Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_exit.c
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1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD: releng/5.3/sys/kern/kern_exit.c 137004 2004-10-28 02:49:32Z kensmith $"); 39 40 #include "opt_compat.h" 41 #include "opt_ktrace.h" 42 #include "opt_mac.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/sysproto.h> 47 #include <sys/eventhandler.h> 48 #include <sys/kernel.h> 49 #include <sys/malloc.h> 50 #include <sys/lock.h> 51 #include <sys/mutex.h> 52 #include <sys/proc.h> 53 #include <sys/pioctl.h> 54 #include <sys/tty.h> 55 #include <sys/wait.h> 56 #include <sys/vmmeter.h> 57 #include <sys/vnode.h> 58 #include <sys/resourcevar.h> 59 #include <sys/signalvar.h> 60 #include <sys/sched.h> 61 #include <sys/sx.h> 62 #include <sys/ptrace.h> 63 #include <sys/acct.h> /* for acct_process() function prototype */ 64 #include <sys/filedesc.h> 65 #include <sys/mac.h> 66 #include <sys/shm.h> 67 #include <sys/sem.h> 68 #ifdef KTRACE 69 #include <sys/ktrace.h> 70 #endif 71 72 #include <vm/vm.h> 73 #include <vm/vm_extern.h> 74 #include <vm/vm_param.h> 75 #include <vm/pmap.h> 76 #include <vm/vm_map.h> 77 #include <vm/vm_page.h> 78 #include <vm/uma.h> 79 #include <sys/user.h> 80 81 /* Required to be non-static for SysVR4 emulator */ 82 MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status"); 83 84 /* 85 * exit -- 86 * Death of process. 87 * 88 * MPSAFE 89 */ 90 void 91 sys_exit(struct thread *td, struct sys_exit_args *uap) 92 { 93 94 exit1(td, W_EXITCODE(uap->rval, 0)); 95 /* NOTREACHED */ 96 } 97 98 /* 99 * Exit: deallocate address space and other resources, change proc state 100 * to zombie, and unlink proc from allproc and parent's lists. Save exit 101 * status and rusage for wait(). Check for child processes and orphan them. 102 */ 103 void 104 exit1(struct thread *td, int rv) 105 { 106 struct bintime new_switchtime; 107 struct proc *p, *nq, *q; 108 struct tty *tp; 109 struct vnode *ttyvp; 110 struct vmspace *vm; 111 struct vnode *vtmp; 112 #ifdef KTRACE 113 struct vnode *tracevp; 114 struct ucred *tracecred; 115 #endif 116 struct plimit *plim; 117 int refcnt; 118 119 /* 120 * Drop Giant if caller has it. Eventually we should warn about 121 * being called with Giant held. 122 */ 123 while (mtx_owned(&Giant)) 124 mtx_unlock(&Giant); 125 126 p = td->td_proc; 127 if (p == initproc) { 128 printf("init died (signal %d, exit %d)\n", 129 WTERMSIG(rv), WEXITSTATUS(rv)); 130 panic("Going nowhere without my init!"); 131 } 132 133 /* 134 * MUST abort all other threads before proceeding past here. 135 */ 136 PROC_LOCK(p); 137 if (p->p_flag & P_HADTHREADS) { 138 retry: 139 /* 140 * First check if some other thread got here before us.. 141 * if so, act apropriatly, (exit or suspend); 142 */ 143 thread_suspend_check(0); 144 145 /* 146 * Kill off the other threads. This requires 147 * Some co-operation from other parts of the kernel 148 * so it may not be instant. 149 * With this state set: 150 * Any thread entering the kernel from userspace will 151 * thread_exit() in trap(). Any thread attempting to 152 * sleep will return immediatly with EINTR or EWOULDBLOCK, 153 * which will hopefully force them to back out to userland, 154 * freeing resources as they go, and anything attempting 155 * to return to userland will thread_exit() from userret(). 