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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
170 if ((crtcs_in & mask_in) != 0) {
171 uint32_t mask_out = 1ul << count_out;
172
173 crtcs_out |= mask_out;
174 }
175 count_out++;
176 }
177 count_in++;
178 }
179 mutex_unlock(&master->dev->mode_config.idr_mutex);
180 return crtcs_out;
181}
182
183/*
184 * drm_lease_create - create a new drm_master with leased objects (idr_mutex not held)
185 * @lessor: lease holder (or owner) of objects
186 * @leases: objects to lease to the new drm_master
187 *
188 * Uses drm_master_create to allocate a new drm_master, then checks to
189 * make sure all of the desired objects can be leased, atomically
190 * leasing them to the new drmmaster.
191 *
192 * ERR_PTR(-EACCES) some other master holds the title to any object
193 * ERR_PTR(-ENOENT) some object is not a valid DRM object for this device
194 * ERR_PTR(-EBUSY) some other lessee holds title to this object
195 * ERR_PTR(-EEXIST) same object specified more than once in the provided list
196 * ERR_PTR(-ENOMEM) allocation failed
197 */
198static struct drm_master *drm_lease_create(struct drm_master *lessor, struct idr *leases)
199{
200 struct drm_device *dev = lessor->dev;
201 int error;
202 struct drm_master *lessee;
203 int object;
204 int id;
205 void *entry;
206
207 DRM_DEBUG_LEASE("lessor %d\n", lessor->lessee_id);
208
209 lessee = drm_master_create(lessor->dev);
210 if (!lessee) {
211 DRM_DEBUG_LEASE("drm_master_create failed\n");
212 return ERR_PTR(-ENOMEM);
213 }
214
215 mutex_lock(&dev->mode_config.idr_mutex);
216
217 idr_for_each_entry(leases, entry, object) {
218 error = 0;
219 if (!idr_find(&dev->mode_config.object_idr, object))
220 error = -ENOENT;
221 else if (_drm_has_leased(lessor, object))
222 error = -EBUSY;
223
224 if (error != 0) {
225 DRM_DEBUG_LEASE("object %d failed %d\n", object, error);
226 goto out_lessee;
227 }
228 }
229
230 /* Insert the new lessee into the tree */
231 id = idr_alloc(&(drm_lease_owner(lessor)->lessee_idr), lessee, 1, 0, GFP_KERNEL);
232 if (id < 0) {
233 error = id;
234 goto out_lessee;
235 }
236
237 lessee->lessee_id = id;
238 lessee->lessor = drm_master_get(lessor);
239 list_add_tail(&lessee->lessee_list, &lessor->lessees);
240
241 /* Move the leases over */
242 lessee->leases = *leases;
243 DRM_DEBUG_LEASE("new lessee %d %p, lessor %d %p\n", lessee->lessee_id, lessee, lessor->lessee_id, lessor);
244
245 mutex_unlock(&dev->mode_config.idr_mutex);
246 return lessee;
247
248out_lessee:
249 mutex_unlock(&dev->mode_config.idr_mutex);
250
251 drm_master_put(&lessee);
252
253 return ERR_PTR(error);
254}
255
256/**
257 * drm_lease_destroy - a master is going away (idr_mutex not held)
258 * @master: the drm_master being destroyed
259 *
260 * All lessees will have been destroyed as they
261 * hold a reference on their lessor. Notify any
262 * lessor for this master so that it can check
263 * the list of lessees.
