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1/**
2 * \file drm_ioctl.c
3 * IOCTL processing for DRM
4 *
5 * \author Rickard E. (Rik) Faith <faith@valinux.com>
6 * \author Gareth Hughes <gareth@valinux.com>
7 */
8
9/*
10 * Created: Fri Jan 8 09:01:26 1999 by faith@valinux.com
11 *
12 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
14 * All Rights Reserved.
15 *
16 * Permission is hereby granted, free of charge, to any person obtaining a
17 * copy of this software and associated documentation files (the "Software"),
18 * to deal in the Software without restriction, including without limitation
19 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
20 * and/or sell copies of the Software, and to permit persons to whom the
21 * Software is furnished to do so, subject to the following conditions:
22 *
23 * The above copyright notice and this permission notice (including the next
24 * paragraph) shall be included in all copies or substantial portions of the
25 * Software.
26 *
27 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
28 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
29 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
30 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
31 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
32 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
33 * OTHER DEALINGS IN THE SOFTWARE.
34 */
35
36#include "drmP.h"
37#include "drm_core.h"
38
39#include "linux/pci.h"
40
41/**
42 * Get the bus id.
43 *
44 * \param inode device inode.
45 * \param file_priv DRM file private.
46 * \param cmd command.
47 * \param arg user argument, pointing to a drm_unique structure.
48 * \return zero on success or a negative number on failure.
49 *
50 * Copies the bus id from drm_device::unique into user space.
51 */
52int drm_getunique(struct drm_device *dev, void *data,
53 struct drm_file *file_priv)
54{
55 struct drm_unique *u = data;
56 struct drm_master *master = file_priv->master;
57
58 if (u->unique_len >= master->unique_len) {
59 if (copy_to_user(u->unique, master->unique, master->unique_len))
60 return -EFAULT;
61 }
62 u->unique_len = master->unique_len;
63
64 return 0;
65}
66
67static void
68drm_unset_busid(struct drm_device *dev,
69 struct drm_master *master)
70{
71 kfree(dev->devname);
72 dev->devname = NULL;
73
74 kfree(master->unique);
75 master->unique = NULL;
76 master->unique_len = 0;
77 master->unique_size = 0;
78}
79
80/**
81 * Set the bus id.
82 *
83 * \param inode device inode.
84 * \param file_priv DRM file private.
85 * \param cmd command.
86 * \param arg user argument, pointing to a drm_unique structure.
87 * \return zero on success or a negative number on failure.
88 *
89 * Copies the bus id from userspace into drm_device::unique, and verifies that
90 * it matches the device this DRM is attached to (EINVAL otherwise). Deprecated
91 * in interface version 1.1 and will return EBUSY when setversion has requested
92 * version 1.1 or greater.
93 */
94int drm_setunique(struct drm_device *dev, void *data,
95 struct drm_file *file_priv)
96{
97 struct drm_unique *u = data;
98 struct drm_master *master = file_priv->master;
99 int ret;
100
101 if (master->unique_len || master->unique)
102 return -EBUSY;
103
104 if (!u->unique_len || u->unique_len > 1024)
105 return -EINVAL;
106
107 if (!dev->driver->bus->set_unique)
108 return -EINVAL;
109
110 ret = dev->driver->bus->set_unique(dev, master, u);
111 if (ret)
112 goto err;
113
114 return 0;
115
116err:
117 drm_unset_busid(dev, master);
118 return ret;
119}
120
121static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
122{
123 struct drm_master *master = file_priv->master;
124 int ret;
125
126 if (master->unique != NULL)
127 drm_unset_busid(dev, master);
128
129 ret = dev->driver->bus->set_busid(dev, master);
130 if (ret)
131 goto err;
132 return 0;
133err:
134 drm_unset_busid(dev, master);
135 return ret;
136}
137
138/**
139 * Get a mapping information.
140 *
141 * \param inode device inode.
142 * \param file_priv DRM file private.
143 * \param cmd command.
144 * \param arg user argument, pointing to a drm_map structure.
145 *
146 * \return zero on success or a negative number on failure.
