xref: /openbmc/linux/drivers/gpu/drm/drm_ioctl.c (revision 2c684d89)
1 /*
2  * Created: Fri Jan  8 09:01:26 1999 by faith@valinux.com
3  *
4  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
5  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
6  * All Rights Reserved.
7  *
8  * Author Rickard E. (Rik) Faith <faith@valinux.com>
9  * Author Gareth Hughes <gareth@valinux.com>
10  *
11  * Permission is hereby granted, free of charge, to any person obtaining a
12  * copy of this software and associated documentation files (the "Software"),
13  * to deal in the Software without restriction, including without limitation
14  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
15  * and/or sell copies of the Software, and to permit persons to whom the
16  * Software is furnished to do so, subject to the following conditions:
17  *
18  * The above copyright notice and this permission notice (including the next
19  * paragraph) shall be included in all copies or substantial portions of the
20  * Software.
21  *
22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
25  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
26  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
27  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
28  * OTHER DEALINGS IN THE SOFTWARE.
29  */
30 
31 #include <drm/drmP.h>
32 #include <drm/drm_core.h>
33 #include "drm_legacy.h"
34 #include "drm_internal.h"
35 #include "drm_crtc_internal.h"
36 
37 #include <linux/pci.h>
38 #include <linux/export.h>
39 
40 static int drm_version(struct drm_device *dev, void *data,
41 		       struct drm_file *file_priv);
42 
43 /*
44  * Get the bus id.
45  *
46  * \param inode device inode.
47  * \param file_priv DRM file private.
48  * \param cmd command.
49  * \param arg user argument, pointing to a drm_unique structure.
50  * \return zero on success or a negative number on failure.
51  *
52  * Copies the bus id from drm_device::unique into user space.
53  */
54 static int drm_getunique(struct drm_device *dev, void *data,
55 		  struct drm_file *file_priv)
56 {
57 	struct drm_unique *u = data;
58 	struct drm_master *master = file_priv->master;
59 
60 	if (u->unique_len >= master->unique_len) {
61 		if (copy_to_user(u->unique, master->unique, master->unique_len))
62 			return -EFAULT;
63 	}
64 	u->unique_len = master->unique_len;
65 
66 	return 0;
67 }
68 
69 static void
70 drm_unset_busid(struct drm_device *dev,
71 		struct drm_master *master)
72 {
73 	kfree(master->unique);
74 	master->unique = NULL;
75 	master->unique_len = 0;
76 }
77 
78 /*
79  * Set the bus id.
80  *
81  * \param inode device inode.
82  * \param file_priv DRM file private.
83  * \param cmd command.
84  * \param arg user argument, pointing to a drm_unique structure.
85  * \return zero on success or a negative number on failure.
86  *
87  * Copies the bus id from userspace into drm_device::unique, and verifies that
88  * it matches the device this DRM is attached to (EINVAL otherwise).  Deprecated
89  * in interface version 1.1 and will return EBUSY when setversion has requested
90  * version 1.1 or greater. Also note that KMS is all version 1.1 and later and
91  * UMS was only ever supported on pci devices.
92  */
93 static int drm_setunique(struct drm_device *dev, void *data,
94 		  struct drm_file *file_priv)
95 {
96 	struct drm_unique *u = data;
97 	struct drm_master *master = file_priv->master;
98 	int ret;
99 
100 	if (master->unique_len || master->unique)
101 		return -EBUSY;
102 
103 	if (!u->unique_len || u->unique_len > 1024)
104 		return -EINVAL;
105 
106 	if (drm_core_check_feature(dev, DRIVER_MODESET))
107 		return 0;
108 
109 	if (WARN_ON(!dev->pdev))
110 		return -EINVAL;
111 
112 	ret = drm_pci_set_unique(dev, master, u);
113 	if (ret)
114 		goto err;
115 
116 	return 0;
117 
118 err:
119 	drm_unset_busid(dev, master);
120 	return ret;
121 }
122 
123 static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
124 {
125 	struct drm_master *master = file_priv->master;
126 	int ret;
127 
128 	if (master->unique != NULL)
129 		drm_unset_busid(dev, master);
130 
131 	if (dev->driver->set_busid) {
132 		ret = dev->driver->set_busid(dev, master);
133 		if (ret) {
134 			drm_unset_busid(dev, master);
135 			return ret;
136 		}
137 	} else {
138 		if (WARN(dev->unique == NULL,
139 			 "No drm_driver.set_busid() implementation provided by "
140 			 "%ps. Use drm_dev_set_unique() to set the unique "
141 			 "name explicitly.", dev->driver))
142 			return -EINVAL;
143 
144 		master->unique = kstrdup(dev->unique, GFP_KERNEL);
145 		if (master->unique)
146 			master->unique_len = strlen(dev->unique);
147 	}
148 
149 	return 0;
150 }
151 
152 /*
153  * Get a mapping information.
