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_auth.h> 37 #include <drm/drm_crtc.h> 38 #include <drm/drm_drv.h> 39 #include <drm/drm_file.h> 40 #include <drm/drm_ioctl.h> 41 #include <drm/drm_print.h> 42 43 #include "drm_crtc_internal.h" 44 #include "drm_internal.h" 45 46 /** 47 * DOC: getunique and setversion story 48 * 49 * BEWARE THE DRAGONS! MIND THE TRAPDOORS! 50 * 51 * In an attempt to warn anyone else who's trying to figure out what's going 52 * on here, I'll try to summarize the story. First things first, let's clear up 53 * the names, because the kernel internals, libdrm and the ioctls are all named 54 * differently: 55 * 56 * - GET_UNIQUE ioctl, implemented by drm_getunique is wrapped up in libdrm 57 * through the drmGetBusid function. 58 * - The libdrm drmSetBusid function is backed by the SET_UNIQUE ioctl. All 59 * that code is nerved in the kernel with drm_invalid_op(). 60 * - The internal set_busid kernel functions and driver callbacks are 61 * exclusively use by the SET_VERSION ioctl, because only drm 1.0 (which is 62 * nerved) allowed userspace to set the busid through the above ioctl. 63 * - Other ioctls and functions involved are named consistently. 64 * 65 * For anyone wondering what's the difference between drm 1.1 and 1.4: Correctly 66 * handling pci domains in the busid on ppc. Doing this correctly was only 67 * implemented in libdrm in 2010, hence can't be nerved yet. No one knows what's 68 * special with drm 1.2 and 1.3. 69 * 70 * Now the actual horror story of how device lookup in drm works. At large, 71 * there's 2 different ways, either by busid, or by device driver name. 72 * 73 * Opening by busid is fairly simple: 74 * 75 * 1. First call SET_VERSION to make sure pci domains are handled properly. As a 76 * side-effect this fills out the unique name in the master structure. 77 * 2. Call GET_UNIQUE to read out the unique name from the master structure, 78 * which matches the busid thanks to step 1. If it doesn't, proceed to try 79 * the next device node. 80 * 81 * Opening by name is slightly different: 82 * 83 * 1. Directly call VERSION to get the version and to match against the driver 84 * name returned by that ioctl. Note that SET_VERSION is not called, which 85 * means the unique name for the master node just opening is _not_ filled 86 * out. This despite that with current drm device nodes are always bound to 87 * one device, and can't be runtime assigned like with drm 1.0. 88 * 2. Match driver name. If it mismatches, proceed to the next device node. 89 * 3. Call GET_UNIQUE, and check whether the unique name has length zero (by 90 * checking that the first byte in the string is 0). If that's not the case 91 * libdrm skips and proceeds to the next device node. Probably this is just 92 * copypasta from drm 1.0 times where a set unique name meant that the driver 93 * was in use already, but that's just conjecture. 94 * 95 * Long story short: To keep the open by name logic working, GET_UNIQUE must 96 * _not_ return a unique string when SET_VERSION hasn't been called yet, 97 * otherwise libdrm breaks. Even when that unique string can't ever change, and 98 * is totally irrelevant for actually opening the device because runtime 99 * assignable device instances were only support in drm 1.0, which is long dead. 100 * But the libdrm code in drmOpenByName somehow survived, hence this can't be 101 * broken. 102 */ 103 104 /* 105 * Get the bus id. 106 * 107 * \param inode device inode. 108 * \param file_priv DRM file private. 109 * \param cmd command. 110 * \param arg user argument, pointing to a drm_unique structure. 111 * \return zero on success or a negative number on failure. 112 * 113 * Copies the bus id from drm_device::unique into user space. 