thr_init.c revision 176781
1/*
2 * Copyright (c) 2003 Daniel M. Eischen <deischen@freebsd.org>
3 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *	This product includes software developed by John Birrell.
17 * 4. Neither the name of the author nor the names of any co-contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * $FreeBSD: head/lib/libthr/thread/thr_init.c 176781 2008-03-04 03:03:24Z davidxu $
34 */
35
36#include "namespace.h"
37#include <sys/types.h>
38#include <sys/signalvar.h>
39#include <sys/ioctl.h>
40#include <sys/sysctl.h>
41#include <sys/ttycom.h>
42#include <sys/mman.h>
43#include <sys/rtprio.h>
44#include <errno.h>
45#include <fcntl.h>
46#include <paths.h>
47#include <pthread.h>
48#include <pthread_np.h>
49#include <signal.h>
50#include <stdlib.h>
51#include <string.h>
52#include <time.h>
53#include <unistd.h>
54#include "un-namespace.h"
55
56#include "libc_private.h"
57#include "thr_private.h"
58
59char		*_usrstack;
60struct pthread	*_thr_initial;
61int		_libthr_debug;
62int		_thread_event_mask;
63struct pthread	*_thread_last_event;
64pthreadlist	_thread_list = TAILQ_HEAD_INITIALIZER(_thread_list);
65pthreadlist 	_thread_gc_list = TAILQ_HEAD_INITIALIZER(_thread_gc_list);
66int		_thread_active_threads = 1;
67atfork_head	_thr_atfork_list = TAILQ_HEAD_INITIALIZER(_thr_atfork_list);
68struct umutex	_thr_atfork_lock = DEFAULT_UMUTEX;
69
70struct pthread_prio	_thr_priorities[3] = {
71	{RTP_PRIO_MIN,  RTP_PRIO_MAX, 0}, /* FIFO */
72	{0, 0, 63}, /* OTHER */
73	{RTP_PRIO_MIN, RTP_PRIO_MAX, 0}  /* RR */
74};
75
76struct pthread_attr _pthread_attr_default = {
77	.sched_policy = SCHED_OTHER,
78	.sched_inherit = 0,
79	.prio = 0,
80	.suspend = THR_CREATE_RUNNING,
81	.flags = PTHREAD_SCOPE_SYSTEM,
82	.stackaddr_attr = NULL,
83	.stacksize_attr = THR_STACK_DEFAULT,
84	.guardsize_attr = 0,
85	.cpusetsize = 0,
86	.cpuset = NULL
87};
88
89struct pthread_mutex_attr _pthread_mutexattr_default = {
90	.m_type = PTHREAD_MUTEX_DEFAULT,
91	.m_protocol = PTHREAD_PRIO_NONE,
92	.m_ceiling = 0,
93	.m_flags = 0
94};
95
96/* Default condition variable attributes: */
97struct pthread_cond_attr _pthread_condattr_default = {
98	.c_pshared = PTHREAD_PROCESS_PRIVATE,
99	.c_clockid = CLOCK_REALTIME
100};
101
102pid_t		_thr_pid;
103int		_thr_is_smp = 0;
104size_t		_thr_guard_default;
105size_t		_thr_stack_default = THR_STACK_DEFAULT;
106size_t		_thr_stack_initial = THR_STACK_INITIAL;
107int		_thr_page_size;
108int		_thr_spinloops;
109int		_thr_yieldloops;
110int		_gc_count;
111struct umutex	_mutex_static_lock = DEFAULT_UMUTEX;
112struct umutex	_cond_static_lock = DEFAULT_UMUTEX;
113struct umutex	_rwlock_static_lock = DEFAULT_UMUTEX;
114struct umutex	_keytable_lock = DEFAULT_UMUTEX;
115struct umutex	_thr_list_lock = DEFAULT_UMUTEX;
116struct umutex	_thr_event_lock = DEFAULT_UMUTEX;
117
118int	__pthread_cond_wait(pthread_cond_t *, pthread_mutex_t *);
119int	__pthread_mutex_lock(pthread_mutex_t *);
120int	__pthread_mutex_trylock(pthread_mutex_t *);
121void	_thread_init_hack(void) __attribute__ ((constructor));
122
123static void init_private(void);
124static void init_main_thread(struct pthread *thread);
125
126/*
127 * All weak references used within libc should be in this table.
128 * This is so that static libraries will work.
