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_agpsupport.h>
 37#include <drm/drm_auth.h>
 38#include <drm/drm_crtc.h>
 39#include <drm/drm_drv.h>
 40#include <drm/drm_file.h>
 41#include <drm/drm_ioctl.h>
 42#include <drm/drm_print.h>
 43
 44#include "drm_crtc_internal.h"
 45#include "drm_internal.h"
 46#include "drm_legacy.h"
 47
 48/**
 49 * DOC: getunique and setversion story
 50 *
 51 * BEWARE THE DRAGONS! MIND THE TRAPDOORS!
 52 *
 53 * In an attempt to warn anyone else who's trying to figure out what's going
 54 * on here, I'll try to summarize the story. First things first, let's clear up
 55 * the names, because the kernel internals, libdrm and the ioctls are all named
 56 * differently:
 57 *
 58 *  - GET_UNIQUE ioctl, implemented by drm_getunique is wrapped up in libdrm
 59 *    through the drmGetBusid function.
 60 *  - The libdrm drmSetBusid function is backed by the SET_UNIQUE ioctl. All
 61 *    that code is nerved in the kernel with drm_invalid_op().
 62 *  - The internal set_busid kernel functions and driver callbacks are
 63 *    exclusively use by the SET_VERSION ioctl, because only drm 1.0 (which is
 64 *    nerved) allowed userspace to set the busid through the above ioctl.
 65 *  - Other ioctls and functions involved are named consistently.
 66 *
 67 * For anyone wondering what's the difference between drm 1.1 and 1.4: Correctly
 68 * handling pci domains in the busid on ppc. Doing this correctly was only
 69 * implemented in libdrm in 2010, hence can't be nerved yet. No one knows what's
 70 * special with drm 1.2 and 1.3.
 71 *
 72 * Now the actual horror story of how device lookup in drm works. At large,
 73 * there's 2 different ways, either by busid, or by device driver name.
 74 *
 75 * Opening by busid is fairly simple:
 76 *
 77 * 1. First call SET_VERSION to make sure pci domains are handled properly. As a
 78 *    side-effect this fills out the unique name in the master structure.
 79 * 2. Call GET_UNIQUE to read out the unique name from the master structure,
 80 *    which matches the busid thanks to step 1. If it doesn't, proceed to try
 81 *    the next device node.
 82 *
 83 * Opening by name is slightly different:
 84 *
 85 * 1. Directly call VERSION to get the version and to match against the driver
 86 *    name returned by that ioctl. Note that SET_VERSION is not called, which
 87 *    means the the unique name for the master node just opening is _not_ filled
 88 *    out. This despite that with current drm device nodes are always bound to
 89 *    one device, and can't be runtime assigned like with drm 1.0.
 90 * 2. Match driver name. If it mismatches, proceed to the next device node.
 91 * 3. Call GET_UNIQUE, and check whether the unique name has length zero (by
 92 *    checking that the first byte in the string is 0). If that's not the case
 93 *    libdrm skips and proceeds to the next device node. Probably this is just
 94 *    copypasta from drm 1.0 times where a set unique name meant that the driver
 95 *    was in use already, but that's just conjecture.
 96 *
 97 * Long story short: To keep the open by name logic working, GET_UNIQUE must
 98 * _not_ return a unique string when SET_VERSION hasn't been called yet,
 99 * otherwise libdrm breaks. Even when that unique string can't ever change, and
100 * is totally irrelevant for actually opening the device because runtime
101 * assignable device instances were only support in drm 1.0, which is long dead.
102 * But the libdrm code in drmOpenByName somehow survived, hence this can't be
103 * broken.
104 */
105
106/*
107 * Get the bus id.
108 *
109 * \param inode device inode.
110 * \param file_priv DRM file private.
111 * \param cmd command.
112 * \param arg user argument, pointing to a drm_unique structure.
113 * \return zero on success or a negative number on failure.
114 *
115 * Copies the bus id from drm_device::unique into user space.
