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 */
drm_getunique(struct drm_device * dev,void * data,struct drm_file * file_priv)117 int 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;
122
123 mutex_lock(&dev->master_mutex);
124 master = file_priv->master;
125 if (u->unique_len >= master->unique_len) {
126 if (copy_to_user(u->unique, master->unique, master->unique_len)) {
127 mutex_unlock(&dev->master_mutex);
128 return -EFAULT;
129 }
130 }
131 u->unique_len = master->unique_len;
132 mutex_unlock(&dev->master_mutex);
133
134 return 0;
135 }
136
137 static void
drm_unset_busid(struct drm_device * dev,struct drm_master * master)138 drm_unset_busid(struct drm_device *dev,
139 struct drm_master *master)
140 {
141 kfree(master->unique);
142 master->unique = NULL;
143 master->unique_len = 0;
144 }
145
drm_set_busid(struct drm_device * dev,struct drm_file * file_priv)146 static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
147 {
148 struct drm_master *master = file_priv->master;
149 int ret;
150
151 if (master->unique != NULL)
152 drm_unset_busid(dev, master);
153
154 if (dev->dev && dev_is_pci(dev->dev)) {
155 ret = drm_pci_set_busid(dev, master);
156 if (ret) {
157 drm_unset_busid(dev, master);
158 return ret;
159 }
160 } else {
161 WARN_ON(!dev->unique);
162 master->unique = kstrdup(dev->unique, GFP_KERNEL);
163 if (master->unique)
164 master->unique_len = strlen(dev->unique);
165 }
166
167 return 0;
168 }
169
170 /*
171 * Get client information.
172 *
173 * \param inode device inode.
174 * \param file_priv DRM file private.
175 * \param cmd command.
176 * \param arg user argument, pointing to a drm_client structure.
177 *
178 * \return zero on success or a negative number on failure.
179 *
180 * Searches for the client with the specified index and copies its information
181 * into userspace
182 */
drm_getclient(struct drm_device * dev,void * data,struct drm_file * file_priv)183 int drm_getclient(struct drm_device *dev, void *data,
184 struct drm_file *file_priv)
185 {
186 struct drm_client *client = data;
187
188 /*
189 * Hollowed-out getclient ioctl to keep some dead old drm tests/tools
190 * not breaking completely. Userspace tools stop enumerating one they
191 * get -EINVAL, hence this is the return value we need to hand back for
192 * no clients tracked.
193 *
194 * Unfortunately some clients (*cough* libva *cough*) use this in a fun
195 * attempt to figure out whether they're authenticated or not. Since
196 * that's the only thing they care about, give it to the directly
197 * instead of walking one giant list.
198 */
199 if (client->idx == 0) {
200 client->auth = file_priv->authenticated;
201 client->pid = task_pid_vnr(current);
202 client->uid = overflowuid;
203 client->magic = 0;
204 client->iocs = 0;
205
206 return 0;
207 } else {
208 return -EINVAL;
209 }
210 }
211
212 /*
213 * Get statistics information.
214 *
215 * \param inode device inode.
216 * \param file_priv DRM file private.
217 * \param cmd command.
218 * \param arg user argument, pointing to a drm_stats structure.
219 *
220 * \return zero on success or a negative number on failure.
