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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD: releng/5.2/sys/kern/kern_exit.c 122686 2003-11-14 18:49:01Z cognet $"); 43 44 #include "opt_compat.h" 45 #include "opt_ktrace.h" 46 #include "opt_mac.h" 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/sysproto.h> 51 #include <sys/eventhandler.h> 52 #include <sys/kernel.h> 53 #include <sys/malloc.h> 54 #include <sys/lock.h> 55 #include <sys/mutex.h> 56 #include <sys/proc.h> 57 #include <sys/pioctl.h> 58 #include <sys/tty.h> 59 #include <sys/wait.h> 60 #include <sys/vmmeter.h> 61 #include <sys/vnode.h> 62 #include <sys/resourcevar.h> 63 #include <sys/signalvar.h> 64 #include <sys/sched.h> 65 #include <sys/sx.h> 66 #include <sys/ptrace.h> 67 #include <sys/acct.h> /* for acct_process() function prototype */ 68 #include <sys/filedesc.h> 69 #include <sys/mac.h> 70 #include <sys/shm.h> 71 #include <sys/sem.h> 72 #include <sys/jail.h> 73 #ifdef KTRACE 74 #include <sys/ktrace.h> 75 #endif 76 77 #include <vm/vm.h> 78 #include <vm/vm_extern.h> 79 #include <vm/vm_param.h> 80 #include <vm/pmap.h> 81 #include <vm/vm_map.h> 82 #include <vm/vm_page.h> 83 #include <vm/uma.h> 84 #include <sys/user.h> 85 86 /* Required to be non-static for SysVR4 emulator */ 87 MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status"); 88 89 static int wait1(struct thread *, struct wait_args *, int); 90 91 /* 92 * exit -- 93 * Death of process. 94 * 95 * MPSAFE 96 */ 97 void 98 sys_exit(struct thread *td, struct sys_exit_args *uap) 99 { 100 101 mtx_lock(&Giant); 102 exit1(td, W_EXITCODE(uap->rval, 0)); 103 /* NOTREACHED */ 104 } 105 106 /* 107 * Exit: deallocate address space and other resources, change proc state 108 * to zombie, and unlink proc from allproc and parent's lists. Save exit 109 * status and rusage for wait(). Check for child processes and orphan them. 110 */ 111 void 112 exit1(struct thread *td, int rv) 113 { 114 struct proc *p, *nq, *q; 115 struct tty *tp; 116 struct vnode *ttyvp; 117 struct vmspace *vm; 118 struct vnode *vtmp; 119 #ifdef KTRACE 120 struct vnode *tracevp; 121 struct ucred *tracecred; 122 #endif 123 124 GIANT_REQUIRED; 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_SA || p->p_numthreads > 1) { 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 152 * with EINTR or EWOULDBLOCK, which will hopefully force them 153 * to back out to userland, freeing resources as they go, and 154 * anything attempting to return to userland will thread_exit() 155 * from userret(). thread_exit() will unsuspend us 156 * when the last other thread exits. 157 */ 158 if (thread_single(SINGLE_EXIT)) { 159 panic ("Exit: Single threading fouled up"); 160 } 161 /* 162 * All other activity in this process is now stopped. 163 * Remove excess KSEs and KSEGRPS. XXXKSE (when we have them) 164 * ... 165 * Turn off threading support. 166 */ 167 p->p_flag &= ~P_SA; 168 thread_single_end(); /* Don't need this any more. */ 169 } 170 /* 171 * With this state set: 172 * Any thread entering the kernel from userspace will thread_exit() 173 * in trap(). Any thread attempting to sleep will return immediatly 174 * with EINTR or EWOULDBLOCK, which will hopefully force them 175 * to back out to userland, freeing resources as they go, and 176 * anything attempting to return to userland will thread_exit() 177 * from userret(). thread_exit() will do a wakeup on p->p_numthreads 178 * if it transitions to 1. 