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 /* The modesetting DDX has a totally broken idea of atomic. */ 340 if (current->comm[0] == 'X' && req->value == 1) { 341 pr_info("broken atomic modeset userspace detected, disabling atomic\n"); 342 return -EOPNOTSUPP; 343 } 344 if (req->value > 2) 345 return -EINVAL; 346 file_priv->atomic = req->value; 347 file_priv->universal_planes = req->value; 348 /* 349 * No atomic user-space blows up on aspect ratio mode bits. 350 */ 351 file_priv->aspect_ratio_allowed = req->value; 352 break; 353 case DRM_CLIENT_CAP_ASPECT_RATIO: 354 if (req->value > 1) 355 return -EINVAL; 356 file_priv->aspect_ratio_allowed = req->value; 357 break; 358 case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS: 359 if (!file_priv->atomic) 360 return -EINVAL; 361 if (req->value > 1) 362 return -EINVAL; 363 file_priv->writeback_connectors = req->value; 364 break; 365 default: 366 return -EINVAL; 367 } 368 369 return 0; 370 } 371 372 /* 373 * Setversion ioctl. 374 * 375 * \param inode device inode. 376 * \param file_priv DRM file private. 377 * \param cmd command. 378 * \param arg user argument, pointing to a drm_lock structure. 379 * \return zero on success or negative number on failure. 380 * 381 * Sets the requested interface version 382 */ 383 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv) 384 { 385 struct drm_set_version *sv = data; 386 int if_version, retcode = 0; 387 388 mutex_lock(&dev->master_mutex); 389 if (sv->drm_di_major != -1) { 390 if (sv->drm_di_major != DRM_IF_MAJOR || 391 sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) { 392 retcode = -EINVAL; 393 goto done; 394 } 395 if_version = DRM_IF_VERSION(sv->drm_di_major, 396 sv->drm_di_minor); 397 dev->if_version = max(if_version, dev->if_version); 398 if (sv->drm_di_minor >= 1) { 399 /* 400 * Version 1.1 includes tying of DRM to specific device 401 * Version 1.4 has proper PCI domain support 402 */ 403 retcode = drm_set_busid(dev, file_priv); 404 if (retcode) 405 goto done; 406 } 407 } 408 409 if (sv->drm_dd_major != -1) { 410 if (sv->drm_dd_major != dev->driver->major || 411 sv->drm_dd_minor < 0 || sv->drm_dd_minor > 412 dev->driver->minor) { 413 retcode = -EINVAL; 414 goto done; 415 } 416 } 417 418 done: 419 sv->drm_di_major = DRM_IF_MAJOR; 420 sv->drm_di_minor = DRM_IF_MINOR; 421 sv->drm_dd_major = dev->driver->major; 422 sv->drm_dd_minor = dev->driver->minor; 423 mutex_unlock(&dev->master_mutex); 424 425 return retcode; 426 } 427 428 /** 429 * drm_noop - DRM no-op ioctl implemntation 430 * @dev: DRM device for the ioctl 431 * @data: data pointer for the ioctl 432 * @file_priv: DRM file for the ioctl call 433 * 434 * This no-op implementation for drm ioctls is useful for deprecated 435 * functionality where we can't return a failure code because existing userspace 436 * checks the result of the ioctl, but doesn't care about the action. 437 * 438 * Always returns successfully with 0. 439 */ 440 int drm_noop(struct drm_device *dev, void *data, 441 struct drm_file *file_priv) 442 { 443 DRM_DEBUG("\n"); 444 return 0; 445 } 446 EXPORT_SYMBOL(drm_noop); 447 448 /** 449 * drm_invalid_op - DRM invalid ioctl implemntation 450 * @dev: DRM device for the ioctl 451 * @data: data pointer for the ioctl 452 * @file_priv: DRM file for the ioctl call 453 * 454 * This no-op implementation for drm ioctls is useful for deprecated 455 * functionality where we really don't want to allow userspace to call the ioctl 456 * any more. This is the case for old ums interfaces for drivers that 457 * transitioned to kms gradually and so kept the old legacy tables around. This 458 * only applies to radeon and i915 kms drivers, other drivers shouldn't need to 459 * use this function. 460 * 461 * Always fails with a return value of -EINVAL. 462 */ 463 int drm_invalid_op(struct drm_device *dev, void *data, 464 struct drm_file *file_priv) 465 { 466 return -EINVAL; 467 } 468 EXPORT_SYMBOL(drm_invalid_op); 469 470 /* 471 * Copy and IOCTL return string to user space 472 */ 473 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value) 474 { 475 int len; 476 477 /* don't overflow userbuf */ 478 len = strlen(value); 479 if (len > *buf_len) 480 len = *buf_len; 481 482 /* let userspace know exact length of driver value (which could be 483 * larger than the userspace-supplied buffer) */ 484 *buf_len = strlen(value); 485 486 /* finally, try filling in the userbuf */ 487 if (len && buf) 488 if (copy_to_user(buf, value, len)) 489 return -EFAULT; 490 return 0; 491 } 492 493 /* 494 * Get version information 495 * 496 * \param inode device inode. 497 * \param filp file pointer. 498 * \param cmd command. 499 * \param arg user argument, pointing to a drm_version structure. 500 * \return zero on success or negative number on failure. 501 * 502 * Fills in the version information in \p arg. 503 */ 504 int drm_version(struct drm_device *dev, void *data, 505 struct drm_file *file_priv) 506 { 507 struct drm_version *version = data; 508 int err; 509 510 version->version_major = dev->driver->major; 511 version->version_minor = dev->driver->minor; 512 version->version_patchlevel = dev->driver->patchlevel; 513 err = drm_copy_field(version->name, &version->name_len, 514 dev->driver->name); 515 if (!err) 516 err = drm_copy_field(version->date, &version->date_len, 517 dev->driver->date); 518 if (!err) 519 err = drm_copy_field(version->desc, &version->desc_len, 520 dev->driver->desc); 521 522 return err; 523 } 524 525 /** 526 * drm_ioctl_permit - Check ioctl permissions against caller 527 * 528 * @flags: ioctl permission flags. 