264 */
265void drm_lease_destroy(struct drm_master *master)
266{
267 struct drm_device *dev = master->dev;
268
269 mutex_lock(&dev->mode_config.idr_mutex);
270
271 DRM_DEBUG_LEASE("drm_lease_destroy %d\n", master->lessee_id);
272
273 /* This master is referenced by all lessees, hence it cannot be destroyed
274 * until all of them have been
275 */
276 WARN_ON(!list_empty(&master->lessees));
277
278 /* Remove this master from the lessee idr in the owner */
279 if (master->lessee_id != 0) {
280 DRM_DEBUG_LEASE("remove master %d from device list of lessees\n", master->lessee_id);
281 idr_remove(&(drm_lease_owner(master)->lessee_idr), master->lessee_id);
282 }
283
284 /* Remove this master from any lessee list it may be on */
285 list_del(&master->lessee_list);
286
287 mutex_unlock(&dev->mode_config.idr_mutex);
288
289 if (master->lessor) {
290 /* Tell the master to check the lessee list */
291 drm_sysfs_lease_event(dev);
292 drm_master_put(&master->lessor);
293 }
294
295 DRM_DEBUG_LEASE("drm_lease_destroy done %d\n", master->lessee_id);
296}
297
298/**
299 * _drm_lease_revoke - revoke access to all leased objects (idr_mutex held)
300 * @top: the master losing its lease
301 */
302static void _drm_lease_revoke(struct drm_master *top)
303{
304 int object;
305 void *entry;
306 struct drm_master *master = top;
307
308 lockdep_assert_held(&top->dev->mode_config.idr_mutex);
309
310 /*
311 * Walk the tree starting at 'top' emptying all leases. Because
312 * the tree is fully connected, we can do this without recursing
313 */
314 for (;;) {
315 DRM_DEBUG_LEASE("revoke leases for %p %d\n", master, master->lessee_id);
316
317 /* Evacuate the lease */
318 idr_for_each_entry(&master->leases, entry, object)
319 idr_remove(&master->leases, object);
320
321 /* Depth-first list walk */
322
323 /* Down */
324 if (!list_empty(&master->lessees)) {
325 master = list_first_entry(&master->lessees, struct drm_master, lessee_list);
326 } else {
327 /* Up */
328 while (master != top && master == list_last_entry(&master->lessor->lessees, struct drm_master, lessee_list))
329 master = master->lessor;
330
331 if (master == top)
332 break;
333
334 /* Over */
335 master = list_next_entry(master, lessee_list);
336 }
337 }
338}
339
340/**
341 * drm_lease_revoke - revoke access to all leased objects (idr_mutex not held)
342 * @top: the master losing its lease
343 */
344void drm_lease_revoke(struct drm_master *top)
345{
346 mutex_lock(&top->dev->mode_config.idr_mutex);
347 _drm_lease_revoke(top);
348 mutex_unlock(&top->dev->mode_config.idr_mutex);
349}
350
351static int validate_lease(struct drm_device *dev,
352 int object_count,
353 struct drm_mode_object **objects,
354 bool universal_planes)
355{
356 int o;
357 int has_crtc = -1;
358 int has_connector = -1;
359 int has_plane = -1;
360
361 /* we want to confirm that there is at least one crtc, plane
362 connector object. */
363
364 for (o = 0; o < object_count; o++) {
365 if (objects[o]->type == DRM_MODE_OBJECT_CRTC && has_crtc == -1) {
366 has_crtc = o;
367 }
368 if (objects[o]->type == DRM_MODE_OBJECT_CONNECTOR && has_connector == -1)
369 has_connector = o;
370
371 if (universal_planes) {
372 if (objects[o]->type == DRM_MODE_OBJECT_PLANE && has_plane == -1)
373 has_plane = o;
374 }
375 }
376 if (has_crtc == -1 || has_connector == -1)
377 return -EINVAL;
378 if (universal_planes && has_plane == -1)
379 return -EINVAL;
380 return 0;
381}
382
383static int fill_object_idr(struct drm_device *dev,
384 struct drm_file *lessor_priv,
385 struct idr *leases,
386 int object_count,
387 u32 *object_ids)
388{
389 struct drm_mode_object **objects;
390 u32 o;
391 int ret;
392 bool universal_planes = READ_ONCE(lessor_priv->universal_planes);
393
394 objects = kcalloc(object_count, sizeof(struct drm_mode_object *),
395 GFP_KERNEL);
396 if (!objects)
397 return -ENOMEM;
398
399 /* step one - get references to all the mode objects
400 and check for validity. */
401 for (o = 0; o < object_count; o++) {
402 objects[o] = drm_mode_object_find(dev, lessor_priv,
403 object_ids[o],
404 DRM_MODE_OBJECT_ANY);
405 if (!objects[o]) {
406 ret = -ENOENT;
407 goto out_free_objects;
408 }
409
410 if (!drm_mode_object_lease_required(objects[o]->type)) {
411 DRM_DEBUG_KMS("invalid object for lease\n");
412 ret = -EINVAL;
413 goto out_free_objects;
414 }
415 }
416
417 ret = validate_lease(dev, object_count, objects, universal_planes);
418 if (ret) {
419 DRM_DEBUG_LEASE("lease validation failed\n");
420 goto out_free_objects;
421 }
422
423 /* add their IDs to the lease request - taking into account
424 universal planes */
425 for (o = 0; o < object_count; o++) {
426 struct drm_mode_object *obj = objects[o];
427 u32 object_id = objects[o]->id;
428
429 DRM_DEBUG_LEASE("Adding object %d to lease\n", object_id);
430
431 /*
432 * We're using an IDR to hold the set of leased
433 * objects, but we don't need to point at the object's
434 * data structure from the lease as the main object_idr
435 * will be used to actually find that. Instead, all we
436 * really want is a 'leased/not-leased' result, for
437 * which any non-NULL pointer will work fine.
