drm_ioctl.c

  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
 46/**
 47 * DOC: getunique and setversion story
 48 *
 49 * BEWARE THE DRAGONS! MIND THE TRAPDOORS!
 50 *
 51 * In an attempt to warn anyone else who's trying to figure out what's going
 52 * on here, I'll try to summarize the story. First things first, let's clear up
 53 * the names, because the kernel internals, libdrm and the ioctls are all named
 54 * differently:
 55 *
 56 *  - GET_UNIQUE ioctl, implemented by drm_getunique is wrapped up in libdrm
 57 *    through the drmGetBusid function.
 58 *  - The libdrm drmSetBusid function is backed by the SET_UNIQUE ioctl. All
 59 *    that code is nerved in the kernel with drm_invalid_op().
 60 *  - The internal set_busid kernel functions and driver callbacks are
 61 *    exclusively use by the SET_VERSION ioctl, because only drm 1.0 (which is
 62 *    nerved) allowed userspace to set the busid through the above ioctl.
 63 *  - Other ioctls and functions involved are named consistently.
 64 *
 65 * For anyone wondering what's the difference between drm 1.1 and 1.4: Correctly
 66 * handling pci domains in the busid on ppc. Doing this correctly was only
 67 * implemented in libdrm in 2010, hence can't be nerved yet. No one knows what's
 68 * special with drm 1.2 and 1.3.
 69 *
 70 * Now the actual horror story of how device lookup in drm works. At large,
 71 * there's 2 different ways, either by busid, or by device driver name.
 72 *
 73 * Opening by busid is fairly simple:
 74 *
 75 * 1. First call SET_VERSION to make sure pci domains are handled properly. As a
 76 *    side-effect this fills out the unique name in the master structure.
 77 * 2. Call GET_UNIQUE to read out the unique name from the master structure,
 78 *    which matches the busid thanks to step 1. If it doesn't, proceed to try
 79 *    the next device node.
 80 *
 81 * Opening by name is slightly different:
 82 *
 83 * 1. Directly call VERSION to get the version and to match against the driver
 84 *    name returned by that ioctl. Note that SET_VERSION is not called, which
 85 *    means the unique name for the master node just opening is _not_ filled
 86 *    out. This despite that with current drm device nodes are always bound to
 87 *    one device, and can't be runtime assigned like with drm 1.0.
 88 * 2. Match driver name. If it mismatches, proceed to the next device node.
 89 * 3. Call GET_UNIQUE, and check whether the unique name has length zero (by
 90 *    checking that the first byte in the string is 0). If that's not the case
 91 *    libdrm skips and proceeds to the next device node. Probably this is just
 92 *    copypasta from drm 1.0 times where a set unique name meant that the driver
 93 *    was in use already, but that's just conjecture.
 94 *
 95 * Long story short: To keep the open by name logic working, GET_UNIQUE must
 96 * _not_ return a unique string when SET_VERSION hasn't been called yet,
 97 * otherwise libdrm breaks. Even when that unique string can't ever change, and
 98 * is totally irrelevant for actually opening the device because runtime
 99 * assignable device instances were only support in drm 1.0, which is long dead.
100 * But the libdrm code in drmOpenByName somehow survived, hence this can't be
101 * broken.
102 */
103
104/*
105 * Get the bus id.
106 *
107 * \param inode device inode.
108 * \param file_priv DRM file private.
109 * \param cmd command.
110 * \param arg user argument, pointing to a drm_unique structure.
111 * \return zero on success or a negative number on failure.
112 *
113 * Copies the bus id from drm_device::unique into user space.
114 */
115int drm_getunique(struct drm_device *dev, void *data,
116		  struct drm_file *file_priv)
117{
118	struct drm_unique *u = data;
119	struct drm_master *master;
120
121	mutex_lock(&dev->master_mutex);
122	master = file_priv->master;
123	if (u->unique_len >= master->unique_len) {
124		if (copy_to_user(u->unique, master->unique, master->unique_len)) {
125			mutex_unlock(&dev->master_mutex);
126			return -EFAULT;
127		}
128	}
129	u->unique_len = master->unique_len;
130	mutex_unlock(&dev->master_mutex);
131
132	return 0;
133}
134
135static void
136drm_unset_busid(struct drm_device *dev,
137		struct drm_master *master)
138{
139	kfree(master->unique);
140	master->unique = NULL;
141	master->unique_len = 0;
142}
143
144static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
145{
146	struct drm_master *master = file_priv->master;
147	int ret;
148
149	if (master->unique != NULL)
150		drm_unset_busid(dev, master);
151
152	if (dev->dev && dev_is_pci(dev->dev)) {
153		ret = drm_pci_set_busid(dev, master);
154		if (ret) {
155			drm_unset_busid(dev, master);
156			return ret;
157		}
158	} else {
159		WARN_ON(!dev->unique);
160		master->unique = kstrdup(dev->unique, GFP_KERNEL);
161		if (master->unique)
162			master->unique_len = strlen(dev->unique);
163	}
164
165	return 0;
166}
167
168/*
169 * Get client information.
