xref: /linux/drivers/gpu/drm/drm_ioctl.c (revision 7a92fc8b4d20680e4c20289a670d8fca2d1f2c1b)
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 <linux/export.h>
32 #include <linux/nospec.h>
33 #include <linux/pci.h>
34 #include <linux/uaccess.h>
35 
36 #include <drm/drm_auth.h>
37 #include <drm/drm_crtc.h>
38 #include <drm/drm_drv.h>
39 #include <drm/drm_file.h>
40 #include <drm/drm_ioctl.h>
41 #include <drm/drm_print.h>
42 
43 #include "drm_crtc_internal.h"
44 #include "drm_internal.h"
45 #include "drm_legacy.h"
46 
47 /**
48  * DOC: getunique and setversion story
49  *
50  * BEWARE THE DRAGONS! MIND THE TRAPDOORS!
51  *
52  * In an attempt to warn anyone else who's trying to figure out what's going
53  * on here, I'll try to summarize the story. First things first, let's clear up
54  * the names, because the kernel internals, libdrm and the ioctls are all named
55  * differently:
56  *
57  *  - GET_UNIQUE ioctl, implemented by drm_getunique is wrapped up in libdrm
58  *    through the drmGetBusid function.
59  *  - The libdrm drmSetBusid function is backed by the SET_UNIQUE ioctl. All
60  *    that code is nerved in the kernel with drm_invalid_op().
61  *  - The internal set_busid kernel functions and driver callbacks are
62  *    exclusively use by the SET_VERSION ioctl, because only drm 1.0 (which is
63  *    nerved) allowed userspace to set the busid through the above ioctl.
64  *  - Other ioctls and functions involved are named consistently.
65  *
66  * For anyone wondering what's the difference between drm 1.1 and 1.4: Correctly
67  * handling pci domains in the busid on ppc. Doing this correctly was only
68  * implemented in libdrm in 2010, hence can't be nerved yet. No one knows what's
69  * special with drm 1.2 and 1.3.
70  *
71  * Now the actual horror story of how device lookup in drm works. At large,
72  * there's 2 different ways, either by busid, or by device driver name.
73  *
74  * Opening by busid is fairly simple:
75  *
76  * 1. First call SET_VERSION to make sure pci domains are handled properly. As a
77  *    side-effect this fills out the unique name in the master structure.
78  * 2. Call GET_UNIQUE to read out the unique name from the master structure,
79  *    which matches the busid thanks to step 1. If it doesn't, proceed to try
80  *    the next device node.
81  *
82  * Opening by name is slightly different:
83  *
84  * 1. Directly call VERSION to get the version and to match against the driver
85  *    name returned by that ioctl. Note that SET_VERSION is not called, which
86  *    means the unique name for the master node just opening is _not_ filled
87  *    out. This despite that with current drm device nodes are always bound to
88  *    one device, and can't be runtime assigned like with drm 1.0.
89  * 2. Match driver name. If it mismatches, proceed to the next device node.
90  * 3. Call GET_UNIQUE, and check whether the unique name has length zero (by
91  *    checking that the first byte in the string is 0). If that's not the case
92  *    libdrm skips and proceeds to the next device node. Probably this is just
93  *    copypasta from drm 1.0 times where a set unique name meant that the driver
94  *    was in use already, but that's just conjecture.
95  *
96  * Long story short: To keep the open by name logic working, GET_UNIQUE must
97  * _not_ return a unique string when SET_VERSION hasn't been called yet,
98  * otherwise libdrm breaks. Even when that unique string can't ever change, and
99  * is totally irrelevant for actually opening the device because runtime
100  * assignable device instances were only support in drm 1.0, which is long dead.
101  * But the libdrm code in drmOpenByName somehow survived, hence this can't be
102  * broken.
103  */
104 
105 /*
106  * Get the bus id.
107  *
108  * \param inode device inode.
109  * \param file_priv DRM file private.
110  * \param cmd command.
111  * \param arg user argument, pointing to a drm_unique structure.