116 */
117int drm_getunique(struct drm_device *dev, void *data,
118		  struct drm_file *file_priv)
119{
120	struct drm_unique *u = data;
121	struct drm_master *master = file_priv->master;
122
123	mutex_lock(&master->dev->master_mutex);
124	if (u->unique_len >= master->unique_len) {
125		if (copy_to_user(u->unique, master->unique, master->unique_len)) {
126			mutex_unlock(&master->dev->master_mutex);
127			return -EFAULT;
128		}
129	}
130	u->unique_len = master->unique_len;
131	mutex_unlock(&master->dev->master_mutex);
132
133	return 0;
134}
135
136static void
137drm_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
145static 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 */
182int 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 */
221static 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 */
235static 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 |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0;
249		req->value |= dev->driver->prime_handle_to_fd ? DRM_PRIME_CAP_EXPORT : 0;
250		return 0;
251	case DRM_CAP_SYNCOBJ:
252		req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ);
253		return 0;
254	case DRM_CAP_SYNCOBJ_TIMELINE:
255		req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE);
256		return 0;
257	}
258
259	/* Other caps only work with KMS drivers */
260	if (!drm_core_check_feature(dev, DRIVER_MODESET))
261		return -EOPNOTSUPP;
262
263	switch (req->capability) {
264	case DRM_CAP_DUMB_BUFFER:
265		if (dev->driver->dumb_create)
266			req->value = 1;
267		break;
268	case DRM_CAP_VBLANK_HIGH_CRTC:
269		req->value = 1;
270		break;
271	case DRM_CAP_DUMB_PREFERRED_DEPTH:
272		req->value = dev->mode_config.preferred_depth;
273		break;
274	case DRM_CAP_DUMB_PREFER_SHADOW:
275		req->value = dev->mode_config.prefer_shadow;
276		break;
 
 
 
 
 
 
 
277	case DRM_CAP_ASYNC_PAGE_FLIP:
278		req->value = dev->mode_config.async_page_flip;
279		break;
280	case DRM_CAP_PAGE_FLIP_TARGET:
281		req->value = 1;
282		drm_for_each_crtc(crtc, dev) {
283			if (!crtc->funcs->page_flip_target)
284				req->value = 0;
285		}
286		break;
287	case DRM_CAP_CURSOR_WIDTH:
288		if (dev->mode_config.cursor_width)
289			req->value = dev->mode_config.cursor_width;
290		else
291			req->value = 64;
292		break;
293	case DRM_CAP_CURSOR_HEIGHT:
294		if (dev->mode_config.cursor_height)
295			req->value = dev->mode_config.cursor_height;
296		else
297			req->value = 64;
298		break;
299	case DRM_CAP_ADDFB2_MODIFIERS:
300		req->value = dev->mode_config.allow_fb_modifiers;
301		break;
302	case DRM_CAP_CRTC_IN_VBLANK_EVENT:
303		req->value = 1;
304		break;
305	default:
306		return -EINVAL;
307	}
308	return 0;
309}
310
311/*
312 * Set device/driver capabilities
313 */
314static int
315drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
316{
317	struct drm_set_client_cap *req = data;
318
319	/* No render-only settable capabilities for now */
320
321	/* Below caps that only works with KMS drivers */
322	if (!drm_core_check_feature(dev, DRIVER_MODESET))
323		return -EOPNOTSUPP;
324
325	switch (req->capability) {
326	case DRM_CLIENT_CAP_STEREO_3D:
327		if (req->value > 1)
328			return -EINVAL;
329		file_priv->stereo_allowed = req->value;
330		break;
331	case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
332		if (req->value > 1)
333			return -EINVAL;
334		file_priv->universal_planes = req->value;
335		break;
336	case DRM_CLIENT_CAP_ATOMIC:
337		if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
338			return -EOPNOTSUPP;
339		/* The modesetting DDX has a totally broken idea of atomic. */
340		if (current->comm[0] == 'X' && req->value == 1) {
341			pr_info("broken atomic modeset userspace detected, disabling atomic\n");
342			return -EOPNOTSUPP;
343		}
344		if (req->value > 2)
345			return -EINVAL;
346		file_priv->atomic = req->value;
347		file_priv->universal_planes = req->value;
348		/*
349		 * No atomic user-space blows up on aspect ratio mode bits.