170 *
171 * \param inode device inode.
172 * \param file_priv DRM file private.
173 * \param cmd command.
174 * \param arg user argument, pointing to a drm_client structure.
175 *
176 * \return zero on success or a negative number on failure.
177 *
178 * Searches for the client with the specified index and copies its information
179 * into userspace
180 */
181int drm_getclient(struct drm_device *dev, void *data,
182		  struct drm_file *file_priv)
183{
184	struct drm_client *client = data;
185
186	/*
187	 * Hollowed-out getclient ioctl to keep some dead old drm tests/tools
188	 * not breaking completely. Userspace tools stop enumerating one they
189	 * get -EINVAL, hence this is the return value we need to hand back for
190	 * no clients tracked.
191	 *
192	 * Unfortunately some clients (*cough* libva *cough*) use this in a fun
193	 * attempt to figure out whether they're authenticated or not. Since
194	 * that's the only thing they care about, give it to the directly
195	 * instead of walking one giant list.
196	 */
197	if (client->idx == 0) {
198		client->auth = file_priv->authenticated;
199		client->pid = task_pid_vnr(current);
200		client->uid = overflowuid;
201		client->magic = 0;
202		client->iocs = 0;
203
204		return 0;
205	} else {
206		return -EINVAL;
207	}
208}
209
210/*
211 * Get statistics information.
212 *
213 * \param inode device inode.
214 * \param file_priv DRM file private.
215 * \param cmd command.
216 * \param arg user argument, pointing to a drm_stats structure.
217 *
218 * \return zero on success or a negative number on failure.
219 */
220static int drm_getstats(struct drm_device *dev, void *data,
221		 struct drm_file *file_priv)
222{
223	struct drm_stats *stats = data;
224
225	/* Clear stats to prevent userspace from eating its stack garbage. */
226	memset(stats, 0, sizeof(*stats));
227
228	return 0;
229}
230
231/*
232 * Get device/driver capabilities
233 */
234static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
235{
236	struct drm_get_cap *req = data;
237	struct drm_crtc *crtc;
238
239	req->value = 0;
240
241	/* Only some caps make sense with UMS/render-only drivers. */
242	switch (req->capability) {
243	case DRM_CAP_TIMESTAMP_MONOTONIC:
244		req->value = 1;
245		return 0;
246	case DRM_CAP_PRIME:
247		req->value = DRM_PRIME_CAP_IMPORT | DRM_PRIME_CAP_EXPORT;
248		return 0;
249	case DRM_CAP_SYNCOBJ:
250		req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ);
251		return 0;
252	case DRM_CAP_SYNCOBJ_TIMELINE:
253		req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE);
254		return 0;
255	}
256
257	/* Other caps only work with KMS drivers */
258	if (!drm_core_check_feature(dev, DRIVER_MODESET))
259		return -EOPNOTSUPP;
260
261	switch (req->capability) {
262	case DRM_CAP_DUMB_BUFFER:
263		if (dev->driver->dumb_create)
264			req->value = 1;
265		break;
266	case DRM_CAP_VBLANK_HIGH_CRTC:
267		req->value = 1;
268		break;
269	case DRM_CAP_DUMB_PREFERRED_DEPTH:
270		req->value = dev->mode_config.preferred_depth;
271		break;
272	case DRM_CAP_DUMB_PREFER_SHADOW:
273		req->value = dev->mode_config.prefer_shadow;
274		break;
275	case DRM_CAP_ASYNC_PAGE_FLIP:
276		req->value = dev->mode_config.async_page_flip;
277		break;
278	case DRM_CAP_PAGE_FLIP_TARGET:
279		req->value = 1;
280		drm_for_each_crtc(crtc, dev) {
281			if (!crtc->funcs->page_flip_target)
