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 <drm/drm_ioctl.h>
32 #include <drm/drmP.h>
33 #include <drm/drm_auth.h>
34 #include "drm_legacy.h"
35 #include "drm_internal.h"
36 #include "drm_crtc_internal.h"
37
38 #include <linux/pci.h>
39 #include <linux/export.h>
40 #include <linux/nospec.h>
41
42 /**
43 * DOC: getunique and setversion story
44 *
45 * BEWARE THE DRAGONS! MIND THE TRAPDOORS!
46 *
47 * In an attempt to warn anyone else who's trying to figure out what's going
48 * on here, I'll try to summarize the story. First things first, let's clear up
49 * the names, because the kernel internals, libdrm and the ioctls are all named
50 * differently:
51 *
52 * - GET_UNIQUE ioctl, implemented by drm_getunique is wrapped up in libdrm
53 * through the drmGetBusid function.
54 * - The libdrm drmSetBusid function is backed by the SET_UNIQUE ioctl. All
55 * that code is nerved in the kernel with drm_invalid_op().
56 * - The internal set_busid kernel functions and driver callbacks are
57 * exclusively use by the SET_VERSION ioctl, because only drm 1.0 (which is
58 * nerved) allowed userspace to set the busid through the above ioctl.
59 * - Other ioctls and functions involved are named consistently.
60 *
61 * For anyone wondering what's the difference between drm 1.1 and 1.4: Correctly
62 * handling pci domains in the busid on ppc. Doing this correctly was only
63 * implemented in libdrm in 2010, hence can't be nerved yet. No one knows what's
64 * special with drm 1.2 and 1.3.
65 *
66 * Now the actual horror story of how device lookup in drm works. At large,
67 * there's 2 different ways, either by busid, or by device driver name.
68 *
69 * Opening by busid is fairly simple:
70 *
71 * 1. First call SET_VERSION to make sure pci domains are handled properly. As a
72 * side-effect this fills out the unique name in the master structure.
73 * 2. Call GET_UNIQUE to read out the unique name from the master structure,
74 * which matches the busid thanks to step 1. If it doesn't, proceed to try
75 * the next device node.
76 *
77 * Opening by name is slightly different:
78 *
79 * 1. Directly call VERSION to get the version and to match against the driver
80 * name returned by that ioctl. Note that SET_VERSION is not called, which
81 * means the the unique name for the master node just opening is _not_ filled
82 * out. This despite that with current drm device nodes are always bound to
83 * one device, and can't be runtime assigned like with drm 1.0.
84 * 2. Match driver name. If it mismatches, proceed to the next device node.
85 * 3. Call GET_UNIQUE, and check whether the unique name has length zero (by
86 * checking that the first byte in the string is 0). If that's not the case
87 * libdrm skips and proceeds to the next device node. Probably this is just
88 * copypasta from drm 1.0 times where a set unique name meant that the driver
89 * was in use already, but that's just conjecture.
90 *
91 * Long story short: To keep the open by name logic working, GET_UNIQUE must
92 * _not_ return a unique string when SET_VERSION hasn't been called yet,
93 * otherwise libdrm breaks. Even when that unique string can't ever change, and
94 * is totally irrelevant for actually opening the device because runtime
95 * assignable device instances were only support in drm 1.0, which is long dead.
96 * But the libdrm code in drmOpenByName somehow survived, hence this can't be
97 * broken.
98 */
99
100 /*
101 * Get the bus id.
102 *
103 * \param inode device inode.
104 * \param file_priv DRM file private.
105 * \param cmd command.
106 * \param arg user argument, pointing to a drm_unique structure.
107 * \return zero on success or a negative number on failure.
108 *
109 * Copies the bus id from drm_device::unique into user space.
