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 */ 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 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 } 138 139 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 */ 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 */ 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 */ 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 = 1; 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 -EOPNOTSUPP; 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 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 /* No render-only settable capabilities for now */ 311 312 /* Below caps that only works with KMS drivers */ 313 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 314 return -EOPNOTSUPP; 315 316 switch (req->capability) { 317 case DRM_CLIENT_CAP_STEREO_3D: 318 if (req->value > 1) 319 return -EINVAL; 320 file_priv->stereo_allowed = req->value; 321 break; 322 case DRM_CLIENT_CAP_UNIVERSAL_PLANES: 323 if (req->value > 1) 324 return -EINVAL; 325 file_priv->universal_planes = req->value; 326 break; 327 case DRM_CLIENT_CAP_ATOMIC: 328 if (!drm_core_check_feature(dev, DRIVER_ATOMIC)) 329 return -EOPNOTSUPP; 330 if (req->value > 1) 331 return -EINVAL; 332 file_priv->atomic = req->value; 333 file_priv->universal_planes = req->value; 334 /* 335 * No atomic user-space blows up on aspect ratio mode bits. 336 */ 337 file_priv->aspect_ratio_allowed = req->value; 338 break; 339 case DRM_CLIENT_CAP_ASPECT_RATIO: 340 if (req->value > 1) 341 return -EINVAL; 342 file_priv->aspect_ratio_allowed = req->value; 343 break; 344 case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS: 345 if (!file_priv->atomic) 346 return -EINVAL; 347 if (req->value > 1) 348 return -EINVAL; 349 file_priv->writeback_connectors = req->value; 350 break; 351 default: 352 return -EINVAL; 353 } 354 355 return 0; 356 } 357 358 /* 359 * Setversion ioctl. 360 * 361 * \param inode device inode. 362 * \param file_priv DRM file private. 363 * \param cmd command. 364 * \param arg user argument, pointing to a drm_lock structure. 365 * \return zero on success or negative number on failure. 366 * 367 * Sets the requested interface version 368 */ 369 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv) 370 { 371 struct drm_set_version *sv = data; 372 int if_version, retcode = 0; 373 374 mutex_lock(&dev->master_mutex); 375 if (sv->drm_di_major != -1) { 376 if (sv->drm_di_major != DRM_IF_MAJOR || 377 sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) { 378 retcode = -EINVAL; 379 goto done; 380 } 381 if_version = DRM_IF_VERSION(sv->drm_di_major, 382 sv->drm_di_minor); 383 dev->if_version = max(if_version, dev->if_version); 384 if (sv->drm_di_minor >= 1) { 385 /* 386 * Version 1.1 includes tying of DRM to specific device 387 * Version 1.4 has proper PCI domain support 388 */ 389 retcode = drm_set_busid(dev, file_priv); 390 if (retcode) 391 goto done; 392 } 393 } 394 395 if (sv->drm_dd_major != -1) { 396 if (sv->drm_dd_major != dev->driver->major || 397 sv->drm_dd_minor < 0 || sv->drm_dd_minor > 398 dev->driver->minor) { 399 retcode = -EINVAL; 400 goto done; 401 } 402 } 403 404 done: 405 sv->drm_di_major = DRM_IF_MAJOR; 406 sv->drm_di_minor = DRM_IF_MINOR; 407 sv->drm_dd_major = dev->driver->major; 408 sv->drm_dd_minor = dev->driver->minor; 409 mutex_unlock(&dev->master_mutex); 410 411 return retcode; 412 } 413 414 /** 415 * drm_noop - DRM no-op ioctl implemntation 416 * @dev: DRM device for the ioctl 417 * @data: data pointer for the ioctl 418 * @file_priv: DRM file for the ioctl call 419 * 420 * This no-op implementation for drm ioctls is useful for deprecated 421 * functionality where we can't return a failure code because existing userspace 422 * checks the result of the ioctl, but doesn't care about the action. 423 * 424 * Always returns successfully with 0. 425 */ 426 int drm_noop(struct drm_device *dev, void *data, 427 struct drm_file *file_priv) 428 { 429 DRM_DEBUG("\n"); 430 return 0; 431 } 432 EXPORT_SYMBOL(drm_noop); 433 434 /** 435 * drm_invalid_op - DRM invalid ioctl implemntation 436 * @dev: DRM device for the ioctl 437 * @data: data pointer for the ioctl 438 * @file_priv: DRM file for the ioctl call 439 * 440 * This no-op implementation for drm ioctls is useful for deprecated 441 * functionality where we really don't want to allow userspace to call the ioctl 442 * any more. This is the case for old ums interfaces for drivers that 443 * transitioned to kms gradually and so kept the old legacy tables around. This 444 * only applies to radeon and i915 kms drivers, other drivers shouldn't need to 445 * use this function. 