282				req->value = 0;
283		}
284		break;
285	case DRM_CAP_CURSOR_WIDTH:
286		if (dev->mode_config.cursor_width)
287			req->value = dev->mode_config.cursor_width;
288		else
289			req->value = 64;
290		break;
291	case DRM_CAP_CURSOR_HEIGHT:
292		if (dev->mode_config.cursor_height)
293			req->value = dev->mode_config.cursor_height;
294		else
295			req->value = 64;
296		break;
297	case DRM_CAP_ADDFB2_MODIFIERS:
298		req->value = !dev->mode_config.fb_modifiers_not_supported;
299		break;
300	case DRM_CAP_CRTC_IN_VBLANK_EVENT:
301		req->value = 1;
302		break;
303	case DRM_CAP_ATOMIC_ASYNC_PAGE_FLIP:
304		req->value = drm_core_check_feature(dev, DRIVER_ATOMIC) &&
305			     dev->mode_config.async_page_flip;
306		break;
307	default:
308		return -EINVAL;
309	}
310	return 0;
311}
312
313/*
314 * Set device/driver capabilities
315 */
316static int
317drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
318{
319	struct drm_set_client_cap *req = data;
320
321	/* No render-only settable capabilities for now */
322
323	/* Below caps that only works with KMS drivers */
324	if (!drm_core_check_feature(dev, DRIVER_MODESET))
325		return -EOPNOTSUPP;
326
327	switch (req->capability) {
328	case DRM_CLIENT_CAP_STEREO_3D:
329		if (req->value > 1)
330			return -EINVAL;
331		file_priv->stereo_allowed = req->value;
332		break;
333	case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
334		if (req->value > 1)
335			return -EINVAL;
336		file_priv->universal_planes = req->value;
337		break;
338	case DRM_CLIENT_CAP_ATOMIC:
339		if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
340			return -EOPNOTSUPP;
341		/* The modesetting DDX has a totally broken idea of atomic. */
342		if (current->comm[0] == 'X' && req->value == 1) {
343			pr_info("broken atomic modeset userspace detected, disabling atomic\n");
344			return -EOPNOTSUPP;
345		}
346		if (req->value > 2)
347			return -EINVAL;
348		file_priv->atomic = req->value;
349		file_priv->universal_planes = req->value;
350		/*
351		 * No atomic user-space blows up on aspect ratio mode bits.
352		 */
353		file_priv->aspect_ratio_allowed = req->value;
354		break;
355	case DRM_CLIENT_CAP_ASPECT_RATIO:
356		if (req->value > 1)
357			return -EINVAL;
358		file_priv->aspect_ratio_allowed = req->value;
359		break;
360	case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS:
361		if (!file_priv->atomic)
362			return -EINVAL;
363		if (req->value > 1)
364			return -EINVAL;
365		file_priv->writeback_connectors = req->value;
366		break;
367	case DRM_CLIENT_CAP_CURSOR_PLANE_HOTSPOT:
368		if (!drm_core_check_feature(dev, DRIVER_CURSOR_HOTSPOT))
369			return -EOPNOTSUPP;
370		if (!file_priv->atomic)
371			return -EINVAL;
372		if (req->value > 1)
373			return -EINVAL;
374		file_priv->supports_virtualized_cursor_plane = req->value;
375		break;
376	case DRM_CLIENT_CAP_PLANE_COLOR_PIPELINE:
377		if (!file_priv->atomic)
378			return -EINVAL;
379		if (req->value > 1)
380			return -EINVAL;
381		file_priv->plane_color_pipeline = req->value;
382		break;
383	default:
384		return -EINVAL;
385	}
386
387	return 0;
388}
389
390/*
391 * Setversion ioctl.
392 *
393 * \param inode device inode.
394 * \param file_priv DRM file private.
395 * \param cmd command.
396 * \param arg user argument, pointing to a drm_lock structure.
397 * \return zero on success or negative number on failure.
