drm_ioctl.c revision 1.1.1.4
1 /* $NetBSD: drm_ioctl.c,v 1.1.1.4 2021/12/18 20:11:02 riastradh Exp $ */ 2 3 /* 4 * Created: Fri Jan 8 09:01:26 1999 by faith (at) valinux.com 5 * 6 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas. 7 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. 8 * All Rights Reserved. 9 * 10 * Author Rickard E. (Rik) Faith <faith (at) valinux.com> 11 * Author Gareth Hughes <gareth (at) valinux.com> 12 * 13 * Permission is hereby granted, free of charge, to any person obtaining a 14 * copy of this software and associated documentation files (the "Software"), 15 * to deal in the Software without restriction, including without limitation 16 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 17 * and/or sell copies of the Software, and to permit persons to whom the 18 * Software is furnished to do so, subject to the following conditions: 19 * 20 * The above copyright notice and this permission notice (including the next 21 * paragraph) shall be included in all copies or substantial portions of the 22 * Software. 23 * 24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 25 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 26 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 27 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 28 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 29 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 30 * OTHER DEALINGS IN THE SOFTWARE. 31 */ 32 33 #include <sys/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: drm_ioctl.c,v 1.1.1.4 2021/12/18 20:11:02 riastradh Exp $"); 35 36 #include <linux/export.h> 37 #include <linux/nospec.h> 38 #include <linux/pci.h> 39 #include <linux/uaccess.h> 40 41 #include <drm/drm_agpsupport.h> 42 #include <drm/drm_auth.h> 43 #include <drm/drm_crtc.h> 44 #include <drm/drm_drv.h> 45 #include <drm/drm_file.h> 46 #include <drm/drm_ioctl.h> 47 #include <drm/drm_print.h> 48 49 #include "drm_crtc_internal.h" 50 #include "drm_internal.h" 51 #include "drm_legacy.h" 52 53 /** 54 * DOC: getunique and setversion story 55 * 56 * BEWARE THE DRAGONS! MIND THE TRAPDOORS! 57 * 58 * In an attempt to warn anyone else who's trying to figure out what's going 59 * on here, I'll try to summarize the story. First things first, let's clear up 60 * the names, because the kernel internals, libdrm and the ioctls are all named 61 * differently: 62 * 63 * - GET_UNIQUE ioctl, implemented by drm_getunique is wrapped up in libdrm 64 * through the drmGetBusid function. 65 * - The libdrm drmSetBusid function is backed by the SET_UNIQUE ioctl. All 66 * that code is nerved in the kernel with drm_invalid_op(). 67 * - The internal set_busid kernel functions and driver callbacks are 68 * exclusively use by the SET_VERSION ioctl, because only drm 1.0 (which is 69 * nerved) allowed userspace to set the busid through the above ioctl. 70 * - Other ioctls and functions involved are named consistently. 71 * 72 * For anyone wondering what's the difference between drm 1.1 and 1.4: Correctly 73 * handling pci domains in the busid on ppc. Doing this correctly was only 74 * implemented in libdrm in 2010, hence can't be nerved yet. No one knows what's 75 * special with drm 1.2 and 1.3. 76 * 77 * Now the actual horror story of how device lookup in drm works. At large, 78 * there's 2 different ways, either by busid, or by device driver name. 79 * 80 * Opening by busid is fairly simple: 81 * 82 * 1. First call SET_VERSION to make sure pci domains are handled properly. As a 83 * side-effect this fills out the unique name in the master structure. 84 * 2. Call GET_UNIQUE to read out the unique name from the master structure, 85 * which matches the busid thanks to step 1. If it doesn't, proceed to try 86 * the next device node. 87 * 88 * Opening by name is slightly different: 89 * 90 * 1. Directly call VERSION to get the version and to match against the driver 91 * name returned by that ioctl. Note that SET_VERSION is not called, which 92 * means the the unique name for the master node just opening is _not_ filled 93 * out. This despite that with current drm device nodes are always bound to 94 * one device, and can't be runtime assigned like with drm 1.0. 