xref: /freebsd/sys/kern/init_main.c (revision 6949461a180c90c17d6f0adb3ff1ef76e3415bc3)
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_init_path.h"
48 #include "opt_mac.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/ktr.h>
56 #include <sys/lock.h>
57 #include <sys/mac.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 
77 #include <machine/cpu.h>
78 
79 #include <vm/vm.h>
80 #include <vm/vm_param.h>
81 #include <vm/pmap.h>
82 #include <vm/vm_map.h>
83 #include <sys/user.h>
84 #include <sys/copyright.h>
85 
86 void mi_startup(void);				/* Should be elsewhere */
87 
88 /* Components of the first process -- never freed. */
89 static struct session session0;
90 static struct pgrp pgrp0;
91 struct	proc proc0;
92 struct	thread thread0;
93 struct	ksegrp ksegrp0;
94 struct	vmspace vmspace0;
95 struct	proc *initproc;
96 
97 int	boothowto = 0;		/* initialized so that it can be patched */
98 SYSCTL_INT(_debug, OID_AUTO, boothowto, CTLFLAG_RD, &boothowto, 0, "");
99 int	bootverbose;
100 SYSCTL_INT(_debug, OID_AUTO, bootverbose, CTLFLAG_RW, &bootverbose, 0, "");
101 
102 /*
103  * This ensures that there is at least one entry so that the sysinit_set
104  * symbol is not undefined.  A sybsystem ID of SI_SUB_DUMMY is never
105  * executed.
106  */
107 SYSINIT(placeholder, SI_SUB_DUMMY, SI_ORDER_ANY, NULL, NULL)
108 
109 /*
110  * The sysinit table itself.  Items are checked off as the are run.
111  * If we want to register new sysinit types, add them to newsysinit.
112  */
113 SET_DECLARE(sysinit_set, struct sysinit);
114 struct sysinit **sysinit, **sysinit_end;
115 struct sysinit **newsysinit, **newsysinit_end;
116 
117 /*
118  * Merge a new sysinit set into the current set, reallocating it if
119  * necessary.  This can only be called after malloc is running.
120  */
121 void
122 sysinit_add(struct sysinit **set, struct sysinit **set_end)
123 {
124 	struct sysinit **newset;
125 	struct sysinit **sipp;
126 	struct sysinit **xipp;
127 	int count;
128 
129 	count = set_end - set;
130 	if (newsysinit)
131 		count += newsysinit_end - newsysinit;
132 	else
133 		count += sysinit_end - sysinit;
134 	newset = malloc(count * sizeof(*sipp), M_TEMP, M_NOWAIT);
135 	if (newset == NULL)
136 		panic("cannot malloc for sysinit");
137 	xipp = newset;
138 	if (newsysinit)
139 		for (sipp = newsysinit; sipp < newsysinit_end; sipp++)
140 			*xipp++ = *sipp;
141 	else
142 		for (sipp = sysinit; sipp < sysinit_end; sipp++)
143 			*xipp++ = *sipp;
144 	for (sipp = set; sipp < set_end; sipp++)
145 		*xipp++ = *sipp;
146 	if (newsysinit)
147 		free(newsysinit, M_TEMP);
148 	newsysinit = newset;
149 	newsysinit_end = newset + count;
150 }
151 
152 /*
153  * System startup; initialize the world, create process 0, mount root
154  * filesystem, and fork to create init and pagedaemon.  Most of the
155  * hard work is done in the lower-level initialization routines including
156  * startup(), which does memory initialization and autoconfiguration.
157  *
158  * This allows simple addition of new kernel subsystems that require
159  * boot time initialization.  It also allows substitution of subsystem
160  * (for instance, a scheduler, kernel profiler, or VM system) by object
161  * module.  Finally, it allows for optional "kernel threads".
162  */
163 void
164 mi_startup(void)
165 {
166 
167 	register struct sysinit **sipp;		/* system initialization*/
168 	register struct sysinit **xipp;		/* interior loop of sort*/
169 	register struct sysinit *save;		/* bubble*/
170 
171 	if (sysinit == NULL) {
172 		sysinit = SET_BEGIN(sysinit_set);
173 		sysinit_end = SET_LIMIT(sysinit_set);
174 	}
175 
176 restart:
177 	/*
178 	 * Perform a bubble sort of the system initialization objects by
179 	 * their subsystem (primary key) and order (secondary key).
