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(lock: &dev->master_mutex);
122 master = file_priv->master;
123 if (u->unique_len >= master->unique_len) {
124 if (copy_to_user(to: u->unique, from: master->unique, n: master->unique_len)) {
125 mutex_unlock(lock: &dev->master_mutex);
126 return -EFAULT;
127 }
128 }
129 u->unique_len = master->unique_len;
130 mutex_unlock(lock: &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(objp: 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(s: 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(s: stats, c: 0, n: 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, feature: DRIVER_SYNCOBJ);
251 return 0;
252 case DRM_CAP_SYNCOBJ_TIMELINE:
253 req->value = drm_core_check_feature(dev, feature: DRIVER_SYNCOBJ_TIMELINE);
254 return 0;
255 }
256
257 /* Other caps only work with KMS drivers */
258 if (!drm_core_check_feature(dev, feature: 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, feature: 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, feature: 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, feature: 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, feature: 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 default:
377 return -EINVAL;
378 }
379
380 return 0;
381}
382
383/*
384 * Setversion ioctl.
385 *
386 * \param inode device inode.
387 * \param file_priv DRM file private.
388 * \param cmd command.
389 * \param arg user argument, pointing to a drm_lock structure.
390 * \return zero on success or negative number on failure.
391 *
392 * Sets the requested interface version
393 */
394static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
395{
396 struct drm_set_version *sv = data;
397 int if_version, retcode = 0;
398
399 mutex_lock(lock: &dev->master_mutex);
400 if (sv->drm_di_major != -1) {
401 if (sv->drm_di_major != DRM_IF_MAJOR ||
402 sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
403 retcode = -EINVAL;
404 goto done;
405 }
406 if_version = DRM_IF_VERSION(sv->drm_di_major,
407 sv->drm_di_minor);
408 dev->if_version = max(if_version, dev->if_version);
409 if (sv->drm_di_minor >= 1) {
410 /*
411 * Version 1.1 includes tying of DRM to specific device
412 * Version 1.4 has proper PCI domain support
413 */
414 retcode = drm_set_busid(dev, file_priv);
415 if (retcode)
416 goto done;
417 }
418 }
419
420 if (sv->drm_dd_major != -1) {
421 if (sv->drm_dd_major != dev->driver->major ||
422 sv->drm_dd_minor < 0 || sv->drm_dd_minor >
423 dev->driver->minor) {
424 retcode = -EINVAL;
425 goto done;
426 }
427 }
428
429done:
430 sv->drm_di_major = DRM_IF_MAJOR;
431 sv->drm_di_minor = DRM_IF_MINOR;
432 sv->drm_dd_major = dev->driver->major;
433 sv->drm_dd_minor = dev->driver->minor;
434 mutex_unlock(lock: &dev->master_mutex);
435
436 return retcode;
437}
438
439/**
440 * drm_noop - DRM no-op ioctl implementation
441 * @dev: DRM device for the ioctl
442 * @data: data pointer for the ioctl
443 * @file_priv: DRM file for the ioctl call
444 *
445 * This no-op implementation for drm ioctls is useful for deprecated
446 * functionality where we can't return a failure code because existing userspace
447 * checks the result of the ioctl, but doesn't care about the action.
448 *
449 * Always returns successfully with 0.
450 */
451int drm_noop(struct drm_device *dev, void *data,
452 struct drm_file *file_priv)
453{
454 drm_dbg_core(dev, "\n");
455 return 0;
456}
457EXPORT_SYMBOL(drm_noop);
458
459/**
460 * drm_invalid_op - DRM invalid ioctl implementation
461 * @dev: DRM device for the ioctl
462 * @data: data pointer for the ioctl
463 * @file_priv: DRM file for the ioctl call
464 *
465 * This no-op implementation for drm ioctls is useful for deprecated
466 * functionality where we really don't want to allow userspace to call the ioctl
467 * any more. This is the case for old ums interfaces for drivers that
468 * transitioned to kms gradually and so kept the old legacy tables around. This
469 * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
470 * use this function.