156 * thread_exit() will unsuspend us when the last other 157 * thread exits. 158 * If there is already a thread singler after resumption, 159 * calling thread_single will fail, in the case, we just 160 * re-check all suspension request, the thread should 161 * either be suspended there or exit. 162 */ 163 if (thread_single(SINGLE_EXIT)) 164 goto retry; 165 /* 166 * All other activity in this process is now stopped. 167 * Threading support has been turned off. 168 */ 169 } 170 171 p->p_flag |= P_WEXIT; 172 PROC_UNLOCK(p); 173 174 /* Are we a task leader? */ 175 if (p == p->p_leader) { 176 mtx_lock(&ppeers_lock); 177 q = p->p_peers; 178 while (q != NULL) { 179 PROC_LOCK(q); 180 psignal(q, SIGKILL); 181 PROC_UNLOCK(q); 182 q = q->p_peers; 183 } 184 while (p->p_peers != NULL) 185 msleep(p, &ppeers_lock, PWAIT, "exit1", 0); 186 mtx_unlock(&ppeers_lock); 187 } 188 189 PROC_LOCK(p); 190 _STOPEVENT(p, S_EXIT, rv); 191 wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */ 192 PROC_UNLOCK(p); 193 194 /* 195 * Check if any loadable modules need anything done at process exit. 196 * e.g. SYSV IPC stuff 197 * XXX what if one of these generates an error? 198 */ 199 EVENTHANDLER_INVOKE(process_exit, p); 200 201 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 202 M_ZOMBIE, M_WAITOK); 203 /* 204 * If parent is waiting for us to exit or exec, 205 * P_PPWAIT is set; we will wakeup the parent below. 206 */ 207 PROC_LOCK(p); 208 stopprofclock(p); 209 p->p_flag &= ~(P_TRACED | P_PPWAIT); 210 SIGEMPTYSET(p->p_siglist); 211 SIGEMPTYSET(td->td_siglist); 212 213 /* 214 * Stop the real interval timer. If the handler is currently 215 * executing, prevent it from rearming itself and let it finish. 216 */ 217 if (timevalisset(&p->p_realtimer.it_value) && 218 callout_stop(&p->p_itcallout) == 0) { 219 timevalclear(&p->p_realtimer.it_interval); 220 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0); 221 KASSERT(!timevalisset(&p->p_realtimer.it_value), 222 ("realtime timer is still armed")); 223 } 224 PROC_UNLOCK(p); 225 226 /* 227 * Reset any sigio structures pointing to us as a result of 228 * F_SETOWN with our pid. 229 */ 230 mtx_lock(&Giant); /* XXX: not sure if needed */ 231 funsetownlst(&p->p_sigiolst); 232 233 /* 234 * Close open files and release open-file table. 235 * This may block! 236 */ 237 fdfree(td); 238 mtx_unlock(&Giant); 239 240 /* 241 * Remove ourself from our leader's peer list and wake our leader. 242 */ 243 mtx_lock(&ppeers_lock); 244 if (p->p_leader->p_peers) { 245 q = p->p_leader; 246 while (q->p_peers != p) 247 q = q->p_peers; 248 q->p_peers = p->p_peers; 249 wakeup(p->p_leader); 250 } 251 mtx_unlock(&ppeers_lock); 252 253 /* The next two chunks should probably be moved to vmspace_exit. */ 254 vm = p->p_vmspace; 255 /* 256 * Release user portion of address space. 257 * This releases references to vnodes, 258 * which could cause I/O if the file has been unlinked. 259 * Need to do this early enough that we can still sleep. 