1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Copyright (c) 2016 by Delphix. All rights reserved.
25 */
26 /*
27 * Copyright 2016 Joyent, Inc.
28 */
29
30 #include "lint.h"
31 #include "thr_uberdata.h"
32 #include <pthread.h>
33 #include <procfs.h>
34 #include <sys/uio.h>
35 #include <ctype.h>
36 #include "libc.h"
37
38 /*
39 * These symbols should not be exported from libc, but
40 * /lib/libm.so.2 references _thr_main. libm needs to be fixed.
41 * Also, some older versions of the Studio compiler/debugger
42 * components reference them. These need to be fixed, too.
43 */
44 #pragma weak _thr_main = thr_main
45 #pragma weak _thr_create = thr_create
46 #pragma weak _thr_join = thr_join
47 #pragma weak _thr_self = thr_self
48
49 #undef errno
50 extern int errno;
51
52 /*
53 * Between Solaris 2.5 and Solaris 9, __threaded was used to indicate
54 * "we are linked with libthread". The Sun Workshop 6 update 1 compilation
55 * system used it illegally (it is a consolidation private symbol).
56 * To accommodate this and possibly other abusers of the symbol,
57 * we make it always equal to 1 now that libthread has been folded
58 * into libc. The new __libc_threaded symbol is used to indicate
59 * the new meaning, "more than one thread exists".
60 */
61 int __threaded = 1; /* always equal to 1 */
62 int __libc_threaded = 0; /* zero until first thr_create() */
63
64 /*
65 * thr_concurrency and pthread_concurrency are not used by the library.
66 * They exist solely to hold and return the values set by calls to
67 * thr_setconcurrency() and pthread_setconcurrency().
68 * Because thr_concurrency is affected by the THR_NEW_LWP flag
69 * to thr_create(), thr_concurrency is protected by link_lock.
70 */
71 static int thr_concurrency = 1;
72 static int pthread_concurrency;
73
74 #define HASHTBLSZ 1024 /* must be a power of two */
75 #define TIDHASH(tid, udp) (tid & (udp)->hash_mask)
76
77 /* initial allocation, just enough for one lwp */
78 #pragma align 64(init_hash_table)
79 thr_hash_table_t init_hash_table[1] = {
80 { DEFAULTMUTEX, DEFAULTCV, NULL },
81 };
82
83 extern const Lc_interface rtld_funcs[];
84
85 /*
86 * The weak version is known to libc_db and mdb.
87 */
88 #pragma weak _uberdata = __uberdata
89 uberdata_t __uberdata = {
90 { DEFAULTMUTEX, NULL, 0 }, /* link_lock */
91 { RECURSIVEMUTEX, NULL, 0 }, /* ld_lock */
92 { RECURSIVEMUTEX, NULL, 0 }, /* fork_lock */
93 { RECURSIVEMUTEX, NULL, 0 }, /* atfork_lock */
94 { RECURSIVEMUTEX, NULL, 0 }, /* callout_lock */
95 { DEFAULTMUTEX, NULL, 0 }, /* tdb_hash_lock */
96 { 0, }, /* tdb_hash_lock_stats */
97 { { 0 }, }, /* siguaction[NSIG] */
98 {{ DEFAULTMUTEX, NULL, 0 }, /* bucket[NBUCKETS] */
99 { DEFAULTMUTEX, NULL, 0 },
100 { DEFAULTMUTEX, NULL, 0 },
101 { DEFAULTMUTEX, NULL, 0 },
102 { DEFAULTMUTEX, NULL, 0 },
103 { DEFAULTMUTEX, NULL, 0 },
104 { DEFAULTMUTEX, NULL, 0 },
105 { DEFAULTMUTEX, NULL, 0 },
106 { DEFAULTMUTEX, NULL, 0 },
107 { DEFAULTMUTEX, NULL, 0 }},
108 { RECURSIVEMUTEX, NULL, NULL }, /* atexit_root */
109 { RECURSIVEMUTEX, NULL }, /* quickexit_root */
110 { DEFAULTMUTEX, 0, 0, NULL }, /* tsd_metadata */
111 { DEFAULTMUTEX, {0, 0}, {0, 0} }, /* tls_metadata */
112 0, /* primary_map */
113 0, /* bucket_init */
114 0, /* pad[0] */
115 0, /* pad[1] */
116 { 0 }, /* uberflags */
117 NULL, /* queue_head */
118 init_hash_table, /* thr_hash_table */
119 1, /* hash_size: size of the hash table */
120 0, /* hash_mask: hash_size - 1 */
121 NULL, /* ulwp_one */
122 NULL, /* all_lwps */
123 NULL, /* all_zombies */
124 0, /* nthreads */
125 0, /* nzombies */
126 0, /* ndaemons */
127 0, /* pid */
128 sigacthandler, /* sigacthandler */
129 NULL, /* lwp_stacks */
130 NULL, /* lwp_laststack */
131 0, /* nfreestack */
132 10, /* thread_stack_cache */
133 NULL, /* ulwp_freelist */
134 NULL, /* ulwp_lastfree */
135 NULL, /* ulwp_replace_free */
136 NULL, /* ulwp_replace_last */
137 NULL, /* atforklist */
138 NULL, /* robustlocks */
139 NULL, /* robustlist */
140 NULL, /* progname */
141 NULL, /* ub_comm_page */
142 NULL, /* __tdb_bootstrap */
143 { /* tdb */
144 NULL, /* tdb_sync_addr_hash */
145 0, /* tdb_register_count */
146 0, /* tdb_hash_alloc_failed */
147 NULL, /* tdb_sync_addr_free */
148 NULL, /* tdb_sync_addr_last */
149 0, /* tdb_sync_alloc */
150 { 0, 0 }, /* tdb_ev_global_mask */
151 tdb_events, /* tdb_events array */
152 },
153 };
154
155 /*
156 * The weak version is known to libc_db and mdb.
157 */
158 #pragma weak _tdb_bootstrap = __tdb_bootstrap
159 uberdata_t **__tdb_bootstrap = NULL;
160
161 int thread_queue_fifo = 4;
162 int thread_queue_dump = 0;
163 int thread_cond_wait_defer = 0;
164 int thread_error_detection = 0;
165 int thread_async_safe = 0;
166 int thread_stack_cache = 10;
167 int thread_door_noreserve = 0;
168 int thread_locks_misaligned = 0;
169
170 static ulwp_t *ulwp_alloc(void);
171 static void ulwp_free(ulwp_t *);
172
173 /*
174 * Insert the lwp into the hash table.
175 */
176 void
177 hash_in_unlocked(ulwp_t *ulwp, int ix, uberdata_t *udp)
178 {
179 ulwp->ul_hash = udp->thr_hash_table[ix].hash_bucket;
180 udp->thr_hash_table[ix].hash_bucket = ulwp;
181 ulwp->ul_ix = ix;
182 }
183
184 void
185 hash_in(ulwp_t *ulwp, uberdata_t *udp)
186 {
187 int ix = TIDHASH(ulwp->ul_lwpid, udp);
188 mutex_t *mp = &udp->thr_hash_table[ix].hash_lock;
189
190 lmutex_lock(mp);
191 hash_in_unlocked(ulwp, ix, udp);
192 lmutex_unlock(mp);
193 }
194
195 /*
196 * Delete the lwp from the hash table.
197 */
198 void
199 hash_out_unlocked(ulwp_t *ulwp, int ix, uberdata_t *udp)
200 {
201 ulwp_t **ulwpp;
202
203 for (ulwpp = &udp->thr_hash_table[ix].hash_bucket;
204 ulwp != *ulwpp;
205 ulwpp = &(*ulwpp)->ul_hash)
206 ;
207 *ulwpp = ulwp->ul_hash;
208 ulwp->ul_hash = NULL;
209 ulwp->ul_ix = -1;
210 }
211
212 void
213 hash_out(ulwp_t *ulwp, uberdata_t *udp)
214 {
215 int ix;
216
217 if ((ix = ulwp->ul_ix) >= 0) {
218 mutex_t *mp = &udp->thr_hash_table[ix].hash_lock;
219
220 lmutex_lock(mp);
221 hash_out_unlocked(ulwp, ix, udp);
222 lmutex_unlock(mp);
223 }
224 }
225
226 /*
227 * Retain stack information for thread structures that are being recycled for
228 * new threads. All other members of the thread structure should be zeroed.
229 */
230 static void
231 ulwp_clean(ulwp_t *ulwp)
232 {
233 caddr_t stk = ulwp->ul_stk;
234 size_t mapsiz = ulwp->ul_mapsiz;
235 size_t guardsize = ulwp->ul_guardsize;
236 uintptr_t stktop = ulwp->ul_stktop;
237 size_t stksiz = ulwp->ul_stksiz;
238
239 (void) memset(ulwp, 0, sizeof (*ulwp));
240
241 ulwp->ul_stk = stk;
242 ulwp->ul_mapsiz = mapsiz;
243 ulwp->ul_guardsize = guardsize;
244 ulwp->ul_stktop = stktop;
245 ulwp->ul_stksiz = stksiz;
246 }
247
248 static int stackprot;
249
250 /*
251 * Answer the question, "Is the lwp in question really dead?"
252 * We must inquire of the operating system to be really sure
253 * because the lwp may have called lwp_exit() but it has not
254 * yet completed the exit.
255 */
256 static int
257 dead_and_buried(ulwp_t *ulwp)
258 {
259 if (ulwp->ul_lwpid == (lwpid_t)(-1))
260 return (1);
261 if (ulwp->ul_dead && ulwp->ul_detached &&
262 _lwp_kill(ulwp->ul_lwpid, 0) == ESRCH) {
263 ulwp->ul_lwpid = (lwpid_t)(-1);
264 return (1);
265 }
266 return (0);
267 }
268
269 /*
270 * Attempt to keep the stack cache within the specified cache limit.
271 */
272 static void
273 trim_stack_cache(int cache_limit)
274 {
275 ulwp_t *self = curthread;
276 uberdata_t *udp = self->ul_uberdata;
277 ulwp_t *prev = NULL;
278 ulwp_t **ulwpp = &udp->lwp_stacks;
279 ulwp_t *ulwp;
280
281 ASSERT(udp->nthreads <= 1 || MUTEX_OWNED(&udp->link_lock, self));
282
283 while (udp->nfreestack > cache_limit && (ulwp = *ulwpp) != NULL) {
284 if (dead_and_buried(ulwp)) {
285 *ulwpp = ulwp->ul_next;
286 if (ulwp == udp->lwp_laststack)
287 udp->lwp_laststack = prev;
288 hash_out(ulwp, udp);
289 udp->nfreestack--;
290 (void) munmap(ulwp->ul_stk, ulwp->ul_mapsiz);
291 /*
292 * Now put the free ulwp on the ulwp freelist.
293 */
294 ulwp->ul_mapsiz = 0;
295 ulwp->ul_next = NULL;
296 if (udp->ulwp_freelist == NULL)
297 udp->ulwp_freelist = udp->ulwp_lastfree = ulwp;
298 else {
299 udp->ulwp_lastfree->ul_next = ulwp;
300 udp->ulwp_lastfree = ulwp;
301 }
302 } else {
303 prev = ulwp;
304 ulwpp = &ulwp->ul_next;
305 }
306 }
307 }
308
309 /*
310 * Find an unused stack of the requested size
311 * or create a new stack of the requested size.
312 * Return a pointer to the ulwp_t structure referring to the stack, or NULL.
313 * thr_exit() stores 1 in the ul_dead member.
314 * thr_join() stores -1 in the ul_lwpid member.
315 */
316 static ulwp_t *
317 find_stack(size_t stksize, size_t guardsize)
318 {
319 static size_t pagesize = 0;
320
321 uberdata_t *udp = curthread->ul_uberdata;
322 size_t mapsize;
323 ulwp_t *prev;
324 ulwp_t *ulwp;
325 ulwp_t **ulwpp;
326 void *stk;
327
328 /*
329 * The stack is allocated PROT_READ|PROT_WRITE|PROT_EXEC
330 * unless overridden by the system's configuration.
331 */
332 if (stackprot == 0) { /* do this once */
333 long lprot = _sysconf(_SC_STACK_PROT);
334 if (lprot <= 0)
335 lprot = (PROT_READ|PROT_WRITE|PROT_EXEC);
336 stackprot = (int)lprot;
337 }
338 if (pagesize == 0) /* do this once */
339 pagesize = _sysconf(_SC_PAGESIZE);
340
341 /*
342 * One megabyte stacks by default, but subtract off
343 * two pages for the system-created red zones.
344 * Round up a non-zero stack size to a pagesize multiple.
345 */
346 if (stksize == 0)
347 stksize = DEFAULTSTACK - 2 * pagesize;
348 else
349 stksize = ((stksize + pagesize - 1) & -pagesize);
350
351 /*
352 * Round up the mapping size to a multiple of pagesize.
353 * Note: mmap() provides at least one page of red zone
354 * so we deduct that from the value of guardsize.
355 */
356 if (guardsize != 0)
357 guardsize = ((guardsize + pagesize - 1) & -pagesize) - pagesize;
358 mapsize = stksize + guardsize;
359
360 lmutex_lock(&udp->link_lock);
361 for (prev = NULL, ulwpp = &udp->lwp_stacks;
362 (ulwp = *ulwpp) != NULL;
363 prev = ulwp, ulwpp = &ulwp->ul_next) {
364 if (ulwp->ul_mapsiz == mapsize &&
365 ulwp->ul_guardsize == guardsize &&
366 dead_and_buried(ulwp)) {
367 /*
368 * The previous lwp is gone; reuse the stack.
