xref: /netbsd-src/sys/kern/kern_subr.c (revision ce2c90c7c172d95d2402a5b3d96d8f8e6d138a21)
1 /*	$NetBSD: kern_subr.c,v 1.148 2006/10/13 16:53:36 dogcow 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. Neither the name of the University nor the names of its contributors
70  *    may be used to endorse or promote products derived from this software
71  *    without specific prior written permission.
72  *
73  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
74  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
75  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
76  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
77  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
78  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
79  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
80  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
81  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
82  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
83  * SUCH DAMAGE.
84  *
85  *	@(#)kern_subr.c	8.4 (Berkeley) 2/14/95
86  */
87 
88 #include <sys/cdefs.h>
89 __KERNEL_RCSID(0, "$NetBSD: kern_subr.c,v 1.148 2006/10/13 16:53:36 dogcow Exp $");
90 
91 #include "opt_ddb.h"
92 #include "opt_md.h"
93 #include "opt_syscall_debug.h"
94 #include "opt_ktrace.h"
95 #include "opt_ptrace.h"
96 #include "opt_systrace.h"
97 #include "opt_powerhook.h"
98 
99 #include <sys/param.h>
100 #include <sys/systm.h>
101 #include <sys/proc.h>
102 #include <sys/malloc.h>
103 #include <sys/mount.h>
104 #include <sys/device.h>
105 #include <sys/reboot.h>
106 #include <sys/conf.h>
107 #include <sys/disklabel.h>
108 #include <sys/queue.h>
109 #include <sys/systrace.h>
110 #include <sys/ktrace.h>
111 #include <sys/ptrace.h>
112 #include <sys/fcntl.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(const char *);
122 static struct device *getdisk(char *, int, int, dev_t *, int);
123 static struct device *parsedisk(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)(void *);
131 	void	*hk_arg;
132 };
133 typedef LIST_HEAD(, hook_desc) hook_list_t;
134 
135 MALLOC_DEFINE(M_IOV, "iov", "large iov's");
136 
137 void
138 uio_setup_sysspace(struct uio *uio)
139 {
140 
141 	uio->uio_vmspace = vmspace_kernel();
142 }
143 
144 int
145 uiomove(void *buf, size_t n, struct uio *uio)
146 {
147 	struct vmspace *vm = uio->uio_vmspace;
148 	struct iovec *iov;
149 	u_int cnt;
150 	int error = 0;
151 	char *cp = buf;
152 	int hold_count;
153 
154 	hold_count = KERNEL_LOCK_RELEASE_ALL();
155 
156 	ASSERT_SLEEPABLE(NULL, "uiomove");
157 
158 #ifdef DIAGNOSTIC
159 	if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE)
160 		panic("uiomove: mode");
161 #endif
162 	while (n > 0 && uio->uio_resid) {
163 		iov = uio->uio_iov;
164 		cnt = iov->iov_len;
165 		if (cnt == 0) {
166 			KASSERT(uio->uio_iovcnt > 0);
167 			uio->uio_iov++;
168 			uio->uio_iovcnt--;
169 			continue;
170 		}
171 		if (cnt > n)
172 			cnt = n;
173 		if (!VMSPACE_IS_KERNEL_P(vm)) {
174 			if (curcpu()->ci_schedstate.spc_flags &
175 			    SPCF_SHOULDYIELD)
176 				preempt(1);
177 		}
178 
179 		if (uio->uio_rw == UIO_READ) {
180 			error = copyout_vmspace(vm, cp, iov->iov_base,
181 			    cnt);
182 		} else {
183 			error = copyin_vmspace(vm, iov->iov_base, cp,
184 			    cnt);
185 		}
186 		if (error) {
187 			break;
188 		}
189 		iov->iov_base = (caddr_t)iov->iov_base + cnt;
190 		iov->iov_len -= cnt;
191 		uio->uio_resid -= cnt;
192 		uio->uio_offset += cnt;
193 		cp += cnt;
194 		KDASSERT(cnt <= n);
195 		n -= cnt;
196 	}
197 	KERNEL_LOCK_ACQUIRE_COUNT(hold_count);
198 	return (error);
199 }
200 
201 /*
202  * Wrapper for uiomove() that validates the arguments against a known-good
203  * kernel buffer.
204  */
205 int
206 uiomove_frombuf(void *buf, size_t buflen, struct uio *uio)
207 {
208 	size_t offset;
209 
210 	if (uio->uio_offset < 0 || /* uio->uio_resid < 0 || */
211 	    (offset = uio->uio_offset) != uio->uio_offset)
212 		return (EINVAL);
213 	if (offset >= buflen)
214 		return (0);
215 	return (uiomove((char *)buf + offset, buflen - offset, uio));
216 }
217 
218 /*
219  * Give next character to user as result of read.
220  */
221 int
222 ureadc(int c, struct uio *uio)
223 {
224 	struct iovec *iov;
225 
226 	if (uio->uio_resid <= 0)
227 		panic("ureadc: non-positive resid");
228 again:
229 	if (uio->uio_iovcnt <= 0)
230 		panic("ureadc: non-positive iovcnt");
231 	iov = uio->uio_iov;
232 	if (iov->iov_len <= 0) {
233 		uio->uio_iovcnt--;
234 		uio->uio_iov++;
235 		goto again;
236 	}
237 	if (!VMSPACE_IS_KERNEL_P(uio->uio_vmspace)) {
238 		if (subyte(iov->iov_base, c) < 0)
239 			return (EFAULT);
240 	} else {
241 		*(char *)iov->iov_base = c;
242 	}
243 	iov->iov_base = (caddr_t)iov->iov_base + 1;
244 	iov->iov_len--;
245 	uio->uio_resid--;
246 	uio->uio_offset++;
247 	return (0);
248 }
249 
250 /*
251  * Like copyin(), but operates on an arbitrary vmspace.
