lib/libthr/thread/thr_init.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-4-Clause
   3  *
   4  * Copyright (c) 2003 Daniel M. Eischen <deischen@freebsd.org>
   5  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by John Birrell.
  19  * 4. Neither the name of the author nor the names of any co-contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <sys/cdefs.h>
  37 #include "namespace.h"
  38 #include <sys/param.h>
  39 #include <sys/auxv.h>
  40 #include <sys/signalvar.h>
  41 #include <sys/ioctl.h>
  42 #include <sys/link_elf.h>
  43 #include <sys/resource.h>
  44 #include <sys/sysctl.h>
  45 #include <sys/ttycom.h>
  46 #include <sys/mman.h>
  47 #include <sys/rtprio.h>
  48 #include <errno.h>
  49 #include <fcntl.h>
  50 #include <paths.h>
  51 #include <pthread.h>
  52 #include <pthread_np.h>
  53 #include <signal.h>
  54 #include <stdlib.h>
  55 #include <string.h>
  56 #include <time.h>
  57 #include <unistd.h>
  58 #include "un-namespace.h"
  59
  60 #include "libc_private.h"
  61 #include "thr_private.h"
  62
  63 char            *_usrstack;
  64 struct pthread  *_thr_initial;
  65 int             _libthr_debug;
  66 int             _thread_event_mask;
  67 struct pthread  *_thread_last_event;
  68 pthreadlist     _thread_list = TAILQ_HEAD_INITIALIZER(_thread_list);
  69 pthreadlist     _thread_gc_list = TAILQ_HEAD_INITIALIZER(_thread_gc_list);
  70 int             _thread_active_threads = 1;
  71 atfork_head     _thr_atfork_list = TAILQ_HEAD_INITIALIZER(_thr_atfork_list);
  72 struct urwlock  _thr_atfork_lock = DEFAULT_URWLOCK;
  73
  74 struct pthread_prio     _thr_priorities[3] = {
  75         {RTP_PRIO_MIN,  RTP_PRIO_MAX, 0}, /* FIFO */
  76         {0, 0, 63}, /* OTHER */
  77         {RTP_PRIO_MIN, RTP_PRIO_MAX, 0}  /* RR */
  78 };
  79
  80 struct pthread_attr _pthread_attr_default = {
  81         .sched_policy = SCHED_OTHER,
  82         .sched_inherit = PTHREAD_INHERIT_SCHED,
  83         .prio = 0,
  84         .suspend = THR_CREATE_RUNNING,
  85         .flags = PTHREAD_SCOPE_SYSTEM,
  86         .stackaddr_attr = NULL,
  87         .stacksize_attr = THR_STACK_DEFAULT,
  88         .guardsize_attr = 0,
  89         .cpusetsize = 0,
  90         .cpuset = NULL
  91 };
  92
  93 struct pthread_mutex_attr _pthread_mutexattr_default = {
  94         .m_type = PTHREAD_MUTEX_DEFAULT,
  95         .m_protocol = PTHREAD_PRIO_NONE,
  96         .m_ceiling = 0,
  97         .m_pshared = PTHREAD_PROCESS_PRIVATE,
  98         .m_robust = PTHREAD_MUTEX_STALLED,
  99 };
 100
 101 struct pthread_mutex_attr _pthread_mutexattr_adaptive_default = {
 102         .m_type = PTHREAD_MUTEX_ADAPTIVE_NP,
 103         .m_protocol = PTHREAD_PRIO_NONE,
 104         .m_ceiling = 0,
 105         .m_pshared = PTHREAD_PROCESS_PRIVATE,
 106         .m_robust = PTHREAD_MUTEX_STALLED,
 107 };
 108
 109 /* Default condition variable attributes: */
 110 struct pthread_cond_attr _pthread_condattr_default = {
 111         .c_pshared = PTHREAD_PROCESS_PRIVATE,
 112         .c_clockid = CLOCK_REALTIME
