1 /*
2 * Created: Fri Jan 8 09:01:26 1999 by faith@valinux.com
3 *
4 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
5 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
6 * All Rights Reserved.
7 *
8 * Author Rickard E. (Rik) Faith <faith@valinux.com>
9 * Author Gareth Hughes <gareth@valinux.com>
10 *
11 * Permission is hereby granted, free of charge, to any person obtaining a
12 * copy of this software and associated documentation files (the "Software"),
13 * to deal in the Software without restriction, including without limitation
14 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
15 * and/or sell copies of the Software, and to permit persons to whom the
16 * Software is furnished to do so, subject to the following conditions:
17 *
18 * The above copyright notice and this permission notice (including the next
19 * paragraph) shall be included in all copies or substantial portions of the
20 * Software.
21 *
22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
25 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
26 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
27 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
28 * OTHER DEALINGS IN THE SOFTWARE.
29 */
30
31 #include <linux/export.h>
32 #include <linux/nospec.h>
33 #include <linux/pci.h>
34 #include <linux/uaccess.h>
35
36 #include <drm/drm_auth.h>
37 #include <drm/drm_crtc.h>
38 #include <drm/drm_drv.h>
39 #include <drm/drm_file.h>
40 #include <drm/drm_ioctl.h>
41 #include <drm/drm_print.h>
42
43 #include "drm_crtc_internal.h"
44 #include "drm_internal.h"
45 #include "drm_legacy.h"
46
47 /**
48 * DOC: getunique and setversion story
49 *
50 * BEWARE THE DRAGONS! MIND THE TRAPDOORS!
51 *
52 * In an attempt to warn anyone else who's trying to figure out what's going
53 * on here, I'll try to summarize the story. First things first, let's clear up
54 * the names, because the kernel internals, libdrm and the ioctls are all named
55 * differently:
56 *
57 * - GET_UNIQUE ioctl, implemented by drm_getunique is wrapped up in libdrm
58 * through the drmGetBusid function.
59 * - The libdrm drmSetBusid function is backed by the SET_UNIQUE ioctl. All
60 * that code is nerved in the kernel with drm_invalid_op().
61 * - The internal set_busid kernel functions and driver callbacks are
62 * exclusively use by the SET_VERSION ioctl, because only drm 1.0 (which is
63 * nerved) allowed userspace to set the busid through the above ioctl.
64 * - Other ioctls and functions involved are named consistently.
65 *
66 * For anyone wondering what's the difference between drm 1.1 and 1.4: Correctly
67 * handling pci domains in the busid on ppc. Doing this correctly was only
68 * implemented in libdrm in 2010, hence can't be nerved yet. No one knows what's
69 * special with drm 1.2 and 1.3.
70 *
71 * Now the actual horror story of how device lookup in drm works. At large,
72 * there's 2 different ways, either by busid, or by device driver name.
73 *
74 * Opening by busid is fairly simple:
75 *
76 * 1. First call SET_VERSION to make sure pci domains are handled properly. As a
77 * side-effect this fills out the unique name in the master structure.
78 * 2. Call GET_UNIQUE to read out the unique name from the master structure,
79 * which matches the busid thanks to step 1. If it doesn't, proceed to try
80 * the next device node.
81 *
82 * Opening by name is slightly different:
83 *
84 * 1. Directly call VERSION to get the version and to match against the driver
85 * name returned by that ioctl. Note that SET_VERSION is not called, which
86 * means the unique name for the master node just opening is _not_ filled
87 * out. This despite that with current drm device nodes are always bound to
88 * one device, and can't be runtime assigned like with drm 1.0.
89 * 2. Match driver name. If it mismatches, proceed to the next device node.
90 * 3. Call GET_UNIQUE, and check whether the unique name has length zero (by
91 * checking that the first byte in the string is 0). If that's not the case
92 * libdrm skips and proceeds to the next device node. Probably this is just
93 * copypasta from drm 1.0 times where a set unique name meant that the driver
94 * was in use already, but that's just conjecture.