252  */
253 int
254 copyin_vmspace(struct vmspace *vm, const void *uaddr, void *kaddr, size_t len)
255 {
256 	struct iovec iov;
257 	struct uio uio;
258 	int error;
259 
260 	if (len == 0)
261 		return (0);
262 
263 	if (VMSPACE_IS_KERNEL_P(vm)) {
264 		return kcopy(uaddr, kaddr, len);
265 	}
266 	if (__predict_true(vm == curproc->p_vmspace)) {
267 		return copyin(uaddr, kaddr, len);
268 	}
269 
270 	iov.iov_base = kaddr;
271 	iov.iov_len = len;
272 	uio.uio_iov = &iov;
273 	uio.uio_iovcnt = 1;
274 	uio.uio_offset = (off_t)(intptr_t)uaddr;
275 	uio.uio_resid = len;
276 	uio.uio_rw = UIO_READ;
277 	UIO_SETUP_SYSSPACE(&uio);
278 	error = uvm_io(&vm->vm_map, &uio);
279 
280 	return (error);
281 }
282 
283 /*
284  * Like copyout(), but operates on an arbitrary vmspace.
285  */
286 int
287 copyout_vmspace(struct vmspace *vm, const void *kaddr, void *uaddr, size_t len)
288 {
289 	struct iovec iov;
290 	struct uio uio;
291 	int error;
292 
293 	if (len == 0)
294 		return (0);
295 
296 	if (VMSPACE_IS_KERNEL_P(vm)) {
297 		return kcopy(kaddr, uaddr, len);
298 	}
299 	if (__predict_true(vm == curproc->p_vmspace)) {
300 		return copyout(kaddr, uaddr, len);
301 	}
302 
303 	iov.iov_base = __UNCONST(kaddr); /* XXXUNCONST cast away const */
304 	iov.iov_len = len;
305 	uio.uio_iov = &iov;
306 	uio.uio_iovcnt = 1;
307 	uio.uio_offset = (off_t)(intptr_t)uaddr;
308 	uio.uio_resid = len;
309 	uio.uio_rw = UIO_WRITE;
310 	UIO_SETUP_SYSSPACE(&uio);
311 	error = uvm_io(&vm->vm_map, &uio);
312 
313 	return (error);
314 }
315 
316 /*
317  * Like copyin(), but operates on an arbitrary process.
318  */
319 int
320 copyin_proc(struct proc *p, const void *uaddr, void *kaddr, size_t len)
321 {
322 	struct vmspace *vm;
323 	int error;
324 
325 	error = proc_vmspace_getref(p, &vm);
326 	if (error) {
327 		return error;
328 	}
329 	error = copyin_vmspace(vm, uaddr, kaddr, len);
330 	uvmspace_free(vm);
331 
332 	return error;
333 }
334 
335 /*
336  * Like copyout(), but operates on an arbitrary process.
337  */
338 int
339 copyout_proc(struct proc *p, const void *kaddr, void *uaddr, size_t len)
340 {
341 	struct vmspace *vm;
342 	int error;
343 
344 	error = proc_vmspace_getref(p, &vm);
345 	if (error) {
346 		return error;
347 	}
348 	error = copyout_vmspace(vm, kaddr, uaddr, len);
349 	uvmspace_free(vm);
350 
351 	return error;
352 }
353 
354 /*
355  * Like copyin(), except it operates on kernel addresses when the FKIOCTL
356  * flag is passed in `ioctlflags' from the ioctl call.
357  */
358 int
359 ioctl_copyin(int ioctlflags, const void *src, void *dst, size_t len)
360 {
361 	if (ioctlflags & FKIOCTL)
362 		return kcopy(src, dst, len);
363 	return copyin(src, dst, len);
364 }
365 
366 /*
367  * Like copyout(), except it operates on kernel addresses when the FKIOCTL
368  * flag is passed in `ioctlflags' from the ioctl call.
369  */
370 int
371 ioctl_copyout(int ioctlflags, const void *src, void *dst, size_t len)
372 {
373 	if (ioctlflags & FKIOCTL)
374 		return kcopy(src, dst, len);
375 	return copyout(src, dst, len);
376 }
377 
378 /*
379  * General routine to allocate a hash table.
380  * Allocate enough memory to hold at least `elements' list-head pointers.
381  * Return a pointer to the allocated space and set *hashmask to a pattern
382  * suitable for masking a value to use as an index into the returned array.
383  */
384 void *
385 hashinit(u_int elements, enum hashtype htype, struct malloc_type *mtype,
386     int mflags, u_long *hashmask)
387 {
388 	u_long hashsize, i;
389 	LIST_HEAD(, generic) *hashtbl_list;
390 	TAILQ_HEAD(, generic) *hashtbl_tailq;
391 	size_t esize;
392 	void *p;
393 
394 	if (elements == 0)
395 		panic("hashinit: bad cnt");
396 	for (hashsize = 1; hashsize < elements; hashsize <<= 1)
397 		continue;
398 
399 	switch (htype) {
400 	case HASH_LIST:
401 		esize = sizeof(*hashtbl_list);
402 		break;
403 	case HASH_TAILQ:
404 		esize = sizeof(*hashtbl_tailq);
405 		break;
406 	default:
407 #ifdef DIAGNOSTIC
408 		panic("hashinit: invalid table type");
409 #else
410 		return NULL;
411 #endif
412 	}
413 
414 	if ((p = malloc(hashsize * esize, mtype, mflags)) == NULL)
415 		return (NULL);
416 
417 	switch (htype) {
418 	case HASH_LIST:
419 		hashtbl_list = p;
420 		for (i = 0; i < hashsize; i++)
421 			LIST_INIT(&hashtbl_list[i]);
422 		break;
423 	case HASH_TAILQ:
424 		hashtbl_tailq = p;
425 		for (i = 0; i < hashsize; i++)
426 			TAILQ_INIT(&hashtbl_tailq[i]);
427 		break;
428 	}
429 	*hashmask = hashsize - 1;
430 	return (p);
431 }
432 
433 /*
434  * Free memory from hash table previosly allocated via hashinit().