398 *
399 * Sets the requested interface version
400 */
401static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
402{
403	struct drm_set_version *sv = data;
404	int if_version, retcode = 0;
405
406	mutex_lock(&dev->master_mutex);
407	if (sv->drm_di_major != -1) {
408		if (sv->drm_di_major != DRM_IF_MAJOR ||
409		    sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
410			retcode = -EINVAL;
411			goto done;
412		}
413		if_version = DRM_IF_VERSION(sv->drm_di_major,
414					    sv->drm_di_minor);
415		dev->if_version = max(if_version, dev->if_version);
416		if (sv->drm_di_minor >= 1) {
417			/*
418			 * Version 1.1 includes tying of DRM to specific device
419			 * Version 1.4 has proper PCI domain support
420			 */
421			retcode = drm_set_busid(dev, file_priv);
422			if (retcode)
423				goto done;
424		}
425	}
426
427	if (sv->drm_dd_major != -1) {
428		if (sv->drm_dd_major != dev->driver->major ||
429		    sv->drm_dd_minor < 0 || sv->drm_dd_minor >
430		    dev->driver->minor) {
431			retcode = -EINVAL;
432			goto done;
433		}
434	}
435
436done:
437	sv->drm_di_major = DRM_IF_MAJOR;
438	sv->drm_di_minor = DRM_IF_MINOR;
439	sv->drm_dd_major = dev->driver->major;
440	sv->drm_dd_minor = dev->driver->minor;
441	mutex_unlock(&dev->master_mutex);
442
443	return retcode;
444}
445
446/**
447 * drm_noop - DRM no-op ioctl implementation
448 * @dev: DRM device for the ioctl
449 * @data: data pointer for the ioctl
450 * @file_priv: DRM file for the ioctl call
451 *
452 * This no-op implementation for drm ioctls is useful for deprecated
453 * functionality where we can't return a failure code because existing userspace
454 * checks the result of the ioctl, but doesn't care about the action.
455 *
456 * Always returns successfully with 0.
457 */
458int drm_noop(struct drm_device *dev, void *data,
459	     struct drm_file *file_priv)
460{
461	drm_dbg_core(dev, "\n");
462	return 0;
463}
464EXPORT_SYMBOL(drm_noop);
465
466/**
467 * drm_invalid_op - DRM invalid ioctl implementation
468 * @dev: DRM device for the ioctl
469 * @data: data pointer for the ioctl
470 * @file_priv: DRM file for the ioctl call
471 *
472 * This no-op implementation for drm ioctls is useful for deprecated
473 * functionality where we really don't want to allow userspace to call the ioctl
474 * any more. This is the case for old ums interfaces for drivers that
475 * transitioned to kms gradually and so kept the old legacy tables around. This
476 * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
477 * use this function.
478 *
479 * Always fails with a return value of -EINVAL.
480 */
481int drm_invalid_op(struct drm_device *dev, void *data,
482		   struct drm_file *file_priv)
483{
484	return -EINVAL;
485}
486EXPORT_SYMBOL(drm_invalid_op);
487
488/*
489 * Copy and IOCTL return string to user space
490 */
491static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
492{
493	size_t len;
494
495	/* don't attempt to copy a NULL pointer */
496	if (WARN_ONCE(!value, "BUG: the value to copy was not set!")) {
497		*buf_len = 0;
498		return 0;
499	}
500
501	/* don't overflow userbuf */
502	len = strlen(value);
503	if (len > *buf_len)
504		len = *buf_len;
505
506	/* let userspace know exact length of driver value (which could be
507	 * larger than the userspace-supplied buffer) */
508	*buf_len = strlen(value);
509
510	/* finally, try filling in the userbuf */
511	if (len && buf)
512		if (copy_to_user(buf, value, len))
513			return -EFAULT;
514	return 0;
515}
516
517/*
518 * Get version information
519 *
520 * \param inode device inode.
521 * \param filp file pointer.
522 * \param cmd command.
523 * \param arg user argument, pointing to a drm_version structure.
524 * \return zero on success or negative number on failure.
525 *
526 * Fills in the version information in \p arg.
527 */
528int drm_version(struct drm_device *dev, void *data,
529		       struct drm_file *file_priv)
530{
531	struct drm_version *version = data;
532	int err;
533
534	version->version_major = dev->driver->major;
535	version->version_minor = dev->driver->minor;
536	version->version_patchlevel = dev->driver->patchlevel;
537	err = drm_copy_field(version->name, &version->name_len,
538			dev->driver->name);
539
540	/* Driver date is deprecated. Userspace expects a non-empty string. */
541	if (!err)
542		err = drm_copy_field(version->date, &version->date_len, "0");
543	if (!err)
544		err = drm_copy_field(version->desc, &version->desc_len,
545				dev->driver->desc);
546
547	return err;
548}
549
550/*
551 * Check if the passed string contains control char or spaces or
552 * anything that would mess up a formatted output.
