bsd/kern/kern_exit.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /* Copyright (c) 1995, 1997 Apple Computer, Inc. All Rights Reserved */
  23 /*
  24  * Copyright (c) 1982, 1986, 1989, 1991, 1993
  25  *      The Regents of the University of California.  All rights reserved.
  26  * (c) UNIX System Laboratories, Inc.
  27  * All or some portions of this file are derived from material licensed
  28  * to the University of California by American Telephone and Telegraph
  29  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  30  * the permission of UNIX System Laboratories, Inc.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)kern_exit.c 8.7 (Berkeley) 2/12/94
  61  */
  62
  63 #include <machine/reg.h>
  64 #include <machine/psl.h>
  65
  66 #include "compat_43.h"
  67
  68 #include <sys/param.h>
  69 #include <sys/systm.h>
  70 #include <sys/ioctl.h>
  71 #include <sys/proc.h>
  72 #include <sys/tty.h>
  73 #include <sys/time.h>
  74 #include <sys/resource.h>
  75 #include <sys/kernel.h>
  76 #include <sys/buf.h>
  77 #include <sys/wait.h>
  78 #include <sys/file.h>
  79 #include <sys/vnode.h>
  80 #include <sys/syslog.h>
  81 #include <sys/malloc.h>
  82 #include <sys/resourcevar.h>
  83 #include <sys/ptrace.h>
  84 #include <sys/user.h>
  85
  86 #include <mach/mach_types.h>
  87 #include <kern/thread.h>
  88 #include <kern/thread_act.h>
  89 #include <kern/assert.h>
  90
  91 extern char init_task_failure_data[];
  92 void exit1 __P((struct proc *, int));
  93
  94 /*
  95  * exit --
  96  *      Death of process.
  97  */
  98 struct exit_args {
  99         int     rval;
 100 };
 101 void
 102 exit(p, uap, retval)
 103         struct proc *p;
 104         struct exit_args *uap;
 105         int *retval;
 106 {
 107         exit1(p, W_EXITCODE(uap->rval, 0));
 108
 109         /* drop funnel befewo we return */
 110         thread_funnel_set(kernel_flock, FALSE);
 111         thread_exception_return();
 112         /* NOTREACHED */
 113         while (TRUE)
 114                 thread_block(0);
 115         /* NOTREACHED */
 116 }
 117
 118 /*
 119  * Exit: deallocate address space and other resources, change proc state
 120  * to zombie, and unlink proc from allproc and parent's lists.  Save exit
 121  * status and rusage for wait().  Check for child processes and orphan them.
 122  */
 123 void
 124 exit1(p, rv)
 125         register struct proc *p;
 126         int rv;
 127 {
 128         register struct proc *q, *nq;
 129         thread_t self = current_thread();
 130         thread_act_t th_act_self = current_act();
 131         struct task *task = p->task;
 132         register int i,s;
 133         struct uthread *ut;
 134
 135         /*
 136          * If a thread in this task has already
 137          * called exit(), then halt any others
 138          * right here.
