1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /*
28 * Copyright 2024 Oxide Computer Company
29 */
30
31 #include "lint.h"
32 #include "thr_uberdata.h"
33 #include <pthread.h>
34
35 /*
36 * pthread_mutexattr_init: allocates the mutex attribute object and
37 * initializes it with the default values.
38 */
39 #pragma weak _pthread_mutexattr_init = pthread_mutexattr_init
40 int
pthread_mutexattr_init(pthread_mutexattr_t * attr)41 pthread_mutexattr_init(pthread_mutexattr_t *attr)
42 {
43 mattr_t *ap;
44
45 if ((ap = lmalloc(sizeof (mattr_t))) == NULL)
46 return (ENOMEM);
47 ap->pshared = PTHREAD_PROCESS_PRIVATE;
48 ap->type = PTHREAD_MUTEX_DEFAULT;
49 ap->protocol = PTHREAD_PRIO_NONE;
50 ap->robustness = PTHREAD_MUTEX_STALLED;
51 attr->__pthread_mutexattrp = ap;
52 return (0);
53 }
54
55 /*
56 * pthread_mutexattr_destroy: frees the mutex attribute object and
57 * invalidates it with NULL value.
58 */
59 int
pthread_mutexattr_destroy(pthread_mutexattr_t * attr)60 pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
61 {
62 if (attr == NULL || attr->__pthread_mutexattrp == NULL)
63 return (EINVAL);
64 lfree(attr->__pthread_mutexattrp, sizeof (mattr_t));
65 attr->__pthread_mutexattrp = NULL;
66 return (0);
67 }
68
69 /*
70 * pthread_mutexattr_setpshared: sets the shared attribute
71 * to PTHREAD_PROCESS_PRIVATE or PTHREAD_PROCESS_SHARED.
72 * This is equivalent to setting the USYNC_THREAD/USYNC_PROCESS
73 * flag in mutex_init().
74 */
75 int
pthread_mutexattr_setpshared(pthread_mutexattr_t * attr,int pshared)76 pthread_mutexattr_setpshared(pthread_mutexattr_t *attr, int pshared)
77 {
78 mattr_t *ap;
79
80 if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
81 (pshared != PTHREAD_PROCESS_PRIVATE &&
82 pshared != PTHREAD_PROCESS_SHARED))
83 return (EINVAL);
84 ap->pshared = pshared;
85 return (0);
86 }
87
88 /*
89 * pthread_mutexattr_getpshared: gets the shared attribute.
90 */
91 #pragma weak _pthread_mutexattr_getpshared = pthread_mutexattr_getpshared
92 int
pthread_mutexattr_getpshared(const pthread_mutexattr_t * attr,int * pshared)93 pthread_mutexattr_getpshared(const pthread_mutexattr_t *attr, int *pshared)
94 {
95 mattr_t *ap;
96
97 if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
98 pshared == NULL)
99 return (EINVAL);
100 *pshared = ap->pshared;
101 return (0);
102 }
103
104 /*
105 * pthread_mutexattr_setprioceiling: sets the prioceiling attribute.
106 */
107 int
pthread_mutexattr_setprioceiling(pthread_mutexattr_t * attr,int prioceiling)108 pthread_mutexattr_setprioceiling(pthread_mutexattr_t *attr, int prioceiling)
109 {
110 const pcclass_t *pccp = get_info_by_policy(SCHED_FIFO);
111 mattr_t *ap;
112
113 if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
114 prioceiling < pccp->pcc_primin || prioceiling > pccp->pcc_primax)
115 return (EINVAL);
116 ap->prioceiling = prioceiling;
117 return (0);
118 }
119
120 /*
121 * pthread_mutexattr_getprioceiling: gets the prioceiling attribute.
122 */
123 #pragma weak _pthread_mutexattr_getprioceiling = \
124 pthread_mutexattr_getprioceiling
125 int
pthread_mutexattr_getprioceiling(const pthread_mutexattr_t * attr,int * ceiling)126 pthread_mutexattr_getprioceiling(const pthread_mutexattr_t *attr, int *ceiling)
127 {
128 mattr_t *ap;
129
130 if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
131 ceiling == NULL)
132 return (EINVAL);
133 *ceiling = ap->prioceiling;
134 return (0);
135 }
136
137 /*
138 * pthread_mutexattr_setprotocol: sets the protocol attribute.