553 */
554static int drm_validate_value_string(const char *value, size_t len)
555{
556	int i;
557
558	for (i = 0; i < len; i++) {
559		if (!isascii(value[i]) || !isgraph(value[i]))
560			return -EINVAL;
561	}
562	return 0;
563}
564
565static int drm_set_client_name(struct drm_device *dev, void *data,
566			       struct drm_file *file_priv)
567{
568	struct drm_set_client_name *name = data;
569	size_t len = name->name_len;
570	void __user *user_ptr;
571	char *new_name;
572
573	if (len > DRM_CLIENT_NAME_MAX_LEN) {
574		return -EINVAL;
575	} else if (len) {
576		user_ptr = u64_to_user_ptr(name->name);
577
578		new_name = memdup_user_nul(user_ptr, len);
579		if (IS_ERR(new_name))
580			return PTR_ERR(new_name);
581
582		if (strlen(new_name) != len ||
583		    drm_validate_value_string(new_name, len) < 0) {
584			kfree(new_name);
585			return -EINVAL;
586		}
587	} else {
588		new_name = NULL;
589	}
590
591	mutex_lock(&file_priv->client_name_lock);
592	kfree(file_priv->client_name);
593	file_priv->client_name = new_name;
594	mutex_unlock(&file_priv->client_name_lock);
595
596	return 0;
597}
598
599static int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
600{
601	/* ROOT_ONLY is only for CAP_SYS_ADMIN */
602	if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
603		return -EACCES;
604
605	/* AUTH is only for authenticated or render client */
606	if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
607		     !file_priv->authenticated))
608		return -EACCES;
609
610	/* MASTER is only for master or control clients */
611	if (unlikely((flags & DRM_MASTER) &&
612		     !drm_is_current_master(file_priv)))
613		return -EACCES;
614
615	/* Render clients must be explicitly allowed */
616	if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
617		     drm_is_render_client(file_priv)))
618		return -EACCES;
619
620	return 0;
621}
622
623#define DRM_IOCTL_DEF(ioctl, _func, _flags)	\
624	[DRM_IOCTL_NR(ioctl)] = {		\
625		.cmd = ioctl,			\
626		.func = _func,			\
627		.flags = _flags,		\
628		.name = #ioctl			\
629	}
630
631/* Ioctl table */
632static const struct drm_ioctl_desc drm_ioctls[] = {
633	DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_RENDER_ALLOW),
634	DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
635	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0),
636
637	DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, 0),
638	DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0),
639	DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_RENDER_ALLOW),
640	DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
641	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
642
643	DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
644	DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
645	DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
646	DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_MASTER),
647
648	DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, 0),
649	DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, 0),
650
651	DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
652	DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
653
654	DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
655
656	DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, 0),
657
658	DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
659
660	DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_RENDER_ALLOW),
661	DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH),
662	DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH),
663	DRM_IOCTL_DEF(DRM_IOCTL_GEM_CHANGE_HANDLE, drm_gem_change_handle_ioctl, DRM_RENDER_ALLOW),
664
665	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, 0),
666
667	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_RENDER_ALLOW),
668	DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_RENDER_ALLOW),
669
670	DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_NAME, drm_set_client_name, DRM_RENDER_ALLOW),
671
672	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, 0),
673	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, 0),
674	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER),
675	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, 0),
676	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER),
677	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER),
678	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, 0),
679	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER),
680	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, 0),
681	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, 0),
682	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER),
683	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER),
684	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, 0),
685	DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_connector_property_set_ioctl, DRM_MASTER),
686	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, 0),
687	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, 0),
688	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB2, drm_mode_getfb2_ioctl, 0),
689	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb_ioctl, 0),
690	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2_ioctl, 0),
691	DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb_ioctl, 0),
692	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CLOSEFB, drm_mode_closefb_ioctl, 0),
693	DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER),
694	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER),