147 *
148 * Searches for the mapping with the specified offset and copies its information
149 * into userspace
150 */
151int drm_getmap(struct drm_device *dev, void *data,
152 struct drm_file *file_priv)
153{
154 struct drm_map *map = data;
155 struct drm_map_list *r_list = NULL;
156 struct list_head *list;
157 int idx;
158 int i;
159
160 idx = map->offset;
161
162 mutex_lock(&dev->struct_mutex);
163 if (idx < 0) {
164 mutex_unlock(&dev->struct_mutex);
165 return -EINVAL;
166 }
167
168 i = 0;
169 list_for_each(list, &dev->maplist) {
170 if (i == idx) {
171 r_list = list_entry(list, struct drm_map_list, head);
172 break;
173 }
174 i++;
175 }
176 if (!r_list || !r_list->map) {
177 mutex_unlock(&dev->struct_mutex);
178 return -EINVAL;
179 }
180
181 map->offset = r_list->map->offset;
182 map->size = r_list->map->size;
183 map->type = r_list->map->type;
184 map->flags = r_list->map->flags;
185 map->handle = (void *)(unsigned long) r_list->user_token;
186 map->mtrr = r_list->map->mtrr;
187 mutex_unlock(&dev->struct_mutex);
188
189 return 0;
190}
191
192/**
193 * Get client information.
194 *
195 * \param inode device inode.
196 * \param file_priv DRM file private.
197 * \param cmd command.
198 * \param arg user argument, pointing to a drm_client structure.
199 *
200 * \return zero on success or a negative number on failure.
201 *
202 * Searches for the client with the specified index and copies its information
203 * into userspace
204 */
205int drm_getclient(struct drm_device *dev, void *data,
206 struct drm_file *file_priv)
207{
208 struct drm_client *client = data;
209 struct drm_file *pt;
210 int idx;
211 int i;
212
213 idx = client->idx;
214 mutex_lock(&dev->struct_mutex);
215
216 i = 0;
217 list_for_each_entry(pt, &dev->filelist, lhead) {
218 if (i++ >= idx) {
219 client->auth = pt->authenticated;
220 client->pid = pt->pid;
221 client->uid = pt->uid;
222 client->magic = pt->magic;
223 client->iocs = pt->ioctl_count;
224 mutex_unlock(&dev->struct_mutex);
225
226 return 0;
227 }
228 }
229 mutex_unlock(&dev->struct_mutex);
230
231 return -EINVAL;
232}
233
234/**
235 * Get statistics information.
236 *
237 * \param inode device inode.
238 * \param file_priv DRM file private.
239 * \param cmd command.
240 * \param arg user argument, pointing to a drm_stats structure.
241 *
242 * \return zero on success or a negative number on failure.
243 */
244int drm_getstats(struct drm_device *dev, void *data,
245 struct drm_file *file_priv)
246{
247 struct drm_stats *stats = data;
248 int i;
249
250 memset(stats, 0, sizeof(*stats));
251
252 mutex_lock(&dev->struct_mutex);
253
254 for (i = 0; i < dev->counters; i++) {
255 if (dev->types[i] == _DRM_STAT_LOCK)
256 stats->data[i].value =
257 (file_priv->master->lock.hw_lock ? file_priv->master->lock.hw_lock->lock : 0);
258 else
259 stats->data[i].value = atomic_read(&dev->counts[i]);
260 stats->data[i].type = dev->types[i];
261 }
262
263 stats->count = dev->counters;
264
265 mutex_unlock(&dev->struct_mutex);
266
267 return 0;
268}
269
270/**
271 * Get device/driver capabilities
272 */
273int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
274{
275 struct drm_get_cap *req = data;
276
277 req->value = 0;
278 switch (req->capability) {
279 case DRM_CAP_DUMB_BUFFER:
280 if (dev->driver->dumb_create)
281 req->value = 1;
282 break;
283 case DRM_CAP_VBLANK_HIGH_CRTC:
284 req->value = 1;
285 break;
286 default:
287 return -EINVAL;
288 }
289 return 0;
290}
291
292/**
293 * Setversion ioctl.
