1/* 2 * Copyright (c) 2003 Daniel M. Eischen <deischen@freebsd.org> 3 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the author nor the names of any co-contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * $FreeBSD$ 31 */ 32 33/* Allocate space for global thread variables here: */ 34#define GLOBAL_PTHREAD_PRIVATE 35 36#include "namespace.h" 37#include <sys/param.h> 38#include <sys/types.h> 39#include <sys/signalvar.h> 40#include <machine/reg.h> 41 42#include <sys/ioctl.h> 43#include <sys/mount.h> 44#include <sys/uio.h> 45#include <sys/socket.h> 46#include <sys/event.h> 47#include <sys/stat.h> 48#include <sys/sysctl.h> 49#include <sys/time.h> 50#include <sys/ttycom.h> 51#include <sys/wait.h> 52#include <sys/mman.h> 53#include <dirent.h> 54#include <errno.h> 55#include <fcntl.h> 56#include <paths.h> 57#include <pthread.h> 58#include <pthread_np.h> 59#include <signal.h> 60#include <stdio.h> 61#include <stdlib.h> 62#include <string.h> 63#include <unistd.h> 64#include "un-namespace.h" 65 66#include "libc_private.h" 67#include "thr_private.h" 68 69int __pthread_cond_wait(pthread_cond_t *, pthread_mutex_t *); 70int __pthread_mutex_lock(pthread_mutex_t *); 71int __pthread_mutex_trylock(pthread_mutex_t *); 72void _thread_init_hack(void); 73extern int _thread_state_running; 74 75static void init_private(void); 76static void init_main_thread(struct pthread *thread); 77 78/* 79 * All weak references used within libc should be in this table. 80 * This is so that static libraries will work. 81 */ 82static void *references[] = { 83 &_accept, 84 &_bind, 85 &_close, 86 &_connect, 87 &_dup, 88 &_dup2, 89 &_execve, 90 &_fcntl, 91 &_flock, 92 &_flockfile, 93 &_fstat, 94 &_fstatfs, 95 &_fsync, 96 &_funlockfile, 97 &_getdirentries, 98 &_getlogin, 99 &_getpeername, 100 &_getsockname, 101 &_getsockopt, 102 &_ioctl, 103 &_kevent, 104 &_listen, 105 &_nanosleep, 106 &_open, 107 &_pthread_getspecific, 108 &_pthread_key_create, 109 &_pthread_key_delete, 110 &_pthread_mutex_destroy, 111 &_pthread_mutex_init, 112 &_pthread_mutex_lock, 113 &_pthread_mutex_trylock, 114 &_pthread_mutex_unlock, 115 &_pthread_mutexattr_init, 116 &_pthread_mutexattr_destroy, 117 &_pthread_mutexattr_settype, 118 &_pthread_once, 119 &_pthread_setspecific, 120 &_read, 121 &_readv, 122 &_recvfrom, 123 &_recvmsg, 124 &_select, 125 &_sendmsg, 126 &_sendto, 127 &_setsockopt, 128 &_sigaction, 129 &_sigprocmask, 130 &_sigsuspend, 131 &_socket, 132 &_socketpair, 133 &_thread_init_hack, 134 &_wait4, 135 &_write, 136 &_writev 137}; 138 139/* 140 * These are needed when linking statically. All references within 141 * libgcc (and in the future libc) to these routines are weak, but 142 * if they are not (strongly) referenced by the application or other 143 * libraries, then the actual functions will not be loaded. 