1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
30 #include <sys/kernel.h>
31 #include <sys/systm.h>
32 #include <sys/bio.h>
33 #include <sys/devctl.h>
34 #include <sys/lock.h>
35 #include <sys/mutex.h>
36 #include <sys/module.h>
37 #include <sys/malloc.h>
38 #include <sys/conf.h>
39 #include <sys/vnode.h>
40 #include <sys/queue.h>
41 #include <sys/poll.h>
42 #include <sys/sx.h>
43 #include <sys/ctype.h>
44 #include <sys/ucred.h>
45 #include <sys/taskqueue.h>
46 #include <machine/stdarg.h>
47
48 #include <fs/devfs/devfs_int.h>
49 #include <vm/vm.h>
50
51 static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage");
52
53 struct mtx devmtx;
54 static void destroy_devl(struct cdev *dev);
55 static int destroy_dev_sched_cbl(struct cdev *dev,
56 void (*cb)(void *), void *arg);
57 static void destroy_dev_tq(void *ctx, int pending);
58 static void destroy_dev_tq_giant(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
dev_lock(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
dev_unlock_and_free(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 dev_lock_assert_locked();
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
dev_free_devlocked(struct cdev * cdev)113 dev_free_devlocked(struct cdev *cdev)
114 {
115 struct cdev_priv *cdp;
116
117 dev_lock_assert_locked();
118 cdp = cdev2priv(cdev);
119 KASSERT((cdp->cdp_flags & CDP_UNREF_DTR) == 0,
120 ("destroy_dev() was not called after delist_dev(%p)", cdev));
121 KASSERT((cdp->cdp_flags & CDP_ON_ACTIVE_LIST) == 0,
122 ("%s: cdp %p (%s) on active list", __func__, cdp, cdev->si_name));
123 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list);
124 }
125
126 static void
cdevsw_free_devlocked(struct cdevsw * csw)127 cdevsw_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
134 void
dev_unlock(void)135 dev_unlock(void)
136 {
137
138 mtx_unlock(&devmtx);
139 }
140
141 void
dev_ref(struct cdev * dev)142 dev_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
151 void
dev_refl(struct cdev * dev)152 dev_refl(struct cdev *dev)
153 {
154
155 dev_lock_assert_locked();
156 dev->si_refcount++;
157 }
158
159 void
dev_rel(struct cdev * dev)160 dev_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
178 struct cdevsw *
dev_refthread(struct cdev * dev,int * ref)179 dev_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
204 struct cdevsw *
devvn_refthread(struct vnode * vp,struct cdev ** devp,int * ref)205 devvn_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
248 void
dev_relthread(struct cdev * dev,int ref)249 dev_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
260 int
nullop(void)261 nullop(void)
262 {
263
264 return (0);
265 }
266
267 int
eopnotsupp(void)268 eopnotsupp(void)
269 {
270
271 return (EOPNOTSUPP);
272 }
273
274 static int
enxio(void)275 enxio(void)
276 {
277 return (ENXIO);
278 }
279
280 static int
enodev(void)281 enodev(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
296 static void
dead_strategy(struct bio * bp)297 dead_strategy(struct bio *bp)
298 {
299
300 biofinish(bp, NULL, ENXIO);
301 }
302
303 #define dead_kqfilter (d_kqfilter_t *)enxio
304 #define dead_mmap_single (d_mmap_single_t *)enodev
305
306 static struct cdevsw dead_cdevsw = {
307 .d_version = D_VERSION,
308 .d_open = dead_open,
309 .d_close = dead_close,
310 .d_read = dead_read,
311 .d_write = dead_write,
312 .d_ioctl = dead_ioctl,
313 .d_poll = dead_poll,
314 .d_mmap = dead_mmap,
315 .d_strategy = dead_strategy,
316 .d_name = "dead",
317 .d_kqfilter = dead_kqfilter,
318 .d_mmap_single = dead_mmap_single
319 };
320
321 /* Default methods if driver does not specify method */
322
323 #define null_open (d_open_t *)nullop
324 #define null_close (d_close_t *)nullop
325 #define no_read (d_read_t *)enodev
326 #define no_write (d_write_t *)enodev
327 #define no_ioctl (d_ioctl_t *)enodev
328 #define no_mmap (d_mmap_t *)enodev
329 #define no_kqfilter (d_kqfilter_t *)enodev
330 #define no_mmap_single (d_mmap_single_t *)enodev
331
332 static void
no_strategy(struct bio * bp)333 no_strategy(struct bio *bp)
334 {
335
336 biofinish(bp, NULL, ENODEV);
337 }
338
339 static int
no_poll(struct cdev * dev __unused,int events,struct thread * td __unused)340 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
341 {
342
343 return (poll_no_poll(events));
344 }
345
346 static int
giant_open(struct cdev * dev,int oflags,int devtype,struct thread * td)347 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
348 {
349 struct cdevsw *dsw;
350 int ref, retval;
351
352 dsw = dev_refthread(dev, &ref);
353 if (dsw == NULL)
354 return (ENXIO);
355 mtx_lock(&Giant);
356 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
357 mtx_unlock(&Giant);
358 dev_relthread(dev, ref);
359 return (retval);
360 }
361
362 static int
giant_fdopen(struct cdev * dev,int oflags,struct thread * td,struct file * fp)363 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
364 {
365 struct cdevsw *dsw;
366 int ref, retval;
367
368 dsw = dev_refthread(dev, &ref);
369 if (dsw == NULL)
370 return (ENXIO);
371 mtx_lock(&Giant);
372 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
373 mtx_unlock(&Giant);
374 dev_relthread(dev, ref);
375 return (retval);
376 }
377
378 static int
giant_close(struct cdev * dev,int fflag,int devtype,struct thread * td)379 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
380 {
381 struct cdevsw *dsw;
382 int ref, retval;
383
384 dsw = dev_refthread(dev, &ref);
385 if (dsw == NULL)
386 return (ENXIO);
387 mtx_lock(&Giant);
388 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