369 * Remove the ulwp from the stack list.
370 */
371 *ulwpp = ulwp->ul_next;
372 ulwp->ul_next = NULL;
373 if (ulwp == udp->lwp_laststack)
374 udp->lwp_laststack = prev;
375 hash_out(ulwp, udp);
376 udp->nfreestack--;
377 lmutex_unlock(&udp->link_lock);
378 ulwp_clean(ulwp);
379 return (ulwp);
380 }
381 }
382
383 /*
384 * None of the cached stacks matched our mapping size.
385 * Reduce the stack cache to get rid of possibly
386 * very old stacks that will never be reused.
387 */
388 if (udp->nfreestack > udp->thread_stack_cache)
389 trim_stack_cache(udp->thread_stack_cache);
390 else if (udp->nfreestack > 0)
391 trim_stack_cache(udp->nfreestack - 1);
392 lmutex_unlock(&udp->link_lock);
393
394 /*
395 * Create a new stack.
396 */
397 if ((stk = mmap(NULL, mapsize, stackprot,
398 MAP_PRIVATE|MAP_NORESERVE|MAP_ANON, -1, (off_t)0)) != MAP_FAILED) {
399 /*
400 * We have allocated our stack. Now allocate the ulwp.
401 */
402 ulwp = ulwp_alloc();
403 if (ulwp == NULL)
404 (void) munmap(stk, mapsize);
405 else {
406 ulwp->ul_stk = stk;
407 ulwp->ul_mapsiz = mapsize;
408 ulwp->ul_guardsize = guardsize;
409 ulwp->ul_stktop = (uintptr_t)stk + mapsize;
410 ulwp->ul_stksiz = stksize;
411 if (guardsize) /* protect the extra red zone */
412 (void) mprotect(stk, guardsize, PROT_NONE);
413 }
414 }
415 return (ulwp);
416 }
417
418 /*
419 * Get a ulwp_t structure from the free list or allocate a new one.
420 * Such ulwp_t's do not have a stack allocated by the library.
421 */
422 static ulwp_t *
423 ulwp_alloc(void)
424 {
425 ulwp_t *self = curthread;
426 uberdata_t *udp = self->ul_uberdata;
427 size_t tls_size;
428 ulwp_t *prev;
429 ulwp_t *ulwp;
430 ulwp_t **ulwpp;
431 caddr_t data;
432
433 lmutex_lock(&udp->link_lock);
434 for (prev = NULL, ulwpp = &udp->ulwp_freelist;
435 (ulwp = *ulwpp) != NULL;
436 prev = ulwp, ulwpp = &ulwp->ul_next) {
437 if (dead_and_buried(ulwp)) {
438 *ulwpp = ulwp->ul_next;
439 ulwp->ul_next = NULL;
440 if (ulwp == udp->ulwp_lastfree)
441 udp->ulwp_lastfree = prev;
442 hash_out(ulwp, udp);
443 lmutex_unlock(&udp->link_lock);
444 ulwp_clean(ulwp);
445 return (ulwp);
446 }
447 }
448 lmutex_unlock(&udp->link_lock);
449
450 tls_size = roundup64(udp->tls_metadata.static_tls.tls_size);
451 data = lmalloc(sizeof (*ulwp) + tls_size);
452 if (data != NULL) {
453 /* LINTED pointer cast may result in improper alignment */
454 ulwp = (ulwp_t *)(data + tls_size);
455 }
456 return (ulwp);
457 }
458
459 /*
460 * Free a ulwp structure.
461 * If there is an associated stack, put it on the stack list and
462 * munmap() previously freed stacks up to the residual cache limit.
463 * Else put it on the ulwp free list and never call lfree() on it.
464 */
465 static void
466 ulwp_free(ulwp_t *ulwp)
467 {
468 uberdata_t *udp = curthread->ul_uberdata;
469
470 ASSERT(udp->nthreads <= 1 || MUTEX_OWNED(&udp->link_lock, curthread));
471 ulwp->ul_next = NULL;
472 if (ulwp == udp->ulwp_one) /* don't reuse the primoridal stack */
473 /*EMPTY*/;
474 else if (ulwp->ul_mapsiz != 0) {
475 if (udp->lwp_stacks == NULL)
476 udp->lwp_stacks = udp->lwp_laststack = ulwp;
477 else {
478 udp->lwp_laststack->ul_next = ulwp;
479 udp->lwp_laststack = ulwp;
480 }
481 if (++udp->nfreestack > udp->thread_stack_cache)
482 trim_stack_cache(udp->thread_stack_cache);
483 } else {
484 if (udp->ulwp_freelist == NULL)
485 udp->ulwp_freelist = udp->ulwp_lastfree = ulwp;
486 else {
487 udp->ulwp_lastfree->ul_next = ulwp;
488 udp->ulwp_lastfree = ulwp;
489 }
490 }
491 }
492
493 /*
494 * Find a named lwp and return a pointer to its hash list location.
495 * On success, returns with the hash lock held.
496 */
497 ulwp_t **
498 find_lwpp(thread_t tid)
499 {
500 uberdata_t *udp = curthread->ul_uberdata;
501 int ix = TIDHASH(tid, udp);
502 mutex_t *mp = &udp->thr_hash_table[ix].hash_lock;
503 ulwp_t *ulwp;
504 ulwp_t **ulwpp;
505
506 if (tid == 0)
507 return (NULL);
508
509 lmutex_lock(mp);
510 for (ulwpp = &udp->thr_hash_table[ix].hash_bucket;
511 (ulwp = *ulwpp) != NULL;
512 ulwpp = &ulwp->ul_hash) {
513 if (ulwp->ul_lwpid == tid)
514 return (ulwpp);
515 }
516 lmutex_unlock(mp);
517 return (NULL);
518 }
519
520 /*
521 * Wake up all lwps waiting on this lwp for some reason.
522 */
523 void
524 ulwp_broadcast(ulwp_t *ulwp)
525 {
526 ulwp_t *self = curthread;
527 uberdata_t *udp = self->ul_uberdata;
528
529 ASSERT(MUTEX_OWNED(ulwp_mutex(ulwp, udp), self));
530 (void) cond_broadcast(ulwp_condvar(ulwp, udp));
531 }
532
533 /*
534 * Find a named lwp and return a pointer to it.
535 * Returns with the hash lock held.
536 */
537 ulwp_t *
538 find_lwp(thread_t tid)
539 {
540 ulwp_t *self = curthread;
541 uberdata_t *udp = self->ul_uberdata;
542 ulwp_t *ulwp = NULL;
543 ulwp_t **ulwpp;
544
545 if (self->ul_lwpid == tid) {
546 ulwp = self;
547 ulwp_lock(ulwp, udp);
548 } else if ((ulwpp = find_lwpp(tid)) != NULL) {
549 ulwp = *ulwpp;
550 }
551
552 if (ulwp && ulwp->ul_dead) {
553 ulwp_unlock(ulwp, udp);
554 ulwp = NULL;
555 }
556
557 return (ulwp);
558 }
559
560 int
561 _thrp_create(void *stk, size_t stksize, void *(*func)(void *), void *arg,
562 long flags, thread_t *new_thread, size_t guardsize)
563 {
564 ulwp_t *self = curthread;
565 uberdata_t *udp = self->ul_uberdata;
566 ucontext_t uc;
567 uint_t lwp_flags;
568 thread_t tid;
569 int error;
570 ulwp_t *ulwp;
571
572 /*
573 * Enforce the restriction of not creating any threads
574 * until the primary link map has been initialized.
575 * Also, disallow thread creation to a child of vfork().
576 */
577 if (!self->ul_primarymap || self->ul_vfork)
578 return (ENOTSUP);
579
580 if (udp->hash_size == 1)
581 finish_init();
582
583 if ((stk || stksize) && stksize < MINSTACK)
584 return (EINVAL);
585
586 if (stk == NULL) {
587 if ((ulwp = find_stack(stksize, guardsize)) == NULL)
588 return (ENOMEM);
589 stksize = ulwp->ul_mapsiz - ulwp->ul_guardsize;
590 } else {
591 /* initialize the private stack */
592 if ((ulwp = ulwp_alloc()) == NULL)
593 return (ENOMEM);
594 ulwp->ul_stk = stk;
595 ulwp->ul_stktop = (uintptr_t)stk + stksize;
596 ulwp->ul_stksiz = stksize;
597 }
598 /* ulwp is not in the hash table; make sure hash_out() doesn't fail */
599 ulwp->ul_ix = -1;
600 ulwp->ul_errnop = &ulwp->ul_errno;
601
602 lwp_flags = LWP_SUSPENDED;
603 if (flags & (THR_DETACHED|THR_DAEMON)) {
604 flags |= THR_DETACHED;
605 lwp_flags |= LWP_DETACHED;
606 }
607 if (flags & THR_DAEMON)
608 lwp_flags |= LWP_DAEMON;
609
610 /* creating a thread: enforce mt-correctness in mutex_lock() */
611 self->ul_async_safe = 1;
612
613 /* per-thread copies of global variables, for speed */
614 ulwp->ul_queue_fifo = self->ul_queue_fifo;
615 ulwp->ul_cond_wait_defer = self->ul_cond_wait_defer;
616 ulwp->ul_error_detection = self->ul_error_detection;
617 ulwp->ul_async_safe = self->ul_async_safe;
618 ulwp->ul_max_spinners = self->ul_max_spinners;
619 ulwp->ul_adaptive_spin = self->ul_adaptive_spin;
620 ulwp->ul_queue_spin = self->ul_queue_spin;
621 ulwp->ul_door_noreserve = self->ul_door_noreserve;
622 ulwp->ul_misaligned = self->ul_misaligned;
623
624 /* new thread inherits creating thread's scheduling parameters */
625 ulwp->ul_policy = self->ul_policy;
626 ulwp->ul_pri = (self->ul_epri? self->ul_epri : self->ul_pri);
627 ulwp->ul_cid = self->ul_cid;
628 ulwp->ul_rtclassid = self->ul_rtclassid;
629
630 ulwp->ul_primarymap = self->ul_primarymap;
631 ulwp->ul_self = ulwp;
632 ulwp->ul_uberdata = udp;
633
634 /* debugger support */
635 ulwp->ul_usropts = flags;
636
637 #ifdef __sparc
638 /*
639 * We cache several instructions in the thread structure for use
640 * by the fasttrap DTrace provider. When changing this, read the
641 * comment in fasttrap.h for the all the other places that must
642 * be changed.
643 */
644 ulwp->ul_dsave = 0x9de04000; /* save %g1, %g0, %sp */
645 ulwp->ul_drestore = 0x81e80000; /* restore %g0, %g0, %g0 */
646 ulwp->ul_dftret = 0x91d0203a; /* ta 0x3a */
647 ulwp->ul_dreturn = 0x81ca0000; /* return %o0 */
648 #endif
649
650 ulwp->ul_startpc = func;
651 ulwp->ul_startarg = arg;
652 _fpinherit(ulwp);
653 /*
654 * Defer signals on the new thread until its TLS constructors
655 * have been called. _thrp_setup() will call sigon() after
656 * it has called tls_setup().
657 */
658 ulwp->ul_sigdefer = 1;
659
660 error = setup_context(&uc, _thrp_setup, ulwp,
661 (caddr_t)ulwp->ul_stk + ulwp->ul_guardsize, stksize);
662 if (error != 0 && stk != NULL) /* inaccessible stack */
663 error = EFAULT;
664
665 /*
666 * Call enter_critical() to avoid being suspended until we
667 * have linked the new thread into the proper lists.
668 * This is necessary because forkall() and fork1() must
669 * suspend all threads and they must see a complete list.
670 */
671 enter_critical(self);
672 uc.uc_sigmask = ulwp->ul_sigmask = self->ul_sigmask;
673 if (error != 0 ||
674 (error = __lwp_create(&uc, lwp_flags, &tid)) != 0) {
675 exit_critical(self);
676 ulwp->ul_lwpid = (lwpid_t)(-1);
677 ulwp->ul_dead = 1;
678 ulwp->ul_detached = 1;
679 lmutex_lock(&udp->link_lock);
680 ulwp_free(ulwp);
681 lmutex_unlock(&udp->link_lock);
682 return (error);
683 }
684 self->ul_nocancel = 0; /* cancellation is now possible */
685 udp->uberflags.uf_mt = 1;
686 if (new_thread)
687 *new_thread = tid;
688 if (flags & THR_DETACHED)
689 ulwp->ul_detached = 1;
690 ulwp->ul_lwpid = tid;
691 ulwp->ul_stop = TSTP_REGULAR;
692 if (flags & THR_SUSPENDED)
693 ulwp->ul_created = 1;
694
695 lmutex_lock(&udp->link_lock);
696 ulwp->ul_forw = udp->all_lwps;
697 ulwp->ul_back = udp->all_lwps->ul_back;
698 ulwp->ul_back->ul_forw = ulwp;
699 ulwp->ul_forw->ul_back = ulwp;
700 hash_in(ulwp, udp);
701 udp->nthreads++;
702 if (flags & THR_DAEMON)
703 udp->ndaemons++;
704 if (flags & THR_NEW_LWP)
705 thr_concurrency++;
706 __libc_threaded = 1; /* inform stdio */
707 lmutex_unlock(&udp->link_lock);
708
709 if (__td_event_report(self, TD_CREATE, udp)) {
710 self->ul_td_evbuf.eventnum = TD_CREATE;
711 self->ul_td_evbuf.eventdata = (void *)(uintptr_t)tid;
712 tdb_event(TD_CREATE, udp);
713 }
714
715 exit_critical(self);
716
717 if (!(flags & THR_SUSPENDED))
718 (void) _thrp_continue(tid, TSTP_REGULAR);
719
720 return (0);
721 }
722
723 int
724 thr_create(void *stk, size_t stksize, void *(*func)(void *), void *arg,
725 long flags, thread_t *new_thread)
726 {
727 return (_thrp_create(stk, stksize, func, arg, flags, new_thread, 0));
728 }
729
730 /*
731 * A special cancellation cleanup hook for DCE.
