xref: /freebsd/lib/libthr/thread/thr_exit.c (revision 6f066bb387cfcbb776040caf40cbe8cbe88ec2c1)
1bb535300SJeff Roberson /*
2bb535300SJeff Roberson  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
3bb535300SJeff Roberson  * All rights reserved.
4bb535300SJeff Roberson  *
5bb535300SJeff Roberson  * Redistribution and use in source and binary forms, with or without
6bb535300SJeff Roberson  * modification, are permitted provided that the following conditions
7bb535300SJeff Roberson  * are met:
8bb535300SJeff Roberson  * 1. Redistributions of source code must retain the above copyright
9bb535300SJeff Roberson  *    notice, this list of conditions and the following disclaimer.
10bb535300SJeff Roberson  * 2. Redistributions in binary form must reproduce the above copyright
11bb535300SJeff Roberson  *    notice, this list of conditions and the following disclaimer in the
12bb535300SJeff Roberson  *    documentation and/or other materials provided with the distribution.
13fed32d75SWarner Losh  * 3. Neither the name of the author nor the names of any co-contributors
14bb535300SJeff Roberson  *    may be used to endorse or promote products derived from this software
15bb535300SJeff Roberson  *    without specific prior written permission.
16bb535300SJeff Roberson  *
17bb535300SJeff Roberson  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
18bb535300SJeff Roberson  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19bb535300SJeff Roberson  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20bb535300SJeff Roberson  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21bb535300SJeff Roberson  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22bb535300SJeff Roberson  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23bb535300SJeff Roberson  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24bb535300SJeff Roberson  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25bb535300SJeff Roberson  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26bb535300SJeff Roberson  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27bb535300SJeff Roberson  * SUCH DAMAGE.
28bb535300SJeff Roberson  *
29bb535300SJeff Roberson  * $FreeBSD$
30bb535300SJeff Roberson  */
31a091d823SDavid Xu 
32e03efb02SRuslan Ermilov #include "namespace.h"
33bb535300SJeff Roberson #include <errno.h>
343832fd24SDavid Xu #ifdef _PTHREAD_FORCED_UNWIND
353832fd24SDavid Xu #include <dlfcn.h>
363832fd24SDavid Xu #endif
37bb535300SJeff Roberson #include <stdio.h>
38bb535300SJeff Roberson #include <stdlib.h>
39bb535300SJeff Roberson #include <pthread.h>
4002c3c858SDavid Xu #include <sys/types.h>
4102c3c858SDavid Xu #include <sys/signalvar.h>
42e03efb02SRuslan Ermilov #include "un-namespace.h"
43a091d823SDavid Xu 
44d6742bfbSJason Evans #include "libc_private.h"
45bb535300SJeff Roberson #include "thr_private.h"
46bb535300SJeff Roberson 
47a091d823SDavid Xu void	_pthread_exit(void *status);
48a091d823SDavid Xu 
493832fd24SDavid Xu static void	exit_thread(void) __dead2;
503832fd24SDavid Xu 
51bb535300SJeff Roberson __weak_reference(_pthread_exit, pthread_exit);
52bb535300SJeff Roberson 
533832fd24SDavid Xu #ifdef _PTHREAD_FORCED_UNWIND
543832fd24SDavid Xu 
553832fd24SDavid Xu static void thread_unwind(void) __dead2;
563832fd24SDavid Xu #ifdef PIC
