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