1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2003 Daniel M. Eischen <deischen@gdeb.com>
5 * Copyright (c) 2005, David Xu <davidxu@freebsd.org>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice unmodified, this list of conditions, and the following
13 * disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include "namespace.h"
31 #include <sys/types.h>
32 #include <sys/rtprio.h>
33 #include <sys/signalvar.h>
34 #include <errno.h>
35 #include <link.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <stddef.h>
39 #include <pthread.h>
40 #include <pthread_np.h>
41 #include "un-namespace.h"
42
43 #include "libc_private.h"
44 #include "thr_private.h"
45
46 static int create_stack(struct pthread_attr *pattr);
47 static void thread_start(struct pthread *curthread);
48
49 __weak_reference(_pthread_create, pthread_create);
50
51 int
_pthread_create(pthread_t * __restrict thread,const pthread_attr_t * __restrict attr,void * (* start_routine)(void *),void * __restrict arg)52 _pthread_create(pthread_t * __restrict thread,
53 const pthread_attr_t * __restrict attr, void *(*start_routine) (void *),
54 void * __restrict arg)
55 {
56 struct pthread *curthread, *new_thread;
57 struct thr_param param;
58 struct sched_param sched_param;
59 struct rtprio rtp;
60 sigset_t set, oset;
61 cpuset_t *cpusetp;
62 int i, cpusetsize, create_suspended, locked, old_stack_prot, ret;
63
64 cpusetp = NULL;
65 ret = cpusetsize = 0;
66 _thr_check_init();
67
68 /*
69 * Tell libc and others now they need lock to protect their data.
70 */
71 if (_thr_isthreaded() == 0) {
72 _malloc_first_thread();
73 _thr_setthreaded(1);
74 }
75
76 curthread = _get_curthread();
77 if ((new_thread = _thr_alloc(curthread)) == NULL)
78 return (EAGAIN);
79
80 memset(¶m, 0, sizeof(param));
81
82 if (attr == NULL || *attr == NULL)
83 /* Use the default thread attributes: */
84 new_thread->attr = _pthread_attr_default;
85 else {
86 new_thread->attr = *(*attr);
87 cpusetp = new_thread->attr.cpuset;
88 cpusetsize = new_thread->attr.cpusetsize;
89 new_thread->attr.cpuset = NULL;
90 new_thread->attr.cpusetsize = 0;
91 }
92 if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
93 /* inherit scheduling contention scope */
94 if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
95 new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
96 else
97 new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
98
99 new_thread->attr.prio = curthread->attr.prio;
100 new_thread->attr.sched_policy = curthread->attr.sched_policy;
101 }
102
103 new_thread->tid = TID_TERMINATED;
104
105 old_stack_prot = _rtld_get_stack_prot();
106 if (create_stack(&new_thread->attr) != 0) {
107 /* Insufficient memory to create a stack: */
108 _thr_free(curthread, new_thread);
109 return (EAGAIN);
110 }
111 /*
112 * Write a magic value to the thread structure
113 * to help identify valid ones:
114 */
115 new_thread->magic = THR_MAGIC;
116 new_thread->start_routine = start_routine;
117 new_thread->arg = arg;
118 new_thread->cancel_enable = 1;
119 new_thread->cancel_async = 0;
120 /* Initialize the mutex queue: */
121 for (i = 0; i < TMQ_NITEMS; i++)
122 TAILQ_INIT(&new_thread->mq[i]);
123
124 /* Initialise hooks in the thread structure: */
125 if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) {
126 new_thread->flags = THR_FLAGS_NEED_SUSPEND;
127 create_suspended = 1;
128 } else {
129 create_suspended = 0;
130 }
131
132 new_thread->state = PS_RUNNING;
133
134 if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED)
135 new_thread->flags |= THR_FLAGS_DETACHED;
136
137 /* Add the new thread. */
138 new_thread->refcount = 1;
139 _thr_link(curthread, new_thread);
140
141 /*
142 * Handle the race between __pthread_map_stacks_exec and
143 * thread linkage.
