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 static void exit_thread(void) __dead2;
51 __weak_reference(_pthread_exit, pthread_exit);
53 #ifdef _PTHREAD_FORCED_UNWIND
54 static int message_printed;
56 static void thread_unwind(void) __dead2;
58 static void thread_uw_init(void);
59 static _Unwind_Reason_Code thread_unwind_stop(int version,
60 _Unwind_Action actions,
62 struct _Unwind_Exception *exc_obj,
63 struct _Unwind_Context *context, void *stop_parameter);
64 /* unwind library pointers */
65 static _Unwind_Reason_Code (*uwl_forcedunwind)(struct _Unwind_Exception *,
66 _Unwind_Stop_Fn, void *);
67 static unsigned long (*uwl_getcfa)(struct _Unwind_Context *);
72 static int inited = 0;
75 void *forcedunwind, *getcfa;
79 handle = RTLD_DEFAULT;
80 if ((forcedunwind = dlsym(handle, "_Unwind_ForcedUnwind")) != NULL) {
81 if (dladdr(forcedunwind, &dli)) {
83 * Make sure the address is always valid by holding the library,
84 * also assume functions are in same library.
86 if ((handle = dlopen(dli.dli_fname, RTLD_LAZY)) != NULL) {
87 forcedunwind = dlsym(handle, "_Unwind_ForcedUnwind");
88 getcfa = dlsym(handle, "_Unwind_GetCFA");
89 if (forcedunwind != NULL && getcfa != NULL) {
91 atomic_store_rel_ptr((volatile void *)&uwl_forcedunwind,
92 (uintptr_t)forcedunwind);
103 _Unwind_ForcedUnwind(struct _Unwind_Exception *ex, _Unwind_Stop_Fn stop_func,
106 return (*uwl_forcedunwind)(ex, stop_func, stop_arg);
110 _Unwind_GetCFA(struct _Unwind_Context *context)
112 return (*uwl_getcfa)(context);
115 #pragma weak _Unwind_GetCFA
116 #pragma weak _Unwind_ForcedUnwind
120 thread_unwind_cleanup(_Unwind_Reason_Code code __unused,
121 struct _Unwind_Exception *e __unused)
124 * Specification said that _Unwind_Resume should not be used here,
125 * instead, user should rethrow the exception. For C++ user, they
126 * should put "throw" sentence in catch(...) block.
128 PANIC("exception should be rethrown");
131 static _Unwind_Reason_Code
132 thread_unwind_stop(int version __unused, _Unwind_Action actions,
133 int64_t exc_class __unused,
134 struct _Unwind_Exception *exc_obj __unused,
135 struct _Unwind_Context *context, void *stop_parameter __unused)
137 struct pthread *curthread = _get_curthread();
138 struct pthread_cleanup *cur;
142 /* XXX assume stack grows down to lower address */
144 cfa = _Unwind_GetCFA(context);
145 if (actions & _UA_END_OF_STACK ||
146 cfa >= (uintptr_t)curthread->unwind_stackend) {
150 while ((cur = curthread->cleanup) != NULL &&
151 (done || (uintptr_t)cur <= cfa)) {
152 __pthread_cleanup_pop_imp(1);
156 /* Tell libc that it should call non-trivial TLS dtors. */
157 __cxa_thread_call_dtors();
159 exit_thread(); /* Never return! */
162 return (_URC_NO_REASON);
168 struct pthread *curthread = _get_curthread();
170 curthread->ex.exception_class = 0;
171 curthread->ex.exception_cleanup = thread_unwind_cleanup;
172 _Unwind_ForcedUnwind(&curthread->ex, thread_unwind_stop, NULL);
173 PANIC("_Unwind_ForcedUnwind returned");
179 _thread_exitf(const char *fname, int lineno, const char *fmt, ...)
183 /* Write an error message to the standard error file descriptor: */
184 _thread_printf(STDERR_FILENO, "Fatal error '");
187 _thread_vprintf(STDERR_FILENO, fmt, ap);
190 _thread_printf(STDERR_FILENO, "' at line %d in file %s (errno = %d)\n",
191 lineno, fname, errno);
197 _thread_exit(const char *fname, int lineno, const char *msg)
200 _thread_exitf(fname, lineno, "%s", msg);
204 _pthread_exit(void *status)
206 _pthread_exit_mask(status, NULL);
210 _pthread_exit_mask(void *status, sigset_t *mask)
212 struct pthread *curthread = _get_curthread();
214 /* Check if this thread is already in the process of exiting: */
215 if (curthread->cancelling)
216 PANIC("Thread %p has called "
217 "pthread_exit() from a destructor. POSIX 1003.1 "
218 "1996 s16.2.5.2 does not allow this!", curthread);
220 /* Flag this thread as exiting. */
221 curthread->cancelling = 1;
222 curthread->no_cancel = 1;
223 curthread->cancel_async = 0;
224 curthread->cancel_point = 0;
226 __sys_sigprocmask(SIG_SETMASK, mask, NULL);
227 if (curthread->unblock_sigcancel) {
230 curthread->unblock_sigcancel = 0;
232 SIGADDSET(set, SIGCANCEL);
233 __sys_sigprocmask(SIG_UNBLOCK, mask, NULL);
236 /* Save the return value: */
237 curthread->ret = status;
238 #ifdef _PTHREAD_FORCED_UNWIND
242 if (uwl_forcedunwind != NULL) {
244 if (_Unwind_ForcedUnwind != NULL) {
246 if (curthread->unwind_disabled) {
247 if (message_printed == 0) {
249 _thread_printf(2, "Warning: old _pthread_cleanup_push was called, "
250 "stack unwinding is disabled.\n");
258 while (curthread->cleanup != NULL) {
259 __pthread_cleanup_pop_imp(1);
261 __cxa_thread_call_dtors();
267 while (curthread->cleanup != NULL) {
268 __pthread_cleanup_pop_imp(1);
270 __cxa_thread_call_dtors();
273 #endif /* _PTHREAD_FORCED_UNWIND */
279 struct pthread *curthread = _get_curthread();
281 /* Check if there is thread specific data: */
282 if (curthread->specific != NULL) {
283 /* Run the thread-specific data destructors: */
284 _thread_cleanupspecific();
287 if (!_thr_isthreaded())
290 if (atomic_fetchadd_int(&_thread_active_threads, -1) == 1) {
295 /* Tell malloc that the thread is exiting. */
296 _malloc_thread_cleanup();
299 curthread->state = PS_DEAD;
300 if (curthread->flags & THR_FLAGS_NEED_SUSPEND) {
302 _thr_umtx_wake(&curthread->cycle, INT_MAX, 0);
304 if (!curthread->force_exit && SHOULD_REPORT_EVENT(curthread, TD_DEATH))
305 _thr_report_death(curthread);
307 * Thread was created with initial refcount 1, we drop the
308 * reference count to allow it to be garbage collected.
310 curthread->refcount--;
311 _thr_try_gc(curthread, curthread); /* thread lock released */
313 #if defined(_PTHREADS_INVARIANTS)
314 if (THR_IN_CRITICAL(curthread))
315 PANIC("thread %p exits with resources held!", curthread);
318 * Kernel will do wakeup at the address, so joiner thread
319 * will be resumed if it is sleeping at the address.
321 thr_exit(&curthread->tid);
322 PANIC("thr_exit() returned");