732 * cleanuphndlr, when it is not NULL, will contain a callback
733 * function to be called before a thread is terminated in
734 * thr_exit() as a result of being cancelled.
735 */
736 static void (*cleanuphndlr)(void) = NULL;
737
738 /*
739 * _pthread_setcleanupinit: sets the cleanup hook.
740 */
741 int
742 _pthread_setcleanupinit(void (*func)(void))
743 {
744 cleanuphndlr = func;
745 return (0);
746 }
747
748 void
749 _thrp_exit()
750 {
751 ulwp_t *self = curthread;
752 uberdata_t *udp = self->ul_uberdata;
753 ulwp_t *replace = NULL;
754
755 if (__td_event_report(self, TD_DEATH, udp)) {
756 self->ul_td_evbuf.eventnum = TD_DEATH;
757 tdb_event(TD_DEATH, udp);
758 }
759
760 ASSERT(self->ul_sigdefer != 0);
761
762 lmutex_lock(&udp->link_lock);
763 udp->nthreads--;
764 if (self->ul_usropts & THR_NEW_LWP)
765 thr_concurrency--;
766 if (self->ul_usropts & THR_DAEMON)
767 udp->ndaemons--;
768 else if (udp->nthreads == udp->ndaemons) {
769 /*
770 * We are the last non-daemon thread exiting.
771 * Exit the process. We retain our TSD and TLS so
772 * that atexit() application functions can use them.
773 */
774 lmutex_unlock(&udp->link_lock);
775 exit(0);
776 thr_panic("_thrp_exit(): exit(0) returned");
777 }
778 lmutex_unlock(&udp->link_lock);
779
780 tmem_exit(); /* deallocate tmem allocations */
781 tsd_exit(); /* deallocate thread-specific data */
782 tls_exit(); /* deallocate thread-local storage */
783 heldlock_exit(); /* deal with left-over held locks */
784
785 /* block all signals to finish exiting */
786 block_all_signals(self);
787 /* also prevent ourself from being suspended */
788 enter_critical(self);
789 rwl_free(self);
790 lmutex_lock(&udp->link_lock);
791 ulwp_free(self);
792 (void) ulwp_lock(self, udp);
793
794 if (self->ul_mapsiz && !self->ul_detached) {
795 /*
796 * We want to free the stack for reuse but must keep
797 * the ulwp_t struct for the benefit of thr_join().
798 * For this purpose we allocate a replacement ulwp_t.
799 */
800 if ((replace = udp->ulwp_replace_free) == NULL)
801 replace = lmalloc(REPLACEMENT_SIZE);
802 else if ((udp->ulwp_replace_free = replace->ul_next) == NULL)
803 udp->ulwp_replace_last = NULL;
804 }
805
806 if (udp->all_lwps == self)
807 udp->all_lwps = self->ul_forw;
808 if (udp->all_lwps == self)
809 udp->all_lwps = NULL;
810 else {
811 self->ul_forw->ul_back = self->ul_back;
812 self->ul_back->ul_forw = self->ul_forw;
813 }
814 self->ul_forw = self->ul_back = NULL;
815 #if defined(THREAD_DEBUG)
816 /* collect queue lock statistics before marking ourself dead */
817 record_spin_locks(self);
818 #endif
819 self->ul_dead = 1;
820 self->ul_pleasestop = 0;
821 if (replace != NULL) {
822 int ix = self->ul_ix; /* the hash index */
823 (void) memcpy(replace, self, REPLACEMENT_SIZE);
824 replace->ul_self = replace;
825 replace->ul_next = NULL; /* clone not on stack list */
826 replace->ul_mapsiz = 0; /* allows clone to be freed */
827 replace->ul_replace = 1; /* requires clone to be freed */
828 hash_out_unlocked(self, ix, udp);
829 hash_in_unlocked(replace, ix, udp);
830 ASSERT(!(self->ul_detached));
831 self->ul_detached = 1; /* this frees the stack */
832 self->ul_schedctl = NULL;
833 self->ul_schedctl_called = &udp->uberflags;
834 set_curthread(self = replace);
835 /*
836 * Having just changed the address of curthread, we
837 * must reset the ownership of the locks we hold so
838 * that assertions will not fire when we release them.
839 */
840 udp->link_lock.mutex_owner = (uintptr_t)self;
841 ulwp_mutex(self, udp)->mutex_owner = (uintptr_t)self;
842 /*
843 * NOTE:
844 * On i386, %gs still references the original, not the
845 * replacement, ulwp structure. Fetching the replacement
846 * curthread pointer via %gs:0 works correctly since the
847 * original ulwp structure will not be reallocated until
848 * this lwp has completed its lwp_exit() system call (see
849 * dead_and_buried()), but from here on out, we must make
850 * no references to %gs:<offset> other than %gs:0.
851 */
852 }
853 /*
854 * Put non-detached terminated threads in the all_zombies list.
855 */
856 if (!self->ul_detached) {
857 udp->nzombies++;
858 if (udp->all_zombies == NULL) {
859 ASSERT(udp->nzombies == 1);
860 udp->all_zombies = self->ul_forw = self->ul_back = self;
861 } else {
862 self->ul_forw = udp->all_zombies;
863 self->ul_back = udp->all_zombies->ul_back;
864 self->ul_back->ul_forw = self;
865 self->ul_forw->ul_back = self;
866 }
867 }
868 /*
869 * Notify everyone waiting for this thread.
870 */
871 ulwp_broadcast(self);
872 (void) ulwp_unlock(self, udp);
873 /*
874 * Prevent any more references to the schedctl data.
875 * We are exiting and continue_fork() may not find us.
876 * Do this just before dropping link_lock, since fork
877 * serializes on link_lock.
878 */
879 self->ul_schedctl = NULL;
880 self->ul_schedctl_called = &udp->uberflags;
881 lmutex_unlock(&udp->link_lock);
882
883 ASSERT(self->ul_critical == 1);
884 ASSERT(self->ul_preempt == 0);
885 _lwp_terminate(); /* never returns */
886 thr_panic("_thrp_exit(): _lwp_terminate() returned");
887 }
888
889 #if defined(THREAD_DEBUG)
890 void
891 collect_queue_statistics()
892 {
893 uberdata_t *udp = curthread->ul_uberdata;
894 ulwp_t *ulwp;
895
896 if (thread_queue_dump) {
897 lmutex_lock(&udp->link_lock);
898 if ((ulwp = udp->all_lwps) != NULL) {
899 do {
900 record_spin_locks(ulwp);
901 } while ((ulwp = ulwp->ul_forw) != udp->all_lwps);
902 }
903 lmutex_unlock(&udp->link_lock);
904 }
905 }
906 #endif
907
908 static void __NORETURN
909 _thrp_exit_common(void *status, int unwind)
910 {
911 ulwp_t *self = curthread;
912 int cancelled = (self->ul_cancel_pending && status == PTHREAD_CANCELED);
913
914 ASSERT(self->ul_critical == 0 && self->ul_preempt == 0);
915
916 /*
917 * Disable cancellation and call the special DCE cancellation
918 * cleanup hook if it is enabled. Do nothing else before calling
919 * the DCE cancellation cleanup hook; it may call longjmp() and
920 * never return here.
921 */
922 self->ul_cancel_disabled = 1;
923 self->ul_cancel_async = 0;
924 self->ul_save_async = 0;
925 self->ul_cancelable = 0;
926 self->ul_cancel_pending = 0;
927 set_cancel_pending_flag(self, 1);
928 if (cancelled && cleanuphndlr != NULL)
929 (*cleanuphndlr)();
930
931 /*
932 * Block application signals while we are exiting.
933 * We call out to C++, TSD, and TLS destructors while exiting
934 * and these are application-defined, so we cannot be assured
935 * that they won't reset the signal mask. We use sigoff() to
936 * defer any signals that may be received as a result of this
937 * bad behavior. Such signals will be lost to the process
938 * when the thread finishes exiting.
939 */
940 (void) thr_sigsetmask(SIG_SETMASK, &maskset, NULL);
941 sigoff(self);
942
943 self->ul_rval = status;
944
945 /*
946 * If thr_exit is being called from the places where
947 * C++ destructors are to be called such as cancellation
948 * points, then set this flag. It is checked in _t_cancel()
949 * to decide whether _ex_unwind() is to be called or not.
950 */
951 if (unwind)
952 self->ul_unwind = 1;
953
954 /*
955 * _thrp_unwind() will eventually call _thrp_exit().
956 * It never returns.
957 */
958 _thrp_unwind(NULL);
959 thr_panic("_thrp_exit_common(): _thrp_unwind() returned");
960
961 for (;;) /* to shut the compiler up about __NORETURN */
962 continue;
963 }
964
965 /*
966 * Called when a thread returns from its start function.
967 * We are at the top of the stack; no unwinding is necessary.
968 */
969 void
970 _thrp_terminate(void *status)
971 {
972 _thrp_exit_common(status, 0);
973 }
974
975 #pragma weak pthread_exit = thr_exit
976 #pragma weak _thr_exit = thr_exit
977 void
978 thr_exit(void *status)
979 {
980 _thrp_exit_common(status, 1);
981 }
982
983 int
984 _thrp_join(thread_t tid, thread_t *departed, void **status, int do_cancel)
985 {
986 uberdata_t *udp = curthread->ul_uberdata;
987 mutex_t *mp;
988 void *rval;
989 thread_t found;
990 ulwp_t *ulwp;
991 ulwp_t **ulwpp;
992 int replace;
993 int error;
994
995 if (do_cancel)
996 error = lwp_wait(tid, &found);
997 else {
998 while ((error = __lwp_wait(tid, &found)) == EINTR)
999 ;
1000 }
1001 if (error)
1002 return (error);
1003
1004 /*
1005 * We must hold link_lock to avoid a race condition with find_stack().
1006 */
1007 lmutex_lock(&udp->link_lock);
1008 if ((ulwpp = find_lwpp(found)) == NULL) {
1009 /*
1010 * lwp_wait() found an lwp that the library doesn't know
1011 * about. It must have been created with _lwp_create().
1012 * Just return its lwpid; we can't know its status.
1013 */
1014 lmutex_unlock(&udp->link_lock);
1015 rval = NULL;
1016 } else {
1017 /*
1018 * Remove ulwp from the hash table.
1019 */
1020 ulwp = *ulwpp;
1021 *ulwpp = ulwp->ul_hash;
1022 ulwp->ul_hash = NULL;
1023 /*
1024 * Remove ulwp from all_zombies list.
1025 */
1026 ASSERT(udp->nzombies >= 1);
1027 if (udp->all_zombies == ulwp)
1028 udp->all_zombies = ulwp->ul_forw;
1029 if (udp->all_zombies == ulwp)
1030 udp->all_zombies = NULL;
1031 else {
1032 ulwp->ul_forw->ul_back = ulwp->ul_back;
1033 ulwp->ul_back->ul_forw = ulwp->ul_forw;
1034 }
1035 ulwp->ul_forw = ulwp->ul_back = NULL;
1036 udp->nzombies--;
1037 ASSERT(ulwp->ul_dead && !ulwp->ul_detached &&
1038 !(ulwp->ul_usropts & (THR_DETACHED|THR_DAEMON)));
1039 /*
1040 * We can't call ulwp_unlock(ulwp) after we set
1041 * ulwp->ul_ix = -1 so we have to get a pointer to the
1042 * ulwp's hash table mutex now in order to unlock it below.
1043 */
1044 mp = ulwp_mutex(ulwp, udp);
1045 ulwp->ul_lwpid = (lwpid_t)(-1);
1046 ulwp->ul_ix = -1;
1047 rval = ulwp->ul_rval;
1048 replace = ulwp->ul_replace;
1049 lmutex_unlock(mp);
1050 if (replace) {
1051 ulwp->ul_next = NULL;
1052 if (udp->ulwp_replace_free == NULL)
1053 udp->ulwp_replace_free =
1054 udp->ulwp_replace_last = ulwp;
1055 else {
1056 udp->ulwp_replace_last->ul_next = ulwp;
1057 udp->ulwp_replace_last = ulwp;
1058 }
1059 }
1060 lmutex_unlock(&udp->link_lock);
1061 }
1062
1063 if (departed != NULL)
1064 *departed = found;
1065 if (status != NULL)
1066 *status = rval;
1067 return (0);
1068 }
1069
1070 int
1071 thr_join(thread_t tid, thread_t *departed, void **status)
1072 {
1073 int error = _thrp_join(tid, departed, status, 1);
1074 return ((error == EINVAL)? ESRCH : error);
1075 }
1076
1077 /*
1078 * pthread_join() differs from Solaris thr_join():
1079 * It does not return the departed thread's id
1080 * and hence does not have a "departed" argument.
1081 * It returns EINVAL if tid refers to a detached thread.
