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	bool ret;
111	struct drm_master *master;
112
113	if (!file_priv)
114		return true;
115
116	master = drm_file_get_master(file_priv);
117	if (!master)
118		return true;
119	ret = _drm_lease_held_master(master, id);
120	drm_master_put(&master);
121
122	return ret;
123}
124
125/**
126 * drm_lease_held - check drm_mode_object lease status (idr_mutex not held)
127 * @file_priv: the master drm_file
128 * @id: the object id
129 *
130 * Checks if the specified master holds a lease on the object. Return
131 * value:
132 *
133 *	true		'master' holds a lease on (or owns) the object
134 *	false		'master' does not hold a lease.
135 */
136bool drm_lease_held(struct drm_file *file_priv, int id)
137{
138	struct drm_master *master;
139	bool ret;
140
141	if (!file_priv)
142		return true;
143
144	master = drm_file_get_master(file_priv);
145	if (!master)
146		return true;
147	if (!master->lessor) {
148		ret = true;
149		goto out;
150	}
151	mutex_lock(&master->dev->mode_config.idr_mutex);
152	ret = _drm_lease_held_master(master, id);
153	mutex_unlock(&master->dev->mode_config.idr_mutex);
154
155out:
156	drm_master_put(&master);
157	return ret;
158}
159
160/**
161 * drm_lease_filter_crtcs - restricted crtc set to leased values (idr_mutex not held)
162 * @file_priv: requestor file
163 * @crtcs_in: bitmask of crtcs to check
164 *
165 * Reconstructs a crtc mask based on the crtcs which are visible
166 * through the specified file.
167 */
168uint32_t drm_lease_filter_crtcs(struct drm_file *file_priv, uint32_t crtcs_in)
169{
170	struct drm_master *master;
171	struct drm_device *dev;
172	struct drm_crtc *crtc;
173	int count_in, count_out;
174	uint32_t crtcs_out = 0;
175
176	if (!file_priv)
177		return crtcs_in;
178
179	master = drm_file_get_master(file_priv);
180	if (!master)
181		return crtcs_in;
182	if (!master->lessor) {
183		crtcs_out = crtcs_in;
184		goto out;
185	}
186	dev = master->dev;
187
188	count_in = count_out = 0;
189	mutex_lock(&master->dev->mode_config.idr_mutex);
190	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
191		if (_drm_lease_held_master(master, crtc->base.id)) {
192			uint32_t mask_in = 1ul << count_in;
193
194			if ((crtcs_in & mask_in) != 0) {
195				uint32_t mask_out = 1ul << count_out;
196
197				crtcs_out |= mask_out;
198			}
199			count_out++;
200		}
201		count_in++;
202	}
203	mutex_unlock(&master->dev->mode_config.idr_mutex);
204
205out:
206	drm_master_put(&master);
207	return crtcs_out;
208}
209
210/*
211 * drm_lease_create - create a new drm_master with leased objects (idr_mutex not held)
212 * @lessor: lease holder (or owner) of objects
213 * @leases: objects to lease to the new drm_master
214 *
215 * Uses drm_master_create to allocate a new drm_master, then checks to
216 * make sure all of the desired objects can be leased, atomically
217 * leasing them to the new drmmaster.
