2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the author nor the names of any co-contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
33 #include "namespace.h"
35 #ifdef _PTHREAD_FORCED_UNWIND
42 #include <sys/types.h>
43 #include <sys/signalvar.h>
44 #include "un-namespace.h"
46 #include "libc_private.h"
47 #include "thr_private.h"
49 void _pthread_exit(void *status);
51 static void exit_thread(void) __dead2;
53 __weak_reference(_pthread_exit, pthread_exit);
55 #ifdef _PTHREAD_FORCED_UNWIND
56 static int message_printed;
58 static void thread_unwind(void) __dead2;
60 static void thread_uw_init(void);
61 static _Unwind_Reason_Code thread_unwind_stop(int version,
62 _Unwind_Action actions,
64 struct _Unwind_Exception *exc_obj,
65 struct _Unwind_Context *context, void *stop_parameter);
66 /* unwind library pointers */
67 static _Unwind_Reason_Code (*uwl_forcedunwind)(struct _Unwind_Exception *,
68 _Unwind_Stop_Fn, void *);
69 static unsigned long (*uwl_getcfa)(struct _Unwind_Context *);
74 static int inited = 0;
77 void *forcedunwind, *getcfa;
81 handle = RTLD_DEFAULT;
82 if ((forcedunwind = dlsym(handle, "_Unwind_ForcedUnwind")) != NULL) {
83 if (dladdr(forcedunwind, &dlinfo)) {
85 * Make sure the address is always valid by holding the library,
86 * also assume functions are in same library.
88 if ((handle = dlopen(dlinfo.dli_fname, RTLD_LAZY)) != NULL) {
89 forcedunwind = dlsym(handle, "_Unwind_ForcedUnwind");
90 getcfa = dlsym(handle, "_Unwind_GetCFA");
91 if (forcedunwind != NULL && getcfa != NULL) {
93 atomic_store_rel_ptr((volatile void *)&uwl_forcedunwind,
94 (uintptr_t)forcedunwind);
105 _Unwind_ForcedUnwind(struct _Unwind_Exception *ex, _Unwind_Stop_Fn stop_func,
108 return (*uwl_forcedunwind)(ex, stop_func, stop_arg);
112 _Unwind_GetCFA(struct _Unwind_Context *context)
114 return (*uwl_getcfa)(context);
117 #pragma weak _Unwind_GetCFA
118 #pragma weak _Unwind_ForcedUnwind
122 thread_unwind_cleanup(_Unwind_Reason_Code code, struct _Unwind_Exception *e)
125 * Specification said that _Unwind_Resume should not be used here,
126 * instead, user should rethrow the exception. For C++ user, they
127 * should put "throw" sentence in catch(...) block.
129 PANIC("exception should be rethrown");
132 static _Unwind_Reason_Code
133 thread_unwind_stop(int version, _Unwind_Action actions,
135 struct _Unwind_Exception *exc_obj,
136 struct _Unwind_Context *context, void *stop_parameter)
138 struct pthread *curthread = _get_curthread();
139 struct pthread_cleanup *cur;
143 /* XXX assume stack grows down to lower address */
145 cfa = _Unwind_GetCFA(context);
146 if (actions & _UA_END_OF_STACK ||
147 cfa >= (uintptr_t)curthread->unwind_stackend) {
151 while ((cur = curthread->cleanup) != NULL &&
152 (done || (uintptr_t)cur <= cfa)) {
153 __pthread_cleanup_pop_imp(1);
157 /* Tell libc that it should call non-trivial TLS dtors. */
158 __cxa_thread_call_dtors();
160 exit_thread(); /* Never return! */
163 return (_URC_NO_REASON);
169 struct pthread *curthread = _get_curthread();
171 curthread->ex.exception_class = 0;
172 curthread->ex.exception_cleanup = thread_unwind_cleanup;
173 _Unwind_ForcedUnwind(&curthread->ex, thread_unwind_stop, NULL);
174 PANIC("_Unwind_ForcedUnwind returned");
180 _thread_exitf(const char *fname, int lineno, const char *fmt, ...)
184 /* Write an error message to the standard error file descriptor: */
185 _thread_printf(STDERR_FILENO, "Fatal error '");
188 _thread_vprintf(STDERR_FILENO, fmt, ap);
191 _thread_printf(STDERR_FILENO, "' at line %d in file %s (errno = %d)\n",
192 lineno, fname, errno);
198 _thread_exit(const char *fname, int lineno, const char *msg)
201 _thread_exitf(fname, lineno, "%s", msg);
205 _pthread_exit(void *status)
207 _pthread_exit_mask(status, NULL);
211 _pthread_exit_mask(void *status, sigset_t *mask)
213 struct pthread *curthread = _get_curthread();
215 /* Check if this thread is already in the process of exiting: */
216 if (curthread->cancelling)
217 PANIC("Thread %p has called "
218 "pthread_exit() from a destructor. POSIX 1003.1 "
219 "1996 s16.2.5.2 does not allow this!", curthread);
221 /* Flag this thread as exiting. */
222 curthread->cancelling = 1;
223 curthread->no_cancel = 1;
224 curthread->cancel_async = 0;
225 curthread->cancel_point = 0;
227 __sys_sigprocmask(SIG_SETMASK, mask, NULL);
228 if (curthread->unblock_sigcancel) {
231 curthread->unblock_sigcancel = 0;
233 SIGADDSET(set, SIGCANCEL);
234 __sys_sigprocmask(SIG_UNBLOCK, mask, NULL);
237 /* Save the return value: */
238 curthread->ret = status;
239 #ifdef _PTHREAD_FORCED_UNWIND
243 if (uwl_forcedunwind != NULL) {
245 if (_Unwind_ForcedUnwind != NULL) {
247 if (curthread->unwind_disabled) {
248 if (message_printed == 0) {
250 _thread_printf(2, "Warning: old _pthread_cleanup_push was called, "
251 "stack unwinding is disabled.\n");
259 while (curthread->cleanup != NULL) {
260 __pthread_cleanup_pop_imp(1);
262 __cxa_thread_call_dtors();
268 while (curthread->cleanup != NULL) {
269 __pthread_cleanup_pop_imp(1);
271 __cxa_thread_call_dtors();
274 #endif /* _PTHREAD_FORCED_UNWIND */
280 struct pthread *curthread = _get_curthread();
282 /* Check if there is thread specific data: */
283 if (curthread->specific != NULL) {
284 /* Run the thread-specific data destructors: */
285 _thread_cleanupspecific();
288 if (!_thr_isthreaded())
291 if (atomic_fetchadd_int(&_thread_active_threads, -1) == 1) {
296 /* Tell malloc that the thread is exiting. */
297 _malloc_thread_cleanup();
300 curthread->state = PS_DEAD;
301 if (curthread->flags & THR_FLAGS_NEED_SUSPEND) {
303 _thr_umtx_wake(&curthread->cycle, INT_MAX, 0);
305 if (!curthread->force_exit && SHOULD_REPORT_EVENT(curthread, TD_DEATH))
306 _thr_report_death(curthread);
308 * Thread was created with initial refcount 1, we drop the
309 * reference count to allow it to be garbage collected.
311 curthread->refcount--;
312 _thr_try_gc(curthread, curthread); /* thread lock released */
314 #if defined(_PTHREADS_INVARIANTS)
315 if (THR_IN_CRITICAL(curthread))
316 PANIC("thread %p exits with resources held!", curthread);
319 * Kernel will do wakeup at the address, so joiner thread
320 * will be resumed if it is sleeping at the address.
322 thr_exit(&curthread->tid);
323 PANIC("thr_exit() returned");