144 */ 145static void *libgcc_references[] = { 146 &_pthread_once, 147 &_pthread_key_create, 148 &_pthread_key_delete, 149 &_pthread_getspecific, 150 &_pthread_setspecific, 151 &_pthread_mutex_init, 152 &_pthread_mutex_destroy, 153 &_pthread_mutex_lock, 154 &_pthread_mutex_trylock, 155 &_pthread_mutex_unlock 156}; 157 158#define DUAL_ENTRY(entry) \ 159 (pthread_func_t)entry, (pthread_func_t)entry 160 161static pthread_func_t jmp_table[][2] = { 162 {DUAL_ENTRY(_pthread_atfork)}, /* PJT_ATFORK */ 163 {DUAL_ENTRY(_pthread_attr_destroy)}, /* PJT_ATTR_DESTROY */ 164 {DUAL_ENTRY(_pthread_attr_getdetachstate)}, /* PJT_ATTR_GETDETACHSTATE */ 165 {DUAL_ENTRY(_pthread_attr_getguardsize)}, /* PJT_ATTR_GETGUARDSIZE */ 166 {DUAL_ENTRY(_pthread_attr_getinheritsched)}, /* PJT_ATTR_GETINHERITSCHED */ 167 {DUAL_ENTRY(_pthread_attr_getschedparam)}, /* PJT_ATTR_GETSCHEDPARAM */ 168 {DUAL_ENTRY(_pthread_attr_getschedpolicy)}, /* PJT_ATTR_GETSCHEDPOLICY */ 169 {DUAL_ENTRY(_pthread_attr_getscope)}, /* PJT_ATTR_GETSCOPE */ 170 {DUAL_ENTRY(_pthread_attr_getstackaddr)}, /* PJT_ATTR_GETSTACKADDR */ 171 {DUAL_ENTRY(_pthread_attr_getstacksize)}, /* PJT_ATTR_GETSTACKSIZE */ 172 {DUAL_ENTRY(_pthread_attr_init)}, /* PJT_ATTR_INIT */ 173 {DUAL_ENTRY(_pthread_attr_setdetachstate)}, /* PJT_ATTR_SETDETACHSTATE */ 174 {DUAL_ENTRY(_pthread_attr_setguardsize)}, /* PJT_ATTR_SETGUARDSIZE */ 175 {DUAL_ENTRY(_pthread_attr_setinheritsched)}, /* PJT_ATTR_SETINHERITSCHED */ 176 {DUAL_ENTRY(_pthread_attr_setschedparam)}, /* PJT_ATTR_SETSCHEDPARAM */ 177 {DUAL_ENTRY(_pthread_attr_setschedpolicy)}, /* PJT_ATTR_SETSCHEDPOLICY */ 178 {DUAL_ENTRY(_pthread_attr_setscope)}, /* PJT_ATTR_SETSCOPE */ 179 {DUAL_ENTRY(_pthread_attr_setstackaddr)}, /* PJT_ATTR_SETSTACKADDR */ 180 {DUAL_ENTRY(_pthread_attr_setstacksize)}, /* PJT_ATTR_SETSTACKSIZE */ 181 {DUAL_ENTRY(_pthread_cancel)}, /* PJT_CANCEL */ 182 {DUAL_ENTRY(_pthread_cleanup_pop)}, /* PJT_CLEANUP_POP */ 183 {DUAL_ENTRY(_pthread_cleanup_push)}, /* PJT_CLEANUP_PUSH */ 184 {DUAL_ENTRY(_pthread_cond_broadcast)}, /* PJT_COND_BROADCAST */ 185 {DUAL_ENTRY(_pthread_cond_destroy)}, /* PJT_COND_DESTROY */ 186 {DUAL_ENTRY(_pthread_cond_init)}, /* PJT_COND_INIT */ 187 {DUAL_ENTRY(_pthread_cond_signal)}, /* PJT_COND_SIGNAL */ 188 {DUAL_ENTRY(_pthread_cond_timedwait)}, /* PJT_COND_TIMEDWAIT */ 189 {(pthread_func_t)__pthread_cond_wait, 190 (pthread_func_t)_pthread_cond_wait}, /* PJT_COND_WAIT */ 191 {DUAL_ENTRY(_pthread_detach)}, /* PJT_DETACH */ 192 {DUAL_ENTRY(_pthread_equal)}, /* PJT_EQUAL */ 193 {DUAL_ENTRY(_pthread_exit)}, /* PJT_EXIT */ 194 {DUAL_ENTRY(_pthread_getspecific)}, /* PJT_GETSPECIFIC */ 195 {DUAL_ENTRY(_pthread_join)}, /* PJT_JOIN */ 196 {DUAL_ENTRY(_pthread_key_create)}, /* PJT_KEY_CREATE */ 197 {DUAL_ENTRY(_pthread_key_delete)}, /* PJT_KEY_DELETE*/ 198 {DUAL_ENTRY(_pthread_kill)}, /* PJT_KILL */ 199 {DUAL_ENTRY(_pthread_main_np)}, /* PJT_MAIN_NP */ 200 {DUAL_ENTRY(_pthread_mutexattr_destroy)}, /* PJT_MUTEXATTR_DESTROY */ 201 {DUAL_ENTRY(_pthread_mutexattr_init)}, /* PJT_MUTEXATTR_INIT */ 202 {DUAL_ENTRY(_pthread_mutexattr_settype)}, /* PJT_MUTEXATTR_SETTYPE */ 203 {DUAL_ENTRY(_pthread_mutex_destroy)}, /* PJT_MUTEX_DESTROY */ 204 {DUAL_ENTRY(_pthread_mutex_init)}, /* PJT_MUTEX_INIT */ 205 {(pthread_func_t)__pthread_mutex_lock, 206 (pthread_func_t)_pthread_mutex_lock}, /* PJT_MUTEX_LOCK */ 207 {(pthread_func_t)__pthread_mutex_trylock, 208 (pthread_func_t)_pthread_mutex_trylock},/* PJT_MUTEX_TRYLOCK */ 209 {DUAL_ENTRY(_pthread_mutex_unlock)}, /* PJT_MUTEX_UNLOCK */ 210 {DUAL_ENTRY(_pthread_once)}, /* PJT_ONCE */ 211 {DUAL_ENTRY(_pthread_rwlock_destroy)}, /* PJT_RWLOCK_DESTROY */ 212 {DUAL_ENTRY(_pthread_rwlock_init)}, /* PJT_RWLOCK_INIT */ 213 {DUAL_ENTRY(_pthread_rwlock_rdlock)}, /* PJT_RWLOCK_RDLOCK */ 214 {DUAL_ENTRY(_pthread_rwlock_tryrdlock)},/* PJT_RWLOCK_TRYRDLOCK */ 215 {DUAL_ENTRY(_pthread_rwlock_trywrlock)},/* PJT_RWLOCK_TRYWRLOCK */ 216 {DUAL_ENTRY(_pthread_rwlock_unlock)}, /* PJT_RWLOCK_UNLOCK */ 217 {DUAL_ENTRY(_pthread_rwlock_wrlock)}, /* PJT_RWLOCK_WRLOCK */ 218 {DUAL_ENTRY(_pthread_self)}, /* PJT_SELF */ 219 {DUAL_ENTRY(_pthread_setcancelstate)}, /* PJT_SETCANCELSTATE */ 220 {DUAL_ENTRY(_pthread_setcanceltype)}, /* PJT_SETCANCELTYPE */ 221 {DUAL_ENTRY(_pthread_setspecific)}, /* PJT_SETSPECIFIC */ 222 {DUAL_ENTRY(_pthread_sigmask)}, /* PJT_SIGMASK */ 223 {DUAL_ENTRY(_pthread_testcancel)} /* PJT_TESTCANCEL */ 224}; 225 226static int init_once = 0; 227 228/* 229 * Threaded process initialization. 230 * 231 * This is only called under two conditions: 232 * 233 * 1) Some thread routines have detected that the library hasn't yet 234 * been initialized (_thr_initial == NULL && curthread == NULL), or 235 * 236 * 2) An explicit call to reinitialize after a fork (indicated 237 * by curthread != NULL) 238 */ 239void 240_libpthread_init(struct pthread *curthread) 241{ 242 int fd; 243 244 /* Check if this function has already been called: */ 245 if ((_thr_initial != NULL) && (curthread == NULL)) 246 /* Only initialize the threaded application once. */ 247 return; 248 249 /* 250 * Make gcc quiescent about {,libgcc_}references not being 251 * referenced: 252 */ 253 if ((references[0] == NULL) || (libgcc_references[0] == NULL)) 254 PANIC("Failed loading mandatory references in _thread_init"); 255 256 /* Pull debug symbols in for static binary */ 257 _thread_state_running = PS_RUNNING; 258 259 /* 260 * Check the size of the jump table to make sure it is preset 261 * with the correct number of entries. 