xref: /openbmc/linux/drivers/gpu/drm/drm_ioctl.c (revision f3a8b664)
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 	struct drm_master *master = file_priv->master;
117 
118 	if (u->unique_len >= master->unique_len) {
119 		if (copy_to_user(u->unique, master->unique, master->unique_len))
120 			return -EFAULT;
121 	}
122 	u->unique_len = master->unique_len;
123 
124 	return 0;
125 }
126 
127 static void
128 drm_unset_busid(struct drm_device *dev,
129 		struct drm_master *master)
130 {
131 	kfree(master->unique);
132 	master->unique = NULL;
133 	master->unique_len = 0;
134 }
135 
136 static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
137 {
138 	struct drm_master *master = file_priv->master;
139 	int ret;
140 
141 	if (master->unique != NULL)
142 		drm_unset_busid(dev, master);
143 
144 	if (dev->driver->set_busid) {
145 		ret = dev->driver->set_busid(dev, master);
146 		if (ret) {
147 			drm_unset_busid(dev, master);
148 			return ret;
149 		}
150 	} else {
151 		WARN_ON(!dev->unique);
152 		master->unique = kstrdup(dev->unique, GFP_KERNEL);
153 		if (master->unique)
154 			master->unique_len = strlen(dev->unique);
155 	}
156 
157 	return 0;
158 }
159 
160 /*
161  * Get client information.
162  *
163  * \param inode device inode.
164  * \param file_priv DRM file private.
165  * \param cmd command.
166  * \param arg user argument, pointing to a drm_client structure.
167  *
168  * \return zero on success or a negative number on failure.
169  *
170  * Searches for the client with the specified index and copies its information
171  * into userspace
172  */
173 static int drm_getclient(struct drm_device *dev, void *data,
174 		  struct drm_file *file_priv)
175 {
176 	struct drm_client *client = data;
177 
178 	/*
179 	 * Hollowed-out getclient ioctl to keep some dead old drm tests/tools
180 	 * not breaking completely. Userspace tools stop enumerating one they
181 	 * get -EINVAL, hence this is the return value we need to hand back for
182 	 * no clients tracked.
183 	 *
184 	 * Unfortunately some clients (*cough* libva *cough*) use this in a fun
185 	 * attempt to figure out whether they're authenticated or not. Since
186 	 * that's the only thing they care about, give it to the directly
187 	 * instead of walking one giant list.
188 	 */
189 	if (client->idx == 0) {
190 		client->auth = file_priv->authenticated;
191 		client->pid = task_pid_vnr(current);
192 		client->uid = overflowuid;
193 		client->magic = 0;
194 		client->iocs = 0;
195 
196 		return 0;
197 	} else {
198 		return -EINVAL;
199 	}
200 }
201 
202 /*
203  * Get statistics information.
204  *
205  * \param inode device inode.
206  * \param file_priv DRM file private.
207  * \param cmd command.
208  * \param arg user argument, pointing to a drm_stats structure.
209  *
210  * \return zero on success or a negative number on failure.