 139          */
 140         signal_lock(p);
 141         while (p->exit_thread != self) {
 142                 if (sig_try_locked(p) <= 0) {
 143                         if (get_threadtask(th_act_self) != task) {
 144                                 signal_unlock(p);
 145                                 return;
 146                         }
 147                         signal_unlock(p);
 148                         thread_terminate(th_act_self);
 149                         thread_funnel_set(kernel_flock, FALSE);
 150                         thread_exception_return();
 151                         /* NOTREACHED */
 152                 }
 153                 sig_lock_to_exit(p);
 154         }
 155         signal_unlock(p);
 156         if (p->p_pid == 1) {
 157                 printf("pid 1 exited (signal %d, exit %d)",
 158                     WTERMSIG(rv), WEXITSTATUS(rv));
 159                 panic("init died\nState at Last Exception:\n\n%s",
 160                                                         init_task_failure_data);
 161         }
 162
 163         s = splsched();
 164         p->p_flag |= P_WEXIT;
 165         splx(s);
 166         proc_prepareexit(p);
 167         p->p_xstat = rv;
 168
 169         /* task terminate will call proc_terminate and that cleans it up */
 170         task_terminate_internal(task);
 171
 172         /*
 173          * we come back and returns to AST which
 174          * should cleanup the rest
 175          */
 176 #if 0
 177         if (task == current_task()) {
 178                 thread_exception_return();
 179                 /*NOTREACHED*/
 180         }
 181
 182         while (task == current_task()) {
 183                 thread_terminate_self();
 184                 /*NOTREACHED*/
 185         }
 186 #endif
 187 }
 188
 189 void
 190 proc_prepareexit(struct proc *p)
 191 {
 192         int s;
 193         struct uthread *ut;
 194         thread_t self = current_thread();
 195         thread_act_t th_act_self = current_act();
 196
 197
 198         /*
 199          * Remove proc from allproc queue and from pidhash chain.
 200          * Need to do this before we do anything that can block.
 201          * Not doing causes things like mount() find this on allproc
 202          * in partially cleaned state.
 203          */
 204         LIST_REMOVE(p, p_list);
 205         LIST_REMOVE(p, p_hash);
 206
 207 #ifdef PGINPROF
 208         vmsizmon();
 209 #endif
 210         /*
 211          * If parent is waiting for us to exit or exec,
 212          * P_PPWAIT is set; we will wakeup the parent below.
 213          */
 214         p->p_flag &= ~(P_TRACED | P_PPWAIT);
 215         p->p_sigignore = ~0;
 216         p->p_siglist = 0;
 217         ut = get_bsdthread_info(th_act_self);
 218         ut->uu_sig = 0;
 219         untimeout(realitexpire, (caddr_t)p);
 220
 221 }
 222
 223 void
 224 proc_exit(struct proc *p)
 225 {
 226         register struct proc *q, *nq;
 227         thread_t self = current_thread();
 228         thread_act_t th_act_self = current_act();
 229         struct task *task = p->task;
 230         register int i,s;
 231         struct uthread *ut;
 232         boolean_t funnel_state;
 233
 234         /* This can happen if thread_terminate of the single thread
 235          * process
 236          */
 237
 238         funnel_state = thread_funnel_set(kernel_flock, TRUE);
 239         if( !(p->p_flag & P_WEXIT)) {
 240                 s = splsched();
 241                 p->p_flag |= P_WEXIT;
 242                 splx(s);
 243                 proc_prepareexit(p);
 244         }
 245
 246         MALLOC_ZONE(p->p_ru, struct rusage *,
 247                         sizeof (*p->p_ru), M_ZOMBIE, M_WAITOK);
 248
 249         /*
 250          * Close open files and release open-file table.
 251          * This may block!
 252          */
 253         fdfree(p);
 254
 255         /* Close ref SYSV Shared memory*/
 256         if (p->vm_shm)
 257                 shmexit(p);
 258
 259         if (SESS_LEADER(p)) {
 260                 register struct session *sp = p->p_session;
 261
 262                 if (sp->s_ttyvp) {
 263                         /*
 264                          * Controlling process.
 265                          * Signal foreground pgrp,
 266                          * drain controlling terminal
 267                          * and revoke access to controlling terminal.
 268                          */
 269                         if (sp->s_ttyp->t_session == sp) {
 270                                 if (sp->s_ttyp->t_pgrp)
 271                                         pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
 272                                 (void) ttywait(sp->s_ttyp);
 273                                 /*
 274                                  * The tty could have been revoked
 275                                  * if we blocked.