446 * 447 * Always fails with a return value of -EINVAL. 448 */ 449 int drm_invalid_op(struct drm_device *dev, void *data, 450 struct drm_file *file_priv) 451 { 452 return -EINVAL; 453 } 454 EXPORT_SYMBOL(drm_invalid_op); 455 456 /* 457 * Copy and IOCTL return string to user space 458 */ 459 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value) 460 { 461 int len; 462 463 /* don't overflow userbuf */ 464 len = strlen(value); 465 if (len > *buf_len) 466 len = *buf_len; 467 468 /* let userspace know exact length of driver value (which could be 469 * larger than the userspace-supplied buffer) */ 470 *buf_len = strlen(value); 471 472 /* finally, try filling in the userbuf */ 473 if (len && buf) 474 if (copy_to_user(buf, value, len)) 475 return -EFAULT; 476 return 0; 477 } 478 479 /* 480 * Get version information 481 * 482 * \param inode device inode. 483 * \param filp file pointer. 484 * \param cmd command. 485 * \param arg user argument, pointing to a drm_version structure. 486 * \return zero on success or negative number on failure. 487 * 488 * Fills in the version information in \p arg. 489 */ 490 int drm_version(struct drm_device *dev, void *data, 491 struct drm_file *file_priv) 492 { 493 struct drm_version *version = data; 494 int err; 495 496 version->version_major = dev->driver->major; 497 version->version_minor = dev->driver->minor; 498 version->version_patchlevel = dev->driver->patchlevel; 499 err = drm_copy_field(version->name, &version->name_len, 500 dev->driver->name); 501 if (!err) 502 err = drm_copy_field(version->date, &version->date_len, 503 dev->driver->date); 504 if (!err) 505 err = drm_copy_field(version->desc, &version->desc_len, 506 dev->driver->desc); 507 508 return err; 509 } 510 511 static inline bool 512 drm_render_driver_and_ioctl(const struct drm_device *dev, u32 flags) 513 { 514 return drm_core_check_feature(dev, DRIVER_RENDER) && 515 (flags & DRM_RENDER_ALLOW); 516 } 517 518 /** 519 * drm_ioctl_permit - Check ioctl permissions against caller 520 * 521 * @flags: ioctl permission flags. 522 * @file_priv: Pointer to struct drm_file identifying the caller. 523 * 524 * Checks whether the caller is allowed to run an ioctl with the 525 * indicated permissions. 526 * 527 * Returns: 528 * Zero if allowed, -EACCES otherwise. 529 */ 530 int drm_ioctl_permit(u32 flags, struct drm_file *file_priv) 531 { 532 const struct drm_device *dev = file_priv->minor->dev; 533 534 /* ROOT_ONLY is only for CAP_SYS_ADMIN */ 535 if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN))) 536 return -EACCES; 537 538 /* AUTH is only for master ... */ 539 if (unlikely((flags & DRM_AUTH) && drm_is_primary_client(file_priv))) { 540 /* authenticated ones, or render capable on DRM_RENDER_ALLOW. */ 541 if (!file_priv->authenticated && 542 !drm_render_driver_and_ioctl(dev, flags)) 543 return -EACCES; 544 } 545 546 /* MASTER is only for master or control clients */ 547 if (unlikely((flags & DRM_MASTER) && 548 !drm_is_current_master(file_priv))) 549 return -EACCES; 550 551 /* Render clients must be explicitly allowed */ 552 if (unlikely(!(flags & DRM_RENDER_ALLOW) && 553 drm_is_render_client(file_priv))) 554 return -EACCES; 555 556 return 0; 557 } 558 EXPORT_SYMBOL(drm_ioctl_permit); 559 560 #define DRM_IOCTL_DEF(ioctl, _func, _flags) \ 561 [DRM_IOCTL_NR(ioctl)] = { \ 562 .cmd = ioctl, \ 563 .func = _func, \ 564 .flags = _flags, \ 565 .name = #ioctl \ 566 } 567 568 /* Ioctl table */ 569 static const struct drm_ioctl_desc drm_ioctls[] = { 570 DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, 571 DRM_UNLOCKED|DRM_RENDER_ALLOW), 572 DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, DRM_UNLOCKED), 573 DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, DRM_UNLOCKED), 574 DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY), 575 DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, DRM_UNLOCKED), 576 DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED), 577 DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED), 578 DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED|DRM_RENDER_ALLOW), 579 DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, DRM_UNLOCKED), 580 DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_UNLOCKED | DRM_MASTER), 581 582 DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 583 DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 584 DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 585 DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_UNLOCKED|DRM_MASTER), 586 587 DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 588 DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH), 589 590 DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 591 DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH), 592 593 DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY), 594 DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY), 595 596 DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY), 597 DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 598 DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 599 DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH), 600 DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 601 DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 602 DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH), 603 604 DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 605 DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 606 607 DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH), 608 DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH), 609 610 DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH), 611 612 DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 613 DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 614 DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH), 615 DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH), 616 DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH), 617 DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH), 618 619 DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_legacy_irq_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 620 621 #if IS_ENABLED(CONFIG_AGP) 622 DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 623 DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 624 DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 625 DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH), 626 DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 627 DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 628 DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 629 DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 630 #endif 631 632 DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 633 DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 634 635 DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, DRM_UNLOCKED), 636 637 DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_legacy_modeset_ctl_ioctl, 0), 638 639 DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 640 641 DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW), 642 DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED), 643 DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED), 644 645 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_UNLOCKED), 646 647 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW), 648 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW), 649 650 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_UNLOCKED), 651 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_UNLOCKED), 652 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_UNLOCKED), 653 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_UNLOCKED), 654 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_UNLOCKED), 655 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_UNLOCKED), 656 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_UNLOCKED), 657 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED), 658 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_UNLOCKED), 659 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_UNLOCKED), 660 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER|DRM_UNLOCKED), 661 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER|DRM_UNLOCKED), 662 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_UNLOCKED), 663 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_connector_property_set_ioctl, DRM_MASTER|DRM_UNLOCKED), 664 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_UNLOCKED), 665 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_UNLOCKED), 666 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb_ioctl, DRM_UNLOCKED), 667 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2_ioctl, DRM_UNLOCKED), 668 DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb_ioctl, DRM_UNLOCKED), 669 DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_UNLOCKED), 670 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_UNLOCKED), 671 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_UNLOCKED), 672 DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_UNLOCKED), 673 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_UNLOCKED), 674 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_UNLOCKED), 675 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_UNLOCKED), 676 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_UNLOCKED), 677 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER|DRM_UNLOCKED), 678 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, DRM_UNLOCKED), 679 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, DRM_UNLOCKED), 680 681 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_CREATE, drm_syncobj_create_ioctl, 682 DRM_UNLOCKED|DRM_RENDER_ALLOW), 683 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_DESTROY, drm_syncobj_destroy_ioctl, 684 DRM_UNLOCKED|DRM_RENDER_ALLOW), 685 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, drm_syncobj_handle_to_fd_ioctl, 686 DRM_UNLOCKED|DRM_RENDER_ALLOW), 687 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, drm_syncobj_fd_to_handle_ioctl, 688 DRM_UNLOCKED|DRM_RENDER_ALLOW), 689 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl, 690 DRM_UNLOCKED|DRM_RENDER_ALLOW), 691 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl, 692 DRM_UNLOCKED|DRM_RENDER_ALLOW), 693 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl, 694 DRM_UNLOCKED|DRM_RENDER_ALLOW), 695 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, DRM_UNLOCKED), 696 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, DRM_UNLOCKED), 697 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER|DRM_UNLOCKED), 698 DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER|DRM_UNLOCKED), 699 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER|DRM_UNLOCKED), 700 DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER|DRM_UNLOCKED), 701 }; 702 703 #define DRM_CORE_IOCTL_COUNT ARRAY_SIZE( drm_ioctls ) 704 705 /** 706 * DOC: driver specific ioctls 707 * 708 * First things first, driver private IOCTLs should only be needed for drivers 709 * supporting rendering. Kernel modesetting is all standardized, and extended 710 * through properties. There are a few exceptions in some existing drivers, 711 * which define IOCTL for use by the display DRM master, but they all predate 712 * properties. 713 * 714 * Now if you do have a render driver you always have to support it through 715 * driver private properties. There's a few steps needed to wire all the things 716 * up. 717 * 718 * First you need to define the structure for your IOCTL in your driver private 719 * UAPI header in ``include/uapi/drm/my_driver_drm.h``:: 720 * 721 * struct my_driver_operation { 722 * u32 some_thing; 723 * u32 another_thing; 724 * }; 725 * 726 * Please make sure that you follow all the best practices from 727 * ``Documentation/ioctl/botching-up-ioctls.txt``. Note that drm_ioctl() 728 * automatically zero-extends structures, hence make sure you can add more stuff 729 * at the end, i.e. don't put a variable sized array there. 730 * 731 * Then you need to define your IOCTL number, using one of DRM_IO(), DRM_IOR(), 732 * DRM_IOW() or DRM_IOWR(). It must start with the DRM_IOCTL\_ prefix:: 733 * 734 * ##define DRM_IOCTL_MY_DRIVER_OPERATION \ 735 * DRM_IOW(DRM_COMMAND_BASE, struct my_driver_operation) 736 * 737 * DRM driver private IOCTL must be in the range from DRM_COMMAND_BASE to 738 * DRM_COMMAND_END. Finally you need an array of &struct drm_ioctl_desc to wire 739 * up the handlers and set the access rights:: 740 * 741 * static const struct drm_ioctl_desc my_driver_ioctls[] = { 742 * DRM_IOCTL_DEF_DRV(MY_DRIVER_OPERATION, my_driver_operation, 743 * DRM_AUTH|DRM_RENDER_ALLOW), 744 * }; 745 * 746 * And then assign this to the &drm_driver.ioctls field in your driver 747 * structure. 