95 * 2. Match driver name. If it mismatches, proceed to the next device node. 96 * 3. Call GET_UNIQUE, and check whether the unique name has length zero (by 97 * checking that the first byte in the string is 0). If that's not the case 98 * libdrm skips and proceeds to the next device node. Probably this is just 99 * copypasta from drm 1.0 times where a set unique name meant that the driver 100 * was in use already, but that's just conjecture. 101 * 102 * Long story short: To keep the open by name logic working, GET_UNIQUE must 103 * _not_ return a unique string when SET_VERSION hasn't been called yet, 104 * otherwise libdrm breaks. Even when that unique string can't ever change, and 105 * is totally irrelevant for actually opening the device because runtime 106 * assignable device instances were only support in drm 1.0, which is long dead. 107 * But the libdrm code in drmOpenByName somehow survived, hence this can't be 108 * broken. 109 */ 110 111 /* 112 * Get the bus id. 113 * 114 * \param inode device inode. 115 * \param file_priv DRM file private. 116 * \param cmd command. 117 * \param arg user argument, pointing to a drm_unique structure. 118 * \return zero on success or a negative number on failure. 119 * 120 * Copies the bus id from drm_device::unique into user space. 121 */ 122 int drm_getunique(struct drm_device *dev, void *data, 123 struct drm_file *file_priv) 124 { 125 struct drm_unique *u = data; 126 struct drm_master *master = file_priv->master; 127 128 mutex_lock(&master->dev->master_mutex); 129 if (u->unique_len >= master->unique_len) { 130 if (copy_to_user(u->unique, master->unique, master->unique_len)) { 131 mutex_unlock(&master->dev->master_mutex); 132 return -EFAULT; 133 } 134 } 135 u->unique_len = master->unique_len; 136 mutex_unlock(&master->dev->master_mutex); 137 138 return 0; 139 } 140 141 static void 142 drm_unset_busid(struct drm_device *dev, 143 struct drm_master *master) 144 { 145 kfree(master->unique); 146 master->unique = NULL; 147 master->unique_len = 0; 148 } 149 150 static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv) 151 { 152 struct drm_master *master = file_priv->master; 153 int ret; 154 155 if (master->unique != NULL) 156 drm_unset_busid(dev, master); 157 158 if (dev->dev && dev_is_pci(dev->dev)) { 159 ret = drm_pci_set_busid(dev, master); 160 if (ret) { 161 drm_unset_busid(dev, master); 162 return ret; 163 } 164 } else { 165 WARN_ON(!dev->unique); 166 master->unique = kstrdup(dev->unique, GFP_KERNEL); 167 if (master->unique) 168 master->unique_len = strlen(dev->unique); 169 } 170 171 return 0; 172 } 173 174 /* 175 * Get client information. 176 * 177 * \param inode device inode. 178 * \param file_priv DRM file private. 179 * \param cmd command. 180 * \param arg user argument, pointing to a drm_client structure. 181 * 182 * \return zero on success or a negative number on failure. 183 * 184 * Searches for the client with the specified index and copies its information 185 * into userspace 186 */ 187 int drm_getclient(struct drm_device *dev, void *data, 188 struct drm_file *file_priv) 189 { 190 struct drm_client *client = data; 191 192 /* 193 * Hollowed-out getclient ioctl to keep some dead old drm tests/tools 194 * not breaking completely. Userspace tools stop enumerating one they 195 * get -EINVAL, hence this is the return value we need to hand back for 196 * no clients tracked. 197 * 198 * Unfortunately some clients (*cough* libva *cough*) use this in a fun 199 * attempt to figure out whether they're authenticated or not. Since 200 * that's the only thing they care about, give it to the directly 201 * instead of walking one giant list. 202 */ 203 if (client->idx == 0) { 204 client->auth = file_priv->authenticated; 205 client->pid = task_pid_vnr(current); 206 client->uid = overflowuid; 207 client->magic = 0; 208 client->iocs = 0; 209 210 return 0; 211 } else { 212 return -EINVAL; 213 } 214 } 215 216 /* 217 * Get statistics information. 218 * 219 * \param inode device inode. 220 * \param file_priv DRM file private. 