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 = task_pid_vnr(current);
 193                 client->uid = overflowuid;
 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         struct drm_crtc *crtc;
 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_PAGE_FLIP_TARGET:
 258                 req->value = 1;
 259                 drm_for_each_crtc(crtc, dev) {
 260                         if (!crtc->funcs->page_flip_target)
 261                                 req->value = 0;
 262                 }
 263                 break;
 264         case DRM_CAP_CURSOR_WIDTH:
 265                 if (dev->mode_config.cursor_width)
 266                         req->value = dev->mode_config.cursor_width;
 267                 else
 268                         req->value = 64;
 269                 break;
 270         case DRM_CAP_CURSOR_HEIGHT:
 271                 if (dev->mode_config.cursor_height)
 272                         req->value = dev->mode_config.cursor_height;
 273                 else
 274                         req->value = 64;
 275                 break;
 276         case DRM_CAP_ADDFB2_MODIFIERS:
 277                 req->value = dev->mode_config.allow_fb_modifiers;
 278                 break;
 279         default:
 280                 return -EINVAL;
 281         }
 282         return 0;
 283 }
 284
 285 /*
 286  * Set device/driver capabilities
 287  */
 288 static int
 289 drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
 290 {
 291         struct drm_set_client_cap *req = data;
 292
 293         switch (req->capability) {
 294         case DRM_CLIENT_CAP_STEREO_3D:
 295                 if (req->value > 1)
 296                         return -EINVAL;
 297                 file_priv->stereo_allowed = req->value;
 298                 break;
 299         case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
 300                 if (req->value > 1)
 301                         return -EINVAL;
 302                 file_priv->universal_planes = req->value;
 303                 break;
 304         case DRM_CLIENT_CAP_ATOMIC:
 305                 if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
 306                         return -EINVAL;
 307                 if (req->value > 1)
 308                         return -EINVAL;
 309                 file_priv->atomic = req->value;
 310                 file_priv->universal_planes = req->value;
 311                 break;
 312         default:
 313                 return -EINVAL;
 314         }
 315
 316         return 0;
 317 }
 318
 319 /*
 320  * Setversion ioctl.
 321  *
 322  * \param inode device inode.
 323  * \param file_priv DRM file private.
 324  * \param cmd command.
 325  * \param arg user argument, pointing to a drm_lock structure.
 326  * \return zero on success or negative number on failure.
 327  *
 328  * Sets the requested interface version
 329  */
 330 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
 331 {
 332         struct drm_set_version *sv = data;
 333         int if_version, retcode = 0;
 334
 335         if (sv->drm_di_major != -1) {
 336                 if (sv->drm_di_major != DRM_IF_MAJOR ||
 337                     sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
 338                         retcode = -EINVAL;
 339                         goto done;
 340                 }
 341                 if_version = DRM_IF_VERSION(sv->drm_di_major,
 342                                             sv->drm_di_minor);
 343                 dev->if_version = max(if_version, dev->if_version);
 344                 if (sv->drm_di_minor >= 1) {
 345                         /*
 346                          * Version 1.1 includes tying of DRM to specific device
 347                          * Version 1.4 has proper PCI domain support
 348                          */
 349                         retcode = drm_set_busid(dev, file_priv);
 350                         if (retcode)
 351                                 goto done;
 352                 }
 353         }
 354
 355         if (sv->drm_dd_major != -1) {
 356                 if (sv->drm_dd_major != dev->driver->major ||
 357                     sv->drm_dd_minor < 0 || sv->drm_dd_minor >
 358                     dev->driver->minor) {
 359                         retcode = -EINVAL;
 360                         goto done;
 361                 }
 362         }
 363
 364 done:
 365         sv->drm_di_major = DRM_IF_MAJOR;
 366         sv->drm_di_minor = DRM_IF_MINOR;
 367         sv->drm_dd_major = dev->driver->major;
 368         sv->drm_dd_minor = dev->driver->minor;
 369
 370         return retcode;
 371 }
 372
 373 /**
 374  * drm_noop - DRM no-op ioctl implemntation
 375  * @dev: DRM device for the ioctl
 376  * @data: data pointer for the ioctl
 377  * @file_priv: DRM file for the ioctl call
 378  *
 379  * This no-op implementation for drm ioctls is useful for deprecated
 380  * functionality where we can't return a failure code because existing userspace
 381  * checks the result of the ioctl, but doesn't care about the action.
