xref: /freebsd/sys/kern/kern_conf.c (revision 3e65b9c6e6b7b2081d54e1dc40983c3c00eaf738)
1 /*-
2  * Copyright (c) 1999-2002 Poul-Henning Kamp
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/systm.h>
33 #include <sys/bus.h>
34 #include <sys/bio.h>
35 #include <sys/lock.h>
36 #include <sys/mutex.h>
37 #include <sys/module.h>
38 #include <sys/malloc.h>
39 #include <sys/conf.h>
40 #include <sys/vnode.h>
41 #include <sys/queue.h>
42 #include <sys/poll.h>
43 #include <sys/sx.h>
44 #include <sys/ctype.h>
45 #include <sys/ucred.h>
46 #include <sys/taskqueue.h>
47 #include <machine/stdarg.h>
48 
49 #include <fs/devfs/devfs_int.h>
50 #include <vm/vm.h>
51 
52 static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage");
53 
54 struct mtx devmtx;
55 static void destroy_devl(struct cdev *dev);
56 static int destroy_dev_sched_cbl(struct cdev *dev,
57     void (*cb)(void *), void *arg);
58 static void destroy_dev_tq(void *ctx, int pending);
59 static int make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw,
60     int unit, struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
61     va_list ap);
62 
63 static struct cdev_priv_list cdevp_free_list =
64     TAILQ_HEAD_INITIALIZER(cdevp_free_list);
65 static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list =
66     SLIST_HEAD_INITIALIZER(cdevsw_gt_post_list);
67 
68 void
69 dev_lock(void)
70 {
71 
72 	mtx_lock(&devmtx);
73 }
74 
75 /*
76  * Free all the memory collected while the cdev mutex was
77  * locked. Since devmtx is after the system map mutex, free() cannot
78  * be called immediately and is postponed until cdev mutex can be
79  * dropped.
80  */
81 static void
82 dev_unlock_and_free(void)
83 {
84 	struct cdev_priv_list cdp_free;
85 	struct free_cdevsw csw_free;
86 	struct cdev_priv *cdp;
87 	struct cdevsw *csw;
88 
89 	mtx_assert(&devmtx, MA_OWNED);
90 
91 	/*
92 	 * Make the local copy of the list heads while the dev_mtx is
93 	 * held. Free it later.
94 	 */
95 	TAILQ_INIT(&cdp_free);
96 	TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list);
97 	csw_free = cdevsw_gt_post_list;
98 	SLIST_INIT(&cdevsw_gt_post_list);
99 
100 	mtx_unlock(&devmtx);
101 
102 	while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) {
103 		TAILQ_REMOVE(&cdp_free, cdp, cdp_list);
104 		devfs_free(&cdp->cdp_c);
105 	}
106 	while ((csw = SLIST_FIRST(&csw_free)) != NULL) {
107 		SLIST_REMOVE_HEAD(&csw_free, d_postfree_list);
108 		free(csw, M_DEVT);
109 	}
110 }
111 
112 static void
113 dev_free_devlocked(struct cdev *cdev)
114 {
115 	struct cdev_priv *cdp;
116 
117 	mtx_assert(&devmtx, MA_OWNED);
118 	cdp = cdev2priv(cdev);
119 	TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list);
120 }
121 
122 static void
123 cdevsw_free_devlocked(struct cdevsw *csw)
124 {
125 
126 	mtx_assert(&devmtx, MA_OWNED);
127 	SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list);
128 }
129 
130 void
131 dev_unlock(void)
132 {
133 
134 	mtx_unlock(&devmtx);
135 }
136 
137 void
138 dev_ref(struct cdev *dev)
139 {
140 
141 	mtx_assert(&devmtx, MA_NOTOWNED);
142 	mtx_lock(&devmtx);
143 	dev->si_refcount++;
144 	mtx_unlock(&devmtx);
145 }
146 
147 void
148 dev_refl(struct cdev *dev)
149 {
150 
151 	mtx_assert(&devmtx, MA_OWNED);
152 	dev->si_refcount++;
153 }
154 
155 void
156 dev_rel(struct cdev *dev)
157 {
158 	int flag = 0;
159 
160 	mtx_assert(&devmtx, MA_NOTOWNED);
161 	dev_lock();
162 	dev->si_refcount--;
163 	KASSERT(dev->si_refcount >= 0,
164 	    ("dev_rel(%s) gave negative count", devtoname(dev)));
165 #if 0
166 	if (dev->si_usecount == 0 &&
167 	    (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED))
168 		;
169 	else
170 #endif
171 	if (dev->si_devsw == NULL && dev->si_refcount == 0) {
172 		LIST_REMOVE(dev, si_list);
173 		flag = 1;
174 	}
175 	dev_unlock();
176 	if (flag)
177 		devfs_free(dev);
178 }
179 
180 struct cdevsw *
181 dev_refthread(struct cdev *dev, int *ref)
182 {
183 	struct cdevsw *csw;
184 	struct cdev_priv *cdp;
185 
186 	mtx_assert(&devmtx, MA_NOTOWNED);
187 	if ((dev->si_flags & SI_ETERNAL) != 0) {
188 		*ref = 0;
189 		return (dev->si_devsw);
190 	}
191 	dev_lock();
192 	csw = dev->si_devsw;
193 	if (csw != NULL) {
194 		cdp = cdev2priv(dev);
195 		if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
196 			dev->si_threadcount++;
197 		else
198 			csw = NULL;
199 	}
200 	dev_unlock();
201 	*ref = 1;
202 	return (csw);
203 }
204 
205 struct cdevsw *
206 devvn_refthread(struct vnode *vp, struct cdev **devp, int *ref)
207 {
208 	struct cdevsw *csw;
209 	struct cdev_priv *cdp;
210 	struct cdev *dev;
211 
212 	mtx_assert(&devmtx, MA_NOTOWNED);
213 	if ((vp->v_vflag & VV_ETERNALDEV) != 0) {
214 		dev = vp->v_rdev;
215 		if (dev == NULL)
216 			return (NULL);
217 		KASSERT((dev->si_flags & SI_ETERNAL) != 0,
