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