1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1999-2002 Poul-Henning Kamp
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31
32#include <sys/param.h>
33#include <sys/kernel.h>
34#include <sys/systm.h>
35#include <sys/bio.h>
36#include <sys/devctl.h>
37#include <sys/lock.h>
38#include <sys/mutex.h>
39#include <sys/module.h>
40#include <sys/malloc.h>
41#include <sys/conf.h>
42#include <sys/vnode.h>
43#include <sys/queue.h>
44#include <sys/poll.h>
45#include <sys/sx.h>
46#include <sys/ctype.h>
47#include <sys/ucred.h>
48#include <sys/taskqueue.h>
49#include <machine/stdarg.h>
50
51#include <fs/devfs/devfs_int.h>
52#include <vm/vm.h>
53
54static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage");
55
56struct mtx devmtx;
57static void destroy_devl(struct cdev *dev);
58static int destroy_dev_sched_cbl(struct cdev *dev,
59    void (*cb)(void *), void *arg);
60static void destroy_dev_tq(void *ctx, int pending);
61static int make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw,
62    int unit, struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
63    va_list ap);
64
65static struct cdev_priv_list cdevp_free_list =
66    TAILQ_HEAD_INITIALIZER(cdevp_free_list);
67static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list =
68    SLIST_HEAD_INITIALIZER(cdevsw_gt_post_list);
69
70void
71dev_lock(void)
72{
73
74	mtx_lock(&devmtx);
75}
76
77/*
78 * Free all the memory collected while the cdev mutex was
79 * locked. Since devmtx is after the system map mutex, free() cannot
80 * be called immediately and is postponed until cdev mutex can be
81 * dropped.
82 */
83static void
84dev_unlock_and_free(void)
85{
86	struct cdev_priv_list cdp_free;
87	struct free_cdevsw csw_free;
88	struct cdev_priv *cdp;
89	struct cdevsw *csw;
90
91	dev_lock_assert_locked();
92
93	/*
94	 * Make the local copy of the list heads while the dev_mtx is
95	 * held. Free it later.
96	 */
97	TAILQ_INIT(&cdp_free);
98	TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list);
99	csw_free = cdevsw_gt_post_list;
100	SLIST_INIT(&cdevsw_gt_post_list);
101
102	mtx_unlock(&devmtx);
103
104	while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) {
105		TAILQ_REMOVE(&cdp_free, cdp, cdp_list);
106		devfs_free(&cdp->cdp_c);
107	}
108	while ((csw = SLIST_FIRST(&csw_free)) != NULL) {
109		SLIST_REMOVE_HEAD(&csw_free, d_postfree_list);
110		free(csw, M_DEVT);
111	}
112}
113
114static void
115dev_free_devlocked(struct cdev *cdev)
116{
117	struct cdev_priv *cdp;
118
119	dev_lock_assert_locked();
120	cdp = cdev2priv(cdev);
121	KASSERT((cdp->cdp_flags & CDP_UNREF_DTR) == 0,
122	    ("destroy_dev() was not called after delist_dev(%p)", cdev));
123	TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list);
124}
125
126static void
127cdevsw_free_devlocked(struct cdevsw *csw)
128{
129
130	dev_lock_assert_locked();
131	SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list);
132}
133
134void
135dev_unlock(void)
136{
137
138	mtx_unlock(&devmtx);
139}
140
141void
142dev_ref(struct cdev *dev)
143{
144
145	dev_lock_assert_unlocked();
146	mtx_lock(&devmtx);
147	dev->si_refcount++;
148	mtx_unlock(&devmtx);
149}
150
151void
152dev_refl(struct cdev *dev)
153{
154
155	dev_lock_assert_locked();
156	dev->si_refcount++;
157}
158
159void
160dev_rel(struct cdev *dev)
161{
162	int flag = 0;
163
164	dev_lock_assert_unlocked();
165	dev_lock();
166	dev->si_refcount--;
167	KASSERT(dev->si_refcount >= 0,
168	    ("dev_rel(%s) gave negative count", devtoname(dev)));
169	if (dev->si_devsw == NULL && dev->si_refcount == 0) {
170		LIST_REMOVE(dev, si_list);
171		flag = 1;
172	}
173	dev_unlock();
174	if (flag)
175		devfs_free(dev);
176}
177
178struct cdevsw *
179dev_refthread(struct cdev *dev, int *ref)
180{
181	struct cdevsw *csw;
182	struct cdev_priv *cdp;
183
184	dev_lock_assert_unlocked();
185	if ((dev->si_flags & SI_ETERNAL) != 0) {
186		*ref = 0;
187		return (dev->si_devsw);
188	}
189	cdp = cdev2priv(dev);
190	mtx_lock(&cdp->cdp_threadlock);
191	csw = dev->si_devsw;
192	if (csw != NULL) {
193		if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
194			atomic_add_long(&dev->si_threadcount, 1);
195		else
196			csw = NULL;
197	}
198	mtx_unlock(&cdp->cdp_threadlock);
199	if (csw != NULL)
200		*ref = 1;
201	return (csw);
202}
203
204struct cdevsw *
205devvn_refthread(struct vnode *vp, struct cdev **devp, int *ref)
206{
207	struct cdevsw *csw;
208	struct cdev_priv *cdp;
209	struct cdev *dev;
210
211	dev_lock_assert_unlocked();
212	if ((vp->v_vflag & VV_ETERNALDEV) != 0) {
213		dev = vp->v_rdev;
214		if (dev == NULL)
215			return (NULL);
216		KASSERT((dev->si_flags & SI_ETERNAL) != 0,
217		    ("Not eternal cdev"));
218		*ref = 0;
219		csw = dev->si_devsw;
220		KASSERT(csw != NULL, ("Eternal cdev is destroyed"));
221		*devp = dev;
222		return (csw);
223	}
224
225	csw = NULL;
226	VI_LOCK(vp);
227	dev = vp->v_rdev;
228	if (dev == NULL) {
229		VI_UNLOCK(vp);
230		return (NULL);
231	}
232	cdp = cdev2priv(dev);
233	mtx_lock(&cdp->cdp_threadlock);
234	if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
235		csw = dev->si_devsw;
236		if (csw != NULL)
237			atomic_add_long(&dev->si_threadcount, 1);