218 		    ("Not eternal cdev"));
219 		*ref = 0;
220 		csw = dev->si_devsw;
221 		KASSERT(csw != NULL, ("Eternal cdev is destroyed"));
222 		*devp = dev;
223 		return (csw);
224 	}
225 
226 	csw = NULL;
227 	dev_lock();
228 	dev = vp->v_rdev;
229 	if (dev == NULL) {
230 		dev_unlock();
231 		return (NULL);
232 	}
233 	cdp = cdev2priv(dev);
234 	if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
235 		csw = dev->si_devsw;
236 		if (csw != NULL)
237 			dev->si_threadcount++;
238 	}
239 	dev_unlock();
240 	if (csw != NULL) {
241 		*devp = dev;
242 		*ref = 1;
243 	}
244 	return (csw);
245 }
246 
247 void
248 dev_relthread(struct cdev *dev, int ref)
249 {
250 
251 	mtx_assert(&devmtx, MA_NOTOWNED);
252 	if (!ref)
253 		return;
254 	dev_lock();
255 	KASSERT(dev->si_threadcount > 0,
256 	    ("%s threadcount is wrong", dev->si_name));
257 	dev->si_threadcount--;
258 	dev_unlock();
259 }
260 
261 int
262 nullop(void)
263 {
264 
265 	return (0);
266 }
267 
268 int
269 eopnotsupp(void)
270 {
271 
272 	return (EOPNOTSUPP);
273 }
274 
275 static int
276 enxio(void)
277 {
278 	return (ENXIO);
279 }
280 
281 static int
282 enodev(void)
283 {
284 	return (ENODEV);
285 }
286 
287 /* Define a dead_cdevsw for use when devices leave unexpectedly. */
288 
289 #define dead_open	(d_open_t *)enxio
290 #define dead_close	(d_close_t *)enxio
291 #define dead_read	(d_read_t *)enxio
292 #define dead_write	(d_write_t *)enxio
293 #define dead_ioctl	(d_ioctl_t *)enxio
294 #define dead_poll	(d_poll_t *)enodev
295 #define dead_mmap	(d_mmap_t *)enodev
296 
297 static void
298 dead_strategy(struct bio *bp)
299 {
300 
301 	biofinish(bp, NULL, ENXIO);
302 }
303 
304 #define dead_dump	(dumper_t *)enxio
305 #define dead_kqfilter	(d_kqfilter_t *)enxio
306 #define dead_mmap_single (d_mmap_single_t *)enodev
307 
308 static struct cdevsw dead_cdevsw = {
309 	.d_version =	D_VERSION,
310 	.d_flags =	D_NEEDGIANT, /* XXX: does dead_strategy need this ? */
311 	.d_open =	dead_open,
312 	.d_close =	dead_close,
313 	.d_read =	dead_read,
314 	.d_write =	dead_write,
315 	.d_ioctl =	dead_ioctl,
316 	.d_poll =	dead_poll,
317 	.d_mmap =	dead_mmap,
318 	.d_strategy =	dead_strategy,
319 	.d_name =	"dead",
320 	.d_dump =	dead_dump,
321 	.d_kqfilter =	dead_kqfilter,
322 	.d_mmap_single = dead_mmap_single
323 };
324 
325 /* Default methods if driver does not specify method */
326 
327 #define null_open	(d_open_t *)nullop
328 #define null_close	(d_close_t *)nullop
329 #define no_read		(d_read_t *)enodev
330 #define no_write	(d_write_t *)enodev
331 #define no_ioctl	(d_ioctl_t *)enodev
332 #define no_mmap		(d_mmap_t *)enodev
333 #define no_kqfilter	(d_kqfilter_t *)enodev
334 #define no_mmap_single	(d_mmap_single_t *)enodev
335 
336 static void
337 no_strategy(struct bio *bp)
338 {
339 
340 	biofinish(bp, NULL, ENODEV);
341 }
342 
343 static int
344 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
345 {
346 
347 	return (poll_no_poll(events));
348 }
349 
350 #define no_dump		(dumper_t *)enodev
351 
352 static int
353 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
354 {
355 	struct cdevsw *dsw;
356 	int ref, retval;
357 
358 	dsw = dev_refthread(dev, &ref);
359 	if (dsw == NULL)
360 		return (ENXIO);
361 	mtx_lock(&Giant);
362 	retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
363 	mtx_unlock(&Giant);
364 	dev_relthread(dev, ref);
365 	return (retval);
366 }
367 
368 static int
369 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
370 {
371 	struct cdevsw *dsw;
372 	int ref, retval;
373 
374 	dsw = dev_refthread(dev, &ref);
375 	if (dsw == NULL)
376 		return (ENXIO);
377 	mtx_lock(&Giant);
378 	retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
379 	mtx_unlock(&Giant);
380 	dev_relthread(dev, ref);
381 	return (retval);
382 }
383 
384 static int
385 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
386 {
387 	struct cdevsw *dsw;
388 	int ref, retval;
389 
390 	dsw = dev_refthread(dev, &ref);
391 	if (dsw == NULL)
392 		return (ENXIO);
393 	mtx_lock(&Giant);
394 	retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
395 	mtx_unlock(&Giant);
396 	dev_relthread(dev, ref);
397 	return (retval);
398 }
399 
400 static void
401 giant_strategy(struct bio *bp)
402 {
403 	struct cdevsw *dsw;
404 	struct cdev *dev;
405 	int ref;
406 
407 	dev = bp->bio_dev;
408 	dsw = dev_refthread(dev, &ref);
409 	if (dsw == NULL) {
410 		biofinish(bp, NULL, ENXIO);
411 		return;
412 	}
413 	mtx_lock(&Giant);
414 	dsw->d_gianttrick->d_strategy(bp);
415 	mtx_unlock(&Giant);
416 	dev_relthread(dev, ref);
417 }
418 
419 static int
420 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
421 {
422 	struct cdevsw *dsw;
423 	int ref, retval;
424 
425 	dsw = dev_refthread(dev, &ref);
426 	if (dsw == NULL)
