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