112  * \return zero on success or a negative number on failure.
113  *
114  * Copies the bus id from drm_device::unique into user space.
115  */
116 int drm_getunique(struct drm_device *dev, void *data,
117 		  struct drm_file *file_priv)
118 {
119 	struct drm_unique *u = data;
120 	struct drm_master *master;
121 
122 	mutex_lock(&dev->master_mutex);
123 	master = file_priv->master;
124 	if (u->unique_len >= master->unique_len) {
125 		if (copy_to_user(u->unique, master->unique, master->unique_len)) {
126 			mutex_unlock(&dev->master_mutex);
127 			return -EFAULT;
128 		}
129 	}
130 	u->unique_len = master->unique_len;
131 	mutex_unlock(&dev->master_mutex);
132 
133 	return 0;
134 }
135 
136 static void
137 drm_unset_busid(struct drm_device *dev,
138 		struct drm_master *master)
139 {
140 	kfree(master->unique);
141 	master->unique = NULL;
142 	master->unique_len = 0;
143 }
144 
145 static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
146 {
147 	struct drm_master *master = file_priv->master;
148 	int ret;
149 
150 	if (master->unique != NULL)
151 		drm_unset_busid(dev, master);
152 
153 	if (dev->dev && dev_is_pci(dev->dev)) {
154 		ret = drm_pci_set_busid(dev, master);
155 		if (ret) {
156 			drm_unset_busid(dev, master);
157 			return ret;
158 		}
159 	} else {
160 		WARN_ON(!dev->unique);
161 		master->unique = kstrdup(dev->unique, GFP_KERNEL);
162 		if (master->unique)
163 			master->unique_len = strlen(dev->unique);
164 	}
165 
166 	return 0;
167 }
168 
169 /*
170  * Get client information.
171  *
172  * \param inode device inode.
173  * \param file_priv DRM file private.
174  * \param cmd command.
175  * \param arg user argument, pointing to a drm_client structure.
176  *
177  * \return zero on success or a negative number on failure.
178  *
179  * Searches for the client with the specified index and copies its information
180  * into userspace
181  */
182 int drm_getclient(struct drm_device *dev, void *data,
183 		  struct drm_file *file_priv)
184 {
185 	struct drm_client *client = data;
186 
187 	/*
188 	 * Hollowed-out getclient ioctl to keep some dead old drm tests/tools
189 	 * not breaking completely. Userspace tools stop enumerating one they
190 	 * get -EINVAL, hence this is the return value we need to hand back for
191 	 * no clients tracked.
192 	 *
193 	 * Unfortunately some clients (*cough* libva *cough*) use this in a fun
194 	 * attempt to figure out whether they're authenticated or not. Since
195 	 * that's the only thing they care about, give it to the directly
196 	 * instead of walking one giant list.
197 	 */
198 	if (client->idx == 0) {
199 		client->auth = file_priv->authenticated;
200 		client->pid = task_pid_vnr(current);
201 		client->uid = overflowuid;
202 		client->magic = 0;
203 		client->iocs = 0;
204 
205 		return 0;
206 	} else {
207 		return -EINVAL;
208 	}
209 }
210 
211 /*
212  * Get statistics information.
213  *
214  * \param inode device inode.
215  * \param file_priv DRM file private.
216  * \param cmd command.
217  * \param arg user argument, pointing to a drm_stats structure.
218  *
219  * \return zero on success or a negative number on failure.
