kern_exit.c revision 132016
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: head/sys/kern/kern_exit.c 132016 2004-07-12 05:07:50Z marcel $"); 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 */ 82MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status"); 83 84/* 85 * exit -- 86 * Death of process. 87 * 88 * MPSAFE 89 */ 90void 91sys_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 */ 103void 104exit1(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; 117 118 /* 119 * Drop Giant if caller has it. Eventually we should warn about 120 * being called with Giant held. 121 */ 122 while (mtx_owned(&Giant)) 123 mtx_unlock(&Giant); 124 125 p = td->td_proc; 126 if (p == initproc) { 127 printf("init died (signal %d, exit %d)\n", 128 WTERMSIG(rv), WEXITSTATUS(rv)); 129 panic("Going nowhere without my init!"); 130 } 131 132 /* 133 * MUST abort all other threads before proceeding past here. 134 */ 135 PROC_LOCK(p); 136 if (p->p_flag & P_SA || p->p_numthreads > 1) { 137retry: 138 /* 139 * First check if some other thread got here before us.. 140 * if so, act apropriatly, (exit or suspend); 141 */ 142 thread_suspend_check(0); 143 144 /* 145 * Kill off the other threads. This requires 146 * Some co-operation from other parts of the kernel 147 * so it may not be instant. 148 * With this state set: 149 * Any thread entering the kernel from userspace will 150 * thread_exit() in trap(). Any thread attempting to 151 * sleep will return immediatly with EINTR or EWOULDBLOCK, 152 * which will hopefully force them to back out to userland, 153 * freeing resources as they go, and anything attempting 154 * to return to userland will thread_exit() from userret(). 155 * thread_exit() will unsuspend us when the last other 156 * thread exits. 157 * If there is already a thread singler after resumption, 158 * calling thread_single will fail, in the case, we just 159 * re-check all suspension request, the thread should 160 * either be suspended there or exit. 161 */ 162 if (thread_single(SINGLE_EXIT)) 163 goto retry; 164 /* 165 * All other activity in this process is now stopped. 166 * Remove excess KSEs and KSEGRPS. XXXKSE (when we have them) 167 * ... 168 * Turn off threading support. 169 */ 170 p->p_flag &= ~P_SA; 171 td->td_pflags &= ~TDP_SA; 172 thread_single_end(); /* Don't need this any more. */ 173 } 174 175 p->p_flag |= P_WEXIT; 176 PROC_UNLOCK(p); 177 178 /* Are we a task leader? */ 179 if (p == p->p_leader) { 180 mtx_lock(&ppeers_lock); 181 q = p->p_peers; 182 while (q != NULL) { 183 PROC_LOCK(q); 184 psignal(q, SIGKILL); 185 PROC_UNLOCK(q); 186 q = q->p_peers; 187 } 188 while (p->p_peers != NULL) 189 msleep(p, &ppeers_lock, PWAIT, "exit1", 0); 190 mtx_unlock(&ppeers_lock); 191 } 192 193 PROC_LOCK(p); 194 _STOPEVENT(p, S_EXIT, rv); 195 wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */ 196 PROC_UNLOCK(p); 197 198 /* 199 * Check if any loadable modules need anything done at process exit. 200 * e.g. SYSV IPC stuff 201 * XXX what if one of these generates an error? 202 */ 203 EVENTHANDLER_INVOKE(process_exit, p); 204 205 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 206 M_ZOMBIE, M_WAITOK); 207 /* 208 * If parent is waiting for us to exit or exec, 209 * P_PPWAIT is set; we will wakeup the parent below. 210 */ 211 PROC_LOCK(p); 212 stopprofclock(p); 213 p->p_flag &= ~(P_TRACED | P_PPWAIT); 214 SIGEMPTYSET(p->p_siglist); 215 SIGEMPTYSET(td->td_siglist); 216 217 /* 218 * Stop the real interval timer. If the handler is currently 219 * executing, prevent it from rearming itself and let it finish. 