221 * \param cmd command. 222 * \param arg user argument, pointing to a drm_stats structure. 223 * 224 * \return zero on success or a negative number on failure. 225 */ 226 static int drm_getstats(struct drm_device *dev, void *data, 227 struct drm_file *file_priv) 228 { 229 struct drm_stats *stats = data; 230 231 /* Clear stats to prevent userspace from eating its stack garbage. */ 232 memset(stats, 0, sizeof(*stats)); 233 234 return 0; 235 } 236 237 /* 238 * Get device/driver capabilities 239 */ 240 static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv) 241 { 242 struct drm_get_cap *req = data; 243 struct drm_crtc *crtc; 244 245 req->value = 0; 246 247 /* Only some caps make sense with UMS/render-only drivers. */ 248 switch (req->capability) { 249 case DRM_CAP_TIMESTAMP_MONOTONIC: 250 req->value = 1; 251 return 0; 252 case DRM_CAP_PRIME: 253 req->value |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0; 254 req->value |= dev->driver->prime_handle_to_fd ? DRM_PRIME_CAP_EXPORT : 0; 255 return 0; 256 case DRM_CAP_SYNCOBJ: 257 req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ); 258 return 0; 259 case DRM_CAP_SYNCOBJ_TIMELINE: 260 req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE); 261 return 0; 262 } 263 264 /* Other caps only work with KMS drivers */ 265 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 266 return -EOPNOTSUPP; 267 268 switch (req->capability) { 269 case DRM_CAP_DUMB_BUFFER: 270 if (dev->driver->dumb_create) 271 req->value = 1; 272 break; 273 case DRM_CAP_VBLANK_HIGH_CRTC: 274 req->value = 1; 275 break; 276 case DRM_CAP_DUMB_PREFERRED_DEPTH: 277 req->value = dev->mode_config.preferred_depth; 278 break; 279 case DRM_CAP_DUMB_PREFER_SHADOW: 280 req->value = dev->mode_config.prefer_shadow; 281 break; 282 case DRM_CAP_ASYNC_PAGE_FLIP: 283 req->value = dev->mode_config.async_page_flip; 284 break; 285 case DRM_CAP_PAGE_FLIP_TARGET: 286 req->value = 1; 287 drm_for_each_crtc(crtc, dev) { 288 if (!crtc->funcs->page_flip_target) 289 req->value = 0; 290 } 291 break; 292 case DRM_CAP_CURSOR_WIDTH: 293 if (dev->mode_config.cursor_width) 294 req->value = dev->mode_config.cursor_width; 295 else 296 req->value = 64; 297 break; 298 case DRM_CAP_CURSOR_HEIGHT: 299 if (dev->mode_config.cursor_height) 300 req->value = dev->mode_config.cursor_height; 301 else 302 req->value = 64; 303 break; 304 case DRM_CAP_ADDFB2_MODIFIERS: 305 req->value = dev->mode_config.allow_fb_modifiers; 306 break; 307 case DRM_CAP_CRTC_IN_VBLANK_EVENT: 308 req->value = 1; 309 break; 310 default: 311 return -EINVAL; 312 } 313 return 0; 314 } 315 316 /* 317 * Set device/driver capabilities 318 */ 319 static int 320 drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv) 321 { 322 struct drm_set_client_cap *req = data; 323 324 /* No render-only settable capabilities for now */ 325 326 /* Below caps that only works with KMS drivers */ 327 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 328 return -EOPNOTSUPP; 329 330 switch (req->capability) { 331 case DRM_CLIENT_CAP_STEREO_3D: 332 if (req->value > 1) 333 return -EINVAL; 334 file_priv->stereo_allowed = req->value; 335 break; 336 case DRM_CLIENT_CAP_UNIVERSAL_PLANES: 337 if (req->value > 1) 338 return -EINVAL; 339 file_priv->universal_planes = req->value; 340 break; 341 case DRM_CLIENT_CAP_ATOMIC: 342 if (!drm_core_check_feature(dev, DRIVER_ATOMIC)) 343 return -EOPNOTSUPP; 344 /* The modesetting DDX has a totally broken idea of atomic. */ 345 if (current->comm[0] == 'X' && req->value == 1) { 346 pr_info("broken atomic modeset userspace detected, disabling atomic\n"); 347 return -EOPNOTSUPP; 348 } 349 if (req->value > 2) 350 return -EINVAL; 351 file_priv->atomic = req->value; 352 file_priv->universal_planes = req->value; 353 /* 354 * No atomic user-space blows up on aspect ratio mode bits. 355 */ 356 file_priv->aspect_ratio_allowed = req->value; 357 break; 358 case DRM_CLIENT_CAP_ASPECT_RATIO: 359 if (req->value > 1) 360 return -EINVAL; 361 file_priv->aspect_ratio_allowed = req->value; 362 break; 363 case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS: 364 if (!file_priv->atomic) 365 return -EINVAL; 366 if (req->value > 1) 367 return -EINVAL; 368 file_priv->writeback_connectors = req->value; 369 break; 370 default: 371 return -EINVAL; 372 } 373 374 return 0; 375 } 376 377 /* 378 * Setversion ioctl. 