1 /*-
2 * Copyright (c) 2015, 2016 The FreeBSD Foundation
3 * Copyright (c) 2004, David Xu <davidxu@freebsd.org>
4 * Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org>
5 * All rights reserved.
6 *
7 * Portions of this software were developed by Konstantin Belousov
8 * under sponsorship from the FreeBSD Foundation.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice unmodified, this list of conditions, and the following
15 * disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34
35 #include "opt_compat.h"
36 #include "opt_umtx_profiling.h"
37
38 #include <sys/param.h>
39 #include <sys/kernel.h>
40 #include <sys/fcntl.h>
41 #include <sys/file.h>
42 #include <sys/filedesc.h>
43 #include <sys/limits.h>
44 #include <sys/lock.h>
45 #include <sys/malloc.h>
46 #include <sys/mman.h>
47 #include <sys/mutex.h>
48 #include <sys/priv.h>
49 #include <sys/proc.h>
50 #include <sys/resource.h>
51 #include <sys/resourcevar.h>
52 #include <sys/rwlock.h>
53 #include <sys/sbuf.h>
54 #include <sys/sched.h>
55 #include <sys/smp.h>
56 #include <sys/sysctl.h>
57 #include <sys/sysent.h>
58 #include <sys/systm.h>
59 #include <sys/sysproto.h>
60 #include <sys/syscallsubr.h>
61 #include <sys/taskqueue.h>
62 #include <sys/time.h>
63 #include <sys/eventhandler.h>
64 #include <sys/umtx.h>
65
66 #include <security/mac/mac_framework.h>
67
68 #include <vm/vm.h>
69 #include <vm/vm_param.h>
70 #include <vm/pmap.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 #ifdef COMPAT_FREEBSD32
78 #include <compat/freebsd32/freebsd32_proto.h>
79 #endif
80
81 #define _UMUTEX_TRY 1
82 #define _UMUTEX_WAIT 2
83
84 #ifdef UMTX_PROFILING
85 #define UPROF_PERC_BIGGER(w, f, sw, sf) \
86 (((w) > (sw)) || ((w) == (sw) && (f) > (sf)))
87 #endif
88
89 /* Priority inheritance mutex info. */
90 struct umtx_pi {
91 /* Owner thread */
92 struct thread *pi_owner;
93
94 /* Reference count */
95 int pi_refcount;
96
97 /* List entry to link umtx holding by thread */
98 TAILQ_ENTRY(umtx_pi) pi_link;
99
100 /* List entry in hash */
101 TAILQ_ENTRY(umtx_pi) pi_hashlink;
102
103 /* List for waiters */
104 TAILQ_HEAD(,umtx_q) pi_blocked;
105
106 /* Identify a userland lock object */
107 struct umtx_key pi_key;
108 };
109
110 /* A userland synchronous object user. */
111 struct umtx_q {
112 /* Linked list for the hash. */
113 TAILQ_ENTRY(umtx_q) uq_link;
114
115 /* Umtx key. */
116 struct umtx_key uq_key;
117
118 /* Umtx flags. */
119 int uq_flags;
120 #define UQF_UMTXQ 0x0001
121
122 /* The thread waits on. */
123 struct thread *uq_thread;
124
125 /*
126 * Blocked on PI mutex. read can use chain lock
127 * or umtx_lock, write must have both chain lock and
128 * umtx_lock being hold.
129 */
130 struct umtx_pi *uq_pi_blocked;
131
132 /* On blocked list */
133 TAILQ_ENTRY(umtx_q) uq_lockq;
134
135 /* Thread contending with us */
136 TAILQ_HEAD(,umtx_pi) uq_pi_contested;
137
138 /* Inherited priority from PP mutex */
139 u_char uq_inherited_pri;
140
141 /* Spare queue ready to be reused */
142 struct umtxq_queue *uq_spare_queue;
143
144 /* The queue we on */
145 struct umtxq_queue *uq_cur_queue;
146 };
147
148 TAILQ_HEAD(umtxq_head, umtx_q);
149
150 /* Per-key wait-queue */
151 struct umtxq_queue {
152 struct umtxq_head head;
153 struct umtx_key key;
154 LIST_ENTRY(umtxq_queue) link;
155 int length;
156 };
157
158 LIST_HEAD(umtxq_list, umtxq_queue);
159
160 /* Userland lock object's wait-queue chain */
161 struct umtxq_chain {
162 /* Lock for this chain. */
163 struct mtx uc_lock;
164
165 /* List of sleep queues. */
166 struct umtxq_list uc_queue[2];
167 #define UMTX_SHARED_QUEUE 0
168 #define UMTX_EXCLUSIVE_QUEUE 1
169
170 LIST_HEAD(, umtxq_queue) uc_spare_queue;
171
172 /* Busy flag */
173 char uc_busy;
174
175 /* Chain lock waiters */
176 int uc_waiters;
177
178 /* All PI in the list */
179 TAILQ_HEAD(,umtx_pi) uc_pi_list;
180
181 #ifdef UMTX_PROFILING
182 u_int length;
183 u_int max_length;
184 #endif
185 };
186
187 #define UMTXQ_LOCKED_ASSERT(uc) mtx_assert(&(uc)->uc_lock, MA_OWNED)
188
189 /*
190 * Don't propagate time-sharing priority, there is a security reason,
191 * a user can simply introduce PI-mutex, let thread A lock the mutex,
192 * and let another thread B block on the mutex, because B is
193 * sleeping, its priority will be boosted, this causes A's priority to
194 * be boosted via priority propagating too and will never be lowered even
195 * if it is using 100%CPU, this is unfair to other processes.
196 */
197
198 #define UPRI(td) (((td)->td_user_pri >= PRI_MIN_TIMESHARE &&\
199 (td)->td_user_pri <= PRI_MAX_TIMESHARE) ?\
200 PRI_MAX_TIMESHARE : (td)->td_user_pri)
201
202 #define GOLDEN_RATIO_PRIME 2654404609U
203 #define UMTX_CHAINS 512
204 #define UMTX_SHIFTS (__WORD_BIT - 9)
205
206 #define GET_SHARE(flags) \
207 (((flags) & USYNC_PROCESS_SHARED) == 0 ? THREAD_SHARE : PROCESS_SHARE)
208
209 #define BUSY_SPINS 200
210
211 struct abs_timeout {
212 int clockid;
213 bool is_abs_real; /* TIMER_ABSTIME && CLOCK_REALTIME* */
214 struct timespec cur;
215 struct timespec end;
216 };
217
218 #ifdef COMPAT_FREEBSD32
219 struct umutex32 {
220 volatile __lwpid_t m_owner; /* Owner of the mutex */
221 __uint32_t m_flags; /* Flags of the mutex */
222 __uint32_t m_ceilings[2]; /* Priority protect ceiling */
223 __uint32_t m_rb_lnk; /* Robust linkage */
224 __uint32_t m_pad;
225 __uint32_t m_spare[2];
226 };
227
228 _Static_assert(sizeof(struct umutex) == sizeof(struct umutex32), "umutex32");
229 _Static_assert(__offsetof(struct umutex, m_spare[0]) ==
230 __offsetof(struct umutex32, m_spare[0]), "m_spare32");
231 #endif
232
233 int umtx_shm_vnobj_persistent = 0;
234 SYSCTL_INT(_kern_ipc, OID_AUTO, umtx_vnode_persistent, CTLFLAG_RWTUN,
235 &umtx_shm_vnobj_persistent, 0,
236 "False forces destruction of umtx attached to file, on last close");
237 static int umtx_max_rb = 1000;
238 SYSCTL_INT(_kern_ipc, OID_AUTO, umtx_max_robust, CTLFLAG_RWTUN,
239 &umtx_max_rb, 0,
240 "");
241
242 static uma_zone_t umtx_pi_zone;
243 static struct umtxq_chain umtxq_chains[2][UMTX_CHAINS];
244 static MALLOC_DEFINE(M_UMTX, "umtx", "UMTX queue memory");
245 static int umtx_pi_allocated;
246
247 static SYSCTL_NODE(_debug, OID_AUTO, umtx, CTLFLAG_RW, 0, "umtx debug");
248 SYSCTL_INT(_debug_umtx, OID_AUTO, umtx_pi_allocated, CTLFLAG_RD,
249 &umtx_pi_allocated, 0, "Allocated umtx_pi");
250 static int umtx_verbose_rb = 1;
251 SYSCTL_INT(_debug_umtx, OID_AUTO, robust_faults_verbose, CTLFLAG_RWTUN,
252 &umtx_verbose_rb, 0,
253 "");
254
255 #ifdef UMTX_PROFILING
256 static long max_length;
257 SYSCTL_LONG(_debug_umtx, OID_AUTO, max_length, CTLFLAG_RD, &max_length, 0, "max_length");
258 static SYSCTL_NODE(_debug_umtx, OID_AUTO, chains, CTLFLAG_RD, 0, "umtx chain stats");
259 #endif
260
261 static void abs_timeout_update(struct abs_timeout *timo);
262
263 static void umtx_shm_init(void);
264 static void umtxq_sysinit(void *);
265 static void umtxq_hash(struct umtx_key *key);
266 static struct umtxq_chain *umtxq_getchain(struct umtx_key *key);
267 static void umtxq_lock(struct umtx_key *key);
268 static void umtxq_unlock(struct umtx_key *key);
269 static void umtxq_busy(struct umtx_key *key);
270 static void umtxq_unbusy(struct umtx_key *key);
271 static void umtxq_insert_queue(struct umtx_q *uq, int q);
272 static void umtxq_remove_queue(struct umtx_q *uq, int q);
273 static int umtxq_sleep(struct umtx_q *uq, const char *wmesg, struct abs_timeout *);
274 static int umtxq_count(struct umtx_key *key);
275 static struct umtx_pi *umtx_pi_alloc(int);
276 static void umtx_pi_free(struct umtx_pi *pi);
277 static int do_unlock_pp(struct thread *td, struct umutex *m, uint32_t flags,
278 bool rb);
279 static void umtx_thread_cleanup(struct thread *td);
280 static void umtx_exec_hook(void *arg __unused, struct proc *p __unused,
281 struct image_params *imgp __unused);
282 SYSINIT(umtx, SI_SUB_EVENTHANDLER+1, SI_ORDER_MIDDLE, umtxq_sysinit, NULL);
283
284 #define umtxq_signal(key, nwake) umtxq_signal_queue((key), (nwake), UMTX_SHARED_QUEUE)
285 #define umtxq_insert(uq) umtxq_insert_queue((uq), UMTX_SHARED_QUEUE)
286 #define umtxq_remove(uq) umtxq_remove_queue((uq), UMTX_SHARED_QUEUE)
287
288 static struct mtx umtx_lock;
289
290 #ifdef UMTX_PROFILING
291 static void
umtx_init_profiling(void)292 umtx_init_profiling(void)
293 {
294 struct sysctl_oid *chain_oid;
295 char chain_name[10];
296 int i;
297
298 for (i = 0; i < UMTX_CHAINS; ++i) {
299 snprintf(chain_name, sizeof(chain_name), "%d", i);
300 chain_oid = SYSCTL_ADD_NODE(NULL,
301 SYSCTL_STATIC_CHILDREN(_debug_umtx_chains), OID_AUTO,
302 chain_name, CTLFLAG_RD, NULL, "umtx hash stats");
303 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO,
304 "max_length0", CTLFLAG_RD, &umtxq_chains[0][i].max_length, 0, NULL);
305 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO,
306 "max_length1", CTLFLAG_RD, &umtxq_chains[1][i].max_length, 0, NULL);
307 }
308 }
309
310 static int
sysctl_debug_umtx_chains_peaks(SYSCTL_HANDLER_ARGS)311 sysctl_debug_umtx_chains_peaks(SYSCTL_HANDLER_ARGS)
312 {
313 char buf[512];
314 struct sbuf sb;
315 struct umtxq_chain *uc;
316 u_int fract, i, j, tot, whole;
317 u_int sf0, sf1, sf2, sf3, sf4;
318 u_int si0, si1, si2, si3, si4;
319 u_int sw0, sw1, sw2, sw3, sw4;
320
321 sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN);
322 for (i = 0; i < 2; i++) {
323 tot = 0;
324 for (j = 0; j < UMTX_CHAINS; ++j) {
325 uc = &umtxq_chains[i][j];
326 mtx_lock(&uc->uc_lock);
327 tot += uc->max_length;
328 mtx_unlock(&uc->uc_lock);
329 }
330 if (tot == 0)
331 sbuf_printf(&sb, "%u) Empty ", i);
332 else {
333 sf0 = sf1 = sf2 = sf3 = sf4 = 0;
334 si0 = si1 = si2 = si3 = si4 = 0;
335 sw0 = sw1 = sw2 = sw3 = sw4 = 0;
336 for (j = 0; j < UMTX_CHAINS; j++) {
337 uc = &umtxq_chains[i][j];
338 mtx_lock(&uc->uc_lock);
339 whole = uc->max_length * 100;
340 mtx_unlock(&uc->uc_lock);
341 fract = (whole % tot) * 100;
342 if (UPROF_PERC_BIGGER(whole, fract, sw0, sf0)) {
343 sf0 = fract;
344 si0 = j;
345 sw0 = whole;
346 } else if (UPROF_PERC_BIGGER(whole, fract, sw1,
347 sf1)) {
348 sf1 = fract;
349 si1 = j;
350 sw1 = whole;
351 } else if (UPROF_PERC_BIGGER(whole, fract, sw2,
352 sf2)) {
353 sf2 = fract;
354 si2 = j;
355 sw2 = whole;
356 } else if (UPROF_PERC_BIGGER(whole, fract, sw3,
357 sf3)) {
358 sf3 = fract;
359 si3 = j;
360 sw3 = whole;
361 } else if (UPROF_PERC_BIGGER(whole, fract, sw4,
362 sf4)) {
363 sf4 = fract;
364 si4 = j;
365 sw4 = whole;
366 }
367 }
368 sbuf_printf(&sb, "queue %u:\n", i);
369 sbuf_printf(&sb, "1st: %u.%u%% idx: %u\n", sw0 / tot,
370 sf0 / tot, si0);
371 sbuf_printf(&sb, "2nd: %u.%u%% idx: %u\n", sw1 / tot,
372 sf1 / tot, si1);
373 sbuf_printf(&sb, "3rd: %u.%u%% idx: %u\n", sw2 / tot,
374 sf2 / tot, si2);
375 sbuf_printf(&sb, "4th: %u.%u%% idx: %u\n", sw3 / tot,
376 sf3 / tot, si3);
377 sbuf_printf(&sb, "5th: %u.%u%% idx: %u\n", sw4 / tot,
378 sf4 / tot, si4);
379 }
380 }
381 sbuf_trim(&sb);
382 sbuf_finish(&sb);
383 sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
384 sbuf_delete(&sb);
385 return (0);
386 }
387
388 static int
sysctl_debug_umtx_chains_clear(SYSCTL_HANDLER_ARGS)389 sysctl_debug_umtx_chains_clear(SYSCTL_HANDLER_ARGS)
390 {
391 struct umtxq_chain *uc;
392 u_int i, j;
393 int clear, error;
394
395 clear = 0;
396 error = sysctl_handle_int(oidp, &clear, 0, req);
397 if (error != 0 || req->newptr == NULL)
398 return (error);
399
400 if (clear != 0) {
401 for (i = 0; i < 2; ++i) {
402 for (j = 0; j < UMTX_CHAINS; ++j) {
403 uc = &umtxq_chains[i][j];
404 mtx_lock(&uc->uc_lock);
405 uc->length = 0;
406 uc->max_length = 0;
407 mtx_unlock(&uc->uc_lock);
408 }
409 }
410 }
411 return (0);
412 }
413
414 SYSCTL_PROC(_debug_umtx_chains, OID_AUTO, clear,
415 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0,
416 sysctl_debug_umtx_chains_clear, "I", "Clear umtx chains statistics");
417 SYSCTL_PROC(_debug_umtx_chains, OID_AUTO, peaks,
418 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0,
419 sysctl_debug_umtx_chains_peaks, "A", "Highest peaks in chains max length");
420 #endif
421
422 static void
umtxq_sysinit(void * arg __unused)423 umtxq_sysinit(void *arg __unused)
424 {
425 int i, j;
426
427 umtx_pi_zone = uma_zcreate("umtx pi", sizeof(struct umtx_pi),
428 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
429 for (i = 0; i < 2; ++i) {
430 for (j = 0; j < UMTX_CHAINS; ++j) {
431 mtx_init(&umtxq_chains[i][j].uc_lock, "umtxql", NULL,
432 MTX_DEF | MTX_DUPOK);
433 LIST_INIT(&umtxq_chains[i][j].uc_queue[0]);
434 LIST_INIT(&umtxq_chains[i][j].uc_queue[1]);
435 LIST_INIT(&umtxq_chains[i][j].uc_spare_queue);
436 TAILQ_INIT(&umtxq_chains[i][j].uc_pi_list);
437 umtxq_chains[i][j].uc_busy = 0;
438 umtxq_chains[i][j].uc_waiters = 0;
439 #ifdef UMTX_PROFILING
440 umtxq_chains[i][j].length = 0;
441 umtxq_chains[i][j].max_length = 0;
442 #endif
443 }
444 }
445 #ifdef UMTX_PROFILING
446 umtx_init_profiling();
447 #endif
448 mtx_init(&umtx_lock, "umtx lock", NULL, MTX_DEF);
449 EVENTHANDLER_REGISTER(process_exec, umtx_exec_hook, NULL,
450 EVENTHANDLER_PRI_ANY);
451 umtx_shm_init();
452 }
453
454 struct umtx_q *
umtxq_alloc(void)455 umtxq_alloc(void)
456 {
457 struct umtx_q *uq;
458
459 uq = malloc(sizeof(struct umtx_q), M_UMTX, M_WAITOK | M_ZERO);
460 uq->uq_spare_queue = malloc(sizeof(struct umtxq_queue), M_UMTX,
461 M_WAITOK | M_ZERO);
462 TAILQ_INIT(&uq->uq_spare_queue->head);
463 TAILQ_INIT(&uq->uq_pi_contested);
464 uq->uq_inherited_pri = PRI_MAX;
465 return (uq);
466 }
467
468 void
umtxq_free(struct umtx_q * uq)469 umtxq_free(struct umtx_q *uq)
470 {
471
472 MPASS(uq->uq_spare_queue != NULL);
473 free(uq->uq_spare_queue, M_UMTX);
474 free(uq, M_UMTX);
475 }
476
477 static inline void
umtxq_hash(struct umtx_key * key)478 umtxq_hash(struct umtx_key *key)
479 {
480 unsigned n;
481
482 n = (uintptr_t)key->info.both.a + key->info.both.b;
483 key->hash = ((n * GOLDEN_RATIO_PRIME) >> UMTX_SHIFTS) % UMTX_CHAINS;
484 }
485
486 static inline struct umtxq_chain *
umtxq_getchain(struct umtx_key * key)487 umtxq_getchain(struct umtx_key *key)
488 {
489
490 if (key->type <= TYPE_SEM)
491 return (&umtxq_chains[1][key->hash]);
492 return (&umtxq_chains[0][key->hash]);
493 }
494
495 /*
496 * Lock a chain.
497 */
498 static inline void
umtxq_lock(struct umtx_key * key)499 umtxq_lock(struct umtx_key *key)
500 {
501 struct umtxq_chain *uc;
502
503 uc = umtxq_getchain(key);
504 mtx_lock(&uc->uc_lock);
505 }
506
507 /*
508 * Unlock a chain.
509 */
510 static inline void
umtxq_unlock(struct umtx_key * key)511 umtxq_unlock(struct umtx_key *key)
512 {
513 struct umtxq_chain *uc;
514
515 uc = umtxq_getchain(key);
516 mtx_unlock(&uc->uc_lock);
517 }
518
519 /*
520 * Set chain to busy state when following operation
521 * may be blocked (kernel mutex can not be used).
522 */
523 static inline void
umtxq_busy(struct umtx_key * key)524 umtxq_busy(struct umtx_key *key)
525 {
526 struct umtxq_chain *uc;
527
528 uc = umtxq_getchain(key);
529 mtx_assert(&uc->uc_lock, MA_OWNED);
530 if (uc->uc_busy) {
531 #ifdef SMP
532 if (smp_cpus > 1) {
533 int count = BUSY_SPINS;
534 if (count > 0) {
535 umtxq_unlock(key);
536 while (uc->uc_busy && --count > 0)
537 cpu_spinwait();
538 umtxq_lock(key);
539 }
540 }
541 #endif
542 while (uc->uc_busy) {
543 uc->uc_waiters++;
544 msleep(uc, &uc->uc_lock, 0, "umtxqb", 0);
545 uc->uc_waiters--;
546 }
547 }
548 uc->uc_busy = 1;
549 }
550
551 /*
552 * Unbusy a chain.
