drivers/gpu/drm/drm_ioctl.c

   1 /*
   2  * Created: Fri Jan  8 09:01:26 1999 by faith@valinux.com
   3  *
   4  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
   5  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
   6  * All Rights Reserved.
   7  *
   8  * Author Rickard E. (Rik) Faith <faith@valinux.com>
   9  * Author Gareth Hughes <gareth@valinux.com>
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a
  12  * copy of this software and associated documentation files (the "Software"),
  13  * to deal in the Software without restriction, including without limitation
  14  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  15  * and/or sell copies of the Software, and to permit persons to whom the
  16  * Software is furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice (including the next
  19  * paragraph) shall be included in all copies or substantial portions of the
  20  * Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  25  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  26  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  27  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  28  * OTHER DEALINGS IN THE SOFTWARE.
  29  */
  30
  31 #include <drm/drm_ioctl.h>
  32 #include <drm/drmP.h>
  33 #include <drm/drm_auth.h>
  34 #include "drm_legacy.h"
  35 #include "drm_internal.h"
  36 #include "drm_crtc_internal.h"
  37
  38 #include <linux/pci.h>
  39 #include <linux/export.h>
  40
  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 /*
 100  * Get the bus id.
 101  *
 102  * \param inode device inode.
 103  * \param file_priv DRM file private.
 104  * \param cmd command.
 105  * \param arg user argument, pointing to a drm_unique structure.
 106  * \return zero on success or a negative number on failure.
 107  *
 108  * Copies the bus id from drm_device::unique into user space.
 109  */
 110 int drm_getunique(struct drm_device *dev, void *data,
 111                   struct drm_file *file_priv)
 112 {
 113         struct drm_unique *u = data;
 114         struct drm_master *master = file_priv->master;
 115
 116         mutex_lock(&master->dev->master_mutex);
 117         if (u->unique_len >= master->unique_len) {
 118                 if (copy_to_user(u->unique, master->unique, master->unique_len)) {
 119                         mutex_unlock(&master->dev->master_mutex);
 120                         return -EFAULT;
 121                 }
 122         }
 123         u->unique_len = master->unique_len;
 124         mutex_unlock(&master->dev->master_mutex);
 125
 126         return 0;
 127 }
 128
 129 static void
 130 drm_unset_busid(struct drm_device *dev,
 131                 struct drm_master *master)
 132 {
 133         kfree(master->unique);
 134         master->unique = NULL;
 135         master->unique_len = 0;
 136 }
 137
 138 static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
 139 {
 140         struct drm_master *master = file_priv->master;
 141         int ret;
 142
 143         if (master->unique != NULL)
 144                 drm_unset_busid(dev, master);
 145
 146         if (dev->dev && dev_is_pci(dev->dev)) {
 147                 ret = drm_pci_set_busid(dev, master);
 148                 if (ret) {
 149                         drm_unset_busid(dev, master);
 150                         return ret;
 151                 }
 152         } else {
 153                 WARN_ON(!dev->unique);
 154                 master->unique = kstrdup(dev->unique, GFP_KERNEL);
 155                 if (master->unique)
 156                         master->unique_len = strlen(dev->unique);
 157         }
 158
 159         return 0;
 160 }
 161
 162 /*
 163  * Get client information.
 164  *
 165  * \param inode device inode.
 166  * \param file_priv DRM file private.
 167  * \param cmd command.
 168  * \param arg user argument, pointing to a drm_client structure.
 169  *
 170  * \return zero on success or a negative number on failure.
 171  *
 172  * Searches for the client with the specified index and copies its information
 173  * into userspace
 174  */
 175 int drm_getclient(struct drm_device *dev, void *data,
 176                   struct drm_file *file_priv)
 177 {
 178         struct drm_client *client = data;
 179
 180         /*
 181          * Hollowed-out getclient ioctl to keep some dead old drm tests/tools
 182          * not breaking completely. Userspace tools stop enumerating one they
 183          * get -EINVAL, hence this is the return value we need to hand back for
 184          * no clients tracked.
 185          *
 186          * Unfortunately some clients (*cough* libva *cough*) use this in a fun
 187          * attempt to figure out whether they're authenticated or not. Since
 188          * that's the only thing they care about, give it to the directly
 189          * instead of walking one giant list.