154  *
155  * \param inode device inode.
156  * \param file_priv DRM file private.
157  * \param cmd command.
158  * \param arg user argument, pointing to a drm_map structure.
159  *
160  * \return zero on success or a negative number on failure.
161  *
162  * Searches for the mapping with the specified offset and copies its information
163  * into userspace
164  */
165 static int drm_getmap(struct drm_device *dev, void *data,
166 	       struct drm_file *file_priv)
167 {
168 	struct drm_map *map = data;
169 	struct drm_map_list *r_list = NULL;
170 	struct list_head *list;
171 	int idx;
172 	int i;
173 
174 	idx = map->offset;
175 	if (idx < 0)
176 		return -EINVAL;
177 
178 	i = 0;
179 	mutex_lock(&dev->struct_mutex);
180 	list_for_each(list, &dev->maplist) {
181 		if (i == idx) {
182 			r_list = list_entry(list, struct drm_map_list, head);
183 			break;
184 		}
185 		i++;
186 	}
187 	if (!r_list || !r_list->map) {
188 		mutex_unlock(&dev->struct_mutex);
189 		return -EINVAL;
190 	}
191 
192 	map->offset = r_list->map->offset;
193 	map->size = r_list->map->size;
194 	map->type = r_list->map->type;
195 	map->flags = r_list->map->flags;
196 	map->handle = (void *)(unsigned long) r_list->user_token;
197 	map->mtrr = arch_phys_wc_index(r_list->map->mtrr);
198 
199 	mutex_unlock(&dev->struct_mutex);
200 
201 	return 0;
202 }
203 
204 /*
205  * Get client information.
206  *
207  * \param inode device inode.
208  * \param file_priv DRM file private.
209  * \param cmd command.
210  * \param arg user argument, pointing to a drm_client structure.
211  *
212  * \return zero on success or a negative number on failure.
213  *
214  * Searches for the client with the specified index and copies its information
215  * into userspace
216  */
217 static int drm_getclient(struct drm_device *dev, void *data,
218 		  struct drm_file *file_priv)
219 {
220 	struct drm_client *client = data;
221 
222 	/*
223 	 * Hollowed-out getclient ioctl to keep some dead old drm tests/tools
224 	 * not breaking completely. Userspace tools stop enumerating one they
225 	 * get -EINVAL, hence this is the return value we need to hand back for
226 	 * no clients tracked.
227 	 *
228 	 * Unfortunately some clients (*cough* libva *cough*) use this in a fun
229 	 * attempt to figure out whether they're authenticated or not. Since
230 	 * that's the only thing they care about, give it to the directly
231 	 * instead of walking one giant list.
232 	 */
233 	if (client->idx == 0) {
234 		client->auth = file_priv->authenticated;
235 		client->pid = pid_vnr(file_priv->pid);
236 		client->uid = from_kuid_munged(current_user_ns(),
237 					       file_priv->uid);
238 		client->magic = 0;
239 		client->iocs = 0;
240 
241 		return 0;
242 	} else {
243 		return -EINVAL;
244 	}
245 }
246 
247 /*
248  * Get statistics information.
249  *
250  * \param inode device inode.
251  * \param file_priv DRM file private.
252  * \param cmd command.
253  * \param arg user argument, pointing to a drm_stats structure.
254  *
255  * \return zero on success or a negative number on failure.
