtx_copyout_timeoutx32(void *uaddr, size_t sz, struct timespec *tsp)
4871 {
4872 struct timespecx32 remain32 = {
4873 .tv_sec = tsp->tv_sec,
4874 .tv_nsec = tsp->tv_nsec,
4875 };
4876
4877 /*
4878 * Should be guaranteed by the caller, sz == uaddr1 - sizeof(_umtx_time)
4879 * and we're only called if sz >= sizeof(timespec) as supplied in the
4880 * copyops.
4881 */
4882 KASSERT(sz >= sizeof(remain32),
4883 ("umtx_copyops specifies incorrect sizes"));
4884
4885 return (copyout(&remain32, uaddr, sizeof(remain32)));
4886 }
4887 #endif /* __i386__ || __LP64__ */
4888
4889 typedef int (*_umtx_op_func)(struct thread *td, struct _umtx_op_args *uap,
4890 const struct umtx_copyops *umtx_ops);
4891
4892 static const _umtx_op_func op_table[] = {
4893 #ifdef COMPAT_FREEBSD10
4894 [UMTX_OP_LOCK] = __umtx_op_lock_umtx,
4895 [UMTX_OP_UNLOCK] = __umtx_op_unlock_umtx,
4896 #else
4897 [UMTX_OP_LOCK] = __umtx_op_unimpl,
4898 [UMTX_OP_UNLOCK] = __umtx_op_unimpl,
4899 #endif
4900 [UMTX_OP_WAIT] = __umtx_op_wait,
4901 [UMTX_OP_WAKE] = __umtx_op_wake,
4902 [UMTX_OP_MUTEX_TRYLOCK] = __umtx_op_trylock_umutex,
4903 [UMTX_OP_MUTEX_LOCK] = __umtx_op_lock_umutex,
4904 [UMTX_OP_MUTEX_UNLOCK] = __umtx_op_unlock_umutex,
4905 [UMTX_OP_SET_CEILING] = __umtx_op_set_ceiling,
4906 [UMTX_OP_CV_WAIT] = __umtx_op_cv_wait,
4907 [UMTX_OP_CV_SIGNAL] = __umtx_op_cv_signal,
4908 [UMTX_OP_CV_BROADCAST] = __umtx_op_cv_broadcast,
4909 [UMTX_OP_WAIT_UINT] = __umtx_op_wait_uint,
4910 [UMTX_OP_RW_RDLOCK] = __umtx_op_rw_rdlock,
4911 [UMTX_OP_RW_WRLOCK] = __umtx_op_rw_wrlock,
4912 [UMTX_OP_RW_UNLOCK] = __umtx_op_rw_unlock,
4913 [UMTX_OP_WAIT_UINT_PRIVATE] = __umtx_op_wait_uint_private,
4914 [UMTX_OP_WAKE_PRIVATE] = __umtx_op_wake_private,
4915 [UMTX_OP_MUTEX_WAIT] = __umtx_op_wait_umutex,
4916 [UMTX_OP_MUTEX_WAKE] = __umtx_op_wake_umutex,
4917 #if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
4918 [UMTX_OP_SEM_WAIT] = __umtx_op_sem_wait,
4919 [UMTX_OP_SEM_WAKE] = __umtx_op_sem_wake,
4920 #else
4921 [UMTX_OP_SEM_WAIT] = __umtx_op_unimpl,
4922 [UMTX_OP_SEM_WAKE] = __umtx_op_unimpl,
4923 #endif
4924 [UMTX_OP_NWAKE_PRIVATE] = __umtx_op_nwake_private,
4925 [UMTX_OP_MUTEX_WAKE2] = __umtx_op_wake2_umutex,
4926 [UMTX_OP_SEM2_WAIT] = __umtx_op_sem2_wait,
4927 [UMTX_OP_SEM2_WAKE] = __umtx_op_sem2_wake,
4928 [UMTX_OP_SHM] = __umtx_op_shm,
4929 [UMTX_OP_ROBUST_LISTS] = __umtx_op_robust_lists,
4930 [UMTX_OP_GET_MIN_TIMEOUT] = __umtx_op_get_min_timeout,
4931 [UMTX_OP_SET_MIN_TIMEOUT] = __umtx_op_set_min_timeout,
4932 };
4933
4934 static const struct umtx_copyops umtx_native_ops = {
4935 .copyin_timeout = umtx_copyin_timeout,
4936 .copyin_umtx_time = umtx_copyin_umtx_time,
4937 .copyin_robust_lists = umtx_copyin_robust_lists,
4938 .copyout_timeout = umtx_copyout_timeout,
4939 .timespec_sz = sizeof(struct timespec),
4940 .umtx_time_sz = sizeof(struct _umtx_time),
4941 };
4942
4943 #ifndef __i386__
4944 static const struct umtx_copyops umtx_native_opsi386 = {
4945 .copyin_timeout = umtx_copyin_timeouti386,
4946 .copyin_umtx_time = umtx_copyin_umtx_timei386,
4947 .copyin_robust_lists = umtx_copyin_robust_lists32,
4948 .copyout_timeout = umtx_copyout_timeouti386,
4949 .timespec_sz = sizeof(struct timespeci386),
4950 .umtx_time_sz = sizeof(struct umtx_timei386),
4951 .compat32 = true,
4952 };
4953 #endif
4954
4955 #if defined(__i386__) || defined(__LP64__)
4956 /* i386 can emulate other 32-bit archs, too! */
4957 static const struct umtx_copyops umtx_native_opsx32 = {
4958 .copyin_timeout = umtx_copyin_timeoutx32,
