drivers/infiniband/core/uverbs_ioctl.c

   1 /*
   2  * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  */
  32
  33 #include <rdma/rdma_user_ioctl.h>
  34 #include <rdma/uverbs_ioctl.h>
  35 #include "rdma_core.h"
  36 #include "uverbs.h"
  37
  38 struct bundle_alloc_head {
  39         struct bundle_alloc_head *next;
  40         u8 data[];
  41 };
  42
  43 struct bundle_priv {
  44         /* Must be first */
  45         struct bundle_alloc_head alloc_head;
  46         struct bundle_alloc_head *allocated_mem;
  47         size_t internal_avail;
  48         size_t internal_used;
  49
  50         struct radix_tree_root *radix;
  51         const struct uverbs_api_ioctl_method *method_elm;
  52         void __rcu **radix_slots;
  53         unsigned long radix_slots_len;
  54         u32 method_key;
  55
  56         struct ib_uverbs_attr __user *user_attrs;
  57         struct ib_uverbs_attr *uattrs;
  58
  59         DECLARE_BITMAP(uobj_finalize, UVERBS_API_ATTR_BKEY_LEN);
  60         DECLARE_BITMAP(spec_finalize, UVERBS_API_ATTR_BKEY_LEN);
  61
  62         /*
  63          * Must be last. bundle ends in a flex array which overlaps
  64          * internal_buffer.
  65          */
  66         struct uverbs_attr_bundle bundle;
  67         u64 internal_buffer[32];
  68 };
  69
  70 /*
  71  * Each method has an absolute minimum amount of memory it needs to allocate,
  72  * precompute that amount and determine if the onstack memory can be used or
  73  * if allocation is need.
  74  */
  75 void uapi_compute_bundle_size(struct uverbs_api_ioctl_method *method_elm,
  76                               unsigned int num_attrs)
  77 {
  78         struct bundle_priv *pbundle;
  79         size_t bundle_size =
  80                 offsetof(struct bundle_priv, internal_buffer) +
  81                 sizeof(*pbundle->bundle.attrs) * method_elm->key_bitmap_len +
  82                 sizeof(*pbundle->uattrs) * num_attrs;
  83
  84         method_elm->use_stack = bundle_size <= sizeof(*pbundle);
  85         method_elm->bundle_size =
  86                 ALIGN(bundle_size + 256, sizeof(*pbundle->internal_buffer));
  87
  88         /* Do not want order-2 allocations for this. */
  89         WARN_ON_ONCE(method_elm->bundle_size > PAGE_SIZE);
  90 }
  91
  92 /**
  93  * uverbs_alloc() - Quickly allocate memory for use with a bundle
  94  * @bundle: The bundle
  95  * @size: Number of bytes to allocate
  96  * @flags: Allocator flags
  97  *
  98  * The bundle allocator is intended for allocations that are connected with
  99  * processing the system call related to the bundle. The allocated memory is
 100  * always freed once the system call completes, and cannot be freed any other
 101  * way.
 102  *
 103  * This tries to use a small pool of pre-allocated memory for performance.
