xref: /dragonfly/sys/dev/drm/drm_ioctl.c (revision c880cbaf)
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_auth.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 /**
41  * DOC: getunique and setversion story
42  *
43  * BEWARE THE DRAGONS! MIND THE TRAPDOORS!
44  *
45  * In an attempt to warn anyone else who's trying to figure out what's going
46  * on here, I'll try to summarize the story. First things first, let's clear up
47  * the names, because the kernel internals, libdrm and the ioctls are all named
48  * differently:
49  *
50  *  - GET_UNIQUE ioctl, implemented by drm_getunique is wrapped up in libdrm
51  *    through the drmGetBusid function.
52  *  - The libdrm drmSetBusid function is backed by the SET_UNIQUE ioctl. All
53  *    that code is nerved in the kernel with drm_invalid_op().
54  *  - The internal set_busid kernel functions and driver callbacks are
55  *    exclusively use by the SET_VERSION ioctl, because only drm 1.0 (which is
56  *    nerved) allowed userspace to set the busid through the above ioctl.
57  *  - Other ioctls and functions involved are named consistently.
58  *
59  * For anyone wondering what's the difference between drm 1.1 and 1.4: Correctly
60  * handling pci domains in the busid on ppc. Doing this correctly was only
61  * implemented in libdrm in 2010, hence can't be nerved yet. No one knows what's
62  * special with drm 1.2 and 1.3.
63  *
64  * Now the actual horror story of how device lookup in drm works. At large,
65  * there's 2 different ways, either by busid, or by device driver name.
66  *
67  * Opening by busid is fairly simple:
68  *
69  * 1. First call SET_VERSION to make sure pci domains are handled properly. As a
70  *    side-effect this fills out the unique name in the master structure.
71  * 2. Call GET_UNIQUE to read out the unique name from the master structure,
72  *    which matches the busid thanks to step 1. If it doesn't, proceed to try
73  *    the next device node.
74  *
75  * Opening by name is slightly different:
76  *
77  * 1. Directly call VERSION to get the version and to match against the driver
78  *    name returned by that ioctl. Note that SET_VERSION is not called, which
79  *    means the the unique name for the master node just opening is _not_ filled
80  *    out. This despite that with current drm device nodes are always bound to
81  *    one device, and can't be runtime assigned like with drm 1.0.
82  * 2. Match driver name. If it mismatches, proceed to the next device node.
83  * 3. Call GET_UNIQUE, and check whether the unique name has length zero (by
84  *    checking that the first byte in the string is 0). If that's not the case
85  *    libdrm skips and proceeds to the next device node. Probably this is just
86  *    copypasta from drm 1.0 times where a set unique name meant that the driver
87  *    was in use already, but that's just conjecture.
88  *
89  * Long story short: To keep the open by name logic working, GET_UNIQUE must
90  * _not_ return a unique string when SET_VERSION hasn't been called yet,
91  * otherwise libdrm breaks. Even when that unique string can't ever change, and
92  * is totally irrelevant for actually opening the device because runtime
93  * assignable device instances were only support in drm 1.0, which is long dead.
94  * But the libdrm code in drmOpenByName somehow survived, hence this can't be
95  * broken.
96  */
97 
98 static int drm_version(struct drm_device *dev, void *data,
99 		       struct drm_file *file_priv);
100 
101 /*
102  * Get the bus id.
103  *
104  * \param inode device inode.
105  * \param file_priv DRM file private.
106  * \param cmd command.
107  * \param arg user argument, pointing to a drm_unique structure.
108  * \return zero on success or a negative number on failure.
109  *
110  * Copies the bus id from drm_device::unique into user space.
111  */
112 static int drm_getunique(struct drm_device *dev, void *data,
113 		  struct drm_file *file_priv)
114 {
115 	struct drm_unique *u = data;
116 
117 	if (u->unique_len >= dev->unique_len) {
118 		if (copy_to_user(u->unique, dev->unique, dev->unique_len))
119 			return -EFAULT;
120 	}
121 	u->unique_len = dev->unique_len;
122 
123 	return 0;
124 }
125 
126 static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
127 {
128 
129 	DRM_LOCK(dev);
130 
131 	dev->unique_len = 20;
132 	dev->unique = kmalloc(dev->unique_len + 1, M_DRM, M_WAITOK | M_NULLOK);
133 	if (dev->unique == NULL) {
134 		DRM_UNLOCK(dev);
135 		return -ENOMEM;
136 	}
137 
138 	ksnprintf(dev->unique, dev->unique_len, "pci:%04x:%02x:%02x.%1x",
139 	    dev->pci_domain, dev->pci_bus, dev->pci_slot, dev->pci_func);
140 
141 	DRM_UNLOCK(dev);
142 
143 	return 0;
144 }
145 
146 /*
147  * Get client information.