238	}
239	mtx_unlock(&cdp->cdp_threadlock);
240	VI_UNLOCK(vp);
241	if (csw != NULL) {
242		*devp = dev;
243		*ref = 1;
244	}
245	return (csw);
246}
247
248void
249dev_relthread(struct cdev *dev, int ref)
250{
251
252	dev_lock_assert_unlocked();
253	if (!ref)
254		return;
255	KASSERT(dev->si_threadcount > 0,
256	    ("%s threadcount is wrong", dev->si_name));
257	atomic_subtract_rel_long(&dev->si_threadcount, 1);
258}
259
260int
261nullop(void)
262{
263
264	return (0);
265}
266
267int
268eopnotsupp(void)
269{
270
271	return (EOPNOTSUPP);
272}
273
274static int
275enxio(void)
276{
277	return (ENXIO);
278}
279
280static int
281enodev(void)
282{
283	return (ENODEV);
284}
285
286/* Define a dead_cdevsw for use when devices leave unexpectedly. */
287
288#define dead_open	(d_open_t *)enxio
289#define dead_close	(d_close_t *)enxio
290#define dead_read	(d_read_t *)enxio
291#define dead_write	(d_write_t *)enxio
292#define dead_ioctl	(d_ioctl_t *)enxio
293#define dead_poll	(d_poll_t *)enodev
294#define dead_mmap	(d_mmap_t *)enodev
295
296static void
297dead_strategy(struct bio *bp)
298{
299
300	biofinish(bp, NULL, ENXIO);
301}
302
303#define dead_dump	(dumper_t *)enxio
304#define dead_kqfilter	(d_kqfilter_t *)enxio
305#define dead_mmap_single (d_mmap_single_t *)enodev
306
307static struct cdevsw dead_cdevsw = {
308	.d_version =	D_VERSION,
309	.d_open =	dead_open,
310	.d_close =	dead_close,
311	.d_read =	dead_read,
312	.d_write =	dead_write,
313	.d_ioctl =	dead_ioctl,
314	.d_poll =	dead_poll,
315	.d_mmap =	dead_mmap,
316	.d_strategy =	dead_strategy,
317	.d_name =	"dead",
318	.d_dump =	dead_dump,
319	.d_kqfilter =	dead_kqfilter,
320	.d_mmap_single = dead_mmap_single
321};
322
323/* Default methods if driver does not specify method */
324
325#define null_open	(d_open_t *)nullop
326#define null_close	(d_close_t *)nullop
327#define no_read		(d_read_t *)enodev
328#define no_write	(d_write_t *)enodev
329#define no_ioctl	(d_ioctl_t *)enodev
330#define no_mmap		(d_mmap_t *)enodev
331#define no_kqfilter	(d_kqfilter_t *)enodev
332#define no_mmap_single	(d_mmap_single_t *)enodev
333
334static void
335no_strategy(struct bio *bp)
336{
337
338	biofinish(bp, NULL, ENODEV);
339}
340
341static int
342no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
343{
344
345	return (poll_no_poll(events));
346}
347
348#define no_dump		(dumper_t *)enodev
349
350static int
351giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
352{
353	struct cdevsw *dsw;
354	int ref, retval;
355
356	dsw = dev_refthread(dev, &ref);
357	if (dsw == NULL)
358		return (ENXIO);
359	mtx_lock(&Giant);
360	retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
361	mtx_unlock(&Giant);
362	dev_relthread(dev, ref);
363	return (retval);
364}
365
366static int
367giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
368{
369	struct cdevsw *dsw;
370	int ref, retval;
371
372	dsw = dev_refthread(dev, &ref);
373	if (dsw == NULL)
374		return (ENXIO);
375	mtx_lock(&Giant);
376	retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
377	mtx_unlock(&Giant);
378	dev_relthread(dev, ref);
379	return (retval);
380}
381
382static int
383giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
384{
385	struct cdevsw *dsw;
386	int ref, retval;
387
388	dsw = dev_refthread(dev, &ref);
389	if (dsw == NULL)
390		return (ENXIO);
391	mtx_lock(&Giant);
392	retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
393	mtx_unlock(&Giant);
394	dev_relthread(dev, ref);
395	return (retval);
396}
397
398static void
399giant_strategy(struct bio *bp)
400{
401	struct cdevsw *dsw;
402	struct cdev *dev;
403	int ref;
404
405	dev = bp->bio_dev;
406	dsw = dev_refthread(dev, &ref);
407	if (dsw == NULL) {
408		biofinish(bp, NULL, ENXIO);
409		return;
410	}
411	mtx_lock(&Giant);
412	dsw->d_gianttrick->d_strategy(bp);
413	mtx_unlock(&Giant);
414	dev_relthread(dev, ref);
415}
416
417static int
418giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
419{
420	struct cdevsw *dsw;
421	int ref, retval;
422
423	dsw = dev_refthread(dev, &ref);
424	if (dsw == NULL)
425		return (ENXIO);
426	mtx_lock(&Giant);
427	retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
428	mtx_unlock(&Giant);
429	dev_relthread(dev, ref);
430	return (retval);
431}
432
433static int
434giant_read(struct cdev *dev, struct uio *uio, int ioflag)
435{
436	struct cdevsw *dsw;
437	int ref, retval;
438
439	dsw = dev_refthread(dev, &ref);
440	if (dsw == NULL)
441		return (ENXIO);
442	mtx_lock(&Giant);
443	retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
444	mtx_unlock(&Giant);
445	dev_relthread(dev, ref);
446	return (retval);
447}
448
449static int
450giant_write(struct cdev *dev, struct uio *uio, int ioflag)
451{
452	struct cdevsw *dsw;
453	int ref, retval;
454
455	dsw = dev_refthread(dev, &ref);
456	if (dsw == NULL)
457		return (ENXIO);
458	mtx_lock(&Giant);
459	retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
460	mtx_unlock(&Giant);
461	dev_relthread(dev, ref);
462	return (retval);
463}
464
465static int
466giant_poll(struct cdev *dev, int events, struct thread *td)
467{
468	struct cdevsw *dsw;
469	int ref, retval;
470
