drivers/infiniband/core/uverbs_uapi.c

   1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
   2 /*
   3  * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.
   4  */
   5 #include <rdma/uverbs_ioctl.h>
   6 #include <rdma/rdma_user_ioctl.h>
   7 #include <linux/bitops.h>
   8 #include "rdma_core.h"
   9 #include "uverbs.h"
  10
  11 static int ib_uverbs_notsupp(struct uverbs_attr_bundle *attrs)
  12 {
  13         return -EOPNOTSUPP;
  14 }
  15
  16 static void *uapi_add_elm(struct uverbs_api *uapi, u32 key, size_t alloc_size)
  17 {
  18         void *elm;
  19         int rc;
  20
  21         if (key == UVERBS_API_KEY_ERR)
  22                 return ERR_PTR(-EOVERFLOW);
  23
  24         elm = kzalloc(alloc_size, GFP_KERNEL);
  25         if (!elm)
  26                 return ERR_PTR(-ENOMEM);
  27         rc = radix_tree_insert(&uapi->radix, key, elm);
  28         if (rc) {
  29                 kfree(elm);
  30                 return ERR_PTR(rc);
  31         }
  32
  33         return elm;
  34 }
  35
  36 static void *uapi_add_get_elm(struct uverbs_api *uapi, u32 key,
  37                               size_t alloc_size, bool *exists)
  38 {
  39         void *elm;
  40
  41         elm = uapi_add_elm(uapi, key, alloc_size);
  42         if (!IS_ERR(elm)) {
  43                 *exists = false;
  44                 return elm;
  45         }
  46
  47         if (elm != ERR_PTR(-EEXIST))
  48                 return elm;
  49
  50         elm = radix_tree_lookup(&uapi->radix, key);
  51         if (WARN_ON(!elm))
  52                 return ERR_PTR(-EINVAL);
  53         *exists = true;
  54         return elm;
  55 }
  56
  57 static int uapi_create_write(struct uverbs_api *uapi,
  58                              struct ib_device *ibdev,
  59                              const struct uapi_definition *def,
  60                              u32 obj_key,
  61                              u32 *cur_method_key)
  62 {
  63         struct uverbs_api_write_method *method_elm;
  64         u32 method_key = obj_key;
  65         bool exists;
  66
  67         if (def->write.is_ex)
  68                 method_key |= uapi_key_write_ex_method(def->write.command_num);
  69         else
  70                 method_key |= uapi_key_write_method(def->write.command_num);
  71
  72         method_elm = uapi_add_get_elm(uapi, method_key, sizeof(*method_elm),
  73                                       &exists);
  74         if (IS_ERR(method_elm))
  75                 return PTR_ERR(method_elm);
  76
  77         if (WARN_ON(exists && (def->write.is_ex != method_elm->is_ex)))
  78                 return -EINVAL;
  79
  80         method_elm->is_ex = def->write.is_ex;
  81         method_elm->handler = def->func_write;
  82         if (def->write.is_ex)
  83                 method_elm->disabled = !(ibdev->uverbs_ex_cmd_mask &
  84                                          BIT_ULL(def->write.command_num));
  85         else
  86                 method_elm->disabled = !(ibdev->uverbs_cmd_mask &
  87                                          BIT_ULL(def->write.command_num));
  88
  89         if (!def->write.is_ex && def->func_write) {
  90                 method_elm->has_udata = def->write.has_udata;
  91                 method_elm->has_resp = def->write.has_resp;
  92                 method_elm->req_size = def->write.req_size;
  93                 method_elm->resp_size = def->write.resp_size;
  94         }
  95
  96         *cur_method_key = method_key;
  97         return 0;
  98 }
  99
 100 static int uapi_merge_method(struct uverbs_api *uapi,
 101                              struct uverbs_api_object *obj_elm, u32 obj_key,
 102                              const struct uverbs_method_def *method,
 103                              bool is_driver)
 104 {
 105         u32 method_key = obj_key | uapi_key_ioctl_method(method->id);
 106         struct uverbs_api_ioctl_method *method_elm;
 107         unsigned int i;
 108         bool exists;
 109
 110         if (!method->attrs)
 111                 return 0;
 112
 113         method_elm = uapi_add_get_elm(uapi, method_key, sizeof(*method_elm),
 114                                       &exists);
 115         if (IS_ERR(method_elm))
 116                 return PTR_ERR(method_elm);
 117         if (exists) {
 118                 /*
 119                  * This occurs when a driver uses ADD_UVERBS_ATTRIBUTES_SIMPLE
 120                  */
 121                 if (WARN_ON(method->handler))
 122                         return -EINVAL;
 123         } else {
 124                 WARN_ON(!method->handler);
 125                 rcu_assign_pointer(method_elm->handler, method->handler);
 126                 if (method->handler != uverbs_destroy_def_handler)
 127                         method_elm->driver_method = is_driver;
 128         }
 129
 130         for (i = 0; i != method->num_attrs; i++) {
 131                 const struct uverbs_attr_def *attr = (*method->attrs)[i];
 132                 struct uverbs_api_attr *attr_slot;
 133
 134                 if (!attr)
 135                         continue;
 136
 137                 /*
 138                  * ENUM_IN contains the 'ids' pointer to the driver's .rodata,
 139                  * so if it is specified by a driver then it always makes this
 140                  * into a driver method.