114 */ drm_getunique(struct drm_device * dev,void * data,struct drm_file * file_priv)115 int drm_getunique(struct drm_device *dev, void *data, 116 struct drm_file *file_priv) 117 { 118 struct drm_unique *u = data; 119 struct drm_master *master; 120 121 mutex_lock(&dev->master_mutex); 122 master = file_priv->master; 123 if (u->unique_len >= master->unique_len) { 124 if (copy_to_user(u->unique, master->unique, master->unique_len)) { 125 mutex_unlock(&dev->master_mutex); 126 return -EFAULT; 127 } 128 } 129 u->unique_len = master->unique_len; 130 mutex_unlock(&dev->master_mutex); 131 132 return 0; 133 } 134 135 static void drm_unset_busid(struct drm_device * dev,struct drm_master * master)136 drm_unset_busid(struct drm_device *dev, 137 struct drm_master *master) 138 { 139 kfree(master->unique); 140 master->unique = NULL; 141 master->unique_len = 0; 142 } 143 drm_set_busid(struct drm_device * dev,struct drm_file * file_priv)144 static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv) 145 { 146 struct drm_master *master = file_priv->master; 147 int ret; 148 149 if (master->unique != NULL) 150 drm_unset_busid(dev, master); 151 152 if (dev->dev && dev_is_pci(dev->dev)) { 153 ret = drm_pci_set_busid(dev, master); 154 if (ret) { 155 drm_unset_busid(dev, master); 156 return ret; 157 } 158 } else { 159 WARN_ON(!dev->unique); 160 master->unique = kstrdup(dev->unique, GFP_KERNEL); 161 if (master->unique) 162 master->unique_len = strlen(dev->unique); 163 } 164 165 return 0; 166 } 167 168 /* 169 * Get client information. 170 * 171 * \param inode device inode. 172 * \param file_priv DRM file private. 173 * \param cmd command. 174 * \param arg user argument, pointing to a drm_client structure. 175 * 176 * \return zero on success or a negative number on failure. 177 * 178 * Searches for the client with the specified index and copies its information 179 * into userspace 180 */ drm_getclient(struct drm_device * dev,void * data,struct drm_file * file_priv)181 int drm_getclient(struct drm_device *dev, void *data, 182 struct drm_file *file_priv) 183 { 184 struct drm_client *client = data; 185 186 /* 187 * Hollowed-out getclient ioctl to keep some dead old drm tests/tools 188 * not breaking completely. Userspace tools stop enumerating one they 189 * get -EINVAL, hence this is the return value we need to hand back for 190 * no clients tracked. 191 * 192 * Unfortunately some clients (*cough* libva *cough*) use this in a fun 193 * attempt to figure out whether they're authenticated or not. Since 194 * that's the only thing they care about, give it to the directly 195 * instead of walking one giant list. 196 */ 197 if (client->idx == 0) { 198 client->auth = file_priv->authenticated; 199 client->pid = task_pid_vnr(current); 200 client->uid = overflowuid; 201 client->magic = 0; 202 client->iocs = 0; 203 204 return 0; 205 } else { 206 return -EINVAL; 207 } 208 } 209 210 /* 211 * Get statistics information. 212 * 213 * \param inode device inode. 214 * \param file_priv DRM file private. 215 * \param cmd command. 216 * \param arg user argument, pointing to a drm_stats structure. 217 * 218 * \return zero on success or a negative number on failure. 219 */ drm_getstats(struct drm_device * dev,void * data,struct drm_file * file_priv)220 static int drm_getstats(struct drm_device *dev, void *data, 221 struct drm_file *file_priv) 222 { 223 struct drm_stats *stats = data; 224 225 /* Clear stats to prevent userspace from eating its stack garbage. */ 226 memset(stats, 0, sizeof(*stats)); 227 228 return 0; 229 } 230 231 /* 232 * Get device/driver capabilities 233 */ drm_getcap(struct drm_device * dev,void * data,struct drm_file * file_priv)234 static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv) 235 { 236 struct drm_get_cap *req = data; 237 struct drm_crtc *crtc; 238 239 req->value = 0; 240 241 /* Only some caps make sense with UMS/render-only drivers. */ 242 switch (req->capability) { 243 case DRM_CAP_TIMESTAMP_MONOTONIC: 244 req->value = 1; 245 return 0; 246 case DRM_CAP_PRIME: 247 req->value = DRM_PRIME_CAP_IMPORT | DRM_PRIME_CAP_EXPORT; 248 return 0; 249 case DRM_CAP_SYNCOBJ: 250 req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ); 251 return 0; 252 case DRM_CAP_SYNCOBJ_TIMELINE: 253 req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE); 254 return 0; 255 } 256 257 /* Other caps only work with KMS drivers */ 258 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 259 return -EOPNOTSUPP; 260 261 switch (req->capability) { 262 case DRM_CAP_DUMB_BUFFER: 263 if (dev->driver->dumb_create) 264 req->value = 1; 265 break; 266 case DRM_CAP_VBLANK_HIGH_CRTC: 267 req->value = 1; 268 break; 269 case DRM_CAP_DUMB_PREFERRED_DEPTH: 270 req->value = dev->mode_config.preferred_depth; 271 break; 272 case DRM_CAP_DUMB_PREFER_SHADOW: 273 req->value = dev->mode_config.prefer_shadow; 274 break; 275 case DRM_CAP_ASYNC_PAGE_FLIP: 276 req->value = dev->mode_config.async_page_flip; 277 break; 278 case DRM_CAP_PAGE_FLIP_TARGET: 279 req->value = 1; 280 drm_for_each_crtc(crtc, dev) { 281 if (!crtc->funcs->page_flip_target) 282 req->value = 0; 283 } 284 break; 285 case DRM_CAP_CURSOR_WIDTH: 286 if (dev->mode_config.cursor_width) 287 req->value = dev->mode_config.cursor_width; 288 else 289 req->value = 64; 290 break; 291 case DRM_CAP_CURSOR_HEIGHT: 292 if (dev->mode_config.cursor_height) 293 req->value = dev->mode_config.cursor_height; 294 else 295 req->value = 64; 296 break; 297 case DRM_CAP_ADDFB2_MODIFIERS: 298 req->value = !dev->mode_config.fb_modifiers_not_supported; 299 break; 300 case DRM_CAP_CRTC_IN_VBLANK_EVENT: 301 req->value = 1; 302 break; 303 case DRM_CAP_ATOMIC_ASYNC_PAGE_FLIP: 304 req->value = drm_core_check_feature(dev, DRIVER_ATOMIC) && 305 dev->mode_config.async_page_flip; 306 break; 307 default: 308 return -EINVAL; 309 } 310 return 0; 311 } 312 313 /* 314 * Set device/driver capabilities 315 */ 316 static int drm_setclientcap(struct drm_device * dev,void * data,struct drm_file * file_priv)317 drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv) 318 { 319 struct drm_set_client_cap *req = data; 320 321 /* No render-only settable capabilities for now */ 322 323 /* Below caps that only works with KMS drivers */ 324 if (!drm_core_check_feature(dev, DRIVER_MODESET)) 325 return -EOPNOTSUPP; 326 327 switch (req->capability) { 328 case DRM_CLIENT_CAP_STEREO_3D: 329 if (req->value > 1) 330 return -EINVAL; 331 file_priv->stereo_allowed = req->value; 332 break; 333 case DRM_CLIENT_CAP_UNIVERSAL_PLANES: 334 if (req->value > 1) 335 return -EINVAL; 336 file_priv->universal_planes = req->value; 337 break; 338 case DRM_CLIENT_CAP_ATOMIC: 339 if (!drm_core_check_feature(dev, DRIVER_ATOMIC)) 340 return -EOPNOTSUPP; 341 /* The modesetting DDX has a totally broken idea of atomic. */ 342 if (current->comm[0] == 'X' && req->value == 1) { 343 pr_info("broken atomic modeset userspace detected, disabling atomic\n"); 344 return -EOPNOTSUPP; 345 } 346 if (req->value > 2) 347 return -EINVAL; 348 file_priv->atomic = req->value; 349 file_priv->universal_planes = req->value; 350 /* 351 * No atomic user-space blows up on aspect ratio mode bits. 352 */ 353 file_priv->aspect_ratio_allowed = req->value; 354 break; 355 case DRM_CLIENT_CAP_ASPECT_RATIO: 356 if (req->value > 1) 357 return -EINVAL; 358 file_priv->aspect_ratio_allowed = req->value; 359 break; 360 case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS: 361 if (!file_priv->atomic) 362 return -EINVAL; 363 if (req->value > 1) 364 return -EINVAL; 365 file_priv->writeback_connectors = req->value; 366 break; 367 case DRM_CLIENT_CAP_CURSOR_PLANE_HOTSPOT: 368 if (!drm_core_check_feature(dev, DRIVER_CURSOR_HOTSPOT)) 369 return -EOPNOTSUPP; 370 if (!file_priv->atomic) 371 return -EINVAL; 372 if (req->value > 1) 373 return -EINVAL; 374 file_priv->supports_virtualized_cursor_plane = req->value; 375 break; 376 default: 377 return -EINVAL; 378 } 379 380 return 0; 381 } 382 383 /* 384 * Setversion ioctl. 385 * 386 * \param inode device inode. 387 * \param file_priv DRM file private. 388 * \param cmd command. 389 * \param arg user argument, pointing to a drm_lock structure. 390 * \return zero on success or negative number on failure. 391 * 392 * Sets the requested interface version 393 */ drm_setversion(struct drm_device * dev,void * data,struct drm_file * file_priv)394 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv) 395 { 396 struct drm_set_version *sv = data; 397 int if_version, retcode = 0; 398 399 mutex_lock(&dev->master_mutex); 400 if (sv->drm_di_major != -1) { 401 if (sv->drm_di_major != DRM_IF_MAJOR || 402 sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) { 403 retcode = -EINVAL; 404 goto done; 405 } 406 if_version = DRM_IF_VERSION(sv->drm_di_major, 407 sv->drm_di_minor); 408 dev->if_version = max(if_version, dev->if_version); 409 if (sv->drm_di_minor >= 1) { 410 /* 411 * Version 1.1 includes tying of DRM to specific device 412 * Version 1.4 has proper PCI domain support 413 */ 414 retcode = drm_set_busid(dev, file_priv); 415 if (retcode) 416 goto done; 417 } 418 } 419 420 if (sv->drm_dd_major != -1) { 421 