 104  */
 105 __malloc void *_uverbs_alloc(struct uverbs_attr_bundle *bundle, size_t size,
 106                              gfp_t flags)
 107 {
 108         struct bundle_priv *pbundle =
 109                 container_of(bundle, struct bundle_priv, bundle);
 110         size_t new_used;
 111         void *res;
 112
 113         if (check_add_overflow(size, pbundle->internal_used, &new_used))
 114                 return ERR_PTR(-EOVERFLOW);
 115
 116         if (new_used > pbundle->internal_avail) {
 117                 struct bundle_alloc_head *buf;
 118
 119                 buf = kvmalloc(struct_size(buf, data, size), flags);
 120                 if (!buf)
 121                         return ERR_PTR(-ENOMEM);
 122                 buf->next = pbundle->allocated_mem;
 123                 pbundle->allocated_mem = buf;
 124                 return buf->data;
 125         }
 126
 127         res = (void *)pbundle->internal_buffer + pbundle->internal_used;
 128         pbundle->internal_used =
 129                 ALIGN(new_used, sizeof(*pbundle->internal_buffer));
 130         if (flags & __GFP_ZERO)
 131                 memset(res, 0, size);
 132         return res;
 133 }
 134 EXPORT_SYMBOL(_uverbs_alloc);
 135
 136 static bool uverbs_is_attr_cleared(const struct ib_uverbs_attr *uattr,
 137                                    u16 len)
 138 {
 139         if (uattr->len > sizeof(((struct ib_uverbs_attr *)0)->data))
 140                 return ib_is_buffer_cleared(u64_to_user_ptr(uattr->data) + len,
 141                                             uattr->len - len);
 142
 143         return !memchr_inv((const void *)&uattr->data + len,
 144                            0, uattr->len - len);
 145 }
 146
 147 static int uverbs_process_idrs_array(struct bundle_priv *pbundle,
 148                                      const struct uverbs_api_attr *attr_uapi,
 149                                      struct uverbs_objs_arr_attr *attr,
 150                                      struct ib_uverbs_attr *uattr,
 151                                      u32 attr_bkey)
 152 {
 153         const struct uverbs_attr_spec *spec = &attr_uapi->spec;
 154         size_t array_len;
 155         u32 *idr_vals;
 156         int ret = 0;
 157         size_t i;
 158
 159         if (uattr->attr_data.reserved)
 160                 return -EINVAL;
 161
 162         if (uattr->len % sizeof(u32))
 163                 return -EINVAL;
 164
 165         array_len = uattr->len / sizeof(u32);
 166         if (array_len < spec->u2.objs_arr.min_len ||
 167             array_len > spec->u2.objs_arr.max_len)
 168                 return -EINVAL;
 169
 170         attr->uobjects =
 171                 uverbs_alloc(&pbundle->bundle,
 172                              array_size(array_len, sizeof(*attr->uobjects)));
 173         if (IS_ERR(attr->uobjects))
 174                 return PTR_ERR(attr->uobjects);
 175
 176         /*
 177          * Since idr is 4B and *uobjects is >= 4B, we can use attr->uobjects
 178          * to store idrs array and avoid additional memory allocation. The
 179          * idrs array is offset to the end of the uobjects array so we will be
 180          * able to read idr and replace with a pointer.
 181          */
 182         idr_vals = (u32 *)(attr->uobjects + array_len) - array_len;
 183
 184         if (uattr->len > sizeof(uattr->data)) {
 185                 ret = copy_from_user(idr_vals, u64_to_user_ptr(uattr->data),
 186                                      uattr->len);
 187                 if (ret)
 188                         return -EFAULT;
 189         } else {
 190                 memcpy(idr_vals, &uattr->data, uattr->len);
 191         }
 192
 193         for (i = 0; i != array_len; i++) {
 194                 attr->uobjects[i] = uverbs_get_uobject_from_file(
 195                         spec->u2.objs_arr.obj_type, pbundle->bundle.ufile,
 196                         spec->u2.objs_arr.access, idr_vals[i]);
 197                 if (IS_ERR(attr->uobjects[i])) {
 198                         ret = PTR_ERR(attr->uobjects[i]);
 199                         break;
 200                 }
 201         }
 202
 203         attr->len = i;
 204         __set_bit(attr_bkey, pbundle->spec_finalize);
 205         return ret;
 206 }
 207
 208 static int uverbs_free_idrs_array(const struct uverbs_api_attr *attr_uapi,
 209                                   struct uverbs_objs_arr_attr *attr,
 210                                   bool commit)
 211 {
 212         const struct uverbs_attr_spec *spec = &attr_uapi->spec;
 213         int current_ret;
 214         int ret = 0;
 215         size_t i;
 216
 217         for (i = 0; i != attr->len; i++) {
 218                 current_ret = uverbs_finalize_object(
 219                         attr->uobjects[i], spec->u2.objs_arr.access, commit);
 220                 if (!ret)
 221                         ret = current_ret;
 222         }
 223
 224         return ret;
 225 }
 226
 227 static int uverbs_process_attr(struct bundle_priv *pbundle,
 228                                const struct uverbs_api_attr *attr_uapi,
 229                                struct ib_uverbs_attr *uattr, u32 attr_bkey)
 230 {
 231         const struct uverbs_attr_spec *spec = &attr_uapi->spec;
 232         struct uverbs_attr *e = &pbundle->bundle.attrs[attr_bkey];
 233         const struct uverbs_attr_spec *val_spec = spec;
 234         struct uverbs_obj_attr *o_attr;
