xref: /netbsd/sys/kern/kern_subr.c (revision c4a72b64)
1 /*	$NetBSD: kern_subr.c,v 1.93 2002/11/16 07:40:41 uebayasi Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center, and by Luke Mewburn.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the NetBSD
22  *	Foundation, Inc. and its contributors.
23  * 4. Neither the name of The NetBSD Foundation nor the names of its
24  *    contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37  * POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 /*
41  * Copyright (c) 1982, 1986, 1991, 1993
42  *	The Regents of the University of California.  All rights reserved.
43  * (c) UNIX System Laboratories, Inc.
44  * All or some portions of this file are derived from material licensed
45  * to the University of California by American Telephone and Telegraph
46  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
47  * the permission of UNIX System Laboratories, Inc.
48  *
49  * Copyright (c) 1992, 1993
50  *	The Regents of the University of California.  All rights reserved.
51  *
52  * This software was developed by the Computer Systems Engineering group
53  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
54  * contributed to Berkeley.
55  *
56  * All advertising materials mentioning features or use of this software
57  * must display the following acknowledgement:
58  *	This product includes software developed by the University of
59  *	California, Lawrence Berkeley Laboratory.
60  *
61  * Redistribution and use in source and binary forms, with or without
62  * modification, are permitted provided that the following conditions
63  * are met:
64  * 1. Redistributions of source code must retain the above copyright
65  *    notice, this list of conditions and the following disclaimer.
66  * 2. Redistributions in binary form must reproduce the above copyright
67  *    notice, this list of conditions and the following disclaimer in the
68  *    documentation and/or other materials provided with the distribution.
69  * 3. All advertising materials mentioning features or use of this software
70  *    must display the following acknowledgement:
71  *	This product includes software developed by the University of
72  *	California, Berkeley and its contributors.
73  * 4. Neither the name of the University nor the names of its contributors
74  *    may be used to endorse or promote products derived from this software
75  *    without specific prior written permission.
76  *
77  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
78  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
79  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
80  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
81  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
82  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
83  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
84  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
85  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
86  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
87  * SUCH DAMAGE.
88  *
89  *	@(#)kern_subr.c	8.4 (Berkeley) 2/14/95
90  */
91 
92 #include <sys/cdefs.h>
93 __KERNEL_RCSID(0, "$NetBSD: kern_subr.c,v 1.93 2002/11/16 07:40:41 uebayasi Exp $");
94 
95 #include "opt_ddb.h"
96 #include "opt_md.h"
97 #include "opt_syscall_debug.h"
98 #include "opt_ktrace.h"
99 #include "opt_systrace.h"
100 
101 #include <sys/param.h>
102 #include <sys/systm.h>
103 #include <sys/proc.h>
104 #include <sys/malloc.h>
105 #include <sys/mount.h>
106 #include <sys/device.h>
107 #include <sys/reboot.h>
108 #include <sys/conf.h>
109 #include <sys/disklabel.h>
110 #include <sys/queue.h>
111 #include <sys/systrace.h>
112 #include <sys/ktrace.h>
113 
114 #include <uvm/uvm_extern.h>
115 
116 #include <dev/cons.h>
117 
118 #include <net/if.h>
119 
120 /* XXX these should eventually move to subr_autoconf.c */
121 static struct device *finddevice __P((const char *));
122 static struct device *getdisk __P((char *, int, int, dev_t *, int));
123 static struct device *parsedisk __P((char *, int, int, dev_t *));
124 
125 /*
126  * A generic linear hook.
127  */
128 struct hook_desc {
129 	LIST_ENTRY(hook_desc) hk_list;
130 	void	(*hk_fn) __P((void *));
131 	void	*hk_arg;
132 };
133 typedef LIST_HEAD(, hook_desc) hook_list_t;
134 
135 static void *hook_establish __P((hook_list_t *, void (*)(void *), void *));
136 static void hook_disestablish __P((hook_list_t *, void *));
137 static void hook_destroy __P((hook_list_t *));
138 static void hook_proc_run __P((hook_list_t *, struct proc *));
139 
140 int
141 uiomove(buf, n, uio)
142 	void *buf;
143 	size_t n;
144 	struct uio *uio;
145 {
146 	struct iovec *iov;
147 	u_int cnt;
148 	int error = 0;
149 	char *cp = buf;
150 	struct proc *p = uio->uio_procp;
151 
152 #ifdef DIAGNOSTIC
153 	if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE)
154 		panic("uiomove: mode");
155 #endif
156 	while (n > 0 && uio->uio_resid) {
157 		iov = uio->uio_iov;
158 		cnt = iov->iov_len;
159 		if (cnt == 0) {
160 			uio->uio_iov++;
161 			uio->uio_iovcnt--;
162 			continue;
163 		}
164 		if (cnt > n)
165 			cnt = n;
166 		switch (uio->uio_segflg) {
167 
168 		case UIO_USERSPACE:
169 			if (curproc->p_cpu->ci_schedstate.spc_flags &
170 			    SPCF_SHOULDYIELD)
171 				preempt(NULL);
172 			if (__predict_true(p == curproc)) {
173 				if (uio->uio_rw == UIO_READ)
174 					error = copyout(cp, iov->iov_base, cnt);
175 				else
176 					error = copyin(iov->iov_base, cp, cnt);
177 			} else {
178 				if (uio->uio_rw == UIO_READ)
179 					error = copyout_proc(p, cp,
180 					    iov->iov_base, cnt);
181 				else
182 					error = copyin_proc(p, iov->iov_base,
183 					    cp, cnt);
184 			}
185 			if (error)
186 				return (error);
187 			break;
188 
189 		case UIO_SYSSPACE:
190 			if (uio->uio_rw == UIO_READ)
191 				error = kcopy(cp, iov->iov_base, cnt);
192 			else
193 				error = kcopy(iov->iov_base, cp, cnt);
194 			if (error)
195 				return (error);
196 			break;
197 		}
198 		iov->iov_base = (caddr_t)iov->iov_base + cnt;
199 		iov->iov_len -= cnt;
200 		uio->uio_resid -= cnt;
201 		uio->uio_offset += cnt;
202 		cp += cnt;
203 		KDASSERT(cnt <= n);
204 		n -= cnt;
205 	}
206 	return (error);
207 }
208 
209 /*
210  * Give next character to user as result of read.