110 */
drm_getunique(struct drm_device * dev,void * data,struct drm_file * file_priv)111 int drm_getunique(struct drm_device *dev, void *data,
112 struct drm_file *file_priv)
113 {
114 struct drm_unique *u = data;
115 struct drm_master *master = file_priv->master;
116
117 mutex_lock(&master->dev->master_mutex);
118 if (u->unique_len >= master->unique_len) {
119 if (copy_to_user(u->unique, master->unique, master->unique_len)) {
120 mutex_unlock(&master->dev->master_mutex);
121 return -EFAULT;
122 }
123 }
124 u->unique_len = master->unique_len;
125 mutex_unlock(&master->dev->master_mutex);
126
127 return 0;
128 }
129
130 static void
drm_unset_busid(struct drm_device * dev,struct drm_master * master)131 drm_unset_busid(struct drm_device *dev,
132 struct drm_master *master)
133 {
134 kfree(master->unique);
135 master->unique = NULL;
136 master->unique_len = 0;
137 }
138
drm_set_busid(struct drm_device * dev,struct drm_file * file_priv)139 static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
140 {
141 struct drm_master *master = file_priv->master;
142 int ret;
143
144 if (master->unique != NULL)
145 drm_unset_busid(dev, master);
146
147 if (dev->dev && dev_is_pci(dev->dev)) {
148 ret = drm_pci_set_busid(dev, master);
149 if (ret) {
150 drm_unset_busid(dev, master);
151 return ret;
152 }
153 } else {
154 WARN_ON(!dev->unique);
155 master->unique = kstrdup(dev->unique, GFP_KERNEL);
156 if (master->unique)
157 master->unique_len = strlen(dev->unique);
158 }
159
160 return 0;
161 }
162
163 /*
164 * Get client information.
165 *
166 * \param inode device inode.
167 * \param file_priv DRM file private.
168 * \param cmd command.
169 * \param arg user argument, pointing to a drm_client structure.
170 *
171 * \return zero on success or a negative number on failure.
172 *
173 * Searches for the client with the specified index and copies its information
174 * into userspace
175 */
drm_getclient(struct drm_device * dev,void * data,struct drm_file * file_priv)176 int drm_getclient(struct drm_device *dev, void *data,
177 struct drm_file *file_priv)
178 {
179 struct drm_client *client = data;
180
181 /*
182 * Hollowed-out getclient ioctl to keep some dead old drm tests/tools
183 * not breaking completely. Userspace tools stop enumerating one they
184 * get -EINVAL, hence this is the return value we need to hand back for
185 * no clients tracked.
186 *
187 * Unfortunately some clients (*cough* libva *cough*) use this in a fun
188 * attempt to figure out whether they're authenticated or not. Since
189 * that's the only thing they care about, give it to the directly
190 * instead of walking one giant list.
191 */
192 if (client->idx == 0) {
193 client->auth = file_priv->authenticated;
194 client->pid = task_pid_vnr(current);
195 client->uid = overflowuid;
196 client->magic = 0;
197 client->iocs = 0;
198
199 return 0;
200 } else {
201 return -EINVAL;
202 }
203 }
204
205 /*
206 * Get statistics information.
207 *
208 * \param inode device inode.
209 * \param file_priv DRM file private.
210 * \param cmd command.
211 * \param arg user argument, pointing to a drm_stats structure.
212 *
213 * \return zero on success or a negative number on failure.
