xref: /freebsd/sys/kern/init_main.c (revision 9fd69f37d28cfd7438cac3eeb45fe9dd46b4d7dd)
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);
799