 141                  */
 142                 if (attr->attr.type == UVERBS_ATTR_TYPE_ENUM_IN)
 143                         method_elm->driver_method |= is_driver;
 144
 145                 /*
 146                  * Like other uobject based things we only support a single
 147                  * uobject being NEW'd or DESTROY'd
 148                  */
 149                 if (attr->attr.type == UVERBS_ATTR_TYPE_IDRS_ARRAY) {
 150                         u8 access = attr->attr.u2.objs_arr.access;
 151
 152                         if (WARN_ON(access == UVERBS_ACCESS_NEW ||
 153                                     access == UVERBS_ACCESS_DESTROY))
 154                                 return -EINVAL;
 155                 }
 156
 157                 attr_slot =
 158                         uapi_add_elm(uapi, method_key | uapi_key_attr(attr->id),
 159                                      sizeof(*attr_slot));
 160                 /* Attributes are not allowed to be modified by drivers */
 161                 if (IS_ERR(attr_slot))
 162                         return PTR_ERR(attr_slot);
 163
 164                 attr_slot->spec = attr->attr;
 165         }
 166
 167         return 0;
 168 }
 169
 170 static int uapi_merge_obj_tree(struct uverbs_api *uapi,
 171                                const struct uverbs_object_def *obj,
 172                                bool is_driver)
 173 {
 174         struct uverbs_api_object *obj_elm;
 175         unsigned int i;
 176         u32 obj_key;
 177         bool exists;
 178         int rc;
 179
 180         obj_key = uapi_key_obj(obj->id);
 181         obj_elm = uapi_add_get_elm(uapi, obj_key, sizeof(*obj_elm), &exists);
 182         if (IS_ERR(obj_elm))
 183                 return PTR_ERR(obj_elm);
 184
 185         if (obj->type_attrs) {
 186                 if (WARN_ON(obj_elm->type_attrs))
 187                         return -EINVAL;
 188
 189                 obj_elm->id = obj->id;
 190                 obj_elm->type_attrs = obj->type_attrs;
 191                 obj_elm->type_class = obj->type_attrs->type_class;
 192                 /*
 193                  * Today drivers are only permitted to use idr_class and
 194                  * fd_class types. We can revoke the IDR types during
 195                  * disassociation, and the FD types require the driver to use
 196                  * struct file_operations.owner to prevent the driver module
 197                  * code from unloading while the file is open. This provides
 198                  * enough safety that uverbs_uobject_fd_release() will
 199                  * continue to work.  Drivers using FD are responsible to
 200                  * handle disassociation of the device on their own.