350		 */
351		file_priv->aspect_ratio_allowed = req->value;
352		break;
353	case DRM_CLIENT_CAP_ASPECT_RATIO:
354		if (req->value > 1)
355			return -EINVAL;
356		file_priv->aspect_ratio_allowed = req->value;
357		break;
358	case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS:
359		if (!file_priv->atomic)
360			return -EINVAL;
361		if (req->value > 1)
362			return -EINVAL;
363		file_priv->writeback_connectors = req->value;
364		break;
365	default:
366		return -EINVAL;
367	}
368
369	return 0;
370}
371
372/*
373 * Setversion ioctl.
374 *
375 * \param inode device inode.
376 * \param file_priv DRM file private.
377 * \param cmd command.
378 * \param arg user argument, pointing to a drm_lock structure.
379 * \return zero on success or negative number on failure.
380 *
381 * Sets the requested interface version
382 */
383static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
384{
385	struct drm_set_version *sv = data;
386	int if_version, retcode = 0;
387
388	mutex_lock(&dev->master_mutex);
389	if (sv->drm_di_major != -1) {
390		if (sv->drm_di_major != DRM_IF_MAJOR ||
391		    sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
392			retcode = -EINVAL;
393			goto done;
394		}
395		if_version = DRM_IF_VERSION(sv->drm_di_major,
396					    sv->drm_di_minor);
397		dev->if_version = max(if_version, dev->if_version);
398		if (sv->drm_di_minor >= 1) {
399			/*
400			 * Version 1.1 includes tying of DRM to specific device
401			 * Version 1.4 has proper PCI domain support
402			 */
403			retcode = drm_set_busid(dev, file_priv);
404			if (retcode)
405				goto done;
406		}
407	}
408
409	if (sv->drm_dd_major != -1) {
410		if (sv->drm_dd_major != dev->driver->major ||
411		    sv->drm_dd_minor < 0 || sv->drm_dd_minor >
412		    dev->driver->minor) {
413			retcode = -EINVAL;
414			goto done;
415		}
416	}
417
418done:
419	sv->drm_di_major = DRM_IF_MAJOR;
420	sv->drm_di_minor = DRM_IF_MINOR;
421	sv->drm_dd_major = dev->driver->major;
422	sv->drm_dd_minor = dev->driver->minor;
423	mutex_unlock(&dev->master_mutex);
424
425	return retcode;
426}
427
428/**
429 * drm_noop - DRM no-op ioctl implemntation
430 * @dev: DRM device for the ioctl
431 * @data: data pointer for the ioctl
432 * @file_priv: DRM file for the ioctl call
433 *
434 * This no-op implementation for drm ioctls is useful for deprecated
435 * functionality where we can't return a failure code because existing userspace
436 * checks the result of the ioctl, but doesn't care about the action.
437 *
438 * Always returns successfully with 0.
439 */
440int drm_noop(struct drm_device *dev, void *data,
441	     struct drm_file *file_priv)
442{
443	DRM_DEBUG("\n");
444	return 0;
445}
446EXPORT_SYMBOL(drm_noop);
447
448/**
449 * drm_invalid_op - DRM invalid ioctl implemntation
450 * @dev: DRM device for the ioctl
451 * @data: data pointer for the ioctl
452 * @file_priv: DRM file for the ioctl call
453 *
454 * This no-op implementation for drm ioctls is useful for deprecated
455 * functionality where we really don't want to allow userspace to call the ioctl
456 * any more. This is the case for old ums interfaces for drivers that
457 * transitioned to kms gradually and so kept the old legacy tables around. This
458 * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
459 * use this function.
460 *
461 * Always fails with a return value of -EINVAL.
462 */
463int drm_invalid_op(struct drm_device *dev, void *data,
464		   struct drm_file *file_priv)
465{
466	return -EINVAL;
467}
468EXPORT_SYMBOL(drm_invalid_op);
469
470/*
471 * Copy and IOCTL return string to user space
472 */
473static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
474{
475	int len;
476
477	/* don't overflow userbuf */
478	len = strlen(value);
479	if (len > *buf_len)
480		len = *buf_len;
481
482	/* let userspace know exact length of driver value (which could be
483	 * larger than the userspace-supplied buffer) */
484	*buf_len = strlen(value);
485
486	/* finally, try filling in the userbuf */
487	if (len && buf)
488		if (copy_to_user(buf, value, len))
489			return -EFAULT;
490	return 0;
491}
492
493/*
494 * Get version information
495 *
496 * \param inode device inode.