748 * 749 * See the separate chapter on :ref:`file operations<drm_driver_fops>` for how 750 * the driver-specific IOCTLs are wired up. 751 */ 752 753 long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata, 754 u32 flags) 755 { 756 struct drm_file *file_priv = file->private_data; 757 struct drm_device *dev = file_priv->minor->dev; 758 int retcode; 759 760 if (drm_dev_is_unplugged(dev)) 761 return -ENODEV; 762 763 retcode = drm_ioctl_permit(flags, file_priv); 764 if (unlikely(retcode)) 765 return retcode; 766 767 /* Enforce sane locking for modern driver ioctls. */ 768 if (!drm_core_check_feature(dev, DRIVER_LEGACY) || 769 (flags & DRM_UNLOCKED)) 770 retcode = func(dev, kdata, file_priv); 771 else { 772 mutex_lock(&drm_global_mutex); 773 retcode = func(dev, kdata, file_priv); 774 mutex_unlock(&drm_global_mutex); 775 } 776 return retcode; 777 } 778 EXPORT_SYMBOL(drm_ioctl_kernel); 779 780 /** 781 * drm_ioctl - ioctl callback implementation for DRM drivers 782 * @filp: file this ioctl is called on 783 * @cmd: ioctl cmd number 784 * @arg: user argument 785 * 786 * Looks up the ioctl function in the DRM core and the driver dispatch table, 787 * stored in &drm_driver.ioctls. It checks for necessary permission by calling 788 * drm_ioctl_permit(), and dispatches to the respective function. 789 * 790 * Returns: 791 * Zero on success, negative error code on failure. 792 */ 793 long drm_ioctl(struct file *filp, 794 unsigned int cmd, unsigned long arg) 795 { 796 struct drm_file *file_priv = filp->private_data; 797 struct drm_device *dev; 798 const struct drm_ioctl_desc *ioctl = NULL; 799 drm_ioctl_t *func; 800 unsigned int nr = DRM_IOCTL_NR(cmd); 801 int retcode = -EINVAL; 802 char stack_kdata[128]; 803 char *kdata = NULL; 804 unsigned int in_size, out_size, drv_size, ksize; 805 bool is_driver_ioctl; 806 807 dev = file_priv->minor->dev; 808 809 if (drm_dev_is_unplugged(dev)) 810 return -ENODEV; 811 812 is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END; 813 814 if (is_driver_ioctl) { 815 /* driver ioctl */ 816 unsigned int index = nr - DRM_COMMAND_BASE; 817 818 if (index >= dev->driver->num_ioctls) 819 goto err_i1; 820 index = array_index_nospec(index, dev->driver->num_ioctls); 821 ioctl = &dev->driver->ioctls[index]; 822 } else { 823 /* core ioctl */ 824 if (nr >= DRM_CORE_IOCTL_COUNT) 825 goto err_i1; 826 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT); 827 ioctl = &drm_ioctls[nr]; 828 } 829 830 drv_size = _IOC_SIZE(ioctl->cmd); 831 out_size = in_size = _IOC_SIZE(cmd); 832 if ((cmd & ioctl->cmd & IOC_IN) == 0) 833 in_size = 0; 834 if ((cmd & ioctl->cmd & IOC_OUT) == 0) 835 out_size = 0; 836 ksize = max(max(in_size, out_size), drv_size); 837 838 DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n", 839 task_pid_nr(current), 840 (long)old_encode_dev(file_priv->minor->kdev->devt), 841 file_priv->authenticated, ioctl->name); 842 843 /* Do not trust userspace, use our own definition */ 844 func = ioctl->func; 845 846 if (unlikely(!func)) { 847 DRM_DEBUG("no function\n"); 848 retcode = -EINVAL; 849 goto err_i1; 850 } 851 852 if (ksize <= sizeof(stack_kdata)) { 853 kdata = stack_kdata; 854 } else { 855 kdata = kmalloc(ksize, GFP_KERNEL); 856 if (!kdata) { 857 retcode = -ENOMEM; 858 goto err_i1; 859 } 860 } 861 862 if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) { 863 retcode = -EFAULT; 864 goto err_i1; 865 } 866 867 if (ksize > in_size) 868 memset(kdata + in_size, 0, ksize - in_size); 869 870 retcode = drm_ioctl_kernel(filp, func, kdata, ioctl->flags); 871 if (copy_to_user((void __user *)arg, kdata, out_size) != 0) 872 retcode = -EFAULT; 873 874 err_i1: 875 if (!ioctl) 876 DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n", 877 task_pid_nr(current), 878 (long)old_encode_dev(file_priv->minor->kdev->devt), 879 file_priv->authenticated, cmd, nr); 880 881 if (kdata != stack_kdata) 882 kfree(kdata); 883 if (retcode) 884 DRM_DEBUG("pid=%d, ret = %d\n", task_pid_nr(current), retcode); 885 return retcode; 886 } 887 EXPORT_SYMBOL(drm_ioctl); 888 889 /** 890 * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags 891 * @nr: ioctl number 892 * @flags: where to return the ioctl permission flags 893 * 894 * This ioctl is only used by the vmwgfx driver to augment the access checks 895 * done by the drm core and insofar a pretty decent layering violation. This 896 * shouldn't be used by any drivers. 897 * 898 * Returns: 899 * True if the @nr corresponds to a DRM core ioctl number, false otherwise. 900 */ 901 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags) 902 { 903 if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END) 904 return false; 905 906 if (nr >= DRM_CORE_IOCTL_COUNT) 907 return false; 908 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT); 909 910 *flags = drm_ioctls[nr].flags; 911 return true; 912 } 913 EXPORT_SYMBOL(drm_ioctl_flags); 914