 190          */
 191         if (client->idx == 0) {
 192                 client->auth = file_priv->authenticated;
 193                 client->pid = task_pid_vnr(current);
 194                 client->uid = overflowuid;
 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         struct drm_crtc *crtc;
 232
 233         req->value = 0;
 234
 235         /* Only some caps make sense with UMS/render-only drivers. */
 236         switch (req->capability) {
 237         case DRM_CAP_TIMESTAMP_MONOTONIC:
 238                 req->value = 1;
 239                 return 0;
 240         case DRM_CAP_PRIME:
 241                 req->value |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0;
 242                 req->value |= dev->driver->prime_handle_to_fd ? DRM_PRIME_CAP_EXPORT : 0;
 243                 return 0;
 244         case DRM_CAP_SYNCOBJ:
 245                 req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ);
 246                 return 0;
 247         }
 248
 249         /* Other caps only work with KMS drivers */
 250         if (!drm_core_check_feature(dev, DRIVER_MODESET))
 251                 return -ENOTSUPP;
 252
 253         switch (req->capability) {
 254         case DRM_CAP_DUMB_BUFFER:
 255                 if (dev->driver->dumb_create)
 256                         req->value = 1;
 257                 break;
 258         case DRM_CAP_VBLANK_HIGH_CRTC:
 259                 req->value = 1;
 260                 break;
 261         case DRM_CAP_DUMB_PREFERRED_DEPTH:
 262                 req->value = dev->mode_config.preferred_depth;
 263                 break;
 264         case DRM_CAP_DUMB_PREFER_SHADOW:
 265                 req->value = dev->mode_config.prefer_shadow;
 266                 break;
 267         case DRM_CAP_ASYNC_PAGE_FLIP:
 268                 req->value = dev->mode_config.async_page_flip;
 269                 break;
 270         case DRM_CAP_PAGE_FLIP_TARGET:
 271                 req->value = 1;
 272                 drm_for_each_crtc(crtc, dev) {
 273                         if (!crtc->funcs->page_flip_target)
 274                                 req->value = 0;
 275                 }
 276                 break;
 277         case DRM_CAP_CURSOR_WIDTH:
 278                 if (dev->mode_config.cursor_width)
 279                         req->value = dev->mode_config.cursor_width;
 280                 else
 281                         req->value = 64;
 282                 break;
 283         case DRM_CAP_CURSOR_HEIGHT:
 284                 if (dev->mode_config.cursor_height)
 285                         req->value = dev->mode_config.cursor_height;
 286                 else
 287                         req->value = 64;
 288                 break;
 289         case DRM_CAP_ADDFB2_MODIFIERS:
 290                 req->value = dev->mode_config.allow_fb_modifiers;
 291                 break;
 292         case DRM_CAP_CRTC_IN_VBLANK_EVENT:
 293                 req->value = 1;
 294                 break;
 295         default:
 296                 return -EINVAL;
 297         }
 298         return 0;
 299 }
 300
 301 /*
 302  * Set device/driver capabilities
 303  */
 304 static int
 305 drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
 306 {
 307         struct drm_set_client_cap *req = data;
 308
 309         switch (req->capability) {
 310         case DRM_CLIENT_CAP_STEREO_3D:
 311                 if (req->value > 1)
 312                         return -EINVAL;
 313                 file_priv->stereo_allowed = req->value;
 314                 break;
 315         case DRM_CLIENT_CAP_UNIVERSAL_PLANES:
 316                 if (req->value > 1)
 317                         return -EINVAL;
 318                 file_priv->universal_planes = req->value;
 319                 break;
 320         case DRM_CLIENT_CAP_ATOMIC:
 321                 if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
 322                         return -EINVAL;
 323                 if (req->value > 1)
 324                         return -EINVAL;
 325                 file_priv->atomic = req->value;
 326                 file_priv->universal_planes = req->value;
 327                 /*
 328                  * No atomic user-space blows up on aspect ratio mode bits.
 329                  */
 330                 file_priv->aspect_ratio_allowed = req->value;
 331                 break;
 332         case DRM_CLIENT_CAP_ASPECT_RATIO:
 333                 if (req->value > 1)
 334                         return -EINVAL;
 335                 file_priv->aspect_ratio_allowed = req->value;
 336                 break;
 337         case DRM_CLIENT_CAP_WRITEBACK_CONNECTORS:
 338                 if (!file_priv->atomic)
 339                         return -EINVAL;
 340                 if (req->value > 1)
 341                         return -EINVAL;
 342                 file_priv->writeback_connectors = req->value;
 343                 break;
 344         default:
 345                 return -EINVAL;
 346         }
 347
 348         return 0;
 349 }
 350
 351 /*
 352  * Setversion ioctl.
