xref: /linux/drivers/gpu/drm/drm_ioctl.c (revision 99a97a8ba9881fc47901ff36b057e5cd0bf06af0)
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/drm_ioctl.h>
32 #include <drm/drmP.h>
33 #include <drm/drm_auth.h>
34 #include "drm_legacy.h"
35 #include "drm_internal.h"
36 #include "drm_crtc_internal.h"
37 
38 #include <linux/pci.h>
39 #include <linux/export.h>
40 
41 /**
42  * DOC: getunique and setversion story
43  *
44  * BEWARE THE DRAGONS! MIND THE TRAPDOORS!
45  *
46  * In an attempt to warn anyone else who's trying to figure out what's going
47  * on here, I'll try to summarize the story. First things first, let's clear up
48  * the names, because the kernel internals, libdrm and the ioctls are all named
49  * differently:
50  *
51  *  - GET_UNIQUE ioctl, implemented by drm_getunique is wrapped up in libdrm
52  *    through the drmGetBusid function.
53  *  - The libdrm drmSetBusid function is backed by the SET_UNIQUE ioctl. All
54  *    that code is nerved in the kernel with drm_invalid_op().
55  *  - The internal set_busid kernel functions and driver callbacks are
56  *    exclusively use by the SET_VERSION ioctl, because only drm 1.0 (which is
57  *    nerved) allowed userspace to set the busid through the above ioctl.
58  *  - Other ioctls and functions involved are named consistently.
59  *
60  * For anyone wondering what's the difference between drm 1.1 and 1.4: Correctly
61  * handling pci domains in the busid on ppc. Doing this correctly was only
62  * implemented in libdrm in 2010, hence can't be nerved yet. No one knows what's
63  * special with drm 1.2 and 1.3.
64  *
65  * Now the actual horror story of how device lookup in drm works. At large,
66  * there's 2 different ways, either by busid, or by device driver name.
67  *
68  * Opening by busid is fairly simple:
69  *
70  * 1. First call SET_VERSION to make sure pci domains are handled properly. As a
71  *    side-effect this fills out the unique name in the master structure.
72  * 2. Call GET_UNIQUE to read out the unique name from the master structure,
73  *    which matches the busid thanks to step 1. If it doesn't, proceed to try
74  *    the next device node.
75  *
76  * Opening by name is slightly different:
77  *
78  * 1. Directly call VERSION to get the version and to match against the driver
79  *    name returned by that ioctl. Note that SET_VERSION is not called, which
80  *    means the the unique name for the master node just opening is _not_ filled
81  *    out. This despite that with current drm device nodes are always bound to
82  *    one device, and can't be runtime assigned like with drm 1.0.
83  * 2. Match driver name. If it mismatches, proceed to the next device node.
84  * 3. Call GET_UNIQUE, and check whether the unique name has length zero (by
85  *    checking that the first byte in the string is 0). If that's not the case
86  *    libdrm skips and proceeds to the next device node. Probably this is just
87  *    copypasta from drm 1.0 times where a set unique name meant that the driver
88  *    was in use already, but that's just conjecture.
89  *
90  * Long story short: To keep the open by name logic working, GET_UNIQUE must
91  * _not_ return a unique string when SET_VERSION hasn't been called yet,
92  * otherwise libdrm breaks. Even when that unique string can't ever change, and
93  * is totally irrelevant for actually opening the device because runtime
94  * assignable device instances were only support in drm 1.0, which is long dead.
95  * But the libdrm code in drmOpenByName somehow survived, hence this can't be
96  * broken.
97  */
98 
99 /*
100  * Get the bus id.
101  *
102  * \param inode device inode.
103  * \param file_priv DRM file private.
104  * \param cmd command.
105  * \param arg user argument, pointing to a drm_unique structure.
106  * \return zero on success or a negative number on failure.
107  *
108  * Copies the bus id from drm_device::unique into user space.
