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/5.4/sys/kern/kern_exit.c 145648 2005-04-28 23:45:03Z davidxu $"); 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 80 /* Required to be non-static for SysVR4 emulator */ 81 MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status"); 82 83 /* 84 * exit -- 85 * Death of process. 86 * 87 * MPSAFE 88 */ 89 void 90 sys_exit(struct thread *td, struct sys_exit_args *uap) 91 { 92 93 exit1(td, W_EXITCODE(uap->rval, 0)); 94 /* NOTREACHED */ 95 } 96 97 /* 98 * Exit: deallocate address space and other resources, change proc state 99 * to zombie, and unlink proc from allproc and parent's lists. Save exit 100 * status and rusage for wait(). Check for child processes and orphan them. 101 */ 102 void 103 exit1(struct thread *td, int rv) 104 { 105 struct bintime new_switchtime; 106 struct proc *p, *nq, *q; 107 struct tty *tp; 108 struct vnode *ttyvp; 109 struct vmspace *vm; 110 struct vnode *vtmp; 111 #ifdef KTRACE 112 struct vnode *tracevp; 113 struct ucred *tracecred; 114 #endif 115 struct plimit *plim; 116 int refcnt; 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_HADTHREADS) { 137 retry: 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 * Threading support has been turned off. 167 */ 168 } 169 170 p->p_flag |= P_WEXIT; 171 PROC_UNLOCK(p); 172 173 /* Are we a task leader? */ 174 if (p == p->p_leader) { 175 mtx_lock(&ppeers_lock); 176 q = p->p_peers; 177 while (q != NULL) { 178 PROC_LOCK(q); 179 psignal(q, SIGKILL); 180 PROC_UNLOCK(q); 181 q = q->p_peers; 182 } 183 while (p->p_peers != NULL) 184 msleep(p, &ppeers_lock, PWAIT, "exit1", 0); 185 mtx_unlock(&ppeers_lock); 186 } 187 188 PROC_LOCK(p); 189 _STOPEVENT(p, S_EXIT, rv); 190 wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */ 191 PROC_UNLOCK(p); 192 193 /* 194 * Check if any loadable modules need anything done at process exit. 195 * e.g. SYSV IPC stuff 196 * XXX what if one of these generates an error? 197 */ 198 EVENTHANDLER_INVOKE(process_exit, p); 199 200 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 201 M_ZOMBIE, M_WAITOK); 202 /* 203 * If parent is waiting for us to exit or exec, 204 * P_PPWAIT is set; we will wakeup the parent below. 205 */ 206 PROC_LOCK(p); 207 stopprofclock(p); 208 p->p_flag &= ~(P_TRACED | P_PPWAIT); 209 SIGEMPTYSET(p->p_siglist); 210 SIGEMPTYSET(td->td_siglist); 211 212 /* 213 * Stop the real interval timer. If the handler is currently 214 * executing, prevent it from rearming itself and let it finish. 215 */ 216 if (timevalisset(&p->p_realtimer.it_value) && 217 callout_stop(&p->p_itcallout) == 0) { 218 timevalclear(&p->p_realtimer.it_interval); 219 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0); 220 KASSERT(!timevalisset(&p->p_realtimer.it_value), 221 ("realtime timer is still armed")); 222 } 223 PROC_UNLOCK(p); 224 225 /* 226 * Reset any sigio structures pointing to us as a result of 227 * F_SETOWN with our pid. 228 */ 229 mtx_lock(&Giant); /* XXX: not sure if needed */ 230 funsetownlst(&p->p_sigiolst); 231 232 /* 233 * Close open files and release open-file table. 234 * This may block! 235 */ 236 fdfree(td); 237 mtx_unlock(&Giant); 238 239 /* 240 * If this thread tickled GEOM, we need to wait for the giggling to 241 * stop before we return to userland 242 */ 243 if (td->td_pflags & TDP_GEOM) 244 g_waitidle(); 245 246 /* 247 * Remove ourself from our leader's peer list and wake our leader. 