 113 };
 114
 115 int             _thr_is_smp = 0;
 116 size_t          _thr_guard_default;
 117 size_t          _thr_stack_default = THR_STACK_DEFAULT;
 118 size_t          _thr_stack_initial = THR_STACK_INITIAL;
 119 int             _thr_page_size;
 120 int             _thr_spinloops;
 121 int             _thr_yieldloops;
 122 int             _thr_queuefifo = 4;
 123 int             _gc_count;
 124 struct umutex   _mutex_static_lock = DEFAULT_UMUTEX;
 125 struct umutex   _cond_static_lock = DEFAULT_UMUTEX;
 126 struct umutex   _rwlock_static_lock = DEFAULT_UMUTEX;
 127 struct umutex   _keytable_lock = DEFAULT_UMUTEX;
 128 struct urwlock  _thr_list_lock = DEFAULT_URWLOCK;
 129 struct umutex   _thr_event_lock = DEFAULT_UMUTEX;
 130 struct umutex   _suspend_all_lock = DEFAULT_UMUTEX;
 131 struct pthread  *_single_thread;
 132 int             _suspend_all_cycle;
 133 int             _suspend_all_waiters;
 134
 135 int     __pthread_cond_wait(pthread_cond_t *, pthread_mutex_t *);
 136 int     __pthread_mutex_lock(pthread_mutex_t *);
 137 int     __pthread_mutex_trylock(pthread_mutex_t *);
 138 void    _thread_init_hack(void) __attribute__ ((constructor));
 139
 140 static void init_private(void);
 141 static void init_main_thread(struct pthread *thread);
 142
 143 /*
 144  * All weak references used within libc should be in this table.
 145  * This is so that static libraries will work.
 146  */
 147
 148 STATIC_LIB_REQUIRE(_fork);
 149 STATIC_LIB_REQUIRE(_pthread_getspecific);
 150 STATIC_LIB_REQUIRE(_pthread_key_create);
 151 STATIC_LIB_REQUIRE(_pthread_key_delete);
 152 STATIC_LIB_REQUIRE(_pthread_mutex_destroy);
 153 STATIC_LIB_REQUIRE(_pthread_mutex_init);
 154 STATIC_LIB_REQUIRE(_pthread_mutex_lock);
 155 STATIC_LIB_REQUIRE(_pthread_mutex_trylock);
 156 STATIC_LIB_REQUIRE(_pthread_mutex_unlock);
 157 STATIC_LIB_REQUIRE(_pthread_mutexattr_init);
 158 STATIC_LIB_REQUIRE(_pthread_mutexattr_destroy);
 159 STATIC_LIB_REQUIRE(_pthread_mutexattr_settype);
 160 STATIC_LIB_REQUIRE(_pthread_once);
 161 STATIC_LIB_REQUIRE(_pthread_setspecific);
 162 STATIC_LIB_REQUIRE(_raise);
 163 STATIC_LIB_REQUIRE(_sem_destroy);
 164 STATIC_LIB_REQUIRE(_sem_getvalue);
 165 STATIC_LIB_REQUIRE(_sem_init);
 166 STATIC_LIB_REQUIRE(_sem_post);
 167 STATIC_LIB_REQUIRE(_sem_timedwait);
 168 STATIC_LIB_REQUIRE(_sem_trywait);
 169 STATIC_LIB_REQUIRE(_sem_wait);
 170 STATIC_LIB_REQUIRE(_sigaction);
 171 STATIC_LIB_REQUIRE(_sigprocmask);
 172 STATIC_LIB_REQUIRE(_sigsuspend);
 173 STATIC_LIB_REQUIRE(_sigtimedwait);
 174 STATIC_LIB_REQUIRE(_sigwait);
 175 STATIC_LIB_REQUIRE(_sigwaitinfo);
 176 STATIC_LIB_REQUIRE(_spinlock);
 177 STATIC_LIB_REQUIRE(_spinunlock);
 178 STATIC_LIB_REQUIRE(_thread_init_hack);
 179
 180 /*
 181  * These are needed when linking statically.  All references within
 182  * libgcc (and in the future libc) to these routines are weak, but
 183  * if they are not (strongly) referenced by the application or other
 184  * libraries, then the actual functions will not be loaded.
