summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/drm_ioctl.c
blob: a7c61c23685a618caf888461c0c2492338ba7534 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
/*
 * Created: Fri Jan  8 09:01:26 1999 by faith@valinux.com
 *
 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * All Rights Reserved.
 *
 * Author Rickard E. (Rik) Faith <faith@valinux.com>
 * Author Gareth Hughes <gareth@valinux.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include <drm/drmP.h>
#include <drm/drm_auth.h>
#include "drm_legacy.h"
#include "drm_internal.h"
#include "drm_crtc_internal.h"

#include <linux/pci.h>
#include <linux/export.h>

/**
 * DOC: getunique and setversion story
 *
 * BEWARE THE DRAGONS! MIND THE TRAPDOORS!
 *
 * In an attempt to warn anyone else who's trying to figure out what's going
 * on here, I'll try to summarize the story. First things first, let's clear up
 * the names, because the kernel internals, libdrm and the ioctls are all named
 * differently:
 *
 *  - GET_UNIQUE ioctl, implemented by drm_getunique is wrapped up in libdrm
 *    through the drmGetBusid function.
 *  - The libdrm drmSetBusid function is backed by the SET_UNIQUE ioctl. All
 *    that code is nerved in the kernel with drm_invalid_op().
 *  - The internal set_busid kernel functions and driver callbacks are
 *    exclusively use by the SET_VERSION ioctl, because only drm 1.0 (which is
 *    nerved) allowed userspace to set the busid through the above ioctl.
 *  - Other ioctls and functions involved are named consistently.
 *
 * For anyone wondering what's the difference between drm 1.1 and 1.4: Correctly
 * handling pci domains in the busid on ppc. Doing this correctly was only
 * implemented in libdrm in 2010, hence can't be nerved yet. No one knows what's
 * special with drm 1.2 and 1.3.
 *
 * Now the actual horror story of how device lookup in drm works. At large,
 * there's 2 different ways, either by busid, or by device driver name.
 *
 * Opening by busid is fairly simple:
 *
 * 1. First call SET_VERSION to make sure pci domains are handled properly. As a
 *    side-effect this fills out the unique name in the master structure.
 * 2. Call GET_UNIQUE to read out the unique name from the master structure,
 *    which matches the busid thanks to step 1. If it doesn't, proceed to try
 *    the next device node.
 *
 * Opening by name is slightly different:
 *
 * 1. Directly call VERSION to get the version and to match against the driver
 *    name returned by that ioctl. Note that SET_VERSION is not called, which
 *    means the the unique name for the master node just opening is _not_ filled
 *    out. This despite that with current drm device nodes are always bound to
 *    one device, and can't be runtime assigned like with drm 1.0.
 * 2. Match driver name. If it mismatches, proceed to the next device node.
 * 3. Call GET_UNIQUE, and check whether the unique name has length zero (by
 *    checking that the first byte in the string is 0). If that's not the case
 *    libdrm skips and proceeds to the next device node. Probably this is just
 *    copypasta from drm 1.0 times where a set unique name meant that the driver
 *    was in use already, but that's just conjecture.
 *
 * Long story short: To keep the open by name logic working, GET_UNIQUE must
 * _not_ return a unique string when SET_VERSION hasn't been called yet,
 * otherwise libdrm breaks. Even when that unique string can't ever change, and
 * is totally irrelevant for actually opening the device because runtime
 * assignable device instances were only support in drm 1.0, which is long dead.
 * But the libdrm code in drmOpenByName somehow survived, hence this can't be
 * broken.
 */