294 *
295 * \param inode device inode.
296 * \param file_priv DRM file private.
297 * \param cmd command.
298 * \param arg user argument, pointing to a drm_lock structure.
299 * \return zero on success or negative number on failure.
300 *
301 * Sets the requested interface version
302 */
303int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
304{
305 struct drm_set_version *sv = data;
306 int if_version, retcode = 0;
307
308 if (sv->drm_di_major != -1) {
309 if (sv->drm_di_major != DRM_IF_MAJOR ||
310 sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
311 retcode = -EINVAL;
312 goto done;
313 }
314 if_version = DRM_IF_VERSION(sv->drm_di_major,
315 sv->drm_di_minor);
316 dev->if_version = max(if_version, dev->if_version);
317 if (sv->drm_di_minor >= 1) {
318 /*
319 * Version 1.1 includes tying of DRM to specific device
320 * Version 1.4 has proper PCI domain support
321 */
322 retcode = drm_set_busid(dev, file_priv);
323 if (retcode)
324 goto done;
325 }
326 }
327
328 if (sv->drm_dd_major != -1) {
329 if (sv->drm_dd_major != dev->driver->major ||
330 sv->drm_dd_minor < 0 || sv->drm_dd_minor >
331 dev->driver->minor) {
332 retcode = -EINVAL;
333 goto done;
334 }
335
336 if (dev->driver->set_version)
337 dev->driver->set_version(dev, sv);
338 }
339
340done:
341 sv->drm_di_major = DRM_IF_MAJOR;
342 sv->drm_di_minor = DRM_IF_MINOR;
343 sv->drm_dd_major = dev->driver->major;
344 sv->drm_dd_minor = dev->driver->minor;
345
346 return retcode;
347}
348
349/** No-op ioctl. */
350int drm_noop(struct drm_device *dev, void *data,
351 struct drm_file *file_priv)
352{
353 DRM_DEBUG("\n");
354 return 0;
355}
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 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 */
116int 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
136static void
137drm_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
145static 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 */
182int 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 */
221static 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 */
235static 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 |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0;
249 req->value |= dev->driver->prime_handle_to_fd ? DRM_PRIME_CAP_EXPORT : 0;
250 return 0;
251 case DRM_CAP_SYNCOBJ:
252 req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ);
253 return 0;
254 case DRM_CAP_SYNCOBJ_TIMELINE:
255 req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE);
256 return 0;
257 }
258
259 /* Other caps only work with KMS drivers */
260 if (!drm_core_check_feature(dev, DRIVER_MODESET))
261 return -EOPNOTSUPP;
262
263 switch (req->capability) {
264 case DRM_CAP_DUMB_BUFFER:
265 if (dev->driver->dumb_create)
266 req->value = 1;
267 break;
268 case DRM_CAP_VBLANK_HIGH_CRTC:
269 req->value = 1;
270 break;
271 case DRM_CAP_DUMB_PREFERRED_DEPTH:
272 req->value = dev->mode_config.preferred_depth;
273 break;
274 case DRM_CAP_DUMB_PREFER_SHADOW:
275 req->value = dev->mode_config.prefer_shadow;
276 break;
277 case DRM_CAP_ASYNC_PAGE_FLIP:
278 req->value = dev->mode_config.async_page_flip;
279 break;
280 case DRM_CAP_PAGE_FLIP_TARGET:
281 req->value = 1;
282 drm_for_each_crtc(crtc, dev) {
283 if (!crtc->funcs->page_flip_target)
284 req->value = 0;
285 }
286 break;
287 case DRM_CAP_CURSOR_WIDTH:
288 if (dev->mode_config.cursor_width)
289 req->value = dev->mode_config.cursor_width;
290 else
291 req->value = 64;
292 break;
293 case DRM_CAP_CURSOR_HEIGHT:
294 if (dev->mode_config.cursor_height)
295 req->value = dev->mode_config.cursor_height;
296 else
297 req->value = 64;
298 break;
299 case DRM_CAP_ADDFB2_MODIFIERS:
300 req->value = dev->mode_config.allow_fb_modifiers;
301 break;
302 case DRM_CAP_CRTC_IN_VBLANK_EVENT:
303 req->value = 1;
304 break;
305 default:
306 return -EINVAL;
307 }
308 return 0;
309}
310
311/*
312 * Set device/driver capabilities
313 */
314static int
315drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
316{
317 struct drm_set_client_cap *req = data;
318
319 /* No render-only settable capabilities for now */
320
321 /* Below caps that only works with KMS drivers */
322 if (!drm_core_check_feature(dev, DRIVER_MODESET))
323 return -EOPNOTSUPP;
324
325 switch (req->capability) {
326 case DRM_CLIENT_CAP_STEREO_3D:
327 if (req->value > 1)
328 return -EINVAL;
329 file_priv->stereo_allowed = req->value;
330 break;
331 case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
332 if (req->value > 1)
333 return -EINVAL;
334 file_priv->universal_planes = req->value;
335 break;
336 case DRM_CLIENT_CAP_ATOMIC:
337 if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
338 return -EOPNOTSUPP;
339 /* The modesetting DDX has a totally broken idea of atomic. */
340 if (current->comm[0] == 'X' && req->value == 1) {
341 pr_info("broken atomic modeset userspace detected, disabling atomic\n");
342 return -EOPNOTSUPP;
343 }
344 if (req->value > 2)
345 return -EINVAL;
346 file_priv->atomic = req->value;
347 file_priv->universal_planes = req->value;
348 /*
349 * No atomic user-space blows up on aspect ratio mode bits.
350 */
351 file_priv->aspect_ratio_allowed = req->value;
352 break;
353 case DRM_CLIENT_CAP_ASPECT_RATIO:
354 if (req->value > 1)
355 return -EINVAL;
356 file_priv->aspect_ratio_allowed = req->value;
357 break;
358 case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS:
359 if (!file_priv->atomic)
360 return -EINVAL;
361 if (req->value > 1)
362 return -EINVAL;
363 file_priv->writeback_connectors = req->value;
364 break;
365 default:
366 return -EINVAL;
367 }
368
369 return 0;
370}
371
372/*
373 * Setversion ioctl.
374 *
375 * \param inode device inode.
376 * \param file_priv DRM file private.
377 * \param cmd command.
378 * \param arg user argument, pointing to a drm_lock structure.
379 * \return zero on success or negative number on failure.
380 *
381 * Sets the requested interface version
382 */
383static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
384{
385 struct drm_set_version *sv = data;
386 int if_version, retcode = 0;
387
388 mutex_lock(&dev->master_mutex);
389 if (sv->drm_di_major != -1) {
390 if (sv->drm_di_major != DRM_IF_MAJOR ||
391 sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
392 retcode = -EINVAL;
393 goto done;
394 }
395 if_version = DRM_IF_VERSION(sv->drm_di_major,
396 sv->drm_di_minor);
397 dev->if_version = max(if_version, dev->if_version);
398 if (sv->drm_di_minor >= 1) {
399 /*
400 * Version 1.1 includes tying of DRM to specific device
401 * Version 1.4 has proper PCI domain support
402 */
403 retcode = drm_set_busid(dev, file_priv);
404 if (retcode)
405 goto done;
406 }
407 }
408
409 if (sv->drm_dd_major != -1) {
410 if (sv->drm_dd_major != dev->driver->major ||
411 sv->drm_dd_minor < 0 || sv->drm_dd_minor >
412 dev->driver->minor) {
413 retcode = -EINVAL;
414 goto done;
415 }
416 }
417
418done:
419 sv->drm_di_major = DRM_IF_MAJOR;
420 sv->drm_di_minor = DRM_IF_MINOR;
421 sv->drm_dd_major = dev->driver->major;
422 sv->drm_dd_minor = dev->driver->minor;
423 mutex_unlock(&dev->master_mutex);
424
425 return retcode;
426}
427
428/**
429 * drm_noop - DRM no-op ioctl implemntation
430 * @dev: DRM device for the ioctl
431 * @data: data pointer for the ioctl
432 * @file_priv: DRM file for the ioctl call
433 *
434 * This no-op implementation for drm ioctls is useful for deprecated
435 * functionality where we can't return a failure code because existing userspace
436 * checks the result of the ioctl, but doesn't care about the action.