139 */
140 int
pthread_mutexattr_setprotocol(pthread_mutexattr_t * attr,int protocol)141 pthread_mutexattr_setprotocol(pthread_mutexattr_t *attr, int protocol)
142 {
143 mattr_t *ap;
144
145 if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL)
146 return (EINVAL);
147 if (protocol != PTHREAD_PRIO_NONE &&
148 protocol != PTHREAD_PRIO_INHERIT &&
149 protocol != PTHREAD_PRIO_PROTECT)
150 return (ENOTSUP);
151 ap->protocol = protocol;
152 return (0);
153 }
154
155 /*
156 * pthread_mutexattr_getprotocol: gets the protocol attribute.
157 */
158 #pragma weak _pthread_mutexattr_getprotocol = pthread_mutexattr_getprotocol
159 int
pthread_mutexattr_getprotocol(const pthread_mutexattr_t * attr,int * protocol)160 pthread_mutexattr_getprotocol(const pthread_mutexattr_t *attr, int *protocol)
161 {
162 mattr_t *ap;
163
164 if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
165 protocol == NULL)
166 return (EINVAL);
167 *protocol = ap->protocol;
168 return (0);
169 }
170
171 /*
172 * pthread_mutexattr_setrobust: set the mutex robust attribute.
173 * pthread_mutexattr_setrobust_np: the historical name.
174 */
175 #pragma weak pthread_mutexattr_setrobust_np = pthread_mutexattr_setrobust
176 int
pthread_mutexattr_setrobust(pthread_mutexattr_t * attr,int robust)177 pthread_mutexattr_setrobust(pthread_mutexattr_t *attr, int robust)
178 {
179 mattr_t *ap;
180
181 if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
182 (robust != PTHREAD_MUTEX_ROBUST && robust != PTHREAD_MUTEX_STALLED))
183 return (EINVAL);
184 ap->robustness = robust;
185 return (0);
186 }
187
188 /*
189 * pthread_mutexattr_getrobust: get the mutex robust attribute.
190 * pthread_mutexattr_getrobust_np: the historical name.
191 */
192 #pragma weak pthread_mutexattr_getrobust_np = pthread_mutexattr_getrobust
193 int
pthread_mutexattr_getrobust(const pthread_mutexattr_t * attr,int * robust)194 pthread_mutexattr_getrobust(const pthread_mutexattr_t *attr, int *robust)
195 {
196 mattr_t *ap;
197
198 if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
199 robust == NULL)
200 return (EINVAL);
201 *robust = ap->robustness;
202 return (0);
203 }
204
205 /*
206 * pthread_mutex_init: Initializes the mutex object. It copies the various
207 * attributes into one type argument and calls mutex_init(). Unlike other
208 * values, the types that are used in the mutex attributes are not 1:1 mapped to
209 * our underlying lock types at this time so we can properly honor the semantics
210 * of someone asking for a PTHREAD_MUTEX_NORMAL lock that must deadlock. The
211 * underlying threads implementation does not do this by default for
212 * USYNC_THREAD and so we don't do this unless explicitly asked for it.
213 */
214 #pragma weak _pthread_mutex_init = pthread_mutex_init
215 int
pthread_mutex_init(pthread_mutex_t * _RESTRICT_KYWD mutex,const pthread_mutexattr_t * _RESTRICT_KYWD attr)216 pthread_mutex_init(pthread_mutex_t *_RESTRICT_KYWD mutex,
217 const pthread_mutexattr_t *_RESTRICT_KYWD attr)
218 {
219 mattr_t *ap;
220 int type, ret;
221 int prioceiling = 0;
222 uint16_t flags = 0;
223
224 /*
225 * All of the pshared, type, protocol, robust attributes
226 * translate to bits in the mutex_type field.
227 */
228 if (attr != NULL) {
229 if ((ap = attr->__pthread_mutexattrp) == NULL)
230 return (EINVAL);
231 switch (ap->type) {
232 case PTHREAD_MUTEX_NORMAL:
233 type = LOCK_NORMAL;
234 flags = LOCK_DEADLOCK;
235 break;
236 case PTHREAD_MUTEX_ERRORCHECK:
237 type = LOCK_ERRORCHECK;
238 break;
239 case PTHREAD_MUTEX_RECURSIVE:
240 type = LOCK_RECURSIVE | LOCK_ERRORCHECK;
241 break;
242 default:
243 /*
244 * This covers PTHREAD_MUTEX_DEFAULT, which should be
245 * the only remaining valid value.