695	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, 0),
696	DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, 0),
697	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, 0),
698	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, 0),
699	DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER),
700	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER),
701	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER),
702	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, 0),
703	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, 0),
704
705	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_CREATE, drm_syncobj_create_ioctl,
706		      DRM_RENDER_ALLOW),
707	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_DESTROY, drm_syncobj_destroy_ioctl,
708		      DRM_RENDER_ALLOW),
709	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, drm_syncobj_handle_to_fd_ioctl,
710		      DRM_RENDER_ALLOW),
711	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, drm_syncobj_fd_to_handle_ioctl,
712		      DRM_RENDER_ALLOW),
713	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TRANSFER, drm_syncobj_transfer_ioctl,
714		      DRM_RENDER_ALLOW),
715	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl,
716		      DRM_RENDER_ALLOW),
717	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT, drm_syncobj_timeline_wait_ioctl,
718		      DRM_RENDER_ALLOW),
719	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_EVENTFD, drm_syncobj_eventfd_ioctl,
720		      DRM_RENDER_ALLOW),
721	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl,
722		      DRM_RENDER_ALLOW),
723	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl,
724		      DRM_RENDER_ALLOW),
725	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL, drm_syncobj_timeline_signal_ioctl,
726		      DRM_RENDER_ALLOW),
727	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_QUERY, drm_syncobj_query_ioctl,
728		      DRM_RENDER_ALLOW),
729	DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, 0),
730	DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, 0),
731	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER),
732	DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER),
733	DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER),
734	DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER),
735};
736
737#define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE(drm_ioctls)
738
739/**
740 * DOC: driver specific ioctls
741 *
742 * First things first, driver private IOCTLs should only be needed for drivers
743 * supporting rendering. Kernel modesetting is all standardized, and extended
744 * through properties. There are a few exceptions in some existing drivers,
745 * which define IOCTL for use by the display DRM master, but they all predate
746 * properties.
747 *
748 * Now if you do have a render driver you always have to support it through
749 * driver private properties. There's a few steps needed to wire all the things
750 * up.
751 *
752 * First you need to define the structure for your IOCTL in your driver private
753 * UAPI header in ``include/uapi/drm/my_driver_drm.h``::
754 *
755 *     struct my_driver_operation {
756 *             u32 some_thing;
757 *             u32 another_thing;
758 *     };
759 *
760 * Please make sure that you follow all the best practices from
761 * ``Documentation/process/botching-up-ioctls.rst``. Note that drm_ioctl()
762 * automatically zero-extends structures, hence make sure you can add more stuff
763 * at the end, i.e. don't put a variable sized array there.
764 *
765 * Then you need to define your IOCTL number, using one of DRM_IO(), DRM_IOR(),
766 * DRM_IOW() or DRM_IOWR(). It must start with the DRM_IOCTL\_ prefix::
767 *
768 *     ##define DRM_IOCTL_MY_DRIVER_OPERATION \
769 *         DRM_IOW(DRM_COMMAND_BASE, struct my_driver_operation)
770 *
771 * DRM driver private IOCTL must be in the range from DRM_COMMAND_BASE to
772 * DRM_COMMAND_END. Finally you need an array of &struct drm_ioctl_desc to wire
773 * up the handlers and set the access rights::
774 *
775 *     static const struct drm_ioctl_desc my_driver_ioctls[] = {
776 *         DRM_IOCTL_DEF_DRV(MY_DRIVER_OPERATION, my_driver_operation,
777 *                 DRM_AUTH|DRM_RENDER_ALLOW),
778 *     };
779 *
780 * And then assign this to the &drm_driver.ioctls field in your driver
781 * structure.
782 *
783 * See the separate chapter on :ref:`file operations<drm_driver_fops>` for how
784 * the driver-specific IOCTLs are wired up.
785 */
786
787long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
788		      u32 flags)
789{
790	struct drm_file *file_priv = file->private_data;
791	struct drm_device *dev = file_priv->minor->dev;
792	int ret;
793
794	/* Update drm_file owner if fd was passed along. */
795	drm_file_update_pid(file_priv);
796
797	if (drm_dev_is_unplugged(dev))
798		return -ENODEV;
799
800	ret = drm_ioctl_permit(flags, file_priv);
801	if (unlikely(ret))
802		return ret;
803
804	return func(dev, kdata, file_priv);
805}
806EXPORT_SYMBOL(drm_ioctl_kernel);
807
808/**
809 * drm_ioctl - ioctl callback implementation for DRM drivers
810 * @filp: file this ioctl is called on
811 * @cmd: ioctl cmd number
812 * @arg: user argument
813 *
814 * Looks up the ioctl function in the DRM core and the driver dispatch table,
815 * stored in &drm_driver.ioctls. It checks for necessary permission by calling
816 * drm_ioctl_permit(), and dispatches to the respective function.
817 *
818 * Returns:
819 * Zero on success, negative error code on failure.