109  */
110 static int drm_getunique(struct drm_device *dev, void *data,
111 		  struct drm_file *file_priv)
112 {
113 	struct drm_unique *u = data;
114 	struct drm_master *master = file_priv->master;
115 
116 	mutex_lock(&master->dev->master_mutex);
117 	if (u->unique_len >= master->unique_len) {
118 		if (copy_to_user(u->unique, master->unique, master->unique_len)) {
119 			mutex_unlock(&master->dev->master_mutex);
120 			return -EFAULT;
121 		}
122 	}
123 	u->unique_len = master->unique_len;
124 	mutex_unlock(&master->dev->master_mutex);
125 
126 	return 0;
127 }
128 
129 static void
130 drm_unset_busid(struct drm_device *dev,
131 		struct drm_master *master)
132 {
133 	kfree(master->unique);
134 	master->unique = NULL;
135 	master->unique_len = 0;
136 }
137 
138 static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
139 {
140 	struct drm_master *master = file_priv->master;
141 	int ret;
142 
143 	if (master->unique != NULL)
144 		drm_unset_busid(dev, master);
145 
146 	if (dev->driver->set_busid) {
147 		ret = dev->driver->set_busid(dev, master);
148 		if (ret) {
149 			drm_unset_busid(dev, master);
150 			return ret;
151 		}
152 	} else {
153 		WARN_ON(!dev->unique);
154 		master->unique = kstrdup(dev->unique, GFP_KERNEL);
155 		if (master->unique)
156 			master->unique_len = strlen(dev->unique);
157 	}
158 
159 	return 0;
160 }
161 
162 /*
163  * Get client information.
164  *
165  * \param inode device inode.
166  * \param file_priv DRM file private.
167  * \param cmd command.
168  * \param arg user argument, pointing to a drm_client structure.
169  *
170  * \return zero on success or a negative number on failure.
171  *
172  * Searches for the client with the specified index and copies its information
173  * into userspace
174  */
175 static int drm_getclient(struct drm_device *dev, void *data,
176 		  struct drm_file *file_priv)
177 {
178 	struct drm_client *client = data;
179 
180 	/*
181 	 * Hollowed-out getclient ioctl to keep some dead old drm tests/tools
182 	 * not breaking completely. Userspace tools stop enumerating one they
183 	 * get -EINVAL, hence this is the return value we need to hand back for
184 	 * no clients tracked.
185 	 *
186 	 * Unfortunately some clients (*cough* libva *cough*) use this in a fun
187 	 * attempt to figure out whether they're authenticated or not. Since
188 	 * that's the only thing they care about, give it to the directly
189 	 * instead of walking one giant list.
190 	 */
191 	if (client->idx == 0) {
192 		client->auth = file_priv->authenticated;
193 		client->pid = task_pid_vnr(current);
194 		client->uid = overflowuid;
195 		client->magic = 0;
196 		client->iocs = 0;
197 
198 		return 0;
199 	} else {
200 		return -EINVAL;
201 	}
202 }
203 
204 /*
205  * Get statistics 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_stats structure.
211  *
212  * \return zero on success or a negative number on failure.