220 */ 221 if (timevalisset(&p->p_realtimer.it_value) && 222 callout_stop(&p->p_itcallout) == 0) { 223 timevalclear(&p->p_realtimer.it_interval); 224 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0); 225 KASSERT(!timevalisset(&p->p_realtimer.it_value), 226 ("realtime timer is still armed")); 227 } 228 PROC_UNLOCK(p); 229 230 /* 231 * Reset any sigio structures pointing to us as a result of 232 * F_SETOWN with our pid. 233 */ 234 mtx_lock(&Giant); /* XXX: not sure if needed */ 235 funsetownlst(&p->p_sigiolst); 236 237 /* 238 * Close open files and release open-file table. 239 * This may block! 240 */ 241 fdfree(td); 242 mtx_unlock(&Giant); 243 244 /* 245 * Remove ourself from our leader's peer list and wake our leader. 246 */ 247 mtx_lock(&ppeers_lock); 248 if (p->p_leader->p_peers) { 249 q = p->p_leader; 250 while (q->p_peers != p) 251 q = q->p_peers; 252 q->p_peers = p->p_peers; 253 wakeup(p->p_leader); 254 } 255 mtx_unlock(&ppeers_lock); 256 257 mtx_lock(&Giant); 258 /* The next two chunks should probably be moved to vmspace_exit. */ 259 vm = p->p_vmspace; 260 /* 261 * Release user portion of address space. 262 * This releases references to vnodes, 263 * which could cause I/O if the file has been unlinked. 264 * Need to do this early enough that we can still sleep. 265 * Can't free the entire vmspace as the kernel stack 266 * may be mapped within that space also. 267 * 268 * Processes sharing the same vmspace may exit in one order, and 269 * get cleaned up by vmspace_exit() in a different order. The 270 * last exiting process to reach this point releases as much of 271 * the environment as it can, and the last process cleaned up 272 * by vmspace_exit() (which decrements exitingcnt) cleans up the 273 * remainder. 274 */ 275 ++vm->vm_exitingcnt; 276 if (--vm->vm_refcnt == 0) { 277 shmexit(vm); 278 vm_page_lock_queues(); 279 pmap_remove_pages(vmspace_pmap(vm), vm_map_min(&vm->vm_map), 280 vm_map_max(&vm->vm_map)); 281 vm_page_unlock_queues(); 282 (void) vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map), 283 vm_map_max(&vm->vm_map)); 284 } 285 286 sx_xlock(&proctree_lock); 287 if (SESS_LEADER(p)) { 288 struct session *sp; 289 290 sp = p->p_session; 291 if (sp->s_ttyvp) { 292 /* 293 * Controlling process. 294 * Signal foreground pgrp, 295 * drain controlling terminal 296 * and revoke access to controlling terminal. 297 */ 298 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) { 299 tp = sp->s_ttyp; 300 if (sp->s_ttyp->t_pgrp) { 301 PGRP_LOCK(sp->s_ttyp->t_pgrp); 302 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 303 PGRP_UNLOCK(sp->s_ttyp->t_pgrp); 304 } 305 /* XXX tp should be locked. */ 306 sx_xunlock(&proctree_lock); 307 (void) ttywait(tp); 308 sx_xlock(&proctree_lock); 309 /* 310 * The tty could have been revoked 311 * if we blocked. 312 */ 313 if (sp->s_ttyvp) { 314 ttyvp = sp->s_ttyvp; 315 SESS_LOCK(p->p_session); 316 sp->s_ttyvp = NULL; 317 SESS_UNLOCK(p->p_session); 318 sx_xunlock(&proctree_lock); 319 VOP_REVOKE(ttyvp, REVOKEALL); 320 vrele(ttyvp); 321 sx_xlock(&proctree_lock); 322 } 323 } 324 if (sp->s_ttyvp) { 325 ttyvp = sp->s_ttyvp; 326 SESS_LOCK(p->p_session); 327 sp->s_ttyvp = NULL; 328 SESS_UNLOCK(p->p_session); 329 vrele(ttyvp); 330 } 331 /* 332 * s_ttyp is not zero'd; we use this to indicate 333 * that the session once had a controlling terminal. 