 276                                  */
 277                                 if (sp->s_ttyvp)
 278                                         VOP_REVOKE(sp->s_ttyvp, REVOKEALL);
 279                         }
 280                         if (sp->s_ttyvp)
 281                                 vrele(sp->s_ttyvp);
 282                         sp->s_ttyvp = NULL;
 283                         /*
 284                          * s_ttyp is not zero'd; we use this to indicate
 285                          * that the session once had a controlling terminal.
 286                          * (for logging and informational purposes)
 287                          */
 288                 }
 289                 sp->s_leader = NULL;
 290         }
 291
 292         fixjobc(p, p->p_pgrp, 0);
 293         p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
 294 #if KTRACE
 295         /*
 296          * release trace file
 297          */
 298         p->p_traceflag = 0;     /* don't trace the vrele() */
 299         if (p->p_tracep)
 300                 vrele(p->p_tracep);
 301 #endif
 302
 303
 304         q = p->p_children.lh_first;
 305         if (q)          /* only need this if any child is S_ZOMB */
 306                 wakeup((caddr_t) initproc);
 307         for (; q != 0; q = nq) {
 308                 nq = q->p_sibling.le_next;
 309                 proc_reparent(q, initproc);
 310                 /*
 311                  * Traced processes are killed
 312                  * since their existence means someone is messing up.
 313                  */
 314                 if (q->p_flag & P_TRACED) {
 315                         q->p_flag &= ~P_TRACED;
 316                         if (q->sigwait_thread) {
 317                                 thread_t sig_shuttle  = getshuttle_thread(q->sigwait_thread);
 318                                 /*
 319                                  * The sigwait_thread could be stopped at a
 320                                  * breakpoint. Wake it up to kill.
 321                                  * Need to do this as it could be a thread which is not
 322                                  * the first thread in the task. So any attempts to kill
 323                                  * the process would result into a deadlock on q->sigwait.
 324                                  */
 325                                 thread_resume((struct thread *)q->sigwait_thread);
 326                                 clear_wait(sig_shuttle, THREAD_INTERRUPTED);
 327                                 threadsignal(q->sigwait_thread, SIGKILL, 0);
 328                         }
 329                         psignal(q, SIGKILL);
 330                 }
 331         }
 332
 333
 334         /*
 335          * Save exit status and final rusage info, adding in child rusage
 336          * info and self times.
 337          */
 338         *p->p_ru = p->p_stats->p_ru;
 339
 340         timerclear(&p->p_ru->ru_utime);
 341         timerclear(&p->p_ru->ru_stime);
 342
 343         if (task) {
 344                 task_basic_info_data_t tinfo;
 345                 task_thread_times_info_data_t ttimesinfo;
 346                 int task_info_stuff, task_ttimes_stuff;
 347                 struct timeval ut,st;
 348
 349                 task_info_stuff = TASK_BASIC_INFO_COUNT;
 350                 task_info(task, TASK_BASIC_INFO,
 351                           &tinfo, &task_info_stuff);
 352                 p->p_ru->ru_utime.tv_sec = tinfo.user_time.seconds;
 353                 p->p_ru->ru_utime.tv_usec = tinfo.user_time.microseconds;
 354                 p->p_ru->ru_stime.tv_sec = tinfo.system_time.seconds;
 355                 p->p_ru->ru_stime.tv_usec = tinfo.system_time.microseconds;
 356
 357                 task_ttimes_stuff = TASK_THREAD_TIMES_INFO_COUNT;
 358                 task_info(task, TASK_THREAD_TIMES_INFO,
 359                           &ttimesinfo, &task_ttimes_stuff);
 360
 361                 ut.tv_sec = ttimesinfo.user_time.seconds;
 362                 ut.tv_usec = ttimesinfo.user_time.microseconds;
 363                 st.tv_sec = ttimesinfo.system_time.seconds;
 364                 st.tv_usec = ttimesinfo.system_time.microseconds;
 365                 timeradd(&ut,&p->p_ru->ru_utime,&p->p_ru->ru_utime);
 366                 timeradd(&st,&p->p_ru->ru_stime,&p->p_ru->ru_stime);
 367         }
 368
 369
 370         ruadd(p->p_ru, &p->p_stats->p_cru);
 371
 372         /*
 373          * Free up profiling buffers.
