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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright © 2017 Keith Packard <keithp@keithp.com>
4 */
5#include <linux/file.h>
6#include <linux/uaccess.h>
7
8#include <drm/drm_auth.h>
9#include <drm/drm_crtc_helper.h>
10#include <drm/drm_drv.h>
11#include <drm/drm_file.h>
12#include <drm/drm_lease.h>
13#include <drm/drm_print.h>
14
15#include "drm_crtc_internal.h"
16#include "drm_internal.h"
17#include "drm_legacy.h"
18
19#define drm_for_each_lessee(lessee, lessor) \
20 list_for_each_entry((lessee), &(lessor)->lessees, lessee_list)
21
22static uint64_t drm_lease_idr_object;
23
24/**
25 * drm_lease_owner - return ancestor owner drm_master
26 * @master: drm_master somewhere within tree of lessees and lessors
27 *
28 * RETURN:
29 *
30 * drm_master at the top of the tree (i.e, with lessor NULL
31 */
32struct drm_master *drm_lease_owner(struct drm_master *master)
33{
34 while (master->lessor != NULL)
35 master = master->lessor;
36 return master;
37}
38
39/**
40 * _drm_find_lessee - find lessee by id (idr_mutex held)
41 * @master: drm_master of lessor
42 * @lessee_id: id
43 *
44 * RETURN:
45 *
46 * drm_master of the lessee if valid, NULL otherwise
47 */
48
49static struct drm_master*
50_drm_find_lessee(struct drm_master *master, int lessee_id)
51{
52 lockdep_assert_held(&master->dev->mode_config.idr_mutex);
53 return idr_find(&drm_lease_owner(master)->lessee_idr, lessee_id);
54}
55
56/**
57 * _drm_lease_held_master - check to see if an object is leased (or owned) by master (idr_mutex held)
58 * @master: the master to check the lease status of
59 * @id: the id to check
60 *
61 * Checks if the specified master holds a lease on the object. Return
62 * value:
63 *
64 * true 'master' holds a lease on (or owns) the object
65 * false 'master' does not hold a lease.
66 */
67static int _drm_lease_held_master(struct drm_master *master, int id)
68{
69 lockdep_assert_held(&master->dev->mode_config.idr_mutex);
70 if (master->lessor)
71 return idr_find(&master->leases, id) != NULL;
72 return true;
73}
74
75/**
76 * _drm_has_leased - check to see if an object has been leased (idr_mutex held)
77 * @master: the master to check the lease status of
78 * @id: the id to check
79 *
80 * Checks if any lessee of 'master' holds a lease on 'id'. Return
81 * value:
82 *
83 * true Some lessee holds a lease on the object.
84 * false No lessee has a lease on the object.
85 */
86static bool _drm_has_leased(struct drm_master *master, int id)
87{
88 struct drm_master *lessee;
89
90 lockdep_assert_held(&master->dev->mode_config.idr_mutex);
91 drm_for_each_lessee(lessee, master)
92 if (_drm_lease_held_master(lessee, id))
93 return true;
94 return false;
95}
96
97/**
98 * _drm_lease_held - check drm_mode_object lease status (idr_mutex held)
99 * @file_priv: the master drm_file
100 * @id: the object id
101 *
102 * Checks if the specified master holds a lease on the object. Return
103 * value:
104 *
105 * true 'master' holds a lease on (or owns) the object
106 * false 'master' does not hold a lease.
107 */
108bool _drm_lease_held(struct drm_file *file_priv, int id)
109{
110 if (!file_priv || !file_priv->master)
111 return true;
112
113 return _drm_lease_held_master(file_priv->master, id);
114}
115
116/**
117 * drm_lease_held - check drm_mode_object lease status (idr_mutex not held)
118 * @file_priv: the master drm_file
119 * @id: the object id
120 *
121 * Checks if the specified master holds a lease on the object. Return
122 * value:
123 *
124 * true 'master' holds a lease on (or owns) the object
125 * false 'master' does not hold a lease.
126 */
127bool drm_lease_held(struct drm_file *file_priv, int id)
128{
129 struct drm_master *master;
130 bool ret;
131
132 if (!file_priv || !file_priv->master || !file_priv->master->lessor)
133 return true;
134
135 master = file_priv->master;
136 mutex_lock(&master->dev->mode_config.idr_mutex);
137 ret = _drm_lease_held_master(master, id);
138 mutex_unlock(&master->dev->mode_config.idr_mutex);
139 return ret;
140}
141
142/**
143 * drm_lease_filter_crtcs - restricted crtc set to leased values (idr_mutex not held)
144 * @file_priv: requestor file
145 * @crtcs_in: bitmask of crtcs to check
146 *
147 * Reconstructs a crtc mask based on the crtcs which are visible
148 * through the specified file.
149 */
150uint32_t drm_lease_filter_crtcs(struct drm_file *file_priv, uint32_t crtcs_in)
151{
152 struct drm_master *master;
153 struct drm_device *dev;
154 struct drm_crtc *crtc;
155 int count_in, count_out;
156 uint32_t crtcs_out = 0;
157
158 if (!file_priv || !file_priv->master || !file_priv->master->lessor)
159 return crtcs_in;
160
161 master = file_priv->master;
162 dev = master->dev;
163
164 count_in = count_out = 0;
165 mutex_lock(&master->dev->mode_config.idr_mutex);
166 list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
167 if (_drm_lease_held_master(master, crtc->base.id)) {
168 uint32_t mask_in = 1ul << count_in;
169 if ((crtcs_in & mask_in) != 0) {
170 uint32_t mask_out = 1ul << count_out;
171 crtcs_out |= mask_out;
172 }
173 count_out++;
174 }
175 count_in++;
176 }
177 mutex_unlock(&master->dev->mode_config.idr_mutex);
178 return crtcs_out;
179}
180
181/*
182 * drm_lease_create - create a new drm_master with leased objects (idr_mutex not held)
183 * @lessor: lease holder (or owner) of objects
184 * @leases: objects to lease to the new drm_master
185 *
186 * Uses drm_master_create to allocate a new drm_master, then checks to
187 * make sure all of the desired objects can be leased, atomically
188 * leasing them to the new drmmaster.