 235
 236         switch (spec->type) {
 237         case UVERBS_ATTR_TYPE_ENUM_IN:
 238                 if (uattr->attr_data.enum_data.elem_id >= spec->u.enum_def.num_elems)
 239                         return -EOPNOTSUPP;
 240
 241                 if (uattr->attr_data.enum_data.reserved)
 242                         return -EINVAL;
 243
 244                 val_spec = &spec->u2.enum_def.ids[uattr->attr_data.enum_data.elem_id];
 245
 246                 /* Currently we only support PTR_IN based enums */
 247                 if (val_spec->type != UVERBS_ATTR_TYPE_PTR_IN)
 248                         return -EOPNOTSUPP;
 249
 250                 e->ptr_attr.enum_id = uattr->attr_data.enum_data.elem_id;
 251         /* fall through */
 252         case UVERBS_ATTR_TYPE_PTR_IN:
 253                 /* Ensure that any data provided by userspace beyond the known
 254                  * struct is zero. Userspace that knows how to use some future
 255                  * longer struct will fail here if used with an old kernel and
 256                  * non-zero content, making ABI compat/discovery simpler.
 257                  */
 258                 if (uattr->len > val_spec->u.ptr.len &&
 259                     val_spec->zero_trailing &&
 260                     !uverbs_is_attr_cleared(uattr, val_spec->u.ptr.len))
 261                         return -EOPNOTSUPP;
 262
 263         /* fall through */
 264         case UVERBS_ATTR_TYPE_PTR_OUT:
 265                 if (uattr->len < val_spec->u.ptr.min_len ||
 266                     (!val_spec->zero_trailing &&
 267                      uattr->len > val_spec->u.ptr.len))
 268                         return -EINVAL;
 269
 270                 if (spec->type != UVERBS_ATTR_TYPE_ENUM_IN &&
 271                     uattr->attr_data.reserved)
 272                         return -EINVAL;
 273
 274                 e->ptr_attr.uattr_idx = uattr - pbundle->uattrs;
 275                 e->ptr_attr.len = uattr->len;
 276
 277                 if (val_spec->alloc_and_copy && !uverbs_attr_ptr_is_inline(e)) {
 278                         void *p;
 279
 280                         p = uverbs_alloc(&pbundle->bundle, uattr->len);
 281                         if (IS_ERR(p))
 282                                 return PTR_ERR(p);
 283
 284                         e->ptr_attr.ptr = p;
 285
 286                         if (copy_from_user(p, u64_to_user_ptr(uattr->data),
 287                                            uattr->len))
 288                                 return -EFAULT;
 289                 } else {
 290                         e->ptr_attr.data = uattr->data;
 291                 }
 292                 break;
 293
 294         case UVERBS_ATTR_TYPE_IDR:
 295         case UVERBS_ATTR_TYPE_FD:
 296                 if (uattr->attr_data.reserved)
 297                         return -EINVAL;
 298
 299                 if (uattr->len != 0)
 300                         return -EINVAL;
 301
 302                 o_attr = &e->obj_attr;
 303                 o_attr->attr_elm = attr_uapi;
 304
 305                 /*
 306                  * The type of uattr->data is u64 for UVERBS_ATTR_TYPE_IDR and
 307                  * s64 for UVERBS_ATTR_TYPE_FD. We can cast the u64 to s64
 308                  * here without caring about truncation as we know that the
 309                  * IDR implementation today rejects negative IDs
 310                  */
 311                 o_attr->uobject = uverbs_get_uobject_from_file(
 312                                         spec->u.obj.obj_type,
 313                                         pbundle->bundle.ufile,
 314                                         spec->u.obj.access,
 315                                         uattr->data_s64);
 316                 if (IS_ERR(o_attr->uobject))
 317                         return PTR_ERR(o_attr->uobject);
 318                 __set_bit(attr_bkey, pbundle->uobj_finalize);
 319
 320                 if (spec->u.obj.access == UVERBS_ACCESS_NEW) {
 321                         unsigned int uattr_idx = uattr - pbundle->uattrs;
 322                         s64 id = o_attr->uobject->id;
 323
 324                         /* Copy the allocated id to the user-space */
 325                         if (put_user(id, &pbundle->user_attrs[uattr_idx].data))
 326                                 return -EFAULT;
 327                 }
 328
 329                 break;
 330
 331         case UVERBS_ATTR_TYPE_IDRS_ARRAY:
 332                 return uverbs_process_idrs_array(pbundle, attr_uapi,
 333                                                  &e->objs_arr_attr, uattr,
 334                                                  attr_bkey);
 335         default:
 336                 return -EOPNOTSUPP;
 337         }
 338
 339         return 0;
 340 }
 341
 342 /*
 343  * We search the radix tree with the method prefix and now we want to fast
 344  * search the suffix bits to get a particular attribute pointer. It is not
 345  * totally clear to me if this breaks the radix tree encasulation or not, but
 346  * it uses the iter data to determine if the method iter points at the same
 347  * chunk that will store the attribute, if so it just derefs it directly. By
 348  * construction in most kernel configs the method and attrs will all fit in a
 349  * single radix chunk, so in most cases this will have no search. Other cases
 350  * this falls back to a full search.