95 *
96 * Long story short: To keep the open by name logic working, GET_UNIQUE must
97 * _not_ return a unique string when SET_VERSION hasn't been called yet,
98 * otherwise libdrm breaks. Even when that unique string can't ever change, and
99 * is totally irrelevant for actually opening the device because runtime
100 * assignable device instances were only support in drm 1.0, which is long dead.
101 * But the libdrm code in drmOpenByName somehow survived, hence this can't be
102 * broken.
103 */
104
105 /*
106 * Get the bus id.
107 *
108 * \param inode device inode.
109 * \param file_priv DRM file private.
110 * \param cmd command.
111 * \param arg user argument, pointing to a drm_unique structure.
112 * \return zero on success or a negative number on failure.
113 *
114 * Copies the bus id from drm_device::unique into user space.
115 */
drm_getunique(struct drm_device * dev,void * data,struct drm_file * file_priv)116 int drm_getunique(struct drm_device *dev, void *data,
117 struct drm_file *file_priv)
118 {
119 struct drm_unique *u = data;
120 struct drm_master *master;
121
122 mutex_lock(&dev->master_mutex);
123 master = file_priv->master;
124 if (u->unique_len >= master->unique_len) {
125 if (copy_to_user(u->unique, master->unique, master->unique_len)) {
126 mutex_unlock(&dev->master_mutex);
127 return -EFAULT;
128 }
129 }
130 u->unique_len = master->unique_len;
131 mutex_unlock(&dev->master_mutex);
132
133 return 0;
134 }
135
136 static void
drm_unset_busid(struct drm_device * dev,struct drm_master * master)137 drm_unset_busid(struct drm_device *dev,
138 struct drm_master *master)
139 {
140 kfree(master->unique);
141 master->unique = NULL;
142 master->unique_len = 0;
143 }
144
drm_set_busid(struct drm_device * dev,struct drm_file * file_priv)145 static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
146 {
147 struct drm_master *master = file_priv->master;
148 int ret;
149
150 if (master->unique != NULL)
151 drm_unset_busid(dev, master);
152
153 if (dev->dev && dev_is_pci(dev->dev)) {
154 ret = drm_pci_set_busid(dev, master);
155 if (ret) {
156 drm_unset_busid(dev, master);
157 return ret;
158 }
159 } else {
160 WARN_ON(!dev->unique);
161 master->unique = kstrdup(dev->unique, GFP_KERNEL);
162 if (master->unique)
163 master->unique_len = strlen(dev->unique);
164 }
165
166 return 0;
167 }
168
169 /*
170 * Get client information.
171 *
172 * \param inode device inode.
173 * \param file_priv DRM file private.
174 * \param cmd command.
175 * \param arg user argument, pointing to a drm_client structure.
176 *
177 * \return zero on success or a negative number on failure.
178 *
179 * Searches for the client with the specified index and copies its information
180 * into userspace
181 */
drm_getclient(struct drm_device * dev,void * data,struct drm_file * file_priv)182 int drm_getclient(struct drm_device *dev, void *data,
183 struct drm_file *file_priv)
184 {
185 struct drm_client *client = data;
186
187 /*
188 * Hollowed-out getclient ioctl to keep some dead old drm tests/tools
189 * not breaking completely. Userspace tools stop enumerating one they
190 * get -EINVAL, hence this is the return value we need to hand back for
191 * no clients tracked.
192 *
193 * Unfortunately some clients (*cough* libva *cough*) use this in a fun
194 * attempt to figure out whether they're authenticated or not. Since
195 * that's the only thing they care about, give it to the directly
196 * instead of walking one giant list.
197 */
198 if (client->idx == 0) {
199 client->auth = file_priv->authenticated;
200 client->pid = task_pid_vnr(current);
201 client->uid = overflowuid;
202 client->magic = 0;
203 client->iocs = 0;
204
205 return 0;
206 } else {
207 return -EINVAL;
208 }
209 }
210
211 /*
212 * Get statistics information.
213 *
214 * \param inode device inode.
215 * \param file_priv DRM file private.
216 * \param cmd command.
217 * \param arg user argument, pointing to a drm_stats structure.