260 * Can't free the entire vmspace as the kernel stack 261 * may be mapped within that space also. 262 * 263 * Processes sharing the same vmspace may exit in one order, and 264 * get cleaned up by vmspace_exit() in a different order. The 265 * last exiting process to reach this point releases as much of 266 * the environment as it can, and the last process cleaned up 267 * by vmspace_exit() (which decrements exitingcnt) cleans up the 268 * remainder. 269 */ 270 atomic_add_int(&vm->vm_exitingcnt, 1); 271 do 272 refcnt = vm->vm_refcnt; 273 while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt - 1)); 274 if (refcnt == 1) { 275 shmexit(vm); 276 pmap_remove_pages(vmspace_pmap(vm), vm_map_min(&vm->vm_map), 277 vm_map_max(&vm->vm_map)); 278 (void) vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map), 279 vm_map_max(&vm->vm_map)); 280 } 281 282 mtx_lock(&Giant); 283 sx_xlock(&proctree_lock); 284 if (SESS_LEADER(p)) { 285 struct session *sp; 286 287 sp = p->p_session; 288 if (sp->s_ttyvp) { 289 /* 290 * Controlling process. 291 * Signal foreground pgrp, 292 * drain controlling terminal 293 * and revoke access to controlling terminal. 294 */ 295 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) { 296 tp = sp->s_ttyp; 297 if (sp->s_ttyp->t_pgrp) { 298 PGRP_LOCK(sp->s_ttyp->t_pgrp); 299 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 300 PGRP_UNLOCK(sp->s_ttyp->t_pgrp); 301 } 302 /* XXX tp should be locked. */ 303 sx_xunlock(&proctree_lock); 304 (void) ttywait(tp); 305 sx_xlock(&proctree_lock); 306 /* 307 * The tty could have been revoked 308 * if we blocked. 309 */ 310 if (sp->s_ttyvp) { 311 ttyvp = sp->s_ttyvp; 312 SESS_LOCK(p->p_session); 313 sp->s_ttyvp = NULL; 314 SESS_UNLOCK(p->p_session); 315 sx_xunlock(&proctree_lock); 316 VOP_REVOKE(ttyvp, REVOKEALL); 317 vrele(ttyvp); 318 sx_xlock(&proctree_lock); 319 } 320 } 321 if (sp->s_ttyvp) { 322 ttyvp = sp->s_ttyvp; 323 SESS_LOCK(p->p_session); 324 sp->s_ttyvp = NULL; 325 SESS_UNLOCK(p->p_session); 326 vrele(ttyvp); 327 } 328 /* 329 * s_ttyp is not zero'd; we use this to indicate 330 * that the session once had a controlling terminal. 331 * (for logging and informational purposes) 332 */ 333 } 334 SESS_LOCK(p->p_session); 335 sp->s_leader = NULL; 336 SESS_UNLOCK(p->p_session); 337 } 338 fixjobc(p, p->p_pgrp, 0); 339 sx_xunlock(&proctree_lock); 340 (void)acct_process(td); 341 mtx_unlock(&Giant); 342 #ifdef KTRACE 343 /* 344 * release trace file 345 */ 346 PROC_LOCK(p); 347 mtx_lock(&ktrace_mtx); 348 p->p_traceflag = 0; /* don't trace the vrele() */ 349 tracevp = p->p_tracevp; 350 p->p_tracevp = NULL; 351 tracecred = p->p_tracecred; 352 p->p_tracecred = NULL; 353 mtx_unlock(&ktrace_mtx); 354 PROC_UNLOCK(p); 355 if (tracevp != NULL) { 356 mtx_lock(&Giant); 357 vrele(tracevp); 358 mtx_unlock(&Giant); 359 } 360 if (tracecred != NULL) 361 crfree(tracecred); 362 #endif 363 /* 364 * Release reference to text vnode 365 */ 366 if ((vtmp = p->p_textvp) != NULL) { 367 p->p_textvp = NULL; 368 mtx_lock(&Giant); 369 vrele(vtmp); 370 mtx_unlock(&Giant); 371 } 372 373 /* 374 * Release our limits structure. 375 */ 376 PROC_LOCK(p); 377 plim = p->p_limit; 378 p->p_limit = NULL; 379 PROC_UNLOCK(p); 380 lim_free(plim); 381 382 /* 383 * Remove proc from allproc queue and pidhash chain. 