211  */
212 static int drm_getstats(struct drm_device *dev, void *data,
213 		 struct drm_file *file_priv)
214 {
215 	struct drm_stats *stats = data;
216 
217 	/* Clear stats to prevent userspace from eating its stack garbage. */
218 	memset(stats, 0, sizeof(*stats));
219 
220 	return 0;
221 }
222 
223 /*
224  * Get device/driver capabilities
225  */
226 static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
227 {
228 	struct drm_get_cap *req = data;
229 	struct drm_crtc *crtc;
230 
231 	req->value = 0;
232 	switch (req->capability) {
233 	case DRM_CAP_DUMB_BUFFER:
234 		if (dev->driver->dumb_create)
235 			req->value = 1;
236 		break;
237 	case DRM_CAP_VBLANK_HIGH_CRTC:
238 		req->value = 1;
239 		break;
240 	case DRM_CAP_DUMB_PREFERRED_DEPTH:
241 		req->value = dev->mode_config.preferred_depth;
242 		break;
243 	case DRM_CAP_DUMB_PREFER_SHADOW:
244 		req->value = dev->mode_config.prefer_shadow;
245 		break;
246 	case DRM_CAP_PRIME:
247 		req->value |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0;
248 		req->value |= dev->driver->prime_handle_to_fd ? DRM_PRIME_CAP_EXPORT : 0;
249 		break;
250 	case DRM_CAP_TIMESTAMP_MONOTONIC:
251 		req->value = drm_timestamp_monotonic;
252 		break;
253 	case DRM_CAP_ASYNC_PAGE_FLIP:
254 		req->value = dev->mode_config.async_page_flip;
255 		break;
256 	case DRM_CAP_PAGE_FLIP_TARGET:
257 		req->value = 1;
258 		drm_for_each_crtc(crtc, dev) {
259 			if (!crtc->funcs->page_flip_target)
260 				req->value = 0;
261 		}
262 		break;
263 	case DRM_CAP_CURSOR_WIDTH:
264 		if (dev->mode_config.cursor_width)
265 			req->value = dev->mode_config.cursor_width;
266 		else
267 			req->value = 64;
268 		break;
269 	case DRM_CAP_CURSOR_HEIGHT:
270 		if (dev->mode_config.cursor_height)
271 			req->value = dev->mode_config.cursor_height;
272 		else
273 			req->value = 64;
274 		break;
275 	case DRM_CAP_ADDFB2_MODIFIERS:
276 		req->value = dev->mode_config.allow_fb_modifiers;
277 		break;
278 	default:
279 		return -EINVAL;
280 	}
281 	return 0;
282 }
283 
284 /*
285  * Set device/driver capabilities
286  */
287 static int
288 drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
289 {
290 	struct drm_set_client_cap *req = data;
291 
292 	switch (req->capability) {
293 	case DRM_CLIENT_CAP_STEREO_3D:
294 		if (req->value > 1)
295 			return -EINVAL;
296 		file_priv->stereo_allowed = req->value;
297 		break;
298 	case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
299 		if (req->value > 1)
300 			return -EINVAL;
301 		file_priv->universal_planes = req->value;
302 		break;
303 	case DRM_CLIENT_CAP_ATOMIC:
304 		if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
305 			return -EINVAL;
306 		if (req->value > 1)
307 			return -EINVAL;
308 		file_priv->atomic = req->value;
309 		file_priv->universal_planes = req->value;
310 		break;
311 	default:
312 		return -EINVAL;
313 	}
314 
315 	return 0;
316 }
317 
318 /*
319  * Setversion ioctl.
320  *
321  * \param inode device inode.
322  * \param file_priv DRM file private.
323  * \param cmd command.
324  * \param arg user argument, pointing to a drm_lock structure.
325  * \return zero on success or negative number on failure.
326  *
327  * Sets the requested interface version
328  */
329 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
330 {
331 	struct drm_set_version *sv = data;
332 	int if_version, retcode = 0;
333 
334 	if (sv->drm_di_major != -1) {
335 		if (sv->drm_di_major != DRM_IF_MAJOR ||
336 		    sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
337 			retcode = -EINVAL;
338 			goto done;
339 		}
340 		if_version = DRM_IF_VERSION(sv->drm_di_major,
341 					    sv->drm_di_minor);
342 		dev->if_version = max(if_version, dev->if_version);
343 		if (sv->drm_di_minor >= 1) {
344 			/*
345 			 * Version 1.1 includes tying of DRM to specific device
346 			 * Version 1.4 has proper PCI domain support
347 			 */
348 			retcode = drm_set_busid(dev, file_priv);
349 			if (retcode)
350 				goto done;
351 		}
352 	}
353 
354 	if (sv->drm_dd_major != -1) {
355 		if (sv->drm_dd_major != dev->driver->major ||
356 		    sv->drm_dd_minor < 0 || sv->drm_dd_minor >
357 		    dev->driver->minor) {
358 			retcode = -EINVAL;
359 			goto done;
360 		}
361 	}
362 
363 done:
364 	sv->drm_di_major = DRM_IF_MAJOR;
365 	sv->drm_di_minor = DRM_IF_MINOR;
366 	sv->drm_dd_major = dev->driver->major;
367 	sv->drm_dd_minor = dev->driver->minor;
368 
369 	return retcode;
370 }
371 
372 /**
373  * drm_noop - DRM no-op ioctl implemntation
374  * @dev: DRM device for the ioctl
375  * @data: data pointer for the ioctl
376  * @file_priv: DRM file for the ioctl call
377  *
378  * This no-op implementation for drm ioctls is useful for deprecated
379  * functionality where we can't return a failure code because existing userspace
380  * checks the result of the ioctl, but doesn't care about the action.