189 *
190 * ERR_PTR(-EACCES) some other master holds the title to any object
191 * ERR_PTR(-ENOENT) some object is not a valid DRM object for this device
192 * ERR_PTR(-EBUSY) some other lessee holds title to this object
193 * ERR_PTR(-EEXIST) same object specified more than once in the provided list
194 * ERR_PTR(-ENOMEM) allocation failed
195 */
196static struct drm_master *drm_lease_create(struct drm_master *lessor, struct idr *leases)
197{
198 struct drm_device *dev = lessor->dev;
199 int error;
200 struct drm_master *lessee;
201 int object;
202 int id;
203 void *entry;
204
205 DRM_DEBUG_LEASE("lessor %d\n", lessor->lessee_id);
206
207 lessee = drm_master_create(lessor->dev);
208 if (!lessee) {
209 DRM_DEBUG_LEASE("drm_master_create failed\n");
210 return ERR_PTR(-ENOMEM);
211 }
212
213 mutex_lock(&dev->mode_config.idr_mutex);
214
215 idr_for_each_entry(leases, entry, object) {
216 error = 0;
217 if (!idr_find(&dev->mode_config.object_idr, object))
218 error = -ENOENT;
219 else if (_drm_has_leased(lessor, object))
220 error = -EBUSY;
221
222 if (error != 0) {
223 DRM_DEBUG_LEASE("object %d failed %d\n", object, error);
224 goto out_lessee;
225 }
226 }
227
228 /* Insert the new lessee into the tree */
229 id = idr_alloc(&(drm_lease_owner(lessor)->lessee_idr), lessee, 1, 0, GFP_KERNEL);
230 if (id < 0) {
231 error = id;
232 goto out_lessee;
233 }
234
235 lessee->lessee_id = id;
236 lessee->lessor = drm_master_get(lessor);
237 list_add_tail(&lessee->lessee_list, &lessor->lessees);
238
239 /* Move the leases over */
240 lessee->leases = *leases;
241 DRM_DEBUG_LEASE("new lessee %d %p, lessor %d %p\n", lessee->lessee_id, lessee, lessor->lessee_id, lessor);
242
243 mutex_unlock(&dev->mode_config.idr_mutex);
244 return lessee;
245
246out_lessee:
247 mutex_unlock(&dev->mode_config.idr_mutex);
248
249 drm_master_put(&lessee);
250
251 return ERR_PTR(error);
252}
253
254/**
255 * drm_lease_destroy - a master is going away (idr_mutex not held)
256 * @master: the drm_master being destroyed
257 *
258 * All lessees will have been destroyed as they
259 * hold a reference on their lessor. Notify any
260 * lessor for this master so that it can check
261 * the list of lessees.
262 */
263void drm_lease_destroy(struct drm_master *master)
264{
265 struct drm_device *dev = master->dev;
266
267 mutex_lock(&dev->mode_config.idr_mutex);
268
269 DRM_DEBUG_LEASE("drm_lease_destroy %d\n", master->lessee_id);
270
271 /* This master is referenced by all lessees, hence it cannot be destroyed
272 * until all of them have been
273 */
274 WARN_ON(!list_empty(&master->lessees));
275
276 /* Remove this master from the lessee idr in the owner */
277 if (master->lessee_id != 0) {
278 DRM_DEBUG_LEASE("remove master %d from device list of lessees\n", master->lessee_id);
279 idr_remove(&(drm_lease_owner(master)->lessee_idr), master->lessee_id);
280 }
281
282 /* Remove this master from any lessee list it may be on */
283 list_del(&master->lessee_list);
284
285 mutex_unlock(&dev->mode_config.idr_mutex);
286
287 if (master->lessor) {
288 /* Tell the master to check the lessee list */
289 drm_sysfs_lease_event(dev);
290 drm_master_put(&master->lessor);
291 }
292
293 DRM_DEBUG_LEASE("drm_lease_destroy done %d\n", master->lessee_id);
294}
295
296/**
297 * _drm_lease_revoke - revoke access to all leased objects (idr_mutex held)
298 * @top: the master losing its lease
299 */
300static void _drm_lease_revoke(struct drm_master *top)
301{
302 int object;
303 void *entry;
304 struct drm_master *master = top;
305
306 lockdep_assert_held(&top->dev->mode_config.idr_mutex);
307
308 /*
309 * Walk the tree starting at 'top' emptying all leases. Because
310 * the tree is fully connected, we can do this without recursing
311 */
312 for (;;) {
313 DRM_DEBUG_LEASE("revoke leases for %p %d\n", master, master->lessee_id);
314
315 /* Evacuate the lease */
316 idr_for_each_entry(&master->leases, entry, object)
317 idr_remove(&master->leases, object);
318
319 /* Depth-first list walk */
320
321 /* Down */
322 if (!list_empty(&master->lessees)) {
323 master = list_first_entry(&master->lessees, struct drm_master, lessee_list);
324 } else {
325 /* Up */
326 while (master != top && master == list_last_entry(&master->lessor->lessees, struct drm_master, lessee_list))
327 master = master->lessor;
328
329 if (master == top)
330 break;
331
332 /* Over */
333 master = list_next_entry(master, lessee_list);
334 }
335 }
336}
337
338/**
339 * drm_lease_revoke - revoke access to all leased objects (idr_mutex not held)
340 * @top: the master losing its lease
341 */
342void drm_lease_revoke(struct drm_master *top)
343{
344 mutex_lock(&top->dev->mode_config.idr_mutex);
345 _drm_lease_revoke(top);
346 mutex_unlock(&top->dev->mode_config.idr_mutex);
347}
348
349static int validate_lease(struct drm_device *dev,
350 int object_count,
351 struct drm_mode_object **objects,
352 bool universal_planes)
353{
354 int o;
355 int has_crtc = -1;
356 int has_connector = -1;
357 int has_plane = -1;
358
359 /* we want to confirm that there is at least one crtc, plane
360 connector object. */
361
362 for (o = 0; o < object_count; o++) {
363 if (objects[o]->type == DRM_MODE_OBJECT_CRTC && has_crtc == -1) {
364 has_crtc = o;
365 }
366 if (objects[o]->type == DRM_MODE_OBJECT_CONNECTOR && has_connector == -1)
367 has_connector = o;
368
369 if (universal_planes) {
370 if (objects[o]->type == DRM_MODE_OBJECT_PLANE && has_plane == -1)
371 has_plane = o;
372 }
373 }
374 if (has_crtc == -1 || has_connector == -1)
375 return -EINVAL;
376 if (universal_planes && has_plane == -1)
377 return -EINVAL;
378 return 0;
379}
380
381static int fill_object_idr(struct drm_device *dev,
382 struct drm_file *lessor_priv,
383 struct idr *leases,
384 int object_count,
385 u32 *object_ids)
386{
387 struct drm_mode_object **objects;
388 u32 o;
389 int ret;
390 bool universal_planes = READ_ONCE(lessor_priv->universal_planes);
391
392 objects = kcalloc(object_count, sizeof(struct drm_mode_object *),
393 GFP_KERNEL);
394 if (!objects)
395 return -ENOMEM;
396
397 /* step one - get references to all the mode objects
398 and check for validity. */
399 for (o = 0; o < object_count; o++) {
400 objects[o] = drm_mode_object_find(dev, lessor_priv,
401 object_ids[o],
402 DRM_MODE_OBJECT_ANY);
403 if (!objects[o]) {
404 ret = -ENOENT;
405 goto out_free_objects;
406 }
407
408 if (!drm_mode_object_lease_required(objects[o]->type)) {
409 DRM_DEBUG_KMS("invalid object for lease\n");
410 ret = -EINVAL;
411 goto out_free_objects;
412 }
413 }
414
415 ret = validate_lease(dev, object_count, objects, universal_planes);
416 if (ret) {
417 DRM_DEBUG_LEASE("lease validation failed\n");
418 goto out_free_objects;
419 }
420
421 /* add their IDs to the lease request - taking into account
422 universal planes */
423 for (o = 0; o < object_count; o++) {
424 struct drm_mode_object *obj = objects[o];
425 u32 object_id = objects[o]->id;
426 DRM_DEBUG_LEASE("Adding object %d to lease\n", object_id);
427
428 /*
429 * We're using an IDR to hold the set of leased
430 * objects, but we don't need to point at the object's
431 * data structure from the lease as the main object_idr
432 * will be used to actually find that. Instead, all we
433 * really want is a 'leased/not-leased' result, for
434 * which any non-NULL pointer will work fine.