218 *
219 * \return zero on success or a negative number on failure.
220 */
drm_getstats(struct drm_device * dev,void * data,struct drm_file * file_priv)221 static int drm_getstats(struct drm_device *dev, void *data,
222 struct drm_file *file_priv)
223 {
224 struct drm_stats *stats = data;
225
226 /* Clear stats to prevent userspace from eating its stack garbage. */
227 memset(stats, 0, sizeof(*stats));
228
229 return 0;
230 }
231
232 /*
233 * Get device/driver capabilities
234 */
drm_getcap(struct drm_device * dev,void * data,struct drm_file * file_priv)235 static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
236 {
237 struct drm_get_cap *req = data;
238 struct drm_crtc *crtc;
239
240 req->value = 0;
241
242 /* Only some caps make sense with UMS/render-only drivers. */
243 switch (req->capability) {
244 case DRM_CAP_TIMESTAMP_MONOTONIC:
245 req->value = 1;
246 return 0;
247 case DRM_CAP_PRIME:
248 req->value = DRM_PRIME_CAP_IMPORT | DRM_PRIME_CAP_EXPORT;
249 return 0;
250 case DRM_CAP_SYNCOBJ:
251 req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ);
252 return 0;
253 case DRM_CAP_SYNCOBJ_TIMELINE:
254 req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE);
255 return 0;
256 }
257
258 /* Other caps only work with KMS drivers */
259 if (!drm_core_check_feature(dev, DRIVER_MODESET))
260 return -EOPNOTSUPP;
261
262 switch (req->capability) {
263 case DRM_CAP_DUMB_BUFFER:
264 if (dev->driver->dumb_create)
265 req->value = 1;
266 break;
267 case DRM_CAP_VBLANK_HIGH_CRTC:
268 req->value = 1;
269 break;
270 case DRM_CAP_DUMB_PREFERRED_DEPTH:
271 req->value = dev->mode_config.preferred_depth;
272 break;
273 case DRM_CAP_DUMB_PREFER_SHADOW:
274 req->value = dev->mode_config.prefer_shadow;
275 break;
276 case DRM_CAP_ASYNC_PAGE_FLIP:
277 req->value = dev->mode_config.async_page_flip;
278 break;
279 case DRM_CAP_PAGE_FLIP_TARGET:
280 req->value = 1;
281 drm_for_each_crtc(crtc, dev) {
282 if (!crtc->funcs->page_flip_target)
283 req->value = 0;
284 }
285 break;
286 case DRM_CAP_CURSOR_WIDTH:
287 if (dev->mode_config.cursor_width)
288 req->value = dev->mode_config.cursor_width;
289 else
290 req->value = 64;
291 break;
292 case DRM_CAP_CURSOR_HEIGHT:
293 if (dev->mode_config.cursor_height)
294 req->value = dev->mode_config.cursor_height;
295 else
296 req->value = 64;
297 break;
298 case DRM_CAP_ADDFB2_MODIFIERS:
299 req->value = !dev->mode_config.fb_modifiers_not_supported;
300 break;
301 case DRM_CAP_CRTC_IN_VBLANK_EVENT:
302 req->value = 1;
303 break;
304 default:
305 return -EINVAL;
306 }
307 return 0;
308 }
309
310 /*
311 * Set device/driver capabilities
312 */
313 static int
drm_setclientcap(struct drm_device * dev,void * data,struct drm_file * file_priv)314 drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
315 {
316 struct drm_set_client_cap *req = data;
317
318 /* No render-only settable capabilities for now */
319
320 /* Below caps that only works with KMS drivers */
321 if (!drm_core_check_feature(dev, DRIVER_MODESET))
322 return -EOPNOTSUPP;
323
324 switch (req->capability) {
325 case DRM_CLIENT_CAP_STEREO_3D:
326 if (req->value > 1)
327 return -EINVAL;
328 file_priv->stereo_allowed = req->value;
329 break;
330 case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
331 if (req->value > 1)
332 return -EINVAL;
333 file_priv->universal_planes = req->value;
334 break;
335 case DRM_CLIENT_CAP_ATOMIC:
336 if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
337 return -EOPNOTSUPP;
338 /* The modesetting DDX has a totally broken idea of atomic. */
339 if (current->comm[0] == 'X' && req->value == 1) {
340 pr_info("broken atomic modeset userspace detected, disabling atomic\n");
341 return -EOPNOTSUPP;
342 }
343 if (req->value > 2)
344 return -EINVAL;
345 file_priv->atomic = req->value;
346 file_priv->universal_planes = req->value;
347 /*
348 * No atomic user-space blows up on aspect ratio mode bits.