 374          */
 375         {
 376                 struct uprof *p0 = &p->p_stats->p_prof, *p1, *pn;
 377
 378                 p1 = p0->pr_next;
 379                 p0->pr_next = NULL;
 380                 p0->pr_scale = 0;
 381
 382                 for (; p1 != NULL; p1 = pn) {
 383                         pn = p1->pr_next;
 384                         kfree((vm_offset_t)p1, sizeof *p1);
 385                 }
 386         }
 387
 388         /*
 389          * Other substructures are freed from wait().
 390          */
 391         FREE_ZONE(p->p_stats, sizeof *p->p_stats, M_SUBPROC);
 392         p->p_stats = NULL;
 393
 394         FREE_ZONE(p->p_sigacts, sizeof *p->p_sigacts, M_SUBPROC);
 395         p->p_sigacts = NULL;
 396
 397         if (--p->p_limit->p_refcnt == 0)
 398                 FREE_ZONE(p->p_limit, sizeof *p->p_limit, M_SUBPROC);
 399         p->p_limit = NULL;
 400
 401         /*
 402          * Finish up by terminating the task
 403          * and halt this thread (only if a
 404          * member of the task exiting).
 405          */
 406         p->task = TASK_NULL;
 407         //task->proc = NULL;
 408         set_bsdtask_info(task, NULL);
 409
 410         /*
 411          * Notify parent that we're gone.
 412          */
 413         psignal(p->p_pptr, SIGCHLD);
 414
 415         /* Place onto zombproc. */
 416         LIST_INSERT_HEAD(&zombproc, p, p_list);
 417         p->p_stat = SZOMB;
 418
 419         /* and now wakeup the parent */
 420         wakeup((caddr_t)p->p_pptr);
 421
 422         (void) thread_funnel_set(kernel_flock, funnel_state);
 423 }
 424
 425
 426 struct wait4_args {
 427         int     pid;
 428         int *status;
 429         int options;
 430         struct rusage *rusage;
 431 };
 432
 433 #if COMPAT_43
 434 int
 435 owait(p, uap, retval)
 436         struct proc *p;
 437         void *uap;
 438         int *retval;
 439 {
 440         struct wait4_args *a;
 441
 442         a = (struct wait4_args *)get_bsduthreadarg(current_act());
 443
 444         a->options = 0;
 445         a->rusage = NULL;
 446         a->pid = WAIT_ANY;
 447         a->status = NULL;
 448         return (wait1(p, a, retval, 1));
 449 }
 450
 451 int
 452 wait4(p, uap, retval)
 453         struct proc *p;
 454         struct wait4_args *uap;
 455         int *retval;
 456 {
 457
 458         return (wait1(p, uap, retval, 0));
 459 }
 460
 461 struct owait3_args {
 462         int *status;
 463         int options;
 464         struct rusage *rusage;
 465 };
 466
 467 int
 468 owait3(p, uap, retval)
 469         struct proc *p;
 470         struct owait3_args *uap;
 471         int *retval;
 472 {
 473         struct wait4_args *a;
 474
 475         a = (struct wait4_args *)get_bsduthreadarg(current_act);
 476
 477         a->rusage = uap->rusage;
 478         a->options = uap->options;
 479         a->status = uap->status;
 480         a->pid = WAIT_ANY;
 481
 482         return (wait1(p, a, retval, 1));
 483 }
 484
 485 #else
 486 #define wait1   wait4
 487 #endif
 488
 489 int
 490 wait1continue(result)
 491 {
 492   void *vt;
 493   thread_act_t thread;
 494   struct uthread *ut;
 495   int *retval;
 496   struct proc *p;
 497
 498         p = get_bsdtask_info(current_task());
 499         p->p_flag &= ~P_WAITING;
 500
 501       if (result != 0) {
 502           return(result);
 503         }
 504
 505     thread = current_act();
 506         ut = get_bsdthread_info(thread);
 507         vt = get_bsduthreadarg(thread);
 508         retval = get_bsduthreadrval(thread);
 509         wait1((struct proc *)p, (struct wait4_args *)vt, retval, 0);
 510 }
 511
 512 int