389 mtx_unlock(&Giant);
390 dev_relthread(dev, ref);
391 return (retval);
392 }
393
394 static void
giant_strategy(struct bio * bp)395 giant_strategy(struct bio *bp)
396 {
397 struct cdevsw *dsw;
398 struct cdev *dev;
399 int ref;
400
401 dev = bp->bio_dev;
402 dsw = dev_refthread(dev, &ref);
403 if (dsw == NULL) {
404 biofinish(bp, NULL, ENXIO);
405 return;
406 }
407 mtx_lock(&Giant);
408 dsw->d_gianttrick->d_strategy(bp);
409 mtx_unlock(&Giant);
410 dev_relthread(dev, ref);
411 }
412
413 static int
giant_ioctl(struct cdev * dev,u_long cmd,caddr_t data,int fflag,struct thread * td)414 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
415 {
416 struct cdevsw *dsw;
417 int ref, retval;
418
419 dsw = dev_refthread(dev, &ref);
420 if (dsw == NULL)
421 return (ENXIO);
422 mtx_lock(&Giant);
423 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
424 mtx_unlock(&Giant);
425 dev_relthread(dev, ref);
426 return (retval);
427 }
428
429 static int
giant_read(struct cdev * dev,struct uio * uio,int ioflag)430 giant_read(struct cdev *dev, struct uio *uio, int ioflag)
431 {
432 struct cdevsw *dsw;
433 int ref, retval;
434
435 dsw = dev_refthread(dev, &ref);
436 if (dsw == NULL)
437 return (ENXIO);
438 mtx_lock(&Giant);
439 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
440 mtx_unlock(&Giant);
441 dev_relthread(dev, ref);
442 return (retval);
443 }
444
445 static int
giant_write(struct cdev * dev,struct uio * uio,int ioflag)446 giant_write(struct cdev *dev, struct uio *uio, int ioflag)
447 {
448 struct cdevsw *dsw;
449 int ref, retval;
450
451 dsw = dev_refthread(dev, &ref);
452 if (dsw == NULL)
453 return (ENXIO);
454 mtx_lock(&Giant);
455 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
456 mtx_unlock(&Giant);
457 dev_relthread(dev, ref);
458 return (retval);
459 }
460
461 static int
giant_poll(struct cdev * dev,int events,struct thread * td)462 giant_poll(struct cdev *dev, int events, struct thread *td)
463 {
464 struct cdevsw *dsw;
465 int ref, retval;
466
467 dsw = dev_refthread(dev, &ref);
468 if (dsw == NULL)
469 return (ENXIO);
470 mtx_lock(&Giant);
471 retval = dsw->d_gianttrick->d_poll(dev, events, td);
472 mtx_unlock(&Giant);
473 dev_relthread(dev, ref);
474 return (retval);
475 }
476
477 static int
giant_kqfilter(struct cdev * dev,struct knote * kn)478 giant_kqfilter(struct cdev *dev, struct knote *kn)
479 {
480 struct cdevsw *dsw;
481 int ref, retval;
482
483 dsw = dev_refthread(dev, &ref);
484 if (dsw == NULL)
485 return (ENXIO);
486 mtx_lock(&Giant);
487 retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
488 mtx_unlock(&Giant);
489 dev_relthread(dev, ref);
490 return (retval);
491 }
492
493 static int
giant_mmap(struct cdev * dev,vm_ooffset_t offset,vm_paddr_t * paddr,int nprot,vm_memattr_t * memattr)494 giant_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, int nprot,
495 vm_memattr_t *memattr)
496 {
497 struct cdevsw *dsw;
498 int ref, retval;
499
500 dsw = dev_refthread(dev, &ref);
501 if (dsw == NULL)
502 return (ENXIO);
503 mtx_lock(&Giant);
504 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot,
505 memattr);
506 mtx_unlock(&Giant);
507 dev_relthread(dev, ref);
508 return (retval);
509 }
510
511 static int
giant_mmap_single(struct cdev * dev,vm_ooffset_t * offset,vm_size_t size,vm_object_t * object,int nprot)512 giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
513 vm_object_t *object, int nprot)
514 {
515 struct cdevsw *dsw;
516 int ref, retval;
517
518 dsw = dev_refthread(dev, &ref);
519 if (dsw == NULL)
520 return (ENXIO);
521 mtx_lock(&Giant);
522 retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object,
523 nprot);
524 mtx_unlock(&Giant);
525 dev_relthread(dev, ref);
526 return (retval);
527 }
528
529 static void
notify(struct cdev * dev,const char * ev,int flags)530 notify(struct cdev *dev, const char *ev, int flags)
531 {
532 static const char prefix[] = "cdev=";
533 char *data;
534 int namelen, mflags;
535
536 if (cold)
537 return;
538 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
539 namelen = strlen(dev->si_name);
540 data = malloc(namelen + sizeof(prefix), M_TEMP, mflags);
541 if (data == NULL)
542 return;
543 memcpy(data, prefix, sizeof(prefix) - 1);
544 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
545 devctl_notify("DEVFS", "CDEV", ev, data);
546 free(data, M_TEMP);
547 }
548
549 static void
notify_create(struct cdev * dev,int flags)550 notify_create(struct cdev *dev, int flags)
551 {
552
553 notify(dev, "CREATE", flags);
554 }
555
556 static void
notify_destroy(struct cdev * dev)557 notify_destroy(struct cdev *dev)
558 {
559
560 notify(dev, "DESTROY", MAKEDEV_WAITOK);
561 }
562
563 static struct cdev *
newdev(struct make_dev_args * args,struct cdev * si)564 newdev(struct make_dev_args *args, struct cdev *si)
565 {
566 struct cdev *si2;
567 struct cdevsw *csw;
568
569 dev_lock_assert_locked();
570 csw = args->mda_devsw;
571 si2 = NULL;
572 if (csw->d_flags & D_NEEDMINOR) {
573 /* We may want to return an existing device */
574 LIST_FOREACH(si2, &csw->d_devs, si_list) {
575 if (dev2unit(si2) == args->mda_unit) {
576 dev_free_devlocked(si);
577 si = si2;
578 break;
579 }
580 }
581
582 /*
583 * If we're returning an existing device, we should make sure
584 * it isn't already initialized. This would have been caught
585 * in consumers anyways, but it's good to catch such a case
586 * early. We still need to complete initialization of the
587 * device, and we'll use whatever make_dev_args were passed in
588 * to do so.