 201                  */
 202                 if (WARN_ON(is_driver &&
 203                             obj->type_attrs->type_class != &uverbs_idr_class &&
 204                             obj->type_attrs->type_class != &uverbs_fd_class))
 205                         return -EINVAL;
 206         }
 207
 208         if (!obj->methods)
 209                 return 0;
 210
 211         for (i = 0; i != obj->num_methods; i++) {
 212                 const struct uverbs_method_def *method = (*obj->methods)[i];
 213
 214                 if (!method)
 215                         continue;
 216
 217                 rc = uapi_merge_method(uapi, obj_elm, obj_key, method,
 218                                        is_driver);
 219                 if (rc)
 220                         return rc;
 221         }
 222
 223         return 0;
 224 }
 225
 226 static int uapi_disable_elm(struct uverbs_api *uapi,
 227                             const struct uapi_definition *def,
 228                             u32 obj_key,
 229                             u32 method_key)
 230 {
 231         bool exists;
 232
 233         if (def->scope == UAPI_SCOPE_OBJECT) {
 234                 struct uverbs_api_object *obj_elm;
 235
 236                 obj_elm = uapi_add_get_elm(
 237                         uapi, obj_key, sizeof(*obj_elm), &exists);
 238                 if (IS_ERR(obj_elm))
 239                         return PTR_ERR(obj_elm);
 240                 obj_elm->disabled = 1;
 241                 return 0;
 242         }
 243
 244         if (def->scope == UAPI_SCOPE_METHOD &&
 245             uapi_key_is_ioctl_method(method_key)) {
 246                 struct uverbs_api_ioctl_method *method_elm;
 247
 248                 method_elm = uapi_add_get_elm(uapi, method_key,
 249                                               sizeof(*method_elm), &exists);
 250                 if (IS_ERR(method_elm))
 251                         return PTR_ERR(method_elm);
 252                 method_elm->disabled = 1;
 253                 return 0;
 254         }
 255
 256         if (def->scope == UAPI_SCOPE_METHOD &&
 257             (uapi_key_is_write_method(method_key) ||
 258              uapi_key_is_write_ex_method(method_key))) {
 259                 struct uverbs_api_write_method *write_elm;
 260
 261                 write_elm = uapi_add_get_elm(uapi, method_key,
 262                                              sizeof(*write_elm), &exists);
 263                 if (IS_ERR(write_elm))
 264                         return PTR_ERR(write_elm);
 265                 write_elm->disabled = 1;
 266                 return 0;
 267         }
 268
 269         WARN_ON(true);
 270         return -EINVAL;
 271 }
 272
 273 static int uapi_merge_def(struct uverbs_api *uapi, struct ib_device *ibdev,
 274                           const struct uapi_definition *def_list,
 275                           bool is_driver)
 276 {
 277         const struct uapi_definition *def = def_list;
 278         u32 cur_obj_key = UVERBS_API_KEY_ERR;
 279         u32 cur_method_key = UVERBS_API_KEY_ERR;
 280         bool exists;
 281         int rc;
 282
 283         if (!def_list)
 284                 return 0;
 285
 286         for (;; def++) {
 287                 switch ((enum uapi_definition_kind)def->kind) {
 288                 case UAPI_DEF_CHAIN:
 289                         rc = uapi_merge_def(uapi, ibdev, def->chain, is_driver);
 290                         if (rc)
 291                                 return rc;
 292                         continue;
 293
 294                 case UAPI_DEF_CHAIN_OBJ_TREE:
 295                         if (WARN_ON(def->object_start.object_id !=
 296                                     def->chain_obj_tree->id))
 297                                 return -EINVAL;
 298
 299                         cur_obj_key = uapi_key_obj(def->object_start.object_id);
 300                         rc = uapi_merge_obj_tree(uapi, def->chain_obj_tree,