211  */
212 int
213 ureadc(c, uio)
214 	int c;
215 	struct uio *uio;
216 {
217 	struct iovec *iov;
218 
219 	if (uio->uio_resid <= 0)
220 		panic("ureadc: non-positive resid");
221 again:
222 	if (uio->uio_iovcnt <= 0)
223 		panic("ureadc: non-positive iovcnt");
224 	iov = uio->uio_iov;
225 	if (iov->iov_len <= 0) {
226 		uio->uio_iovcnt--;
227 		uio->uio_iov++;
228 		goto again;
229 	}
230 	switch (uio->uio_segflg) {
231 
232 	case UIO_USERSPACE:
233 		if (subyte(iov->iov_base, c) < 0)
234 			return (EFAULT);
235 		break;
236 
237 	case UIO_SYSSPACE:
238 		*(char *)iov->iov_base = c;
239 		break;
240 	}
241 	iov->iov_base = (caddr_t)iov->iov_base + 1;
242 	iov->iov_len--;
243 	uio->uio_resid--;
244 	uio->uio_offset++;
245 	return (0);
246 }
247 
248 /*
249  * Like copyin(), but operates on an arbitrary process.
250  */
251 int
252 copyin_proc(struct proc *p, const void *uaddr, void *kaddr, size_t len)
253 {
254 	struct iovec iov;
255 	struct uio uio;
256 	int error;
257 
258 	if (len == 0)
259 		return (0);
260 
261 	iov.iov_base = kaddr;
262 	iov.iov_len = len;
263 	uio.uio_iov = &iov;
264 	uio.uio_iovcnt = 1;
265 	uio.uio_offset = (off_t)(intptr_t)uaddr;
266 	uio.uio_resid = len;
267 	uio.uio_segflg = UIO_SYSSPACE;
268 	uio.uio_rw = UIO_READ;
269 	uio.uio_procp = NULL;
270 
271 	/* XXXCDC: how should locking work here? */
272 	if ((p->p_flag & P_WEXIT) || (p->p_vmspace->vm_refcnt < 1))
273 		return (EFAULT);
274 	p->p_vmspace->vm_refcnt++;	/* XXX */
275 	error = uvm_io(&p->p_vmspace->vm_map, &uio);
276 	uvmspace_free(p->p_vmspace);
277 
278 	return (error);
279 }
280 
281 /*
282  * Like copyout(), but operates on an arbitrary process.
283  */
284 int
285 copyout_proc(struct proc *p, const void *kaddr, void *uaddr, size_t len)
286 {
287 	struct iovec iov;
288 	struct uio uio;
289 	int error;
290 
291 	if (len == 0)
292 		return (0);
293 
294 	iov.iov_base = (void *) kaddr;	/* XXX cast away const */
295 	iov.iov_len = len;
296 	uio.uio_iov = &iov;
297 	uio.uio_iovcnt = 1;
298 	uio.uio_offset = (off_t)(intptr_t)uaddr;
299 	uio.uio_resid = len;
300 	uio.uio_segflg = UIO_SYSSPACE;
301 	uio.uio_rw = UIO_WRITE;
302 	uio.uio_procp = NULL;
303 
304 	/* XXXCDC: how should locking work here? */
305 	if ((p->p_flag & P_WEXIT) || (p->p_vmspace->vm_refcnt < 1))
306 		return (EFAULT);
307 	p->p_vmspace->vm_refcnt++;	/* XXX */
308 	error = uvm_io(&p->p_vmspace->vm_map, &uio);
309 	uvmspace_free(p->p_vmspace);
310 
311 	return (error);
312 }
313 
314 /*
315  * General routine to allocate a hash table.
316  * Allocate enough memory to hold at least `elements' list-head pointers.
317  * Return a pointer to the allocated space and set *hashmask to a pattern
318  * suitable for masking a value to use as an index into the returned array.