 353  *
 354  * \param inode device inode.
 355  * \param file_priv DRM file private.
 356  * \param cmd command.
 357  * \param arg user argument, pointing to a drm_lock structure.
 358  * \return zero on success or negative number on failure.
 359  *
 360  * Sets the requested interface version
 361  */
 362 static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
 363 {
 364         struct drm_set_version *sv = data;
 365         int if_version, retcode = 0;
 366
 367         mutex_lock(&dev->master_mutex);
 368         if (sv->drm_di_major != -1) {
 369                 if (sv->drm_di_major != DRM_IF_MAJOR ||
 370                     sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
 371                         retcode = -EINVAL;
 372                         goto done;
 373                 }
 374                 if_version = DRM_IF_VERSION(sv->drm_di_major,
 375                                             sv->drm_di_minor);
 376                 dev->if_version = max(if_version, dev->if_version);
 377                 if (sv->drm_di_minor >= 1) {
 378                         /*
 379                          * Version 1.1 includes tying of DRM to specific device
 380                          * Version 1.4 has proper PCI domain support
 381                          */
 382                         retcode = drm_set_busid(dev, file_priv);
 383                         if (retcode)
 384                                 goto done;
 385                 }
 386         }
 387
 388         if (sv->drm_dd_major != -1) {
 389                 if (sv->drm_dd_major != dev->driver->major ||
 390                     sv->drm_dd_minor < 0 || sv->drm_dd_minor >
 391                     dev->driver->minor) {
 392                         retcode = -EINVAL;
 393                         goto done;
 394                 }
 395         }
 396
 397 done:
 398         sv->drm_di_major = DRM_IF_MAJOR;
 399         sv->drm_di_minor = DRM_IF_MINOR;
 400         sv->drm_dd_major = dev->driver->major;
 401         sv->drm_dd_minor = dev->driver->minor;
 402         mutex_unlock(&dev->master_mutex);
 403
 404         return retcode;
 405 }
 406
 407 /**
 408  * drm_noop - DRM no-op ioctl implemntation
 409  * @dev: DRM device for the ioctl
 410  * @data: data pointer for the ioctl
 411  * @file_priv: DRM file for the ioctl call
 412  *
 413  * This no-op implementation for drm ioctls is useful for deprecated
 414  * functionality where we can't return a failure code because existing userspace
 415  * checks the result of the ioctl, but doesn't care about the action.
 416  *
 417  * Always returns successfully with 0.
 418  */
 419 int drm_noop(struct drm_device *dev, void *data,
 420              struct drm_file *file_priv)
 421 {
 422         DRM_DEBUG("\n");
 423         return 0;
 424 }
 425 EXPORT_SYMBOL(drm_noop);
 426
 427 /**
 428  * drm_invalid_op - DRM invalid ioctl implemntation
 429  * @dev: DRM device for the ioctl
 430  * @data: data pointer for the ioctl
 431  * @file_priv: DRM file for the ioctl call
 432  *
 433  * This no-op implementation for drm ioctls is useful for deprecated
 434  * functionality where we really don't want to allow userspace to call the ioctl
 435  * any more. This is the case for old ums interfaces for drivers that
 436  * transitioned to kms gradually and so kept the old legacy tables around. This
 437  * only applies to radeon and i915 kms drivers, other drivers shouldn't need to
 438  * use this function.
 439  *
 440  * Always fails with a return value of -EINVAL.
 441  */
 442 int drm_invalid_op(struct drm_device *dev, void *data,
 443                    struct drm_file *file_priv)
 444 {
 445         return -EINVAL;
 446 }
 447 EXPORT_SYMBOL(drm_invalid_op);
 448
 449 /*
 450  * Copy and IOCTL return string to user space
 451  */
 452 static int drm_copy_field(char __user *buf, size_t *buf_len, const char *value)
 453 {
 454         int len;
 455
 456         /* don't overflow userbuf */
 457         len = strlen(value);
 458         if (len > *buf_len)
 459                 len = *buf_len;
 460
 461         /* let userspace know exact length of driver value (which could be
 462          * larger than the userspace-supplied buffer) */
 463         *buf_len = strlen(value);
 464
 465         /* finally, try filling in the userbuf */
 466         if (len && buf)
 467                 if (copy_to_user(buf, value, len))
 468                         return -EFAULT;
 469         return 0;
 470 }
 471
 472 /*
 473  * Get version information
 474  *
 475  * \param inode device inode.
 476  * \param filp file pointer.
 477  * \param cmd command.