248 */ 249 mtx_lock(&ppeers_lock); 250 if (p->p_leader->p_peers) { 251 q = p->p_leader; 252 while (q->p_peers != p) 253 q = q->p_peers; 254 q->p_peers = p->p_peers; 255 wakeup(p->p_leader); 256 } 257 mtx_unlock(&ppeers_lock); 258 259 /* The next two chunks should probably be moved to vmspace_exit. */ 260 vm = p->p_vmspace; 261 /* 262 * Release user portion of address space. 263 * This releases references to vnodes, 264 * which could cause I/O if the file has been unlinked. 265 * Need to do this early enough that we can still sleep. 266 * Can't free the entire vmspace as the kernel stack 267 * may be mapped within that space also. 268 * 269 * Processes sharing the same vmspace may exit in one order, and 270 * get cleaned up by vmspace_exit() in a different order. The 271 * last exiting process to reach this point releases as much of 272 * the environment as it can, and the last process cleaned up 273 * by vmspace_exit() (which decrements exitingcnt) cleans up the 274 * remainder. 275 */ 276 atomic_add_int(&vm->vm_exitingcnt, 1); 277 do 278 refcnt = vm->vm_refcnt; 279 while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt - 1)); 280 if (refcnt == 1) { 281 shmexit(vm); 282 pmap_remove_pages(vmspace_pmap(vm), vm_map_min(&vm->vm_map), 283 vm_map_max(&vm->vm_map)); 284 (void) vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map), 285 vm_map_max(&vm->vm_map)); 286 } 287 288 mtx_lock(&Giant); 289 sx_xlock(&proctree_lock); 290 if (SESS_LEADER(p)) { 291 struct session *sp; 292 293 sp = p->p_session; 294 if (sp->s_ttyvp) { 295 /* 296 * Controlling process. 297 * Signal foreground pgrp, 298 * drain controlling terminal 299 * and revoke access to controlling terminal. 300 */ 301 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) { 302 tp = sp->s_ttyp; 303 if (sp->s_ttyp->t_pgrp) { 304 PGRP_LOCK(sp->s_ttyp->t_pgrp); 305 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 306 PGRP_UNLOCK(sp->s_ttyp->t_pgrp); 307 } 308 /* XXX tp should be locked. */ 309 sx_xunlock(&proctree_lock); 310 (void) ttywait(tp); 311 sx_xlock(&proctree_lock); 312 /* 313 * The tty could have been revoked 314 * if we blocked. 315 */ 316 if (sp->s_ttyvp) { 317 ttyvp = sp->s_ttyvp; 318 SESS_LOCK(p->p_session); 319 sp->s_ttyvp = NULL; 320 SESS_UNLOCK(p->p_session); 321 sx_xunlock(&proctree_lock); 322 VOP_REVOKE(ttyvp, REVOKEALL); 323 vrele(ttyvp); 324 sx_xlock(&proctree_lock); 325 } 326 } 327 if (sp->s_ttyvp) { 328 ttyvp = sp->s_ttyvp; 329 SESS_LOCK(p->p_session); 330 sp->s_ttyvp = NULL; 331 SESS_UNLOCK(p->p_session); 332 vrele(ttyvp); 333 } 334 /* 335 * s_ttyp is not zero'd; we use this to indicate 336 * that the session once had a controlling terminal. 337 * (for logging and informational purposes) 338 */ 339 } 340 SESS_LOCK(p->p_session); 341 sp->s_leader = NULL; 342 SESS_UNLOCK(p->p_session); 343 } 344 fixjobc(p, p->p_pgrp, 0); 345 sx_xunlock(&proctree_lock); 346 (void)acct_process(td); 347 mtx_unlock(&Giant); 348 #ifdef KTRACE 349 /* 350 * release trace file 351 */ 352 PROC_LOCK(p); 353 mtx_lock(&ktrace_mtx); 354 p->p_traceflag = 0; /* don't trace the vrele() */ 355 tracevp = p->p_tracevp; 356 p->p_tracevp = NULL; 357 tracecred = p->p_tracecred; 358 p->p_tracecred = NULL; 359 mtx_unlock(&ktrace_mtx); 360 PROC_UNLOCK(p); 361 if (tracevp != NULL) { 362 mtx_lock(&Giant); 363 vrele(tracevp); 364 mtx_unlock(&Giant); 365 } 366 if (tracecred != NULL) 367 crfree(tracecred); 368 #endif 369 /* 370 * Release reference to text vnode 371 */ 372 if ((vtmp = p->p_textvp) != NULL) { 373 p->p_textvp = NULL; 374 mtx_lock(&Giant); 375 vrele(vtmp); 376 mtx_unlock(&Giant); 377 } 378 379 /* 380 * Release our limits structure. 