 382  *
 383  * Always returns successfully with 0.
 384  */
 385 int drm_noop(struct drm_device *dev, void *data,
 386              struct drm_file *file_priv)
 387 {
 388         DRM_DEBUG("\n");
 389         return 0;
 390 }
 391 EXPORT_SYMBOL(drm_noop);
 392
 393 /**
 394  * drm_invalid_op - DRM invalid ioctl implemntation
 395  * @dev: DRM device for the ioctl
 396  * @data: data pointer for the ioctl
 397  * @file_priv: DRM file for the ioctl call
 398  *
 399  * This no-op implementation for drm ioctls is useful for deprecated
 400  * functionality where we really don't want to allow userspace to call the ioctl
 401  * any more. This is the case for old ums interfaces for drivers that
 402  * transitioned to kms gradually and so kept the old legacy tables around. This
 403  * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
 404  * use this function.
 405  *
 406  * Always fails with a return value of -EINVAL.
 407  */
 408 int drm_invalid_op(struct drm_device *dev, void *data,
 409                    struct drm_file *file_priv)
 410 {
 411         return -EINVAL;
 412 }
 413 EXPORT_SYMBOL(drm_invalid_op);
 414
 415 /*
 416  * Copy and IOCTL return string to user space
 417  */
 418 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
 419 {
 420         int len;
 421
 422         /* don't overflow userbuf */
 423         len = strlen(value);
 424         if (len > *buf_len)
 425                 len = *buf_len;
 426
 427         /* let userspace know exact length of driver value (which could be
 428          * larger than the userspace-supplied buffer) */
 429         *buf_len = strlen(value);
 430
 431         /* finally, try filling in the userbuf */
 432         if (len && buf)
 433                 if (copy_to_user(buf, value, len))
 434                         return -EFAULT;
 435         return 0;
 436 }
 437
 438 /*
 439  * Get version information
 440  *
 441  * \param inode device inode.
 442  * \param filp file pointer.
 443  * \param cmd command.
 444  * \param arg user argument, pointing to a drm_version structure.
 445  * \return zero on success or negative number on failure.
 446  *
 447  * Fills in the version information in \p arg.
 448  */
 449 static int drm_version(struct drm_device *dev, void *data,
 450                        struct drm_file *file_priv)
 451 {
 452         struct drm_version *version = data;
 453         int err;
 454
 455         version->version_major = dev->driver->major;
 456         version->version_minor = dev->driver->minor;
 457         version->version_patchlevel = dev->driver->patchlevel;
 458         err = drm_copy_field(version->name, &version->name_len,
 459                         dev->driver->name);
 460         if (!err)
 461                 err = drm_copy_field(version->date, &version->date_len,
 462                                 dev->driver->date);
 463         if (!err)
 464                 err = drm_copy_field(version->desc, &version->desc_len,
 465                                 dev->driver->desc);
 466
 467         return err;
 468 }
 469
 470 /*
 471  * drm_ioctl_permit - Check ioctl permissions against caller
 472  *
 473  * @flags: ioctl permission flags.
 474  * @file_priv: Pointer to struct drm_file identifying the caller.
 475  *
 476  * Checks whether the caller is allowed to run an ioctl with the
 477  * indicated permissions. If so, returns zero. Otherwise returns an
 478  * error code suitable for ioctl return.