435  */
436 void
437 hashdone(void *hashtbl, struct malloc_type *mtype)
438 {
439 
440 	free(hashtbl, mtype);
441 }
442 
443 
444 static void *
445 hook_establish(hook_list_t *list, void (*fn)(void *), void *arg)
446 {
447 	struct hook_desc *hd;
448 
449 	hd = malloc(sizeof(*hd), M_DEVBUF, M_NOWAIT);
450 	if (hd == NULL)
451 		return (NULL);
452 
453 	hd->hk_fn = fn;
454 	hd->hk_arg = arg;
455 	LIST_INSERT_HEAD(list, hd, hk_list);
456 
457 	return (hd);
458 }
459 
460 static void
461 hook_disestablish(hook_list_t *list __unused, void *vhook)
462 {
463 #ifdef DIAGNOSTIC
464 	struct hook_desc *hd;
465 
466 	LIST_FOREACH(hd, list, hk_list) {
467                 if (hd == vhook)
468 			break;
469 	}
470 
471 	if (hd == NULL)
472 		panic("hook_disestablish: hook %p not established", vhook);
473 #endif
474 	LIST_REMOVE((struct hook_desc *)vhook, hk_list);
475 	free(vhook, M_DEVBUF);
476 }
477 
478 static void
479 hook_destroy(hook_list_t *list)
480 {
481 	struct hook_desc *hd;
482 
483 	while ((hd = LIST_FIRST(list)) != NULL) {
484 		LIST_REMOVE(hd, hk_list);
485 		free(hd, M_DEVBUF);
486 	}
487 }
488 
489 static void
490 hook_proc_run(hook_list_t *list, struct proc *p)
491 {
492 	struct hook_desc *hd;
493 
494 	for (hd = LIST_FIRST(list); hd != NULL; hd = LIST_NEXT(hd, hk_list)) {
495 		((void (*)(struct proc *, void *))*hd->hk_fn)(p,
496 		    hd->hk_arg);
497 	}
498 }
499 
500 /*
501  * "Shutdown hook" types, functions, and variables.
502  *
503  * Should be invoked immediately before the
504  * system is halted or rebooted, i.e. after file systems unmounted,
505  * after crash dump done, etc.
506  *
507  * Each shutdown hook is removed from the list before it's run, so that
508  * it won't be run again.
509  */
510 
511 static hook_list_t shutdownhook_list;
512 
513 void *
514 shutdownhook_establish(void (*fn)(void *), void *arg)
515 {
516 	return hook_establish(&shutdownhook_list, fn, arg);
517 }
518 
519 void
520 shutdownhook_disestablish(void *vhook)
521 {
522 	hook_disestablish(&shutdownhook_list, vhook);
523 }
524 
525 /*
526  * Run shutdown hooks.  Should be invoked immediately before the
527  * system is halted or rebooted, i.e. after file systems unmounted,
528  * after crash dump done, etc.
529  *
530  * Each shutdown hook is removed from the list before it's run, so that
531  * it won't be run again.
532  */
533 void
534 doshutdownhooks(void)
535 {
536 	struct hook_desc *dp;
537 
538 	while ((dp = LIST_FIRST(&shutdownhook_list)) != NULL) {
539 		LIST_REMOVE(dp, hk_list);
540 		(*dp->hk_fn)(dp->hk_arg);
541 #if 0
542 		/*
543 		 * Don't bother freeing the hook structure,, since we may
544 		 * be rebooting because of a memory corruption problem,
545 		 * and this might only make things worse.  It doesn't
546 		 * matter, anyway, since the system is just about to
547 		 * reboot.
548 		 */
549 		free(dp, M_DEVBUF);
550 #endif
551 	}
552 }
553 
554 /*
555  * "Mountroot hook" types, functions, and variables.
556  */
557 
558 static hook_list_t mountroothook_list;
559 
560 void *
561 mountroothook_establish(void (*fn)(struct device *), struct device *dev)
562 {
563 	return hook_establish(&mountroothook_list, (void (*)(void *))fn, dev);
564 }
565 
566 void
567 mountroothook_disestablish(void *vhook)
568 {
569 	hook_disestablish(&mountroothook_list, vhook);
570 }
571 
572 void
573 mountroothook_destroy(void)
574 {
575 	hook_destroy(&mountroothook_list);
576 }
577 
578 void
579 domountroothook(void)
580 {
581 	struct hook_desc *hd;
582 
583 	LIST_FOREACH(hd, &mountroothook_list, hk_list) {
584 		if (hd->hk_arg == (void *)root_device) {
585 			(*hd->hk_fn)(hd->hk_arg);
586 			return;
587 		}
588 	}
589 }
590 
591 static hook_list_t exechook_list;
592 
593 void *
594 exechook_establish(void (*fn)(struct proc *, void *), void *arg)
595 {
596 	return hook_establish(&exechook_list, (void (*)(void *))fn, arg);
597 }
598 
599 void
600 exechook_disestablish(void *vhook)
601 {
602 	hook_disestablish(&exechook_list, vhook);
603 }
604 
605 /*
606  * Run exec hooks.
607  */
608 void
609 doexechooks(struct proc *p)
610 {
611 	hook_proc_run(&exechook_list, p);
612 }
613 
614 static hook_list_t exithook_list;
615 
616 void *
617 exithook_establish(void (*fn)(struct proc *, void *), void *arg)
618 {
619 	return hook_establish(&exithook_list, (void (*)(void *))fn, arg);
620 }
621 
622 void
623 exithook_disestablish(void *vhook)
624 {
625 	hook_disestablish(&exithook_list, vhook);
626 }
627 
628 /*
629  * Run exit hooks.
630  */
631 void
632 doexithooks(struct proc *p)
633 {
634 	hook_proc_run(&exithook_list, p);
635 }
636 
637 static hook_list_t forkhook_list;
638 
639 void *
640 forkhook_establish(void (*fn)(struct proc *, struct proc *))
641 {
642 	return hook_establish(&forkhook_list, (void (*)(void *))fn, NULL);
643 }
644 
645 void
646 forkhook_disestablish(void *vhook)
647 {
648 	hook_disestablish(&forkhook_list, vhook);
649 }
650 
651 /*
652  * Run fork hooks.
