1 /* $NetBSD: thread-stub.c,v 1.31 2021/02/06 00:08:58 jdolecek Exp $ */ 2 3 /*- 4 * Copyright (c) 2003, 2009 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe. 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, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 __RCSID("$NetBSD: thread-stub.c,v 1.31 2021/02/06 00:08:58 jdolecek Exp $"); 35 #endif /* LIBC_SCCS and not lint */ 36 37 /* 38 * Stubs for thread operations, for use when threads are not used by 39 * the application. See "reentrant.h" for details. 40 */ 41 42 #ifdef _REENTRANT 43 44 #define __LIBC_THREAD_STUBS 45 46 #define pthread_join __libc_pthread_join 47 #define pthread_detach __libc_pthread_detach 48 #include "namespace.h" 49 #include "reentrant.h" 50 #include "tsd.h" 51 52 #include <errno.h> 53 #include <signal.h> 54 #include <stdlib.h> 55 #include <unistd.h> 56 57 extern int __isthreaded; 58 59 #define DIE() (void)raise(SIGABRT) 60 61 #define CHECK_NOT_THREADED_ALWAYS() \ 62 do { \ 63 if (__isthreaded) \ 64 DIE(); \ 65 } while (/*CONSTCOND*/0) 66 67 #if 1 68 #define CHECK_NOT_THREADED() CHECK_NOT_THREADED_ALWAYS() 69 #else 70 #define CHECK_NOT_THREADED() /* nothing */ 71 #endif 72 73 __weak_alias(pthread_join, __libc_pthread_join) 74 __weak_alias(pthread_detach, __libc_pthread_detach) 75 76 int 77 pthread_join(pthread_t thread, void **valptr) 78 { 79 80 if (thread == pthread_self()) 81 return EDEADLK; 82 return ESRCH; 83 } 84 85 int 86 pthread_detach(pthread_t thread) 87 { 88 89 if (thread == pthread_self()) 90 return 0; 91 return ESRCH; 92 } 93 94 /* mutexes */ 95 96 int __libc_mutex_catchall_stub(mutex_t *); 97 98 __weak_alias(__libc_mutex_init,__libc_mutex_init_stub) 99 __weak_alias(__libc_mutex_lock,__libc_mutex_catchall_stub) 100 __weak_alias(__libc_mutex_trylock,__libc_mutex_catchall_stub) 101 __weak_alias(__libc_mutex_unlock,__libc_mutex_catchall_stub) 102 __weak_alias(__libc_mutex_destroy,__libc_mutex_catchall_stub) 103 104 __strong_alias(__libc_mutex_lock_stub,__libc_mutex_catchall_stub) 105 __strong_alias(__libc_mutex_trylock_stub,__libc_mutex_catchall_stub) 106 __strong_alias(__libc_mutex_unlock_stub,__libc_mutex_catchall_stub) 107 __strong_alias(__libc_mutex_destroy_stub,__libc_mutex_catchall_stub) 108 109 int __libc_mutexattr_catchall_stub(mutexattr_t *); 110 111 __weak_alias(__libc_mutexattr_init,__libc_mutexattr_catchall_stub) 112 __weak_alias(__libc_mutexattr_destroy,__libc_mutexattr_catchall_stub) 113 __weak_alias(__libc_mutexattr_settype,__libc_mutexattr_settype_stub) 114 115 __strong_alias(__libc_mutexattr_init_stub,__libc_mutexattr_catchall_stub) 116 __strong_alias(__libc_mutexattr_destroy_stub,__libc_mutexattr_catchall_stub) 117 118 int 119 __libc_mutex_init_stub(mutex_t *m, const mutexattr_t *a) 120 { 121 /* LINTED deliberate lack of effect */ 122 (void)m; 123 /* LINTED deliberate lack of effect */ 124 (void)a; 125 126 CHECK_NOT_THREADED(); 127 128 return (0); 129 } 130 131 int 132 __libc_mutex_catchall_stub(mutex_t *m) 133 { 134 /* LINTED deliberate lack of effect */ 135 (void)m; 136 137 CHECK_NOT_THREADED(); 138 139 return (0); 140 } 141 142 int 143 __libc_mutexattr_settype_stub(mutexattr_t *ma, int type) 144 { 145 /* LINTED deliberate lack of effect */ 146 (void)ma; 147 /* LINTED deliberate lack of effect */ 148 (void)type; 149 150 CHECK_NOT_THREADED(); 151 152 return (0); 153 } 154 155 int 156 __libc_mutexattr_catchall_stub(mutexattr_t *ma) 157 { 158 /* LINTED deliberate lack of effect */ 159 (void)ma; 160 161 CHECK_NOT_THREADED(); 162 163 return (0); 164 } 165 166 /* condition variables */ 167 168 int __libc_cond_catchall_stub(cond_t *); 169 170 __weak_alias(__libc_cond_init,__libc_cond_init_stub) 171 __weak_alias(__libc_cond_signal,__libc_cond_catchall_stub) 172 __weak_alias(__libc_cond_broadcast,__libc_cond_catchall_stub) 173 __weak_alias(__libc_cond_wait,__libc_cond_catchall_stub) 174 __weak_alias(__libc_cond_timedwait,__libc_cond_timedwait_stub) 175 __weak_alias(__libc_cond_destroy,__libc_cond_catchall_stub) 176 177 __strong_alias(__libc_cond_signal_stub,__libc_cond_catchall_stub) 178 __strong_alias(__libc_cond_broadcast_stub,__libc_cond_catchall_stub) 179 __strong_alias(__libc_cond_destroy_stub,__libc_cond_catchall_stub) 180 181 int 182 __libc_cond_init_stub(cond_t *c, const condattr_t *a) 183 { 184 /* LINTED deliberate lack of effect */ 185 (void)c; 186 /* LINTED deliberate lack of effect */ 187 (void)a; 188 189 CHECK_NOT_THREADED(); 190 191 return (0); 192 } 193 194 int 195 __libc_cond_wait_stub(cond_t *c, mutex_t *m) 196 { 197 /* LINTED deliberate lack of effect */ 198 (void)c; 199 /* LINTED deliberate lack of effect */ 200 (void)m; 201 202 CHECK_NOT_THREADED(); 203 204 return (0); 205 } 206 207 int 208 __libc_cond_timedwait_stub(cond_t *c, mutex_t *m, const struct timespec *t) 209 { 210 /* LINTED deliberate lack of effect */ 211 (void)c; 212 /* LINTED deliberate lack of effect */ 213 (void)m; 214 /* LINTED deliberate lack of effect */ 215 (void)t; 216 217 CHECK_NOT_THREADED(); 218 219 return (0); 220 } 221 222 int 223 __libc_cond_catchall_stub(cond_t *c) 224 { 225 /* LINTED deliberate lack of effect */ 226 (void)c; 227 228 CHECK_NOT_THREADED(); 229 230 return (0); 231 } 232 233 234 /* read-write locks */ 235 236 int __libc_rwlock_catchall_stub(rwlock_t *); 237 238 __weak_alias(__libc_rwlock_init,__libc_rwlock_init_stub) 239 __weak_alias(__libc_rwlock_rdlock,__libc_rwlock_catchall_stub) 240 __weak_alias(__libc_rwlock_wrlock,__libc_rwlock_catchall_stub) 241 __weak_alias(__libc_rwlock_tryrdlock,__libc_rwlock_catchall_stub) 242 __weak_alias(__libc_rwlock_trywrlock,__libc_rwlock_catchall_stub) 243 __weak_alias(__libc_rwlock_unlock,__libc_rwlock_catchall_stub) 244 __weak_alias(__libc_rwlock_destroy,__libc_rwlock_catchall_stub) 245 246 __strong_alias(__libc_rwlock_rdlock_stub,__libc_rwlock_catchall_stub) 247 __strong_alias(__libc_rwlock_wrlock_stub,__libc_rwlock_catchall_stub) 248 __strong_alias(__libc_rwlock_tryrdlock_stub,__libc_rwlock_catchall_stub) 249 __strong_alias(__libc_rwlock_trywrlock_stub,__libc_rwlock_catchall_stub) 250 __strong_alias(__libc_rwlock_unlock_stub,__libc_rwlock_catchall_stub) 251 __strong_alias(__libc_rwlock_destroy_stub,__libc_rwlock_catchall_stub) 252 253 254 int 255 __libc_rwlock_init_stub(rwlock_t *l, const rwlockattr_t *a) 256 { 257 /* LINTED deliberate lack of effect */ 258 (void)l; 259 /* LINTED deliberate lack of effect */ 260 (void)a; 261 262 CHECK_NOT_THREADED(); 263 264 return (0); 265 } 266 267 int 268 __libc_rwlock_catchall_stub(rwlock_t *l) 269 { 270 /* LINTED deliberate lack of effect */ 271 (void)l; 272 273 CHECK_NOT_THREADED(); 274 275 return (0); 276 } 277 278 279 /* 280 * thread-specific data; we need to actually provide a simple TSD 281 * implementation, since some thread-safe libraries want to use it. 282 */ 283 284 struct __libc_tsd __libc_tsd[TSD_KEYS_MAX]; 285 static int __libc_tsd_nextkey; 286 287 __weak_alias(__libc_thr_keycreate,__libc_thr_keycreate_stub) 288 __weak_alias(__libc_thr_setspecific,__libc_thr_setspecific_stub) 289 __weak_alias(__libc_thr_getspecific,__libc_thr_getspecific_stub) 290 __weak_alias(__libc_thr_keydelete,__libc_thr_keydelete_stub) 291 292 int 293 __libc_thr_keycreate_stub(thread_key_t *k, void (*d)(void *)) 294 { 295 int i; 296 297 for (i = __libc_tsd_nextkey; i < TSD_KEYS_MAX; i++) { 298 if (__libc_tsd[i].tsd_inuse == 0) 299 goto out; 300 } 301 302 for (i = 0; i < __libc_tsd_nextkey; i++) { 303 if (__libc_tsd[i].tsd_inuse == 0) 304 goto out; 305 } 306 307 return (EAGAIN); 308 309 out: 310 /* 311 * XXX We don't actually do anything with the destructor. We 312 * XXX probably should. 313 */ 314 __libc_tsd[i].tsd_inuse = 1; 315 __libc_tsd_nextkey = (i + i) % TSD_KEYS_MAX; 316 __libc_tsd[i].tsd_dtor = d; 317 *k = i; 318 319 return (0); 320 } 321 322 int 323 __libc_thr_setspecific_stub(thread_key_t k, const void *v) 324 { 325 326 __libc_tsd[k].tsd_val = __UNCONST(v); 327 328 return (0); 329 } 330 331 void * 332 __libc_thr_getspecific_stub(thread_key_t k) 333 { 334 335 return (__libc_tsd[k].tsd_val); 336 } 337 338 int 339 __libc_thr_keydelete_stub(thread_key_t k) 340 { 341 342 /* 343 * XXX Do not recycle key; see big comment in libpthread. 344 */ 345 346 __libc_tsd[k].tsd_dtor = NULL; 347 348 return (0); 349 } 350 351 352 /* misc. */ 353 354 __weak_alias(__libc_thr_once,__libc_thr_once_stub) 355 __weak_alias(__libc_thr_sigsetmask,__libc_thr_sigsetmask_stub) 356 __weak_alias(__libc_thr_self,__libc_thr_self_stub) 357 __weak_alias(__libc_thr_yield,__libc_thr_yield_stub) 358 __weak_alias(__libc_thr_create,__libc_thr_create_stub) 359 __weak_alias(__libc_thr_exit,__libc_thr_exit_stub) 360 __weak_alias(__libc_thr_setcancelstate,__libc_thr_setcancelstate_stub) 361 __weak_alias(__libc_thr_equal,__libc_thr_equal_stub) 362 __weak_alias(__libc_thr_curcpu,__libc_thr_curcpu_stub) 363 364 365 int 366 __libc_thr_once_stub(once_t *o, void (*r)(void)) 367 { 368 369 /* XXX Knowledge of libpthread types. */ 370 371 if (o->pto_done == 0) { 372 (*r)(); 373 o->pto_done = 1; 374 } 375 376 return (0); 377 } 378 379 int 380 __libc_thr_sigsetmask_stub(int h, const sigset_t *s, sigset_t *o) 381 { 382 383 CHECK_NOT_THREADED(); 384 385 if (sigprocmask(h, s, o)) 386 return errno; 387 return 0; 388 } 389 390 thr_t 391 __libc_thr_self_stub(void) 392 { 393 394 return ((thr_t) -1); 395 } 396 397 /* This is the strong symbol generated for sched_yield(2) via WSYSCALL() */ 398 int _sys_sched_yield(void); 399 400 int 401 __libc_thr_yield_stub(void) 402 { 403 return _sys_sched_yield(); 404 } 405 406 int 407 __libc_thr_create_stub(thr_t *tp, const thrattr_t *ta, 408 void *(*f)(void *), void *a) 409 { 410 /* LINTED deliberate lack of effect */ 411 (void)tp; 412 /* LINTED deliberate lack of effect */ 413 (void)ta; 414 /* LINTED deliberate lack of effect */ 415 (void)f; 416 /* LINTED deliberate lack of effect */ 417 (void)a; 418 419 DIE(); 420 421 return (EOPNOTSUPP); 422 } 423 424 __dead void 425 __libc_thr_exit_stub(void *v) 426 { 427 /* LINTED deliberate lack of effect */ 428 (void)v; 429 exit(0); 430 } 431 432 int 433 __libc_thr_setcancelstate_stub(int new, int *old) 434 { 435 /* LINTED deliberate lack of effect */ 436 (void)new; 437 438 /* LINTED deliberate lack of effect */ 439 (void)old; 440 441 CHECK_NOT_THREADED(); 442 443 return (0); 444 } 445 446 int 447 __libc_thr_equal_stub(pthread_t t1, pthread_t t2) 448 { 449 450 /* assert that t1=t2=pthread_self() */ 451 return (t1 == t2); 452 } 453 454 unsigned int 455 __libc_thr_curcpu_stub(void) 456 { 457 458 return (0); 459 } 460 461 #endif /* _REENTRANT */ 462