435 */
436 ret = idr_alloc(leases, &drm_lease_idr_object , object_id, object_id + 1, GFP_KERNEL);
437 if (ret < 0) {
438 DRM_DEBUG_LEASE("Object %d cannot be inserted into leases (%d)\n",
439 object_id, ret);
440 goto out_free_objects;
441 }
442 if (obj->type == DRM_MODE_OBJECT_CRTC && !universal_planes) {
443 struct drm_crtc *crtc = obj_to_crtc(obj);
444 ret = idr_alloc(leases, &drm_lease_idr_object, crtc->primary->base.id, crtc->primary->base.id + 1, GFP_KERNEL);
445 if (ret < 0) {
446 DRM_DEBUG_LEASE("Object primary plane %d cannot be inserted into leases (%d)\n",
447 object_id, ret);
448 goto out_free_objects;
449 }
450 if (crtc->cursor) {
451 ret = idr_alloc(leases, &drm_lease_idr_object, crtc->cursor->base.id, crtc->cursor->base.id + 1, GFP_KERNEL);
452 if (ret < 0) {
453 DRM_DEBUG_LEASE("Object cursor plane %d cannot be inserted into leases (%d)\n",
454 object_id, ret);
455 goto out_free_objects;
456 }
457 }
458 }
459 }
460
461 ret = 0;
462out_free_objects:
463 for (o = 0; o < object_count; o++) {
464 if (objects[o])
465 drm_mode_object_put(objects[o]);
466 }
467 kfree(objects);
468 return ret;
469}
470
471/**
472 * drm_mode_create_lease_ioctl - create a new lease
473 * @dev: the drm device
474 * @data: pointer to struct drm_mode_create_lease
475 * @lessor_priv: the file being manipulated
476 *
477 * The master associated with the specified file will have a lease
478 * created containing the objects specified in the ioctl structure.
479 * A file descriptor will be allocated for that and returned to the
480 * application.
481 */
482int drm_mode_create_lease_ioctl(struct drm_device *dev,
483 void *data, struct drm_file *lessor_priv)
484{
485 struct drm_mode_create_lease *cl = data;
486 size_t object_count;
487 int ret = 0;
488 struct idr leases;
489 struct drm_master *lessor = lessor_priv->master;
490 struct drm_master *lessee = NULL;
491 struct file *lessee_file = NULL;
492 struct file *lessor_file = lessor_priv->filp;
493 struct drm_file *lessee_priv;
494 int fd = -1;
495 uint32_t *object_ids;
496
497 /* Can't lease without MODESET */
498 if (!drm_core_check_feature(dev, DRIVER_MODESET))
499 return -EOPNOTSUPP;
500
501 /* Do not allow sub-leases */
502 if (lessor->lessor) {
503 DRM_DEBUG_LEASE("recursive leasing not allowed\n");
504 return -EINVAL;
505 }
506
507 /* need some objects */
508 if (cl->object_count == 0) {
509 DRM_DEBUG_LEASE("no objects in lease\n");
510 return -EINVAL;
511 }
512
513 if (cl->flags && (cl->flags & ~(O_CLOEXEC | O_NONBLOCK))) {
514 DRM_DEBUG_LEASE("invalid flags\n");
515 return -EINVAL;
516 }
517
518 object_count = cl->object_count;
519
520 object_ids = memdup_user(u64_to_user_ptr(cl->object_ids),
521 array_size(object_count, sizeof(__u32)));
522 if (IS_ERR(object_ids))
523 return PTR_ERR(object_ids);
524
525 idr_init(&leases);
526
527 /* fill and validate the object idr */
528 ret = fill_object_idr(dev, lessor_priv, &leases,
529 object_count, object_ids);
530 kfree(object_ids);
531 if (ret) {
532 DRM_DEBUG_LEASE("lease object lookup failed: %i\n", ret);
533 idr_destroy(&leases);
534 return ret;
535 }
536
537 /* Allocate a file descriptor for the lease */
538 fd = get_unused_fd_flags(cl->flags & (O_CLOEXEC | O_NONBLOCK));
539 if (fd < 0) {
540 idr_destroy(&leases);
541 return fd;
542 }
543
544 DRM_DEBUG_LEASE("Creating lease\n");
545 lessee = drm_lease_create(lessor, &leases);
546
547 if (IS_ERR(lessee)) {
548 ret = PTR_ERR(lessee);
549 goto out_leases;
550 }
551
552 /* Clone the lessor file to create a new file for us */
553 DRM_DEBUG_LEASE("Allocating lease file\n");
554 lessee_file = file_clone_open(lessor_file);
555 if (IS_ERR(lessee_file)) {
556 ret = PTR_ERR(lessee_file);
557 goto out_lessee;
558 }
559
560 lessee_priv = lessee_file->private_data;
561 /* Change the file to a master one */
562 drm_master_put(&lessee_priv->master);
563 lessee_priv->master = lessee;
564 lessee_priv->is_master = 1;
565 lessee_priv->authenticated = 1;
566
567 /* Pass fd back to userspace */
568 DRM_DEBUG_LEASE("Returning fd %d id %d\n", fd, lessee->lessee_id);
569 cl->fd = fd;
570 cl->lessee_id = lessee->lessee_id;
571
572 /* Hook up the fd */
573 fd_install(fd, lessee_file);
574
575 DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl succeeded\n");
576 return 0;
577
578out_lessee:
579 drm_master_put(&lessee);
580
581out_leases:
582 put_unused_fd(fd);
583 idr_destroy(&leases);
584
585 DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret);
586 return ret;
587}
588
589/**
590 * drm_mode_list_lessees_ioctl - list lessee ids
591 * @dev: the drm device
592 * @data: pointer to struct drm_mode_list_lessees
593 * @lessor_priv: the file being manipulated
594 *
595 * Starting from the master associated with the specified file,
596 * the master with the provided lessee_id is found, and then
597 * an array of lessee ids associated with leases from that master
598 * are returned.