381  *
382  * Always returns successfully with 0.
383  */
384 int drm_noop(struct drm_device *dev, void *data,
385 	     struct drm_file *file_priv)
386 {
387 	DRM_DEBUG("\n");
388 	return 0;
389 }
390 EXPORT_SYMBOL(drm_noop);
391 
392 /**
393  * drm_invalid_op - DRM invalid ioctl implemntation
394  * @dev: DRM device for the ioctl
395  * @data: data pointer for the ioctl
396  * @file_priv: DRM file for the ioctl call
397  *
398  * This no-op implementation for drm ioctls is useful for deprecated
399  * functionality where we really don't want to allow userspace to call the ioctl
400  * any more. This is the case for old ums interfaces for drivers that
401  * transitioned to kms gradually and so kept the old legacy tables around. This
402  * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
403  * use this function.
404  *
405  * Always fails with a return value of -EINVAL.
406  */
407 int drm_invalid_op(struct drm_device *dev, void *data,
408 		   struct drm_file *file_priv)
409 {
410 	return -EINVAL;
411 }
412 EXPORT_SYMBOL(drm_invalid_op);
413 
414 /*
415  * Copy and IOCTL return string to user space
416  */
417 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
418 {
419 	int len;
420 
421 	/* don't overflow userbuf */
422 	len = strlen(value);
423 	if (len > *buf_len)
424 		len = *buf_len;
425 
426 	/* let userspace know exact length of driver value (which could be
427 	 * larger than the userspace-supplied buffer) */
428 	*buf_len = strlen(value);
429 
430 	/* finally, try filling in the userbuf */
431 	if (len && buf)
432 		if (copy_to_user(buf, value, len))
433 			return -EFAULT;
434 	return 0;
435 }
436 
437 /*
438  * Get version information
439  *
440  * \param inode device inode.
441  * \param filp file pointer.
442  * \param cmd command.
443  * \param arg user argument, pointing to a drm_version structure.
444  * \return zero on success or negative number on failure.
445  *
446  * Fills in the version information in \p arg.
447  */
448 static int drm_version(struct drm_device *dev, void *data,
449 		       struct drm_file *file_priv)
450 {
451 	struct drm_version *version = data;
452 	int err;
453 
454 	version->version_major = dev->driver->major;
455 	version->version_minor = dev->driver->minor;
456 	version->version_patchlevel = dev->driver->patchlevel;
457 	err = drm_copy_field(version->name, &version->name_len,
458 			dev->driver->name);
459 	if (!err)
460 		err = drm_copy_field(version->date, &version->date_len,
461 				dev->driver->date);
462 	if (!err)
463 		err = drm_copy_field(version->desc, &version->desc_len,
464 				dev->driver->desc);
465 
466 	return err;
467 }
468 
469 /*
470  * drm_ioctl_permit - Check ioctl permissions against caller
471  *
472  * @flags: ioctl permission flags.
473  * @file_priv: Pointer to struct drm_file identifying the caller.
474  *
475  * Checks whether the caller is allowed to run an ioctl with the
476  * indicated permissions. If so, returns zero. Otherwise returns an
477  * error code suitable for ioctl return.