 185  */
 186 STATIC_LIB_REQUIRE(_pthread_once);
 187 STATIC_LIB_REQUIRE(_pthread_key_create);
 188 STATIC_LIB_REQUIRE(_pthread_key_delete);
 189 STATIC_LIB_REQUIRE(_pthread_getspecific);
 190 STATIC_LIB_REQUIRE(_pthread_setspecific);
 191 STATIC_LIB_REQUIRE(_pthread_mutex_init);
 192 STATIC_LIB_REQUIRE(_pthread_mutex_destroy);
 193 STATIC_LIB_REQUIRE(_pthread_mutex_lock);
 194 STATIC_LIB_REQUIRE(_pthread_mutex_trylock);
 195 STATIC_LIB_REQUIRE(_pthread_mutex_unlock);
 196 STATIC_LIB_REQUIRE(_pthread_create);
 197
 198 /* Pull in all symbols required by libthread_db */
 199 STATIC_LIB_REQUIRE(_thread_state_running);
 200
 201 #define DUAL_ENTRY(entry)       \
 202         (pthread_func_t)entry, (pthread_func_t)entry
 203
 204 static pthread_func_t jmp_table[][2] = {
 205         [PJT_ATFORK] = {DUAL_ENTRY(_thr_atfork)},
 206         [PJT_ATTR_DESTROY] = {DUAL_ENTRY(_thr_attr_destroy)},
 207         [PJT_ATTR_GETDETACHSTATE] = {DUAL_ENTRY(_thr_attr_getdetachstate)},
 208         [PJT_ATTR_GETGUARDSIZE] = {DUAL_ENTRY(_thr_attr_getguardsize)},
 209         [PJT_ATTR_GETINHERITSCHED] = {DUAL_ENTRY(_thr_attr_getinheritsched)},
 210         [PJT_ATTR_GETSCHEDPARAM] = {DUAL_ENTRY(_thr_attr_getschedparam)},
 211         [PJT_ATTR_GETSCHEDPOLICY] = {DUAL_ENTRY(_thr_attr_getschedpolicy)},
 212         [PJT_ATTR_GETSCOPE] = {DUAL_ENTRY(_thr_attr_getscope)},
 213         [PJT_ATTR_GETSTACKADDR] = {DUAL_ENTRY(_thr_attr_getstackaddr)},
 214         [PJT_ATTR_GETSTACKSIZE] = {DUAL_ENTRY(_thr_attr_getstacksize)},
 215         [PJT_ATTR_INIT] = {DUAL_ENTRY(_thr_attr_init)},
 216         [PJT_ATTR_SETDETACHSTATE] = {DUAL_ENTRY(_thr_attr_setdetachstate)},
 217         [PJT_ATTR_SETGUARDSIZE] = {DUAL_ENTRY(_thr_attr_setguardsize)},
 218         [PJT_ATTR_SETINHERITSCHED] = {DUAL_ENTRY(_thr_attr_setinheritsched)},
 219         [PJT_ATTR_SETSCHEDPARAM] = {DUAL_ENTRY(_thr_attr_setschedparam)},
 220         [PJT_ATTR_SETSCHEDPOLICY] = {DUAL_ENTRY(_thr_attr_setschedpolicy)},
 221         [PJT_ATTR_SETSCOPE] = {DUAL_ENTRY(_thr_attr_setscope)},
 222         [PJT_ATTR_SETSTACKADDR] = {DUAL_ENTRY(_thr_attr_setstackaddr)},
 223         [PJT_ATTR_SETSTACKSIZE] = {DUAL_ENTRY(_thr_attr_setstacksize)},
 224         [PJT_CANCEL] = {DUAL_ENTRY(_thr_cancel)},
 225         [PJT_CLEANUP_POP] = {DUAL_ENTRY(_thr_cleanup_pop)},
 226         [PJT_CLEANUP_PUSH] = {DUAL_ENTRY(_thr_cleanup_push)},
 227         [PJT_COND_BROADCAST] = {DUAL_ENTRY(_thr_cond_broadcast)},
 228         [PJT_COND_DESTROY] = {DUAL_ENTRY(_thr_cond_destroy)},
 229         [PJT_COND_INIT] = {DUAL_ENTRY(_thr_cond_init)},
 230         [PJT_COND_SIGNAL] = {DUAL_ENTRY(_thr_cond_signal)},
 231         [PJT_COND_TIMEDWAIT] = {DUAL_ENTRY(_thr_cond_timedwait)},