/*
 * Get the bus id.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_unique structure.
 * \return zero on success or a negative number on failure.
 *
 * Copies the bus id from drm_device::unique into user space.
 */
static int drm_getunique(struct drm_device *dev, void *data,
		  struct drm_file *file_priv)
{
	struct drm_unique *u = data;
	struct drm_master *master = file_priv->master;

	mutex_lock(&master->dev->master_mutex);
	if (u->unique_len >= master->unique_len) {
		if (copy_to_user(u->unique, master->unique, master->unique_len)) {
			mutex_unlock(&master->dev->master_mutex);
			return -EFAULT;
		}
	}
	u->unique_len = master->unique_len;
	mutex_unlock(&master->dev->master_mutex);

	return 0;
}

static void
drm_unset_busid(struct drm_device *dev,
		struct drm_master *master)
{
	kfree(master->unique);
	master->unique = NULL;
	master->unique_len = 0;
}

static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
{
	struct drm_master *master = file_priv->master;
	int ret;

	if (master->unique != NULL)
		drm_unset_busid(dev, master);

	if (dev->driver->set_busid) {
		ret = dev->driver->set_busid(dev, master);
		if (ret) {
			drm_unset_busid(dev, master);
			return ret;
		}
	} else {
		WARN_ON(!dev->unique);
		master->unique = kstrdup(dev->unique, GFP_KERNEL);
		if (master->unique)
			master->unique_len = strlen(dev->unique);
	}

	return 0;
}

/*
 * Get client information.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_client structure.
 *
 * \return zero on success or a negative number on failure.
 *
 * Searches for the client with the specified index and copies its information
 * into userspace
 */
static int drm_getclient(struct drm_device *dev, void *data,
		  struct drm_file *file_priv)
{
	struct drm_client *client = data;

	/*
	 * Hollowed-out getclient ioctl to keep some dead old drm tests/tools
	 * not breaking completely. Userspace tools stop enumerating one they
	 * get -EINVAL, hence this is the return value we need to hand back for
	 * no clients tracked.
	 *
	 * Unfortunately some clients (*cough* libva *cough*) use this in a fun
	 * attempt to figure out whether they're authenticated or not. Since
	 * that's the only thing they care about, give it to the directly
	 * instead of walking one giant list.
	 */
	if (client->idx == 0) {
		client->auth = file_priv->authenticated;
		client->pid = task_pid_vnr(current);
		client->uid = overflowuid;
		client->magic = 0;
		client->iocs = 0;

		return 0;
	} else {
		return -EINVAL;
	}
}

/*
 * Get statistics information.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_stats structure.
 *
 * \return zero on success or a negative number on failure.
 */
static int drm_getstats(struct drm_device *dev, void *data,
		 struct drm_file *file_priv)
{
	struct drm_stats *stats = data;

	/* Clear stats to prevent userspace from eating its stack garbage. */
	memset(stats, 0, sizeof(*stats));

	return 0;
}

/*
 * Get device/driver capabilities
 */
static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
	struct drm_get_cap *req = data;
	struct drm_crtc *crtc;

	req->value = 0;

	/* Only some caps make sense with UMS/render-only drivers. */
	switch (req->capability) {
	case DRM_CAP_TIMESTAMP_MONOTONIC:
		req->value = drm_timestamp_monotonic;
		return 0;
	case DRM_CAP_PRIME:
		req->value |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0;
		req->value |= dev->driver->prime_handle_to_fd ? DRM_PRIME_CAP_EXPORT : 0;
		return 0;
	}

	/* Other caps only work with KMS drivers */
	if (!drm_core_check_feature(dev, DRIVER_MODESET))
		return -ENOTSUPP;

	switch (req->capability) {
	case DRM_CAP_DUMB_BUFFER:
		if (dev->driver->dumb_create)
			req->value = 1;
		break;
	case DRM_CAP_VBLANK_HIGH_CRTC:
		req->value = 1;
		break;
	case DRM_CAP_DUMB_PREFERRED_DEPTH:
		req->value = dev->mode_config.preferred_depth;
		break;
	case DRM_CAP_DUMB_PREFER_SHADOW:
		req->value = dev->mode_config.prefer_shadow;
		break;
	case DRM_CAP_ASYNC_PAGE_FLIP:
		req->value = dev->mode_config.async_page_flip;
		break;
	case DRM_CAP_PAGE_FLIP_TARGET:
		req->value = 1;
		drm_for_each_crtc(crtc, dev) {
			if (!crtc->funcs->page_flip_target)
				req->value = 0;
		}
		break;
	case DRM_CAP_CURSOR_WIDTH:
		if (dev->mode_config.cursor_width)
			req->value = dev->mode_config.cursor_width;
		else
			req->value = 64;
		break;
	case DRM_CAP_CURSOR_HEIGHT:
		if (dev->mode_config.cursor_height)
			req->value = dev->mode_config.cursor_height;
		else
			req->value = 64;
		break;
	case DRM_CAP_ADDFB2_MODIFIERS:
		req->value = dev->mode_config.allow_fb_modifiers;
		break;
	default:
		return -EINVAL;
	}
	return 0;
}