478  */
479 int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
480 {
481 	/* ROOT_ONLY is only for CAP_SYS_ADMIN */
482 	if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
483 		return -EACCES;
484 
485 	/* AUTH is only for authenticated or render client */
486 	if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
487 		     !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 	/* Control clients must be explicitly allowed */
497 	if (unlikely(!(flags & DRM_CONTROL_ALLOW) &&
498 		     drm_is_control_client(file_priv)))
499 		return -EACCES;
500 
501 	/* Render clients must be explicitly allowed */
502 	if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
503 		     drm_is_render_client(file_priv)))
504 		return -EACCES;
505 
506 	return 0;
507 }
508 EXPORT_SYMBOL(drm_ioctl_permit);
509 
510 #define DRM_IOCTL_DEF(ioctl, _func, _flags)	\
511 	[DRM_IOCTL_NR(ioctl)] = {		\
512 		.cmd = ioctl,			\
513 		.func = _func,			\
514 		.flags = _flags,		\
515 		.name = #ioctl			\
516 	}
517 
518 /* Ioctl table */
519 static const struct drm_ioctl_desc drm_ioctls[] = {
520 	DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version,
521 		      DRM_UNLOCKED|DRM_RENDER_ALLOW|DRM_CONTROL_ALLOW),
522 	DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
523 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, DRM_UNLOCKED),
524 	DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
525 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, DRM_UNLOCKED),
526 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED),
527 	DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),
528 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED|DRM_RENDER_ALLOW),
529 	DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
530 	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
531 
532 	DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
533 	DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
534 	DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
535 	DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_UNLOCKED|DRM_MASTER),
536 
537 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
538 	DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),
539 
540 	DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
541 	DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),
542 
543 	DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
544 	DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
545 
546 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
547 	DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
548 	DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
549 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
550 	DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
551 	DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
552 	DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),
553 
554 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
555 	DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
556 
557 	DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH),
558 	DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH),
559 
560 	DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
561 
562 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
563 	DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
564 	DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH),
565 	DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH),
566 	DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH),
567 	DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH),
568 
569 	DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
570 
571 #if IS_ENABLED(CONFIG_AGP)
572 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
573 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
574 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
575 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
576 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
577 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
578 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
579 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
580 #endif
581 
582 	DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
583 	DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
584 
585 	DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank, DRM_UNLOCKED),
586 
587 	DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_modeset_ctl, 0),
588 
589 	DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
590 
591 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
592 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED),
593 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED),
594 
595 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
596 
597 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
598 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
599 
600 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
601 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
602 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
603 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
604 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
605 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
606 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_UNLOCKED),
607 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
608 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
609 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
610 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
611 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
612 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
613 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_mode_connector_property_set_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
614 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
615 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
616 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
617 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
618 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
619 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
620 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
621 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
622 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
623 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
624 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
625 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
626 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
627 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
628 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
629 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
630 };
631 
632 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
633 
634 /**
635  * drm_ioctl - ioctl callback implementation for DRM drivers
636  * @filp: file this ioctl is called on
637  * @cmd: ioctl cmd number
638  * @arg: user argument
639  *
640  * Looks up the ioctl function in the ::ioctls table, checking for root
641  * previleges if so required, and dispatches to the respective function.
642  *
643  * Returns:
644  * Zero on success, negative error code on failure.