246 */
247 type = LOCK_NORMAL;
248 break;
249 }
250
251 type |= ap->pshared | ap->protocol | ap->robustness;
252 if (ap->protocol == PTHREAD_PRIO_PROTECT)
253 prioceiling = ap->prioceiling;
254 } else {
255 type = PTHREAD_PROCESS_PRIVATE | LOCK_NORMAL |
256 PTHREAD_PRIO_NONE | PTHREAD_MUTEX_STALLED;
257 }
258
259 /*
260 * POSIX mutexes (this interface) make no guarantee about the state of
261 * the mutex before pthread_mutex_init(3C) is called. Sun mutexes, upon
262 * which these are built and which mutex_init(3C) below represents
263 * require that a robust mutex be initialized to all 0s _prior_ to
264 * mutex_init() being called, and that mutex_init() of an initialized
265 * mutex return EBUSY.
266 *
267 * We respect both these behaviors by zeroing the mutex here in the
268 * POSIX implementation if and only if the mutex magic is incorrect,
269 * and the mutex is robust.
270 */
271 if (((type & PTHREAD_MUTEX_ROBUST) != 0) &&
272 (((mutex_t *)mutex)->mutex_magic != MUTEX_MAGIC)) {
273 (void) memset(mutex, 0, sizeof (*mutex));
274 }
275
276 ret = mutex_init((mutex_t *)mutex, type, &prioceiling);
277
278 /*
279 * If we have a normal mutex, we need to set that deadlock behavior is
280 * required.
281 */
282 if (ret == 0 && flags != 0) {
283 mutex_t *mp = (mutex_t *)mutex;
284 mp->mutex_flag |= flags;
285 }
286
287 return (ret);
288 }
289
290 /*
291 * pthread_mutex_setprioceiling: sets the prioceiling.
292 * From the SUSv3 (POSIX) specification for pthread_mutex_setprioceiling():
293 * The process of locking the mutex need not
294 * adhere to the priority protect protocol.
295 * We pass the MUTEX_NOCEIL flag to mutex_lock_internal() so that
296 * a non-realtime thread can successfully execute this operation.
297 */
298 int
pthread_mutex_setprioceiling(pthread_mutex_t * mutex,int ceil,int * oceil)299 pthread_mutex_setprioceiling(pthread_mutex_t *mutex, int ceil, int *oceil)
300 {
301 mutex_t *mp = (mutex_t *)mutex;
302 const pcclass_t *pccp = get_info_by_policy(SCHED_FIFO);
303 int error;
304
305 if (!(mp->mutex_type & PTHREAD_PRIO_PROTECT) ||
306 ceil < pccp->pcc_primin || ceil > pccp->pcc_primax)
307 return (EINVAL);
308 error = mutex_lock_internal(mp, NULL, MUTEX_LOCK | MUTEX_NOCEIL);
309 if (error == 0 || error == EOWNERDEAD || error == ELOCKUNMAPPED) {
310 if (oceil)
311 *oceil = mp->mutex_ceiling;
312 mp->mutex_ceiling = ceil;
313 error = mutex_unlock_internal(mp, 1);
314 }
315 return (error);
316 }
317
318 /*
319 * pthread_mutex_getprioceiling: gets the prioceiling.
320 */
321 #pragma weak _pthread_mutex_getprioceiling = pthread_mutex_getprioceiling
322 int
pthread_mutex_getprioceiling(const pthread_mutex_t * mp,int * ceiling)323 pthread_mutex_getprioceiling(const pthread_mutex_t *mp, int *ceiling)
324 {
325 *ceiling = ((mutex_t *)mp)->mutex_ceiling;
326 return (0);
327 }
328
329 /*
330 * UNIX98
331 * pthread_mutexattr_settype: sets the type attribute
332 *
333 * Type attributes are kept in terms of POSIX mutex types until the mutex is
334 * initialized, after which it is translated into the corresponding underlying
335 * lock type.
336 */
337 int
pthread_mutexattr_settype(pthread_mutexattr_t * attr,int type)338 pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type)
339 {
340 mattr_t *ap;
341
342 if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL)
343 return (EINVAL);
344 switch (type) {
345 case PTHREAD_MUTEX_NORMAL:
346 case PTHREAD_MUTEX_ERRORCHECK:
347 case PTHREAD_MUTEX_RECURSIVE:
348 case PTHREAD_MUTEX_DEFAULT:
349 break;
350 default:
351 return (EINVAL);
352 }
353 ap->type = type;
354 return (0);
355 }
356
357 /*
358 * UNIX98
359 * pthread_mutexattr_gettype: gets the type attribute.
360 */
361 int
pthread_mutexattr_gettype(const pthread_mutexattr_t * attr,int * typep)362 pthread_mutexattr_gettype(const pthread_mutexattr_t *attr, int *typep)
363 {
364 mattr_t *ap;
365 int type;
366
367 if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
368 typep == NULL)
369 return (EINVAL);
370 *typep = type;
371 return (0);
372 }
373