 478  * \param arg user argument, pointing to a drm_version structure.
 479  * \return zero on success or negative number on failure.
 480  *
 481  * Fills in the version information in \p arg.
 482  */
 483 int drm_version(struct drm_device *dev, void *data,
 484                        struct drm_file *file_priv)
 485 {
 486         struct drm_version *version = data;
 487         int err;
 488
 489         version->version_major = dev->driver->major;
 490         version->version_minor = dev->driver->minor;
 491         version->version_patchlevel = dev->driver->patchlevel;
 492         err = drm_copy_field(version->name, &version->name_len,
 493                         dev->driver->name);
 494         if (!err)
 495                 err = drm_copy_field(version->date, &version->date_len,
 496                                 dev->driver->date);
 497         if (!err)
 498                 err = drm_copy_field(version->desc, &version->desc_len,
 499                                 dev->driver->desc);
 500
 501         return err;
 502 }
 503
 504 /**
 505  * drm_ioctl_permit - Check ioctl permissions against caller
 506  *
 507  * @flags: ioctl permission flags.
 508  * @file_priv: Pointer to struct drm_file identifying the caller.
 509  *
 510  * Checks whether the caller is allowed to run an ioctl with the
 511  * indicated permissions.
 512  *
 513  * Returns:
 514  * Zero if allowed, -EACCES otherwise.
 515  */
 516 int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
 517 {
 518         /* ROOT_ONLY is only for CAP_SYS_ADMIN */
 519         if (unlikely((flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)))
 520                 return -EACCES;
 521
 522         /* AUTH is only for authenticated or render client */
 523         if (unlikely((flags & DRM_AUTH) && !drm_is_render_client(file_priv) &&
 524                      !file_priv->authenticated))
 525                 return -EACCES;
 526
 527         /* MASTER is only for master or control clients */
 528         if (unlikely((flags & DRM_MASTER) &&
 529                      !drm_is_current_master(file_priv)))
 530                 return -EACCES;
 531
 532         /* Render clients must be explicitly allowed */
 533         if (unlikely(!(flags & DRM_RENDER_ALLOW) &&
 534                      drm_is_render_client(file_priv)))
 535                 return -EACCES;
 536
 537         return 0;
 538 }
 539 EXPORT_SYMBOL(drm_ioctl_permit);
 540
 541 #define DRM_IOCTL_DEF(ioctl, _func, _flags)     \
 542         [DRM_IOCTL_NR(ioctl)] = {               \
 543                 .cmd = ioctl,                   \
 544                 .func = _func,                  \
 545                 .flags = _flags,                \
 546                 .name = #ioctl                  \
 547         }
 548
 549 /* Ioctl table */
 550 static const struct drm_ioctl_desc drm_ioctls[] = {
 551         DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version,
 552                       DRM_UNLOCKED|DRM_RENDER_ALLOW),
 553         DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, DRM_UNLOCKED),
 554         DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, DRM_UNLOCKED),
 555         DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
 556         DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, DRM_UNLOCKED),
 557         DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED),
 558         DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),
 559         DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED|DRM_RENDER_ALLOW),
 560         DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, DRM_UNLOCKED),
 561         DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_UNLOCKED | DRM_MASTER),
 562
 563         DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 564         DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 565         DRM_IOCTL_DEF(DRM_IOCTL_UNBLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 566         DRM_IOCTL_DEF(DRM_IOCTL_AUTH_MAGIC, drm_authmagic, DRM_AUTH|DRM_UNLOCKED|DRM_MASTER),
 567
 568         DRM_IOCTL_DEF(DRM_IOCTL_ADD_MAP, drm_legacy_addmap_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 569         DRM_IOCTL_DEF(DRM_IOCTL_RM_MAP, drm_legacy_rmmap_ioctl, DRM_AUTH),
 570
 571         DRM_IOCTL_DEF(DRM_IOCTL_SET_SAREA_CTX, drm_legacy_setsareactx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 572         DRM_IOCTL_DEF(DRM_IOCTL_GET_SAREA_CTX, drm_legacy_getsareactx, DRM_AUTH),
 573
 574         DRM_IOCTL_DEF(DRM_IOCTL_SET_MASTER, drm_setmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