213  */
214 static int drm_getstats(struct drm_device *dev, void *data,
215 		 struct drm_file *file_priv)
216 {
217 	struct drm_stats *stats = data;
218 
219 	/* Clear stats to prevent userspace from eating its stack garbage. */
220 	memset(stats, 0, sizeof(*stats));
221 
222 	return 0;
223 }
224 
225 /*
226  * Get device/driver capabilities
227  */
228 static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
229 {
230 	struct drm_get_cap *req = data;
231 	struct drm_crtc *crtc;
232 
233 	req->value = 0;
234 
235 	/* Only some caps make sense with UMS/render-only drivers. */
236 	switch (req->capability) {
237 	case DRM_CAP_TIMESTAMP_MONOTONIC:
238 		req->value = drm_timestamp_monotonic;
239 		return 0;
240 	case DRM_CAP_PRIME:
241 		req->value |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0;
242 		req->value |= dev->driver->prime_handle_to_fd ? DRM_PRIME_CAP_EXPORT : 0;
243 		return 0;
244 	}
245 
246 	/* Other caps only work with KMS drivers */
247 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
248 		return -ENOTSUPP;
249 
250 	switch (req->capability) {
251 	case DRM_CAP_DUMB_BUFFER:
252 		if (dev->driver->dumb_create)
253 			req->value = 1;
254 		break;
255 	case DRM_CAP_VBLANK_HIGH_CRTC:
256 		req->value = 1;
257 		break;
258 	case DRM_CAP_DUMB_PREFERRED_DEPTH:
259 		req->value = dev->mode_config.preferred_depth;
260 		break;
261 	case DRM_CAP_DUMB_PREFER_SHADOW:
262 		req->value = dev->mode_config.prefer_shadow;
263 		break;
264 	case DRM_CAP_ASYNC_PAGE_FLIP:
265 		req->value = dev->mode_config.async_page_flip;
266 		break;
267 	case DRM_CAP_PAGE_FLIP_TARGET:
268 		req->value = 1;
269 		drm_for_each_crtc(crtc, dev) {
270 			if (!crtc->funcs->page_flip_target)
271 				req->value = 0;
272 		}
273 		break;
274 	case DRM_CAP_CURSOR_WIDTH:
275 		if (dev->mode_config.cursor_width)
276 			req->value = dev->mode_config.cursor_width;
277 		else
278 			req->value = 64;
279 		break;
280 	case DRM_CAP_CURSOR_HEIGHT:
281 		if (dev->mode_config.cursor_height)
282 			req->value = dev->mode_config.cursor_height;
283 		else
284 			req->value = 64;
285 		break;
286 	case DRM_CAP_ADDFB2_MODIFIERS:
287 		req->value = dev->mode_config.allow_fb_modifiers;
288 		break;
289 	default:
290 		return -EINVAL;
291 	}
292 	return 0;
293 }
294 
295 /*
296  * Set device/driver capabilities
297  */
298 static int
299 drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
300 {
301 	struct drm_set_client_cap *req = data;
302 
303 	switch (req->capability) {
304 	case DRM_CLIENT_CAP_STEREO_3D:
305 		if (req->value > 1)
306 			return -EINVAL;
307 		file_priv->stereo_allowed = req->value;
308 		break;
309 	case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
310 		if (req->value > 1)
311 			return -EINVAL;
312 		file_priv->universal_planes = req->value;
313 		break;
314 	case DRM_CLIENT_CAP_ATOMIC:
315 		if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
316 			return -EINVAL;
317 		if (req->value > 1)
318 			return -EINVAL;
319 		file_priv->atomic = req->value;
320 		file_priv->universal_planes = req->value;
321 		break;
322 	default:
323 		return -EINVAL;
324 	}
325 
326 	return 0;
327 }
328 
329 /*
330  * Setversion ioctl.
331  *
332  * \param inode device inode.
333  * \param file_priv DRM file private.
334  * \param cmd command.
335  * \param arg user argument, pointing to a drm_lock structure.
336  * \return zero on success or negative number on failure.
337  *
338  * Sets the requested interface version
339  */
340 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
341 {
342 	struct drm_set_version *sv = data;
343 	int if_version, retcode = 0;
344 
345 	mutex_lock(&dev->master_mutex);
346 	if (sv->drm_di_major != -1) {
347 		if (sv->drm_di_major != DRM_IF_MAJOR ||
348 		    sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
349 			retcode = -EINVAL;
350 			goto done;
351 		}
352 		if_version = DRM_IF_VERSION(sv->drm_di_major,
353 					    sv->drm_di_minor);
354 		dev->if_version = max(if_version, dev->if_version);
355 		if (sv->drm_di_minor >= 1) {
356 			/*
357 			 * Version 1.1 includes tying of DRM to specific device
358 			 * Version 1.4 has proper PCI domain support
359 			 */
360 			retcode = drm_set_busid(dev, file_priv);
361 			if (retcode)
362 				goto done;
363 		}
364 	}
365 
366 	if (sv->drm_dd_major != -1) {
367 		if (sv->drm_dd_major != dev->driver->major ||
368 		    sv->drm_dd_minor < 0 || sv->drm_dd_minor >
369 		    dev->driver->minor) {
370 			retcode = -EINVAL;
371 			goto done;
372 		}
373 	}
374 
375 done:
376 	sv->drm_di_major = DRM_IF_MAJOR;
377 	sv->drm_di_minor = DRM_IF_MINOR;
378 	sv->drm_dd_major = dev->driver->major;
379 	sv->drm_dd_minor = dev->driver->minor;
380 	mutex_unlock(&dev->master_mutex);
381 
382 	return retcode;
383 }
384 
385 /**
386  * drm_noop - DRM no-op ioctl implemntation
387  * @dev: DRM device for the ioctl
388  * @data: data pointer for the ioctl
389  * @file_priv: DRM file for the ioctl call
390  *
391  * This no-op implementation for drm ioctls is useful for deprecated
392  * functionality where we can't return a failure code because existing userspace
393  * checks the result of the ioctl, but doesn't care about the action.