497 * \param filp file pointer.
498 * \param cmd command.
499 * \param arg user argument, pointing to a drm_version structure.
500 * \return zero on success or negative number on failure.
501 *
502 * Fills in the version information in \p arg.
503 */
504int drm_version(struct drm_device *dev, void *data,
505		       struct drm_file *file_priv)
506{
507	struct drm_version *version = data;
508	int err;
509
510	version->version_major = dev->driver->major;
511	version->version_minor = dev->driver->minor;
512	version->version_patchlevel = dev->driver->patchlevel;
513	err = drm_copy_field(version->name, &version->name_len,
514			dev->driver->name);
515	if (!err)
516		err = drm_copy_field(version->date, &version->date_len,
517				dev->driver->date);
518	if (!err)
519		err = drm_copy_field(version->desc, &version->desc_len,
520				dev->driver->desc);
521
522	return err;
523}
524
525/**
526 * drm_ioctl_permit - Check ioctl permissions against caller
527 *
528 * @flags: ioctl permission flags.
529 * @file_priv: Pointer to struct drm_file identifying the caller.
530 *
531 * Checks whether the caller is allowed to run an ioctl with the
532 * indicated permissions.
533 *
534 * Returns:
535 * Zero if allowed, -EACCES otherwise.
536 */
537int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
538{
539	/* ROOT_ONLY is only for CAP_SYS_ADMIN */
540	if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
541		return -EACCES;
542
543	/* AUTH is only for authenticated or render client */
544	if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
545		     !file_priv->authenticated))
546		return -EACCES;
547
548	/* MASTER is only for master or control clients */
549	if (unlikely((flags & DRM_MASTER) &&
550		     !drm_is_current_master(file_priv)))
551		return -EACCES;
552
553	/* Render clients must be explicitly allowed */
554	if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
555		     drm_is_render_client(file_priv)))
556		return -EACCES;
557
558	return 0;
559}
560EXPORT_SYMBOL(drm_ioctl_permit);
561
562#define DRM_IOCTL_DEF(ioctl, _func, _flags)	\
563	[DRM_IOCTL_NR(ioctl)] = {		\
564		.cmd = ioctl,			\
565		.func = _func,			\
566		.flags = _flags,		\
567		.name = #ioctl			\
568	}
569
570#if IS_ENABLED(CONFIG_DRM_LEGACY)
571#define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags)  DRM_IOCTL_DEF(ioctl, _func, _flags)
572#else
573#define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags) DRM_IOCTL_DEF(ioctl, drm_invalid_op, _flags)
574#endif
575
576/* Ioctl table */
577static const struct drm_ioctl_desc drm_ioctls[] = {
578	DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_RENDER_ALLOW),
579	DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
580	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0),
581	DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
582
583	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, 0),
584
585	DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, 0),
586	DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0),
587	DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_RENDER_ALLOW),
588	DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
589	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
590
591	DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
592	DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
593	DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
594	DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_MASTER),
595
596	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
597	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),
598
599	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
600	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),
601
602	DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, 0),
603	DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, 0),
604
605	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
606	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
607	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
608	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
609	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
610	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
611	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),
612
613	DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
614	DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
615
616	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH),
617	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH),
618
619	DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
620
621	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
622	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
623	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH),
624	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH),
625	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH),
626	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH),
627	DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_legacy_irq_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
628
629#if IS_ENABLED(CONFIG_AGP)
630	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
631	DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
632	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
633	DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
634	DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
635	DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
636	DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
637	DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, 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_RESET, drm_syncobj_reset_ioctl,
705		      DRM_RENDER_ALLOW),
706	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl,
707		      DRM_RENDER_ALLOW),
708	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL, drm_syncobj_timeline_signal_ioctl,
709		      DRM_RENDER_ALLOW),
710	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_QUERY, drm_syncobj_query_ioctl,
711		      DRM_RENDER_ALLOW),
712	DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, 0),
713	DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, 0),
714	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER),
715	DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER),
716	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER),
717	DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER),
718};
719
720#define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
721
722/**
723 * DOC: driver specific ioctls
724 *
725 * First things first, driver private IOCTLs should only be needed for drivers
726 * supporting rendering. Kernel modesetting is all standardized, and extended
727 * through properties. There are a few exceptions in some existing drivers,
728 * which define IOCTL for use by the display DRM master, but they all predate
729 * properties.