4959 .copyin_umtx_time = umtx_copyin_umtx_timex32,
4960 .copyin_robust_lists = umtx_copyin_robust_lists32,
4961 .copyout_timeout = umtx_copyout_timeoutx32,
4962 .timespec_sz = sizeof(struct timespecx32),
4963 .umtx_time_sz = sizeof(struct umtx_timex32),
4964 .compat32 = true,
4965 };
4966
4967 #ifdef COMPAT_FREEBSD32
4968 #ifdef __amd64__
4969 #define umtx_native_ops32 umtx_native_opsi386
4970 #else
4971 #define umtx_native_ops32 umtx_native_opsx32
4972 #endif
4973 #endif /* COMPAT_FREEBSD32 */
4974 #endif /* __i386__ || __LP64__ */
4975
4976 #define UMTX_OP__FLAGS (UMTX_OP__32BIT | UMTX_OP__I386)
4977
4978 static int
kern__umtx_op(struct thread * td,void * obj,int op,unsigned long val,void * uaddr1,void * uaddr2,const struct umtx_copyops * ops)4979 kern__umtx_op(struct thread *td, void *obj, int op, unsigned long val,
4980 void *uaddr1, void *uaddr2, const struct umtx_copyops *ops)
4981 {
4982 struct _umtx_op_args uap = {
4983 .obj = obj,
4984 .op = op & ~UMTX_OP__FLAGS,
4985 .val = val,
4986 .uaddr1 = uaddr1,
4987 .uaddr2 = uaddr2
4988 };
4989
4990 if ((uap.op >= nitems(op_table)))
4991 return (EINVAL);
4992 return ((*op_table[uap.op])(td, &uap, ops));
4993 }
4994
4995 int
sys__umtx_op(struct thread * td,struct _umtx_op_args * uap)4996 sys__umtx_op(struct thread *td, struct _umtx_op_args *uap)
4997 {
4998 static const struct umtx_copyops *umtx_ops;
4999
5000 umtx_ops = &umtx_native_ops;
5001 #ifdef __LP64__
5002 if ((uap->op & (UMTX_OP__32BIT | UMTX_OP__I386)) != 0) {
5003 if ((uap->op & UMTX_OP__I386) != 0)
5004 umtx_ops = &umtx_native_opsi386;
5005 else
5006 umtx_ops = &umtx_native_opsx32;
5007 }
5008 #elif !defined(__i386__)
5009 /* We consider UMTX_OP__32BIT a nop on !i386 ILP32. */
5010 if ((uap->op & UMTX_OP__I386) != 0)
5011 umtx_ops = &umtx_native_opsi386;
5012 #else
5013 /* Likewise, UMTX_OP__I386 is a nop on i386. */
5014 if ((uap->op & UMTX_OP__32BIT) != 0)
5015 umtx_ops = &umtx_native_opsx32;
5016 #endif
5017 return (kern__umtx_op(td, uap->obj, uap->op, uap->val, uap->uaddr1,
5018 uap->uaddr2, umtx_ops));
5019 }
5020
5021 #ifdef COMPAT_FREEBSD32
5022 #ifdef COMPAT_FREEBSD10
5023 int
freebsd10_freebsd32__umtx_lock(struct thread * td,struct freebsd10_freebsd32__umtx_lock_args * uap)5024 freebsd10_freebsd32__umtx_lock(struct thread *td,
5025 struct freebsd10_freebsd32__umtx_lock_args *uap)
5026 {
5027 return (do_lock_umtx32(td, (uint32_t *)uap->umtx, td->td_tid, NULL));
5028 }
5029
5030 int
freebsd10_freebsd32__umtx_unlock(struct thread * td,struct freebsd10_freebsd32__umtx_unlock_args * uap)5031 freebsd10_freebsd32__umtx_unlock(struct thread *td,
5032 struct freebsd10_freebsd32__umtx_unlock_args *uap)
5033 {
5034 return (do_unlock_umtx32(td, (uint32_t *)uap->umtx, td->td_tid));
5035 }
5036 #endif /* COMPAT_FREEBSD10 */
5037
5038 int
freebsd32__umtx_op(struct thread * td,struct freebsd32__umtx_op_args * uap)5039 freebsd32__umtx_op(struct thread *td, struct freebsd32__umtx_op_args *uap)
5040 {
5041
5042 return (kern__umtx_op(td, uap->obj, uap->op, uap->val, uap->uaddr1,
5043 uap->uaddr2, &umtx_native_ops32));
5044 }
5045 #endif /* COMPAT_FREEBSD32 */
5046
5047 void
umtx_thread_init(struct thread * td)5048 umtx_thread_init(struct thread *td)
5049 {
5050
5051 td->td_umtxq = umtxq_alloc();
5052 td->td_umtxq->uq_thread = td;
5053 }
5054
5055 void
umtx_thread_fini(struct thread * td)5056 umtx_thread_fini(struct thread *td)
5057 {
5058
5059 umtxq_free(td->td_umtxq);
5060 }
5061
5062 /*
5063 * It will be called when new thread is created, e.g fork().