553 */
554 static inline void
umtxq_unbusy(struct umtx_key * key)555 umtxq_unbusy(struct umtx_key *key)
556 {
557 struct umtxq_chain *uc;
558
559 uc = umtxq_getchain(key);
560 mtx_assert(&uc->uc_lock, MA_OWNED);
561 KASSERT(uc->uc_busy != 0, ("not busy"));
562 uc->uc_busy = 0;
563 if (uc->uc_waiters)
564 wakeup_one(uc);
565 }
566
567 static inline void
umtxq_unbusy_unlocked(struct umtx_key * key)568 umtxq_unbusy_unlocked(struct umtx_key *key)
569 {
570
571 umtxq_lock(key);
572 umtxq_unbusy(key);
573 umtxq_unlock(key);
574 }
575
576 static struct umtxq_queue *
umtxq_queue_lookup(struct umtx_key * key,int q)577 umtxq_queue_lookup(struct umtx_key *key, int q)
578 {
579 struct umtxq_queue *uh;
580 struct umtxq_chain *uc;
581
582 uc = umtxq_getchain(key);
583 UMTXQ_LOCKED_ASSERT(uc);
584 LIST_FOREACH(uh, &uc->uc_queue[q], link) {
585 if (umtx_key_match(&uh->key, key))
586 return (uh);
587 }
588
589 return (NULL);
590 }
591
592 static inline void
umtxq_insert_queue(struct umtx_q * uq,int q)593 umtxq_insert_queue(struct umtx_q *uq, int q)
594 {
595 struct umtxq_queue *uh;
596 struct umtxq_chain *uc;
597
598 uc = umtxq_getchain(&uq->uq_key);
599 UMTXQ_LOCKED_ASSERT(uc);
600 KASSERT((uq->uq_flags & UQF_UMTXQ) == 0, ("umtx_q is already on queue"));
601 uh = umtxq_queue_lookup(&uq->uq_key, q);
602 if (uh != NULL) {
603 LIST_INSERT_HEAD(&uc->uc_spare_queue, uq->uq_spare_queue, link);
604 } else {
605 uh = uq->uq_spare_queue;
606 uh->key = uq->uq_key;
607 LIST_INSERT_HEAD(&uc->uc_queue[q], uh, link);
608 #ifdef UMTX_PROFILING
609 uc->length++;
610 if (uc->length > uc->max_length) {
611 uc->max_length = uc->length;
612 if (uc->max_length > max_length)
613 max_length = uc->max_length;
614 }
615 #endif
616 }
617 uq->uq_spare_queue = NULL;
618
619 TAILQ_INSERT_TAIL(&uh->head, uq, uq_link);
620 uh->length++;
621 uq->uq_flags |= UQF_UMTXQ;
622 uq->uq_cur_queue = uh;
623 return;
624 }
625
626 static inline void
umtxq_remove_queue(struct umtx_q * uq,int q)627 umtxq_remove_queue(struct umtx_q *uq, int q)
628 {
629 struct umtxq_chain *uc;
630 struct umtxq_queue *uh;
631
632 uc = umtxq_getchain(&uq->uq_key);
633 UMTXQ_LOCKED_ASSERT(uc);
634 if (uq->uq_flags & UQF_UMTXQ) {
635 uh = uq->uq_cur_queue;
636 TAILQ_REMOVE(&uh->head, uq, uq_link);
637 uh->length--;
638 uq->uq_flags &= ~UQF_UMTXQ;
639 if (TAILQ_EMPTY(&uh->head)) {
640 KASSERT(uh->length == 0,
641 ("inconsistent umtxq_queue length"));
642 #ifdef UMTX_PROFILING
643 uc->length--;
644 #endif
645 LIST_REMOVE(uh, link);
646 } else {
647 uh = LIST_FIRST(&uc->uc_spare_queue);
648 KASSERT(uh != NULL, ("uc_spare_queue is empty"));
649 LIST_REMOVE(uh, link);
650 }
651 uq->uq_spare_queue = uh;
652 uq->uq_cur_queue = NULL;
653 }
654 }
655
656 /*
657 * Check if there are multiple waiters
658 */
659 static int
umtxq_count(struct umtx_key * key)660 umtxq_count(struct umtx_key *key)
661 {
662 struct umtxq_chain *uc;
663 struct umtxq_queue *uh;
664
665 uc = umtxq_getchain(key);
666 UMTXQ_LOCKED_ASSERT(uc);
667 uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE);
668 if (uh != NULL)
669 return (uh->length);
670 return (0);
671 }
672
673 /*
674 * Check if there are multiple PI waiters and returns first
675 * waiter.
676 */
677 static int
umtxq_count_pi(struct umtx_key * key,struct umtx_q ** first)678 umtxq_count_pi(struct umtx_key *key, struct umtx_q **first)
679 {
680 struct umtxq_chain *uc;
681 struct umtxq_queue *uh;
682
683 *first = NULL;
684 uc = umtxq_getchain(key);
685 UMTXQ_LOCKED_ASSERT(uc);
686 uh = umtxq_queue_lookup(key, UMTX_SHARED_QUEUE);
687 if (uh != NULL) {
688 *first = TAILQ_FIRST(&uh->head);
689 return (uh->length);
690 }
691 return (0);
692 }
693
694 static int
umtxq_check_susp(struct thread * td)695 umtxq_check_susp(struct thread *td)
696 {
697 struct proc *p;
698 int error;
699
700 /*
701 * The check for TDF_NEEDSUSPCHK is racy, but it is enough to
702 * eventually break the lockstep loop.
703 */
704 if ((td->td_flags & TDF_NEEDSUSPCHK) == 0)
705 return (0);
706 error = 0;
707 p = td->td_proc;
708 PROC_LOCK(p);
709 if (P_SHOULDSTOP(p) ||
710 ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_SUSPEND))) {
711 if (p->p_flag & P_SINGLE_EXIT)
712 error = EINTR;
713 else
714 error = ERESTART;
715 }
716 PROC_UNLOCK(p);
717 return (error);
718 }
719
720 /*
721 * Wake up threads waiting on an userland object.
722 */
723
724 static int
umtxq_signal_queue(struct umtx_key * key,int n_wake,int q)725 umtxq_signal_queue(struct umtx_key *key, int n_wake, int q)
726 {
727 struct umtxq_chain *uc;
728 struct umtxq_queue *uh;
729 struct umtx_q *uq;
730 int ret;
731
732 ret = 0;
733 uc = umtxq_getchain(key);
734 UMTXQ_LOCKED_ASSERT(uc);
735 uh = umtxq_queue_lookup(key, q);
736 if (uh != NULL) {
737 while ((uq = TAILQ_FIRST(&uh->head)) != NULL) {
738 umtxq_remove_queue(uq, q);
739 wakeup(uq);
740 if (++ret >= n_wake)
741 return (ret);
742 }
743 }
744 return (ret);
745 }
746
747
748 /*
749 * Wake up specified thread.
750 */
751 static inline void
umtxq_signal_thread(struct umtx_q * uq)752 umtxq_signal_thread(struct umtx_q *uq)
753 {
754 struct umtxq_chain *uc;
755
756 uc = umtxq_getchain(&uq->uq_key);
757 UMTXQ_LOCKED_ASSERT(uc);
758 umtxq_remove(uq);
759 wakeup(uq);
760 }
761
762 static inline int
tstohz(const struct timespec * tsp)763 tstohz(const struct timespec *tsp)
764 {
765 struct timeval tv;
766
767 TIMESPEC_TO_TIMEVAL(&tv, tsp);
768 return tvtohz(&tv);
769 }
770
771 static void
abs_timeout_init(struct abs_timeout * timo,int clockid,int absolute,const struct timespec * timeout)772 abs_timeout_init(struct abs_timeout *timo, int clockid, int absolute,
773 const struct timespec *timeout)
774 {
775
776 timo->clockid = clockid;
777 if (!absolute) {
778 timo->is_abs_real = false;
779 abs_timeout_update(timo);
780 timo->end = timo->cur;
781 timespecadd(&timo->end, timeout);
782 } else {
783 timo->end = *timeout;
784 timo->is_abs_real = clockid == CLOCK_REALTIME ||
785 clockid == CLOCK_REALTIME_FAST ||
786 clockid == CLOCK_REALTIME_PRECISE;
787 /*
788 * If is_abs_real, umtxq_sleep will read the clock
789 * after setting td_rtcgen; otherwise, read it here.
790 */
791 if (!timo->is_abs_real) {
792 abs_timeout_update(timo);
793 }
794 }
795 }
796
797 static void
abs_timeout_init2(struct abs_timeout * timo,const struct _umtx_time * umtxtime)798 abs_timeout_init2(struct abs_timeout *timo, const struct _umtx_time *umtxtime)
799 {
800
801 abs_timeout_init(timo, umtxtime->_clockid,
802 (umtxtime->_flags & UMTX_ABSTIME) != 0, &umtxtime->_timeout);
803 }
804
805 static inline void
abs_timeout_update(struct abs_timeout * timo)806 abs_timeout_update(struct abs_timeout *timo)
807 {
808
809 kern_clock_gettime(curthread, timo->clockid, &timo->cur);
810 }
811
812 static int
abs_timeout_gethz(struct abs_timeout * timo)813 abs_timeout_gethz(struct abs_timeout *timo)
814 {
815 struct timespec tts;
816
817 if (timespeccmp(&timo->end, &timo->cur, <=))
818 return (-1);
819 tts = timo->end;
820 timespecsub(&tts, &timo->cur);
821 return (tstohz(&tts));
822 }
823
824 static uint32_t
umtx_unlock_val(uint32_t flags,bool rb)825 umtx_unlock_val(uint32_t flags, bool rb)
826 {
827
828 if (rb)
829 return (UMUTEX_RB_OWNERDEAD);
830 else if ((flags & UMUTEX_NONCONSISTENT) != 0)
831 return (UMUTEX_RB_NOTRECOV);
832 else
833 return (UMUTEX_UNOWNED);
834
835 }
836
837 /*
838 * Put thread into sleep state, before sleeping, check if
839 * thread was removed from umtx queue.
840 */
841 static inline int
umtxq_sleep(struct umtx_q * uq,const char * wmesg,struct abs_timeout * abstime)842 umtxq_sleep(struct umtx_q *uq, const char *wmesg, struct abs_timeout *abstime)
843 {
844 struct umtxq_chain *uc;
845 int error, timo;
846
847 if (abstime != NULL && abstime->is_abs_real) {
848 curthread->td_rtcgen = atomic_load_acq_int(&rtc_generation);
849 abs_timeout_update(abstime);
850 }
851
852 uc = umtxq_getchain(&uq->uq_key);
853 UMTXQ_LOCKED_ASSERT(uc);
854 for (;;) {
855 if (!(uq->uq_flags & UQF_UMTXQ)) {
856 error = 0;
857 break;
858 }
859 if (abstime != NULL) {
860 timo = abs_timeout_gethz(abstime);
861 if (timo < 0) {
862 error = ETIMEDOUT;
863 break;
864 }
865 } else
866 timo = 0;
867 error = msleep(uq, &uc->uc_lock, PCATCH | PDROP, wmesg, timo);
868 if (error == EINTR || error == ERESTART) {
869 umtxq_lock(&uq->uq_key);
870 break;
871 }
872 if (abstime != NULL) {
873 if (abstime->is_abs_real)
874 curthread->td_rtcgen =
875 atomic_load_acq_int(&rtc_generation);
876 abs_timeout_update(abstime);
877 }
878 umtxq_lock(&uq->uq_key);
879 }
880
881 curthread->td_rtcgen = 0;
882 return (error);
883 }
884
885 /*
886 * Convert userspace address into unique logical address.
887 */
888 int
umtx_key_get(const void * addr,int type,int share,struct umtx_key * key)889 umtx_key_get(const void *addr, int type, int share, struct umtx_key *key)
890 {
891 struct thread *td = curthread;
892 vm_map_t map;
893 vm_map_entry_t entry;
894 vm_pindex_t pindex;
895 vm_prot_t prot;
896 boolean_t wired;
897
898 key->type = type;
899 if (share == THREAD_SHARE) {
900 key->shared = 0;
901 key->info.private.vs = td->td_proc->p_vmspace;
902 key->info.private.addr = (uintptr_t)addr;
903 } else {
904 MPASS(share == PROCESS_SHARE || share == AUTO_SHARE);
905 map = &td->td_proc->p_vmspace->vm_map;
906 if (vm_map_lookup(&map, (vm_offset_t)addr, VM_PROT_WRITE,
907 &entry, &key->info.shared.object, &pindex, &prot,
908 &wired) != KERN_SUCCESS) {
909 return (EFAULT);
910 }
911
912 if ((share == PROCESS_SHARE) ||
913 (share == AUTO_SHARE &&
914 VM_INHERIT_SHARE == entry->inheritance)) {
915 key->shared = 1;
916 key->info.shared.offset = (vm_offset_t)addr -
917 entry->start + entry->offset;
918 vm_object_reference(key->info.shared.object);
919 } else {
920 key->shared = 0;
921 key->info.private.vs = td->td_proc->p_vmspace;
922 key->info.private.addr = (uintptr_t)addr;
923 }
924 vm_map_lookup_done(map, entry);
925 }
926
927 umtxq_hash(key);
928 return (0);
929 }
930
931 /*
932 * Release key.
933 */
934 void
umtx_key_release(struct umtx_key * key)935 umtx_key_release(struct umtx_key *key)
936 {
937 if (key->shared)
938 vm_object_deallocate(key->info.shared.object);
939 }
940
941 /*
942 * Fetch and compare value, sleep on the address if value is not changed.
943 */
944 static int
do_wait(struct thread * td,void * addr,u_long id,struct _umtx_time * timeout,int compat32,int is_private)945 do_wait(struct thread *td, void *addr, u_long id,
946 struct _umtx_time *timeout, int compat32, int is_private)
947 {
948 struct abs_timeout timo;
949 struct umtx_q *uq;
950 u_long tmp;
951 uint32_t tmp32;
952 int error = 0;
953
954 uq = td->td_umtxq;
955 if ((error = umtx_key_get(addr, TYPE_SIMPLE_WAIT,
956 is_private ? THREAD_SHARE : AUTO_SHARE, &uq->uq_key)) != 0)
957 return (error);
958
959 if (timeout != NULL)
960 abs_timeout_init2(&timo, timeout);
961
962 umtxq_lock(&uq->uq_key);
963 umtxq_insert(uq);
964 umtxq_unlock(&uq->uq_key);
965 if (compat32 == 0) {
966 error = fueword(addr, &tmp);
967 if (error != 0)
968 error = EFAULT;
969 } else {
970 error = fueword32(addr, &tmp32);
971 if (error == 0)
972 tmp = tmp32;
973 else
974 error = EFAULT;
975 }
976 umtxq_lock(&uq->uq_key);
977 if (error == 0) {
978 if (tmp == id)
979 error = umtxq_sleep(uq, "uwait", timeout == NULL ?
980 NULL : &timo);
981 if ((uq->uq_flags & UQF_UMTXQ) == 0)
982 error = 0;
983 else
984 umtxq_remove(uq);
985 } else if ((uq->uq_flags & UQF_UMTXQ) != 0) {
986 umtxq_remove(uq);
987 }
988 umtxq_unlock(&uq->uq_key);
989 umtx_key_release(&uq->uq_key);
990 if (error == ERESTART)
991 error = EINTR;
992 return (error);
993 }
994
995 /*
996 * Wake up threads sleeping on the specified address.
997 */
998 int
kern_umtx_wake(struct thread * td,void * uaddr,int n_wake,int is_private)999 kern_umtx_wake(struct thread *td, void *uaddr, int n_wake, int is_private)
1000 {
1001 struct umtx_key key;
1002 int ret;
1003
1004 if ((ret = umtx_key_get(uaddr, TYPE_SIMPLE_WAIT,
1005 is_private ? THREAD_SHARE : AUTO_SHARE, &key)) != 0)
1006 return (ret);
1007 umtxq_lock(&key);
1008 umtxq_signal(&key, n_wake);
1009 umtxq_unlock(&key);
1010 umtx_key_release(&key);
1011 return (0);
1012 }
1013
1014 /*
1015 * Lock PTHREAD_PRIO_NONE protocol POSIX mutex.
1016 */
1017 static int
do_lock_normal(struct thread * td,struct umutex * m,uint32_t flags,struct _umtx_time * timeout,int mode)1018 do_lock_normal(struct thread *td, struct umutex *m, uint32_t flags,
1019 struct _umtx_time *timeout, int mode)
1020 {
1021 struct abs_timeout timo;
1022 struct umtx_q *uq;
1023 uint32_t owner, old, id;
1024 int error, rv;
1025
1026 id = td->td_tid;
1027 uq = td->td_umtxq;
1028 error = 0;
1029 if (timeout != NULL)
1030 abs_timeout_init2(&timo, timeout);
1031
1032 /*
1033 * Care must be exercised when dealing with umtx structure. It
1034 * can fault on any access.
1035 */
1036 for (;;) {
1037 rv = fueword32(&m->m_owner, &owner);
1038 if (rv == -1)
1039 return (EFAULT);
1040 if (mode == _UMUTEX_WAIT) {
1041 if (owner == UMUTEX_UNOWNED ||
1042 owner == UMUTEX_CONTESTED ||
1043 owner == UMUTEX_RB_OWNERDEAD ||
1044 owner == UMUTEX_RB_NOTRECOV)
1045 return (0);
1046 } else {
1047 /*
1048 * Robust mutex terminated. Kernel duty is to
1049 * return EOWNERDEAD to the userspace. The
1050 * umutex.m_flags UMUTEX_NONCONSISTENT is set
1051 * by the common userspace code.
1052 */
1053 if (owner == UMUTEX_RB_OWNERDEAD) {
1054 rv = casueword32(&m->m_owner,
1055 UMUTEX_RB_OWNERDEAD, &owner,
1056 id | UMUTEX_CONTESTED);
1057 if (rv == -1)
1058 return (EFAULT);
1059 if (owner == UMUTEX_RB_OWNERDEAD)
1060 return (EOWNERDEAD); /* success */
1061 rv = umtxq_check_susp(td);
1062 if (rv != 0)
1063 return (rv);
1064 continue;
1065 }
1066 if (owner == UMUTEX_RB_NOTRECOV)
1067 return (ENOTRECOVERABLE);
1068
1069 /*
1070 * Try the uncontested case. This should be
1071 * done in userland.
1072 */
1073 rv = casueword32(&m->m_owner, UMUTEX_UNOWNED,
1074 &owner, id);
1075 /* The address was invalid. */
1076 if (rv == -1)
1077 return (EFAULT);
1078
1079 /* The acquire succeeded. */
1080 if (owner == UMUTEX_UNOWNED)
1081 return (0);
1082
1083 /*
1084 * If no one owns it but it is contested try
1085 * to acquire it.
1086 */
1087 if (owner == UMUTEX_CONTESTED) {
1088 rv = casueword32(&m->m_owner,
1089 UMUTEX_CONTESTED, &owner,
1090 id | UMUTEX_CONTESTED);
1091 /* The address was invalid. */
1092 if (rv == -1)
1093 return (EFAULT);
1094
1095 if (owner == UMUTEX_CONTESTED)
1096 return (0);
1097
1098 rv = umtxq_check_susp(td);
1099 if (rv != 0)
1100 return (rv);
1101
1102 /*
1103 * If this failed the lock has
1104 * changed, restart.
1105 */
1106 continue;
1107 }
1108 }
1109
1110 if (mode == _UMUTEX_TRY)
1111 return (EBUSY);
1112
1113 /*
1114 * If we caught a signal, we have retried and now
1115 * exit immediately.
1116 */
1117 if (error != 0)
1118 return (error);
1119
1120 if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX,
1121 GET_SHARE(flags), &uq->uq_key)) != 0)
1122 return (error);
1123
1124 umtxq_lock(&uq->uq_key);
1125 umtxq_busy(&uq->uq_key);
1126 umtxq_insert(uq);
1127 umtxq_unlock(&uq->uq_key);
1128
1129 /*
1130 * Set the contested bit so that a release in user space
1131 * knows to use the system call for unlock. If this fails
1132 * either some one else has acquired the lock or it has been
1133 * released.
1134 */
1135 rv = casueword32(&m->m_owner, owner, &old,
1136 owner | UMUTEX_CONTESTED);
1137
1138 /* The address was invalid. */
1139 if (rv == -1) {
1140 umtxq_lock(&uq->uq_key);
1141 umtxq_remove(uq);
1142 umtxq_unbusy(&uq->uq_key);
1143 umtxq_unlock(&uq->uq_key);
1144 umtx_key_release(&uq->uq_key);
1145 return (EFAULT);
1146 }
1147
1148 /*
1149 * We set the contested bit, sleep. Otherwise the lock changed
1150 * and we need to retry or we lost a race to the thread
1151 * unlocking the umtx.
1152 */
1153 umtxq_lock(&uq->uq_key);
1154 umtxq_unbusy(&uq->uq_key);
1155 if (old == owner)
1156 error = umtxq_sleep(uq, "umtxn", timeout == NULL ?
1157 NULL : &timo);
1158 umtxq_remove(uq);
1159 umtxq_unlock(&uq->uq_key);
1160 umtx_key_release(&uq->uq_key);
1161
1162 if (error == 0)
1163 error = umtxq_check_susp(td);
1164 }
1165
1166 return (0);
1167 }
1168
1169 /*
1170 * Unlock PTHREAD_PRIO_NONE protocol POSIX mutex.
1171 */
1172 static int
do_unlock_normal(struct thread * td,struct umutex * m,uint32_t flags,bool rb)1173 do_unlock_normal(struct thread *td, struct umutex *m, uint32_t flags, bool rb)
1174 {
1175 struct umtx_key key;
1176 uint32_t owner, old, id, newlock;
1177 int error, count;
1178
1179 id = td->td_tid;
1180 /*
1181 * Make sure we own this mtx.
1182 */
1183 error = fueword32(&m->m_owner, &owner);
1184 if (error == -1)
1185 return (EFAULT);
1186
1187 if ((owner & ~UMUTEX_CONTESTED) != id)
1188 return (EPERM);
1189
1190 newlock = umtx_unlock_val(flags, rb);
1191 if ((owner & UMUTEX_CONTESTED) == 0) {
1192 error = casueword32(&m->m_owner, owner, &old, newlock);
1193 if (error == -1)
1194 return (EFAULT);
1195 if (old == owner)
1196 return (0);
1197 owner = old;
1198 }
1199
1200 /* We should only ever be in here for contested locks */
1201 if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX, GET_SHARE(flags),
1202 &key)) != 0)
1203 return (error);
1204
1205 umtxq_lock(&key);
1206 umtxq_busy(&key);
1207 count = umtxq_count(&key);
1208 umtxq_unlock(&key);
1209
1210 /*
1211 * When unlocking the umtx, it must be marked as unowned if
1212 * there is zero or one thread only waiting for it.
1213 * Otherwise, it must be marked as contested.