if (sv->drm_dd_major != dev->driver->major || 422 sv->drm_dd_minor < 0 || sv->drm_dd_minor > 423 dev->driver->minor) { 424 retcode = -EINVAL; 425 goto done; 426 } 427 } 428 429 done: 430 sv->drm_di_major = DRM_IF_MAJOR; 431 sv->drm_di_minor = DRM_IF_MINOR; 432 sv->drm_dd_major = dev->driver->major; 433 sv->drm_dd_minor = dev->driver->minor; 434 mutex_unlock(&dev->master_mutex); 435 436 return retcode; 437 } 438 439 /** 440 * drm_noop - DRM no-op ioctl implementation 441 * @dev: DRM device for the ioctl 442 * @data: data pointer for the ioctl 443 * @file_priv: DRM file for the ioctl call 444 * 445 * This no-op implementation for drm ioctls is useful for deprecated 446 * functionality where we can't return a failure code because existing userspace 447 * checks the result of the ioctl, but doesn't care about the action. 448 * 449 * Always returns successfully with 0. 450 */ drm_noop(struct drm_device * dev,void * data,struct drm_file * file_priv)451 int drm_noop(struct drm_device *dev, void *data, 452 struct drm_file *file_priv) 453 { 454 drm_dbg_core(dev, "\n"); 455 return 0; 456 } 457 EXPORT_SYMBOL(drm_noop); 458 459 /** 460 * drm_invalid_op - DRM invalid ioctl implementation 461 * @dev: DRM device for the ioctl 462 * @data: data pointer for the ioctl 463 * @file_priv: DRM file for the ioctl call 464 * 465 * This no-op implementation for drm ioctls is useful for deprecated 466 * functionality where we really don't want to allow userspace to call the ioctl 467 * any more. This is the case for old ums interfaces for drivers that 468 * transitioned to kms gradually and so kept the old legacy tables around. This 469 * only applies to radeon and i915 kms drivers, other drivers shouldn't need to 470 * use this function. 471 * 472 * Always fails with a return value of -EINVAL. 473 */ drm_invalid_op(struct drm_device * dev,void * data,struct drm_file * file_priv)474 int drm_invalid_op(struct drm_device *dev, void *data, 475 struct drm_file *file_priv) 476 { 477 return -EINVAL; 478 } 479 EXPORT_SYMBOL(drm_invalid_op); 480 481 /* 482 * Copy and IOCTL return string to user space 483 */ drm_copy_field(char __user * buf,size_t * buf_len,const char * value)484 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value) 485 { 486 size_t len; 487 488 /* don't attempt to copy a NULL pointer */ 489 if (WARN_ONCE(!value, "BUG: the value to copy was not set!")) { 490 *buf_len = 0; 491 return 0; 492 } 493 494 /* don't overflow userbuf */ 495 len = strlen(value); 496 if (len > *buf_len) 497 len = *buf_len; 498 499 /* let userspace know exact length of driver value (which could be 500 * larger than the userspace-supplied buffer) */ 501 *buf_len = strlen(value); 502 503 /* finally, try filling in the userbuf */ 504 if (len && buf) 505 if (copy_to_user(buf, value, len)) 506 return -EFAULT; 507 return 0; 508 } 509 510 /* 511 * Get version information 512 * 513 * \param inode device inode. 514 * \param filp file pointer. 515 * \param cmd command. 516 * \param arg user argument, pointing to a drm_version structure. 517 * \return zero on success or negative number on failure. 518 * 519 * Fills in the version information in \p arg. 520 */ drm_version(struct drm_device * dev,void * data,struct drm_file * file_priv)521 int drm_version(struct drm_device *dev, void *data, 522 struct drm_file *file_priv) 523 { 524 struct drm_version *version = data; 525 int err; 526 527 version->version_major = dev->driver->major; 528 version->version_minor = dev->driver->minor; 529 version->version_patchlevel = dev->driver->patchlevel; 530 err = drm_copy_field(version->name, &version->name_len, 531 dev->driver->name); 532 533 /* Driver date is deprecated. Userspace expects a non-empty string. */ 534 if (!err) 535 err = drm_copy_field(version->date, &version->date_len, "0"); 536 if (!err) 537 err = drm_copy_field(version->desc, &version->desc_len, 538 dev->driver->desc); 539 540 return err; 541 } 542 drm_ioctl_permit(u32 flags,struct drm_file * file_priv)543 static int drm_ioctl_permit(u32 flags, struct drm_file *file_priv) 544 { 545 /* ROOT_ONLY is only for CAP_SYS_ADMIN */ 546 if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN))) 547 return -EACCES; 548 549 /* AUTH is only for authenticated or render client */ 550 if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) && 551 !file_priv->authenticated)) 552 return -EACCES; 553 554 /* MASTER is only for master or control clients */ 555 if (unlikely((flags & DRM_MASTER) && 556 !drm_is_current_master(file_priv))) 557 return -EACCES; 558 559 /* Render clients must be explicitly allowed */ 560 if (unlikely(!