589 */
590 KASSERT(si2 == NULL || (si2->si_flags & SI_NAMED) == 0,
591 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
592 args->mda_devsw->d_name, dev2unit(si2), devtoname(si2)));
593 }
594 si->si_drv0 = args->mda_unit;
595 si->si_drv1 = args->mda_si_drv1;
596 si->si_drv2 = args->mda_si_drv2;
597 /* Only push to csw->d_devs if it's not a cloned device. */
598 if (si2 == NULL) {
599 si->si_devsw = csw;
600 LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
601 } else {
602 KASSERT(si->si_devsw == csw,
603 ("%s: inconsistent devsw between clone_create() and make_dev()",
604 __func__));
605 }
606 return (si);
607 }
608
609 static void
fini_cdevsw(struct cdevsw * devsw)610 fini_cdevsw(struct cdevsw *devsw)
611 {
612 struct cdevsw *gt;
613
614 if (devsw->d_gianttrick != NULL) {
615 gt = devsw->d_gianttrick;
616 memcpy(devsw, gt, sizeof *devsw);
617 cdevsw_free_devlocked(gt);
618 devsw->d_gianttrick = NULL;
619 }
620 devsw->d_flags &= ~D_INIT;
621 }
622
623 static int
prep_cdevsw(struct cdevsw * devsw,int flags)624 prep_cdevsw(struct cdevsw *devsw, int flags)
625 {
626 struct cdevsw *dsw2;
627
628 dev_lock_assert_locked();
629 if (devsw->d_flags & D_INIT)
630 return (0);
631 if (devsw->d_flags & D_NEEDGIANT) {
632 dev_unlock();
633 dsw2 = malloc(sizeof *dsw2, M_DEVT,
634 (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
635 dev_lock();
636 if (dsw2 == NULL && !(devsw->d_flags & D_INIT))
637 return (ENOMEM);
638 } else
639 dsw2 = NULL;
640 if (devsw->d_flags & D_INIT) {
641 if (dsw2 != NULL)
642 cdevsw_free_devlocked(dsw2);
643 return (0);
644 }
645
646 if (devsw->d_version != D_VERSION_04) {
647 printf(
648 "WARNING: Device driver \"%s\" has wrong version %s\n",
649 devsw->d_name == NULL ? "???" : devsw->d_name,
650 "and is disabled. Recompile KLD module.");
651 devsw->d_open = dead_open;
652 devsw->d_close = dead_close;
653 devsw->d_read = dead_read;
654 devsw->d_write = dead_write;
655 devsw->d_ioctl = dead_ioctl;
656 devsw->d_poll = dead_poll;
657 devsw->d_mmap = dead_mmap;
658 devsw->d_mmap_single = dead_mmap_single;
659 devsw->d_strategy = dead_strategy;
660 devsw->d_kqfilter = dead_kqfilter;
661 }
662
663 if ((devsw->d_flags & D_NEEDGIANT) != 0) {
664 if ((devsw->d_flags & D_GIANTOK) == 0) {
665 printf(
666 "WARNING: Device \"%s\" is Giant locked and may be "
667 "deleted before FreeBSD 15.0.\n",
668 devsw->d_name == NULL ? "???" : devsw->d_name);
669 }
670 if (devsw->d_gianttrick == NULL) {
671 memcpy(dsw2, devsw, sizeof *dsw2);
672 devsw->d_gianttrick = dsw2;
673 dsw2 = NULL;
674 }
675 }
676
677 #define FIXUP(member, noop, giant) \
678 do { \
679 if (devsw->member == NULL) { \
680 devsw->member = noop; \
681 } else if (devsw->d_flags & D_NEEDGIANT) \
682 devsw->member = giant; \
683 } \
684 while (0)
685
686 FIXUP(d_open, null_open, giant_open);
687 FIXUP(d_fdopen, NULL, giant_fdopen);
688 FIXUP(d_close, null_close, giant_close);
689 FIXUP(d_read, no_read, giant_read);
690 FIXUP(d_write, no_write, giant_write);
691 FIXUP(d_ioctl, no_ioctl, giant_ioctl);
692 FIXUP(d_poll, no_poll, giant_poll);
693 FIXUP(d_mmap, no_mmap, giant_mmap);
694 FIXUP(d_strategy, no_strategy, giant_strategy);
695 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter);
696 FIXUP(d_mmap_single, no_mmap_single, giant_mmap_single);
697
698 LIST_INIT(&devsw->d_devs);
699
700 devsw->d_flags |= D_INIT;
701
702 if (dsw2 != NULL)
703 cdevsw_free_devlocked(dsw2);
704 return (0);
705 }
706
707 static int
prep_devname(struct cdev * dev,const char * fmt,va_list ap)708 prep_devname(struct cdev *dev, const char *fmt, va_list ap)
709 {
710 int len;
711 char *from, *q, *s, *to;
712
713 dev_lock_assert_locked();
714
715 len = vsnrprintf(dev->si_name, sizeof(dev->si_name), 32, fmt, ap);
716 if (len > sizeof(dev->si_name) - 1)
717 return (ENAMETOOLONG);
718
719 /* Strip leading slashes. */
720 for (from = dev->si_name; *from == '/'; from++)
721 ;
722
723 for (to = dev->si_name; *from != '\0'; from++, to++) {
724 /*
725 * Spaces and double quotation marks cause
726 * problems for the devctl(4) protocol.
727 * Reject names containing those characters.
728 */
729 if (isspace(*from) || *from == '"')
730 return (EINVAL);
731 /* Treat multiple sequential slashes as single. */
732 while (from[0] == '/' && from[1] == '/')
733 from++;
734 /* Trailing slash is considered invalid. */
735 if (from[0] == '/' && from[1] == '\0')
736 return (EINVAL);
737 *to = *from;
738 }
739 *to = '\0';
740
741 if (dev->si_name[0] == '\0')
742 return (EINVAL);
743
744 /* Disallow "." and ".." components. */
745 for (s = dev->si_name;;) {
746 for (q = s; *q != '/' && *q != '\0'; q++)
747 ;
748 if (q - s == 1 && s[0] == '.')
749 return (EINVAL);
750 if (q - s == 2 && s[0] == '.' && s[1] == '.')