 575         DRM_IOCTL_DEF(DRM_IOCTL_DROP_MASTER, drm_dropmaster_ioctl, DRM_UNLOCKED|DRM_ROOT_ONLY),
 576
 577         DRM_IOCTL_DEF(DRM_IOCTL_ADD_CTX, drm_legacy_addctx, DRM_AUTH|DRM_ROOT_ONLY),
 578         DRM_IOCTL_DEF(DRM_IOCTL_RM_CTX, drm_legacy_rmctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 579         DRM_IOCTL_DEF(DRM_IOCTL_MOD_CTX, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 580         DRM_IOCTL_DEF(DRM_IOCTL_GET_CTX, drm_legacy_getctx, DRM_AUTH),
 581         DRM_IOCTL_DEF(DRM_IOCTL_SWITCH_CTX, drm_legacy_switchctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 582         DRM_IOCTL_DEF(DRM_IOCTL_NEW_CTX, drm_legacy_newctx, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 583         DRM_IOCTL_DEF(DRM_IOCTL_RES_CTX, drm_legacy_resctx, DRM_AUTH),
 584
 585         DRM_IOCTL_DEF(DRM_IOCTL_ADD_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 586         DRM_IOCTL_DEF(DRM_IOCTL_RM_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 587
 588         DRM_IOCTL_DEF(DRM_IOCTL_LOCK, drm_legacy_lock, DRM_AUTH),
 589         DRM_IOCTL_DEF(DRM_IOCTL_UNLOCK, drm_legacy_unlock, DRM_AUTH),
 590
 591         DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),
 592
 593         DRM_IOCTL_DEF(DRM_IOCTL_ADD_BUFS, drm_legacy_addbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 594         DRM_IOCTL_DEF(DRM_IOCTL_MARK_BUFS, drm_legacy_markbufs, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 595         DRM_IOCTL_DEF(DRM_IOCTL_INFO_BUFS, drm_legacy_infobufs, DRM_AUTH),
 596         DRM_IOCTL_DEF(DRM_IOCTL_MAP_BUFS, drm_legacy_mapbufs, DRM_AUTH),
 597         DRM_IOCTL_DEF(DRM_IOCTL_FREE_BUFS, drm_legacy_freebufs, DRM_AUTH),
 598         DRM_IOCTL_DEF(DRM_IOCTL_DMA, drm_legacy_dma_ioctl, DRM_AUTH),
 599
 600         DRM_IOCTL_DEF(DRM_IOCTL_CONTROL, drm_legacy_irq_control, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 601
 602 #if IS_ENABLED(CONFIG_AGP)
 603         DRM_IOCTL_DEF(DRM_IOCTL_AGP_ACQUIRE, drm_agp_acquire_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 604         DRM_IOCTL_DEF(DRM_IOCTL_AGP_RELEASE, drm_agp_release_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 605         DRM_IOCTL_DEF(DRM_IOCTL_AGP_ENABLE, drm_agp_enable_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 606         DRM_IOCTL_DEF(DRM_IOCTL_AGP_INFO, drm_agp_info_ioctl, DRM_AUTH),
 607         DRM_IOCTL_DEF(DRM_IOCTL_AGP_ALLOC, drm_agp_alloc_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 608         DRM_IOCTL_DEF(DRM_IOCTL_AGP_FREE, drm_agp_free_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 609         DRM_IOCTL_DEF(DRM_IOCTL_AGP_BIND, drm_agp_bind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 610         DRM_IOCTL_DEF(DRM_IOCTL_AGP_UNBIND, drm_agp_unbind_ioctl, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 611 #endif
 612
 613         DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 614         DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 615
 616         DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, DRM_UNLOCKED),
 617
 618         DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_legacy_modeset_ctl_ioctl, 0),
 619
 620         DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
 621
 622         DRM_IOCTL_DEF(DRM_IOCTL_GEM_CLOSE, drm_gem_close_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
 623         DRM_IOCTL_DEF(DRM_IOCTL_GEM_FLINK, drm_gem_flink_ioctl, DRM_AUTH|DRM_UNLOCKED),
 624         DRM_IOCTL_DEF(DRM_IOCTL_GEM_OPEN, drm_gem_open_ioctl, DRM_AUTH|DRM_UNLOCKED),
 625
 626         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETRESOURCES, drm_mode_getresources, DRM_UNLOCKED),
 627
 628         DRM_IOCTL_DEF(DRM_IOCTL_PRIME_HANDLE_TO_FD, drm_prime_handle_to_fd_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
 629         DRM_IOCTL_DEF(DRM_IOCTL_PRIME_FD_TO_HANDLE, drm_prime_fd_to_handle_ioctl, DRM_AUTH|DRM_UNLOCKED|DRM_RENDER_ALLOW),
 630
 631         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANERESOURCES, drm_mode_getplane_res, DRM_UNLOCKED),
 632         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCRTC, drm_mode_getcrtc, DRM_UNLOCKED),
 633         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETCRTC, drm_mode_setcrtc, DRM_MASTER|DRM_UNLOCKED),
 634         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPLANE, drm_mode_getplane, DRM_UNLOCKED),
 635         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPLANE, drm_mode_setplane, DRM_MASTER|DRM_UNLOCKED),
 636         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR, drm_mode_cursor_ioctl, DRM_MASTER|DRM_UNLOCKED),
