xref: /openbmc/linux/drivers/gpu/drm/drm_ioctl.c (revision a8c5cb99)
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 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->dev && dev_is_pci(dev->dev)) {
147 		ret = drm_pci_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 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 = 1;
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 	case DRM_CAP_SYNCOBJ:
245 		req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ);
246 		return 0;
247 	}
248 
249 	/* Other caps only work with KMS drivers */
250 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
251 		return -ENOTSUPP;
252 
253 	switch (req->capability) {
254 	case DRM_CAP_DUMB_BUFFER:
255 		if (dev->driver->dumb_create)
256 			req->value = 1;
257 		break;
258 	case DRM_CAP_VBLANK_HIGH_CRTC:
259 		req->value = 1;
260 		break;
261 	case DRM_CAP_DUMB_PREFERRED_DEPTH:
262 		req->value = dev->mode_config.preferred_depth;
263 		break;
264 	case DRM_CAP_DUMB_PREFER_SHADOW:
265 		req->value = dev->mode_config.prefer_shadow;
266 		break;
267 	case DRM_CAP_ASYNC_PAGE_FLIP:
268 		req->value = dev->mode_config.async_page_flip;
269 		break;
270 	case DRM_CAP_PAGE_FLIP_TARGET:
271 		req->value = 1;
272 		drm_for_each_crtc(crtc, dev) {
273 			if (!crtc->funcs->page_flip_target)
274 				req->value = 0;
275 		}
276 		break;
277 	case DRM_CAP_CURSOR_WIDTH:
278 		if (dev->mode_config.cursor_width)
279 			req->value = dev->mode_config.cursor_width;
280 		else
281 			req->value = 64;
282 		break;
283 	case DRM_CAP_CURSOR_HEIGHT:
284 		if (dev->mode_config.cursor_height)
285 			req->value = dev->mode_config.cursor_height;
286 		else
287 			req->value = 64;
288 		break;
289 	case DRM_CAP_ADDFB2_MODIFIERS:
290 		req->value = dev->mode_config.allow_fb_modifiers;
291 		break;
292 	case DRM_CAP_CRTC_IN_VBLANK_EVENT:
293 		req->value = 1;
294 		break;
295 	default:
296 		return -EINVAL;
297 	}
298 	return 0;
299 }
300 
301 /*
302  * Set device/driver capabilities
303  */
304 static int
305 drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
306 {
307 	struct drm_set_client_cap *req = data;
308 
309 	switch (req->capability) {
310 	case DRM_CLIENT_CAP_STEREO_3D:
311 		if (req->value > 1)
312 			return -EINVAL;
313 		file_priv->stereo_allowed = req->value;
314 		break;
315 	case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
316 		if (req->value > 1)
317 			return -EINVAL;
318 		file_priv->universal_planes = req->value;
319 		break;
320 	case DRM_CLIENT_CAP_ATOMIC:
321 		if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
322 			return -EINVAL;
323 		if (req->value > 1)
324 			return -EINVAL;
325 		file_priv->atomic = req->value;
326 		file_priv->universal_planes = req->value;
327 		/*
328 		 * No atomic user-space blows up on aspect ratio mode bits.
329 		 */
330 		file_priv->aspect_ratio_allowed = req->value;
331 		break;
332 	case DRM_CLIENT_CAP_ASPECT_RATIO:
333 		if (req->value > 1)
334 			return -EINVAL;
335 		file_priv->aspect_ratio_allowed = req->value;
336 		break;
337 	default:
338 		return -EINVAL;
339 	}
340 
341 	return 0;
342 }
343 
344 /*
345  * Setversion ioctl.
346  *
347  * \param inode device inode.
348  * \param file_priv DRM file private.
349  * \param cmd command.
350  * \param arg user argument, pointing to a drm_lock structure.
351  * \return zero on success or negative number on failure.