334 * (for logging and informational purposes) 335 */ 336 } 337 SESS_LOCK(p->p_session); 338 sp->s_leader = NULL; 339 SESS_UNLOCK(p->p_session); 340 } 341 fixjobc(p, p->p_pgrp, 0); 342 sx_xunlock(&proctree_lock); 343 (void)acct_process(td); 344 mtx_unlock(&Giant); 345#ifdef KTRACE 346 /* 347 * release trace file 348 */ 349 PROC_LOCK(p); 350 mtx_lock(&ktrace_mtx); 351 p->p_traceflag = 0; /* don't trace the vrele() */ 352 tracevp = p->p_tracevp; 353 p->p_tracevp = NULL; 354 tracecred = p->p_tracecred; 355 p->p_tracecred = NULL; 356 mtx_unlock(&ktrace_mtx); 357 PROC_UNLOCK(p); 358 if (tracevp != NULL) { 359 mtx_lock(&Giant); 360 vrele(tracevp); 361 mtx_unlock(&Giant); 362 } 363 if (tracecred != NULL) 364 crfree(tracecred); 365#endif 366 /* 367 * Release reference to text vnode 368 */ 369 if ((vtmp = p->p_textvp) != NULL) { 370 p->p_textvp = NULL; 371 mtx_lock(&Giant); 372 vrele(vtmp); 373 mtx_unlock(&Giant); 374 } 375 376 /* 377 * Release our limits structure. 378 */ 379 PROC_LOCK(p); 380 plim = p->p_limit; 381 p->p_limit = NULL; 382 PROC_UNLOCK(p); 383 lim_free(plim); 384 385 /* 386 * Release this thread's reference to the ucred. The actual proc 387 * reference will stay around until the proc is harvested by 388 * wait(). At this point the ucred is immutable (no other threads 389 * from this proc are around that can change it) so we leave the 390 * per-thread ucred pointer intact in case it is needed although 391 * in theory nothing should be using it at this point. 392 */ 393 crfree(td->td_ucred); 394 395 /* 396 * Remove proc from allproc queue and pidhash chain. 397 * Place onto zombproc. Unlink from parent's child list. 398 */ 399 sx_xlock(&allproc_lock); 400 LIST_REMOVE(p, p_list); 401 LIST_INSERT_HEAD(&zombproc, p, p_list); 402 LIST_REMOVE(p, p_hash); 403 sx_xunlock(&allproc_lock); 404 405 sx_xlock(&proctree_lock); 406 q = LIST_FIRST(&p->p_children); 407 if (q != NULL) /* only need this if any child is S_ZOMB */ 408 wakeup(initproc); 409 for (; q != NULL; q = nq) { 410 nq = LIST_NEXT(q, p_sibling); 411 PROC_LOCK(q); 412 proc_reparent(q, initproc); 413 q->p_sigparent = SIGCHLD; 414 /* 415 * Traced processes are killed 416 * since their existence means someone is screwing up. 417 */ 418 if (q->p_flag & P_TRACED) { 419 q->p_flag &= ~P_TRACED; 420 psignal(q, SIGKILL); 421 } 422 PROC_UNLOCK(q); 423 } 424 425 /* 426 * Save exit status and final rusage info, adding in child rusage 427 * info and self times. 428 */ 429 mtx_lock(&Giant); 430 PROC_LOCK(p); 431 p->p_xstat = rv; 432 p->p_xlwpid = td->td_tid; 433 *p->p_ru = p->p_stats->p_ru; 434 mtx_lock_spin(&sched_lock); 435 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 436 mtx_unlock_spin(&sched_lock); 437 ruadd(p->p_ru, &p->p_stats->p_cru); 438 439 /* 440 * Notify interested parties of our demise. 441 */ 442 KNOTE(&p->p_klist, NOTE_EXIT); 443 mtx_unlock(&Giant); 444 /* 445 * Just delete all entries in the p_klist. At this point we won't 446 * report any more events, and there are nasty race conditions that 447 * can beat us if we don't. 448 */ 449 while (SLIST_FIRST(&p->p_klist)) 450 SLIST_REMOVE_HEAD(&p->p_klist, kn_selnext); 451 452 /* 453 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT 454 * flag set, or if the handler is set to SIG_IGN, notify process 455 * 1 instead (and hope it will handle this situation). 456 */ 457 PROC_LOCK(p->p_pptr); 458 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx); 459 if (p->p_pptr->p_sigacts->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 460 struct proc *pp; 461 462 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 463 pp = p->p_pptr; 464 PROC_UNLOCK(pp); 465 proc_reparent(p, initproc); 466 p->p_sigparent = SIGCHLD; 467 PROC_LOCK(p->p_pptr); 468 /* 469 * If this was the last child of our parent, notify 470 * parent, so in case he was wait(2)ing, he will 471 * continue. 