349 */
350 file_priv->aspect_ratio_allowed = req->value;
351 break;
352 case DRM_CLIENT_CAP_ASPECT_RATIO:
353 if (req->value > 1)
354 return -EINVAL;
355 file_priv->aspect_ratio_allowed = req->value;
356 break;
357 case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS:
358 if (!file_priv->atomic)
359 return -EINVAL;
360 if (req->value > 1)
361 return -EINVAL;
362 file_priv->writeback_connectors = req->value;
363 break;
364 default:
365 return -EINVAL;
366 }
367
368 return 0;
369 }
370
371 /*
372 * Setversion ioctl.
373 *
374 * \param inode device inode.
375 * \param file_priv DRM file private.
376 * \param cmd command.
377 * \param arg user argument, pointing to a drm_lock structure.
378 * \return zero on success or negative number on failure.
379 *
380 * Sets the requested interface version
381 */
drm_setversion(struct drm_device * dev,void * data,struct drm_file * file_priv)382 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
383 {
384 struct drm_set_version *sv = data;
385 int if_version, retcode = 0;
386
387 mutex_lock(&dev->master_mutex);
388 if (sv->drm_di_major != -1) {
389 if (sv->drm_di_major != DRM_IF_MAJOR ||
390 sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
391 retcode = -EINVAL;
392 goto done;
393 }
394 if_version = DRM_IF_VERSION(sv->drm_di_major,
395 sv->drm_di_minor);
396 dev->if_version = max(if_version, dev->if_version);
397 if (sv->drm_di_minor >= 1) {
398 /*
399 * Version 1.1 includes tying of DRM to specific device
400 * Version 1.4 has proper PCI domain support
401 */
402 retcode = drm_set_busid(dev, file_priv);
403 if (retcode)
404 goto done;
405 }
406 }
407
408 if (sv->drm_dd_major != -1) {
409 if (sv->drm_dd_major != dev->driver->major ||
410 sv->drm_dd_minor < 0 || sv->drm_dd_minor >
411 dev->driver->minor) {
412 retcode = -EINVAL;
413 goto done;
414 }
415 }
416
417 done:
418 sv->drm_di_major = DRM_IF_MAJOR;
419 sv->drm_di_minor = DRM_IF_MINOR;
420 sv->drm_dd_major = dev->driver->major;
421 sv->drm_dd_minor = dev->driver->minor;
422 mutex_unlock(&dev->master_mutex);
423
424 return retcode;
425 }
426
427 /**
428 * drm_noop - DRM no-op ioctl implementation
429 * @dev: DRM device for the ioctl
430 * @data: data pointer for the ioctl
431 * @file_priv: DRM file for the ioctl call
432 *
433 * This no-op implementation for drm ioctls is useful for deprecated
434 * functionality where we can't return a failure code because existing userspace
435 * checks the result of the ioctl, but doesn't care about the action.
436 *
437 * Always returns successfully with 0.
438 */
drm_noop(struct drm_device * dev,void * data,struct drm_file * file_priv)439 int drm_noop(struct drm_device *dev, void *data,
440 struct drm_file *file_priv)
441 {
442 drm_dbg_core(dev, "\n");
443 return 0;
444 }
445 EXPORT_SYMBOL(drm_noop);
446
447 /**
448 * drm_invalid_op - DRM invalid ioctl implementation
449 * @dev: DRM device for the ioctl
450 * @data: data pointer for the ioctl
451 * @file_priv: DRM file for the ioctl call
452 *
453 * This no-op implementation for drm ioctls is useful for deprecated
454 * functionality where we really don't want to allow userspace to call the ioctl
455 * any more. This is the case for old ums interfaces for drivers that
456 * transitioned to kms gradually and so kept the old legacy tables around. This
457 * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
458 * use this function.