384 * Place onto zombproc. Unlink from parent's child list. 385 */ 386 sx_xlock(&allproc_lock); 387 LIST_REMOVE(p, p_list); 388 LIST_INSERT_HEAD(&zombproc, p, p_list); 389 LIST_REMOVE(p, p_hash); 390 sx_xunlock(&allproc_lock); 391 392 sx_xlock(&proctree_lock); 393 q = LIST_FIRST(&p->p_children); 394 if (q != NULL) /* only need this if any child is S_ZOMB */ 395 wakeup(initproc); 396 for (; q != NULL; q = nq) { 397 nq = LIST_NEXT(q, p_sibling); 398 PROC_LOCK(q); 399 proc_reparent(q, initproc); 400 q->p_sigparent = SIGCHLD; 401 /* 402 * Traced processes are killed 403 * since their existence means someone is screwing up. 404 */ 405 if (q->p_flag & P_TRACED) { 406 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE); 407 psignal(q, SIGKILL); 408 } 409 PROC_UNLOCK(q); 410 } 411 412 /* 413 * Save exit status and final rusage info, adding in child rusage 414 * info and self times. 415 */ 416 mtx_lock(&Giant); 417 PROC_LOCK(p); 418 p->p_xstat = rv; 419 p->p_xthread = td; 420 *p->p_ru = p->p_stats->p_ru; 421 mtx_lock_spin(&sched_lock); 422 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 423 mtx_unlock_spin(&sched_lock); 424 ruadd(p->p_ru, &p->p_stats->p_cru); 425 426 mtx_unlock(&Giant); 427 /* 428 * Notify interested parties of our demise. 429 */ 430 KNOTE_LOCKED(&p->p_klist, NOTE_EXIT); 431 /* 432 * Just delete all entries in the p_klist. At this point we won't 433 * report any more events, and there are nasty race conditions that 434 * can beat us if we don't. 435 */ 436 knlist_clear(&p->p_klist, 1); 437 438 /* 439 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT 440 * flag set, or if the handler is set to SIG_IGN, notify process 441 * 1 instead (and hope it will handle this situation). 442 */ 443 PROC_LOCK(p->p_pptr); 444 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx); 445 if (p->p_pptr->p_sigacts->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 446 struct proc *pp; 447 448 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 449 pp = p->p_pptr; 450 PROC_UNLOCK(pp); 451 proc_reparent(p, initproc); 452 p->p_sigparent = SIGCHLD; 453 PROC_LOCK(p->p_pptr); 454 /* 455 * If this was the last child of our parent, notify 456 * parent, so in case he was wait(2)ing, he will 457 * continue. 458 */ 459 if (LIST_EMPTY(&pp->p_children)) 460 wakeup(pp); 461 } else 462 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 463 464 if (p->p_pptr == initproc) 465 psignal(p->p_pptr, SIGCHLD); 466 else if (p->p_sigparent != 0) 467 psignal(p->p_pptr, p->p_sigparent); 468 PROC_UNLOCK(p->p_pptr); 469 470 /* 471 * If this is a kthread, then wakeup anyone waiting for it to exit. 472 */ 473 if (p->p_flag & P_KTHREAD) 474 wakeup(p); 475 PROC_UNLOCK(p); 476 477 /* 478 * Finally, call machine-dependent code to release the remaining 479 * resources including address space. 480 * The address space is released by "vmspace_exitfree(p)" in 481 * vm_waitproc(). 482 */ 483 cpu_exit(td); 484 485 PROC_LOCK(p); 486 PROC_LOCK(p->p_pptr); 487 sx_xunlock(&proctree_lock); 488 489 while (mtx_owned(&Giant)) 490 mtx_unlock(&Giant); 491 492 /* 493 * We have to wait until after acquiring all locks before 494 * changing p_state. We need to avoid any possibly context 495 * switches while marked as a zombie including blocking on 496 * a mutex. 