129 */
130
131STATIC_LIB_REQUIRE(_fork);
132STATIC_LIB_REQUIRE(_pthread_getspecific);
133STATIC_LIB_REQUIRE(_pthread_key_create);
134STATIC_LIB_REQUIRE(_pthread_key_delete);
135STATIC_LIB_REQUIRE(_pthread_mutex_destroy);
136STATIC_LIB_REQUIRE(_pthread_mutex_init);
137STATIC_LIB_REQUIRE(_pthread_mutex_lock);
138STATIC_LIB_REQUIRE(_pthread_mutex_trylock);
139STATIC_LIB_REQUIRE(_pthread_mutex_unlock);
140STATIC_LIB_REQUIRE(_pthread_mutexattr_init);
141STATIC_LIB_REQUIRE(_pthread_mutexattr_destroy);
142STATIC_LIB_REQUIRE(_pthread_mutexattr_settype);
143STATIC_LIB_REQUIRE(_pthread_once);
144STATIC_LIB_REQUIRE(_pthread_setspecific);
145STATIC_LIB_REQUIRE(_raise);
146STATIC_LIB_REQUIRE(_sem_destroy);
147STATIC_LIB_REQUIRE(_sem_getvalue);
148STATIC_LIB_REQUIRE(_sem_init);
149STATIC_LIB_REQUIRE(_sem_post);
150STATIC_LIB_REQUIRE(_sem_timedwait);
151STATIC_LIB_REQUIRE(_sem_trywait);
152STATIC_LIB_REQUIRE(_sem_wait);
153STATIC_LIB_REQUIRE(_sigaction);
154STATIC_LIB_REQUIRE(_sigprocmask);
155STATIC_LIB_REQUIRE(_sigsuspend);
156STATIC_LIB_REQUIRE(_sigtimedwait);
157STATIC_LIB_REQUIRE(_sigwait);
158STATIC_LIB_REQUIRE(_sigwaitinfo);
159STATIC_LIB_REQUIRE(_spinlock);
160STATIC_LIB_REQUIRE(_spinlock_debug);
161STATIC_LIB_REQUIRE(_spinunlock);
162STATIC_LIB_REQUIRE(_thread_init_hack);
163STATIC_LIB_REQUIRE(_vfork);
164
165/*
166 * These are needed when linking statically.  All references within
167 * libgcc (and in the future libc) to these routines are weak, but
168 * if they are not (strongly) referenced by the application or other
169 * libraries, then the actual functions will not be loaded.
170 */
171STATIC_LIB_REQUIRE(_pthread_once);
172STATIC_LIB_REQUIRE(_pthread_key_create);
173STATIC_LIB_REQUIRE(_pthread_key_delete);
174STATIC_LIB_REQUIRE(_pthread_getspecific);
175STATIC_LIB_REQUIRE(_pthread_setspecific);
176STATIC_LIB_REQUIRE(_pthread_mutex_init);
177STATIC_LIB_REQUIRE(_pthread_mutex_destroy);
178STATIC_LIB_REQUIRE(_pthread_mutex_lock);
179STATIC_LIB_REQUIRE(_pthread_mutex_trylock);
180STATIC_LIB_REQUIRE(_pthread_mutex_unlock);
181STATIC_LIB_REQUIRE(_pthread_create);
182
183/* Pull in all symbols required by libthread_db */
184STATIC_LIB_REQUIRE(_thread_state_running);
185
186#define	DUAL_ENTRY(entry)	\
187	(pthread_func_t)entry, (pthread_func_t)entry
188
189static pthread_func_t jmp_table[][2] = {
190	{DUAL_ENTRY(_pthread_atfork)},	/* PJT_ATFORK */
191	{DUAL_ENTRY(_pthread_attr_destroy)},	/* PJT_ATTR_DESTROY */
192	{DUAL_ENTRY(_pthread_attr_getdetachstate)},	/* PJT_ATTR_GETDETACHSTATE */
193	{DUAL_ENTRY(_pthread_attr_getguardsize)},	/* PJT_ATTR_GETGUARDSIZE */
194	{DUAL_ENTRY(_pthread_attr_getinheritsched)},	/* PJT_ATTR_GETINHERITSCHED */
195	{DUAL_ENTRY(_pthread_attr_getschedparam)},	/* PJT_ATTR_GETSCHEDPARAM */
196	{DUAL_ENTRY(_pthread_attr_getschedpolicy)},	/* PJT_ATTR_GETSCHEDPOLICY */
197	{DUAL_ENTRY(_pthread_attr_getscope)},	/* PJT_ATTR_GETSCOPE */
198	{DUAL_ENTRY(_pthread_attr_getstackaddr)},	/* PJT_ATTR_GETSTACKADDR */
199	{DUAL_ENTRY(_pthread_attr_getstacksize)},	/* PJT_ATTR_GETSTACKSIZE */
200	{DUAL_ENTRY(_pthread_attr_init)},	/* PJT_ATTR_INIT */
201	{DUAL_ENTRY(_pthread_attr_setdetachstate)},	/* PJT_ATTR_SETDETACHSTATE */