471 *
472 * Always fails with a return value of -EINVAL.
473 */
474int drm_invalid_op(struct drm_device *dev, void *data,
475 struct drm_file *file_priv)
476{
477 return -EINVAL;
478}
479EXPORT_SYMBOL(drm_invalid_op);
480
481/*
482 * Copy and IOCTL return string to user space
483 */
484static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
485{
486 size_t len;
487
488 /* don't attempt to copy a NULL pointer */
489 if (WARN_ONCE(!value, "BUG: the value to copy was not set!")) {
490 *buf_len = 0;
491 return 0;
492 }
493
494 /* don't overflow userbuf */
495 len = strlen(value);
496 if (len > *buf_len)
497 len = *buf_len;
498
499 /* let userspace know exact length of driver value (which could be
500 * larger than the userspace-supplied buffer) */
501 *buf_len = strlen(value);
502
503 /* finally, try filling in the userbuf */
504 if (len && buf)
505 if (copy_to_user(to: buf, from: value, n: len))
506 return -EFAULT;
507 return 0;
508}
509
510/*
511 * Get version information
512 *
513 * \param inode device inode.
514 * \param filp file pointer.
515 * \param cmd command.
516 * \param arg user argument, pointing to a drm_version structure.
517 * \return zero on success or negative number on failure.
518 *
519 * Fills in the version information in \p arg.
520 */
521int drm_version(struct drm_device *dev, void *data,
522 struct drm_file *file_priv)
523{
524 struct drm_version *version = data;
525 int err;
526
527 version->version_major = dev->driver->major;
528 version->version_minor = dev->driver->minor;
529 version->version_patchlevel = dev->driver->patchlevel;
530 err = drm_copy_field(buf: version->name, buf_len: &version->name_len,
531 value: dev->driver->name);
532
533 /* Driver date is deprecated. Userspace expects a non-empty string. */
534 if (!err)
535 err = drm_copy_field(buf: version->date, buf_len: &version->date_len, value: "0");
536 if (!err)
537 err = drm_copy_field(buf: version->desc, buf_len: &version->desc_len,
538 value: dev->driver->desc);
539
540 return err;
541}
542
543/*
544 * Check if the passed string contains control char or spaces or
545 * anything that would mess up a formatted output.
546 */
547static int drm_validate_value_string(const char *value, size_t len)
548{
549 int i;
550
551 for (i = 0; i < len; i++) {
552 if (!isascii(value[i]) || !isgraph(value[i]))
553 return -EINVAL;
554 }
555 return 0;
556}
557
558static int drm_set_client_name(struct drm_device *dev, void *data,
559 struct drm_file *file_priv)
560{
561 struct drm_set_client_name *name = data;
562 size_t len = name->name_len;
563 void __user *user_ptr;
564 char *new_name;
565
566 if (len > DRM_CLIENT_NAME_MAX_LEN) {
567 return -EINVAL;
568 } else if (len) {
569 user_ptr = u64_to_user_ptr(name->name);
570
571 new_name = memdup_user_nul(user_ptr, len);
572 if (IS_ERR(ptr: new_name))
573 return PTR_ERR(ptr: new_name);
574
575 if (strlen(new_name) != len ||
576 drm_validate_value_string(value: new_name, len) < 0) {
577 kfree(objp: new_name);
578 return -EINVAL;
579 }
580 } else {
581 new_name = NULL;
582 }
583
584 mutex_lock(lock: &file_priv->client_name_lock);
585 kfree(objp: file_priv->client_name);
586 file_priv->client_name = new_name;
587 mutex_unlock(lock: &file_priv->client_name_lock);
588
589 return 0;
590}
591
592static int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
593{
594 /* ROOT_ONLY is only for CAP_SYS_ADMIN */
595 if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
596 return -EACCES;
597
598 /* AUTH is only for authenticated or render client */
599 if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
600 !file_priv->authenticated))
601 return -EACCES;
602
603 /* MASTER is only for master or control clients */
604 if (unlikely((flags & DRM_MASTER) &&
605 !drm_is_current_master(file_priv)))
606 return -EACCES;
607
608 /* Render clients must be explicitly allowed */
609 if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
610 drm_is_render_client(file_priv)))
611 return -EACCES;
612
613 return 0;
614}
615
616#define DRM_IOCTL_DEF(ioctl, _func, _flags) \
617 [DRM_IOCTL_NR(ioctl)] = { \
618 .cmd = ioctl, \
619 .func = _func, \
620 .flags = _flags, \
621 .name = #ioctl \
622 }
623
624/* Ioctl table */
625static const struct drm_ioctl_desc drm_ioctls[] = {
626 DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_RENDER_ALLOW),
627 DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
628 DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0),
629
630 DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, 0),
631 DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0),
632 DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_RENDER_ALLOW),
633 DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
634 DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
635
636 DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
637 DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
638 DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
639 DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_MASTER),
640
641 DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, 0),
642 DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, 0),
643