1082 */
1083 #pragma weak _pthread_join = pthread_join
1084 int
1085 pthread_join(pthread_t tid, void **status)
1086 {
1087 return ((tid == 0)? ESRCH : _thrp_join(tid, NULL, status, 1));
1088 }
1089
1090 int
1091 pthread_detach(pthread_t tid)
1092 {
1093 uberdata_t *udp = curthread->ul_uberdata;
1094 ulwp_t *ulwp;
1095 ulwp_t **ulwpp;
1096 int error = 0;
1097
1098 if ((ulwpp = find_lwpp(tid)) == NULL)
1099 return (ESRCH);
1100 ulwp = *ulwpp;
1101
1102 if (ulwp->ul_dead) {
1103 ulwp_unlock(ulwp, udp);
1104 error = _thrp_join(tid, NULL, NULL, 0);
1105 } else {
1106 error = __lwp_detach(tid);
1107 ulwp->ul_detached = 1;
1108 ulwp->ul_usropts |= THR_DETACHED;
1109 ulwp_unlock(ulwp, udp);
1110 }
1111 return (error);
1112 }
1113
1114 static const char *
1115 ematch(const char *ev, const char *match)
1116 {
1117 int c;
1118
1119 while ((c = *match++) != '\0') {
1120 if (*ev++ != c)
1121 return (NULL);
1122 }
1123 if (*ev++ != '=')
1124 return (NULL);
1125 return (ev);
1126 }
1127
1128 static int
1129 envvar(const char *ev, const char *match, int limit)
1130 {
1131 int val = -1;
1132 const char *ename;
1133
1134 if ((ename = ematch(ev, match)) != NULL) {
1135 int c;
1136 for (val = 0; (c = *ename) != '\0'; ename++) {
1137 if (!isdigit(c)) {
1138 val = -1;
1139 break;
1140 }
1141 val = val * 10 + (c - '0');
1142 if (val > limit) {
1143 val = limit;
1144 break;
1145 }
1146 }
1147 }
1148 return (val);
1149 }
1150
1151 static void
1152 etest(const char *ev)
1153 {
1154 int value;
1155
1156 if ((value = envvar(ev, "QUEUE_SPIN", 1000000)) >= 0)
1157 thread_queue_spin = value;
1158 if ((value = envvar(ev, "ADAPTIVE_SPIN", 1000000)) >= 0)
1159 thread_adaptive_spin = value;
1160 if ((value = envvar(ev, "MAX_SPINNERS", 255)) >= 0)
1161 thread_max_spinners = value;
1162 if ((value = envvar(ev, "QUEUE_FIFO", 8)) >= 0)
1163 thread_queue_fifo = value;
1164 #if defined(THREAD_DEBUG)
1165 if ((value = envvar(ev, "QUEUE_VERIFY", 1)) >= 0)
1166 thread_queue_verify = value;
1167 if ((value = envvar(ev, "QUEUE_DUMP", 1)) >= 0)
1168 thread_queue_dump = value;
1169 #endif
1170 if ((value = envvar(ev, "STACK_CACHE", 10000)) >= 0)
1171 thread_stack_cache = value;
1172 if ((value = envvar(ev, "COND_WAIT_DEFER", 1)) >= 0)
1173 thread_cond_wait_defer = value;
1174 if ((value = envvar(ev, "ERROR_DETECTION", 2)) >= 0)
1175 thread_error_detection = value;
1176 if ((value = envvar(ev, "ASYNC_SAFE", 1)) >= 0)
1177 thread_async_safe = value;
1178 if ((value = envvar(ev, "DOOR_NORESERVE", 1)) >= 0)
1179 thread_door_noreserve = value;
1180 if ((value = envvar(ev, "LOCKS_MISALIGNED", 1)) >= 0)
1181 thread_locks_misaligned = value;
1182 }
1183
1184 /*
1185 * Look for and evaluate environment variables of the form "_THREAD_*".
1186 * For compatibility with the past, we also look for environment
1187 * names of the form "LIBTHREAD_*".
1188 */
1189 static void
1190 set_thread_vars()
1191 {
1192 extern const char **_environ;
1193 const char **pev;
1194 const char *ev;
1195 char c;
1196
1197 if ((pev = _environ) == NULL)
1198 return;
1199 while ((ev = *pev++) != NULL) {
1200 c = *ev;
1201 if (c == '_' && strncmp(ev, "_THREAD_", 8) == 0)
1202 etest(ev + 8);
1203 if (c == 'L' && strncmp(ev, "LIBTHREAD_", 10) == 0)
1204 etest(ev + 10);
1205 }
1206 }
1207
1208 /* PROBE_SUPPORT begin */
1209 #pragma weak __tnf_probe_notify
1210 extern void __tnf_probe_notify(void);
1211 /* PROBE_SUPPORT end */
1212
1213 /* same as atexit() but private to the library */
1214 extern int _atexit(void (*)(void));
1215
1216 /* same as _cleanup() but private to the library */
1217 extern void __cleanup(void);
1218
1219 extern void atfork_init(void);
1220
1221 #ifdef __amd64
1222 extern void __proc64id(void);
1223 #endif
1224
1225 static void
1226 init_auxv_data(uberdata_t *udp)
1227 {
1228 Dl_argsinfo_t args;
1229
1230 udp->ub_comm_page = NULL;
1231 if (dlinfo(RTLD_SELF, RTLD_DI_ARGSINFO, &args) < 0)
1232 return;
1233
1234 while (args.dla_auxv->a_type != AT_NULL) {
1235 if (args.dla_auxv->a_type == AT_SUN_COMMPAGE) {
1236 udp->ub_comm_page = args.dla_auxv->a_un.a_ptr;
1237 }
1238 args.dla_auxv++;
1239 }
1240 }
1241
1242 /*
1243 * libc_init() is called by ld.so.1 for library initialization.
1244 * We perform minimal initialization; enough to work with the main thread.
1245 */
1246 void
1247 libc_init(void)
1248 {
1249 uberdata_t *udp = &__uberdata;
1250 ulwp_t *oldself = __curthread();
1251 ucontext_t uc;
1252 ulwp_t *self;
1253 struct rlimit rl;
1254 caddr_t data;
1255 size_t tls_size;
1256 int setmask;
1257
1258 /*
1259 * For the initial stage of initialization, we must be careful
1260 * not to call any function that could possibly call _cerror().
1261 * For this purpose, we call only the raw system call wrappers.
1262 */
1263
1264 #ifdef __amd64
1265 /*
1266 * Gather information about cache layouts for optimized
1267 * AMD and Intel assembler strfoo() and memfoo() functions.
1268 */
1269 __proc64id();
1270 #endif
1271
1272 /*
1273 * Every libc, regardless of which link map, must register __cleanup().
1274 */
1275 (void) _atexit(__cleanup);
1276
1277 /*
1278 * Every libc, regardless of link map, needs to go through and check
1279 * its aux vectors. Doing so will indicate whether or not this has
1280 * been given a comm page (to optimize certain system actions).
1281 */
1282 init_auxv_data(udp);
1283
1284 /*
1285 * We keep our uberdata on one of (a) the first alternate link map
1286 * or (b) the primary link map. We switch to the primary link map
1287 * and stay there once we see it. All intermediate link maps are
1288 * subject to being unloaded at any time.
1289 */
1290 if (oldself != NULL && (oldself->ul_primarymap || !primary_link_map)) {
1291 __tdb_bootstrap = oldself->ul_uberdata->tdb_bootstrap;
1292 mutex_setup();
1293 atfork_init(); /* every link map needs atfork() processing */
1294 init_progname();
1295 return;
1296 }
1297
1298 /*
1299 * To establish the main stack information, we have to get our context.
1300 * This is also convenient to use for getting our signal mask.
1301 */
1302 uc.uc_flags = UC_ALL;
1303 (void) __getcontext(&uc);
1304 ASSERT(uc.uc_link == NULL);
1305
1306 tls_size = roundup64(udp->tls_metadata.static_tls.tls_size);
1307 ASSERT(primary_link_map || tls_size == 0);
1308 data = lmalloc(sizeof (ulwp_t) + tls_size);
1309 if (data == NULL)
1310 thr_panic("cannot allocate thread structure for main thread");
1311 /* LINTED pointer cast may result in improper alignment */
1312 self = (ulwp_t *)(data + tls_size);
1313 init_hash_table[0].hash_bucket = self;
1314
1315 self->ul_sigmask = uc.uc_sigmask;
1316 delete_reserved_signals(&self->ul_sigmask);
1317 /*
1318 * Are the old and new sets different?
1319 * (This can happen if we are currently blocking SIGCANCEL.)
1320 * If so, we must explicitly set our signal mask, below.
1321 */
1322 setmask =
1323 ((self->ul_sigmask.__sigbits[0] ^ uc.uc_sigmask.__sigbits[0]) |
1324 (self->ul_sigmask.__sigbits[1] ^ uc.uc_sigmask.__sigbits[1]) |
1325 (self->ul_sigmask.__sigbits[2] ^ uc.uc_sigmask.__sigbits[2]) |
1326 (self->ul_sigmask.__sigbits[3] ^ uc.uc_sigmask.__sigbits[3]));
1327
1328 #ifdef __sparc
1329 /*
1330 * We cache several instructions in the thread structure for use
1331 * by the fasttrap DTrace provider. When changing this, read the
1332 * comment in fasttrap.h for the all the other places that must
1333 * be changed.
1334 */
1335 self->ul_dsave = 0x9de04000; /* save %g1, %g0, %sp */
1336 self->ul_drestore = 0x81e80000; /* restore %g0, %g0, %g0 */
1337 self->ul_dftret = 0x91d0203a; /* ta 0x3a */
1338 self->ul_dreturn = 0x81ca0000; /* return %o0 */
1339 #endif
1340
1341 self->ul_stktop = (uintptr_t)uc.uc_stack.ss_sp + uc.uc_stack.ss_size;
1342 (void) getrlimit(RLIMIT_STACK, &rl);
1343 self->ul_stksiz = rl.rlim_cur;
1344 self->ul_stk = (caddr_t)(self->ul_stktop - self->ul_stksiz);
1345
1346 self->ul_forw = self->ul_back = self;
1347 self->ul_hash = NULL;
1348 self->ul_ix = 0;
1349 self->ul_lwpid = 1; /* _lwp_self() */
1350 self->ul_main = 1;
1351 self->ul_self = self;
1352 self->ul_policy = -1; /* initialize only when needed */
1353 self->ul_pri = 0;
1354 self->ul_cid = 0;
1355 self->ul_rtclassid = -1;
1356 self->ul_uberdata = udp;
1357 if (oldself != NULL) {
1358 int i;
1359
1360 ASSERT(primary_link_map);
1361 ASSERT(oldself->ul_main == 1);
1362 self->ul_stsd = oldself->ul_stsd;
1363 for (i = 0; i < TSD_NFAST; i++)
1364 self->ul_ftsd[i] = oldself->ul_ftsd[i];
1365 self->ul_tls = oldself->ul_tls;
1366 /*
1367 * Retrieve all pointers to uberdata allocated
1368 * while running on previous link maps.
1369 * We would like to do a structure assignment here, but
1370 * gcc turns structure assignments into calls to memcpy(),
1371 * a function exported from libc. We can't call any such
1372 * external functions until we establish curthread, below,
1373 * so we just call our private version of memcpy().
1374 */
1375 (void) memcpy(udp, oldself->ul_uberdata, sizeof (*udp));
1376 /*
1377 * These items point to global data on the primary link map.
1378 */
1379 udp->thr_hash_table = init_hash_table;
1380 udp->sigacthandler = sigacthandler;
1381 udp->tdb.tdb_events = tdb_events;
1382 ASSERT(udp->nthreads == 1 && !udp->uberflags.uf_mt);
1383 ASSERT(udp->lwp_stacks == NULL);
1384 ASSERT(udp->ulwp_freelist == NULL);
1385 ASSERT(udp->ulwp_replace_free == NULL);
1386 ASSERT(udp->hash_size == 1);
1387 }
1388 udp->all_lwps = self;
1389 udp->ulwp_one = self;
1390 udp->pid = getpid();
1391 udp->nthreads = 1;
1392 /*
1393 * In every link map, tdb_bootstrap points to the same piece of
1394 * allocated memory. When the primary link map is initialized,
1395 * the allocated memory is assigned a pointer to the one true
1396 * uberdata. This allows libc_db to initialize itself regardless
1397 * of which instance of libc it finds in the address space.
1398 */
1399 if (udp->tdb_bootstrap == NULL)
1400 udp->tdb_bootstrap = lmalloc(sizeof (uberdata_t *));
1401 __tdb_bootstrap = udp->tdb_bootstrap;
1402 if (primary_link_map) {
1403 self->ul_primarymap = 1;
1404 udp->primary_map = 1;
1405 *udp->tdb_bootstrap = udp;
1406 }
1407 /*
1408 * Cancellation can't happen until:
1409 * pthread_cancel() is called
1410 * or:
1411 * another thread is created
1412 * For now, as a single-threaded process, set the flag that tells
1413 * PROLOGUE/EPILOGUE (in scalls.c) that cancellation can't happen.
1414 */
1415 self->ul_nocancel = 1;
1416
1417 #if defined(__amd64)
1418 (void) ___lwp_private(_LWP_SETPRIVATE, _LWP_FSBASE, self);
1419 #elif defined(__i386)
1420 (void) ___lwp_private(_LWP_SETPRIVATE, _LWP_GSBASE, self);
1421 #endif /* __i386 || __amd64 */
1422 set_curthread(self); /* redundant on i386 */
1423 /*
1424 * Now curthread is established and it is safe to call any
1425 * function in libc except one that uses thread-local storage.