202	{DUAL_ENTRY(_pthread_attr_setguardsize)},	/* PJT_ATTR_SETGUARDSIZE */
203	{DUAL_ENTRY(_pthread_attr_setinheritsched)},	/* PJT_ATTR_SETINHERITSCHED */
204	{DUAL_ENTRY(_pthread_attr_setschedparam)},	/* PJT_ATTR_SETSCHEDPARAM */
205	{DUAL_ENTRY(_pthread_attr_setschedpolicy)},	/* PJT_ATTR_SETSCHEDPOLICY */
206	{DUAL_ENTRY(_pthread_attr_setscope)},	/* PJT_ATTR_SETSCOPE */
207	{DUAL_ENTRY(_pthread_attr_setstackaddr)},	/* PJT_ATTR_SETSTACKADDR */
208	{DUAL_ENTRY(_pthread_attr_setstacksize)},	/* PJT_ATTR_SETSTACKSIZE */
209	{DUAL_ENTRY(_pthread_cancel)},	/* PJT_CANCEL */
210	{DUAL_ENTRY(_pthread_cleanup_pop)},	/* PJT_CLEANUP_POP */
211	{DUAL_ENTRY(_pthread_cleanup_push)},	/* PJT_CLEANUP_PUSH */
212	{DUAL_ENTRY(_pthread_cond_broadcast)},	/* PJT_COND_BROADCAST */
213	{DUAL_ENTRY(_pthread_cond_destroy)},	/* PJT_COND_DESTROY */
214	{DUAL_ENTRY(_pthread_cond_init)},	/* PJT_COND_INIT */
215	{DUAL_ENTRY(_pthread_cond_signal)},	/* PJT_COND_SIGNAL */
216	{DUAL_ENTRY(_pthread_cond_timedwait)},	/* PJT_COND_TIMEDWAIT */
217	{(pthread_func_t)__pthread_cond_wait,
218	 (pthread_func_t)_pthread_cond_wait},	/* PJT_COND_WAIT */
219	{DUAL_ENTRY(_pthread_detach)},	/* PJT_DETACH */
220	{DUAL_ENTRY(_pthread_equal)},	/* PJT_EQUAL */
221	{DUAL_ENTRY(_pthread_exit)},	/* PJT_EXIT */
222	{DUAL_ENTRY(_pthread_getspecific)},	/* PJT_GETSPECIFIC */
223	{DUAL_ENTRY(_pthread_join)},	/* PJT_JOIN */
224	{DUAL_ENTRY(_pthread_key_create)},	/* PJT_KEY_CREATE */
225	{DUAL_ENTRY(_pthread_key_delete)},	/* PJT_KEY_DELETE*/
226	{DUAL_ENTRY(_pthread_kill)},	/* PJT_KILL */
227	{DUAL_ENTRY(_pthread_main_np)},		/* PJT_MAIN_NP */
228	{DUAL_ENTRY(_pthread_mutexattr_destroy)}, /* PJT_MUTEXATTR_DESTROY */
229	{DUAL_ENTRY(_pthread_mutexattr_init)},	/* PJT_MUTEXATTR_INIT */
230	{DUAL_ENTRY(_pthread_mutexattr_settype)}, /* PJT_MUTEXATTR_SETTYPE */
231	{DUAL_ENTRY(_pthread_mutex_destroy)},	/* PJT_MUTEX_DESTROY */
232	{DUAL_ENTRY(_pthread_mutex_init)},	/* PJT_MUTEX_INIT */
233	{(pthread_func_t)__pthread_mutex_lock,
234	 (pthread_func_t)_pthread_mutex_lock},	/* PJT_MUTEX_LOCK */
235	{(pthread_func_t)__pthread_mutex_trylock,
236	 (pthread_func_t)_pthread_mutex_trylock},/* PJT_MUTEX_TRYLOCK */
237	{DUAL_ENTRY(_pthread_mutex_unlock)},	/* PJT_MUTEX_UNLOCK */
238	{DUAL_ENTRY(_pthread_once)},		/* PJT_ONCE */
239	{DUAL_ENTRY(_pthread_rwlock_destroy)},	/* PJT_RWLOCK_DESTROY */
240	{DUAL_ENTRY(_pthread_rwlock_init)},	/* PJT_RWLOCK_INIT */
241	{DUAL_ENTRY(_pthread_rwlock_rdlock)},	/* PJT_RWLOCK_RDLOCK */
242	{DUAL_ENTRY(_pthread_rwlock_tryrdlock)},/* PJT_RWLOCK_TRYRDLOCK */
243	{DUAL_ENTRY(_pthread_rwlock_trywrlock)},/* PJT_RWLOCK_TRYWRLOCK */
244	{DUAL_ENTRY(_pthread_rwlock_unlock)},	/* PJT_RWLOCK_UNLOCK */
245	{DUAL_ENTRY(_pthread_rwlock_wrlock)},	/* PJT_RWLOCK_WRLOCK */
246	{DUAL_ENTRY(_pthread_self)},		/* PJT_SELF */
247	{DUAL_ENTRY(_pthread_setcancelstate)},	/* PJT_SETCANCELSTATE */
248	{DUAL_ENTRY(_pthread_setcanceltype)},	/* PJT_SETCANCELTYPE */
249	{DUAL_ENTRY(_pthread_setspecific)},	/* PJT_SETSPECIFIC */
250	{DUAL_ENTRY(_pthread_sigmask)},		/* PJT_SIGMASK */
251	{DUAL_ENTRY(_pthread_testcancel)}	/* PJT_TESTCANCEL */
252};
253
254static int init_once = 0;
255
256/*
257 * For the shared version of the threads library, the above is sufficient.