 513 wait1(q, uap, retval, compat)
 514         register struct proc *q;
 515         register struct wait4_args *uap;
 516         register_t *retval;
 517 #if COMPAT_43
 518         int compat;
 519 #endif
 520 {
 521         register int nfound;
 522         register struct proc *p, *t;
 523         int status, error;
 524
 525
 526 #if 0
 527         /* since we are funneled we don't need to do this atomically, yet */
 528         if (q->p_flag & P_WAITING) {
 529           return(EINVAL);
 530         }
 531         q->p_flag |= P_WAITING;   /* only allow single thread to wait() */
 532 #endif
 533
 534         if (uap->pid == 0)
 535                 uap->pid = -q->p_pgid;
 536
 537 loop:
 538         nfound = 0;
 539         for (p = q->p_children.lh_first; p != 0; p = p->p_sibling.le_next) {
 540                 if (uap->pid != WAIT_ANY &&
 541                     p->p_pid != uap->pid &&
 542                     p->p_pgid != -(uap->pid))
 543                         continue;
 544                 nfound++;
 545                 if (p->p_stat == SZOMB) {
 546                         retval[0] = p->p_pid;
 547 #if COMPAT_43
 548                         if (compat)
 549                                 retval[1] = p->p_xstat;
 550                         else
 551 #endif
 552                         if (uap->status) {
 553                                 status = p->p_xstat;    /* convert to int */
 554                                 if (error = copyout((caddr_t)&status,
 555                                     (caddr_t)uap->status,
 556                                                     sizeof(status))) {
 557                                         q->p_flag &= ~P_WAITING;
 558                                         return (error);
 559                                 }
 560                         }
 561                         if (uap->rusage &&
 562                             (error = copyout((caddr_t)p->p_ru,
 563                             (caddr_t)uap->rusage,
 564                                              sizeof (struct rusage)))) {
 565                                         q->p_flag &= ~P_WAITING;
 566                                 return (error);
 567                         }
 568                         /*
 569                          * If we got the child via a ptrace 'attach',
 570                          * we need to give it back to the old parent.
 571                          */
 572                         if (p->p_oppid && (t = pfind(p->p_oppid))) {
 573                                 p->p_oppid = 0;
 574                                 proc_reparent(p, t);
 575                                 psignal(t, SIGCHLD);
 576                                 wakeup((caddr_t)t);
 577                                         q->p_flag &= ~P_WAITING;
 578                                 return (0);
 579                         }
 580                         p->p_xstat = 0;
 581                         if (p->p_ru) {
 582                                 ruadd(&q->p_stats->p_cru, p->p_ru);
 583                                 FREE_ZONE(p->p_ru, sizeof *p->p_ru, M_ZOMBIE);
 584                                 p->p_ru = NULL;
 585                         } else {
 586                                 printf("Warning : lost p_ru for %s\n", p->p_comm);
 587                         }
 588
 589                         /*
 590                          * Decrement the count of procs running with this uid.
 591                          */
 592                         (void)chgproccnt(p->p_cred->p_ruid, -1);
 593
 594                         /*
 595                          * Free up credentials.