/*
 * Set device/driver capabilities
 */
static int
drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
	struct drm_set_client_cap *req = data;

	switch (req->capability) {
	case DRM_CLIENT_CAP_STEREO_3D:
		if (req->value > 1)
			return -EINVAL;
		file_priv->stereo_allowed = req->value;
		break;
	case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
		if (req->value > 1)
			return -EINVAL;
		file_priv->universal_planes = req->value;
		break;
	case DRM_CLIENT_CAP_ATOMIC:
		if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
			return -EINVAL;
		if (req->value > 1)
			return -EINVAL;
		file_priv->atomic = req->value;
		file_priv->universal_planes = req->value;
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

/*
 * Setversion ioctl.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_lock structure.
 * \return zero on success or negative number on failure.
 *
 * Sets the requested interface version
 */
static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
	struct drm_set_version *sv = data;
	int if_version, retcode = 0;

	mutex_lock(&dev->master_mutex);
	if (sv->drm_di_major != -1) {
		if (sv->drm_di_major != DRM_IF_MAJOR ||
		    sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
			retcode = -EINVAL;
			goto done;
		}
		if_version = DRM_IF_VERSION(sv->drm_di_major,
					    sv->drm_di_minor);
		dev->if_version = max(if_version, dev->if_version);
		if (sv->drm_di_minor >= 1) {
			/*
			 * Version 1.1 includes tying of DRM to specific device
			 * Version 1.4 has proper PCI domain support
			 */
			retcode = drm_set_busid(dev, file_priv);
			if (retcode)
				goto done;
		}
	}

	if (sv->drm_dd_major != -1) {
		if (sv->drm_dd_major != dev->driver->major ||
		    sv->drm_dd_minor < 0 || sv->drm_dd_minor >
		    dev->driver->minor) {
			retcode = -EINVAL;
			goto done;
		}
	}

done:
	sv->drm_di_major = DRM_IF_MAJOR;
	sv->drm_di_minor = DRM_IF_MINOR;
	sv->drm_dd_major = dev->driver->major;
	sv->drm_dd_minor = dev->driver->minor;
	mutex_unlock(&dev->master_mutex);

	return retcode;
}

/**
 * drm_noop - DRM no-op ioctl implemntation
 * @dev: DRM device for the ioctl
 * @data: data pointer for the ioctl
 * @file_priv: DRM file for the ioctl call
 *
 * This no-op implementation for drm ioctls is useful for deprecated
 * functionality where we can't return a failure code because existing userspace
 * checks the result of the ioctl, but doesn't care about the action.
 *
 * Always returns successfully with 0.
 */
int drm_noop(struct drm_device *dev, void *data,
	     struct drm_file *file_priv)
{
	DRM_DEBUG("\n");
	return 0;
}
EXPORT_SYMBOL(drm_noop);

/**
 * drm_invalid_op - DRM invalid ioctl implemntation
 * @dev: DRM device for the ioctl
 * @data: data pointer for the ioctl
 * @file_priv: DRM file for the ioctl call
 *
 * This no-op implementation for drm ioctls is useful for deprecated
 * functionality where we really don't want to allow userspace to call the ioctl
 * any more. This is the case for old ums interfaces for drivers that
 * transitioned to kms gradually and so kept the old legacy tables around. This
 * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
 * use this function.
 *
 * Always fails with a return value of -EINVAL.
 */
int drm_invalid_op(struct drm_device *dev, void *data,
		   struct drm_file *file_priv)
{
	return -EINVAL;
}
EXPORT_SYMBOL(drm_invalid_op);