437 *
438 * Always returns successfully with 0.
439 */
440int drm_noop(struct drm_device *dev, void *data,
441 struct drm_file *file_priv)
442{
443 DRM_DEBUG("\n");
444 return 0;
445}
446EXPORT_SYMBOL(drm_noop);
447
448/**
449 * drm_invalid_op - DRM invalid ioctl implemntation
450 * @dev: DRM device for the ioctl
451 * @data: data pointer for the ioctl
452 * @file_priv: DRM file for the ioctl call
453 *
454 * This no-op implementation for drm ioctls is useful for deprecated
455 * functionality where we really don't want to allow userspace to call the ioctl
456 * any more. This is the case for old ums interfaces for drivers that
457 * transitioned to kms gradually and so kept the old legacy tables around. This
458 * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
459 * use this function.
460 *
461 * Always fails with a return value of -EINVAL.
462 */
463int drm_invalid_op(struct drm_device *dev, void *data,
464 struct drm_file *file_priv)
465{
466 return -EINVAL;
467}
468EXPORT_SYMBOL(drm_invalid_op);
469
470/*
471 * Copy and IOCTL return string to user space
472 */
473static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
474{
475 int len;
476
477 /* don't overflow userbuf */
478 len = strlen(value);
479 if (len > *buf_len)
480 len = *buf_len;
481
482 /* let userspace know exact length of driver value (which could be
483 * larger than the userspace-supplied buffer) */
484 *buf_len = strlen(value);
485
486 /* finally, try filling in the userbuf */
487 if (len && buf)
488 if (copy_to_user(buf, value, len))
489 return -EFAULT;
490 return 0;
491}
492
493/*
494 * Get version information
495 *
496 * \param inode device inode.
497 * \param filp file pointer.
498 * \param cmd command.
499 * \param arg user argument, pointing to a drm_version structure.
500 * \return zero on success or negative number on failure.
501 *
502 * Fills in the version information in \p arg.
503 */
504int drm_version(struct drm_device *dev, void *data,
505 struct drm_file *file_priv)
506{
507 struct drm_version *version = data;
508 int err;
509
510 version->version_major = dev->driver->major;
511 version->version_minor = dev->driver->minor;
512 version->version_patchlevel = dev->driver->patchlevel;
513 err = drm_copy_field(version->name, &version->name_len,
514 dev->driver->name);
515 if (!err)
516 err = drm_copy_field(version->date, &version->date_len,
517 dev->driver->date);
518 if (!err)
519 err = drm_copy_field(version->desc, &version->desc_len,
520 dev->driver->desc);
521
522 return err;
523}
524
525/**
526 * drm_ioctl_permit - Check ioctl permissions against caller
527 *
528 * @flags: ioctl permission flags.
529 * @file_priv: Pointer to struct drm_file identifying the caller.
530 *
531 * Checks whether the caller is allowed to run an ioctl with the
532 * indicated permissions.
533 *
534 * Returns:
535 * Zero if allowed, -EACCES otherwise.