497 */ 498 mtx_lock_spin(&sched_lock); 499 p->p_state = PRS_ZOMBIE; 500 critical_enter(); 501 mtx_unlock_spin(&sched_lock); 502 503 wakeup(p->p_pptr); 504 PROC_UNLOCK(p->p_pptr); 505 506 mtx_lock_spin(&sched_lock); 507 critical_exit(); 508 509 /* Do the same timestamp bookkeeping that mi_switch() would do. */ 510 binuptime(&new_switchtime); 511 bintime_add(&p->p_runtime, &new_switchtime); 512 bintime_sub(&p->p_runtime, PCPU_PTR(switchtime)); 513 PCPU_SET(switchtime, new_switchtime); 514 PCPU_SET(switchticks, ticks); 515 516 cnt.v_swtch++; 517 sched_exit(p->p_pptr, td); 518 519 /* 520 * hopefully no one will try to deliver a signal to the process this 521 * late in the game. 522 */ 523 knlist_destroy(&p->p_klist); 524 525 /* 526 * Make sure the scheduler takes this thread out of its tables etc. 527 * This will also release this thread's reference to the ucred. 528 * Other thread parts to release include pcb bits and such. 529 */ 530 thread_exit(); 531 } 532 533 #ifdef COMPAT_43 534 /* 535 * MPSAFE. The dirty work is handled by kern_wait(). 536 */ 537 int 538 owait(struct thread *td, struct owait_args *uap __unused) 539 { 540 int error, status; 541 542 error = kern_wait(td, WAIT_ANY, &status, 0, NULL); 543 if (error == 0) 544 td->td_retval[1] = status; 545 return (error); 546 } 547 #endif /* COMPAT_43 */ 548 549 /* 550 * MPSAFE. The dirty work is handled by kern_wait(). 551 */ 552 int 553 wait4(struct thread *td, struct wait_args *uap) 554 { 555 struct rusage ru; 556 int error, status; 557 558 error = kern_wait(td, uap->pid, &status, uap->options, &ru); 559 if (uap->status != NULL && error == 0) 560 error = copyout(&status, uap->status, sizeof(status)); 561 if (uap->rusage != NULL && error == 0) 562 error = copyout(&ru, uap->rusage, sizeof(struct rusage)); 563 return (error); 564 } 565 566 int 567 kern_wait(struct thread *td, pid_t pid, int *status, int options, struct rusage *rusage) 568 { 569 int nfound; 570 struct proc *p, *q, *t; 571 int error; 572 573 q = td->td_proc; 574 if (pid == 0) { 575 PROC_LOCK(q); 576 pid = -q->p_pgid; 577 PROC_UNLOCK(q); 578 } 579 if (options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE)) 580 return (EINVAL); 581 loop: 582 nfound = 0; 583 sx_xlock(&proctree_lock); 584 LIST_FOREACH(p, &q->p_children, p_sibling) { 585 PROC_LOCK(p); 586 if (pid != WAIT_ANY && 587 p->p_pid != pid && p->p_pgid != -pid) { 588 PROC_UNLOCK(p); 589 continue; 590 } 591 592 /* 593 * This special case handles a kthread spawned by linux_clone 594 * (see linux_misc.c). The linux_wait4 and linux_waitpid 595 * functions need to be able to distinguish between waiting 596 * on a process and waiting on a thread. It is a thread if 597 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 598 * signifies we want to wait for threads and not processes. 599 */ 600 if ((p->p_sigparent != SIGCHLD) ^ 601 ((options & WLINUXCLONE) != 0)) { 602 PROC_UNLOCK(p); 603 continue; 604 } 605 606 nfound++; 607 if (p->p_state == PRS_ZOMBIE) { 608 td->td_retval[0] = p->p_pid; 609 if (status) 610 *status = p->p_xstat; /* convert to int */ 611 if (rusage) 612 bcopy(p->p_ru, rusage, sizeof(struct rusage)); 613 614 /* 615 * If we got the child via a ptrace 'attach', 616 * we need to give it back to the old parent. 617 */ 618 PROC_UNLOCK(p); 619 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) { 620 PROC_LOCK(p); 621 p->p_oppid = 0; 622 proc_reparent(p, t); 623 PROC_UNLOCK(p); 624 psignal(t, SIGCHLD); 625 wakeup(t); 626 PROC_UNLOCK(t); 627 sx_xunlock(&proctree_lock); 628 return (0); 629 } 630 631 /* 632 * Remove other references to this process to ensure 633 * we have an exclusive reference. 