drivers/gpu/drm/drm_ioctl.c

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