 301                                                  is_driver);
 302                         if (rc)
 303                                 return rc;
 304                         continue;
 305
 306                 case UAPI_DEF_END:
 307                         return 0;
 308
 309                 case UAPI_DEF_IS_SUPPORTED_DEV_FN: {
 310                         void **ibdev_fn =
 311                                 (void *)(&ibdev->ops) + def->needs_fn_offset;
 312
 313                         if (*ibdev_fn)
 314                                 continue;
 315                         rc = uapi_disable_elm(
 316                                 uapi, def, cur_obj_key, cur_method_key);
 317                         if (rc)
 318                                 return rc;
 319                         continue;
 320                 }
 321
 322                 case UAPI_DEF_IS_SUPPORTED_FUNC:
 323                         if (def->func_is_supported(ibdev))
 324                                 continue;
 325                         rc = uapi_disable_elm(
 326                                 uapi, def, cur_obj_key, cur_method_key);
 327                         if (rc)
 328                                 return rc;
 329                         continue;
 330
 331                 case UAPI_DEF_OBJECT_START: {
 332                         struct uverbs_api_object *obj_elm;
 333
 334                         cur_obj_key = uapi_key_obj(def->object_start.object_id);
 335                         obj_elm = uapi_add_get_elm(uapi, cur_obj_key,
 336                                                    sizeof(*obj_elm), &exists);
 337                         if (IS_ERR(obj_elm))
 338                                 return PTR_ERR(obj_elm);
 339                         continue;
 340                 }
 341
 342                 case UAPI_DEF_WRITE:
 343                         rc = uapi_create_write(
 344                                 uapi, ibdev, def, cur_obj_key, &cur_method_key);
 345                         if (rc)
 346                                 return rc;
 347                         continue;
 348                 }
 349                 WARN_ON(true);
 350                 return -EINVAL;
 351         }
 352 }
 353
 354 static int
 355 uapi_finalize_ioctl_method(struct uverbs_api *uapi,
 356                            struct uverbs_api_ioctl_method *method_elm,
 357                            u32 method_key)
 358 {
 359         struct radix_tree_iter iter;
 360         unsigned int num_attrs = 0;
 361         unsigned int max_bkey = 0;
 362         bool single_uobj = false;
 363         void __rcu **slot;
 364
 365         method_elm->destroy_bkey = UVERBS_API_ATTR_BKEY_LEN;
 366         radix_tree_for_each_slot (slot, &uapi->radix, &iter,
 367                                   uapi_key_attrs_start(method_key)) {
 368                 struct uverbs_api_attr *elm =
 369                         rcu_dereference_protected(*slot, true);
 370                 u32 attr_key = iter.index & UVERBS_API_ATTR_KEY_MASK;
 371                 u32 attr_bkey = uapi_bkey_attr(attr_key);
 372                 u8 type = elm->spec.type;
 373
 374                 if (uapi_key_attr_to_ioctl_method(iter.index) !=
 375                     uapi_key_attr_to_ioctl_method(method_key))
 376                         break;
 377
 378                 if (elm->spec.mandatory)
 379                         __set_bit(attr_bkey, method_elm->attr_mandatory);
 380
 381                 if (elm->spec.is_udata)
 382                         method_elm->has_udata = true;
 383
 384                 if (type == UVERBS_ATTR_TYPE_IDR ||
 385                     type == UVERBS_ATTR_TYPE_FD) {
 386                         u8 access = elm->spec.u.obj.access;
 387
 388                         /*
 389                          * Verbs specs may only have one NEW/DESTROY, we don't
 390                          * have the infrastructure to abort multiple NEW's or
 391                          * cope with multiple DESTROY failure.