471	dsw = dev_refthread(dev, &ref);
472	if (dsw == NULL)
473		return (ENXIO);
474	mtx_lock(&Giant);
475	retval = dsw->d_gianttrick->d_poll(dev, events, td);
476	mtx_unlock(&Giant);
477	dev_relthread(dev, ref);
478	return (retval);
479}
480
481static int
482giant_kqfilter(struct cdev *dev, struct knote *kn)
483{
484	struct cdevsw *dsw;
485	int ref, retval;
486
487	dsw = dev_refthread(dev, &ref);
488	if (dsw == NULL)
489		return (ENXIO);
490	mtx_lock(&Giant);
491	retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
492	mtx_unlock(&Giant);
493	dev_relthread(dev, ref);
494	return (retval);
495}
496
497static int
498giant_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, int nprot,
499    vm_memattr_t *memattr)
500{
501	struct cdevsw *dsw;
502	int ref, retval;
503
504	dsw = dev_refthread(dev, &ref);
505	if (dsw == NULL)
506		return (ENXIO);
507	mtx_lock(&Giant);
508	retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot,
509	    memattr);
510	mtx_unlock(&Giant);
511	dev_relthread(dev, ref);
512	return (retval);
513}
514
515static int
516giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
517    vm_object_t *object, int nprot)
518{
519	struct cdevsw *dsw;
520	int ref, retval;
521
522	dsw = dev_refthread(dev, &ref);
523	if (dsw == NULL)
524		return (ENXIO);
525	mtx_lock(&Giant);
526	retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object,
527	    nprot);
528	mtx_unlock(&Giant);
529	dev_relthread(dev, ref);
530	return (retval);
531}
532
533static void
534notify(struct cdev *dev, const char *ev, int flags)
535{
536	static const char prefix[] = "cdev=";
537	char *data;
538	int namelen, mflags;
539
540	if (cold)
541		return;
542	mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
543	namelen = strlen(dev->si_name);
544	data = malloc(namelen + sizeof(prefix), M_TEMP, mflags);
545	if (data == NULL)
546		return;
547	memcpy(data, prefix, sizeof(prefix) - 1);
548	memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
549	devctl_notify("DEVFS", "CDEV", ev, data);
550	free(data, M_TEMP);
551}
552
553static void
554notify_create(struct cdev *dev, int flags)
555{
556
557	notify(dev, "CREATE", flags);
558}
559
560static void
561notify_destroy(struct cdev *dev)
562{
563
564	notify(dev, "DESTROY", MAKEDEV_WAITOK);
565}
566
567static struct cdev *
568newdev(struct make_dev_args *args, struct cdev *si)
569{
570	struct cdev *si2;
571	struct cdevsw *csw;
572
573	dev_lock_assert_locked();
574	csw = args->mda_devsw;
575	si2 = NULL;
576	if (csw->d_flags & D_NEEDMINOR) {
577		/* We may want to return an existing device */
578		LIST_FOREACH(si2, &csw->d_devs, si_list) {
579			if (dev2unit(si2) == args->mda_unit) {
580				dev_free_devlocked(si);
581				si = si2;
582				break;
583			}
584		}
585
586		/*
587		 * If we're returning an existing device, we should make sure
588		 * it isn't already initialized.  This would have been caught
589		 * in consumers anyways, but it's good to catch such a case
590		 * early.  We still need to complete initialization of the
591		 * device, and we'll use whatever make_dev_args were passed in
592		 * to do so.
593		 */
594		KASSERT(si2 == NULL || (si2->si_flags & SI_NAMED) == 0,
595		    ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
596		    args->mda_devsw->d_name, dev2unit(si2), devtoname(si2)));
597	}
598	si->si_drv0 = args->mda_unit;
599	si->si_drv1 = args->mda_si_drv1;
600	si->si_drv2 = args->mda_si_drv2;
601	/* Only push to csw->d_devs if it's not a cloned device. */
602	if (si2 == NULL) {
603		si->si_devsw = csw;
604		LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
605	} else {
606		KASSERT(si->si_devsw == csw,
607		    ("%s: inconsistent devsw between clone_create() and make_dev()",
608		    __func__));
609	}
610	return (si);
611}
612
613static void
614fini_cdevsw(struct cdevsw *devsw)
615{
616	struct cdevsw *gt;
617
618	if (devsw->d_gianttrick != NULL) {
619		gt = devsw->d_gianttrick;
620		memcpy(devsw, gt, sizeof *devsw);
621		cdevsw_free_devlocked(gt);
622		devsw->d_gianttrick = NULL;
623	}
624	devsw->d_flags &= ~D_INIT;
625}
626
627static int
628prep_cdevsw(struct cdevsw *devsw, int flags)
629{
630	struct cdevsw *dsw2;
631
632	dev_lock_assert_locked();
633	if (devsw->d_flags & D_INIT)
634		return (0);
635	if (devsw->d_flags & D_NEEDGIANT) {
636		dev_unlock();
637		dsw2 = malloc(sizeof *dsw2, M_DEVT,
638		     (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
639		dev_lock();
640		if (dsw2 == NULL && !(devsw->d_flags & D_INIT))
641			return (ENOMEM);
642	} else
643		dsw2 = NULL;
644	if (devsw->d_flags & D_INIT) {
645		if (dsw2 != NULL)
646			cdevsw_free_devlocked(dsw2);
647		return (0);
648	}
649
650	if (devsw->d_version != D_VERSION_04) {
651		printf(
652		    "WARNING: Device driver \"%s\" has wrong version %s\n",
653		    devsw->d_name == NULL ? "???" : devsw->d_name,
654		    "and is disabled.  Recompile KLD module.");
655		devsw->d_open = dead_open;
656		devsw->d_close = dead_close;
657		devsw->d_read = dead_read;
658		devsw->d_write = dead_write;
659		devsw->d_ioctl = dead_ioctl;
660		devsw->d_poll = dead_poll;
661		devsw->d_mmap = dead_mmap;
662		devsw->d_mmap_single = dead_mmap_single;