634 */ 635 sx_xlock(&allproc_lock); 636 LIST_REMOVE(p, p_list); /* off zombproc */ 637 sx_xunlock(&allproc_lock); 638 LIST_REMOVE(p, p_sibling); 639 leavepgrp(p); 640 sx_xunlock(&proctree_lock); 641 642 /* 643 * As a side effect of this lock, we know that 644 * all other writes to this proc are visible now, so 645 * no more locking is needed for p. 646 */ 647 mtx_lock(&Giant); 648 PROC_LOCK(p); 649 p->p_xstat = 0; /* XXX: why? */ 650 PROC_UNLOCK(p); 651 PROC_LOCK(q); 652 ruadd(&q->p_stats->p_cru, p->p_ru); 653 PROC_UNLOCK(q); 654 FREE(p->p_ru, M_ZOMBIE); 655 p->p_ru = NULL; 656 mtx_unlock(&Giant); 657 658 /* 659 * Decrement the count of procs running with this uid. 660 */ 661 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 662 663 /* 664 * Free credentials, arguments, and sigacts 665 */ 666 crfree(p->p_ucred); 667 p->p_ucred = NULL; 668 pargs_drop(p->p_args); 669 p->p_args = NULL; 670 sigacts_free(p->p_sigacts); 671 p->p_sigacts = NULL; 672 673 /* 674 * do any thread-system specific cleanups 675 */ 676 thread_wait(p); 677 678 /* 679 * Give vm and machine-dependent layer a chance 680 * to free anything that cpu_exit couldn't 681 * release while still running in process context. 682 */ 683 vm_waitproc(p); 684 #ifdef MAC 685 mac_destroy_proc(p); 686 #endif 687 KASSERT(FIRST_THREAD_IN_PROC(p), 688 ("kern_wait: no residual thread!")); 689 uma_zfree(proc_zone, p); 690 sx_xlock(&allproc_lock); 691 nprocs--; 692 sx_xunlock(&allproc_lock); 693 return (0); 694 } 695 mtx_lock_spin(&sched_lock); 696 if (P_SHOULDSTOP(p) && (p->p_suspcount == p->p_numthreads) && 697 ((p->p_flag & P_WAITED) == 0) && 698 (p->p_flag & P_TRACED || options & WUNTRACED)) { 699 mtx_unlock_spin(&sched_lock); 700 p->p_flag |= P_WAITED; 701 sx_xunlock(&proctree_lock); 702 td->td_retval[0] = p->p_pid; 703 if (status) 704 *status = W_STOPCODE(p->p_xstat); 705 PROC_UNLOCK(p); 706 return (0); 707 } 708 mtx_unlock_spin(&sched_lock); 709 if (options & WCONTINUED && (p->p_flag & P_CONTINUED)) { 710 sx_xunlock(&proctree_lock); 711 td->td_retval[0] = p->p_pid; 712 p->p_flag &= ~P_CONTINUED; 713 PROC_UNLOCK(p); 714 715 if (status) 716 *status = SIGCONT; 717 return (0); 718 } 719 PROC_UNLOCK(p); 720 } 721 if (nfound == 0) { 722 sx_xunlock(&proctree_lock); 723 return (ECHILD); 724 } 725 if (options & WNOHANG) { 726 sx_xunlock(&proctree_lock); 727 td->td_retval[0] = 0; 728 return (0); 729 } 730 PROC_LOCK(q); 731 sx_xunlock(&proctree_lock); 732 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0); 733 PROC_UNLOCK(q); 734 if (error) 735 return (error); 736 goto loop; 737 } 738 739 /* 740 * Make process 'parent' the new parent of process 'child'. 741 * Must be called with an exclusive hold of proctree lock. 742 */ 743 void 744 proc_reparent(struct proc *child, struct proc *parent) 745 { 746 747 sx_assert(&proctree_lock, SX_XLOCKED); 748 PROC_LOCK_ASSERT(child, MA_OWNED); 749 if (child->p_pptr == parent) 750 return; 751 752 LIST_REMOVE(child, p_sibling); 753 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 754 child->p_pptr = parent; 755 }
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