2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the author nor the names of any co-contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
35 #include "namespace.h"
37 #ifdef _PTHREAD_FORCED_UNWIND
44 #include <sys/types.h>
45 #include <sys/signalvar.h>
46 #include "un-namespace.h"
48 #include "libc_private.h"
49 #include "thr_private.h"
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, &dli)) {
85 * Make sure the address is always valid by holding the library,
86 * also assume functions are in same library.
88 if ((handle = dlopen(dli.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 __unused,
123 struct _Unwind_Exception *e __unused)
126 * Specification said that _Unwind_Resume should not be used here,
127 * instead, user should rethrow the exception. For C++ user, they
128 * should put "throw" sentence in catch(...) block.
130 PANIC("exception should be rethrown");
133 static _Unwind_Reason_Code
134 thread_unwind_stop(int version __unused, _Unwind_Action actions,
135 int64_t exc_class __unused,
136 struct _Unwind_Exception *exc_obj __unused,
137 struct _Unwind_Context *context, void *stop_parameter __unused)
139 struct pthread *curthread = _get_curthread();
140 struct pthread_cleanup *cur;
144 /* XXX assume stack grows down to lower address */
146 cfa = _Unwind_GetCFA(context);
147 if (actions & _UA_END_OF_STACK ||
148 cfa >= (uintptr_t)curthread->unwind_stackend) {
152 while ((cur = curthread->cleanup) != NULL &&
153 (done || (uintptr_t)cur <= cfa)) {
154 __pthread_cleanup_pop_imp(1);
158 /* Tell libc that it should call non-trivial TLS dtors. */
159 __cxa_thread_call_dtors();
161 exit_thread(); /* Never return! */
164 return (_URC_NO_REASON);
170 struct pthread *curthread = _get_curthread();
172 curthread->ex.exception_class = 0;
173 curthread->ex.exception_cleanup = thread_unwind_cleanup;
174 _Unwind_ForcedUnwind(&curthread->ex, thread_unwind_stop, NULL);
175 PANIC("_Unwind_ForcedUnwind returned");
181 _thread_exitf(const char *fname, int lineno, const char *fmt, ...)
185 /* Write an error message to the standard error file descriptor: */
186 _thread_printf(STDERR_FILENO, "Fatal error '");
189 _thread_vprintf(STDERR_FILENO, fmt, ap);
192 _thread_printf(STDERR_FILENO, "' at line %d in file %s (errno = %d)\n",
193 lineno, fname, errno);
199 _thread_exit(const char *fname, int lineno, const char *msg)
202 _thread_exitf(fname, lineno, "%s", msg);
206 _pthread_exit(void *status)
208 _pthread_exit_mask(status, NULL);
212 _pthread_exit_mask(void *status, sigset_t *mask)
214 struct pthread *curthread = _get_curthread();
216 /* Check if this thread is already in the process of exiting: */
217 if (curthread->cancelling)
218 PANIC("Thread %p has called "
219 "pthread_exit() from a destructor. POSIX 1003.1 "
220 "1996 s16.2.5.2 does not allow this!", curthread);
222 /* Flag this thread as exiting. */
223 curthread->cancelling = 1;
224 curthread->no_cancel = 1;
225 curthread->cancel_async = 0;
226 curthread->cancel_point = 0;
228 __sys_sigprocmask(SIG_SETMASK, mask, NULL);
229 if (curthread->unblock_sigcancel) {
232 curthread->unblock_sigcancel = 0;
234 SIGADDSET(set, SIGCANCEL);
235 __sys_sigprocmask(SIG_UNBLOCK, mask, NULL);
238 /* Save the return value: */
239 curthread->ret = status;
240 #ifdef _PTHREAD_FORCED_UNWIND
244 if (uwl_forcedunwind != NULL) {
246 if (_Unwind_ForcedUnwind != NULL) {
248 if (curthread->unwind_disabled) {
249 if (message_printed == 0) {
251 _thread_printf(2, "Warning: old _pthread_cleanup_push was called, "
252 "stack unwinding is disabled.\n");
260 while (curthread->cleanup != NULL) {
261 __pthread_cleanup_pop_imp(1);
263 __cxa_thread_call_dtors();
269 while (curthread->cleanup != NULL) {
270 __pthread_cleanup_pop_imp(1);
272 __cxa_thread_call_dtors();
275 #endif /* _PTHREAD_FORCED_UNWIND */
281 struct pthread *curthread = _get_curthread();
283 /* Check if there is thread specific data: */
284 if (curthread->specific != NULL) {
285 /* Run the thread-specific data destructors: */
286 _thread_cleanupspecific();
289 if (!_thr_isthreaded())
292 if (atomic_fetchadd_int(&_thread_active_threads, -1) == 1) {
297 /* Tell malloc that the thread is exiting. */
298 _malloc_thread_cleanup();
301 curthread->state = PS_DEAD;
302 if (curthread->flags & THR_FLAGS_NEED_SUSPEND) {
304 _thr_umtx_wake(&curthread->cycle, INT_MAX, 0);
306 if (!curthread->force_exit && SHOULD_REPORT_EVENT(curthread, TD_DEATH))
307 _thr_report_death(curthread);
309 * Thread was created with initial refcount 1, we drop the
310 * reference count to allow it to be garbage collected.
312 curthread->refcount--;
313 _thr_try_gc(curthread, curthread); /* thread lock released */
315 #if defined(_PTHREADS_INVARIANTS)
316 if (THR_IN_CRITICAL(curthread))
317 PANIC("thread %p exits with resources held!", curthread);
320 * Kernel will do wakeup at the address, so joiner thread
321 * will be resumed if it is sleeping at the address.
323 thr_exit(&curthread->tid);
324 PANIC("thr_exit() returned");