394  *
395  * Always returns successfully with 0.
396  */
397 int drm_noop(struct drm_device *dev, void *data,
398 	     struct drm_file *file_priv)
399 {
400 	DRM_DEBUG("\n");
401 	return 0;
402 }
403 EXPORT_SYMBOL(drm_noop);
404 
405 /**
406  * drm_invalid_op - DRM invalid ioctl implemntation
407  * @dev: DRM device for the ioctl
408  * @data: data pointer for the ioctl
409  * @file_priv: DRM file for the ioctl call
410  *
411  * This no-op implementation for drm ioctls is useful for deprecated
412  * functionality where we really don't want to allow userspace to call the ioctl
413  * any more. This is the case for old ums interfaces for drivers that
414  * transitioned to kms gradually and so kept the old legacy tables around. This
415  * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
416  * use this function.
417  *
418  * Always fails with a return value of -EINVAL.
419  */
420 int drm_invalid_op(struct drm_device *dev, void *data,
421 		   struct drm_file *file_priv)
422 {
423 	return -EINVAL;
424 }
425 EXPORT_SYMBOL(drm_invalid_op);
426 
427 /*
428  * Copy and IOCTL return string to user space
429  */
430 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
431 {
432 	int len;
433 
434 	/* don't overflow userbuf */
435 	len = strlen(value);
436 	if (len > *buf_len)
437 		len = *buf_len;
438 
439 	/* let userspace know exact length of driver value (which could be
440 	 * larger than the userspace-supplied buffer) */
441 	*buf_len = strlen(value);
442 
443 	/* finally, try filling in the userbuf */
444 	if (len && buf)
445 		if (copy_to_user(buf, value, len))
446 			return -EFAULT;
447 	return 0;
448 }
449 
450 /*
451  * Get version information
452  *
453  * \param inode device inode.
454  * \param filp file pointer.
455  * \param cmd command.
456  * \param arg user argument, pointing to a drm_version structure.
457  * \return zero on success or negative number on failure.
458  *
459  * Fills in the version information in \p arg.
460  */
461 static int drm_version(struct drm_device *dev, void *data,
462 		       struct drm_file *file_priv)
463 {
464 	struct drm_version *version = data;
465 	int err;
466 
467 	version->version_major = dev->driver->major;
468 	version->version_minor = dev->driver->minor;
469 	version->version_patchlevel = dev->driver->patchlevel;
470 	err = drm_copy_field(version->name, &version->name_len,
471 			dev->driver->name);
472 	if (!err)
473 		err = drm_copy_field(version->date, &version->date_len,
474 				dev->driver->date);
475 	if (!err)
476 		err = drm_copy_field(version->desc, &version->desc_len,
477 				dev->driver->desc);
478 
479 	return err;
480 }
481 
482 /**
483  * drm_ioctl_permit - Check ioctl permissions against caller
484  *
485  * @flags: ioctl permission flags.
486  * @file_priv: Pointer to struct drm_file identifying the caller.
487  *
488  * Checks whether the caller is allowed to run an ioctl with the
489  * indicated permissions.
490  *
491  * Returns:
492  * Zero if allowed, -EACCES otherwise.
