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/drmP.h>
  32 #include <drm/drm_core.h>
  33 #include "drm_legacy.h"
  34 #include "drm_internal.h"
  35 #include "drm_crtc_internal.h"
  36
  37 #include <linux/pci.h>
  38 #include <linux/export.h>
  39
  40 /**
  41  * DOC: getunique and setversion story
  42  *
  43  * BEWARE THE DRAGONS! MIND THE TRAPDOORS!
  44  *
  45  * In an attempt to warn anyone else who's trying to figure out what's going
  46  * on here, I'll try to summarize the story. First things first, let's clear up
  47  * the names, because the kernel internals, libdrm and the ioctls are all named
  48  * differently:
  49  *
  50  *  - GET_UNIQUE ioctl, implemented by drm_getunique is wrapped up in libdrm
  51  *    through the drmGetBusid function.
  52  *  - The libdrm drmSetBusid function is backed by the SET_UNIQUE ioctl. All
  53  *    that code is nerved in the kernel with drm_invalid_op().
  54  *  - The internal set_busid kernel functions and driver callbacks are
  55  *    exclusively use by the SET_VERSION ioctl, because only drm 1.0 (which is
  56  *    nerved) allowed userspace to set the busid through the above ioctl.
  57  *  - Other ioctls and functions involved are named consistently.
  58  *
  59  * For anyone wondering what's the difference between drm 1.1 and 1.4: Correctly
  60  * handling pci domains in the busid on ppc. Doing this correctly was only
  61  * implemented in libdrm in 2010, hence can't be nerved yet. No one knows what's
  62  * special with drm 1.2 and 1.3.
  63  *
  64  * Now the actual horror story of how device lookup in drm works. At large,
  65  * there's 2 different ways, either by busid, or by device driver name.
  66  *
  67  * Opening by busid is fairly simple:
  68  *
  69  * 1. First call SET_VERSION to make sure pci domains are handled properly. As a
  70  *    side-effect this fills out the unique name in the master structure.
  71  * 2. Call GET_UNIQUE to read out the unique name from the master structure,
  72  *    which matches the busid thanks to step 1. If it doesn't, proceed to try
  73  *    the next device node.
  74  *
  75  * Opening by name is slightly different:
  76  *
  77  * 1. Directly call VERSION to get the version and to match against the driver
  78  *    name returned by that ioctl. Note that SET_VERSION is not called, which
  79  *    means the the unique name for the master node just opening is _not_ filled
  80  *    out. This despite that with current drm device nodes are always bound to
  81  *    one device, and can't be runtime assigned like with drm 1.0.
  82  * 2. Match driver name. If it mismatches, proceed to the next device node.
  83  * 3. Call GET_UNIQUE, and check whether the unique name has length zero (by
  84  *    checking that the first byte in the string is 0). If that's not the case
  85  *    libdrm skips and proceeds to the next device node. Probably this is just
  86  *    copypasta from drm 1.0 times where a set unique name meant that the driver
  87  *    was in use already, but that's just conjecture.
  88  *
  89  * Long story short: To keep the open by name logic working, GET_UNIQUE must
  90  * _not_ return a unique string when SET_VERSION hasn't been called yet,
  91  * otherwise libdrm breaks. Even when that unique string can't ever change, and
  92  * is totally irrelevant for actually opening the device because runtime
  93  * assignable device instances were only support in drm 1.0, which is long dead.
  94  * But the libdrm code in drmOpenByName somehow survived, hence this can't be
  95  * broken.
  96  */
  97
  98 static int drm_version(struct drm_device *dev, void *data,
  99                        struct drm_file *file_priv);
 100
 101 /*
 102  * Get the bus id.
 103  *
 104  * \param inode device inode.
 105  * \param file_priv DRM file private.
 106  * \param cmd command.
 107  * \param arg user argument, pointing to a drm_unique structure.
 108  * \return zero on success or a negative number on failure.
 109  *
 110  * Copies the bus id from drm_device::unique into user space.