573832fd24SDavid Xu static void thread_uw_init(void);
583832fd24SDavid Xu static _Unwind_Reason_Code thread_unwind_stop(int version,
593832fd24SDavid Xu 	_Unwind_Action actions,
603832fd24SDavid Xu 	_Unwind_Exception_Class exc_class,
613832fd24SDavid Xu 	struct _Unwind_Exception *exc_obj,
623832fd24SDavid Xu 	struct _Unwind_Context *context, void *stop_parameter);
633832fd24SDavid Xu /* unwind library pointers */
643832fd24SDavid Xu static _Unwind_Reason_Code (*uwl_forcedunwind)(struct _Unwind_Exception *,
653832fd24SDavid Xu 	_Unwind_Stop_Fn, void *);
663832fd24SDavid Xu static _Unwind_Word (*uwl_getcfa)(struct _Unwind_Context *);
673832fd24SDavid Xu 
683832fd24SDavid Xu static void
693832fd24SDavid Xu thread_uw_init(void)
703832fd24SDavid Xu {
713832fd24SDavid Xu 	static int inited = 0;
724da1da4bSDavid Xu 	Dl_info dlinfo;
733832fd24SDavid Xu 	void *handle;
74a5793db9SDavid Xu 	void *forcedunwind, *getcfa;
753832fd24SDavid Xu 
763832fd24SDavid Xu 	if (inited)
773832fd24SDavid Xu 	    return;
783832fd24SDavid Xu 	handle = RTLD_DEFAULT;
794da1da4bSDavid Xu 	if ((forcedunwind = dlsym(handle, "_Unwind_ForcedUnwind")) != NULL) {
804da1da4bSDavid Xu 	    if (dladdr(forcedunwind, &dlinfo)) {
81a5793db9SDavid Xu 		/*
82a5793db9SDavid Xu 		 * Make sure the address is always valid by holding the library,
83a5793db9SDavid Xu 		 * also assume functions are in same library.
84a5793db9SDavid Xu 		 */
854da1da4bSDavid Xu 		if ((handle = dlopen(dlinfo.dli_fname, RTLD_LAZY)) != NULL) {
864da1da4bSDavid Xu 		    forcedunwind = dlsym(handle, "_Unwind_ForcedUnwind");
874da1da4bSDavid Xu 		    getcfa = dlsym(handle, "_Unwind_GetCFA");
88a5793db9SDavid Xu 		    if (forcedunwind != NULL && getcfa != NULL) {
894da1da4bSDavid Xu 			uwl_getcfa = getcfa;
90a5793db9SDavid Xu 			atomic_store_rel_ptr((volatile void *)&uwl_forcedunwind,
91a5793db9SDavid Xu 				(uintptr_t)forcedunwind);
924da1da4bSDavid Xu 		    } else {
934da1da4bSDavid Xu 			dlclose(handle);
943832fd24SDavid Xu 		    }
953832fd24SDavid Xu 		}
964da1da4bSDavid Xu 	    }
974da1da4bSDavid Xu 	}
984da1da4bSDavid Xu 	inited = 1;
994da1da4bSDavid Xu }
1003832fd24SDavid Xu 
1013832fd24SDavid Xu _Unwind_Reason_Code
1023832fd24SDavid Xu _Unwind_ForcedUnwind(struct _Unwind_Exception *ex, _Unwind_Stop_Fn stop_func,
1033832fd24SDavid Xu 	void *stop_arg)
1043832fd24SDavid Xu {
1053832fd24SDavid Xu 	return (*uwl_forcedunwind)(ex, stop_func, stop_arg);
1063832fd24SDavid Xu }
1073832fd24SDavid Xu 
1083832fd24SDavid Xu _Unwind_Word
1093832fd24SDavid Xu _Unwind_GetCFA(struct _Unwind_Context *context)
1103832fd24SDavid Xu {
1113832fd24SDavid Xu 	return (*uwl_getcfa)(context);
1123832fd24SDavid Xu }
1133832fd24SDavid Xu #else
1143832fd24SDavid Xu #pragma weak _Unwind_GetCFA
1153832fd24SDavid Xu #pragma weak _Unwind_ForcedUnwind
1163832fd24SDavid Xu #endif /* PIC */
1173832fd24SDavid Xu 
1183832fd24SDavid Xu static void
1193832fd24SDavid Xu thread_unwind_cleanup(_Unwind_Reason_Code code, struct _Unwind_Exception *e)
1203832fd24SDavid Xu {
1213832fd24SDavid Xu 	/*
1223832fd24SDavid Xu 	 * Specification said that _Unwind_Resume should not be used here,
1233832fd24SDavid Xu 	 * instead, user should rethrow the exception. For C++ user, they
1243832fd24SDavid Xu 	 * should put "throw" sentence in catch(...) block.