438 */
439 ret = idr_alloc(leases, &drm_lease_idr_object , object_id, object_id + 1, GFP_KERNEL);
440 if (ret < 0) {
441 DRM_DEBUG_LEASE("Object %d cannot be inserted into leases (%d)\n",
442 object_id, ret);
443 goto out_free_objects;
444 }
445 if (obj->type == DRM_MODE_OBJECT_CRTC && !universal_planes) {
446 struct drm_crtc *crtc = obj_to_crtc(obj);
447
448 ret = idr_alloc(leases, &drm_lease_idr_object, crtc->primary->base.id, crtc->primary->base.id + 1, GFP_KERNEL);
449 if (ret < 0) {
450 DRM_DEBUG_LEASE("Object primary plane %d cannot be inserted into leases (%d)\n",
451 object_id, ret);
452 goto out_free_objects;
453 }
454 if (crtc->cursor) {
455 ret = idr_alloc(leases, &drm_lease_idr_object, crtc->cursor->base.id, crtc->cursor->base.id + 1, GFP_KERNEL);
456 if (ret < 0) {
457 DRM_DEBUG_LEASE("Object cursor plane %d cannot be inserted into leases (%d)\n",
458 object_id, ret);
459 goto out_free_objects;
460 }
461 }
462 }
463 }
464
465 ret = 0;
466out_free_objects:
467 for (o = 0; o < object_count; o++) {
468 if (objects[o])
469 drm_mode_object_put(objects[o]);
470 }
471 kfree(objects);
472 return ret;
473}
474
475/**
476 * drm_mode_create_lease_ioctl - create a new lease
477 * @dev: the drm device
478 * @data: pointer to struct drm_mode_create_lease
479 * @lessor_priv: the file being manipulated
480 *
481 * The master associated with the specified file will have a lease
482 * created containing the objects specified in the ioctl structure.
483 * A file descriptor will be allocated for that and returned to the
484 * application.