653  */
654 void
655 doforkhooks(struct proc *p2, struct proc *p1)
656 {
657 	struct hook_desc *hd;
658 
659 	LIST_FOREACH(hd, &forkhook_list, hk_list) {
660 		((void (*)(struct proc *, struct proc *))*hd->hk_fn)
661 		    (p2, p1);
662 	}
663 }
664 
665 /*
666  * "Power hook" types, functions, and variables.
667  * The list of power hooks is kept ordered with the last registered hook
668  * first.
669  * When running the hooks on power down the hooks are called in reverse
670  * registration order, when powering up in registration order.
671  */
672 struct powerhook_desc {
673 	CIRCLEQ_ENTRY(powerhook_desc) sfd_list;
674 	void	(*sfd_fn)(int, void *);
675 	void	*sfd_arg;
676 	char	sfd_name[16];
677 };
678 
679 static CIRCLEQ_HEAD(, powerhook_desc) powerhook_list =
680     CIRCLEQ_HEAD_INITIALIZER(powerhook_list);
681 
682 void *
683 powerhook_establish(const char *name, void (*fn)(int, void *), void *arg)
684 {
685 	struct powerhook_desc *ndp;
686 
687 	ndp = (struct powerhook_desc *)
688 	    malloc(sizeof(*ndp), M_DEVBUF, M_NOWAIT);
689 	if (ndp == NULL)
690 		return (NULL);
691 
692 	ndp->sfd_fn = fn;
693 	ndp->sfd_arg = arg;
694 	strlcpy(ndp->sfd_name, name, sizeof(ndp->sfd_name));
695 	CIRCLEQ_INSERT_HEAD(&powerhook_list, ndp, sfd_list);
696 
697 	return (ndp);
698 }
699 
700 void
701 powerhook_disestablish(void *vhook)
702 {
703 #ifdef DIAGNOSTIC
704 	struct powerhook_desc *dp;
705 
706 	CIRCLEQ_FOREACH(dp, &powerhook_list, sfd_list)
707                 if (dp == vhook)
708 			goto found;
709 	panic("powerhook_disestablish: hook %p not established", vhook);
710  found:
711 #endif
712 
713 	CIRCLEQ_REMOVE(&powerhook_list, (struct powerhook_desc *)vhook,
714 	    sfd_list);
715 	free(vhook, M_DEVBUF);
716 }
717 
718 /*
719  * Run power hooks.
720  */
721 void
722 dopowerhooks(int why)
723 {
724 	struct powerhook_desc *dp;
725 
726 #ifdef POWERHOOK_DEBUG
727 	printf("dopowerhooks ");
728 	switch (why) {
729 	case PWR_RESUME:
730 		printf("resume");
731 		break;
732 	case PWR_SOFTRESUME:
733 		printf("softresume");
734 		break;
735 	case PWR_SUSPEND:
736 		printf("suspend");
737 		break;
738 	case PWR_SOFTSUSPEND:
739 		printf("softsuspend");
740 		break;
741 	case PWR_STANDBY:
742 		printf("standby");
743 		break;
744 	}
745 	printf(":");
746 #endif
747 
748 	if (why == PWR_RESUME || why == PWR_SOFTRESUME) {
749 		CIRCLEQ_FOREACH_REVERSE(dp, &powerhook_list, sfd_list) {
750 #ifdef POWERHOOK_DEBUG
751 			printf(" %s", dp->sfd_name);
752 #endif
753 			(*dp->sfd_fn)(why, dp->sfd_arg);
754 		}
755 	} else {
756 		CIRCLEQ_FOREACH(dp, &powerhook_list, sfd_list) {
757 #ifdef POWERHOOK_DEBUG
758 			printf(" %s", dp->sfd_name);
759 #endif
760 			(*dp->sfd_fn)(why, dp->sfd_arg);
761 		}
762 	}
763 
764 #ifdef POWERHOOK_DEBUG
765 	printf(".\n");
766 #endif
767 }
768 
769 /*
770  * Determine the root device and, if instructed to, the root file system.
771  */
772 
773 #include "md.h"
774 #if NMD == 0
775 #undef MEMORY_DISK_HOOKS
776 #endif
777 
778 #ifdef MEMORY_DISK_HOOKS
779 static struct device fakemdrootdev[NMD];
780 extern struct cfdriver md_cd;
781 #endif
782 
783 #ifdef MEMORY_DISK_IS_ROOT
784 #define BOOT_FROM_MEMORY_HOOKS 1
785 #endif
786 
787 /*
788  * The device and wedge that we booted from.  If booted_wedge is NULL,
789  * the we might consult booted_partition.
790  */
791 struct device *booted_device;
792 struct device *booted_wedge;
793 int booted_partition;
794 
795 /*
796  * Use partition letters if it's a disk class but not a wedge.
797  * XXX Check for wedge is kinda gross.
798  */
799 #define	DEV_USES_PARTITIONS(dv)						\
800 	(device_class((dv)) == DV_DISK &&				\
801 	 !device_is_a((dv), "dk"))
802 
803 void
804 setroot(struct device *bootdv, int bootpartition)
805 {
806 	struct device *dv;
807 	int len;
808 #ifdef MEMORY_DISK_HOOKS
809 	int i;
810 #endif
811 	dev_t nrootdev;
812 	dev_t ndumpdev = NODEV;
813 	char buf[128];
814 	const char *rootdevname;
815 	const char *dumpdevname;
816 	struct device *rootdv = NULL;		/* XXX gcc -Wuninitialized */
817 	struct device *dumpdv = NULL;
818 	struct ifnet *ifp;
819 	const char *deffsname;
820 	struct vfsops *vops;
821 
822 #ifdef MEMORY_DISK_HOOKS
823 	for (i = 0; i < NMD; i++) {
824 		fakemdrootdev[i].dv_class  = DV_DISK;
825 		fakemdrootdev[i].dv_cfdata = NULL;
826 		fakemdrootdev[i].dv_cfdriver = &md_cd;
827 		fakemdrootdev[i].dv_unit   = i;
828 		fakemdrootdev[i].dv_parent = NULL;
829 		snprintf(fakemdrootdev[i].dv_xname,
830 		    sizeof(fakemdrootdev[i].dv_xname), "md%d", i);
831 	}
832 #endif /* MEMORY_DISK_HOOKS */
833 
834 #ifdef MEMORY_DISK_IS_ROOT
835 	bootdv = &fakemdrootdev[0];
836 	bootpartition = 0;
837 #endif
838 
839 	/*
840 	 * If NFS is specified as the file system, and we found
841 	 * a DV_DISK boot device (or no boot device at all), then
842 	 * find a reasonable network interface for "rootspec".