179 */ 180 181 p->p_flag |= P_WEXIT; 182 PROC_UNLOCK(p); 183 184 /* Are we a task leader? */ 185 if (p == p->p_leader) { 186 mtx_lock(&ppeers_lock); 187 q = p->p_peers; 188 while (q != NULL) { 189 PROC_LOCK(q); 190 psignal(q, SIGKILL); 191 PROC_UNLOCK(q); 192 q = q->p_peers; 193 } 194 while (p->p_peers != NULL) 195 msleep(p, &ppeers_lock, PWAIT, "exit1", 0); 196 mtx_unlock(&ppeers_lock); 197 } 198 199 #ifdef PGINPROF 200 vmsizmon(); 201 #endif 202 STOPEVENT(p, S_EXIT, rv); 203 wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */ 204 205 /* 206 * Check if any loadable modules need anything done at process exit. 207 * e.g. SYSV IPC stuff 208 * XXX what if one of these generates an error? 209 */ 210 EVENTHANDLER_INVOKE(process_exit, p); 211 212 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 213 M_ZOMBIE, M_WAITOK); 214 /* 215 * If parent is waiting for us to exit or exec, 216 * P_PPWAIT is set; we will wakeup the parent below. 217 */ 218 PROC_LOCK(p); 219 stopprofclock(p); 220 p->p_flag &= ~(P_TRACED | P_PPWAIT); 221 SIGEMPTYSET(p->p_siglist); 222 SIGEMPTYSET(td->td_siglist); 223 224 /* 225 * Stop the real interval timer. If the handler is currently 226 * executing, prevent it from rearming itself and let it finish. 227 */ 228 if (timevalisset(&p->p_realtimer.it_value) && 229 callout_stop(&p->p_itcallout) == 0) { 230 timevalclear(&p->p_realtimer.it_interval); 231 msleep(&p->p_itcallout, &p->p_mtx, PWAIT, "ritwait", 0); 232 KASSERT(!timevalisset(&p->p_realtimer.it_value), 233 ("realtime timer is still armed")); 234 } 235 PROC_UNLOCK(p); 236 237 /* 238 * Reset any sigio structures pointing to us as a result of 239 * F_SETOWN with our pid. 240 */ 241 funsetownlst(&p->p_sigiolst); 242 243 /* 244 * Close open files and release open-file table. 245 * This may block! 246 */ 247 fdfree(td); 248 249 /* 250 * Remove ourself from our leader's peer list and wake our leader. 251 */ 252 mtx_lock(&ppeers_lock); 253 if (p->p_leader->p_peers) { 254 q = p->p_leader; 255 while (q->p_peers != p) 256 q = q->p_peers; 257 q->p_peers = p->p_peers; 258 wakeup(p->p_leader); 259 } 260 mtx_unlock(&ppeers_lock); 261 262 /* The next two chunks should probably be moved to vmspace_exit. */ 263 vm = p->p_vmspace; 264 /* 265 * Release user portion of address space. 266 * This releases references to vnodes, 267 * which could cause I/O if the file has been unlinked. 268 * Need to do this early enough that we can still sleep. 269 * Can't free the entire vmspace as the kernel stack 270 * may be mapped within that space also. 271 * 272 * Processes sharing the same vmspace may exit in one order, and 273 * get cleaned up by vmspace_exit() in a different order. The 274 * last exiting process to reach this point releases as much of 275 * the environment as it can, and the last process cleaned up 276 * by vmspace_exit() (which decrements exitingcnt) cleans up the 277 * remainder. 