1426 */
1427 self->ul_errnop = &errno;
1428 if (oldself != NULL) {
1429 /* tls_size was zero when oldself was allocated */
1430 lfree(oldself, sizeof (ulwp_t));
1431 }
1432 mutex_setup();
1433 atfork_init();
1434 signal_init();
1435
1436 /*
1437 * If the stack is unlimited, we set the size to zero to disable
1438 * stack checking.
1439 * XXX: Work harder here. Get the stack size from /proc/self/rmap
1440 */
1441 if (self->ul_stksiz == RLIM_INFINITY) {
1442 self->ul_ustack.ss_sp = (void *)self->ul_stktop;
1443 self->ul_ustack.ss_size = 0;
1444 } else {
1445 self->ul_ustack.ss_sp = self->ul_stk;
1446 self->ul_ustack.ss_size = self->ul_stksiz;
1447 }
1448 self->ul_ustack.ss_flags = 0;
1449 (void) setustack(&self->ul_ustack);
1450
1451 /*
1452 * Get the variables that affect thread behavior from the environment.
1453 */
1454 set_thread_vars();
1455 udp->uberflags.uf_thread_error_detection = (char)thread_error_detection;
1456 udp->thread_stack_cache = thread_stack_cache;
1457
1458 /*
1459 * Make per-thread copies of global variables, for speed.
1460 */
1461 self->ul_queue_fifo = (char)thread_queue_fifo;
1462 self->ul_cond_wait_defer = (char)thread_cond_wait_defer;
1463 self->ul_error_detection = (char)thread_error_detection;
1464 self->ul_async_safe = (char)thread_async_safe;
1465 self->ul_door_noreserve = (char)thread_door_noreserve;
1466 self->ul_misaligned = (char)thread_locks_misaligned;
1467 self->ul_max_spinners = (uint8_t)thread_max_spinners;
1468 self->ul_adaptive_spin = thread_adaptive_spin;
1469 self->ul_queue_spin = thread_queue_spin;
1470
1471 #if defined(__sparc) && !defined(_LP64)
1472 if (self->ul_misaligned) {
1473 /*
1474 * Tell the kernel to fix up ldx/stx instructions that
1475 * refer to non-8-byte aligned data instead of giving
1476 * the process an alignment trap and generating SIGBUS.
1477 *
1478 * Programs compiled for 32-bit sparc with the Studio SS12
1479 * compiler get this done for them automatically (in _init()).
1480 * We do it here for the benefit of programs compiled with
1481 * other compilers, like gcc.
1482 *
1483 * This is necessary for the _THREAD_LOCKS_MISALIGNED=1
1484 * environment variable horrible hack to work.
1485 */
1486 extern void _do_fix_align(void);
1487 _do_fix_align();
1488 }
1489 #endif
1490
1491 /*
1492 * When we have initialized the primary link map, inform
1493 * the dynamic linker about our interface functions.
1494 * Set up our pointer to the program name.
1495 */
1496 if (self->ul_primarymap)
1497 _ld_libc((void *)rtld_funcs);
1498 init_progname();
1499
1500 /*
1501 * Defer signals until TLS constructors have been called.
1502 */
1503 sigoff(self);
1504 tls_setup();
1505 sigon(self);
1506 if (setmask)
1507 (void) restore_signals(self);
1508
1509 /*
1510 * Make private copies of __xpg4 and __xpg6 so libc can test
1511 * them after this point without invoking the dynamic linker.
1512 */
1513 libc__xpg4 = __xpg4;
1514 libc__xpg6 = __xpg6;
1515
1516 /* PROBE_SUPPORT begin */
1517 if (self->ul_primarymap && __tnf_probe_notify != NULL)
1518 __tnf_probe_notify();
1519 /* PROBE_SUPPORT end */
1520
1521 init_sigev_thread();
1522 init_aio();
1523
1524 /*
1525 * We need to reset __threaded dynamically at runtime, so that
1526 * __threaded can be bound to __threaded outside libc which may not
1527 * have initial value of 1 (without a copy relocation in a.out).
1528 */
1529 __threaded = 1;
1530 }
1531
1532 #pragma fini(libc_fini)
1533 void
1534 libc_fini()
1535 {
1536 /*
1537 * If we are doing fini processing for the instance of libc
1538 * on the first alternate link map (this happens only when
1539 * the dynamic linker rejects a bad audit library), then clear
1540 * __curthread(). We abandon whatever memory was allocated by
1541 * lmalloc() while running on this alternate link-map but we
1542 * don't care (and can't find the memory in any case); we just
1543 * want to protect the application from this bad audit library.
1544 * No fini processing is done by libc in the normal case.
1545 */
1546
1547 uberdata_t *udp = curthread->ul_uberdata;
1548
1549 if (udp->primary_map == 0 && udp == &__uberdata)
1550 set_curthread(NULL);
1551 }
1552
1553 /*
1554 * finish_init is called when we are about to become multi-threaded,
1555 * that is, on the first call to thr_create().
1556 */
1557 void
1558 finish_init()
1559 {
1560 ulwp_t *self = curthread;
1561 uberdata_t *udp = self->ul_uberdata;
1562 thr_hash_table_t *htp;
1563 void *data;
1564 int i;
1565
1566 /*
1567 * No locks needed here; we are single-threaded on the first call.
1568 * We can be called only after the primary link map has been set up.
1569 */
1570 ASSERT(self->ul_primarymap);
1571 ASSERT(self == udp->ulwp_one);
1572 ASSERT(!udp->uberflags.uf_mt);
1573 ASSERT(udp->hash_size == 1);
1574
1575 /*
1576 * Initialize self->ul_policy, self->ul_cid, and self->ul_pri.
1577 */
1578 update_sched(self);
1579
1580 /*
1581 * Allocate the queue_head array if not already allocated.
1582 */
1583 if (udp->queue_head == NULL)
1584 queue_alloc();
1585
1586 /*
1587 * Now allocate the thread hash table.
1588 */
1589 if ((data = mmap(NULL, HASHTBLSZ * sizeof (thr_hash_table_t),
1590 PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, (off_t)0))
1591 == MAP_FAILED)
1592 thr_panic("cannot allocate thread hash table");
1593
1594 udp->thr_hash_table = htp = (thr_hash_table_t *)data;
1595 udp->hash_size = HASHTBLSZ;
1596 udp->hash_mask = HASHTBLSZ - 1;
1597
1598 for (i = 0; i < HASHTBLSZ; i++, htp++) {
1599 htp->hash_lock.mutex_flag = LOCK_INITED;
1600 htp->hash_lock.mutex_magic = MUTEX_MAGIC;
1601 htp->hash_cond.cond_magic = COND_MAGIC;
1602 }
1603 hash_in_unlocked(self, TIDHASH(self->ul_lwpid, udp), udp);
1604
1605 /*
1606 * Set up the SIGCANCEL handler for threads cancellation.
1607 */
1608 setup_cancelsig(SIGCANCEL);
1609
1610 /*
1611 * Arrange to do special things on exit --
1612 * - collect queue statistics from all remaining active threads.
1613 * - dump queue statistics to stderr if _THREAD_QUEUE_DUMP is set.
1614 * - grab assert_lock to ensure that assertion failures
1615 * and a core dump take precedence over _exit().
1616 * (Functions are called in the reverse order of their registration.)
1617 */
1618 (void) _atexit(grab_assert_lock);
1619 #if defined(THREAD_DEBUG)
1620 (void) _atexit(dump_queue_statistics);
1621 (void) _atexit(collect_queue_statistics);
1622 #endif
1623 }
1624
1625 /*
1626 * Used only by postfork1_child(), below.
1627 */
1628 static void
1629 mark_dead_and_buried(ulwp_t *ulwp)
1630 {
1631 ulwp->ul_dead = 1;
1632 ulwp->ul_lwpid = (lwpid_t)(-1);
1633 ulwp->ul_hash = NULL;
1634 ulwp->ul_ix = -1;
1635 ulwp->ul_schedctl = NULL;
1636 ulwp->ul_schedctl_called = NULL;
1637 }
1638
1639 /*
1640 * This is called from fork1() in the child.
1641 * Reset our data structures to reflect one lwp.
1642 */
1643 void
1644 postfork1_child()
1645 {
1646 ulwp_t *self = curthread;
1647 uberdata_t *udp = self->ul_uberdata;
1648 queue_head_t *qp;
1649 ulwp_t *next;
1650 ulwp_t *ulwp;
1651 int i;
1652
1653 /* daemon threads shouldn't call fork1(), but oh well... */
1654 self->ul_usropts &= ~THR_DAEMON;
1655 udp->nthreads = 1;
1656 udp->ndaemons = 0;
1657 udp->uberflags.uf_mt = 0;
1658 __libc_threaded = 0;
1659 for (i = 0; i < udp->hash_size; i++)
1660 udp->thr_hash_table[i].hash_bucket = NULL;
1661 self->ul_lwpid = _lwp_self();
1662 hash_in_unlocked(self, TIDHASH(self->ul_lwpid, udp), udp);
1663
1664 /*
1665 * Some thread in the parent might have been suspended
1666 * while holding udp->callout_lock or udp->ld_lock.
1667 * Reinitialize the child's copies.
1668 */
1669 (void) mutex_init(&udp->callout_lock,
1670 USYNC_THREAD | LOCK_RECURSIVE, NULL);
1671 (void) mutex_init(&udp->ld_lock,
1672 USYNC_THREAD | LOCK_RECURSIVE, NULL);
1673
1674 /* no one in the child is on a sleep queue; reinitialize */
1675 if ((qp = udp->queue_head) != NULL) {
1676 (void) memset(qp, 0, 2 * QHASHSIZE * sizeof (queue_head_t));
1677 for (i = 0; i < 2 * QHASHSIZE; qp++, i++) {
1678 qp->qh_type = (i < QHASHSIZE)? MX : CV;
1679 qp->qh_lock.mutex_flag = LOCK_INITED;
1680 qp->qh_lock.mutex_magic = MUTEX_MAGIC;
1681 qp->qh_hlist = &qp->qh_def_root;
1682 #if defined(THREAD_DEBUG)
1683 qp->qh_hlen = 1;
1684 qp->qh_hmax = 1;
1685 #endif
1686 }
1687 }
1688
1689 /*
1690 * Do post-fork1 processing for subsystems that need it.
1691 * We need to do this before unmapping all of the abandoned
1692 * threads' stacks, below(), because the post-fork1 actions
1693 * might require access to those stacks.
1694 */
1695 postfork1_child_sigev_aio();
1696 postfork1_child_sigev_mq();
1697 postfork1_child_sigev_timer();
1698 postfork1_child_aio();
1699 /*
1700 * The above subsystems use thread pools, so this action
1701 * must be performed after those actions.
1702 */
1703 postfork1_child_tpool();
1704
1705 /*
1706 * All lwps except ourself are gone. Mark them so.
1707 * First mark all of the lwps that have already been freed.
1708 * Then mark and free all of the active lwps except ourself.
1709 * Since we are single-threaded, no locks are required here.
1710 */
1711 for (ulwp = udp->lwp_stacks; ulwp != NULL; ulwp = ulwp->ul_next)
1712 mark_dead_and_buried(ulwp);
1713 for (ulwp = udp->ulwp_freelist; ulwp != NULL; ulwp = ulwp->ul_next)
1714 mark_dead_and_buried(ulwp);
1715 for (ulwp = self->ul_forw; ulwp != self; ulwp = next) {
1716 next = ulwp->ul_forw;
1717 ulwp->ul_forw = ulwp->ul_back = NULL;
1718 mark_dead_and_buried(ulwp);
1719 tsd_free(ulwp);
1720 tls_free(ulwp);
1721 rwl_free(ulwp);
1722 heldlock_free(ulwp);
1723 ulwp_free(ulwp);
1724 }
1725 self->ul_forw = self->ul_back = udp->all_lwps = self;
1726 if (self != udp->ulwp_one)
1727 mark_dead_and_buried(udp->ulwp_one);
1728 if ((ulwp = udp->all_zombies) != NULL) {
1729 ASSERT(udp->nzombies != 0);
1730 do {
1731 next = ulwp->ul_forw;
1732 ulwp->ul_forw = ulwp->ul_back = NULL;
1733 mark_dead_and_buried(ulwp);
1734 udp->nzombies--;
1735 if (ulwp->ul_replace) {
1736 ulwp->ul_next = NULL;
1737 if (udp->ulwp_replace_free == NULL) {
1738 udp->ulwp_replace_free =
1739 udp->ulwp_replace_last = ulwp;
1740 } else {
1741 udp->ulwp_replace_last->ul_next = ulwp;
1742 udp->ulwp_replace_last = ulwp;
1743 }
1744 }
1745 } while ((ulwp = next) != udp->all_zombies);
1746 ASSERT(udp->nzombies == 0);
1747 udp->all_zombies = NULL;
1748 udp->nzombies = 0;
1749 }
1750 trim_stack_cache(0);
1751 }
1752
1753 lwpid_t
1754 lwp_self(void)
1755 {
1756 return (curthread->ul_lwpid);
1757 }
1758
1759 #pragma weak _ti_thr_self = thr_self
1760 #pragma weak pthread_self = thr_self
1761 thread_t
1762 thr_self()
1763 {
1764 return (curthread->ul_lwpid);
1765 }
1766
1767 int
1768 thr_main()
1769 {
1770 ulwp_t *self = __curthread();
1771
1772 return ((self == NULL)? -1 : self->ul_main);
1773 }
1774
1775 int
1776 _thrp_cancelled(void)
1777 {
1778 return (curthread->ul_rval == PTHREAD_CANCELED);
1779 }
1780
1781 int
1782 _thrp_stksegment(ulwp_t *ulwp, stack_t *stk)
1783 {
1784 stk->ss_sp = (void *)ulwp->ul_stktop;
1785 stk->ss_size = ulwp->ul_stksiz;
1786 stk->ss_flags = 0;
1787 return (0);
1788 }
1789
1790 #pragma weak _thr_stksegment = thr_stksegment
1791 int
1792 thr_stksegment(stack_t *stk)
1793 {
1794 return (_thrp_stksegment(curthread, stk));
1795 }
1796
1797 void
1798 force_continue(ulwp_t *ulwp)
1799 {
1800 #if defined(THREAD_DEBUG)
1801 ulwp_t *self = curthread;
1802 uberdata_t *udp = self->ul_uberdata;
1803 #endif
1804 int error;
1805 timespec_t ts;
1806
1807 ASSERT(MUTEX_OWNED(&udp->fork_lock, self));
1808 ASSERT(MUTEX_OWNED(ulwp_mutex(ulwp, udp), self));
1809
1810 for (;;) {
1811 error = _lwp_continue(ulwp->ul_lwpid);
1812 if (error != 0 && error != EINTR)
1813 break;
1814 error = 0;
1815 if (ulwp->ul_stopping) { /* it is stopping itsself */
1816 ts.tv_sec = 0; /* give it a chance to run */
1817 ts.tv_nsec = 100000; /* 100 usecs or clock tick */
1818 (void) __nanosleep(&ts, NULL);
1819 }
1820 if (!ulwp->ul_stopping) /* it is running now */
1821 break; /* so we are done */
1822 /*
1823 * It is marked as being in the process of stopping
1824 * itself. Loop around and continue it again.