 111  */
 112 static int drm_getunique(struct drm_device *dev, void *data,
 113                   struct drm_file *file_priv)
 114 {
 115         struct drm_unique *u = data;
 116         struct drm_master *master = file_priv->master;
 117
 118         if (u->unique_len >= master->unique_len) {
 119                 if (copy_to_user(u->unique, master->unique, master->unique_len))
 120                         return -EFAULT;
 121         }
 122         u->unique_len = master->unique_len;
 123
 124         return 0;
 125 }
 126
 127 static void
 128 drm_unset_busid(struct drm_device *dev,
 129                 struct drm_master *master)
 130 {
 131         kfree(master->unique);
 132         master->unique = NULL;
 133         master->unique_len = 0;
 134 }
 135
 136 static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
 137 {
 138         struct drm_master *master = file_priv->master;
 139         int ret;
 140
 141         if (master->unique != NULL)
 142                 drm_unset_busid(dev, master);
 143
 144         if (dev->driver->set_busid) {
 145                 ret = dev->driver->set_busid(dev, master);
 146                 if (ret) {
 147                         drm_unset_busid(dev, master);
 148                         return ret;
 149                 }
 150         } else {
 151                 WARN_ON(!dev->unique);
 152                 master->unique = kstrdup(dev->unique, GFP_KERNEL);
 153                 if (master->unique)
 154                         master->unique_len = strlen(dev->unique);
 155         }
 156
 157         return 0;
 158 }
 159
 160 /*
 161  * Get client information.
 162  *
 163  * \param inode device inode.
 164  * \param file_priv DRM file private.
 165  * \param cmd command.
 166  * \param arg user argument, pointing to a drm_client structure.
 167  *
 168  * \return zero on success or a negative number on failure.
 169  *
 170  * Searches for the client with the specified index and copies its information
 171  * into userspace
 172  */
 173 static int drm_getclient(struct drm_device *dev, void *data,
 174                   struct drm_file *file_priv)
 175 {
 176         struct drm_client *client = data;
 177
 178         /*
 179          * Hollowed-out getclient ioctl to keep some dead old drm tests/tools
 180          * not breaking completely. Userspace tools stop enumerating one they
 181          * get -EINVAL, hence this is the return value we need to hand back for
 182          * no clients tracked.
 183          *
 184          * Unfortunately some clients (*cough* libva *cough*) use this in a fun
 185          * attempt to figure out whether they're authenticated or not. Since
 186          * that's the only thing they care about, give it to the directly
 187          * instead of walking one giant list.
 188          */
 189         if (client->idx == 0) {
 190                 client->auth = file_priv->authenticated;
 191                 client->pid = pid_vnr(file_priv->pid);
 192                 client->uid = from_kuid_munged(current_user_ns(),
 193                                                file_priv->uid);
 194                 client->magic = 0;
 195                 client->iocs = 0;
 196
 197                 return 0;
 198         } else {
 199                 return -EINVAL;
 200         }
 201 }
 202
 203 /*
 204  * Get statistics information.
 205  *
 206  * \param inode device inode.
 207  * \param file_priv DRM file private.
 208  * \param cmd command.
 209  * \param arg user argument, pointing to a drm_stats structure.
 210  *
 211  * \return zero on success or a negative number on failure.