221 */
drm_getstats(struct drm_device * dev,void * data,struct drm_file * file_priv)222 static int drm_getstats(struct drm_device *dev, void *data,
223 struct drm_file *file_priv)
224 {
225 struct drm_stats *stats = data;
226
227 /* Clear stats to prevent userspace from eating its stack garbage. */
228 memset(stats, 0, sizeof(*stats));
229
230 return 0;
231 }
232
233 /*
234 * Get device/driver capabilities
235 */
drm_getcap(struct drm_device * dev,void * data,struct drm_file * file_priv)236 static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
237 {
238 struct drm_get_cap *req = data;
239 struct drm_crtc *crtc;
240
241 req->value = 0;
242
243 /* Only some caps make sense with UMS/render-only drivers. */
244 switch (req->capability) {
245 case DRM_CAP_TIMESTAMP_MONOTONIC:
246 req->value = 1;
247 return 0;
248 case DRM_CAP_PRIME:
249 req->value |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0;
250 req->value |= dev->driver->prime_handle_to_fd ? DRM_PRIME_CAP_EXPORT : 0;
251 return 0;
252 case DRM_CAP_SYNCOBJ:
253 req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ);
254 return 0;
255 case DRM_CAP_SYNCOBJ_TIMELINE:
256 req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE);
257 return 0;
258 }
259
260 /* Other caps only work with KMS drivers */
261 if (!drm_core_check_feature(dev, DRIVER_MODESET))
262 return -EOPNOTSUPP;
263
264 switch (req->capability) {
265 case DRM_CAP_DUMB_BUFFER:
266 if (dev->driver->dumb_create)
267 req->value = 1;
268 break;
269 case DRM_CAP_VBLANK_HIGH_CRTC:
270 req->value = 1;
271 break;
272 case DRM_CAP_DUMB_PREFERRED_DEPTH:
273 req->value = dev->mode_config.preferred_depth;
274 break;
275 case DRM_CAP_DUMB_PREFER_SHADOW:
276 req->value = dev->mode_config.prefer_shadow;
277 break;
278 case DRM_CAP_ASYNC_PAGE_FLIP:
279 req->value = dev->mode_config.async_page_flip;
280 break;
281 case DRM_CAP_PAGE_FLIP_TARGET:
282 req->value = 1;
283 drm_for_each_crtc(crtc, dev) {
284 if (!crtc->funcs->page_flip_target)
285 req->value = 0;
286 }
287 break;
288 case DRM_CAP_CURSOR_WIDTH:
289 if (dev->mode_config.cursor_width)
290 req->value = dev->mode_config.cursor_width;
291 else
292 req->value = 64;
293 break;
294 case DRM_CAP_CURSOR_HEIGHT:
295 if (dev->mode_config.cursor_height)
296 req->value = dev->mode_config.cursor_height;
297 else
298 req->value = 64;
299 break;
300 case DRM_CAP_ADDFB2_MODIFIERS:
301 req->value = dev->mode_config.allow_fb_modifiers;
302 break;
303 case DRM_CAP_CRTC_IN_VBLANK_EVENT:
304 req->value = 1;
305 break;
306 default:
307 return -EINVAL;
308 }
309 return 0;
310 }
311
312 /*
313 * Set device/driver capabilities
314 */
315 static int
drm_setclientcap(struct drm_device * dev,void * data,struct drm_file * file_priv)316 drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
317 {
318 struct drm_set_client_cap *req = data;
319
320 /* No render-only settable capabilities for now */
321
322 /* Below caps that only works with KMS drivers */
323 if (!drm_core_check_feature(dev, DRIVER_MODESET))
324 return -EOPNOTSUPP;
325
326 switch (req->capability) {
327 case DRM_CLIENT_CAP_STEREO_3D:
328 if (req->value > 1)
329 return -EINVAL;
330 file_priv->stereo_allowed = req->value;
331 break;
332 case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
333 if (req->value > 1)
334 return -EINVAL;
335 file_priv->universal_planes = req->value;
336 break;
337 case DRM_CLIENT_CAP_ATOMIC:
338 if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
339 return -EOPNOTSUPP;
340 /* The modesetting DDX has a totally broken idea of atomic. */
341 if (current->comm[0] == 'X' && req->value == 1) {
342 pr_info("broken atomic modeset userspace detected, disabling atomic\n");
343 return -EOPNOTSUPP;
344 }
345 if (req->value > 2)
346 return -EINVAL;
347 file_priv->atomic = req->value;
348 file_priv->universal_planes = req->value;
349 /*
350 * No atomic user-space blows up on aspect ratio mode bits.
351 */
352 file_priv->aspect_ratio_allowed = req->value;
353 break;
354 case DRM_CLIENT_CAP_ASPECT_RATIO:
355 if (req->value > 1)
356 return -EINVAL;
357 file_priv->aspect_ratio_allowed = req->value;
358 break;
359 case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS:
360 if (!file_priv->atomic)
361 return -EINVAL;
362 if (req->value > 1)
363 return -EINVAL;
364 file_priv->writeback_connectors = req->value;
365 break;
366 default:
367 return -EINVAL;
368 }
369
370 return 0;
371 }
372
373 /*
374 * Setversion ioctl.
375 *
376 * \param inode device inode.
377 * \param file_priv DRM file private.
378 * \param cmd command.
379 * \param arg user argument, pointing to a drm_lock structure.
380 * \return zero on success or negative number on failure.
