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_cmd_mask &
  84                                          BIT_ULL(def->write.command_num));
  85
  86         if (!def->write.is_ex && def->func_write) {
  87                 method_elm->has_udata = def->write.has_udata;
  88                 method_elm->has_resp = def->write.has_resp;
  89                 method_elm->req_size = def->write.req_size;
  90                 method_elm->resp_size = def->write.resp_size;
  91         }
  92
  93         *cur_method_key = method_key;
  94         return 0;
  95 }
  96
  97 static int uapi_merge_method(struct uverbs_api *uapi,
  98                              struct uverbs_api_object *obj_elm, u32 obj_key,
  99                              const struct uverbs_method_def *method,
 100                              bool is_driver)
 101 {
 102         u32 method_key = obj_key | uapi_key_ioctl_method(method->id);
 103         struct uverbs_api_ioctl_method *method_elm;
 104         unsigned int i;
 105         bool exists;
 106
 107         if (!method->attrs)
 108                 return 0;
 109
 110         method_elm = uapi_add_get_elm(uapi, method_key, sizeof(*method_elm),
 111                                       &exists);
 112         if (IS_ERR(method_elm))
 113                 return PTR_ERR(method_elm);
 114         if (exists) {
 115                 /*
 116                  * This occurs when a driver uses ADD_UVERBS_ATTRIBUTES_SIMPLE
 117                  */
 118                 if (WARN_ON(method->handler))
 119                         return -EINVAL;
 120         } else {
 121                 WARN_ON(!method->handler);
 122                 rcu_assign_pointer(method_elm->handler, method->handler);
 123                 if (method->handler != uverbs_destroy_def_handler)
 124                         method_elm->driver_method = is_driver;
 125         }
 126
 127         for (i = 0; i != method->num_attrs; i++) {
 128                 const struct uverbs_attr_def *attr = (*method->attrs)[i];
 129                 struct uverbs_api_attr *attr_slot;
 130
 131                 if (!attr)
 132                         continue;
 133
 134                 /*
 135                  * ENUM_IN contains the 'ids' pointer to the driver's .rodata,
 136                  * so if it is specified by a driver then it always makes this
 137                  * into a driver method.
 138                  */
 139                 if (attr->attr.type == UVERBS_ATTR_TYPE_ENUM_IN)
 140                         method_elm->driver_method |= is_driver;
 141
 142                 /*
 143                  * Like other uobject based things we only support a single
 144                  * uobject being NEW'd or DESTROY'd
 145                  */
 146                 if (attr->attr.type == UVERBS_ATTR_TYPE_IDRS_ARRAY) {
 147                         u8 access = attr->attr.u2.objs_arr.access;
 148
 149                         if (WARN_ON(access == UVERBS_ACCESS_NEW ||
 150                                     access == UVERBS_ACCESS_DESTROY))
 151                                 return -EINVAL;
 152                 }
 153
 154                 attr_slot =
 155                         uapi_add_elm(uapi, method_key | uapi_key_attr(attr->id),
 156                                      sizeof(*attr_slot));
 157                 /* Attributes are not allowed to be modified by drivers */
 158                 if (IS_ERR(attr_slot))
 159                         return PTR_ERR(attr_slot);
 160
 161                 attr_slot->spec = attr->attr;
 162         }
 163
 164         return 0;
 165 }
 166
 167 static int uapi_merge_obj_tree(struct uverbs_api *uapi,
 168                                const struct uverbs_object_def *obj,
 169                                bool is_driver)
 170 {
 171         struct uverbs_api_object *obj_elm;
 172         unsigned int i;
 173         u32 obj_key;
 174         bool exists;
 175         int rc;
 176
 177         obj_key = uapi_key_obj(obj->id);
 178         obj_elm = uapi_add_get_elm(uapi, obj_key, sizeof(*obj_elm), &exists);
 179         if (IS_ERR(obj_elm))
 180                 return PTR_ERR(obj_elm);
 181
 182         if (obj->type_attrs) {
 183                 if (WARN_ON(obj_elm->type_attrs))
 184                         return -EINVAL;
 185
 186                 obj_elm->id = obj->id;
 187                 obj_elm->type_attrs = obj->type_attrs;
 188                 obj_elm->type_class = obj->type_attrs->type_class;
 189                 /*
 190                  * Today drivers are only permitted to use idr_class and
 191                  * fd_class types. We can revoke the IDR types during
 192                  * disassociation, and the FD types require the driver to use
 193                  * struct file_operations.owner to prevent the driver module
 194                  * code from unloading while the file is open. This provides
 195                  * enough safety that uverbs_uobject_fd_release() will
 196                  * continue to work.  Drivers using FD are responsible to
 197                  * handle disassociation of the device on their own.