5064 */
5065 void
umtx_thread_alloc(struct thread * td)5066 umtx_thread_alloc(struct thread *td)
5067 {
5068 struct umtx_q *uq;
5069
5070 uq = td->td_umtxq;
5071 uq->uq_inherited_pri = PRI_MAX;
5072
5073 KASSERT(uq->uq_flags == 0, ("uq_flags != 0"));
5074 KASSERT(uq->uq_thread == td, ("uq_thread != td"));
5075 KASSERT(uq->uq_pi_blocked == NULL, ("uq_pi_blocked != NULL"));
5076 KASSERT(TAILQ_EMPTY(&uq->uq_pi_contested), ("uq_pi_contested is not empty"));
5077 }
5078
5079 /*
5080 * exec() hook.
5081 *
5082 * Clear robust lists for all process' threads, not delaying the
5083 * cleanup to thread exit, since the relevant address space is
5084 * destroyed right now.
5085 */
5086 void
umtx_exec(struct proc * p)5087 umtx_exec(struct proc *p)
5088 {
5089 struct thread *td;
5090
5091 KASSERT(p == curproc, ("need curproc"));
5092 KASSERT((p->p_flag & P_HADTHREADS) == 0 ||
5093 (p->p_flag & P_STOPPED_SINGLE) != 0,
5094 ("curproc must be single-threaded"));
5095 /*
5096 * There is no need to lock the list as only this thread can be
5097 * running.
5098 */
5099 FOREACH_THREAD_IN_PROC(p, td) {
5100 KASSERT(td == curthread ||
5101 ((td->td_flags & TDF_BOUNDARY) != 0 && TD_IS_SUSPENDED(td)),
5102 ("running thread %p %p", p, td));
5103 umtx_thread_cleanup(td);
5104 td->td_rb_list = td->td_rbp_list = td->td_rb_inact = 0;
5105 }
5106
5107 p->p_umtx_min_timeout = 0;
5108 }
5109
5110 /*
5111 * thread exit hook.
5112 */
5113 void
umtx_thread_exit(struct thread * td)5114 umtx_thread_exit(struct thread *td)
5115 {
5116
5117 umtx_thread_cleanup(td);
5118 }
5119
5120 static int
umtx_read_uptr(struct thread * td,uintptr_t ptr,uintptr_t * res,bool compat32)5121 umtx_read_uptr(struct thread *td, uintptr_t ptr, uintptr_t *res, bool compat32)
5122 {
5123 u_long res1;
5124 uint32_t res32;
5125 int error;
5126
5127 if (compat32) {
5128 error = fueword32((void *)ptr, &res32);
5129 if (error == 0)
5130 res1 = res32;
5131 } else {
5132 error = fueword((void *)ptr, &res1);
5133 }
5134 if (error == 0)
5135 *res = res1;
5136 else
5137 error = EFAULT;
5138 return (error);
5139 }
5140
5141 static void
umtx_read_rb_list(struct thread * td,struct umutex * m,uintptr_t * rb_list,bool compat32)5142 umtx_read_rb_list(struct thread *td, struct umutex *m, uintptr_t *rb_list,
5143 bool compat32)
5144 {
5145 struct umutex32 m32;
5146
5147 if (compat32) {
5148 memcpy(&m32, m, sizeof(m32));
5149 *rb_list = m32.m_rb_lnk;
5150 } else {
5151 *rb_list = m->m_rb_lnk;
5152 }
5153 }
5154
5155 static int
umtx_handle_rb(struct thread * td,uintptr_t rbp,uintptr_t * rb_list,bool inact,bool compat32)5156 umtx_handle_rb(struct thread *td, uintptr_t rbp, uintptr_t *rb_list, bool inact,
5157 bool compat32)
5158 {
5159 struct umutex m;
5160 int error;
5161
5162 KASSERT(td->td_proc == curproc, ("need current vmspace"));
5163 error = copyin((void *)rbp, &m, sizeof(m));
5164 if (error != 0)