319  */
320 void *
321 hashinit(elements, htype, mtype, mflags, hashmask)
322 	u_int elements;
323 	enum hashtype htype;
324 	int mtype, mflags;
325 	u_long *hashmask;
326 {
327 	u_long hashsize, i;
328 	LIST_HEAD(, generic) *hashtbl_list;
329 	TAILQ_HEAD(, generic) *hashtbl_tailq;
330 	size_t esize;
331 	void *p;
332 
333 	if (elements == 0)
334 		panic("hashinit: bad cnt");
335 	for (hashsize = 1; hashsize < elements; hashsize <<= 1)
336 		continue;
337 
338 	switch (htype) {
339 	case HASH_LIST:
340 		esize = sizeof(*hashtbl_list);
341 		break;
342 	case HASH_TAILQ:
343 		esize = sizeof(*hashtbl_tailq);
344 		break;
345 #ifdef DIAGNOSTIC
346 	default:
347 		panic("hashinit: invalid table type");
348 #endif
349 	}
350 
351 	if ((p = malloc(hashsize * esize, mtype, mflags)) == NULL)
352 		return (NULL);
353 
354 	switch (htype) {
355 	case HASH_LIST:
356 		hashtbl_list = p;
357 		for (i = 0; i < hashsize; i++)
358 			LIST_INIT(&hashtbl_list[i]);
359 		break;
360 	case HASH_TAILQ:
361 		hashtbl_tailq = p;
362 		for (i = 0; i < hashsize; i++)
363 			TAILQ_INIT(&hashtbl_tailq[i]);
364 		break;
365 	}
366 	*hashmask = hashsize - 1;
367 	return (p);
368 }
369 
370 /*
371  * Free memory from hash table previosly allocated via hashinit().
372  */
373 void
374 hashdone(hashtbl, mtype)
375 	void *hashtbl;
376 	int mtype;
377 {
378 
379 	free(hashtbl, mtype);
380 }
381 
382 
383 static void *
384 hook_establish(list, fn, arg)
385 	hook_list_t *list;
386 	void (*fn) __P((void *));
387 	void *arg;
388 {
389 	struct hook_desc *hd;
390 
391 	hd = malloc(sizeof(*hd), M_DEVBUF, M_NOWAIT);
392 	if (hd == NULL)
393 		return (NULL);
394 
395 	hd->hk_fn = fn;
396 	hd->hk_arg = arg;
397 	LIST_INSERT_HEAD(list, hd, hk_list);
398 
399 	return (hd);
400 }
401 
402 static void
403 hook_disestablish(list, vhook)
404 	hook_list_t *list;
405 	void *vhook;
406 {
407 #ifdef DIAGNOSTIC
408 	struct hook_desc *hd;
409 
410 	LIST_FOREACH(hd, list, hk_list) {
411                 if (hd == vhook)
412 			break;
413 	}
414 
415 	if (hd == NULL)
416 		panic("hook_disestablish: hook %p not established", vhook);
417 #endif
418 	LIST_REMOVE((struct hook_desc *)vhook, hk_list);
419 	free(vhook, M_DEVBUF);
420 }
421 
422 static void
423 hook_destroy(list)
424 	hook_list_t *list;
425 {
426 	struct hook_desc *hd;
427 
428 	while ((hd = LIST_FIRST(list)) != NULL) {
429 		LIST_REMOVE(hd, hk_list);
430 		free(hd, M_DEVBUF);
431 	}
432 }
433 
434 static void
435 hook_proc_run(list, p)
436 	hook_list_t *list;
437 	struct proc *p;
438 {
439 	struct hook_desc *hd;
440 
441 	for (hd = LIST_FIRST(list); hd != NULL; hd = LIST_NEXT(hd, hk_list)) {
442 		((void (*) __P((struct proc *, void *)))*hd->hk_fn)(p,
443 		    hd->hk_arg);
444 	}
445 }
446 
447 /*
448  * "Shutdown hook" types, functions, and variables.
449  *
450  * Should be invoked immediately before the
451  * system is halted or rebooted, i.e. after file systems unmounted,
452  * after crash dump done, etc.
453  *
454  * Each shutdown hook is removed from the list before it's run, so that
455  * it won't be run again.
456  */
457 
458 hook_list_t shutdownhook_list;
459 
460 void *
461 shutdownhook_establish(fn, arg)
462 	void (*fn) __P((void *));
463 	void *arg;
464 {
465 	return hook_establish(&shutdownhook_list, fn, arg);
466 }
467 
468 void
469 shutdownhook_disestablish(vhook)
470 	void *vhook;
471 {
472 	hook_disestablish(&shutdownhook_list, vhook);
473 }
474 
475 /*
476  * Run shutdown hooks.  Should be invoked immediately before the
477  * system is halted or rebooted, i.e. after file systems unmounted,
478  * after crash dump done, etc.
479  *
480  * Each shutdown hook is removed from the list before it's run, so that
481  * it won't be run again.
482  */
483 void
484 doshutdownhooks()
485 {
486 	struct hook_desc *dp;
487 
488 	while ((dp = LIST_FIRST(&shutdownhook_list)) != NULL) {
489 		LIST_REMOVE(dp, hk_list);
490 		(*dp->hk_fn)(dp->hk_arg);
491 #if 0
492 		/*
493 		 * Don't bother freeing the hook structure,, since we may
494 		 * be rebooting because of a memory corruption problem,
495 		 * and this might only make things worse.  It doesn't
496 		 * matter, anyway, since the system is just about to
497 		 * reboot.
498 		 */
499 		free(dp, M_DEVBUF);
500 #endif
501 	}
502 }
503 
504 /*
505  * "Mountroot hook" types, functions, and variables.