220  */
221 static int drm_getstats(struct drm_device *dev, void *data,
222 		 struct drm_file *file_priv)
223 {
224 	struct drm_stats *stats = data;
225 
226 	/* Clear stats to prevent userspace from eating its stack garbage. */
227 	memset(stats, 0, sizeof(*stats));
228 
229 	return 0;
230 }
231 
232 /*
233  * Get device/driver capabilities
234  */
235 static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
236 {
237 	struct drm_get_cap *req = data;
238 	struct drm_crtc *crtc;
239 
240 	req->value = 0;
241 
242 	/* Only some caps make sense with UMS/render-only drivers. */
243 	switch (req->capability) {
244 	case DRM_CAP_TIMESTAMP_MONOTONIC:
245 		req->value = 1;
246 		return 0;
247 	case DRM_CAP_PRIME:
248 		req->value = DRM_PRIME_CAP_IMPORT | DRM_PRIME_CAP_EXPORT;
249 		return 0;
250 	case DRM_CAP_SYNCOBJ:
251 		req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ);
252 		return 0;
253 	case DRM_CAP_SYNCOBJ_TIMELINE:
254 		req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE);
255 		return 0;
256 	}
257 
258 	/* Other caps only work with KMS drivers */
259 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
260 		return -EOPNOTSUPP;
261 
262 	switch (req->capability) {
263 	case DRM_CAP_DUMB_BUFFER:
264 		if (dev->driver->dumb_create)
265 			req->value = 1;
266 		break;
267 	case DRM_CAP_VBLANK_HIGH_CRTC:
268 		req->value = 1;
269 		break;
270 	case DRM_CAP_DUMB_PREFERRED_DEPTH:
271 		req->value = dev->mode_config.preferred_depth;
272 		break;
273 	case DRM_CAP_DUMB_PREFER_SHADOW:
274 		req->value = dev->mode_config.prefer_shadow;
275 		break;
276 	case DRM_CAP_ASYNC_PAGE_FLIP:
277 		req->value = dev->mode_config.async_page_flip;
278 		break;
279 	case DRM_CAP_PAGE_FLIP_TARGET:
280 		req->value = 1;
281 		drm_for_each_crtc(crtc, dev) {
282 			if (!crtc->funcs->page_flip_target)
283 				req->value = 0;
284 		}
285 		break;
286 	case DRM_CAP_CURSOR_WIDTH:
287 		if (dev->mode_config.cursor_width)
288 			req->value = dev->mode_config.cursor_width;
289 		else
290 			req->value = 64;
291 		break;
292 	case DRM_CAP_CURSOR_HEIGHT:
293 		if (dev->mode_config.cursor_height)
294 			req->value = dev->mode_config.cursor_height;
295 		else
296 			req->value = 64;
297 		break;
298 	case DRM_CAP_ADDFB2_MODIFIERS:
299 		req->value = !dev->mode_config.fb_modifiers_not_supported;
300 		break;
301 	case DRM_CAP_CRTC_IN_VBLANK_EVENT:
302 		req->value = 1;
303 		break;
304 	default:
305 		return -EINVAL;
306 	}
307 	return 0;
308 }
309 
310 /*
311  * Set device/driver capabilities
312  */
313 static int
314 drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
315 {
316 	struct drm_set_client_cap *req = data;
317 
318 	/* No render-only settable capabilities for now */
319 
320 	/* Below caps that only works with KMS drivers */
321 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
322 		return -EOPNOTSUPP;
323 
324 	switch (req->capability) {
325 	case DRM_CLIENT_CAP_STEREO_3D:
326 		if (req->value > 1)
327 			return -EINVAL;
328 		file_priv->stereo_allowed = req->value;
329 		break;
330 	case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
331 		if (req->value > 1)
332 			return -EINVAL;
333 		file_priv->universal_planes = req->value;
334 		break;
335 	case DRM_CLIENT_CAP_ATOMIC:
336 		if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
337 			return -EOPNOTSUPP;
338 		/* The modesetting DDX has a totally broken idea of atomic. */
339 		if (current->comm[0] == 'X' && req->value == 1) {
340 			pr_info("broken atomic modeset userspace detected, disabling atomic\n");
341 			return -EOPNOTSUPP;
342 		}
343 		if (req->value > 2)
344 			return -EINVAL;
345 		file_priv->atomic = req->value;
346 		file_priv->universal_planes = req->value;
347 		/*
348 		 * No atomic user-space blows up on aspect ratio mode bits.