144 */
145 if (old_stack_prot != _rtld_get_stack_prot())
146 _thr_stack_fix_protection(new_thread);
147
148 /* Return thread pointer eariler so that new thread can use it. */
149 (*thread) = new_thread;
150 if (SHOULD_REPORT_EVENT(curthread, TD_CREATE) || cpusetp != NULL) {
151 THR_THREAD_LOCK(curthread, new_thread);
152 locked = 1;
153 } else
154 locked = 0;
155 param.start_func = (void (*)(void *)) thread_start;
156 param.arg = new_thread;
157 param.stack_base = new_thread->attr.stackaddr_attr;
158 param.stack_size = new_thread->attr.stacksize_attr;
159 param.tls_base = (char *)new_thread->tcb;
160 param.tls_size = sizeof(struct tcb);
161 param.child_tid = &new_thread->tid;
162 param.parent_tid = &new_thread->tid;
163 param.flags = 0;
164 if (new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM)
165 param.flags |= THR_SYSTEM_SCOPE;
166 if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED)
167 param.rtp = NULL;
168 else {
169 sched_param.sched_priority = new_thread->attr.prio;
170 _schedparam_to_rtp(new_thread->attr.sched_policy,
171 &sched_param, &rtp);
172 param.rtp = &rtp;
173 }
174
175 /* Schedule the new thread. */
176 if (create_suspended) {
177 SIGFILLSET(set);
178 SIGDELSET(set, SIGTRAP);
179 __sys_sigprocmask(SIG_SETMASK, &set, &oset);
180 new_thread->sigmask = oset;
181 SIGDELSET(new_thread->sigmask, SIGCANCEL);
182 }
183
184 ret = thr_new(¶m, sizeof(param));
185
186 if (ret != 0) {
187 ret = errno;
188 /*
189 * Translate EPROCLIM into well-known POSIX code EAGAIN.
190 */
191 if (ret == EPROCLIM)
192 ret = EAGAIN;
193 }
194
195 if (create_suspended)
196 __sys_sigprocmask(SIG_SETMASK, &oset, NULL);
197
198 if (ret != 0) {
199 if (!locked)
200 THR_THREAD_LOCK(curthread, new_thread);
201 new_thread->state = PS_DEAD;
202 new_thread->tid = TID_TERMINATED;
203 new_thread->flags |= THR_FLAGS_DETACHED;
204 new_thread->refcount--;
205 if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
206 new_thread->cycle++;
207 _thr_umtx_wake(&new_thread->cycle, INT_MAX, 0);
208 }
209 _thr_try_gc(curthread, new_thread); /* thread lock released */
210 atomic_add_int(&_thread_active_threads, -1);
211 } else if (locked) {
212 if (cpusetp != NULL) {
213 if (cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TID,
214 TID(new_thread), cpusetsize, cpusetp)) {
215 ret = errno;
216 /* kill the new thread */
217 new_thread->force_exit = 1;
218 new_thread->flags |= THR_FLAGS_DETACHED;
219 _thr_try_gc(curthread, new_thread);
220 /* thread lock released */
221 goto out;
222 }
223 }
224
225 _thr_report_creation(curthread, new_thread);
226 THR_THREAD_UNLOCK(curthread, new_thread);
227 }
228 out:
229 if (ret)
230 (*thread) = 0;
231 return (ret);
232 }
233
234 static int
create_stack(struct pthread_attr * pattr)235 create_stack(struct pthread_attr *pattr)
236 {
237 int ret;
238
239 /* Check if a stack was specified in the thread attributes: */
240 if ((pattr->stackaddr_attr) != NULL) {
241 pattr->guardsize_attr = 0;
242 pattr->flags |= THR_STACK_USER;
243 ret = 0;
244 }
245 else
246 ret = _thr_stack_alloc(pattr);
247 return (ret);
248 }
249
250 static void
thread_start(struct pthread * curthread)251 thread_start(struct pthread *curthread)
252 {
253 sigset_t set;
254
255 if (curthread->attr.suspend == THR_CREATE_SUSPENDED)
256 set = curthread->sigmask;
257 _thr_signal_block_setup(curthread);
258
259 /*
260 * This is used as a serialization point to allow parent
261 * to report 'new thread' event to debugger or tweak new thread's
262 * attributes before the new thread does real-world work.
263 */
264 THR_LOCK(curthread);
265 THR_UNLOCK(curthread);
266
267 if (curthread->force_exit)
268 _pthread_exit(PTHREAD_CANCELED);
269
270 if (curthread->attr.suspend == THR_CREATE_SUSPENDED) {
271 #if 0
272 /* Done in THR_UNLOCK() */
273 _thr_ast(curthread);
274 #endif
275
276 /*
277 * Parent thread have stored signal mask for us,
278 * we should restore it now.
279 */
280 __sys_sigprocmask(SIG_SETMASK, &set, NULL);
281 }
282
283 #ifdef _PTHREAD_FORCED_UNWIND
284 curthread->unwind_stackend = (char *)curthread->attr.stackaddr_attr +
285 curthread->attr.stacksize_attr;
286 #endif
287
288 /* Run the current thread's start routine with argument: */
289 _pthread_exit(curthread->start_routine(curthread->arg));
290
291 /* This point should never be reached. */
292 PANIC("Thread has resumed after exit");
293 }
294