352  *
353  * Sets the requested interface version
354  */
355 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
356 {
357 	struct drm_set_version *sv = data;
358 	int if_version, retcode = 0;
359 
360 	mutex_lock(&dev->master_mutex);
361 	if (sv->drm_di_major != -1) {
362 		if (sv->drm_di_major != DRM_IF_MAJOR ||
363 		    sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
364 			retcode = -EINVAL;
365 			goto done;
366 		}
367 		if_version = DRM_IF_VERSION(sv->drm_di_major,
368 					    sv->drm_di_minor);
369 		dev->if_version = max(if_version, dev->if_version);
370 		if (sv->drm_di_minor >= 1) {
371 			/*
372 			 * Version 1.1 includes tying of DRM to specific device
373 			 * Version 1.4 has proper PCI domain support
374 			 */
375 			retcode = drm_set_busid(dev, file_priv);
376 			if (retcode)
377 				goto done;
378 		}
379 	}
380 
381 	if (sv->drm_dd_major != -1) {
382 		if (sv->drm_dd_major != dev->driver->major ||
383 		    sv->drm_dd_minor < 0 || sv->drm_dd_minor >
384 		    dev->driver->minor) {
385 			retcode = -EINVAL;
386 			goto done;
387 		}
388 	}
389 
390 done:
391 	sv->drm_di_major = DRM_IF_MAJOR;
392 	sv->drm_di_minor = DRM_IF_MINOR;
393 	sv->drm_dd_major = dev->driver->major;
394 	sv->drm_dd_minor = dev->driver->minor;
395 	mutex_unlock(&dev->master_mutex);
396 
397 	return retcode;
398 }
399 
400 /**
401  * drm_noop - DRM no-op ioctl implemntation
402  * @dev: DRM device for the ioctl
403  * @data: data pointer for the ioctl
404  * @file_priv: DRM file for the ioctl call
405  *
406  * This no-op implementation for drm ioctls is useful for deprecated
407  * functionality where we can't return a failure code because existing userspace
408  * checks the result of the ioctl, but doesn't care about the action.
409  *
410  * Always returns successfully with 0.
411  */
412 int drm_noop(struct drm_device *dev, void *data,
413 	     struct drm_file *file_priv)
414 {
415 	DRM_DEBUG("\n");
416 	return 0;
417 }
418 EXPORT_SYMBOL(drm_noop);
419 
420 /**
421  * drm_invalid_op - DRM invalid ioctl implemntation
422  * @dev: DRM device for the ioctl
423  * @data: data pointer for the ioctl
424  * @file_priv: DRM file for the ioctl call
425  *
426  * This no-op implementation for drm ioctls is useful for deprecated
427  * functionality where we really don't want to allow userspace to call the ioctl
428  * any more. This is the case for old ums interfaces for drivers that
429  * transitioned to kms gradually and so kept the old legacy tables around. This
430  * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
431  * use this function.
432  *
433  * Always fails with a return value of -EINVAL.
434  */
435 int drm_invalid_op(struct drm_device *dev, void *data,
436 		   struct drm_file *file_priv)
437 {
438 	return -EINVAL;
439 }
440 EXPORT_SYMBOL(drm_invalid_op);
441 
442 /*
443  * Copy and IOCTL return string to user space
444  */
445 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
446 {
447 	int len;
448 
449 	/* don't overflow userbuf */
450 	len = strlen(value);
451 	if (len > *buf_len)
452 		len = *buf_len;
453 
454 	/* let userspace know exact length of driver value (which could be
455 	 * larger than the userspace-supplied buffer) */
456 	*buf_len = strlen(value);
457 
458 	/* finally, try filling in the userbuf */
459 	if (len && buf)
460 		if (copy_to_user(buf, value, len))
461 			return -EFAULT;
462 	return 0;
463 }
464 
465 /*
466  * Get version information
467  *
468  * \param inode device inode.
469  * \param filp file pointer.
470  * \param cmd command.
471  * \param arg user argument, pointing to a drm_version structure.
472  * \return zero on success or negative number on failure.
473  *
474  * Fills in the version information in \p arg.
475  */
476 int drm_version(struct drm_device *dev, void *data,
477 		       struct drm_file *file_priv)
478 {
479 	struct drm_version *version = data;
480 	int err;
481 
482 	version->version_major = dev->driver->major;
483 	version->version_minor = dev->driver->minor;
484 	version->version_patchlevel = dev->driver->patchlevel;
485 	err = drm_copy_field(version->name, &version->name_len,
486 			dev->driver->name);
487 	if (!err)
488 		err = drm_copy_field(version->date, &version->date_len,
489 				dev->driver->date);
490 	if (!err)
491 		err = drm_copy_field(version->desc, &version->desc_len,
492 				dev->driver->desc);
493 
494 	return err;
495 }
496 
497 /**
498  * drm_ioctl_permit - Check ioctl permissions against caller
499  *
500  * @flags: ioctl permission flags.