 351  */
 352 static void __rcu **uapi_get_attr_for_method(struct bundle_priv *pbundle,
 353                                              u32 attr_key)
 354 {
 355         void __rcu **slot;
 356
 357         if (likely(attr_key < pbundle->radix_slots_len)) {
 358                 void *entry;
 359
 360                 slot = pbundle->radix_slots + attr_key;
 361                 entry = rcu_dereference_raw(*slot);
 362                 if (likely(!radix_tree_is_internal_node(entry) && entry))
 363                         return slot;
 364         }
 365
 366         return radix_tree_lookup_slot(pbundle->radix,
 367                                       pbundle->method_key | attr_key);
 368 }
 369
 370 static int uverbs_set_attr(struct bundle_priv *pbundle,
 371                            struct ib_uverbs_attr *uattr)
 372 {
 373         u32 attr_key = uapi_key_attr(uattr->attr_id);
 374         u32 attr_bkey = uapi_bkey_attr(attr_key);
 375         const struct uverbs_api_attr *attr;
 376         void __rcu **slot;
 377         int ret;
 378
 379         slot = uapi_get_attr_for_method(pbundle, attr_key);
 380         if (!slot) {
 381                 /*
 382                  * Kernel does not support the attribute but user-space says it
 383                  * is mandatory
 384                  */
 385                 if (uattr->flags & UVERBS_ATTR_F_MANDATORY)
 386                         return -EPROTONOSUPPORT;
 387                 return 0;
 388         }
 389         attr = rcu_dereference_protected(*slot, true);
 390
 391         /* Reject duplicate attributes from user-space */
 392         if (test_bit(attr_bkey, pbundle->bundle.attr_present))
 393                 return -EINVAL;
 394
 395         ret = uverbs_process_attr(pbundle, attr, uattr, attr_bkey);
 396         if (ret)
 397                 return ret;
 398
 399         __set_bit(attr_bkey, pbundle->bundle.attr_present);
 400
 401         return 0;
 402 }
 403
 404 static int ib_uverbs_run_method(struct bundle_priv *pbundle,
 405                                 unsigned int num_attrs)
 406 {
 407         int (*handler)(struct uverbs_attr_bundle *attrs);
 408         size_t uattrs_size = array_size(sizeof(*pbundle->uattrs), num_attrs);
 409         unsigned int destroy_bkey = pbundle->method_elm->destroy_bkey;
 410         unsigned int i;
 411         int ret;
 412
 413         /* See uverbs_disassociate_api() */
 414         handler = srcu_dereference(
 415                 pbundle->method_elm->handler,
 416                 &pbundle->bundle.ufile->device->disassociate_srcu);
 417         if (!handler)
 418                 return -EIO;
 419
 420         pbundle->uattrs = uverbs_alloc(&pbundle->bundle, uattrs_size);
 421         if (IS_ERR(pbundle->uattrs))
 422                 return PTR_ERR(pbundle->uattrs);
 423         if (copy_from_user(pbundle->uattrs, pbundle->user_attrs, uattrs_size))
 424                 return -EFAULT;
 425
 426         for (i = 0; i != num_attrs; i++) {
 427                 ret = uverbs_set_attr(pbundle, &pbundle->uattrs[i]);
 428                 if (unlikely(ret))
 429                         return ret;
 430         }
 431
 432         /* User space did not provide all the mandatory attributes */
 433         if (unlikely(!bitmap_subset(pbundle->method_elm->attr_mandatory,
 434                                     pbundle->bundle.attr_present,
 435                                     pbundle->method_elm->key_bitmap_len)))
 436                 return -EINVAL;
 437