599 */
600
601int drm_mode_list_lessees_ioctl(struct drm_device *dev,
602 void *data, struct drm_file *lessor_priv)
603{
604 struct drm_mode_list_lessees *arg = data;
605 __u32 __user *lessee_ids = (__u32 __user *) (uintptr_t) (arg->lessees_ptr);
606 __u32 count_lessees = arg->count_lessees;
607 struct drm_master *lessor = lessor_priv->master, *lessee;
608 int count;
609 int ret = 0;
610
611 if (arg->pad)
612 return -EINVAL;
613
614 /* Can't lease without MODESET */
615 if (!drm_core_check_feature(dev, DRIVER_MODESET))
616 return -EOPNOTSUPP;
617
618 DRM_DEBUG_LEASE("List lessees for %d\n", lessor->lessee_id);
619
620 mutex_lock(&dev->mode_config.idr_mutex);
621
622 count = 0;
623 drm_for_each_lessee(lessee, lessor) {
624 /* Only list un-revoked leases */
625 if (!idr_is_empty(&lessee->leases)) {
626 if (count_lessees > count) {
627 DRM_DEBUG_LEASE("Add lessee %d\n", lessee->lessee_id);
628 ret = put_user(lessee->lessee_id, lessee_ids + count);
629 if (ret)
630 break;
631 }
632 count++;
633 }
634 }
635
636 DRM_DEBUG_LEASE("Lessor leases to %d\n", count);
637 if (ret == 0)
638 arg->count_lessees = count;
639
640 mutex_unlock(&dev->mode_config.idr_mutex);
641
642 return ret;
643}
644
645/**
646 * drm_mode_get_lease_ioctl - list leased objects
647 * @dev: the drm device
648 * @data: pointer to struct drm_mode_get_lease
649 * @lessee_priv: the file being manipulated
650 *
651 * Return the list of leased objects for the specified lessee
652 */
653
654int drm_mode_get_lease_ioctl(struct drm_device *dev,
655 void *data, struct drm_file *lessee_priv)
656{
657 struct drm_mode_get_lease *arg = data;
658 __u32 __user *object_ids = (__u32 __user *) (uintptr_t) (arg->objects_ptr);
659 __u32 count_objects = arg->count_objects;
660 struct drm_master *lessee = lessee_priv->master;
661 struct idr *object_idr;
662 int count;
663 void *entry;
664 int object;
665 int ret = 0;
666
667 if (arg->pad)
668 return -EINVAL;
669
670 /* Can't lease without MODESET */
671 if (!drm_core_check_feature(dev, DRIVER_MODESET))
672 return -EOPNOTSUPP;
673
674 DRM_DEBUG_LEASE("get lease for %d\n", lessee->lessee_id);
675
676 mutex_lock(&dev->mode_config.idr_mutex);
677
678 if (lessee->lessor == NULL)
679 /* owner can use all objects */
680 object_idr = &lessee->dev->mode_config.object_idr;
681 else
682 /* lessee can only use allowed object */
683 object_idr = &lessee->leases;
684
685 count = 0;
686 idr_for_each_entry(object_idr, entry, object) {
687 if (count_objects > count) {
688 DRM_DEBUG_LEASE("adding object %d\n", object);
689 ret = put_user(object, object_ids + count);
690 if (ret)
691 break;
692 }
693 count++;
694 }
695
696 DRM_DEBUG("lease holds %d objects\n", count);
697 if (ret == 0)
698 arg->count_objects = count;
699
700 mutex_unlock(&dev->mode_config.idr_mutex);
701
702 return ret;
703}
704
705/**
706 * drm_mode_revoke_lease_ioctl - revoke lease
707 * @dev: the drm device
708 * @data: pointer to struct drm_mode_revoke_lease
709 * @lessor_priv: the file being manipulated
710 *
711 * This removes all of the objects from the lease without
712 * actually getting rid of the lease itself; that way all
713 * references to it still work correctly
714 */
715int drm_mode_revoke_lease_ioctl(struct drm_device *dev,
716 void *data, struct drm_file *lessor_priv)
717{
718 struct drm_mode_revoke_lease *arg = data;
719 struct drm_master *lessor = lessor_priv->master;
720 struct drm_master *lessee;
721 int ret = 0;
722
723 DRM_DEBUG_LEASE("revoke lease for %d\n", arg->lessee_id);
724
725 /* Can't lease without MODESET */
726 if (!drm_core_check_feature(dev, DRIVER_MODESET))
727 return -EOPNOTSUPP;
728
729 mutex_lock(&dev->mode_config.idr_mutex);
730
731 lessee = _drm_find_lessee(lessor, arg->lessee_id);
732
733 /* No such lessee */
734 if (!lessee) {
735 ret = -ENOENT;
736 goto fail;
737 }
738
739 /* Lease is not held by lessor */
740 if (lessee->lessor != lessor) {
741 ret = -EACCES;
742 goto fail;
743 }
744
745 _drm_lease_revoke(lessee);
746
747fail:
748 mutex_unlock(&dev->mode_config.idr_mutex);
749
750 return ret;
751}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright © 2017 Keith Packard <keithp@keithp.com>
4 */
5#include <linux/file.h>
6#include <linux/uaccess.h>
7
8#include <drm/drm_auth.h>
9#include <drm/drm_crtc_helper.h>
10#include <drm/drm_drv.h>
11#include <drm/drm_file.h>
12#include <drm/drm_lease.h>
13#include <drm/drm_print.h>
14
15#include "drm_crtc_internal.h"
16#include "drm_internal.h"
17
18#define drm_for_each_lessee(lessee, lessor) \
19 list_for_each_entry((lessee), &(lessor)->lessees, lessee_list)
20
21static uint64_t drm_lease_idr_object;
22
23/**
24 * drm_lease_owner - return ancestor owner drm_master
25 * @master: drm_master somewhere within tree of lessees and lessors
26 *
27 * RETURN:
28 *
29 * drm_master at the top of the tree (i.e, with lessor NULL
30 */
31struct drm_master *drm_lease_owner(struct drm_master *master)
32{
33 while (master->lessor != NULL)
34 master = master->lessor;
35 return master;
36}
37
38/**
39 * _drm_find_lessee - find lessee by id (idr_mutex held)
40 * @master: drm_master of lessor
41 * @lessee_id: id
42 *
43 * RETURN:
44 *
45 * drm_master of the lessee if valid, NULL otherwise
46 */
47
48static struct drm_master*
49_drm_find_lessee(struct drm_master *master, int lessee_id)
50{
51 lockdep_assert_held(&master->dev->mode_config.idr_mutex);
52 return idr_find(&drm_lease_owner(master)->lessee_idr, lessee_id);
53}
54
55/**
56 * _drm_lease_held_master - check to see if an object is leased (or owned) by master (idr_mutex held)
57 * @master: the master to check the lease status of
58 * @id: the id to check
59 *
60 * Checks if the specified master holds a lease on the object. Return
61 * value:
62 *
63 * true 'master' holds a lease on (or owns) the object
64 * false 'master' does not hold a lease.