459 *
460 * Always fails with a return value of -EINVAL.
461 */
drm_invalid_op(struct drm_device * dev,void * data,struct drm_file * file_priv)462 int drm_invalid_op(struct drm_device *dev, void *data,
463 struct drm_file *file_priv)
464 {
465 return -EINVAL;
466 }
467 EXPORT_SYMBOL(drm_invalid_op);
468
469 /*
470 * Copy and IOCTL return string to user space
471 */
drm_copy_field(char __user * buf,size_t * buf_len,const char * value)472 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
473 {
474 size_t len;
475
476 /* don't attempt to copy a NULL pointer */
477 if (WARN_ONCE(!value, "BUG: the value to copy was not set!")) {
478 *buf_len = 0;
479 return 0;
480 }
481
482 /* don't overflow userbuf */
483 len = strlen(value);
484 if (len > *buf_len)
485 len = *buf_len;
486
487 /* let userspace know exact length of driver value (which could be
488 * larger than the userspace-supplied buffer) */
489 *buf_len = strlen(value);
490
491 /* finally, try filling in the userbuf */
492 if (len && buf)
493 if (copy_to_user(buf, value, len))
494 return -EFAULT;
495 return 0;
496 }
497
498 /*
499 * Get version information
500 *
501 * \param inode device inode.
502 * \param filp file pointer.
503 * \param cmd command.
504 * \param arg user argument, pointing to a drm_version structure.
505 * \return zero on success or negative number on failure.
506 *
507 * Fills in the version information in \p arg.
508 */
drm_version(struct drm_device * dev,void * data,struct drm_file * file_priv)509 int drm_version(struct drm_device *dev, void *data,
510 struct drm_file *file_priv)
511 {
512 struct drm_version *version = data;
513 int err;
514
515 version->version_major = dev->driver->major;
516 version->version_minor = dev->driver->minor;
517 version->version_patchlevel = dev->driver->patchlevel;
518 err = drm_copy_field(version->name, &version->name_len,
519 dev->driver->name);
520 if (!err)
521 err = drm_copy_field(version->date, &version->date_len,
522 dev->driver->date);
523 if (!err)
524 err = drm_copy_field(version->desc, &version->desc_len,
525 dev->driver->desc);
526
527 return err;
528 }
529
drm_ioctl_permit(u32 flags,struct drm_file * file_priv)530 static int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
531 {
532 /* ROOT_ONLY is only for CAP_SYS_ADMIN */
533 if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
534 return -EACCES;
535
536 /* AUTH is only for authenticated or render client */
537 if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
538 !file_priv->authenticated))
539 return -EACCES;
540
541 /* MASTER is only for master or control clients */
542 if (unlikely((flags & DRM_MASTER) &&
543 !drm_is_current_master(file_priv)))
544 return -EACCES;
545
546 /* Render clients must be explicitly allowed */
547 if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
548 drm_is_render_client(file_priv)))
549 return -EACCES;
550
551 return 0;
552 }
553
554 #define DRM_IOCTL_DEF(ioctl, _func, _flags) \
555 [DRM_IOCTL_NR(ioctl)] = { \
556 .cmd = ioctl, \
557 .func = _func, \
558 .flags = _flags, \
559 .name = #ioctl \
560 }
561
562 #if IS_ENABLED(CONFIG_DRM_LEGACY)
563 #define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags) DRM_IOCTL_DEF(ioctl, _func, _flags)
564 #else
565 #define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags) DRM_IOCTL_DEF(ioctl, drm_invalid_op, _flags)
566 #endif
567
568 /* Ioctl table */
569 static const struct drm_ioctl_desc drm_ioctls[] = {
570 DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_RENDER_ALLOW),
571 DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
572 DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0),
573 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_legacy_irq_by_busid,
574 DRM_MASTER|DRM_ROOT_ONLY),
575
576 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, 0),
577
578 DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, 0),
579 DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0),
580 DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_RENDER_ALLOW),
581 DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
582 DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
583
584 DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
585 DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
586 DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
587 DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_MASTER),
588
589 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
590 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),
591
592 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
593 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),
594
595 DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, 0),
596 DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, 0),
597
598 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
599 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
600 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
601 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
602 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
603 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
604 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),
605
606 DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
607 DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
608
609 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH),
610 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH),
611
612 DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
613
614 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
615 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
616 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH),
617 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH),
618 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH),
619 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH),
620 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_legacy_irq_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
621
622 #if IS_ENABLED(CONFIG_AGP)