427 		return (ENXIO);
428 	mtx_lock(&Giant);
429 	retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
430 	mtx_unlock(&Giant);
431 	dev_relthread(dev, ref);
432 	return (retval);
433 }
434 
435 static int
436 giant_read(struct cdev *dev, struct uio *uio, int ioflag)
437 {
438 	struct cdevsw *dsw;
439 	int ref, retval;
440 
441 	dsw = dev_refthread(dev, &ref);
442 	if (dsw == NULL)
443 		return (ENXIO);
444 	mtx_lock(&Giant);
445 	retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
446 	mtx_unlock(&Giant);
447 	dev_relthread(dev, ref);
448 	return (retval);
449 }
450 
451 static int
452 giant_write(struct cdev *dev, struct uio *uio, int ioflag)
453 {
454 	struct cdevsw *dsw;
455 	int ref, retval;
456 
457 	dsw = dev_refthread(dev, &ref);
458 	if (dsw == NULL)
459 		return (ENXIO);
460 	mtx_lock(&Giant);
461 	retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
462 	mtx_unlock(&Giant);
463 	dev_relthread(dev, ref);
464 	return (retval);
465 }
466 
467 static int
468 giant_poll(struct cdev *dev, int events, struct thread *td)
469 {
470 	struct cdevsw *dsw;
471 	int ref, retval;
472 
473 	dsw = dev_refthread(dev, &ref);
474 	if (dsw == NULL)
475 		return (ENXIO);
476 	mtx_lock(&Giant);
477 	retval = dsw->d_gianttrick->d_poll(dev, events, td);
478 	mtx_unlock(&Giant);
479 	dev_relthread(dev, ref);
480 	return (retval);
481 }
482 
483 static int
484 giant_kqfilter(struct cdev *dev, struct knote *kn)
485 {
486 	struct cdevsw *dsw;
487 	int ref, retval;
488 
489 	dsw = dev_refthread(dev, &ref);
490 	if (dsw == NULL)
491 		return (ENXIO);
492 	mtx_lock(&Giant);
493 	retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
494 	mtx_unlock(&Giant);
495 	dev_relthread(dev, ref);
496 	return (retval);
497 }
498 
499 static int
500 giant_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, int nprot,
501     vm_memattr_t *memattr)
502 {
503 	struct cdevsw *dsw;
504 	int ref, retval;
505 
506 	dsw = dev_refthread(dev, &ref);
507 	if (dsw == NULL)
508 		return (ENXIO);
509 	mtx_lock(&Giant);
510 	retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot,
511 	    memattr);
512 	mtx_unlock(&Giant);
513 	dev_relthread(dev, ref);
514 	return (retval);
515 }
516 
517 static int
518 giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
519     vm_object_t *object, int nprot)
520 {
521 	struct cdevsw *dsw;
522 	int ref, retval;
523 
524 	dsw = dev_refthread(dev, &ref);
525 	if (dsw == NULL)
526 		return (ENXIO);
527 	mtx_lock(&Giant);
528 	retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object,
529 	    nprot);
530 	mtx_unlock(&Giant);
531 	dev_relthread(dev, ref);
532 	return (retval);
533 }
534 
535 static void
536 notify(struct cdev *dev, const char *ev, int flags)
537 {
538 	static const char prefix[] = "cdev=";
539 	char *data;
540 	int namelen, mflags;
541 
542 	if (cold)
543 		return;
544 	mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
545 	namelen = strlen(dev->si_name);
546 	data = malloc(namelen + sizeof(prefix), M_TEMP, mflags);
547 	if (data == NULL)
548 		return;
549 	memcpy(data, prefix, sizeof(prefix) - 1);
550 	memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
551 	devctl_notify_f("DEVFS", "CDEV", ev, data, mflags);
552 	free(data, M_TEMP);
553 }
554 
555 static void
556 notify_create(struct cdev *dev, int flags)
557 {
558 
559 	notify(dev, "CREATE", flags);
560 }
561 
562 static void
563 notify_destroy(struct cdev *dev)
564 {
565 
566 	notify(dev, "DESTROY", MAKEDEV_WAITOK);
567 }
568 
569 static struct cdev *
570 newdev(struct cdevsw *csw, int unit, struct cdev *si)
571 {
572 	struct cdev *si2;
573 
574 	mtx_assert(&devmtx, MA_OWNED);
575 	if (csw->d_flags & D_NEEDMINOR) {
576 		/* We may want to return an existing device */
577 		LIST_FOREACH(si2, &csw->d_devs, si_list) {
578 			if (dev2unit(si2) == unit) {
579 				dev_free_devlocked(si);
580 				return (si2);
581 			}
582 		}
583 	}
584 	si->si_drv0 = unit;
585 	si->si_devsw = csw;
586 	LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
587 	return (si);
588 }
589 
590 static void
591 fini_cdevsw(struct cdevsw *devsw)
592 {
593 	struct cdevsw *gt;
594 
595 	if (devsw->d_gianttrick != NULL) {
596 		gt = devsw->d_gianttrick;
597 		memcpy(devsw, gt, sizeof *devsw);
598 		cdevsw_free_devlocked(gt);
599 		devsw->d_gianttrick = NULL;
600 	}
601 	devsw->d_flags &= ~D_INIT;
602 }
603 
604 static int
605 prep_cdevsw(struct cdevsw *devsw, int flags)
606 {
607 	struct cdevsw *dsw2;
608 
609 	mtx_assert(&devmtx, MA_OWNED);
610 	if (devsw->d_flags & D_INIT)
611 		return (0);
612 	if (devsw->d_flags & D_NEEDGIANT) {
613 		dev_unlock();
614 		dsw2 = malloc(sizeof *dsw2, M_DEVT,
615 		     (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
616 		dev_lock();
617 		if (dsw2 == NULL && !(devsw->d_flags & D_INIT))