65 */
66static int _drm_lease_held_master(struct drm_master *master, int id)
67{
68 lockdep_assert_held(&master->dev->mode_config.idr_mutex);
69 if (master->lessor)
70 return idr_find(&master->leases, id) != NULL;
71 return true;
72}
73
74/**
75 * _drm_has_leased - check to see if an object has been leased (idr_mutex held)
76 * @master: the master to check the lease status of
77 * @id: the id to check
78 *
79 * Checks if any lessee of 'master' holds a lease on 'id'. Return
80 * value:
81 *
82 * true Some lessee holds a lease on the object.
83 * false No lessee has a lease on the object.
84 */
85static bool _drm_has_leased(struct drm_master *master, int id)
86{
87 struct drm_master *lessee;
88
89 lockdep_assert_held(&master->dev->mode_config.idr_mutex);
90 drm_for_each_lessee(lessee, master)
91 if (_drm_lease_held_master(lessee, id))
92 return true;
93 return false;
94}
95
96/**
97 * _drm_lease_held - check drm_mode_object lease status (idr_mutex held)
98 * @file_priv: the master drm_file
99 * @id: the object id
100 *
101 * Checks if the specified master holds a lease on the object. Return
102 * value:
103 *
104 * true 'master' holds a lease on (or owns) the object
105 * false 'master' does not hold a lease.
106 */
107bool _drm_lease_held(struct drm_file *file_priv, int id)
108{
109 bool ret;
110 struct drm_master *master;
111
112 if (!file_priv)
113 return true;
114
115 master = drm_file_get_master(file_priv);
116 if (!master)
117 return true;
118 ret = _drm_lease_held_master(master, id);
119 drm_master_put(&master);
120
121 return ret;
122}
123
124/**
125 * drm_lease_held - check drm_mode_object lease status (idr_mutex not held)
126 * @file_priv: the master drm_file
127 * @id: the object id
128 *
129 * Checks if the specified master holds a lease on the object. Return
130 * value:
131 *
132 * true 'master' holds a lease on (or owns) the object
133 * false 'master' does not hold a lease.
134 */
135bool drm_lease_held(struct drm_file *file_priv, int id)
136{
137 struct drm_master *master;
138 bool ret;
139
140 if (!file_priv)
141 return true;
142
143 master = drm_file_get_master(file_priv);
144 if (!master)
145 return true;
146 if (!master->lessor) {
147 ret = true;
148 goto out;
149 }
150 mutex_lock(&master->dev->mode_config.idr_mutex);
151 ret = _drm_lease_held_master(master, id);
152 mutex_unlock(&master->dev->mode_config.idr_mutex);
153
154out:
155 drm_master_put(&master);
156 return ret;
157}
158
159/**
160 * drm_lease_filter_crtcs - restricted crtc set to leased values (idr_mutex not held)
161 * @file_priv: requestor file
162 * @crtcs_in: bitmask of crtcs to check
163 *
164 * Reconstructs a crtc mask based on the crtcs which are visible
165 * through the specified file.
166 */
167uint32_t drm_lease_filter_crtcs(struct drm_file *file_priv, uint32_t crtcs_in)
168{
169 struct drm_master *master;
170 struct drm_device *dev;
171 struct drm_crtc *crtc;
172 int count_in, count_out;
173 uint32_t crtcs_out = 0;
174
175 if (!file_priv)
176 return crtcs_in;
177
178 master = drm_file_get_master(file_priv);
179 if (!master)
180 return crtcs_in;
181 if (!master->lessor) {
182 crtcs_out = crtcs_in;
183 goto out;
184 }
185 dev = master->dev;
186
187 count_in = count_out = 0;
188 mutex_lock(&master->dev->mode_config.idr_mutex);
189 list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
190 if (_drm_lease_held_master(master, crtc->base.id)) {
191 uint32_t mask_in = 1ul << count_in;
192
193 if ((crtcs_in & mask_in) != 0) {
194 uint32_t mask_out = 1ul << count_out;
195
196 crtcs_out |= mask_out;
197 }
198 count_out++;
199 }
200 count_in++;
201 }
202 mutex_unlock(&master->dev->mode_config.idr_mutex);
203
204out:
205 drm_master_put(&master);
206 return crtcs_out;
207}
208
209/*
210 * drm_lease_create - create a new drm_master with leased objects (idr_mutex not held)
211 * @lessor: lease holder (or owner) of objects
212 * @leases: objects to lease to the new drm_master
213 *
214 * Uses drm_master_create to allocate a new drm_master, then checks to
215 * make sure all of the desired objects can be leased, atomically
216 * leasing them to the new drmmaster.