381 *
382 * Sets the requested interface version
383 */
drm_setversion(struct drm_device * dev,void * data,struct drm_file * file_priv)384 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
385 {
386 struct drm_set_version *sv = data;
387 int if_version, retcode = 0;
388
389 mutex_lock(&dev->master_mutex);
390 if (sv->drm_di_major != -1) {
391 if (sv->drm_di_major != DRM_IF_MAJOR ||
392 sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
393 retcode = -EINVAL;
394 goto done;
395 }
396 if_version = DRM_IF_VERSION(sv->drm_di_major,
397 sv->drm_di_minor);
398 dev->if_version = max(if_version, dev->if_version);
399 if (sv->drm_di_minor >= 1) {
400 /*
401 * Version 1.1 includes tying of DRM to specific device
402 * Version 1.4 has proper PCI domain support
403 */
404 retcode = drm_set_busid(dev, file_priv);
405 if (retcode)
406 goto done;
407 }
408 }
409
410 if (sv->drm_dd_major != -1) {
411 if (sv->drm_dd_major != dev->driver->major ||
412 sv->drm_dd_minor < 0 || sv->drm_dd_minor >
413 dev->driver->minor) {
414 retcode = -EINVAL;
415 goto done;
416 }
417 }
418
419 done:
420 sv->drm_di_major = DRM_IF_MAJOR;
421 sv->drm_di_minor = DRM_IF_MINOR;
422 sv->drm_dd_major = dev->driver->major;
423 sv->drm_dd_minor = dev->driver->minor;
424 mutex_unlock(&dev->master_mutex);
425
426 return retcode;
427 }
428
429 /**
430 * drm_noop - DRM no-op ioctl implemntation
431 * @dev: DRM device for the ioctl
432 * @data: data pointer for the ioctl
433 * @file_priv: DRM file for the ioctl call
434 *
435 * This no-op implementation for drm ioctls is useful for deprecated
436 * functionality where we can't return a failure code because existing userspace
437 * checks the result of the ioctl, but doesn't care about the action.
438 *
439 * Always returns successfully with 0.
440 */
drm_noop(struct drm_device * dev,void * data,struct drm_file * file_priv)441 int drm_noop(struct drm_device *dev, void *data,
442 struct drm_file *file_priv)
443 {
444 DRM_DEBUG("\n");
445 return 0;
446 }
447 EXPORT_SYMBOL(drm_noop);
448
449 /**
450 * drm_invalid_op - DRM invalid ioctl implemntation
451 * @dev: DRM device for the ioctl
452 * @data: data pointer for the ioctl
453 * @file_priv: DRM file for the ioctl call
454 *
455 * This no-op implementation for drm ioctls is useful for deprecated
456 * functionality where we really don't want to allow userspace to call the ioctl
457 * any more. This is the case for old ums interfaces for drivers that
458 * transitioned to kms gradually and so kept the old legacy tables around. This
459 * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
460 * use this function.
461 *
462 * Always fails with a return value of -EINVAL.
463 */
drm_invalid_op(struct drm_device * dev,void * data,struct drm_file * file_priv)464 int drm_invalid_op(struct drm_device *dev, void *data,
465 struct drm_file *file_priv)
466 {
467 return -EINVAL;
468 }
469 EXPORT_SYMBOL(drm_invalid_op);
470
471 /*
472 * Copy and IOCTL return string to user space
473 */
drm_copy_field(char __user * buf,size_t * buf_len,const char * value)474 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
475 {
476 size_t len;
477
478 /* don't attempt to copy a NULL pointer */
479 if (WARN_ONCE(!value, "BUG: the value to copy was not set!")) {
480 *buf_len = 0;
481 return 0;
482 }
483
484 /* don't overflow userbuf */
485 len = strlen(value);
486 if (len > *buf_len)
487 len = *buf_len;
488
489 /* let userspace know exact length of driver value (which could be
490 * larger than the userspace-supplied buffer) */
491 *buf_len = strlen(value);
492
493 /* finally, try filling in the userbuf */
494 if (len && buf)
495 if (copy_to_user(buf, value, len))
496 return -EFAULT;
497 return 0;
498 }
499
500 /*
501 * Get version information
502 *
503 * \param inode device inode.
504 * \param filp file pointer.
505 * \param cmd command.
506 * \param arg user argument, pointing to a drm_version structure.
507 * \return zero on success or negative number on failure.
508 *
509 * Fills in the version information in \p arg.