349 		 */
350 		file_priv->aspect_ratio_allowed = req->value;
351 		break;
352 	case DRM_CLIENT_CAP_ASPECT_RATIO:
353 		if (req->value > 1)
354 			return -EINVAL;
355 		file_priv->aspect_ratio_allowed = req->value;
356 		break;
357 	case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS:
358 		if (!file_priv->atomic)
359 			return -EINVAL;
360 		if (req->value > 1)
361 			return -EINVAL;
362 		file_priv->writeback_connectors = req->value;
363 		break;
364 	default:
365 		return -EINVAL;
366 	}
367 
368 	return 0;
369 }
370 
371 /*
372  * Setversion ioctl.
373  *
374  * \param inode device inode.
375  * \param file_priv DRM file private.
376  * \param cmd command.
377  * \param arg user argument, pointing to a drm_lock structure.
378  * \return zero on success or negative number on failure.
379  *
380  * Sets the requested interface version
381  */
382 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
383 {
384 	struct drm_set_version *sv = data;
385 	int if_version, retcode = 0;
386 
387 	mutex_lock(&dev->master_mutex);
388 	if (sv->drm_di_major != -1) {
389 		if (sv->drm_di_major != DRM_IF_MAJOR ||
390 		    sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
391 			retcode = -EINVAL;
392 			goto done;
393 		}
394 		if_version = DRM_IF_VERSION(sv->drm_di_major,
395 					    sv->drm_di_minor);
396 		dev->if_version = max(if_version, dev->if_version);
397 		if (sv->drm_di_minor >= 1) {
398 			/*
399 			 * Version 1.1 includes tying of DRM to specific device
400 			 * Version 1.4 has proper PCI domain support
401 			 */
402 			retcode = drm_set_busid(dev, file_priv);
403 			if (retcode)
404 				goto done;
405 		}
406 	}
407 
408 	if (sv->drm_dd_major != -1) {
409 		if (sv->drm_dd_major != dev->driver->major ||
410 		    sv->drm_dd_minor < 0 || sv->drm_dd_minor >
411 		    dev->driver->minor) {
412 			retcode = -EINVAL;
413 			goto done;
414 		}
415 	}
416 
417 done:
418 	sv->drm_di_major = DRM_IF_MAJOR;
419 	sv->drm_di_minor = DRM_IF_MINOR;
420 	sv->drm_dd_major = dev->driver->major;
421 	sv->drm_dd_minor = dev->driver->minor;
422 	mutex_unlock(&dev->master_mutex);
423 
424 	return retcode;
425 }
426 
427 /**
428  * drm_noop - DRM no-op ioctl implementation
429  * @dev: DRM device for the ioctl
430  * @data: data pointer for the ioctl
431  * @file_priv: DRM file for the ioctl call
432  *
433  * This no-op implementation for drm ioctls is useful for deprecated
434  * functionality where we can't return a failure code because existing userspace
435  * checks the result of the ioctl, but doesn't care about the action.
436  *
437  * Always returns successfully with 0.
438  */
439 int drm_noop(struct drm_device *dev, void *data,
440 	     struct drm_file *file_priv)
441 {
442 	drm_dbg_core(dev, "\n");
443 	return 0;
444 }
445 EXPORT_SYMBOL(drm_noop);
446 
447 /**
448  * drm_invalid_op - DRM invalid ioctl implementation
449  * @dev: DRM device for the ioctl
450  * @data: data pointer for the ioctl
451  * @file_priv: DRM file for the ioctl call
452  *
453  * This no-op implementation for drm ioctls is useful for deprecated
454  * functionality where we really don't want to allow userspace to call the ioctl
455  * any more. This is the case for old ums interfaces for drivers that
456  * transitioned to kms gradually and so kept the old legacy tables around. This
457  * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
458  * use this function.
459  *
460  * Always fails with a return value of -EINVAL.