1214 */
1215 if (count > 1)
1216 newlock |= UMUTEX_CONTESTED;
1217 error = casueword32(&m->m_owner, owner, &old, newlock);
1218 umtxq_lock(&key);
1219 umtxq_signal(&key, 1);
1220 umtxq_unbusy(&key);
1221 umtxq_unlock(&key);
1222 umtx_key_release(&key);
1223 if (error == -1)
1224 return (EFAULT);
1225 if (old != owner)
1226 return (EINVAL);
1227 return (0);
1228 }
1229
1230 /*
1231 * Check if the mutex is available and wake up a waiter,
1232 * only for simple mutex.
1233 */
1234 static int
do_wake_umutex(struct thread * td,struct umutex * m)1235 do_wake_umutex(struct thread *td, struct umutex *m)
1236 {
1237 struct umtx_key key;
1238 uint32_t owner;
1239 uint32_t flags;
1240 int error;
1241 int count;
1242
1243 error = fueword32(&m->m_owner, &owner);
1244 if (error == -1)
1245 return (EFAULT);
1246
1247 if ((owner & ~UMUTEX_CONTESTED) != 0 && owner != UMUTEX_RB_OWNERDEAD &&
1248 owner != UMUTEX_RB_NOTRECOV)
1249 return (0);
1250
1251 error = fueword32(&m->m_flags, &flags);
1252 if (error == -1)
1253 return (EFAULT);
1254
1255 /* We should only ever be in here for contested locks */
1256 if ((error = umtx_key_get(m, TYPE_NORMAL_UMUTEX, GET_SHARE(flags),
1257 &key)) != 0)
1258 return (error);
1259
1260 umtxq_lock(&key);
1261 umtxq_busy(&key);
1262 count = umtxq_count(&key);
1263 umtxq_unlock(&key);
1264
1265 if (count <= 1 && owner != UMUTEX_RB_OWNERDEAD &&
1266 owner != UMUTEX_RB_NOTRECOV) {
1267 error = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner,
1268 UMUTEX_UNOWNED);
1269 if (error == -1)
1270 error = EFAULT;
1271 }
1272
1273 umtxq_lock(&key);
1274 if (error == 0 && count != 0 && ((owner & ~UMUTEX_CONTESTED) == 0 ||
1275 owner == UMUTEX_RB_OWNERDEAD || owner == UMUTEX_RB_NOTRECOV))
1276 umtxq_signal(&key, 1);
1277 umtxq_unbusy(&key);
1278 umtxq_unlock(&key);
1279 umtx_key_release(&key);
1280 return (error);
1281 }
1282
1283 /*
1284 * Check if the mutex has waiters and tries to fix contention bit.
1285 */
1286 static int
do_wake2_umutex(struct thread * td,struct umutex * m,uint32_t flags)1287 do_wake2_umutex(struct thread *td, struct umutex *m, uint32_t flags)
1288 {
1289 struct umtx_key key;
1290 uint32_t owner, old;
1291 int type;
1292 int error;
1293 int count;
1294
1295 switch (flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT |
1296 UMUTEX_ROBUST)) {
1297 case 0:
1298 case UMUTEX_ROBUST:
1299 type = TYPE_NORMAL_UMUTEX;
1300 break;
1301 case UMUTEX_PRIO_INHERIT:
1302 type = TYPE_PI_UMUTEX;
1303 break;
1304 case (UMUTEX_PRIO_INHERIT | UMUTEX_ROBUST):
1305 type = TYPE_PI_ROBUST_UMUTEX;
1306 break;
1307 case UMUTEX_PRIO_PROTECT:
1308 type = TYPE_PP_UMUTEX;
1309 break;
1310 case (UMUTEX_PRIO_PROTECT | UMUTEX_ROBUST):
1311 type = TYPE_PP_ROBUST_UMUTEX;
1312 break;
1313 default:
1314 return (EINVAL);
1315 }
1316 if ((error = umtx_key_get(m, type, GET_SHARE(flags), &key)) != 0)
1317 return (error);
1318
1319 owner = 0;
1320 umtxq_lock(&key);
1321 umtxq_busy(&key);
1322 count = umtxq_count(&key);
1323 umtxq_unlock(&key);
1324 /*
1325 * Only repair contention bit if there is a waiter, this means the mutex
1326 * is still being referenced by userland code, otherwise don't update
1327 * any memory.
1328 */
1329 if (count > 1) {
1330 error = fueword32(&m->m_owner, &owner);
1331 if (error == -1)
1332 error = EFAULT;
1333 while (error == 0 && (owner & UMUTEX_CONTESTED) == 0) {
1334 error = casueword32(&m->m_owner, owner, &old,
1335 owner | UMUTEX_CONTESTED);
1336 if (error == -1) {
1337 error = EFAULT;
1338 break;
1339 }
1340 if (old == owner)
1341 break;
1342 owner = old;
1343 error = umtxq_check_susp(td);
1344 if (error != 0)
1345 break;
1346 }
1347 } else if (count == 1) {
1348 error = fueword32(&m->m_owner, &owner);
1349 if (error == -1)
1350 error = EFAULT;
1351 while (error == 0 && (owner & ~UMUTEX_CONTESTED) != 0 &&
1352 (owner & UMUTEX_CONTESTED) == 0) {
1353 error = casueword32(&m->m_owner, owner, &old,
1354 owner | UMUTEX_CONTESTED);
1355 if (error == -1) {
1356 error = EFAULT;
1357 break;
1358 }
1359 if (old == owner)
1360 break;
1361 owner = old;
1362 error = umtxq_check_susp(td);
1363 if (error != 0)
1364 break;
1365 }
1366 }
1367 umtxq_lock(&key);
1368 if (error == EFAULT) {
1369 umtxq_signal(&key, INT_MAX);
1370 } else if (count != 0 && ((owner & ~UMUTEX_CONTESTED) == 0 ||
1371 owner == UMUTEX_RB_OWNERDEAD || owner == UMUTEX_RB_NOTRECOV))
1372 umtxq_signal(&key, 1);
1373 umtxq_unbusy(&key);
1374 umtxq_unlock(&key);
1375 umtx_key_release(&key);
1376 return (error);
1377 }
1378
1379 static inline struct umtx_pi *
umtx_pi_alloc(int flags)1380 umtx_pi_alloc(int flags)
1381 {
1382 struct umtx_pi *pi;
1383
1384 pi = uma_zalloc(umtx_pi_zone, M_ZERO | flags);
1385 TAILQ_INIT(&pi->pi_blocked);
1386 atomic_add_int(&umtx_pi_allocated, 1);
1387 return (pi);
1388 }
1389
1390 static inline void
umtx_pi_free(struct umtx_pi * pi)1391 umtx_pi_free(struct umtx_pi *pi)
1392 {
1393 uma_zfree(umtx_pi_zone, pi);
1394 atomic_add_int(&umtx_pi_allocated, -1);
1395 }
1396
1397 /*
1398 * Adjust the thread's position on a pi_state after its priority has been
1399 * changed.
1400 */
1401 static int
umtx_pi_adjust_thread(struct umtx_pi * pi,struct thread * td)1402 umtx_pi_adjust_thread(struct umtx_pi *pi, struct thread *td)
1403 {
1404 struct umtx_q *uq, *uq1, *uq2;
1405 struct thread *td1;
1406
1407 mtx_assert(&umtx_lock, MA_OWNED);
1408 if (pi == NULL)
1409 return (0);
1410
1411 uq = td->td_umtxq;
1412
1413 /*
1414 * Check if the thread needs to be moved on the blocked chain.
1415 * It needs to be moved if either its priority is lower than
1416 * the previous thread or higher than the next thread.
1417 */
1418 uq1 = TAILQ_PREV(uq, umtxq_head, uq_lockq);
1419 uq2 = TAILQ_NEXT(uq, uq_lockq);
1420 if ((uq1 != NULL && UPRI(td) < UPRI(uq1->uq_thread)) ||
1421 (uq2 != NULL && UPRI(td) > UPRI(uq2->uq_thread))) {
1422 /*
1423 * Remove thread from blocked chain and determine where
1424 * it should be moved to.
1425 */
1426 TAILQ_REMOVE(&pi->pi_blocked, uq, uq_lockq);
1427 TAILQ_FOREACH(uq1, &pi->pi_blocked, uq_lockq) {
1428 td1 = uq1->uq_thread;
1429 MPASS(td1->td_proc->p_magic == P_MAGIC);
1430 if (UPRI(td1) > UPRI(td))
1431 break;
1432 }
1433
1434 if (uq1 == NULL)
1435 TAILQ_INSERT_TAIL(&pi->pi_blocked, uq, uq_lockq);
1436 else
1437 TAILQ_INSERT_BEFORE(uq1, uq, uq_lockq);
1438 }
1439 return (1);
1440 }
1441
1442 static struct umtx_pi *
umtx_pi_next(struct umtx_pi * pi)1443 umtx_pi_next(struct umtx_pi *pi)
1444 {
1445 struct umtx_q *uq_owner;
1446
1447 if (pi->pi_owner == NULL)
1448 return (NULL);
1449 uq_owner = pi->pi_owner->td_umtxq;
1450 if (uq_owner == NULL)
1451 return (NULL);
1452 return (uq_owner->uq_pi_blocked);
1453 }
1454
1455 /*
1456 * Floyd's Cycle-Finding Algorithm.
1457 */
1458 static bool
umtx_pi_check_loop(struct umtx_pi * pi)1459 umtx_pi_check_loop(struct umtx_pi *pi)
1460 {
1461 struct umtx_pi *pi1; /* fast iterator */
1462
1463 mtx_assert(&umtx_lock, MA_OWNED);
1464 if (pi == NULL)
1465 return (false);
1466 pi1 = pi;
1467 for (;;) {
1468 pi = umtx_pi_next(pi);
1469 if (pi == NULL)
1470 break;
1471 pi1 = umtx_pi_next(pi1);
1472 if (pi1 == NULL)
1473 break;
1474 pi1 = umtx_pi_next(pi1);
1475 if (pi1 == NULL)
1476 break;
1477 if (pi == pi1)
1478 return (true);
1479 }
1480 return (false);
1481 }
1482
1483 /*
1484 * Propagate priority when a thread is blocked on POSIX
1485 * PI mutex.
1486 */
1487 static void
umtx_propagate_priority(struct thread * td)1488 umtx_propagate_priority(struct thread *td)
1489 {
1490 struct umtx_q *uq;
1491 struct umtx_pi *pi;
1492 int pri;
1493
1494 mtx_assert(&umtx_lock, MA_OWNED);
1495 pri = UPRI(td);
1496 uq = td->td_umtxq;
1497 pi = uq->uq_pi_blocked;
1498 if (pi == NULL)
1499 return;
1500 if (umtx_pi_check_loop(pi))
1501 return;
1502
1503 for (;;) {
1504 td = pi->pi_owner;
1505 if (td == NULL || td == curthread)
1506 return;
1507
1508 MPASS(td->td_proc != NULL);
1509 MPASS(td->td_proc->p_magic == P_MAGIC);
1510
1511 thread_lock(td);
1512 if (td->td_lend_user_pri > pri)
1513 sched_lend_user_prio(td, pri);
1514 else {
1515 thread_unlock(td);
1516 break;
1517 }
1518 thread_unlock(td);
1519
1520 /*
1521 * Pick up the lock that td is blocked on.
1522 */
1523 uq = td->td_umtxq;
1524 pi = uq->uq_pi_blocked;
1525 if (pi == NULL)
1526 break;
1527 /* Resort td on the list if needed. */
1528 umtx_pi_adjust_thread(pi, td);
1529 }
1530 }
1531
1532 /*
1533 * Unpropagate priority for a PI mutex when a thread blocked on
1534 * it is interrupted by signal or resumed by others.
1535 */
1536 static void
umtx_repropagate_priority(struct umtx_pi * pi)1537 umtx_repropagate_priority(struct umtx_pi *pi)
1538 {
1539 struct umtx_q *uq, *uq_owner;
1540 struct umtx_pi *pi2;
1541 int pri;
1542
1543 mtx_assert(&umtx_lock, MA_OWNED);
1544
1545 if (umtx_pi_check_loop(pi))
1546 return;
1547 while (pi != NULL && pi->pi_owner != NULL) {
1548 pri = PRI_MAX;
1549 uq_owner = pi->pi_owner->td_umtxq;
1550
1551 TAILQ_FOREACH(pi2, &uq_owner->uq_pi_contested, pi_link) {
1552 uq = TAILQ_FIRST(&pi2->pi_blocked);
1553 if (uq != NULL) {
1554 if (pri > UPRI(uq->uq_thread))
1555 pri = UPRI(uq->uq_thread);
1556 }
1557 }
1558
1559 if (pri > uq_owner->uq_inherited_pri)
1560 pri = uq_owner->uq_inherited_pri;
1561 thread_lock(pi->pi_owner);
1562 sched_lend_user_prio(pi->pi_owner, pri);
1563 thread_unlock(pi->pi_owner);
1564 if ((pi = uq_owner->uq_pi_blocked) != NULL)
1565 umtx_pi_adjust_thread(pi, uq_owner->uq_thread);
1566 }
1567 }
1568
1569 /*
1570 * Insert a PI mutex into owned list.
1571 */
1572 static void
umtx_pi_setowner(struct umtx_pi * pi,struct thread * owner)1573 umtx_pi_setowner(struct umtx_pi *pi, struct thread *owner)
1574 {
1575 struct umtx_q *uq_owner;
1576
1577 uq_owner = owner->td_umtxq;
1578 mtx_assert(&umtx_lock, MA_OWNED);
1579 MPASS(pi->pi_owner == NULL);
1580 pi->pi_owner = owner;
1581 TAILQ_INSERT_TAIL(&uq_owner->uq_pi_contested, pi, pi_link);
1582 }
1583
1584
1585 /*
1586 * Disown a PI mutex, and remove it from the owned list.
1587 */
1588 static void
umtx_pi_disown(struct umtx_pi * pi)1589 umtx_pi_disown(struct umtx_pi *pi)
1590 {
1591
1592 mtx_assert(&umtx_lock, MA_OWNED);
1593 TAILQ_REMOVE(&pi->pi_owner->td_umtxq->uq_pi_contested, pi, pi_link);
1594 pi->pi_owner = NULL;
1595 }
1596
1597 /*
1598 * Claim ownership of a PI mutex.
1599 */
1600 static int
umtx_pi_claim(struct umtx_pi * pi,struct thread * owner)1601 umtx_pi_claim(struct umtx_pi *pi, struct thread *owner)
1602 {
1603 struct umtx_q *uq;
1604 int pri;
1605
1606 mtx_lock(&umtx_lock);
1607 if (pi->pi_owner == owner) {
1608 mtx_unlock(&umtx_lock);
1609 return (0);
1610 }
1611
1612 if (pi->pi_owner != NULL) {
1613 /*
1614 * userland may have already messed the mutex, sigh.
1615 */
1616 mtx_unlock(&umtx_lock);
1617 return (EPERM);
1618 }
1619 umtx_pi_setowner(pi, owner);
1620 uq = TAILQ_FIRST(&pi->pi_blocked);
1621 if (uq != NULL) {
1622 pri = UPRI(uq->uq_thread);
1623 thread_lock(owner);
1624 if (pri < UPRI(owner))
1625 sched_lend_user_prio(owner, pri);
1626 thread_unlock(owner);
1627 }
1628 mtx_unlock(&umtx_lock);
1629 return (0);
1630 }
1631
1632 /*
1633 * Adjust a thread's order position in its blocked PI mutex,
1634 * this may result new priority propagating process.
1635 */
1636 void
umtx_pi_adjust(struct thread * td,u_char oldpri)1637 umtx_pi_adjust(struct thread *td, u_char oldpri)
1638 {
1639 struct umtx_q *uq;
1640 struct umtx_pi *pi;
1641
1642 uq = td->td_umtxq;
1643 mtx_lock(&umtx_lock);
1644 /*
1645 * Pick up the lock that td is blocked on.
1646 */
1647 pi = uq->uq_pi_blocked;
1648 if (pi != NULL) {
1649 umtx_pi_adjust_thread(pi, td);
1650 umtx_repropagate_priority(pi);
1651 }
1652 mtx_unlock(&umtx_lock);
1653 }
1654
1655 /*
1656 * Sleep on a PI mutex.
1657 */
1658 static int
umtxq_sleep_pi(struct umtx_q * uq,struct umtx_pi * pi,uint32_t owner,const char * wmesg,struct abs_timeout * timo,bool shared)1659 umtxq_sleep_pi(struct umtx_q *uq, struct umtx_pi *pi, uint32_t owner,
1660 const char *wmesg, struct abs_timeout *timo, bool shared)
1661 {
1662 struct umtxq_chain *uc;
1663 struct thread *td, *td1;
1664 struct umtx_q *uq1;
1665 int error, pri;
1666
1667 error = 0;
1668 td = uq->uq_thread;
1669 KASSERT(td == curthread, ("inconsistent uq_thread"));
1670 uc = umtxq_getchain(&uq->uq_key);
1671 UMTXQ_LOCKED_ASSERT(uc);
1672 KASSERT(uc->uc_busy != 0, ("umtx chain is not busy"));
1673 umtxq_insert(uq);
1674 mtx_lock(&umtx_lock);
1675 if (pi->pi_owner == NULL) {
1676 mtx_unlock(&umtx_lock);
1677 td1 = tdfind(owner, shared ? -1 : td->td_proc->p_pid);
1678 mtx_lock(&umtx_lock);
1679 if (td1 != NULL) {
1680 if (pi->pi_owner == NULL)
1681 umtx_pi_setowner(pi, td1);
1682 PROC_UNLOCK(td1->td_proc);
1683 }
1684 }
1685
1686 TAILQ_FOREACH(uq1, &pi->pi_blocked, uq_lockq) {
1687 pri = UPRI(uq1->uq_thread);
1688 if (pri > UPRI(td))
1689 break;
1690 }
1691
1692 if (uq1 != NULL)
1693 TAILQ_INSERT_BEFORE(uq1, uq, uq_lockq);
1694 else
1695 TAILQ_INSERT_TAIL(&pi->pi_blocked, uq, uq_lockq);
1696
1697 uq->uq_pi_blocked = pi;
1698 thread_lock(td);
1699 td->td_flags |= TDF_UPIBLOCKED;
1700 thread_unlock(td);
1701 umtx_propagate_priority(td);
1702 mtx_unlock(&umtx_lock);
1703 umtxq_unbusy(&uq->uq_key);
1704
1705 error = umtxq_sleep(uq, wmesg, timo);
1706 umtxq_remove(uq);
1707
1708 mtx_lock(&umtx_lock);
1709 uq->uq_pi_blocked = NULL;
1710 thread_lock(td);
1711 td->td_flags &= ~TDF_UPIBLOCKED;
1712 thread_unlock(td);
1713 TAILQ_REMOVE(&pi->pi_blocked, uq, uq_lockq);
1714 umtx_repropagate_priority(pi);
1715 mtx_unlock(&umtx_lock);
1716 umtxq_unlock(&uq->uq_key);
1717
1718 return (error);
1719 }
1720
1721 /*
1722 * Add reference count for a PI mutex.
1723 */
1724 static void
umtx_pi_ref(struct umtx_pi * pi)1725 umtx_pi_ref(struct umtx_pi *pi)
1726 {
1727 struct umtxq_chain *uc;
1728
1729 uc = umtxq_getchain(&pi->pi_key);
1730 UMTXQ_LOCKED_ASSERT(uc);
1731 pi->pi_refcount++;
1732 }
1733
1734 /*
1735 * Decrease reference count for a PI mutex, if the counter
1736 * is decreased to zero, its memory space is freed.
1737 */
1738 static void
umtx_pi_unref(struct umtx_pi * pi)1739 umtx_pi_unref(struct umtx_pi *pi)
1740 {
1741 struct umtxq_chain *uc;
1742
1743 uc = umtxq_getchain(&pi->pi_key);
1744 UMTXQ_LOCKED_ASSERT(uc);
1745 KASSERT(pi->pi_refcount > 0, ("invalid reference count"));
1746 if (--pi->pi_refcount == 0) {
1747 mtx_lock(&umtx_lock);
1748 if (pi->pi_owner != NULL)
1749 umtx_pi_disown(pi);
1750 KASSERT(TAILQ_EMPTY(&pi->pi_blocked),
1751 ("blocked queue not empty"));
1752 mtx_unlock(&umtx_lock);
1753 TAILQ_REMOVE(&uc->uc_pi_list, pi, pi_hashlink);
1754 umtx_pi_free(pi);
1755 }
1756 }
1757
1758 /*
1759 * Find a PI mutex in hash table.
1760 */
1761 static struct umtx_pi *
umtx_pi_lookup(struct umtx_key * key)1762 umtx_pi_lookup(struct umtx_key *key)
1763 {
1764 struct umtxq_chain *uc;
1765 struct umtx_pi *pi;
1766
1767 uc = umtxq_getchain(key);
1768 UMTXQ_LOCKED_ASSERT(uc);
1769
1770 TAILQ_FOREACH(pi, &uc->uc_pi_list, pi_hashlink) {
1771 if (umtx_key_match(&pi->pi_key, key)) {
1772 return (pi);
1773 }
1774 }
1775 return (NULL);
1776 }
1777
1778 /*
1779 * Insert a PI mutex into hash table.
1780 */
1781 static inline void
umtx_pi_insert(struct umtx_pi * pi)1782 umtx_pi_insert(struct umtx_pi *pi)
1783 {
1784 struct umtxq_chain *uc;
1785
1786 uc = umtxq_getchain(&pi->pi_key);
1787 UMTXQ_LOCKED_ASSERT(uc);
1788 TAILQ_INSERT_TAIL(&uc->uc_pi_list, pi, pi_hashlink);
1789 }
1790
1791 /*
1792 * Lock a PI mutex.