506  */
507 
508 hook_list_t mountroothook_list;
509 
510 void *
511 mountroothook_establish(fn, dev)
512 	void (*fn) __P((struct device *));
513 	struct device *dev;
514 {
515 	return hook_establish(&mountroothook_list, (void (*)__P((void *)))fn,
516 	    dev);
517 }
518 
519 void
520 mountroothook_disestablish(vhook)
521 	void *vhook;
522 {
523 	hook_disestablish(&mountroothook_list, vhook);
524 }
525 
526 void
527 mountroothook_destroy()
528 {
529 	hook_destroy(&mountroothook_list);
530 }
531 
532 void
533 domountroothook()
534 {
535 	struct hook_desc *hd;
536 
537 	LIST_FOREACH(hd, &mountroothook_list, hk_list) {
538 		if (hd->hk_arg == (void *)root_device) {
539 			(*hd->hk_fn)(hd->hk_arg);
540 			return;
541 		}
542 	}
543 }
544 
545 hook_list_t exechook_list;
546 
547 void *
548 exechook_establish(fn, arg)
549 	void (*fn) __P((struct proc *, void *));
550 	void *arg;
551 {
552 	return hook_establish(&exechook_list, (void (*) __P((void *)))fn, arg);
553 }
554 
555 void
556 exechook_disestablish(vhook)
557 	void *vhook;
558 {
559 	hook_disestablish(&exechook_list, vhook);
560 }
561 
562 /*
563  * Run exec hooks.
564  */
565 void
566 doexechooks(p)
567 	struct proc *p;
568 {
569 	hook_proc_run(&exechook_list, p);
570 }
571 
572 hook_list_t exithook_list;
573 
574 void *
575 exithook_establish(fn, arg)
576 	void (*fn) __P((struct proc *, void *));
577 	void *arg;
578 {
579 	return hook_establish(&exithook_list, (void (*) __P((void *)))fn, arg);
580 }
581 
582 void
583 exithook_disestablish(vhook)
584 	void *vhook;
585 {
586 	hook_disestablish(&exithook_list, vhook);
587 }
588 
589 /*
590  * Run exit hooks.
591  */
592 void
593 doexithooks(p)
594 	struct proc *p;
595 {
596 	hook_proc_run(&exithook_list, p);
597 }
598 
599 /*
600  * "Power hook" types, functions, and variables.
601  * The list of power hooks is kept ordered with the last registered hook
602  * first.
603  * When running the hooks on power down the hooks are called in reverse
604  * registration order, when powering up in registration order.
605  */
606 struct powerhook_desc {
607 	CIRCLEQ_ENTRY(powerhook_desc) sfd_list;
608 	void	(*sfd_fn) __P((int, void *));
609 	void	*sfd_arg;
610 };
611 
612 CIRCLEQ_HEAD(, powerhook_desc) powerhook_list =
613 	CIRCLEQ_HEAD_INITIALIZER(powerhook_list);
614 
615 void *
616 powerhook_establish(fn, arg)
617 	void (*fn) __P((int, void *));
618 	void *arg;
619 {
620 	struct powerhook_desc *ndp;
621 
622 	ndp = (struct powerhook_desc *)
623 	    malloc(sizeof(*ndp), M_DEVBUF, M_NOWAIT);
624 	if (ndp == NULL)
625 		return (NULL);
626 
627 	ndp->sfd_fn = fn;
628 	ndp->sfd_arg = arg;
629 	CIRCLEQ_INSERT_HEAD(&powerhook_list, ndp, sfd_list);
630 
631 	return (ndp);
632 }
633 
634 void
635 powerhook_disestablish(vhook)
636 	void *vhook;
637 {
638 #ifdef DIAGNOSTIC
639 	struct powerhook_desc *dp;
640 
641 	CIRCLEQ_FOREACH(dp, &powerhook_list, sfd_list)
642                 if (dp == vhook)
643 			goto found;
644 	panic("powerhook_disestablish: hook %p not established", vhook);
645  found:
646 #endif
647 
648 	CIRCLEQ_REMOVE(&powerhook_list, (struct powerhook_desc *)vhook,
649 	    sfd_list);
650 	free(vhook, M_DEVBUF);
651 }
652 
653 /*
654  * Run power hooks.
655  */
656 void
657 dopowerhooks(why)
658 	int why;
659 {
660 	struct powerhook_desc *dp;
661 
662 	if (why == PWR_RESUME || why == PWR_SOFTRESUME) {
663 		CIRCLEQ_FOREACH_REVERSE(dp, &powerhook_list, sfd_list) {
664 			(*dp->sfd_fn)(why, dp->sfd_arg);
665 		}
666 	} else {
667 		CIRCLEQ_FOREACH(dp, &powerhook_list, sfd_list) {
668 			(*dp->sfd_fn)(why, dp->sfd_arg);
669 		}
670 	}
671 }
672 
673 /*
674  * Determine the root device and, if instructed to, the root file system.