 392                          */
 393                         if (access == UVERBS_ACCESS_NEW ||
 394                             access == UVERBS_ACCESS_DESTROY) {
 395                                 if (WARN_ON(single_uobj))
 396                                         return -EINVAL;
 397
 398                                 single_uobj = true;
 399                                 if (WARN_ON(!elm->spec.mandatory))
 400                                         return -EINVAL;
 401                         }
 402
 403                         if (access == UVERBS_ACCESS_DESTROY)
 404                                 method_elm->destroy_bkey = attr_bkey;
 405                 }
 406
 407                 max_bkey = max(max_bkey, attr_bkey);
 408                 num_attrs++;
 409         }
 410
 411         method_elm->key_bitmap_len = max_bkey + 1;
 412         WARN_ON(method_elm->key_bitmap_len > UVERBS_API_ATTR_BKEY_LEN);
 413
 414         uapi_compute_bundle_size(method_elm, num_attrs);
 415         return 0;
 416 }
 417
 418 static int uapi_finalize(struct uverbs_api *uapi)
 419 {
 420         const struct uverbs_api_write_method **data;
 421         unsigned long max_write_ex = 0;
 422         unsigned long max_write = 0;
 423         struct radix_tree_iter iter;
 424         void __rcu **slot;
 425         int rc;
 426         int i;
 427
 428         radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
 429                 struct uverbs_api_ioctl_method *method_elm =
 430                         rcu_dereference_protected(*slot, true);
 431
 432                 if (uapi_key_is_ioctl_method(iter.index)) {
 433                         rc = uapi_finalize_ioctl_method(uapi, method_elm,
 434                                                         iter.index);
 435                         if (rc)
 436                                 return rc;
 437                 }
 438
 439                 if (uapi_key_is_write_method(iter.index))
 440                         max_write = max(max_write,
 441                                         iter.index & UVERBS_API_ATTR_KEY_MASK);
 442                 if (uapi_key_is_write_ex_method(iter.index))
 443                         max_write_ex =
 444                                 max(max_write_ex,
 445                                     iter.index & UVERBS_API_ATTR_KEY_MASK);
 446         }
 447
 448         uapi->notsupp_method.handler = ib_uverbs_notsupp;
 449         uapi->num_write = max_write + 1;
 450         uapi->num_write_ex = max_write_ex + 1;
 451         data = kmalloc_array(uapi->num_write + uapi->num_write_ex,
 452                              sizeof(*uapi->write_methods), GFP_KERNEL);
 453         for (i = 0; i != uapi->num_write + uapi->num_write_ex; i++)
 454                 data[i] = &uapi->notsupp_method;
 455         uapi->write_methods = data;
 456         uapi->write_ex_methods = data + uapi->num_write;
 457
 458         radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
 459                 if (uapi_key_is_write_method(iter.index))
 460                         uapi->write_methods[iter.index &
 461                                             UVERBS_API_ATTR_KEY_MASK] =
 462                                 rcu_dereference_protected(*slot, true);
 463                 if (uapi_key_is_write_ex_method(iter.index))
 464                         uapi->write_ex_methods[iter.index &
 465                                                UVERBS_API_ATTR_KEY_MASK] =
 466                                 rcu_dereference_protected(*slot, true);
 467         }
 468
 469         return 0;
 470 }
 471
 472 static void uapi_remove_range(struct uverbs_api *uapi, u32 start, u32 last)
 473 {
 474         struct radix_tree_iter iter;
 475         void __rcu **slot;
 476
 477         radix_tree_for_each_slot (slot, &uapi->radix, &iter, start) {
 478                 if (iter.index > last)
 479                         return;
 480                 kfree(rcu_dereference_protected(*slot, true));
 481                 radix_tree_iter_delete(&uapi->radix, &iter, slot);
 482         }
 483 }
 484
 485 static void uapi_remove_object(struct uverbs_api *uapi, u32 obj_key)
 486 {
 487         uapi_remove_range(uapi, obj_key,
 488                           obj_key | UVERBS_API_METHOD_KEY_MASK |
 489                                   UVERBS_API_ATTR_KEY_MASK);
 490 }
 491
 492 static void uapi_remove_method(struct uverbs_api *uapi, u32 method_key)
 493 {
 494         uapi_remove_range(uapi, method_key,
 495                           method_key | UVERBS_API_ATTR_KEY_MASK);
 496 }
 497
 498
 499 static u32 uapi_get_obj_id(struct uverbs_attr_spec *spec)
 500 {
 501         if (spec->type == UVERBS_ATTR_TYPE_IDR ||