217 *
218 * ERR_PTR(-EACCES) some other master holds the title to any object
219 * ERR_PTR(-ENOENT) some object is not a valid DRM object for this device
220 * ERR_PTR(-EBUSY) some other lessee holds title to this object
221 * ERR_PTR(-EEXIST) same object specified more than once in the provided list
222 * ERR_PTR(-ENOMEM) allocation failed
223 */
224static struct drm_master *drm_lease_create(struct drm_master *lessor, struct idr *leases)
225{
226 struct drm_device *dev = lessor->dev;
227 int error;
228 struct drm_master *lessee;
229 int object;
230 int id;
231 void *entry;
232
233 DRM_DEBUG_LEASE("lessor %d\n", lessor->lessee_id);
234
235 lessee = drm_master_create(lessor->dev);
236 if (!lessee) {
237 DRM_DEBUG_LEASE("drm_master_create failed\n");
238 return ERR_PTR(-ENOMEM);
239 }
240
241 mutex_lock(&dev->mode_config.idr_mutex);
242
243 idr_for_each_entry(leases, entry, object) {
244 error = 0;
245 if (!idr_find(&dev->mode_config.object_idr, object))
246 error = -ENOENT;
247 else if (_drm_has_leased(lessor, object))
248 error = -EBUSY;
249
250 if (error != 0) {
251 DRM_DEBUG_LEASE("object %d failed %d\n", object, error);
252 goto out_lessee;
253 }
254 }
255
256 /* Insert the new lessee into the tree */
257 id = idr_alloc(&(drm_lease_owner(lessor)->lessee_idr), lessee, 1, 0, GFP_KERNEL);
258 if (id < 0) {
259 error = id;
260 goto out_lessee;
261 }
262
263 lessee->lessee_id = id;
264 lessee->lessor = drm_master_get(lessor);
265 list_add_tail(&lessee->lessee_list, &lessor->lessees);
266
267 /* Move the leases over */
268 lessee->leases = *leases;
269 DRM_DEBUG_LEASE("new lessee %d %p, lessor %d %p\n", lessee->lessee_id, lessee, lessor->lessee_id, lessor);
270
271 mutex_unlock(&dev->mode_config.idr_mutex);
272 return lessee;
273
274out_lessee:
275 mutex_unlock(&dev->mode_config.idr_mutex);
276
277 drm_master_put(&lessee);
278
279 return ERR_PTR(error);
280}
281
282/**
283 * drm_lease_destroy - a master is going away (idr_mutex not held)
284 * @master: the drm_master being destroyed
285 *
286 * All lessees will have been destroyed as they
287 * hold a reference on their lessor. Notify any
288 * lessor for this master so that it can check
289 * the list of lessees.
290 */
291void drm_lease_destroy(struct drm_master *master)
292{
293 struct drm_device *dev = master->dev;
294
295 mutex_lock(&dev->mode_config.idr_mutex);
296
297 DRM_DEBUG_LEASE("drm_lease_destroy %d\n", master->lessee_id);
298
299 /* This master is referenced by all lessees, hence it cannot be destroyed
300 * until all of them have been
301 */
302 WARN_ON(!list_empty(&master->lessees));
303
304 /* Remove this master from the lessee idr in the owner */
305 if (master->lessee_id != 0) {
306 DRM_DEBUG_LEASE("remove master %d from device list of lessees\n", master->lessee_id);
307 idr_remove(&(drm_lease_owner(master)->lessee_idr), master->lessee_id);
308 }
309
310 /* Remove this master from any lessee list it may be on */
311 list_del(&master->lessee_list);
312
313 mutex_unlock(&dev->mode_config.idr_mutex);
314
315 if (master->lessor) {
316 /* Tell the master to check the lessee list */
317 drm_sysfs_lease_event(dev);
318 drm_master_put(&master->lessor);
319 }
320
321 DRM_DEBUG_LEASE("drm_lease_destroy done %d\n", master->lessee_id);
322}
323
324/**
325 * _drm_lease_revoke - revoke access to all leased objects (idr_mutex held)
326 * @top: the master losing its lease
327 */
328static void _drm_lease_revoke(struct drm_master *top)
329{
330 int object;
331 void *entry;
332 struct drm_master *master = top;
333
334 lockdep_assert_held(&top->dev->mode_config.idr_mutex);
335
336 /*
337 * Walk the tree starting at 'top' emptying all leases. Because
338 * the tree is fully connected, we can do this without recursing
339 */
340 for (;;) {
341 DRM_DEBUG_LEASE("revoke leases for %p %d\n", master, master->lessee_id);
342
343 /* Evacuate the lease */
344 idr_for_each_entry(&master->leases, entry, object)
345 idr_remove(&master->leases, object);
346
347 /* Depth-first list walk */
348
349 /* Down */
350 if (!list_empty(&master->lessees)) {
351 master = list_first_entry(&master->lessees, struct drm_master, lessee_list);
352 } else {
353 /* Up */
354 while (master != top && master == list_last_entry(&master->lessor->lessees, struct drm_master, lessee_list))
355 master = master->lessor;
356
357 if (master == top)
358 break;
359
360 /* Over */
361 master = list_next_entry(master, lessee_list);
362 }
363 }
364}
365
366/**
367 * drm_lease_revoke - revoke access to all leased objects (idr_mutex not held)
368 * @top: the master losing its lease
369 */
370void drm_lease_revoke(struct drm_master *top)
371{
372 mutex_lock(&top->dev->mode_config.idr_mutex);
373 _drm_lease_revoke(top);
374 mutex_unlock(&top->dev->mode_config.idr_mutex);
375}
376
377static int validate_lease(struct drm_device *dev,
378 int object_count,
379 struct drm_mode_object **objects,
380 bool universal_planes)
381{
382 int o;
383 int has_crtc = -1;
384 int has_connector = -1;
385 int has_plane = -1;
386
387 /* we want to confirm that there is at least one crtc, plane
388 connector object. */
389
390 for (o = 0; o < object_count; o++) {
391 if (objects[o]->type == DRM_MODE_OBJECT_CRTC && has_crtc == -1) {
392 has_crtc = o;
393 }
394 if (objects[o]->type == DRM_MODE_OBJECT_CONNECTOR && has_connector == -1)
395 has_connector = o;
396
397 if (universal_planes) {
398 if (objects[o]->type == DRM_MODE_OBJECT_PLANE && has_plane == -1)
399 has_plane = o;
400 }
401 }
402 if (has_crtc == -1 || has_connector == -1)
403 return -EINVAL;
404 if (universal_planes && has_plane == -1)
405 return -EINVAL;
406 return 0;
407}
408
409static int fill_object_idr(struct drm_device *dev,
410 struct drm_file *lessor_priv,
411 struct idr *leases,
412 int object_count,
413 u32 *object_ids)
414{
415 struct drm_mode_object **objects;
416 u32 o;
417 int ret;
418 bool universal_planes = READ_ONCE(lessor_priv->universal_planes);
419
420 objects = kcalloc(object_count, sizeof(struct drm_mode_object *),
421 GFP_KERNEL);
422 if (!objects)
423 return -ENOMEM;
424
425 /* step one - get references to all the mode objects
426 and check for validity. */
427 for (o = 0; o < object_count; o++) {
428 objects[o] = drm_mode_object_find(dev, lessor_priv,
429 object_ids[o],
430 DRM_MODE_OBJECT_ANY);
431 if (!objects[o]) {
432 ret = -ENOENT;
433 goto out_free_objects;
434 }
435
436 if (!drm_mode_object_lease_required(objects[o]->type)) {
437 DRM_DEBUG_KMS("invalid object for lease\n");
438 ret = -EINVAL;
439 goto out_free_objects;
440 }
441 }
442
443 ret = validate_lease(dev, object_count, objects, universal_planes);
444 if (ret) {
445 DRM_DEBUG_LEASE("lease validation failed\n");
446 goto out_free_objects;
447 }
448
449 /* add their IDs to the lease request - taking into account
450 universal planes */
451 for (o = 0; o < object_count; o++) {
452 struct drm_mode_object *obj = objects[o];
453 u32 object_id = objects[o]->id;
454
455 DRM_DEBUG_LEASE("Adding object %d to lease\n", object_id);
456
457 /*
458 * We're using an IDR to hold the set of leased
459 * objects, but we don't need to point at the object's
460 * data structure from the lease as the main object_idr
461 * will be used to actually find that. Instead, all we
462 * really want is a 'leased/not-leased' result, for
463 * which any non-NULL pointer will work fine.