623 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_legacy_agp_acquire_ioctl,
624 DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
625 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_legacy_agp_release_ioctl,
626 DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
627 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_legacy_agp_enable_ioctl,
628 DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
629 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_legacy_agp_info_ioctl, DRM_AUTH),
630 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_legacy_agp_alloc_ioctl,
631 DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
632 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_legacy_agp_free_ioctl,
633 DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
634 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_legacy_agp_bind_ioctl,
635 DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
636 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_legacy_agp_unbind_ioctl,
637 DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
638 #endif
639
640 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
641 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
642
643 DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, DRM_UNLOCKED),
644
645 DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_legacy_modeset_ctl_ioctl, 0),
646
647 DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
648
649 DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_RENDER_ALLOW),
650 DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH),
651 DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH),
652
653 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, 0),
654
655 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_RENDER_ALLOW),
656 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_RENDER_ALLOW),
657
658 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, 0),
659 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, 0),
660 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER),
661 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, 0),
662 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER),
663 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER),
664 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, 0),
665 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER),
666 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, 0),
667 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, 0),
668 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER),
669 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER),
670 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, 0),
671 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_connector_property_set_ioctl, DRM_MASTER),
672 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, 0),
673 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, 0),
674 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB2, drm_mode_getfb2_ioctl, 0),
675 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb_ioctl, 0),
676 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2_ioctl, 0),
677 DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb_ioctl, 0),
678 DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER),
679 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER),
680 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, 0),
681 DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, 0),
682 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, 0),
683 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, 0),
684 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER),
685 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER),
686 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER),
687 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, 0),
688 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, 0),
689
690 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_CREATE, drm_syncobj_create_ioctl,
691 DRM_RENDER_ALLOW),
692 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_DESTROY, drm_syncobj_destroy_ioctl,
693 DRM_RENDER_ALLOW),
694 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, drm_syncobj_handle_to_fd_ioctl,
695 DRM_RENDER_ALLOW),
696 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, drm_syncobj_fd_to_handle_ioctl,
697 DRM_RENDER_ALLOW),
698 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TRANSFER, drm_syncobj_transfer_ioctl,
699 DRM_RENDER_ALLOW),
700 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl,
701 DRM_RENDER_ALLOW),
702 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT, drm_syncobj_timeline_wait_ioctl,
703 DRM_RENDER_ALLOW),
704 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_EVENTFD, drm_syncobj_eventfd_ioctl,
705 DRM_RENDER_ALLOW),
706 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl,
707 DRM_RENDER_ALLOW),
708 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl,
709 DRM_RENDER_ALLOW),
710 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL, drm_syncobj_timeline_signal_ioctl,
711 DRM_RENDER_ALLOW),
712 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_QUERY, drm_syncobj_query_ioctl,
713 DRM_RENDER_ALLOW),
714 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, 0),
715 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, 0),
716 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER),
717 DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER),
718 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER),
719 DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER),
720 };
721
722 #define DRM_CORE_IOCTL_COUNT ARRAY_SIZE(drm_ioctls)
723
724 /**
725 * DOC: driver specific ioctls
726 *
727 * First things first, driver private IOCTLs should only be needed for drivers
728 * supporting rendering. Kernel modesetting is all standardized, and extended
729 * through properties. There are a few exceptions in some existing drivers,
730 * which define IOCTL for use by the display DRM master, but they all predate
731 * properties.