663		devsw->d_strategy = dead_strategy;
664		devsw->d_dump = dead_dump;
665		devsw->d_kqfilter = dead_kqfilter;
666	}
667
668	if ((devsw->d_flags & D_NEEDGIANT) != 0) {
669		if ((devsw->d_flags & D_GIANTOK) == 0) {
670			printf(
671			    "WARNING: Device \"%s\" is Giant locked and may be "
672			    "deleted before FreeBSD 14.0.\n",
673			    devsw->d_name == NULL ? "???" : devsw->d_name);
674		}
675		if (devsw->d_gianttrick == NULL) {
676			memcpy(dsw2, devsw, sizeof *dsw2);
677			devsw->d_gianttrick = dsw2;
678			dsw2 = NULL;
679		}
680	}
681
682#define FIXUP(member, noop, giant) 				\
683	do {							\
684		if (devsw->member == NULL) {			\
685			devsw->member = noop;			\
686		} else if (devsw->d_flags & D_NEEDGIANT)	\
687			devsw->member = giant;			\
688		}						\
689	while (0)
690
691	FIXUP(d_open,		null_open,	giant_open);
692	FIXUP(d_fdopen,		NULL,		giant_fdopen);
693	FIXUP(d_close,		null_close,	giant_close);
694	FIXUP(d_read,		no_read,	giant_read);
695	FIXUP(d_write,		no_write,	giant_write);
696	FIXUP(d_ioctl,		no_ioctl,	giant_ioctl);
697	FIXUP(d_poll,		no_poll,	giant_poll);
698	FIXUP(d_mmap,		no_mmap,	giant_mmap);
699	FIXUP(d_strategy,	no_strategy,	giant_strategy);
700	FIXUP(d_kqfilter,	no_kqfilter,	giant_kqfilter);
701	FIXUP(d_mmap_single,	no_mmap_single,	giant_mmap_single);
702
703	if (devsw->d_dump == NULL)	devsw->d_dump = no_dump;
704
705	LIST_INIT(&devsw->d_devs);
706
707	devsw->d_flags |= D_INIT;
708
709	if (dsw2 != NULL)
710		cdevsw_free_devlocked(dsw2);
711	return (0);
712}
713
714static int
715prep_devname(struct cdev *dev, const char *fmt, va_list ap)
716{
717	int len;
718	char *from, *q, *s, *to;
719
720	dev_lock_assert_locked();
721
722	len = vsnrprintf(dev->si_name, sizeof(dev->si_name), 32, fmt, ap);
723	if (len > sizeof(dev->si_name) - 1)
724		return (ENAMETOOLONG);
725
726	/* Strip leading slashes. */
727	for (from = dev->si_name; *from == '/'; from++)
728		;
729
730	for (to = dev->si_name; *from != '\0'; from++, to++) {
731		/*
732		 * Spaces and double quotation marks cause
733		 * problems for the devctl(4) protocol.
734		 * Reject names containing those characters.
735		 */
736		if (isspace(*from) || *from == '"')
737			return (EINVAL);
738		/* Treat multiple sequential slashes as single. */
739		while (from[0] == '/' && from[1] == '/')
740			from++;
741		/* Trailing slash is considered invalid. */
742		if (from[0] == '/' && from[1] == '\0')
743			return (EINVAL);
744		*to = *from;
745	}
746	*to = '\0';
747
748	if (dev->si_name[0] == '\0')
749		return (EINVAL);
750
751	/* Disallow "." and ".." components. */
752	for (s = dev->si_name;;) {
753		for (q = s; *q != '/' && *q != '\0'; q++)
754			;
755		if (q - s == 1 && s[0] == '.')
756			return (EINVAL);
757		if (q - s == 2 && s[0] == '.' && s[1] == '.')
758			return (EINVAL);
759		if (*q != '/')
760			break;
761		s = q + 1;
762	}
763
764	if (devfs_dev_exists(dev->si_name) != 0)
765		return (EEXIST);
766
767	return (0);
768}
769
770void
771make_dev_args_init_impl(struct make_dev_args *args, size_t sz)
772{
773
774	bzero(args, sz);
775	args->mda_size = sz;
776}
777
778static int
779make_dev_sv(struct make_dev_args *args1, struct cdev **dres,
780    const char *fmt, va_list ap)
781{
782	struct cdev *dev, *dev_new;
783	struct make_dev_args args;
784	int res;
785
786	bzero(&args, sizeof(args));
787	if (sizeof(args) < args1->mda_size)
788		return (EINVAL);
789	bcopy(args1, &args, args1->mda_size);
790	KASSERT((args.mda_flags & MAKEDEV_WAITOK) == 0 ||
791	    (args.mda_flags & MAKEDEV_NOWAIT) == 0,
792	    ("make_dev_sv: both WAITOK and NOWAIT specified"));
793	dev_new = devfs_alloc(args.mda_flags);
794	if (dev_new == NULL)
795		return (ENOMEM);
796	dev_lock();
797	res = prep_cdevsw(args.mda_devsw, args.mda_flags);
798	if (res != 0) {
799		dev_unlock();
800		devfs_free(dev_new);
801		return (res);
802	}
803	dev = newdev(&args, dev_new);
804	if ((dev->si_flags & SI_NAMED) == 0) {
805		res = prep_devname(dev, fmt, ap);
806		if (res != 0) {
807			if ((args.mda_flags & MAKEDEV_CHECKNAME) == 0) {
808				panic(
809			"make_dev_sv: bad si_name (error=%d, si_name=%s)",
810				    res, dev->si_name);
811			}
812			if (dev == dev_new) {
813				LIST_REMOVE(dev, si_list);
814				dev_unlock();
815				devfs_free(dev);
816			} else
817				dev_unlock();
818			return (res);
819		}
820	}
821	if ((args.mda_flags & MAKEDEV_REF) != 0)
822		dev_refl(dev);
823	if ((args.mda_flags & MAKEDEV_ETERNAL) != 0)
824		dev->si_flags |= SI_ETERNAL;
825	KASSERT(!(dev->si_flags & SI_NAMED),
826	    ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
827	    args.mda_devsw->d_name, dev2unit(dev), devtoname(dev)));
828	dev->si_flags |= SI_NAMED;
829	if (args.mda_cr != NULL)
830		dev->si_cred = crhold(args.mda_cr);
831	dev->si_uid = args.mda_uid;
832	dev->si_gid = args.mda_gid;
833	dev->si_mode = args.mda_mode;
834
835	devfs_create(dev);
836	clean_unrhdrl(devfs_inos);
837	dev_unlock_and_free();
838
839	notify_create(dev, args.mda_flags);
840
841	*dres = dev;
842	return (0);
843}
844
845int
846make_dev_s(struct make_dev_args *args, struct cdev **dres,
847    const char *fmt, ...)
