sys/kern/init_main.c

   1 /*-
   2  * Copyright (c) 1995 Terrence R. Lambert
   3  * All rights reserved.
   4  *
   5  * Copyright (c) 1982, 1986, 1989, 1991, 1992, 1993
   6  *      The Regents of the University of California.  All rights reserved.
   7  * (c) UNIX System Laboratories, Inc.
   8  * All or some portions of this file are derived from material licensed
   9  * to the University of California by American Telephone and Telegraph
  10  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  11  * the permission of UNIX System Laboratories, Inc.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. All advertising materials mentioning features or use of this software
  22  *    must display the following acknowledgement:
  23  *      This product includes software developed by the University of
  24  *      California, Berkeley and its contributors.
  25  * 4. Neither the name of the University nor the names of its contributors
  26  *    may be used to endorse or promote products derived from this software
  27  *    without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  39  * SUCH DAMAGE.
  40  *
  41  *      @(#)init_main.c 8.9 (Berkeley) 1/21/94
  42  */
  43
  44 #include <sys/cdefs.h>
  45 __FBSDID("$FreeBSD$");
  46
  47 #include "opt_ddb.h"
  48 #include "opt_init_path.h"
  49
  50 #include <sys/param.h>
  51 #include <sys/kernel.h>
  52 #include <sys/exec.h>
  53 #include <sys/file.h>
  54 #include <sys/filedesc.h>
  55 #include <sys/jail.h>
  56 #include <sys/ktr.h>
  57 #include <sys/lock.h>
  58 #include <sys/mount.h>
  59 #include <sys/mutex.h>
  60 #include <sys/syscallsubr.h>
  61 #include <sys/sysctl.h>
  62 #include <sys/proc.h>
  63 #include <sys/resourcevar.h>
  64 #include <sys/systm.h>
  65 #include <sys/signalvar.h>
  66 #include <sys/vnode.h>
  67 #include <sys/sysent.h>
  68 #include <sys/reboot.h>
  69 #include <sys/sched.h>
  70 #include <sys/sx.h>
  71 #include <sys/sysproto.h>
  72 #include <sys/vmmeter.h>
  73 #include <sys/unistd.h>
  74 #include <sys/malloc.h>
  75 #include <sys/conf.h>
  76 #include <sys/cpuset.h>
  77
  78 #include <machine/cpu.h>
  79
  80 #include <security/audit/audit.h>
  81 #include <security/mac/mac_framework.h>
  82
  83 #include <vm/vm.h>
  84 #include <vm/vm_param.h>
  85 #include <vm/pmap.h>
  86 #include <vm/vm_map.h>
  87 #include <sys/copyright.h>
  88
  89 #include <ddb/ddb.h>
  90 #include <ddb/db_sym.h>
  91
  92 void mi_startup(void);                          /* Should be elsewhere */
  93
  94 /* Components of the first process -- never freed. */
  95 static struct session session0;
  96 static struct pgrp pgrp0;
  97 struct  proc proc0;
  98 struct  thread thread0 __aligned(16);
  99 struct  vmspace vmspace0;
 100 struct  proc *initproc;
 101
 102 int     boothowto = 0;          /* initialized so that it can be patched */
 103 SYSCTL_INT(_debug, OID_AUTO, boothowto, CTLFLAG_RD, &boothowto, 0, "");
 104 int     bootverbose;
 105 SYSCTL_INT(_debug, OID_AUTO, bootverbose, CTLFLAG_RW, &bootverbose, 0, "");
 106
 107 /*
 108  * This ensures that there is at least one entry so that the sysinit_set
 109  * symbol is not undefined.  A sybsystem ID of SI_SUB_DUMMY is never
 110  * executed.
 111  */
 112 SYSINIT(placeholder, SI_SUB_DUMMY, SI_ORDER_ANY, NULL, NULL);
 113
 114 /*
 115  * The sysinit table itself.  Items are checked off as the are run.
 116  * If we want to register new sysinit types, add them to newsysinit.