536 */
537int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
538{
539 /* ROOT_ONLY is only for CAP_SYS_ADMIN */
540 if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
541 return -EACCES;
542
543 /* AUTH is only for authenticated or render client */
544 if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
545 !file_priv->authenticated))
546 return -EACCES;
547
548 /* MASTER is only for master or control clients */
549 if (unlikely((flags & DRM_MASTER) &&
550 !drm_is_current_master(file_priv)))
551 return -EACCES;
552
553 /* Render clients must be explicitly allowed */
554 if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
555 drm_is_render_client(file_priv)))
556 return -EACCES;
557
558 return 0;
559}
560EXPORT_SYMBOL(drm_ioctl_permit);
561
562#define DRM_IOCTL_DEF(ioctl, _func, _flags) \
563 [DRM_IOCTL_NR(ioctl)] = { \
564 .cmd = ioctl, \
565 .func = _func, \
566 .flags = _flags, \
567 .name = #ioctl \
568 }
569
570#if IS_ENABLED(CONFIG_DRM_LEGACY)
571#define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags) DRM_IOCTL_DEF(ioctl, _func, _flags)
572#else
573#define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags) DRM_IOCTL_DEF(ioctl, drm_invalid_op, _flags)
574#endif
575
576/* Ioctl table */
577static const struct drm_ioctl_desc drm_ioctls[] = {
578 DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_RENDER_ALLOW),
579 DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
580 DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0),
581 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_legacy_irq_by_busid,
582 DRM_MASTER|DRM_ROOT_ONLY),
583
584 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, 0),
585
586 DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, 0),
587 DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0),
588 DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_RENDER_ALLOW),
589 DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
590 DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
591
592 DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
593 DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
594 DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
595 DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_MASTER),
596
597 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
598 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),
599
600 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
601 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),
602
603 DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, 0),
604 DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, 0),
605
606 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
607 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
608 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
609 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
610 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
611 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
612 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),
613
614 DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
615 DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
616
617 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH),
618 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH),
619
620 DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
621
622 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
623 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
624 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH),
625 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH),
626 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH),
627 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH),
628 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_legacy_irq_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
629
630#if IS_ENABLED(CONFIG_AGP)
631 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_legacy_agp_acquire_ioctl,
632 DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
633 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_legacy_agp_release_ioctl,
634 DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
635 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_legacy_agp_enable_ioctl,
636 DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
637 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_legacy_agp_info_ioctl, DRM_AUTH),
638 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_legacy_agp_alloc_ioctl,
639 DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
640 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_legacy_agp_free_ioctl,
641 DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
642 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_legacy_agp_bind_ioctl,
643 DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
644 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_legacy_agp_unbind_ioctl,
645 DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
646#endif
647
648 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
649 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
650
651 DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, DRM_UNLOCKED),
652
653 DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_legacy_modeset_ctl_ioctl, 0),
654
655 DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
656
657 DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_RENDER_ALLOW),
658 DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH),
659 DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH),
660
661 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, 0),
662
663 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_RENDER_ALLOW),
664 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_RENDER_ALLOW),
665
666 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, 0),
667 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, 0),
668 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER),
669 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, 0),
670 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER),
671 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER),
672 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, 0),
673 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER),
674 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, 0),
675 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, 0),
676 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER),
677 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER),
678 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, 0),
679 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_connector_property_set_ioctl, DRM_MASTER),
680 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, 0),
681 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, 0),
682 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB2, drm_mode_getfb2_ioctl, 0),
683 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb_ioctl, 0),
684 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2_ioctl, 0),
685 DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb_ioctl, 0),
686 DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER),
687 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER),
688 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, 0),
689 DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, 0),
690 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, 0),
691 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, 0),
692 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER),
693 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER),
694 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER),
695 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, 0),
696 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, 0),
697
698 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_CREATE, drm_syncobj_create_ioctl,
699 DRM_RENDER_ALLOW),
700 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_DESTROY, drm_syncobj_destroy_ioctl,
701 DRM_RENDER_ALLOW),
702 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, drm_syncobj_handle_to_fd_ioctl,
703 DRM_RENDER_ALLOW),
704 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, drm_syncobj_fd_to_handle_ioctl,
705 DRM_RENDER_ALLOW),
706 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TRANSFER, drm_syncobj_transfer_ioctl,
707 DRM_RENDER_ALLOW),
708 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl,
709 DRM_RENDER_ALLOW),
710 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT, drm_syncobj_timeline_wait_ioctl,
711 DRM_RENDER_ALLOW),
712 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl,
713 DRM_RENDER_ALLOW),
714 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl,
715 DRM_RENDER_ALLOW),
716 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL, drm_syncobj_timeline_signal_ioctl,
717 DRM_RENDER_ALLOW),
718 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_QUERY, drm_syncobj_query_ioctl,
719 DRM_RENDER_ALLOW),
720 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, 0),
721 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, 0),
722 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER),
723 DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER),
724 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER),
725 DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER),
726};
727
728#define DRM_CORE_IOCTL_COUNT ARRAY_SIZE( drm_ioctls )
729
730/**
731 * DOC: driver specific ioctls
732 *
733 * First things first, driver private IOCTLs should only be needed for drivers
734 * supporting rendering. Kernel modesetting is all standardized, and extended
735 * through properties. There are a few exceptions in some existing drivers,
736 * which define IOCTL for use by the display DRM master, but they all predate
737 * properties.