214 */
drm_getstats(struct drm_device * dev,void * data,struct drm_file * file_priv)215 static int drm_getstats(struct drm_device *dev, void *data,
216 struct drm_file *file_priv)
217 {
218 struct drm_stats *stats = data;
219
220 /* Clear stats to prevent userspace from eating its stack garbage. */
221 memset(stats, 0, sizeof(*stats));
222
223 return 0;
224 }
225
226 /*
227 * Get device/driver capabilities
228 */
drm_getcap(struct drm_device * dev,void * data,struct drm_file * file_priv)229 static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
230 {
231 struct drm_get_cap *req = data;
232 struct drm_crtc *crtc;
233
234 req->value = 0;
235
236 /* Only some caps make sense with UMS/render-only drivers. */
237 switch (req->capability) {
238 case DRM_CAP_TIMESTAMP_MONOTONIC:
239 req->value = drm_timestamp_monotonic;
240 return 0;
241 case DRM_CAP_PRIME:
242 req->value |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0;
243 req->value |= dev->driver->prime_handle_to_fd ? DRM_PRIME_CAP_EXPORT : 0;
244 return 0;
245 case DRM_CAP_SYNCOBJ:
246 req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ);
247 return 0;
248 }
249
250 /* Other caps only work with KMS drivers */
251 if (!drm_core_check_feature(dev, DRIVER_MODESET))
252 return -ENOTSUPP;
253
254 switch (req->capability) {
255 case DRM_CAP_DUMB_BUFFER:
256 if (dev->driver->dumb_create)
257 req->value = 1;
258 break;
259 case DRM_CAP_VBLANK_HIGH_CRTC:
260 req->value = 1;
261 break;
262 case DRM_CAP_DUMB_PREFERRED_DEPTH:
263 req->value = dev->mode_config.preferred_depth;
264 break;
265 case DRM_CAP_DUMB_PREFER_SHADOW:
266 req->value = dev->mode_config.prefer_shadow;
267 break;
268 case DRM_CAP_ASYNC_PAGE_FLIP:
269 req->value = dev->mode_config.async_page_flip;
270 break;
271 case DRM_CAP_PAGE_FLIP_TARGET:
272 req->value = 1;
273 drm_for_each_crtc(crtc, dev) {
274 if (!crtc->funcs->page_flip_target)
275 req->value = 0;
276 }
277 break;
278 case DRM_CAP_CURSOR_WIDTH:
279 if (dev->mode_config.cursor_width)
280 req->value = dev->mode_config.cursor_width;
281 else
282 req->value = 64;
283 break;
284 case DRM_CAP_CURSOR_HEIGHT:
285 if (dev->mode_config.cursor_height)
286 req->value = dev->mode_config.cursor_height;
287 else
288 req->value = 64;
289 break;
290 case DRM_CAP_ADDFB2_MODIFIERS:
291 req->value = dev->mode_config.allow_fb_modifiers;
292 break;
293 case DRM_CAP_CRTC_IN_VBLANK_EVENT:
294 req->value = 1;
295 break;
296 default:
297 return -EINVAL;
298 }
299 return 0;
300 }
301
302 /*
303 * Set device/driver capabilities
304 */
305 static int
drm_setclientcap(struct drm_device * dev,void * data,struct drm_file * file_priv)306 drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
307 {
308 struct drm_set_client_cap *req = data;
309
310 switch (req->capability) {
311 case DRM_CLIENT_CAP_STEREO_3D:
312 if (req->value > 1)
313 return -EINVAL;
314 file_priv->stereo_allowed = req->value;
315 break;
316 case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
317 if (req->value > 1)
318 return -EINVAL;
319 file_priv->universal_planes = req->value;
320 break;
321 case DRM_CLIENT_CAP_ATOMIC:
322 if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
323 return -EINVAL;
324 if (req->value > 1)
325 return -EINVAL;
326 file_priv->atomic = req->value;
327 file_priv->universal_planes = req->value;
328 break;
329 default:
330 return -EINVAL;
331 }
332
333 return 0;
334 }
335
336 /*
337 * Setversion ioctl.
338 *
339 * \param inode device inode.
340 * \param file_priv DRM file private.
341 * \param cmd command.
342 * \param arg user argument, pointing to a drm_lock structure.
343 * \return zero on success or negative number on failure.