256  */
257 static int drm_getstats(struct drm_device *dev, void *data,
258 		 struct drm_file *file_priv)
259 {
260 	struct drm_stats *stats = data;
261 
262 	/* Clear stats to prevent userspace from eating its stack garbage. */
263 	memset(stats, 0, sizeof(*stats));
264 
265 	return 0;
266 }
267 
268 /*
269  * Get device/driver capabilities
270  */
271 static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
272 {
273 	struct drm_get_cap *req = data;
274 
275 	req->value = 0;
276 	switch (req->capability) {
277 	case DRM_CAP_DUMB_BUFFER:
278 		if (dev->driver->dumb_create)
279 			req->value = 1;
280 		break;
281 	case DRM_CAP_VBLANK_HIGH_CRTC:
282 		req->value = 1;
283 		break;
284 	case DRM_CAP_DUMB_PREFERRED_DEPTH:
285 		req->value = dev->mode_config.preferred_depth;
286 		break;
287 	case DRM_CAP_DUMB_PREFER_SHADOW:
288 		req->value = dev->mode_config.prefer_shadow;
289 		break;
290 	case DRM_CAP_PRIME:
291 		req->value |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0;
292 		req->value |= dev->driver->prime_handle_to_fd ? DRM_PRIME_CAP_EXPORT : 0;
293 		break;
294 	case DRM_CAP_TIMESTAMP_MONOTONIC:
295 		req->value = drm_timestamp_monotonic;
296 		break;
297 	case DRM_CAP_ASYNC_PAGE_FLIP:
298 		req->value = dev->mode_config.async_page_flip;
299 		break;
300 	case DRM_CAP_CURSOR_WIDTH:
301 		if (dev->mode_config.cursor_width)
302 			req->value = dev->mode_config.cursor_width;
303 		else
304 			req->value = 64;
305 		break;
306 	case DRM_CAP_CURSOR_HEIGHT:
307 		if (dev->mode_config.cursor_height)
308 			req->value = dev->mode_config.cursor_height;
309 		else
310 			req->value = 64;
311 		break;
312 	case DRM_CAP_ADDFB2_MODIFIERS:
313 		req->value = dev->mode_config.allow_fb_modifiers;
314 		break;
315 	default:
316 		return -EINVAL;
317 	}
318 	return 0;
319 }
320 
321 /*
322  * Set device/driver capabilities
323  */
324 static int
325 drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
326 {
327 	struct drm_set_client_cap *req = data;
328 
329 	switch (req->capability) {
330 	case DRM_CLIENT_CAP_STEREO_3D:
331 		if (req->value > 1)
332 			return -EINVAL;
333 		file_priv->stereo_allowed = req->value;
334 		break;
335 	case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
336 		if (req->value > 1)
337 			return -EINVAL;
338 		file_priv->universal_planes = req->value;
339 		break;
340 	case DRM_CLIENT_CAP_ATOMIC:
341 		if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
342 			return -EINVAL;
343 		if (req->value > 1)
344 			return -EINVAL;
345 		file_priv->atomic = req->value;
346 		file_priv->universal_planes = req->value;
347 		break;
348 	default:
349 		return -EINVAL;
350 	}
351 
352 	return 0;
353 }
354 
355 /*
356  * Setversion ioctl.
357  *
358  * \param inode device inode.
359  * \param file_priv DRM file private.
360  * \param cmd command.
361  * \param arg user argument, pointing to a drm_lock structure.
362  * \return zero on success or negative number on failure.