 212  */
 213 static int drm_getstats(struct drm_device *dev, void *data,
 214                  struct drm_file *file_priv)
 215 {
 216         struct drm_stats *stats = data;
 217
 218         /* Clear stats to prevent userspace from eating its stack garbage. */
 219         memset(stats, 0, sizeof(*stats));
 220
 221         return 0;
 222 }
 223
 224 /*
 225  * Get device/driver capabilities
 226  */
 227 static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
 228 {
 229         struct drm_get_cap *req = data;
 230
 231         req->value = 0;
 232         switch (req->capability) {
 233         case DRM_CAP_DUMB_BUFFER:
 234                 if (dev->driver->dumb_create)
 235                         req->value = 1;
 236                 break;
 237         case DRM_CAP_VBLANK_HIGH_CRTC:
 238                 req->value = 1;
 239                 break;
 240         case DRM_CAP_DUMB_PREFERRED_DEPTH:
 241                 req->value = dev->mode_config.preferred_depth;
 242                 break;
 243         case DRM_CAP_DUMB_PREFER_SHADOW:
 244                 req->value = dev->mode_config.prefer_shadow;
 245                 break;
 246         case DRM_CAP_PRIME:
 247                 req->value |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0;
 248                 req->value |= dev->driver->prime_handle_to_fd ? DRM_PRIME_CAP_EXPORT : 0;
 249                 break;
 250         case DRM_CAP_TIMESTAMP_MONOTONIC:
 251                 req->value = drm_timestamp_monotonic;
 252                 break;
 253         case DRM_CAP_ASYNC_PAGE_FLIP:
 254                 req->value = dev->mode_config.async_page_flip;
 255                 break;
 256         case DRM_CAP_CURSOR_WIDTH:
 257                 if (dev->mode_config.cursor_width)
 258                         req->value = dev->mode_config.cursor_width;
 259                 else
 260                         req->value = 64;
 261                 break;
 262         case DRM_CAP_CURSOR_HEIGHT:
 263                 if (dev->mode_config.cursor_height)
 264                         req->value = dev->mode_config.cursor_height;
 265                 else
 266                         req->value = 64;
 267                 break;
 268         case DRM_CAP_ADDFB2_MODIFIERS:
 269                 req->value = dev->mode_config.allow_fb_modifiers;
 270                 break;
 271         default:
 272                 return -EINVAL;
 273         }
 274         return 0;
 275 }
 276
 277 /*
 278  * Set device/driver capabilities
 279  */
 280 static int
 281 drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
 282 {
 283         struct drm_set_client_cap *req = data;
 284
 285         switch (req->capability) {
 286         case DRM_CLIENT_CAP_STEREO_3D:
 287                 if (req->value > 1)
 288                         return -EINVAL;
 289                 file_priv->stereo_allowed = req->value;
 290                 break;
 291         case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
 292                 if (req->value > 1)
 293                         return -EINVAL;
 294                 file_priv->universal_planes = req->value;
 295                 break;
 296         case DRM_CLIENT_CAP_ATOMIC:
 297                 if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
 298                         return -EINVAL;
 299                 if (req->value > 1)
 300                         return -EINVAL;
 301                 file_priv->atomic = req->value;
 302                 file_priv->universal_planes = req->value;
 303                 break;
 304         default:
 305                 return -EINVAL;
 306         }
 307
 308         return 0;
 309 }
 310
 311 /*
 312  * Setversion ioctl.
 313  *
 314  * \param inode device inode.
 315  * \param file_priv DRM file private.
 316  * \param cmd command.
 317  * \param arg user argument, pointing to a drm_lock structure.
 318  * \return zero on success or negative number on failure.
 319  *
 320  * Sets the requested interface version
 321  */
 322 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
 323 {
 324         struct drm_set_version *sv = data;
 325         int if_version, retcode = 0;
 326
 327         if (sv->drm_di_major != -1) {
 328                 if (sv->drm_di_major != DRM_IF_MAJOR ||
 329                     sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
 330                         retcode = -EINVAL;
 331                         goto done;
 332                 }
 333                 if_version = DRM_IF_VERSION(sv->drm_di_major,
 334                                             sv->drm_di_minor);
 335                 dev->if_version = max(if_version, dev->if_version);
 336                 if (sv->drm_di_minor >= 1) {
 337                         /*
 338                          * Version 1.1 includes tying of DRM to specific device
 339                          * Version 1.4 has proper PCI domain support
 340                          */
 341                         retcode = drm_set_busid(dev, file_priv);
 342                         if (retcode)
 343                                 goto done;
 344                 }
 345         }
 346
 347         if (sv->drm_dd_major != -1) {
 348                 if (sv->drm_dd_major != dev->driver->major ||
 349                     sv->drm_dd_minor < 0 || sv->drm_dd_minor >
 350                     dev->driver->minor) {
 351                         retcode = -EINVAL;
 352                         goto done;
 353                 }
 354         }
 355
 356 done:
 357         sv->drm_di_major = DRM_IF_MAJOR;
 358         sv->drm_di_minor = DRM_IF_MINOR;
 359         sv->drm_dd_major = dev->driver->major;
 360         sv->drm_dd_minor = dev->driver->minor;
 361
 362         return retcode;
 363 }
 364
 365 /**
 366  * drm_noop - DRM no-op ioctl implemntation
 367  * @dev: DRM device for the ioctl
 368  * @data: data pointer for the ioctl
 369  * @file_priv: DRM file for the ioctl call
 370  *
 371  * This no-op implementation for drm ioctls is useful for deprecated
 372  * functionality where we can't return a failure code because existing userspace
 373  * checks the result of the ioctl, but doesn't care about the action.