381 */ 382 PROC_LOCK(p); 383 plim = p->p_limit; 384 p->p_limit = NULL; 385 PROC_UNLOCK(p); 386 lim_free(plim); 387 388 /* 389 * Remove proc from allproc queue and pidhash chain. 390 * Place onto zombproc. Unlink from parent's child list. 391 */ 392 sx_xlock(&allproc_lock); 393 LIST_REMOVE(p, p_list); 394 LIST_INSERT_HEAD(&zombproc, p, p_list); 395 LIST_REMOVE(p, p_hash); 396 sx_xunlock(&allproc_lock); 397 398 sx_xlock(&proctree_lock); 399 q = LIST_FIRST(&p->p_children); 400 if (q != NULL) /* only need this if any child is S_ZOMB */ 401 wakeup(initproc); 402 for (; q != NULL; q = nq) { 403 nq = LIST_NEXT(q, p_sibling); 404 PROC_LOCK(q); 405 proc_reparent(q, initproc); 406 q->p_sigparent = SIGCHLD; 407 /* 408 * Traced processes are killed 409 * since their existence means someone is screwing up. 410 */ 411 if (q->p_flag & P_TRACED) { 412 q->p_flag &= ~(P_TRACED | P_STOPPED_TRACE); 413 psignal(q, SIGKILL); 414 } 415 PROC_UNLOCK(q); 416 } 417 418 /* 419 * Save exit status and final rusage info, adding in child rusage 420 * info and self times. 421 */ 422 mtx_lock(&Giant); 423 PROC_LOCK(p); 424 p->p_xstat = rv; 425 p->p_xthread = td; 426 *p->p_ru = p->p_stats->p_ru; 427 mtx_lock_spin(&sched_lock); 428 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 429 mtx_unlock_spin(&sched_lock); 430 ruadd(p->p_ru, &p->p_stats->p_cru); 431 432 mtx_unlock(&Giant); 433 /* 434 * Notify interested parties of our demise. 435 */ 436 KNOTE_LOCKED(&p->p_klist, NOTE_EXIT); 437 /* 438 * Just delete all entries in the p_klist. At this point we won't 439 * report any more events, and there are nasty race conditions that 440 * can beat us if we don't. 441 */ 442 knlist_clear(&p->p_klist, 1); 443 444 /* 445 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT 446 * flag set, or if the handler is set to SIG_IGN, notify process 447 * 1 instead (and hope it will handle this situation). 448 */ 449 PROC_LOCK(p->p_pptr); 450 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx); 451 if (p->p_pptr->p_sigacts->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 452 struct proc *pp; 453 454 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 455 pp = p->p_pptr; 456 PROC_UNLOCK(pp); 457 proc_reparent(p, initproc); 458 p->p_sigparent = SIGCHLD; 459 PROC_LOCK(p->p_pptr); 460 /* 461 * If this was the last child of our parent, notify 462 * parent, so in case he was wait(2)ing, he will 463 * continue. 464 */ 465 if (LIST_EMPTY(&pp->p_children)) 466 wakeup(pp); 467 } else 468 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 469 470 if (p->p_pptr == initproc) 471 psignal(p->p_pptr, SIGCHLD); 472 else if (p->p_sigparent != 0) 473 psignal(p->p_pptr, p->p_sigparent); 474 PROC_UNLOCK(p->p_pptr); 475 476 /* 477 * If this is a kthread, then wakeup anyone waiting for it to exit. 478 */ 479 if (p->p_flag & P_KTHREAD) 480 wakeup(p); 481 PROC_UNLOCK(p); 482 483 /* 484 * Finally, call machine-dependent code to release the remaining 485 * resources including address space. 486 * The address space is released by "vmspace_exitfree(p)" in 487 * vm_waitproc(). 488 */ 489 cpu_exit(td); 490 491 PROC_LOCK(p); 492 PROC_LOCK(p->p_pptr); 493 sx_xunlock(&proctree_lock); 494 495 while (mtx_owned(&Giant)) 496 mtx_unlock(&Giant); 497 498 /* 499 * We have to wait until after acquiring all locks before 500 * changing p_state. We need to avoid any possibly context 501 * switches while marked as a zombie including blocking on 502 * a mutex. 