363  *
364  * Sets the requested interface version
365  */
366 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
367 {
368 	struct drm_set_version *sv = data;
369 	int if_version, retcode = 0;
370 
371 	if (sv->drm_di_major != -1) {
372 		if (sv->drm_di_major != DRM_IF_MAJOR ||
373 		    sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
374 			retcode = -EINVAL;
375 			goto done;
376 		}
377 		if_version = DRM_IF_VERSION(sv->drm_di_major,
378 					    sv->drm_di_minor);
379 		dev->if_version = max(if_version, dev->if_version);
380 		if (sv->drm_di_minor >= 1) {
381 			/*
382 			 * Version 1.1 includes tying of DRM to specific device
383 			 * Version 1.4 has proper PCI domain support
384 			 */
385 			retcode = drm_set_busid(dev, file_priv);
386 			if (retcode)
387 				goto done;
388 		}
389 	}
390 
391 	if (sv->drm_dd_major != -1) {
392 		if (sv->drm_dd_major != dev->driver->major ||
393 		    sv->drm_dd_minor < 0 || sv->drm_dd_minor >
394 		    dev->driver->minor) {
395 			retcode = -EINVAL;
396 			goto done;
397 		}
398 	}
399 
400 done:
401 	sv->drm_di_major = DRM_IF_MAJOR;
402 	sv->drm_di_minor = DRM_IF_MINOR;
403 	sv->drm_dd_major = dev->driver->major;
404 	sv->drm_dd_minor = dev->driver->minor;
405 
406 	return retcode;
407 }
408 
409 /**
410  * drm_noop - DRM no-op ioctl implemntation
411  * @dev: DRM device for the ioctl
412  * @data: data pointer for the ioctl
413  * @file_priv: DRM file for the ioctl call
414  *
415  * This no-op implementation for drm ioctls is useful for deprecated
416  * functionality where we can't return a failure code because existing userspace
417  * checks the result of the ioctl, but doesn't care about the action.
418  *
419  * Always returns successfully with 0.
420  */
421 int drm_noop(struct drm_device *dev, void *data,
422 	     struct drm_file *file_priv)
423 {
424 	DRM_DEBUG("\n");
425 	return 0;
426 }
427 EXPORT_SYMBOL(drm_noop);
428 
429 /**
430  * drm_invalid_op - DRM invalid ioctl implemntation
431  * @dev: DRM device for the ioctl
432  * @data: data pointer for the ioctl
433  * @file_priv: DRM file for the ioctl call
434  *
435  * This no-op implementation for drm ioctls is useful for deprecated
436  * functionality where we really don't want to allow userspace to call the ioctl
437  * any more. This is the case for old ums interfaces for drivers that
438  * transitioned to kms gradually and so kept the old legacy tables around. This
439  * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
440  * use this function.
441  *
442  * Always fails with a return value of -EINVAL.
443  */
444 int drm_invalid_op(struct drm_device *dev, void *data,
445 		   struct drm_file *file_priv)
446 {
447 	return -EINVAL;
448 }
449 EXPORT_SYMBOL(drm_invalid_op);
450 
451 /*
452  * Copy and IOCTL return string to user space
453  */
454 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
455 {
456 	int len;
457 
458 	/* don't overflow userbuf */
459 	len = strlen(value);
460 	if (len > *buf_len)
461 		len = *buf_len;
462 
463 	/* let userspace know exact length of driver value (which could be
464 	 * larger than the userspace-supplied buffer) */
465 	*buf_len = strlen(value);
466 
467 	/* finally, try filling in the userbuf */
468 	if (len && buf)
469 		if (copy_to_user(buf, value, len))
470 			return -EFAULT;
471 	return 0;
472 }
473 
474 /*
475  * Get version information
476  *
477  * \param inode device inode.
478  * \param filp file pointer.
479  * \param cmd command.
480  * \param arg user argument, pointing to a drm_version structure.
481  * \return zero on success or negative number on failure.
482  *
483  * Fills in the version information in \p arg.
484  */
485 static int drm_version(struct drm_device *dev, void *data,
486 		       struct drm_file *file_priv)
487 {
488 	struct drm_version *version = data;
489 	int err;
490 
491 	version->version_major = dev->driver->major;
492 	version->version_minor = dev->driver->minor;
493 	version->version_patchlevel = dev->driver->patchlevel;
494 	err = drm_copy_field(version->name, &version->name_len,
495 			dev->driver->name);
496 	if (!err)
497 		err = drm_copy_field(version->date, &version->date_len,
498 				dev->driver->date);
499 	if (!err)
500 		err = drm_copy_field(version->desc, &version->desc_len,
501 				dev->driver->desc);
502 
503 	return err;
504 }
505 
506 /*
507  * drm_ioctl_permit - Check ioctl permissions against caller
508  *
509  * @flags: ioctl permission flags.
510  * @file_priv: Pointer to struct drm_file identifying the caller.
511  *
512  * Checks whether the caller is allowed to run an ioctl with the
513  * indicated permissions. If so, returns zero. Otherwise returns an
514  * error code suitable for ioctl return.