843 	 */
844 	vops = vfs_getopsbyname("nfs");
845 	if (vops != NULL && vops->vfs_mountroot == mountroot &&
846 	    rootspec == NULL &&
847 	    (bootdv == NULL || device_class(bootdv) != DV_IFNET)) {
848 		IFNET_FOREACH(ifp) {
849 			if ((ifp->if_flags &
850 			     (IFF_LOOPBACK|IFF_POINTOPOINT)) == 0)
851 				break;
852 		}
853 		if (ifp == NULL) {
854 			/*
855 			 * Can't find a suitable interface; ask the
856 			 * user.
857 			 */
858 			boothowto |= RB_ASKNAME;
859 		} else {
860 			/*
861 			 * Have a suitable interface; behave as if
862 			 * the user specified this interface.
863 			 */
864 			rootspec = (const char *)ifp->if_xname;
865 		}
866 	}
867 
868 	/*
869 	 * If wildcarded root and we the boot device wasn't determined,
870 	 * ask the user.
871 	 */
872 	if (rootspec == NULL && bootdv == NULL)
873 		boothowto |= RB_ASKNAME;
874 
875  top:
876 	if (boothowto & RB_ASKNAME) {
877 		struct device *defdumpdv;
878 
879 		for (;;) {
880 			printf("root device");
881 			if (bootdv != NULL) {
882 				printf(" (default %s", bootdv->dv_xname);
883 				if (DEV_USES_PARTITIONS(bootdv))
884 					printf("%c", bootpartition + 'a');
885 				printf(")");
886 			}
887 			printf(": ");
888 			len = cngetsn(buf, sizeof(buf));
889 			if (len == 0 && bootdv != NULL) {
890 				strlcpy(buf, bootdv->dv_xname, sizeof(buf));
891 				len = strlen(buf);
892 			}
893 			if (len > 0 && buf[len - 1] == '*') {
894 				buf[--len] = '\0';
895 				dv = getdisk(buf, len, 1, &nrootdev, 0);
896 				if (dv != NULL) {
897 					rootdv = dv;
898 					break;
899 				}
900 			}
901 			dv = getdisk(buf, len, bootpartition, &nrootdev, 0);
902 			if (dv != NULL) {
903 				rootdv = dv;
904 				break;
905 			}
906 		}
907 
908 		/*
909 		 * Set up the default dump device.  If root is on
910 		 * a network device, there is no default dump
911 		 * device, since we don't support dumps to the
912 		 * network.
913 		 */
914 		if (DEV_USES_PARTITIONS(rootdv) == 0)
915 			defdumpdv = NULL;
916 		else
917 			defdumpdv = rootdv;
918 
919 		for (;;) {
920 			printf("dump device");
921 			if (defdumpdv != NULL) {
922 				/*
923 				 * Note, we know it's a disk if we get here.
924 				 */
925 				printf(" (default %sb)", defdumpdv->dv_xname);
926 			}
927 			printf(": ");
928 			len = cngetsn(buf, sizeof(buf));
929 			if (len == 0) {
930 				if (defdumpdv != NULL) {
931 					ndumpdev = MAKEDISKDEV(major(nrootdev),
932 					    DISKUNIT(nrootdev), 1);
933 				}
934 				dumpdv = defdumpdv;
935 				break;
936 			}
937 			if (len == 4 && strcmp(buf, "none") == 0) {
938 				dumpdv = NULL;
939 				break;
940 			}
941 			dv = getdisk(buf, len, 1, &ndumpdev, 1);
942 			if (dv != NULL) {
943 				dumpdv = dv;
944 				break;
945 			}
946 		}
947 
948 		rootdev = nrootdev;
949 		dumpdev = ndumpdev;
950 
951 		for (vops = LIST_FIRST(&vfs_list); vops != NULL;
952 		     vops = LIST_NEXT(vops, vfs_list)) {
953 			if (vops->vfs_mountroot != NULL &&
954 			    vops->vfs_mountroot == mountroot)
955 			break;
956 		}
957 
958 		if (vops == NULL) {
959 			mountroot = NULL;
960 			deffsname = "generic";
961 		} else
962 			deffsname = vops->vfs_name;
963 
964 		for (;;) {
965 			printf("file system (default %s): ", deffsname);
966 			len = cngetsn(buf, sizeof(buf));
967 			if (len == 0)
968 				break;
969 			if (len == 4 && strcmp(buf, "halt") == 0)
970 				cpu_reboot(RB_HALT, NULL);
971 			else if (len == 6 && strcmp(buf, "reboot") == 0)
972 				cpu_reboot(0, NULL);
973 #if defined(DDB)
974 			else if (len == 3 && strcmp(buf, "ddb") == 0) {
975 				console_debugger();
976 			}
977 #endif
978 			else if (len == 7 && strcmp(buf, "generic") == 0) {
979 				mountroot = NULL;
980 				break;
981 			}
982 			vops = vfs_getopsbyname(buf);
983 			if (vops == NULL || vops->vfs_mountroot == NULL) {
984 				printf("use one of: generic");
985 				for (vops = LIST_FIRST(&vfs_list);
986 				     vops != NULL;
987 				     vops = LIST_NEXT(vops, vfs_list)) {
988 					if (vops->vfs_mountroot != NULL)
989 						printf(" %s", vops->vfs_name);
990 				}
991 #if defined(DDB)
992 				printf(" ddb");
993 #endif
994 				printf(" halt reboot\n");
995 			} else {
996 				mountroot = vops->vfs_mountroot;
997 				break;
998 			}
999 		}
1000 
1001 	} else if (rootspec == NULL) {
1002 		int majdev;
1003 
1004 		/*
1005 		 * Wildcarded root; use the boot device.