485 */
486int drm_mode_create_lease_ioctl(struct drm_device *dev,
487 void *data, struct drm_file *lessor_priv)
488{
489 struct drm_mode_create_lease *cl = data;
490 size_t object_count;
491 int ret = 0;
492 struct idr leases;
493 struct drm_master *lessor = lessor_priv->master;
494 struct drm_master *lessee = NULL;
495 struct file *lessee_file = NULL;
496 struct file *lessor_file = lessor_priv->filp;
497 struct drm_file *lessee_priv;
498 int fd = -1;
499 uint32_t *object_ids;
500
501 /* Can't lease without MODESET */
502 if (!drm_core_check_feature(dev, DRIVER_MODESET))
503 return -EOPNOTSUPP;
504
505 /* Do not allow sub-leases */
506 if (lessor->lessor) {
507 DRM_DEBUG_LEASE("recursive leasing not allowed\n");
508 return -EINVAL;
509 }
510
511 /* need some objects */
512 if (cl->object_count == 0) {
513 DRM_DEBUG_LEASE("no objects in lease\n");
514 return -EINVAL;
515 }
516
517 if (cl->flags && (cl->flags & ~(O_CLOEXEC | O_NONBLOCK))) {
518 DRM_DEBUG_LEASE("invalid flags\n");
519 return -EINVAL;
520 }
521
522 object_count = cl->object_count;
523
524 object_ids = memdup_user(u64_to_user_ptr(cl->object_ids),
525 array_size(object_count, sizeof(__u32)));
526 if (IS_ERR(object_ids))
527 return PTR_ERR(object_ids);
528
529 idr_init(&leases);
530
531 /* fill and validate the object idr */
532 ret = fill_object_idr(dev, lessor_priv, &leases,
533 object_count, object_ids);
534 kfree(object_ids);
535 if (ret) {
536 DRM_DEBUG_LEASE("lease object lookup failed: %i\n", ret);
537 idr_destroy(&leases);
538 return ret;
539 }
540
541 /* Allocate a file descriptor for the lease */
542 fd = get_unused_fd_flags(cl->flags & (O_CLOEXEC | O_NONBLOCK));
543 if (fd < 0) {
544 idr_destroy(&leases);
545 return fd;
546 }
547
548 DRM_DEBUG_LEASE("Creating lease\n");
549 /* lessee will take the ownership of leases */
550 lessee = drm_lease_create(lessor, &leases);
551
552 if (IS_ERR(lessee)) {
553 ret = PTR_ERR(lessee);
554 idr_destroy(&leases);
555 goto out_leases;
556 }
557
558 /* Clone the lessor file to create a new file for us */
559 DRM_DEBUG_LEASE("Allocating lease file\n");
560 lessee_file = file_clone_open(lessor_file);
561 if (IS_ERR(lessee_file)) {
562 ret = PTR_ERR(lessee_file);
563 goto out_lessee;
564 }
565
566 lessee_priv = lessee_file->private_data;
567 /* Change the file to a master one */
568 drm_master_put(&lessee_priv->master);
569 lessee_priv->master = lessee;
570 lessee_priv->is_master = 1;
571 lessee_priv->authenticated = 1;
572
573 /* Pass fd back to userspace */
574 DRM_DEBUG_LEASE("Returning fd %d id %d\n", fd, lessee->lessee_id);
575 cl->fd = fd;
576 cl->lessee_id = lessee->lessee_id;
577
578 /* Hook up the fd */
579 fd_install(fd, lessee_file);
580
581 DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl succeeded\n");
582 return 0;
583
584out_lessee:
585 drm_master_put(&lessee);
586
587out_leases:
588 put_unused_fd(fd);
589
590 DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret);
591 return ret;
592}
593
594/**
595 * drm_mode_list_lessees_ioctl - list lessee ids
596 * @dev: the drm device
597 * @data: pointer to struct drm_mode_list_lessees
598 * @lessor_priv: the file being manipulated
599 *
600 * Starting from the master associated with the specified file,
601 * the master with the provided lessee_id is found, and then
602 * an array of lessee ids associated with leases from that master
603 * are returned.