618 			return (ENOMEM);
619 	} else
620 		dsw2 = NULL;
621 	if (devsw->d_flags & D_INIT) {
622 		if (dsw2 != NULL)
623 			cdevsw_free_devlocked(dsw2);
624 		return (0);
625 	}
626 
627 	if (devsw->d_version != D_VERSION_03) {
628 		printf(
629 		    "WARNING: Device driver \"%s\" has wrong version %s\n",
630 		    devsw->d_name == NULL ? "???" : devsw->d_name,
631 		    "and is disabled.  Recompile KLD module.");
632 		devsw->d_open = dead_open;
633 		devsw->d_close = dead_close;
634 		devsw->d_read = dead_read;
635 		devsw->d_write = dead_write;
636 		devsw->d_ioctl = dead_ioctl;
637 		devsw->d_poll = dead_poll;
638 		devsw->d_mmap = dead_mmap;
639 		devsw->d_mmap_single = dead_mmap_single;
640 		devsw->d_strategy = dead_strategy;
641 		devsw->d_dump = dead_dump;
642 		devsw->d_kqfilter = dead_kqfilter;
643 	}
644 
645 	if (devsw->d_flags & D_NEEDGIANT) {
646 		if (devsw->d_gianttrick == NULL) {
647 			memcpy(dsw2, devsw, sizeof *dsw2);
648 			devsw->d_gianttrick = dsw2;
649 			dsw2 = NULL;
650 		}
651 	}
652 
653 #define FIXUP(member, noop, giant) 				\
654 	do {							\
655 		if (devsw->member == NULL) {			\
656 			devsw->member = noop;			\
657 		} else if (devsw->d_flags & D_NEEDGIANT)	\
658 			devsw->member = giant;			\
659 		}						\
660 	while (0)
661 
662 	FIXUP(d_open,		null_open,	giant_open);
663 	FIXUP(d_fdopen,		NULL,		giant_fdopen);
664 	FIXUP(d_close,		null_close,	giant_close);
665 	FIXUP(d_read,		no_read,	giant_read);
666 	FIXUP(d_write,		no_write,	giant_write);
667 	FIXUP(d_ioctl,		no_ioctl,	giant_ioctl);
668 	FIXUP(d_poll,		no_poll,	giant_poll);
669 	FIXUP(d_mmap,		no_mmap,	giant_mmap);
670 	FIXUP(d_strategy,	no_strategy,	giant_strategy);
671 	FIXUP(d_kqfilter,	no_kqfilter,	giant_kqfilter);
672 	FIXUP(d_mmap_single,	no_mmap_single,	giant_mmap_single);
673 
674 	if (devsw->d_dump == NULL)	devsw->d_dump = no_dump;
675 
676 	LIST_INIT(&devsw->d_devs);
677 
678 	devsw->d_flags |= D_INIT;
679 
680 	if (dsw2 != NULL)
681 		cdevsw_free_devlocked(dsw2);
682 	return (0);
683 }
684 
685 static int
686 prep_devname(struct cdev *dev, const char *fmt, va_list ap)
687 {
688 	int len;
689 	char *from, *q, *s, *to;
690 
691 	mtx_assert(&devmtx, MA_OWNED);
692 
693 	len = vsnrprintf(dev->__si_namebuf, sizeof(dev->__si_namebuf), 32,
694 	    fmt, ap);
695 	if (len > sizeof(dev->__si_namebuf) - 1)
696 		return (ENAMETOOLONG);
697 
698 	/* Strip leading slashes. */
699 	for (from = dev->__si_namebuf; *from == '/'; from++)
700 		;
701 
702 	for (to = dev->__si_namebuf; *from != '\0'; from++, to++) {
703 		/* Treat multiple sequential slashes as single. */
704 		while (from[0] == '/' && from[1] == '/')
705 			from++;
706 		/* Trailing slash is considered invalid. */
707 		if (from[0] == '/' && from[1] == '\0')
708 			return (EINVAL);
709 		*to = *from;
710 	}
711 	*to = '\0';
712 
713 	if (dev->__si_namebuf[0] == '\0')
714 		return (EINVAL);
715 
716 	/* Disallow "." and ".." components. */
717 	for (s = dev->__si_namebuf;;) {
718 		for (q = s; *q != '/' && *q != '\0'; q++)
719 			;
720 		if (q - s == 1 && s[0] == '.')
721 			return (EINVAL);
722 		if (q - s == 2 && s[0] == '.' && s[1] == '.')
723 			return (EINVAL);
724 		if (*q != '/')
725 			break;
726 		s = q + 1;
727 	}
728 
729 	if (devfs_dev_exists(dev->__si_namebuf) != 0)
730 		return (EEXIST);
731 
732 	return (0);
733 }
734 
735 static int
736 make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw, int unit,
737     struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
738     va_list ap)
739 {
740 	struct cdev *dev, *dev_new;
741 	int res;
742 
743 	KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
744 	    ("make_dev_credv: both WAITOK and NOWAIT specified"));
745 	dev_new = devfs_alloc(flags);
746 	if (dev_new == NULL)
747 		return (ENOMEM);
748 	dev_lock();
749 	res = prep_cdevsw(devsw, flags);
750 	if (res != 0) {
751 		dev_unlock();
752 		devfs_free(dev_new);
753 		return (res);
754 	}
755 	dev = newdev(devsw, unit, dev_new);
756 	if ((dev->si_flags & SI_NAMED) == 0) {
757 		res = prep_devname(dev, fmt, ap);
758 		if (res != 0) {
759 			if ((flags & MAKEDEV_CHECKNAME) == 0) {
760 				panic(
761 			"make_dev_credv: bad si_name (error=%d, si_name=%s)",
762 				    res, dev->si_name);
763 			}
764 			if (dev == dev_new) {
765 				LIST_REMOVE(dev, si_list);
766 				dev_unlock();
767 				devfs_free(dev);
768 			} else
769 				dev_unlock();
770 			return (res);
771 		}
772 	}
773 	if (flags & MAKEDEV_REF)
774 		dev_refl(dev);
775 	if (flags & MAKEDEV_ETERNAL)
776 		dev->si_flags |= SI_ETERNAL;
777 	if (dev->si_flags & SI_CHEAPCLONE &&
778 	    dev->si_flags & SI_NAMED) {
779 		/*
780 		 * This is allowed as it removes races and generally
781 		 * simplifies cloning devices.
782 		 * XXX: still ??