218 *
219 * 	ERR_PTR(-EACCES)	some other master holds the title to any object
220 * 	ERR_PTR(-ENOENT)	some object is not a valid DRM object for this device
221 * 	ERR_PTR(-EBUSY)		some other lessee holds title to this object
222 *	ERR_PTR(-EEXIST)	same object specified more than once in the provided list
223 *	ERR_PTR(-ENOMEM)	allocation failed
224 */
225static struct drm_master *drm_lease_create(struct drm_master *lessor, struct idr *leases)
226{
227	struct drm_device *dev = lessor->dev;
228	int error;
229	struct drm_master *lessee;
230	int object;
231	int id;
232	void *entry;
233
234	DRM_DEBUG_LEASE("lessor %d\n", lessor->lessee_id);
235
236	lessee = drm_master_create(lessor->dev);
237	if (!lessee) {
238		DRM_DEBUG_LEASE("drm_master_create failed\n");
239		return ERR_PTR(-ENOMEM);
240	}
241
242	mutex_lock(&dev->mode_config.idr_mutex);
243
244	idr_for_each_entry(leases, entry, object) {
245		error = 0;
246		if (!idr_find(&dev->mode_config.object_idr, object))
247			error = -ENOENT;
248		else if (_drm_has_leased(lessor, object))
249			error = -EBUSY;
250
251		if (error != 0) {
252			DRM_DEBUG_LEASE("object %d failed %d\n", object, error);
253			goto out_lessee;
254		}
255	}
256
257	/* Insert the new lessee into the tree */
258	id = idr_alloc(&(drm_lease_owner(lessor)->lessee_idr), lessee, 1, 0, GFP_KERNEL);
259	if (id < 0) {
260		error = id;
261		goto out_lessee;
262	}
263
264	lessee->lessee_id = id;
265	lessee->lessor = drm_master_get(lessor);
266	list_add_tail(&lessee->lessee_list, &lessor->lessees);
267
268	/* Move the leases over */
269	lessee->leases = *leases;
270	DRM_DEBUG_LEASE("new lessee %d %p, lessor %d %p\n", lessee->lessee_id, lessee, lessor->lessee_id, lessor);
271
272	mutex_unlock(&dev->mode_config.idr_mutex);
273	return lessee;
274
275out_lessee:
276	mutex_unlock(&dev->mode_config.idr_mutex);
277
278	drm_master_put(&lessee);
279
280	return ERR_PTR(error);
281}
282
283/**
284 * drm_lease_destroy - a master is going away (idr_mutex not held)
285 * @master: the drm_master being destroyed
286 *
287 * All lessees will have been destroyed as they
288 * hold a reference on their lessor. Notify any
289 * lessor for this master so that it can check
290 * the list of lessees.
291 */
292void drm_lease_destroy(struct drm_master *master)
293{
294	struct drm_device *dev = master->dev;
295
296	mutex_lock(&dev->mode_config.idr_mutex);
297
298	DRM_DEBUG_LEASE("drm_lease_destroy %d\n", master->lessee_id);
299
300	/* This master is referenced by all lessees, hence it cannot be destroyed
301	 * until all of them have been
302	 */
303	WARN_ON(!list_empty(&master->lessees));
304
305	/* Remove this master from the lessee idr in the owner */
306	if (master->lessee_id != 0) {
307		DRM_DEBUG_LEASE("remove master %d from device list of lessees\n", master->lessee_id);
308		idr_remove(&(drm_lease_owner(master)->lessee_idr), master->lessee_id);
309	}
310
311	/* Remove this master from any lessee list it may be on */
312	list_del(&master->lessee_list);
313
314	mutex_unlock(&dev->mode_config.idr_mutex);
315
316	if (master->lessor) {
317		/* Tell the master to check the lessee list */
318		drm_sysfs_lease_event(dev);
319		drm_master_put(&master->lessor);
320	}
321
322	DRM_DEBUG_LEASE("drm_lease_destroy done %d\n", master->lessee_id);
323}
324
325/**
326 * _drm_lease_revoke - revoke access to all leased objects (idr_mutex held)
327 * @top: the master losing its lease
328 */
329static void _drm_lease_revoke(struct drm_master *top)
330{
331	int object;
332	void *entry;
333	struct drm_master *master = top;
334
335	lockdep_assert_held(&top->dev->mode_config.idr_mutex);
336
337	/*
338	 * Walk the tree starting at 'top' emptying all leases. Because
339	 * the tree is fully connected, we can do this without recursing