 502             spec->type == UVERBS_ATTR_TYPE_FD)
 503                 return spec->u.obj.obj_type;
 504         if (spec->type == UVERBS_ATTR_TYPE_IDRS_ARRAY)
 505                 return spec->u2.objs_arr.obj_type;
 506         return UVERBS_API_KEY_ERR;
 507 }
 508
 509 static void uapi_key_okay(u32 key)
 510 {
 511         unsigned int count = 0;
 512
 513         if (uapi_key_is_object(key))
 514                 count++;
 515         if (uapi_key_is_ioctl_method(key))
 516                 count++;
 517         if (uapi_key_is_write_method(key))
 518                 count++;
 519         if (uapi_key_is_write_ex_method(key))
 520                 count++;
 521         if (uapi_key_is_attr(key))
 522                 count++;
 523         WARN(count != 1, "Bad count %d key=%x", count, key);
 524 }
 525
 526 static void uapi_finalize_disable(struct uverbs_api *uapi)
 527 {
 528         struct radix_tree_iter iter;
 529         u32 starting_key = 0;
 530         bool scan_again = false;
 531         void __rcu **slot;
 532
 533 again:
 534         radix_tree_for_each_slot (slot, &uapi->radix, &iter, starting_key) {
 535                 uapi_key_okay(iter.index);
 536
 537                 if (uapi_key_is_object(iter.index)) {
 538                         struct uverbs_api_object *obj_elm =
 539                                 rcu_dereference_protected(*slot, true);
 540
 541                         if (obj_elm->disabled) {
 542                                 /* Have to check all the attrs again */
 543                                 scan_again = true;
 544                                 starting_key = iter.index;
 545                                 uapi_remove_object(uapi, iter.index);
 546                                 goto again;
 547                         }
 548                         continue;
 549                 }
 550
 551                 if (uapi_key_is_ioctl_method(iter.index)) {
 552                         struct uverbs_api_ioctl_method *method_elm =
 553                                 rcu_dereference_protected(*slot, true);
 554
 555                         if (method_elm->disabled) {
 556                                 starting_key = iter.index;
 557                                 uapi_remove_method(uapi, iter.index);
 558                                 goto again;
 559                         }
 560                         continue;
 561                 }
 562
 563                 if (uapi_key_is_write_method(iter.index) ||
 564                     uapi_key_is_write_ex_method(iter.index)) {
 565                         struct uverbs_api_write_method *method_elm =
 566                                 rcu_dereference_protected(*slot, true);
 567
 568                         if (method_elm->disabled) {
 569                                 kfree(method_elm);
 570                                 radix_tree_iter_delete(&uapi->radix, &iter, slot);
 571                         }
 572                         continue;
 573                 }
 574
 575                 if (uapi_key_is_attr(iter.index)) {
 576                         struct uverbs_api_attr *attr_elm =
 577                                 rcu_dereference_protected(*slot, true);
 578                         const struct uverbs_api_object *tmp_obj;
 579                         u32 obj_key;
 580
 581                         /*
 582                          * If the method has a mandatory object handle
 583                          * attribute which relies on an object which is not
 584                          * present then the entire method is uncallable.
 585                          */
 586                         if (!attr_elm->spec.mandatory)
 587                                 continue;
 588                         obj_key = uapi_get_obj_id(&attr_elm->spec);
 589                         if (obj_key == UVERBS_API_KEY_ERR)
 590                                 continue;
 591                         tmp_obj = uapi_get_object(uapi, obj_key);
 592                         if (IS_ERR(tmp_obj)) {
 593                                 if (PTR_ERR(tmp_obj) == -ENOMSG)
 594                                         continue;
 595                         } else {
 596                                 if (!tmp_obj->disabled)
 597                                         continue;
 598                         }
 599
 600                         starting_key = iter.index;
 601                         uapi_remove_method(
 602                                 uapi,
 603                                 iter.index & (UVERBS_API_OBJ_KEY_MASK |
 604                                               UVERBS_API_METHOD_KEY_MASK));