5165 return (error);
5166 if (rb_list != NULL)
5167 umtx_read_rb_list(td, &m, rb_list, compat32);
5168 if ((m.m_flags & UMUTEX_ROBUST) == 0)
5169 return (EINVAL);
5170 if ((m.m_owner & ~UMUTEX_CONTESTED) != td->td_tid)
5171 /* inact is cleared after unlock, allow the inconsistency */
5172 return (inact ? 0 : EINVAL);
5173 return (do_unlock_umutex(td, (struct umutex *)rbp, true));
5174 }
5175
5176 static void
umtx_cleanup_rb_list(struct thread * td,uintptr_t rb_list,uintptr_t * rb_inact,const char * name,bool compat32)5177 umtx_cleanup_rb_list(struct thread *td, uintptr_t rb_list, uintptr_t *rb_inact,
5178 const char *name, bool compat32)
5179 {
5180 int error, i;
5181 uintptr_t rbp;
5182 bool inact;
5183
5184 if (rb_list == 0)
5185 return;
5186 error = umtx_read_uptr(td, rb_list, &rbp, compat32);
5187 for (i = 0; error == 0 && rbp != 0 && i < umtx_max_rb; i++) {
5188 if (rbp == *rb_inact) {
5189 inact = true;
5190 *rb_inact = 0;
5191 } else
5192 inact = false;
5193 error = umtx_handle_rb(td, rbp, &rbp, inact, compat32);
5194 }
5195 if (i == umtx_max_rb && umtx_verbose_rb) {
5196 uprintf("comm %s pid %d: reached umtx %smax rb %d\n",
5197 td->td_proc->p_comm, td->td_proc->p_pid, name, umtx_max_rb);
5198 }
5199 if (error != 0 && umtx_verbose_rb) {
5200 uprintf("comm %s pid %d: handling %srb error %d\n",
5201 td->td_proc->p_comm, td->td_proc->p_pid, name, error);
5202 }
5203 }
5204
5205 /*
5206 * Clean up umtx data.
5207 */
5208 static void
umtx_thread_cleanup(struct thread * td)5209 umtx_thread_cleanup(struct thread *td)
5210 {
5211 struct umtx_q *uq;
5212 struct umtx_pi *pi;
5213 uintptr_t rb_inact;
5214 bool compat32;
5215
5216 /*
5217 * Disown pi mutexes.
5218 */
5219 uq = td->td_umtxq;
5220 if (uq != NULL) {
5221 if (uq->uq_inherited_pri != PRI_MAX ||
5222 !TAILQ_EMPTY(&uq->uq_pi_contested)) {
5223 mtx_lock(&umtx_lock);
5224 uq->uq_inherited_pri = PRI_MAX;
5225 while ((pi = TAILQ_FIRST(&uq->uq_pi_contested)) != NULL) {
5226 pi->pi_owner = NULL;
5227 TAILQ_REMOVE(&uq->uq_pi_contested, pi, pi_link);
5228 }
5229 mtx_unlock(&umtx_lock);
5230 }
5231 sched_lend_user_prio_cond(td, PRI_MAX);
5232 }
5233
5234 compat32 = (td->td_pflags2 & TDP2_COMPAT32RB) != 0;
5235 td->td_pflags2 &= ~TDP2_COMPAT32RB;
5236
5237 if (td->td_rb_inact == 0 && td->td_rb_list == 0 && td->td_rbp_list == 0)
5238 return;
5239
5240 /*
5241 * Handle terminated robust mutexes. Must be done after
5242 * robust pi disown, otherwise unlock could see unowned
5243 * entries.
5244 */
5245 rb_inact = td->td_rb_inact;
5246 if (rb_inact != 0)
5247 (void)umtx_read_uptr(td, rb_inact, &rb_inact, compat32);
5248 umtx_cleanup_rb_list(td, td->td_rb_list, &rb_inact, "", compat32);
5249 umtx_cleanup_rb_list(td, td->td_rbp_list, &rb_inact, "priv ", compat32);
5250 if (rb_inact != 0)
5251 (void)umtx_handle_rb(td, rb_inact, NULL, true, compat32);
5252 }
5253