783 		 */
784 		dev_unlock_and_free();
785 		*dres = dev;
786 		return (0);
787 	}
788 	KASSERT(!(dev->si_flags & SI_NAMED),
789 	    ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
790 	    devsw->d_name, dev2unit(dev), devtoname(dev)));
791 	dev->si_flags |= SI_NAMED;
792 	if (cr != NULL)
793 		dev->si_cred = crhold(cr);
794 	dev->si_uid = uid;
795 	dev->si_gid = gid;
796 	dev->si_mode = mode;
797 
798 	devfs_create(dev);
799 	clean_unrhdrl(devfs_inos);
800 	dev_unlock_and_free();
801 
802 	notify_create(dev, flags);
803 
804 	*dres = dev;
805 	return (0);
806 }
807 
808 struct cdev *
809 make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
810     const char *fmt, ...)
811 {
812 	struct cdev *dev;
813 	va_list ap;
814 	int res;
815 
816 	va_start(ap, fmt);
817 	res = make_dev_credv(0, &dev, devsw, unit, NULL, uid, gid, mode, fmt,
818 	    ap);
819 	va_end(ap);
820 	KASSERT(res == 0 && dev != NULL,
821 	    ("make_dev: failed make_dev_credv (error=%d)", res));
822 	return (dev);
823 }
824 
825 struct cdev *
826 make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
827     gid_t gid, int mode, const char *fmt, ...)
828 {
829 	struct cdev *dev;
830 	va_list ap;
831 	int res;
832 
833 	va_start(ap, fmt);
834 	res = make_dev_credv(0, &dev, devsw, unit, cr, uid, gid, mode, fmt, ap);
835 	va_end(ap);
836 
837 	KASSERT(res == 0 && dev != NULL,
838 	    ("make_dev_cred: failed make_dev_credv (error=%d)", res));
839 	return (dev);
840 }
841 
842 struct cdev *
843 make_dev_credf(int flags, struct cdevsw *devsw, int unit, struct ucred *cr,
844     uid_t uid, gid_t gid, int mode, const char *fmt, ...)
845 {
846 	struct cdev *dev;
847 	va_list ap;
848 	int res;
849 
850 	va_start(ap, fmt);
851 	res = make_dev_credv(flags, &dev, devsw, unit, cr, uid, gid, mode,
852 	    fmt, ap);
853 	va_end(ap);
854 
855 	KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
856 	    ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
857 	    ("make_dev_credf: failed make_dev_credv (error=%d)", res));
858 	return (res == 0 ? dev : NULL);
859 }
860 
861 int
862 make_dev_p(int flags, struct cdev **cdev, struct cdevsw *devsw,
863     struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, ...)
864 {
865 	va_list ap;
866 	int res;
867 
868 	va_start(ap, fmt);
869 	res = make_dev_credv(flags, cdev, devsw, 0, cr, uid, gid, mode,
870 	    fmt, ap);
871 	va_end(ap);
872 
873 	KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
874 	    ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
875 	    ("make_dev_p: failed make_dev_credv (error=%d)", res));
876 	return (res);
877 }
878 
879 static void
880 dev_dependsl(struct cdev *pdev, struct cdev *cdev)
881 {
882 
883 	cdev->si_parent = pdev;
884 	cdev->si_flags |= SI_CHILD;
885 	LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
886 }
887 
888 
889 void
890 dev_depends(struct cdev *pdev, struct cdev *cdev)
891 {
892 
893 	dev_lock();
894 	dev_dependsl(pdev, cdev);
895 	dev_unlock();
896 }
897 
898 static int
899 make_dev_alias_v(int flags, struct cdev **cdev, struct cdev *pdev,
900     const char *fmt, va_list ap)
901 {
902 	struct cdev *dev;
903 	int error;
904 
905 	KASSERT(pdev != NULL, ("make_dev_alias_v: pdev is NULL"));
906 	KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
907 	    ("make_dev_alias_v: both WAITOK and NOWAIT specified"));
908 	KASSERT((flags & ~(MAKEDEV_WAITOK | MAKEDEV_NOWAIT |
909 	    MAKEDEV_CHECKNAME)) == 0,
910 	    ("make_dev_alias_v: invalid flags specified (flags=%02x)", flags));
911 
912 	dev = devfs_alloc(flags);
913 	if (dev == NULL)
914 		return (ENOMEM);
915 	dev_lock();
916 	dev->si_flags |= SI_ALIAS;
917 	error = prep_devname(dev, fmt, ap);
918 	if (error != 0) {
919 		if ((flags & MAKEDEV_CHECKNAME) == 0) {
920 			panic("make_dev_alias_v: bad si_name "
921 			    "(error=%d, si_name=%s)", error, dev->si_name);
922 		}
923 		dev_unlock();
924 		devfs_free(dev);
925 		return (error);
926 	}
927 	dev->si_flags |= SI_NAMED;
928 	devfs_create(dev);
929 	dev_dependsl(pdev, dev);
930 	clean_unrhdrl(devfs_inos);
931 	dev_unlock();
932 
933 	notify_create(dev, flags);
934 	*cdev = dev;
935 
936 	return (0);
937 }
938 
939 struct cdev *
940 make_dev_alias(struct cdev *pdev, const char *fmt, ...)
941 {
942 	struct cdev *dev;
943 	va_list ap;
944 	int res;
945 
946 	va_start(ap, fmt);
947 	res = make_dev_alias_v(MAKEDEV_WAITOK, &dev, pdev, fmt, ap);
948 	va_end(ap);
949 
950 	KASSERT(res == 0 && dev != NULL,
951 	    ("make_dev_alias: failed make_dev_alias_v (error=%d)", res));
952 	return (dev);
953 }
954 
955 int
956 make_dev_alias_p(int flags, struct cdev **cdev, struct cdev *pdev,
957     const char *fmt, ...)