344 *
345 * Sets the requested interface version
346 */
drm_setversion(struct drm_device * dev,void * data,struct drm_file * file_priv)347 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
348 {
349 struct drm_set_version *sv = data;
350 int if_version, retcode = 0;
351
352 mutex_lock(&dev->master_mutex);
353 if (sv->drm_di_major != -1) {
354 if (sv->drm_di_major != DRM_IF_MAJOR ||
355 sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
356 retcode = -EINVAL;
357 goto done;
358 }
359 if_version = DRM_IF_VERSION(sv->drm_di_major,
360 sv->drm_di_minor);
361 dev->if_version = max(if_version, dev->if_version);
362 if (sv->drm_di_minor >= 1) {
363 /*
364 * Version 1.1 includes tying of DRM to specific device
365 * Version 1.4 has proper PCI domain support
366 */
367 retcode = drm_set_busid(dev, file_priv);
368 if (retcode)
369 goto done;
370 }
371 }
372
373 if (sv->drm_dd_major != -1) {
374 if (sv->drm_dd_major != dev->driver->major ||
375 sv->drm_dd_minor < 0 || sv->drm_dd_minor >
376 dev->driver->minor) {
377 retcode = -EINVAL;
378 goto done;
379 }
380 }
381
382 done:
383 sv->drm_di_major = DRM_IF_MAJOR;
384 sv->drm_di_minor = DRM_IF_MINOR;
385 sv->drm_dd_major = dev->driver->major;
386 sv->drm_dd_minor = dev->driver->minor;
387 mutex_unlock(&dev->master_mutex);
388
389 return retcode;
390 }
391
392 /**
393 * drm_noop - DRM no-op ioctl implemntation
394 * @dev: DRM device for the ioctl
395 * @data: data pointer for the ioctl
396 * @file_priv: DRM file for the ioctl call
397 *
398 * This no-op implementation for drm ioctls is useful for deprecated
399 * functionality where we can't return a failure code because existing userspace
400 * checks the result of the ioctl, but doesn't care about the action.
401 *
402 * Always returns successfully with 0.
403 */
drm_noop(struct drm_device * dev,void * data,struct drm_file * file_priv)404 int drm_noop(struct drm_device *dev, void *data,
405 struct drm_file *file_priv)
406 {
407 DRM_DEBUG("\n");
408 return 0;
409 }
410 EXPORT_SYMBOL(drm_noop);
411
412 /**
413 * drm_invalid_op - DRM invalid ioctl implemntation
414 * @dev: DRM device for the ioctl
415 * @data: data pointer for the ioctl
416 * @file_priv: DRM file for the ioctl call
417 *
418 * This no-op implementation for drm ioctls is useful for deprecated
419 * functionality where we really don't want to allow userspace to call the ioctl
420 * any more. This is the case for old ums interfaces for drivers that
421 * transitioned to kms gradually and so kept the old legacy tables around. This
422 * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
423 * use this function.
424 *
425 * Always fails with a return value of -EINVAL.
426 */
drm_invalid_op(struct drm_device * dev,void * data,struct drm_file * file_priv)427 int drm_invalid_op(struct drm_device *dev, void *data,
428 struct drm_file *file_priv)
429 {
430 return -EINVAL;
431 }
432 EXPORT_SYMBOL(drm_invalid_op);
433
434 /*
435 * Copy and IOCTL return string to user space
436 */
drm_copy_field(char __user * buf,size_t * buf_len,const char * value)437 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
438 {
439 int len;
440
441 /* don't overflow userbuf */
442 len = strlen(value);
443 if (len > *buf_len)
444 len = *buf_len;
445
446 /* let userspace know exact length of driver value (which could be
447 * larger than the userspace-supplied buffer) */
448 *buf_len = strlen(value);
449
450 /* finally, try filling in the userbuf */
451 if (len && buf)
452 if (copy_to_user(buf, value, len))
453 return -EFAULT;
454 return 0;
455 }
456
457 /*
458 * Get version information
459 *
460 * \param inode device inode.
461 * \param filp file pointer.
462 * \param cmd command.
463 * \param arg user argument, pointing to a drm_version structure.
464 * \return zero on success or negative number on failure.
465 *
466 * Fills in the version information in \p arg.
467 */
drm_version(struct drm_device * dev,void * data,struct drm_file * file_priv)468 int drm_version(struct drm_device *dev, void *data,
469 struct drm_file *file_priv)
470 {
471 struct drm_version *version = data;
472 int err;
473
474 version->version_major = dev->driver->major;
475 version->version_minor = dev->driver->minor;
476 version->version_patchlevel = dev->driver->patchlevel;
477 err = drm_copy_field(version->name, &version->name_len,
478 dev->driver->name);
479 if (!err)
480 err = drm_copy_field(version->date, &version->date_len,
481 dev->driver->date);
482 if (!err)
483 err = drm_copy_field(version->desc, &version->desc_len,
484 dev->driver->desc);
485
486 return err;
487 }
488
489 /**
490 * drm_ioctl_permit - Check ioctl permissions against caller
491 *
492 * @flags: ioctl permission flags.