461  */
462 int drm_invalid_op(struct drm_device *dev, void *data,
463 		   struct drm_file *file_priv)
464 {
465 	return -EINVAL;
466 }
467 EXPORT_SYMBOL(drm_invalid_op);
468 
469 /*
470  * Copy and IOCTL return string to user space
471  */
472 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
473 {
474 	size_t len;
475 
476 	/* don't attempt to copy a NULL pointer */
477 	if (WARN_ONCE(!value, "BUG: the value to copy was not set!")) {
478 		*buf_len = 0;
479 		return 0;
480 	}
481 
482 	/* don't overflow userbuf */
483 	len = strlen(value);
484 	if (len > *buf_len)
485 		len = *buf_len;
486 
487 	/* let userspace know exact length of driver value (which could be
488 	 * larger than the userspace-supplied buffer) */
489 	*buf_len = strlen(value);
490 
491 	/* finally, try filling in the userbuf */
492 	if (len && buf)
493 		if (copy_to_user(buf, value, len))
494 			return -EFAULT;
495 	return 0;
496 }
497 
498 /*
499  * Get version information
500  *
501  * \param inode device inode.
502  * \param filp file pointer.
503  * \param cmd command.
504  * \param arg user argument, pointing to a drm_version structure.
505  * \return zero on success or negative number on failure.
506  *
507  * Fills in the version information in \p arg.
508  */
509 int drm_version(struct drm_device *dev, void *data,
510 		       struct drm_file *file_priv)
511 {
512 	struct drm_version *version = data;
513 	int err;
514 
515 	version->version_major = dev->driver->major;
516 	version->version_minor = dev->driver->minor;
517 	version->version_patchlevel = dev->driver->patchlevel;
518 	err = drm_copy_field(version->name, &version->name_len,
519 			dev->driver->name);
520 	if (!err)
521 		err = drm_copy_field(version->date, &version->date_len,
522 				dev->driver->date);
523 	if (!err)
524 		err = drm_copy_field(version->desc, &version->desc_len,
525 				dev->driver->desc);
526 
527 	return err;
528 }
529 
530 static int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
531 {
532 	/* ROOT_ONLY is only for CAP_SYS_ADMIN */
533 	if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
534 		return -EACCES;
535 
536 	/* AUTH is only for authenticated or render client */
537 	if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
538 		     !file_priv->authenticated))
539 		return -EACCES;
540 
541 	/* MASTER is only for master or control clients */
542 	if (unlikely((flags & DRM_MASTER) &&
543 		     !drm_is_current_master(file_priv)))
544 		return -EACCES;
545 
546 	/* Render clients must be explicitly allowed */
547 	if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
548 		     drm_is_render_client(file_priv)))
549 		return -EACCES;
550 
551 	return 0;
552 }
553 
554 #define DRM_IOCTL_DEF(ioctl, _func, _flags)	\
555 	[DRM_IOCTL_NR(ioctl)] = {		\
556 		.cmd = ioctl,			\
557 		.func = _func,			\
558 		.flags = _flags,		\
559 		.name = #ioctl			\
560 	}
561 
562 #if IS_ENABLED(CONFIG_DRM_LEGACY)
563 #define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags)  DRM_IOCTL_DEF(ioctl, _func, _flags)
564 #else
565 #define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags) DRM_IOCTL_DEF(ioctl, drm_invalid_op, _flags)
566 #endif
567 
568 /* Ioctl table */
569 static const struct drm_ioctl_desc drm_ioctls[] = {
570 	DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_RENDER_ALLOW),
571 	DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
572 	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0),
573 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_legacy_irq_by_busid,
574 			     DRM_MASTER|DRM_ROOT_ONLY),
575 
576 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, 0),
577 
578 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, 0),
579 	DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0),
580 	DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_RENDER_ALLOW),
581 	DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
582 	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
583 
584 	DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
585 	DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
586 	DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
587 	DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_MASTER),
588 
589 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
590 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),
591 
592 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
593 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),
594 
595 	DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, 0),
596 	DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, 0),
597 
598 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
599 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
600 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
601 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
602 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
603 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
604 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),
605 
606 	DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
607 	DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
608 
609 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH),
610 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH),
611 
612 	DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
613 
614 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
615 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
616 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH),
617 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH),
618 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH),
619 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH),
620 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_legacy_irq_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
621 
622 #if IS_ENABLED(CONFIG_AGP)
623 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_legacy_agp_acquire_ioctl,
624 			     DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
625 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_legacy_agp_release_ioctl,
626 			     DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