958 {
959 	va_list ap;
960 	int res;
961 
962 	va_start(ap, fmt);
963 	res = make_dev_alias_v(flags, cdev, pdev, fmt, ap);
964 	va_end(ap);
965 	return (res);
966 }
967 
968 int
969 make_dev_physpath_alias(int flags, struct cdev **cdev, struct cdev *pdev,
970     struct cdev *old_alias, const char *physpath)
971 {
972 	char *devfspath;
973 	int physpath_len;
974 	int max_parentpath_len;
975 	int parentpath_len;
976 	int devfspathbuf_len;
977 	int mflags;
978 	int ret;
979 
980 	*cdev = NULL;
981 	devfspath = NULL;
982 	physpath_len = strlen(physpath);
983 	ret = EINVAL;
984 	if (physpath_len == 0)
985 		goto out;
986 
987 	if (strncmp("id1,", physpath, 4) == 0) {
988 		physpath += 4;
989 		physpath_len -= 4;
990 		if (physpath_len == 0)
991 			goto out;
992 	}
993 
994 	max_parentpath_len = SPECNAMELEN - physpath_len - /*/*/1;
995 	parentpath_len = strlen(pdev->si_name);
996 	if (max_parentpath_len < parentpath_len) {
997 		printf("make_dev_physpath_alias: WARNING - Unable to alias %s "
998 		    "to %s/%s - path too long\n",
999 		    pdev->si_name, physpath, pdev->si_name);
1000 		ret = ENAMETOOLONG;
1001 		goto out;
1002 	}
1003 
1004 	mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
1005 	devfspathbuf_len = physpath_len + /*/*/1 + parentpath_len + /*NUL*/1;
1006 	devfspath = malloc(devfspathbuf_len, M_DEVBUF, mflags);
1007 	if (devfspath == NULL) {
1008 		ret = ENOMEM;
1009 		goto out;
1010 	}
1011 
1012 	sprintf(devfspath, "%s/%s", physpath, pdev->si_name);
1013 	if (old_alias != NULL && strcmp(old_alias->si_name, devfspath) == 0) {
1014 		/* Retain the existing alias. */
1015 		*cdev = old_alias;
1016 		old_alias = NULL;
1017 		ret = 0;
1018 	} else {
1019 		ret = make_dev_alias_p(flags, cdev, pdev, "%s", devfspath);
1020 	}
1021 out:
1022 	if (old_alias != NULL)
1023 		destroy_dev(old_alias);
1024 	if (devfspath != NULL)
1025 		free(devfspath, M_DEVBUF);
1026 	return (ret);
1027 }
1028 
1029 static void
1030 destroy_devl(struct cdev *dev)
1031 {
1032 	struct cdevsw *csw;
1033 	struct cdev_privdata *p;
1034 
1035 	mtx_assert(&devmtx, MA_OWNED);
1036 	KASSERT(dev->si_flags & SI_NAMED,
1037 	    ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
1038 	KASSERT((dev->si_flags & SI_ETERNAL) == 0,
1039 	    ("WARNING: Driver mistake: destroy_dev on eternal %d\n",
1040 	     dev2unit(dev)));
1041 
1042 	devfs_destroy(dev);
1043 
1044 	/* Remove name marking */
1045 	dev->si_flags &= ~SI_NAMED;
1046 
1047 	dev->si_refcount++;	/* Avoid race with dev_rel() */
1048 
1049 	/* If we are a child, remove us from the parents list */
1050 	if (dev->si_flags & SI_CHILD) {
1051 		LIST_REMOVE(dev, si_siblings);
1052 		dev->si_flags &= ~SI_CHILD;
1053 	}
1054 
1055 	/* Kill our children */
1056 	while (!LIST_EMPTY(&dev->si_children))
1057 		destroy_devl(LIST_FIRST(&dev->si_children));
1058 
1059 	/* Remove from clone list */
1060 	if (dev->si_flags & SI_CLONELIST) {
1061 		LIST_REMOVE(dev, si_clone);
1062 		dev->si_flags &= ~SI_CLONELIST;
1063 	}
1064 
1065 	csw = dev->si_devsw;
1066 	dev->si_devsw = NULL;	/* already NULL for SI_ALIAS */
1067 	while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
1068 		csw->d_purge(dev);
1069 		msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
1070 		if (dev->si_threadcount)
1071 			printf("Still %lu threads in %s\n",
1072 			    dev->si_threadcount, devtoname(dev));
1073 	}
1074 	while (dev->si_threadcount != 0) {
1075 		/* Use unique dummy wait ident */
1076 		msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
1077 	}
1078 
1079 	dev_unlock();
1080 	notify_destroy(dev);
1081 	mtx_lock(&cdevpriv_mtx);
1082 	while ((p = LIST_FIRST(&cdev2priv(dev)->cdp_fdpriv)) != NULL) {
1083 		devfs_destroy_cdevpriv(p);
1084 		mtx_lock(&cdevpriv_mtx);
1085 	}
1086 	mtx_unlock(&cdevpriv_mtx);
1087 	dev_lock();
1088 
1089 	dev->si_drv1 = 0;
1090 	dev->si_drv2 = 0;
1091 	bzero(&dev->__si_u, sizeof(dev->__si_u));
1092 
1093 	if (!(dev->si_flags & SI_ALIAS)) {
1094 		/* Remove from cdevsw list */
1095 		LIST_REMOVE(dev, si_list);
1096 
1097 		/* If cdevsw has no more struct cdev *'s, clean it */
1098 		if (LIST_EMPTY(&csw->d_devs)) {
1099 			fini_cdevsw(csw);
1100 			wakeup(&csw->d_devs);
1101 		}
1102 	}
1103 	dev->si_flags &= ~SI_ALIAS;
1104 	dev->si_refcount--;	/* Avoid race with dev_rel() */
1105 
1106 	if (dev->si_refcount > 0) {
1107 		LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
1108 	} else {
1109 		dev_free_devlocked(dev);
1110 	}
1111 }
1112 
1113 void
1114 destroy_dev(struct cdev *dev)
1115 {
1116 
1117 	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
1118 	dev_lock();
1119 	destroy_devl(dev);
1120 	dev_unlock_and_free();
1121 }
1122 
1123 const char *
1124 devtoname(struct cdev *dev)
1125 {
1126 
1127 	return (dev->si_name);
1128 }
1129 
1130 int
1131 dev_stdclone(char *name, char **namep, const char *stem, int *unit)
1132 {
1133 	int u, i;
1134 
1135 	i = strlen(stem);
1136 	if (bcmp(stem, name, i) != 0)
1137 		return (0);
1138 	if (!isdigit(name[i]))
1139 		return (0);
1140 	u = 0;
1141 	if (name[i] == '0' && isdigit(name[i+1]))
1142 		return (0);
1143 	while (isdigit(name[i])) {
1144 		u *= 10;
1145 		u += name[i++] - '0';
1146 	}
1147 	if (u > 0xffffff)
1148 		return (0);
1149 	*unit = u;
1150 	if (namep)
1151 		*namep = &name[i];
1152 	if (name[i])
1153 		return (2);
1154 	return (1);
1155 }
1156 
1157 /*
1158  * Helper functions for cloning device drivers.
