1 /* 2 * Copyright (c) 2005, David Xu <davidxu@freebsd.org> 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 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 * 25 */ 26 27 #include "namespace.h" 28 #include <sys/signalvar.h> 29 #include <machine/tls.h> 30 #include <signal.h> 31 #include <errno.h> 32 #include <string.h> 33 #include <pthread.h> 34 #include "un-namespace.h" 35 36 #include "thr_private.h" 37 38 #if defined(_PTHREADS_DEBUGGING) || defined(_PTHREADS_DEBUGGING2) 39 #include <sys/file.h> 40 #include <stdio.h> 41 #endif 42 43 /* #define DEBUG_SIGNAL */ 44 #ifdef DEBUG_SIGNAL 45 #define DBG_MSG stdout_debug 46 #else 47 #define DBG_MSG(x...) 48 #endif 49 50 int __sigwait(const sigset_t *set, int *sig); 51 int __sigwaitinfo(const sigset_t *set, siginfo_t *info); 52 int __sigtimedwait(const sigset_t *set, siginfo_t *info, 53 const struct timespec * timeout); 54 55 #if defined(_PTHREADS_DEBUGGING) || defined(_PTHREADS_DEBUGGING2) 56 static void _thr_debug_sig(int signo); 57 #endif 58 59 static void 60 sigcancel_handler(int sig __unused, siginfo_t *info __unused, 61 ucontext_t *ucp __unused) 62 { 63 struct pthread *curthread = tls_get_curthread(); 64 65 if (curthread->cancelflags & THR_CANCEL_AT_POINT) 66 _pthread_testcancel(); 67 _thr_ast(curthread); 68 } 69 70 void 71 _thr_ast(struct pthread *curthread) 72 { 73 if (!THR_IN_CRITICAL(curthread)) { 74 if (__predict_false((curthread->flags & 75 (THR_FLAGS_NEED_SUSPEND | THR_FLAGS_SUSPENDED)) 76 == THR_FLAGS_NEED_SUSPEND)) 77 _thr_suspend_check(curthread); 78 } 79 } 80 81 void 82 _thr_suspend_check(struct pthread *curthread) 83 { 84 umtx_t cycle; 85 86 /* 87 * Blocks SIGCANCEL which other threads must send. 88 */ 89 _thr_signal_block(curthread); 90 91 /* 92 * Increase critical_count, here we don't use THR_LOCK/UNLOCK 93 * because we are leaf code, we don't want to recursively call 94 * ourself. 95 */ 96 curthread->critical_count++; 97 THR_UMTX_LOCK(curthread, &(curthread)->lock); 98 while ((curthread->flags & (THR_FLAGS_NEED_SUSPEND | 99 THR_FLAGS_SUSPENDED)) == THR_FLAGS_NEED_SUSPEND) { 100 curthread->cycle++; 101 cycle = curthread->cycle; 102 103 /* Wake the thread suspending us. */ 104 _thr_umtx_wake(&curthread->cycle, 0); 105 106 /* 107 * if we are from pthread_exit, we don't want to 108 * suspend, just go and die. 109 */ 110 if (curthread->state == PS_DEAD) 111 break; 112 curthread->flags |= THR_FLAGS_SUSPENDED; 113 THR_UMTX_UNLOCK(curthread, &(curthread)->lock); 114 _thr_umtx_wait(&curthread->cycle, cycle, NULL, 0); 115 THR_UMTX_LOCK(curthread, &(curthread)->lock); 116 curthread->flags &= ~THR_FLAGS_SUSPENDED; 117 } 118 THR_UMTX_UNLOCK(curthread, &(curthread)->lock); 119 curthread->critical_count--; 120 121 _thr_signal_unblock(curthread); 122 } 123 124 void 125 _thr_signal_init(void) 126 { 127 struct sigaction act; 128 129 /* Install cancel handler. */ 130 SIGEMPTYSET(act.sa_mask); 131 act.sa_flags = SA_SIGINFO | SA_RESTART; 132 act.sa_sigaction = (__siginfohandler_t *)&sigcancel_handler; 133 __sys_sigaction(SIGCANCEL, &act, NULL); 134 135 #if defined(_PTHREADS_DEBUGGING) || defined(_PTHREADS_DEBUGGING2) 136 /* 137 * If enabled, rwlock, mutex, and condition variable operations 138 * are recorded in a text buffer and signal 63 dumps the buffer 139 * to /tmp/cond${pid}.log. 140 */ 141 act.sa_flags = SA_RESTART; 142 act.sa_handler = _thr_debug_sig; 143 __sys_sigaction(63, &act, NULL); 144 #endif 145 } 146 147 void 148 _thr_signal_deinit(void) 149 { 150 } 151 152 int 153 _sigaction(int sig, const struct sigaction * act, struct sigaction * oact) 154 { 155 /* Check if the signal number is out of range: */ 156 if (sig < 1 || sig > _SIG_MAXSIG || sig == SIGCANCEL) { 157 /* Return an invalid argument: */ 158 errno = EINVAL; 159 return (-1); 160 } 161 162 return __sys_sigaction(sig, act, oact); 163 } 164 165 __strong_reference(_sigaction, sigaction); 166 167 int 168 _sigprocmask(int how, const sigset_t *set, sigset_t *oset) 169 { 170 const sigset_t *p = set; 171 sigset_t newset; 172 173 if (how != SIG_UNBLOCK) { 174 if (set != NULL) { 175 newset = *set; 176 SIGDELSET(newset, SIGCANCEL); 177 p = &newset; 178 } 179 } 180 return (__sys_sigprocmask(how, p, oset)); 181 } 182 183 __strong_reference(_sigprocmask, sigprocmask); 184 185 int 186 _pthread_sigmask(int how, const sigset_t *set, sigset_t *oset) 187 { 188 if (_sigprocmask(how, set, oset)) 189 return (errno); 190 return (0); 191 } 192 193 __strong_reference(_pthread_sigmask, pthread_sigmask); 194 195 int 196 _sigsuspend(const sigset_t * set) 197 { 198 struct pthread *curthread = tls_get_curthread(); 199 sigset_t newset; 200 const sigset_t *pset; 201 int oldcancel; 202 int ret; 203 204 if (SIGISMEMBER(*set, SIGCANCEL)) { 205 newset = *set; 206 SIGDELSET(newset, SIGCANCEL); 207 pset = &newset; 208 } else 209 pset = set; 210 211 oldcancel = _thr_cancel_enter(curthread); 212 ret = __sys_sigsuspend(pset); 213 _thr_cancel_leave(curthread, oldcancel); 214 215 return (ret); 216 } 217 218 __strong_reference(_sigsuspend, sigsuspend); 219 220 int 221 __sigtimedwait(const sigset_t *set, siginfo_t *info, 222 const struct timespec * timeout) 223 { 224 struct pthread *curthread = tls_get_curthread(); 225 sigset_t newset; 226 const sigset_t *pset; 227 int oldcancel; 228 int ret; 229 230 if (SIGISMEMBER(*set, SIGCANCEL)) { 231 newset = *set; 232 SIGDELSET(newset, SIGCANCEL); 233 pset = &newset; 234 } else 235 pset = set; 236 oldcancel = _thr_cancel_enter(curthread); 237 ret = __sys_sigtimedwait(pset, info, timeout); 238 _thr_cancel_leave(curthread, oldcancel); 239 return (ret); 240 } 241 242 __strong_reference(__sigtimedwait, sigtimedwait); 243 244 int 245 __sigwaitinfo(const sigset_t *set, siginfo_t *info) 246 { 247 struct pthread *curthread = tls_get_curthread(); 248 sigset_t newset; 249 const sigset_t *pset; 250 int oldcancel; 251 int ret; 252 253 if (SIGISMEMBER(*set, SIGCANCEL)) { 254 newset = *set; 255 SIGDELSET(newset, SIGCANCEL); 256 pset = &newset; 257 } else 258 pset = set; 259 260 oldcancel = _thr_cancel_enter(curthread); 261 ret = __sys_sigwaitinfo(pset, info); 262 _thr_cancel_leave(curthread, oldcancel); 263 return (ret); 264 } 265 266 __strong_reference(__sigwaitinfo, sigwaitinfo); 267 268 int 269 __sigwait(const sigset_t *set, int *sig) 270 { 271 int s; 272 273 s = __sigwaitinfo(set, NULL); 274 if (s > 0) { 275 *sig = s; 276 return (0); 277 } 278 return (errno); 279 } 280 281 __strong_reference(__sigwait, sigwait); 282 283 #if defined(_PTHREADS_DEBUGGING) || defined(_PTHREADS_DEBUGGING2) 284 285 #define LOGBUF_SIZE (4 * 1024 * 1024) 286 #define LOGBUF_MASK (LOGBUF_SIZE - 1) 287 288 char LogBuf[LOGBUF_SIZE]; 289 unsigned long LogWIndex; 290 291 void 292 _thr_log(const char *buf, size_t bytes) 293 { 294 struct pthread *curthread; 295 unsigned long i; 296 char prefix[32]; 297 size_t plen; 298 299 curthread = tls_get_curthread(); 300 if (curthread) { 301 plen = snprintf(prefix, sizeof(prefix), "%d.%d: ", 302 (int)__sys_getpid(), 303 curthread->tid); 304 } else { 305 plen = snprintf(prefix, sizeof(prefix), "unknown: "); 306 } 307 308 if (bytes == 0) 309 bytes = strlen(buf); 310 i = atomic_fetchadd_long(&LogWIndex, plen + bytes); 311 i = i & LOGBUF_MASK; 312 if (plen <= (size_t)(LOGBUF_SIZE - i)) { 313 bcopy(prefix, LogBuf + i, plen); 314 } else { 315 bcopy(prefix, LogBuf + i, LOGBUF_SIZE - i); 316 plen -= LOGBUF_SIZE - i; 317 bcopy(prefix, LogBuf, plen); 318 } 319 320 i += plen; 321 i = i & LOGBUF_MASK; 322 if (bytes <= (size_t)(LOGBUF_SIZE - i)) { 323 bcopy(buf, LogBuf + i, bytes); 324 } else { 325 bcopy(buf, LogBuf + i, LOGBUF_SIZE - i); 326 bytes -= LOGBUF_SIZE - i; 327 bcopy(buf, LogBuf, bytes); 328 } 329 } 330 331 static void 332 _thr_debug_sig(int signo __unused) 333 { 334 char buf[256]; 335 int fd; 336 unsigned long i; 337 338 snprintf(buf, sizeof(buf), "/tmp/cond%d.log", (int)__sys_getpid()); 339 fd = open(buf, O_RDWR|O_CREAT|O_TRUNC|O_CLOEXEC, 0666); 340 if (fd >= 0) { 341 i = LogWIndex; 342 if (i < LOGBUF_SIZE) { 343 write(fd, LogBuf, i); 344 } else { 345 i &= LOGBUF_MASK; 346 write(fd, LogBuf + i, LOGBUF_SIZE - i); 347 write(fd, LogBuf, i); 348 } 349 close(fd); 350 } 351 } 352 353 #endif 354