848{
849	va_list ap;
850	int res;
851
852	va_start(ap, fmt);
853	res = make_dev_sv(args, dres, fmt, ap);
854	va_end(ap);
855	return (res);
856}
857
858static int
859make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw, int unit,
860    struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
861    va_list ap)
862{
863	struct make_dev_args args;
864
865	make_dev_args_init(&args);
866	args.mda_flags = flags;
867	args.mda_devsw = devsw;
868	args.mda_cr = cr;
869	args.mda_uid = uid;
870	args.mda_gid = gid;
871	args.mda_mode = mode;
872	args.mda_unit = unit;
873	return (make_dev_sv(&args, dres, fmt, ap));
874}
875
876struct cdev *
877make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
878    const char *fmt, ...)
879{
880	struct cdev *dev;
881	va_list ap;
882	int res __unused;
883
884	va_start(ap, fmt);
885	res = make_dev_credv(0, &dev, devsw, unit, NULL, uid, gid, mode, fmt,
886		      ap);
887	va_end(ap);
888	KASSERT(res == 0 && dev != NULL,
889	    ("make_dev: failed make_dev_credv (error=%d)", res));
890	return (dev);
891}
892
893struct cdev *
894make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
895    gid_t gid, int mode, const char *fmt, ...)
896{
897	struct cdev *dev;
898	va_list ap;
899	int res __unused;
900
901	va_start(ap, fmt);
902	res = make_dev_credv(0, &dev, devsw, unit, cr, uid, gid, mode, fmt, ap);
903	va_end(ap);
904
905	KASSERT(res == 0 && dev != NULL,
906	    ("make_dev_cred: failed make_dev_credv (error=%d)", res));
907	return (dev);
908}
909
910struct cdev *
911make_dev_credf(int flags, struct cdevsw *devsw, int unit, struct ucred *cr,
912    uid_t uid, gid_t gid, int mode, const char *fmt, ...)
913{
914	struct cdev *dev;
915	va_list ap;
916	int res;
917
918	va_start(ap, fmt);
919	res = make_dev_credv(flags, &dev, devsw, unit, cr, uid, gid, mode,
920	    fmt, ap);
921	va_end(ap);
922
923	KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
924	    ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
925	    ("make_dev_credf: failed make_dev_credv (error=%d)", res));
926	return (res == 0 ? dev : NULL);
927}
928
929int
930make_dev_p(int flags, struct cdev **cdev, struct cdevsw *devsw,
931    struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, ...)
932{
933	va_list ap;
934	int res;
935
936	va_start(ap, fmt);
937	res = make_dev_credv(flags, cdev, devsw, 0, cr, uid, gid, mode,
938	    fmt, ap);
939	va_end(ap);
940
941	KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
942	    ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
943	    ("make_dev_p: failed make_dev_credv (error=%d)", res));
944	return (res);
945}
946
947static void
948dev_dependsl(struct cdev *pdev, struct cdev *cdev)
949{
950
951	cdev->si_parent = pdev;
952	cdev->si_flags |= SI_CHILD;
953	LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
954}
955
956void
957dev_depends(struct cdev *pdev, struct cdev *cdev)
958{
959
960	dev_lock();
961	dev_dependsl(pdev, cdev);
962	dev_unlock();
963}
964
965static int
966make_dev_alias_v(int flags, struct cdev **cdev, struct cdev *pdev,
967    const char *fmt, va_list ap)
968{
969	struct cdev *dev;
970	int error;
971
972	KASSERT(pdev != NULL, ("make_dev_alias_v: pdev is NULL"));
973	KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
974	    ("make_dev_alias_v: both WAITOK and NOWAIT specified"));
975	KASSERT((flags & ~(MAKEDEV_WAITOK | MAKEDEV_NOWAIT |
976	    MAKEDEV_CHECKNAME)) == 0,
977	    ("make_dev_alias_v: invalid flags specified (flags=%02x)", flags));
978
979	dev = devfs_alloc(flags);
980	if (dev == NULL)
981		return (ENOMEM);
982	dev_lock();
983	dev->si_flags |= SI_ALIAS;
984	error = prep_devname(dev, fmt, ap);
985	if (error != 0) {
986		if ((flags & MAKEDEV_CHECKNAME) == 0) {
987			panic("make_dev_alias_v: bad si_name "
988			    "(error=%d, si_name=%s)", error, dev->si_name);
989		}
990		dev_unlock();
991		devfs_free(dev);
992		return (error);
993	}
994	dev->si_flags |= SI_NAMED;
995	devfs_create(dev);
996	dev_dependsl(pdev, dev);
997	clean_unrhdrl(devfs_inos);
998	dev_unlock();
999
1000	notify_create(dev, flags);
1001	*cdev = dev;
1002
1003	return (0);
1004}
1005
1006struct cdev *
1007make_dev_alias(struct cdev *pdev, const char *fmt, ...)
1008{
1009	struct cdev *dev;
1010	va_list ap;
1011	int res __unused;
1012
1013	va_start(ap, fmt);
1014	res = make_dev_alias_v(MAKEDEV_WAITOK, &dev, pdev, fmt, ap);
1015	va_end(ap);
1016
1017	KASSERT(res == 0 && dev != NULL,
1018	    ("make_dev_alias: failed make_dev_alias_v (error=%d)", res));
1019	return (dev);
1020}
1021
1022int
1023make_dev_alias_p(int flags, struct cdev **cdev, struct cdev *pdev,
1024    const char *fmt, ...)