 637         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETGAMMA, drm_mode_gamma_get_ioctl, DRM_UNLOCKED),
 638         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETGAMMA, drm_mode_gamma_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
 639         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETENCODER, drm_mode_getencoder, DRM_UNLOCKED),
 640         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETCONNECTOR, drm_mode_getconnector, DRM_UNLOCKED),
 641         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATTACHMODE, drm_noop, DRM_MASTER|DRM_UNLOCKED),
 642         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DETACHMODE, drm_noop, DRM_MASTER|DRM_UNLOCKED),
 643         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPERTY, drm_mode_getproperty_ioctl, DRM_UNLOCKED),
 644         DRM_IOCTL_DEF(DRM_IOCTL_MODE_SETPROPERTY, drm_connector_property_set_ioctl, DRM_MASTER|DRM_UNLOCKED),
 645         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_UNLOCKED),
 646         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_UNLOCKED),
 647         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb_ioctl, DRM_UNLOCKED),
 648         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_UNLOCKED),
 649         DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb_ioctl, DRM_UNLOCKED),
 650         DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_UNLOCKED),
 651         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_UNLOCKED),
 652         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_DUMB, drm_mode_create_dumb_ioctl, DRM_UNLOCKED),
 653         DRM_IOCTL_DEF(DRM_IOCTL_MODE_MAP_DUMB, drm_mode_mmap_dumb_ioctl, DRM_UNLOCKED),
 654         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROY_DUMB, drm_mode_destroy_dumb_ioctl, DRM_UNLOCKED),
 655         DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_GETPROPERTIES, drm_mode_obj_get_properties_ioctl, DRM_UNLOCKED),
 656         DRM_IOCTL_DEF(DRM_IOCTL_MODE_OBJ_SETPROPERTY, drm_mode_obj_set_property_ioctl, DRM_MASTER|DRM_UNLOCKED),
 657         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CURSOR2, drm_mode_cursor2_ioctl, DRM_MASTER|DRM_UNLOCKED),
 658         DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER|DRM_UNLOCKED),
 659         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, DRM_UNLOCKED),
 660         DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, DRM_UNLOCKED),
 661
 662         DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_CREATE, drm_syncobj_create_ioctl,
 663                       DRM_UNLOCKED|DRM_RENDER_ALLOW),
 664         DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_DESTROY, drm_syncobj_destroy_ioctl,
 665                       DRM_UNLOCKED|DRM_RENDER_ALLOW),
 666         DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, drm_syncobj_handle_to_fd_ioctl,
 667                       DRM_UNLOCKED|DRM_RENDER_ALLOW),
 668         DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, drm_syncobj_fd_to_handle_ioctl,
 669                       DRM_UNLOCKED|DRM_RENDER_ALLOW),
 670         DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl,
 671                       DRM_UNLOCKED|DRM_RENDER_ALLOW),
 672         DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl,
 673                       DRM_UNLOCKED|DRM_RENDER_ALLOW),
 674         DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl,
 675                       DRM_UNLOCKED|DRM_RENDER_ALLOW),
 676         DRM_IOCTL_DEF(DRM_IOCTL_CRTC_GET_SEQUENCE, drm_crtc_get_sequence_ioctl, DRM_UNLOCKED),
 677         DRM_IOCTL_DEF(DRM_IOCTL_CRTC_QUEUE_SEQUENCE, drm_crtc_queue_sequence_ioctl, DRM_UNLOCKED),
 678         DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATE_LEASE, drm_mode_create_lease_ioctl, DRM_MASTER|DRM_UNLOCKED),
 679         DRM_IOCTL_DEF(DRM_IOCTL_MODE_LIST_LESSEES, drm_mode_list_lessees_ioctl, DRM_MASTER|DRM_UNLOCKED),
 680         DRM_IOCTL_DEF(DRM_IOCTL_MODE_GET_LEASE, drm_mode_get_lease_ioctl, DRM_MASTER|DRM_UNLOCKED),
 681         DRM_IOCTL_DEF(DRM_IOCTL_MODE_REVOKE_LEASE, drm_mode_revoke_lease_ioctl, DRM_MASTER|DRM_UNLOCKED),
 682 };
 683
 684 #define DRM_CORE_IOCTL_COUNT    ARRAY_SIZE( drm_ioctls )
 685
 686 /**
 687  * DOC: driver specific ioctls
 688  *
 689  * First things first, driver private IOCTLs should only be needed for drivers
 690  * supporting rendering. Kernel modesetting is all standardized, and extended
 691  * through properties. There are a few exceptions in some existing drivers,
 692  * which define IOCTL for use by the display DRM master, but they all predate
 693  * properties.