340	 */
341	for (;;) {
342		DRM_DEBUG_LEASE("revoke leases for %p %d\n", master, master->lessee_id);
343
344		/* Evacuate the lease */
345		idr_for_each_entry(&master->leases, entry, object)
346			idr_remove(&master->leases, object);
347
348		/* Depth-first list walk */
349
350		/* Down */
351		if (!list_empty(&master->lessees)) {
352			master = list_first_entry(&master->lessees, struct drm_master, lessee_list);
353		} else {
354			/* Up */
355			while (master != top && master == list_last_entry(&master->lessor->lessees, struct drm_master, lessee_list))
356				master = master->lessor;
357
358			if (master == top)
359				break;
360
361			/* Over */
362			master = list_next_entry(master, lessee_list);
363		}
364	}
365}
366
367/**
368 * drm_lease_revoke - revoke access to all leased objects (idr_mutex not held)
369 * @top: the master losing its lease
370 */
371void drm_lease_revoke(struct drm_master *top)
372{
373	mutex_lock(&top->dev->mode_config.idr_mutex);
374	_drm_lease_revoke(top);
375	mutex_unlock(&top->dev->mode_config.idr_mutex);
376}
377
378static int validate_lease(struct drm_device *dev,
379			  int object_count,
380			  struct drm_mode_object **objects,
381			  bool universal_planes)
382{
383	int o;
384	int has_crtc = -1;
385	int has_connector = -1;
386	int has_plane = -1;
387
388	/* we want to confirm that there is at least one crtc, plane
389	   connector object. */
390
391	for (o = 0; o < object_count; o++) {
392		if (objects[o]->type == DRM_MODE_OBJECT_CRTC && has_crtc == -1) {
393			has_crtc = o;
394		}
395		if (objects[o]->type == DRM_MODE_OBJECT_CONNECTOR && has_connector == -1)
396			has_connector = o;
397
398		if (universal_planes) {
399			if (objects[o]->type == DRM_MODE_OBJECT_PLANE && has_plane == -1)
400				has_plane = o;
401		}
402	}
403	if (has_crtc == -1 || has_connector == -1)
404		return -EINVAL;
405	if (universal_planes && has_plane == -1)
406		return -EINVAL;
407	return 0;
408}
409
410static int fill_object_idr(struct drm_device *dev,
411			   struct drm_file *lessor_priv,
412			   struct idr *leases,
413			   int object_count,
414			   u32 *object_ids)
415{
416	struct drm_mode_object **objects;
417	u32 o;
418	int ret;
419	bool universal_planes = READ_ONCE(lessor_priv->universal_planes);
420
421	objects = kcalloc(object_count, sizeof(struct drm_mode_object *),
422			  GFP_KERNEL);
423	if (!objects)
424		return -ENOMEM;
425
426	/* step one - get references to all the mode objects
427	   and check for validity. */
428	for (o = 0; o < object_count; o++) {
429		objects[o] = drm_mode_object_find(dev, lessor_priv,
430						  object_ids[o],
431						  DRM_MODE_OBJECT_ANY);
432		if (!objects[o]) {
433			ret = -ENOENT;
434			goto out_free_objects;
435		}
436
437		if (!drm_mode_object_lease_required(objects[o]->type)) {
438			DRM_DEBUG_KMS("invalid object for lease\n");
439			ret = -EINVAL;
440			goto out_free_objects;
441		}
442	}
443
444	ret = validate_lease(dev, object_count, objects, universal_planes);
445	if (ret) {
446		DRM_DEBUG_LEASE("lease validation failed\n");
447		goto out_free_objects;
448	}
449
450	/* add their IDs to the lease request - taking into account
451	   universal planes */
452	for (o = 0; o < object_count; o++) {
453		struct drm_mode_object *obj = objects[o];
454		u32 object_id = objects[o]->id;
455
456		DRM_DEBUG_LEASE("Adding object %d to lease\n", object_id);
457
458		/*
459		 * We're using an IDR to hold the set of leased
460		 * objects, but we don't need to point at the object's
461		 * data structure from the lease as the main object_idr
462		 * will be used to actually find that. Instead, all we
463		 * really want is a 'leased/not-leased' result, for
464		 * which any non-NULL pointer will work fine.