515  */
516 int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
517 {
518 	/* ROOT_ONLY is only for CAP_SYS_ADMIN */
519 	if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
520 		return -EACCES;
521 
522 	/* AUTH is only for authenticated or render client */
523 	if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
524 		     !file_priv->authenticated))
525 		return -EACCES;
526 
527 	/* MASTER is only for master or control clients */
528 	if (unlikely((flags & DRM_MASTER) && !file_priv->is_master &&
529 		     !drm_is_control_client(file_priv)))
530 		return -EACCES;
531 
532 	/* Control clients must be explicitly allowed */
533 	if (unlikely(!(flags & DRM_CONTROL_ALLOW) &&
534 		     drm_is_control_client(file_priv)))
535 		return -EACCES;
536 
537 	/* Render clients must be explicitly allowed */
538 	if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
539 		     drm_is_render_client(file_priv)))
540 		return -EACCES;
541 
542 	return 0;
543 }
544 EXPORT_SYMBOL(drm_ioctl_permit);
545 
546 #define DRM_IOCTL_DEF(ioctl, _func, _flags)	\
547 	[DRM_IOCTL_NR(ioctl)] = {		\
548 		.cmd = ioctl,			\
549 		.func = _func,			\
550 		.flags = _flags,		\
551 		.name = #ioctl			\
552 	}
553 
554 /* Ioctl table */
555 static const struct drm_ioctl_desc drm_ioctls[] = {
556 	DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version,
557 		      DRM_UNLOCKED|DRM_RENDER_ALLOW|DRM_CONTROL_ALLOW),
558 	DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
559 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0),
560 	DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
561 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_getmap, DRM_UNLOCKED),
562 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED),
563 	DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),
564 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED|DRM_RENDER_ALLOW),
565 	DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
566 	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
567 
568 	DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_setunique, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
569 	DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
570 	DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
571 	DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_MASTER),
572 
573 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
574 	DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),
575 
576 	DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
577 	DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),
578 
579 	DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_ROOT_ONLY),
580 	DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_ROOT_ONLY),
581 
582 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
583 	DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
584 	DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
585 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
586 	DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
587 	DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
588 	DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),
589 
590 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
591 	DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
592 
593 	DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH),
594 	DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH),
595 
596 	DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
597 
598 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
599 	DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
600 	DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH),
601 	DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH),
602 	DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH),
603 	DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH),
604 
605 	DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
606 
607 #if IS_ENABLED(CONFIG_AGP)
608 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
609 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
610 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
611 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
612 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
613 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
614 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
615 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
616 #endif
617 
618 	DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
619 	DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
620 
621 	DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank, DRM_UNLOCKED),
622 
623 	DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_modeset_ctl, 0),
624 
625 	DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
626 
627 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
628 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED),
629 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED),
630 
631 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
632 
633 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
634 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
635 
636 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
637 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
638 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
639 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
640 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
641 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
642 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_UNLOCKED),
643 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
644 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
645 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
646 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
647 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
648 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
649 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_mode_connector_property_set_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
650 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
651 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
652 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
653 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
654 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
655 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
656 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
657 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
658 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
659 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
660 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
661 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
662 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
663 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
664 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
665 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
666 };
667 
668 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
669 
670 /**
671  * drm_ioctl - ioctl callback implementation for DRM drivers
672  * @filp: file this ioctl is called on
673  * @cmd: ioctl cmd number
674  * @arg: user argument
675  *
676  * Looks up the ioctl function in the ::ioctls table, checking for root
677  * previleges if so required, and dispatches to the respective function.
678  *
679  * Returns:
680  * Zero on success, negative error code on failure.