1006 		 */
1007 		rootdv = bootdv;
1008 
1009 		majdev = devsw_name2blk(bootdv->dv_xname, NULL, 0);
1010 		if (majdev >= 0) {
1011 			/*
1012 			 * Root is on a disk.  `bootpartition' is root,
1013 			 * unless the device does not use partitions.
1014 			 */
1015 			if (DEV_USES_PARTITIONS(bootdv))
1016 				rootdev = MAKEDISKDEV(majdev,
1017 						      device_unit(bootdv),
1018 						      bootpartition);
1019 			else
1020 				rootdev = makedev(majdev, device_unit(bootdv));
1021 		}
1022 	} else {
1023 
1024 		/*
1025 		 * `root on <dev> ...'
1026 		 */
1027 
1028 		/*
1029 		 * If it's a network interface, we can bail out
1030 		 * early.
1031 		 */
1032 		dv = finddevice(rootspec);
1033 		if (dv != NULL && device_class(dv) == DV_IFNET) {
1034 			rootdv = dv;
1035 			goto haveroot;
1036 		}
1037 
1038 		rootdevname = devsw_blk2name(major(rootdev));
1039 		if (rootdevname == NULL) {
1040 			printf("unknown device major 0x%x\n", rootdev);
1041 			boothowto |= RB_ASKNAME;
1042 			goto top;
1043 		}
1044 		memset(buf, 0, sizeof(buf));
1045 		snprintf(buf, sizeof(buf), "%s%d", rootdevname,
1046 		    DISKUNIT(rootdev));
1047 
1048 		rootdv = finddevice(buf);
1049 		if (rootdv == NULL) {
1050 			printf("device %s (0x%x) not configured\n",
1051 			    buf, rootdev);
1052 			boothowto |= RB_ASKNAME;
1053 			goto top;
1054 		}
1055 	}
1056 
1057  haveroot:
1058 
1059 	root_device = rootdv;
1060 
1061 	switch (device_class(rootdv)) {
1062 	case DV_IFNET:
1063 	case DV_DISK:
1064 		aprint_normal("root on %s", rootdv->dv_xname);
1065 		if (DEV_USES_PARTITIONS(rootdv))
1066 			aprint_normal("%c", DISKPART(rootdev) + 'a');
1067 		break;
1068 
1069 	default:
1070 		printf("can't determine root device\n");
1071 		boothowto |= RB_ASKNAME;
1072 		goto top;
1073 	}
1074 
1075 	/*
1076 	 * Now configure the dump device.
1077 	 *
1078 	 * If we haven't figured out the dump device, do so, with
1079 	 * the following rules:
1080 	 *
1081 	 *	(a) We already know dumpdv in the RB_ASKNAME case.
1082 	 *
1083 	 *	(b) If dumpspec is set, try to use it.  If the device
1084 	 *	    is not available, punt.
1085 	 *
1086 	 *	(c) If dumpspec is not set, the dump device is
1087 	 *	    wildcarded or unspecified.  If the root device
1088 	 *	    is DV_IFNET, punt.  Otherwise, use partition b
1089 	 *	    of the root device.
1090 	 */
1091 
1092 	if (boothowto & RB_ASKNAME) {		/* (a) */
1093 		if (dumpdv == NULL)
1094 			goto nodumpdev;
1095 	} else if (dumpspec != NULL) {		/* (b) */
1096 		if (strcmp(dumpspec, "none") == 0 || dumpdev == NODEV) {
1097 			/*
1098 			 * Operator doesn't want a dump device.
1099 			 * Or looks like they tried to pick a network
1100 			 * device.  Oops.
1101 			 */
1102 			goto nodumpdev;
1103 		}
1104 
1105 		dumpdevname = devsw_blk2name(major(dumpdev));
1106 		if (dumpdevname == NULL)
1107 			goto nodumpdev;
1108 		memset(buf, 0, sizeof(buf));
1109 		snprintf(buf, sizeof(buf), "%s%d", dumpdevname,
1110 		    DISKUNIT(dumpdev));
1111 
1112 		dumpdv = finddevice(buf);
1113 		if (dumpdv == NULL) {
1114 			/*
1115 			 * Device not configured.