510 */
drm_version(struct drm_device * dev,void * data,struct drm_file * file_priv)511 int drm_version(struct drm_device *dev, void *data,
512 struct drm_file *file_priv)
513 {
514 struct drm_version *version = data;
515 int err;
516
517 version->version_major = dev->driver->major;
518 version->version_minor = dev->driver->minor;
519 version->version_patchlevel = dev->driver->patchlevel;
520 err = drm_copy_field(version->name, &version->name_len,
521 dev->driver->name);
522 if (!err)
523 err = drm_copy_field(version->date, &version->date_len,
524 dev->driver->date);
525 if (!err)
526 err = drm_copy_field(version->desc, &version->desc_len,
527 dev->driver->desc);
528
529 return err;
530 }
531
532 /**
533 * drm_ioctl_permit - Check ioctl permissions against caller
534 *
535 * @flags: ioctl permission flags.
536 * @file_priv: Pointer to struct drm_file identifying the caller.
537 *
538 * Checks whether the caller is allowed to run an ioctl with the
539 * indicated permissions.
540 *
541 * Returns:
542 * Zero if allowed, -EACCES otherwise.
543 */
drm_ioctl_permit(u32 flags,struct drm_file * file_priv)544 int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
545 {
546 /* ROOT_ONLY is only for CAP_SYS_ADMIN */
547 if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
548 return -EACCES;
549
550 /* AUTH is only for authenticated or render client */
551 if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
552 !file_priv->authenticated))
553 return -EACCES;
554
555 /* MASTER is only for master or control clients */
556 if (unlikely((flags & DRM_MASTER) &&
557 !drm_is_current_master(file_priv)))
558 return -EACCES;
559
560 /* Render clients must be explicitly allowed */
561 if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
562 drm_is_render_client(file_priv)))
563 return -EACCES;
564
565 return 0;
566 }
567 EXPORT_SYMBOL(drm_ioctl_permit);
568
569 #define DRM_IOCTL_DEF(ioctl, _func, _flags) \
570 [DRM_IOCTL_NR(ioctl)] = { \
571 .cmd = ioctl, \
572 .func = _func, \
573 .flags = _flags, \
574 .name = #ioctl \
575 }
576
577 #if IS_ENABLED(CONFIG_DRM_LEGACY)
578 #define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags) DRM_IOCTL_DEF(ioctl, _func, _flags)
579 #else
580 #define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags) DRM_IOCTL_DEF(ioctl, drm_invalid_op, _flags)
581 #endif
582
583 /* Ioctl table */
584 static const struct drm_ioctl_desc drm_ioctls[] = {
585 DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_RENDER_ALLOW),
586 DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
587 DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0),
588 DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
589
590 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, 0),
591
592 DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, 0),
593 DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0),
594 DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_RENDER_ALLOW),
595 DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
596 DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
597
598 DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
599 DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
600 DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
601 DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_MASTER),
602
603 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
604 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),
605
606 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
607 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),
608
609 DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, 0),
610 DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, 0),
611
612 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
613 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
614 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
615 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
616 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
617 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
618 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),
619
620 DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
621 DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
622
623 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH),
624 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH),
625
626 DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
627
628 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
629 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
630 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH),
631 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH),
632 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH),
633 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH),
634 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_legacy_irq_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
635
636 #if IS_ENABLED(CONFIG_AGP)
637 DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
638 DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
639 DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
640 DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
641 DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
642 DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
643 DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
644 DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
645 #endif
646
647 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
648 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
649
650 DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, DRM_UNLOCKED),
651
652 DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_legacy_modeset_ctl_ioctl, 0),
653
654 DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
655
656 DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_RENDER_ALLOW),
657 DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH),
658 DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH),
659
660 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, 0),
661
662 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_RENDER_ALLOW),
663 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, 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_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER),
686 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER),
687 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_RENDER_ALLOW),
688 DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_RENDER_ALLOW),
689 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_RENDER_ALLOW),
690 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, 0),
691 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER),
692 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER),
693 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER),
694 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, 0),
695 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, 0),
696
697 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_CREATE, drm_syncobj_create_ioctl,
698 DRM_RENDER_ALLOW),
699 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_DESTROY, drm_syncobj_destroy_ioctl,
700 DRM_RENDER_ALLOW),
701 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, drm_syncobj_handle_to_fd_ioctl,
702 DRM_RENDER_ALLOW),
703 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, drm_syncobj_fd_to_handle_ioctl,
704 DRM_RENDER_ALLOW),
705 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TRANSFER, drm_syncobj_transfer_ioctl,
706 DRM_RENDER_ALLOW),
707 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl,
708 DRM_RENDER_ALLOW),
709 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT, drm_syncobj_timeline_wait_ioctl,
710 DRM_RENDER_ALLOW),
711 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl,
712 DRM_RENDER_ALLOW),
713 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl,
714 DRM_RENDER_ALLOW),
715 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL, drm_syncobj_timeline_signal_ioctl,
716 DRM_RENDER_ALLOW),
717 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_QUERY, drm_syncobj_query_ioctl,
718 DRM_RENDER_ALLOW),
719 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, 0),
720 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, 0),
721 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER),
722 DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER),
723 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER),
724 DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER),
725 };
726
727 #define DRM_CORE_IOCTL_COUNT ARRAY_SIZE( drm_ioctls )
728
729 /**
730 * DOC: driver specific ioctls
731 *
732 * First things first, driver private IOCTLs should only be needed for drivers
733 * supporting rendering. Kernel modesetting is all standardized, and extended
734 * through properties. There are a few exceptions in some existing drivers,
735 * which define IOCTL for use by the display DRM master, but they all predate
736 * properties.
