lib/libthr/thread/thr_create.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2003 Daniel M. Eischen <deischen@gdeb.com>
   5  * Copyright (c) 2005, David Xu <davidxu@freebsd.org>
   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 unmodified, this list of conditions, and the following
  13  *    disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #include <sys/cdefs.h>
  31 __FBSDID("$FreeBSD$");
  32
  33 #include "namespace.h"
  34 #include <sys/types.h>
  35 #include <sys/rtprio.h>
  36 #include <sys/signalvar.h>
  37 #include <errno.h>
  38 #include <link.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41 #include <stddef.h>
  42 #include <pthread.h>
  43 #include <pthread_np.h>
  44 #include "un-namespace.h"
  45
  46 #include "libc_private.h"
  47 #include "thr_private.h"
  48
  49 static int  create_stack(struct pthread_attr *pattr);
  50 static void thread_start(struct pthread *curthread);
  51
  52 __weak_reference(_pthread_create, pthread_create);
  53
  54 int
  55 _pthread_create(pthread_t * __restrict thread,
  56     const pthread_attr_t * __restrict attr, void *(*start_routine) (void *),
  57     void * __restrict arg)
  58 {
  59         struct pthread *curthread, *new_thread;
  60         struct thr_param param;
  61         struct sched_param sched_param;
  62         struct rtprio rtp;
  63         sigset_t set, oset;
  64         cpuset_t *cpusetp;
  65         int i, cpusetsize, create_suspended, locked, old_stack_prot, ret;
  66
  67         cpusetp = NULL;
  68         ret = cpusetsize = 0;
  69         _thr_check_init();
  70
  71         /*
  72          * Tell libc and others now they need lock to protect their data.
  73          */
  74         if (_thr_isthreaded() == 0) {
  75                 _malloc_first_thread();
  76                 if (_thr_setthreaded(1))
  77                         return (EAGAIN);
  78         }
  79
  80         curthread = _get_curthread();
  81         if ((new_thread = _thr_alloc(curthread)) == NULL)
  82                 return (EAGAIN);
  83
  84         memset(&param, 0, sizeof(param));
  85
  86         if (attr == NULL || *attr == NULL)
  87                 /* Use the default thread attributes: */
  88                 new_thread->attr = _pthread_attr_default;
  89         else {
  90                 new_thread->attr = *(*attr);
  91                 cpusetp = new_thread->attr.cpuset;
  92                 cpusetsize = new_thread->attr.cpusetsize;
  93                 new_thread->attr.cpuset = NULL;
  94                 new_thread->attr.cpusetsize = 0;
  95         }
  96         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
  97                 /* inherit scheduling contention scope */
  98                 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
  99                         new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
 100                 else
 101                         new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
 102
 103                 new_thread->attr.prio = curthread->attr.prio;
 104                 new_thread->attr.sched_policy = curthread->attr.sched_policy;
 105         }
 106
 107         new_thread->tid = TID_TERMINATED;
 108
 109         old_stack_prot = _rtld_get_stack_prot();
 110         if (create_stack(&new_thread->attr) != 0) {
 111                 /* Insufficient memory to create a stack: */
 112                 _thr_free(curthread, new_thread);
 113                 return (EAGAIN);
 114         }
 115         /*
 116          * Write a magic value to the thread structure
 117          * to help identify valid ones:
 118          */
 119         new_thread->magic = THR_MAGIC;
 120         new_thread->start_routine = start_routine;
 121         new_thread->arg = arg;
 122         new_thread->cancel_enable = 1;
 123         new_thread->cancel_async = 0;
 124         /* Initialize the mutex queue: */
 125         for (i = 0; i < TMQ_NITEMS; i++)
 126                 TAILQ_INIT(&new_thread->mq[i]);
 127
 128         /* Initialise hooks in the thread structure: */
 129         if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) {
 130                 new_thread->flags = THR_FLAGS_NEED_SUSPEND;
 131                 create_suspended = 1;
 132         } else {
 133                 create_suspended = 0;
 134         }
 135
 136         new_thread->state = PS_RUNNING;
 137
 138         if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED)
 139                 new_thread->flags |= THR_FLAGS_DETACHED;
 140
 141         /* Add the new thread. */
 142         new_thread->refcount = 1;
 143         _thr_link(curthread, new_thread);
 144
 145         /*
 146          * Handle the race between __pthread_map_stacks_exec and
 147          * thread linkage.