465		 */
466		ret = idr_alloc(leases, &drm_lease_idr_object , object_id, object_id + 1, GFP_KERNEL);
467		if (ret < 0) {
468			DRM_DEBUG_LEASE("Object %d cannot be inserted into leases (%d)\n",
469					object_id, ret);
470			goto out_free_objects;
471		}
472		if (obj->type == DRM_MODE_OBJECT_CRTC && !universal_planes) {
473			struct drm_crtc *crtc = obj_to_crtc(obj);
474
475			ret = idr_alloc(leases, &drm_lease_idr_object, crtc->primary->base.id, crtc->primary->base.id + 1, GFP_KERNEL);
476			if (ret < 0) {
477				DRM_DEBUG_LEASE("Object primary plane %d cannot be inserted into leases (%d)\n",
478						object_id, ret);
479				goto out_free_objects;
480			}
481			if (crtc->cursor) {
482				ret = idr_alloc(leases, &drm_lease_idr_object, crtc->cursor->base.id, crtc->cursor->base.id + 1, GFP_KERNEL);
483				if (ret < 0) {
484					DRM_DEBUG_LEASE("Object cursor plane %d cannot be inserted into leases (%d)\n",
485							object_id, ret);
486					goto out_free_objects;
487				}
488			}
489		}
490	}
491
492	ret = 0;
493out_free_objects:
494	for (o = 0; o < object_count; o++) {
495		if (objects[o])
496			drm_mode_object_put(objects[o]);
497	}
498	kfree(objects);
499	return ret;
500}
501
502/**
503 * drm_mode_create_lease_ioctl - create a new lease
504 * @dev: the drm device
505 * @data: pointer to struct drm_mode_create_lease
506 * @lessor_priv: the file being manipulated
507 *
508 * The master associated with the specified file will have a lease
509 * created containing the objects specified in the ioctl structure.
510 * A file descriptor will be allocated for that and returned to the
511 * application.
512 */
513int drm_mode_create_lease_ioctl(struct drm_device *dev,
514				void *data, struct drm_file *lessor_priv)
515{
516	struct drm_mode_create_lease *cl = data;
517	size_t object_count;
518	int ret = 0;
519	struct idr leases;
520	struct drm_master *lessor;
521	struct drm_master *lessee = NULL;
522	struct file *lessee_file = NULL;
523	struct file *lessor_file = lessor_priv->filp;
524	struct drm_file *lessee_priv;
525	int fd = -1;
526	uint32_t *object_ids;
527
528	/* Can't lease without MODESET */
529	if (!drm_core_check_feature(dev, DRIVER_MODESET))
530		return -EOPNOTSUPP;
531
532	/* need some objects */
533	if (cl->object_count == 0) {
534		DRM_DEBUG_LEASE("no objects in lease\n");
535		return -EINVAL;
536	}
537
538	if (cl->flags && (cl->flags & ~(O_CLOEXEC | O_NONBLOCK))) {
539		DRM_DEBUG_LEASE("invalid flags\n");
540		return -EINVAL;
541	}
542
543	lessor = drm_file_get_master(lessor_priv);
544	/* Do not allow sub-leases */
545	if (lessor->lessor) {
546		DRM_DEBUG_LEASE("recursive leasing not allowed\n");
547		ret = -EINVAL;
548		goto out_lessor;
549	}
550
551	object_count = cl->object_count;
552
553	object_ids = memdup_user(u64_to_user_ptr(cl->object_ids),
554			array_size(object_count, sizeof(__u32)));
555	if (IS_ERR(object_ids)) {
556		ret = PTR_ERR(object_ids);
557		goto out_lessor;
558	}
559
560	idr_init(&leases);
561
562	/* fill and validate the object idr */
563	ret = fill_object_idr(dev, lessor_priv, &leases,
564			      object_count, object_ids);
565	kfree(object_ids);
566	if (ret) {