1253832fd24SDavid Xu 	 */
1263832fd24SDavid Xu 	PANIC("exception should be rethrown");
1273832fd24SDavid Xu }
1283832fd24SDavid Xu 
1293832fd24SDavid Xu static _Unwind_Reason_Code
1303832fd24SDavid Xu thread_unwind_stop(int version, _Unwind_Action actions,
1313832fd24SDavid Xu 	_Unwind_Exception_Class exc_class,
1323832fd24SDavid Xu 	struct _Unwind_Exception *exc_obj,
1333832fd24SDavid Xu 	struct _Unwind_Context *context, void *stop_parameter)
1343832fd24SDavid Xu {
1353832fd24SDavid Xu 	struct pthread *curthread = _get_curthread();
1363832fd24SDavid Xu 	struct pthread_cleanup *cur;
1373832fd24SDavid Xu 	uintptr_t cfa;
1383832fd24SDavid Xu 	int done = 0;
1393832fd24SDavid Xu 
1403832fd24SDavid Xu 	/* XXX assume stack grows down to lower address */
1413832fd24SDavid Xu 
1423832fd24SDavid Xu 	cfa = _Unwind_GetCFA(context);
143*6f066bb3SDavid Xu 	if (actions & _UA_END_OF_STACK ||
144*6f066bb3SDavid Xu 	    cfa >= (uintptr_t)curthread->unwind_stackend) {
1453832fd24SDavid Xu 		done = 1;
1463832fd24SDavid Xu 	}
1473832fd24SDavid Xu 
1483832fd24SDavid Xu 	while ((cur = curthread->cleanup) != NULL &&
149*6f066bb3SDavid Xu 	       (done || (uintptr_t)cur <= cfa)) {
1503832fd24SDavid Xu 		__pthread_cleanup_pop_imp(1);
1513832fd24SDavid Xu 	}
1523832fd24SDavid Xu 
1533832fd24SDavid Xu 	if (done)
1543832fd24SDavid Xu 		exit_thread(); /* Never return! */
1553832fd24SDavid Xu 
1563832fd24SDavid Xu 	return (_URC_NO_REASON);
1573832fd24SDavid Xu }
1583832fd24SDavid Xu 
1593832fd24SDavid Xu static void
1603832fd24SDavid Xu thread_unwind(void)
1613832fd24SDavid Xu {
1623832fd24SDavid Xu 	struct pthread  *curthread = _get_curthread();
1633832fd24SDavid Xu 
1643832fd24SDavid Xu 	curthread->ex.exception_class = 0;
1653832fd24SDavid Xu 	curthread->ex.exception_cleanup = thread_unwind_cleanup;
1663832fd24SDavid Xu 	_Unwind_ForcedUnwind(&curthread->ex, thread_unwind_stop, NULL);
1673832fd24SDavid Xu 	PANIC("_Unwind_ForcedUnwind returned");
1683832fd24SDavid Xu }
1693832fd24SDavid Xu 
1703832fd24SDavid Xu #endif
1713832fd24SDavid Xu 
172bb535300SJeff Roberson void
17337a6356bSDavid Xu _thread_exit(const char *fname, int lineno, const char *msg)
174bb535300SJeff Roberson {
175bb535300SJeff Roberson 
176a091d823SDavid Xu 	/* Write an error message to the standard error file descriptor: */
177a091d823SDavid Xu 	_thread_printf(2,
178bb535300SJeff Roberson 	    "Fatal error '%s' at line %d in file %s (errno = %d)\n",
179a091d823SDavid Xu 	    msg, lineno, fname, errno);
180bb535300SJeff Roberson 
181bb535300SJeff Roberson 	abort();
182bb535300SJeff Roberson }
183bb535300SJeff Roberson 