501  * @file_priv: Pointer to struct drm_file identifying the caller.
502  *
503  * Checks whether the caller is allowed to run an ioctl with the
504  * indicated permissions.
505  *
506  * Returns:
507  * Zero if allowed, -EACCES otherwise.
508  */
509 int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
510 {
511 	/* ROOT_ONLY is only for CAP_SYS_ADMIN */
512 	if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
513 		return -EACCES;
514 
515 	/* AUTH is only for authenticated or render client */
516 	if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
517 		     !file_priv->authenticated))
518 		return -EACCES;
519 
520 	/* MASTER is only for master or control clients */
521 	if (unlikely((flags & DRM_MASTER) &&
522 		     !drm_is_current_master(file_priv)))
523 		return -EACCES;
524 
525 	/* Render clients must be explicitly allowed */
526 	if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
527 		     drm_is_render_client(file_priv)))
528 		return -EACCES;
529 
530 	return 0;
531 }
532 EXPORT_SYMBOL(drm_ioctl_permit);
533 
534 #define DRM_IOCTL_DEF(ioctl, _func, _flags)	\
535 	[DRM_IOCTL_NR(ioctl)] = {		\
536 		.cmd = ioctl,			\
537 		.func = _func,			\
538 		.flags = _flags,		\
539 		.name = #ioctl			\
540 	}
541 
542 /* Ioctl table */
543 static const struct drm_ioctl_desc drm_ioctls[] = {
544 	DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version,
545 		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
546 	DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, DRM_UNLOCKED),
547 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, DRM_UNLOCKED),
548 	DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
549 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, DRM_UNLOCKED),
550 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED),
551 	DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),
552 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED|DRM_RENDER_ALLOW),
553 	DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, DRM_UNLOCKED),
554 	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_UNLOCKED | DRM_MASTER),
555 
556 	DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
557 	DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
558 	DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
559 	DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_UNLOCKED|DRM_MASTER),
560 
561 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
562 	DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),
563 
564 	DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
565 	DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),
566 
567 	DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
568 	DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
569 
570 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
571 	DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
572 	DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
573 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
574 	DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
575 	DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
576 	DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),
577 
578 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
579 	DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
580 
581 	DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH),
582 	DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH),
583 
584 	DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
585 
586 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
587 	DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
588 	DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH),
589 	DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH),
590 	DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH),
591 	DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH),
592 
593 	DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_legacy_irq_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
594 
595 #if IS_ENABLED(CONFIG_AGP)
596 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
597 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
598 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
599 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
600 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
601 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
602 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
603 	DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
604 #endif
605 
606 	DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
607 	DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
608 
609 	DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, DRM_UNLOCKED),
610 
611 	DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_legacy_modeset_ctl_ioctl, 0),
612 
613 	DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
614 
615 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
616 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED),
617 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED),
618 
619 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_UNLOCKED),
620 
621 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
622 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
623 
624 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_UNLOCKED),
625 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_UNLOCKED),
626 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_UNLOCKED),
627 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_UNLOCKED),
628 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_UNLOCKED),
629 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_UNLOCKED),
630 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_UNLOCKED),
631 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
632 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_UNLOCKED),
633 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_UNLOCKED),
634 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER|DRM_UNLOCKED),
635 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER|DRM_UNLOCKED),
636 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_UNLOCKED),
637 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_mode_connector_property_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
638 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_UNLOCKED),
639 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_UNLOCKED),
640 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_UNLOCKED),
641 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_UNLOCKED),
642 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_UNLOCKED),
643 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_UNLOCKED),
644 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_UNLOCKED),
645 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_UNLOCKED),
646 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_UNLOCKED),
647 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_UNLOCKED),
648 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_UNLOCKED),
649 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_UNLOCKED),
650 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_UNLOCKED),
651 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER|DRM_UNLOCKED),
652 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, DRM_UNLOCKED),
653 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, DRM_UNLOCKED),
654 
655 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_CREATE, drm_syncobj_create_ioctl,
656 		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
657 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_DESTROY, drm_syncobj_destroy_ioctl,
658 		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
659 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, drm_syncobj_handle_to_fd_ioctl,
660 		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
661 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, drm_syncobj_fd_to_handle_ioctl,
662 		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
663 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl,
664 		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
665 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl,
666 		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
667 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl,
668 		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
669 	DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, DRM_UNLOCKED),
670 	DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, DRM_UNLOCKED),
671 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER|DRM_UNLOCKED),
672 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER|DRM_UNLOCKED),
673 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER|DRM_UNLOCKED),
674 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER|DRM_UNLOCKED),
675 };
676 
677 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
678 
679 /**
680  * DOC: driver specific ioctls
681  *
682  * First things first, driver private IOCTLs should only be needed for drivers
683  * supporting rendering. Kernel modesetting is all standardized, and extended
684  * through properties. There are a few exceptions in some existing drivers,
685  * which define IOCTL for use by the display DRM master, but they all predate
686  * properties.
