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 #include "namespace.h" 34 #include <sys/mman.h> 35 #include <signal.h> 36 #include <stdlib.h> 37 #include <string.h> 38 #include <errno.h> 39 #include <pthread.h> 40 #include "un-namespace.h" 41 #include "libc_private.h" 42 43 #include "thr_private.h" 44 45 /* Used in symbol lookup of libthread_db */ 46 struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX]; 47 48 __weak_reference(_thr_key_create, pthread_key_create); 49 __weak_reference(_thr_key_create, _pthread_key_create); 50 __weak_reference(_thr_key_delete, pthread_key_delete); 51 __weak_reference(_thr_key_delete, _pthread_key_delete); 52 __weak_reference(_thr_getspecific, pthread_getspecific); 53 __weak_reference(_thr_getspecific, _pthread_getspecific); 54 __weak_reference(_thr_setspecific, pthread_setspecific); 55 __weak_reference(_thr_setspecific, _pthread_setspecific); 56 57 int 58 _thr_key_create(pthread_key_t *key, void (*destructor)(void *)) 59 { 60 struct pthread *curthread; 61 int i; 62 63 _thr_check_init(); 64 65 curthread = _get_curthread(); 66 67 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 68 for (i = 0; i < PTHREAD_KEYS_MAX; i++) { 69 70 if (_thread_keytable[i].allocated == 0) { 71 _thread_keytable[i].allocated = 1; 72 _thread_keytable[i].destructor = destructor; 73 _thread_keytable[i].seqno++; 74 75 THR_LOCK_RELEASE(curthread, &_keytable_lock); 76 *key = i + 1; 77 return (0); 78 } 79 80 } 81 THR_LOCK_RELEASE(curthread, &_keytable_lock); 82 return (EAGAIN); 83 } 84 85 int 86 _thr_key_delete(pthread_key_t userkey) 87 { 88 struct pthread *curthread; 89 int key, ret; 90 91 key = userkey - 1; 92 if ((unsigned int)key >= PTHREAD_KEYS_MAX) 93 return (EINVAL); 94 curthread = _get_curthread(); 95 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 96 if (_thread_keytable[key].allocated) { 97 _thread_keytable[key].allocated = 0; 98 ret = 0; 99 } else { 100 ret = EINVAL; 101 } 102 THR_LOCK_RELEASE(curthread, &_keytable_lock); 103 return (ret); 104 } 105 106 void 107 _thread_cleanupspecific(void) 108 { 109 struct pthread *curthread; 110 void (*destructor)(void *); 111 const void *data; 112 int i, key; 113 114 curthread = _get_curthread(); 115 if (curthread->specific == NULL) 116 return; 117 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 118 for (i = 0; i < PTHREAD_DESTRUCTOR_ITERATIONS && 119 curthread->specific_data_count > 0; i++) { 120 for (key = 0; key < PTHREAD_KEYS_MAX && 121 curthread->specific_data_count > 0; key++) { 122 destructor = NULL; 123 124 if (_thread_keytable[key].allocated && 125 (curthread->specific[key].data != NULL)) { 126 if (curthread->specific[key].seqno == 127 _thread_keytable[key].seqno) { 128 data = curthread->specific[key].data; 129 destructor = _thread_keytable[key]. 130 destructor; 131 } 132 curthread->specific[key].data = NULL; 133 curthread->specific_data_count--; 134 } else if (curthread->specific[key].data != NULL) { 135 /* 136 * This can happen if the key is 137 * deleted via pthread_key_delete 138 * without first setting the value to 139 * NULL in all threads. POSIX says 140 * that the destructor is not invoked 141 * in this case. 142 */ 143 curthread->specific[key].data = NULL; 144 curthread->specific_data_count--; 145 } 146 147 /* 148 * If there is a destructor, call it with the 149 * key table entry unlocked. 150 */ 151 if (destructor != NULL) { 152 THR_LOCK_RELEASE(curthread, &_keytable_lock); 153 destructor(__DECONST(void *, data)); 154 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 155 } 156 } 157 } 158 THR_LOCK_RELEASE(curthread, &_keytable_lock); 159 __thr_free(curthread->specific); 160 curthread->specific = NULL; 161 if (curthread->specific_data_count > 0) { 162 stderr_debug("Thread %p has exited with leftover " 163 "thread-specific data after %d destructor iterations\n", 164 curthread, PTHREAD_DESTRUCTOR_ITERATIONS); 165 } 166 } 167 168 int 169 _thr_setspecific(pthread_key_t userkey, const void *value) 170 { 171 struct pthread *pthread; 172 void *tmp; 173 pthread_key_t key; 174 175 key = userkey - 1; 176 if ((unsigned int)key >= PTHREAD_KEYS_MAX || 177 !_thread_keytable[key].allocated) 178 return (EINVAL); 179 180 pthread = _get_curthread(); 181 if (pthread->specific == NULL) { 182 tmp = __thr_calloc(PTHREAD_KEYS_MAX, 183 sizeof(struct pthread_specific_elem)); 184 if (tmp == NULL) 185 return (ENOMEM); 186 pthread->specific = tmp; 187 } 188 if (pthread->specific[key].data == NULL) { 189 if (value != NULL) 190 pthread->specific_data_count++; 191 } else if (value == NULL) 192 pthread->specific_data_count--; 193 pthread->specific[key].data = value; 194 pthread->specific[key].seqno = _thread_keytable[key].seqno; 195 return (0); 196 } 197 198 void * 199 _thr_getspecific(pthread_key_t userkey) 200 { 201 struct pthread *pthread; 202 const void *data; 203 pthread_key_t key; 204 205 /* Check if there is specific data. */ 206 key = userkey - 1; 207 if ((unsigned int)key >= PTHREAD_KEYS_MAX) 208 return (NULL); 209 210 pthread = _get_curthread(); 211 /* Check if this key has been used before. */ 212 if (_thread_keytable[key].allocated && pthread->specific != NULL && 213 pthread->specific[key].seqno == _thread_keytable[key].seqno) { 214 /* Return the value: */ 215 data = pthread->specific[key].data; 216 } else { 217 /* 218 * This key has not been used before, so return NULL 219 * instead. 220 */ 221 data = NULL; 222 } 223 return (__DECONST(void *, data)); 224 } 225 226 void 227 _thr_tsd_unload(struct dl_phdr_info *phdr_info) 228 { 229 struct pthread *curthread; 230 void (*destructor)(void *); 231 int key; 232 233 curthread = _get_curthread(); 234 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 235 for (key = 0; key < PTHREAD_KEYS_MAX; key++) { 236 if (!_thread_keytable[key].allocated) 237 continue; 238 destructor = _thread_keytable[key].destructor; 239 if (destructor == NULL) 240 continue; 241 if (__elf_phdr_match_addr(phdr_info, destructor)) 242 _thread_keytable[key].destructor = NULL; 243 } 244 THR_LOCK_RELEASE(curthread, &_keytable_lock); 245 } 246