(flags & DRM_RENDER_ALLOW) && 561 drm_is_render_client(file_priv))) 562 return -EACCES; 563 564 return 0; 565 } 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 /* Ioctl table */ 576 static const struct drm_ioctl_desc drm_ioctls[] = { 577 DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version, DRM_RENDER_ALLOW), 578 DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0), 579 DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0), 580 581 DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, 0), 582 DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0), 583 DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_RENDER_ALLOW), 584 DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0), 585 DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, 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_MASTER), 591 592 DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, 0), 593 DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, 0), 594 595 DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 596 DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 597 598 DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH), 599 600 DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, 0), 601 602 DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY), 603 604 DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_RENDER_ALLOW), 605 DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH), 606 DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH), 607 608 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, 0), 609 610 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_RENDER_ALLOW), 611 DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_RENDER_ALLOW), 612 613 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, 0), 614 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, 0), 615 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER), 616 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, 0), 617 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER), 618 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER), 619 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, 0), 620 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER), 621 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, 0), 622 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, 0), 623 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER), 624 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER), 625 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, 0), 626 DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_connector_property_set_ioctl, DRM_MASTER), 627 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, 0), 628 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, 0), 629 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB2, drm_mode_getfb2_ioctl, 0), 630 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb_ioctl, 0), 631 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2_ioctl, 0), 632 DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb_ioctl, 0), 633 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CLOSEFB, drm_mode_closefb_ioctl, 0), 634 DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER), 635 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER), 636 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, 0), 637 DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, 0), 638 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, 0), 639 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, 0), 640 DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER), 641 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER), 642 DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER), 643 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, 0), 644 DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, 0), 645 646 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_CREATE, drm_syncobj_create_ioctl, 647 DRM_RENDER_ALLOW), 