472 */ 473 if (LIST_EMPTY(&pp->p_children)) 474 wakeup(pp); 475 } else 476 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 477 478 if (p->p_pptr == initproc) 479 psignal(p->p_pptr, SIGCHLD); 480 else if (p->p_sigparent != 0) 481 psignal(p->p_pptr, p->p_sigparent); 482 PROC_UNLOCK(p->p_pptr); 483 484 /* 485 * If this is a kthread, then wakeup anyone waiting for it to exit. 486 */ 487 if (p->p_flag & P_KTHREAD) 488 wakeup(p); 489 PROC_UNLOCK(p); 490 491 /* 492 * Finally, call machine-dependent code to release the remaining 493 * resources including address space. 494 * The address space is released by "vmspace_exitfree(p)" in 495 * vm_waitproc(). 496 */ 497 cpu_exit(td); 498 499 PROC_LOCK(p); 500 PROC_LOCK(p->p_pptr); 501 sx_xunlock(&proctree_lock); 502 503 while (mtx_owned(&Giant)) 504 mtx_unlock(&Giant); 505 506 /* 507 * We have to wait until after acquiring all locks before 508 * changing p_state. We need to avoid any possibly context 509 * switches while marked as a zombie including blocking on 510 * a mutex. 511 */ 512 mtx_lock_spin(&sched_lock); 513 p->p_state = PRS_ZOMBIE; 514 critical_enter(); 515 mtx_unlock_spin(&sched_lock); 516 517 wakeup(p->p_pptr); 518 PROC_UNLOCK(p->p_pptr); 519 520 mtx_lock_spin(&sched_lock); 521 critical_exit(); 522 523 /* Do the same timestamp bookkeeping that mi_switch() would do. */ 524 binuptime(&new_switchtime); 525 bintime_add(&p->p_runtime, &new_switchtime); 526 bintime_sub(&p->p_runtime, PCPU_PTR(switchtime)); 527 PCPU_SET(switchtime, new_switchtime); 528 PCPU_SET(switchticks, ticks); 529 530 cnt.v_swtch++; 531 sched_exit(p->p_pptr, p); 532 533 /* 534 * Make sure the scheduler takes this thread out of its tables etc. 535 * This will also release this thread's reference to the ucred. 536 * Other thread parts to release include pcb bits and such. 537 */ 538 thread_exit(); 539} 540 541#ifdef COMPAT_43 542/* 543 * MPSAFE. The dirty work is handled by kern_wait(). 544 */ 545int 546owait(struct thread *td, struct owait_args *uap __unused) 547{ 548 int error, status; 549 550 error = kern_wait(td, WAIT_ANY, &status, 0, NULL); 551 if (error == 0) 552 td->td_retval[1] = status; 553 return (error); 554} 555#endif /* COMPAT_43 */ 556 557/* 558 * MPSAFE. The dirty work is handled by kern_wait(). 559 */ 560int 561wait4(struct thread *td, struct wait_args *uap) 562{ 563 struct rusage ru; 564 int error, status; 565 566 error = kern_wait(td, uap->pid, &status, uap->options, &ru); 567 if (uap->status != NULL && error == 0) 568 error = copyout(&status, uap->status, sizeof(status)); 569 if (uap->rusage != NULL && error == 0) 570 error = copyout(&ru, uap->rusage, sizeof(struct rusage)); 571 return (error); 572} 573 574int 575kern_wait(struct thread *td, pid_t pid, int *status, int options, struct rusage *rusage) 576{ 577 int nfound; 578 struct proc *p, *q, *t; 579 int error; 580 581 q = td->td_proc; 582 if (pid == 0) { 583 PROC_LOCK(q); 584 pid = -q->p_pgid; 585 PROC_UNLOCK(q); 586 } 587 if (options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE)) 588 return (EINVAL); 589loop: 590 nfound = 0; 591 sx_xlock(&proctree_lock); 592 LIST_FOREACH(p, &q->p_children, p_sibling) { 593 PROC_LOCK(p); 594 if (pid != WAIT_ANY && 595 p->p_pid != pid && p->p_pgid != -pid) { 596 PROC_UNLOCK(p); 597 continue; 598 } 599 600 /* 601 * This special case handles a kthread spawned by linux_clone 602 * (see linux_misc.c). The linux_wait4 and linux_waitpid 603 * functions need to be able to distinguish between waiting 604 * on a process and waiting on a thread. It is a thread if 605 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 606 * signifies we want to wait for threads and not processes. 607 */ 608 if ((p->p_sigparent != SIGCHLD) ^ 609 ((options & WLINUXCLONE) != 0)) { 610 PROC_UNLOCK(p); 611 continue; 612 } 613 614 nfound++; 615 if (p->p_state == PRS_ZOMBIE) { 616 td->td_retval[0] = p->p_pid; 617 if (status) 618 *status = p->p_xstat; /* convert to int */ 619 if (rusage) 620 bcopy(p->p_ru, rusage, sizeof(struct rusage)); 621 622 /* 623 * If we got the child via a ptrace 'attach', 624 * we need to give it back to the old parent. 