 694  *
 695  * Now if you do have a render driver you always have to support it through
 696  * driver private properties. There's a few steps needed to wire all the things
 697  * up.
 698  *
 699  * First you need to define the structure for your IOCTL in your driver private
 700  * UAPI header in ``include/uapi/drm/my_driver_drm.h``::
 701  *
 702  *     struct my_driver_operation {
 703  *             u32 some_thing;
 704  *             u32 another_thing;
 705  *     };
 706  *
 707  * Please make sure that you follow all the best practices from
 708  * ``Documentation/ioctl/botching-up-ioctls.txt``. Note that drm_ioctl()
 709  * automatically zero-extends structures, hence make sure you can add more stuff
 710  * at the end, i.e. don't put a variable sized array there.
 711  *
 712  * Then you need to define your IOCTL number, using one of DRM_IO(), DRM_IOR(),
 713  * DRM_IOW() or DRM_IOWR(). It must start with the DRM_IOCTL\_ prefix::
 714  *
 715  *     ##define DRM_IOCTL_MY_DRIVER_OPERATION \
 716  *         DRM_IOW(DRM_COMMAND_BASE, struct my_driver_operation)
 717  *
 718  * DRM driver private IOCTL must be in the range from DRM_COMMAND_BASE to
 719  * DRM_COMMAND_END. Finally you need an array of &struct drm_ioctl_desc to wire
 720  * up the handlers and set the access rights::
 721  *
 722  *     static const struct drm_ioctl_desc my_driver_ioctls[] = {
 723  *         DRM_IOCTL_DEF_DRV(MY_DRIVER_OPERATION, my_driver_operation,
 724  *                 DRM_AUTH|DRM_RENDER_ALLOW),
 725  *     };
 726  *
 727  * And then assign this to the &drm_driver.ioctls field in your driver
 728  * structure.
 729  *
 730  * See the separate chapter on :ref:`file operations<drm_driver_fops>` for how
 731  * the driver-specific IOCTLs are wired up.
 732  */
 733
 734 long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata,
 735                       u32 flags)
 736 {
 737         struct drm_file *file_priv = file->private_data;
 738         struct drm_device *dev = file_priv->minor->dev;
 739         int retcode;
 740
 741         if (drm_dev_is_unplugged(dev))
 742                 return -ENODEV;
 743
 744         retcode = drm_ioctl_permit(flags, file_priv);
 745         if (unlikely(retcode))
 746                 return retcode;
 747
 748         /* Enforce sane locking for modern driver ioctls. */
 749         if (!drm_core_check_feature(dev, DRIVER_LEGACY) ||
 750             (flags & DRM_UNLOCKED))
 751                 retcode = func(dev, kdata, file_priv);
 752         else {
 753                 mutex_lock(&drm_global_mutex);
 754                 retcode = func(dev, kdata, file_priv);
 755                 mutex_unlock(&drm_global_mutex);
 756         }
 757         return retcode;
 758 }
 759 EXPORT_SYMBOL(drm_ioctl_kernel);
 760
 761 /**
 762  * drm_ioctl - ioctl callback implementation for DRM drivers
 763  * @filp: file this ioctl is called on
 764  * @cmd: ioctl cmd number
 765  * @arg: user argument
 766  *
 767  * Looks up the ioctl function in the DRM core and the driver dispatch table,
 768  * stored in &drm_driver.ioctls. It checks for necessary permission by calling
 769  * drm_ioctl_permit(), and dispatches to the respective function.
 770  *
 771  * Returns:
 772  * Zero on success, negative error code on failure.