1793 */
1794 static int
do_lock_pi(struct thread * td,struct umutex * m,uint32_t flags,struct _umtx_time * timeout,int try)1795 do_lock_pi(struct thread *td, struct umutex *m, uint32_t flags,
1796 struct _umtx_time *timeout, int try)
1797 {
1798 struct abs_timeout timo;
1799 struct umtx_q *uq;
1800 struct umtx_pi *pi, *new_pi;
1801 uint32_t id, old_owner, owner, old;
1802 int error, rv;
1803
1804 id = td->td_tid;
1805 uq = td->td_umtxq;
1806
1807 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
1808 TYPE_PI_ROBUST_UMUTEX : TYPE_PI_UMUTEX, GET_SHARE(flags),
1809 &uq->uq_key)) != 0)
1810 return (error);
1811
1812 if (timeout != NULL)
1813 abs_timeout_init2(&timo, timeout);
1814
1815 umtxq_lock(&uq->uq_key);
1816 pi = umtx_pi_lookup(&uq->uq_key);
1817 if (pi == NULL) {
1818 new_pi = umtx_pi_alloc(M_NOWAIT);
1819 if (new_pi == NULL) {
1820 umtxq_unlock(&uq->uq_key);
1821 new_pi = umtx_pi_alloc(M_WAITOK);
1822 umtxq_lock(&uq->uq_key);
1823 pi = umtx_pi_lookup(&uq->uq_key);
1824 if (pi != NULL) {
1825 umtx_pi_free(new_pi);
1826 new_pi = NULL;
1827 }
1828 }
1829 if (new_pi != NULL) {
1830 new_pi->pi_key = uq->uq_key;
1831 umtx_pi_insert(new_pi);
1832 pi = new_pi;
1833 }
1834 }
1835 umtx_pi_ref(pi);
1836 umtxq_unlock(&uq->uq_key);
1837
1838 /*
1839 * Care must be exercised when dealing with umtx structure. It
1840 * can fault on any access.
1841 */
1842 for (;;) {
1843 /*
1844 * Try the uncontested case. This should be done in userland.
1845 */
1846 rv = casueword32(&m->m_owner, UMUTEX_UNOWNED, &owner, id);
1847 /* The address was invalid. */
1848 if (rv == -1) {
1849 error = EFAULT;
1850 break;
1851 }
1852
1853 /* The acquire succeeded. */
1854 if (owner == UMUTEX_UNOWNED) {
1855 error = 0;
1856 break;
1857 }
1858
1859 if (owner == UMUTEX_RB_NOTRECOV) {
1860 error = ENOTRECOVERABLE;
1861 break;
1862 }
1863
1864 /* If no one owns it but it is contested try to acquire it. */
1865 if (owner == UMUTEX_CONTESTED || owner == UMUTEX_RB_OWNERDEAD) {
1866 old_owner = owner;
1867 rv = casueword32(&m->m_owner, owner, &owner,
1868 id | UMUTEX_CONTESTED);
1869 /* The address was invalid. */
1870 if (rv == -1) {
1871 error = EFAULT;
1872 break;
1873 }
1874
1875 if (owner == old_owner) {
1876 umtxq_lock(&uq->uq_key);
1877 umtxq_busy(&uq->uq_key);
1878 error = umtx_pi_claim(pi, td);
1879 umtxq_unbusy(&uq->uq_key);
1880 umtxq_unlock(&uq->uq_key);
1881 if (error != 0) {
1882 /*
1883 * Since we're going to return an
1884 * error, restore the m_owner to its
1885 * previous, unowned state to avoid
1886 * compounding the problem.
1887 */
1888 (void)casuword32(&m->m_owner,
1889 id | UMUTEX_CONTESTED,
1890 old_owner);
1891 }
1892 if (error == 0 &&
1893 old_owner == UMUTEX_RB_OWNERDEAD)
1894 error = EOWNERDEAD;
1895 break;
1896 }
1897
1898 error = umtxq_check_susp(td);
1899 if (error != 0)
1900 break;
1901
1902 /* If this failed the lock has changed, restart. */
1903 continue;
1904 }
1905
1906 if ((owner & ~UMUTEX_CONTESTED) == id) {
1907 error = EDEADLK;
1908 break;
1909 }
1910
1911 if (try != 0) {
1912 error = EBUSY;
1913 break;
1914 }
1915
1916 /*
1917 * If we caught a signal, we have retried and now
1918 * exit immediately.
1919 */
1920 if (error != 0)
1921 break;
1922
1923 umtxq_lock(&uq->uq_key);
1924 umtxq_busy(&uq->uq_key);
1925 umtxq_unlock(&uq->uq_key);
1926
1927 /*
1928 * Set the contested bit so that a release in user space
1929 * knows to use the system call for unlock. If this fails
1930 * either some one else has acquired the lock or it has been
1931 * released.
1932 */
1933 rv = casueword32(&m->m_owner, owner, &old, owner |
1934 UMUTEX_CONTESTED);
1935
1936 /* The address was invalid. */
1937 if (rv == -1) {
1938 umtxq_unbusy_unlocked(&uq->uq_key);
1939 error = EFAULT;
1940 break;
1941 }
1942
1943 umtxq_lock(&uq->uq_key);
1944 /*
1945 * We set the contested bit, sleep. Otherwise the lock changed
1946 * and we need to retry or we lost a race to the thread
1947 * unlocking the umtx. Note that the UMUTEX_RB_OWNERDEAD
1948 * value for owner is impossible there.
1949 */
1950 if (old == owner) {
1951 error = umtxq_sleep_pi(uq, pi,
1952 owner & ~UMUTEX_CONTESTED,
1953 "umtxpi", timeout == NULL ? NULL : &timo,
1954 (flags & USYNC_PROCESS_SHARED) != 0);
1955 if (error != 0)
1956 continue;
1957 } else {
1958 umtxq_unbusy(&uq->uq_key);
1959 umtxq_unlock(&uq->uq_key);
1960 }
1961
1962 error = umtxq_check_susp(td);
1963 if (error != 0)
1964 break;
1965 }
1966
1967 umtxq_lock(&uq->uq_key);
1968 umtx_pi_unref(pi);
1969 umtxq_unlock(&uq->uq_key);
1970
1971 umtx_key_release(&uq->uq_key);
1972 return (error);
1973 }
1974
1975 /*
1976 * Unlock a PI mutex.
1977 */
1978 static int
do_unlock_pi(struct thread * td,struct umutex * m,uint32_t flags,bool rb)1979 do_unlock_pi(struct thread *td, struct umutex *m, uint32_t flags, bool rb)
1980 {
1981 struct umtx_key key;
1982 struct umtx_q *uq_first, *uq_first2, *uq_me;
1983 struct umtx_pi *pi, *pi2;
1984 uint32_t id, new_owner, old, owner;
1985 int count, error, pri;
1986
1987 id = td->td_tid;
1988 /*
1989 * Make sure we own this mtx.
1990 */
1991 error = fueword32(&m->m_owner, &owner);
1992 if (error == -1)
1993 return (EFAULT);
1994
1995 if ((owner & ~UMUTEX_CONTESTED) != id)
1996 return (EPERM);
1997
1998 new_owner = umtx_unlock_val(flags, rb);
1999
2000 /* This should be done in userland */
2001 if ((owner & UMUTEX_CONTESTED) == 0) {
2002 error = casueword32(&m->m_owner, owner, &old, new_owner);
2003 if (error == -1)
2004 return (EFAULT);
2005 if (old == owner)
2006 return (0);
2007 owner = old;
2008 }
2009
2010 /* We should only ever be in here for contested locks */
2011 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
2012 TYPE_PI_ROBUST_UMUTEX : TYPE_PI_UMUTEX, GET_SHARE(flags),
2013 &key)) != 0)
2014 return (error);
2015
2016 umtxq_lock(&key);
2017 umtxq_busy(&key);
2018 count = umtxq_count_pi(&key, &uq_first);
2019 if (uq_first != NULL) {
2020 mtx_lock(&umtx_lock);
2021 pi = uq_first->uq_pi_blocked;
2022 KASSERT(pi != NULL, ("pi == NULL?"));
2023 if (pi->pi_owner != td && !(rb && pi->pi_owner == NULL)) {
2024 mtx_unlock(&umtx_lock);
2025 umtxq_unbusy(&key);
2026 umtxq_unlock(&key);
2027 umtx_key_release(&key);
2028 /* userland messed the mutex */
2029 return (EPERM);
2030 }
2031 uq_me = td->td_umtxq;
2032 if (pi->pi_owner == td)
2033 umtx_pi_disown(pi);
2034 /* get highest priority thread which is still sleeping. */
2035 uq_first = TAILQ_FIRST(&pi->pi_blocked);
2036 while (uq_first != NULL &&
2037 (uq_first->uq_flags & UQF_UMTXQ) == 0) {
2038 uq_first = TAILQ_NEXT(uq_first, uq_lockq);
2039 }
2040 pri = PRI_MAX;
2041 TAILQ_FOREACH(pi2, &uq_me->uq_pi_contested, pi_link) {
2042 uq_first2 = TAILQ_FIRST(&pi2->pi_blocked);
2043 if (uq_first2 != NULL) {
2044 if (pri > UPRI(uq_first2->uq_thread))
2045 pri = UPRI(uq_first2->uq_thread);
2046 }
2047 }
2048 thread_lock(td);
2049 sched_lend_user_prio(td, pri);
2050 thread_unlock(td);
2051 mtx_unlock(&umtx_lock);
2052 if (uq_first)
2053 umtxq_signal_thread(uq_first);
2054 } else {
2055 pi = umtx_pi_lookup(&key);
2056 /*
2057 * A umtx_pi can exist if a signal or timeout removed the
2058 * last waiter from the umtxq, but there is still
2059 * a thread in do_lock_pi() holding the umtx_pi.
2060 */
2061 if (pi != NULL) {
2062 /*
2063 * The umtx_pi can be unowned, such as when a thread
2064 * has just entered do_lock_pi(), allocated the
2065 * umtx_pi, and unlocked the umtxq.
2066 * If the current thread owns it, it must disown it.
2067 */
2068 mtx_lock(&umtx_lock);
2069 if (pi->pi_owner == td)
2070 umtx_pi_disown(pi);
2071 mtx_unlock(&umtx_lock);
2072 }
2073 }
2074 umtxq_unlock(&key);
2075
2076 /*
2077 * When unlocking the umtx, it must be marked as unowned if
2078 * there is zero or one thread only waiting for it.
2079 * Otherwise, it must be marked as contested.
2080 */
2081
2082 if (count > 1)
2083 new_owner |= UMUTEX_CONTESTED;
2084 error = casueword32(&m->m_owner, owner, &old, new_owner);
2085
2086 umtxq_unbusy_unlocked(&key);
2087 umtx_key_release(&key);
2088 if (error == -1)
2089 return (EFAULT);
2090 if (old != owner)
2091 return (EINVAL);
2092 return (0);
2093 }
2094
2095 /*
2096 * Lock a PP mutex.
2097 */
2098 static int
do_lock_pp(struct thread * td,struct umutex * m,uint32_t flags,struct _umtx_time * timeout,int try)2099 do_lock_pp(struct thread *td, struct umutex *m, uint32_t flags,
2100 struct _umtx_time *timeout, int try)
2101 {
2102 struct abs_timeout timo;
2103 struct umtx_q *uq, *uq2;
2104 struct umtx_pi *pi;
2105 uint32_t ceiling;
2106 uint32_t owner, id;
2107 int error, pri, old_inherited_pri, su, rv;
2108
2109 id = td->td_tid;
2110 uq = td->td_umtxq;
2111 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
2112 TYPE_PP_ROBUST_UMUTEX : TYPE_PP_UMUTEX, GET_SHARE(flags),
2113 &uq->uq_key)) != 0)
2114 return (error);
2115
2116 if (timeout != NULL)
2117 abs_timeout_init2(&timo, timeout);
2118
2119 su = (priv_check(td, PRIV_SCHED_RTPRIO) == 0);
2120 for (;;) {
2121 old_inherited_pri = uq->uq_inherited_pri;
2122 umtxq_lock(&uq->uq_key);
2123 umtxq_busy(&uq->uq_key);
2124 umtxq_unlock(&uq->uq_key);
2125
2126 rv = fueword32(&m->m_ceilings[0], &ceiling);
2127 if (rv == -1) {
2128 error = EFAULT;
2129 goto out;
2130 }
2131 ceiling = RTP_PRIO_MAX - ceiling;
2132 if (ceiling > RTP_PRIO_MAX) {
2133 error = EINVAL;
2134 goto out;
2135 }
2136
2137 mtx_lock(&umtx_lock);
2138 if (UPRI(td) < PRI_MIN_REALTIME + ceiling) {
2139 mtx_unlock(&umtx_lock);
2140 error = EINVAL;
2141 goto out;
2142 }
2143 if (su && PRI_MIN_REALTIME + ceiling < uq->uq_inherited_pri) {
2144 uq->uq_inherited_pri = PRI_MIN_REALTIME + ceiling;
2145 thread_lock(td);
2146 if (uq->uq_inherited_pri < UPRI(td))
2147 sched_lend_user_prio(td, uq->uq_inherited_pri);
2148 thread_unlock(td);
2149 }
2150 mtx_unlock(&umtx_lock);
2151
2152 rv = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner,
2153 id | UMUTEX_CONTESTED);
2154 /* The address was invalid. */
2155 if (rv == -1) {
2156 error = EFAULT;
2157 break;
2158 }
2159
2160 if (owner == UMUTEX_CONTESTED) {
2161 error = 0;
2162 break;
2163 } else if (owner == UMUTEX_RB_OWNERDEAD) {
2164 rv = casueword32(&m->m_owner, UMUTEX_RB_OWNERDEAD,
2165 &owner, id | UMUTEX_CONTESTED);
2166 if (rv == -1) {
2167 error = EFAULT;
2168 break;
2169 }
2170 if (owner == UMUTEX_RB_OWNERDEAD) {
2171 error = EOWNERDEAD; /* success */
2172 break;
2173 }
2174 error = 0;
2175 } else if (owner == UMUTEX_RB_NOTRECOV) {
2176 error = ENOTRECOVERABLE;
2177 break;
2178 }
2179
2180 if (try != 0) {
2181 error = EBUSY;
2182 break;
2183 }
2184
2185 /*
2186 * If we caught a signal, we have retried and now
2187 * exit immediately.
2188 */
2189 if (error != 0)
2190 break;
2191
2192 umtxq_lock(&uq->uq_key);
2193 umtxq_insert(uq);
2194 umtxq_unbusy(&uq->uq_key);
2195 error = umtxq_sleep(uq, "umtxpp", timeout == NULL ?
2196 NULL : &timo);
2197 umtxq_remove(uq);
2198 umtxq_unlock(&uq->uq_key);
2199
2200 mtx_lock(&umtx_lock);
2201 uq->uq_inherited_pri = old_inherited_pri;
2202 pri = PRI_MAX;
2203 TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) {
2204 uq2 = TAILQ_FIRST(&pi->pi_blocked);
2205 if (uq2 != NULL) {
2206 if (pri > UPRI(uq2->uq_thread))
2207 pri = UPRI(uq2->uq_thread);
2208 }
2209 }
2210 if (pri > uq->uq_inherited_pri)
2211 pri = uq->uq_inherited_pri;
2212 thread_lock(td);
2213 sched_lend_user_prio(td, pri);
2214 thread_unlock(td);
2215 mtx_unlock(&umtx_lock);
2216 }
2217
2218 if (error != 0 && error != EOWNERDEAD) {
2219 mtx_lock(&umtx_lock);
2220 uq->uq_inherited_pri = old_inherited_pri;
2221 pri = PRI_MAX;
2222 TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) {
2223 uq2 = TAILQ_FIRST(&pi->pi_blocked);
2224 if (uq2 != NULL) {
2225 if (pri > UPRI(uq2->uq_thread))
2226 pri = UPRI(uq2->uq_thread);
2227 }
2228 }
2229 if (pri > uq->uq_inherited_pri)
2230 pri = uq->uq_inherited_pri;
2231 thread_lock(td);
2232 sched_lend_user_prio(td, pri);
2233 thread_unlock(td);
2234 mtx_unlock(&umtx_lock);
2235 }
2236
2237 out:
2238 umtxq_unbusy_unlocked(&uq->uq_key);
2239 umtx_key_release(&uq->uq_key);
2240 return (error);
2241 }
2242
2243 /*
2244 * Unlock a PP mutex.
2245 */
2246 static int
do_unlock_pp(struct thread * td,struct umutex * m,uint32_t flags,bool rb)2247 do_unlock_pp(struct thread *td, struct umutex *m, uint32_t flags, bool rb)
2248 {
2249 struct umtx_key key;
2250 struct umtx_q *uq, *uq2;
2251 struct umtx_pi *pi;
2252 uint32_t id, owner, rceiling;
2253 int error, pri, new_inherited_pri, su;
2254
2255 id = td->td_tid;
2256 uq = td->td_umtxq;
2257 su = (priv_check(td, PRIV_SCHED_RTPRIO) == 0);
2258
2259 /*
2260 * Make sure we own this mtx.
2261 */
2262 error = fueword32(&m->m_owner, &owner);
2263 if (error == -1)
2264 return (EFAULT);
2265
2266 if ((owner & ~UMUTEX_CONTESTED) != id)
2267 return (EPERM);
2268
2269 error = copyin(&m->m_ceilings[1], &rceiling, sizeof(uint32_t));
2270 if (error != 0)
2271 return (error);
2272
2273 if (rceiling == -1)
2274 new_inherited_pri = PRI_MAX;
2275 else {
2276 rceiling = RTP_PRIO_MAX - rceiling;
2277 if (rceiling > RTP_PRIO_MAX)
2278 return (EINVAL);
2279 new_inherited_pri = PRI_MIN_REALTIME + rceiling;
2280 }
2281
2282 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
2283 TYPE_PP_ROBUST_UMUTEX : TYPE_PP_UMUTEX, GET_SHARE(flags),
2284 &key)) != 0)
2285 return (error);
2286 umtxq_lock(&key);
2287 umtxq_busy(&key);
2288 umtxq_unlock(&key);
2289 /*
2290 * For priority protected mutex, always set unlocked state
2291 * to UMUTEX_CONTESTED, so that userland always enters kernel
2292 * to lock the mutex, it is necessary because thread priority
2293 * has to be adjusted for such mutex.
2294 */
2295 error = suword32(&m->m_owner, umtx_unlock_val(flags, rb) |
2296 UMUTEX_CONTESTED);
2297
2298 umtxq_lock(&key);
2299 if (error == 0)
2300 umtxq_signal(&key, 1);
2301 umtxq_unbusy(&key);
2302 umtxq_unlock(&key);
2303
2304 if (error == -1)
2305 error = EFAULT;
2306 else {
2307 mtx_lock(&umtx_lock);
2308 if (su != 0)
2309 uq->uq_inherited_pri = new_inherited_pri;
2310 pri = PRI_MAX;
2311 TAILQ_FOREACH(pi, &uq->uq_pi_contested, pi_link) {
2312 uq2 = TAILQ_FIRST(&pi->pi_blocked);
2313 if (uq2 != NULL) {
2314 if (pri > UPRI(uq2->uq_thread))
2315 pri = UPRI(uq2->uq_thread);
2316 }
2317 }
2318 if (pri > uq->uq_inherited_pri)
2319 pri = uq->uq_inherited_pri;
2320 thread_lock(td);
2321 sched_lend_user_prio(td, pri);
2322 thread_unlock(td);
2323 mtx_unlock(&umtx_lock);
2324 }
2325 umtx_key_release(&key);
2326 return (error);
2327 }
2328
2329 static int
do_set_ceiling(struct thread * td,struct umutex * m,uint32_t ceiling,uint32_t * old_ceiling)2330 do_set_ceiling(struct thread *td, struct umutex *m, uint32_t ceiling,
2331 uint32_t *old_ceiling)
2332 {
2333 struct umtx_q *uq;
2334 uint32_t flags, id, owner, save_ceiling;
2335 int error, rv, rv1;
2336
2337 error = fueword32(&m->m_flags, &flags);
2338 if (error == -1)
2339 return (EFAULT);
2340 if ((flags & UMUTEX_PRIO_PROTECT) == 0)
2341 return (EINVAL);
2342 if (ceiling > RTP_PRIO_MAX)
2343 return (EINVAL);
2344 id = td->td_tid;
2345 uq = td->td_umtxq;
2346 if ((error = umtx_key_get(m, (flags & UMUTEX_ROBUST) != 0 ?
2347 TYPE_PP_ROBUST_UMUTEX : TYPE_PP_UMUTEX, GET_SHARE(flags),
2348 &uq->uq_key)) != 0)
2349 return (error);
2350 for (;;) {
2351 umtxq_lock(&uq->uq_key);
2352 umtxq_busy(&uq->uq_key);
2353 umtxq_unlock(&uq->uq_key);
2354
2355 rv = fueword32(&m->m_ceilings[0], &save_ceiling);
2356 if (rv == -1) {
2357 error = EFAULT;
2358 break;
2359 }
2360
2361 rv = casueword32(&m->m_owner, UMUTEX_CONTESTED, &owner,
2362 id | UMUTEX_CONTESTED);
2363 if (rv == -1) {
2364 error = EFAULT;
2365 break;
2366 }
2367
2368 if (owner == UMUTEX_CONTESTED) {
2369 rv = suword32(&m->m_ceilings[0], ceiling);
2370 rv1 = suword32(&m->m_owner, UMUTEX_CONTESTED);
2371 error = (rv == 0 && rv1 == 0) ? 0: EFAULT;
2372 break;
2373 }
2374
2375 if ((owner & ~UMUTEX_CONTESTED) == id) {
2376 rv = suword32(&m->m_ceilings[0], ceiling);
2377 error = rv == 0 ? 0 : EFAULT;
2378 break;
2379 }
2380
2381 if (owner == UMUTEX_RB_OWNERDEAD) {
2382 error = EOWNERDEAD;
2383 break;
2384 } else if (owner == UMUTEX_RB_NOTRECOV) {
2385 error = ENOTRECOVERABLE;
2386 break;
2387 }
2388
2389 /*
2390 * If we caught a signal, we have retried and now
2391 * exit immediately.
2392 */
2393 if (error != 0)
2394 break;
2395
2396 /*
2397 * We set the contested bit, sleep. Otherwise the lock changed
2398 * and we need to retry or we lost a race to the thread
2399 * unlocking the umtx.