 117  */
 118 SET_DECLARE(sysinit_set, struct sysinit);
 119 struct sysinit **sysinit, **sysinit_end;
 120 struct sysinit **newsysinit, **newsysinit_end;
 121
 122 /*
 123  * Merge a new sysinit set into the current set, reallocating it if
 124  * necessary.  This can only be called after malloc is running.
 125  */
 126 void
 127 sysinit_add(struct sysinit **set, struct sysinit **set_end)
 128 {
 129         struct sysinit **newset;
 130         struct sysinit **sipp;
 131         struct sysinit **xipp;
 132         int count;
 133
 134         count = set_end - set;
 135         if (newsysinit)
 136                 count += newsysinit_end - newsysinit;
 137         else
 138                 count += sysinit_end - sysinit;
 139         newset = malloc(count * sizeof(*sipp), M_TEMP, M_NOWAIT);
 140         if (newset == NULL)
 141                 panic("cannot malloc for sysinit");
 142         xipp = newset;
 143         if (newsysinit)
 144                 for (sipp = newsysinit; sipp < newsysinit_end; sipp++)
 145                         *xipp++ = *sipp;
 146         else
 147                 for (sipp = sysinit; sipp < sysinit_end; sipp++)
 148                         *xipp++ = *sipp;
 149         for (sipp = set; sipp < set_end; sipp++)
 150                 *xipp++ = *sipp;
 151         if (newsysinit)
 152                 free(newsysinit, M_TEMP);
 153         newsysinit = newset;
 154         newsysinit_end = newset + count;
 155 }
 156
 157 /*
 158  * System startup; initialize the world, create process 0, mount root
 159  * filesystem, and fork to create init and pagedaemon.  Most of the
 160  * hard work is done in the lower-level initialization routines including
 161  * startup(), which does memory initialization and autoconfiguration.
 162  *
 163  * This allows simple addition of new kernel subsystems that require
 164  * boot time initialization.  It also allows substitution of subsystem
 165  * (for instance, a scheduler, kernel profiler, or VM system) by object
 166  * module.  Finally, it allows for optional "kernel threads".
 167  */
 168 void
 169 mi_startup(void)
 170 {
 171
 172         register struct sysinit **sipp;         /* system initialization*/
 173         register struct sysinit **xipp;         /* interior loop of sort*/
 174         register struct sysinit *save;          /* bubble*/
 175
 176 #if defined(VERBOSE_SYSINIT)
 177         int last;
 178         int verbose;
 179 #endif
 180
 181         if (sysinit == NULL) {
 182                 sysinit = SET_BEGIN(sysinit_set);
 183                 sysinit_end = SET_LIMIT(sysinit_set);
 184         }
 185
 186 restart:
 187         /*
 188          * Perform a bubble sort of the system initialization objects by
 189          * their subsystem (primary key) and order (secondary key).
 190          */
 191         for (sipp = sysinit; sipp < sysinit_end; sipp++) {
 192                 for (xipp = sipp + 1; xipp < sysinit_end; xipp++) {
 193                         if ((*sipp)->subsystem < (*xipp)->subsystem ||
 194                              ((*sipp)->subsystem == (*xipp)->subsystem &&
 195                               (*sipp)->order <= (*xipp)->order))
 196                                 continue;       /* skip*/
 197                         save = *sipp;
 198                         *sipp = *xipp;
 199                         *xipp = save;
 200                 }
 201         }
 202
 203 #if defined(VERBOSE_SYSINIT)
 204         last = SI_SUB_COPYRIGHT;
 205         verbose = 0;
 206 #if !defined(DDB)
 207         printf("VERBOSE_SYSINIT: DDB not enabled, symbol lookups disabled.\n");
 208 #endif
 209 #endif
 210
 211         /*
 212          * Traverse the (now) ordered list of system initialization tasks.
 213          * Perform each task, and continue on to the next task.
 214          *
 215          * The last item on the list is expected to be the scheduler,
 216          * which will not return.