751 return (EINVAL);
752 if (*q != '/')
753 break;
754 s = q + 1;
755 }
756
757 if (devfs_dev_exists(dev->si_name) != 0)
758 return (EEXIST);
759
760 return (0);
761 }
762
763 void
make_dev_args_init_impl(struct make_dev_args * args,size_t sz)764 make_dev_args_init_impl(struct make_dev_args *args, size_t sz)
765 {
766
767 bzero(args, sz);
768 args->mda_size = sz;
769 }
770
771 static int
make_dev_sv(struct make_dev_args * args1,struct cdev ** dres,const char * fmt,va_list ap)772 make_dev_sv(struct make_dev_args *args1, struct cdev **dres,
773 const char *fmt, va_list ap)
774 {
775 struct cdev *dev, *dev_new;
776 struct make_dev_args args;
777 int res;
778
779 bzero(&args, sizeof(args));
780 if (sizeof(args) < args1->mda_size)
781 return (EINVAL);
782 bcopy(args1, &args, args1->mda_size);
783 KASSERT((args.mda_flags & MAKEDEV_WAITOK) == 0 ||
784 (args.mda_flags & MAKEDEV_NOWAIT) == 0,
785 ("make_dev_sv: both WAITOK and NOWAIT specified"));
786 dev_new = devfs_alloc(args.mda_flags);
787 if (dev_new == NULL)
788 return (ENOMEM);
789 dev_lock();
790 res = prep_cdevsw(args.mda_devsw, args.mda_flags);
791 if (res != 0) {
792 dev_unlock();
793 devfs_free(dev_new);
794 return (res);
795 }
796 dev = newdev(&args, dev_new);
797 if ((dev->si_flags & SI_NAMED) == 0) {
798 res = prep_devname(dev, fmt, ap);
799 if (res != 0) {
800 if ((args.mda_flags & MAKEDEV_CHECKNAME) == 0) {
801 panic(
802 "make_dev_sv: bad si_name (error=%d, si_name=%s)",
803 res, dev->si_name);
804 }
805 if (dev == dev_new) {
806 LIST_REMOVE(dev, si_list);
807 dev_unlock();
808 devfs_free(dev);
809 } else
810 dev_unlock();
811 return (res);
812 }
813 }
814 if ((args.mda_flags & MAKEDEV_REF) != 0)
815 dev_refl(dev);
816 if ((args.mda_flags & MAKEDEV_ETERNAL) != 0)
817 dev->si_flags |= SI_ETERNAL;
818 KASSERT(!(dev->si_flags & SI_NAMED),
819 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
820 args.mda_devsw->d_name, dev2unit(dev), devtoname(dev)));
821 dev->si_flags |= SI_NAMED;
822 if (args.mda_cr != NULL)
823 dev->si_cred = crhold(args.mda_cr);
824 dev->si_uid = args.mda_uid;
825 dev->si_gid = args.mda_gid;
826 dev->si_mode = args.mda_mode;
827
828 devfs_create(dev);
829 clean_unrhdrl(devfs_inos);
830 dev_unlock_and_free();
831
832 notify_create(dev, args.mda_flags);
833
834 *dres = dev;
835 return (0);
836 }
837
838 int
make_dev_s(struct make_dev_args * args,struct cdev ** dres,const char * fmt,...)839 make_dev_s(struct make_dev_args *args, struct cdev **dres,
840 const char *fmt, ...)
841 {
842 va_list ap;
843 int res;
844
845 va_start(ap, fmt);
846 res = make_dev_sv(args, dres, fmt, ap);
847 va_end(ap);
848 return (res);
849 }
850
851 static int
make_dev_credv(int flags,struct cdev ** dres,struct cdevsw * devsw,int unit,struct ucred * cr,uid_t uid,gid_t gid,int mode,const char * fmt,va_list ap)852 make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw, int unit,
853 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
854 va_list ap)
855 {
856 struct make_dev_args args;
857
858 make_dev_args_init(&args);
859 args.mda_flags = flags;
860 args.mda_devsw = devsw;
861 args.mda_cr = cr;
862 args.mda_uid = uid;
863 args.mda_gid = gid;
864 args.mda_mode = mode;
865 args.mda_unit = unit;
866 return (make_dev_sv(&args, dres, fmt, ap));
867 }
868
869 struct cdev *
make_dev(struct cdevsw * devsw,int unit,uid_t uid,gid_t gid,int mode,const char * fmt,...)870 make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
871 const char *fmt, ...)
872 {
873 struct cdev *dev;
874 va_list ap;
875 int res __unused;
876
877 va_start(ap, fmt);
878 res = make_dev_credv(0, &dev, devsw, unit, NULL, uid, gid, mode, fmt,
879 ap);
880 va_end(ap);
881 KASSERT(res == 0 && dev != NULL,
882 ("make_dev: failed make_dev_credv (error=%d)", res));
883 return (dev);
884 }
885
886 struct cdev *
make_dev_cred(struct cdevsw * devsw,int unit,struct ucred * cr,uid_t uid,gid_t gid,int mode,const char * fmt,...)887 make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
888 gid_t gid, int mode, const char *fmt, ...)
889 {
890 struct cdev *dev;
891 va_list ap;
892 int res __unused;
893
894 va_start(ap, fmt);
895 res = make_dev_credv(0, &dev, devsw, unit, cr, uid, gid, mode, fmt, ap);
896 va_end(ap);
897
898 KASSERT(res == 0 && dev != NULL,
899 ("make_dev_cred: failed make_dev_credv (error=%d)", res));
900 return (dev);
901 }
902
903 struct cdev *
make_dev_credf(int flags,struct cdevsw * devsw,int unit,struct ucred * cr,uid_t uid,gid_t gid,int mode,const char * fmt,...)904 make_dev_credf(int flags, struct cdevsw *devsw, int unit, struct ucred *cr,
905 uid_t uid, gid_t gid, int mode, const char *fmt, ...)
906 {
907 struct cdev *dev;
908 va_list ap;
909 int res;
910
911 va_start(ap, fmt);
912 res = make_dev_credv(flags, &dev, devsw, unit, cr, uid, gid, mode,
913 fmt, ap);
914 va_end(ap);
915
916 KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
917 ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
918 ("make_dev_credf: failed make_dev_credv (error=%d)", res));
919 return (res == 0 ? dev : NULL);
920 }
921
922 int
make_dev_p(int flags,struct cdev ** cdev,struct cdevsw * devsw,struct ucred * cr,uid_t uid,gid_t gid,int mode,const char * fmt,...)923 make_dev_p(int flags, struct cdev **cdev, struct cdevsw *devsw,
924 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, ...)