180 	 */
181 	for (sipp = sysinit; sipp < sysinit_end; sipp++) {
182 		for (xipp = sipp + 1; xipp < sysinit_end; xipp++) {
183 			if ((*sipp)->subsystem < (*xipp)->subsystem ||
184 			     ((*sipp)->subsystem == (*xipp)->subsystem &&
185 			      (*sipp)->order <= (*xipp)->order))
186 				continue;	/* skip*/
187 			save = *sipp;
188 			*sipp = *xipp;
189 			*xipp = save;
190 		}
191 	}
192 
193 	/*
194 	 * Traverse the (now) ordered list of system initialization tasks.
195 	 * Perform each task, and continue on to the next task.
196 	 *
197 	 * The last item on the list is expected to be the scheduler,
198 	 * which will not return.
199 	 */
200 	for (sipp = sysinit; sipp < sysinit_end; sipp++) {
201 
202 		if ((*sipp)->subsystem == SI_SUB_DUMMY)
203 			continue;	/* skip dummy task(s)*/
204 
205 		if ((*sipp)->subsystem == SI_SUB_DONE)
206 			continue;
207 
208 		/* Call function */
209 		(*((*sipp)->func))((*sipp)->udata);
210 
211 		/* Check off the one we're just done */
212 		(*sipp)->subsystem = SI_SUB_DONE;
213 
214 		/* Check if we've installed more sysinit items via KLD */
215 		if (newsysinit != NULL) {
216 			if (sysinit != SET_BEGIN(sysinit_set))
217 				free(sysinit, M_TEMP);
218 			sysinit = newsysinit;
219 			sysinit_end = newsysinit_end;
220 			newsysinit = NULL;
221 			newsysinit_end = NULL;
222 			goto restart;
223 		}
224 	}
225 
226 	panic("Shouldn't get here!");
227 	/* NOTREACHED*/
228 }
229 
230 
231 /*
232  ***************************************************************************
233  ****
234  **** The following SYSINIT's belong elsewhere, but have not yet
235  **** been moved.
236  ****
237  ***************************************************************************
238  */
239 static void
240 print_caddr_t(void *data __unused)
241 {
242 	printf("%s", (char *)data);
243 }
244 SYSINIT(announce, SI_SUB_COPYRIGHT, SI_ORDER_FIRST, print_caddr_t, copyright)
245 SYSINIT(version, SI_SUB_COPYRIGHT, SI_ORDER_SECOND, print_caddr_t, version)
246 
247 #ifdef WITNESS
248 static char wit_warn[] =
249      "WARNING: WITNESS option enabled, expect reduced performance.\n";
250 SYSINIT(witwarn, SI_SUB_COPYRIGHT, SI_ORDER_SECOND + 1,
251    print_caddr_t, wit_warn)
252 #endif
253 
254 #ifdef DIAGNOSTIC
255 static char diag_warn[] =
256      "WARNING: DIAGNOSTIC option enabled, expect reduced performance.\n";
257 SYSINIT(diagwarn, SI_SUB_COPYRIGHT, SI_ORDER_SECOND + 2,
258     print_caddr_t, diag_warn)
259 #endif
260 
261 static void
262 set_boot_verbose(void *data __unused)
263 {
264 
265 	if (boothowto & RB_VERBOSE)
266 		bootverbose++;
267 }
268 SYSINIT(boot_verbose, SI_SUB_TUNABLES, SI_ORDER_ANY, set_boot_verbose, NULL)
269 
270 struct sysentvec null_sysvec = {
271 	0,
272 	NULL,
273 	0,
274 	0,
275 	NULL,
276 	0,
277 	NULL,
278 	NULL,
279 	NULL,
280 	NULL,
281 	NULL,
282 	NULL,
283 	NULL,
284 	"null",
285 	NULL,
286 	NULL,
287 	0,
288 	PAGE_SIZE,
289 	VM_MIN_ADDRESS,
290 	VM_MAXUSER_ADDRESS,
291 	USRSTACK,
292 	PS_STRINGS,
293 	VM_PROT_ALL,
294 	NULL,
295 	NULL,
296 	NULL
297 };
298 
299 /*
300  ***************************************************************************
301  ****
302  **** The two following SYSINIT's are proc0 specific glue code.  I am not
303  **** convinced that they can not be safely combined, but their order of
304  **** operation has been maintained as the same as the original init_main.c
305  **** for right now.