 596                          */
 597                         if (--p->p_cred->p_refcnt == 0) {
 598                                 struct ucred *ucr = p->p_ucred;
 599                                 struct pcred *pcr;
 600
 601                                 if (ucr != NOCRED) {
 602                                         p->p_ucred = NOCRED;
 603                                         crfree(ucr);
 604                                 }
 605                                 pcr = p->p_cred;
 606                                 p->p_cred = NULL;
 607                                 FREE_ZONE(pcr, sizeof *pcr, M_SUBPROC);
 608                         }
 609
 610                         /*
 611                          * Release reference to text vnode
 612                          */
 613                         if (p->p_textvp)
 614                                 vrele(p->p_textvp);
 615
 616                         /*
 617                          * Finally finished with old proc entry.
 618                          * Unlink it from its process group and free it.
 619                          */
 620                         leavepgrp(p);
 621                         LIST_REMOVE(p, p_list); /* off zombproc */
 622                         LIST_REMOVE(p, p_sibling);
 623                         FREE_ZONE(p, sizeof *p, M_PROC);
 624                         nprocs--;
 625                                         q->p_flag &= ~P_WAITING;
 626                         return (0);
 627                 }
 628                 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 &&
 629                     (p->p_flag & P_TRACED || uap->options & WUNTRACED)) {
 630                         p->p_flag |= P_WAITED;
 631                         retval[0] = p->p_pid;
 632 #if COMPAT_43
 633                         if (compat) {
 634                                 retval[1] = W_STOPCODE(p->p_xstat);
 635                                 error = 0;
 636                         } else
 637 #endif
 638                         if (uap->status) {
 639                                 status = W_STOPCODE(p->p_xstat);
 640                                 error = copyout((caddr_t)&status,
 641                                     (caddr_t)uap->status,
 642                                     sizeof(status));
 643                         } else
 644                                 error = 0;
 645                                         q->p_flag &= ~P_WAITING;
 646                         return (error);
 647                 }
 648         }
 649         if (nfound == 0) {
 650                                         q->p_flag &= ~P_WAITING;
 651                 return (ECHILD);
 652         }
 653         if (uap->options & WNOHANG) {
 654                 retval[0] = 0;
 655                                         q->p_flag &= ~P_WAITING;
 656                 return (0);
 657         }
 658
 659         if (error = tsleep0((caddr_t)q, PWAIT | PCATCH, "wait", 0, wait1continue)) {
 660                                         q->p_flag &= ~P_WAITING;
 661                 return (error);
 662         }
 663         goto loop;
 664 }
 665
 666 /*
 667  * make process 'parent' the new parent of process 'child'.
 668  */
 669 void
 670 proc_reparent(child, parent)
 671         register struct proc *child;
 672         register struct proc *parent;
 673 {
 674
 675         if (child->p_pptr == parent)
 676                 return;
 677
 678         LIST_REMOVE(child, p_sibling);
 679         LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
 680         child->p_pptr = parent;
 681 }
 682
 683 kern_return_t
 684 init_process(void)
 685 /*
 686  *      Make the current process an "init" process, meaning
 687  *      that it doesn't have a parent, and that it won't be
 688  *      gunned down by kill(-1, 0).
 689  */
 690 {
 691         register struct proc *p = current_proc();
 692
 693         if (suser(p->p_ucred, &p->p_acflag))
 694                 return(KERN_NO_ACCESS);
 695
 696         if (p->p_pid != 1 && p->p_pgid != p->p_pid)
 697                 enterpgrp(p, p->p_pid, 0);
 698         p->p_flag |= P_SYSTEM;
 699
 700         /*
 701          *      Take us out of the sibling chain, and
 702          *      out of our parent's child chain.
 703          */
 704         LIST_REMOVE(p, p_sibling);
 705         p->p_sibling.le_prev = NULL;
 706         p->p_sibling.le_next = NULL;
 707         p->p_pptr = kernproc;
 708
 709         return(KERN_SUCCESS);
 710 }
 711
 712 void
 713 process_terminate_self(void)
 714 {
 715         struct proc *p = current_proc();
 716
 717         if (p != NULL) {
 718                 exit1(p, W_EXITCODE(0, SIGKILL));
 719                 /*NOTREACHED*/
 720         }
 721 }