737 *
738 * Now if you do have a render driver you always have to support it through
739 * driver private properties. There's a few steps needed to wire all the things
740 * up.
741 *
742 * First you need to define the structure for your IOCTL in your driver private
743 * UAPI header in ``include/uapi/drm/my_driver_drm.h``::
744 *
745 * struct my_driver_operation {
746 * u32 some_thing;
747 * u32 another_thing;
748 * };
749 *
750 * Please make sure that you follow all the best practices from
751 * ``Documentation/process/botching-up-ioctls.rst``. Note that drm_ioctl()
752 * automatically zero-extends structures, hence make sure you can add more stuff
753 * at the end, i.e. don't put a variable sized array there.
754 *
755 * Then you need to define your IOCTL number, using one of DRM_IO(), DRM_IOR(),
756 * DRM_IOW() or DRM_IOWR(). It must start with the DRM_IOCTL\_ prefix::
757 *
758 * ##define DRM_IOCTL_MY_DRIVER_OPERATION \
759 * DRM_IOW(DRM_COMMAND_BASE, struct my_driver_operation)
760 *
761 * DRM driver private IOCTL must be in the range from DRM_COMMAND_BASE to
762 * DRM_COMMAND_END. Finally you need an array of &struct drm_ioctl_desc to wire
763 * up the handlers and set the access rights::
764 *
765 * static const struct drm_ioctl_desc my_driver_ioctls[] = {
766 * DRM_IOCTL_DEF_DRV(MY_DRIVER_OPERATION, my_driver_operation,
767 * DRM_AUTH|DRM_RENDER_ALLOW),
768 * };
769 *
770 * And then assign this to the &drm_driver.ioctls field in your driver
771 * structure.
772 *
773 * See the separate chapter on :ref:`file operations<drm_driver_fops>` for how
774 * the driver-specific IOCTLs are wired up.
775 */
776
drm_ioctl_kernel(struct file * file,drm_ioctl_t * func,void * kdata,u32 flags)777 long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
778 u32 flags)
779 {
780 struct drm_file *file_priv = file->private_data;
781 struct drm_device *dev = file_priv->minor->dev;
782 int retcode;
783
784 if (drm_dev_is_unplugged(dev))
785 return -ENODEV;
786
787 retcode = drm_ioctl_permit(flags, file_priv);
788 if (unlikely(retcode))
789 return retcode;
790
791 /* Enforce sane locking for modern driver ioctls. */
792 if (likely(!drm_core_check_feature(dev, DRIVER_LEGACY)) ||
793 (flags & DRM_UNLOCKED))
794 retcode = func(dev, kdata, file_priv);
795 else {
796 mutex_lock(&drm_global_mutex);
797 retcode = func(dev, kdata, file_priv);
798 mutex_unlock(&drm_global_mutex);
799 }
800 return retcode;
801 }
802 EXPORT_SYMBOL(drm_ioctl_kernel);
803
804 /**
805 * drm_ioctl - ioctl callback implementation for DRM drivers
806 * @filp: file this ioctl is called on
807 * @cmd: ioctl cmd number
808 * @arg: user argument
809 *
810 * Looks up the ioctl function in the DRM core and the driver dispatch table,
811 * stored in &drm_driver.ioctls. It checks for necessary permission by calling
812 * drm_ioctl_permit(), and dispatches to the respective function.
813 *
814 * Returns:
815 * Zero on success, negative error code on failure.