644 DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
645 DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
646
647 DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
648
649 DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, 0),
650
651 DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
652
653 DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_RENDER_ALLOW),
654 DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH),
655 DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH),
656 DRM_IOCTL_DEF(DRM_IOCTL_GEM_CHANGE_HANDLE, drm_gem_change_handle_ioctl, DRM_RENDER_ALLOW),
657
658 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, 0),
659
660 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_RENDER_ALLOW),
661 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_RENDER_ALLOW),
662
663 DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_NAME, drm_set_client_name, DRM_RENDER_ALLOW),
664
665 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, 0),
666 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, 0),
667 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER),
668 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, 0),
669 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER),
670 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER),
671 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, 0),
672 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER),
673 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, 0),
674 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, 0),
675 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER),
676 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER),
677 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, 0),
678 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_connector_property_set_ioctl, DRM_MASTER),
679 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, 0),
680 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, 0),
681 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB2, drm_mode_getfb2_ioctl, 0),
682 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb_ioctl, 0),
683 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2_ioctl, 0),
684 DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb_ioctl, 0),
685 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CLOSEFB, drm_mode_closefb_ioctl, 0),
686 DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER),
687 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER),
688 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, 0),
689 DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, 0),
690 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, 0),
691 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, 0),
692 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER),
693 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER),
694 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER),
695 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, 0),
696 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, 0),
697
698 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_CREATE, drm_syncobj_create_ioctl,
699 DRM_RENDER_ALLOW),
700 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_DESTROY, drm_syncobj_destroy_ioctl,
701 DRM_RENDER_ALLOW),
702 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, drm_syncobj_handle_to_fd_ioctl,
703 DRM_RENDER_ALLOW),
704 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, drm_syncobj_fd_to_handle_ioctl,
705 DRM_RENDER_ALLOW),
706 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TRANSFER, drm_syncobj_transfer_ioctl,
707 DRM_RENDER_ALLOW),
708 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl,
709 DRM_RENDER_ALLOW),
710 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT, drm_syncobj_timeline_wait_ioctl,
711 DRM_RENDER_ALLOW),
712 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_EVENTFD, drm_syncobj_eventfd_ioctl,
713 DRM_RENDER_ALLOW),
714 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl,
715 DRM_RENDER_ALLOW),
716 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl,
717 DRM_RENDER_ALLOW),
718 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL, drm_syncobj_timeline_signal_ioctl,
719 DRM_RENDER_ALLOW),
720 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_QUERY, drm_syncobj_query_ioctl,
721 DRM_RENDER_ALLOW),
722 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, 0),
723 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, 0),
724 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER),
725 DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER),
726 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER),
727 DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER),
728};
729
730#define DRM_CORE_IOCTL_COUNT ARRAY_SIZE(drm_ioctls)
731
732/**
733 * DOC: driver specific ioctls
734 *
735 * First things first, driver private IOCTLs should only be needed for drivers
736 * supporting rendering. Kernel modesetting is all standardized, and extended
737 * through properties. There are a few exceptions in some existing drivers,
738 * which define IOCTL for use by the display DRM master, but they all predate
739 * properties.