258 * But for the archive version of the library, we need a little bit more.
259 * Namely, we must arrange for this particular module to be pulled in from
260 * the archive library at link time.  To accomplish that, we define and
261 * initialize a variable, "_thread_autoinit_dummy_decl".  This variable is
262 * referenced (as an extern) from libc/stdlib/exit.c. This will always
263 * create a need for this module, ensuring that it is present in the
264 * executable.
265 */
266extern int _thread_autoinit_dummy_decl;
267int _thread_autoinit_dummy_decl = 0;
268
269void
270_thread_init_hack(void)
271{
272
273	_libpthread_init(NULL);
274}
275
276
277/*
278 * Threaded process initialization.
279 *
280 * This is only called under two conditions:
281 *
282 *   1) Some thread routines have detected that the library hasn't yet
283 *      been initialized (_thr_initial == NULL && curthread == NULL), or
284 *
285 *   2) An explicit call to reinitialize after a fork (indicated
286 *      by curthread != NULL)
287 */
288void
289_libpthread_init(struct pthread *curthread)
290{
291	int fd, first = 0;
292	sigset_t sigset, oldset;
293
294	/* Check if this function has already been called: */
295	if ((_thr_initial != NULL) && (curthread == NULL))
296		/* Only initialize the threaded application once. */
297		return;
298
299	/*
300	 * Check the size of the jump table to make sure it is preset
301	 * with the correct number of entries.
302	 */
303	if (sizeof(jmp_table) != (sizeof(pthread_func_t) * PJT_MAX * 2))
304		PANIC("Thread jump table not properly initialized");
305	memcpy(__thr_jtable, jmp_table, sizeof(jmp_table));
306
307	/*
308	 * Check for the special case of this process running as
309	 * or in place of init as pid = 1:
310	 */
311	if ((_thr_pid = getpid()) == 1) {
312		/*
313		 * Setup a new session for this process which is
314		 * assumed to be running as root.
315		 */
316		if (setsid() == -1)
317			PANIC("Can't set session ID");
318		if (revoke(_PATH_CONSOLE) != 0)
319			PANIC("Can't revoke console");
320		if ((fd = __sys_open(_PATH_CONSOLE, O_RDWR)) < 0)
321			PANIC("Can't open console");
322		if (setlogin("root") == -1)
323			PANIC("Can't set login to root");
324		if (_ioctl(fd, TIOCSCTTY, (char *) NULL) == -1)
325			PANIC("Can't set controlling terminal");
326	}
327
328	/* Initialize pthread private data. */
329	init_private();
330
331	/* Set the initial thread. */
332	if (curthread == NULL) {
333		first = 1;
334		/* Create and initialize the initial thread. */
335		curthread = _thr_alloc(NULL);
336		if (curthread == NULL)
337			PANIC("Can't allocate initial thread");
338		init_main_thread(curthread);
339	}
340	/*
341	 * Add the thread to the thread list queue.