1025{
1026	va_list ap;
1027	int res;
1028
1029	va_start(ap, fmt);
1030	res = make_dev_alias_v(flags, cdev, pdev, fmt, ap);
1031	va_end(ap);
1032	return (res);
1033}
1034
1035int
1036make_dev_physpath_alias(int flags, struct cdev **cdev, struct cdev *pdev,
1037    struct cdev *old_alias, const char *physpath)
1038{
1039	char *devfspath;
1040	int physpath_len;
1041	int max_parentpath_len;
1042	int parentpath_len;
1043	int devfspathbuf_len;
1044	int mflags;
1045	int ret;
1046
1047	*cdev = NULL;
1048	devfspath = NULL;
1049	physpath_len = strlen(physpath);
1050	ret = EINVAL;
1051	if (physpath_len == 0)
1052		goto out;
1053
1054	if (strncmp("id1,", physpath, 4) == 0) {
1055		physpath += 4;
1056		physpath_len -= 4;
1057		if (physpath_len == 0)
1058			goto out;
1059	}
1060
1061	max_parentpath_len = SPECNAMELEN - physpath_len - /*/*/1;
1062	parentpath_len = strlen(pdev->si_name);
1063	if (max_parentpath_len < parentpath_len) {
1064		if (bootverbose)
1065			printf("WARNING: Unable to alias %s "
1066			    "to %s/%s - path too long\n",
1067			    pdev->si_name, physpath, pdev->si_name);
1068		ret = ENAMETOOLONG;
1069		goto out;
1070	}
1071
1072	mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
1073	devfspathbuf_len = physpath_len + /*/*/1 + parentpath_len + /*NUL*/1;
1074	devfspath = malloc(devfspathbuf_len, M_DEVBUF, mflags);
1075	if (devfspath == NULL) {
1076		ret = ENOMEM;
1077		goto out;
1078	}
1079
1080	sprintf(devfspath, "%s/%s", physpath, pdev->si_name);
1081	if (old_alias != NULL && strcmp(old_alias->si_name, devfspath) == 0) {
1082		/* Retain the existing alias. */
1083		*cdev = old_alias;
1084		old_alias = NULL;
1085		ret = 0;
1086	} else {
1087		ret = make_dev_alias_p(flags, cdev, pdev, "%s", devfspath);
1088	}
1089out:
1090	if (old_alias != NULL)
1091		destroy_dev(old_alias);
1092	if (devfspath != NULL)
1093		free(devfspath, M_DEVBUF);
1094	return (ret);
1095}
1096
1097static void
1098destroy_devl(struct cdev *dev)
1099{
1100	struct cdevsw *csw;
1101	struct cdev_privdata *p;
1102	struct cdev_priv *cdp;
1103
1104	dev_lock_assert_locked();
1105	KASSERT(dev->si_flags & SI_NAMED,
1106	    ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
1107	KASSERT((dev->si_flags & SI_ETERNAL) == 0,
1108	    ("WARNING: Driver mistake: destroy_dev on eternal %d\n",
1109	     dev2unit(dev)));
1110
1111	cdp = cdev2priv(dev);
1112	if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
1113		/*
1114		 * Avoid race with dev_rel(), e.g. from the populate
1115		 * loop.  If CDP_UNREF_DTR flag is set, the reference
1116		 * to be dropped at the end of destroy_devl() was
1117		 * already taken by delist_dev_locked().
1118		 */
1119		dev_refl(dev);
1120
1121		devfs_destroy(dev);
1122	}
1123
1124	/* Remove name marking */
1125	dev->si_flags &= ~SI_NAMED;
1126
1127	/* If we are a child, remove us from the parents list */
1128	if (dev->si_flags & SI_CHILD) {
1129		LIST_REMOVE(dev, si_siblings);
1130		dev->si_flags &= ~SI_CHILD;
1131	}
1132
1133	/* Kill our children */
1134	while (!LIST_EMPTY(&dev->si_children))
1135		destroy_devl(LIST_FIRST(&dev->si_children));
1136
1137	/* Remove from clone list */
1138	if (dev->si_flags & SI_CLONELIST) {
1139		LIST_REMOVE(dev, si_clone);
1140		dev->si_flags &= ~SI_CLONELIST;
1141	}
1142
1143	mtx_lock(&cdp->cdp_threadlock);
1144	csw = dev->si_devsw;
1145	dev->si_devsw = NULL;	/* already NULL for SI_ALIAS */
1146	while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
1147		csw->d_purge(dev);
1148		mtx_unlock(&cdp->cdp_threadlock);
1149		msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
1150		mtx_lock(&cdp->cdp_threadlock);
1151		if (dev->si_threadcount)
1152			printf("Still %lu threads in %s\n",
1153			    dev->si_threadcount, devtoname(dev));
1154	}
1155	while (dev->si_threadcount != 0) {
1156		/* Use unique dummy wait ident */
1157		mtx_unlock(&cdp->cdp_threadlock);
1158		msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
1159		mtx_lock(&cdp->cdp_threadlock);
1160	}
1161
1162	mtx_unlock(&cdp->cdp_threadlock);
1163	dev_unlock();
1164	if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
1165		/* avoid out of order notify events */
1166		notify_destroy(dev);
1167	}
1168	mtx_lock(&cdevpriv_mtx);
1169	while ((p = LIST_FIRST(&cdp->cdp_fdpriv)) != NULL) {
1170		devfs_destroy_cdevpriv(p);
1171		mtx_lock(&cdevpriv_mtx);
1172	}
1173	mtx_unlock(&cdevpriv_mtx);
1174	dev_lock();
1175
1176	dev->si_drv1 = 0;
1177	dev->si_drv2 = 0;
1178
1179	if (!(dev->si_flags & SI_ALIAS)) {
1180		/* Remove from cdevsw list */
1181		LIST_REMOVE(dev, si_list);
1182
1183		/* If cdevsw has no more struct cdev *'s, clean it */
1184		if (LIST_EMPTY(&csw->d_devs)) {
1185			fini_cdevsw(csw);
1186			wakeup(&csw->d_devs);
1187		}
1188	}
1189	dev->si_flags &= ~SI_ALIAS;
1190	cdp->cdp_flags &= ~CDP_UNREF_DTR;
1191	dev->si_refcount--;
1192
1193	if (dev->si_refcount > 0)
1194		LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
1195	else
1196		dev_free_devlocked(dev);
1197}
1198
1199static void
1200delist_dev_locked(struct cdev *dev)
1201{
1202	struct cdev_priv *cdp;
1203	struct cdev *child;
1204
1205	dev_lock_assert_locked();
1206	cdp = cdev2priv(dev);
1207	if ((cdp->cdp_flags & CDP_UNREF_DTR) != 0)
1208		return;
1209	cdp->cdp_flags |= CDP_UNREF_DTR;
1210	dev_refl(dev);
1211	devfs_destroy(dev);
1212	LIST_FOREACH(child, &dev->si_children, si_siblings)
1213		delist_dev_locked(child);
1214	dev_unlock();
1215	/* ensure the destroy event is queued in order */
1216	notify_destroy(dev);
1217	dev_lock();
1218}
1219
1220/*
1221 * This function will delist a character device and its children from
1222 * the directory listing and create a destroy event without waiting
1223 * for all character device references to go away. At some later point
1224 * destroy_dev() must be called to complete the character device
1225 * destruction. After calling this function the character device name
1226 * can instantly be re-used.