 232         [PJT_COND_WAIT] = {(pthread_func_t)__thr_cond_wait,
 233             (pthread_func_t)_thr_cond_wait},
 234         [PJT_DETACH] = {DUAL_ENTRY(_thr_detach)},
 235         [PJT_EQUAL] = {DUAL_ENTRY(_thr_equal)},
 236         [PJT_EXIT] = {DUAL_ENTRY(_Tthr_exit)},
 237         [PJT_GETSPECIFIC] = {DUAL_ENTRY(_thr_getspecific)},
 238         [PJT_JOIN] = {DUAL_ENTRY(_thr_join)},
 239         [PJT_KEY_CREATE] = {DUAL_ENTRY(_thr_key_create)},
 240         [PJT_KEY_DELETE] = {DUAL_ENTRY(_thr_key_delete)},
 241         [PJT_KILL] = {DUAL_ENTRY(_Tthr_kill)},
 242         [PJT_MAIN_NP] = {DUAL_ENTRY(_thr_main_np)},
 243         [PJT_MUTEXATTR_DESTROY] = {DUAL_ENTRY(_thr_mutexattr_destroy)},
 244         [PJT_MUTEXATTR_INIT] = {DUAL_ENTRY(_thr_mutexattr_init)},
 245         [PJT_MUTEXATTR_SETTYPE] = {DUAL_ENTRY(_thr_mutexattr_settype)},
 246         [PJT_MUTEX_DESTROY] = {DUAL_ENTRY(_thr_mutex_destroy)},
 247         [PJT_MUTEX_INIT] = {DUAL_ENTRY(__Tthr_mutex_init)},
 248         [PJT_MUTEX_LOCK] = {DUAL_ENTRY(__Tthr_mutex_lock)},
 249         [PJT_MUTEX_TRYLOCK] = {DUAL_ENTRY(__Tthr_mutex_trylock)},
 250         [PJT_MUTEX_UNLOCK] = {DUAL_ENTRY(_thr_mutex_unlock)},
 251         [PJT_ONCE] = {DUAL_ENTRY(_thr_once)},
 252         [PJT_RWLOCK_DESTROY] = {DUAL_ENTRY(_thr_rwlock_destroy)},
 253         [PJT_RWLOCK_INIT] = {DUAL_ENTRY(_thr_rwlock_init)},
 254         [PJT_RWLOCK_RDLOCK] = {DUAL_ENTRY(_Tthr_rwlock_rdlock)},
 255         [PJT_RWLOCK_TRYRDLOCK] = {DUAL_ENTRY(_Tthr_rwlock_tryrdlock)},
 256         [PJT_RWLOCK_TRYWRLOCK] = {DUAL_ENTRY(_Tthr_rwlock_trywrlock)},
 257         [PJT_RWLOCK_UNLOCK] = {DUAL_ENTRY(_Tthr_rwlock_unlock)},
 258         [PJT_RWLOCK_WRLOCK] = {DUAL_ENTRY(_Tthr_rwlock_wrlock)},
 259         [PJT_SELF] = {DUAL_ENTRY(_Tthr_self)},
 260         [PJT_SETCANCELSTATE] = {DUAL_ENTRY(_thr_setcancelstate)},
 261         [PJT_SETCANCELTYPE] = {DUAL_ENTRY(_thr_setcanceltype)},
 262         [PJT_SETSPECIFIC] = {DUAL_ENTRY(_thr_setspecific)},
 263         [PJT_SIGMASK] = {DUAL_ENTRY(_thr_sigmask)},
 264         [PJT_TESTCANCEL] = {DUAL_ENTRY(_Tthr_testcancel)},
 265         [PJT_CLEANUP_POP_IMP] = {DUAL_ENTRY(__thr_cleanup_pop_imp)},
 266         [PJT_CLEANUP_PUSH_IMP] = {DUAL_ENTRY(__thr_cleanup_push_imp)},
 267         [PJT_CANCEL_ENTER] = {DUAL_ENTRY(_Tthr_cancel_enter)},
 268         [PJT_CANCEL_LEAVE] = {DUAL_ENTRY(_Tthr_cancel_leave)},
 269         [PJT_MUTEX_CONSISTENT] = {DUAL_ENTRY(_Tthr_mutex_consistent)},
 270         [PJT_MUTEXATTR_GETROBUST] = {DUAL_ENTRY(_thr_mutexattr_getrobust)},
 271         [PJT_MUTEXATTR_SETROBUST] = {DUAL_ENTRY(_thr_mutexattr_setrobust)},
 272         [PJT_GETTHREADID_NP] = {DUAL_ENTRY(_thr_getthreadid_np)},