306  ****
307  **** These probably belong in init_proc.c or kern_proc.c, since they
308  **** deal with proc0 (the fork template process).
309  ****
310  ***************************************************************************
311  */
312 /* ARGSUSED*/
313 static void
314 proc0_init(void *dummy __unused)
315 {
316 	struct proc *p;
317 	unsigned i;
318 	struct thread *td;
319 	struct ksegrp *kg;
320 
321 	GIANT_REQUIRED;
322 	p = &proc0;
323 	td = &thread0;
324 	kg = &ksegrp0;
325 
326 	/*
327 	 * Initialize magic number.
328 	 */
329 	p->p_magic = P_MAGIC;
330 
331 	/*
332 	 * Initialize thread, process and ksegrp structures.
333 	 */
334 	procinit();	/* set up proc zone */
335 	threadinit();	/* set up thead, upcall and KSEGRP zones */
336 
337 	/*
338 	 * Initialise scheduler resources.
339 	 * Add scheduler specific parts to proc, ksegrp, thread as needed.
340 	 */
341 	schedinit();	/* scheduler gets its house in order */
342 	/*
343 	 * Initialize sleep queue hash table
344 	 */
345 	sleepinit();
346 
347 	/*
348 	 * additional VM structures
349 	 */
350 	vm_init2();
351 
352 	/*
353 	 * Create process 0 (the swapper).
354 	 */
355 	LIST_INSERT_HEAD(&allproc, p, p_list);
356 	LIST_INSERT_HEAD(PIDHASH(0), p, p_hash);
357 	mtx_init(&pgrp0.pg_mtx, "process group", NULL, MTX_DEF | MTX_DUPOK);
358 	p->p_pgrp = &pgrp0;
359 	LIST_INSERT_HEAD(PGRPHASH(0), &pgrp0, pg_hash);
360 	LIST_INIT(&pgrp0.pg_members);
361 	LIST_INSERT_HEAD(&pgrp0.pg_members, p, p_pglist);
362 
363 	pgrp0.pg_session = &session0;
364 	mtx_init(&session0.s_mtx, "session", NULL, MTX_DEF);
365 	session0.s_count = 1;
366 	session0.s_leader = p;
367 
368 	p->p_sysent = &null_sysvec;
369 	p->p_flag = P_SYSTEM;
370 	p->p_sflag = PS_INMEM;
371 	p->p_state = PRS_NORMAL;
372 	knlist_init(&p->p_klist, &p->p_mtx);
373 	p->p_nice = NZERO;
374 	td->td_state = TDS_RUNNING;
375 	kg->kg_pri_class = PRI_TIMESHARE;
376 	kg->kg_user_pri = PUSER;
377 	td->td_priority = PVM;
378 	td->td_base_pri = PUSER;
379 	td->td_oncpu = 0;
380 	p->p_peers = 0;
381 	p->p_leader = p;
382 
383 
384 	bcopy("swapper", p->p_comm, sizeof ("swapper"));
385 
386 	callout_init(&p->p_itcallout, CALLOUT_MPSAFE);
387 	callout_init(&td->td_slpcallout, CALLOUT_MPSAFE);
388 
389 	/* Create credentials. */
390 	p->p_ucred = crget();
391 	p->p_ucred->cr_ngroups = 1;	/* group 0 */
392 	p->p_ucred->cr_uidinfo = uifind(0);
393 	p->p_ucred->cr_ruidinfo = uifind(0);
394 	p->p_ucred->cr_prison = NULL;	/* Don't jail it. */
395 #ifdef MAC
396 	mac_create_proc0(p->p_ucred);
397 #endif
398 	td->td_ucred = crhold(p->p_ucred);
399 
400 	/* Create sigacts. */
401 	p->p_sigacts = sigacts_alloc();
402 
403 	/* Initialize signal state for process 0. */
404 	siginit(&proc0);
405 
406 	/* Create the file descriptor table. */
407 	p->p_fd = fdinit(NULL);
408 	p->p_fdtol = NULL;
409 