 374  *
 375  * Always returns successfully with 0.
 376  */
 377 int drm_noop(struct drm_device *dev, void *data,
 378              struct drm_file *file_priv)
 379 {
 380         DRM_DEBUG("\n");
 381         return 0;
 382 }
 383 EXPORT_SYMBOL(drm_noop);
 384
 385 /**
 386  * drm_invalid_op - DRM invalid ioctl implemntation
 387  * @dev: DRM device for the ioctl
 388  * @data: data pointer for the ioctl
 389  * @file_priv: DRM file for the ioctl call
 390  *
 391  * This no-op implementation for drm ioctls is useful for deprecated
 392  * functionality where we really don't want to allow userspace to call the ioctl
 393  * any more. This is the case for old ums interfaces for drivers that
 394  * transitioned to kms gradually and so kept the old legacy tables around. This
 395  * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
 396  * use this function.
 397  *
 398  * Always fails with a return value of -EINVAL.
 399  */
 400 int drm_invalid_op(struct drm_device *dev, void *data,
 401                    struct drm_file *file_priv)
 402 {
 403         return -EINVAL;
 404 }
 405 EXPORT_SYMBOL(drm_invalid_op);
 406
 407 /*
 408  * Copy and IOCTL return string to user space
 409  */
 410 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
 411 {
 412         int len;
 413
 414         /* don't overflow userbuf */
 415         len = strlen(value);
 416         if (len > *buf_len)
 417                 len = *buf_len;
 418
 419         /* let userspace know exact length of driver value (which could be
 420          * larger than the userspace-supplied buffer) */
 421         *buf_len = strlen(value);
 422
 423         /* finally, try filling in the userbuf */
 424         if (len && buf)
 425                 if (copy_to_user(buf, value, len))
 426                         return -EFAULT;
 427         return 0;
 428 }
 429
 430 /*
 431  * Get version information
 432  *
 433  * \param inode device inode.
 434  * \param filp file pointer.
 435  * \param cmd command.
 436  * \param arg user argument, pointing to a drm_version structure.
 437  * \return zero on success or negative number on failure.
 438  *
 439  * Fills in the version information in \p arg.
 440  */
 441 static int drm_version(struct drm_device *dev, void *data,
 442                        struct drm_file *file_priv)
 443 {
 444         struct drm_version *version = data;
 445         int err;
 446
 447         version->version_major = dev->driver->major;
 448         version->version_minor = dev->driver->minor;
 449         version->version_patchlevel = dev->driver->patchlevel;
 450         err = drm_copy_field(version->name, &version->name_len,
 451                         dev->driver->name);
 452         if (!err)
 453                 err = drm_copy_field(version->date, &version->date_len,
 454                                 dev->driver->date);
 455         if (!err)
 456                 err = drm_copy_field(version->desc, &version->desc_len,
 457                                 dev->driver->desc);
 458
 459         return err;
 460 }
 461
 462 /*
 463  * drm_ioctl_permit - Check ioctl permissions against caller
 464  *
 465  * @flags: ioctl permission flags.
 466  * @file_priv: Pointer to struct drm_file identifying the caller.
 467  *
 468  * Checks whether the caller is allowed to run an ioctl with the
 469  * indicated permissions. If so, returns zero. Otherwise returns an
 470  * error code suitable for ioctl return.