1227 */
1228void
1229delist_dev(struct cdev *dev)
1230{
1231
1232	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "delist_dev");
1233	dev_lock();
1234	delist_dev_locked(dev);
1235	dev_unlock();
1236}
1237
1238void
1239destroy_dev(struct cdev *dev)
1240{
1241
1242	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
1243	dev_lock();
1244	destroy_devl(dev);
1245	dev_unlock_and_free();
1246}
1247
1248const char *
1249devtoname(struct cdev *dev)
1250{
1251
1252	return (dev->si_name);
1253}
1254
1255int
1256dev_stdclone(char *name, char **namep, const char *stem, int *unit)
1257{
1258	int u, i;
1259
1260	i = strlen(stem);
1261	if (strncmp(stem, name, i) != 0)
1262		return (0);
1263	if (!isdigit(name[i]))
1264		return (0);
1265	u = 0;
1266	if (name[i] == '0' && isdigit(name[i+1]))
1267		return (0);
1268	while (isdigit(name[i])) {
1269		u *= 10;
1270		u += name[i++] - '0';
1271	}
1272	if (u > 0xffffff)
1273		return (0);
1274	*unit = u;
1275	if (namep)
1276		*namep = &name[i];
1277	if (name[i])
1278		return (2);
1279	return (1);
1280}
1281
1282/*
1283 * Helper functions for cloning device drivers.
1284 *
1285 * The objective here is to make it unnecessary for the device drivers to
1286 * use rman or similar to manage their unit number space.  Due to the way
1287 * we do "on-demand" devices, using rman or other "private" methods
1288 * will be very tricky to lock down properly once we lock down this file.
1289 *
1290 * Instead we give the drivers these routines which puts the struct cdev *'s
1291 * that are to be managed on their own list, and gives the driver the ability
1292 * to ask for the first free unit number or a given specified unit number.
1293 *
1294 * In addition these routines support paired devices (pty, nmdm and similar)
1295 * by respecting a number of "flag" bits in the minor number.
1296 *
1297 */
1298
1299struct clonedevs {
1300	LIST_HEAD(,cdev)	head;
1301};
1302
1303void
1304clone_setup(struct clonedevs **cdp)
1305{
1306
1307	*cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
1308	LIST_INIT(&(*cdp)->head);
1309}
1310
1311int
1312clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up,
1313    struct cdev **dp, int extra)
1314{
1315	struct clonedevs *cd;
1316	struct cdev *dev, *ndev, *dl, *de;
1317	struct make_dev_args args;
1318	int unit, low, u;
1319
1320	KASSERT(*cdp != NULL,
1321	    ("clone_setup() not called in driver \"%s\"", csw->d_name));
1322	KASSERT(!(extra & CLONE_UNITMASK),
1323	    ("Illegal extra bits (0x%x) in clone_create", extra));
1324	KASSERT(*up <= CLONE_UNITMASK,
1325	    ("Too high unit (0x%x) in clone_create", *up));
1326	KASSERT(csw->d_flags & D_NEEDMINOR,
1327	    ("clone_create() on cdevsw without minor numbers"));
1328
1329	/*
1330	 * Search the list for a lot of things in one go:
1331	 *   A preexisting match is returned immediately.
1332	 *   The lowest free unit number if we are passed -1, and the place
1333	 *	 in the list where we should insert that new element.
1334	 *   The place to insert a specified unit number, if applicable
1335	 *       the end of the list.
1336	 */
1337	unit = *up;
1338	ndev = devfs_alloc(MAKEDEV_WAITOK);
1339	dev_lock();
1340	prep_cdevsw(csw, MAKEDEV_WAITOK);
1341	low = extra;
1342	de = dl = NULL;
1343	cd = *cdp;
1344	LIST_FOREACH(dev, &cd->head, si_clone) {
1345		KASSERT(dev->si_flags & SI_CLONELIST,
1346		    ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1347		u = dev2unit(dev);
1348		if (u == (unit | extra)) {
1349			*dp = dev;
1350			dev_unlock();
1351			devfs_free(ndev);
1352			return (0);
1353		}
1354		if (unit == -1 && u == low) {
1355			low++;
1356			de = dev;
1357			continue;
1358		} else if (u < (unit | extra)) {
1359			de = dev;
1360			continue;
1361		} else if (u > (unit | extra)) {
1362			dl = dev;
1363			break;
1364		}
1365	}
1366	if (unit == -1)
1367		unit = low & CLONE_UNITMASK;
1368	make_dev_args_init(&args);
1369	args.mda_unit = unit | extra;
1370	args.mda_devsw = csw;
1371	dev = newdev(&args, ndev);
1372	if (dev->si_flags & SI_CLONELIST) {
1373		printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
1374		printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
1375		LIST_FOREACH(dev, &cd->head, si_clone) {
1376			printf("\t%p %s\n", dev, dev->si_name);
1377		}
1378		panic("foo");
1379	}
1380	KASSERT(!(dev->si_flags & SI_CLONELIST),
1381	    ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
1382	if (dl != NULL)
1383		LIST_INSERT_BEFORE(dl, dev, si_clone);
1384	else if (de != NULL)
1385		LIST_INSERT_AFTER(de, dev, si_clone);
1386	else
1387		LIST_INSERT_HEAD(&cd->head, dev, si_clone);
1388	dev->si_flags |= SI_CLONELIST;
1389	*up = unit;
1390	dev_unlock_and_free();
1391	return (1);
1392}
1393
1394/*
1395 * Kill everything still on the list.  The driver should already have
1396 * disposed of any softc hung of the struct cdev *'s at this time.