503 */ 504 mtx_lock_spin(&sched_lock); 505 p->p_state = PRS_ZOMBIE; 506 critical_enter(); 507 mtx_unlock_spin(&sched_lock); 508 509 wakeup(p->p_pptr); 510 /* 511 * XXX hack, swap in parent process, please see TDP_WAKEPROC0 512 * code, because TDP_WAKEPROC0 is only useful if thread is 513 * leaving critical region, but here we never leave and 514 * thread_exit() will call cpu_throw(), TDP_WAKEPROC0 is never 515 * cleared. 516 */ 517 if (p->p_pptr->p_sflag & PS_SWAPINREQ) 518 wakeup(&proc0); 519 PROC_UNLOCK(p->p_pptr); 520 521 mtx_lock_spin(&sched_lock); 522 critical_exit(); 523 524 /* Do the same timestamp bookkeeping that mi_switch() would do. */ 525 binuptime(&new_switchtime); 526 bintime_add(&p->p_runtime, &new_switchtime); 527 bintime_sub(&p->p_runtime, PCPU_PTR(switchtime)); 528 PCPU_SET(switchtime, new_switchtime); 529 PCPU_SET(switchticks, ticks); 530 531 cnt.v_swtch++; 532 sched_exit(p->p_pptr, td); 533 534 /* 535 * hopefully no one will try to deliver a signal to the process this 536 * late in the game. 537 */ 538 knlist_destroy(&p->p_klist); 539 540 /* 541 * Make sure the scheduler takes this thread out of its tables etc. 542 * This will also release this thread's reference to the ucred. 543 * Other thread parts to release include pcb bits and such. 544 */ 545 thread_exit(); 546 } 547 548 #ifdef COMPAT_43 549 /* 550 * MPSAFE. The dirty work is handled by kern_wait(). 551 */ 552 int 553 owait(struct thread *td, struct owait_args *uap __unused) 554 { 555 int error, status; 556 557 error = kern_wait(td, WAIT_ANY, &status, 0, NULL); 558 if (error == 0) 559 td->td_retval[1] = status; 560 return (error); 561 } 562 #endif /* COMPAT_43 */ 563 564 /* 565 * MPSAFE. The dirty work is handled by kern_wait(). 566 */ 567 int 568 wait4(struct thread *td, struct wait_args *uap) 569 { 570 struct rusage ru; 571 int error, status; 572 573 error = kern_wait(td, uap->pid, &status, uap->options, &ru); 574 if (uap->status != NULL && error == 0) 575 error = copyout(&status, uap->status, sizeof(status)); 576 if (uap->rusage != NULL && error == 0) 577 error = copyout(&ru, uap->rusage, sizeof(struct rusage)); 578 return (error); 579 } 580 581 int 582 kern_wait(struct thread *td, pid_t pid, int *status, int options, struct rusage *rusage) 583 { 584 int nfound; 585 struct proc *p, *q, *t; 586 int error; 587 588 q = td->td_proc; 589 if (pid == 0) { 590 PROC_LOCK(q); 591 pid = -q->p_pgid; 592 PROC_UNLOCK(q); 593 } 594 if (options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE)) 595 return (EINVAL); 596 loop: 597 if (q->p_flag & P_STATCHILD) { 598 PROC_LOCK(q); 599 q->p_flag &= ~P_STATCHILD; 600 PROC_UNLOCK(q); 601 } 602 nfound = 0; 603 sx_xlock(&proctree_lock); 604 LIST_FOREACH(p, &q->p_children, p_sibling) { 605 PROC_LOCK(p); 606 if (pid != WAIT_ANY && 607 p->p_pid != pid && p->p_pgid != -pid) { 608 PROC_UNLOCK(p); 609 continue; 610 } 611 612 /* 613 * This special case handles a kthread spawned by linux_clone 614 * (see linux_misc.c). The linux_wait4 and linux_waitpid 615 * functions need to be able to distinguish between waiting 616 * on a process and waiting on a thread. It is a thread if 617 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 618 * signifies we want to wait for threads and not processes. 619 */ 620 if ((p->p_sigparent != SIGCHLD) ^ 621 ((options & WLINUXCLONE) != 0)) { 622 PROC_UNLOCK(p); 623 continue; 624 } 625 626 nfound++; 627 if (p->p_state == PRS_ZOMBIE) { 628 td->td_retval[0] = p->p_pid; 629 if (status) 630 *status = p->p_xstat; /* convert to int */ 631 if (rusage) 632 *rusage = *p->p_ru; 633 634 /* 635 * If we got the child via a ptrace 'attach', 636 * we need to give it back to the old parent. 