1116 			 */
1117 			goto nodumpdev;
1118 		}
1119 	} else {				/* (c) */
1120 		if (DEV_USES_PARTITIONS(rootdv) == 0)
1121 			goto nodumpdev;
1122 		else {
1123 			dumpdv = rootdv;
1124 			dumpdev = MAKEDISKDEV(major(rootdev),
1125 			    device_unit(dumpdv), 1);
1126 		}
1127 	}
1128 
1129 	aprint_normal(" dumps on %s", dumpdv->dv_xname);
1130 	if (DEV_USES_PARTITIONS(dumpdv))
1131 		aprint_normal("%c", DISKPART(dumpdev) + 'a');
1132 	aprint_normal("\n");
1133 	return;
1134 
1135  nodumpdev:
1136 	dumpdev = NODEV;
1137 	aprint_normal("\n");
1138 }
1139 
1140 static struct device *
1141 finddevice(const char *name)
1142 {
1143 	struct device *dv;
1144 #if defined(BOOT_FROM_MEMORY_HOOKS)
1145 	int j;
1146 #endif /* BOOT_FROM_MEMORY_HOOKS */
1147 
1148 #ifdef BOOT_FROM_MEMORY_HOOKS
1149 	for (j = 0; j < NMD; j++) {
1150 		if (strcmp(name, fakemdrootdev[j].dv_xname) == 0) {
1151 			dv = &fakemdrootdev[j];
1152 			return (dv);
1153 		}
1154 	}
1155 #endif /* BOOT_FROM_MEMORY_HOOKS */
1156 
1157 	for (dv = TAILQ_FIRST(&alldevs); dv != NULL;
1158 	    dv = TAILQ_NEXT(dv, dv_list))
1159 		if (strcmp(dv->dv_xname, name) == 0)
1160 			break;
1161 	return (dv);
1162 }
1163 
1164 static struct device *
1165 getdisk(char *str, int len, int defpart, dev_t *devp, int isdump)
1166 {
1167 	struct device	*dv;
1168 #ifdef MEMORY_DISK_HOOKS
1169 	int		i;
1170 #endif
1171 
1172 	if ((dv = parsedisk(str, len, defpart, devp)) == NULL) {
1173 		printf("use one of:");
1174 #ifdef MEMORY_DISK_HOOKS
1175 		if (isdump == 0)
1176 			for (i = 0; i < NMD; i++)
1177 				printf(" %s[a-%c]", fakemdrootdev[i].dv_xname,
1178 				    'a' + MAXPARTITIONS - 1);
1179 #endif
1180 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
1181 			if (DEV_USES_PARTITIONS(dv))
1182 				printf(" %s[a-%c]", dv->dv_xname,
1183 				    'a' + MAXPARTITIONS - 1);
1184 			else if (device_class(dv) == DV_DISK)
1185 				printf(" %s", dv->dv_xname);
1186 			if (isdump == 0 && device_class(dv) == DV_IFNET)
1187 				printf(" %s", dv->dv_xname);
1188 		}
1189 		if (isdump)
1190 			printf(" none");
1191 #if defined(DDB)
1192 		printf(" ddb");
1193 #endif
1194 		printf(" halt reboot\n");
1195 	}
1196 	return (dv);
1197 }
1198 
1199 static struct device *
1200 parsedisk(char *str, int len, int defpart, dev_t *devp)
1201 {
1202 	struct device *dv;
1203 	char *cp, c;
1204 	int majdev, part;
1205 #ifdef MEMORY_DISK_HOOKS
1206 	int i;
1207 #endif
1208 	if (len == 0)
1209 		return (NULL);
1210 
1211 	if (len == 4 && strcmp(str, "halt") == 0)
1212 		cpu_reboot(RB_HALT, NULL);
1213 	else if (len == 6 && strcmp(str, "reboot") == 0)
1214 		cpu_reboot(0, NULL);
1215 #if defined(DDB)
1216 	else if (len == 3 && strcmp(str, "ddb") == 0)
1217 		console_debugger();
1218 #endif
1219 
1220 	cp = str + len - 1;
1221 	c = *cp;
1222 	if (c >= 'a' && c <= ('a' + MAXPARTITIONS - 1)) {
1223 		part = c - 'a';
1224 		*cp = '\0';
1225 	} else
1226 		part = defpart;
1227 
1228 #ifdef MEMORY_DISK_HOOKS
1229 	for (i = 0; i < NMD; i++)
1230 		if (strcmp(str, fakemdrootdev[i].dv_xname) == 0) {
1231 			dv = &fakemdrootdev[i];
1232 			goto gotdisk;
1233 		}
1234 #endif
1235 
1236 	dv = finddevice(str);
1237 	if (dv != NULL) {
1238 		if (device_class(dv) == DV_DISK) {
1239 #ifdef MEMORY_DISK_HOOKS
1240  gotdisk:
1241 #endif
1242 			majdev = devsw_name2blk(dv->dv_xname, NULL, 0);
1243 			if (majdev < 0)
1244 				panic("parsedisk");
1245 			if (DEV_USES_PARTITIONS(dv))
1246 				*devp = MAKEDISKDEV(majdev, device_unit(dv),
1247 						    part);
1248 			else
1249 				*devp = makedev(majdev, device_unit(dv));
1250 		}
1251 
1252 		if (device_class(dv) == DV_IFNET)
1253 			*devp = NODEV;
1254 	}
1255 
1256 	*cp = c;
1257 	return (dv);
1258 }
1259 
1260 /*
1261  * snprintf() `bytes' into `buf', reformatting it so that the number,
1262  * plus a possible `x' + suffix extension) fits into len bytes (including
1263  * the terminating NUL).
1264  * Returns the number of bytes stored in buf, or -1 if there was a problem.
1265  * E.g, given a len of 9 and a suffix of `B':
1266  *	bytes		result
1267  *	-----		------
1268  *	99999		`99999 B'
1269  *	100000		`97 kB'
1270  *	66715648	`65152 kB'
1271  *	252215296	`240 MB'
1272  */
1273 int
1274 humanize_number(char *buf, size_t len, uint64_t bytes, const char *suffix,
1275     int divisor)
1276 {
1277        	/* prefixes are: (none), kilo, Mega, Giga, Tera, Peta, Exa */
1278 	const char *prefixes;
1279 	int		r;
1280 	uint64_t	umax;
1281 	size_t		i, suffixlen;
1282 
1283 	if (buf == NULL || suffix == NULL)
1284 		return (-1);
1285 	if (len > 0)
1286 		buf[0] = '\0';
1287 	suffixlen = strlen(suffix);
1288 	/* check if enough room for `x y' + suffix + `\0' */
1289 	if (len < 4 + suffixlen)
1290 		return (-1);
1291 
1292 	if (divisor == 1024) {
1293 		/*
1294 		 * binary multiplies
1295 		 * XXX IEC 60027-2 recommends Ki, Mi, Gi...