 605                         goto again;
 606                 }
 607
 608                 WARN_ON(false);
 609         }
 610
 611         if (!scan_again)
 612                 return;
 613         scan_again = false;
 614         starting_key = 0;
 615         goto again;
 616 }
 617
 618 void uverbs_destroy_api(struct uverbs_api *uapi)
 619 {
 620         if (!uapi)
 621                 return;
 622
 623         uapi_remove_range(uapi, 0, U32_MAX);
 624         kfree(uapi->write_methods);
 625         kfree(uapi);
 626 }
 627
 628 static const struct uapi_definition uverbs_core_api[] = {
 629         UAPI_DEF_CHAIN(uverbs_def_obj_async_fd),
 630         UAPI_DEF_CHAIN(uverbs_def_obj_counters),
 631         UAPI_DEF_CHAIN(uverbs_def_obj_cq),
 632         UAPI_DEF_CHAIN(uverbs_def_obj_device),
 633         UAPI_DEF_CHAIN(uverbs_def_obj_dm),
 634         UAPI_DEF_CHAIN(uverbs_def_obj_flow_action),
 635         UAPI_DEF_CHAIN(uverbs_def_obj_intf),
 636         UAPI_DEF_CHAIN(uverbs_def_obj_mr),
 637         UAPI_DEF_CHAIN(uverbs_def_write_intf),
 638         {},
 639 };
 640
 641 struct uverbs_api *uverbs_alloc_api(struct ib_device *ibdev)
 642 {
 643         struct uverbs_api *uapi;
 644         int rc;
 645
 646         uapi = kzalloc(sizeof(*uapi), GFP_KERNEL);
 647         if (!uapi)
 648                 return ERR_PTR(-ENOMEM);
 649
 650         INIT_RADIX_TREE(&uapi->radix, GFP_KERNEL);
 651         uapi->driver_id = ibdev->ops.driver_id;
 652
 653         rc = uapi_merge_def(uapi, ibdev, uverbs_core_api, false);
 654         if (rc)
 655                 goto err;
 656         rc = uapi_merge_def(uapi, ibdev, ibdev->driver_def, true);
 657         if (rc)
 658                 goto err;
 659
 660         uapi_finalize_disable(uapi);
 661         rc = uapi_finalize(uapi);
 662         if (rc)
 663                 goto err;
 664
 665         return uapi;
 666 err:
 667         if (rc != -ENOMEM)
 668                 dev_err(&ibdev->dev,
 669                         "Setup of uverbs_api failed, kernel parsing tree description is not valid (%d)??\n",
 670                         rc);
 671
 672         uverbs_destroy_api(uapi);
 673         return ERR_PTR(rc);
 674 }
 675
 676 /*
 677  * The pre version is done before destroying the HW objects, it only blocks
 678  * off method access. All methods that require the ib_dev or the module data
 679  * must test one of these assignments prior to continuing.
 680  */
 681 void uverbs_disassociate_api_pre(struct ib_uverbs_device *uverbs_dev)
 682 {
 683         struct uverbs_api *uapi = uverbs_dev->uapi;
 684         struct radix_tree_iter iter;
 685         void __rcu **slot;
 686
 687         rcu_assign_pointer(uverbs_dev->ib_dev, NULL);
 688
 689         radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
 690                 if (uapi_key_is_ioctl_method(iter.index)) {
 691                         struct uverbs_api_ioctl_method *method_elm =
 692                                 rcu_dereference_protected(*slot, true);
 693
 694                         if (method_elm->driver_method)
 695                                 rcu_assign_pointer(method_elm->handler, NULL);
 696                 }
 697         }
 698
 699         synchronize_srcu(&uverbs_dev->disassociate_srcu);
 700 }
 701
 702 /*
 703  * Called when a driver disassociates from the ib_uverbs_device. The
 704  * assumption is that the driver module will unload after. Replace everything
 705  * related to the driver with NULL as a safety measure.
 706  */
 707 void uverbs_disassociate_api(struct uverbs_api *uapi)
 708 {
 709         struct radix_tree_iter iter;
 710         void __rcu **slot;
 711
 712         radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
 713                 if (uapi_key_is_object(iter.index)) {
 714                         struct uverbs_api_object *object_elm =
 715                                 rcu_dereference_protected(*slot, true);
 716
 717                         /*
 718                          * Some type_attrs are in the driver module. We don't
 719                          * bother to keep track of which since there should be
 720                          * no use of this after disassociate.
 721                          */
 722                         object_elm->type_attrs = NULL;
 723                 } else if (uapi_key_is_attr(iter.index)) {
 724                         struct uverbs_api_attr *elm =
 725                                 rcu_dereference_protected(*slot, true);
 726
 727                         if (elm->spec.type == UVERBS_ATTR_TYPE_ENUM_IN)
 728                                 elm->spec.u2.enum_def.ids = NULL;
 729                 }
 730         }
 731 }