529 * @file_priv: Pointer to struct drm_file identifying the caller. 530 * 531 * Checks whether the caller is allowed to run an ioctl with the 532 * indicated permissions. 533 * 534 * Returns: 535 * Zero if allowed, -EACCES otherwise. 536 */ 537 int drm_ioctl_permit(u32 flags, struct drm_file *file_priv) 538 { 539 /* ROOT_ONLY is only for CAP_SYS_ADMIN */ 540 if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN))) 541 return -EACCES; 542 543 /* AUTH is only for authenticated or render client */ 544 if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) && 545 !file_priv->authenticated)) 546 return -EACCES; 547 548 /* MASTER is only for master or control clients */ 549 if (unlikely((flags & DRM_MASTER) && 550 !drm_is_current_master(file_priv))) 551 return -EACCES; 552 553 /* Render clients must be explicitly allowed */ 554 if (unlikely(!(flags & DRM_RENDER_ALLOW) && 555 drm_is_render_client(file_priv))) 556 return -EACCES; 557 558 return 0; 559 } 560 EXPORT_SYMBOL(drm_ioctl_permit); 561 562 #define DRM_IOCTL_DEF(ioctl, _func, _flags) \ 563 [DRM_IOCTL_NR(ioctl)] = { \ 564 .cmd = ioctl, \ 565 .func = _func, \ 566 .flags = _flags, \ 567 .name = #ioctl \ 568 } 569 570 #if IS_ENABLED(CONFIG_DRM_LEGACY) 571 #define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags) DRM_IOCTL_DEF(ioctl, _func, _flags) 572 #else 573 #define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags) DRM_IOCTL_DEF(ioctl, drm_invalid_op, _flags) 574 #endif 575 576 /* Ioctl table */ 577 static const struct drm_ioctl_desc drm_ioctls[] = { 578 DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_RENDER_ALLOW), 579 DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0), 580 DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0), 581 DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY), 582 583 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, 0), 584 585 DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, 0), 586 DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0), 587 DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_RENDER_ALLOW), 588 DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0), 589 DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER), 590 591 DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 592 DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 593 DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 594 DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_MASTER), 595 596 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 597 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH), 598 599 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 600 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH), 601 602 DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_ROOT_ONLY), 603 DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_ROOT_ONLY), 604 605 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY), 606 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 607 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 608 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH), 609 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 610 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 611 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH), 612 613 DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 614 DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 615 616 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH), 617 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH), 618 619 DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH), 620 621 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 622 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 623 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH), 624 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH), 625 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH), 626 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH), 627 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_legacy_irq_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 628 629 #if IS_ENABLED(CONFIG_AGP) 630 DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 631 DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 632 DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 633 DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH), 634 DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 635 DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 636 DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 637 DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 638 #endif 639 640 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 641 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 642 643 DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, DRM_UNLOCKED), 644 645 DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_legacy_modeset_ctl_ioctl, 0), 646 647 DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 648 649 DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_RENDER_ALLOW), 650 DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH), 651 DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH), 652 653 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, 0), 654 655 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_RENDER_ALLOW), 656 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_RENDER_ALLOW), 657 658 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, 0), 659 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, 0), 660 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER), 661 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, 0), 662 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER), 663 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER), 664 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, 0), 665 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER), 666 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, 0), 667 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, 0), 668 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER), 669 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER), 670 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, 0), 671 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_connector_property_set_ioctl, DRM_MASTER), 672 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, 0), 673 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, 0), 674 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB2, drm_mode_getfb2_ioctl, 0), 675 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb_ioctl, 0), 676 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2_ioctl, 0), 677 DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb_ioctl, 0), 678 DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER), 679 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER), 680 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, 0), 681 DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, 0), 682 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, 0), 683 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, 0), 684 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER), 685 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER), 686 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER), 687 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, 0), 688 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, 0), 689 690 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_CREATE, drm_syncobj_create_ioctl, 691 DRM_RENDER_ALLOW), 692 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_DESTROY, drm_syncobj_destroy_ioctl, 693 DRM_RENDER_ALLOW), 694 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, drm_syncobj_handle_to_fd_ioctl, 695 DRM_RENDER_ALLOW), 696 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, drm_syncobj_fd_to_handle_ioctl, 697 DRM_RENDER_ALLOW), 698 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TRANSFER, drm_syncobj_transfer_ioctl, 699 DRM_RENDER_ALLOW), 700 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl, 701 DRM_RENDER_ALLOW), 702 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT, drm_syncobj_timeline_wait_ioctl, 703 DRM_RENDER_ALLOW), 704 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl, 705 DRM_RENDER_ALLOW), 706 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl, 707 DRM_RENDER_ALLOW), 708 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL, drm_syncobj_timeline_signal_ioctl, 709 DRM_RENDER_ALLOW), 710 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_QUERY, drm_syncobj_query_ioctl, 711 DRM_RENDER_ALLOW), 712 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, 0), 713 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, 0), 714 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER), 715 DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER), 716 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER), 717 DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER), 718 }; 719 720 #define DRM_CORE_IOCTL_COUNT ARRAY_SIZE( drm_ioctls ) 721 722 /** 723 * DOC: driver specific ioctls 724 * 725 * First things first, driver private IOCTLs should only be needed for drivers 726 * supporting rendering. Kernel modesetting is all standardized, and extended 727 * through properties. There are a few exceptions in some existing drivers, 728 * which define IOCTL for use by the display DRM master, but they all predate 729 * properties. 730 * 731 * Now if you do have a render driver you always have to support it through 732 * driver private properties. There's a few steps needed to wire all the things 733 * up. 734 * 735 * First you need to define the structure for your IOCTL in your driver private 736 * UAPI header in ``include/uapi/drm/my_driver_drm.h``:: 737 * 738 * struct my_driver_operation { 739 * u32 some_thing; 740 * u32 another_thing; 741 * }; 742 * 743 * Please make sure that you follow all the best practices from 744 * ``Documentation/ioctl/botching-up-ioctls.rst``. Note that drm_ioctl() 745 * automatically zero-extends structures, hence make sure you can add more stuff 746 * at the end, i.e. don't put a variable sized array there. 