730 *
731 * Now if you do have a render driver you always have to support it through
732 * driver private properties. There's a few steps needed to wire all the things
733 * up.
734 *
735 * First you need to define the structure for your IOCTL in your driver private
736 * UAPI header in ``include/uapi/drm/my_driver_drm.h``::
737 *
738 *     struct my_driver_operation {
739 *             u32 some_thing;
740 *             u32 another_thing;
741 *     };
742 *
743 * Please make sure that you follow all the best practices from
744 * ``Documentation/process/botching-up-ioctls.rst``. Note that drm_ioctl()
745 * automatically zero-extends structures, hence make sure you can add more stuff
746 * at the end, i.e. don't put a variable sized array there.
747 *
748 * Then you need to define your IOCTL number, using one of DRM_IO(), DRM_IOR(),
749 * DRM_IOW() or DRM_IOWR(). It must start with the DRM_IOCTL\_ prefix::
750 *
751 *     ##define DRM_IOCTL_MY_DRIVER_OPERATION \
752 *         DRM_IOW(DRM_COMMAND_BASE, struct my_driver_operation)
753 *
754 * DRM driver private IOCTL must be in the range from DRM_COMMAND_BASE to
755 * DRM_COMMAND_END. Finally you need an array of &struct drm_ioctl_desc to wire
756 * up the handlers and set the access rights::
757 *
758 *     static const struct drm_ioctl_desc my_driver_ioctls[] = {
759 *         DRM_IOCTL_DEF_DRV(MY_DRIVER_OPERATION, my_driver_operation,
760 *                 DRM_AUTH|DRM_RENDER_ALLOW),
761 *     };
762 *
763 * And then assign this to the &drm_driver.ioctls field in your driver
764 * structure.
765 *
766 * See the separate chapter on :ref:`file operations<drm_driver_fops>` for how
767 * the driver-specific IOCTLs are wired up.
768 */
769
770long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
771		      u32 flags)
772{
773	struct drm_file *file_priv = file->private_data;
774	struct drm_device *dev = file_priv->minor->dev;
775	int retcode;
776
777	if (drm_dev_is_unplugged(dev))
778		return -ENODEV;
779
780	retcode = drm_ioctl_permit(flags, file_priv);
781	if (unlikely(retcode))
782		return retcode;
783
784	/* Enforce sane locking for modern driver ioctls. */
785	if (likely(!drm_core_check_feature(dev, DRIVER_LEGACY)) ||
786	    (flags & DRM_UNLOCKED))
787		retcode = func(dev, kdata, file_priv);
788	else {
789		mutex_lock(&drm_global_mutex);
790		retcode = func(dev, kdata, file_priv);
791		mutex_unlock(&drm_global_mutex);
792	}
793	return retcode;
794}
795EXPORT_SYMBOL(drm_ioctl_kernel);
796
797/**
798 * drm_ioctl - ioctl callback implementation for DRM drivers
799 * @filp: file this ioctl is called on
800 * @cmd: ioctl cmd number
801 * @arg: user argument
802 *
803 * Looks up the ioctl function in the DRM core and the driver dispatch table,
804 * stored in &drm_driver.ioctls. It checks for necessary permission by calling
805 * drm_ioctl_permit(), and dispatches to the respective function.
806 *
807 * Returns:
808 * Zero on success, negative error code on failure.