 273         [PJT_ATTR_GET_NP] = {DUAL_ENTRY(_thr_attr_get_np)},
 274         [PJT_GETNAME_NP] = {DUAL_ENTRY(_thr_getname_np)},
 275 };
 276
 277 static int init_once = 0;
 278
 279 /*
 280  * For the shared version of the threads library, the above is sufficient.
 281  * But for the archive version of the library, we need a little bit more.
 282  * Namely, we must arrange for this particular module to be pulled in from
 283  * the archive library at link time.  To accomplish that, we define and
 284  * initialize a variable, "_thread_autoinit_dummy_decl".  This variable is
 285  * referenced (as an extern) from libc/stdlib/exit.c. This will always
 286  * create a need for this module, ensuring that it is present in the
 287  * executable.
 288  */
 289 extern int _thread_autoinit_dummy_decl;
 290 int _thread_autoinit_dummy_decl = 0;
 291
 292 void
 293 _thread_init_hack(void)
 294 {
 295
 296         _libpthread_init(NULL);
 297 }
 298
 299
 300 /*
 301  * Threaded process initialization.
 302  *
 303  * This is only called under two conditions:
 304  *
 305  *   1) Some thread routines have detected that the library hasn't yet
 306  *      been initialized (_thr_initial == NULL && curthread == NULL), or
 307  *
 308  *   2) An explicit call to reinitialize after a fork (indicated
 309  *      by curthread != NULL)
 310  */
 311 void
 312 _libpthread_init(struct pthread *curthread)
 313 {
 314         int first, dlopened;
 315
 316         /* Check if this function has already been called: */
 317         if (_thr_initial != NULL && curthread == NULL)
 318                 /* Only initialize the threaded application once. */
 319                 return;
 320
 321         /*
 322          * Check the size of the jump table to make sure it is preset
 323          * with the correct number of entries.
 324          */
 325         if (sizeof(jmp_table) != sizeof(pthread_func_t) * PJT_MAX * 2)
 326                 PANIC("Thread jump table not properly initialized");
 327         memcpy(__thr_jtable, jmp_table, sizeof(jmp_table));
 328         __thr_interpose_libc();
 329
 330         /* Initialize pthread private data. */
 331         init_private();
 332
 333         /* Set the initial thread. */
 334         if (curthread == NULL) {
 335                 first = 1;
 336                 /* Create and initialize the initial thread. */
 337                 curthread = _thr_alloc(NULL);
 338                 if (curthread == NULL)
 339                         PANIC("Can't allocate initial thread");
 340                 init_main_thread(curthread);
 341         } else {
 342                 first = 0;
 343         }
 344
 345         /*
 346          * Add the thread to the thread list queue.