2400 */
2401 umtxq_lock(&uq->uq_key);
2402 umtxq_insert(uq);
2403 umtxq_unbusy(&uq->uq_key);
2404 error = umtxq_sleep(uq, "umtxpp", NULL);
2405 umtxq_remove(uq);
2406 umtxq_unlock(&uq->uq_key);
2407 }
2408 umtxq_lock(&uq->uq_key);
2409 if (error == 0)
2410 umtxq_signal(&uq->uq_key, INT_MAX);
2411 umtxq_unbusy(&uq->uq_key);
2412 umtxq_unlock(&uq->uq_key);
2413 umtx_key_release(&uq->uq_key);
2414 if (error == 0 && old_ceiling != NULL) {
2415 rv = suword32(old_ceiling, save_ceiling);
2416 error = rv == 0 ? 0 : EFAULT;
2417 }
2418 return (error);
2419 }
2420
2421 /*
2422 * Lock a userland POSIX mutex.
2423 */
2424 static int
do_lock_umutex(struct thread * td,struct umutex * m,struct _umtx_time * timeout,int mode)2425 do_lock_umutex(struct thread *td, struct umutex *m,
2426 struct _umtx_time *timeout, int mode)
2427 {
2428 uint32_t flags;
2429 int error;
2430
2431 error = fueword32(&m->m_flags, &flags);
2432 if (error == -1)
2433 return (EFAULT);
2434
2435 switch (flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT)) {
2436 case 0:
2437 error = do_lock_normal(td, m, flags, timeout, mode);
2438 break;
2439 case UMUTEX_PRIO_INHERIT:
2440 error = do_lock_pi(td, m, flags, timeout, mode);
2441 break;
2442 case UMUTEX_PRIO_PROTECT:
2443 error = do_lock_pp(td, m, flags, timeout, mode);
2444 break;
2445 default:
2446 return (EINVAL);
2447 }
2448 if (timeout == NULL) {
2449 if (error == EINTR && mode != _UMUTEX_WAIT)
2450 error = ERESTART;
2451 } else {
2452 /* Timed-locking is not restarted. */
2453 if (error == ERESTART)
2454 error = EINTR;
2455 }
2456 return (error);
2457 }
2458
2459 /*
2460 * Unlock a userland POSIX mutex.
2461 */
2462 static int
do_unlock_umutex(struct thread * td,struct umutex * m,bool rb)2463 do_unlock_umutex(struct thread *td, struct umutex *m, bool rb)
2464 {
2465 uint32_t flags;
2466 int error;
2467
2468 error = fueword32(&m->m_flags, &flags);
2469 if (error == -1)
2470 return (EFAULT);
2471
2472 switch (flags & (UMUTEX_PRIO_INHERIT | UMUTEX_PRIO_PROTECT)) {
2473 case 0:
2474 return (do_unlock_normal(td, m, flags, rb));
2475 case UMUTEX_PRIO_INHERIT:
2476 return (do_unlock_pi(td, m, flags, rb));
2477 case UMUTEX_PRIO_PROTECT:
2478 return (do_unlock_pp(td, m, flags, rb));
2479 }
2480
2481 return (EINVAL);
2482 }
2483
2484 static int
do_cv_wait(struct thread * td,struct ucond * cv,struct umutex * m,struct timespec * timeout,u_long wflags)2485 do_cv_wait(struct thread *td, struct ucond *cv, struct umutex *m,
2486 struct timespec *timeout, u_long wflags)
2487 {
2488 struct abs_timeout timo;
2489 struct umtx_q *uq;
2490 uint32_t flags, clockid, hasw;
2491 int error;
2492
2493 uq = td->td_umtxq;
2494 error = fueword32(&cv->c_flags, &flags);
2495 if (error == -1)
2496 return (EFAULT);
2497 error = umtx_key_get(cv, TYPE_CV, GET_SHARE(flags), &uq->uq_key);
2498 if (error != 0)
2499 return (error);
2500
2501 if ((wflags & CVWAIT_CLOCKID) != 0) {
2502 error = fueword32(&cv->c_clockid, &clockid);
2503 if (error == -1) {
2504 umtx_key_release(&uq->uq_key);
2505 return (EFAULT);
2506 }
2507 if (clockid < CLOCK_REALTIME ||
2508 clockid >= CLOCK_THREAD_CPUTIME_ID) {
2509 /* hmm, only HW clock id will work. */
2510 umtx_key_release(&uq->uq_key);
2511 return (EINVAL);
2512 }
2513 } else {
2514 clockid = CLOCK_REALTIME;
2515 }
2516
2517 umtxq_lock(&uq->uq_key);
2518 umtxq_busy(&uq->uq_key);
2519 umtxq_insert(uq);
2520 umtxq_unlock(&uq->uq_key);
2521
2522 /*
2523 * Set c_has_waiters to 1 before releasing user mutex, also
2524 * don't modify cache line when unnecessary.
2525 */
2526 error = fueword32(&cv->c_has_waiters, &hasw);
2527 if (error == 0 && hasw == 0)
2528 suword32(&cv->c_has_waiters, 1);
2529
2530 umtxq_unbusy_unlocked(&uq->uq_key);
2531
2532 error = do_unlock_umutex(td, m, false);
2533
2534 if (timeout != NULL)
2535 abs_timeout_init(&timo, clockid, (wflags & CVWAIT_ABSTIME) != 0,
2536 timeout);
2537
2538 umtxq_lock(&uq->uq_key);
2539 if (error == 0) {
2540 error = umtxq_sleep(uq, "ucond", timeout == NULL ?
2541 NULL : &timo);
2542 }
2543
2544 if ((uq->uq_flags & UQF_UMTXQ) == 0)
2545 error = 0;
2546 else {
2547 /*
2548 * This must be timeout,interrupted by signal or
2549 * surprious wakeup, clear c_has_waiter flag when
2550 * necessary.
2551 */
2552 umtxq_busy(&uq->uq_key);
2553 if ((uq->uq_flags & UQF_UMTXQ) != 0) {
2554 int oldlen = uq->uq_cur_queue->length;
2555 umtxq_remove(uq);
2556 if (oldlen == 1) {
2557 umtxq_unlock(&uq->uq_key);
2558 suword32(&cv->c_has_waiters, 0);
2559 umtxq_lock(&uq->uq_key);
2560 }
2561 }
2562 umtxq_unbusy(&uq->uq_key);
2563 if (error == ERESTART)
2564 error = EINTR;
2565 }
2566
2567 umtxq_unlock(&uq->uq_key);
2568 umtx_key_release(&uq->uq_key);
2569 return (error);
2570 }
2571
2572 /*
2573 * Signal a userland condition variable.
2574 */
2575 static int
do_cv_signal(struct thread * td,struct ucond * cv)2576 do_cv_signal(struct thread *td, struct ucond *cv)
2577 {
2578 struct umtx_key key;
2579 int error, cnt, nwake;
2580 uint32_t flags;
2581
2582 error = fueword32(&cv->c_flags, &flags);
2583 if (error == -1)
2584 return (EFAULT);
2585 if ((error = umtx_key_get(cv, TYPE_CV, GET_SHARE(flags), &key)) != 0)
2586 return (error);
2587 umtxq_lock(&key);
2588 umtxq_busy(&key);
2589 cnt = umtxq_count(&key);
2590 nwake = umtxq_signal(&key, 1);
2591 if (cnt <= nwake) {
2592 umtxq_unlock(&key);
2593 error = suword32(&cv->c_has_waiters, 0);
2594 if (error == -1)
2595 error = EFAULT;
2596 umtxq_lock(&key);
2597 }
2598 umtxq_unbusy(&key);
2599 umtxq_unlock(&key);
2600 umtx_key_release(&key);
2601 return (error);
2602 }
2603
2604 static int
do_cv_broadcast(struct thread * td,struct ucond * cv)2605 do_cv_broadcast(struct thread *td, struct ucond *cv)
2606 {
2607 struct umtx_key key;
2608 int error;
2609 uint32_t flags;
2610
2611 error = fueword32(&cv->c_flags, &flags);
2612 if (error == -1)
2613 return (EFAULT);
2614 if ((error = umtx_key_get(cv, TYPE_CV, GET_SHARE(flags), &key)) != 0)
2615 return (error);
2616
2617 umtxq_lock(&key);
2618 umtxq_busy(&key);
2619 umtxq_signal(&key, INT_MAX);
2620 umtxq_unlock(&key);
2621
2622 error = suword32(&cv->c_has_waiters, 0);
2623 if (error == -1)
2624 error = EFAULT;
2625
2626 umtxq_unbusy_unlocked(&key);
2627
2628 umtx_key_release(&key);
2629 return (error);
2630 }
2631
2632 static int
do_rw_rdlock(struct thread * td,struct urwlock * rwlock,long fflag,struct _umtx_time * timeout)2633 do_rw_rdlock(struct thread *td, struct urwlock *rwlock, long fflag,
2634 struct _umtx_time *timeout)
2635 {
2636 struct abs_timeout timo;
2637 struct umtx_q *uq;
2638 uint32_t flags, wrflags;
2639 int32_t state, oldstate;
2640 int32_t blocked_readers;
2641 int error, error1, rv;
2642
2643 uq = td->td_umtxq;
2644 error = fueword32(&rwlock->rw_flags, &flags);
2645 if (error == -1)
2646 return (EFAULT);
2647 error = umtx_key_get(rwlock, TYPE_RWLOCK, GET_SHARE(flags), &uq->uq_key);
2648 if (error != 0)
2649 return (error);
2650
2651 if (timeout != NULL)
2652 abs_timeout_init2(&timo, timeout);
2653
2654 wrflags = URWLOCK_WRITE_OWNER;
2655 if (!(fflag & URWLOCK_PREFER_READER) && !(flags & URWLOCK_PREFER_READER))
2656 wrflags |= URWLOCK_WRITE_WAITERS;
2657
2658 for (;;) {
2659 rv = fueword32(&rwlock->rw_state, &state);
2660 if (rv == -1) {
2661 umtx_key_release(&uq->uq_key);
2662 return (EFAULT);
2663 }
2664
2665 /* try to lock it */
2666 while (!(state & wrflags)) {
2667 if (__predict_false(URWLOCK_READER_COUNT(state) ==
2668 URWLOCK_MAX_READERS)) {
2669 umtx_key_release(&uq->uq_key);
2670 return (EAGAIN);
2671 }
2672 rv = casueword32(&rwlock->rw_state, state,
2673 &oldstate, state + 1);
2674 if (rv == -1) {
2675 umtx_key_release(&uq->uq_key);
2676 return (EFAULT);
2677 }
2678 if (oldstate == state) {
2679 umtx_key_release(&uq->uq_key);
2680 return (0);
2681 }
2682 error = umtxq_check_susp(td);
2683 if (error != 0)
2684 break;
2685 state = oldstate;
2686 }
2687
2688 if (error)
2689 break;
2690
2691 /* grab monitor lock */
2692 umtxq_lock(&uq->uq_key);
2693 umtxq_busy(&uq->uq_key);
2694 umtxq_unlock(&uq->uq_key);
2695
2696 /*
2697 * re-read the state, in case it changed between the try-lock above
2698 * and the check below
2699 */
2700 rv = fueword32(&rwlock->rw_state, &state);
2701 if (rv == -1)
2702 error = EFAULT;
2703
2704 /* set read contention bit */
2705 while (error == 0 && (state & wrflags) &&
2706 !(state & URWLOCK_READ_WAITERS)) {
2707 rv = casueword32(&rwlock->rw_state, state,
2708 &oldstate, state | URWLOCK_READ_WAITERS);
2709 if (rv == -1) {
2710 error = EFAULT;
2711 break;
2712 }
2713 if (oldstate == state)
2714 goto sleep;
2715 state = oldstate;
2716 error = umtxq_check_susp(td);
2717 if (error != 0)
2718 break;
2719 }
2720 if (error != 0) {
2721 umtxq_unbusy_unlocked(&uq->uq_key);
2722 break;
2723 }
2724
2725 /* state is changed while setting flags, restart */
2726 if (!(state & wrflags)) {
2727 umtxq_unbusy_unlocked(&uq->uq_key);
2728 error = umtxq_check_susp(td);
2729 if (error != 0)
2730 break;
2731 continue;
2732 }
2733
2734 sleep:
2735 /*
2736 * Contention bit is set, before sleeping, increase
2737 * read waiter count.
2738 */
2739 rv = fueword32(&rwlock->rw_blocked_readers,
2740 &blocked_readers);
2741 if (rv == -1) {
2742 umtxq_unbusy_unlocked(&uq->uq_key);
2743 error = EFAULT;
2744 break;
2745 }
2746 suword32(&rwlock->rw_blocked_readers, blocked_readers+1);
2747
2748 while (state & wrflags) {
2749 umtxq_lock(&uq->uq_key);
2750 umtxq_insert(uq);
2751 umtxq_unbusy(&uq->uq_key);
2752
2753 error = umtxq_sleep(uq, "urdlck", timeout == NULL ?
2754 NULL : &timo);
2755
2756 umtxq_busy(&uq->uq_key);
2757 umtxq_remove(uq);
2758 umtxq_unlock(&uq->uq_key);
2759 if (error)
2760 break;
2761 rv = fueword32(&rwlock->rw_state, &state);
2762 if (rv == -1) {
2763 error = EFAULT;
2764 break;
2765 }
2766 }
2767
2768 /* decrease read waiter count, and may clear read contention bit */
2769 rv = fueword32(&rwlock->rw_blocked_readers,
2770 &blocked_readers);
2771 if (rv == -1) {
2772 umtxq_unbusy_unlocked(&uq->uq_key);
2773 error = EFAULT;
2774 break;
2775 }
2776 suword32(&rwlock->rw_blocked_readers, blocked_readers-1);
2777 if (blocked_readers == 1) {
2778 rv = fueword32(&rwlock->rw_state, &state);
2779 if (rv == -1) {
2780 umtxq_unbusy_unlocked(&uq->uq_key);
2781 error = EFAULT;
2782 break;
2783 }
2784 for (;;) {
2785 rv = casueword32(&rwlock->rw_state, state,
2786 &oldstate, state & ~URWLOCK_READ_WAITERS);
2787 if (rv == -1) {
2788 error = EFAULT;
2789 break;
2790 }
2791 if (oldstate == state)
2792 break;
2793 state = oldstate;
2794 error1 = umtxq_check_susp(td);
2795 if (error1 != 0) {
2796 if (error == 0)
2797 error = error1;
2798 break;
2799 }
2800 }
2801 }
2802
2803 umtxq_unbusy_unlocked(&uq->uq_key);
2804 if (error != 0)
2805 break;
2806 }
2807 umtx_key_release(&uq->uq_key);
2808 if (error == ERESTART)
2809 error = EINTR;
2810 return (error);
2811 }
2812
2813 static int
do_rw_wrlock(struct thread * td,struct urwlock * rwlock,struct _umtx_time * timeout)2814 do_rw_wrlock(struct thread *td, struct urwlock *rwlock, struct _umtx_time *timeout)
2815 {
2816 struct abs_timeout timo;
2817 struct umtx_q *uq;
2818 uint32_t flags;
2819 int32_t state, oldstate;
2820 int32_t blocked_writers;
2821 int32_t blocked_readers;
2822 int error, error1, rv;
2823
2824 uq = td->td_umtxq;
2825 error = fueword32(&rwlock->rw_flags, &flags);
2826 if (error == -1)
2827 return (EFAULT);
2828 error = umtx_key_get(rwlock, TYPE_RWLOCK, GET_SHARE(flags), &uq->uq_key);
2829 if (error != 0)
2830 return (error);
2831
2832 if (timeout != NULL)
2833 abs_timeout_init2(&timo, timeout);
2834
2835 blocked_readers = 0;
2836 for (;;) {
2837 rv = fueword32(&rwlock->rw_state, &state);
2838 if (rv == -1) {
2839 umtx_key_release(&uq->uq_key);
2840 return (EFAULT);
2841 }
2842 while ((state & URWLOCK_WRITE_OWNER) == 0 &&
2843 URWLOCK_READER_COUNT(state) == 0) {
2844 rv = casueword32(&rwlock->rw_state, state,
2845 &oldstate, state | URWLOCK_WRITE_OWNER);
2846 if (rv == -1) {
2847 umtx_key_release(&uq->uq_key);
2848 return (EFAULT);
2849 }
2850 if (oldstate == state) {
2851 umtx_key_release(&uq->uq_key);
2852 return (0);
2853 }
2854 state = oldstate;
2855 error = umtxq_check_susp(td);
2856 if (error != 0)
2857 break;
2858 }
2859
2860 if (error) {
2861 if (!(state & (URWLOCK_WRITE_OWNER|URWLOCK_WRITE_WAITERS)) &&
2862 blocked_readers != 0) {
2863 umtxq_lock(&uq->uq_key);
2864 umtxq_busy(&uq->uq_key);
2865 umtxq_signal_queue(&uq->uq_key, INT_MAX, UMTX_SHARED_QUEUE);
2866 umtxq_unbusy(&uq->uq_key);
2867 umtxq_unlock(&uq->uq_key);
2868 }
2869
2870 break;
2871 }
2872
2873 /* grab monitor lock */
2874 umtxq_lock(&uq->uq_key);
2875 umtxq_busy(&uq->uq_key);
2876 umtxq_unlock(&uq->uq_key);
2877
2878 /*
2879 * Re-read the state, in case it changed between the
2880 * try-lock above and the check below.
2881 */
2882 rv = fueword32(&rwlock->rw_state, &state);
2883 if (rv == -1)
2884 error = EFAULT;
2885
2886 while (error == 0 && ((state & URWLOCK_WRITE_OWNER) ||
2887 URWLOCK_READER_COUNT(state) != 0) &&
2888 (state & URWLOCK_WRITE_WAITERS) == 0) {
2889 rv = casueword32(&rwlock->rw_state, state,
2890 &oldstate, state | URWLOCK_WRITE_WAITERS);
2891 if (rv == -1) {
2892 error = EFAULT;
2893 break;
2894 }
2895 if (oldstate == state)
2896 goto sleep;
2897 state = oldstate;
2898 error = umtxq_check_susp(td);
2899 if (error != 0)
2900 break;
2901 }
2902 if (error != 0) {
2903 umtxq_unbusy_unlocked(&uq->uq_key);
2904 break;
2905 }
2906
2907 if ((state & URWLOCK_WRITE_OWNER) == 0 &&
2908 URWLOCK_READER_COUNT(state) == 0) {
2909 umtxq_unbusy_unlocked(&uq->uq_key);
2910 error = umtxq_check_susp(td);
2911 if (error != 0)
2912 break;
2913 continue;
2914 }
2915 sleep:
2916 rv = fueword32(&rwlock->rw_blocked_writers,
2917 &blocked_writers);
2918 if (rv == -1) {
2919 umtxq_unbusy_unlocked(&uq->uq_key);
2920 error = EFAULT;
2921 break;
2922 }
2923 suword32(&rwlock->rw_blocked_writers, blocked_writers + 1);
2924
2925 while ((state & URWLOCK_WRITE_OWNER) ||
2926 URWLOCK_READER_COUNT(state) != 0) {
2927 umtxq_lock(&uq->uq_key);
2928 umtxq_insert_queue(uq, UMTX_EXCLUSIVE_QUEUE);
2929 umtxq_unbusy(&uq->uq_key);
2930
2931 error = umtxq_sleep(uq, "uwrlck", timeout == NULL ?
2932 NULL : &timo);
2933
2934 umtxq_busy(&uq->uq_key);
2935 umtxq_remove_queue(uq, UMTX_EXCLUSIVE_QUEUE);
2936 umtxq_unlock(&uq->uq_key);
2937 if (error)
2938 break;
2939 rv = fueword32(&rwlock->rw_state, &state);
2940 if (rv == -1) {
2941 error = EFAULT;
2942 break;
2943 }
2944 }
2945
2946 rv = fueword32(&rwlock->rw_blocked_writers,
2947 &blocked_writers);
2948 if (rv == -1) {
2949 umtxq_unbusy_unlocked(&uq->uq_key);
2950 error = EFAULT;
2951 break;
2952 }
2953 suword32(&rwlock->rw_blocked_writers, blocked_writers-1);
2954 if (blocked_writers == 1) {
2955 rv = fueword32(&rwlock->rw_state, &state);
2956 if (rv == -1) {
2957 umtxq_unbusy_unlocked(&uq->uq_key);
2958 error = EFAULT;
2959 break;
2960 }
2961 for (;;) {
2962 rv = casueword32(&rwlock->rw_state, state,
2963 &oldstate, state & ~URWLOCK_WRITE_WAITERS);
2964 if (rv == -1) {
2965 error = EFAULT;
2966 break;
2967 }
2968 if (oldstate == state)
2969 break;
2970 state = oldstate;
2971 error1 = umtxq_check_susp(td);
2972 /*
2973 * We are leaving the URWLOCK_WRITE_WAITERS
2974 * behind, but this should not harm the
2975 * correctness.