493  */
494 int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
495 {
496 	/* ROOT_ONLY is only for CAP_SYS_ADMIN */
497 	if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
498 		return -EACCES;
499 
500 	/* AUTH is only for authenticated or render client */
501 	if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
502 		     !file_priv->authenticated))
503 		return -EACCES;
504 
505 	/* MASTER is only for master or control clients */
506 	if (unlikely((flags & DRM_MASTER) &&
507 		     !drm_is_current_master(file_priv) &&
508 		     !drm_is_control_client(file_priv)))
509 		return -EACCES;
510 
511 	/* Control clients must be explicitly allowed */
512 	if (unlikely(!(flags & DRM_CONTROL_ALLOW) &&
513 		     drm_is_control_client(file_priv)))
514 		return -EACCES;
515 
516 	/* Render clients must be explicitly allowed */
517 	if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
518 		     drm_is_render_client(file_priv)))
519 		return -EACCES;
520 
521 	return 0;
522 }
523 EXPORT_SYMBOL(drm_ioctl_permit);
524 
525 #define DRM_IOCTL_DEF(ioctl, _func, _flags)	\
526 	[DRM_IOCTL_NR(ioctl)] = {		\
527 		.cmd = ioctl,			\
528 		.func = _func,			\
529 		.flags = _flags,		\
530 		.name = #ioctl			\
531 	}
532 
533 /* Ioctl table */
534 static const struct drm_ioctl_desc drm_ioctls[] = {
535 	DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version,
536 		      DRM_UNLOCKED|DRM_RENDER_ALLOW|DRM_CONTROL_ALLOW),
537 	DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, DRM_UNLOCKED),
538 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, DRM_UNLOCKED),
539 	DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
540 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, DRM_UNLOCKED),
541 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED),
542 	DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),
543 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED|DRM_RENDER_ALLOW),
544 	DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, DRM_UNLOCKED),
545 	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_UNLOCKED | DRM_MASTER),
546 
547 	DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
548 	DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
549 	DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
550 	DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_UNLOCKED|DRM_MASTER),
551 
552 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
553 	DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),
554 
555 	DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
556 	DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),
557 
558 	DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
559 	DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
560 
561 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
562 	DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
563 	DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
564 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
565 	DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
566 	DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
567 	DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),
568 
569 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
570 	DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
571 
572 	DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH),
573 	DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH),
574 
575 	DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
576 
577 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
578 	DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
579 	DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH),
580 	DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH),
581 	DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH),
582 	DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH),
583 
584 	DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_legacy_irq_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
585 
586 #if IS_ENABLED(CONFIG_AGP)
587 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
588 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
589 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
590 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
591 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
592 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
593 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
594 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
595 #endif
596 
597 	DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
598 	DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
599 
600 	DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank, DRM_UNLOCKED),
601 
602 	DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_legacy_modeset_ctl, 0),
603 
604 	DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
605 
606 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
607 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED),
608 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED),
609 
610 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
611 
612 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
613 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
614 
615 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
616 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
617 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
618 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
619 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
620 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
621 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_UNLOCKED),
622 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
623 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
624 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
625 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
626 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
627 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
628 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_mode_connector_property_set_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
629 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
630 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
631 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
632 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
633 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
634 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
635 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
636 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
637 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
638 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
639 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
640 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
641 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
642 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
643 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
644 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
645 };
646 
647 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
648 
649 /**
650  * drm_ioctl - ioctl callback implementation for DRM drivers
651  * @filp: file this ioctl is called on
652  * @cmd: ioctl cmd number
653  * @arg: user argument
654  *
655  * Looks up the ioctl function in the ::ioctls table, checking for root
656  * previleges if so required, and dispatches to the respective function.
657  *
658  * Returns:
659  * Zero on success, negative error code on failure.