675  */
676 
677 #include "md.h"
678 #if NMD == 0
679 #undef MEMORY_DISK_HOOKS
680 #endif
681 
682 #ifdef MEMORY_DISK_HOOKS
683 static struct device fakemdrootdev[NMD];
684 #endif
685 
686 #include "raid.h"
687 #if NRAID == 1
688 #define BOOT_FROM_RAID_HOOKS 1
689 #endif
690 
691 #ifdef BOOT_FROM_RAID_HOOKS
692 extern int numraid;
693 extern struct device *raidrootdev;
694 #endif
695 
696 void
697 setroot(bootdv, bootpartition)
698 	struct device *bootdv;
699 	int bootpartition;
700 {
701 	struct device *dv;
702 	int len;
703 #ifdef MEMORY_DISK_HOOKS
704 	int i;
705 #endif
706 	dev_t nrootdev;
707 	dev_t ndumpdev = NODEV;
708 	char buf[128];
709 	const char *rootdevname;
710 	const char *dumpdevname;
711 	struct device *rootdv = NULL;		/* XXX gcc -Wuninitialized */
712 	struct device *dumpdv = NULL;
713 	struct ifnet *ifp;
714 	const char *deffsname;
715 	struct vfsops *vops;
716 
717 #ifdef MEMORY_DISK_HOOKS
718 	for (i = 0; i < NMD; i++) {
719 		fakemdrootdev[i].dv_class  = DV_DISK;
720 		fakemdrootdev[i].dv_cfdata = NULL;
721 		fakemdrootdev[i].dv_unit   = i;
722 		fakemdrootdev[i].dv_parent = NULL;
723 		sprintf(fakemdrootdev[i].dv_xname, "md%d", i);
724 	}
725 #endif /* MEMORY_DISK_HOOKS */
726 
727 #ifdef MEMORY_DISK_IS_ROOT
728 	bootdv = &fakemdrootdev[0];
729 	bootpartition = 0;
730 #endif
731 
732 	/*
733 	 * If NFS is specified as the file system, and we found
734 	 * a DV_DISK boot device (or no boot device at all), then
735 	 * find a reasonable network interface for "rootspec".
736 	 */
737 	vops = vfs_getopsbyname("nfs");
738 	if (vops != NULL && vops->vfs_mountroot == mountroot &&
739 	    rootspec == NULL &&
740 	    (bootdv == NULL || bootdv->dv_class != DV_IFNET)) {
741 		TAILQ_FOREACH(ifp, &ifnet, if_list) {
742 			if ((ifp->if_flags &
743 			     (IFF_LOOPBACK|IFF_POINTOPOINT)) == 0)
744 				break;
745 		}
746 		if (ifp == NULL) {
747 			/*
748 			 * Can't find a suitable interface; ask the
749 			 * user.
750 			 */
751 			boothowto |= RB_ASKNAME;
752 		} else {
753 			/*
754 			 * Have a suitable interface; behave as if
755 			 * the user specified this interface.
756 			 */
757 			rootspec = (const char *)ifp->if_xname;
758 		}
759 	}
760 
761 	/*
762 	 * If wildcarded root and we the boot device wasn't determined,
763 	 * ask the user.
764 	 */
765 	if (rootspec == NULL && bootdv == NULL)
766 		boothowto |= RB_ASKNAME;
767 
768  top:
769 	if (boothowto & RB_ASKNAME) {
770 		struct device *defdumpdv;
771 
772 		for (;;) {
773 			printf("root device");
774 			if (bootdv != NULL) {
775 				printf(" (default %s", bootdv->dv_xname);
776 				if (bootdv->dv_class == DV_DISK)
777 					printf("%c", bootpartition + 'a');
778 				printf(")");
779 			}
780 			printf(": ");
781 			len = cngetsn(buf, sizeof(buf));
782 			if (len == 0 && bootdv != NULL) {
783 				strcpy(buf, bootdv->dv_xname);
784 				len = strlen(buf);
785 			}
786 			if (len > 0 && buf[len - 1] == '*') {
787 				buf[--len] = '\0';
788 				dv = getdisk(buf, len, 1, &nrootdev, 0);
789 				if (dv != NULL) {
790 					rootdv = dv;
791 					break;
792 				}
793 			}
794 			dv = getdisk(buf, len, bootpartition, &nrootdev, 0);
795 			if (dv != NULL) {
796 				rootdv = dv;
797 				break;
798 			}
799 		}
800 
801 		/*
802 		 * Set up the default dump device.  If root is on
803 		 * a network device, there is no default dump
804 		 * device, since we don't support dumps to the
805 		 * network.
806 		 */
807 		if (rootdv->dv_class == DV_IFNET)
808 			defdumpdv = NULL;
809 		else
810 			defdumpdv = rootdv;
811 
812 		for (;;) {
813 			printf("dump device");
814 			if (defdumpdv != NULL) {
815 				/*
816 				 * Note, we know it's a disk if we get here.