379 * 380 * \param inode device inode. 381 * \param file_priv DRM file private. 382 * \param cmd command. 383 * \param arg user argument, pointing to a drm_lock structure. 384 * \return zero on success or negative number on failure. 385 * 386 * Sets the requested interface version 387 */ 388 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv) 389 { 390 struct drm_set_version *sv = data; 391 int if_version, retcode = 0; 392 393 mutex_lock(&dev->master_mutex); 394 if (sv->drm_di_major != -1) { 395 if (sv->drm_di_major != DRM_IF_MAJOR || 396 sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) { 397 retcode = -EINVAL; 398 goto done; 399 } 400 if_version = DRM_IF_VERSION(sv->drm_di_major, 401 sv->drm_di_minor); 402 dev->if_version = max(if_version, dev->if_version); 403 if (sv->drm_di_minor >= 1) { 404 /* 405 * Version 1.1 includes tying of DRM to specific device 406 * Version 1.4 has proper PCI domain support 407 */ 408 retcode = drm_set_busid(dev, file_priv); 409 if (retcode) 410 goto done; 411 } 412 } 413 414 if (sv->drm_dd_major != -1) { 415 if (sv->drm_dd_major != dev->driver->major || 416 sv->drm_dd_minor < 0 || sv->drm_dd_minor > 417 dev->driver->minor) { 418 retcode = -EINVAL; 419 goto done; 420 } 421 } 422 423 done: 424 sv->drm_di_major = DRM_IF_MAJOR; 425 sv->drm_di_minor = DRM_IF_MINOR; 426 sv->drm_dd_major = dev->driver->major; 427 sv->drm_dd_minor = dev->driver->minor; 428 mutex_unlock(&dev->master_mutex); 429 430 return retcode; 431 } 432 433 /** 434 * drm_noop - DRM no-op ioctl implemntation 435 * @dev: DRM device for the ioctl 436 * @data: data pointer for the ioctl 437 * @file_priv: DRM file for the ioctl call 438 * 439 * This no-op implementation for drm ioctls is useful for deprecated 440 * functionality where we can't return a failure code because existing userspace 441 * checks the result of the ioctl, but doesn't care about the action. 442 * 443 * Always returns successfully with 0. 444 */ 445 int drm_noop(struct drm_device *dev, void *data, 446 struct drm_file *file_priv) 447 { 448 DRM_DEBUG("\n"); 449 return 0; 450 } 451 EXPORT_SYMBOL(drm_noop); 452 453 /** 454 * drm_invalid_op - DRM invalid ioctl implemntation 455 * @dev: DRM device for the ioctl 456 * @data: data pointer for the ioctl 457 * @file_priv: DRM file for the ioctl call 458 * 459 * This no-op implementation for drm ioctls is useful for deprecated 460 * functionality where we really don't want to allow userspace to call the ioctl 461 * any more. This is the case for old ums interfaces for drivers that 462 * transitioned to kms gradually and so kept the old legacy tables around. This 463 * only applies to radeon and i915 kms drivers, other drivers shouldn't need to 464 * use this function. 465 * 466 * Always fails with a return value of -EINVAL. 467 */ 468 int drm_invalid_op(struct drm_device *dev, void *data, 469 struct drm_file *file_priv) 470 { 471 return -EINVAL; 472 } 473 EXPORT_SYMBOL(drm_invalid_op); 474 475 /* 476 * Copy and IOCTL return string to user space 477 */ 478 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value) 479 { 480 int len; 481 482 /* don't overflow userbuf */ 483 len = strlen(value); 484 if (len > *buf_len) 485 len = *buf_len; 486 487 /* let userspace know exact length of driver value (which could be 488 * larger than the userspace-supplied buffer) */ 489 *buf_len = strlen(value); 490 491 /* finally, try filling in the userbuf */ 492 if (len && buf) 493 if (copy_to_user(buf, value, len)) 494 return -EFAULT; 495 return 0; 496 } 497 498 /* 499 * Get version information 500 * 501 * \param inode device inode. 502 * \param filp file pointer. 503 * \param cmd command. 504 * \param arg user argument, pointing to a drm_version structure. 505 * \return zero on success or negative number on failure. 