732 *
733 * Now if you do have a render driver you always have to support it through
734 * driver private properties. There's a few steps needed to wire all the things
735 * up.
736 *
737 * First you need to define the structure for your IOCTL in your driver private
738 * UAPI header in ``include/uapi/drm/my_driver_drm.h``::
739 *
740 * struct my_driver_operation {
741 * u32 some_thing;
742 * u32 another_thing;
743 * };
744 *
745 * Please make sure that you follow all the best practices from
746 * ``Documentation/process/botching-up-ioctls.rst``. Note that drm_ioctl()
747 * automatically zero-extends structures, hence make sure you can add more stuff
748 * at the end, i.e. don't put a variable sized array there.
749 *
750 * Then you need to define your IOCTL number, using one of DRM_IO(), DRM_IOR(),
751 * DRM_IOW() or DRM_IOWR(). It must start with the DRM_IOCTL\_ prefix::
752 *
753 * ##define DRM_IOCTL_MY_DRIVER_OPERATION \
754 * DRM_IOW(DRM_COMMAND_BASE, struct my_driver_operation)
755 *
756 * DRM driver private IOCTL must be in the range from DRM_COMMAND_BASE to
757 * DRM_COMMAND_END. Finally you need an array of &struct drm_ioctl_desc to wire
758 * up the handlers and set the access rights::
759 *
760 * static const struct drm_ioctl_desc my_driver_ioctls[] = {
761 * DRM_IOCTL_DEF_DRV(MY_DRIVER_OPERATION, my_driver_operation,
762 * DRM_AUTH|DRM_RENDER_ALLOW),
763 * };
764 *
765 * And then assign this to the &drm_driver.ioctls field in your driver
766 * structure.
767 *
768 * See the separate chapter on :ref:`file operations<drm_driver_fops>` for how
769 * the driver-specific IOCTLs are wired up.
770 */
771
drm_ioctl_kernel(struct file * file,drm_ioctl_t * func,void * kdata,u32 flags)772 long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
773 u32 flags)
774 {
775 struct drm_file *file_priv = file->private_data;
776 struct drm_device *dev = file_priv->minor->dev;
777 int retcode;
778
779 /* Update drm_file owner if fd was passed along. */
780 drm_file_update_pid(file_priv);
781
782 if (drm_dev_is_unplugged(dev))
783 return -ENODEV;
784
785 retcode = drm_ioctl_permit(flags, file_priv);
786 if (unlikely(retcode))
787 return retcode;
788
789 /* Enforce sane locking for modern driver ioctls. */
790 if (likely(!drm_core_check_feature(dev, DRIVER_LEGACY)) ||
791 (flags & DRM_UNLOCKED))
792 retcode = func(dev, kdata, file_priv);
793 else {
794 mutex_lock(&drm_global_mutex);
795 retcode = func(dev, kdata, file_priv);
796 mutex_unlock(&drm_global_mutex);
797 }
798 return retcode;
799 }
800 EXPORT_SYMBOL(drm_ioctl_kernel);
801
802 /**
803 * drm_ioctl - ioctl callback implementation for DRM drivers
804 * @filp: file this ioctl is called on
805 * @cmd: ioctl cmd number
806 * @arg: user argument
807 *
808 * Looks up the ioctl function in the DRM core and the driver dispatch table,
809 * stored in &drm_driver.ioctls. It checks for necessary permission by calling
810 * drm_ioctl_permit(), and dispatches to the respective function.
811 *
812 * Returns:
813 * Zero on success, negative error code on failure.