 217          */
 218         for (sipp = sysinit; sipp < sysinit_end; sipp++) {
 219
 220                 if ((*sipp)->subsystem == SI_SUB_DUMMY)
 221                         continue;       /* skip dummy task(s)*/
 222
 223                 if ((*sipp)->subsystem == SI_SUB_DONE)
 224                         continue;
 225
 226 #if defined(VERBOSE_SYSINIT)
 227                 if ((*sipp)->subsystem > last) {
 228                         verbose = 1;
 229                         last = (*sipp)->subsystem;
 230                         printf("subsystem %x\n", last);
 231                 }
 232                 if (verbose) {
 233 #if defined(DDB)
 234                         const char *name;
 235                         c_db_sym_t sym;
 236                         db_expr_t  offset;
 237
 238                         sym = db_search_symbol((vm_offset_t)(*sipp)->func,
 239                             DB_STGY_PROC, &offset);
 240                         db_symbol_values(sym, &name, NULL);
 241                         if (name != NULL)
 242                                 printf("   %s(%p)... ", name, (*sipp)->udata);
 243                         else
 244 #endif
 245                                 printf("   %p(%p)... ", (*sipp)->func,
 246                                     (*sipp)->udata);
 247                 }
 248 #endif
 249
 250                 /* Call function */
 251                 (*((*sipp)->func))((*sipp)->udata);
 252
 253 #if defined(VERBOSE_SYSINIT)
 254                 if (verbose)
 255                         printf("done.\n");
 256 #endif
 257
 258                 /* Check off the one we're just done */
 259                 (*sipp)->subsystem = SI_SUB_DONE;
 260
 261                 /* Check if we've installed more sysinit items via KLD */
 262                 if (newsysinit != NULL) {
 263                         if (sysinit != SET_BEGIN(sysinit_set))
 264                                 free(sysinit, M_TEMP);
 265                         sysinit = newsysinit;
 266                         sysinit_end = newsysinit_end;
 267                         newsysinit = NULL;
 268                         newsysinit_end = NULL;
 269                         goto restart;
 270                 }
 271         }
 272
 273         panic("Shouldn't get here!");
 274         /* NOTREACHED*/
 275 }
 276
 277
 278 /*
 279  ***************************************************************************
 280  ****
 281  **** The following SYSINIT's belong elsewhere, but have not yet
 282  **** been moved.
 283  ****
 284  ***************************************************************************
 285  */
 286 static void
 287 print_caddr_t(void *data)
 288 {
 289         printf("%s", (char *)data);
 290 }
 291
 292 static void
 293 print_version(void *data __unused)
 294 {
 295         int len;
 296
 297         /* Strip a trailing newline from version. */
 298         len = strlen(version);
 299         while (len > 0 && version[len - 1] == '\n')
 300                 len--;
 301         printf("%.*s %s\n", len, version, machine);
 302 }
 303
 304 SYSINIT(announce, SI_SUB_COPYRIGHT, SI_ORDER_FIRST, print_caddr_t,
 305     copyright);
 306 SYSINIT(trademark, SI_SUB_COPYRIGHT, SI_ORDER_SECOND, print_caddr_t,
 307     trademark);
 308 SYSINIT(version, SI_SUB_COPYRIGHT, SI_ORDER_THIRD, print_version, NULL);
 309
 310 #ifdef WITNESS
 311 static char wit_warn[] =
 312      "WARNING: WITNESS option enabled, expect reduced performance.\n";
 313 SYSINIT(witwarn, SI_SUB_COPYRIGHT, SI_ORDER_THIRD + 1,