747 * 748 * Then you need to define your IOCTL number, using one of DRM_IO(), DRM_IOR(), 749 * DRM_IOW() or DRM_IOWR(). It must start with the DRM_IOCTL\_ prefix:: 750 * 751 * ##define DRM_IOCTL_MY_DRIVER_OPERATION \ 752 * DRM_IOW(DRM_COMMAND_BASE, struct my_driver_operation) 753 * 754 * DRM driver private IOCTL must be in the range from DRM_COMMAND_BASE to 755 * DRM_COMMAND_END. Finally you need an array of &struct drm_ioctl_desc to wire 756 * up the handlers and set the access rights:: 757 * 758 * static const struct drm_ioctl_desc my_driver_ioctls[] = { 759 * DRM_IOCTL_DEF_DRV(MY_DRIVER_OPERATION, my_driver_operation, 760 * DRM_AUTH|DRM_RENDER_ALLOW), 761 * }; 762 * 763 * And then assign this to the &drm_driver.ioctls field in your driver 764 * structure. 765 * 766 * See the separate chapter on :ref:`file operations<drm_driver_fops>` for how 767 * the driver-specific IOCTLs are wired up. 768 */ 769 770 long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata, 771 u32 flags) 772 { 773 struct drm_file *file_priv = file->private_data; 774 struct drm_device *dev = file_priv->minor->dev; 775 int retcode; 776 777 if (drm_dev_is_unplugged(dev)) 778 return -ENODEV; 779 780 retcode = drm_ioctl_permit(flags, file_priv); 781 if (unlikely(retcode)) 782 return retcode; 783 784 /* Enforce sane locking for modern driver ioctls. */ 785 if (likely(!drm_core_check_feature(dev, DRIVER_LEGACY)) || 786 (flags & DRM_UNLOCKED)) 787 retcode = func(dev, kdata, file_priv); 788 else { 789 mutex_lock(&drm_global_mutex); 790 retcode = func(dev, kdata, file_priv); 791 mutex_unlock(&drm_global_mutex); 792 } 793 return retcode; 794 } 795 EXPORT_SYMBOL(drm_ioctl_kernel); 796 797 /** 798 * drm_ioctl - ioctl callback implementation for DRM drivers 799 * @filp: file this ioctl is called on 800 * @cmd: ioctl cmd number 801 * @arg: user argument 802 * 803 * Looks up the ioctl function in the DRM core and the driver dispatch table, 804 * stored in &drm_driver.ioctls. It checks for necessary permission by calling 805 * drm_ioctl_permit(), and dispatches to the respective function. 806 * 807 * Returns: 808 * Zero on success, negative error code on failure. 809 */ 810 long drm_ioctl(struct file *filp, 811 unsigned int cmd, unsigned long arg) 812 { 813 struct drm_file *file_priv = filp->private_data; 814 struct drm_device *dev; 815 const struct drm_ioctl_desc *ioctl = NULL; 816 drm_ioctl_t *func; 817 unsigned int nr = DRM_IOCTL_NR(cmd); 818 int retcode = -EINVAL; 819 char stack_kdata[128]; 820 char *kdata = NULL; 821 unsigned int in_size, out_size, drv_size, ksize; 822 bool is_driver_ioctl; 823 824 dev = file_priv->minor->dev; 825 826 if (drm_dev_is_unplugged(dev)) 827 return -ENODEV; 828 829 is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END; 830 831 if (is_driver_ioctl) { 832 /* driver ioctl */ 833 unsigned int index = nr - DRM_COMMAND_BASE; 834 835 if (index >= dev->driver->num_ioctls) 836 goto err_i1; 837 index = array_index_nospec(index, dev->driver->num_ioctls); 838 ioctl = &dev->driver->ioctls[index]; 839 } else { 840 /* core ioctl */ 841 if (nr >= DRM_CORE_IOCTL_COUNT) 842 goto err_i1; 843 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT); 844 ioctl = &drm_ioctls[nr]; 845 } 846 847 drv_size = _IOC_SIZE(ioctl->cmd); 848 out_size = in_size = _IOC_SIZE(cmd); 849 if ((cmd & ioctl->cmd & IOC_IN) == 0) 850 in_size = 0; 851 if ((cmd & ioctl->cmd & IOC_OUT) == 0) 852 out_size = 0; 853 ksize = max(max(in_size, out_size), drv_size); 854 855 DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n", 856 task_pid_nr(current), 857 (long)old_encode_dev(file_priv->minor->kdev->devt), 858 file_priv->authenticated, ioctl->name); 859 860 /* Do not trust userspace, use our own definition */ 861 func = ioctl->func; 862 863 if (unlikely(!func)) { 864 DRM_DEBUG("no function\n"); 865 retcode = -EINVAL; 866 goto err_i1; 867 } 868 869 if (ksize <= sizeof(stack_kdata)) { 870 kdata = stack_kdata; 871 } else { 872 kdata = kmalloc(ksize, GFP_KERNEL); 873 if (!kdata) { 874 retcode = -ENOMEM; 875 goto err_i1; 876 } 877 } 878 879 if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) { 880 retcode = -EFAULT; 881 goto err_i1; 882 } 883 884 if (ksize > in_size) 885 memset(kdata + in_size, 0, ksize - in_size); 886 887 retcode = drm_ioctl_kernel(filp, func, kdata, ioctl->flags); 888 if (copy_to_user((void __user *)arg, kdata, out_size) != 0) 889 retcode = -EFAULT; 890 891 err_i1: 892 if (!ioctl) 893 DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n", 894 task_pid_nr(current), 895 (long)old_encode_dev(file_priv->minor->kdev->devt), 896 file_priv->authenticated, cmd, nr); 897 898 if (kdata != stack_kdata) 899 kfree(kdata); 900 if (retcode) 901 DRM_DEBUG("pid=%d, ret = %d\n", task_pid_nr(current), retcode); 902 return retcode; 903 } 904 EXPORT_SYMBOL(drm_ioctl); 905 906 /** 907 * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags 908 * @nr: ioctl number 909 * @flags: where to return the ioctl permission flags 910 * 911 * This ioctl is only used by the vmwgfx driver to augment the access checks 912 * done by the drm core and insofar a pretty decent layering violation. This 913 * shouldn't be used by any drivers. 914 * 915 * Returns: 916 * True if the @nr corresponds to a DRM core ioctl number, false otherwise. 917 */ 918 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags) 919 { 920 if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END) 921 return false; 922 923 if (nr >= DRM_CORE_IOCTL_COUNT) 924 return false; 925 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT); 926 927 *flags = drm_ioctls[nr].flags; 928 return true; 929 } 930 EXPORT_SYMBOL(drm_ioctl_flags); 931