925 {
926 va_list ap;
927 int res;
928
929 va_start(ap, fmt);
930 res = make_dev_credv(flags, cdev, devsw, 0, cr, uid, gid, mode,
931 fmt, ap);
932 va_end(ap);
933
934 KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
935 ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
936 ("make_dev_p: failed make_dev_credv (error=%d)", res));
937 return (res);
938 }
939
940 static void
dev_dependsl(struct cdev * pdev,struct cdev * cdev)941 dev_dependsl(struct cdev *pdev, struct cdev *cdev)
942 {
943
944 cdev->si_parent = pdev;
945 cdev->si_flags |= SI_CHILD;
946 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
947 }
948
949 void
dev_depends(struct cdev * pdev,struct cdev * cdev)950 dev_depends(struct cdev *pdev, struct cdev *cdev)
951 {
952
953 dev_lock();
954 dev_dependsl(pdev, cdev);
955 dev_unlock();
956 }
957
958 static int
make_dev_alias_v(int flags,struct cdev ** cdev,struct cdev * pdev,const char * fmt,va_list ap)959 make_dev_alias_v(int flags, struct cdev **cdev, struct cdev *pdev,
960 const char *fmt, va_list ap)
961 {
962 struct cdev *dev;
963 int error;
964
965 KASSERT(pdev != NULL, ("make_dev_alias_v: pdev is NULL"));
966 KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
967 ("make_dev_alias_v: both WAITOK and NOWAIT specified"));
968 KASSERT((flags & ~(MAKEDEV_WAITOK | MAKEDEV_NOWAIT |
969 MAKEDEV_CHECKNAME)) == 0,
970 ("make_dev_alias_v: invalid flags specified (flags=%02x)", flags));
971
972 dev = devfs_alloc(flags);
973 if (dev == NULL)
974 return (ENOMEM);
975 dev_lock();
976 dev->si_flags |= SI_ALIAS;
977 error = prep_devname(dev, fmt, ap);
978 if (error != 0) {
979 if ((flags & MAKEDEV_CHECKNAME) == 0) {
980 panic("make_dev_alias_v: bad si_name "
981 "(error=%d, si_name=%s)", error, dev->si_name);
982 }
983 dev_unlock();
984 devfs_free(dev);
985 return (error);
986 }
987 dev->si_flags |= SI_NAMED;
988 devfs_create(dev);
989 dev_dependsl(pdev, dev);
990 clean_unrhdrl(devfs_inos);
991 dev_unlock();
992
993 notify_create(dev, flags);
994 *cdev = dev;
995
996 return (0);
997 }
998
999 struct cdev *
make_dev_alias(struct cdev * pdev,const char * fmt,...)1000 make_dev_alias(struct cdev *pdev, const char *fmt, ...)
1001 {
1002 struct cdev *dev;
1003 va_list ap;
1004 int res __unused;
1005
1006 va_start(ap, fmt);
1007 res = make_dev_alias_v(MAKEDEV_WAITOK, &dev, pdev, fmt, ap);
1008 va_end(ap);
1009
1010 KASSERT(res == 0 && dev != NULL,
1011 ("make_dev_alias: failed make_dev_alias_v (error=%d)", res));
1012 return (dev);
1013 }
1014
1015 int
make_dev_alias_p(int flags,struct cdev ** cdev,struct cdev * pdev,const char * fmt,...)1016 make_dev_alias_p(int flags, struct cdev **cdev, struct cdev *pdev,
1017 const char *fmt, ...)
1018 {
1019 va_list ap;
1020 int res;
1021
1022 va_start(ap, fmt);
1023 res = make_dev_alias_v(flags, cdev, pdev, fmt, ap);
1024 va_end(ap);
1025 return (res);
1026 }
1027
1028 int
make_dev_physpath_alias(int flags,struct cdev ** cdev,struct cdev * pdev,struct cdev * old_alias,const char * physpath)1029 make_dev_physpath_alias(int flags, struct cdev **cdev, struct cdev *pdev,
1030 struct cdev *old_alias, const char *physpath)
1031 {
1032 char *devfspath;
1033 int physpath_len;
1034 int max_parentpath_len;
1035 int parentpath_len;
1036 int devfspathbuf_len;
1037 int mflags;
1038 int ret;
1039
1040 *cdev = NULL;
1041 devfspath = NULL;
1042 physpath_len = strlen(physpath);
1043 ret = EINVAL;
1044 if (physpath_len == 0)
1045 goto out;
1046
1047 if (strncmp("id1,", physpath, 4) == 0) {
1048 physpath += 4;
1049 physpath_len -= 4;
1050 if (physpath_len == 0)
1051 goto out;
1052 }
1053
1054 max_parentpath_len = SPECNAMELEN - physpath_len - /*/*/1;
1055 parentpath_len = strlen(pdev->si_name);
1056 if (max_parentpath_len < parentpath_len) {
1057 if (bootverbose)
1058 printf("WARNING: Unable to alias %s "
1059 "to %s/%s - path too long\n",
1060 pdev->si_name, physpath, pdev->si_name);
1061 ret = ENAMETOOLONG;
1062 goto out;
1063 }
1064
1065 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
1066 devfspathbuf_len = physpath_len + /*/*/1 + parentpath_len + /*NUL*/1;
1067 devfspath = malloc(devfspathbuf_len, M_DEVBUF, mflags);
1068 if (devfspath == NULL) {
1069 ret = ENOMEM;
1070 goto out;
1071 }
1072
1073 sprintf(devfspath, "%s/%s", physpath, pdev->si_name);
1074 if (old_alias != NULL && strcmp(old_alias->si_name, devfspath) == 0) {
1075 /* Retain the existing alias. */
1076 *cdev = old_alias;
1077 old_alias = NULL;
1078 ret = 0;
1079 } else {
1080 ret = make_dev_alias_p(flags, cdev, pdev, "%s", devfspath);
1081 }
1082 out:
1083 if (old_alias != NULL)
1084 destroy_dev(old_alias);
1085 if (devfspath != NULL)
1086 free(devfspath, M_DEVBUF);
1087 return (ret);
1088 }
1089
1090 static void
destroy_devl(struct cdev * dev)1091 destroy_devl(struct cdev *dev)
1092 {
1093 struct cdevsw *csw;
1094 struct cdev_privdata *p;
1095 struct cdev_priv *cdp;
1096
1097 dev_lock_assert_locked();
1098 KASSERT(dev->si_flags & SI_NAMED,
1099 ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
1100 KASSERT((dev->si_flags & SI_ETERNAL) == 0,
1101 ("WARNING: Driver mistake: destroy_dev on eternal %d\n",
1102 dev2unit(dev)));
1103
1104 cdp = cdev2priv(dev);
1105 if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
1106 /*
1107 * Avoid race with dev_rel(), e.g. from the populate
1108 * loop. If CDP_UNREF_DTR flag is set, the reference
1109 * to be dropped at the end of destroy_devl() was
1110 * already taken by delist_dev_locked().