148  *
149  * \param inode device inode.
150  * \param file_priv DRM file private.
151  * \param cmd command.
152  * \param arg user argument, pointing to a drm_client structure.
153  *
154  * \return zero on success or a negative number on failure.
155  *
156  * Searches for the client with the specified index and copies its information
157  * into userspace
158  */
159 static int drm_getclient(struct drm_device *dev, void *data,
160 		  struct drm_file *file_priv)
161 {
162 	struct drm_client *client = data;
163 
164 	/*
165 	 * Hollowed-out getclient ioctl to keep some dead old drm tests/tools
166 	 * not breaking completely. Userspace tools stop enumerating one they
167 	 * get -EINVAL, hence this is the return value we need to hand back for
168 	 * no clients tracked.
169 	 *
170 	 * Unfortunately some clients (*cough* libva *cough*) use this in a fun
171 	 * attempt to figure out whether they're authenticated or not. Since
172 	 * that's the only thing they care about, give it to the directly
173 	 * instead of walking one giant list.
174 	 */
175 	if (client->idx == 0) {
176 		client->auth = file_priv->authenticated;
177 		client->pid = curproc->p_pid;
178 		client->uid = -1;
179 		client->magic = 0;
180 		client->iocs = 0;
181 
182 		return 0;
183 	} else {
184 		return -EINVAL;
185 	}
186 }
187 
188 /*
189  * Get statistics information.
190  *
191  * \param inode device inode.
192  * \param file_priv DRM file private.
193  * \param cmd command.
194  * \param arg user argument, pointing to a drm_stats structure.
195  *
196  * \return zero on success or a negative number on failure.
197  */
198 static int drm_getstats(struct drm_device *dev, void *data,
199 		 struct drm_file *file_priv)
200 {
201 	struct drm_stats *stats = data;
202 
203 	/* Clear stats to prevent userspace from eating its stack garbage. */
204 	memset(stats, 0, sizeof(*stats));
205 
206 	return 0;
207 }
208 
209 /*
210  * Get device/driver capabilities
211  */
212 static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
213 {
214 	struct drm_get_cap *req = data;
215 	struct drm_crtc *crtc;
216 
217 	req->value = 0;
218 	switch (req->capability) {
219 	case DRM_CAP_DUMB_BUFFER:
220 		if (dev->driver->dumb_create)
221 			req->value = 1;
222 		break;
223 	case DRM_CAP_VBLANK_HIGH_CRTC:
224 		req->value = 1;
225 		break;
226 	case DRM_CAP_DUMB_PREFERRED_DEPTH:
227 		req->value = dev->mode_config.preferred_depth;
228 		break;
229 	case DRM_CAP_DUMB_PREFER_SHADOW:
230 		req->value = dev->mode_config.prefer_shadow;
231 		break;
232 	case DRM_CAP_PRIME:
233 #ifndef __DragonFly__
234 		req->value |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0;
235 		req->value |= dev->driver->prime_handle_to_fd ? DRM_PRIME_CAP_EXPORT : 0;
236 #endif
237 		break;
238 	case DRM_CAP_TIMESTAMP_MONOTONIC:
239 		req->value = drm_timestamp_monotonic;
240 		break;
241 	case DRM_CAP_ASYNC_PAGE_FLIP:
242 		req->value = dev->mode_config.async_page_flip;
243 		break;
244 	case DRM_CAP_PAGE_FLIP_TARGET:
245 		if (drm_core_check_feature(dev, DRIVER_MODESET)) {
246 			req->value = 1;
247 			drm_for_each_crtc(crtc, dev) {
248 				if (!crtc->funcs->page_flip_target)
249 					req->value = 0;
250 			}
251 		}
252 		break;
253 	case DRM_CAP_CURSOR_WIDTH:
254 		if (dev->mode_config.cursor_width)
255 			req->value = dev->mode_config.cursor_width;
256 		else
257 			req->value = 64;
258 		break;
259 	case DRM_CAP_CURSOR_HEIGHT:
260 		if (dev->mode_config.cursor_height)
261 			req->value = dev->mode_config.cursor_height;
262 		else
263 			req->value = 64;
264 		break;
265 	case DRM_CAP_ADDFB2_MODIFIERS:
266 		req->value = dev->mode_config.allow_fb_modifiers;
267 		break;
268 	case DRM_CAP_CRTC_IN_VBLANK_EVENT:
269 		req->value = 1;
270 		break;
271 	default:
272 		return -EINVAL;
273 	}
274 	return 0;
275 }
276 
277 /*
278  * Set device/driver capabilities
279  */
280 static int
281 drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
282 {
283 	struct drm_set_client_cap *req = data;
284 
285 	switch (req->capability) {
286 	case DRM_CLIENT_CAP_STEREO_3D:
287 		if (req->value > 1)
288 			return -EINVAL;
289 		file_priv->stereo_allowed = req->value;
290 		break;
291 	case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
292 		if (req->value > 1)
293 			return -EINVAL;
294 		file_priv->universal_planes = req->value;
295 		break;
296 	case DRM_CLIENT_CAP_ATOMIC:
297 		if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
298 			return -EINVAL;
299 		if (req->value > 1)
300 			return -EINVAL;
301 		file_priv->atomic = req->value;
302 		file_priv->universal_planes = req->value;
303 		break;
304 	default:
305 		return -EINVAL;
306 	}
307 
308 	return 0;
309 }
310 
311 /*
312  * Setversion ioctl.