1159  *
1160  * The objective here is to make it unnecessary for the device drivers to
1161  * use rman or similar to manage their unit number space.  Due to the way
1162  * we do "on-demand" devices, using rman or other "private" methods
1163  * will be very tricky to lock down properly once we lock down this file.
1164  *
1165  * Instead we give the drivers these routines which puts the struct cdev *'s
1166  * that are to be managed on their own list, and gives the driver the ability
1167  * to ask for the first free unit number or a given specified unit number.
1168  *
1169  * In addition these routines support paired devices (pty, nmdm and similar)
1170  * by respecting a number of "flag" bits in the minor number.
1171  *
1172  */
1173 
1174 struct clonedevs {
1175 	LIST_HEAD(,cdev)	head;
1176 };
1177 
1178 void
1179 clone_setup(struct clonedevs **cdp)
1180 {
1181 
1182 	*cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
1183 	LIST_INIT(&(*cdp)->head);
1184 }
1185 
1186 int
1187 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up,
1188     struct cdev **dp, int extra)
1189 {
1190 	struct clonedevs *cd;
1191 	struct cdev *dev, *ndev, *dl, *de;
1192 	int unit, low, u;
1193 
1194 	KASSERT(*cdp != NULL,
1195 	    ("clone_setup() not called in driver \"%s\"", csw->d_name));
1196 	KASSERT(!(extra & CLONE_UNITMASK),
1197 	    ("Illegal extra bits (0x%x) in clone_create", extra));
1198 	KASSERT(*up <= CLONE_UNITMASK,
1199 	    ("Too high unit (0x%x) in clone_create", *up));
1200 	KASSERT(csw->d_flags & D_NEEDMINOR,
1201 	    ("clone_create() on cdevsw without minor numbers"));
1202 
1203 
1204 	/*
1205 	 * Search the list for a lot of things in one go:
1206 	 *   A preexisting match is returned immediately.
1207 	 *   The lowest free unit number if we are passed -1, and the place
1208 	 *	 in the list where we should insert that new element.
1209 	 *   The place to insert a specified unit number, if applicable
1210 	 *       the end of the list.
1211 	 */
1212 	unit = *up;
1213 	ndev = devfs_alloc(MAKEDEV_WAITOK);
1214 	dev_lock();
1215 	prep_cdevsw(csw, MAKEDEV_WAITOK);
1216 	low = extra;
1217 	de = dl = NULL;
1218 	cd = *cdp;
1219 	LIST_FOREACH(dev, &cd->head, si_clone) {
1220 		KASSERT(dev->si_flags & SI_CLONELIST,
1221 		    ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1222 		u = dev2unit(dev);
1223 		if (u == (unit | extra)) {
1224 			*dp = dev;
1225 			dev_unlock();
1226 			devfs_free(ndev);
1227 			return (0);
1228 		}
1229 		if (unit == -1 && u == low) {
1230 			low++;
1231 			de = dev;
1232 			continue;
1233 		} else if (u < (unit | extra)) {
1234 			de = dev;
1235 			continue;
1236 		} else if (u > (unit | extra)) {
1237 			dl = dev;
1238 			break;
1239 		}
1240 	}
1241 	if (unit == -1)
1242 		unit = low & CLONE_UNITMASK;
1243 	dev = newdev(csw, unit | extra, ndev);
1244 	if (dev->si_flags & SI_CLONELIST) {
1245 		printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
1246 		printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
1247 		LIST_FOREACH(dev, &cd->head, si_clone) {
1248 			printf("\t%p %s\n", dev, dev->si_name);
1249 		}
1250 		panic("foo");
1251 	}
1252 	KASSERT(!(dev->si_flags & SI_CLONELIST),
1253 	    ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
1254 	if (dl != NULL)
1255 		LIST_INSERT_BEFORE(dl, dev, si_clone);
1256 	else if (de != NULL)
1257 		LIST_INSERT_AFTER(de, dev, si_clone);
1258 	else
1259 		LIST_INSERT_HEAD(&cd->head, dev, si_clone);
1260 	dev->si_flags |= SI_CLONELIST;
1261 	*up = unit;
1262 	dev_unlock_and_free();
1263 	return (1);
1264 }
1265 
1266 /*
1267  * Kill everything still on the list.  The driver should already have
1268  * disposed of any softc hung of the struct cdev *'s at this time.