 148          */
 149         if (old_stack_prot != _rtld_get_stack_prot())
 150                 _thr_stack_fix_protection(new_thread);
 151
 152         /* Return thread pointer eariler so that new thread can use it. */
 153         (*thread) = new_thread;
 154         if (SHOULD_REPORT_EVENT(curthread, TD_CREATE) || cpusetp != NULL) {
 155                 THR_THREAD_LOCK(curthread, new_thread);
 156                 locked = 1;
 157         } else
 158                 locked = 0;
 159         param.start_func = (void (*)(void *)) thread_start;
 160         param.arg = new_thread;
 161         param.stack_base = new_thread->attr.stackaddr_attr;
 162         param.stack_size = new_thread->attr.stacksize_attr;
 163         param.tls_base = (char *)new_thread->tcb;
 164         param.tls_size = sizeof(struct tcb);
 165         param.child_tid = &new_thread->tid;
 166         param.parent_tid = &new_thread->tid;
 167         param.flags = 0;
 168         if (new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM)
 169                 param.flags |= THR_SYSTEM_SCOPE;
 170         if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED)
 171                 param.rtp = NULL;
 172         else {
 173                 sched_param.sched_priority = new_thread->attr.prio;
 174                 _schedparam_to_rtp(new_thread->attr.sched_policy,
 175                         &sched_param, &rtp);
 176                 param.rtp = &rtp;
 177         }
 178
 179         /* Schedule the new thread. */
 180         if (create_suspended) {
 181                 SIGFILLSET(set);
 182                 SIGDELSET(set, SIGTRAP);
 183                 __sys_sigprocmask(SIG_SETMASK, &set, &oset);
 184                 new_thread->sigmask = oset;
 185                 SIGDELSET(new_thread->sigmask, SIGCANCEL);
 186         }
 187
 188         ret = thr_new(&param, sizeof(param));
 189
 190         if (ret != 0) {
 191                 ret = errno;
 192                 /*
 193                  * Translate EPROCLIM into well-known POSIX code EAGAIN.
 194                  */
 195                 if (ret == EPROCLIM)
 196                         ret = EAGAIN;
 197         }
 198
 199         if (create_suspended)
 200                 __sys_sigprocmask(SIG_SETMASK, &oset, NULL);
 201
 202         if (ret != 0) {
 203                 if (!locked)
 204                         THR_THREAD_LOCK(curthread, new_thread);
 205                 new_thread->state = PS_DEAD;
 206                 new_thread->tid = TID_TERMINATED;
 207                 new_thread->flags |= THR_FLAGS_DETACHED;
 208                 new_thread->refcount--;
 209                 if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
 210                         new_thread->cycle++;
 211                         _thr_umtx_wake(&new_thread->cycle, INT_MAX, 0);
 212                 }
 213                 _thr_try_gc(curthread, new_thread); /* thread lock released */
 214                 atomic_add_int(&_thread_active_threads, -1);
 215         } else if (locked) {
 216                 if (cpusetp != NULL) {
 217                         if (cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TID,
 218                                 TID(new_thread), cpusetsize, cpusetp)) {
 219                                 ret = errno;
 220                                 /* kill the new thread */
 221                                 new_thread->force_exit = 1;
 222                                 new_thread->flags |= THR_FLAGS_DETACHED;
 223                                 _thr_try_gc(curthread, new_thread);
 224                                  /* thread lock released */
 225                                 goto out;
 226                         }
 227                 }
 228
 229                 _thr_report_creation(curthread, new_thread);
 230                 THR_THREAD_UNLOCK(curthread, new_thread);
 231         }
 232 out:
 233         if (ret)
 234                 (*thread) = 0;
 235         return (ret);
 236 }
 237
 238 static int
 239 create_stack(struct pthread_attr *pattr)
 240 {
 241         int ret;
 242
 243         /* Check if a stack was specified in the thread attributes: */
 244         if ((pattr->stackaddr_attr) != NULL) {
 245                 pattr->guardsize_attr = 0;
 246                 pattr->flags |= THR_STACK_USER;
 247                 ret = 0;
 248         }
 249         else
 250                 ret = _thr_stack_alloc(pattr);
 251         return (ret);
 252 }
 253
 254 static void
 255 thread_start(struct pthread *curthread)
 256 {
 257         sigset_t set;
 258
 259         if (curthread->attr.suspend == THR_CREATE_SUSPENDED)
 260                 set = curthread->sigmask;
 261
 262         /*
 263          * This is used as a serialization point to allow parent
 264          * to report 'new thread' event to debugger or tweak new thread's
 265          * attributes before the new thread does real-world work.
 266          */
 267         THR_LOCK(curthread);
 268         THR_UNLOCK(curthread);
 269
 270         if (curthread->force_exit)
 271                 _pthread_exit(PTHREAD_CANCELED);
 272
 273         if (curthread->attr.suspend == THR_CREATE_SUSPENDED) {
 274 #if 0
 275                 /* Done in THR_UNLOCK() */
 276                 _thr_ast(curthread);
 277 #endif
 278
 279                 /*
 280                  * Parent thread have stored signal mask for us,
 281                  * we should restore it now.
 282                  */
 283                 __sys_sigprocmask(SIG_SETMASK, &set, NULL);
 284         }
 285
 286 #ifdef _PTHREAD_FORCED_UNWIND
 287         curthread->unwind_stackend = (char *)curthread->attr.stackaddr_attr +
 288                 curthread->attr.stacksize_attr;
 289 #endif
 290
 291         /* Run the current thread's start routine with argument: */
 292         _pthread_exit(curthread->start_routine(curthread->arg));
 293
 294         /* This point should never be reached. */
 295         PANIC("Thread has resumed after exit");
 296 }