313  *
314  * \param inode device inode.
315  * \param file_priv DRM file private.
316  * \param cmd command.
317  * \param arg user argument, pointing to a drm_lock structure.
318  * \return zero on success or negative number on failure.
319  *
320  * Sets the requested interface version
321  */
322 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
323 {
324 	struct drm_set_version *sv = data;
325 	int if_version, retcode = 0;
326 
327 	if (sv->drm_di_major != -1) {
328 		if (sv->drm_di_major != DRM_IF_MAJOR ||
329 		    sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
330 			retcode = -EINVAL;
331 			goto done;
332 		}
333 		if_version = DRM_IF_VERSION(sv->drm_di_major,
334 					    sv->drm_di_minor);
335 		dev->if_version = max(if_version, dev->if_version);
336 		if (sv->drm_di_minor >= 1) {
337 			/*
338 			 * Version 1.1 includes tying of DRM to specific device
339 			 * Version 1.4 has proper PCI domain support
340 			 */
341 			retcode = drm_set_busid(dev, file_priv);
342 			if (retcode)
343 				goto done;
344 		}
345 	}
346 
347 	if (sv->drm_dd_major != -1) {
348 		if (sv->drm_dd_major != dev->driver->major ||
349 		    sv->drm_dd_minor < 0 || sv->drm_dd_minor >
350 		    dev->driver->minor) {
351 			retcode = -EINVAL;
352 			goto done;
353 		}
354 	}
355 
356 done:
357 	sv->drm_di_major = DRM_IF_MAJOR;
358 	sv->drm_di_minor = DRM_IF_MINOR;
359 	sv->drm_dd_major = dev->driver->major;
360 	sv->drm_dd_minor = dev->driver->minor;
361 
362 	return retcode;
363 }
364 
365 /**
366  * drm_noop - DRM no-op ioctl implemntation
367  * @dev: DRM device for the ioctl
368  * @data: data pointer for the ioctl
369  * @file_priv: DRM file for the ioctl call
370  *
371  * This no-op implementation for drm ioctls is useful for deprecated
372  * functionality where we can't return a failure code because existing userspace
373  * checks the result of the ioctl, but doesn't care about the action.
374  *
375  * Always returns successfully with 0.
376  */
377 int drm_noop(struct drm_device *dev, void *data,
378 	     struct drm_file *file_priv)
379 {
380 	DRM_DEBUG("\n");
381 	return 0;
382 }
383 EXPORT_SYMBOL(drm_noop);
384 
385 /**
386  * drm_invalid_op - DRM invalid 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 really don't want to allow userspace to call the ioctl
393  * any more. This is the case for old ums interfaces for drivers that
394  * transitioned to kms gradually and so kept the old legacy tables around. This
395  * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
396  * use this function.
397  *
398  * Always fails with a return value of -EINVAL.
399  */
400 int drm_invalid_op(struct drm_device *dev, void *data,
401 		   struct drm_file *file_priv)
402 {
403 	return -EINVAL;
404 }
405 EXPORT_SYMBOL(drm_invalid_op);
406 
407 /*
408  * Copy and IOCTL return string to user space
409  */
410 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
411 {
412 	int len;
413 
414 	/* don't overflow userbuf */
415 	len = strlen(value);
416 	if (len > *buf_len)
417 		len = *buf_len;
418 
419 	/* let userspace know exact length of driver value (which could be
420 	 * larger than the userspace-supplied buffer) */
421 	*buf_len = strlen(value);
422 
423 	/* finally, try filling in the userbuf */
424 	if (len && buf)
425 		if (copy_to_user(buf, value, len))
426 			return -EFAULT;
427 	return 0;
428 }
429 
430 /*
431  * Get version information
432  *
433  * \param inode device inode.