567		DRM_DEBUG_LEASE("lease object lookup failed: %i\n", ret);
568		idr_destroy(&leases);
569		goto out_lessor;
570	}
571
572	/* Allocate a file descriptor for the lease */
573	fd = get_unused_fd_flags(cl->flags & (O_CLOEXEC | O_NONBLOCK));
574	if (fd < 0) {
575		idr_destroy(&leases);
576		ret = fd;
577		goto out_lessor;
578	}
579
580	DRM_DEBUG_LEASE("Creating lease\n");
581	/* lessee will take the ownership of leases */
582	lessee = drm_lease_create(lessor, &leases);
583
584	if (IS_ERR(lessee)) {
585		ret = PTR_ERR(lessee);
586		idr_destroy(&leases);
587		goto out_leases;
588	}
589
590	/* Clone the lessor file to create a new file for us */
591	DRM_DEBUG_LEASE("Allocating lease file\n");
592	lessee_file = file_clone_open(lessor_file);
593	if (IS_ERR(lessee_file)) {
594		ret = PTR_ERR(lessee_file);
595		goto out_lessee;
596	}
597
598	lessee_priv = lessee_file->private_data;
599	/* Change the file to a master one */
600	drm_master_put(&lessee_priv->master);
601	lessee_priv->master = lessee;
602	lessee_priv->is_master = 1;
603	lessee_priv->authenticated = 1;
604
605	/* Pass fd back to userspace */
606	DRM_DEBUG_LEASE("Returning fd %d id %d\n", fd, lessee->lessee_id);
607	cl->fd = fd;
608	cl->lessee_id = lessee->lessee_id;
609
610	/* Hook up the fd */
611	fd_install(fd, lessee_file);
612
613	drm_master_put(&lessor);
614	DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl succeeded\n");
615	return 0;
616
617out_lessee:
618	drm_master_put(&lessee);
619
620out_leases:
621	put_unused_fd(fd);
622
623out_lessor:
624	drm_master_put(&lessor);
625	DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret);
626	return ret;
627}
628
629/**
630 * drm_mode_list_lessees_ioctl - list lessee ids
631 * @dev: the drm device
632 * @data: pointer to struct drm_mode_list_lessees
633 * @lessor_priv: the file being manipulated
634 *
635 * Starting from the master associated with the specified file,
636 * the master with the provided lessee_id is found, and then
637 * an array of lessee ids associated with leases from that master
638 * are returned.
639 */
640
641int drm_mode_list_lessees_ioctl(struct drm_device *dev,
642			       void *data, struct drm_file *lessor_priv)
643{
644	struct drm_mode_list_lessees *arg = data;
645	__u32 __user *lessee_ids = (__u32 __user *) (uintptr_t) (arg->lessees_ptr);
646	__u32 count_lessees = arg->count_lessees;
647	struct drm_master *lessor, *lessee;
648	int count;
649	int ret = 0;
650
651	if (arg->pad)
652		return -EINVAL;
653
654	/* Can't lease without MODESET */
655	if (!drm_core_check_feature(dev, DRIVER_MODESET))
656		return -EOPNOTSUPP;
657
658	lessor = drm_file_get_master(lessor_priv);
659	DRM_DEBUG_LEASE("List lessees for %d\n", lessor->lessee_id);
660
661	mutex_lock(&dev->mode_config.idr_mutex);
662
663	count = 0;
664	drm_for_each_lessee(lessee, lessor) {
665		/* Only list un-revoked leases */
666		if (!idr_is_empty(&lessee->leases)) {
667			if (count_lessees > count) {
668				DRM_DEBUG_LEASE("Add lessee %d\n", lessee->lessee_id);
669				ret = put_user(lessee->lessee_id, lessee_ids + count);
670				if (ret)
671					break;
672			}
673			count++;
674		}
675	}
676
677	DRM_DEBUG_LEASE("Lessor leases to %d\n", count);