 314    print_caddr_t, wit_warn);
 315 SYSINIT(witwarn2, SI_SUB_RUN_SCHEDULER, SI_ORDER_THIRD + 1,
 316    print_caddr_t, wit_warn);
 317 #endif
 318
 319 #ifdef DIAGNOSTIC
 320 static char diag_warn[] =
 321      "WARNING: DIAGNOSTIC option enabled, expect reduced performance.\n";
 322 SYSINIT(diagwarn, SI_SUB_COPYRIGHT, SI_ORDER_THIRD + 2,
 323     print_caddr_t, diag_warn);
 324 SYSINIT(diagwarn2, SI_SUB_RUN_SCHEDULER, SI_ORDER_THIRD + 2,
 325     print_caddr_t, diag_warn);
 326 #endif
 327
 328 static void
 329 set_boot_verbose(void *data __unused)
 330 {
 331
 332         if (boothowto & RB_VERBOSE)
 333                 bootverbose++;
 334 }
 335 SYSINIT(boot_verbose, SI_SUB_TUNABLES, SI_ORDER_ANY, set_boot_verbose, NULL);
 336
 337 struct sysentvec null_sysvec = {
 338         .sv_size        = 0,
 339         .sv_table       = NULL,
 340         .sv_mask        = 0,
 341         .sv_sigsize     = 0,
 342         .sv_sigtbl      = NULL,
 343         .sv_errsize     = 0,
 344         .sv_errtbl      = NULL,
 345         .sv_transtrap   = NULL,
 346         .sv_fixup       = NULL,
 347         .sv_sendsig     = NULL,
 348         .sv_sigcode     = NULL,
 349         .sv_szsigcode   = NULL,
 350         .sv_prepsyscall = NULL,
 351         .sv_name        = "null",
 352         .sv_coredump    = NULL,
 353         .sv_imgact_try  = NULL,
 354         .sv_minsigstksz = 0,
 355         .sv_pagesize    = PAGE_SIZE,
 356         .sv_minuser     = VM_MIN_ADDRESS,
 357         .sv_maxuser     = VM_MAXUSER_ADDRESS,
 358         .sv_usrstack    = USRSTACK,
 359         .sv_psstrings   = PS_STRINGS,
 360         .sv_stackprot   = VM_PROT_ALL,
 361         .sv_copyout_strings     = NULL,
 362         .sv_setregs     = NULL,
 363         .sv_fixlimit    = NULL,
 364         .sv_maxssiz     = NULL
 365 };
 366
 367 /*
 368  ***************************************************************************
 369  ****
 370  **** The two following SYSINIT's are proc0 specific glue code.  I am not
 371  **** convinced that they can not be safely combined, but their order of
 372  **** operation has been maintained as the same as the original init_main.c
 373  **** for right now.
 374  ****
 375  **** These probably belong in init_proc.c or kern_proc.c, since they
 376  **** deal with proc0 (the fork template process).
 377  ****
 378  ***************************************************************************
 379  */
 380 /* ARGSUSED*/
 381 static void
 382 proc0_init(void *dummy __unused)
 383 {
 384         struct proc *p;
 385         unsigned i;
 386         struct thread *td;
 387
 388         GIANT_REQUIRED;
 389         p = &proc0;
 390         td = &thread0;
 391
 392         /*
 393          * Initialize magic number and osrel.
 394          */
 395         p->p_magic = P_MAGIC;
 396         p->p_osrel = osreldate;
 397
 398         /*
 399          * Initialize thread and process structures.
 400          */
 401         procinit();     /* set up proc zone */
 402         threadinit();   /* set up UMA zones */
 403
 404         /*
 405          * Initialise scheduler resources.
 406          * Add scheduler specific parts to proc, thread as needed.
 407          */
 408         schedinit();    /* scheduler gets its house in order */
 409         /*
 410          * Initialize sleep queue hash table
 411          */
 412         sleepinit();
 413
 414         /*
 415          * additional VM structures
 416          */
 417         vm_init2();
 418
 419         /*
 420          * Create process 0 (the swapper).