627 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_legacy_agp_enable_ioctl,
628 			     DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
629 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_legacy_agp_info_ioctl, DRM_AUTH),
630 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_legacy_agp_alloc_ioctl,
631 			     DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
632 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_legacy_agp_free_ioctl,
633 			     DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
634 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_legacy_agp_bind_ioctl,
635 			     DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
636 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_legacy_agp_unbind_ioctl,
637 			     DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
638 #endif
639 
640 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
641 	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
642 
643 	DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, DRM_UNLOCKED),
644 
645 	DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_legacy_modeset_ctl_ioctl, 0),
646 
647 	DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
648 
649 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_RENDER_ALLOW),
650 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH),
651 	DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH),
652 
653 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, 0),
654 
655 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_RENDER_ALLOW),
656 	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_RENDER_ALLOW),
657 
658 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, 0),
659 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, 0),
660 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER),
661 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, 0),
662 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER),
663 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER),
664 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, 0),
665 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER),
666 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, 0),
667 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, 0),
668 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER),
669 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER),
670 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, 0),
671 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_connector_property_set_ioctl, DRM_MASTER),
672 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, 0),
673 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, 0),
674 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB2, drm_mode_getfb2_ioctl, 0),
675 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb_ioctl, 0),
676 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2_ioctl, 0),
677 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb_ioctl, 0),
678 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER),
679 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER),
680 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, 0),
681 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, 0),
682 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, 0),
683 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, 0),
684 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER),
685 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER),
686 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER),
687 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, 0),
688 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, 0),
689 
690 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_CREATE, drm_syncobj_create_ioctl,
691 		      DRM_RENDER_ALLOW),
692 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_DESTROY, drm_syncobj_destroy_ioctl,
693 		      DRM_RENDER_ALLOW),
694 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, drm_syncobj_handle_to_fd_ioctl,
695 		      DRM_RENDER_ALLOW),
696 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, drm_syncobj_fd_to_handle_ioctl,
697 		      DRM_RENDER_ALLOW),
698 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TRANSFER, drm_syncobj_transfer_ioctl,
699 		      DRM_RENDER_ALLOW),
700 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl,
701 		      DRM_RENDER_ALLOW),
702 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT, drm_syncobj_timeline_wait_ioctl,
703 		      DRM_RENDER_ALLOW),
704 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_EVENTFD, drm_syncobj_eventfd_ioctl,
705 		      DRM_RENDER_ALLOW),
706 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl,
707 		      DRM_RENDER_ALLOW),
708 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl,
709 		      DRM_RENDER_ALLOW),
710 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL, drm_syncobj_timeline_signal_ioctl,
711 		      DRM_RENDER_ALLOW),
712 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_QUERY, drm_syncobj_query_ioctl,
713 		      DRM_RENDER_ALLOW),
714 	DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, 0),
715 	DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, 0),
716 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER),
717 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER),
718 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER),
719 	DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER),
720 };
721 
722 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE(drm_ioctls)
723 
724 /**
725  * DOC: driver specific ioctls
726  *
727  * First things first, driver private IOCTLs should only be needed for drivers
728  * supporting rendering. Kernel modesetting is all standardized, and extended
729  * through properties. There are a few exceptions in some existing drivers,
730  * which define IOCTL for use by the display DRM master, but they all predate
731  * properties.
732  *
733  * Now if you do have a render driver you always have to support it through
734  * driver private properties. There's a few steps needed to wire all the things
735  * up.