1111 */
1112 dev_refl(dev);
1113
1114 devfs_destroy(dev);
1115 }
1116
1117 /* Remove name marking */
1118 dev->si_flags &= ~SI_NAMED;
1119
1120 /* If we are a child, remove us from the parents list */
1121 if (dev->si_flags & SI_CHILD) {
1122 LIST_REMOVE(dev, si_siblings);
1123 dev->si_flags &= ~SI_CHILD;
1124 }
1125
1126 /* Kill our children */
1127 while (!LIST_EMPTY(&dev->si_children))
1128 destroy_devl(LIST_FIRST(&dev->si_children));
1129
1130 /* Remove from clone list */
1131 if (dev->si_flags & SI_CLONELIST) {
1132 LIST_REMOVE(dev, si_clone);
1133 dev->si_flags &= ~SI_CLONELIST;
1134 }
1135
1136 mtx_lock(&cdp->cdp_threadlock);
1137 csw = dev->si_devsw;
1138 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */
1139 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
1140 csw->d_purge(dev);
1141 mtx_unlock(&cdp->cdp_threadlock);
1142 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
1143 mtx_lock(&cdp->cdp_threadlock);
1144 if (dev->si_threadcount)
1145 printf("Still %lu threads in %s\n",
1146 dev->si_threadcount, devtoname(dev));
1147 }
1148 while (dev->si_threadcount != 0) {
1149 /* Use unique dummy wait ident */
1150 mtx_unlock(&cdp->cdp_threadlock);
1151 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
1152 mtx_lock(&cdp->cdp_threadlock);
1153 }
1154
1155 mtx_unlock(&cdp->cdp_threadlock);
1156 dev_unlock();
1157 if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
1158 /* avoid out of order notify events */
1159 notify_destroy(dev);
1160 }
1161 mtx_lock(&cdevpriv_mtx);
1162 while ((p = LIST_FIRST(&cdp->cdp_fdpriv)) != NULL) {
1163 devfs_destroy_cdevpriv(p);
1164 mtx_lock(&cdevpriv_mtx);
1165 }
1166 mtx_unlock(&cdevpriv_mtx);
1167 dev_lock();
1168
1169 dev->si_drv1 = 0;
1170 dev->si_drv2 = 0;
1171
1172 if (!(dev->si_flags & SI_ALIAS)) {
1173 /* Remove from cdevsw list */
1174 LIST_REMOVE(dev, si_list);
1175
1176 /* If cdevsw has no more struct cdev *'s, clean it */
1177 if (LIST_EMPTY(&csw->d_devs)) {
1178 fini_cdevsw(csw);
1179 wakeup(&csw->d_devs);
1180 }
1181 }
1182 dev->si_flags &= ~SI_ALIAS;
1183 cdp->cdp_flags &= ~CDP_UNREF_DTR;
1184 dev->si_refcount--;
1185
1186 if (dev->si_refcount > 0)
1187 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
1188 else
1189 dev_free_devlocked(dev);
1190 }
1191
1192 static void
delist_dev_locked(struct cdev * dev)1193 delist_dev_locked(struct cdev *dev)
1194 {
1195 struct cdev_priv *cdp;
1196 struct cdev *child;
1197
1198 dev_lock_assert_locked();
1199 cdp = cdev2priv(dev);
1200 if ((cdp->cdp_flags & CDP_UNREF_DTR) != 0)
1201 return;
1202 cdp->cdp_flags |= CDP_UNREF_DTR;
1203 dev_refl(dev);
1204 devfs_destroy(dev);
1205 LIST_FOREACH(child, &dev->si_children, si_siblings)
1206 delist_dev_locked(child);
1207 dev_unlock();
1208 /* ensure the destroy event is queued in order */
1209 notify_destroy(dev);
1210 dev_lock();
1211 }
1212
1213 /*
1214 * This function will delist a character device and its children from
1215 * the directory listing and create a destroy event without waiting
1216 * for all character device references to go away. At some later point
1217 * destroy_dev() must be called to complete the character device
1218 * destruction. After calling this function the character device name
1219 * can instantly be re-used.
1220 */
1221 void
delist_dev(struct cdev * dev)1222 delist_dev(struct cdev *dev)
1223 {
1224
1225 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "delist_dev");
1226 dev_lock();
1227 delist_dev_locked(dev);
1228 dev_unlock();
1229 }
1230
1231 void
destroy_dev(struct cdev * dev)1232 destroy_dev(struct cdev *dev)
1233 {
1234
1235 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
1236 dev_lock();
1237 destroy_devl(dev);
1238 dev_unlock_and_free();
1239 }
1240
1241 const char *
devtoname(struct cdev * dev)1242 devtoname(struct cdev *dev)
1243 {
1244
1245 return (dev->si_name);
1246 }
1247
1248 int
dev_stdclone(char * name,char ** namep,const char * stem,int * unit)1249 dev_stdclone(char *name, char **namep, const char *stem, int *unit)
1250 {
1251 int u, i;
1252
1253 i = strlen(stem);
1254 if (strncmp(stem, name, i) != 0)
1255 return (0);
1256 if (!isdigit(name[i]))
1257 return (0);
1258 u = 0;
1259 if (name[i] == '0' && isdigit(name[i+1]))
1260 return (0);
1261 while (isdigit(name[i])) {
1262 u *= 10;
1263 u += name[i++] - '0';
1264 }
1265 if (u > 0xffffff)
1266 return (0);
1267 *unit = u;
1268 if (namep)
1269 *namep = &name[i];
1270 if (name[i])
1271 return (2);
1272 return (1);
1273 }
1274
1275 /*
1276 * Helper functions for cloning device drivers.