 421          */
 422         LIST_INSERT_HEAD(&allproc, p, p_list);
 423         LIST_INSERT_HEAD(PIDHASH(0), p, p_hash);
 424         mtx_init(&pgrp0.pg_mtx, "process group", NULL, MTX_DEF | MTX_DUPOK);
 425         p->p_pgrp = &pgrp0;
 426         LIST_INSERT_HEAD(PGRPHASH(0), &pgrp0, pg_hash);
 427         LIST_INIT(&pgrp0.pg_members);
 428         LIST_INSERT_HEAD(&pgrp0.pg_members, p, p_pglist);
 429
 430         pgrp0.pg_session = &session0;
 431         mtx_init(&session0.s_mtx, "session", NULL, MTX_DEF);
 432         refcount_init(&session0.s_count, 1);
 433         session0.s_leader = p;
 434
 435         p->p_sysent = &null_sysvec;
 436         p->p_flag = P_SYSTEM | P_INMEM;
 437         p->p_state = PRS_NORMAL;
 438         knlist_init_mtx(&p->p_klist, &p->p_mtx);
 439         STAILQ_INIT(&p->p_ktr);
 440         p->p_nice = NZERO;
 441         td->td_tid = PID_MAX + 1;
 442         td->td_state = TDS_RUNNING;
 443         td->td_pri_class = PRI_TIMESHARE;
 444         td->td_user_pri = PUSER;
 445         td->td_base_user_pri = PUSER;
 446         td->td_priority = PVM;
 447         td->td_base_pri = PUSER;
 448         td->td_oncpu = 0;
 449         td->td_flags = TDF_INMEM|TDP_KTHREAD;
 450         td->td_cpuset = cpuset_thread0();
 451         prison0.pr_cpuset = cpuset_ref(td->td_cpuset);
 452         p->p_peers = 0;
 453         p->p_leader = p;
 454
 455
 456         strncpy(p->p_comm, "kernel", sizeof (p->p_comm));
 457         strncpy(td->td_name, "swapper", sizeof (td->td_name));
 458
 459         callout_init(&p->p_itcallout, CALLOUT_MPSAFE);
 460         callout_init_mtx(&p->p_limco, &p->p_mtx, 0);
 461         callout_init(&td->td_slpcallout, CALLOUT_MPSAFE);
 462
 463         /* Create credentials. */
 464         p->p_ucred = crget();
 465         p->p_ucred->cr_ngroups = 1;     /* group 0 */
 466         p->p_ucred->cr_uidinfo = uifind(0);
 467         p->p_ucred->cr_ruidinfo = uifind(0);
 468         p->p_ucred->cr_prison = &prison0;
 469 #ifdef AUDIT
 470         audit_cred_kproc0(p->p_ucred);
 471 #endif
 472 #ifdef MAC
 473         mac_cred_create_swapper(p->p_ucred);
 474 #endif
 475         td->td_ucred = crhold(p->p_ucred);
 476
 477         /* Create sigacts. */
 478         p->p_sigacts = sigacts_alloc();
 479
 480         /* Initialize signal state for process 0. */
 481         siginit(&proc0);
 482
 483         /* Create the file descriptor table. */
 484         p->p_fd = fdinit(NULL);
 485         p->p_fdtol = NULL;
 486
 487         /* Create the limits structures. */
 488         p->p_limit = lim_alloc();
 489         for (i = 0; i < RLIM_NLIMITS; i++)
 490                 p->p_limit->pl_rlimit[i].rlim_cur =
 491                     p->p_limit->pl_rlimit[i].rlim_max = RLIM_INFINITY;
 492         p->p_limit->pl_rlimit[RLIMIT_NOFILE].rlim_cur =
 493             p->p_limit->pl_rlimit[RLIMIT_NOFILE].rlim_max = maxfiles;
 494         p->p_limit->pl_rlimit[RLIMIT_NPROC].rlim_cur =
 495             p->p_limit->pl_rlimit[RLIMIT_NPROC].rlim_max = maxproc;
 496         i = ptoa(cnt.v_free_count);
 497         p->p_limit->pl_rlimit[RLIMIT_RSS].rlim_max = i;
 498         p->p_limit->pl_rlimit[RLIMIT_MEMLOCK].rlim_max = i;
 499         p->p_limit->pl_rlimit[RLIMIT_MEMLOCK].rlim_cur = i / 3;
 500         p->p_cpulimit = RLIM_INFINITY;
 501
 502         p->p_stats = pstats_alloc();
 503
 504         /* Allocate a prototype map so we have something to fork. */
 505         pmap_pinit0(vmspace_pmap(&vmspace0));
 506         p->p_vmspace = &vmspace0;
 507         vmspace0.vm_refcnt = 1;
 508
 509         /*
 510          * proc0 is not expected to enter usermode, so there is no special
 511          * handling for sv_minuser here, like is done for exec_new_vmspace().
