lib/libthr/thread/thr_spec.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the author nor the names of any co-contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 __FBSDID("$FreeBSD$");
  34
  35 #include "namespace.h"
  36 #include <sys/mman.h>
  37 #include <signal.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <errno.h>
  41 #include <pthread.h>
  42 #include "un-namespace.h"
  43 #include "libc_private.h"
  44
  45 #include "thr_private.h"
  46
  47 /* Used in symbol lookup of libthread_db */
  48 struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX];
  49
  50 __weak_reference(_pthread_key_create, pthread_key_create);
  51 __weak_reference(_pthread_key_delete, pthread_key_delete);
  52 __weak_reference(_pthread_getspecific, pthread_getspecific);
  53 __weak_reference(_pthread_setspecific, pthread_setspecific);
  54
  55
  56 int
  57 _pthread_key_create(pthread_key_t *key, void (*destructor)(void *))
  58 {
  59         struct pthread *curthread;
  60         int i;
  61
  62         _thr_check_init();
  63
  64         curthread = _get_curthread();
  65
  66         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
  67         for (i = 0; i < PTHREAD_KEYS_MAX; i++) {
  68
  69                 if (_thread_keytable[i].allocated == 0) {
  70                         _thread_keytable[i].allocated = 1;
  71                         _thread_keytable[i].destructor = destructor;
  72                         _thread_keytable[i].seqno++;
  73
  74                         THR_LOCK_RELEASE(curthread, &_keytable_lock);
  75                         *key = i + 1;
  76                         return (0);
  77                 }
  78
  79         }
  80         THR_LOCK_RELEASE(curthread, &_keytable_lock);
  81         return (EAGAIN);
  82 }
  83
  84 int
  85 _pthread_key_delete(pthread_key_t userkey)
  86 {
  87         struct pthread *curthread;
  88         int key, ret;
  89
  90         key = userkey - 1;
  91         if ((unsigned int)key >= PTHREAD_KEYS_MAX)
  92                 return (EINVAL);
  93         curthread = _get_curthread();
  94         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
  95         if (_thread_keytable[key].allocated) {
  96                 _thread_keytable[key].allocated = 0;
  97                 ret = 0;
  98         } else {
  99                 ret = EINVAL;
 100         }
 101         THR_LOCK_RELEASE(curthread, &_keytable_lock);
 102         return (ret);
 103 }
 104
 105 void
 106 _thread_cleanupspecific(void)
 107 {
 108         struct pthread *curthread;
 109         void (*destructor)(void *);
 110         const void *data;
 111         int i, key;
 112
 113         curthread = _get_curthread();
 114         if (curthread->specific == NULL)
 115                 return;
 116         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
 117         for (i = 0; i < PTHREAD_DESTRUCTOR_ITERATIONS &&
 118             curthread->specific_data_count > 0; i++) {
 119                 for (key = 0; key < PTHREAD_KEYS_MAX &&
 120                     curthread->specific_data_count > 0; key++) {
 121                         destructor = NULL;
 122
 123                         if (_thread_keytable[key].allocated &&
 124                             (curthread->specific[key].data != NULL)) {
 125                                 if (curthread->specific[key].seqno ==
 126                                     _thread_keytable[key].seqno) {
 127                                         data = curthread->specific[key].data;
 128                                         destructor = _thread_keytable[key].
 129                                             destructor;
 130                                 }
 131                                 curthread->specific[key].data = NULL;
 132                                 curthread->specific_data_count--;
 133                         } else if (curthread->specific[key].data != NULL) {
 134                                 /*
 135                                  * This can happen if the key is
 136                                  * deleted via pthread_key_delete
 137                                  * without first setting the value to
 138                                  * NULL in all threads.  POSIX says
 139                                  * that the destructor is not invoked
 140                                  * in this case.
 141                                  */
 142                                 curthread->specific[key].data = NULL;
 143                                 curthread->specific_data_count--;
 144                         }
 145
 146                         /*
 147                          * If there is a destructor, call it with the
 148                          * key table entry unlocked.
 149                          */
 150                         if (destructor != NULL) {
 151                                 THR_LOCK_RELEASE(curthread, &_keytable_lock);
 152                                 destructor(__DECONST(void *, data));
 153                                 THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
 154                         }
 155                 }
 156         }
 157         THR_LOCK_RELEASE(curthread, &_keytable_lock);
 158         __thr_free(curthread->specific);
 159         curthread->specific = NULL;
 160         if (curthread->specific_data_count > 0) {
 161                 stderr_debug("Thread %p has exited with leftover "
 162                     "thread-specific data after %d destructor iterations\n",
 163                     curthread, PTHREAD_DESTRUCTOR_ITERATIONS);
 164         }
 165 }
 166
 167 int
 168 _pthread_setspecific(pthread_key_t userkey, const void *value)
 169 {
 170         struct pthread *pthread;
 171         void *tmp;
 172         pthread_key_t key;
 173
 174         key = userkey - 1;
 175         if ((unsigned int)key >= PTHREAD_KEYS_MAX ||
 176             !_thread_keytable[key].allocated)
 177                 return (EINVAL);
 178
 179         pthread = _get_curthread();
 180         if (pthread->specific == NULL) {
 181                 tmp = __thr_calloc(PTHREAD_KEYS_MAX,
 182                     sizeof(struct pthread_specific_elem));
 183                 if (tmp == NULL)
 184                         return (ENOMEM);
 185                 pthread->specific = tmp;
 186         }
 187         if (pthread->specific[key].data == NULL) {
 188                 if (value != NULL)
 189                         pthread->specific_data_count++;
 190         } else if (value == NULL)
 191                 pthread->specific_data_count--;
 192         pthread->specific[key].data = value;
 193         pthread->specific[key].seqno = _thread_keytable[key].seqno;
 194         return (0);
 195 }
 196
 197 void *
 198 _pthread_getspecific(pthread_key_t userkey)
 199 {
 200         struct pthread *pthread;
 201         const void *data;
 202         pthread_key_t key;
 203
 204         /* Check if there is specific data. */
 205         key = userkey - 1;
 206         if ((unsigned int)key >= PTHREAD_KEYS_MAX)
 207                 return (NULL);
 208
 209         pthread = _get_curthread();
 210         /* Check if this key has been used before. */
 211         if (_thread_keytable[key].allocated && pthread->specific != NULL &&
 212             pthread->specific[key].seqno == _thread_keytable[key].seqno) {
 213                 /* Return the value: */
 214                 data = pthread->specific[key].data;
 215         } else {
 216                 /*
 217                  * This key has not been used before, so return NULL
 218                  * instead.
 219                  */
 220                 data = NULL;
 221         }
 222         return (__DECONST(void *, data));
 223 }
 224
 225 void
 226 _thr_tsd_unload(struct dl_phdr_info *phdr_info)
 227 {
 228         struct pthread *curthread;
 229         void (*destructor)(void *);
 230         int key;
 231
 232         curthread = _get_curthread();
 233         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
 234         for (key = 0; key < PTHREAD_KEYS_MAX; key++) {
 235                 if (!_thread_keytable[key].allocated)
 236                         continue;
 237                 destructor = _thread_keytable[key].destructor;
 238                 if (destructor == NULL)
 239                         continue;
 240                 if (__elf_phdr_match_addr(phdr_info, destructor))
 241                         _thread_keytable[key].destructor = NULL;
 242         }
 243         THR_LOCK_RELEASE(curthread, &_keytable_lock);
 244 }