278 */ 279 ++vm->vm_exitingcnt; 280 if (--vm->vm_refcnt == 0) { 281 shmexit(vm); 282 vm_page_lock_queues(); 283 pmap_remove_pages(vmspace_pmap(vm), vm_map_min(&vm->vm_map), 284 vm_map_max(&vm->vm_map)); 285 vm_page_unlock_queues(); 286 (void) vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map), 287 vm_map_max(&vm->vm_map)); 288 } 289 290 sx_xlock(&proctree_lock); 291 if (SESS_LEADER(p)) { 292 struct session *sp; 293 294 sp = p->p_session; 295 if (sp->s_ttyvp) { 296 /* 297 * Controlling process. 298 * Signal foreground pgrp, 299 * drain controlling terminal 300 * and revoke access to controlling terminal. 301 */ 302 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) { 303 tp = sp->s_ttyp; 304 if (sp->s_ttyp->t_pgrp) { 305 PGRP_LOCK(sp->s_ttyp->t_pgrp); 306 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 307 PGRP_UNLOCK(sp->s_ttyp->t_pgrp); 308 } 309 /* XXX tp should be locked. */ 310 sx_xunlock(&proctree_lock); 311 (void) ttywait(tp); 312 sx_xlock(&proctree_lock); 313 /* 314 * The tty could have been revoked 315 * if we blocked. 316 */ 317 if (sp->s_ttyvp) { 318 ttyvp = sp->s_ttyvp; 319 SESS_LOCK(p->p_session); 320 sp->s_ttyvp = NULL; 321 SESS_UNLOCK(p->p_session); 322 sx_xunlock(&proctree_lock); 323 VOP_REVOKE(ttyvp, REVOKEALL); 324 vrele(ttyvp); 325 sx_xlock(&proctree_lock); 326 } 327 } 328 if (sp->s_ttyvp) { 329 ttyvp = sp->s_ttyvp; 330 SESS_LOCK(p->p_session); 331 sp->s_ttyvp = NULL; 332 SESS_UNLOCK(p->p_session); 333 vrele(ttyvp); 334 } 335 /* 336 * s_ttyp is not zero'd; we use this to indicate 337 * that the session once had a controlling terminal. 338 * (for logging and informational purposes) 339 */ 340 } 341 SESS_LOCK(p->p_session); 342 sp->s_leader = NULL; 343 SESS_UNLOCK(p->p_session); 344 } 345 fixjobc(p, p->p_pgrp, 0); 346 sx_xunlock(&proctree_lock); 347 (void)acct_process(td); 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 vrele(tracevp); 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 vrele(vtmp); 372 } 373 374 /* 375 * Release our limits structure. 376 */ 377 mtx_assert(&Giant, MA_OWNED); 378 if (--p->p_limit->p_refcnt == 0) { 379 FREE(p->p_limit, M_SUBPROC); 380 p->p_limit = NULL; 381 } 382 383 /* 384 * Release this thread's reference to the ucred. The actual proc 385 * reference will stay around until the proc is harvested by 386 * wait(). At this point the ucred is immutable (no other threads 387 * from this proc are around that can change it) so we leave the 388 * per-thread ucred pointer intact in case it is needed although 389 * in theory nothing should be using it at this point. 390 */ 391 crfree(td->td_ucred); 392 393 /* 394 * Remove proc from allproc queue and pidhash chain. 395 * Place onto zombproc. Unlink from parent's child list. 396 */ 397 sx_xlock(&allproc_lock); 398 LIST_REMOVE(p, p_list); 399 LIST_INSERT_HEAD(&zombproc, p, p_list); 400 LIST_REMOVE(p, p_hash); 401 sx_xunlock(&allproc_lock); 402 403 sx_xlock(&proctree_lock); 404 q = LIST_FIRST(&p->p_children); 405 if (q != NULL) /* only need this if any child is S_ZOMB */ 406 wakeup(initproc); 407 for (; q != NULL; q = nq) { 408 nq = LIST_NEXT(q, p_sibling); 409 PROC_LOCK(q); 410 proc_reparent(q, initproc); 411 q->p_sigparent = SIGCHLD; 412 /* 413 * Traced processes are killed 414 * since their existence means someone is screwing up. 415 */ 416 if (q->p_flag & P_TRACED) { 417 q->p_flag &= ~P_TRACED; 418 psignal(q, SIGKILL); 419 } 420 PROC_UNLOCK(q); 421 } 422 423 /* 424 * Save exit status and final rusage info, adding in child rusage 425 * info and self times. 