262 */ 263 if (sizeof(jmp_table) != (sizeof(pthread_func_t) * PJT_MAX * 2)) 264 PANIC("Thread jump table not properly initialized"); 265 memcpy(__thr_jtable, jmp_table, sizeof(jmp_table)); 266 267 /* 268 * Check for the special case of this process running as 269 * or in place of init as pid = 1: 270 */ 271 if ((_thr_pid = getpid()) == 1) { 272 /* 273 * Setup a new session for this process which is 274 * assumed to be running as root. 275 */ 276 if (setsid() == -1) 277 PANIC("Can't set session ID"); 278 if (revoke(_PATH_CONSOLE) != 0) 279 PANIC("Can't revoke console"); 280 if ((fd = __sys_open(_PATH_CONSOLE, O_RDWR)) < 0) 281 PANIC("Can't open console"); 282 if (setlogin("root") == -1) 283 PANIC("Can't set login to root"); 284 if (__sys_ioctl(fd, TIOCSCTTY, (char *) NULL) == -1) 285 PANIC("Can't set controlling terminal"); 286 } 287 288 /* Initialize pthread private data. */ 289 init_private(); 290 _kse_init(); 291 292 /* Initialize the initial kse and kseg. */ 293 _kse_initial = _kse_alloc(NULL, _thread_scope_system > 0); 294 if (_kse_initial == NULL) 295 PANIC("Can't allocate initial kse."); 296 _kse_initial->k_kseg = _kseg_alloc(NULL); 297 if (_kse_initial->k_kseg == NULL) 298 PANIC("Can't allocate initial kseg."); 299 _kse_initial->k_kseg->kg_flags |= KGF_SINGLE_THREAD; 300 _kse_initial->k_schedq = &_kse_initial->k_kseg->kg_schedq; 301 302 TAILQ_INSERT_TAIL(&_kse_initial->k_kseg->kg_kseq, _kse_initial, k_kgqe); 303 _kse_initial->k_kseg->kg_ksecount = 1; 304 305 /* Set the initial thread. */ 306 if (curthread == NULL) { 307 /* Create and initialize the initial thread. */ 308 curthread = _thr_alloc(NULL); 309 if (curthread == NULL) 310 PANIC("Can't allocate initial thread"); 311 _thr_initial = curthread; 312 init_main_thread(curthread); 313 } else { 314 /* 315 * The initial thread is the current thread. It is 316 * assumed that the current thread is already initialized 317 * because it is left over from a fork(). 318 */ 319 _thr_initial = curthread; 320 } 321 _kse_initial->k_kseg->kg_threadcount = 0; 322 _thr_initial->kse = _kse_initial; 323 _thr_initial->kseg = _kse_initial->k_kseg; 324 _thr_initial->active = 1; 325 326 /* 327 * Add the thread to the thread list and to the KSEG's thread 328 * queue. 329 */ 330 THR_LIST_ADD(_thr_initial); 331 KSEG_THRQ_ADD(_kse_initial->k_kseg, _thr_initial); 332 333 /* Setup the KSE/thread specific data for the current KSE/thread. */ 334 _thr_initial->kse->k_curthread = _thr_initial; 335 _kcb_set(_thr_initial->kse->k_kcb); 336 _tcb_set(_thr_initial->kse->k_kcb, _thr_initial->tcb); 337 _thr_initial->kse->k_flags |= KF_INITIALIZED; 338 339 _thr_signal_init(); 340 _kse_critical_leave(&_thr_initial->tcb->tcb_tmbx); 341 /* 342 * activate threaded mode as soon as possible if we are 343 * being debugged 344 */ 345 if (_libkse_debug) 346 _kse_setthreaded(1); 347} 348 349/* 350 * This function and pthread_create() do a lot of the same things. 351 * It'd be nice to consolidate the common stuff in one place. 