1269  */
1270 void
1271 clone_cleanup(struct clonedevs **cdp)
1272 {
1273 	struct cdev *dev;
1274 	struct cdev_priv *cp;
1275 	struct clonedevs *cd;
1276 
1277 	cd = *cdp;
1278 	if (cd == NULL)
1279 		return;
1280 	dev_lock();
1281 	while (!LIST_EMPTY(&cd->head)) {
1282 		dev = LIST_FIRST(&cd->head);
1283 		LIST_REMOVE(dev, si_clone);
1284 		KASSERT(dev->si_flags & SI_CLONELIST,
1285 		    ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1286 		dev->si_flags &= ~SI_CLONELIST;
1287 		cp = cdev2priv(dev);
1288 		if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
1289 			cp->cdp_flags |= CDP_SCHED_DTR;
1290 			KASSERT(dev->si_flags & SI_NAMED,
1291 				("Driver has goofed in cloning underways udev %x unit %x", dev2udev(dev), dev2unit(dev)));
1292 			destroy_devl(dev);
1293 		}
1294 	}
1295 	dev_unlock_and_free();
1296 	free(cd, M_DEVBUF);
1297 	*cdp = NULL;
1298 }
1299 
1300 static TAILQ_HEAD(, cdev_priv) dev_ddtr =
1301 	TAILQ_HEAD_INITIALIZER(dev_ddtr);
1302 static struct task dev_dtr_task = TASK_INITIALIZER(0, destroy_dev_tq, NULL);
1303 
1304 static void
1305 destroy_dev_tq(void *ctx, int pending)
1306 {
1307 	struct cdev_priv *cp;
1308 	struct cdev *dev;
1309 	void (*cb)(void *);
1310 	void *cb_arg;
1311 
1312 	dev_lock();
1313 	while (!TAILQ_EMPTY(&dev_ddtr)) {
1314 		cp = TAILQ_FIRST(&dev_ddtr);
1315 		dev = &cp->cdp_c;
1316 		KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
1317 		    ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
1318 		TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list);
1319 		cb = cp->cdp_dtr_cb;
1320 		cb_arg = cp->cdp_dtr_cb_arg;
1321 		destroy_devl(dev);
1322 		dev_unlock_and_free();
1323 		dev_rel(dev);
1324 		if (cb != NULL)
1325 			cb(cb_arg);
1326 		dev_lock();
1327 	}
1328 	dev_unlock();
1329 }
1330 
1331 /*
1332  * devmtx shall be locked on entry. devmtx will be unlocked after
1333  * function return.
1334  */
1335 static int
1336 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
1337 {
1338 	struct cdev_priv *cp;
1339 
1340 	mtx_assert(&devmtx, MA_OWNED);
1341 	cp = cdev2priv(dev);
1342 	if (cp->cdp_flags & CDP_SCHED_DTR) {
1343 		dev_unlock();
1344 		return (0);
1345 	}
1346 	dev_refl(dev);
1347 	cp->cdp_flags |= CDP_SCHED_DTR;
1348 	cp->cdp_dtr_cb = cb;
1349 	cp->cdp_dtr_cb_arg = arg;
1350 	TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
1351 	dev_unlock();
1352 	taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task);
1353 	return (1);
1354 }
1355 
1356 int
1357 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
1358 {
1359 
1360 	dev_lock();
1361 	return (destroy_dev_sched_cbl(dev, cb, arg));
1362 }
1363 
1364 int
1365 destroy_dev_sched(struct cdev *dev)
1366 {
1367 
1368 	return (destroy_dev_sched_cb(dev, NULL, NULL));
1369 }
1370 
1371 void
1372 destroy_dev_drain(struct cdevsw *csw)
1373 {
1374 
1375 	dev_lock();
1376 	while (!LIST_EMPTY(&csw->d_devs)) {
1377 		msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
1378 	}
1379 	dev_unlock();
1380 }
1381 
1382 void
1383 drain_dev_clone_events(void)
1384 {
1385 
1386 	sx_xlock(&clone_drain_lock);
1387 	sx_xunlock(&clone_drain_lock);
1388 }
1389 
1390 #include "opt_ddb.h"
1391 #ifdef DDB
1392 #include <sys/kernel.h>
1393 
1394 #include <ddb/ddb.h>
1395 
1396 DB_SHOW_COMMAND(cdev, db_show_cdev)
1397 {
1398 	struct cdev_priv *cdp;
1399 	struct cdev *dev;
1400 	u_int flags;
1401 	char buf[512];
1402 
1403 	if (!have_addr) {
1404 		TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
1405 			dev = &cdp->cdp_c;
1406 			db_printf("%s %p\n", dev->si_name, dev);
1407 			if (db_pager_quit)
1408 				break;
1409 		}
1410 		return;
1411 	}
1412 
1413 	dev = (struct cdev *)addr;
1414 	cdp = cdev2priv(dev);
1415 	db_printf("dev %s ref %d use %ld thr %ld inuse %u fdpriv %p\n",
1416 	    dev->si_name, dev->si_refcount, dev->si_usecount,
1417 	    dev->si_threadcount, cdp->cdp_inuse, cdp->cdp_fdpriv.lh_first);
1418 	db_printf("devsw %p si_drv0 %d si_drv1 %p si_drv2 %p\n",
1419 	    dev->si_devsw, dev->si_drv0, dev->si_drv1, dev->si_drv2);
1420 	flags = dev->si_flags;
1421 #define	SI_FLAG(flag)	do {						\
1422 	if (flags & (flag)) {						\
1423 		if (buf[0] != '\0')					\
1424 			strlcat(buf, ", ", sizeof(buf));		\
1425 		strlcat(buf, (#flag) + 3, sizeof(buf));			\
1426 		flags &= ~(flag);					\
1427 	}								\
1428 } while (0)
1429 	buf[0] = '\0';
1430 	SI_FLAG(SI_ETERNAL);
1431 	SI_FLAG(SI_ALIAS);
1432 	SI_FLAG(SI_NAMED);
1433 	SI_FLAG(SI_CHEAPCLONE);
1434 	SI_FLAG(SI_CHILD);
1435 	SI_FLAG(SI_DEVOPEN);
1436 	SI_FLAG(SI_CONSOPEN);
1437 	SI_FLAG(SI_DUMPDEV);
1438 	SI_FLAG(SI_CANDELETE);
1439 	SI_FLAG(SI_CLONELIST);
1440 	db_printf("si_flags %s\n", buf);
1441 
1442 	flags = cdp->cdp_flags;
1443 #define	CDP_FLAG(flag)	do {						\
1444 	if (flags & (flag)) {						\
1445 		if (buf[0] != '\0')					\
1446 			strlcat(buf, ", ", sizeof(buf));		\
1447 		strlcat(buf, (#flag) + 4, sizeof(buf));			\
1448 		flags &= ~(flag);					\
1449 	}								\
1450 } while (0)
1451 	buf[0] = '\0';
1452 	CDP_FLAG(CDP_ACTIVE);
1453 	CDP_FLAG(CDP_SCHED_DTR);
1454 	db_printf("cdp_flags %s\n", buf);
1455 }
1456 #endif
1457