 512          */
 513         vm_map_init(&vmspace0.vm_map, p->p_sysent->sv_minuser,
 514             p->p_sysent->sv_maxuser);
 515         vmspace0.vm_map.pmap = vmspace_pmap(&vmspace0);
 516
 517         /*-
 518          * call the init and ctor for the new thread and proc
 519          * we wait to do this until all other structures
 520          * are fairly sane.
 521          */
 522         EVENTHANDLER_INVOKE(process_init, p);
 523         EVENTHANDLER_INVOKE(thread_init, td);
 524         EVENTHANDLER_INVOKE(process_ctor, p);
 525         EVENTHANDLER_INVOKE(thread_ctor, td);
 526
 527         /*
 528          * Charge root for one process.
 529          */
 530         (void)chgproccnt(p->p_ucred->cr_ruidinfo, 1, 0);
 531 }
 532 SYSINIT(p0init, SI_SUB_INTRINSIC, SI_ORDER_FIRST, proc0_init, NULL);
 533
 534 /* ARGSUSED*/
 535 static void
 536 proc0_post(void *dummy __unused)
 537 {
 538         struct timespec ts;
 539         struct proc *p;
 540         struct rusage ru;
 541         struct thread *td;
 542
 543         /*
 544          * Now we can look at the time, having had a chance to verify the
 545          * time from the filesystem.  Pretend that proc0 started now.
 546          */
 547         sx_slock(&allproc_lock);
 548         FOREACH_PROC_IN_SYSTEM(p) {
 549                 microuptime(&p->p_stats->p_start);
 550                 PROC_SLOCK(p);
 551                 rufetch(p, &ru);        /* Clears thread stats */
 552                 PROC_SUNLOCK(p);
 553                 p->p_rux.rux_runtime = 0;
 554                 p->p_rux.rux_uticks = 0;
 555                 p->p_rux.rux_sticks = 0;
 556                 p->p_rux.rux_iticks = 0;
 557                 FOREACH_THREAD_IN_PROC(p, td) {
 558                         td->td_runtime = 0;
 559                 }
 560         }
 561         sx_sunlock(&allproc_lock);
 562         PCPU_SET(switchtime, cpu_ticks());
 563         PCPU_SET(switchticks, ticks);
 564
 565         /*
 566          * Give the ``random'' number generator a thump.
 567          */
 568         nanotime(&ts);
 569         srandom(ts.tv_sec ^ ts.tv_nsec);
 570 }
 571 SYSINIT(p0post, SI_SUB_INTRINSIC_POST, SI_ORDER_FIRST, proc0_post, NULL);
 572
 573 static void
 574 random_init(void *dummy __unused)
 575 {
 576
 577         /*
 578          * After CPU has been started we have some randomness on most
 579          * platforms via get_cyclecount().  For platforms that don't
 580          * we will reseed random(9) in proc0_post() as well.
 581          */
 582         srandom(get_cyclecount());
 583 }
 584 SYSINIT(random, SI_SUB_RANDOM, SI_ORDER_FIRST, random_init, NULL);
 585
 586 /*
 587  ***************************************************************************
 588  ****
 589  **** The following SYSINIT's and glue code should be moved to the
 590  **** respective files on a per subsystem basis.