352 */ 353static void 354init_main_thread(struct pthread *thread) 355{ 356 /* Setup the thread attributes. */ 357 thread->attr = _pthread_attr_default; 358 thread->attr.flags |= PTHREAD_SCOPE_SYSTEM; 359 /* 360 * Set up the thread stack. 361 * 362 * Create a red zone below the main stack. All other stacks 363 * are constrained to a maximum size by the parameters 364 * passed to mmap(), but this stack is only limited by 365 * resource limits, so this stack needs an explicitly mapped 366 * red zone to protect the thread stack that is just beyond. 367 */ 368 if (mmap((void *)((uintptr_t)_usrstack - _thr_stack_initial - 369 _thr_guard_default), _thr_guard_default, 0, MAP_ANON, 370 -1, 0) == MAP_FAILED) 371 PANIC("Cannot allocate red zone for initial thread"); 372 373 /* 374 * Mark the stack as an application supplied stack so that it 375 * isn't deallocated. 376 * 377 * XXX - I'm not sure it would hurt anything to deallocate 378 * the main thread stack because deallocation doesn't 379 * actually free() it; it just puts it in the free 380 * stack queue for later reuse. 381 */ 382 thread->attr.stackaddr_attr = (void *)((uintptr_t)_usrstack - 383 _thr_stack_initial); 384 thread->attr.stacksize_attr = _thr_stack_initial; 385 thread->attr.guardsize_attr = _thr_guard_default; 386 thread->attr.flags |= THR_STACK_USER; 387 388 /* 389 * Write a magic value to the thread structure 390 * to help identify valid ones: 391 */ 392 thread->magic = THR_MAGIC; 393 394 thread->slice_usec = -1; 395 thread->cancelflags = PTHREAD_CANCEL_ENABLE | PTHREAD_CANCEL_DEFERRED; 396 thread->name = strdup("initial thread"); 397 398 /* Initialize the thread for signals: */ 399 SIGEMPTYSET(thread->sigmask); 400 401 /* 402 * Set up the thread mailbox. The threads saved context 403 * is also in the mailbox. 404 */ 405 thread->tcb->tcb_tmbx.tm_udata = thread; 406 thread->tcb->tcb_tmbx.tm_context.uc_stack.ss_size = 407 thread->attr.stacksize_attr; 408 thread->tcb->tcb_tmbx.tm_context.uc_stack.ss_sp = 409 thread->attr.stackaddr_attr; 410 411 /* Default the priority of the initial thread: */ 412 thread->base_priority = THR_DEFAULT_PRIORITY; 413 thread->active_priority = THR_DEFAULT_PRIORITY; 414 thread->inherited_priority = 0; 415 416 /* Initialize the mutex queue: */ 417 TAILQ_INIT(&thread->mutexq); 418 419 /* Initialize hooks in the thread structure: */ 420 thread->specific = NULL; 421 thread->cleanup = NULL; 422 thread->flags = 0; 423 thread->sigbackout = NULL; 424 thread->continuation = NULL; 425 426 thread->state = PS_RUNNING; 427 thread->uniqueid = 0; 428} 429 430static void 431init_private(void) 432{ 433 struct clockinfo clockinfo; 434 size_t len; 435 int mib[2]; 436 437 /* 438 * Avoid reinitializing some things if they don't need to be, 439 * e.g. after a fork(). 