648 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_DESTROY, drm_syncobj_destroy_ioctl, 649 DRM_RENDER_ALLOW), 650 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, drm_syncobj_handle_to_fd_ioctl, 651 DRM_RENDER_ALLOW), 652 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, drm_syncobj_fd_to_handle_ioctl, 653 DRM_RENDER_ALLOW), 654 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TRANSFER, drm_syncobj_transfer_ioctl, 655 DRM_RENDER_ALLOW), 656 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl, 657 DRM_RENDER_ALLOW), 658 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT, drm_syncobj_timeline_wait_ioctl, 659 DRM_RENDER_ALLOW), 660 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_EVENTFD, drm_syncobj_eventfd_ioctl, 661 DRM_RENDER_ALLOW), 662 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl, 663 DRM_RENDER_ALLOW), 664 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl, 665 DRM_RENDER_ALLOW), 666 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_SIGNAL, drm_syncobj_timeline_signal_ioctl, 667 DRM_RENDER_ALLOW), 668 DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_QUERY, drm_syncobj_query_ioctl, 669 DRM_RENDER_ALLOW), 670 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, 0), 671 DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, 0), 672 DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER), 673 DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER), 674 DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER), 675 DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER), 676 }; 677 678 #define DRM_CORE_IOCTL_COUNT ARRAY_SIZE(drm_ioctls) 679 680 /** 681 * DOC: driver specific ioctls 682 * 683 * First things first, driver private IOCTLs should only be needed for drivers 684 * supporting rendering. Kernel modesetting is all standardized, and extended 685 * through properties. There are a few exceptions in some existing drivers, 686 * which define IOCTL for use by the display DRM master, but they all predate 687 * properties. 688 * 689 * Now if you do have a render driver you always have to support it through 690 * driver private properties. There's a few steps needed to wire all the things 691 * up. 692 * 693 * First you need to define the structure for your IOCTL in your driver private 694 * UAPI header in ``include/uapi/drm/my_driver_drm.h``:: 695 * 696 * struct my_driver_operation { 697 * u32 some_thing; 698 * u32 another_thing; 699 * }; 700 * 701 * Please make sure that you follow all the best practices from 702 * ``Documentation/process/botching-up-ioctls.rst``. Note that drm_ioctl() 703 * automatically zero-extends structures, hence make sure you can add more stuff 704 * at the end, i.e. don't put a variable sized array there. 705 * 706 * Then you need to define your IOCTL number, using one of DRM_IO(), DRM_IOR(), 707 * DRM_IOW() or DRM_IOWR(). It must start with the DRM_IOCTL\_ prefix:: 708 * 709 * ##define DRM_IOCTL_MY_DRIVER_OPERATION \ 710 * DRM_IOW(DRM_COMMAND_BASE, struct my_driver_operation) 711 * 712 * DRM driver private IOCTL must be in the range from DRM_COMMAND_BASE to 713 * DRM_COMMAND_END. Finally you need an array of &struct drm_ioctl_desc to wire 714 * up the handlers and set the access rights:: 715 * 716 * static const struct drm_ioctl_desc my_driver_ioctls[] = { 717 * DRM_IOCTL_DEF_DRV(MY_DRIVER_OPERATION, my_driver_operation, 718 * DRM_AUTH|DRM_RENDER_ALLOW), 719 * }; 720 * 721 * And then assign this to the &drm_driver.ioctls field in your driver 722 * structure. 723 * 724 * See the separate chapter on :ref:`file operations<drm_driver_fops>` for how 725 * the driver-specific IOCTLs are wired up. 726 */ 727 drm_ioctl_kernel(struct file * file,drm_ioctl_t * func,void * kdata,u32 flags)728 long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata, 729 u32 flags) 730 { 731 struct drm_file *file_priv = file->private_data; 732 struct drm_device *dev = file_priv->minor->dev; 733 int ret; 734 735 /* Update drm_file owner if fd was passed along. */ 736 drm_file_update_pid(file_priv); 737 738 if (drm_dev_is_unplugged(dev)) 739 return -ENODEV; 740 741 ret = drm_ioctl_permit(flags, file_priv); 742 if (unlikely(ret)) 743 return ret; 744 745 return func(dev, kdata, file_priv); 746 } 747 EXPORT_SYMBOL(drm_ioctl_kernel); 748 749 /** 750 * drm_ioctl - ioctl callback implementation for DRM drivers 751 * @filp: file this ioctl is called on 752 * @cmd: ioctl cmd number 753 * @arg: user argument 754 * 755 * Looks up the ioctl function in the DRM core and the driver dispatch table, 756 * stored in &drm_driver.ioctls. It checks for necessary permission by calling 757 * drm_ioctl_permit(), and dispatches to the respective function. 