426 */ 427 PROC_LOCK(p); 428 p->p_xstat = rv; 429 *p->p_ru = p->p_stats->p_ru; 430 mtx_lock_spin(&sched_lock); 431 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL); 432 mtx_unlock_spin(&sched_lock); 433 ruadd(p->p_ru, &p->p_stats->p_cru); 434 435 /* 436 * Notify interested parties of our demise. 437 */ 438 KNOTE(&p->p_klist, NOTE_EXIT); 439 /* 440 * Just delete all entries in the p_klist. At this point we won't 441 * report any more events, and there are nasty race conditions that 442 * can beat us if we don't. 443 */ 444 while (SLIST_FIRST(&p->p_klist)) 445 SLIST_REMOVE_HEAD(&p->p_klist, kn_selnext); 446 447 /* 448 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT 449 * flag set, or if the handler is set to SIG_IGN, notify process 450 * 1 instead (and hope it will handle this situation). 451 */ 452 PROC_LOCK(p->p_pptr); 453 mtx_lock(&p->p_pptr->p_sigacts->ps_mtx); 454 if (p->p_pptr->p_sigacts->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) { 455 struct proc *pp; 456 457 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 458 pp = p->p_pptr; 459 PROC_UNLOCK(pp); 460 proc_reparent(p, initproc); 461 PROC_LOCK(p->p_pptr); 462 /* 463 * If this was the last child of our parent, notify 464 * parent, so in case he was wait(2)ing, he will 465 * continue. 466 */ 467 if (LIST_EMPTY(&pp->p_children)) 468 wakeup(pp); 469 } else 470 mtx_unlock(&p->p_pptr->p_sigacts->ps_mtx); 471 472 if (p->p_sigparent && p->p_pptr != initproc) 473 psignal(p->p_pptr, p->p_sigparent); 474 else 475 psignal(p->p_pptr, SIGCHLD); 476 PROC_UNLOCK(p->p_pptr); 477 478 /* 479 * If this is a kthread, then wakeup anyone waiting for it to exit. 480 */ 481 if (p->p_flag & P_KTHREAD) 482 wakeup(p); 483 PROC_UNLOCK(p); 484 485 /* 486 * Finally, call machine-dependent code to release the remaining 487 * resources including address space. 488 * The address space is released by "vmspace_exitfree(p)" in 489 * vm_waitproc(). 490 */ 491 cpu_exit(td); 492 493 PROC_LOCK(p); 494 PROC_LOCK(p->p_pptr); 495 sx_xunlock(&proctree_lock); 496 mtx_lock_spin(&sched_lock); 497 498 while (mtx_owned(&Giant)) 499 mtx_unlock(&Giant); 500 501 /* 502 * We have to wait until after acquiring all locks before 503 * changing p_state. If we block on a mutex then we will be 504 * back at SRUN when we resume and our parent will never 505 * harvest us. 506 */ 507 p->p_state = PRS_ZOMBIE; 508 509 wakeup(p->p_pptr); 510 PROC_UNLOCK(p->p_pptr); 511 cnt.v_swtch++; 512 binuptime(PCPU_PTR(switchtime)); 513 PCPU_SET(switchticks, ticks); 514 515 cpu_sched_exit(td); /* XXXKSE check if this should be in thread_exit */ 516 /* 517 * Allow the scheduler to adjust the priority of the 518 * parent when a kseg is exiting. 519 */ 520 if (p->p_pid != 1) 521 sched_exit(p->p_pptr, p); 522 523 /* 524 * Make sure the scheduler takes this thread out of its tables etc. 525 * This will also release this thread's reference to the ucred. 526 * Other thread parts to release include pcb bits and such. 527 */ 528 thread_exit(); 529 } 530 531 #ifdef COMPAT_43 532 /* 533 * MPSAFE. The dirty work is handled by wait1(). 