809 */
810long drm_ioctl(struct file *filp,
811	      unsigned int cmd, unsigned long arg)
812{
813	struct drm_file *file_priv = filp->private_data;
814	struct drm_device *dev;
815	const struct drm_ioctl_desc *ioctl = NULL;
816	drm_ioctl_t *func;
817	unsigned int nr = DRM_IOCTL_NR(cmd);
818	int retcode = -EINVAL;
819	char stack_kdata[128];
820	char *kdata = NULL;
821	unsigned int in_size, out_size, drv_size, ksize;
822	bool is_driver_ioctl;
823
824	dev = file_priv->minor->dev;
825
826	if (drm_dev_is_unplugged(dev))
827		return -ENODEV;
828
829	is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
830
831	if (is_driver_ioctl) {
832		/* driver ioctl */
833		unsigned int index = nr - DRM_COMMAND_BASE;
834
835		if (index >= dev->driver->num_ioctls)
836			goto err_i1;
837		index = array_index_nospec(index, dev->driver->num_ioctls);
838		ioctl = &dev->driver->ioctls[index];
839	} else {
840		/* core ioctl */
841		if (nr >= DRM_CORE_IOCTL_COUNT)
842			goto err_i1;
843		nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
844		ioctl = &drm_ioctls[nr];
845	}
846
847	drv_size = _IOC_SIZE(ioctl->cmd);
848	out_size = in_size = _IOC_SIZE(cmd);
849	if ((cmd & ioctl->cmd & IOC_IN) == 0)
850		in_size = 0;
851	if ((cmd & ioctl->cmd & IOC_OUT) == 0)
852		out_size = 0;
853	ksize = max(max(in_size, out_size), drv_size);
854
855	DRM_DEBUG("comm=\"%s\" pid=%d, dev=0x%lx, auth=%d, %s\n",
856		  current->comm, task_pid_nr(current),
857		  (long)old_encode_dev(file_priv->minor->kdev->devt),
858		  file_priv->authenticated, ioctl->name);
859
860	/* Do not trust userspace, use our own definition */
861	func = ioctl->func;
862
863	if (unlikely(!func)) {
864		DRM_DEBUG("no function\n");
865		retcode = -EINVAL;
866		goto err_i1;
867	}
868
869	if (ksize <= sizeof(stack_kdata)) {
870		kdata = stack_kdata;
871	} else {
872		kdata = kmalloc(ksize, GFP_KERNEL);
873		if (!kdata) {
874			retcode = -ENOMEM;
875			goto err_i1;
876		}
877	}
878
879	if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) {
880		retcode = -EFAULT;
881		goto err_i1;
882	}
883
884	if (ksize > in_size)
885		memset(kdata + in_size, 0, ksize - in_size);
886
887	retcode = drm_ioctl_kernel(filp, func, kdata, ioctl->flags);
888	if (copy_to_user((void __user *)arg, kdata, out_size) != 0)
889		retcode = -EFAULT;
890
891      err_i1:
892	if (!ioctl)
893		DRM_DEBUG("invalid ioctl: comm=\"%s\", pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
894			  current->comm, task_pid_nr(current),
895			  (long)old_encode_dev(file_priv->minor->kdev->devt),
896			  file_priv->authenticated, cmd, nr);
897
898	if (kdata != stack_kdata)
899		kfree(kdata);
900	if (retcode)
901		DRM_DEBUG("comm=\"%s\", pid=%d, ret=%d\n", current->comm,
902			  task_pid_nr(current), retcode);
903	return retcode;
904}
905EXPORT_SYMBOL(drm_ioctl);
906
907/**
908 * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
909 * @nr: ioctl number
910 * @flags: where to return the ioctl permission flags
911 *
912 * This ioctl is only used by the vmwgfx driver to augment the access checks
913 * done by the drm core and insofar a pretty decent layering violation. This
914 * shouldn't be used by any drivers.
915 *
916 * Returns:
917 * True if the @nr corresponds to a DRM core ioctl number, false otherwise.
918 */
919bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
920{
921	if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
922		return false;
923
924	if (nr >= DRM_CORE_IOCTL_COUNT)
925		return false;
926	nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
927
928	*flags = drm_ioctls[nr].flags;
929	return true;
930}
931EXPORT_SYMBOL(drm_ioctl_flags);