2976 */
2977 if (error1 != 0) {
2978 if (error == 0)
2979 error = error1;
2980 break;
2981 }
2982 }
2983 rv = fueword32(&rwlock->rw_blocked_readers,
2984 &blocked_readers);
2985 if (rv == -1) {
2986 umtxq_unbusy_unlocked(&uq->uq_key);
2987 error = EFAULT;
2988 break;
2989 }
2990 } else
2991 blocked_readers = 0;
2992
2993 umtxq_unbusy_unlocked(&uq->uq_key);
2994 }
2995
2996 umtx_key_release(&uq->uq_key);
2997 if (error == ERESTART)
2998 error = EINTR;
2999 return (error);
3000 }
3001
3002 static int
do_rw_unlock(struct thread * td,struct urwlock * rwlock)3003 do_rw_unlock(struct thread *td, struct urwlock *rwlock)
3004 {
3005 struct umtx_q *uq;
3006 uint32_t flags;
3007 int32_t state, oldstate;
3008 int error, rv, q, count;
3009
3010 uq = td->td_umtxq;
3011 error = fueword32(&rwlock->rw_flags, &flags);
3012 if (error == -1)
3013 return (EFAULT);
3014 error = umtx_key_get(rwlock, TYPE_RWLOCK, GET_SHARE(flags), &uq->uq_key);
3015 if (error != 0)
3016 return (error);
3017
3018 error = fueword32(&rwlock->rw_state, &state);
3019 if (error == -1) {
3020 error = EFAULT;
3021 goto out;
3022 }
3023 if (state & URWLOCK_WRITE_OWNER) {
3024 for (;;) {
3025 rv = casueword32(&rwlock->rw_state, state,
3026 &oldstate, state & ~URWLOCK_WRITE_OWNER);
3027 if (rv == -1) {
3028 error = EFAULT;
3029 goto out;
3030 }
3031 if (oldstate != state) {
3032 state = oldstate;
3033 if (!(oldstate & URWLOCK_WRITE_OWNER)) {
3034 error = EPERM;
3035 goto out;
3036 }
3037 error = umtxq_check_susp(td);
3038 if (error != 0)
3039 goto out;
3040 } else
3041 break;
3042 }
3043 } else if (URWLOCK_READER_COUNT(state) != 0) {
3044 for (;;) {
3045 rv = casueword32(&rwlock->rw_state, state,
3046 &oldstate, state - 1);
3047 if (rv == -1) {
3048 error = EFAULT;
3049 goto out;
3050 }
3051 if (oldstate != state) {
3052 state = oldstate;
3053 if (URWLOCK_READER_COUNT(oldstate) == 0) {
3054 error = EPERM;
3055 goto out;
3056 }
3057 error = umtxq_check_susp(td);
3058 if (error != 0)
3059 goto out;
3060 } else
3061 break;
3062 }
3063 } else {
3064 error = EPERM;
3065 goto out;
3066 }
3067
3068 count = 0;
3069
3070 if (!(flags & URWLOCK_PREFER_READER)) {
3071 if (state & URWLOCK_WRITE_WAITERS) {
3072 count = 1;
3073 q = UMTX_EXCLUSIVE_QUEUE;
3074 } else if (state & URWLOCK_READ_WAITERS) {
3075 count = INT_MAX;
3076 q = UMTX_SHARED_QUEUE;
3077 }
3078 } else {
3079 if (state & URWLOCK_READ_WAITERS) {
3080 count = INT_MAX;
3081 q = UMTX_SHARED_QUEUE;
3082 } else if (state & URWLOCK_WRITE_WAITERS) {
3083 count = 1;
3084 q = UMTX_EXCLUSIVE_QUEUE;
3085 }
3086 }
3087
3088 if (count) {
3089 umtxq_lock(&uq->uq_key);
3090 umtxq_busy(&uq->uq_key);
3091 umtxq_signal_queue(&uq->uq_key, count, q);
3092 umtxq_unbusy(&uq->uq_key);
3093 umtxq_unlock(&uq->uq_key);
3094 }
3095 out:
3096 umtx_key_release(&uq->uq_key);
3097 return (error);
3098 }
3099
3100 #if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
3101 static int
do_sem_wait(struct thread * td,struct _usem * sem,struct _umtx_time * timeout)3102 do_sem_wait(struct thread *td, struct _usem *sem, struct _umtx_time *timeout)
3103 {
3104 struct abs_timeout timo;
3105 struct umtx_q *uq;
3106 uint32_t flags, count, count1;
3107 int error, rv;
3108
3109 uq = td->td_umtxq;
3110 error = fueword32(&sem->_flags, &flags);
3111 if (error == -1)
3112 return (EFAULT);
3113 error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &uq->uq_key);
3114 if (error != 0)
3115 return (error);
3116
3117 if (timeout != NULL)
3118 abs_timeout_init2(&timo, timeout);
3119
3120 umtxq_lock(&uq->uq_key);
3121 umtxq_busy(&uq->uq_key);
3122 umtxq_insert(uq);
3123 umtxq_unlock(&uq->uq_key);
3124 rv = casueword32(&sem->_has_waiters, 0, &count1, 1);
3125 if (rv == 0)
3126 rv = fueword32(&sem->_count, &count);
3127 if (rv == -1 || count != 0) {
3128 umtxq_lock(&uq->uq_key);
3129 umtxq_unbusy(&uq->uq_key);
3130 umtxq_remove(uq);
3131 umtxq_unlock(&uq->uq_key);
3132 umtx_key_release(&uq->uq_key);
3133 return (rv == -1 ? EFAULT : 0);
3134 }
3135 umtxq_lock(&uq->uq_key);
3136 umtxq_unbusy(&uq->uq_key);
3137
3138 error = umtxq_sleep(uq, "usem", timeout == NULL ? NULL : &timo);
3139
3140 if ((uq->uq_flags & UQF_UMTXQ) == 0)
3141 error = 0;
3142 else {
3143 umtxq_remove(uq);
3144 /* A relative timeout cannot be restarted. */
3145 if (error == ERESTART && timeout != NULL &&
3146 (timeout->_flags & UMTX_ABSTIME) == 0)
3147 error = EINTR;
3148 }
3149 umtxq_unlock(&uq->uq_key);
3150 umtx_key_release(&uq->uq_key);
3151 return (error);
3152 }
3153
3154 /*
3155 * Signal a userland semaphore.
3156 */
3157 static int
do_sem_wake(struct thread * td,struct _usem * sem)3158 do_sem_wake(struct thread *td, struct _usem *sem)
3159 {
3160 struct umtx_key key;
3161 int error, cnt;
3162 uint32_t flags;
3163
3164 error = fueword32(&sem->_flags, &flags);
3165 if (error == -1)
3166 return (EFAULT);
3167 if ((error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &key)) != 0)
3168 return (error);
3169 umtxq_lock(&key);
3170 umtxq_busy(&key);
3171 cnt = umtxq_count(&key);
3172 if (cnt > 0) {
3173 /*
3174 * Check if count is greater than 0, this means the memory is
3175 * still being referenced by user code, so we can safely
3176 * update _has_waiters flag.
3177 */
3178 if (cnt == 1) {
3179 umtxq_unlock(&key);
3180 error = suword32(&sem->_has_waiters, 0);
3181 umtxq_lock(&key);
3182 if (error == -1)
3183 error = EFAULT;
3184 }
3185 umtxq_signal(&key, 1);
3186 }
3187 umtxq_unbusy(&key);
3188 umtxq_unlock(&key);
3189 umtx_key_release(&key);
3190 return (error);
3191 }
3192 #endif
3193
3194 static int
do_sem2_wait(struct thread * td,struct _usem2 * sem,struct _umtx_time * timeout)3195 do_sem2_wait(struct thread *td, struct _usem2 *sem, struct _umtx_time *timeout)
3196 {
3197 struct abs_timeout timo;
3198 struct umtx_q *uq;
3199 uint32_t count, flags;
3200 int error, rv;
3201
3202 uq = td->td_umtxq;
3203 flags = fuword32(&sem->_flags);
3204 error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &uq->uq_key);
3205 if (error != 0)
3206 return (error);
3207
3208 if (timeout != NULL)
3209 abs_timeout_init2(&timo, timeout);
3210
3211 umtxq_lock(&uq->uq_key);
3212 umtxq_busy(&uq->uq_key);
3213 umtxq_insert(uq);
3214 umtxq_unlock(&uq->uq_key);
3215 rv = fueword32(&sem->_count, &count);
3216 if (rv == -1) {
3217 umtxq_lock(&uq->uq_key);
3218 umtxq_unbusy(&uq->uq_key);
3219 umtxq_remove(uq);
3220 umtxq_unlock(&uq->uq_key);
3221 umtx_key_release(&uq->uq_key);
3222 return (EFAULT);
3223 }
3224 for (;;) {
3225 if (USEM_COUNT(count) != 0) {
3226 umtxq_lock(&uq->uq_key);
3227 umtxq_unbusy(&uq->uq_key);
3228 umtxq_remove(uq);
3229 umtxq_unlock(&uq->uq_key);
3230 umtx_key_release(&uq->uq_key);
3231 return (0);
3232 }
3233 if (count == USEM_HAS_WAITERS)
3234 break;
3235 rv = casueword32(&sem->_count, 0, &count, USEM_HAS_WAITERS);
3236 if (rv == -1) {
3237 umtxq_lock(&uq->uq_key);
3238 umtxq_unbusy(&uq->uq_key);
3239 umtxq_remove(uq);
3240 umtxq_unlock(&uq->uq_key);
3241 umtx_key_release(&uq->uq_key);
3242 return (EFAULT);
3243 }
3244 if (count == 0)
3245 break;
3246 }
3247 umtxq_lock(&uq->uq_key);
3248 umtxq_unbusy(&uq->uq_key);
3249
3250 error = umtxq_sleep(uq, "usem", timeout == NULL ? NULL : &timo);
3251
3252 if ((uq->uq_flags & UQF_UMTXQ) == 0)
3253 error = 0;
3254 else {
3255 umtxq_remove(uq);
3256 if (timeout != NULL && (timeout->_flags & UMTX_ABSTIME) == 0) {
3257 /* A relative timeout cannot be restarted. */
3258 if (error == ERESTART)
3259 error = EINTR;
3260 if (error == EINTR) {
3261 abs_timeout_update(&timo);
3262 timeout->_timeout = timo.end;
3263 timespecsub(&timeout->_timeout, &timo.cur);
3264 }
3265 }
3266 }
3267 umtxq_unlock(&uq->uq_key);
3268 umtx_key_release(&uq->uq_key);
3269 return (error);
3270 }
3271
3272 /*
3273 * Signal a userland semaphore.
3274 */
3275 static int
do_sem2_wake(struct thread * td,struct _usem2 * sem)3276 do_sem2_wake(struct thread *td, struct _usem2 *sem)
3277 {
3278 struct umtx_key key;
3279 int error, cnt, rv;
3280 uint32_t count, flags;
3281
3282 rv = fueword32(&sem->_flags, &flags);
3283 if (rv == -1)
3284 return (EFAULT);
3285 if ((error = umtx_key_get(sem, TYPE_SEM, GET_SHARE(flags), &key)) != 0)
3286 return (error);
3287 umtxq_lock(&key);
3288 umtxq_busy(&key);
3289 cnt = umtxq_count(&key);
3290 if (cnt > 0) {
3291 /*
3292 * If this was the last sleeping thread, clear the waiters
3293 * flag in _count.
3294 */
3295 if (cnt == 1) {
3296 umtxq_unlock(&key);
3297 rv = fueword32(&sem->_count, &count);
3298 while (rv != -1 && count & USEM_HAS_WAITERS)
3299 rv = casueword32(&sem->_count, count, &count,
3300 count & ~USEM_HAS_WAITERS);
3301 if (rv == -1)
3302 error = EFAULT;
3303 umtxq_lock(&key);
3304 }
3305
3306 umtxq_signal(&key, 1);
3307 }
3308 umtxq_unbusy(&key);
3309 umtxq_unlock(&key);
3310 umtx_key_release(&key);
3311 return (error);
3312 }
3313
3314 inline int
umtx_copyin_timeout(const void * addr,struct timespec * tsp)3315 umtx_copyin_timeout(const void *addr, struct timespec *tsp)
3316 {
3317 int error;
3318
3319 error = copyin(addr, tsp, sizeof(struct timespec));
3320 if (error == 0) {
3321 if (tsp->tv_sec < 0 ||
3322 tsp->tv_nsec >= 1000000000 ||
3323 tsp->tv_nsec < 0)
3324 error = EINVAL;
3325 }
3326 return (error);
3327 }
3328
3329 static inline int
umtx_copyin_umtx_time(const void * addr,size_t size,struct _umtx_time * tp)3330 umtx_copyin_umtx_time(const void *addr, size_t size, struct _umtx_time *tp)
3331 {
3332 int error;
3333
3334 if (size <= sizeof(struct timespec)) {
3335 tp->_clockid = CLOCK_REALTIME;
3336 tp->_flags = 0;
3337 error = copyin(addr, &tp->_timeout, sizeof(struct timespec));
3338 } else
3339 error = copyin(addr, tp, sizeof(struct _umtx_time));
3340 if (error != 0)
3341 return (error);
3342 if (tp->_timeout.tv_sec < 0 ||
3343 tp->_timeout.tv_nsec >= 1000000000 || tp->_timeout.tv_nsec < 0)
3344 return (EINVAL);
3345 return (0);
3346 }
3347
3348 static int
__umtx_op_unimpl(struct thread * td,struct _umtx_op_args * uap)3349 __umtx_op_unimpl(struct thread *td, struct _umtx_op_args *uap)
3350 {
3351
3352 return (EOPNOTSUPP);
3353 }
3354
3355 static int
__umtx_op_wait(struct thread * td,struct _umtx_op_args * uap)3356 __umtx_op_wait(struct thread *td, struct _umtx_op_args *uap)
3357 {
3358 struct _umtx_time timeout, *tm_p;
3359 int error;
3360
3361 if (uap->uaddr2 == NULL)
3362 tm_p = NULL;
3363 else {
3364 error = umtx_copyin_umtx_time(
3365 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
3366 if (error != 0)
3367 return (error);
3368 tm_p = &timeout;
3369 }
3370 return (do_wait(td, uap->obj, uap->val, tm_p, 0, 0));
3371 }
3372
3373 static int
__umtx_op_wait_uint(struct thread * td,struct _umtx_op_args * uap)3374 __umtx_op_wait_uint(struct thread *td, struct _umtx_op_args *uap)
3375 {
3376 struct _umtx_time timeout, *tm_p;
3377 int error;
3378
3379 if (uap->uaddr2 == NULL)
3380 tm_p = NULL;
3381 else {
3382 error = umtx_copyin_umtx_time(
3383 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
3384 if (error != 0)
3385 return (error);
3386 tm_p = &timeout;
3387 }
3388 return (do_wait(td, uap->obj, uap->val, tm_p, 1, 0));
3389 }
3390
3391 static int
__umtx_op_wait_uint_private(struct thread * td,struct _umtx_op_args * uap)3392 __umtx_op_wait_uint_private(struct thread *td, struct _umtx_op_args *uap)
3393 {
3394 struct _umtx_time *tm_p, timeout;
3395 int error;
3396
3397 if (uap->uaddr2 == NULL)
3398 tm_p = NULL;
3399 else {
3400 error = umtx_copyin_umtx_time(
3401 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
3402 if (error != 0)
3403 return (error);
3404 tm_p = &timeout;
3405 }
3406 return (do_wait(td, uap->obj, uap->val, tm_p, 1, 1));
3407 }
3408
3409 static int
__umtx_op_wake(struct thread * td,struct _umtx_op_args * uap)3410 __umtx_op_wake(struct thread *td, struct _umtx_op_args *uap)
3411 {
3412
3413 return (kern_umtx_wake(td, uap->obj, uap->val, 0));
3414 }
3415
3416 #define BATCH_SIZE 128
3417 static int
__umtx_op_nwake_private(struct thread * td,struct _umtx_op_args * uap)3418 __umtx_op_nwake_private(struct thread *td, struct _umtx_op_args *uap)
3419 {
3420 char *uaddrs[BATCH_SIZE], **upp;
3421 int count, error, i, pos, tocopy;
3422
3423 upp = (char **)uap->obj;
3424 error = 0;
3425 for (count = uap->val, pos = 0; count > 0; count -= tocopy,
3426 pos += tocopy) {
3427 tocopy = MIN(count, BATCH_SIZE);
3428 error = copyin(upp + pos, uaddrs, tocopy * sizeof(char *));
3429 if (error != 0)
3430 break;
3431 for (i = 0; i < tocopy; ++i)
3432 kern_umtx_wake(td, uaddrs[i], INT_MAX, 1);
3433 maybe_yield();
3434 }
3435 return (error);
3436 }
3437
3438 static int
__umtx_op_wake_private(struct thread * td,struct _umtx_op_args * uap)3439 __umtx_op_wake_private(struct thread *td, struct _umtx_op_args *uap)
3440 {
3441
3442 return (kern_umtx_wake(td, uap->obj, uap->val, 1));
3443 }
3444
3445 static int
__umtx_op_lock_umutex(struct thread * td,struct _umtx_op_args * uap)3446 __umtx_op_lock_umutex(struct thread *td, struct _umtx_op_args *uap)
3447 {
3448 struct _umtx_time *tm_p, timeout;
3449 int error;
3450
3451 /* Allow a null timespec (wait forever). */
3452 if (uap->uaddr2 == NULL)
3453 tm_p = NULL;
3454 else {
3455 error = umtx_copyin_umtx_time(
3456 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
3457 if (error != 0)
3458 return (error);
3459 tm_p = &timeout;
3460 }
3461 return (do_lock_umutex(td, uap->obj, tm_p, 0));
3462 }
3463
3464 static int
__umtx_op_trylock_umutex(struct thread * td,struct _umtx_op_args * uap)3465 __umtx_op_trylock_umutex(struct thread *td, struct _umtx_op_args *uap)
3466 {
3467
3468 return (do_lock_umutex(td, uap->obj, NULL, _UMUTEX_TRY));
3469 }
3470
3471 static int
__umtx_op_wait_umutex(struct thread * td,struct _umtx_op_args * uap)3472 __umtx_op_wait_umutex(struct thread *td, struct _umtx_op_args *uap)
3473 {
3474 struct _umtx_time *tm_p, timeout;
3475 int error;
3476
3477 /* Allow a null timespec (wait forever). */
3478 if (uap->uaddr2 == NULL)
3479 tm_p = NULL;
3480 else {
3481 error = umtx_copyin_umtx_time(
3482 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
3483 if (error != 0)
3484 return (error);
3485 tm_p = &timeout;
3486 }
3487 return (do_lock_umutex(td, uap->obj, tm_p, _UMUTEX_WAIT));
3488 }
3489
3490 static int
__umtx_op_wake_umutex(struct thread * td,struct _umtx_op_args * uap)3491 __umtx_op_wake_umutex(struct thread *td, struct _umtx_op_args *uap)
3492 {
3493
3494 return (do_wake_umutex(td, uap->obj));
3495 }
3496
3497 static int
__umtx_op_unlock_umutex(struct thread * td,struct _umtx_op_args * uap)3498 __umtx_op_unlock_umutex(struct thread *td, struct _umtx_op_args *uap)
3499 {
3500
3501 return (do_unlock_umutex(td, uap->obj, false));
3502 }
3503
3504 static int
__umtx_op_set_ceiling(struct thread * td,struct _umtx_op_args * uap)3505 __umtx_op_set_ceiling(struct thread *td, struct _umtx_op_args *uap)
3506 {
3507
3508 return (do_set_ceiling(td, uap->obj, uap->val, uap->uaddr1));
3509 }
3510
3511 static int
__umtx_op_cv_wait(struct thread * td,struct _umtx_op_args * uap)3512 __umtx_op_cv_wait(struct thread *td, struct _umtx_op_args *uap)
3513 {
3514 struct timespec *ts, timeout;
3515 int error;
3516
3517 /* Allow a null timespec (wait forever). */
3518 if (uap->uaddr2 == NULL)
3519 ts = NULL;
3520 else {
3521 error = umtx_copyin_timeout(uap->uaddr2, &timeout);
3522 if (error != 0)
3523 return (error);
3524 ts = &timeout;
3525 }
3526 return (do_cv_wait(td, uap->obj, uap->uaddr1, ts, uap->val));
3527 }
3528
3529 static int
__umtx_op_cv_signal(struct thread * td,struct _umtx_op_args * uap)3530 __umtx_op_cv_signal(struct thread *td, struct _umtx_op_args *uap)
3531 {
3532
3533 return (do_cv_signal(td, uap->obj));
3534 }
3535
3536 static int
__umtx_op_cv_broadcast(struct thread * td,struct _umtx_op_args * uap)3537 __umtx_op_cv_broadcast(struct thread *td, struct _umtx_op_args *uap)
3538 {
3539
3540 return (do_cv_broadcast(td, uap->obj));
3541 }
3542
3543 static int
__umtx_op_rw_rdlock(struct thread * td,struct _umtx_op_args * uap)3544 __umtx_op_rw_rdlock(struct thread *td, struct _umtx_op_args *uap)
3545 {
3546 struct _umtx_time timeout;
3547 int error;
3548
3549 /* Allow a null timespec (wait forever). */
3550 if (uap->uaddr2 == NULL) {
3551 error = do_rw_rdlock(td, uap->obj, uap->val, 0);