 198                  */
 199                 if (WARN_ON(is_driver &&
 200                             obj->type_attrs->type_class != &uverbs_idr_class &&
 201                             obj->type_attrs->type_class != &uverbs_fd_class))
 202                         return -EINVAL;
 203         }
 204
 205         if (!obj->methods)
 206                 return 0;
 207
 208         for (i = 0; i != obj->num_methods; i++) {
 209                 const struct uverbs_method_def *method = (*obj->methods)[i];
 210
 211                 if (!method)
 212                         continue;
 213
 214                 rc = uapi_merge_method(uapi, obj_elm, obj_key, method,
 215                                        is_driver);
 216                 if (rc)
 217                         return rc;
 218         }
 219
 220         return 0;
 221 }
 222
 223 static int uapi_disable_elm(struct uverbs_api *uapi,
 224                             const struct uapi_definition *def,
 225                             u32 obj_key,
 226                             u32 method_key)
 227 {
 228         bool exists;
 229
 230         if (def->scope == UAPI_SCOPE_OBJECT) {
 231                 struct uverbs_api_object *obj_elm;
 232
 233                 obj_elm = uapi_add_get_elm(
 234                         uapi, obj_key, sizeof(*obj_elm), &exists);
 235                 if (IS_ERR(obj_elm))
 236                         return PTR_ERR(obj_elm);
 237                 obj_elm->disabled = 1;
 238                 return 0;
 239         }
 240
 241         if (def->scope == UAPI_SCOPE_METHOD &&
 242             uapi_key_is_ioctl_method(method_key)) {
 243                 struct uverbs_api_ioctl_method *method_elm;
 244
 245                 method_elm = uapi_add_get_elm(uapi, method_key,
 246                                               sizeof(*method_elm), &exists);
 247                 if (IS_ERR(method_elm))
 248                         return PTR_ERR(method_elm);
 249                 method_elm->disabled = 1;
 250                 return 0;
 251         }
 252
 253         if (def->scope == UAPI_SCOPE_METHOD &&
 254             (uapi_key_is_write_method(method_key) ||
 255              uapi_key_is_write_ex_method(method_key))) {
 256                 struct uverbs_api_write_method *write_elm;
 257
 258                 write_elm = uapi_add_get_elm(uapi, method_key,
 259                                              sizeof(*write_elm), &exists);
 260                 if (IS_ERR(write_elm))
 261                         return PTR_ERR(write_elm);
 262                 write_elm->disabled = 1;
 263                 return 0;
 264         }
 265
 266         WARN_ON(true);
 267         return -EINVAL;
 268 }
 269
 270 static int uapi_merge_def(struct uverbs_api *uapi, struct ib_device *ibdev,
 271                           const struct uapi_definition *def_list,
 272                           bool is_driver)
 273 {
 274         const struct uapi_definition *def = def_list;
 275         u32 cur_obj_key = UVERBS_API_KEY_ERR;
 276         u32 cur_method_key = UVERBS_API_KEY_ERR;
 277         bool exists;
 278         int rc;
 279
 280         if (!def_list)
 281                 return 0;
 282
 283         for (;; def++) {
 284                 switch ((enum uapi_definition_kind)def->kind) {
 285                 case UAPI_DEF_CHAIN:
 286                         rc = uapi_merge_def(uapi, ibdev, def->chain, is_driver);
 287                         if (rc)
 288                                 return rc;
 289                         continue;
 290
 291                 case UAPI_DEF_CHAIN_OBJ_TREE:
 292                         if (WARN_ON(def->object_start.object_id !=
 293                                     def->chain_obj_tree->id))
 294                                 return -EINVAL;
 295
 296                         cur_obj_key = uapi_key_obj(def->object_start.object_id);
 297                         rc = uapi_merge_obj_tree(uapi, def->chain_obj_tree,
 298                                                  is_driver);
 299                         if (rc)
 300                                 return rc;
 301                         continue;
 302
 303                 case UAPI_DEF_END:
 304                         return 0;
 305
 306                 case UAPI_DEF_IS_SUPPORTED_DEV_FN: {
 307                         void **ibdev_fn =
 308                                 (void *)(&ibdev->ops) + def->needs_fn_offset;
 309
 310                         if (*ibdev_fn)
 311                                 continue;
 312                         rc = uapi_disable_elm(
 313                                 uapi, def, cur_obj_key, cur_method_key);
 314                         if (rc)
 315                                 return rc;
 316                         continue;
 317                 }
 318
 319                 case UAPI_DEF_IS_SUPPORTED_FUNC:
 320                         if (def->func_is_supported(ibdev))
 321                                 continue;
 322                         rc = uapi_disable_elm(
 323                                 uapi, def, cur_obj_key, cur_method_key);
 324                         if (rc)
 325                                 return rc;
 326                         continue;
 327
 328                 case UAPI_DEF_OBJECT_START: {
 329                         struct uverbs_api_object *obj_elm;
 330
 331                         cur_obj_key = uapi_key_obj(def->object_start.object_id);
 332                         obj_elm = uapi_add_get_elm(uapi, cur_obj_key,
 333                                                    sizeof(*obj_elm), &exists);
 334                         if (IS_ERR(obj_elm))
 335                                 return PTR_ERR(obj_elm);
 336                         continue;
 337                 }
 338
 339                 case UAPI_DEF_WRITE:
 340                         rc = uapi_create_write(
 341                                 uapi, ibdev, def, cur_obj_key, &cur_method_key);
 342                         if (rc)
 343                                 return rc;
 344                         continue;
 345                 }
 346                 WARN_ON(true);
 347                 return -EINVAL;
 348         }
 349 }
 350
 351 static int
 352 uapi_finalize_ioctl_method(struct uverbs_api *uapi,
 353                            struct uverbs_api_ioctl_method *method_elm,
 354                            u32 method_key)
 355 {
 356         struct radix_tree_iter iter;
 357         unsigned int num_attrs = 0;
 358         unsigned int max_bkey = 0;
 359         bool single_uobj = false;
 360         void __rcu **slot;
 361
 362         method_elm->destroy_bkey = UVERBS_API_ATTR_BKEY_LEN;
 363         radix_tree_for_each_slot (slot, &uapi->radix, &iter,
 364                                   uapi_key_attrs_start(method_key)) {
 365                 struct uverbs_api_attr *elm =
 366                         rcu_dereference_protected(*slot, true);
 367                 u32 attr_key = iter.index & UVERBS_API_ATTR_KEY_MASK;
 368                 u32 attr_bkey = uapi_bkey_attr(attr_key);
 369                 u8 type = elm->spec.type;
 370
 371                 if (uapi_key_attr_to_ioctl_method(iter.index) !=
 372                     uapi_key_attr_to_ioctl_method(method_key))
 373                         break;
 374
 375                 if (elm->spec.mandatory)
 376                         __set_bit(attr_bkey, method_elm->attr_mandatory);
 377
 378                 if (elm->spec.is_udata)
 379                         method_elm->has_udata = true;
 380
 381                 if (type == UVERBS_ATTR_TYPE_IDR ||
 382                     type == UVERBS_ATTR_TYPE_FD) {
 383                         u8 access = elm->spec.u.obj.access;
 384
 385                         /*
 386                          * Verbs specs may only have one NEW/DESTROY, we don't
 387                          * have the infrastructure to abort multiple NEW's or
 388                          * cope with multiple DESTROY failure.
 389                          */
 390                         if (access == UVERBS_ACCESS_NEW ||
 391                             access == UVERBS_ACCESS_DESTROY) {
 392                                 if (WARN_ON(single_uobj))
 393                                         return -EINVAL;
 394
 395                                 single_uobj = true;
 396                                 if (WARN_ON(!elm->spec.mandatory))
 397                                         return -EINVAL;
 398                         }
 399
 400                         if (access == UVERBS_ACCESS_DESTROY)
 401                                 method_elm->destroy_bkey = attr_bkey;
 402                 }
 403
 404                 max_bkey = max(max_bkey, attr_bkey);
 405                 num_attrs++;
 406         }
 407
 408         method_elm->key_bitmap_len = max_bkey + 1;
 409         WARN_ON(method_elm->key_bitmap_len > UVERBS_API_ATTR_BKEY_LEN);
 410
 411         uapi_compute_bundle_size(method_elm, num_attrs);
 412         return 0;
 413 }
 414
 415 static int uapi_finalize(struct uverbs_api *uapi)
 416 {
 417         const struct uverbs_api_write_method **data;
 418         unsigned long max_write_ex = 0;
 419         unsigned long max_write = 0;
 420         struct radix_tree_iter iter;
 421         void __rcu **slot;
 422         int rc;
 423         int i;
 424
 425         radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
 426                 struct uverbs_api_ioctl_method *method_elm =
 427                         rcu_dereference_protected(*slot, true);
 428
 429                 if (uapi_key_is_ioctl_method(iter.index)) {
 430                         rc = uapi_finalize_ioctl_method(uapi, method_elm,
 431                                                         iter.index);