814 */
drm_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)815 long drm_ioctl(struct file *filp,
816 unsigned int cmd, unsigned long arg)
817 {
818 struct drm_file *file_priv = filp->private_data;
819 struct drm_device *dev;
820 const struct drm_ioctl_desc *ioctl = NULL;
821 drm_ioctl_t *func;
822 unsigned int nr = DRM_IOCTL_NR(cmd);
823 int retcode = -EINVAL;
824 char stack_kdata[128];
825 char *kdata = NULL;
826 unsigned int in_size, out_size, drv_size, ksize;
827 bool is_driver_ioctl;
828
829 dev = file_priv->minor->dev;
830
831 if (drm_dev_is_unplugged(dev))
832 return -ENODEV;
833
834 if (DRM_IOCTL_TYPE(cmd) != DRM_IOCTL_BASE)
835 return -ENOTTY;
836
837 is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
838
839 if (is_driver_ioctl) {
840 /* driver ioctl */
841 unsigned int index = nr - DRM_COMMAND_BASE;
842
843 if (index >= dev->driver->num_ioctls)
844 goto err_i1;
845 index = array_index_nospec(index, dev->driver->num_ioctls);
846 ioctl = &dev->driver->ioctls[index];
847 } else {
848 /* core ioctl */
849 if (nr >= DRM_CORE_IOCTL_COUNT)
850 goto err_i1;
851 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
852 ioctl = &drm_ioctls[nr];
853 }
854
855 drv_size = _IOC_SIZE(ioctl->cmd);
856 out_size = in_size = _IOC_SIZE(cmd);
857 if ((cmd & ioctl->cmd & IOC_IN) == 0)
858 in_size = 0;
859 if ((cmd & ioctl->cmd & IOC_OUT) == 0)
860 out_size = 0;
861 ksize = max(max(in_size, out_size), drv_size);
862
863 drm_dbg_core(dev, "comm=\"%s\" pid=%d, dev=0x%lx, auth=%d, %s\n",
864 current->comm, task_pid_nr(current),
865 (long)old_encode_dev(file_priv->minor->kdev->devt),
866 file_priv->authenticated, ioctl->name);
867
868 /* Do not trust userspace, use our own definition */
869 func = ioctl->func;
870
871 if (unlikely(!func)) {
872 drm_dbg_core(dev, "no function\n");
873 retcode = -EINVAL;
874 goto err_i1;
875 }
876
877 if (ksize <= sizeof(stack_kdata)) {
878 kdata = stack_kdata;
879 } else {
880 kdata = kmalloc(ksize, GFP_KERNEL);
881 if (!kdata) {
882 retcode = -ENOMEM;
883 goto err_i1;
884 }
885 }
886
887 if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) {
888 retcode = -EFAULT;
889 goto err_i1;
890 }
891
892 if (ksize > in_size)
893 memset(kdata + in_size, 0, ksize - in_size);
894
895 retcode = drm_ioctl_kernel(filp, func, kdata, ioctl->flags);
896 if (copy_to_user((void __user *)arg, kdata, out_size) != 0)
897 retcode = -EFAULT;
898
899 err_i1:
900 if (!ioctl)
901 drm_dbg_core(dev,
902 "invalid ioctl: comm=\"%s\", pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
903 current->comm, task_pid_nr(current),
904 (long)old_encode_dev(file_priv->minor->kdev->devt),
905 file_priv->authenticated, cmd, nr);
906
907 if (kdata != stack_kdata)
908 kfree(kdata);
909 if (retcode)
910 drm_dbg_core(dev, "comm=\"%s\", pid=%d, ret=%d\n",
911 current->comm, task_pid_nr(current), retcode);
912 return retcode;
913 }
914 EXPORT_SYMBOL(drm_ioctl);
915
916 /**
917 * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
918 * @nr: ioctl number
919 * @flags: where to return the ioctl permission flags
920 *
921 * This ioctl is only used by the vmwgfx driver to augment the access checks
922 * done by the drm core and insofar a pretty decent layering violation. This
923 * shouldn't be used by any drivers.
924 *
925 * Returns:
926 * True if the @nr corresponds to a DRM core ioctl number, false otherwise.
927 */
drm_ioctl_flags(unsigned int nr,unsigned int * flags)928 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
929 {
930 if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
931 return false;
932
933 if (nr >= DRM_CORE_IOCTL_COUNT)
934 return false;
935 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
936
937 *flags = drm_ioctls[nr].flags;
938 return true;
939 }
940 EXPORT_SYMBOL(drm_ioctl_flags);
941