738 *
739 * Now if you do have a render driver you always have to support it through
740 * driver private properties. There's a few steps needed to wire all the things
741 * up.
742 *
743 * First you need to define the structure for your IOCTL in your driver private
744 * UAPI header in ``include/uapi/drm/my_driver_drm.h``::
745 *
746 * struct my_driver_operation {
747 * u32 some_thing;
748 * u32 another_thing;
749 * };
750 *
751 * Please make sure that you follow all the best practices from
752 * ``Documentation/process/botching-up-ioctls.rst``. Note that drm_ioctl()
753 * automatically zero-extends structures, hence make sure you can add more stuff
754 * at the end, i.e. don't put a variable sized array there.
755 *
756 * Then you need to define your IOCTL number, using one of DRM_IO(), DRM_IOR(),
757 * DRM_IOW() or DRM_IOWR(). It must start with the DRM_IOCTL\_ prefix::
758 *
759 * ##define DRM_IOCTL_MY_DRIVER_OPERATION \
760 * DRM_IOW(DRM_COMMAND_BASE, struct my_driver_operation)
761 *
762 * DRM driver private IOCTL must be in the range from DRM_COMMAND_BASE to
763 * DRM_COMMAND_END. Finally you need an array of &struct drm_ioctl_desc to wire
764 * up the handlers and set the access rights::
765 *
766 * static const struct drm_ioctl_desc my_driver_ioctls[] = {
767 * DRM_IOCTL_DEF_DRV(MY_DRIVER_OPERATION, my_driver_operation,
768 * DRM_AUTH|DRM_RENDER_ALLOW),
769 * };
770 *
771 * And then assign this to the &drm_driver.ioctls field in your driver
772 * structure.
773 *
774 * See the separate chapter on :ref:`file operations<drm_driver_fops>` for how
775 * the driver-specific IOCTLs are wired up.
776 */
777
778long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
779 u32 flags)
780{
781 struct drm_file *file_priv = file->private_data;
782 struct drm_device *dev = file_priv->minor->dev;
783 int retcode;
784
785 if (drm_dev_is_unplugged(dev))
786 return -ENODEV;
787
788 retcode = drm_ioctl_permit(flags, file_priv);
789 if (unlikely(retcode))
790 return retcode;
791
792 /* Enforce sane locking for modern driver ioctls. */
793 if (likely(!drm_core_check_feature(dev, DRIVER_LEGACY)) ||
794 (flags & DRM_UNLOCKED))
795 retcode = func(dev, kdata, file_priv);
796 else {
797 mutex_lock(&drm_global_mutex);
798 retcode = func(dev, kdata, file_priv);
799 mutex_unlock(&drm_global_mutex);
800 }
801 return retcode;
802}
803EXPORT_SYMBOL(drm_ioctl_kernel);
804
805/**
806 * drm_ioctl - ioctl callback implementation for DRM drivers
807 * @filp: file this ioctl is called on
808 * @cmd: ioctl cmd number
809 * @arg: user argument
810 *
811 * Looks up the ioctl function in the DRM core and the driver dispatch table,
812 * stored in &drm_driver.ioctls. It checks for necessary permission by calling
813 * drm_ioctl_permit(), and dispatches to the respective function.
814 *
815 * Returns:
816 * Zero on success, negative error code on failure.