506 * 507 * Fills in the version information in \p arg. 508 */ 509 int drm_version(struct drm_device *dev, void *data, 510 struct drm_file *file_priv) 511 { 512 struct drm_version *version = data; 513 int err; 514 515 version->version_major = dev->driver->major; 516 version->version_minor = dev->driver->minor; 517 version->version_patchlevel = dev->driver->patchlevel; 518 err = drm_copy_field(version->name, &version->name_len, 519 dev->driver->name); 520 if (!err) 521 err = drm_copy_field(version->date, &version->date_len, 522 dev->driver->date); 523 if (!err) 524 err = drm_copy_field(version->desc, &version->desc_len, 525 dev->driver->desc); 526 527 return err; 528 } 529 530 /** 531 * drm_ioctl_permit - Check ioctl permissions against caller 532 * 533 * @flags: ioctl permission flags. 534 * @file_priv: Pointer to struct drm_file identifying the caller. 535 * 536 * Checks whether the caller is allowed to run an ioctl with the 537 * indicated permissions. 538 * 539 * Returns: 540 * Zero if allowed, -EACCES otherwise. 541 */ 542 int drm_ioctl_permit(u32 flags, struct drm_file *file_priv) 543 { 544 /* ROOT_ONLY is only for CAP_SYS_ADMIN */ 545 if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN))) 546 return -EACCES; 547 548 /* AUTH is only for authenticated or render client */ 549 if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) && 550 !file_priv->authenticated)) 551 return -EACCES; 552 553 /* MASTER is only for master or control clients */ 554 if (unlikely((flags & DRM_MASTER) && 555 !drm_is_current_master(file_priv))) 556 return -EACCES; 557 558 /* Render clients must be explicitly allowed */ 559 if (unlikely(!(flags & DRM_RENDER_ALLOW) && 560 drm_is_render_client(file_priv))) 561 return -EACCES; 562 563 return 0; 564 } 565 EXPORT_SYMBOL(drm_ioctl_permit); 566 567 #define DRM_IOCTL_DEF(ioctl, _func, _flags) \ 568 [DRM_IOCTL_NR(ioctl)] = { \ 569 .cmd = ioctl, \ 570 .func = _func, \ 571 .flags = _flags, \ 572 .name = #ioctl \ 573 } 574 575 #if IS_ENABLED(CONFIG_DRM_LEGACY) 576 #define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags) DRM_IOCTL_DEF(ioctl, _func, _flags) 577 #else 578 #define DRM_LEGACY_IOCTL_DEF(ioctl, _func, _flags) DRM_IOCTL_DEF(ioctl, drm_invalid_op, _flags) 579 #endif 580 581 /* Ioctl table */ 582 static const struct drm_ioctl_desc drm_ioctls[] = { 583 DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_RENDER_ALLOW), 584 DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0), 585 DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0), 586 DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY), 587 588 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, 0), 589 590 DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, 0), 591 DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0), 592 DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_RENDER_ALLOW), 593 DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0), 594 DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER), 595 596 DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 597 DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 598 DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 599 DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_MASTER), 600 601 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 602 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH), 603 604 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 605 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH), 606 607 DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_ROOT_ONLY), 608 DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_ROOT_ONLY), 609 610 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY), 611 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 612 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 613 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH), 614 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 615 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 616 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH), 617 618 DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 619 DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 620 621 