817 				 */
818 				printf(" (default %sb)", defdumpdv->dv_xname);
819 			}
820 			printf(": ");
821 			len = cngetsn(buf, sizeof(buf));
822 			if (len == 0) {
823 				if (defdumpdv != NULL) {
824 					ndumpdev = MAKEDISKDEV(major(nrootdev),
825 					    DISKUNIT(nrootdev), 1);
826 				}
827 				dumpdv = defdumpdv;
828 				break;
829 			}
830 			if (len == 4 && strcmp(buf, "none") == 0) {
831 				dumpdv = NULL;
832 				break;
833 			}
834 			dv = getdisk(buf, len, 1, &ndumpdev, 1);
835 			if (dv != NULL) {
836 				dumpdv = dv;
837 				break;
838 			}
839 		}
840 
841 		rootdev = nrootdev;
842 		dumpdev = ndumpdev;
843 
844 		for (vops = LIST_FIRST(&vfs_list); vops != NULL;
845 		     vops = LIST_NEXT(vops, vfs_list)) {
846 			if (vops->vfs_mountroot != NULL &&
847 			    vops->vfs_mountroot == mountroot)
848 			break;
849 		}
850 
851 		if (vops == NULL) {
852 			mountroot = NULL;
853 			deffsname = "generic";
854 		} else
855 			deffsname = vops->vfs_name;
856 
857 		for (;;) {
858 			printf("file system (default %s): ", deffsname);
859 			len = cngetsn(buf, sizeof(buf));
860 			if (len == 0)
861 				break;
862 			if (len == 4 && strcmp(buf, "halt") == 0)
863 				cpu_reboot(RB_HALT, NULL);
864 			else if (len == 6 && strcmp(buf, "reboot") == 0)
865 				cpu_reboot(0, NULL);
866 #if defined(DDB)
867 			else if (len == 3 && strcmp(buf, "ddb") == 0) {
868 				console_debugger();
869 			}
870 #endif
871 			else if (len == 7 && strcmp(buf, "generic") == 0) {
872 				mountroot = NULL;
873 				break;
874 			}
875 			vops = vfs_getopsbyname(buf);
876 			if (vops == NULL || vops->vfs_mountroot == NULL) {
877 				printf("use one of: generic");
878 				for (vops = LIST_FIRST(&vfs_list);
879 				     vops != NULL;
880 				     vops = LIST_NEXT(vops, vfs_list)) {
881 					if (vops->vfs_mountroot != NULL)
882 						printf(" %s", vops->vfs_name);
883 				}
884 #if defined(DDB)
885 				printf(" ddb");
886 #endif
887 				printf(" halt reboot\n");
888 			} else {
889 				mountroot = vops->vfs_mountroot;
890 				break;
891 			}
892 		}
893 
894 	} else if (rootspec == NULL) {
895 		int majdev;
896 
897 		/*
898 		 * Wildcarded root; use the boot device.
899 		 */
900 		rootdv = bootdv;
901 
902 		majdev = devsw_name2blk(bootdv->dv_xname, NULL, 0);
903 		if (majdev >= 0) {
904 			/*
905 			 * Root is on a disk.  `bootpartition' is root.
906 			 */
907 			rootdev = MAKEDISKDEV(majdev, bootdv->dv_unit,
908 			    bootpartition);
909 		}
910 	} else {
911 
912 		/*
913 		 * `root on <dev> ...'
914 		 */
915 
916 		/*
917 		 * If it's a network interface, we can bail out
918 		 * early.
919 		 */
920 		dv = finddevice(rootspec);
921 		if (dv != NULL && dv->dv_class == DV_IFNET) {
922 			rootdv = dv;
923 			goto haveroot;
924 		}
925 
926 		rootdevname = devsw_blk2name(major(rootdev));
927 		if (rootdevname == NULL) {
928 			printf("unknown device major 0x%x\n", rootdev);
929 			boothowto |= RB_ASKNAME;
930 			goto top;
931 		}
932 		memset(buf, 0, sizeof(buf));
933 		sprintf(buf, "%s%d", rootdevname, DISKUNIT(rootdev));
934 
935 		rootdv = finddevice(buf);
936 		if (rootdv == NULL) {
937 			printf("device %s (0x%x) not configured\n",
938 			    buf, rootdev);
939 			boothowto |= RB_ASKNAME;
940 			goto top;
941 		}
942 	}
943 
944  haveroot:
945 
946 	root_device = rootdv;
947 
948 	switch (rootdv->dv_class) {
949 	case DV_IFNET:
950 		printf("root on %s", rootdv->dv_xname);
951 		break;
952 
953 	case DV_DISK:
954 		printf("root on %s%c", rootdv->dv_xname,
955 		    DISKPART(rootdev) + 'a');
956 		break;
957 
958 	default:
959 		printf("can't determine root device\n");
960 		boothowto |= RB_ASKNAME;
961 		goto top;
962 	}
963 
964 	/*
965 	 * Now configure the dump device.
966 	 *
967 	 * If we haven't figured out the dump device, do so, with
968 	 * the following rules:
969 	 *
970 	 *	(a) We already know dumpdv in the RB_ASKNAME case.
971 	 *
972 	 *	(b) If dumpspec is set, try to use it.  If the device
973 	 *	    is not available, punt.
974 	 *
975 	 *	(c) If dumpspec is not set, the dump device is
976 	 *	    wildcarded or unspecified.  If the root device
977 	 *	    is DV_IFNET, punt.  Otherwise, use partition b
978 	 *	    of the root device.
979 	 */
980 
981 	if (boothowto & RB_ASKNAME) {		/* (a) */
982 		if (dumpdv == NULL)
983 			goto nodumpdev;
984 	} else if (dumpspec != NULL) {		/* (b) */
985 		if (strcmp(dumpspec, "none") == 0 || dumpdev == NODEV) {
986 			/*
987 			 * Operator doesn't want a dump device.
988 			 * Or looks like they tried to pick a network
989 			 * device.  Oops.
990 			 */
991 			goto nodumpdev;
992 		}
993 
994 		dumpdevname = devsw_blk2name(major(dumpdev));
995 		if (dumpdevname == NULL)
996 			goto nodumpdev;
997 		memset(buf, 0, sizeof(buf));
998 		sprintf(buf, "%s%d", dumpdevname, DISKUNIT(dumpdev));
999 
1000 		dumpdv = finddevice(buf);
1001 		if (dumpdv == NULL) {
1002 			/*
1003 			 * Device not configured.
