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 "namespace.h" 33 #include <sys/mman.h> 34 #include <signal.h> 35 #include <stdlib.h> 36 #include <string.h> 37 #include <errno.h> 38 #include <pthread.h> 39 #include "un-namespace.h" 40 #include "libc_private.h" 41 42 #include "thr_private.h" 43 44 /* Used in symbol lookup of libthread_db */ 45 struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX]; 46 47 __weak_reference(_thr_key_create, pthread_key_create); 48 __weak_reference(_thr_key_create, _pthread_key_create); 49 __weak_reference(_thr_key_delete, pthread_key_delete); 50 __weak_reference(_thr_key_delete, _pthread_key_delete); 51 __weak_reference(_thr_getspecific, pthread_getspecific); 52 __weak_reference(_thr_getspecific, _pthread_getspecific); 53 __weak_reference(_thr_setspecific, pthread_setspecific); 54 __weak_reference(_thr_setspecific, _pthread_setspecific); 55 56 int 57 _thr_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 _thr_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 _thr_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 _thr_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 } 245