 591  ****
 592  ***************************************************************************
 593  */
 594
 595
 596 /*
 597  ***************************************************************************
 598  ****
 599  **** The following code probably belongs in another file, like
 600  **** kern/init_init.c.
 601  ****
 602  ***************************************************************************
 603  */
 604
 605 /*
 606  * List of paths to try when searching for "init".
 607  */
 608 static char init_path[MAXPATHLEN] =
 609 #ifdef  INIT_PATH
 610     __XSTRING(INIT_PATH);
 611 #else
 612     "/sbin/init:/sbin/oinit:/sbin/init.bak:/rescue/init:/stand/sysinstall";
 613 #endif
 614 SYSCTL_STRING(_kern, OID_AUTO, init_path, CTLFLAG_RD, init_path, 0,
 615         "Path used to search the init process");
 616
 617 /*
 618  * Shutdown timeout of init(8).
 619  * Unused within kernel, but used to control init(8), hence do not remove.
 620  */
 621 #ifndef INIT_SHUTDOWN_TIMEOUT
 622 #define INIT_SHUTDOWN_TIMEOUT 120
 623 #endif
 624 static int init_shutdown_timeout = INIT_SHUTDOWN_TIMEOUT;
 625 SYSCTL_INT(_kern, OID_AUTO, init_shutdown_timeout,
 626         CTLFLAG_RW, &init_shutdown_timeout, 0, "");
 627
 628 /*
 629  * Start the initial user process; try exec'ing each pathname in init_path.
 630  * The program is invoked with one argument containing the boot flags.
 631  */
 632 static void
 633 start_init(void *dummy)
 634 {
 635         vm_offset_t addr;
 636         struct execve_args args;
 637         int options, error;
 638         char *var, *path, *next, *s;
 639         char *ucp, **uap, *arg0, *arg1;
 640         struct thread *td;
 641         struct proc *p;
 642
 643         mtx_lock(&Giant);
 644
 645         GIANT_REQUIRED;
 646
 647         td = curthread;
 648         p = td->td_proc;
 649
 650         vfs_mountroot();
 651
 652         /*
 653          * Need just enough stack to hold the faked-up "execve()" arguments.
 654          */
 655         addr = p->p_sysent->sv_usrstack - PAGE_SIZE;
 656         if (vm_map_find(&p->p_vmspace->vm_map, NULL, 0, &addr, PAGE_SIZE,
 657                         FALSE, VM_PROT_ALL, VM_PROT_ALL, 0) != 0)
 658                 panic("init: couldn't allocate argument space");
 659         p->p_vmspace->vm_maxsaddr = (caddr_t)addr;
 660         p->p_vmspace->vm_ssize = 1;
 661
 662         if ((var = getenv("init_path")) != NULL) {
 663                 strlcpy(init_path, var, sizeof(init_path));
 664                 freeenv(var);
 665         }
 666
 667         for (path = init_path; *path != '\0'; path = next) {
 668                 while (*path == ':')
 669                         path++;
 670                 if (*path == '\0')
 671                         break;
 672                 for (next = path; *next != '\0' && *next != ':'; next++)
 673                         /* nothing */ ;
 674                 if (bootverbose)
 675                         printf("start_init: trying %.*s\n", (int)(next - path),
 676                             path);
 677
 678                 /*
 679                  * Move out the boot flag argument.
 680                  */
 681                 options = 0;
 682                 ucp = (char *)p->p_sysent->sv_usrstack;
 683                 (void)subyte(--ucp, 0);         /* trailing zero */
 684                 if (boothowto & RB_SINGLE) {
 685                         (void)subyte(--ucp, 's');
 686                         options = 1;
 687                 }
 688 #ifdef notyet
 689                 if (boothowto & RB_FASTBOOT) {
 690                         (void)subyte(--ucp, 'f');
 691                         options = 1;
 692                 }
 693 #endif
 694
 695 #ifdef BOOTCDROM
 696                 (void)subyte(--ucp, 'C');
 697                 options = 1;
 698 #endif
 699
 700                 if (options == 0)
 701                         (void)subyte(--ucp, '-');
 702                 (void)subyte(--ucp, '-');               /* leading hyphen */
 703                 arg1 = ucp;
 704
 705                 /*
 706                  * Move out the file name (also arg 0).