1825 * It may not have been stopped the first time.
1826 */
1827 }
1828 }
1829
1830 /*
1831 * Suspend an lwp with lwp_suspend(), then move it to a safe point,
1832 * that is, to a point where ul_critical and ul_rtld are both zero.
1833 * On return, the ulwp_lock() is dropped as with ulwp_unlock().
1834 * If 'link_dropped' is non-NULL, then 'link_lock' is held on entry.
1835 * If we have to drop link_lock, we store 1 through link_dropped.
1836 * If the lwp exits before it can be suspended, we return ESRCH.
1837 */
1838 int
1839 safe_suspend(ulwp_t *ulwp, uchar_t whystopped, int *link_dropped)
1840 {
1841 ulwp_t *self = curthread;
1842 uberdata_t *udp = self->ul_uberdata;
1843 cond_t *cvp = ulwp_condvar(ulwp, udp);
1844 mutex_t *mp = ulwp_mutex(ulwp, udp);
1845 thread_t tid = ulwp->ul_lwpid;
1846 int ix = ulwp->ul_ix;
1847 int error = 0;
1848
1849 ASSERT(whystopped == TSTP_REGULAR ||
1850 whystopped == TSTP_MUTATOR ||
1851 whystopped == TSTP_FORK);
1852 ASSERT(ulwp != self);
1853 ASSERT(!ulwp->ul_stop);
1854 ASSERT(MUTEX_OWNED(&udp->fork_lock, self));
1855 ASSERT(MUTEX_OWNED(mp, self));
1856
1857 if (link_dropped != NULL)
1858 *link_dropped = 0;
1859
1860 /*
1861 * We must grab the target's spin lock before suspending it.
1862 * See the comments below and in _thrp_suspend() for why.
1863 */
1864 spin_lock_set(&ulwp->ul_spinlock);
1865 (void) ___lwp_suspend(tid);
1866 spin_lock_clear(&ulwp->ul_spinlock);
1867
1868 top:
1869 if ((ulwp->ul_critical == 0 && ulwp->ul_rtld == 0) ||
1870 ulwp->ul_stopping) {
1871 /* thread is already safe */
1872 ulwp->ul_stop |= whystopped;
1873 } else {
1874 /*
1875 * Setting ul_pleasestop causes the target thread to stop
1876 * itself in _thrp_suspend(), below, after we drop its lock.
1877 * We must continue the critical thread before dropping
1878 * link_lock because the critical thread may be holding
1879 * the queue lock for link_lock. This is delicate.
1880 */
1881 ulwp->ul_pleasestop |= whystopped;
1882 force_continue(ulwp);
1883 if (link_dropped != NULL) {
1884 *link_dropped = 1;
1885 lmutex_unlock(&udp->link_lock);
1886 /* be sure to drop link_lock only once */
1887 link_dropped = NULL;
1888 }
1889
1890 /*
1891 * The thread may disappear by calling thr_exit() so we
1892 * cannot rely on the ulwp pointer after dropping the lock.
1893 * Instead, we search the hash table to find it again.
1894 * When we return, we may find that the thread has been
1895 * continued by some other thread. The suspend/continue
1896 * interfaces are prone to such race conditions by design.
1897 */
1898 while (ulwp && !ulwp->ul_dead && !ulwp->ul_stop &&
1899 (ulwp->ul_pleasestop & whystopped)) {
1900 (void) __cond_wait(cvp, mp);
1901 for (ulwp = udp->thr_hash_table[ix].hash_bucket;
1902 ulwp != NULL; ulwp = ulwp->ul_hash) {
1903 if (ulwp->ul_lwpid == tid)
1904 break;
1905 }
1906 }
1907
1908 if (ulwp == NULL || ulwp->ul_dead)
1909 error = ESRCH;
1910 else {
1911 /*
1912 * Do another lwp_suspend() to make sure we don't
1913 * return until the target thread is fully stopped
1914 * in the kernel. Don't apply lwp_suspend() until
1915 * we know that the target is not holding any
1916 * queue locks, that is, that it has completed
1917 * ulwp_unlock(self) and has, or at least is
1918 * about to, call lwp_suspend() on itself. We do
1919 * this by grabbing the target's spin lock.
1920 */
1921 ASSERT(ulwp->ul_lwpid == tid);
1922 spin_lock_set(&ulwp->ul_spinlock);
1923 (void) ___lwp_suspend(tid);
1924 spin_lock_clear(&ulwp->ul_spinlock);
1925 /*
1926 * If some other thread did a thr_continue()
1927 * on the target thread we have to start over.
1928 */
1929 if (!ulwp->ul_stopping || !(ulwp->ul_stop & whystopped))
1930 goto top;
1931 }
1932 }
1933
1934 (void) cond_broadcast(cvp);
1935 lmutex_unlock(mp);
1936 return (error);
1937 }
1938
1939 int
1940 _thrp_suspend(thread_t tid, uchar_t whystopped)
1941 {
1942 ulwp_t *self = curthread;
1943 uberdata_t *udp = self->ul_uberdata;
1944 ulwp_t *ulwp;
1945 int error = 0;
1946
1947 ASSERT((whystopped & (TSTP_REGULAR|TSTP_MUTATOR|TSTP_FORK)) != 0);
1948 ASSERT((whystopped & ~(TSTP_REGULAR|TSTP_MUTATOR|TSTP_FORK)) == 0);
1949
1950 /*
1951 * We can't suspend anyone except ourself while
1952 * some other thread is performing a fork.
1953 * This also allows only one suspension at a time.
1954 */
1955 if (tid != self->ul_lwpid)
1956 fork_lock_enter();
1957
1958 if ((ulwp = find_lwp(tid)) == NULL)
1959 error = ESRCH;
1960 else if (whystopped == TSTP_MUTATOR && !ulwp->ul_mutator) {
1961 ulwp_unlock(ulwp, udp);
1962 error = EINVAL;
1963 } else if (ulwp->ul_stop) { /* already stopped */
1964 ulwp->ul_stop |= whystopped;
1965 ulwp_broadcast(ulwp);
1966 ulwp_unlock(ulwp, udp);
1967 } else if (ulwp != self) {
1968 /*
1969 * After suspending the other thread, move it out of a
1970 * critical section and deal with the schedctl mappings.
1971 * safe_suspend() suspends the other thread, calls
1972 * ulwp_broadcast(ulwp) and drops the ulwp lock.
1973 */
1974 error = safe_suspend(ulwp, whystopped, NULL);
1975 } else {
1976 int schedctl_after_fork = 0;
1977
1978 /*
1979 * We are suspending ourself. We must not take a signal
1980 * until we return from lwp_suspend() and clear ul_stopping.
1981 * This is to guard against siglongjmp().
1982 */
1983 enter_critical(self);
1984 self->ul_sp = stkptr();
1985 _flush_windows(); /* sparc */
1986 self->ul_pleasestop = 0;
1987 self->ul_stop |= whystopped;
1988 /*
1989 * Grab our spin lock before dropping ulwp_mutex(self).
1990 * This prevents the suspending thread from applying
1991 * lwp_suspend() to us before we emerge from
1992 * lmutex_unlock(mp) and have dropped mp's queue lock.
1993 */
1994 spin_lock_set(&self->ul_spinlock);
1995 self->ul_stopping = 1;
1996 ulwp_broadcast(self);
1997 ulwp_unlock(self, udp);
1998 /*
1999 * From this point until we return from lwp_suspend(),
2000 * we must not call any function that might invoke the
2001 * dynamic linker, that is, we can only call functions
2002 * private to the library.
2003 *
2004 * Also, this is a nasty race condition for a process
2005 * that is undergoing a forkall() operation:
2006 * Once we clear our spinlock (below), we are vulnerable
2007 * to being suspended by the forkall() thread before
2008 * we manage to suspend ourself in ___lwp_suspend().
2009 * See safe_suspend() and force_continue().
2010 *
2011 * To avoid a SIGSEGV due to the disappearance
2012 * of the schedctl mappings in the child process,
2013 * which can happen in spin_lock_clear() if we
2014 * are suspended while we are in the middle of
2015 * its call to preempt(), we preemptively clear
2016 * our own schedctl pointer before dropping our
2017 * spinlock. We reinstate it, in both the parent
2018 * and (if this really is a forkall()) the child.
2019 */
2020 if (whystopped & TSTP_FORK) {
2021 schedctl_after_fork = 1;
2022 self->ul_schedctl = NULL;
2023 self->ul_schedctl_called = &udp->uberflags;
2024 }
2025 spin_lock_clear(&self->ul_spinlock);
2026 (void) ___lwp_suspend(tid);
2027 /*
2028 * Somebody else continued us.
2029 * We can't grab ulwp_lock(self)
2030 * until after clearing ul_stopping.
2031 * force_continue() relies on this.
2032 */
2033 self->ul_stopping = 0;
2034 self->ul_sp = 0;
2035 if (schedctl_after_fork) {
2036 self->ul_schedctl_called = NULL;
2037 self->ul_schedctl = NULL;
2038 (void) setup_schedctl();
2039 }
2040 ulwp_lock(self, udp);
2041 ulwp_broadcast(self);
2042 ulwp_unlock(self, udp);
2043 exit_critical(self);
2044 }
2045
2046 if (tid != self->ul_lwpid)
2047 fork_lock_exit();
2048
2049 return (error);
2050 }
2051
2052 /*
2053 * Suspend all lwps other than ourself in preparation for fork.
2054 */
2055 void
2056 suspend_fork()
2057 {
2058 ulwp_t *self = curthread;
2059 uberdata_t *udp = self->ul_uberdata;
2060 ulwp_t *ulwp;
2061 int link_dropped;
2062
2063 ASSERT(MUTEX_OWNED(&udp->fork_lock, self));
2064 top:
2065 lmutex_lock(&udp->link_lock);
2066
2067 for (ulwp = self->ul_forw; ulwp != self; ulwp = ulwp->ul_forw) {
2068 ulwp_lock(ulwp, udp);
2069 if (ulwp->ul_stop) { /* already stopped */
2070 ulwp->ul_stop |= TSTP_FORK;
2071 ulwp_broadcast(ulwp);
2072 ulwp_unlock(ulwp, udp);
2073 } else {
2074 /*
2075 * Move the stopped lwp out of a critical section.
2076 */
2077 if (safe_suspend(ulwp, TSTP_FORK, &link_dropped) ||
2078 link_dropped)
2079 goto top;
2080 }
2081 }
2082
2083 lmutex_unlock(&udp->link_lock);
2084 }
2085
2086 void
2087 continue_fork(int child)
2088 {
2089 ulwp_t *self = curthread;
2090 uberdata_t *udp = self->ul_uberdata;
2091 ulwp_t *ulwp;
2092
2093 ASSERT(MUTEX_OWNED(&udp->fork_lock, self));
2094
2095 /*
2096 * Clear the schedctl pointers in the child of forkall().
2097 */
2098 if (child) {
2099 for (ulwp = self->ul_forw; ulwp != self; ulwp = ulwp->ul_forw) {
2100 ulwp->ul_schedctl_called =
2101 ulwp->ul_dead? &udp->uberflags : NULL;
2102 ulwp->ul_schedctl = NULL;
2103 }
2104 }
2105
2106 /*
2107 * Set all lwps that were stopped for fork() running again.