342	 */
343	THR_LIST_ADD(curthread);
344	_thread_active_threads = 1;
345
346	/* Setup the thread specific data */
347	_tcb_set(curthread->tcb);
348
349	if (first) {
350		SIGFILLSET(sigset);
351		SIGDELSET(sigset, SIGTRAP);
352		__sys_sigprocmask(SIG_SETMASK, &sigset, &oldset);
353		_thr_signal_init();
354		_thr_initial = curthread;
355		SIGDELSET(oldset, SIGCANCEL);
356		__sys_sigprocmask(SIG_SETMASK, &oldset, NULL);
357		if (_thread_event_mask & TD_CREATE)
358			_thr_report_creation(curthread, curthread);
359	}
360}
361
362/*
363 * This function and pthread_create() do a lot of the same things.
364 * It'd be nice to consolidate the common stuff in one place.
365 */
366static void
367init_main_thread(struct pthread *thread)
368{
369	struct sched_param sched_param;
370
371	/* Setup the thread attributes. */
372	thr_self(&thread->tid);
373	thread->attr = _pthread_attr_default;
374	/*
375	 * Set up the thread stack.
376	 *
377	 * Create a red zone below the main stack.  All other stacks
378	 * are constrained to a maximum size by the parameters
379	 * passed to mmap(), but this stack is only limited by
380	 * resource limits, so this stack needs an explicitly mapped
381	 * red zone to protect the thread stack that is just beyond.
382	 */
383	if (mmap(_usrstack - _thr_stack_initial -
384	    _thr_guard_default, _thr_guard_default, 0, MAP_ANON,
385	    -1, 0) == MAP_FAILED)
386		PANIC("Cannot allocate red zone for initial thread");
387
388	/*
389	 * Mark the stack as an application supplied stack so that it
390	 * isn't deallocated.
391	 *
392	 * XXX - I'm not sure it would hurt anything to deallocate
393	 *       the main thread stack because deallocation doesn't
394	 *       actually free() it; it just puts it in the free
395	 *       stack queue for later reuse.
396	 */
397	thread->attr.stackaddr_attr = _usrstack - _thr_stack_initial;
398	thread->attr.stacksize_attr = _thr_stack_initial;
399	thread->attr.guardsize_attr = _thr_guard_default;
400	thread->attr.flags |= THR_STACK_USER;
401
402	/*
403	 * Write a magic value to the thread structure
404	 * to help identify valid ones:
405	 */
406	thread->magic = THR_MAGIC;
407
408	thread->cancel_enable = 1;
409	thread->cancel_async = 0;
410	thr_set_name(thread->tid, "initial thread");
411
412	/* Initialize the mutex queue: */
413	TAILQ_INIT(&thread->mutexq);
414	TAILQ_INIT(&thread->pp_mutexq);
415
416	thread->state = PS_RUNNING;
417
418	_thr_getscheduler(thread->tid, &thread->attr.sched_policy,
419		 &sched_param);
420	thread->attr.prio = sched_param.sched_priority;
421
422	/* Others cleared to zero by thr_alloc() */
423}
424
425static void
426init_private(void)
427{
428	size_t len;
429	int mib[2];
430	char *env;
431
432	_thr_umutex_init(&_mutex_static_lock);
433	_thr_umutex_init(&_cond_static_lock);
434	_thr_umutex_init(&_rwlock_static_lock);
435	_thr_umutex_init(&_keytable_lock);
436	_thr_umutex_init(&_thr_atfork_lock);
437	_thr_umutex_init(&_thr_event_lock);
438	_thr_once_init();
439	_thr_spinlock_init();
440	_thr_list_init();
441
442	/*
443	 * Avoid reinitializing some things if they don't need to be,
444	 * e.g. after a fork().
445	 */
446	if (init_once == 0) {
447		/* Find the stack top */
448		mib[0] = CTL_KERN;
449		mib[1] = KERN_USRSTACK;
450		len = sizeof (_usrstack);
451		if (sysctl(mib, 2, &_usrstack, &len, NULL, 0) == -1)
452			PANIC("Cannot get kern.usrstack from sysctl");
453		len = sizeof(_thr_is_smp);
454		sysctlbyname("kern.smp.cpus", &_thr_is_smp, &len, NULL, 0);
455		_thr_is_smp = (_thr_is_smp > 1);
456		_thr_page_size = getpagesize();
457		_thr_guard_default = _thr_page_size;
458		_pthread_attr_default.guardsize_attr = _thr_guard_default;
459		_pthread_attr_default.stacksize_attr = _thr_stack_default;
460		env = getenv("LIBPTHREAD_SPINLOOPS");
461		if (env)
462			_thr_spinloops = atoi(env);
463		env = getenv("LIBPTHREAD_YIELDLOOPS");
464		if (env)
465			_thr_yieldloops = atoi(env);
466		TAILQ_INIT(&_thr_atfork_list);
467	}
468	init_once = 1;
469}
470