 479  */
 480 int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
 481 {
 482         /* ROOT_ONLY is only for CAP_SYS_ADMIN */
 483         if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
 484                 return -EACCES;
 485
 486         /* AUTH is only for authenticated or render client */
 487         if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
 488                      !file_priv->authenticated))
 489                 return -EACCES;
 490
 491         /* MASTER is only for master or control clients */
 492         if (unlikely((flags & DRM_MASTER) &&
 493                      !drm_is_current_master(file_priv) &&
 494                      !drm_is_control_client(file_priv)))
 495                 return -EACCES;
 496
 497         /* Control clients must be explicitly allowed */
 498         if (unlikely(!(flags & DRM_CONTROL_ALLOW) &&
 499                      drm_is_control_client(file_priv)))
 500                 return -EACCES;
 501
 502         /* Render clients must be explicitly allowed */
 503         if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
 504                      drm_is_render_client(file_priv)))
 505                 return -EACCES;
 506
 507         return 0;
 508 }
 509 EXPORT_SYMBOL(drm_ioctl_permit);
 510
 511 #define DRM_IOCTL_DEF(ioctl, _func, _flags)     \
 512         [DRM_IOCTL_NR(ioctl)] = {               \
 513                 .cmd = ioctl,                   \
 514                 .func = _func,                  \
 515                 .flags = _flags,                \
 516                 .name = #ioctl                  \
 517         }
 518
 519 /* Ioctl table */
 520 static const struct drm_ioctl_desc drm_ioctls[] = {
 521         DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version,
 522                       DRM_UNLOCKED|DRM_RENDER_ALLOW|DRM_CONTROL_ALLOW),
 523         DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
 524         DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, DRM_UNLOCKED),
 525         DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
 526         DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, DRM_UNLOCKED),
 527         DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED),
 528         DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),
 529         DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED|DRM_RENDER_ALLOW),
 530         DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
 531         DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
 532
 533         DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 534         DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 535         DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 536         DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_UNLOCKED|DRM_MASTER),
 537
 538         DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 539         DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),
 540
 541         DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 542         DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),
 543
 544         DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
 545         DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
 546
 547         DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
 548         DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 549         DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 550         DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
 551         DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 552         DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 553         DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),
 554
 555         DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 556         DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 557
 558         DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH),
 559         DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH),
 560
 561         DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
 562
 563         DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 564         DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 565         DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH),
 566         DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH),
 567         DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH),
 568         DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH),
 569
 570         DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 571
 572 #if IS_ENABLED(CONFIG_AGP)
 573         DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 574         DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 575         DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 576         DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
 577         DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 578         DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 579         DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 580         DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 581 #endif
 582
 583         DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 584         DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 585
 586         DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank, DRM_UNLOCKED),
 587
 588         DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_modeset_ctl, 0),
 589
 590         DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 591
 592         DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
 593         DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED),
 594         DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED),
 595
 596         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 597
 598         DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
 599         DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
 600
 601         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 602         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 603         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 604         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 605         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 606         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 607         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_UNLOCKED),
 608         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
 609         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 610         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 611         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 612         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 613         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 614         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_mode_connector_property_set_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 615         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 616         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 617         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 618         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 619         DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 620         DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 621         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 622         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 623         DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 624         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 625         DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 626         DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 627         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 628         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 629         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 630         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
 631 };
 632
 633 #define DRM_CORE_IOCTL_COUNT    ARRAY_SIZE( drm_ioctls )
 634
 635 /**
 636  * drm_ioctl - ioctl callback implementation for DRM drivers
 637  * @filp: file this ioctl is called on
 638  * @cmd: ioctl cmd number
 639  * @arg: user argument
 640  *
 641  * Looks up the ioctl function in the ::ioctls table, checking for root
 642  * previleges if so required, and dispatches to the respective function.
 643  *
 644  * Returns:
 645  * Zero on success, negative error code on failure.
