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 munmap(curthread->specific, PTHREAD_KEYS_MAX * sizeof(struct 159 pthread_specific_elem)); 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 _pthread_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 = mmap(NULL, PTHREAD_KEYS_MAX * 183 sizeof(struct pthread_specific_elem), 184 PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); 185 if (tmp == MAP_FAILED) 186 return (ENOMEM); 187 pthread->specific = tmp; 188 } 189 if (pthread->specific[key].data == NULL) { 190 if (value != NULL) 191 pthread->specific_data_count++; 192 } else if (value == NULL) 193 pthread->specific_data_count--; 194 pthread->specific[key].data = value; 195 pthread->specific[key].seqno = _thread_keytable[key].seqno; 196 return (0); 197 } 198 199 void * 200 _pthread_getspecific(pthread_key_t userkey) 201 { 202 struct pthread *pthread; 203 const void *data; 204 pthread_key_t key; 205 206 /* Check if there is specific data. */ 207 key = userkey - 1; 208 if ((unsigned int)key >= PTHREAD_KEYS_MAX) 209 return (NULL); 210 211 pthread = _get_curthread(); 212 /* Check if this key has been used before. */ 213 if (_thread_keytable[key].allocated && pthread->specific != NULL && 214 pthread->specific[key].seqno == _thread_keytable[key].seqno) { 215 /* Return the value: */ 216 data = pthread->specific[key].data; 217 } else { 218 /* 219 * This key has not been used before, so return NULL 220 * instead. 221 */ 222 data = NULL; 223 } 224 return (__DECONST(void *, data)); 225 } 226 227 void 228 _thr_tsd_unload(struct dl_phdr_info *phdr_info) 229 { 230 struct pthread *curthread; 231 void (*destructor)(void *); 232 int key; 233 234 curthread = _get_curthread(); 235 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 236 for (key = 0; key < PTHREAD_KEYS_MAX; key++) { 237 if (!_thread_keytable[key].allocated) 238 continue; 239 destructor = _thread_keytable[key].destructor; 240 if (destructor == NULL) 241 continue; 242 if (__elf_phdr_match_addr(phdr_info, destructor)) 243 _thread_keytable[key].destructor = NULL; 244 } 245 THR_LOCK_RELEASE(curthread, &_keytable_lock); 246 } 247