493 * @file_priv: Pointer to struct drm_file identifying the caller.
494 *
495 * Checks whether the caller is allowed to run an ioctl with the
496 * indicated permissions.
497 *
498 * Returns:
499 * Zero if allowed, -EACCES otherwise.
500 */
drm_ioctl_permit(u32 flags,struct drm_file * file_priv)501 int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
502 {
503 /* ROOT_ONLY is only for CAP_SYS_ADMIN */
504 if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
505 return -EACCES;
506
507 /* AUTH is only for authenticated or render client */
508 if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
509 !file_priv->authenticated))
510 return -EACCES;
511
512 /* MASTER is only for master or control clients */
513 if (unlikely((flags & DRM_MASTER) &&
514 !drm_is_current_master(file_priv) &&
515 !drm_is_control_client(file_priv)))
516 return -EACCES;
517
518 /* Control clients must be explicitly allowed */
519 if (unlikely(!(flags & DRM_CONTROL_ALLOW) &&
520 drm_is_control_client(file_priv)))
521 return -EACCES;
522
523 /* Render clients must be explicitly allowed */
524 if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
525 drm_is_render_client(file_priv)))
526 return -EACCES;
527
528 return 0;
529 }
530 EXPORT_SYMBOL(drm_ioctl_permit);
531
532 #define DRM_IOCTL_DEF(ioctl, _func, _flags) \
533 [DRM_IOCTL_NR(ioctl)] = { \
534 .cmd = ioctl, \
535 .func = _func, \
536 .flags = _flags, \
537 .name = #ioctl \
538 }
539
540 /* Ioctl table */
541 static const struct drm_ioctl_desc drm_ioctls[] = {
542 DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version,
543 DRM_UNLOCKED|DRM_RENDER_ALLOW|DRM_CONTROL_ALLOW),
544 DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, DRM_UNLOCKED),
545 DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, DRM_UNLOCKED),
546 DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
547 DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, DRM_UNLOCKED),
548 DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED),
549 DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),
550 DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED|DRM_RENDER_ALLOW),
551 DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, DRM_UNLOCKED),
552 DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_UNLOCKED | DRM_MASTER),
553
554 DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
555 DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
556 DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
557 DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_UNLOCKED|DRM_MASTER),
558
559 DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
560 DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),
561
562 DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
563 DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),
564
565 DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
566 DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
567
568 DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
569 DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
570 DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
571 DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
572 DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
573 DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
574 DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),
575
576 DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
577 DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
578
579 DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH),
580 DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH),
581
582 DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
583
584 DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
585 DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
586 DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH),
587 DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH),
588 DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH),
589 DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH),
590
591 DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_legacy_irq_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
592
593 #if IS_ENABLED(CONFIG_AGP)
594 DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
595 DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
596 DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
597 DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
598 DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
599 DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
600 DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
601 DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
602 #endif
603
604 DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
605 DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
606
607 DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, DRM_UNLOCKED),
608
609 DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_legacy_modeset_ctl_ioctl, 0),
610
611 DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
612
613 DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
614 DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED),
615 DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED),
616
617 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
618
619 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
620 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
621
622 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
623 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
624 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
625 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
626 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
627 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
628 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_UNLOCKED),
629 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
630 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
631 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
632 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
633 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
634 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
635 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_mode_connector_property_set_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
636 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
637 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
638 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
639 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
640 DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
641 DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
642 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
643 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
644 DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
645 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
646 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
647 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
648 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
649 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
650 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
651 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
652
653 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_CREATE, drm_syncobj_create_ioctl,
654 DRM_UNLOCKED|DRM_RENDER_ALLOW),
655 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_DESTROY, drm_syncobj_destroy_ioctl,
656 DRM_UNLOCKED|DRM_RENDER_ALLOW),
657 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, drm_syncobj_handle_to_fd_ioctl,
658 DRM_UNLOCKED|DRM_RENDER_ALLOW),
659 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, drm_syncobj_fd_to_handle_ioctl,
660 DRM_UNLOCKED|DRM_RENDER_ALLOW),
661 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl,
662 DRM_UNLOCKED|DRM_RENDER_ALLOW),
663 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl,
664 DRM_UNLOCKED|DRM_RENDER_ALLOW),
665 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl,
666 DRM_UNLOCKED|DRM_RENDER_ALLOW),
667 };
668
669 #define DRM_CORE_IOCTL_COUNT ARRAY_SIZE( drm_ioctls )
670
671 /**
672 * DOC: driver specific ioctls
673 *
674 * First things first, driver private IOCTLs should only be needed for drivers
675 * supporting rendering. Kernel modesetting is all standardized, and extended
676 * through properties. There are a few exceptions in some existing drivers,
677 * which define IOCTL for use by the display DRM master, but they all predate
678 * properties.