820 */
821long drm_ioctl(struct file *filp,
822	      unsigned int cmd, unsigned long arg)
823{
824	struct drm_file *file_priv = filp->private_data;
825	struct drm_device *dev;
826	const struct drm_ioctl_desc *ioctl = NULL;
827	drm_ioctl_t *func;
828	unsigned int nr = DRM_IOCTL_NR(cmd);
829	int retcode = -EINVAL;
830	char stack_kdata[128];
831	char *kdata = NULL;
832	unsigned int in_size, out_size, drv_size, ksize;
833	bool is_driver_ioctl;
834
835	dev = file_priv->minor->dev;
836
837	if (drm_dev_is_unplugged(dev))
838		return -ENODEV;
839
840	if (DRM_IOCTL_TYPE(cmd) != DRM_IOCTL_BASE)
841		return -ENOTTY;
842
843	is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
844
845	if (is_driver_ioctl) {
846		/* driver ioctl */
847		unsigned int index = nr - DRM_COMMAND_BASE;
848
849		if (index >= dev->driver->num_ioctls)
850			goto err_i1;
851		index = array_index_nospec(index, dev->driver->num_ioctls);
852		ioctl = &dev->driver->ioctls[index];
853	} else {
854		/* core ioctl */
855		if (nr >= DRM_CORE_IOCTL_COUNT)
856			goto err_i1;
857		nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
858		ioctl = &drm_ioctls[nr];
859	}
860
861	drv_size = _IOC_SIZE(ioctl->cmd);
862	out_size = in_size = _IOC_SIZE(cmd);
863	if ((cmd & ioctl->cmd & IOC_IN) == 0)
864		in_size = 0;
865	if ((cmd & ioctl->cmd & IOC_OUT) == 0)
866		out_size = 0;
867	ksize = max(max(in_size, out_size), drv_size);
868
869	drm_dbg_core(dev, "comm=\"%s\" pid=%d, dev=0x%lx, auth=%d, %s\n",
870		     current->comm, task_pid_nr(current),
871		     (long)old_encode_dev(file_priv->minor->kdev->devt),
872		     file_priv->authenticated, ioctl->name);
873
874	/* Do not trust userspace, use our own definition */
875	func = ioctl->func;
876
877	if (unlikely(!func)) {
878		drm_dbg_core(dev, "no function\n");
879		retcode = -EINVAL;
880		goto err_i1;
881	}
882
883	if (ksize <= sizeof(stack_kdata)) {
884		kdata = stack_kdata;
885	} else {
886		kdata = kmalloc(ksize, GFP_KERNEL);
887		if (!kdata) {
888			retcode = -ENOMEM;
889			goto err_i1;
890		}
891	}
892
893	if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) {
894		retcode = -EFAULT;
895		goto err_i1;
896	}
897
898	if (ksize > in_size)
899		memset(kdata + in_size, 0, ksize - in_size);
900
901	retcode = drm_ioctl_kernel(filp, func, kdata, ioctl->flags);
902	if (copy_to_user((void __user *)arg, kdata, out_size) != 0)
903		retcode = -EFAULT;
904
905      err_i1:
906	if (!ioctl)
907		drm_dbg_core(dev,
908			     "invalid ioctl: comm=\"%s\", pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
909			     current->comm, task_pid_nr(current),
910			     (long)old_encode_dev(file_priv->minor->kdev->devt),
911			     file_priv->authenticated, cmd, nr);
912
913	if (kdata != stack_kdata)
914		kfree(kdata);
915	if (retcode)
916		drm_dbg_core(dev, "comm=\"%s\", pid=%d, ret=%d\n",
917			     current->comm, task_pid_nr(current), retcode);
918	return retcode;
919}
920EXPORT_SYMBOL(drm_ioctl);
921
922/**
923 * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
924 * @nr: ioctl number
925 * @flags: where to return the ioctl permission flags
926 *
927 * This ioctl is only used by the vmwgfx driver to augment the access checks
928 * done by the drm core and insofar a pretty decent layering violation. This
929 * shouldn't be used by any drivers.
930 *
931 * Returns:
932 * True if the @nr corresponds to a DRM core ioctl number, false otherwise.
933 */
934bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
935{
936	if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
937		return false;
938
939	if (nr >= DRM_CORE_IOCTL_COUNT)
940		return false;
941	nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
942
943	*flags = drm_ioctls[nr].flags;
944	return true;
945}
946EXPORT_SYMBOL(drm_ioctl_flags);