625 */ 626 PROC_UNLOCK(p); 627 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) { 628 PROC_LOCK(p); 629 p->p_oppid = 0; 630 proc_reparent(p, t); 631 PROC_UNLOCK(p); 632 psignal(t, SIGCHLD); 633 wakeup(t); 634 PROC_UNLOCK(t); 635 sx_xunlock(&proctree_lock); 636 return (0); 637 } 638 639 /* 640 * Remove other references to this process to ensure 641 * we have an exclusive reference. 642 */ 643 sx_xlock(&allproc_lock); 644 LIST_REMOVE(p, p_list); /* off zombproc */ 645 sx_xunlock(&allproc_lock); 646 LIST_REMOVE(p, p_sibling); 647 leavepgrp(p); 648 sx_xunlock(&proctree_lock); 649 650 /* 651 * As a side effect of this lock, we know that 652 * all other writes to this proc are visible now, so 653 * no more locking is needed for p. 654 */ 655 mtx_lock(&Giant); 656 PROC_LOCK(p); 657 p->p_xstat = 0; /* XXX: why? */ 658 PROC_UNLOCK(p); 659 PROC_LOCK(q); 660 ruadd(&q->p_stats->p_cru, p->p_ru); 661 PROC_UNLOCK(q); 662 FREE(p->p_ru, M_ZOMBIE); 663 p->p_ru = NULL; 664 mtx_unlock(&Giant); 665 666 /* 667 * Decrement the count of procs running with this uid. 668 */ 669 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 670 671 /* 672 * Free credentials, arguments, and sigacts 673 */ 674 crfree(p->p_ucred); 675 p->p_ucred = NULL; 676 pargs_drop(p->p_args); 677 p->p_args = NULL; 678 sigacts_free(p->p_sigacts); 679 p->p_sigacts = NULL; 680 681 /* 682 * do any thread-system specific cleanups 683 */ 684 thread_wait(p); 685 686 /* 687 * Give vm and machine-dependent layer a chance 688 * to free anything that cpu_exit couldn't 689 * release while still running in process context. 690 */ 691 mtx_lock(&Giant); 692 vm_waitproc(p); 693 mtx_unlock(&Giant); 694#ifdef MAC 695 mac_destroy_proc(p); 696#endif 697 KASSERT(FIRST_THREAD_IN_PROC(p), 698 ("kern_wait: no residual thread!")); 699 uma_zfree(proc_zone, p); 700 sx_xlock(&allproc_lock); 701 nprocs--; 702 sx_xunlock(&allproc_lock); 703 return (0); 704 } 705 mtx_lock_spin(&sched_lock); 706 if (P_SHOULDSTOP(p) && (p->p_suspcount == p->p_numthreads) && 707 ((p->p_flag & P_WAITED) == 0) && 708 (p->p_flag & P_TRACED || options & WUNTRACED)) { 709 mtx_unlock_spin(&sched_lock); 710 p->p_flag |= P_WAITED; 711 sx_xunlock(&proctree_lock); 712 td->td_retval[0] = p->p_pid; 713 if (status) 714 *status = W_STOPCODE(p->p_xstat); 715 PROC_UNLOCK(p); 716 return (0); 717 } 718 mtx_unlock_spin(&sched_lock); 719 if (options & WCONTINUED && (p->p_flag & P_CONTINUED)) { 720 sx_xunlock(&proctree_lock); 721 td->td_retval[0] = p->p_pid; 722 p->p_flag &= ~P_CONTINUED; 723 PROC_UNLOCK(p); 724 725 if (status) 726 *status = SIGCONT; 727 return (0); 728 } 729 PROC_UNLOCK(p); 730 } 731 if (nfound == 0) { 732 sx_xunlock(&proctree_lock); 733 return (ECHILD); 734 } 735 if (options & WNOHANG) { 736 sx_xunlock(&proctree_lock); 737 td->td_retval[0] = 0; 738 return (0); 739 } 740 PROC_LOCK(q); 741 sx_xunlock(&proctree_lock); 742 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0); 743 PROC_UNLOCK(q); 744 if (error) 745 return (error); 746 goto loop; 747} 748 749/* 750 * Make process 'parent' the new parent of process 'child'. 751 * Must be called with an exclusive hold of proctree lock. 752 */ 753void 754proc_reparent(struct proc *child, struct proc *parent) 755{ 756 757 sx_assert(&proctree_lock, SX_XLOCKED); 758 PROC_LOCK_ASSERT(child, MA_OWNED); 759 if (child->p_pptr == parent) 760 return; 761 762 LIST_REMOVE(child, p_sibling); 763 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 764 child->p_pptr = parent; 765} 766