1004 			 */
1005 			goto nodumpdev;
1006 		}
1007 	} else {				/* (c) */
1008 		if (rootdv->dv_class == DV_IFNET)
1009 			goto nodumpdev;
1010 		else {
1011 			dumpdv = rootdv;
1012 			dumpdev = MAKEDISKDEV(major(rootdev),
1013 			    dumpdv->dv_unit, 1);
1014 		}
1015 	}
1016 
1017 	printf(" dumps on %s%c\n", dumpdv->dv_xname, DISKPART(dumpdev) + 'a');
1018 	return;
1019 
1020  nodumpdev:
1021 	dumpdev = NODEV;
1022 	printf("\n");
1023 }
1024 
1025 static struct device *
1026 finddevice(name)
1027 	const char *name;
1028 {
1029 	struct device *dv;
1030 #ifdef BOOT_FROM_RAID_HOOKS
1031 	int j;
1032 
1033 	for (j = 0; j < numraid; j++) {
1034 		if (strcmp(name, raidrootdev[j].dv_xname) == 0) {
1035 			dv = &raidrootdev[j];
1036 			return (dv);
1037 		}
1038 	}
1039 #endif
1040 
1041 	for (dv = TAILQ_FIRST(&alldevs); dv != NULL;
1042 	    dv = TAILQ_NEXT(dv, dv_list))
1043 		if (strcmp(dv->dv_xname, name) == 0)
1044 			break;
1045 	return (dv);
1046 }
1047 
1048 static struct device *
1049 getdisk(str, len, defpart, devp, isdump)
1050 	char *str;
1051 	int len, defpart;
1052 	dev_t *devp;
1053 	int isdump;
1054 {
1055 	struct device	*dv;
1056 #ifdef MEMORY_DISK_HOOKS
1057 	int		i;
1058 #endif
1059 #ifdef BOOT_FROM_RAID_HOOKS
1060 	int 		j;
1061 #endif
1062 
1063 	if ((dv = parsedisk(str, len, defpart, devp)) == NULL) {
1064 		printf("use one of:");
1065 #ifdef MEMORY_DISK_HOOKS
1066 		if (isdump == 0)
1067 			for (i = 0; i < NMD; i++)
1068 				printf(" %s[a-%c]", fakemdrootdev[i].dv_xname,
1069 				    'a' + MAXPARTITIONS - 1);
1070 #endif
1071 #ifdef BOOT_FROM_RAID_HOOKS
1072 		if (isdump == 0)
1073 			for (j = 0; j < numraid; j++)
1074 				printf(" %s[a-%c]", raidrootdev[j].dv_xname,
1075 				    'a' + MAXPARTITIONS - 1);
1076 #endif
1077 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
1078 			if (dv->dv_class == DV_DISK)
1079 				printf(" %s[a-%c]", dv->dv_xname,
1080 				    'a' + MAXPARTITIONS - 1);
1081 			if (isdump == 0 && dv->dv_class == DV_IFNET)
1082 				printf(" %s", dv->dv_xname);
1083 		}
1084 		if (isdump)
1085 			printf(" none");
1086 #if defined(DDB)
1087 		printf(" ddb");
1088 #endif
1089 		printf(" halt reboot\n");
1090 	}
1091 	return (dv);
1092 }
1093 
1094 static struct device *
1095 parsedisk(str, len, defpart, devp)
1096 	char *str;
1097 	int len, defpart;
1098 	dev_t *devp;
1099 {
1100 	struct device *dv;
1101 	char *cp, c;
1102 	int majdev, part;
1103 #ifdef MEMORY_DISK_HOOKS
1104 	int i;
1105 #endif
1106 	if (len == 0)
1107 		return (NULL);
1108 
1109 	if (len == 4 && strcmp(str, "halt") == 0)
1110 		cpu_reboot(RB_HALT, NULL);
1111 	else if (len == 6 && strcmp(str, "reboot") == 0)
1112 		cpu_reboot(0, NULL);
1113 #if defined(DDB)
1114 	else if (len == 3 && strcmp(str, "ddb") == 0)
1115 		console_debugger();
1116 #endif
1117 
1118 	cp = str + len - 1;
1119 	c = *cp;
1120 	if (c >= 'a' && c <= ('a' + MAXPARTITIONS - 1)) {
1121 		part = c - 'a';
1122 		*cp = '\0';
1123 	} else
1124 		part = defpart;
1125 
1126 #ifdef MEMORY_DISK_HOOKS
1127 	for (i = 0; i < NMD; i++)
1128 		if (strcmp(str, fakemdrootdev[i].dv_xname) == 0) {
1129 			dv = &fakemdrootdev[i];
1130 			goto gotdisk;
1131 		}
1132 #endif
1133 
1134 	dv = finddevice(str);
1135 	if (dv != NULL) {
1136 		if (dv->dv_class == DV_DISK) {
1137 #ifdef MEMORY_DISK_HOOKS
1138  gotdisk:
1139 #endif
1140 			majdev = devsw_name2blk(dv->dv_xname, NULL, 0);
1141 			if (majdev < 0)
1142 				panic("parsedisk");
1143 			*devp = MAKEDISKDEV(majdev, dv->dv_unit, part);
1144 		}
1145 
1146 		if (dv->dv_class == DV_IFNET)
1147 			*devp = NODEV;
1148 	}
1149 
1150 	*cp = c;
1151 	return (dv);
1152 }
1153 
1154 /*
1155  * snprintf() `bytes' into `buf', reformatting it so that the number,
1156  * plus a possible `x' + suffix extension) fits into len bytes (including
1157  * the terminating NUL).