410 	/* Create the limits structures. */
411 	p->p_limit = lim_alloc();
412 	for (i = 0; i < RLIM_NLIMITS; i++)
413 		p->p_limit->pl_rlimit[i].rlim_cur =
414 		    p->p_limit->pl_rlimit[i].rlim_max = RLIM_INFINITY;
415 	p->p_limit->pl_rlimit[RLIMIT_NOFILE].rlim_cur =
416 	    p->p_limit->pl_rlimit[RLIMIT_NOFILE].rlim_max = maxfiles;
417 	p->p_limit->pl_rlimit[RLIMIT_NPROC].rlim_cur =
418 	    p->p_limit->pl_rlimit[RLIMIT_NPROC].rlim_max = maxproc;
419 	i = ptoa(cnt.v_free_count);
420 	p->p_limit->pl_rlimit[RLIMIT_RSS].rlim_max = i;
421 	p->p_limit->pl_rlimit[RLIMIT_MEMLOCK].rlim_max = i;
422 	p->p_limit->pl_rlimit[RLIMIT_MEMLOCK].rlim_cur = i / 3;
423 	p->p_cpulimit = RLIM_INFINITY;
424 
425 	/* Allocate a prototype map so we have something to fork. */
426 	pmap_pinit0(vmspace_pmap(&vmspace0));
427 	p->p_vmspace = &vmspace0;
428 	vmspace0.vm_refcnt = 1;
429 	vm_map_init(&vmspace0.vm_map, p->p_sysent->sv_minuser,
430 	    p->p_sysent->sv_maxuser);
431 	vmspace0.vm_map.pmap = vmspace_pmap(&vmspace0);
432 
433 	/*
434 	 * We continue to place resource usage info
435 	 * in the user struct so that it's pageable.
436 	 */
437 	p->p_stats = &p->p_uarea->u_stats;
438 
439 	/*
440 	 * Charge root for one process.
441 	 */
442 	(void)chgproccnt(p->p_ucred->cr_ruidinfo, 1, 0);
443 }
444 SYSINIT(p0init, SI_SUB_INTRINSIC, SI_ORDER_FIRST, proc0_init, NULL)
445 
446 /* ARGSUSED*/
447 static void
448 proc0_post(void *dummy __unused)
449 {
450 	struct timespec ts;
451 	struct proc *p;
452 
453 	/*
454 	 * Now we can look at the time, having had a chance to verify the
455 	 * time from the filesystem.  Pretend that proc0 started now.
456 	 */
457 	sx_slock(&allproc_lock);
458 	LIST_FOREACH(p, &allproc, p_list) {
459 		microuptime(&p->p_stats->p_start);
460 		p->p_rux.rux_runtime.sec = 0;
461 		p->p_rux.rux_runtime.frac = 0;
462 	}
463 	sx_sunlock(&allproc_lock);
464 	binuptime(PCPU_PTR(switchtime));
465 	PCPU_SET(switchticks, ticks);
466 
467 	/*
468 	 * Give the ``random'' number generator a thump.
469 	 */
470 	nanotime(&ts);
471 	srandom(ts.tv_sec ^ ts.tv_nsec);
472 }
473 SYSINIT(p0post, SI_SUB_INTRINSIC_POST, SI_ORDER_FIRST, proc0_post, NULL)
474 
475 /*
476  ***************************************************************************
477  ****
478  **** The following SYSINIT's and glue code should be moved to the
479  **** respective files on a per subsystem basis.
480  ****
481  ***************************************************************************
482  */
483 
484 
485 /*
486  ***************************************************************************
487  ****
488  **** The following code probably belongs in another file, like
489  **** kern/init_init.c.
490  ****
491  ***************************************************************************
492  */
493 
494 /*
495  * List of paths to try when searching for "init".