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH), 622 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH), 623 624 DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH), 625 626 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 627 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 628 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH), 629 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH), 630 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH), 631 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH), 632 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_legacy_irq_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 633 634 #if IS_ENABLED(CONFIG_AGP) 635 DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 636 DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 637 DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 638 DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH), 639 DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 640 DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 641 DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 642 DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 643 #endif 644 645 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 646 DRM_LEGACY_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 647 648 DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, DRM_UNLOCKED), 649 650 DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_legacy_modeset_ctl_ioctl, 0), 651 652 DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 653 654 DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_RENDER_ALLOW), 655 DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH), 656 DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH), 657 658 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, 0), 659 660 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_RENDER_ALLOW), 661 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_RENDER_ALLOW), 662 663 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, 0), 664 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, 0), 665 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER), 666 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, 0), 667 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER), 668 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER), 669 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, 0), 670 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER), 671 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, 0), 672 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, 0), 673 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER), 674 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER), 675 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, 0), 676 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_connector_property_set_ioctl, DRM_MASTER), 677 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, 0), 678 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, 0), 679 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb_ioctl, 0), 680 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2_ioctl, 0), 681 DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb_ioctl, 0), 682 DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER), 683 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER), 684 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, 0), 685 DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, 0), 686 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, 0), 687 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, 0), 688 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER), 689 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER), 690 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER), 691 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, 0), 692 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, 0), 693 694 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_CREATE, drm_syncobj_create_ioctl, 695 DRM_RENDER_ALLOW), 696 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_DESTROY, drm_syncobj_destroy_ioctl, 