660  */
661 long drm_ioctl(struct file *filp,
662 	      unsigned int cmd, unsigned long arg)
663 {
664 	struct drm_file *file_priv = filp->private_data;
665 	struct drm_device *dev;
666 	const struct drm_ioctl_desc *ioctl = NULL;
667 	drm_ioctl_t *func;
668 	unsigned int nr = DRM_IOCTL_NR(cmd);
669 	int retcode = -EINVAL;
670 	char stack_kdata[128];
671 	char *kdata = NULL;
672 	unsigned int in_size, out_size, drv_size, ksize;
673 	bool is_driver_ioctl;
674 
675 	dev = file_priv->minor->dev;
676 
677 	if (drm_device_is_unplugged(dev))
678 		return -ENODEV;
679 
680 	is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
681 
682 	if (is_driver_ioctl) {
683 		/* driver ioctl */
684 		if (nr - DRM_COMMAND_BASE >= dev->driver->num_ioctls)
685 			goto err_i1;
686 		ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
687 	} else {
688 		/* core ioctl */
689 		if (nr >= DRM_CORE_IOCTL_COUNT)
690 			goto err_i1;
691 		ioctl = &drm_ioctls[nr];
692 	}
693 
694 	drv_size = _IOC_SIZE(ioctl->cmd);
695 	out_size = in_size = _IOC_SIZE(cmd);
696 	if ((cmd & ioctl->cmd & IOC_IN) == 0)
697 		in_size = 0;
698 	if ((cmd & ioctl->cmd & IOC_OUT) == 0)
699 		out_size = 0;
700 	ksize = max(max(in_size, out_size), drv_size);
701 
702 	DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
703 		  task_pid_nr(current),
704 		  (long)old_encode_dev(file_priv->minor->kdev->devt),
705 		  file_priv->authenticated, ioctl->name);
706 
707 	/* Do not trust userspace, use our own definition */
708 	func = ioctl->func;
709 
710 	if (unlikely(!func)) {
711 		DRM_DEBUG("no function\n");
712 		retcode = -EINVAL;
713 		goto err_i1;
714 	}
715 
716 	retcode = drm_ioctl_permit(ioctl->flags, file_priv);
717 	if (unlikely(retcode))
718 		goto err_i1;
719 
720 	if (ksize <= sizeof(stack_kdata)) {
721 		kdata = stack_kdata;
722 	} else {
723 		kdata = kmalloc(ksize, GFP_KERNEL);
724 		if (!kdata) {
725 			retcode = -ENOMEM;
726 			goto err_i1;
727 		}
728 	}
729 
730 	if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) {
731 		retcode = -EFAULT;
732 		goto err_i1;
733 	}
734 
735 	if (ksize > in_size)
736 		memset(kdata + in_size, 0, ksize - in_size);
737 
738 	/* Enforce sane locking for modern driver ioctls. */
739 	if (!drm_core_check_feature(dev, DRIVER_LEGACY) ||
740 	    (ioctl->flags & DRM_UNLOCKED))
741 		retcode = func(dev, kdata, file_priv);
742 	else {
743 		mutex_lock(&drm_global_mutex);
744 		retcode = func(dev, kdata, file_priv);
745 		mutex_unlock(&drm_global_mutex);
746 	}
747 
748 	if (copy_to_user((void __user *)arg, kdata, out_size) != 0)
749 		retcode = -EFAULT;
750 
751       err_i1:
752 	if (!ioctl)
753 		DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
754 			  task_pid_nr(current),
755 			  (long)old_encode_dev(file_priv->minor->kdev->devt),
756 			  file_priv->authenticated, cmd, nr);
757 
758 	if (kdata != stack_kdata)
759 		kfree(kdata);
760 	if (retcode)
761 		DRM_DEBUG("ret = %d\n", retcode);
762 	return retcode;
763 }
764 EXPORT_SYMBOL(drm_ioctl);
765 
766 /**
767  * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
768  * @nr: ioctl number
769  * @flags: where to return the ioctl permission flags
770  *
771  * This ioctl is only used by the vmwgfx driver to augment the access checks
772  * done by the drm core and insofar a pretty decent layering violation. This
773  * shouldn't be used by any drivers.
774  *
775  * Returns:
776  * True if the @nr corresponds to a DRM core ioctl number, false otherwise.
777  */
778 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
779 {
780 	if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
781 		return false;
782 
783 	if (nr >= DRM_CORE_IOCTL_COUNT)
784 		return false;
785 
786 	*flags = drm_ioctls[nr].flags;
787 	return true;
788 }
789 EXPORT_SYMBOL(drm_ioctl_flags);
790