679 *
680 * Now if you do have a render driver you always have to support it through
681 * driver private properties. There's a few steps needed to wire all the things
682 * up.
683 *
684 * First you need to define the structure for your IOCTL in your driver private
685 * UAPI header in ``include/uapi/drm/my_driver_drm.h``::
686 *
687 * struct my_driver_operation {
688 * u32 some_thing;
689 * u32 another_thing;
690 * };
691 *
692 * Please make sure that you follow all the best practices from
693 * ``Documentation/ioctl/botching-up-ioctls.txt``. Note that drm_ioctl()
694 * automatically zero-extends structures, hence make sure you can add more stuff
695 * at the end, i.e. don't put a variable sized array there.
696 *
697 * Then you need to define your IOCTL number, using one of DRM_IO(), DRM_IOR(),
698 * DRM_IOW() or DRM_IOWR(). It must start with the DRM_IOCTL\_ prefix::
699 *
700 * ##define DRM_IOCTL_MY_DRIVER_OPERATION \
701 * DRM_IOW(DRM_COMMAND_BASE, struct my_driver_operation)
702 *
703 * DRM driver private IOCTL must be in the range from DRM_COMMAND_BASE to
704 * DRM_COMMAND_END. Finally you need an array of &struct drm_ioctl_desc to wire
705 * up the handlers and set the access rights::
706 *
707 * static const struct drm_ioctl_desc my_driver_ioctls[] = {
708 * DRM_IOCTL_DEF_DRV(MY_DRIVER_OPERATION, my_driver_operation,
709 * DRM_AUTH|DRM_RENDER_ALLOW),
710 * };
711 *
712 * And then assign this to the &drm_driver.ioctls field in your driver
713 * structure.
714 *
715 * See the separate chapter on :ref:`file operations<drm_driver_fops>` for how
716 * the driver-specific IOCTLs are wired up.
717 */
718
drm_ioctl_kernel(struct file * file,drm_ioctl_t * func,void * kdata,u32 flags)719 long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
720 u32 flags)
721 {
722 struct drm_file *file_priv = file->private_data;
723 struct drm_device *dev = file_priv->minor->dev;
724 int retcode;
725
726 if (drm_dev_is_unplugged(dev))
727 return -ENODEV;
728
729 retcode = drm_ioctl_permit(flags, file_priv);
730 if (unlikely(retcode))
731 return retcode;
732
733 /* Enforce sane locking for modern driver ioctls. */
734 if (!drm_core_check_feature(dev, DRIVER_LEGACY) ||
735 (flags & DRM_UNLOCKED))
736 retcode = func(dev, kdata, file_priv);
737 else {
738 mutex_lock(&drm_global_mutex);
739 retcode = func(dev, kdata, file_priv);
740 mutex_unlock(&drm_global_mutex);
741 }
742 return retcode;
743 }
744 EXPORT_SYMBOL(drm_ioctl_kernel);
745
746 /**
747 * drm_ioctl - ioctl callback implementation for DRM drivers
748 * @filp: file this ioctl is called on
749 * @cmd: ioctl cmd number
750 * @arg: user argument
751 *
752 * Looks up the ioctl function in the DRM core and the driver dispatch table,
753 * stored in &drm_driver.ioctls. It checks for necessary permission by calling
754 * drm_ioctl_permit(), and dispatches to the respective function.
755 *
756 * Returns:
757 * Zero on success, negative error code on failure.