604 */
605
606int drm_mode_list_lessees_ioctl(struct drm_device *dev,
607 void *data, struct drm_file *lessor_priv)
608{
609 struct drm_mode_list_lessees *arg = data;
610 __u32 __user *lessee_ids = (__u32 __user *) (uintptr_t) (arg->lessees_ptr);
611 __u32 count_lessees = arg->count_lessees;
612 struct drm_master *lessor = lessor_priv->master, *lessee;
613 int count;
614 int ret = 0;
615
616 if (arg->pad)
617 return -EINVAL;
618
619 /* Can't lease without MODESET */
620 if (!drm_core_check_feature(dev, DRIVER_MODESET))
621 return -EOPNOTSUPP;
622
623 DRM_DEBUG_LEASE("List lessees for %d\n", lessor->lessee_id);
624
625 mutex_lock(&dev->mode_config.idr_mutex);
626
627 count = 0;
628 drm_for_each_lessee(lessee, lessor) {
629 /* Only list un-revoked leases */
630 if (!idr_is_empty(&lessee->leases)) {
631 if (count_lessees > count) {
632 DRM_DEBUG_LEASE("Add lessee %d\n", lessee->lessee_id);
633 ret = put_user(lessee->lessee_id, lessee_ids + count);
634 if (ret)
635 break;
636 }
637 count++;
638 }
639 }
640
641 DRM_DEBUG_LEASE("Lessor leases to %d\n", count);
642 if (ret == 0)
643 arg->count_lessees = count;
644
645 mutex_unlock(&dev->mode_config.idr_mutex);
646
647 return ret;
648}
649
650/**
651 * drm_mode_get_lease_ioctl - list leased objects
652 * @dev: the drm device
653 * @data: pointer to struct drm_mode_get_lease
654 * @lessee_priv: the file being manipulated
655 *
656 * Return the list of leased objects for the specified lessee
657 */
658
659int drm_mode_get_lease_ioctl(struct drm_device *dev,
660 void *data, struct drm_file *lessee_priv)
661{
662 struct drm_mode_get_lease *arg = data;
663 __u32 __user *object_ids = (__u32 __user *) (uintptr_t) (arg->objects_ptr);
664 __u32 count_objects = arg->count_objects;
665 struct drm_master *lessee = lessee_priv->master;
666 struct idr *object_idr;
667 int count;
668 void *entry;
669 int object;
670 int ret = 0;
671
672 if (arg->pad)
673 return -EINVAL;
674
675 /* Can't lease without MODESET */
676 if (!drm_core_check_feature(dev, DRIVER_MODESET))
677 return -EOPNOTSUPP;
678
679 DRM_DEBUG_LEASE("get lease for %d\n", lessee->lessee_id);
680
681 mutex_lock(&dev->mode_config.idr_mutex);
682
683 if (lessee->lessor == NULL)
684 /* owner can use all objects */
685 object_idr = &lessee->dev->mode_config.object_idr;
686 else
687 /* lessee can only use allowed object */
688 object_idr = &lessee->leases;
689
690 count = 0;
691 idr_for_each_entry(object_idr, entry, object) {
692 if (count_objects > count) {
693 DRM_DEBUG_LEASE("adding object %d\n", object);
694 ret = put_user(object, object_ids + count);
695 if (ret)
696 break;
697 }
698 count++;
699 }
700
701 DRM_DEBUG("lease holds %d objects\n", count);
702 if (ret == 0)
703 arg->count_objects = count;
704
705 mutex_unlock(&dev->mode_config.idr_mutex);
706
707 return ret;
708}
709
710/**
711 * drm_mode_revoke_lease_ioctl - revoke lease
712 * @dev: the drm device
713 * @data: pointer to struct drm_mode_revoke_lease
714 * @lessor_priv: the file being manipulated
715 *
716 * This removes all of the objects from the lease without
717 * actually getting rid of the lease itself; that way all
718 * references to it still work correctly
719 */
720int drm_mode_revoke_lease_ioctl(struct drm_device *dev,
721 void *data, struct drm_file *lessor_priv)
722{
723 struct drm_mode_revoke_lease *arg = data;
724 struct drm_master *lessor = lessor_priv->master;
725 struct drm_master *lessee;
726 int ret = 0;
727
728 DRM_DEBUG_LEASE("revoke lease for %d\n", arg->lessee_id);
729
730 /* Can't lease without MODESET */
731 if (!drm_core_check_feature(dev, DRIVER_MODESET))
732 return -EOPNOTSUPP;
733
734 mutex_lock(&dev->mode_config.idr_mutex);
735
736 lessee = _drm_find_lessee(lessor, arg->lessee_id);
737
738 /* No such lessee */
739 if (!lessee) {
740 ret = -ENOENT;
741 goto fail;
742 }
743
744 /* Lease is not held by lessor */
745 if (lessee->lessor != lessor) {
746 ret = -EACCES;
747 goto fail;
748 }
749
750 _drm_lease_revoke(lessee);
751
752fail:
753 mutex_unlock(&dev->mode_config.idr_mutex);
754
755 return ret;
756}