/*
 * Copy and IOCTL return string to user space
 */
static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
{
	int len;

	/* don't overflow userbuf */
	len = strlen(value);
	if (len > *buf_len)
		len = *buf_len;

	/* let userspace know exact length of driver value (which could be
	 * larger than the userspace-supplied buffer) */
	*buf_len = strlen(value);

	/* finally, try filling in the userbuf */
	if (len && buf)
		if (copy_to_user(buf, value, len))
			return -EFAULT;
	return 0;
}

/*
 * Get version information
 *
 * \param inode device inode.
 * \param filp file pointer.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_version structure.
 * \return zero on success or negative number on failure.
 *
 * Fills in the version information in \p arg.
 */
static int drm_version(struct drm_device *dev, void *data,
		       struct drm_file *file_priv)
{
	struct drm_version *version = data;
	int err;

	version->version_major = dev->driver->major;
	version->version_minor = dev->driver->minor;
	version->version_patchlevel = dev->driver->patchlevel;
	err = drm_copy_field(version->name, &version->name_len,
			dev->driver->name);
	if (!err)
		err = drm_copy_field(version->date, &version->date_len,
				dev->driver->date);
	if (!err)
		err = drm_copy_field(version->desc, &version->desc_len,
				dev->driver->desc);

	return err;
}

/**
 * drm_ioctl_permit - Check ioctl permissions against caller
 *
 * @flags: ioctl permission flags.
 * @file_priv: Pointer to struct drm_file identifying the caller.
 *
 * Checks whether the caller is allowed to run an ioctl with the
 * indicated permissions.
 *
 * Returns:
 * Zero if allowed, -EACCES otherwise.
 */
int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
{
	/* ROOT_ONLY is only for CAP_SYS_ADMIN */
	if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
		return -EACCES;

	/* AUTH is only for authenticated or render client */
	if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
		     !file_priv->authenticated))
		return -EACCES;

	/* MASTER is only for master or control clients */
	if (unlikely((flags & DRM_MASTER) && 
		     !drm_is_current_master(file_priv) &&
		     !drm_is_control_client(file_priv)))
		return -EACCES;

	/* Control clients must be explicitly allowed */
	if (unlikely(!(flags & DRM_CONTROL_ALLOW) &&
		     drm_is_control_client(file_priv)))
		return -EACCES;

	/* Render clients must be explicitly allowed */
	if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
		     drm_is_render_client(file_priv)))
		return -EACCES;

	return 0;
}
EXPORT_SYMBOL(drm_ioctl_permit);

#define DRM_IOCTL_DEF(ioctl, _func, _flags)	\
	[DRM_IOCTL_NR(ioctl)] = {		\
		.cmd = ioctl,			\
		.func = _func,			\
		.flags = _flags,		\
		.name = #ioctl			\
	}

/* Ioctl table */
static const struct drm_ioctl_desc drm_ioctls[] = {
	DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version,
		      DRM_UNLOCKED|DRM_RENDER_ALLOW|DRM_CONTROL_ALLOW),
	DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED|DRM_RENDER_ALLOW),
	DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_UNLOCKED | DRM_MASTER),

	DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_UNLOCKED|DRM_MASTER),

	DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),

	DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),

	DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),

	DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
	DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),

	DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),

	DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH),
	DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH),

	DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),

	DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH),
	DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH),
	DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH),
	DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH),

	DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_legacy_irq_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),

#if IS_ENABLED(CONFIG_AGP)
	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
#endif

	DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
	DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),

	DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank, DRM_UNLOCKED),

	DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_legacy_modeset_ctl, 0),

	DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),

	DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
	DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED),

	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_CONTROL_ALLOW|DRM_UNLOCKED),

	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),

	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_mode_connector_property_set_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
};

#define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )

/**
 * drm_ioctl - ioctl callback implementation for DRM drivers
 * @filp: file this ioctl is called on
 * @cmd: ioctl cmd number
 * @arg: user argument
 *
 * Looks up the ioctl function in the ::ioctls table, checking for root
 * previleges if so required, and dispatches to the respective function.
 *
 * Returns:
 * Zero on success, negative error code on failure.
 */
long drm_ioctl(struct file *filp,
	      unsigned int cmd, unsigned long arg)
{
	struct drm_file *file_priv = filp->private_data;
	struct drm_device *dev;
	const struct drm_ioctl_desc *ioctl = NULL;
	drm_ioctl_t *func;
	unsigned int nr = DRM_IOCTL_NR(cmd);
	int retcode = -EINVAL;
	char stack_kdata[128];
	char *kdata = NULL;
	unsigned int in_size, out_size, drv_size, ksize;
	bool is_driver_ioctl;

	dev = file_priv->minor->dev;

	if (drm_device_is_unplugged(dev))
		return -ENODEV;

	is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;

	if (is_driver_ioctl) {
		/* driver ioctl */
		if (nr - DRM_COMMAND_BASE >= dev->driver->num_ioctls)
			goto err_i1;
		ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
	} else {
		/* core ioctl */
		if (nr >= DRM_CORE_IOCTL_COUNT)
			goto err_i1;
		ioctl = &drm_ioctls[nr];
	}

	drv_size = _IOC_SIZE(ioctl->cmd);
	out_size = in_size = _IOC_SIZE(cmd);
	if ((cmd & ioctl->cmd & IOC_IN) == 0)
		in_size = 0;
	if ((cmd & ioctl->cmd & IOC_OUT) == 0)
		out_size = 0;
	ksize = max(max(in_size, out_size), drv_size);

	DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
		  task_pid_nr(current),
		  (long)old_encode_dev(file_priv->minor->kdev->devt),
		  file_priv->authenticated, ioctl->name);

	/* Do not trust userspace, use our own definition */
	func = ioctl->func;

	if (unlikely(!func)) {
		DRM_DEBUG("no function\n");
		retcode = -EINVAL;
		goto err_i1;
	}

	retcode = drm_ioctl_permit(ioctl->flags, file_priv);
	if (unlikely(retcode))
		goto err_i1;

	if (ksize <= sizeof(stack_kdata)) {
		kdata = stack_kdata;
	} else {
		kdata = kmalloc(ksize, GFP_KERNEL);
		if (!kdata) {
			retcode = -ENOMEM;
			goto err_i1;
		}
	}

	if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) {
		retcode = -EFAULT;
		goto err_i1;
	}

	if (ksize > in_size)
		memset(kdata + in_size, 0, ksize - in_size);

	/* Enforce sane locking for modern driver ioctls. */
	if (!drm_core_check_feature(dev, DRIVER_LEGACY) ||
	    (ioctl->flags & DRM_UNLOCKED))
		retcode = func(dev, kdata, file_priv);
	else {
		mutex_lock(&drm_global_mutex);
		retcode = func(dev, kdata, file_priv);
		mutex_unlock(&drm_global_mutex);
	}

	if (copy_to_user((void __user *)arg, kdata, out_size) != 0)
		retcode = -EFAULT;

      err_i1:
	if (!ioctl)
		DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
			  task_pid_nr(current),
			  (long)old_encode_dev(file_priv->minor->kdev->devt),
			  file_priv->authenticated, cmd, nr);

	if (kdata != stack_kdata)
		kfree(kdata);
	if (retcode)
		DRM_DEBUG("ret = %d\n", retcode);
	return retcode;
}
EXPORT_SYMBOL(drm_ioctl);

/**
 * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
 * @nr: ioctl number
 * @flags: where to return the ioctl permission flags
 *
 * This ioctl is only used by the vmwgfx driver to augment the access checks
 * done by the drm core and insofar a pretty decent layering violation. This
 * shouldn't be used by any drivers.
 *
 * Returns:
 * True if the @nr corresponds to a DRM core ioctl number, false otherwise.
 */
bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
{
	if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
		return false;

	if (nr >= DRM_CORE_IOCTL_COUNT)
		return false;

	*flags = drm_ioctls[nr].flags;
	return true;
}
EXPORT_SYMBOL(drm_ioctl_flags);
OpenPOWER on IntegriCloud