1277 *
1278 * The objective here is to make it unnecessary for the device drivers to
1279 * use rman or similar to manage their unit number space. Due to the way
1280 * we do "on-demand" devices, using rman or other "private" methods
1281 * will be very tricky to lock down properly once we lock down this file.
1282 *
1283 * Instead we give the drivers these routines which puts the struct cdev *'s
1284 * that are to be managed on their own list, and gives the driver the ability
1285 * to ask for the first free unit number or a given specified unit number.
1286 *
1287 * In addition these routines support paired devices (pty, nmdm and similar)
1288 * by respecting a number of "flag" bits in the minor number.
1289 *
1290 */
1291
1292 struct clonedevs {
1293 LIST_HEAD(,cdev) head;
1294 };
1295
1296 void
clone_setup(struct clonedevs ** cdp)1297 clone_setup(struct clonedevs **cdp)
1298 {
1299
1300 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
1301 LIST_INIT(&(*cdp)->head);
1302 }
1303
1304 int
clone_create(struct clonedevs ** cdp,struct cdevsw * csw,int * up,struct cdev ** dp,int extra)1305 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up,
1306 struct cdev **dp, int extra)
1307 {
1308 struct clonedevs *cd;
1309 struct cdev *dev, *ndev, *dl, *de;
1310 struct make_dev_args args;
1311 int unit, low, u;
1312
1313 KASSERT(*cdp != NULL,
1314 ("clone_setup() not called in driver \"%s\"", csw->d_name));
1315 KASSERT(!(extra & CLONE_UNITMASK),
1316 ("Illegal extra bits (0x%x) in clone_create", extra));
1317 KASSERT(*up <= CLONE_UNITMASK,
1318 ("Too high unit (0x%x) in clone_create", *up));
1319 KASSERT(csw->d_flags & D_NEEDMINOR,
1320 ("clone_create() on cdevsw without minor numbers"));
1321
1322 /*
1323 * Search the list for a lot of things in one go:
1324 * A preexisting match is returned immediately.
1325 * The lowest free unit number if we are passed -1, and the place
1326 * in the list where we should insert that new element.
1327 * The place to insert a specified unit number, if applicable
1328 * the end of the list.
1329 */
1330 unit = *up;
1331 ndev = devfs_alloc(MAKEDEV_WAITOK);
1332 dev_lock();
1333 prep_cdevsw(csw, MAKEDEV_WAITOK);
1334 low = extra;
1335 de = dl = NULL;
1336 cd = *cdp;
1337 LIST_FOREACH(dev, &cd->head, si_clone) {
1338 KASSERT(dev->si_flags & SI_CLONELIST,
1339 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1340 u = dev2unit(dev);
1341 if (u == (unit | extra)) {
1342 *dp = dev;
1343 dev_unlock();
1344 devfs_free(ndev);
1345 return (0);
1346 }
1347 if (unit == -1 && u == low) {
1348 low++;
1349 de = dev;
1350 continue;
1351 } else if (u < (unit | extra)) {
1352 de = dev;
1353 continue;
1354 } else if (u > (unit | extra)) {
1355 dl = dev;
1356 break;
1357 }
1358 }
1359 if (unit == -1)
1360 unit = low & CLONE_UNITMASK;
1361 make_dev_args_init(&args);
1362 args.mda_unit = unit | extra;
1363 args.mda_devsw = csw;
1364 dev = newdev(&args, ndev);
1365 if (dev->si_flags & SI_CLONELIST) {
1366 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
1367 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
1368 LIST_FOREACH(dev, &cd->head, si_clone) {
1369 printf("\t%p %s\n", dev, dev->si_name);
1370 }
1371 panic("foo");
1372 }
1373 KASSERT(!(dev->si_flags & SI_CLONELIST),
1374 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
1375 if (dl != NULL)
1376 LIST_INSERT_BEFORE(dl, dev, si_clone);
1377 else if (de != NULL)
1378 LIST_INSERT_AFTER(de, dev, si_clone);
1379 else
1380 LIST_INSERT_HEAD(&cd->head, dev, si_clone);
1381 dev->si_flags |= SI_CLONELIST;
1382 *up = unit;
1383 dev_unlock_and_free();
1384 return (1);
1385 }
1386
1387 /*
1388 * Kill everything still on the list. The driver should already have
1389 * disposed of any softc hung of the struct cdev *'s at this time.
1390 */
1391 void
clone_cleanup(struct clonedevs ** cdp)1392 clone_cleanup(struct clonedevs **cdp)
1393 {
1394 struct cdev *dev;
1395 struct cdev_priv *cp;
1396 struct clonedevs *cd;
1397
1398 cd = *cdp;
1399 if (cd == NULL)
1400 return;
1401 dev_lock();
1402 while (!LIST_EMPTY(&cd->head)) {
1403 dev = LIST_FIRST(&cd->head);
1404 LIST_REMOVE(dev, si_clone);
1405 KASSERT(dev->si_flags & SI_CLONELIST,
1406 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1407 dev->si_flags &= ~SI_CLONELIST;
1408 cp = cdev2priv(dev);
1409 if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
1410 cp->cdp_flags |= CDP_SCHED_DTR;
1411 KASSERT(dev->si_flags & SI_NAMED,
1412 ("Driver has goofed in cloning underways udev %jx unit %x",
1413 (uintmax_t)dev2udev(dev), dev2unit(dev)));
1414 destroy_devl(dev);
1415 }
1416 }
1417 dev_unlock_and_free();
1418 free(cd, M_DEVBUF);
1419 *cdp = NULL;
1420 }
1421
1422 static TAILQ_HEAD(, cdev_priv) dev_ddtr =
1423 TAILQ_HEAD_INITIALIZER(dev_ddtr);
1424 static TAILQ_HEAD(, cdev_priv) dev_ddtr_giant =
1425 TAILQ_HEAD_INITIALIZER(dev_ddtr_giant);
1426 static struct task dev_dtr_task = TASK_INITIALIZER(0, destroy_dev_tq, &dev_ddtr);
1427 static struct task dev_dtr_task_giant = TASK_INITIALIZER(0, destroy_dev_tq_giant,
1428 &dev_ddtr_giant);
1429
1430 static void
destroy_dev_tq(void * ctx,int pending)1431 destroy_dev_tq(void *ctx, int pending)
1432 {
1433 TAILQ_HEAD(, cdev_priv) *ddtr = ctx;
1434 struct cdev_priv *cp;
1435 struct cdev *dev;
1436 void (*cb)(void *);
1437 void *cb_arg;
1438
1439 dev_lock();
1440 while (!TAILQ_EMPTY(ddtr)) {
1441 cp = TAILQ_FIRST(ddtr);
1442 dev = &cp->cdp_c;
1443 KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
1444 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
1445 TAILQ_REMOVE(ddtr, cp, cdp_dtr_list);
1446 cb = cp->cdp_dtr_cb;
1447 cb_arg = cp->cdp_dtr_cb_arg;
1448 destroy_devl(dev);
1449 dev_unlock_and_free();
1450 dev_rel(dev);
1451 if (cb != NULL)
1452 cb(cb_arg);
1453 dev_lock();
1454 }
1455 dev_unlock();
1456 }
1457
1458 static void
destroy_dev_tq_giant(void * ctx,int pending)1459 destroy_dev_tq_giant(void *ctx, int pending)
1460 {
1461 mtx_lock(&Giant);
1462 destroy_dev_tq(ctx, pending);
1463 mtx_unlock(&Giant);
1464 }
1465
1466 /*
1467 * devmtx shall be locked on entry. devmtx will be unlocked after
1468 * function return.