534 */ 535 int 536 owait(struct thread *td, struct owait_args *uap __unused) 537 { 538 struct wait_args w; 539 540 w.options = 0; 541 w.rusage = NULL; 542 w.pid = WAIT_ANY; 543 w.status = NULL; 544 return (wait1(td, &w, 1)); 545 } 546 #endif /* COMPAT_43 */ 547 548 /* 549 * MPSAFE. The dirty work is handled by wait1(). 550 */ 551 int 552 wait4(struct thread *td, struct wait_args *uap) 553 { 554 555 return (wait1(td, uap, 0)); 556 } 557 558 /* 559 * MPSAFE 560 */ 561 static int 562 wait1(struct thread *td, struct wait_args *uap, int compat) 563 { 564 struct rusage ru; 565 int nfound; 566 struct proc *p, *q, *t; 567 int status, error; 568 569 q = td->td_proc; 570 if (uap->pid == 0) { 571 PROC_LOCK(q); 572 uap->pid = -q->p_pgid; 573 PROC_UNLOCK(q); 574 } 575 if (uap->options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE)) 576 return (EINVAL); 577 mtx_lock(&Giant); 578 loop: 579 nfound = 0; 580 sx_xlock(&proctree_lock); 581 LIST_FOREACH(p, &q->p_children, p_sibling) { 582 PROC_LOCK(p); 583 if (uap->pid != WAIT_ANY && 584 p->p_pid != uap->pid && p->p_pgid != -uap->pid) { 585 PROC_UNLOCK(p); 586 continue; 587 } 588 589 /* 590 * This special case handles a kthread spawned by linux_clone 591 * (see linux_misc.c). The linux_wait4 and linux_waitpid 592 * functions need to be able to distinguish between waiting 593 * on a process and waiting on a thread. It is a thread if 594 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option 595 * signifies we want to wait for threads and not processes. 596 */ 597 if ((p->p_sigparent != SIGCHLD) ^ 598 ((uap->options & WLINUXCLONE) != 0)) { 599 PROC_UNLOCK(p); 600 continue; 601 } 602 603 nfound++; 604 if (p->p_state == PRS_ZOMBIE) { 605 td->td_retval[0] = p->p_pid; 606 #ifdef COMPAT_43 607 if (compat) 608 td->td_retval[1] = p->p_xstat; 609 else 610 #endif 611 if (uap->status) { 612 status = p->p_xstat; /* convert to int */ 613 PROC_UNLOCK(p); 614 if ((error = copyout(&status, 615 uap->status, sizeof(status)))) { 616 sx_xunlock(&proctree_lock); 617 mtx_unlock(&Giant); 618 return (error); 619 } 620 PROC_LOCK(p); 621 } 622 if (uap->rusage) { 623 bcopy(p->p_ru, &ru, sizeof(ru)); 624 PROC_UNLOCK(p); 625 if ((error = copyout(&ru, 626 uap->rusage, sizeof (struct rusage)))) { 627 sx_xunlock(&proctree_lock); 628 mtx_unlock(&Giant); 629 return (error); 630 } 631 } else 632 PROC_UNLOCK(p); 633 /* 634 * If we got the child via a ptrace 'attach', 635 * we need to give it back to the old parent. 636 */ 637 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) { 638 PROC_LOCK(p); 639 p->p_oppid = 0; 640 proc_reparent(p, t); 641 PROC_UNLOCK(p); 642 psignal(t, SIGCHLD); 643 wakeup(t); 644 PROC_UNLOCK(t); 645 sx_xunlock(&proctree_lock); 646 mtx_unlock(&Giant); 647 return (0); 648 } 649 650 /* 651 * Remove other references to this process to ensure 652 * we have an exclusive reference. 