3552 } else {
3553 error = umtx_copyin_umtx_time(uap->uaddr2,
3554 (size_t)uap->uaddr1, &timeout);
3555 if (error != 0)
3556 return (error);
3557 error = do_rw_rdlock(td, uap->obj, uap->val, &timeout);
3558 }
3559 return (error);
3560 }
3561
3562 static int
__umtx_op_rw_wrlock(struct thread * td,struct _umtx_op_args * uap)3563 __umtx_op_rw_wrlock(struct thread *td, struct _umtx_op_args *uap)
3564 {
3565 struct _umtx_time timeout;
3566 int error;
3567
3568 /* Allow a null timespec (wait forever). */
3569 if (uap->uaddr2 == NULL) {
3570 error = do_rw_wrlock(td, uap->obj, 0);
3571 } else {
3572 error = umtx_copyin_umtx_time(uap->uaddr2,
3573 (size_t)uap->uaddr1, &timeout);
3574 if (error != 0)
3575 return (error);
3576
3577 error = do_rw_wrlock(td, uap->obj, &timeout);
3578 }
3579 return (error);
3580 }
3581
3582 static int
__umtx_op_rw_unlock(struct thread * td,struct _umtx_op_args * uap)3583 __umtx_op_rw_unlock(struct thread *td, struct _umtx_op_args *uap)
3584 {
3585
3586 return (do_rw_unlock(td, uap->obj));
3587 }
3588
3589 #if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
3590 static int
__umtx_op_sem_wait(struct thread * td,struct _umtx_op_args * uap)3591 __umtx_op_sem_wait(struct thread *td, struct _umtx_op_args *uap)
3592 {
3593 struct _umtx_time *tm_p, timeout;
3594 int error;
3595
3596 /* Allow a null timespec (wait forever). */
3597 if (uap->uaddr2 == NULL)
3598 tm_p = NULL;
3599 else {
3600 error = umtx_copyin_umtx_time(
3601 uap->uaddr2, (size_t)uap->uaddr1, &timeout);
3602 if (error != 0)
3603 return (error);
3604 tm_p = &timeout;
3605 }
3606 return (do_sem_wait(td, uap->obj, tm_p));
3607 }
3608
3609 static int
__umtx_op_sem_wake(struct thread * td,struct _umtx_op_args * uap)3610 __umtx_op_sem_wake(struct thread *td, struct _umtx_op_args *uap)
3611 {
3612
3613 return (do_sem_wake(td, uap->obj));
3614 }
3615 #endif
3616
3617 static int
__umtx_op_wake2_umutex(struct thread * td,struct _umtx_op_args * uap)3618 __umtx_op_wake2_umutex(struct thread *td, struct _umtx_op_args *uap)
3619 {
3620
3621 return (do_wake2_umutex(td, uap->obj, uap->val));
3622 }
3623
3624 static int
__umtx_op_sem2_wait(struct thread * td,struct _umtx_op_args * uap)3625 __umtx_op_sem2_wait(struct thread *td, struct _umtx_op_args *uap)
3626 {
3627 struct _umtx_time *tm_p, timeout;
3628 size_t uasize;
3629 int error;
3630
3631 /* Allow a null timespec (wait forever). */
3632 if (uap->uaddr2 == NULL) {
3633 uasize = 0;
3634 tm_p = NULL;
3635 } else {
3636 uasize = (size_t)uap->uaddr1;
3637 error = umtx_copyin_umtx_time(uap->uaddr2, uasize, &timeout);
3638 if (error != 0)
3639 return (error);
3640 tm_p = &timeout;
3641 }
3642 error = do_sem2_wait(td, uap->obj, tm_p);
3643 if (error == EINTR && uap->uaddr2 != NULL &&
3644 (timeout._flags & UMTX_ABSTIME) == 0 &&
3645 uasize >= sizeof(struct _umtx_time) + sizeof(struct timespec)) {
3646 error = copyout(&timeout._timeout,
3647 (struct _umtx_time *)uap->uaddr2 + 1,
3648 sizeof(struct timespec));
3649 if (error == 0) {
3650 error = EINTR;
3651 }
3652 }
3653
3654 return (error);
3655 }
3656
3657 static int
__umtx_op_sem2_wake(struct thread * td,struct _umtx_op_args * uap)3658 __umtx_op_sem2_wake(struct thread *td, struct _umtx_op_args *uap)
3659 {
3660
3661 return (do_sem2_wake(td, uap->obj));
3662 }
3663
3664 #define USHM_OBJ_UMTX(o) \
3665 ((struct umtx_shm_obj_list *)(&(o)->umtx_data))
3666
3667 #define USHMF_REG_LINKED 0x0001
3668 #define USHMF_OBJ_LINKED 0x0002
3669 struct umtx_shm_reg {
3670 TAILQ_ENTRY(umtx_shm_reg) ushm_reg_link;
3671 LIST_ENTRY(umtx_shm_reg) ushm_obj_link;
3672 struct umtx_key ushm_key;
3673 struct ucred *ushm_cred;
3674 struct shmfd *ushm_obj;
3675 u_int ushm_refcnt;
3676 u_int ushm_flags;
3677 };
3678
3679 LIST_HEAD(umtx_shm_obj_list, umtx_shm_reg);
3680 TAILQ_HEAD(umtx_shm_reg_head, umtx_shm_reg);
3681
3682 static uma_zone_t umtx_shm_reg_zone;
3683 static struct umtx_shm_reg_head umtx_shm_registry[UMTX_CHAINS];
3684 static struct mtx umtx_shm_lock;
3685 static struct umtx_shm_reg_head umtx_shm_reg_delfree =
3686 TAILQ_HEAD_INITIALIZER(umtx_shm_reg_delfree);
3687
3688 static void umtx_shm_free_reg(struct umtx_shm_reg *reg);
3689
3690 static void
umtx_shm_reg_delfree_tq(void * context __unused,int pending __unused)3691 umtx_shm_reg_delfree_tq(void *context __unused, int pending __unused)
3692 {
3693 struct umtx_shm_reg_head d;
3694 struct umtx_shm_reg *reg, *reg1;
3695
3696 TAILQ_INIT(&d);
3697 mtx_lock(&umtx_shm_lock);
3698 TAILQ_CONCAT(&d, &umtx_shm_reg_delfree, ushm_reg_link);
3699 mtx_unlock(&umtx_shm_lock);
3700 TAILQ_FOREACH_SAFE(reg, &d, ushm_reg_link, reg1) {
3701 TAILQ_REMOVE(&d, reg, ushm_reg_link);
3702 umtx_shm_free_reg(reg);
3703 }
3704 }
3705
3706 static struct task umtx_shm_reg_delfree_task =
3707 TASK_INITIALIZER(0, umtx_shm_reg_delfree_tq, NULL);
3708
3709 static struct umtx_shm_reg *
umtx_shm_find_reg_locked(const struct umtx_key * key)3710 umtx_shm_find_reg_locked(const struct umtx_key *key)
3711 {
3712 struct umtx_shm_reg *reg;
3713 struct umtx_shm_reg_head *reg_head;
3714
3715 KASSERT(key->shared, ("umtx_p_find_rg: private key"));
3716 mtx_assert(&umtx_shm_lock, MA_OWNED);
3717 reg_head = &umtx_shm_registry[key->hash];
3718 TAILQ_FOREACH(reg, reg_head, ushm_reg_link) {
3719 KASSERT(reg->ushm_key.shared,
3720 ("non-shared key on reg %p %d", reg, reg->ushm_key.shared));
3721 if (reg->ushm_key.info.shared.object ==
3722 key->info.shared.object &&
3723 reg->ushm_key.info.shared.offset ==
3724 key->info.shared.offset) {
3725 KASSERT(reg->ushm_key.type == TYPE_SHM, ("TYPE_USHM"));
3726 KASSERT(reg->ushm_refcnt > 0,
3727 ("reg %p refcnt 0 onlist", reg));
3728 KASSERT((reg->ushm_flags & USHMF_REG_LINKED) != 0,
3729 ("reg %p not linked", reg));
3730 reg->ushm_refcnt++;
3731 return (reg);
3732 }
3733 }
3734 return (NULL);
3735 }
3736
3737 static struct umtx_shm_reg *
umtx_shm_find_reg(const struct umtx_key * key)3738 umtx_shm_find_reg(const struct umtx_key *key)
3739 {
3740 struct umtx_shm_reg *reg;
3741
3742 mtx_lock(&umtx_shm_lock);
3743 reg = umtx_shm_find_reg_locked(key);
3744 mtx_unlock(&umtx_shm_lock);
3745 return (reg);
3746 }
3747
3748 static void
umtx_shm_free_reg(struct umtx_shm_reg * reg)3749 umtx_shm_free_reg(struct umtx_shm_reg *reg)
3750 {
3751
3752 chgumtxcnt(reg->ushm_cred->cr_ruidinfo, -1, 0);
3753 crfree(reg->ushm_cred);
3754 shm_drop(reg->ushm_obj);
3755 uma_zfree(umtx_shm_reg_zone, reg);
3756 }
3757
3758 static bool
umtx_shm_unref_reg_locked(struct umtx_shm_reg * reg,bool force)3759 umtx_shm_unref_reg_locked(struct umtx_shm_reg *reg, bool force)
3760 {
3761 bool res;
3762
3763 mtx_assert(&umtx_shm_lock, MA_OWNED);
3764 KASSERT(reg->ushm_refcnt > 0, ("ushm_reg %p refcnt 0", reg));
3765 reg->ushm_refcnt--;
3766 res = reg->ushm_refcnt == 0;
3767 if (res || force) {
3768 if ((reg->ushm_flags & USHMF_REG_LINKED) != 0) {
3769 TAILQ_REMOVE(&umtx_shm_registry[reg->ushm_key.hash],
3770 reg, ushm_reg_link);
3771 reg->ushm_flags &= ~USHMF_REG_LINKED;
3772 }
3773 if ((reg->ushm_flags & USHMF_OBJ_LINKED) != 0) {
3774 LIST_REMOVE(reg, ushm_obj_link);
3775 reg->ushm_flags &= ~USHMF_OBJ_LINKED;
3776 }
3777 }
3778 return (res);
3779 }
3780
3781 static void
umtx_shm_unref_reg(struct umtx_shm_reg * reg,bool force)3782 umtx_shm_unref_reg(struct umtx_shm_reg *reg, bool force)
3783 {
3784 vm_object_t object;
3785 bool dofree;
3786
3787 if (force) {
3788 object = reg->ushm_obj->shm_object;
3789 VM_OBJECT_WLOCK(object);
3790 object->flags |= OBJ_UMTXDEAD;
3791 VM_OBJECT_WUNLOCK(object);
3792 }
3793 mtx_lock(&umtx_shm_lock);
3794 dofree = umtx_shm_unref_reg_locked(reg, force);
3795 mtx_unlock(&umtx_shm_lock);
3796 if (dofree)
3797 umtx_shm_free_reg(reg);
3798 }
3799
3800 void
umtx_shm_object_init(vm_object_t object)3801 umtx_shm_object_init(vm_object_t object)
3802 {
3803
3804 LIST_INIT(USHM_OBJ_UMTX(object));
3805 }
3806
3807 void
umtx_shm_object_terminated(vm_object_t object)3808 umtx_shm_object_terminated(vm_object_t object)
3809 {
3810 struct umtx_shm_reg *reg, *reg1;
3811 bool dofree;
3812
3813 dofree = false;
3814 mtx_lock(&umtx_shm_lock);
3815 LIST_FOREACH_SAFE(reg, USHM_OBJ_UMTX(object), ushm_obj_link, reg1) {
3816 if (umtx_shm_unref_reg_locked(reg, true)) {
3817 TAILQ_INSERT_TAIL(&umtx_shm_reg_delfree, reg,
3818 ushm_reg_link);
3819 dofree = true;
3820 }
3821 }
3822 mtx_unlock(&umtx_shm_lock);
3823 if (dofree)
3824 taskqueue_enqueue(taskqueue_thread, &umtx_shm_reg_delfree_task);
3825 }
3826
3827 static int
umtx_shm_create_reg(struct thread * td,const struct umtx_key * key,struct umtx_shm_reg ** res)3828 umtx_shm_create_reg(struct thread *td, const struct umtx_key *key,
3829 struct umtx_shm_reg **res)
3830 {
3831 struct umtx_shm_reg *reg, *reg1;
3832 struct ucred *cred;
3833 int error;
3834
3835 reg = umtx_shm_find_reg(key);
3836 if (reg != NULL) {
3837 *res = reg;
3838 return (0);
3839 }
3840 cred = td->td_ucred;
3841 if (!chgumtxcnt(cred->cr_ruidinfo, 1, lim_cur(td, RLIMIT_UMTXP)))
3842 return (ENOMEM);
3843 reg = uma_zalloc(umtx_shm_reg_zone, M_WAITOK | M_ZERO);
3844 reg->ushm_refcnt = 1;
3845 bcopy(key, ®->ushm_key, sizeof(*key));
3846 reg->ushm_obj = shm_alloc(td->td_ucred, O_RDWR);
3847 reg->ushm_cred = crhold(cred);
3848 error = shm_dotruncate(reg->ushm_obj, PAGE_SIZE);
3849 if (error != 0) {
3850 umtx_shm_free_reg(reg);
3851 return (error);
3852 }
3853 mtx_lock(&umtx_shm_lock);
3854 reg1 = umtx_shm_find_reg_locked(key);
3855 if (reg1 != NULL) {
3856 mtx_unlock(&umtx_shm_lock);
3857 umtx_shm_free_reg(reg);
3858 *res = reg1;
3859 return (0);
3860 }
3861 reg->ushm_refcnt++;
3862 TAILQ_INSERT_TAIL(&umtx_shm_registry[key->hash], reg, ushm_reg_link);
3863 LIST_INSERT_HEAD(USHM_OBJ_UMTX(key->info.shared.object), reg,
3864 ushm_obj_link);
3865 reg->ushm_flags = USHMF_REG_LINKED | USHMF_OBJ_LINKED;
3866 mtx_unlock(&umtx_shm_lock);
3867 *res = reg;
3868 return (0);
3869 }
3870
3871 static int
umtx_shm_alive(struct thread * td,void * addr)3872 umtx_shm_alive(struct thread *td, void *addr)
3873 {
3874 vm_map_t map;
3875 vm_map_entry_t entry;
3876 vm_object_t object;
3877 vm_pindex_t pindex;
3878 vm_prot_t prot;
3879 int res, ret;
3880 boolean_t wired;
3881
3882 map = &td->td_proc->p_vmspace->vm_map;
3883 res = vm_map_lookup(&map, (uintptr_t)addr, VM_PROT_READ, &entry,
3884 &object, &pindex, &prot, &wired);
3885 if (res != KERN_SUCCESS)
3886 return (EFAULT);
3887 if (object == NULL)
3888 ret = EINVAL;
3889 else
3890 ret = (object->flags & OBJ_UMTXDEAD) != 0 ? ENOTTY : 0;
3891 vm_map_lookup_done(map, entry);
3892 return (ret);
3893 }
3894
3895 static void
umtx_shm_init(void)3896 umtx_shm_init(void)
3897 {
3898 int i;
3899
3900 umtx_shm_reg_zone = uma_zcreate("umtx_shm", sizeof(struct umtx_shm_reg),
3901 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
3902 mtx_init(&umtx_shm_lock, "umtxshm", NULL, MTX_DEF);
3903 for (i = 0; i < nitems(umtx_shm_registry); i++)
3904 TAILQ_INIT(&umtx_shm_registry[i]);
3905 }
3906
3907 static int
umtx_shm(struct thread * td,void * addr,u_int flags)3908 umtx_shm(struct thread *td, void *addr, u_int flags)
3909 {
3910 struct umtx_key key;
3911 struct umtx_shm_reg *reg;
3912 struct file *fp;
3913 int error, fd;
3914
3915 if (__bitcount(flags & (UMTX_SHM_CREAT | UMTX_SHM_LOOKUP |
3916 UMTX_SHM_DESTROY| UMTX_SHM_ALIVE)) != 1)
3917 return (EINVAL);
3918 if ((flags & UMTX_SHM_ALIVE) != 0)
3919 return (umtx_shm_alive(td, addr));
3920 error = umtx_key_get(addr, TYPE_SHM, PROCESS_SHARE, &key);
3921 if (error != 0)
3922 return (error);
3923 KASSERT(key.shared == 1, ("non-shared key"));
3924 if ((flags & UMTX_SHM_CREAT) != 0) {
3925 error = umtx_shm_create_reg(td, &key, ®);
3926 } else {
3927 reg = umtx_shm_find_reg(&key);
3928 if (reg == NULL)
3929 error = ESRCH;
3930 }
3931 umtx_key_release(&key);
3932 if (error != 0)
3933 return (error);
3934 KASSERT(reg != NULL, ("no reg"));
3935 if ((flags & UMTX_SHM_DESTROY) != 0) {
3936 umtx_shm_unref_reg(reg, true);
3937 } else {
3938 #if 0
3939 #ifdef MAC
3940 error = mac_posixshm_check_open(td->td_ucred,
3941 reg->ushm_obj, FFLAGS(O_RDWR));
3942 if (error == 0)
3943 #endif
3944 error = shm_access(reg->ushm_obj, td->td_ucred,
3945 FFLAGS(O_RDWR));
3946 if (error == 0)
3947 #endif
3948 error = falloc_caps(td, &fp, &fd, O_CLOEXEC, NULL);
3949 if (error == 0) {
3950 shm_hold(reg->ushm_obj);
3951 finit(fp, FFLAGS(O_RDWR), DTYPE_SHM, reg->ushm_obj,
3952 &shm_ops);
3953 td->td_retval[0] = fd;
3954 fdrop(fp, td);
3955 }
3956 }
3957 umtx_shm_unref_reg(reg, false);
3958 return (error);
3959 }
3960
3961 static int
__umtx_op_shm(struct thread * td,struct _umtx_op_args * uap)3962 __umtx_op_shm(struct thread *td, struct _umtx_op_args *uap)
3963 {
3964
3965 return (umtx_shm(td, uap->uaddr1, uap->val));
3966 }
3967
3968 static int
umtx_robust_lists(struct thread * td,struct umtx_robust_lists_params * rbp)3969 umtx_robust_lists(struct thread *td, struct umtx_robust_lists_params *rbp)
3970 {
3971
3972 td->td_rb_list = rbp->robust_list_offset;
3973 td->td_rbp_list = rbp->robust_priv_list_offset;
3974 td->td_rb_inact = rbp->robust_inact_offset;
3975 return (0);
3976 }
3977
3978 static int
__umtx_op_robust_lists(struct thread * td,struct _umtx_op_args * uap)3979 __umtx_op_robust_lists(struct thread *td, struct _umtx_op_args *uap)
3980 {
3981 struct umtx_robust_lists_params rb;
3982 int error;
3983
3984 if (uap->val > sizeof(rb))
3985 return (EINVAL);
3986 bzero(&rb, sizeof(rb));
3987 error = copyin(uap->uaddr1, &rb, uap->val);
3988 if (error != 0)
3989 return (error);
3990 return (umtx_robust_lists(td, &rb));
3991 }
3992
3993 typedef int (*_umtx_op_func)(struct thread *td, struct _umtx_op_args *uap);
3994
3995 static const _umtx_op_func op_table[] = {
3996 [UMTX_OP_RESERVED0] = __umtx_op_unimpl,
3997 [UMTX_OP_RESERVED1] = __umtx_op_unimpl,
3998 [UMTX_OP_WAIT] = __umtx_op_wait,
3999 [UMTX_OP_WAKE] = __umtx_op_wake,
4000 [UMTX_OP_MUTEX_TRYLOCK] = __umtx_op_trylock_umutex,
4001 [UMTX_OP_MUTEX_LOCK] = __umtx_op_lock_umutex,
4002 [UMTX_OP_MUTEX_UNLOCK] = __umtx_op_unlock_umutex,
4003 [UMTX_OP_SET_CEILING] = __umtx_op_set_ceiling,
4004 [UMTX_OP_CV_WAIT] = __umtx_op_cv_wait,
4005 [UMTX_OP_CV_SIGNAL] = __umtx_op_cv_signal,
4006 [UMTX_OP_CV_BROADCAST] = __umtx_op_cv_broadcast,
4007 [UMTX_OP_WAIT_UINT] = __umtx_op_wait_uint,
4008 [UMTX_OP_RW_RDLOCK] = __umtx_op_rw_rdlock,
4009 [UMTX_OP_RW_WRLOCK] = __umtx_op_rw_wrlock,
4010 [UMTX_OP_RW_UNLOCK] = __umtx_op_rw_unlock,
4011 [UMTX_OP_WAIT_UINT_PRIVATE] = __umtx_op_wait_uint_private,
4012 [UMTX_OP_WAKE_PRIVATE] = __umtx_op_wake_private,
4013 [UMTX_OP_MUTEX_WAIT] = __umtx_op_wait_umutex,
4014 [UMTX_OP_MUTEX_WAKE] = __umtx_op_wake_umutex,
4015 #if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
4016 [UMTX_OP_SEM_WAIT] = __umtx_op_sem_wait,
4017 [UMTX_OP_SEM_WAKE] = __umtx_op_sem_wake,
4018 #else
4019 [UMTX_OP_SEM_WAIT] = __umtx_op_unimpl,
4020 [UMTX_OP_SEM_WAKE] = __umtx_op_unimpl,
4021 #endif
4022 [UMTX_OP_NWAKE_PRIVATE] = __umtx_op_nwake_private,
4023 [UMTX_OP_MUTEX_WAKE2] = __umtx_op_wake2_umutex,
4024 [UMTX_OP_SEM2_WAIT] = __umtx_op_sem2_wait,
4025 [UMTX_OP_SEM2_WAKE] = __umtx_op_sem2_wake,
4026 [UMTX_OP_SHM] = __umtx_op_shm,
4027 [UMTX_OP_ROBUST_LISTS] = __umtx_op_robust_lists,
4028 };
4029
4030 int
sys__umtx_op(struct thread * td,struct _umtx_op_args * uap)4031 sys__umtx_op(struct thread *td, struct _umtx_op_args *uap)
4032 {
4033
4034 if ((unsigned)uap->op < nitems(op_table))
4035 return (*op_table[uap->op])(td, uap);
4036 return (EINVAL);
4037 }
4038
4039 #ifdef COMPAT_FREEBSD32
4040
4041 struct timespec32 {
4042 int32_t tv_sec;
4043 int32_t tv_nsec;
4044 };
4045
4046 struct umtx_time32 {
4047 struct timespec32 timeout;
4048 uint32_t flags;
4049 uint32_t clockid;
4050 };
4051
4052 static inline int
umtx_copyin_timeout32(void * addr,struct timespec * tsp)4053 umtx_copyin_timeout32(void *addr, struct timespec *tsp)
4054 {
4055 struct timespec32 ts32;
4056 int error;
4057
4058 error = copyin(addr, &ts32, sizeof(struct timespec32));
4059 if (error == 0) {
4060 if (ts32.tv_sec < 0 ||
4061 ts32.tv_nsec >= 1000000000 ||
4062 ts32.tv_nsec < 0)
4063 error = EINVAL;
4064 else {
4065 tsp->tv_sec = ts32.tv_sec;
4066 tsp->tv_nsec = ts32.tv_nsec;
4067 }
4068 }