736  *
737  * First you need to define the structure for your IOCTL in your driver private
738  * UAPI header in ``include/uapi/drm/my_driver_drm.h``::
739  *
740  *     struct my_driver_operation {
741  *             u32 some_thing;
742  *             u32 another_thing;
743  *     };
744  *
745  * Please make sure that you follow all the best practices from
746  * ``Documentation/process/botching-up-ioctls.rst``. Note that drm_ioctl()
747  * automatically zero-extends structures, hence make sure you can add more stuff
748  * at the end, i.e. don't put a variable sized array there.
749  *
750  * Then you need to define your IOCTL number, using one of DRM_IO(), DRM_IOR(),
751  * DRM_IOW() or DRM_IOWR(). It must start with the DRM_IOCTL\_ prefix::
752  *
753  *     ##define DRM_IOCTL_MY_DRIVER_OPERATION \
754  *         DRM_IOW(DRM_COMMAND_BASE, struct my_driver_operation)
755  *
756  * DRM driver private IOCTL must be in the range from DRM_COMMAND_BASE to
757  * DRM_COMMAND_END. Finally you need an array of &struct drm_ioctl_desc to wire
758  * up the handlers and set the access rights::
759  *
760  *     static const struct drm_ioctl_desc my_driver_ioctls[] = {
761  *         DRM_IOCTL_DEF_DRV(MY_DRIVER_OPERATION, my_driver_operation,
762  *                 DRM_AUTH|DRM_RENDER_ALLOW),
763  *     };
764  *
765  * And then assign this to the &drm_driver.ioctls field in your driver
766  * structure.
767  *
768  * See the separate chapter on :ref:`file operations<drm_driver_fops>` for how
769  * the driver-specific IOCTLs are wired up.
770  */
771 
772 long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
773 		      u32 flags)
774 {
775 	struct drm_file *file_priv = file->private_data;
776 	struct drm_device *dev = file_priv->minor->dev;
777 	int retcode;
778 
779 	/* Update drm_file owner if fd was passed along. */
780 	drm_file_update_pid(file_priv);
781 
782 	if (drm_dev_is_unplugged(dev))
783 		return -ENODEV;
784 
785 	retcode = drm_ioctl_permit(flags, file_priv);
786 	if (unlikely(retcode))
787 		return retcode;
788 
789 	/* Enforce sane locking for modern driver ioctls. */
790 	if (likely(!drm_core_check_feature(dev, DRIVER_LEGACY)) ||
791 	    (flags & DRM_UNLOCKED))
792 		retcode = func(dev, kdata, file_priv);
793 	else {
794 		mutex_lock(&drm_global_mutex);
795 		retcode = func(dev, kdata, file_priv);
796 		mutex_unlock(&drm_global_mutex);
797 	}
798 	return retcode;
799 }
800 EXPORT_SYMBOL(drm_ioctl_kernel);
801 
802 /**
803  * drm_ioctl - ioctl callback implementation for DRM drivers
804  * @filp: file this ioctl is called on
805  * @cmd: ioctl cmd number
806  * @arg: user argument
807  *
808  * Looks up the ioctl function in the DRM core and the driver dispatch table,
809  * stored in &drm_driver.ioctls. It checks for necessary permission by calling
810  * drm_ioctl_permit(), and dispatches to the respective function.
811  *
812  * Returns:
813  * Zero on success, negative error code on failure.