 347          */
 348         THR_LIST_ADD(curthread);
 349         _thread_active_threads = 1;
 350
 351         /* Setup the thread specific data */
 352         _tcb_set(curthread->tcb);
 353
 354         if (first) {
 355                 _thr_initial = curthread;
 356                 dlopened = _rtld_is_dlopened(&_thread_autoinit_dummy_decl) != 0;
 357                 _thr_signal_init(dlopened);
 358                 if (_thread_event_mask & TD_CREATE)
 359                         _thr_report_creation(curthread, curthread);
 360                 /*
 361                  * Always use our rtld lock implementation.
 362                  * It is faster because it postpones signal handlers
 363                  * instead of calling sigprocmask(2).
 364                  */
 365                 _thr_rtld_init();
 366         }
 367 }
 368
 369 /*
 370  * This function and pthread_create() do a lot of the same things.
 371  * It'd be nice to consolidate the common stuff in one place.
 372  */
 373 static void
 374 init_main_thread(struct pthread *thread)
 375 {
 376         struct sched_param sched_param;
 377         int i;
 378
 379         /* Setup the thread attributes. */
 380         thr_self(&thread->tid);
 381         thread->attr = _pthread_attr_default;
 382         /*
 383          * Set up the thread stack.
 384          *
 385          * Create a red zone below the main stack.  All other stacks
 386          * are constrained to a maximum size by the parameters
 387          * passed to mmap(), but this stack is only limited by
 388          * resource limits, so this stack needs an explicitly mapped
 389          * red zone to protect the thread stack that is just beyond.
 390          */
 391         if (mmap(_usrstack - _thr_stack_initial -
 392             _thr_guard_default, _thr_guard_default, 0, MAP_ANON,
 393             -1, 0) == MAP_FAILED)
 394                 PANIC("Cannot allocate red zone for initial thread");
 395
 396         /*
 397          * Mark the stack as an application supplied stack so that it
 398          * isn't deallocated.
 399          *
 400          * XXX - I'm not sure it would hurt anything to deallocate
 401          *       the main thread stack because deallocation doesn't
 402          *       actually free() it; it just puts it in the free
 403          *       stack queue for later reuse.
 404          */
 405         thread->attr.stackaddr_attr = _usrstack - _thr_stack_initial;
 406         thread->attr.stacksize_attr = _thr_stack_initial;
 407         thread->attr.guardsize_attr = _thr_guard_default;
 408         thread->attr.flags |= THR_STACK_USER;
 409
 410         /*
 411          * Write a magic value to the thread structure
 412          * to help identify valid ones:
 413          */
 414         thread->magic = THR_MAGIC;
 415
 416         thread->cancel_enable = 1;
 417         thread->cancel_async = 0;
 418
 419         /* Initialize the mutex queues */
 420         for (i = 0; i < TMQ_NITEMS; i++)
 421                 TAILQ_INIT(&thread->mq[i]);
 422
 423         thread->state = PS_RUNNING;
 424
 425         _thr_getscheduler(thread->tid, &thread->attr.sched_policy,
 426                  &sched_param);
 427         thread->attr.prio = sched_param.sched_priority;
 428
 429 #ifdef _PTHREAD_FORCED_UNWIND
 430         thread->unwind_stackend = _usrstack;
 431 #endif
 432
 433         /* Others cleared to zero by thr_alloc() */
 434 }
 435
 436 bool
 437 __thr_get_main_stack_base(char **base)
 438 {
 439         size_t len;
 440         int mib[2];
 441
 442         if (elf_aux_info(AT_USRSTACKBASE, base, sizeof(*base)) == 0)
 443                 return (true);
 444
 445         mib[0] = CTL_KERN;