464 */
465 ret = idr_alloc(leases, &drm_lease_idr_object , object_id, object_id + 1, GFP_KERNEL);
466 if (ret < 0) {
467 DRM_DEBUG_LEASE("Object %d cannot be inserted into leases (%d)\n",
468 object_id, ret);
469 goto out_free_objects;
470 }
471 if (obj->type == DRM_MODE_OBJECT_CRTC && !universal_planes) {
472 struct drm_crtc *crtc = obj_to_crtc(obj);
473
474 ret = idr_alloc(leases, &drm_lease_idr_object, crtc->primary->base.id, crtc->primary->base.id + 1, GFP_KERNEL);
475 if (ret < 0) {
476 DRM_DEBUG_LEASE("Object primary plane %d cannot be inserted into leases (%d)\n",
477 object_id, ret);
478 goto out_free_objects;
479 }
480 if (crtc->cursor) {
481 ret = idr_alloc(leases, &drm_lease_idr_object, crtc->cursor->base.id, crtc->cursor->base.id + 1, GFP_KERNEL);
482 if (ret < 0) {
483 DRM_DEBUG_LEASE("Object cursor plane %d cannot be inserted into leases (%d)\n",
484 object_id, ret);
485 goto out_free_objects;
486 }
487 }
488 }
489 }
490
491 ret = 0;
492out_free_objects:
493 for (o = 0; o < object_count; o++) {
494 if (objects[o])
495 drm_mode_object_put(objects[o]);
496 }
497 kfree(objects);
498 return ret;
499}
500
501/**
502 * drm_mode_create_lease_ioctl - create a new lease
503 * @dev: the drm device
504 * @data: pointer to struct drm_mode_create_lease
505 * @lessor_priv: the file being manipulated
506 *
507 * The master associated with the specified file will have a lease
508 * created containing the objects specified in the ioctl structure.
509 * A file descriptor will be allocated for that and returned to the
510 * application.
511 */
512int drm_mode_create_lease_ioctl(struct drm_device *dev,
513 void *data, struct drm_file *lessor_priv)
514{
515 struct drm_mode_create_lease *cl = data;
516 size_t object_count;
517 int ret = 0;
518 struct idr leases;
519 struct drm_master *lessor;
520 struct drm_master *lessee = NULL;
521 struct file *lessee_file = NULL;
522 struct file *lessor_file = lessor_priv->filp;
523 struct drm_file *lessee_priv;
524 int fd = -1;
525 uint32_t *object_ids;
526
527 /* Can't lease without MODESET */
528 if (!drm_core_check_feature(dev, DRIVER_MODESET))
529 return -EOPNOTSUPP;
530
531 /* need some objects */
532 if (cl->object_count == 0) {
533 DRM_DEBUG_LEASE("no objects in lease\n");
534 return -EINVAL;
535 }
536
537 if (cl->flags && (cl->flags & ~(O_CLOEXEC | O_NONBLOCK))) {
538 DRM_DEBUG_LEASE("invalid flags\n");
539 return -EINVAL;
540 }
541
542 lessor = drm_file_get_master(lessor_priv);
543 /* Do not allow sub-leases */
544 if (lessor->lessor) {
545 DRM_DEBUG_LEASE("recursive leasing not allowed\n");
546 ret = -EINVAL;
547 goto out_lessor;
548 }
549
550 object_count = cl->object_count;
551
552 object_ids = memdup_user(u64_to_user_ptr(cl->object_ids),
553 array_size(object_count, sizeof(__u32)));
554 if (IS_ERR(object_ids)) {
555 ret = PTR_ERR(object_ids);
556 goto out_lessor;
557 }
558
559 idr_init(&leases);
560
561 /* fill and validate the object idr */
562 ret = fill_object_idr(dev, lessor_priv, &leases,
563 object_count, object_ids);
564 kfree(object_ids);
565 if (ret) {
566 DRM_DEBUG_LEASE("lease object lookup failed: %i\n", ret);
567 idr_destroy(&leases);
568 goto out_lessor;
569 }
570
571 /* Allocate a file descriptor for the lease */
572 fd = get_unused_fd_flags(cl->flags & (O_CLOEXEC | O_NONBLOCK));
573 if (fd < 0) {
574 idr_destroy(&leases);
575 ret = fd;
576 goto out_lessor;
577 }
578
579 DRM_DEBUG_LEASE("Creating lease\n");
580 /* lessee will take the ownership of leases */
581 lessee = drm_lease_create(lessor, &leases);
582
583 if (IS_ERR(lessee)) {
584 ret = PTR_ERR(lessee);
585 idr_destroy(&leases);
586 goto out_leases;
587 }
588
589 /* Clone the lessor file to create a new file for us */
590 DRM_DEBUG_LEASE("Allocating lease file\n");
591 lessee_file = file_clone_open(lessor_file);
592 if (IS_ERR(lessee_file)) {
593 ret = PTR_ERR(lessee_file);
594 goto out_lessee;
595 }
596
597 lessee_priv = lessee_file->private_data;
598 /* Change the file to a master one */
599 drm_master_put(&lessee_priv->master);
600 lessee_priv->master = lessee;
601 lessee_priv->is_master = 1;
602 lessee_priv->authenticated = 1;
603
604 /* Pass fd back to userspace */
605 DRM_DEBUG_LEASE("Returning fd %d id %d\n", fd, lessee->lessee_id);
606 cl->fd = fd;
607 cl->lessee_id = lessee->lessee_id;
608
609 /* Hook up the fd */
610 fd_install(fd, lessee_file);
611
612 drm_master_put(&lessor);
613 DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl succeeded\n");
614 return 0;
615
616out_lessee:
617 drm_master_put(&lessee);
618
619out_leases:
620 put_unused_fd(fd);
621
622out_lessor:
623 drm_master_put(&lessor);
624 DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret);
625 return ret;
626}
627
628/**
629 * drm_mode_list_lessees_ioctl - list lessee ids
630 * @dev: the drm device
631 * @data: pointer to struct drm_mode_list_lessees
632 * @lessor_priv: the file being manipulated
633 *
634 * Starting from the master associated with the specified file,
635 * the master with the provided lessee_id is found, and then
636 * an array of lessee ids associated with leases from that master
637 * are returned.