637 */ 638 PROC_UNLOCK(p); 639 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) { 640 PROC_LOCK(p); 641 p->p_oppid = 0; 642 proc_reparent(p, t); 643 PROC_UNLOCK(p); 644 psignal(t, SIGCHLD); 645 wakeup(t); 646 PROC_UNLOCK(t); 647 sx_xunlock(&proctree_lock); 648 return (0); 649 } 650 651 /* 652 * Remove other references to this process to ensure 653 * we have an exclusive reference. 654 */ 655 sx_xlock(&allproc_lock); 656 LIST_REMOVE(p, p_list); /* off zombproc */ 657 sx_xunlock(&allproc_lock); 658 LIST_REMOVE(p, p_sibling); 659 leavepgrp(p); 660 sx_xunlock(&proctree_lock); 661 662 /* 663 * As a side effect of this lock, we know that 664 * all other writes to this proc are visible now, so 665 * no more locking is needed for p. 666 */ 667 mtx_lock(&Giant); 668 PROC_LOCK(p); 669 p->p_xstat = 0; /* XXX: why? */ 670 PROC_UNLOCK(p); 671 PROC_LOCK(q); 672 ruadd(&q->p_stats->p_cru, p->p_ru); 673 PROC_UNLOCK(q); 674 FREE(p->p_ru, M_ZOMBIE); 675 p->p_ru = NULL; 676 mtx_unlock(&Giant); 677 678 /* 679 * Decrement the count of procs running with this uid. 680 */ 681 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 682 683 /* 684 * Free credentials, arguments, and sigacts 685 */ 686 crfree(p->p_ucred); 687 p->p_ucred = NULL; 688 pargs_drop(p->p_args); 689 p->p_args = NULL; 690 sigacts_free(p->p_sigacts); 691 p->p_sigacts = NULL; 692 693 /* 694 * do any thread-system specific cleanups 695 */ 696 thread_wait(p); 697 698 /* 699 * Give vm and machine-dependent layer a chance 700 * to free anything that cpu_exit couldn't 701 * release while still running in process context. 702 */ 703 vm_waitproc(p); 704 #ifdef MAC 705 mac_destroy_proc(p); 706 #endif 707 KASSERT(FIRST_THREAD_IN_PROC(p), 708 ("kern_wait: no residual thread!")); 709 uma_zfree(proc_zone, p); 710 sx_xlock(&allproc_lock); 711 nprocs--; 712 sx_xunlock(&allproc_lock); 713 return (0); 714 } 715 mtx_lock_spin(&sched_lock); 716 if (P_SHOULDSTOP(p) && (p->p_suspcount == p->p_numthreads) && 717 ((p->p_flag & P_WAITED) == 0) && 718 (p->p_flag & P_TRACED || options & WUNTRACED)) { 719 mtx_unlock_spin(&sched_lock); 720 p->p_flag |= P_WAITED; 721 sx_xunlock(&proctree_lock); 722 td->td_retval[0] = p->p_pid; 723 if (status) 724 *status = W_STOPCODE(p->p_xstat); 725 PROC_UNLOCK(p); 726 return (0); 727 } 728 mtx_unlock_spin(&sched_lock); 729 if (options & WCONTINUED && (p->p_flag & P_CONTINUED)) { 730 sx_xunlock(&proctree_lock); 731 td->td_retval[0] = p->p_pid; 732 p->p_flag &= ~P_CONTINUED; 733 PROC_UNLOCK(p); 734 735 if (status) 736 *status = SIGCONT; 737 return (0); 738 } 739 PROC_UNLOCK(p); 740 } 741 if (nfound == 0) { 742 sx_xunlock(&proctree_lock); 743 return (ECHILD); 744 } 745 if (options & WNOHANG) { 746 sx_xunlock(&proctree_lock); 747 td->td_retval[0] = 0; 748 return (0); 749 } 750 PROC_LOCK(q); 751 sx_xunlock(&proctree_lock); 752 if (q->p_flag & P_STATCHILD) { 753 q->p_flag &= ~P_STATCHILD; 754 error = 0; 755 } else 756 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0); 757 PROC_UNLOCK(q); 758 if (error) 759 return (error); 760 goto loop; 761 } 762 763 /* 764 * Make process 'parent' the new parent of process 'child'. 765 * Must be called with an exclusive hold of proctree lock. 766 */ 767 void 768 proc_reparent(struct proc *child, struct proc *parent) 769 { 770 771 sx_assert(&proctree_lock, SX_XLOCKED); 772 PROC_LOCK_ASSERT(child, MA_OWNED); 773 if (child->p_pptr == parent) 774 return; 775 776 LIST_REMOVE(child, p_sibling); 777 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 778 child->p_pptr = parent; 779 }
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