740 *
741 * Now if you do have a render driver you always have to support it through
742 * driver private properties. There's a few steps needed to wire all the things
743 * up.
744 *
745 * First you need to define the structure for your IOCTL in your driver private
746 * UAPI header in ``include/uapi/drm/my_driver_drm.h``::
747 *
748 * struct my_driver_operation {
749 * u32 some_thing;
750 * u32 another_thing;
751 * };
752 *
753 * Please make sure that you follow all the best practices from
754 * ``Documentation/process/botching-up-ioctls.rst``. Note that drm_ioctl()
755 * automatically zero-extends structures, hence make sure you can add more stuff
756 * at the end, i.e. don't put a variable sized array there.
757 *
758 * Then you need to define your IOCTL number, using one of DRM_IO(), DRM_IOR(),
759 * DRM_IOW() or DRM_IOWR(). It must start with the DRM_IOCTL\_ prefix::
760 *
761 * ##define DRM_IOCTL_MY_DRIVER_OPERATION \
762 * DRM_IOW(DRM_COMMAND_BASE, struct my_driver_operation)
763 *
764 * DRM driver private IOCTL must be in the range from DRM_COMMAND_BASE to
765 * DRM_COMMAND_END. Finally you need an array of &struct drm_ioctl_desc to wire
766 * up the handlers and set the access rights::
767 *
768 * static const struct drm_ioctl_desc my_driver_ioctls[] = {
769 * DRM_IOCTL_DEF_DRV(MY_DRIVER_OPERATION, my_driver_operation,
770 * DRM_AUTH|DRM_RENDER_ALLOW),
771 * };
772 *
773 * And then assign this to the &drm_driver.ioctls field in your driver
774 * structure.
775 *
776 * See the separate chapter on :ref:`file operations<drm_driver_fops>` for how
777 * the driver-specific IOCTLs are wired up.
778 */
779
780long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
781 u32 flags)
782{
783 struct drm_file *file_priv = file->private_data;
784 struct drm_device *dev = file_priv->minor->dev;
785 int ret;
786
787 /* Update drm_file owner if fd was passed along. */
788 drm_file_update_pid(file_priv);
789
790 if (drm_dev_is_unplugged(dev))
791 return -ENODEV;
792
793 ret = drm_ioctl_permit(flags, file_priv);
794 if (unlikely(ret))
795 return ret;
796
797 return func(dev, kdata, file_priv);
798}
799EXPORT_SYMBOL(drm_ioctl_kernel);
800
801/**
802 * drm_ioctl - ioctl callback implementation for DRM drivers
803 * @filp: file this ioctl is called on
804 * @cmd: ioctl cmd number
805 * @arg: user argument
806 *
807 * Looks up the ioctl function in the DRM core and the driver dispatch table,
808 * stored in &drm_driver.ioctls. It checks for necessary permission by calling
809 * drm_ioctl_permit(), and dispatches to the respective function.
810 *
811 * Returns:
812 * Zero on success, negative error code on failure.