496  */
497 static char init_path[MAXPATHLEN] =
498 #ifdef	INIT_PATH
499     __XSTRING(INIT_PATH);
500 #else
501     "/sbin/init:/sbin/oinit:/sbin/init.bak:/stand/sysinstall";
502 #endif
503 SYSCTL_STRING(_kern, OID_AUTO, init_path, CTLFLAG_RD, init_path, 0,
504 	"Path used to search the init process");
505 
506 /*
507  * Start the initial user process; try exec'ing each pathname in init_path.
508  * The program is invoked with one argument containing the boot flags.
509  */
510 static void
511 start_init(void *dummy)
512 {
513 	vm_offset_t addr;
514 	struct execve_args args;
515 	int options, error;
516 	char *var, *path, *next, *s;
517 	char *ucp, **uap, *arg0, *arg1;
518 	struct thread *td;
519 	struct proc *p;
520 	int init_does_devfs = 0;
521 
522 	mtx_lock(&Giant);
523 
524 	GIANT_REQUIRED;
525 
526 	td = curthread;
527 	p = td->td_proc;
528 
529 	vfs_mountroot();
530 
531 	/* Get the vnode for '/'.  Set p->p_fd->fd_cdir to reference it. */
532 	if (VFS_ROOT(TAILQ_FIRST(&mountlist), &rootvnode, td))
533 		panic("cannot find root vnode");
534 	FILEDESC_LOCK(p->p_fd);
535 	p->p_fd->fd_cdir = rootvnode;
536 	VREF(p->p_fd->fd_cdir);
537 	p->p_fd->fd_rdir = rootvnode;
538 	VREF(p->p_fd->fd_rdir);
539 	FILEDESC_UNLOCK(p->p_fd);
540 	VOP_UNLOCK(rootvnode, 0, td);
541 #ifdef MAC
542 	mac_create_root_mount(td->td_ucred, TAILQ_FIRST(&mountlist));
543 #endif
544 
545 	/*
546 	 * For disk based systems, we probably cannot do this yet
547 	 * since the fs will be read-only.  But a NFS root
548 	 * might be ok.  It is worth a shot.
549 	 */
550 	error = kern_mkdir(td, "/dev", UIO_SYSSPACE, 0700);
551 	if (error == EEXIST)
552 		error = 0;
553 	if (error == 0)
554 		error = kernel_vmount(0, "fstype", "devfs",
555 		    "fspath", "/dev", NULL);
556 	if (error != 0)
557 		init_does_devfs = 1;
558 
559 	/*
560 	 * Need just enough stack to hold the faked-up "execve()" arguments.
561 	 */
562 	addr = p->p_sysent->sv_usrstack - PAGE_SIZE;
563 	if (vm_map_find(&p->p_vmspace->vm_map, NULL, 0, &addr, PAGE_SIZE,
564 			FALSE, VM_PROT_ALL, VM_PROT_ALL, 0) != 0)
565 		panic("init: couldn't allocate argument space");
566 	p->p_vmspace->vm_maxsaddr = (caddr_t)addr;
567 	p->p_vmspace->vm_ssize = 1;
568 
569 	if ((var = getenv("init_path")) != NULL) {
570 		strlcpy(init_path, var, sizeof(init_path));
571 		freeenv(var);
572 	}
573 
574 	for (path = init_path; *path != '\0'; path = next) {
575 		while (*path == ':')
576 			path++;
577 		if (*path == '\0')
578 			break;
579 		for (next = path; *next != '\0' && *next != ':'; next++)
580 			/* nothing */ ;
581 		if (bootverbose)
582 			printf("start_init: trying %.*s\n", (int)(next - path),
583 			    path);
584 
585 		/*
586 		 * Move out the boot flag argument.
587 		 */
588 		options = 0;
589 		ucp = (char *)p->p_sysent->sv_usrstack;
590 		(void)subyte(--ucp, 0);		/* trailing zero */
591 		if (boothowto & RB_SINGLE) {
592 			(void)subyte(--ucp, 's');
593 			options = 1;
594 		}
595 #ifdef notyet
596                 if (boothowto & RB_FASTBOOT) {
597 			(void)subyte(--ucp, 'f');
598 			options = 1;
599 		}
600 #endif
601 
602 #ifdef BOOTCDROM
603 		(void)subyte(--ucp, 'C');
604 		options = 1;
605 #endif
606 		if (init_does_devfs) {
607 			(void)subyte(--ucp, 'd');
608 			options = 1;
609 		}
610 
611 		if (options == 0)
612 			(void)subyte(--ucp, '-');
613 		(void)subyte(--ucp, '-');		/* leading hyphen */
614 		arg1 = ucp;
615 
616 		/*
617 		 * Move out the file name (also arg 0).