1296 		 */
1297 		prefixes = " KMGTPE";
1298 	} else
1299 		prefixes = " kMGTPE"; /* SI for decimal multiplies */
1300 
1301 	umax = 1;
1302 	for (i = 0; i < len - suffixlen - 3; i++)
1303 		umax *= 10;
1304 	for (i = 0; bytes >= umax && prefixes[i + 1]; i++)
1305 		bytes /= divisor;
1306 
1307 	r = snprintf(buf, len, "%qu%s%c%s", (unsigned long long)bytes,
1308 	    i == 0 ? "" : " ", prefixes[i], suffix);
1309 
1310 	return (r);
1311 }
1312 
1313 int
1314 format_bytes(char *buf, size_t len, uint64_t bytes)
1315 {
1316 	int	rv;
1317 	size_t	nlen;
1318 
1319 	rv = humanize_number(buf, len, bytes, "B", 1024);
1320 	if (rv != -1) {
1321 			/* nuke the trailing ` B' if it exists */
1322 		nlen = strlen(buf) - 2;
1323 		if (strcmp(&buf[nlen], " B") == 0)
1324 			buf[nlen] = '\0';
1325 	}
1326 	return (rv);
1327 }
1328 
1329 /*
1330  * Return TRUE if system call tracing is enabled for the specified process.
1331  */
1332 boolean_t
1333 trace_is_enabled(struct proc *p)
1334 {
1335 #ifdef SYSCALL_DEBUG
1336 	return (TRUE);
1337 #endif
1338 #ifdef KTRACE
1339 	if (ISSET(p->p_traceflag, (KTRFAC_SYSCALL | KTRFAC_SYSRET)))
1340 		return (TRUE);
1341 #endif
1342 #ifdef SYSTRACE
1343 	if (ISSET(p->p_flag, P_SYSTRACE))
1344 		return (TRUE);
1345 #endif
1346 #ifdef PTRACE
1347 	if (ISSET(p->p_flag, P_SYSCALL))
1348 		return (TRUE);
1349 #endif
1350 
1351 	return (FALSE);
1352 }
1353 
1354 /*
1355  * Start trace of particular system call. If process is being traced,
1356  * this routine is called by MD syscall dispatch code just before
1357  * a system call is actually executed.
1358  * MD caller guarantees the passed 'code' is within the supported
1359  * system call number range for emulation the process runs under.
1360  */
1361 int
1362 trace_enter(struct lwp *l, register_t code,
1363     register_t realcode, const struct sysent *callp, void *args)
1364 {
1365 	struct proc *p = l->l_proc;
1366 
1367 	do { if (&code) {} } while (/* CONSTCOND */ 0);
1368 	do { if (&realcode) {} } while (/* CONSTCOND */ 0);
1369 	do { if (&callp) {} } while (/* CONSTCOND */ 0);
1370 	do { if (&args) {} } while (/* CONSTCOND */ 0);
1371 	do { if (&p) {} } while (/* CONSTCOND */ 0);
1372 
1373 #if defined(SYSCALL_DEBUG) || defined(KTRACE) || defined(PTRACE) || defined(SYSTRACE)
1374 #ifdef SYSCALL_DEBUG
1375 	scdebug_call(l, code, args);
1376 #endif /* SYSCALL_DEBUG */
1377 
1378 #ifdef KTRACE
1379 	if (KTRPOINT(p, KTR_SYSCALL))
1380 		ktrsyscall(l, code, realcode, callp, args);
1381 #endif /* KTRACE */
1382 
1383 #ifdef PTRACE
1384 	if ((p->p_flag & (P_SYSCALL|P_TRACED)) == (P_SYSCALL|P_TRACED))
1385 		process_stoptrace(l);
1386 #endif
1387 
1388 #ifdef SYSTRACE
1389 	if (ISSET(p->p_flag, P_SYSTRACE))
1390 		return systrace_enter(l, code, args);
1391 #endif
1392 #endif /* SYSCALL_DEBUG || {K,P,SYS}TRACE */
1393 	return 0;
1394 }
1395 
1396 /*
1397  * End trace of particular system call. If process is being traced,
1398  * this routine is called by MD syscall dispatch code just after
1399  * a system call finishes.
1400  * MD caller guarantees the passed 'code' is within the supported
1401  * system call number range for emulation the process runs under.
1402  */
1403 void
1404 trace_exit(struct lwp *l, register_t code, void *args __unused,
1405     register_t rval[], int error)
1406 {
1407 	struct proc *p = l->l_proc;
1408 	do { if (&code) {} } while (/* CONSTCOND */ 0);
1409 	do { if (&rval) {} } while (/* CONSTCOND */ 0);
1410 	do { if (&error) {} } while (/* CONSTCOND */ 0);
1411 	do { if (&p) {} } while (/* CONSTCOND */ 0);
1412 
1413 #if defined(SYSCALL_DEBUG) || defined(KTRACE) || defined(PTRACE) || defined(SYSTRACE)
1414 #ifdef SYSCALL_DEBUG
1415 	scdebug_ret(l, code, error, rval);
1416 #endif /* SYSCALL_DEBUG */
1417 
1418 #ifdef KTRACE
1419 	if (KTRPOINT(p, KTR_SYSRET)) {
1420 		KERNEL_PROC_LOCK(l);
1421 		ktrsysret(l, code, error, rval);
1422 		KERNEL_PROC_UNLOCK(l);
1423 	}
1424 #endif /* KTRACE */
1425 
1426 #ifdef PTRACE
1427 	if ((p->p_flag & (P_SYSCALL|P_TRACED)) == (P_SYSCALL|P_TRACED))
1428 		process_stoptrace(l);
1429 #endif
1430 
1431 #ifdef SYSTRACE
1432 	if (ISSET(p->p_flag, P_SYSTRACE)) {
1433 		KERNEL_PROC_LOCK(l);
1434 		systrace_exit(l, code, args, rval, error);
1435 		KERNEL_PROC_UNLOCK(l);
1436 	}
1437 #endif
1438 #else
1439 	do { if (&code) {} } while (/* CONSTCOND */ 0);
1440 	do { if (&realcode) {} } while (/* CONSTCOND */ 0);
1441 	do { if (&callp) {} } while (/* CONSTCOND */ 0);
1442 	do { if (&args) {} } while (/* CONSTCOND */ 0);
1443 #endif /* SYSCALL_DEBUG || {K,P,SYS}TRACE */
1444 }
1445