687  *
688  * Now if you do have a render driver you always have to support it through
689  * driver private properties. There's a few steps needed to wire all the things
690  * up.
691  *
692  * First you need to define the structure for your IOCTL in your driver private
693  * UAPI header in ``include/uapi/drm/my_driver_drm.h``::
694  *
695  *     struct my_driver_operation {
696  *             u32 some_thing;
697  *             u32 another_thing;
698  *     };
699  *
700  * Please make sure that you follow all the best practices from
701  * ``Documentation/ioctl/botching-up-ioctls.txt``. Note that drm_ioctl()
702  * automatically zero-extends structures, hence make sure you can add more stuff
703  * at the end, i.e. don't put a variable sized array there.
704  *
705  * Then you need to define your IOCTL number, using one of DRM_IO(), DRM_IOR(),
706  * DRM_IOW() or DRM_IOWR(). It must start with the DRM_IOCTL\_ prefix::
707  *
708  *     ##define DRM_IOCTL_MY_DRIVER_OPERATION \
709  *         DRM_IOW(DRM_COMMAND_BASE, struct my_driver_operation)
710  *
711  * DRM driver private IOCTL must be in the range from DRM_COMMAND_BASE to
712  * DRM_COMMAND_END. Finally you need an array of &struct drm_ioctl_desc to wire
713  * up the handlers and set the access rights::
714  *
715  *     static const struct drm_ioctl_desc my_driver_ioctls[] = {
716  *         DRM_IOCTL_DEF_DRV(MY_DRIVER_OPERATION, my_driver_operation,
717  *                 DRM_AUTH|DRM_RENDER_ALLOW),
718  *     };
719  *
720  * And then assign this to the &drm_driver.ioctls field in your driver
721  * structure.
722  *
723  * See the separate chapter on :ref:`file operations<drm_driver_fops>` for how
724  * the driver-specific IOCTLs are wired up.
725  */
726 
727 long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
728 		      u32 flags)
729 {
730 	struct drm_file *file_priv = file->private_data;
731 	struct drm_device *dev = file_priv->minor->dev;
732 	int retcode;
733 
734 	if (drm_dev_is_unplugged(dev))
735 		return -ENODEV;
736 
737 	retcode = drm_ioctl_permit(flags, file_priv);
738 	if (unlikely(retcode))
739 		return retcode;
740 
741 	/* Enforce sane locking for modern driver ioctls. */
742 	if (!drm_core_check_feature(dev, DRIVER_LEGACY) ||
743 	    (flags & DRM_UNLOCKED))
744 		retcode = func(dev, kdata, file_priv);
745 	else {
746 		mutex_lock(&drm_global_mutex);
747 		retcode = func(dev, kdata, file_priv);
748 		mutex_unlock(&drm_global_mutex);
749 	}
750 	return retcode;
751 }
752 EXPORT_SYMBOL(drm_ioctl_kernel);
753 
754 /**
755  * drm_ioctl - ioctl callback implementation for DRM drivers
756  * @filp: file this ioctl is called on
757  * @cmd: ioctl cmd number
758  * @arg: user argument
759  *
760  * Looks up the ioctl function in the DRM core and the driver dispatch table,
761  * stored in &drm_driver.ioctls. It checks for necessary permission by calling
762  * drm_ioctl_permit(), and dispatches to the respective function.