618 		 */
619 		(void)subyte(--ucp, 0);
620 		for (s = next - 1; s >= path; s--)
621 			(void)subyte(--ucp, *s);
622 		arg0 = ucp;
623 
624 		/*
625 		 * Move out the arg pointers.
626 		 */
627 		uap = (char **)((intptr_t)ucp & ~(sizeof(intptr_t)-1));
628 		(void)suword((caddr_t)--uap, (long)0);	/* terminator */
629 		(void)suword((caddr_t)--uap, (long)(intptr_t)arg1);
630 		(void)suword((caddr_t)--uap, (long)(intptr_t)arg0);
631 
632 		/*
633 		 * Point at the arguments.
634 		 */
635 		args.fname = arg0;
636 		args.argv = uap;
637 		args.envv = NULL;
638 
639 		/*
640 		 * Now try to exec the program.  If can't for any reason
641 		 * other than it doesn't exist, complain.
642 		 *
643 		 * Otherwise, return via fork_trampoline() all the way
644 		 * to user mode as init!
645 		 */
646 		if ((error = execve(td, &args)) == 0) {
647 			mtx_unlock(&Giant);
648 			return;
649 		}
650 		if (error != ENOENT)
651 			printf("exec %.*s: error %d\n", (int)(next - path),
652 			    path, error);
653 	}
654 	printf("init: not found in path %s\n", init_path);
655 	panic("no init");
656 }
657 
658 /*
659  * Like kthread_create(), but runs in it's own address space.
660  * We do this early to reserve pid 1.
661  *
662  * Note special case - do not make it runnable yet.  Other work
663  * in progress will change this more.
664  */
665 static void
666 create_init(const void *udata __unused)
667 {
668 	struct ucred *newcred, *oldcred;
669 	int error;
670 
671 	error = fork1(&thread0, RFFDG | RFPROC | RFSTOPPED, 0, &initproc);
672 	if (error)
673 		panic("cannot fork init: %d\n", error);
674 	KASSERT(initproc->p_pid == 1, ("create_init: initproc->p_pid != 1"));
675 	/* divorce init's credentials from the kernel's */
676 	newcred = crget();
677 	PROC_LOCK(initproc);
678 	initproc->p_flag |= P_SYSTEM;
679 	oldcred = initproc->p_ucred;
680 	crcopy(newcred, oldcred);
681 #ifdef MAC
682 	mac_create_proc1(newcred);
683 #endif
684 	initproc->p_ucred = newcred;
685 	PROC_UNLOCK(initproc);
686 	crfree(oldcred);
687 	cred_update_thread(FIRST_THREAD_IN_PROC(initproc));
688 	mtx_lock_spin(&sched_lock);
689 	initproc->p_sflag |= PS_INMEM;
690 	mtx_unlock_spin(&sched_lock);
691 	cpu_set_fork_handler(FIRST_THREAD_IN_PROC(initproc), start_init, NULL);
692 }
693 SYSINIT(init, SI_SUB_CREATE_INIT, SI_ORDER_FIRST, create_init, NULL)
694 
695 /*
696  * Make it runnable now.
697  */
698 static void
699 kick_init(const void *udata __unused)
700 {
701 	struct thread *td;
702 
703 	td = FIRST_THREAD_IN_PROC(initproc);
704 	mtx_lock_spin(&sched_lock);
705 	TD_SET_CAN_RUN(td);
706 	setrunqueue(td, SRQ_BORING);	/* XXXKSE */
707 	mtx_unlock_spin(&sched_lock);
708 }
709 SYSINIT(kickinit, SI_SUB_KTHREAD_INIT, SI_ORDER_FIRST, kick_init, NULL)
710