816 */
drm_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)817 long drm_ioctl(struct file *filp,
818 unsigned int cmd, unsigned long arg)
819 {
820 struct drm_file *file_priv = filp->private_data;
821 struct drm_device *dev;
822 const struct drm_ioctl_desc *ioctl = NULL;
823 drm_ioctl_t *func;
824 unsigned int nr = DRM_IOCTL_NR(cmd);
825 int retcode = -EINVAL;
826 char stack_kdata[128];
827 char *kdata = NULL;
828 unsigned int in_size, out_size, drv_size, ksize;
829 bool is_driver_ioctl;
830
831 dev = file_priv->minor->dev;
832
833 if (drm_dev_is_unplugged(dev))
834 return -ENODEV;
835
836 if (DRM_IOCTL_TYPE(cmd) != DRM_IOCTL_BASE)
837 return -ENOTTY;
838
839 is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
840
841 if (is_driver_ioctl) {
842 /* driver ioctl */
843 unsigned int index = nr - DRM_COMMAND_BASE;
844
845 if (index >= dev->driver->num_ioctls)
846 goto err_i1;
847 index = array_index_nospec(index, dev->driver->num_ioctls);
848 ioctl = &dev->driver->ioctls[index];
849 } else {
850 /* core ioctl */
851 if (nr >= DRM_CORE_IOCTL_COUNT)
852 goto err_i1;
853 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
854 ioctl = &drm_ioctls[nr];
855 }
856
857 drv_size = _IOC_SIZE(ioctl->cmd);
858 out_size = in_size = _IOC_SIZE(cmd);
859 if ((cmd & ioctl->cmd & IOC_IN) == 0)
860 in_size = 0;
861 if ((cmd & ioctl->cmd & IOC_OUT) == 0)
862 out_size = 0;
863 ksize = max(max(in_size, out_size), drv_size);
864
865 DRM_DEBUG("comm=\"%s\" pid=%d, dev=0x%lx, auth=%d, %s\n",
866 current->comm, task_pid_nr(current),
867 (long)old_encode_dev(file_priv->minor->kdev->devt),
868 file_priv->authenticated, ioctl->name);
869
870 /* Do not trust userspace, use our own definition */
871 func = ioctl->func;
872
873 if (unlikely(!func)) {
874 DRM_DEBUG("no function\n");
875 retcode = -EINVAL;
876 goto err_i1;
877 }
878
879 if (ksize <= sizeof(stack_kdata)) {
880 kdata = stack_kdata;
881 } else {
882 kdata = kmalloc(ksize, GFP_KERNEL);
883 if (!kdata) {
884 retcode = -ENOMEM;
885 goto err_i1;
886 }
887 }
888
889 if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) {
890 retcode = -EFAULT;
891 goto err_i1;
892 }
893
894 if (ksize > in_size)
895 memset(kdata + in_size, 0, ksize - in_size);
896
897 retcode = drm_ioctl_kernel(filp, func, kdata, ioctl->flags);
898 if (copy_to_user((void __user *)arg, kdata, out_size) != 0)
899 retcode = -EFAULT;
900
901 err_i1:
902 if (!ioctl)
903 DRM_DEBUG("invalid ioctl: comm=\"%s\", pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
904 current->comm, task_pid_nr(current),
905 (long)old_encode_dev(file_priv->minor->kdev->devt),
906 file_priv->authenticated, cmd, nr);
907
908 if (kdata != stack_kdata)
909 kfree(kdata);
910 if (retcode)
911 DRM_DEBUG("comm=\"%s\", pid=%d, ret=%d\n", current->comm,
912 task_pid_nr(current), retcode);
913 return retcode;
914 }
915 EXPORT_SYMBOL(drm_ioctl);
916
917 /**
918 * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
919 * @nr: ioctl number
920 * @flags: where to return the ioctl permission flags
921 *
922 * This ioctl is only used by the vmwgfx driver to augment the access checks
923 * done by the drm core and insofar a pretty decent layering violation. This
924 * shouldn't be used by any drivers.
925 *
926 * Returns:
927 * True if the @nr corresponds to a DRM core ioctl number, false otherwise.
928 */
drm_ioctl_flags(unsigned int nr,unsigned int * flags)929 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
930 {
931 if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
932 return false;
933
934 if (nr >= DRM_CORE_IOCTL_COUNT)
935 return false;
936 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
937
938 *flags = drm_ioctls[nr].flags;
939 return true;
940 }
941 EXPORT_SYMBOL(drm_ioctl_flags);
942