681  */
682 long drm_ioctl(struct file *filp,
683 	      unsigned int cmd, unsigned long arg)
684 {
685 	struct drm_file *file_priv = filp->private_data;
686 	struct drm_device *dev;
687 	const struct drm_ioctl_desc *ioctl = NULL;
688 	drm_ioctl_t *func;
689 	unsigned int nr = DRM_IOCTL_NR(cmd);
690 	int retcode = -EINVAL;
691 	char stack_kdata[128];
692 	char *kdata = NULL;
693 	unsigned int usize, asize, drv_size;
694 	bool is_driver_ioctl;
695 
696 	dev = file_priv->minor->dev;
697 
698 	if (drm_device_is_unplugged(dev))
699 		return -ENODEV;
700 
701 	is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
702 
703 	if (is_driver_ioctl) {
704 		/* driver ioctl */
705 		if (nr - DRM_COMMAND_BASE >= dev->driver->num_ioctls)
706 			goto err_i1;
707 		ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
708 	} else {
709 		/* core ioctl */
710 		if (nr >= DRM_CORE_IOCTL_COUNT)
711 			goto err_i1;
712 		ioctl = &drm_ioctls[nr];
713 	}
714 
715 	drv_size = _IOC_SIZE(ioctl->cmd);
716 	usize = _IOC_SIZE(cmd);
717 	asize = max(usize, drv_size);
718 	cmd = ioctl->cmd;
719 
720 	DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
721 		  task_pid_nr(current),
722 		  (long)old_encode_dev(file_priv->minor->kdev->devt),
723 		  file_priv->authenticated, ioctl->name);
724 
725 	/* Do not trust userspace, use our own definition */
726 	func = ioctl->func;
727 
728 	if (unlikely(!func)) {
729 		DRM_DEBUG("no function\n");
730 		retcode = -EINVAL;
731 		goto err_i1;
732 	}
733 
734 	retcode = drm_ioctl_permit(ioctl->flags, file_priv);
735 	if (unlikely(retcode))
736 		goto err_i1;
737 
738 	if (cmd & (IOC_IN | IOC_OUT)) {
739 		if (asize <= sizeof(stack_kdata)) {
740 			kdata = stack_kdata;
741 		} else {
742 			kdata = kmalloc(asize, GFP_KERNEL);
743 			if (!kdata) {
744 				retcode = -ENOMEM;
745 				goto err_i1;
746 			}
747 		}
748 		if (asize > usize)
749 			memset(kdata + usize, 0, asize - usize);
750 	}
751 
752 	if (cmd & IOC_IN) {
753 		if (copy_from_user(kdata, (void __user *)arg,
754 				   usize) != 0) {
755 			retcode = -EFAULT;
756 			goto err_i1;
757 		}
758 	} else if (cmd & IOC_OUT) {
759 		memset(kdata, 0, usize);
760 	}
761 
762 	/* Enforce sane locking for kms driver ioctls. Core ioctls are
763 	 * too messy still. */
764 	if ((drm_core_check_feature(dev, DRIVER_MODESET) && is_driver_ioctl) ||
765 	    (ioctl->flags & DRM_UNLOCKED))
766 		retcode = func(dev, kdata, file_priv);
767 	else {
768 		mutex_lock(&drm_global_mutex);
769 		retcode = func(dev, kdata, file_priv);
770 		mutex_unlock(&drm_global_mutex);
771 	}
772 
773 	if (cmd & IOC_OUT) {
774 		if (copy_to_user((void __user *)arg, kdata,
775 				 usize) != 0)
776 			retcode = -EFAULT;
777 	}
778 
779       err_i1:
780 	if (!ioctl)
781 		DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
782 			  task_pid_nr(current),
783 			  (long)old_encode_dev(file_priv->minor->kdev->devt),
784 			  file_priv->authenticated, cmd, nr);
785 
786 	if (kdata != stack_kdata)
787 		kfree(kdata);
788 	if (retcode)
789 		DRM_DEBUG("ret = %d\n", retcode);
790 	return retcode;
791 }
792 EXPORT_SYMBOL(drm_ioctl);
793 
794 /**
795  * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
796  * @nr: ioctl number
797  * @flags: where to return the ioctl permission flags
798  *
799  * This ioctl is only used by the vmwgfx driver to augment the access checks
800  * done by the drm core and insofar a pretty decent layering violation. This
801  * shouldn't be used by any drivers.
802  *
803  * Returns:
804  * True if the @nr corresponds to a DRM core ioctl numer, false otherwise.
805  */
806 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
807 {
808 	if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
809 		return false;
810 
811 	if (nr >= DRM_CORE_IOCTL_COUNT)
812 		return false;
813 
814 	*flags = drm_ioctls[nr].flags;
815 	return true;
816 }
817 EXPORT_SYMBOL(drm_ioctl_flags);
818