1397 */
1398void
1399clone_cleanup(struct clonedevs **cdp)
1400{
1401	struct cdev *dev;
1402	struct cdev_priv *cp;
1403	struct clonedevs *cd;
1404
1405	cd = *cdp;
1406	if (cd == NULL)
1407		return;
1408	dev_lock();
1409	while (!LIST_EMPTY(&cd->head)) {
1410		dev = LIST_FIRST(&cd->head);
1411		LIST_REMOVE(dev, si_clone);
1412		KASSERT(dev->si_flags & SI_CLONELIST,
1413		    ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1414		dev->si_flags &= ~SI_CLONELIST;
1415		cp = cdev2priv(dev);
1416		if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
1417			cp->cdp_flags |= CDP_SCHED_DTR;
1418			KASSERT(dev->si_flags & SI_NAMED,
1419				("Driver has goofed in cloning underways udev %jx unit %x",
1420				(uintmax_t)dev2udev(dev), dev2unit(dev)));
1421			destroy_devl(dev);
1422		}
1423	}
1424	dev_unlock_and_free();
1425	free(cd, M_DEVBUF);
1426	*cdp = NULL;
1427}
1428
1429static TAILQ_HEAD(, cdev_priv) dev_ddtr =
1430	TAILQ_HEAD_INITIALIZER(dev_ddtr);
1431static struct task dev_dtr_task = TASK_INITIALIZER(0, destroy_dev_tq, NULL);
1432
1433static void
1434destroy_dev_tq(void *ctx, int pending)
1435{
1436	struct cdev_priv *cp;
1437	struct cdev *dev;
1438	void (*cb)(void *);
1439	void *cb_arg;
1440
1441	dev_lock();
1442	while (!TAILQ_EMPTY(&dev_ddtr)) {
1443		cp = TAILQ_FIRST(&dev_ddtr);
1444		dev = &cp->cdp_c;
1445		KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
1446		    ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
1447		TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list);
1448		cb = cp->cdp_dtr_cb;
1449		cb_arg = cp->cdp_dtr_cb_arg;
1450		destroy_devl(dev);
1451		dev_unlock_and_free();
1452		dev_rel(dev);
1453		if (cb != NULL)
1454			cb(cb_arg);
1455		dev_lock();
1456	}
1457	dev_unlock();
1458}
1459
1460/*
1461 * devmtx shall be locked on entry. devmtx will be unlocked after
1462 * function return.
1463 */
1464static int
1465destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
1466{
1467	struct cdev_priv *cp;
1468
1469	dev_lock_assert_locked();
1470	cp = cdev2priv(dev);
1471	if (cp->cdp_flags & CDP_SCHED_DTR) {
1472		dev_unlock();
1473		return (0);
1474	}
1475	dev_refl(dev);
1476	cp->cdp_flags |= CDP_SCHED_DTR;
1477	cp->cdp_dtr_cb = cb;
1478	cp->cdp_dtr_cb_arg = arg;
1479	TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
1480	dev_unlock();
1481	taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task);
1482	return (1);
1483}
1484
1485int
1486destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
1487{
1488
1489	dev_lock();
1490	return (destroy_dev_sched_cbl(dev, cb, arg));
1491}
1492
1493int
1494destroy_dev_sched(struct cdev *dev)
1495{
1496
1497	return (destroy_dev_sched_cb(dev, NULL, NULL));
1498}
1499
1500void
1501destroy_dev_drain(struct cdevsw *csw)
1502{
1503
1504	dev_lock();
1505	while (!LIST_EMPTY(&csw->d_devs)) {
1506		msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
1507	}
1508	dev_unlock();
1509}
1510
1511void
1512drain_dev_clone_events(void)
1513{
1514
1515	sx_xlock(&clone_drain_lock);
1516	sx_xunlock(&clone_drain_lock);
1517}
1518
1519#include "opt_ddb.h"
1520#ifdef DDB
1521#include <sys/kernel.h>
1522
1523#include <ddb/ddb.h>
1524
1525DB_SHOW_COMMAND(cdev, db_show_cdev)
1526{
1527	struct cdev_priv *cdp;
1528	struct cdev *dev;
1529	u_int flags;
1530	char buf[512];
1531
1532	if (!have_addr) {
1533		TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
1534			dev = &cdp->cdp_c;
1535			db_printf("%s %p\n", dev->si_name, dev);
1536			if (db_pager_quit)
1537				break;
1538		}
1539		return;
1540	}
1541
1542	dev = (struct cdev *)addr;
1543	cdp = cdev2priv(dev);
1544	db_printf("dev %s ref %d use %ld thr %ld inuse %u fdpriv %p\n",
1545	    dev->si_name, dev->si_refcount, dev->si_usecount,
1546	    dev->si_threadcount, cdp->cdp_inuse, cdp->cdp_fdpriv.lh_first);
1547	db_printf("devsw %p si_drv0 %d si_drv1 %p si_drv2 %p\n",
1548	    dev->si_devsw, dev->si_drv0, dev->si_drv1, dev->si_drv2);
1549	flags = dev->si_flags;
1550#define	SI_FLAG(flag)	do {						\
1551	if (flags & (flag)) {						\
1552		if (buf[0] != '\0')					\
1553			strlcat(buf, ", ", sizeof(buf));		\
1554		strlcat(buf, (#flag) + 3, sizeof(buf));			\
1555		flags &= ~(flag);					\
1556	}								\
1557} while (0)
1558	buf[0] = '\0';
1559	SI_FLAG(SI_ETERNAL);
1560	SI_FLAG(SI_ALIAS);
1561	SI_FLAG(SI_NAMED);
1562	SI_FLAG(SI_CHILD);
1563	SI_FLAG(SI_DUMPDEV);
1564	SI_FLAG(SI_CLONELIST);
1565	db_printf("si_flags %s\n", buf);
1566
1567	flags = cdp->cdp_flags;
1568#define	CDP_FLAG(flag)	do {						\
1569	if (flags & (flag)) {						\
1570		if (buf[0] != '\0')					\
1571			strlcat(buf, ", ", sizeof(buf));		\
1572		strlcat(buf, (#flag) + 4, sizeof(buf));			\
1573		flags &= ~(flag);					\
1574	}								\
1575} while (0)
1576	buf[0] = '\0';
1577	CDP_FLAG(CDP_ACTIVE);
1578	CDP_FLAG(CDP_SCHED_DTR);
1579	db_printf("cdp_flags %s\n", buf);
1580}
1581#endif
1582