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