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
_thr_key_create(pthread_key_t * key,void (* destructor)(void *))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
_thr_key_delete(pthread_key_t userkey)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
_thread_cleanupspecific(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
_thr_setspecific(pthread_key_t userkey,const void * value)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 *
_thr_getspecific(pthread_key_t userkey)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
_thr_tsd_unload(struct dl_phdr_info * phdr_info)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