440 */ 441 if (init_once == 0) { 442 /* Find the stack top */ 443 mib[0] = CTL_KERN; 444 mib[1] = KERN_USRSTACK; 445 len = sizeof (_usrstack); 446 if (sysctl(mib, 2, &_usrstack, &len, NULL, 0) == -1) 447 PANIC("Cannot get kern.usrstack from sysctl"); 448 /* Get the kernel clockrate: */ 449 mib[0] = CTL_KERN; 450 mib[1] = KERN_CLOCKRATE; 451 len = sizeof (struct clockinfo); 452 if (sysctl(mib, 2, &clockinfo, &len, NULL, 0) == 0) 453 _clock_res_usec = 1000000 / clockinfo.stathz; 454 else 455 _clock_res_usec = CLOCK_RES_USEC; 456 457 _thr_page_size = getpagesize(); 458 _thr_guard_default = _thr_page_size; 459 if (sizeof(void *) == 8) { 460 _thr_stack_default = THR_STACK64_DEFAULT; 461 _thr_stack_initial = THR_STACK64_INITIAL; 462 } 463 else { 464 _thr_stack_default = THR_STACK32_DEFAULT; 465 _thr_stack_initial = THR_STACK32_INITIAL; 466 } 467 _pthread_attr_default.guardsize_attr = _thr_guard_default; 468 _pthread_attr_default.stacksize_attr = _thr_stack_default; 469 TAILQ_INIT(&_thr_atfork_list); 470 init_once = 1; /* Don't do this again. */ 471 } else { 472 /* 473 * Destroy the locks before creating them. We don't 474 * know what state they are in so it is better to just 475 * recreate them. 476 */ 477 _lock_destroy(&_thread_signal_lock); 478 _lock_destroy(&_mutex_static_lock); 479 _lock_destroy(&_rwlock_static_lock); 480 _lock_destroy(&_keytable_lock); 481 } 482 483 /* Initialize everything else. */ 484 TAILQ_INIT(&_thread_list); 485 TAILQ_INIT(&_thread_gc_list); 486 _pthread_mutex_init(&_thr_atfork_mutex, NULL); 487 488 /* 489 * Initialize the lock for temporary installation of signal 490 * handlers (to support sigwait() semantics) and for the 491 * process signal mask and pending signal sets. 492 */ 493 if (_lock_init(&_thread_signal_lock, LCK_ADAPTIVE, 494 _kse_lock_wait, _kse_lock_wakeup, calloc) != 0) 495 PANIC("Cannot initialize _thread_signal_lock"); 496 if (_lock_init(&_mutex_static_lock, LCK_ADAPTIVE, 497 _thr_lock_wait, _thr_lock_wakeup, calloc) != 0) 498 PANIC("Cannot initialize mutex static init lock"); 499 if (_lock_init(&_rwlock_static_lock, LCK_ADAPTIVE, 500 _thr_lock_wait, _thr_lock_wakeup, calloc) != 0) 501 PANIC("Cannot initialize rwlock static init lock"); 502 if (_lock_init(&_keytable_lock, LCK_ADAPTIVE, 503 _thr_lock_wait, _thr_lock_wakeup, calloc) != 0) 504 PANIC("Cannot initialize thread specific keytable lock"); 505 _thr_spinlock_init(); 506 507 /* Clear pending signals and get the process signal mask. */ 508 SIGEMPTYSET(_thr_proc_sigpending); 509 510 /* Are we in M:N mode (default) or 1:1 mode? */ 511#ifdef SYSTEM_SCOPE_ONLY 512 _thread_scope_system = 1; 513#else 514 if (getenv("LIBPTHREAD_SYSTEM_SCOPE") != NULL) 515 _thread_scope_system = 1; 516 else if (getenv("LIBPTHREAD_PROCESS_SCOPE") != NULL) 517 _thread_scope_system = -1; 518#endif 519 if (getenv("LIBPTHREAD_DEBUG") != NULL) 520 _thr_debug_flags |= DBG_INFO_DUMP; 521 522 /* 523 * _thread_list_lock and _kse_count are initialized 524 * by _kse_init() 525 */ 526} 527