184bb535300SJeff Roberson void
185bb535300SJeff Roberson _pthread_exit(void *status)
186bb535300SJeff Roberson {
18702c3c858SDavid Xu 	_pthread_exit_mask(status, NULL);
18802c3c858SDavid Xu }
18902c3c858SDavid Xu 
19002c3c858SDavid Xu void
19102c3c858SDavid Xu _pthread_exit_mask(void *status, sigset_t *mask)
19202c3c858SDavid Xu {
193a091d823SDavid Xu 	struct pthread *curthread = _get_curthread();
1944cd18a22SMike Makonnen 
195bb535300SJeff Roberson 	/* Check if this thread is already in the process of exiting: */
196f08e1bf6SDavid Xu 	if (curthread->cancelling) {
197bb535300SJeff Roberson 		char msg[128];
198a091d823SDavid Xu 		snprintf(msg, sizeof(msg), "Thread %p has called "
199a091d823SDavid Xu 		    "pthread_exit() from a destructor. POSIX 1003.1 "
200a091d823SDavid Xu 		    "1996 s16.2.5.2 does not allow this!", curthread);
201bb535300SJeff Roberson 		PANIC(msg);
202bb535300SJeff Roberson 	}
203bb535300SJeff Roberson 
204a091d823SDavid Xu 	/* Flag this thread as exiting. */
205f08e1bf6SDavid Xu 	curthread->cancelling = 1;
2064173ebefSDavid Xu 	curthread->no_cancel = 1;
207cdcffc3fSDavid Xu 	curthread->cancel_async = 0;
20802c3c858SDavid Xu 	curthread->cancel_point = 0;
20902c3c858SDavid Xu 	if (mask != NULL)
21002c3c858SDavid Xu 		__sys_sigprocmask(SIG_SETMASK, mask, NULL);
21102c3c858SDavid Xu 	if (curthread->unblock_sigcancel) {
21202c3c858SDavid Xu 		sigset_t set;
21302c3c858SDavid Xu 
21402c3c858SDavid Xu 		curthread->unblock_sigcancel = 0;
21502c3c858SDavid Xu 		SIGEMPTYSET(set);
21602c3c858SDavid Xu 		SIGADDSET(set, SIGCANCEL);
21702c3c858SDavid Xu 		__sys_sigprocmask(SIG_UNBLOCK, mask, NULL);
21802c3c858SDavid Xu 	}
219a091d823SDavid Xu 
220bb535300SJeff Roberson 	/* Save the return value: */
221bb535300SJeff Roberson 	curthread->ret = status;
2223832fd24SDavid Xu #ifdef _PTHREAD_FORCED_UNWIND
2233832fd24SDavid Xu #ifdef PIC
2243832fd24SDavid Xu 	thread_uw_init();
2253832fd24SDavid Xu 	if (uwl_forcedunwind != NULL) {
2263832fd24SDavid Xu 		thread_unwind();
227bb535300SJeff Roberson 	}
2283832fd24SDavid Xu #else
2293832fd24SDavid Xu 	if (_Unwind_ForcedUnwind != NULL) {
2303832fd24SDavid Xu 		thread_unwind();
2313832fd24SDavid Xu 	}
2323832fd24SDavid Xu #endif /* PIC */
2333832fd24SDavid Xu 
2343832fd24SDavid Xu  	else {
2353832fd24SDavid Xu 		while (curthread->cleanup != NULL) {
2363832fd24SDavid Xu 			__pthread_cleanup_pop_imp(1);
2373832fd24SDavid Xu 		}
2383832fd24SDavid Xu 		exit_thread();
2393832fd24SDavid Xu 	}
2403832fd24SDavid Xu 
2413832fd24SDavid Xu #else
2423832fd24SDavid Xu 	while (curthread->cleanup != NULL) {