 773  */
 774 long drm_ioctl(struct file *filp,
 775               unsigned int cmd, unsigned long arg)
 776 {
 777         struct drm_file *file_priv = filp->private_data;
 778         struct drm_device *dev;
 779         const struct drm_ioctl_desc *ioctl = NULL;
 780         drm_ioctl_t *func;
 781         unsigned int nr = DRM_IOCTL_NR(cmd);
 782         int retcode = -EINVAL;
 783         char stack_kdata[128];
 784         char *kdata = NULL;
 785         unsigned int in_size, out_size, drv_size, ksize;
 786         bool is_driver_ioctl;
 787
 788         dev = file_priv->minor->dev;
 789
 790         if (drm_dev_is_unplugged(dev))
 791                 return -ENODEV;
 792
 793         is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
 794
 795         if (is_driver_ioctl) {
 796                 /* driver ioctl */
 797                 if (nr - DRM_COMMAND_BASE >= dev->driver->num_ioctls)
 798                         goto err_i1;
 799                 ioctl = &dev->driver->ioctls[nr - DRM_COMMAND_BASE];
 800         } else {
 801                 /* core ioctl */
 802                 if (nr >= DRM_CORE_IOCTL_COUNT)
 803                         goto err_i1;
 804                 ioctl = &drm_ioctls[nr];
 805         }
 806
 807         drv_size = _IOC_SIZE(ioctl->cmd);
 808         out_size = in_size = _IOC_SIZE(cmd);
 809         if ((cmd & ioctl->cmd & IOC_IN) == 0)
 810                 in_size = 0;
 811         if ((cmd & ioctl->cmd & IOC_OUT) == 0)
 812                 out_size = 0;
 813         ksize = max(max(in_size, out_size), drv_size);
 814
 815         DRM_DEBUG("pid=%d, dev=0x%lx, auth=%d, %s\n",
 816                   task_pid_nr(current),
 817                   (long)old_encode_dev(file_priv->minor->kdev->devt),
 818                   file_priv->authenticated, ioctl->name);
 819
 820         /* Do not trust userspace, use our own definition */
 821         func = ioctl->func;
 822
 823         if (unlikely(!func)) {
 824                 DRM_DEBUG("no function\n");
 825                 retcode = -EINVAL;
 826                 goto err_i1;
 827         }
 828
 829         if (ksize <= sizeof(stack_kdata)) {
 830                 kdata = stack_kdata;
 831         } else {
 832                 kdata = kmalloc(ksize, GFP_KERNEL);
 833                 if (!kdata) {
 834                         retcode = -ENOMEM;
 835                         goto err_i1;
 836                 }
 837         }
 838
 839         if (copy_from_user(kdata, (void __user *)arg, in_size) != 0) {
 840                 retcode = -EFAULT;
 841                 goto err_i1;
 842         }
 843
 844         if (ksize > in_size)
 845                 memset(kdata + in_size, 0, ksize - in_size);
 846
 847         retcode = drm_ioctl_kernel(filp, func, kdata, ioctl->flags);
 848         if (copy_to_user((void __user *)arg, kdata, out_size) != 0)
 849                 retcode = -EFAULT;
 850
 851       err_i1:
 852         if (!ioctl)
 853                 DRM_DEBUG("invalid ioctl: pid=%d, dev=0x%lx, auth=%d, cmd=0x%02x, nr=0x%02x\n",
 854                           task_pid_nr(current),
 855                           (long)old_encode_dev(file_priv->minor->kdev->devt),
 856                           file_priv->authenticated, cmd, nr);
 857
 858         if (kdata != stack_kdata)
 859                 kfree(kdata);
 860         if (retcode)
 861                 DRM_DEBUG("pid=%d, ret = %d\n", task_pid_nr(current), retcode);
 862         return retcode;
 863 }
 864 EXPORT_SYMBOL(drm_ioctl);
 865
 866 /**
 867  * drm_ioctl_flags - Check for core ioctl and return ioctl permission flags
 868  * @nr: ioctl number
 869  * @flags: where to return the ioctl permission flags
 870  *
 871  * This ioctl is only used by the vmwgfx driver to augment the access checks
 872  * done by the drm core and insofar a pretty decent layering violation. This
 873  * shouldn't be used by any drivers.
 874  *
 875  * Returns:
 876  * True if the @nr corresponds to a DRM core ioctl number, false otherwise.
 877  */
 878 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags)
 879 {
 880         if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END)
 881                 return false;
 882
 883         if (nr >= DRM_CORE_IOCTL_COUNT)
 884                 return false;
 885
 886         *flags = drm_ioctls[nr].flags;
 887         return true;
 888 }
 889 EXPORT_SYMBOL(drm_ioctl_flags);