678	if (ret == 0)
679		arg->count_lessees = count;
680
681	mutex_unlock(&dev->mode_config.idr_mutex);
682	drm_master_put(&lessor);
683
684	return ret;
685}
686
687/**
688 * drm_mode_get_lease_ioctl - list leased objects
689 * @dev: the drm device
690 * @data: pointer to struct drm_mode_get_lease
691 * @lessee_priv: the file being manipulated
692 *
693 * Return the list of leased objects for the specified lessee
694 */
695
696int drm_mode_get_lease_ioctl(struct drm_device *dev,
697			     void *data, struct drm_file *lessee_priv)
698{
699	struct drm_mode_get_lease *arg = data;
700	__u32 __user *object_ids = (__u32 __user *) (uintptr_t) (arg->objects_ptr);
701	__u32 count_objects = arg->count_objects;
702	struct drm_master *lessee;
703	struct idr *object_idr;
704	int count;
705	void *entry;
706	int object;
707	int ret = 0;
708
709	if (arg->pad)
710		return -EINVAL;
711
712	/* Can't lease without MODESET */
713	if (!drm_core_check_feature(dev, DRIVER_MODESET))
714		return -EOPNOTSUPP;
715
716	lessee = drm_file_get_master(lessee_priv);
717	DRM_DEBUG_LEASE("get lease for %d\n", lessee->lessee_id);
718
719	mutex_lock(&dev->mode_config.idr_mutex);
720
721	if (lessee->lessor == NULL)
722		/* owner can use all objects */
723		object_idr = &lessee->dev->mode_config.object_idr;
724	else
725		/* lessee can only use allowed object */
726		object_idr = &lessee->leases;
727
728	count = 0;
729	idr_for_each_entry(object_idr, entry, object) {
730		if (count_objects > count) {
731			DRM_DEBUG_LEASE("adding object %d\n", object);
732			ret = put_user(object, object_ids + count);
733			if (ret)
734				break;
735		}
736		count++;
737	}
738
739	DRM_DEBUG("lease holds %d objects\n", count);
740	if (ret == 0)
741		arg->count_objects = count;
742
743	mutex_unlock(&dev->mode_config.idr_mutex);
744	drm_master_put(&lessee);
745
746	return ret;
747}
748
749/**
750 * drm_mode_revoke_lease_ioctl - revoke lease
751 * @dev: the drm device
752 * @data: pointer to struct drm_mode_revoke_lease
753 * @lessor_priv: the file being manipulated
754 *
755 * This removes all of the objects from the lease without
756 * actually getting rid of the lease itself; that way all
757 * references to it still work correctly
758 */
759int drm_mode_revoke_lease_ioctl(struct drm_device *dev,
760				void *data, struct drm_file *lessor_priv)
761{
762	struct drm_mode_revoke_lease *arg = data;
763	struct drm_master *lessor;
764	struct drm_master *lessee;
765	int ret = 0;
766
767	DRM_DEBUG_LEASE("revoke lease for %d\n", arg->lessee_id);
768
769	/* Can't lease without MODESET */
770	if (!drm_core_check_feature(dev, DRIVER_MODESET))
771		return -EOPNOTSUPP;
772
773	lessor = drm_file_get_master(lessor_priv);
774	mutex_lock(&dev->mode_config.idr_mutex);
775
776	lessee = _drm_find_lessee(lessor, arg->lessee_id);
777
778	/* No such lessee */
779	if (!lessee) {
780		ret = -ENOENT;
781		goto fail;
782	}
783
784	/* Lease is not held by lessor */
785	if (lessee->lessor != lessor) {
786		ret = -EACCES;
787		goto fail;
788	}
789
790	_drm_lease_revoke(lessee);
791
792fail:
793	mutex_unlock(&dev->mode_config.idr_mutex);
794	drm_master_put(&lessor);
795
796	return ret;
797}
798