 646  */
 647 long drm_ioctl(struct file *filp,
 648               unsigned int cmd, unsigned long arg)
 649 {
 650         struct drm_file *file_priv = filp->private_data;
 651         struct drm_device *dev;
 652         const struct drm_ioctl_desc *ioctl = NULL;
 653         drm_ioctl_t *func;
 654         unsigned int nr = DRM_IOCTL_NR(cmd);
 655         int retcode = -EINVAL;
 656         char stack_kdata[128];
 657         char *kdata = NULL;
 658         unsigned int in_size, out_size, drv_size, ksize;
 659         bool is_driver_ioctl;
 660
 661         dev = file_priv->minor->dev;
 662
 663         if (drm_device_is_unplugged(dev))
 664                 return -ENODEV;
 665
 666         is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
 667
 668         if (is_driver_ioctl) {
 669                 /* driver ioctl */
 670                 if (nr - DRM_COMMAND_BASE >= dev->driver->num_ioctls)
 671                         goto err_i1;
 672                 ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
 673         } else {
 674                 /* core ioctl */
 675                 if (nr >= DRM_CORE_IOCTL_COUNT)
 676                         goto err_i1;
 677                 ioctl = &drm_ioctls[nr];
 678         }
 679
 680         drv_size = _IOC_SIZE(ioctl->cmd);
 681         out_size = in_size = _IOC_SIZE(cmd);
 682         if ((cmd & ioctl->cmd & IOC_IN) == 0)
 683                 in_size = 0;
 684         if ((cmd & ioctl->cmd & IOC_OUT) == 0)
 685                 out_size = 0;
 686         ksize = max(max(in_size, out_size), drv_size);
 687
 688         DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
 689                   task_pid_nr(current),
 690                   (long)old_encode_dev(file_priv->minor->kdev->devt),
 691                   file_priv->authenticated, ioctl->name);
 692
 693         /* Do not trust userspace, use our own definition */
 694         func = ioctl->func;
 695
 696         if (unlikely(!func)) {
 697                 DRM_DEBUG("no function\n");
 698                 retcode = -EINVAL;
 699                 goto err_i1;
 700         }
 701
 702         retcode = drm_ioctl_permit(ioctl->flags, file_priv);
 703         if (unlikely(retcode))
 704                 goto err_i1;
 705
 706         if (ksize <= sizeof(stack_kdata)) {
 707                 kdata = stack_kdata;
 708         } else {
 709                 kdata = kmalloc(ksize, GFP_KERNEL);
 710                 if (!kdata) {
 711                         retcode = -ENOMEM;
 712                         goto err_i1;
 713                 }
 714         }
 715
 716         if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) {
 717                 retcode = -EFAULT;
 718                 goto err_i1;
 719         }
 720
 721         if (ksize > in_size)
 722                 memset(kdata + in_size, 0, ksize - in_size);
 723
 724         /* Enforce sane locking for modern driver ioctls. Core ioctls are
 725          * too messy still. */
 726         if ((!drm_core_check_feature(dev, DRIVER_LEGACY) && is_driver_ioctl) ||
 727             (ioctl->flags & DRM_UNLOCKED))
 728                 retcode = func(dev, kdata, file_priv);
 729         else {
 730                 mutex_lock(&drm_global_mutex);
 731                 retcode = func(dev, kdata, file_priv);
 732                 mutex_unlock(&drm_global_mutex);
 733         }
 734
 735         if (copy_to_user((void __user *)arg, kdata, out_size) != 0)
 736                 retcode = -EFAULT;
 737
 738       err_i1:
 739         if (!ioctl)
 740                 DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
 741                           task_pid_nr(current),
 742                           (long)old_encode_dev(file_priv->minor->kdev->devt),
 743                           file_priv->authenticated, cmd, nr);
 744
 745         if (kdata != stack_kdata)
 746                 kfree(kdata);
 747         if (retcode)
 748                 DRM_DEBUG("ret = %d\n", retcode);
 749         return retcode;
 750 }
 751 EXPORT_SYMBOL(drm_ioctl);
 752
 753 /**
 754  * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
 755  * @nr: ioctl number
 756  * @flags: where to return the ioctl permission flags
 757  *
 758  * This ioctl is only used by the vmwgfx driver to augment the access checks
 759  * done by the drm core and insofar a pretty decent layering violation. This
 760  * shouldn't be used by any drivers.
 761  *
 762  * Returns:
 763  * True if the @nr corresponds to a DRM core ioctl number, false otherwise.
 764  */
 765 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
 766 {
 767         if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
 768                 return false;
 769
 770         if (nr >= DRM_CORE_IOCTL_COUNT)
 771                 return false;
 772
 773         *flags = drm_ioctls[nr].flags;
 774         return true;
 775 }
 776 EXPORT_SYMBOL(drm_ioctl_flags);