697 DRM_RENDER_ALLOW), 698 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, drm_syncobj_handle_to_fd_ioctl, 699 DRM_RENDER_ALLOW), 700 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, drm_syncobj_fd_to_handle_ioctl, 701 DRM_RENDER_ALLOW), 702 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TRANSFER, drm_syncobj_transfer_ioctl, 703 DRM_RENDER_ALLOW), 704 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl, 705 DRM_RENDER_ALLOW), 706 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT, drm_syncobj_timeline_wait_ioctl, 707 DRM_RENDER_ALLOW), 708 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl, 709 DRM_RENDER_ALLOW), 710 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl, 711 DRM_RENDER_ALLOW), 712 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL, drm_syncobj_timeline_signal_ioctl, 713 DRM_RENDER_ALLOW), 714 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_QUERY, drm_syncobj_query_ioctl, 715 DRM_RENDER_ALLOW), 716 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, 0), 717 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, 0), 718 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER), 719 DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER), 720 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER), 721 DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER), 722 }; 723 724 #define DRM_CORE_IOCTL_COUNT ARRAY_SIZE( drm_ioctls ) 725 726 /** 727 * DOC: driver specific ioctls 728 * 729 * First things first, driver private IOCTLs should only be needed for drivers 730 * supporting rendering. Kernel modesetting is all standardized, and extended 731 * through properties. There are a few exceptions in some existing drivers, 732 * which define IOCTL for use by the display DRM master, but they all predate 733 * properties. 734 * 735 * Now if you do have a render driver you always have to support it through 736 * driver private properties. There's a few steps needed to wire all the things 737 * up. 738 * 739 * First you need to define the structure for your IOCTL in your driver private 740 * UAPI header in ``include/uapi/drm/my_driver_drm.h``:: 741 * 742 * struct my_driver_operation { 743 * u32 some_thing; 744 * u32 another_thing; 745 * }; 746 * 747 * Please make sure that you follow all the best practices from 748 * ``Documentation/ioctl/botching-up-ioctls.rst``. Note that drm_ioctl() 749 * automatically zero-extends structures, hence make sure you can add more stuff 750 * at the end, i.e. don't put a variable sized array there. 751 * 752 * Then you need to define your IOCTL number, using one of DRM_IO(), DRM_IOR(), 753 * DRM_IOW() or DRM_IOWR(). It must start with the DRM_IOCTL\_ prefix:: 754 * 755 * ##define DRM_IOCTL_MY_DRIVER_OPERATION \ 756 * DRM_IOW(DRM_COMMAND_BASE, struct my_driver_operation) 757 * 758 * DRM driver private IOCTL must be in the range from DRM_COMMAND_BASE to 759 * DRM_COMMAND_END. Finally you need an array of &struct drm_ioctl_desc to wire 760 * up the handlers and set the access rights:: 761 * 762 * static const struct drm_ioctl_desc my_driver_ioctls[] = { 763 * DRM_IOCTL_DEF_DRV(MY_DRIVER_OPERATION, my_driver_operation, 764 * DRM_AUTH|DRM_RENDER_ALLOW), 765 * }; 766 * 767 * And then assign this to the &drm_driver.ioctls field in your driver 768 * structure. 769 * 770 * See the separate chapter on :ref:`file operations<drm_driver_fops>` for how 771 * the driver-specific IOCTLs are wired up. 772 */ 773 774 long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata, 775 u32 flags) 776 { 777 struct drm_file *file_priv = file->private_data; 778 struct drm_device *dev = file_priv->minor->dev; 779 int retcode; 780 781 if (drm_dev_is_unplugged(dev)) 782 return -ENODEV; 783 784 retcode = drm_ioctl_permit(flags, file_priv); 785 if (unlikely(retcode)) 786 return retcode; 787 788 /* Enforce sane locking for modern driver ioctls. */ 789 if (likely(!drm_core_check_feature(dev, DRIVER_LEGACY)) || 790 (flags & DRM_UNLOCKED)) 791 retcode = func(dev, kdata, file_priv); 792 else { 793 mutex_lock(&drm_global_mutex); 794 retcode = func(dev, kdata, file_priv); 795 mutex_unlock(&drm_global_mutex); 796 } 797 return retcode; 798 } 799 EXPORT_SYMBOL(drm_ioctl_kernel); 800 801 /** 802 * drm_ioctl - ioctl callback implementation for DRM drivers 803 * @filp: file this ioctl is called on 804 * @cmd: ioctl cmd number 805 * @arg: user argument 806 * 807 * Looks up the ioctl function in the DRM core and the driver dispatch table, 808 * stored in &drm_driver.ioctls. It checks for necessary permission by calling 809 * drm_ioctl_permit(), and dispatches to the respective function. 