434  * \param filp file pointer.
435  * \param cmd command.
436  * \param arg user argument, pointing to a drm_version structure.
437  * \return zero on success or negative number on failure.
438  *
439  * Fills in the version information in \p arg.
440  */
441 static int drm_version(struct drm_device *dev, void *data,
442 		       struct drm_file *file_priv)
443 {
444 	static int drm_version_initial;
445 	struct drm_version *version = data;
446 	int err;
447 
448 	if (drm_version_initial == 0) {
449 		int dummy;
450 
451 		++drm_version_initial;
452 		tsleep(&dummy, 0, "SDELAY", hz*2);
453 	}
454 
455 	version->version_major = dev->driver->major;
456 	version->version_minor = dev->driver->minor;
457 	version->version_patchlevel = dev->driver->patchlevel;
458 	err = drm_copy_field(version->name, &version->name_len,
459 			dev->driver->name);
460 	if (!err)
461 		err = drm_copy_field(version->date, &version->date_len,
462 				dev->driver->date);
463 	if (!err)
464 		err = drm_copy_field(version->desc, &version->desc_len,
465 				dev->driver->desc);
466 
467 	return err;
468 }
469 
470 /*
471  * drm_ioctl_permit - Check ioctl permissions against caller
472  *
473  * @flags: ioctl permission flags.
474  * @file_priv: Pointer to struct drm_file identifying the caller.
475  *
476  * Checks whether the caller is allowed to run an ioctl with the
477  * indicated permissions. If so, returns zero. Otherwise returns an
478  * error code suitable for ioctl return.
479  */
480 int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
481 {
482 	/* ROOT_ONLY is only for CAP_SYS_ADMIN */
483 	if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
484 		return -EACCES;
485 
486 	/* AUTH is only for authenticated or render client */
487 	if (unlikely((flags & DRM_AUTH) && !file_priv->authenticated))
488 		return -EACCES;
489 
490 	/* MASTER is only for master or control clients */
491 	if (unlikely((flags & DRM_MASTER) &&
492 		     !drm_is_current_master(file_priv) &&
493 		     !drm_is_control_client(file_priv)))
494 		return -EACCES;
495 
496 	return 0;
497 }
498 EXPORT_SYMBOL(drm_ioctl_permit);
499 
500 #define DRM_IOCTL_DEF(ioctl, _func, _flags)	\
501 	[DRM_IOCTL_NR(ioctl)] = {		\
502 		.cmd = ioctl,			\
503 		.func = _func,			\
504 		.flags = _flags,		\
505 		.name = #ioctl			\
506 	}
507 
508 /* Ioctl table */
509 static const struct drm_ioctl_desc drm_ioctls[] = {
510 	DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version,
511 		      DRM_UNLOCKED|DRM_RENDER_ALLOW|DRM_CONTROL_ALLOW),
512 	DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
513 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, DRM_UNLOCKED),
514 	DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
515 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, DRM_UNLOCKED),
516 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED),
517 	DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),
518 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED|DRM_RENDER_ALLOW),
519 	DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
520 	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
521 
522 	DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
523 	DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
524 	DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
525 	DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_UNLOCKED|DRM_MASTER),
526 
527 #ifdef __DragonFly__
528 	DRM_IOCTL_DEF(DRM_IOCTL_GET_PCIINFO, drm_getpciinfo, DRM_UNLOCKED|DRM_RENDER_ALLOW),
529 #else
530 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
531 #endif
532 	DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),
533 
534 	DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
535 	DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),
536 
537 	DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
538 	DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
539 
540 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
541 	DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
542 	DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
543 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
544 	DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
545 	DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
546 	DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),
547 
548 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
549 	DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
550 
551 	DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH),
552 	DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH),
553 
554 	DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
555 
556 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
557 	DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
558 	DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH),
559 	DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH),
560 	DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH),
561 	DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH),
562 
563 	DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
564 
565 #if IS_ENABLED(CONFIG_AGP)
566 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
567 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
568 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
569 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
570 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
571 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
572 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
573 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
574 #endif
575 
576 	DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
577 	DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
578 
579 	DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank, DRM_UNLOCKED),
580 
581 	DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_modeset_ctl, 0),
582 
583 	DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
584 
585 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
586 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED),
587 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED),
588 
589 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
590 
591 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
592 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
593 
594 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
595 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
596 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
597 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
598 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
599 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
600 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_UNLOCKED),
601 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
602 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
603 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
604 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
605 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
606 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
607 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_mode_connector_property_set_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
608 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
609 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
610 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
611 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
612 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
613 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
614 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
615 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
616 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
617 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
618 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
619 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
620 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
621 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
622 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
623 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
624 };
625 
626 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
627 
628 /**
629  * drm_ioctl - ioctl callback implementation for DRM drivers
630  * @filp: file this ioctl is called on
631  * @cmd: ioctl cmd number
632  * @arg: user argument
633  *
634  * Looks up the ioctl function in the ::ioctls table, checking for root
635  * previleges if so required, and dispatches to the respective function.