1158  * Returns the number of bytes stored in buf, or -1 if there was a problem.
1159  * E.g, given a len of 9 and a suffix of `B':
1160  *	bytes		result
1161  *	-----		------
1162  *	99999		`99999 B'
1163  *	100000		`97 kB'
1164  *	66715648	`65152 kB'
1165  *	252215296	`240 MB'
1166  */
1167 int
1168 humanize_number(buf, len, bytes, suffix, divisor)
1169 	char		*buf;
1170 	size_t		 len;
1171 	u_int64_t	 bytes;
1172 	const char	*suffix;
1173 	int 		divisor;
1174 {
1175        	/* prefixes are: (none), kilo, Mega, Giga, Tera, Peta, Exa */
1176 	const char *prefixes;
1177 	int		r;
1178 	u_int64_t	max;
1179 	size_t		i, suffixlen;
1180 
1181 	if (buf == NULL || suffix == NULL)
1182 		return (-1);
1183 	if (len > 0)
1184 		buf[0] = '\0';
1185 	suffixlen = strlen(suffix);
1186 	/* check if enough room for `x y' + suffix + `\0' */
1187 	if (len < 4 + suffixlen)
1188 		return (-1);
1189 
1190 	if (divisor == 1024) {
1191 		/*
1192 		 * binary multiplies
1193 		 * XXX IEC 60027-2 recommends Ki, Mi, Gi...
1194 		 */
1195 		prefixes = " KMGTPE";
1196 	} else
1197 		prefixes = " kMGTPE"; /* SI for decimal multiplies */
1198 
1199 	max = 1;
1200 	for (i = 0; i < len - suffixlen - 3; i++)
1201 		max *= 10;
1202 	for (i = 0; bytes >= max && prefixes[i + 1]; i++)
1203 		bytes /= divisor;
1204 
1205 	r = snprintf(buf, len, "%qu%s%c%s", (unsigned long long)bytes,
1206 	    i == 0 ? "" : " ", prefixes[i], suffix);
1207 
1208 	return (r);
1209 }
1210 
1211 int
1212 format_bytes(buf, len, bytes)
1213 	char		*buf;
1214 	size_t		 len;
1215 	u_int64_t	 bytes;
1216 {
1217 	int	rv;
1218 	size_t	nlen;
1219 
1220 	rv = humanize_number(buf, len, bytes, "B", 1024);
1221 	if (rv != -1) {
1222 			/* nuke the trailing ` B' if it exists */
1223 		nlen = strlen(buf) - 2;
1224 		if (strcmp(&buf[nlen], " B") == 0)
1225 			buf[nlen] = '\0';
1226 	}
1227 	return (rv);
1228 }
1229 
1230 /*
1231  * Start trace of particular system call. If process is being traced,
1232  * this routine is called by MD syscall dispatch code just before
1233  * a system call is actually executed.
1234  * MD caller guarantees the passed 'code' is within the supported
1235  * system call number range for emulation the process runs under.
1236  */
1237 int
1238 trace_enter(struct proc *p, register_t code,
1239 	register_t realcode, void *args, register_t rval[])
1240 {
1241 #ifdef SYSCALL_DEBUG
1242 	scdebug_call(p, code, args);
1243 #endif /* SYSCALL_DEBUG */
1244 
1245 #ifdef KTRACE
1246 	if (KTRPOINT(p, KTR_SYSCALL))
1247 		ktrsyscall(p, code, realcode, args);
1248 #endif /* KTRACE */
1249 
1250 #ifdef SYSTRACE
1251 	if (ISSET(p->p_flag, P_SYSTRACE))
1252 		return systrace_enter(p, code, args, rval);
1253 #endif
1254 	return 0;
1255 }
1256 
1257 /*
1258  * End trace of particular system call. If process is being traced,
1259  * this routine is called by MD syscall dispatch code just after
1260  * a system call finishes.
1261  * MD caller guarantees the passed 'code' is within the supported
1262  * system call number range for emulation the process runs under.
1263  */
1264 void
1265 trace_exit(struct proc *p, register_t code, void *args, register_t rval[],
1266     int error)
1267 {
1268 #ifdef SYSCALL_DEBUG
1269 	scdebug_ret(p, code, error, rval);
1270 #endif /* SYSCALL_DEBUG */
1271 
1272 #ifdef KTRACE
1273 	if (KTRPOINT(p, KTR_SYSRET)) {
1274 		KERNEL_PROC_LOCK(p);
1275 		ktrsysret(p, code, error, rval[0]);
1276 		KERNEL_PROC_UNLOCK(p);
1277 	}
1278 #endif /* KTRACE */
1279 
1280 #ifdef SYSTRACE
1281 	if (ISSET(p->p_flag, P_SYSTRACE))
1282 		systrace_exit(p, code, args, rval, error);
1283 #endif
1284 }
1285