thr_exit.c revision 212838
1/* 2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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. 16 * 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 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD: head/lib/libthr/thread/thr_exit.c 212838 2010-09-19 05:42:29Z davidxu $ 30 */ 31 32#include "namespace.h" 33#include <errno.h> 34#ifdef _PTHREAD_FORCED_UNWIND 35#include <dlfcn.h> 36#endif 37#include <stdio.h> 38#include <stdlib.h> 39#include <pthread.h> 40#include <sys/types.h> 41#include <sys/signalvar.h> 42#include "un-namespace.h" 43 44#include "libc_private.h" 45#include "thr_private.h" 46 47void _pthread_exit(void *status); 48 49static void exit_thread(void) __dead2; 50 51__weak_reference(_pthread_exit, pthread_exit); 52 53#ifdef _PTHREAD_FORCED_UNWIND 54 55static void thread_unwind(void) __dead2; 56#ifdef PIC 57static void thread_uw_init(void); 58static _Unwind_Reason_Code thread_unwind_stop(int version, 59 _Unwind_Action actions, 60 _Unwind_Exception_Class exc_class, 61 struct _Unwind_Exception *exc_obj, 62 struct _Unwind_Context *context, void *stop_parameter); 63/* unwind library pointers */ 64static _Unwind_Reason_Code (*uwl_forcedunwind)(struct _Unwind_Exception *, 65 _Unwind_Stop_Fn, void *); 66static _Unwind_Word (*uwl_getcfa)(struct _Unwind_Context *); 67 68static void 69thread_uw_init(void) 70{ 71 static int inited = 0; 72 Dl_info dlinfo; 73 void *handle; 74 void *forcedunwind, *getcfa; 75 76 if (inited) 77 return; 78 handle = RTLD_DEFAULT; 79 if ((forcedunwind = dlsym(handle, "_Unwind_ForcedUnwind")) != NULL) { 80 if (dladdr(forcedunwind, &dlinfo)) { 81 /* 82 * Make sure the address is always valid by holding the library, 83 * also assume functions are in same library. 84 */ 85 if ((handle = dlopen(dlinfo.dli_fname, RTLD_LAZY)) != NULL) { 86 forcedunwind = dlsym(handle, "_Unwind_ForcedUnwind"); 87 getcfa = dlsym(handle, "_Unwind_GetCFA"); 88 if (forcedunwind != NULL && getcfa != NULL) { 89 uwl_getcfa = getcfa; 90 atomic_store_rel_ptr((volatile void *)&uwl_forcedunwind, 91 (uintptr_t)forcedunwind); 92 } else { 93 dlclose(handle); 94 } 95 } 96 } 97 } 98 inited = 1; 99} 100 101_Unwind_Reason_Code 102_Unwind_ForcedUnwind(struct _Unwind_Exception *ex, _Unwind_Stop_Fn stop_func, 103 void *stop_arg) 104{ 105 return (*uwl_forcedunwind)(ex, stop_func, stop_arg); 106} 107 108_Unwind_Word 109_Unwind_GetCFA(struct _Unwind_Context *context) 110{ 111 return (*uwl_getcfa)(context); 112} 113#else 114#pragma weak _Unwind_GetCFA 115#pragma weak _Unwind_ForcedUnwind 116#endif /* PIC */ 117 118static void 119thread_unwind_cleanup(_Unwind_Reason_Code code, struct _Unwind_Exception *e) 120{ 121 /* 122 * Specification said that _Unwind_Resume should not be used here, 123 * instead, user should rethrow the exception. For C++ user, they 124 * should put "throw" sentence in catch(...) block. 125 */ 126 PANIC("exception should be rethrown"); 127} 128 129static _Unwind_Reason_Code 130thread_unwind_stop(int version, _Unwind_Action actions, 131 _Unwind_Exception_Class exc_class, 132 struct _Unwind_Exception *exc_obj, 133 struct _Unwind_Context *context, void *stop_parameter) 134{ 135 struct pthread *curthread = _get_curthread(); 136 struct pthread_cleanup *cur; 137 uintptr_t cfa; 138 int done = 0; 139 140 /* XXX assume stack grows down to lower address */ 141 142 cfa = _Unwind_GetCFA(context); 143 if (actions & _UA_END_OF_STACK) { 144 done = 1; 145 } else if (cfa >= (uintptr_t)curthread->unwind_stackend) { 146 done = 1; 147 } 148 149 while ((cur = curthread->cleanup) != NULL && 150 (done || 151 ((uintptr_t)cur < (uintptr_t)curthread->unwind_stackend && 152 (uintptr_t)cur >= cfa))) { 153 __pthread_cleanup_pop_imp(1); 154 } 155 156 if (done) 157 exit_thread(); /* Never return! */ 158 159 return (_URC_NO_REASON); 160} 161 162static void 163thread_unwind(void) 164{ 165 struct pthread *curthread = _get_curthread(); 166 167 curthread->ex.exception_class = 0; 168 curthread->ex.exception_cleanup = thread_unwind_cleanup; 169 _Unwind_ForcedUnwind(&curthread->ex, thread_unwind_stop, NULL); 170 PANIC("_Unwind_ForcedUnwind returned"); 171} 172 173#endif 174 175void 176_thread_exit(const char *fname, int lineno, const char *msg) 177{ 178 179 /* Write an error message to the standard error file descriptor: */ 180 _thread_printf(2, 181 "Fatal error '%s' at line %d in file %s (errno = %d)\n", 182 msg, lineno, fname, errno); 183 184 abort(); 185} 186 187void 188_pthread_exit(void *status) 189{ 190 _pthread_exit_mask(status, NULL); 191} 192 193void 194_pthread_exit_mask(void *status, sigset_t *mask) 195{ 196 struct pthread *curthread = _get_curthread(); 197 198 /* Check if this thread is already in the process of exiting: */ 199 if (curthread->cancelling) { 200 char msg[128]; 201 snprintf(msg, sizeof(msg), "Thread %p has called " 202 "pthread_exit() from a destructor. POSIX 1003.1 " 203 "1996 s16.2.5.2 does not allow this!", curthread); 204 PANIC(msg); 205 } 206 207 /* Flag this thread as exiting. */ 208 curthread->cancelling = 1; 209 curthread->cancel_enable = 0; 210 curthread->cancel_async = 0; 211 curthread->cancel_point = 0; 212 if (mask != NULL) 213 __sys_sigprocmask(SIG_SETMASK, mask, NULL); 214 if (curthread->unblock_sigcancel) { 215 sigset_t set; 216 217 curthread->unblock_sigcancel = 0; 218 SIGEMPTYSET(set); 219 SIGADDSET(set, SIGCANCEL); 220 __sys_sigprocmask(SIG_UNBLOCK, mask, NULL); 221 } 222 223 /* Save the return value: */ 224 curthread->ret = status; 225#ifdef _PTHREAD_FORCED_UNWIND 226#ifdef PIC 227 thread_uw_init(); 228 if (uwl_forcedunwind != NULL) { 229 thread_unwind(); 230 } 231#else 232 if (_Unwind_ForcedUnwind != NULL) { 233 thread_unwind(); 234 } 235#endif /* PIC */ 236 237 else { 238 while (curthread->cleanup != NULL) { 239 __pthread_cleanup_pop_imp(1); 240 } 241 exit_thread(); 242 } 243 244#else 245 while (curthread->cleanup != NULL) { 246 __pthread_cleanup_pop_imp(1); 247 } 248 249 exit_thread(); 250#endif /* _PTHREAD_FORCED_UNWIND */ 251} 252 253static void 254exit_thread(void) 255{ 256 struct pthread *curthread = _get_curthread(); 257 258 /* Check if there is thread specific data: */ 259 if (curthread->specific != NULL) { 260 /* Run the thread-specific data destructors: */ 261 _thread_cleanupspecific(); 262 } 263 264 if (!_thr_isthreaded()) 265 exit(0); 266 267 if (atomic_fetchadd_int(&_thread_active_threads, -1) == 1) { 268 exit(0); 269 /* Never reach! */ 270 } 271 272 /* Tell malloc that the thread is exiting. */ 273 _malloc_thread_cleanup(); 274 275 THR_LOCK(curthread); 276 curthread->state = PS_DEAD; 277 if (curthread->flags & THR_FLAGS_NEED_SUSPEND) { 278 curthread->cycle++; 279 _thr_umtx_wake(&curthread->cycle, INT_MAX, 0); 280 } 281 /* 282 * Thread was created with initial refcount 1, we drop the 283 * reference count to allow it to be garbage collected. 284 */ 285 curthread->refcount--; 286 _thr_try_gc(curthread, curthread); /* thread lock released */ 287 288 if (!curthread->force_exit && SHOULD_REPORT_EVENT(curthread, TD_DEATH)) 289 _thr_report_death(curthread); 290 291#if defined(_PTHREADS_INVARIANTS) 292 if (THR_IN_CRITICAL(curthread)) 293 PANIC("thread exits with resources held!"); 294#endif 295 /* 296 * Kernel will do wakeup at the address, so joiner thread 297 * will be resumed if it is sleeping at the address. 298 */ 299 thr_exit(&curthread->tid); 300 PANIC("thr_exit() returned"); 301 /* Never reach! */ 302} 303