810 * 811 * Returns: 812 * Zero on success, negative error code on failure. 813 */ 814 long drm_ioctl(struct file *filp, 815 unsigned int cmd, unsigned long arg) 816 { 817 struct drm_file *file_priv = filp->private_data; 818 struct drm_device *dev; 819 const struct drm_ioctl_desc *ioctl = NULL; 820 drm_ioctl_t *func; 821 unsigned int nr = DRM_IOCTL_NR(cmd); 822 int retcode = -EINVAL; 823 char stack_kdata[128]; 824 char *kdata = NULL; 825 unsigned int in_size, out_size, drv_size, ksize; 826 bool is_driver_ioctl; 827 828 dev = file_priv->minor->dev; 829 830 if (drm_dev_is_unplugged(dev)) 831 return -ENODEV; 832 833 is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END; 834 835 if (is_driver_ioctl) { 836 /* driver ioctl */ 837 unsigned int index = nr - DRM_COMMAND_BASE; 838 839 if (index >= dev->driver->num_ioctls) 840 goto err_i1; 841 index = array_index_nospec(index, dev->driver->num_ioctls); 842 ioctl = &dev->driver->ioctls[index]; 843 } else { 844 /* core ioctl */ 845 if (nr >= DRM_CORE_IOCTL_COUNT) 846 goto err_i1; 847 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT); 848 ioctl = &drm_ioctls[nr]; 849 } 850 851 drv_size = _IOC_SIZE(ioctl->cmd); 852 out_size = in_size = _IOC_SIZE(cmd); 853 if ((cmd & ioctl->cmd & IOC_IN) == 0) 854 in_size = 0; 855 if ((cmd & ioctl->cmd & IOC_OUT) == 0) 856 out_size = 0; 857 ksize = max(max(in_size, out_size), drv_size); 858 859 DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n", 860 task_pid_nr(current), 861 (long)old_encode_dev(file_priv->minor->kdev->devt), 862 file_priv->authenticated, ioctl->name); 863 864 /* Do not trust userspace, use our own definition */ 865 func = ioctl->func; 866 867 if (unlikely(!func)) { 868 DRM_DEBUG("no function\n"); 869 retcode = -EINVAL; 870 goto err_i1; 871 } 872 873 if (ksize <= sizeof(stack_kdata)) { 874 kdata = stack_kdata; 875 } else { 876 kdata = kmalloc(ksize, GFP_KERNEL); 877 if (!kdata) { 878 retcode = -ENOMEM; 879 goto err_i1; 880 } 881 } 882 883 if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) { 884 retcode = -EFAULT; 885 goto err_i1; 886 } 887 888 if (ksize > in_size) 889 memset(kdata + in_size, 0, ksize - in_size); 890 891 retcode = drm_ioctl_kernel(filp, func, kdata, ioctl->flags); 892 if (copy_to_user((void __user *)arg, kdata, out_size) != 0) 893 retcode = -EFAULT; 894 895 err_i1: 896 if (!ioctl) 897 DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n", 898 task_pid_nr(current), 899 (long)old_encode_dev(file_priv->minor->kdev->devt), 900 file_priv->authenticated, cmd, nr); 901 902 if (kdata != stack_kdata) 903 kfree(kdata); 904 if (retcode) 905 DRM_DEBUG("pid=%d, ret = %d\n", task_pid_nr(current), retcode); 906 return retcode; 907 } 908 EXPORT_SYMBOL(drm_ioctl); 909 910 /** 911 * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags 912 * @nr: ioctl number 913 * @flags: where to return the ioctl permission flags 914 * 915 * This ioctl is only used by the vmwgfx driver to augment the access checks 916 * done by the drm core and insofar a pretty decent layering violation. This 917 * shouldn't be used by any drivers. 918 * 919 * Returns: 920 * True if the @nr corresponds to a DRM core ioctl number, false otherwise. 921 */ 922 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags) 923 { 924 if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END) 925 return false; 926 927 if (nr >= DRM_CORE_IOCTL_COUNT) 928 return false; 929 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT); 930 931 *flags = drm_ioctls[nr].flags; 932 return true; 933 } 934 EXPORT_SYMBOL(drm_ioctl_flags); 935
Indexes created Wed Oct 15 16:09:53 GMT 2025