763  *
764  * Returns:
765  * Zero on success, negative error code on failure.
766  */
767 long drm_ioctl(struct file *filp,
768 	      unsigned int cmd, unsigned long arg)
769 {
770 	struct drm_file *file_priv = filp->private_data;
771 	struct drm_device *dev;
772 	const struct drm_ioctl_desc *ioctl = NULL;
773 	drm_ioctl_t *func;
774 	unsigned int nr = DRM_IOCTL_NR(cmd);
775 	int retcode = -EINVAL;
776 	char stack_kdata[128];
777 	char *kdata = NULL;
778 	unsigned int in_size, out_size, drv_size, ksize;
779 	bool is_driver_ioctl;
780 
781 	dev = file_priv->minor->dev;
782 
783 	if (drm_dev_is_unplugged(dev))
784 		return -ENODEV;
785 
786 	is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
787 
788 	if (is_driver_ioctl) {
789 		/* driver ioctl */
790 		if (nr - DRM_COMMAND_BASE >= dev->driver->num_ioctls)
791 			goto err_i1;
792 		ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
793 	} else {
794 		/* core ioctl */
795 		if (nr >= DRM_CORE_IOCTL_COUNT)
796 			goto err_i1;
797 		ioctl = &drm_ioctls[nr];
798 	}
799 
800 	drv_size = _IOC_SIZE(ioctl->cmd);
801 	out_size = in_size = _IOC_SIZE(cmd);
802 	if ((cmd & ioctl->cmd & IOC_IN) == 0)
803 		in_size = 0;
804 	if ((cmd & ioctl->cmd & IOC_OUT) == 0)
805 		out_size = 0;
806 	ksize = max(max(in_size, out_size), drv_size);
807 
808 	DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
809 		  task_pid_nr(current),
810 		  (long)old_encode_dev(file_priv->minor->kdev->devt),
811 		  file_priv->authenticated, ioctl->name);
812 
813 	/* Do not trust userspace, use our own definition */
814 	func = ioctl->func;
815 
816 	if (unlikely(!func)) {
817 		DRM_DEBUG("no function\n");
818 		retcode = -EINVAL;
819 		goto err_i1;
820 	}
821 
822 	if (ksize <= sizeof(stack_kdata)) {
823 		kdata = stack_kdata;
824 	} else {
825 		kdata = kmalloc(ksize, GFP_KERNEL);
826 		if (!kdata) {
827 			retcode = -ENOMEM;
828 			goto err_i1;
829 		}
830 	}
831 
832 	if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) {
833 		retcode = -EFAULT;
834 		goto err_i1;
835 	}
836 
837 	if (ksize > in_size)
838 		memset(kdata + in_size, 0, ksize - in_size);
839 
840 	retcode = drm_ioctl_kernel(filp, func, kdata, ioctl->flags);
841 	if (copy_to_user((void __user *)arg, kdata, out_size) != 0)
842 		retcode = -EFAULT;
843 
844       err_i1:
845 	if (!ioctl)
846 		DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
847 			  task_pid_nr(current),
848 			  (long)old_encode_dev(file_priv->minor->kdev->devt),
849 			  file_priv->authenticated, cmd, nr);
850 
851 	if (kdata != stack_kdata)
852 		kfree(kdata);
853 	if (retcode)
854 		DRM_DEBUG("pid=%d, ret = %d\n", task_pid_nr(current), retcode);
855 	return retcode;
856 }
857 EXPORT_SYMBOL(drm_ioctl);
858 
859 /**
860  * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
861  * @nr: ioctl number
862  * @flags: where to return the ioctl permission flags
863  *
864  * This ioctl is only used by the vmwgfx driver to augment the access checks
865  * done by the drm core and insofar a pretty decent layering violation. This
866  * shouldn't be used by any drivers.
867  *
868  * Returns:
869  * True if the @nr corresponds to a DRM core ioctl number, false otherwise.
870  */
871 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
872 {
873 	if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
874 		return false;
875 
876 	if (nr >= DRM_CORE_IOCTL_COUNT)
877 		return false;
878 
879 	*flags = drm_ioctls[nr].flags;
880 	return true;
881 }
882 EXPORT_SYMBOL(drm_ioctl_flags);
883