2108 */
2109 lmutex_lock(&udp->link_lock);
2110 for (ulwp = self->ul_forw; ulwp != self; ulwp = ulwp->ul_forw) {
2111 mutex_t *mp = ulwp_mutex(ulwp, udp);
2112 lmutex_lock(mp);
2113 ASSERT(ulwp->ul_stop & TSTP_FORK);
2114 ulwp->ul_stop &= ~TSTP_FORK;
2115 ulwp_broadcast(ulwp);
2116 if (!ulwp->ul_stop)
2117 force_continue(ulwp);
2118 lmutex_unlock(mp);
2119 }
2120 lmutex_unlock(&udp->link_lock);
2121 }
2122
2123 int
2124 _thrp_continue(thread_t tid, uchar_t whystopped)
2125 {
2126 uberdata_t *udp = curthread->ul_uberdata;
2127 ulwp_t *ulwp;
2128 mutex_t *mp;
2129 int error = 0;
2130
2131 ASSERT(whystopped == TSTP_REGULAR ||
2132 whystopped == TSTP_MUTATOR);
2133
2134 /*
2135 * We single-thread the entire thread suspend/continue mechanism.
2136 */
2137 fork_lock_enter();
2138
2139 if ((ulwp = find_lwp(tid)) == NULL) {
2140 fork_lock_exit();
2141 return (ESRCH);
2142 }
2143
2144 mp = ulwp_mutex(ulwp, udp);
2145 if ((whystopped == TSTP_MUTATOR && !ulwp->ul_mutator)) {
2146 error = EINVAL;
2147 } else if (ulwp->ul_stop & whystopped) {
2148 ulwp->ul_stop &= ~whystopped;
2149 ulwp_broadcast(ulwp);
2150 if (!ulwp->ul_stop) {
2151 if (whystopped == TSTP_REGULAR && ulwp->ul_created) {
2152 ulwp->ul_sp = 0;
2153 ulwp->ul_created = 0;
2154 }
2155 force_continue(ulwp);
2156 }
2157 }
2158 lmutex_unlock(mp);
2159
2160 fork_lock_exit();
2161 return (error);
2162 }
2163
2164 int
2165 thr_suspend(thread_t tid)
2166 {
2167 return (_thrp_suspend(tid, TSTP_REGULAR));
2168 }
2169
2170 int
2171 thr_continue(thread_t tid)
2172 {
2173 return (_thrp_continue(tid, TSTP_REGULAR));
2174 }
2175
2176 void
2177 thr_yield()
2178 {
2179 yield();
2180 }
2181
2182 #pragma weak pthread_kill = thr_kill
2183 #pragma weak _thr_kill = thr_kill
2184 int
2185 thr_kill(thread_t tid, int sig)
2186 {
2187 if (sig == SIGCANCEL)
2188 return (EINVAL);
2189 return (_lwp_kill(tid, sig));
2190 }
2191
2192 /*
2193 * Exit a critical section, take deferred actions if necessary.
2194 * Called from exit_critical() and from sigon().
2195 */
2196 void
2197 do_exit_critical()
2198 {
2199 ulwp_t *self = curthread;
2200 int sig;
2201
2202 ASSERT(self->ul_critical == 0);
2203
2204 /*
2205 * Don't suspend ourself or take a deferred signal while dying
2206 * or while executing inside the dynamic linker (ld.so.1).
2207 */
2208 if (self->ul_dead || self->ul_rtld)
2209 return;
2210
2211 while (self->ul_pleasestop ||
2212 (self->ul_cursig != 0 && self->ul_sigdefer == 0)) {
2213 /*
2214 * Avoid a recursive call to exit_critical() in _thrp_suspend()
2215 * by keeping self->ul_critical == 1 here.
2216 */
2217 self->ul_critical++;
2218 while (self->ul_pleasestop) {
2219 /*
2220 * Guard against suspending ourself while on a sleep
2221 * queue. See the comments in call_user_handler().
2222 */
2223 unsleep_self();
2224 set_parking_flag(self, 0);
2225 (void) _thrp_suspend(self->ul_lwpid,
2226 self->ul_pleasestop);
2227 }
2228 self->ul_critical--;
2229
2230 if ((sig = self->ul_cursig) != 0 && self->ul_sigdefer == 0) {
2231 /*
2232 * Clear ul_cursig before proceeding.
2233 * This protects us from the dynamic linker's
2234 * calls to bind_guard()/bind_clear() in the
2235 * event that it is invoked to resolve a symbol
2236 * like take_deferred_signal() below.
2237 */
2238 self->ul_cursig = 0;
2239 take_deferred_signal(sig);
2240 ASSERT(self->ul_cursig == 0);
2241 }
2242 }
2243 ASSERT(self->ul_critical == 0);
2244 }
2245
2246 /*
2247 * _ti_bind_guard() and _ti_bind_clear() are called by the dynamic linker
2248 * (ld.so.1) when it has do do something, like resolve a symbol to be called
2249 * by the application or one of its libraries. _ti_bind_guard() is called
2250 * on entry to ld.so.1, _ti_bind_clear() on exit from ld.so.1 back to the
2251 * application. The dynamic linker gets special dispensation from libc to
2252 * run in a critical region (all signals deferred and no thread suspension
2253 * or forking allowed), and to be immune from cancellation for the duration.
2254 */
2255 int
2256 _ti_bind_guard(int flags)
2257 {
2258 ulwp_t *self = curthread;
2259 uberdata_t *udp = self->ul_uberdata;
2260 int bindflag = (flags & THR_FLG_RTLD);
2261
2262 if ((self->ul_bindflags & bindflag) == bindflag)
2263 return (0);
2264 self->ul_bindflags |= bindflag;
2265 if ((flags & (THR_FLG_NOLOCK | THR_FLG_REENTER)) == THR_FLG_NOLOCK) {
2266 sigoff(self); /* see no signals while holding ld_lock */
2267 self->ul_rtld++; /* don't suspend while in ld.so.1 */
2268 (void) mutex_lock(&udp->ld_lock);
2269 }
2270 enter_critical(self);
2271 self->ul_save_state = self->ul_cancel_disabled;
2272 self->ul_cancel_disabled = 1;
2273 set_cancel_pending_flag(self, 0);
2274 return (1);
2275 }
2276
2277 int
2278 _ti_bind_clear(int flags)
2279 {
2280 ulwp_t *self = curthread;
2281 uberdata_t *udp = self->ul_uberdata;
2282 int bindflag = (flags & THR_FLG_RTLD);
2283
2284 if ((self->ul_bindflags & bindflag) == 0)
2285 return (self->ul_bindflags);
2286 self->ul_bindflags &= ~bindflag;
2287 self->ul_cancel_disabled = self->ul_save_state;
2288 set_cancel_pending_flag(self, 0);
2289 exit_critical(self);
2290 if ((flags & (THR_FLG_NOLOCK | THR_FLG_REENTER)) == THR_FLG_NOLOCK) {
2291 if (MUTEX_OWNED(&udp->ld_lock, self)) {
2292 (void) mutex_unlock(&udp->ld_lock);
2293 self->ul_rtld--;
2294 sigon(self); /* reenable signals */
2295 }
2296 }
2297 return (self->ul_bindflags);
2298 }
2299
2300 /*
2301 * Tell the dynamic linker (ld.so.1) whether or not it was entered from
2302 * a critical region in libc. Return zero if not, else return non-zero.
2303 */
2304 int
2305 _ti_critical(void)
2306 {
2307 ulwp_t *self = curthread;
2308 int level = self->ul_critical;
2309
2310 if ((self->ul_bindflags & THR_FLG_RTLD) == 0 || level == 0)
2311 return (level); /* ld.so.1 hasn't (yet) called enter() */
2312 return (level - 1);
2313 }
2314
2315 /*
2316 * sigoff() and sigon() enable cond_wait() to behave (optionally) like
2317 * it does in the old libthread (see the comments in cond_wait_queue()).
2318 * Also, signals are deferred at thread startup until TLS constructors
2319 * have all been called, at which time _thrp_setup() calls sigon().
2320 *
2321 * _sigoff() and _sigon() are external consolidation-private interfaces to
2322 * sigoff() and sigon(), respectively, in libc. These are used in libnsl.
2323 * Also, _sigoff() and _sigon() are called from dbx's run-time checking
2324 * (librtc.so) to defer signals during its critical sections (not to be
2325 * confused with libc critical sections [see exit_critical() above]).
2326 */
2327 void
2328 _sigoff(void)
2329 {
2330 ulwp_t *self = curthread;
2331
2332 sigoff(self);
2333 }
2334
2335 void
2336 _sigon(void)
2337 {
2338 ulwp_t *self = curthread;
2339
2340 ASSERT(self->ul_sigdefer > 0);
2341 sigon(self);
2342 }
2343
2344 int
2345 thr_getconcurrency()
2346 {
2347 return (thr_concurrency);
2348 }
2349
2350 int
2351 pthread_getconcurrency()
2352 {
2353 return (pthread_concurrency);
2354 }
2355
2356 int
2357 thr_setconcurrency(int new_level)
2358 {
2359 uberdata_t *udp = curthread->ul_uberdata;
2360
2361 if (new_level < 0)
2362 return (EINVAL);
2363 if (new_level > 65536) /* 65536 is totally arbitrary */
2364 return (EAGAIN);
2365 lmutex_lock(&udp->link_lock);
2366 if (new_level > thr_concurrency)
2367 thr_concurrency = new_level;
2368 lmutex_unlock(&udp->link_lock);
2369 return (0);
2370 }
2371
2372 int
2373 pthread_setconcurrency(int new_level)
2374 {
2375 if (new_level < 0)
2376 return (EINVAL);
2377 if (new_level > 65536) /* 65536 is totally arbitrary */
2378 return (EAGAIN);
2379 pthread_concurrency = new_level;
2380 return (0);
2381 }
2382
2383 size_t
2384 thr_min_stack(void)
2385 {
2386 return (MINSTACK);
2387 }
2388
2389 int
2390 __nthreads(void)
2391 {
2392 return (curthread->ul_uberdata->nthreads);
2393 }
2394
2395 /*
2396 * XXX
2397 * The remainder of this file implements the private interfaces to java for
2398 * garbage collection. It is no longer used, at least by java 1.2.
2399 * It can all go away once all old JVMs have disappeared.
2400 */
2401
2402 int suspendingallmutators; /* when non-zero, suspending all mutators. */
2403 int suspendedallmutators; /* when non-zero, all mutators suspended. */
2404 int mutatorsbarrier; /* when non-zero, mutators barrier imposed. */
2405 mutex_t mutatorslock = DEFAULTMUTEX; /* used to enforce mutators barrier. */
2406 cond_t mutatorscv = DEFAULTCV; /* where non-mutators sleep. */
2407
2408 /*
2409 * Get the available register state for the target thread.
2410 * Return non-volatile registers: TRS_NONVOLATILE
2411 */
2412 #pragma weak _thr_getstate = thr_getstate
2413 int
2414 thr_getstate(thread_t tid, int *flag, lwpid_t *lwp, stack_t *ss, gregset_t rs)
2415 {
2416 ulwp_t *self = curthread;
2417 uberdata_t *udp = self->ul_uberdata;
2418 ulwp_t **ulwpp;
2419 ulwp_t *ulwp;
2420 int error = 0;
2421 int trs_flag = TRS_LWPID;
2422
2423 if (tid == 0 || self->ul_lwpid == tid) {
2424 ulwp = self;
2425 ulwp_lock(ulwp, udp);
2426 } else if ((ulwpp = find_lwpp(tid)) != NULL) {
2427 ulwp = *ulwpp;
2428 } else {
2429 if (flag)
2430 *flag = TRS_INVALID;
2431 return (ESRCH);
2432 }
2433
2434 if (ulwp->ul_dead) {
2435 trs_flag = TRS_INVALID;
2436 } else if (!ulwp->ul_stop && !suspendedallmutators) {
2437 error = EINVAL;
2438 trs_flag = TRS_INVALID;
2439 } else if (ulwp->ul_stop) {
2440 trs_flag = TRS_NONVOLATILE;
2441 getgregs(ulwp, rs);
2442 }
2443
2444 if (flag)
2445 *flag = trs_flag;
2446 if (lwp)
2447 *lwp = tid;
2448 if (ss != NULL)
2449 (void) _thrp_stksegment(ulwp, ss);
2450
2451 ulwp_unlock(ulwp, udp);
2452 return (error);
2453 }
2454
2455 /*
2456 * Set the appropriate register state for the target thread.
2457 * This is not used by java. It exists solely for the MSTC test suite.