636  *
637  * Returns:
638  * Zero on success, negative error code on failure.
639  */
640 int drm_ioctl(struct dev_ioctl_args *ap)
641 {
642 	struct file *filp = ap->a_fp;
643 	u_long cmd = ap->a_cmd;
644 	struct drm_file *file_priv = filp->private_data;
645 	struct drm_device *dev;
646 	const struct drm_ioctl_desc *ioctl = NULL;
647 	drm_ioctl_t *func;
648 	unsigned int nr = DRM_IOCTL_NR(cmd);
649 	int retcode = -EINVAL;
650 	caddr_t data = ap->a_data;
651 	bool is_driver_ioctl;
652 
653 	dev = drm_get_device_from_kdev(ap->a_head.a_dev);
654 
655 	if (drm_device_is_unplugged(dev))
656 		return -ENODEV;
657 
658 	is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
659 
660 	if (is_driver_ioctl) {
661 		/* driver ioctl */
662 		if (nr - DRM_COMMAND_BASE >= dev->driver->num_ioctls)
663 			goto err_i1;
664 		ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
665 	} else {
666 		/* core ioctl */
667 		if (nr >= DRM_CORE_IOCTL_COUNT)
668 			goto err_i1;
669 		ioctl = &drm_ioctls[nr];
670 	}
671 
672 	DRM_DEBUG_IOCTL("pid=%d, dev=0x%lx, auth=%d, %s\n",
673 		  DRM_CURRENTPID,
674 		  (long)dev->dev,
675 		  file_priv->authenticated, ioctl->name);
676 
677 	/* Do not trust userspace, use our own definition */
678 	func = ioctl->func;
679 
680 	if (unlikely(!func)) {
681 		DRM_DEBUG("no function\n");
682 		retcode = -EINVAL;
683 		goto err_i1;
684 	}
685 
686 	retcode = drm_ioctl_permit(ioctl->flags, file_priv);
687 	if (unlikely(retcode))
688 		goto err_i1;
689 
690 	/* Enforce sane locking for modern driver ioctls. Core ioctls are
691 	 * too messy still. */
692 	if ((!drm_core_check_feature(dev, DRIVER_LEGACY) && is_driver_ioctl) ||
693 	    (ioctl->flags & DRM_UNLOCKED))
694 		retcode = -func(dev, data, file_priv);
695 	else {
696 		mutex_lock(&drm_global_mutex);
697 		retcode = -func(dev, data, file_priv);
698 		mutex_unlock(&drm_global_mutex);
699 	}
700 	if (retcode == ERESTARTSYS)
701 			retcode = EINTR;
702 
703       err_i1:
704 	if (!ioctl)
705 		DRM_DEBUG_FIOCTL("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02lx, nr=0x%02x\n",
706 			  DRM_CURRENTPID,
707 			  (long)dev->dev,
708 			  file_priv->authenticated, cmd, nr);
709 
710 	if (retcode)
711 		DRM_DEBUG_FIOCTL("ret = %d\n", retcode);
712 	return retcode;
713 }
714 EXPORT_SYMBOL(drm_ioctl);
715 
716 /**
717  * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
718  * @nr: ioctl number
719  * @flags: where to return the ioctl permission flags
720  *
721  * This ioctl is only used by the vmwgfx driver to augment the access checks
722  * done by the drm core and insofar a pretty decent layering violation. This
723  * shouldn't be used by any drivers.
724  *
725  * Returns:
726  * True if the @nr corresponds to a DRM core ioctl number, false otherwise.
727  */
728 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
729 {
730 	if ((nr >= DRM_COMMAND_END && nr < DRM_CORE_IOCTL_COUNT) ||
731 	    (nr < DRM_COMMAND_BASE)) {
732 		*flags = drm_ioctls[nr].flags;
733 		return true;
734 	}
735 
736 	return false;
737 }
738 EXPORT_SYMBOL(drm_ioctl_flags);
739