814  */
815 long drm_ioctl(struct file *filp,
816 	      unsigned int cmd, unsigned long arg)
817 {
818 	struct drm_file *file_priv = filp->private_data;
819 	struct drm_device *dev;
820 	const struct drm_ioctl_desc *ioctl = NULL;
821 	drm_ioctl_t *func;
822 	unsigned int nr = DRM_IOCTL_NR(cmd);
823 	int retcode = -EINVAL;
824 	char stack_kdata[128];
825 	char *kdata = NULL;
826 	unsigned int in_size, out_size, drv_size, ksize;
827 	bool is_driver_ioctl;
828 
829 	dev = file_priv->minor->dev;
830 
831 	if (drm_dev_is_unplugged(dev))
832 		return -ENODEV;
833 
834 	if (DRM_IOCTL_TYPE(cmd) != DRM_IOCTL_BASE)
835 		return -ENOTTY;
836 
837 	is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
838 
839 	if (is_driver_ioctl) {
840 		/* driver ioctl */
841 		unsigned int index = nr - DRM_COMMAND_BASE;
842 
843 		if (index >= dev->driver->num_ioctls)
844 			goto err_i1;
845 		index = array_index_nospec(index, dev->driver->num_ioctls);
846 		ioctl = &dev->driver->ioctls[index];
847 	} else {
848 		/* core ioctl */
849 		if (nr >= DRM_CORE_IOCTL_COUNT)
850 			goto err_i1;
851 		nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
852 		ioctl = &drm_ioctls[nr];
853 	}
854 
855 	drv_size = _IOC_SIZE(ioctl->cmd);
856 	out_size = in_size = _IOC_SIZE(cmd);
857 	if ((cmd & ioctl->cmd & IOC_IN) == 0)
858 		in_size = 0;
859 	if ((cmd & ioctl->cmd & IOC_OUT) == 0)
860 		out_size = 0;
861 	ksize = max(max(in_size, out_size), drv_size);
862 
863 	drm_dbg_core(dev, "comm=\"%s\" pid=%d, dev=0x%lx, auth=%d, %s\n",
864 		     current->comm, task_pid_nr(current),
865 		     (long)old_encode_dev(file_priv->minor->kdev->devt),
866 		     file_priv->authenticated, ioctl->name);
867 
868 	/* Do not trust userspace, use our own definition */
869 	func = ioctl->func;
870 
871 	if (unlikely(!func)) {
872 		drm_dbg_core(dev, "no function\n");
873 		retcode = -EINVAL;
874 		goto err_i1;
875 	}
876 
877 	if (ksize <= sizeof(stack_kdata)) {
878 		kdata = stack_kdata;
879 	} else {
880 		kdata = kmalloc(ksize, GFP_KERNEL);
881 		if (!kdata) {
882 			retcode = -ENOMEM;
883 			goto err_i1;
884 		}
885 	}
886 
887 	if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) {
888 		retcode = -EFAULT;
889 		goto err_i1;
890 	}
891 
892 	if (ksize > in_size)
893 		memset(kdata + in_size, 0, ksize - in_size);
894 
895 	retcode = drm_ioctl_kernel(filp, func, kdata, ioctl->flags);
896 	if (copy_to_user((void __user *)arg, kdata, out_size) != 0)
897 		retcode = -EFAULT;
898 
899       err_i1:
900 	if (!ioctl)
901 		drm_dbg_core(dev,
902 			     "invalid ioctl: comm=\"%s\", pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
903 			     current->comm, task_pid_nr(current),
904 			     (long)old_encode_dev(file_priv->minor->kdev->devt),
905 			     file_priv->authenticated, cmd, nr);
906 
907 	if (kdata != stack_kdata)
908 		kfree(kdata);
909 	if (retcode)
910 		drm_dbg_core(dev, "comm=\"%s\", pid=%d, ret=%d\n",
911 			     current->comm, task_pid_nr(current), retcode);
912 	return retcode;
913 }
914 EXPORT_SYMBOL(drm_ioctl);
915 
916 /**
917  * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
918  * @nr: ioctl number
919  * @flags: where to return the ioctl permission flags
920  *
921  * This ioctl is only used by the vmwgfx driver to augment the access checks
922  * done by the drm core and insofar a pretty decent layering violation. This
923  * shouldn't be used by any drivers.
924  *
925  * Returns:
926  * True if the @nr corresponds to a DRM core ioctl number, false otherwise.
927  */
928 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
929 {
930 	if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
931 		return false;
932 
933 	if (nr >= DRM_CORE_IOCTL_COUNT)
934 		return false;
935 	nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
936 
937 	*flags = drm_ioctls[nr].flags;
938 	return true;
939 }
940 EXPORT_SYMBOL(drm_ioctl_flags);
941