758 * 759 * Returns: 760 * Zero on success, negative error code on failure. 761 */ drm_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)762 long drm_ioctl(struct file *filp, 763 unsigned int cmd, unsigned long arg) 764 { 765 struct drm_file *file_priv = filp->private_data; 766 struct drm_device *dev; 767 const struct drm_ioctl_desc *ioctl = NULL; 768 drm_ioctl_t *func; 769 unsigned int nr = DRM_IOCTL_NR(cmd); 770 int retcode = -EINVAL; 771 char stack_kdata[128]; 772 char *kdata = NULL; 773 unsigned int in_size, out_size, drv_size, ksize; 774 bool is_driver_ioctl; 775 776 dev = file_priv->minor->dev; 777 778 if (drm_dev_is_unplugged(dev)) 779 return -ENODEV; 780 781 if (DRM_IOCTL_TYPE(cmd) != DRM_IOCTL_BASE) 782 return -ENOTTY; 783 784 is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END; 785 786 if (is_driver_ioctl) { 787 /* driver ioctl */ 788 unsigned int index = nr - DRM_COMMAND_BASE; 789 790 if (index >= dev->driver->num_ioctls) 791 goto err_i1; 792 index = array_index_nospec(index, dev->driver->num_ioctls); 793 ioctl = &dev->driver->ioctls[index]; 794 } else { 795 /* core ioctl */ 796 if (nr >= DRM_CORE_IOCTL_COUNT) 797 goto err_i1; 798 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT); 799 ioctl = &drm_ioctls[nr]; 800 } 801 802 drv_size = _IOC_SIZE(ioctl->cmd); 803 out_size = in_size = _IOC_SIZE(cmd); 804 if ((cmd & ioctl->cmd & IOC_IN) == 0) 805 in_size = 0; 806 if ((cmd & ioctl->cmd & IOC_OUT) == 0) 807 out_size = 0; 808 ksize = max(max(in_size, out_size), drv_size); 809 810 drm_dbg_core(dev, "comm=\"%s\" pid=%d, dev=0x%lx, auth=%d, %s\n", 811 current->comm, task_pid_nr(current), 812 (long)old_encode_dev(file_priv->minor->kdev->devt), 813 file_priv->authenticated, ioctl->name); 814 815 /* Do not trust userspace, use our own definition */ 816 func = ioctl->func; 817 818 if (unlikely(!func)) { 819 drm_dbg_core(dev, "no function\n"); 820 retcode = -EINVAL; 821 goto err_i1; 822 } 823 824 if (ksize <= sizeof(stack_kdata)) { 825 kdata = stack_kdata; 826 } else { 827 kdata = kmalloc(ksize, GFP_KERNEL); 828 if (!kdata) { 829 retcode = -ENOMEM; 830 goto err_i1; 831 } 832 } 833 834 if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) { 835 retcode = -EFAULT; 836 goto err_i1; 837 } 838 839 if (ksize > in_size) 840 memset(kdata + in_size, 0, ksize - in_size); 841 842 retcode = drm_ioctl_kernel(filp, func, kdata, ioctl->flags); 843 if (copy_to_user((void __user *)arg, kdata, out_size) != 0) 844 retcode = -EFAULT; 845 846 err_i1: 847 if (!ioctl) 848 drm_dbg_core(dev, 849 "invalid ioctl: comm=\"%s\", pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n", 850 current->comm, task_pid_nr(current), 851 (long)old_encode_dev(file_priv->minor->kdev->devt), 852 file_priv->authenticated, cmd, nr); 853 854 if (kdata != stack_kdata) 855 kfree(kdata); 856 if (retcode) 857 drm_dbg_core(dev, "comm=\"%s\", pid=%d, ret=%d\n", 858 current->comm, task_pid_nr(current), retcode); 859 return retcode; 860 } 861 EXPORT_SYMBOL(drm_ioctl); 862 863 /** 864 * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags 865 * @nr: ioctl number 866 * @flags: where to return the ioctl permission flags 867 * 868 * This ioctl is only used by the vmwgfx driver to augment the access checks 869 * done by the drm core and insofar a pretty decent layering violation. This 870 * shouldn't be used by any drivers. 871 * 872 * Returns: 873 * True if the @nr corresponds to a DRM core ioctl number, false otherwise. 874 */ drm_ioctl_flags(unsigned int nr,unsigned int * flags)875 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags) 876 { 877 if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END) 878 return false; 879 880 if (nr >= DRM_CORE_IOCTL_COUNT) 881 return false; 882 nr = array_index_nospec(nr, DRM_CORE_IOCTL_COUNT); 883 884 *flags = drm_ioctls[nr].flags; 885 return true; 886 } 887 EXPORT_SYMBOL(drm_ioctl_flags); 888