653 */ 654 sx_xlock(&allproc_lock); 655 LIST_REMOVE(p, p_list); /* off zombproc */ 656 sx_xunlock(&allproc_lock); 657 LIST_REMOVE(p, p_sibling); 658 leavepgrp(p); 659 sx_xunlock(&proctree_lock); 660 661 /* 662 * As a side effect of this lock, we know that 663 * all other writes to this proc are visible now, so 664 * no more locking is needed for p. 665 */ 666 PROC_LOCK(p); 667 p->p_xstat = 0; /* XXX: why? */ 668 PROC_UNLOCK(p); 669 PROC_LOCK(q); 670 ruadd(&q->p_stats->p_cru, p->p_ru); 671 PROC_UNLOCK(q); 672 FREE(p->p_ru, M_ZOMBIE); 673 p->p_ru = NULL; 674 675 /* 676 * Decrement the count of procs running with this uid. 677 */ 678 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0); 679 680 /* 681 * Free credentials, arguments, and sigacts 682 */ 683 crfree(p->p_ucred); 684 p->p_ucred = NULL; 685 pargs_drop(p->p_args); 686 p->p_args = NULL; 687 sigacts_free(p->p_sigacts); 688 p->p_sigacts = NULL; 689 690 /* 691 * do any thread-system specific cleanups 692 */ 693 thread_wait(p); 694 695 /* 696 * Give vm and machine-dependent layer a chance 697 * to free anything that cpu_exit couldn't 698 * release while still running in process context. 699 */ 700 vm_waitproc(p); 701 #ifdef MAC 702 mac_destroy_proc(p); 703 #endif 704 KASSERT(FIRST_THREAD_IN_PROC(p), 705 ("wait1: no residual thread!")); 706 uma_zfree(proc_zone, p); 707 sx_xlock(&allproc_lock); 708 nprocs--; 709 sx_xunlock(&allproc_lock); 710 mtx_unlock(&Giant); 711 return (0); 712 } 713 mtx_lock_spin(&sched_lock); 714 if (P_SHOULDSTOP(p) && (p->p_suspcount == p->p_numthreads) && 715 ((p->p_flag & P_WAITED) == 0) && 716 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) { 717 mtx_unlock_spin(&sched_lock); 718 p->p_flag |= P_WAITED; 719 sx_xunlock(&proctree_lock); 720 td->td_retval[0] = p->p_pid; 721 #ifdef COMPAT_43 722 if (compat) { 723 td->td_retval[1] = W_STOPCODE(p->p_xstat); 724 PROC_UNLOCK(p); 725 error = 0; 726 } else 727 #endif 728 if (uap->status) { 729 status = W_STOPCODE(p->p_xstat); 730 PROC_UNLOCK(p); 731 error = copyout(&status, 732 uap->status, sizeof(status)); 733 } else { 734 PROC_UNLOCK(p); 735 error = 0; 736 } 737 mtx_unlock(&Giant); 738 return (error); 739 } 740 mtx_unlock_spin(&sched_lock); 741 if (uap->options & WCONTINUED && (p->p_flag & P_CONTINUED)) { 742 sx_xunlock(&proctree_lock); 743 td->td_retval[0] = p->p_pid; 744 p->p_flag &= ~P_CONTINUED; 745 PROC_UNLOCK(p); 746 747 if (uap->status) { 748 status = SIGCONT; 749 error = copyout(&status, 750 uap->status, sizeof(status)); 751 } else 752 error = 0; 753 754 mtx_unlock(&Giant); 755 return (error); 756 } 757 PROC_UNLOCK(p); 758 } 759 if (nfound == 0) { 760 sx_xunlock(&proctree_lock); 761 mtx_unlock(&Giant); 762 return (ECHILD); 763 } 764 if (uap->options & WNOHANG) { 765 sx_xunlock(&proctree_lock); 766 td->td_retval[0] = 0; 767 mtx_unlock(&Giant); 768 return (0); 769 } 770 PROC_LOCK(q); 771 sx_xunlock(&proctree_lock); 772 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0); 773 PROC_UNLOCK(q); 774 if (error) { 775 mtx_unlock(&Giant); 776 return (error); 777 } 778 goto loop; 779 } 780 781 /* 782 * Make process 'parent' the new parent of process 'child'. 783 * Must be called with an exclusive hold of proctree lock. 784 */ 785 void 786 proc_reparent(struct proc *child, struct proc *parent) 787 { 788 789 sx_assert(&proctree_lock, SX_XLOCKED); 790 PROC_LOCK_ASSERT(child, MA_OWNED); 791 if (child->p_pptr == parent) 792 return; 793 794 LIST_REMOVE(child, p_sibling); 795 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling); 796 child->p_pptr = parent; 797 }
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