813 */
814long drm_ioctl(struct file *filp,
815 unsigned int cmd, unsigned long arg)
816{
817 struct drm_file *file_priv = filp->private_data;
818 struct drm_device *dev;
819 const struct drm_ioctl_desc *ioctl = NULL;
820 drm_ioctl_t *func;
821 unsigned int nr = DRM_IOCTL_NR(cmd);
822 int retcode = -EINVAL;
823 char stack_kdata[128];
824 char *kdata = NULL;
825 unsigned int in_size, out_size, drv_size, ksize;
826 bool is_driver_ioctl;
827
828 dev = file_priv->minor->dev;
829
830 if (drm_dev_is_unplugged(dev))
831 return -ENODEV;
832
833 if (DRM_IOCTL_TYPE(cmd) != DRM_IOCTL_BASE)
834 return -ENOTTY;
835
836 is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
837
838 if (is_driver_ioctl) {
839 /* driver ioctl */
840 unsigned int index = nr - DRM_COMMAND_BASE;
841
842 if (index >= dev->driver->num_ioctls)
843 goto err_i1;
844 index = array_index_nospec(index, dev->driver->num_ioctls);
845 ioctl = &dev->driver->ioctls[index];
846 } else {
847 /* core ioctl */
848 if (nr >= DRM_CORE_IOCTL_COUNT)
849 goto err_i1;
850 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
851 ioctl = &drm_ioctls[nr];
852 }
853
854 drv_size = _IOC_SIZE(ioctl->cmd);
855 out_size = in_size = _IOC_SIZE(cmd);
856 if ((cmd & ioctl->cmd & IOC_IN) == 0)
857 in_size = 0;
858 if ((cmd & ioctl->cmd & IOC_OUT) == 0)
859 out_size = 0;
860 ksize = max(max(in_size, out_size), drv_size);
861
862 drm_dbg_core(dev, "comm=\"%s\" pid=%d, dev=0x%lx, auth=%d, %s\n",
863 current->comm, task_pid_nr(current),
864 (long)old_encode_dev(file_priv->minor->kdev->devt),
865 file_priv->authenticated, ioctl->name);
866
867 /* Do not trust userspace, use our own definition */
868 func = ioctl->func;
869
870 if (unlikely(!func)) {
871 drm_dbg_core(dev, "no function\n");
872 retcode = -EINVAL;
873 goto err_i1;
874 }
875
876 if (ksize <= sizeof(stack_kdata)) {
877 kdata = stack_kdata;
878 } else {
879 kdata = kmalloc(ksize, GFP_KERNEL);
880 if (!kdata) {
881 retcode = -ENOMEM;
882 goto err_i1;
883 }
884 }
885
886 if (copy_from_user(to: kdata, from: (void __user *)arg, n: in_size) != 0) {
887 retcode = -EFAULT;
888 goto err_i1;
889 }
890
891 if (ksize > in_size)
892 memset(s: kdata + in_size, c: 0, n: ksize - in_size);
893
894 retcode = drm_ioctl_kernel(filp, func, kdata, ioctl->flags);
895 if (copy_to_user(to: (void __user *)arg, from: kdata, n: out_size) != 0)
896 retcode = -EFAULT;
897
898 err_i1:
899 if (!ioctl)
900 drm_dbg_core(dev,
901 "invalid ioctl: comm=\"%s\", pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
902 current->comm, task_pid_nr(current),
903 (long)old_encode_dev(file_priv->minor->kdev->devt),
904 file_priv->authenticated, cmd, nr);
905
906 if (kdata != stack_kdata)
907 kfree(objp: kdata);
908 if (retcode)
909 drm_dbg_core(dev, "comm=\"%s\", pid=%d, ret=%d\n",
910 current->comm, task_pid_nr(current), retcode);
911 return retcode;
912}
913EXPORT_SYMBOL(drm_ioctl);
914
915/**
916 * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
917 * @nr: ioctl number
918 * @flags: where to return the ioctl permission flags
919 *
920 * This ioctl is only used by the vmwgfx driver to augment the access checks
921 * done by the drm core and insofar a pretty decent layering violation. This
922 * shouldn't be used by any drivers.
923 *
924 * Returns:
925 * True if the @nr corresponds to a DRM core ioctl number, false otherwise.
926 */
927bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
928{
929 if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
930 return false;
931
932 if (nr >= DRM_CORE_IOCTL_COUNT)
933 return false;
934 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
935
936 *flags = drm_ioctls[nr].flags;
937 return true;
938}
939EXPORT_SYMBOL(drm_ioctl_flags);
940