 471  */
 472 int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
 473 {
 474         /* ROOT_ONLY is only for CAP_SYS_ADMIN */
 475         if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
 476                 return -EACCES;
 477
 478         /* AUTH is only for authenticated or render client */
 479         if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
 480                      !file_priv->authenticated))
 481                 return -EACCES;
 482
 483         /* MASTER is only for master or control clients */
 484         if (unlikely((flags & DRM_MASTER) && !file_priv->is_master &&
 485                      !drm_is_control_client(file_priv)))
 486                 return -EACCES;
 487
 488         /* Control clients must be explicitly allowed */
 489         if (unlikely(!(flags & DRM_CONTROL_ALLOW) &&
 490                      drm_is_control_client(file_priv)))
 491                 return -EACCES;
 492
 493         /* Render clients must be explicitly allowed */
 494         if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
 495                      drm_is_render_client(file_priv)))
 496                 return -EACCES;
 497
 498         return 0;
 499 }
 500 EXPORT_SYMBOL(drm_ioctl_permit);
 501
 502 #define DRM_IOCTL_DEF(ioctl, _func, _flags)     \
 503         [DRM_IOCTL_NR(ioctl)] = {               \
 504                 .cmd = ioctl,                   \
 505                 .func = _func,                  \
 506                 .flags = _flags,                \
 507                 .name = #ioctl                  \
 508         }
 509
 510 /* Ioctl table */
 511 static const struct drm_ioctl_desc drm_ioctls[] = {
 512         DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version,
 513                       DRM_UNLOCKED|DRM_RENDER_ALLOW|DRM_CONTROL_ALLOW),
 514         DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
 515         DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, DRM_UNLOCKED),
 516         DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
 517         DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, DRM_UNLOCKED),
 518         DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED),
 519         DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),
 520         DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED|DRM_RENDER_ALLOW),
 521         DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
 522         DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
 523
 524         DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 525         DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 526         DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 527         DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_UNLOCKED|DRM_MASTER),
 528
 529         DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 530         DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),
 531
 532         DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 533         DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),
 534
 535         DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
 536         DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
 537
 538         DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
 539         DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 540         DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 541         DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
 542         DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 543         DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 544         DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),
 545
 546         DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 547         DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 548
 549         DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH),
 550         DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH),
 551
 552         DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
 553
 554         DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 555         DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 556         DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH),
 557         DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH),
 558         DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH),
 559         DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH),
 560
 561         DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 562
 563 #if IS_ENABLED(CONFIG_AGP)
 564         DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 565         DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 566         DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 567         DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
 568         DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 569         DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 570         DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 571         DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 572 #endif
 573
 574         DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 575         DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 576
 577         DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank, DRM_UNLOCKED),
 578
 579         DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_modeset_ctl, 0),
 580
 581         DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 582
 583         DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
 584         DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED),
 585         DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED),
 586
 587         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 588
 589         DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
 590         DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
 591
 592         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 593         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 594         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 595         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 596         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 597         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 598         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_UNLOCKED),
 599         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
 600         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 601         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 602         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 603         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 604         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 605         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_mode_connector_property_set_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 606         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 607         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 608         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 609         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 610         DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 611         DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 612         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 613         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 614         DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 615         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 616         DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 617         DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 618         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 619         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 620         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 621         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 622 };
 623
 624 #define DRM_CORE_IOCTL_COUNT    ARRAY_SIZE( drm_ioctls )
 625
 626 /**
 627  * drm_ioctl - ioctl callback implementation for DRM drivers
 628  * @filp: file this ioctl is called on
 629  * @cmd: ioctl cmd number
 630  * @arg: user argument
 631  *
 632  * Looks up the ioctl function in the ::ioctls table, checking for root
 633  * previleges if so required, and dispatches to the respective function.
 634  *
 635  * Returns:
 636  * Zero on success, negative error code on failure.