 432                         if (rc)
 433                                 return rc;
 434                 }
 435
 436                 if (uapi_key_is_write_method(iter.index))
 437                         max_write = max(max_write,
 438                                         iter.index & UVERBS_API_ATTR_KEY_MASK);
 439                 if (uapi_key_is_write_ex_method(iter.index))
 440                         max_write_ex =
 441                                 max(max_write_ex,
 442                                     iter.index & UVERBS_API_ATTR_KEY_MASK);
 443         }
 444
 445         uapi->notsupp_method.handler = ib_uverbs_notsupp;
 446         uapi->num_write = max_write + 1;
 447         uapi->num_write_ex = max_write_ex + 1;
 448         data = kmalloc_array(uapi->num_write + uapi->num_write_ex,
 449                              sizeof(*uapi->write_methods), GFP_KERNEL);
 450         if (!data)
 451                 return -ENOMEM;
 452
 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 %u 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_obj_qp),
 638         UAPI_DEF_CHAIN(uverbs_def_obj_srq),
 639         UAPI_DEF_CHAIN(uverbs_def_obj_wq),
 640         UAPI_DEF_CHAIN(uverbs_def_write_intf),
 641         {},
 642 };
 643
 644 struct uverbs_api *uverbs_alloc_api(struct ib_device *ibdev)
 645 {
 646         struct uverbs_api *uapi;
 647         int rc;
 648
 649         uapi = kzalloc(sizeof(*uapi), GFP_KERNEL);
 650         if (!uapi)
 651                 return ERR_PTR(-ENOMEM);
 652
 653         INIT_RADIX_TREE(&uapi->radix, GFP_KERNEL);
 654         uapi->driver_id = ibdev->ops.driver_id;
 655
 656         rc = uapi_merge_def(uapi, ibdev, uverbs_core_api, false);
 657         if (rc)
 658                 goto err;
 659         rc = uapi_merge_def(uapi, ibdev, ibdev->driver_def, true);
 660         if (rc)
 661                 goto err;
 662
 663         uapi_finalize_disable(uapi);
 664         rc = uapi_finalize(uapi);
 665         if (rc)
 666                 goto err;
 667
 668         return uapi;
 669 err:
 670         if (rc != -ENOMEM)
 671                 dev_err(&ibdev->dev,
 672                         "Setup of uverbs_api failed, kernel parsing tree description is not valid (%d)??\n",
 673                         rc);
 674
 675         uverbs_destroy_api(uapi);
 676         return ERR_PTR(rc);
 677 }
 678
 679 /*
 680  * The pre version is done before destroying the HW objects, it only blocks
 681  * off method access. All methods that require the ib_dev or the module data
 682  * must test one of these assignments prior to continuing.
 683  */
 684 void uverbs_disassociate_api_pre(struct ib_uverbs_device *uverbs_dev)
 685 {
 686         struct uverbs_api *uapi = uverbs_dev->uapi;
 687         struct radix_tree_iter iter;
 688         void __rcu **slot;
 689
 690         rcu_assign_pointer(uverbs_dev->ib_dev, NULL);
 691
 692         radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
 693                 if (uapi_key_is_ioctl_method(iter.index)) {
 694                         struct uverbs_api_ioctl_method *method_elm =
 695                                 rcu_dereference_protected(*slot, true);
 696
 697                         if (method_elm->driver_method)
 698                                 rcu_assign_pointer(method_elm->handler, NULL);
 699                 }
 700         }
 701
 702         synchronize_srcu(&uverbs_dev->disassociate_srcu);
 703 }
 704
 705 /*
 706  * Called when a driver disassociates from the ib_uverbs_device. The
 707  * assumption is that the driver module will unload after. Replace everything
 708  * related to the driver with NULL as a safety measure.
 709  */
 710 void uverbs_disassociate_api(struct uverbs_api *uapi)
 711 {
 712         struct radix_tree_iter iter;
 713         void __rcu **slot;
 714
 715         radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
 716                 if (uapi_key_is_object(iter.index)) {
 717                         struct uverbs_api_object *object_elm =
 718                                 rcu_dereference_protected(*slot, true);
 719
 720                         /*
 721                          * Some type_attrs are in the driver module. We don't
 722                          * bother to keep track of which since there should be
 723                          * no use of this after disassociate.
 724                          */
 725                         object_elm->type_attrs = NULL;
 726                 } else if (uapi_key_is_attr(iter.index)) {
 727                         struct uverbs_api_attr *elm =
 728                                 rcu_dereference_protected(*slot, true);
 729
 730                         if (elm->spec.type == UVERBS_ATTR_TYPE_ENUM_IN)
 731                                 elm->spec.u2.enum_def.ids = NULL;
 732                 }
 733         }
 734 }