2458 */
2459 #pragma weak _thr_setstate = thr_setstate
2460 int
2461 thr_setstate(thread_t tid, int flag, gregset_t rs)
2462 {
2463 uberdata_t *udp = curthread->ul_uberdata;
2464 ulwp_t *ulwp;
2465 int error = 0;
2466
2467 if ((ulwp = find_lwp(tid)) == NULL)
2468 return (ESRCH);
2469
2470 if (!ulwp->ul_stop && !suspendedallmutators)
2471 error = EINVAL;
2472 else if (rs != NULL) {
2473 switch (flag) {
2474 case TRS_NONVOLATILE:
2475 /* do /proc stuff here? */
2476 if (ulwp->ul_stop)
2477 setgregs(ulwp, rs);
2478 else
2479 error = EINVAL;
2480 break;
2481 case TRS_LWPID: /* do /proc stuff here? */
2482 default:
2483 error = EINVAL;
2484 break;
2485 }
2486 }
2487
2488 ulwp_unlock(ulwp, udp);
2489 return (error);
2490 }
2491
2492 int
2493 getlwpstatus(thread_t tid, struct lwpstatus *sp)
2494 {
2495 extern ssize_t __pread(int, void *, size_t, off_t);
2496 char buf[100];
2497 int fd;
2498
2499 /* "/proc/self/lwp/%u/lwpstatus" w/o stdio */
2500 (void) strcpy(buf, "/proc/self/lwp/");
2501 ultos((uint64_t)tid, 10, buf + strlen(buf));
2502 (void) strcat(buf, "/lwpstatus");
2503 if ((fd = __open(buf, O_RDONLY, 0)) >= 0) {
2504 while (__pread(fd, sp, sizeof (*sp), 0) == sizeof (*sp)) {
2505 if (sp->pr_flags & PR_STOPPED) {
2506 (void) __close(fd);
2507 return (0);
2508 }
2509 yield(); /* give it a chance to stop */
2510 }
2511 (void) __close(fd);
2512 }
2513 return (-1);
2514 }
2515
2516 int
2517 putlwpregs(thread_t tid, prgregset_t prp)
2518 {
2519 extern ssize_t __writev(int, const struct iovec *, int);
2520 char buf[100];
2521 int fd;
2522 long dstop_sreg[2];
2523 long run_null[2];
2524 iovec_t iov[3];
2525
2526 /* "/proc/self/lwp/%u/lwpctl" w/o stdio */
2527 (void) strcpy(buf, "/proc/self/lwp/");
2528 ultos((uint64_t)tid, 10, buf + strlen(buf));
2529 (void) strcat(buf, "/lwpctl");
2530 if ((fd = __open(buf, O_WRONLY, 0)) >= 0) {
2531 dstop_sreg[0] = PCDSTOP; /* direct it to stop */
2532 dstop_sreg[1] = PCSREG; /* set the registers */
2533 iov[0].iov_base = (caddr_t)dstop_sreg;
2534 iov[0].iov_len = sizeof (dstop_sreg);
2535 iov[1].iov_base = (caddr_t)prp; /* from the register set */
2536 iov[1].iov_len = sizeof (prgregset_t);
2537 run_null[0] = PCRUN; /* make it runnable again */
2538 run_null[1] = 0;
2539 iov[2].iov_base = (caddr_t)run_null;
2540 iov[2].iov_len = sizeof (run_null);
2541 if (__writev(fd, iov, 3) >= 0) {
2542 (void) __close(fd);
2543 return (0);
2544 }
2545 (void) __close(fd);
2546 }
2547 return (-1);
2548 }
2549
2550 static ulong_t
2551 gettsp_slow(thread_t tid)
2552 {
2553 char buf[100];
2554 struct lwpstatus status;
2555
2556 if (getlwpstatus(tid, &status) != 0) {
2557 /* "__gettsp(%u): can't read lwpstatus" w/o stdio */
2558 (void) strcpy(buf, "__gettsp(");
2559 ultos((uint64_t)tid, 10, buf + strlen(buf));
2560 (void) strcat(buf, "): can't read lwpstatus");
2561 thr_panic(buf);
2562 }
2563 return (status.pr_reg[R_SP]);
2564 }
2565
2566 ulong_t
2567 __gettsp(thread_t tid)
2568 {
2569 uberdata_t *udp = curthread->ul_uberdata;
2570 ulwp_t *ulwp;
2571 ulong_t result;
2572
2573 if ((ulwp = find_lwp(tid)) == NULL)
2574 return (0);
2575
2576 if (ulwp->ul_stop && (result = ulwp->ul_sp) != 0) {
2577 ulwp_unlock(ulwp, udp);
2578 return (result);
2579 }
2580
2581 result = gettsp_slow(tid);
2582 ulwp_unlock(ulwp, udp);
2583 return (result);
2584 }
2585
2586 /*
2587 * This tells java stack walkers how to find the ucontext
2588 * structure passed to signal handlers.
2589 */
2590 #pragma weak _thr_sighndlrinfo = thr_sighndlrinfo
2591 void
2592 thr_sighndlrinfo(void (**func)(), int *funcsize)
2593 {
2594 *func = &__sighndlr;
2595 *funcsize = (char *)&__sighndlrend - (char *)&__sighndlr;
2596 }
2597
2598 /*
2599 * Mark a thread a mutator or reset a mutator to being a default,
2600 * non-mutator thread.
2601 */
2602 #pragma weak _thr_setmutator = thr_setmutator
2603 int
2604 thr_setmutator(thread_t tid, int enabled)
2605 {
2606 ulwp_t *self = curthread;
2607 uberdata_t *udp = self->ul_uberdata;
2608 ulwp_t *ulwp;
2609 int error;
2610 int cancel_state;
2611
2612 enabled = enabled? 1 : 0;
2613 top:
2614 if (tid == 0) {
2615 ulwp = self;
2616 ulwp_lock(ulwp, udp);
2617 } else if ((ulwp = find_lwp(tid)) == NULL) {
2618 return (ESRCH);
2619 }
2620
2621 /*
2622 * The target thread should be the caller itself or a suspended thread.
2623 * This prevents the target from also changing its ul_mutator field.
2624 */
2625 error = 0;
2626 if (ulwp != self && !ulwp->ul_stop && enabled)
2627 error = EINVAL;
2628 else if (ulwp->ul_mutator != enabled) {
2629 lmutex_lock(&mutatorslock);
2630 if (mutatorsbarrier) {
2631 ulwp_unlock(ulwp, udp);
2632 (void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE,
2633 &cancel_state);
2634 while (mutatorsbarrier)
2635 (void) cond_wait(&mutatorscv, &mutatorslock);
2636 (void) pthread_setcancelstate(cancel_state, NULL);
2637 lmutex_unlock(&mutatorslock);
2638 goto top;
2639 }
2640 ulwp->ul_mutator = enabled;
2641 lmutex_unlock(&mutatorslock);
2642 }
2643
2644 ulwp_unlock(ulwp, udp);
2645 return (error);
2646 }
2647
2648 /*
2649 * Establish a barrier against new mutators. Any non-mutator trying
2650 * to become a mutator is suspended until the barrier is removed.
2651 */
2652 #pragma weak _thr_mutators_barrier = thr_mutators_barrier
2653 void
2654 thr_mutators_barrier(int enabled)
2655 {
2656 int oldvalue;
2657 int cancel_state;
2658
2659 lmutex_lock(&mutatorslock);
2660
2661 /*
2662 * Wait if trying to set the barrier while it is already set.
2663 */
2664 (void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cancel_state);
2665 while (mutatorsbarrier && enabled)
2666 (void) cond_wait(&mutatorscv, &mutatorslock);
2667 (void) pthread_setcancelstate(cancel_state, NULL);
2668
2669 oldvalue = mutatorsbarrier;
2670 mutatorsbarrier = enabled;
2671 /*
2672 * Wakeup any blocked non-mutators when barrier is removed.
2673 */
2674 if (oldvalue && !enabled)
2675 (void) cond_broadcast(&mutatorscv);
2676 lmutex_unlock(&mutatorslock);
2677 }
2678
2679 /*
2680 * Suspend the set of all mutators except for the caller. The list
2681 * of actively running threads is searched and only the mutators
2682 * in this list are suspended. Actively running non-mutators remain
2683 * running. Any other thread is suspended.
2684 */
2685 #pragma weak _thr_suspend_allmutators = thr_suspend_allmutators
2686 int
2687 thr_suspend_allmutators(void)
2688 {
2689 ulwp_t *self = curthread;
2690 uberdata_t *udp = self->ul_uberdata;
2691 ulwp_t *ulwp;
2692 int link_dropped;
2693
2694 /*
2695 * We single-thread the entire thread suspend/continue mechanism.
2696 */
2697 fork_lock_enter();
2698
2699 top:
2700 lmutex_lock(&udp->link_lock);
2701
2702 if (suspendingallmutators || suspendedallmutators) {
2703 lmutex_unlock(&udp->link_lock);
2704 fork_lock_exit();
2705 return (EINVAL);
2706 }
2707 suspendingallmutators = 1;
2708
2709 for (ulwp = self->ul_forw; ulwp != self; ulwp = ulwp->ul_forw) {
2710 ulwp_lock(ulwp, udp);
2711 if (!ulwp->ul_mutator) {
2712 ulwp_unlock(ulwp, udp);
2713 } else if (ulwp->ul_stop) { /* already stopped */
2714 ulwp->ul_stop |= TSTP_MUTATOR;
2715 ulwp_broadcast(ulwp);
2716 ulwp_unlock(ulwp, udp);
2717 } else {
2718 /*
2719 * Move the stopped lwp out of a critical section.
2720 */
2721 if (safe_suspend(ulwp, TSTP_MUTATOR, &link_dropped) ||
2722 link_dropped) {
2723 suspendingallmutators = 0;
2724 goto top;
2725 }
2726 }
2727 }
2728
2729 suspendedallmutators = 1;
2730 suspendingallmutators = 0;
2731 lmutex_unlock(&udp->link_lock);
2732 fork_lock_exit();
2733 return (0);
2734 }
2735
2736 /*
2737 * Suspend the target mutator. The caller is permitted to suspend
2738 * itself. If a mutator barrier is enabled, the caller will suspend
2739 * itself as though it had been suspended by thr_suspend_allmutators().
2740 * When the barrier is removed, this thread will be resumed. Any
2741 * suspended mutator, whether suspended by thr_suspend_mutator(), or by
2742 * thr_suspend_allmutators(), can be resumed by thr_continue_mutator().
2743 */
2744 #pragma weak _thr_suspend_mutator = thr_suspend_mutator
2745 int
2746 thr_suspend_mutator(thread_t tid)
2747 {
2748 if (tid == 0)
2749 tid = curthread->ul_lwpid;
2750 return (_thrp_suspend(tid, TSTP_MUTATOR));
2751 }
2752
2753 /*
2754 * Resume the set of all suspended mutators.
2755 */
2756 #pragma weak _thr_continue_allmutators = thr_continue_allmutators
2757 int
2758 thr_continue_allmutators()
2759 {
2760 ulwp_t *self = curthread;
2761 uberdata_t *udp = self->ul_uberdata;
2762 ulwp_t *ulwp;
2763
2764 /*
2765 * We single-thread the entire thread suspend/continue mechanism.
2766 */
2767 fork_lock_enter();
2768
2769 lmutex_lock(&udp->link_lock);
2770 if (!suspendedallmutators) {
2771 lmutex_unlock(&udp->link_lock);
2772 fork_lock_exit();
2773 return (EINVAL);
2774 }
2775 suspendedallmutators = 0;
2776
2777 for (ulwp = self->ul_forw; ulwp != self; ulwp = ulwp->ul_forw) {
2778 mutex_t *mp = ulwp_mutex(ulwp, udp);
2779 lmutex_lock(mp);
2780 if (ulwp->ul_stop & TSTP_MUTATOR) {
2781 ulwp->ul_stop &= ~TSTP_MUTATOR;
2782 ulwp_broadcast(ulwp);
2783 if (!ulwp->ul_stop)
2784 force_continue(ulwp);
2785 }
2786 lmutex_unlock(mp);
2787 }
2788
2789 lmutex_unlock(&udp->link_lock);
2790 fork_lock_exit();
2791 return (0);
2792 }
2793
2794 /*
2795 * Resume a suspended mutator.
2796 */
2797 #pragma weak _thr_continue_mutator = thr_continue_mutator
2798 int
2799 thr_continue_mutator(thread_t tid)
2800 {
2801 return (_thrp_continue(tid, TSTP_MUTATOR));
2802 }
2803
2804 #pragma weak _thr_wait_mutator = thr_wait_mutator
2805 int
2806 thr_wait_mutator(thread_t tid, int dontwait)
2807 {
2808 uberdata_t *udp = curthread->ul_uberdata;
2809 ulwp_t *ulwp;
2810 int cancel_state;
2811 int error = 0;
2812
2813 (void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cancel_state);
2814 top:
2815 if ((ulwp = find_lwp(tid)) == NULL) {
2816 (void) pthread_setcancelstate(cancel_state, NULL);
2817 return (ESRCH);
2818 }
2819
2820 if (!ulwp->ul_mutator)
2821 error = EINVAL;
2822 else if (dontwait) {
2823 if (!(ulwp->ul_stop & TSTP_MUTATOR))
2824 error = EWOULDBLOCK;
2825 } else if (!(ulwp->ul_stop & TSTP_MUTATOR)) {
2826 cond_t *cvp = ulwp_condvar(ulwp, udp);
2827 mutex_t *mp = ulwp_mutex(ulwp, udp);
2828
2829 (void) cond_wait(cvp, mp);
2830 (void) lmutex_unlock(mp);
2831 goto top;
2832 }
2833
2834 ulwp_unlock(ulwp, udp);
2835 (void) pthread_setcancelstate(cancel_state, NULL);
2836 return (error);
2837 }
2838
2839 /* PROBE_SUPPORT begin */
2840
2841 void
2842 thr_probe_setup(void *data)
2843 {
2844 curthread->ul_tpdp = data;
2845 }
2846
2847 static void *
2848 _thread_probe_getfunc()
2849 {
2850 return (curthread->ul_tpdp);
2851 }
2852
2853 void * (*thr_probe_getfunc_addr)(void) = _thread_probe_getfunc;
2854
2855 /* ARGSUSED */
2856 void
2857 _resume(ulwp_t *ulwp, caddr_t sp, int dontsave)
2858 {
2859 /* never called */
2860 }
2861
2862 /* ARGSUSED */
2863 void
2864 _resume_ret(ulwp_t *oldlwp)
2865 {
2866 /* never called */
2867 }
2868
2869 /* PROBE_SUPPORT end */