 637  */
 638 long drm_ioctl(struct file *filp,
 639               unsigned int cmd, unsigned long arg)
 640 {
 641         struct drm_file *file_priv = filp->private_data;
 642         struct drm_device *dev;
 643         const struct drm_ioctl_desc *ioctl = NULL;
 644         drm_ioctl_t *func;
 645         unsigned int nr = DRM_IOCTL_NR(cmd);
 646         int retcode = -EINVAL;
 647         char stack_kdata[128];
 648         char *kdata = NULL;
 649         unsigned int usize, asize, drv_size;
 650         bool is_driver_ioctl;
 651
 652         dev = file_priv->minor->dev;
 653
 654         if (drm_device_is_unplugged(dev))
 655                 return -ENODEV;
 656
 657         is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
 658
 659         if (is_driver_ioctl) {
 660                 /* driver ioctl */
 661                 if (nr - DRM_COMMAND_BASE >= dev->driver->num_ioctls)
 662                         goto err_i1;
 663                 ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
 664         } else {
 665                 /* core ioctl */
 666                 if (nr >= DRM_CORE_IOCTL_COUNT)
 667                         goto err_i1;
 668                 ioctl = &drm_ioctls[nr];
 669         }
 670
 671         drv_size = _IOC_SIZE(ioctl->cmd);
 672         usize = _IOC_SIZE(cmd);
 673         asize = max(usize, drv_size);
 674         cmd = ioctl->cmd;
 675
 676         DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
 677                   task_pid_nr(current),
 678                   (long)old_encode_dev(file_priv->minor->kdev->devt),
 679                   file_priv->authenticated, ioctl->name);
 680
 681         /* Do not trust userspace, use our own definition */
 682         func = ioctl->func;
 683
 684         if (unlikely(!func)) {
 685                 DRM_DEBUG("no function\n");
 686                 retcode = -EINVAL;
 687                 goto err_i1;
 688         }
 689
 690         retcode = drm_ioctl_permit(ioctl->flags, file_priv);
 691         if (unlikely(retcode))
 692                 goto err_i1;
 693
 694         if (cmd & (IOC_IN | IOC_OUT)) {
 695                 if (asize <= sizeof(stack_kdata)) {
 696                         kdata = stack_kdata;
 697                 } else {
 698                         kdata = kmalloc(asize, GFP_KERNEL);
 699                         if (!kdata) {
 700                                 retcode = -ENOMEM;
 701                                 goto err_i1;
 702                         }
 703                 }
 704                 if (asize > usize)
 705                         memset(kdata + usize, 0, asize - usize);
 706         }
 707
 708         if (cmd & IOC_IN) {
 709                 if (copy_from_user(kdata, (void __user *)arg,
 710                                    usize) != 0) {
 711                         retcode = -EFAULT;
 712                         goto err_i1;
 713                 }
 714         } else if (cmd & IOC_OUT) {
 715                 memset(kdata, 0, usize);
 716         }
 717
 718         /* Enforce sane locking for kms driver ioctls. Core ioctls are
 719          * too messy still. */
 720         if ((drm_core_check_feature(dev, DRIVER_MODESET) && is_driver_ioctl) ||
 721             (ioctl->flags & DRM_UNLOCKED))
 722                 retcode = func(dev, kdata, file_priv);
 723         else {
 724                 mutex_lock(&drm_global_mutex);
 725                 retcode = func(dev, kdata, file_priv);
 726                 mutex_unlock(&drm_global_mutex);
 727         }
 728
 729         if (cmd & IOC_OUT) {
 730                 if (copy_to_user((void __user *)arg, kdata,
 731                                  usize) != 0)
 732                         retcode = -EFAULT;
 733         }
 734
 735       err_i1:
 736         if (!ioctl)
 737                 DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
 738                           task_pid_nr(current),
 739                           (long)old_encode_dev(file_priv->minor->kdev->devt),
 740                           file_priv->authenticated, cmd, nr);
 741
 742         if (kdata != stack_kdata)
 743                 kfree(kdata);
 744         if (retcode)
 745                 DRM_DEBUG("ret = %d\n", retcode);
 746         return retcode;
 747 }
 748 EXPORT_SYMBOL(drm_ioctl);
 749
 750 /**
 751  * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
 752  * @nr: ioctl number
 753  * @flags: where to return the ioctl permission flags
 754  *
 755  * This ioctl is only used by the vmwgfx driver to augment the access checks
 756  * done by the drm core and insofar a pretty decent layering violation. This
 757  * shouldn't be used by any drivers.
 758  *
 759  * Returns:
 760  * True if the @nr corresponds to a DRM core ioctl numer, false otherwise.
 761  */
 762 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
 763 {
 764         if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
 765                 return false;
 766
 767         if (nr >= DRM_CORE_IOCTL_COUNT)
 768                 return false;
 769
 770         *flags = drm_ioctls[nr].flags;
 771         return true;
 772 }
 773 EXPORT_SYMBOL(drm_ioctl_flags);