1469 */
1470 static int
destroy_dev_sched_cbl(struct cdev * dev,void (* cb)(void *),void * arg)1471 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
1472 {
1473 struct cdev_priv *cp;
1474 bool need_giant;
1475
1476 dev_lock_assert_locked();
1477 cp = cdev2priv(dev);
1478 if (cp->cdp_flags & CDP_SCHED_DTR) {
1479 dev_unlock();
1480 return (0);
1481 }
1482 dev_refl(dev);
1483 cp->cdp_flags |= CDP_SCHED_DTR;
1484 cp->cdp_dtr_cb = cb;
1485 cp->cdp_dtr_cb_arg = arg;
1486 need_giant = (dev->si_devsw->d_flags & D_NEEDGIANT) != 0;
1487 if (need_giant)
1488 TAILQ_INSERT_TAIL(&dev_ddtr_giant, cp, cdp_dtr_list);
1489 else
1490 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
1491 dev_unlock();
1492 if (need_giant)
1493 taskqueue_enqueue(taskqueue_thread, &dev_dtr_task_giant);
1494 else
1495 taskqueue_enqueue(taskqueue_thread, &dev_dtr_task);
1496 return (1);
1497 }
1498
1499 int
destroy_dev_sched_cb(struct cdev * dev,void (* cb)(void *),void * arg)1500 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
1501 {
1502
1503 dev_lock();
1504 return (destroy_dev_sched_cbl(dev, cb, arg));
1505 }
1506
1507 int
destroy_dev_sched(struct cdev * dev)1508 destroy_dev_sched(struct cdev *dev)
1509 {
1510
1511 return (destroy_dev_sched_cb(dev, NULL, NULL));
1512 }
1513
1514 void
destroy_dev_drain(struct cdevsw * csw)1515 destroy_dev_drain(struct cdevsw *csw)
1516 {
1517
1518 dev_lock();
1519 while (!LIST_EMPTY(&csw->d_devs)) {
1520 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
1521 }
1522 dev_unlock();
1523 }
1524
1525 #include "opt_ddb.h"
1526 #ifdef DDB
1527 #include <sys/kernel.h>
1528
1529 #include <ddb/ddb.h>
1530
DB_SHOW_COMMAND(cdev,db_show_cdev)1531 DB_SHOW_COMMAND(cdev, db_show_cdev)
1532 {
1533 struct cdev_priv *cdp;
1534 struct cdev *dev;
1535 u_int flags;
1536 char buf[512];
1537
1538 if (!have_addr) {
1539 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
1540 dev = &cdp->cdp_c;
1541 db_printf("%s %p\n", dev->si_name, dev);
1542 if (db_pager_quit)
1543 break;
1544 }
1545 return;
1546 }
1547
1548 dev = (struct cdev *)addr;
1549 cdp = cdev2priv(dev);
1550 db_printf("dev %s ref %d use %ld thr %ld inuse %u fdpriv %p\n",
1551 dev->si_name, dev->si_refcount, dev->si_usecount,
1552 dev->si_threadcount, cdp->cdp_inuse, cdp->cdp_fdpriv.lh_first);
1553 db_printf("devsw %p si_drv0 %d si_drv1 %p si_drv2 %p\n",
1554 dev->si_devsw, dev->si_drv0, dev->si_drv1, dev->si_drv2);
1555 flags = dev->si_flags;
1556 #define SI_FLAG(flag) do { \
1557 if (flags & (flag)) { \
1558 if (buf[0] != '\0') \
1559 strlcat(buf, ", ", sizeof(buf)); \
1560 strlcat(buf, (#flag) + 3, sizeof(buf)); \
1561 flags &= ~(flag); \
1562 } \
1563 } while (0)
1564 buf[0] = '\0';
1565 SI_FLAG(SI_ETERNAL);
1566 SI_FLAG(SI_ALIAS);
1567 SI_FLAG(SI_NAMED);
1568 SI_FLAG(SI_CHILD);
1569 SI_FLAG(SI_DUMPDEV);
1570 SI_FLAG(SI_CLONELIST);
1571 db_printf("si_flags %s\n", buf);
1572
1573 flags = cdp->cdp_flags;
1574 #define CDP_FLAG(flag) do { \
1575 if (flags & (flag)) { \
1576 if (buf[0] != '\0') \
1577 strlcat(buf, ", ", sizeof(buf)); \
1578 strlcat(buf, (#flag) + 4, sizeof(buf)); \
1579 flags &= ~(flag); \
1580 } \
1581 } while (0)
1582 buf[0] = '\0';
1583 CDP_FLAG(CDP_ACTIVE);
1584 CDP_FLAG(CDP_SCHED_DTR);
1585 db_printf("cdp_flags %s\n", buf);
1586 }
1587 #endif
1588