645  */
646 long drm_ioctl(struct file *filp,
647 	      unsigned int cmd, unsigned long arg)
648 {
649 	struct drm_file *file_priv = filp->private_data;
650 	struct drm_device *dev;
651 	const struct drm_ioctl_desc *ioctl = NULL;
652 	drm_ioctl_t *func;
653 	unsigned int nr = DRM_IOCTL_NR(cmd);
654 	int retcode = -EINVAL;
655 	char stack_kdata[128];
656 	char *kdata = NULL;
657 	unsigned int in_size, out_size, drv_size, ksize;
658 	bool is_driver_ioctl;
659 
660 	dev = file_priv->minor->dev;
661 
662 	if (drm_device_is_unplugged(dev))
663 		return -ENODEV;
664 
665 	is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
666 
667 	if (is_driver_ioctl) {
668 		/* driver ioctl */
669 		if (nr - DRM_COMMAND_BASE >= dev->driver->num_ioctls)
670 			goto err_i1;
671 		ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
672 	} else {
673 		/* core ioctl */
674 		if (nr >= DRM_CORE_IOCTL_COUNT)
675 			goto err_i1;
676 		ioctl = &drm_ioctls[nr];
677 	}
678 
679 	drv_size = _IOC_SIZE(ioctl->cmd);
680 	out_size = in_size = _IOC_SIZE(cmd);
681 	if ((cmd & ioctl->cmd & IOC_IN) == 0)
682 		in_size = 0;
683 	if ((cmd & ioctl->cmd & IOC_OUT) == 0)
684 		out_size = 0;
685 	ksize = max(max(in_size, out_size), drv_size);
686 
687 	DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
688 		  task_pid_nr(current),
689 		  (long)old_encode_dev(file_priv->minor->kdev->devt),
690 		  file_priv->authenticated, ioctl->name);
691 
692 	/* Do not trust userspace, use our own definition */
693 	func = ioctl->func;
694 
695 	if (unlikely(!func)) {
696 		DRM_DEBUG("no function\n");
697 		retcode = -EINVAL;
698 		goto err_i1;
699 	}
700 
701 	retcode = drm_ioctl_permit(ioctl->flags, file_priv);
702 	if (unlikely(retcode))
703 		goto err_i1;
704 
705 	if (ksize <= sizeof(stack_kdata)) {
706 		kdata = stack_kdata;
707 	} else {
708 		kdata = kmalloc(ksize, GFP_KERNEL);
709 		if (!kdata) {
710 			retcode = -ENOMEM;
711 			goto err_i1;
712 		}
713 	}
714 
715 	if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) {
716 		retcode = -EFAULT;
717 		goto err_i1;
718 	}
719 
720 	if (ksize > in_size)
721 		memset(kdata + in_size, 0, ksize - in_size);
722 
723 	/* Enforce sane locking for modern driver ioctls. Core ioctls are
724 	 * too messy still. */
725 	if ((!drm_core_check_feature(dev, DRIVER_LEGACY) && is_driver_ioctl) ||
726 	    (ioctl->flags & DRM_UNLOCKED))
727 		retcode = func(dev, kdata, file_priv);
728 	else {
729 		mutex_lock(&drm_global_mutex);
730 		retcode = func(dev, kdata, file_priv);
731 		mutex_unlock(&drm_global_mutex);
732 	}
733 
734 	if (copy_to_user((void __user *)arg, kdata, out_size) != 0)
735 		retcode = -EFAULT;
736 
737       err_i1:
738 	if (!ioctl)
739 		DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
740 			  task_pid_nr(current),
741 			  (long)old_encode_dev(file_priv->minor->kdev->devt),
742 			  file_priv->authenticated, cmd, nr);
743 
744 	if (kdata != stack_kdata)
745 		kfree(kdata);
746 	if (retcode)
747 		DRM_DEBUG("ret = %d\n", retcode);
748 	return retcode;
749 }
750 EXPORT_SYMBOL(drm_ioctl);
751 
752 /**
753  * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
754  * @nr: ioctl number
755  * @flags: where to return the ioctl permission flags
756  *
757  * This ioctl is only used by the vmwgfx driver to augment the access checks
758  * done by the drm core and insofar a pretty decent layering violation. This
759  * shouldn't be used by any drivers.
760  *
761  * Returns:
762  * True if the @nr corresponds to a DRM core ioctl number, false otherwise.
763  */
764 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
765 {
766 	if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
767 		return false;
768 
769 	if (nr >= DRM_CORE_IOCTL_COUNT)
770 		return false;
771 
772 	*flags = drm_ioctls[nr].flags;
773 	return true;
774 }
775 EXPORT_SYMBOL(drm_ioctl_flags);
776