758 */
drm_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)759 long drm_ioctl(struct file *filp,
760 unsigned int cmd, unsigned long arg)
761 {
762 struct drm_file *file_priv = filp->private_data;
763 struct drm_device *dev;
764 const struct drm_ioctl_desc *ioctl = NULL;
765 drm_ioctl_t *func;
766 unsigned int nr = DRM_IOCTL_NR(cmd);
767 int retcode = -EINVAL;
768 char stack_kdata[128];
769 char *kdata = NULL;
770 unsigned int in_size, out_size, drv_size, ksize;
771 bool is_driver_ioctl;
772
773 dev = file_priv->minor->dev;
774
775 if (drm_dev_is_unplugged(dev))
776 return -ENODEV;
777
778 is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
779
780 if (is_driver_ioctl) {
781 /* driver ioctl */
782 unsigned int index = nr - DRM_COMMAND_BASE;
783
784 if (index >= dev->driver->num_ioctls)
785 goto err_i1;
786 index = array_index_nospec(index, dev->driver->num_ioctls);
787 ioctl = &dev->driver->ioctls[index];
788 } else {
789 /* core ioctl */
790 if (nr >= DRM_CORE_IOCTL_COUNT)
791 goto err_i1;
792 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
793 ioctl = &drm_ioctls[nr];
794 }
795
796 drv_size = _IOC_SIZE(ioctl->cmd);
797 out_size = in_size = _IOC_SIZE(cmd);
798 if ((cmd & ioctl->cmd & IOC_IN) == 0)
799 in_size = 0;
800 if ((cmd & ioctl->cmd & IOC_OUT) == 0)
801 out_size = 0;
802 ksize = max(max(in_size, out_size), drv_size);
803
804 DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
805 task_pid_nr(current),
806 (long)old_encode_dev(file_priv->minor->kdev->devt),
807 file_priv->authenticated, ioctl->name);
808
809 /* Do not trust userspace, use our own definition */
810 func = ioctl->func;
811
812 if (unlikely(!func)) {
813 DRM_DEBUG("no function\n");
814 retcode = -EINVAL;
815 goto err_i1;
816 }
817
818 if (ksize <= sizeof(stack_kdata)) {
819 kdata = stack_kdata;
820 } else {
821 kdata = kmalloc(ksize, GFP_KERNEL);
822 if (!kdata) {
823 retcode = -ENOMEM;
824 goto err_i1;
825 }
826 }
827
828 if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) {
829 retcode = -EFAULT;
830 goto err_i1;
831 }
832
833 if (ksize > in_size)
834 memset(kdata + in_size, 0, ksize - in_size);
835
836 retcode = drm_ioctl_kernel(filp, func, kdata, ioctl->flags);
837 if (copy_to_user((void __user *)arg, kdata, out_size) != 0)
838 retcode = -EFAULT;
839
840 err_i1:
841 if (!ioctl)
842 DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
843 task_pid_nr(current),
844 (long)old_encode_dev(file_priv->minor->kdev->devt),
845 file_priv->authenticated, cmd, nr);
846
847 if (kdata != stack_kdata)
848 kfree(kdata);
849 if (retcode)
850 DRM_DEBUG("ret = %d\n", retcode);
851 return retcode;
852 }
853 EXPORT_SYMBOL(drm_ioctl);
854
855 /**
856 * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
857 * @nr: ioctl number
858 * @flags: where to return the ioctl permission flags
859 *
860 * This ioctl is only used by the vmwgfx driver to augment the access checks
861 * done by the drm core and insofar a pretty decent layering violation. This
862 * shouldn't be used by any drivers.
863 *
864 * Returns:
865 * True if the @nr corresponds to a DRM core ioctl number, false otherwise.
866 */
drm_ioctl_flags(unsigned int nr,unsigned int * flags)867 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
868 {
869 if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
870 return false;
871
872 if (nr >= DRM_CORE_IOCTL_COUNT)
873 return false;
874 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
875
876 *flags = drm_ioctls[nr].flags;
877 return true;
878 }
879 EXPORT_SYMBOL(drm_ioctl_flags);
880