2433832fd24SDavid Xu 		__pthread_cleanup_pop_imp(1);
2443832fd24SDavid Xu 	}
2453832fd24SDavid Xu 
2463832fd24SDavid Xu 	exit_thread();
2473832fd24SDavid Xu #endif /* _PTHREAD_FORCED_UNWIND */
2483832fd24SDavid Xu }
2493832fd24SDavid Xu 
2503832fd24SDavid Xu static void
2513832fd24SDavid Xu exit_thread(void)
2523832fd24SDavid Xu {
2533832fd24SDavid Xu 	struct pthread *curthread = _get_curthread();
25437a6356bSDavid Xu 
255bb535300SJeff Roberson 	/* Check if there is thread specific data: */
256bb535300SJeff Roberson 	if (curthread->specific != NULL) {
257bb535300SJeff Roberson 		/* Run the thread-specific data destructors: */
258bb535300SJeff Roberson 		_thread_cleanupspecific();
259bb535300SJeff Roberson 	}
260bb535300SJeff Roberson 
261a091d823SDavid Xu 	if (!_thr_isthreaded())
2624e3f7b6eSMike Makonnen 		exit(0);
263f97591bfSMike Makonnen 
264a9b764e2SDavid Xu 	if (atomic_fetchadd_int(&_thread_active_threads, -1) == 1) {
265a091d823SDavid Xu 		exit(0);
266a091d823SDavid Xu 		/* Never reach! */
267bb535300SJeff Roberson 	}
2685b3842aeSJason Evans 
2695b3842aeSJason Evans 	/* Tell malloc that the thread is exiting. */
2705b3842aeSJason Evans 	_malloc_thread_cleanup();
2715b3842aeSJason Evans 
272bc414752SDavid Xu 	THR_LOCK(curthread);
273bc414752SDavid Xu 	curthread->state = PS_DEAD;
2742ea1f90aSDavid Xu 	if (curthread->flags & THR_FLAGS_NEED_SUSPEND) {
2752ea1f90aSDavid Xu 		curthread->cycle++;
2768d6a11a0SDavid Xu 		_thr_umtx_wake(&curthread->cycle, INT_MAX, 0);
2772ea1f90aSDavid Xu 	}
278bc414752SDavid Xu 	/*
279bc414752SDavid Xu 	 * Thread was created with initial refcount 1, we drop the
280bc414752SDavid Xu 	 * reference count to allow it to be garbage collected.
281bc414752SDavid Xu 	 */
282bc414752SDavid Xu 	curthread->refcount--;
283a9b764e2SDavid Xu 	_thr_try_gc(curthread, curthread); /* thread lock released */
284a9b764e2SDavid Xu 
285697b4b49SDavid Xu 	if (!curthread->force_exit && SHOULD_REPORT_EVENT(curthread, TD_DEATH))
286d245d9e1SDavid Xu 		_thr_report_death(curthread);
287d7f119abSDavid Xu 
288a9b764e2SDavid Xu #if defined(_PTHREADS_INVARIANTS)
289a9b764e2SDavid Xu 	if (THR_IN_CRITICAL(curthread))
290a9b764e2SDavid Xu 		PANIC("thread exits with resources held!");
291a9b764e2SDavid Xu #endif
292d7f119abSDavid Xu 	/*
293d7f119abSDavid Xu 	 * Kernel will do wakeup at the address, so joiner thread
294d7f119abSDavid Xu 	 * will be resumed if it is sleeping at the address.
295d7f119abSDavid Xu 	 */
296d245d9e1SDavid Xu 	thr_exit(&curthread->tid);
297a091d823SDavid Xu 	PANIC("thr_exit() returned");
298a091d823SDavid Xu 	/* Never reach! */
2991c6f6301SMike Makonnen }
300