817 */
818long drm_ioctl(struct file *filp,
819 unsigned int cmd, unsigned long arg)
820{
821 struct drm_file *file_priv = filp->private_data;
822 struct drm_device *dev;
823 const struct drm_ioctl_desc *ioctl = NULL;
824 drm_ioctl_t *func;
825 unsigned int nr = DRM_IOCTL_NR(cmd);
826 int retcode = -EINVAL;
827 char stack_kdata[128];
828 char *kdata = NULL;
829 unsigned int in_size, out_size, drv_size, ksize;
830 bool is_driver_ioctl;
831
832 dev = file_priv->minor->dev;
833
834 if (drm_dev_is_unplugged(dev))
835 return -ENODEV;
836
837 if (DRM_IOCTL_TYPE(cmd) != DRM_IOCTL_BASE)
838 return -ENOTTY;
839
840 is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
841
842 if (is_driver_ioctl) {
843 /* driver ioctl */
844 unsigned int index = nr - DRM_COMMAND_BASE;
845
846 if (index >= dev->driver->num_ioctls)
847 goto err_i1;
848 index = array_index_nospec(index, dev->driver->num_ioctls);
849 ioctl = &dev->driver->ioctls[index];
850 } else {
851 /* core ioctl */
852 if (nr >= DRM_CORE_IOCTL_COUNT)
853 goto err_i1;
854 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
855 ioctl = &drm_ioctls[nr];
856 }
857
858 drv_size = _IOC_SIZE(ioctl->cmd);
859 out_size = in_size = _IOC_SIZE(cmd);
860 if ((cmd & ioctl->cmd & IOC_IN) == 0)
861 in_size = 0;
862 if ((cmd & ioctl->cmd & IOC_OUT) == 0)
863 out_size = 0;
864 ksize = max(max(in_size, out_size), drv_size);
865
866 DRM_DEBUG("comm=\"%s\" pid=%d, dev=0x%lx, auth=%d, %s\n",
867 current->comm, task_pid_nr(current),
868 (long)old_encode_dev(file_priv->minor->kdev->devt),
869 file_priv->authenticated, ioctl->name);
870
871 /* Do not trust userspace, use our own definition */
872 func = ioctl->func;
873
874 if (unlikely(!func)) {
875 DRM_DEBUG("no function\n");
876 retcode = -EINVAL;
877 goto err_i1;
878 }
879
880 if (ksize <= sizeof(stack_kdata)) {
881 kdata = stack_kdata;
882 } else {
883 kdata = kmalloc(ksize, GFP_KERNEL);
884 if (!kdata) {
885 retcode = -ENOMEM;
886 goto err_i1;
887 }
888 }
889
890 if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) {
891 retcode = -EFAULT;
892 goto err_i1;
893 }
894
895 if (ksize > in_size)
896 memset(kdata + in_size, 0, ksize - in_size);
897
898 retcode = drm_ioctl_kernel(filp, func, kdata, ioctl->flags);
899 if (copy_to_user((void __user *)arg, kdata, out_size) != 0)
900 retcode = -EFAULT;
901
902 err_i1:
903 if (!ioctl)
904 DRM_DEBUG("invalid ioctl: comm=\"%s\", pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
905 current->comm, task_pid_nr(current),
906 (long)old_encode_dev(file_priv->minor->kdev->devt),
907 file_priv->authenticated, cmd, nr);
908
909 if (kdata != stack_kdata)
910 kfree(kdata);
911 if (retcode)
912 DRM_DEBUG("comm=\"%s\", pid=%d, ret=%d\n", current->comm,
913 task_pid_nr(current), retcode);
914 return retcode;
915}
916EXPORT_SYMBOL(drm_ioctl);
917
918/**
919 * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
920 * @nr: ioctl number
921 * @flags: where to return the ioctl permission flags
922 *
923 * This ioctl is only used by the vmwgfx driver to augment the access checks
924 * done by the drm core and insofar a pretty decent layering violation. This
925 * shouldn't be used by any drivers.
926 *
927 * Returns:
928 * True if the @nr corresponds to a DRM core ioctl number, false otherwise.
929 */
930bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
931{
932 if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
933 return false;
934
935 if (nr >= DRM_CORE_IOCTL_COUNT)
936 return false;
937 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT);
938
939 *flags = drm_ioctls[nr].flags;
940 return true;
941}
942EXPORT_SYMBOL(drm_ioctl_flags);