638 */
639
640int drm_mode_list_lessees_ioctl(struct drm_device *dev,
641 void *data, struct drm_file *lessor_priv)
642{
643 struct drm_mode_list_lessees *arg = data;
644 __u32 __user *lessee_ids = (__u32 __user *) (uintptr_t) (arg->lessees_ptr);
645 __u32 count_lessees = arg->count_lessees;
646 struct drm_master *lessor, *lessee;
647 int count;
648 int ret = 0;
649
650 if (arg->pad)
651 return -EINVAL;
652
653 /* Can't lease without MODESET */
654 if (!drm_core_check_feature(dev, DRIVER_MODESET))
655 return -EOPNOTSUPP;
656
657 lessor = drm_file_get_master(lessor_priv);
658 DRM_DEBUG_LEASE("List lessees for %d\n", lessor->lessee_id);
659
660 mutex_lock(&dev->mode_config.idr_mutex);
661
662 count = 0;
663 drm_for_each_lessee(lessee, lessor) {
664 /* Only list un-revoked leases */
665 if (!idr_is_empty(&lessee->leases)) {
666 if (count_lessees > count) {
667 DRM_DEBUG_LEASE("Add lessee %d\n", lessee->lessee_id);
668 ret = put_user(lessee->lessee_id, lessee_ids + count);
669 if (ret)
670 break;
671 }
672 count++;
673 }
674 }
675
676 DRM_DEBUG_LEASE("Lessor leases to %d\n", count);
677 if (ret == 0)
678 arg->count_lessees = count;
679
680 mutex_unlock(&dev->mode_config.idr_mutex);
681 drm_master_put(&lessor);
682
683 return ret;
684}
685
686/**
687 * drm_mode_get_lease_ioctl - list leased objects
688 * @dev: the drm device
689 * @data: pointer to struct drm_mode_get_lease
690 * @lessee_priv: the file being manipulated
691 *
692 * Return the list of leased objects for the specified lessee
693 */
694
695int drm_mode_get_lease_ioctl(struct drm_device *dev,
696 void *data, struct drm_file *lessee_priv)
697{
698 struct drm_mode_get_lease *arg = data;
699 __u32 __user *object_ids = (__u32 __user *) (uintptr_t) (arg->objects_ptr);
700 __u32 count_objects = arg->count_objects;
701 struct drm_master *lessee;
702 struct idr *object_idr;
703 int count;
704 void *entry;
705 int object;
706 int ret = 0;
707
708 if (arg->pad)
709 return -EINVAL;
710
711 /* Can't lease without MODESET */
712 if (!drm_core_check_feature(dev, DRIVER_MODESET))
713 return -EOPNOTSUPP;
714
715 lessee = drm_file_get_master(lessee_priv);
716 DRM_DEBUG_LEASE("get lease for %d\n", lessee->lessee_id);
717
718 mutex_lock(&dev->mode_config.idr_mutex);
719
720 if (lessee->lessor == NULL)
721 /* owner can use all objects */
722 object_idr = &lessee->dev->mode_config.object_idr;
723 else
724 /* lessee can only use allowed object */
725 object_idr = &lessee->leases;
726
727 count = 0;
728 idr_for_each_entry(object_idr, entry, object) {
729 if (count_objects > count) {
730 DRM_DEBUG_LEASE("adding object %d\n", object);
731 ret = put_user(object, object_ids + count);
732 if (ret)
733 break;
734 }
735 count++;
736 }
737
738 DRM_DEBUG("lease holds %d objects\n", count);
739 if (ret == 0)
740 arg->count_objects = count;
741
742 mutex_unlock(&dev->mode_config.idr_mutex);
743 drm_master_put(&lessee);
744
745 return ret;
746}
747
748/**
749 * drm_mode_revoke_lease_ioctl - revoke lease
750 * @dev: the drm device
751 * @data: pointer to struct drm_mode_revoke_lease
752 * @lessor_priv: the file being manipulated
753 *
754 * This removes all of the objects from the lease without
755 * actually getting rid of the lease itself; that way all
756 * references to it still work correctly
757 */
758int drm_mode_revoke_lease_ioctl(struct drm_device *dev,
759 void *data, struct drm_file *lessor_priv)
760{
761 struct drm_mode_revoke_lease *arg = data;
762 struct drm_master *lessor;
763 struct drm_master *lessee;
764 int ret = 0;
765
766 DRM_DEBUG_LEASE("revoke lease for %d\n", arg->lessee_id);
767
768 /* Can't lease without MODESET */
769 if (!drm_core_check_feature(dev, DRIVER_MODESET))
770 return -EOPNOTSUPP;
771
772 lessor = drm_file_get_master(lessor_priv);
773 mutex_lock(&dev->mode_config.idr_mutex);
774
775 lessee = _drm_find_lessee(lessor, arg->lessee_id);
776
777 /* No such lessee */
778 if (!lessee) {
779 ret = -ENOENT;
780 goto fail;
781 }
782
783 /* Lease is not held by lessor */
784 if (lessee->lessor != lessor) {
785 ret = -EACCES;
786 goto fail;
787 }
788
789 _drm_lease_revoke(lessee);
790
791fail:
792 mutex_unlock(&dev->mode_config.idr_mutex);
793 drm_master_put(&lessor);
794
795 return ret;
796}