4069 return (error);
4070 }
4071
4072 static inline int
umtx_copyin_umtx_time32(const void * addr,size_t size,struct _umtx_time * tp)4073 umtx_copyin_umtx_time32(const void *addr, size_t size, struct _umtx_time *tp)
4074 {
4075 struct umtx_time32 t32;
4076 int error;
4077
4078 t32.clockid = CLOCK_REALTIME;
4079 t32.flags = 0;
4080 if (size <= sizeof(struct timespec32))
4081 error = copyin(addr, &t32.timeout, sizeof(struct timespec32));
4082 else
4083 error = copyin(addr, &t32, sizeof(struct umtx_time32));
4084 if (error != 0)
4085 return (error);
4086 if (t32.timeout.tv_sec < 0 ||
4087 t32.timeout.tv_nsec >= 1000000000 || t32.timeout.tv_nsec < 0)
4088 return (EINVAL);
4089 tp->_timeout.tv_sec = t32.timeout.tv_sec;
4090 tp->_timeout.tv_nsec = t32.timeout.tv_nsec;
4091 tp->_flags = t32.flags;
4092 tp->_clockid = t32.clockid;
4093 return (0);
4094 }
4095
4096 static int
__umtx_op_wait_compat32(struct thread * td,struct _umtx_op_args * uap)4097 __umtx_op_wait_compat32(struct thread *td, struct _umtx_op_args *uap)
4098 {
4099 struct _umtx_time *tm_p, timeout;
4100 int error;
4101
4102 if (uap->uaddr2 == NULL)
4103 tm_p = NULL;
4104 else {
4105 error = umtx_copyin_umtx_time32(uap->uaddr2,
4106 (size_t)uap->uaddr1, &timeout);
4107 if (error != 0)
4108 return (error);
4109 tm_p = &timeout;
4110 }
4111 return (do_wait(td, uap->obj, uap->val, tm_p, 1, 0));
4112 }
4113
4114 static int
__umtx_op_lock_umutex_compat32(struct thread * td,struct _umtx_op_args * uap)4115 __umtx_op_lock_umutex_compat32(struct thread *td, struct _umtx_op_args *uap)
4116 {
4117 struct _umtx_time *tm_p, timeout;
4118 int error;
4119
4120 /* Allow a null timespec (wait forever). */
4121 if (uap->uaddr2 == NULL)
4122 tm_p = NULL;
4123 else {
4124 error = umtx_copyin_umtx_time32(uap->uaddr2,
4125 (size_t)uap->uaddr1, &timeout);
4126 if (error != 0)
4127 return (error);
4128 tm_p = &timeout;
4129 }
4130 return (do_lock_umutex(td, uap->obj, tm_p, 0));
4131 }
4132
4133 static int
__umtx_op_wait_umutex_compat32(struct thread * td,struct _umtx_op_args * uap)4134 __umtx_op_wait_umutex_compat32(struct thread *td, struct _umtx_op_args *uap)
4135 {
4136 struct _umtx_time *tm_p, timeout;
4137 int error;
4138
4139 /* Allow a null timespec (wait forever). */
4140 if (uap->uaddr2 == NULL)
4141 tm_p = NULL;
4142 else {
4143 error = umtx_copyin_umtx_time32(uap->uaddr2,
4144 (size_t)uap->uaddr1, &timeout);
4145 if (error != 0)
4146 return (error);
4147 tm_p = &timeout;
4148 }
4149 return (do_lock_umutex(td, uap->obj, tm_p, _UMUTEX_WAIT));
4150 }
4151
4152 static int
__umtx_op_cv_wait_compat32(struct thread * td,struct _umtx_op_args * uap)4153 __umtx_op_cv_wait_compat32(struct thread *td, struct _umtx_op_args *uap)
4154 {
4155 struct timespec *ts, timeout;
4156 int error;
4157
4158 /* Allow a null timespec (wait forever). */
4159 if (uap->uaddr2 == NULL)
4160 ts = NULL;
4161 else {
4162 error = umtx_copyin_timeout32(uap->uaddr2, &timeout);
4163 if (error != 0)
4164 return (error);
4165 ts = &timeout;
4166 }
4167 return (do_cv_wait(td, uap->obj, uap->uaddr1, ts, uap->val));
4168 }
4169
4170 static int
__umtx_op_rw_rdlock_compat32(struct thread * td,struct _umtx_op_args * uap)4171 __umtx_op_rw_rdlock_compat32(struct thread *td, struct _umtx_op_args *uap)
4172 {
4173 struct _umtx_time timeout;
4174 int error;
4175
4176 /* Allow a null timespec (wait forever). */
4177 if (uap->uaddr2 == NULL) {
4178 error = do_rw_rdlock(td, uap->obj, uap->val, 0);
4179 } else {
4180 error = umtx_copyin_umtx_time32(uap->uaddr2,
4181 (size_t)uap->uaddr1, &timeout);
4182 if (error != 0)
4183 return (error);
4184 error = do_rw_rdlock(td, uap->obj, uap->val, &timeout);
4185 }
4186 return (error);
4187 }
4188
4189 static int
__umtx_op_rw_wrlock_compat32(struct thread * td,struct _umtx_op_args * uap)4190 __umtx_op_rw_wrlock_compat32(struct thread *td, struct _umtx_op_args *uap)
4191 {
4192 struct _umtx_time timeout;
4193 int error;
4194
4195 /* Allow a null timespec (wait forever). */
4196 if (uap->uaddr2 == NULL) {
4197 error = do_rw_wrlock(td, uap->obj, 0);
4198 } else {
4199 error = umtx_copyin_umtx_time32(uap->uaddr2,
4200 (size_t)uap->uaddr1, &timeout);
4201 if (error != 0)
4202 return (error);
4203 error = do_rw_wrlock(td, uap->obj, &timeout);
4204 }
4205 return (error);
4206 }
4207
4208 static int
__umtx_op_wait_uint_private_compat32(struct thread * td,struct _umtx_op_args * uap)4209 __umtx_op_wait_uint_private_compat32(struct thread *td, struct _umtx_op_args *uap)
4210 {
4211 struct _umtx_time *tm_p, timeout;
4212 int error;
4213
4214 if (uap->uaddr2 == NULL)
4215 tm_p = NULL;
4216 else {
4217 error = umtx_copyin_umtx_time32(
4218 uap->uaddr2, (size_t)uap->uaddr1,&timeout);
4219 if (error != 0)
4220 return (error);
4221 tm_p = &timeout;
4222 }
4223 return (do_wait(td, uap->obj, uap->val, tm_p, 1, 1));
4224 }
4225
4226 #if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
4227 static int
__umtx_op_sem_wait_compat32(struct thread * td,struct _umtx_op_args * uap)4228 __umtx_op_sem_wait_compat32(struct thread *td, struct _umtx_op_args *uap)
4229 {
4230 struct _umtx_time *tm_p, timeout;
4231 int error;
4232
4233 /* Allow a null timespec (wait forever). */
4234 if (uap->uaddr2 == NULL)
4235 tm_p = NULL;
4236 else {
4237 error = umtx_copyin_umtx_time32(uap->uaddr2,
4238 (size_t)uap->uaddr1, &timeout);
4239 if (error != 0)
4240 return (error);
4241 tm_p = &timeout;
4242 }
4243 return (do_sem_wait(td, uap->obj, tm_p));
4244 }
4245 #endif
4246
4247 static int
__umtx_op_sem2_wait_compat32(struct thread * td,struct _umtx_op_args * uap)4248 __umtx_op_sem2_wait_compat32(struct thread *td, struct _umtx_op_args *uap)
4249 {
4250 struct _umtx_time *tm_p, timeout;
4251 size_t uasize;
4252 int error;
4253
4254 /* Allow a null timespec (wait forever). */
4255 if (uap->uaddr2 == NULL) {
4256 uasize = 0;
4257 tm_p = NULL;
4258 } else {
4259 uasize = (size_t)uap->uaddr1;
4260 error = umtx_copyin_umtx_time32(uap->uaddr2, uasize, &timeout);
4261 if (error != 0)
4262 return (error);
4263 tm_p = &timeout;
4264 }
4265 error = do_sem2_wait(td, uap->obj, tm_p);
4266 if (error == EINTR && uap->uaddr2 != NULL &&
4267 (timeout._flags & UMTX_ABSTIME) == 0 &&
4268 uasize >= sizeof(struct umtx_time32) + sizeof(struct timespec32)) {
4269 struct timespec32 remain32 = {
4270 .tv_sec = timeout._timeout.tv_sec,
4271 .tv_nsec = timeout._timeout.tv_nsec
4272 };
4273 error = copyout(&remain32,
4274 (struct umtx_time32 *)uap->uaddr2 + 1,
4275 sizeof(struct timespec32));
4276 if (error == 0) {
4277 error = EINTR;
4278 }
4279 }
4280
4281 return (error);
4282 }
4283
4284 static int
__umtx_op_nwake_private32(struct thread * td,struct _umtx_op_args * uap)4285 __umtx_op_nwake_private32(struct thread *td, struct _umtx_op_args *uap)
4286 {
4287 uint32_t uaddrs[BATCH_SIZE], **upp;
4288 int count, error, i, pos, tocopy;
4289
4290 upp = (uint32_t **)uap->obj;
4291 error = 0;
4292 for (count = uap->val, pos = 0; count > 0; count -= tocopy,
4293 pos += tocopy) {
4294 tocopy = MIN(count, BATCH_SIZE);
4295 error = copyin(upp + pos, uaddrs, tocopy * sizeof(uint32_t));
4296 if (error != 0)
4297 break;
4298 for (i = 0; i < tocopy; ++i)
4299 kern_umtx_wake(td, (void *)(intptr_t)uaddrs[i],
4300 INT_MAX, 1);
4301 maybe_yield();
4302 }
4303 return (error);
4304 }
4305
4306 struct umtx_robust_lists_params_compat32 {
4307 uint32_t robust_list_offset;
4308 uint32_t robust_priv_list_offset;
4309 uint32_t robust_inact_offset;
4310 };
4311
4312 static int
__umtx_op_robust_lists_compat32(struct thread * td,struct _umtx_op_args * uap)4313 __umtx_op_robust_lists_compat32(struct thread *td, struct _umtx_op_args *uap)
4314 {
4315 struct umtx_robust_lists_params rb;
4316 struct umtx_robust_lists_params_compat32 rb32;
4317 int error;
4318
4319 if (uap->val > sizeof(rb32))
4320 return (EINVAL);
4321 bzero(&rb, sizeof(rb));
4322 bzero(&rb32, sizeof(rb32));
4323 error = copyin(uap->uaddr1, &rb32, uap->val);
4324 if (error != 0)
4325 return (error);
4326 rb.robust_list_offset = rb32.robust_list_offset;
4327 rb.robust_priv_list_offset = rb32.robust_priv_list_offset;
4328 rb.robust_inact_offset = rb32.robust_inact_offset;
4329 return (umtx_robust_lists(td, &rb));
4330 }
4331
4332 static const _umtx_op_func op_table_compat32[] = {
4333 [UMTX_OP_RESERVED0] = __umtx_op_unimpl,
4334 [UMTX_OP_RESERVED1] = __umtx_op_unimpl,
4335 [UMTX_OP_WAIT] = __umtx_op_wait_compat32,
4336 [UMTX_OP_WAKE] = __umtx_op_wake,
4337 [UMTX_OP_MUTEX_TRYLOCK] = __umtx_op_trylock_umutex,
4338 [UMTX_OP_MUTEX_LOCK] = __umtx_op_lock_umutex_compat32,
4339 [UMTX_OP_MUTEX_UNLOCK] = __umtx_op_unlock_umutex,
4340 [UMTX_OP_SET_CEILING] = __umtx_op_set_ceiling,
4341 [UMTX_OP_CV_WAIT] = __umtx_op_cv_wait_compat32,
4342 [UMTX_OP_CV_SIGNAL] = __umtx_op_cv_signal,
4343 [UMTX_OP_CV_BROADCAST] = __umtx_op_cv_broadcast,
4344 [UMTX_OP_WAIT_UINT] = __umtx_op_wait_compat32,
4345 [UMTX_OP_RW_RDLOCK] = __umtx_op_rw_rdlock_compat32,
4346 [UMTX_OP_RW_WRLOCK] = __umtx_op_rw_wrlock_compat32,
4347 [UMTX_OP_RW_UNLOCK] = __umtx_op_rw_unlock,
4348 [UMTX_OP_WAIT_UINT_PRIVATE] = __umtx_op_wait_uint_private_compat32,
4349 [UMTX_OP_WAKE_PRIVATE] = __umtx_op_wake_private,
4350 [UMTX_OP_MUTEX_WAIT] = __umtx_op_wait_umutex_compat32,
4351 [UMTX_OP_MUTEX_WAKE] = __umtx_op_wake_umutex,
4352 #if defined(COMPAT_FREEBSD9) || defined(COMPAT_FREEBSD10)
4353 [UMTX_OP_SEM_WAIT] = __umtx_op_sem_wait_compat32,
4354 [UMTX_OP_SEM_WAKE] = __umtx_op_sem_wake,
4355 #else
4356 [UMTX_OP_SEM_WAIT] = __umtx_op_unimpl,
4357 [UMTX_OP_SEM_WAKE] = __umtx_op_unimpl,
4358 #endif
4359 [UMTX_OP_NWAKE_PRIVATE] = __umtx_op_nwake_private32,
4360 [UMTX_OP_MUTEX_WAKE2] = __umtx_op_wake2_umutex,
4361 [UMTX_OP_SEM2_WAIT] = __umtx_op_sem2_wait_compat32,
4362 [UMTX_OP_SEM2_WAKE] = __umtx_op_sem2_wake,
4363 [UMTX_OP_SHM] = __umtx_op_shm,
4364 [UMTX_OP_ROBUST_LISTS] = __umtx_op_robust_lists_compat32,
4365 };
4366
4367 int
freebsd32_umtx_op(struct thread * td,struct freebsd32_umtx_op_args * uap)4368 freebsd32_umtx_op(struct thread *td, struct freebsd32_umtx_op_args *uap)
4369 {
4370
4371 if ((unsigned)uap->op < nitems(op_table_compat32)) {
4372 return (*op_table_compat32[uap->op])(td,
4373 (struct _umtx_op_args *)uap);
4374 }
4375 return (EINVAL);
4376 }
4377 #endif
4378
4379 void
umtx_thread_init(struct thread * td)4380 umtx_thread_init(struct thread *td)
4381 {
4382
4383 td->td_umtxq = umtxq_alloc();
4384 td->td_umtxq->uq_thread = td;
4385 }
4386
4387 void
umtx_thread_fini(struct thread * td)4388 umtx_thread_fini(struct thread *td)
4389 {
4390
4391 umtxq_free(td->td_umtxq);
4392 }
4393
4394 /*
4395 * It will be called when new thread is created, e.g fork().
4396 */
4397 void
umtx_thread_alloc(struct thread * td)4398 umtx_thread_alloc(struct thread *td)
4399 {
4400 struct umtx_q *uq;
4401
4402 uq = td->td_umtxq;
4403 uq->uq_inherited_pri = PRI_MAX;
4404
4405 KASSERT(uq->uq_flags == 0, ("uq_flags != 0"));
4406 KASSERT(uq->uq_thread == td, ("uq_thread != td"));
4407 KASSERT(uq->uq_pi_blocked == NULL, ("uq_pi_blocked != NULL"));
4408 KASSERT(TAILQ_EMPTY(&uq->uq_pi_contested), ("uq_pi_contested is not empty"));
4409 }
4410
4411 /*
4412 * exec() hook.
4413 *
4414 * Clear robust lists for all process' threads, not delaying the
4415 * cleanup to thread_exit hook, since the relevant address space is
4416 * destroyed right now.
4417 */
4418 static void
umtx_exec_hook(void * arg __unused,struct proc * p,struct image_params * imgp __unused)4419 umtx_exec_hook(void *arg __unused, struct proc *p,
4420 struct image_params *imgp __unused)
4421 {
4422 struct thread *td;
4423
4424 KASSERT(p == curproc, ("need curproc"));
4425 PROC_LOCK(p);
4426 KASSERT((p->p_flag & P_HADTHREADS) == 0 ||
4427 (p->p_flag & P_STOPPED_SINGLE) != 0,
4428 ("curproc must be single-threaded"));
4429 FOREACH_THREAD_IN_PROC(p, td) {
4430 KASSERT(td == curthread ||
4431 ((td->td_flags & TDF_BOUNDARY) != 0 && TD_IS_SUSPENDED(td)),
4432 ("running thread %p %p", p, td));
4433 PROC_UNLOCK(p);
4434 umtx_thread_cleanup(td);
4435 PROC_LOCK(p);
4436 td->td_rb_list = td->td_rbp_list = td->td_rb_inact = 0;
4437 }
4438 PROC_UNLOCK(p);
4439 }
4440
4441 /*
4442 * thread_exit() hook.
4443 */
4444 void
umtx_thread_exit(struct thread * td)4445 umtx_thread_exit(struct thread *td)
4446 {
4447
4448 umtx_thread_cleanup(td);
4449 }
4450
4451 static int
umtx_read_uptr(struct thread * td,uintptr_t ptr,uintptr_t * res)4452 umtx_read_uptr(struct thread *td, uintptr_t ptr, uintptr_t *res)
4453 {
4454 u_long res1;
4455 #ifdef COMPAT_FREEBSD32
4456 uint32_t res32;
4457 #endif
4458 int error;
4459
4460 #ifdef COMPAT_FREEBSD32
4461 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
4462 error = fueword32((void *)ptr, &res32);
4463 if (error == 0)
4464 res1 = res32;
4465 } else
4466 #endif
4467 {
4468 error = fueword((void *)ptr, &res1);
4469 }
4470 if (error == 0)
4471 *res = res1;
4472 else
4473 error = EFAULT;
4474 return (error);
4475 }
4476
4477 static void
umtx_read_rb_list(struct thread * td,struct umutex * m,uintptr_t * rb_list)4478 umtx_read_rb_list(struct thread *td, struct umutex *m, uintptr_t *rb_list)
4479 {
4480 #ifdef COMPAT_FREEBSD32
4481 struct umutex32 m32;
4482
4483 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
4484 memcpy(&m32, m, sizeof(m32));
4485 *rb_list = m32.m_rb_lnk;
4486 } else
4487 #endif
4488 *rb_list = m->m_rb_lnk;
4489 }
4490
4491 static int
umtx_handle_rb(struct thread * td,uintptr_t rbp,uintptr_t * rb_list,bool inact)4492 umtx_handle_rb(struct thread *td, uintptr_t rbp, uintptr_t *rb_list, bool inact)
4493 {
4494 struct umutex m;
4495 int error;
4496
4497 KASSERT(td->td_proc == curproc, ("need current vmspace"));
4498 error = copyin((void *)rbp, &m, sizeof(m));
4499 if (error != 0)
4500 return (error);
4501 if (rb_list != NULL)
4502 umtx_read_rb_list(td, &m, rb_list);
4503 if ((m.m_flags & UMUTEX_ROBUST) == 0)
4504 return (EINVAL);
4505 if ((m.m_owner & ~UMUTEX_CONTESTED) != td->td_tid)
4506 /* inact is cleared after unlock, allow the inconsistency */
4507 return (inact ? 0 : EINVAL);
4508 return (do_unlock_umutex(td, (struct umutex *)rbp, true));
4509 }
4510
4511 static void
umtx_cleanup_rb_list(struct thread * td,uintptr_t rb_list,uintptr_t * rb_inact,const char * name)4512 umtx_cleanup_rb_list(struct thread *td, uintptr_t rb_list, uintptr_t *rb_inact,
4513 const char *name)
4514 {
4515 int error, i;
4516 uintptr_t rbp;
4517 bool inact;
4518
4519 if (rb_list == 0)
4520 return;
4521 error = umtx_read_uptr(td, rb_list, &rbp);
4522 for (i = 0; error == 0 && rbp != 0 && i < umtx_max_rb; i++) {
4523 if (rbp == *rb_inact) {
4524 inact = true;
4525 *rb_inact = 0;
4526 } else
4527 inact = false;
4528 error = umtx_handle_rb(td, rbp, &rbp, inact);
4529 }
4530 if (i == umtx_max_rb && umtx_verbose_rb) {
4531 uprintf("comm %s pid %d: reached umtx %smax rb %d\n",
4532 td->td_proc->p_comm, td->td_proc->p_pid, name, umtx_max_rb);
4533 }
4534 if (error != 0 && umtx_verbose_rb) {
4535 uprintf("comm %s pid %d: handling %srb error %d\n",
4536 td->td_proc->p_comm, td->td_proc->p_pid, name, error);
4537 }
4538 }
4539
4540 /*
4541 * Clean up umtx data.
4542 */
4543 static void
umtx_thread_cleanup(struct thread * td)4544 umtx_thread_cleanup(struct thread *td)
4545 {
4546 struct umtx_q *uq;
4547 struct umtx_pi *pi;
4548 uintptr_t rb_inact;
4549
4550 /*
4551 * Disown pi mutexes.
4552 */
4553 uq = td->td_umtxq;
4554 if (uq != NULL) {
4555 mtx_lock(&umtx_lock);
4556 uq->uq_inherited_pri = PRI_MAX;
4557 while ((pi = TAILQ_FIRST(&uq->uq_pi_contested)) != NULL) {
4558 pi->pi_owner = NULL;
4559 TAILQ_REMOVE(&uq->uq_pi_contested, pi, pi_link);
4560 }
4561 mtx_unlock(&umtx_lock);
4562 thread_lock(td);
4563 sched_lend_user_prio(td, PRI_MAX);
4564 thread_unlock(td);
4565 }
4566
4567 /*
4568 * Handle terminated robust mutexes. Must be done after
4569 * robust pi disown, otherwise unlock could see unowned
4570 * entries.
4571 */
4572 rb_inact = td->td_rb_inact;
4573 if (rb_inact != 0)
4574 (void)umtx_read_uptr(td, rb_inact, &rb_inact);
4575 umtx_cleanup_rb_list(td, td->td_rb_list, &rb_inact, "");
4576 umtx_cleanup_rb_list(td, td->td_rbp_list, &rb_inact, "priv ");
4577 if (rb_inact != 0)
4578 (void)umtx_handle_rb(td, rb_inact, NULL, true);
4579 }
4580