 707                  */
 708                 (void)subyte(--ucp, 0);
 709                 for (s = next - 1; s >= path; s--)
 710                         (void)subyte(--ucp, *s);
 711                 arg0 = ucp;
 712
 713                 /*
 714                  * Move out the arg pointers.
 715                  */
 716                 uap = (char **)((intptr_t)ucp & ~(sizeof(intptr_t)-1));
 717                 (void)suword((caddr_t)--uap, (long)0);  /* terminator */
 718                 (void)suword((caddr_t)--uap, (long)(intptr_t)arg1);
 719                 (void)suword((caddr_t)--uap, (long)(intptr_t)arg0);
 720
 721                 /*
 722                  * Point at the arguments.
 723                  */
 724                 args.fname = arg0;
 725                 args.argv = uap;
 726                 args.envv = NULL;
 727
 728                 /*
 729                  * Now try to exec the program.  If can't for any reason
 730                  * other than it doesn't exist, complain.
 731                  *
 732                  * Otherwise, return via fork_trampoline() all the way
 733                  * to user mode as init!
 734                  */
 735                 if ((error = execve(td, &args)) == 0) {
 736                         mtx_unlock(&Giant);
 737                         return;
 738                 }
 739                 if (error != ENOENT)
 740                         printf("exec %.*s: error %d\n", (int)(next - path),
 741                             path, error);
 742         }
 743         printf("init: not found in path %s\n", init_path);
 744         panic("no init");
 745 }
 746
 747 /*
 748  * Like kproc_create(), but runs in it's own address space.
 749  * We do this early to reserve pid 1.
 750  *
 751  * Note special case - do not make it runnable yet.  Other work
 752  * in progress will change this more.
 753  */
 754 static void
 755 create_init(const void *udata __unused)
 756 {
 757         struct ucred *newcred, *oldcred;
 758         int error;
 759
 760         error = fork1(&thread0, RFFDG | RFPROC | RFSTOPPED, 0, &initproc);
 761         if (error)
 762                 panic("cannot fork init: %d\n", error);
 763         KASSERT(initproc->p_pid == 1, ("create_init: initproc->p_pid != 1"));
 764         /* divorce init's credentials from the kernel's */
 765         newcred = crget();
 766         PROC_LOCK(initproc);
 767         initproc->p_flag |= P_SYSTEM | P_INMEM;
 768         oldcred = initproc->p_ucred;
 769         crcopy(newcred, oldcred);
 770 #ifdef MAC
 771         mac_cred_create_init(newcred);
 772 #endif
 773 #ifdef AUDIT
 774         audit_cred_proc1(newcred);
 775 #endif
 776         initproc->p_ucred = newcred;
 777         PROC_UNLOCK(initproc);
 778         crfree(oldcred);
 779         cred_update_thread(FIRST_THREAD_IN_PROC(initproc));
 780         cpu_set_fork_handler(FIRST_THREAD_IN_PROC(initproc), start_init, NULL);
 781 }
 782 SYSINIT(init, SI_SUB_CREATE_INIT, SI_ORDER_FIRST, create_init, NULL);
 783
 784 /*
 785  * Make it runnable now.
 786  */
 787 static void
 788 kick_init(const void *udata __unused)
 789 {
 790         struct thread *td;
 791
 792         td = FIRST_THREAD_IN_PROC(initproc);
 793         thread_lock(td);
 794         TD_SET_CAN_RUN(td);
 795         sched_add(td, SRQ_BORING);
 796         thread_unlock(td);
 797 }
 798 SYSINIT(kickinit, SI_SUB_KTHREAD_INIT, SI_ORDER_FIRST, kick_init, NULL);