 446         mib[1] = KERN_USRSTACK;
 447         len = sizeof(*base);
 448         if (sysctl(mib, nitems(mib), base, &len, NULL, 0) == 0)
 449                 return (true);
 450
 451         return (false);
 452 }
 453
 454 bool
 455 __thr_get_main_stack_lim(size_t *lim)
 456 {
 457         struct rlimit rlim;
 458
 459         if (elf_aux_info(AT_USRSTACKLIM, lim, sizeof(*lim)) == 0)
 460                 return (true);
 461
 462         if (getrlimit(RLIMIT_STACK, &rlim) == 0) {
 463                 *lim = rlim.rlim_cur;
 464                 return (true);
 465         }
 466
 467         return (false);
 468 }
 469
 470 static void
 471 init_private(void)
 472 {
 473         char *env, *env_bigstack, *env_splitstack;
 474
 475         _thr_umutex_init(&_mutex_static_lock);
 476         _thr_umutex_init(&_cond_static_lock);
 477         _thr_umutex_init(&_rwlock_static_lock);
 478         _thr_umutex_init(&_keytable_lock);
 479         _thr_urwlock_init(&_thr_atfork_lock);
 480         _thr_umutex_init(&_thr_event_lock);
 481         _thr_umutex_init(&_suspend_all_lock);
 482         _thr_spinlock_init();
 483         _thr_list_init();
 484         _thr_wake_addr_init();
 485         _sleepq_init();
 486         _single_thread = NULL;
 487         _suspend_all_waiters = 0;
 488
 489         /*
 490          * Avoid reinitializing some things if they don't need to be,
 491          * e.g. after a fork().
 492          */
 493         if (init_once == 0) {
 494                 __thr_pshared_init();
 495                 __thr_malloc_init();
 496
 497                 /* Find the stack top */
 498                 if (!__thr_get_main_stack_base(&_usrstack))
 499                         PANIC("Cannot get kern.usrstack");
 500                 env_bigstack = getenv("LIBPTHREAD_BIGSTACK_MAIN");
 501                 env_splitstack = getenv("LIBPTHREAD_SPLITSTACK_MAIN");
 502                 if (env_bigstack != NULL || env_splitstack == NULL) {
 503                         if (!__thr_get_main_stack_lim(&_thr_stack_initial))
 504                                 PANIC("Cannot get stack rlimit");
 505                 }
 506                 _thr_is_smp = sysconf(_SC_NPROCESSORS_CONF);
 507                 if (_thr_is_smp == -1)
 508                         PANIC("Cannot get _SC_NPROCESSORS_CONF");
 509                 _thr_is_smp = (_thr_is_smp > 1);
 510                 _thr_page_size = getpagesize();
 511                 _thr_guard_default = _thr_page_size;
 512                 _pthread_attr_default.guardsize_attr = _thr_guard_default;
 513                 _pthread_attr_default.stacksize_attr = _thr_stack_default;
 514                 env = getenv("LIBPTHREAD_SPINLOOPS");
 515                 if (env)
 516                         _thr_spinloops = atoi(env);
 517                 env = getenv("LIBPTHREAD_YIELDLOOPS");
 518                 if (env)
 519                         _thr_yieldloops = atoi(env);
 520                 env = getenv("LIBPTHREAD_QUEUE_FIFO");
 521                 if (env)
 522                         _thr_queuefifo = atoi(env);
 523                 TAILQ_INIT(&_thr_atfork_list);
 524                 env = getenv("LIBPTHREAD_UMTX_MIN_TIMEOUT");
 525                 if (env) {
 526                         char *endptr;
 527                         long mint;
 528
 529                         mint = strtol(env, &endptr, 0);
 530                         if (*endptr == '\0' && mint >= 0) {
 531                                 _umtx_op(NULL, UMTX_OP_SET_MIN_TIMEOUT,
 532                                     mint, NULL, NULL);
 533                         }
 534                 }
 535         }
 536         init_once = 1;
 537 }