 438         if (pbundle->method_elm->has_udata)
 439                 uverbs_fill_udata(&pbundle->bundle,
 440                                   &pbundle->bundle.driver_udata,
 441                                   UVERBS_ATTR_UHW_IN, UVERBS_ATTR_UHW_OUT);
 442
 443         if (destroy_bkey != UVERBS_API_ATTR_BKEY_LEN) {
 444                 struct uverbs_obj_attr *destroy_attr =
 445                         &pbundle->bundle.attrs[destroy_bkey].obj_attr;
 446
 447                 ret = uobj_destroy(destroy_attr->uobject);
 448                 if (ret)
 449                         return ret;
 450                 __clear_bit(destroy_bkey, pbundle->uobj_finalize);
 451
 452                 ret = handler(&pbundle->bundle);
 453                 uobj_put_destroy(destroy_attr->uobject);
 454         } else {
 455                 ret = handler(&pbundle->bundle);
 456         }
 457
 458         /*
 459          * EPROTONOSUPPORT is ONLY to be returned if the ioctl framework can
 460          * not invoke the method because the request is not supported.  No
 461          * other cases should return this code.
 462          */
 463         if (WARN_ON_ONCE(ret == -EPROTONOSUPPORT))
 464                 return -EINVAL;
 465
 466         return ret;
 467 }
 468
 469 static int bundle_destroy(struct bundle_priv *pbundle, bool commit)
 470 {
 471         unsigned int key_bitmap_len = pbundle->method_elm->key_bitmap_len;
 472         struct bundle_alloc_head *memblock;
 473         unsigned int i;
 474         int ret = 0;
 475
 476         /* fast path for simple uobjects */
 477         i = -1;
 478         while ((i = find_next_bit(pbundle->uobj_finalize, key_bitmap_len,
 479                                   i + 1)) < key_bitmap_len) {
 480                 struct uverbs_attr *attr = &pbundle->bundle.attrs[i];
 481                 int current_ret;
 482
 483                 current_ret = uverbs_finalize_object(
 484                         attr->obj_attr.uobject,
 485                         attr->obj_attr.attr_elm->spec.u.obj.access, commit);
 486                 if (!ret)
 487                         ret = current_ret;
 488         }
 489
 490         i = -1;
 491         while ((i = find_next_bit(pbundle->spec_finalize, key_bitmap_len,
 492                                   i + 1)) < key_bitmap_len) {
 493                 struct uverbs_attr *attr = &pbundle->bundle.attrs[i];
 494                 const struct uverbs_api_attr *attr_uapi;
 495                 void __rcu **slot;
 496                 int current_ret;
 497
 498                 slot = uapi_get_attr_for_method(
 499                         pbundle,
 500                         pbundle->method_key | uapi_bkey_to_key_attr(i));
 501                 if (WARN_ON(!slot))
 502                         continue;
 503
 504                 attr_uapi = rcu_dereference_protected(*slot, true);
 505
 506                 if (attr_uapi->spec.type == UVERBS_ATTR_TYPE_IDRS_ARRAY) {
 507                         current_ret = uverbs_free_idrs_array(
 508                                 attr_uapi, &attr->objs_arr_attr, commit);
 509                         if (!ret)
 510                                 ret = current_ret;
 511                 }
 512         }
 513
 514         for (memblock = pbundle->allocated_mem; memblock;) {
 515                 struct bundle_alloc_head *tmp = memblock;
 516
 517                 memblock = memblock->next;
 518                 kvfree(tmp);
 519         }
 520
 521         return ret;
 522 }
 523
 524 static int ib_uverbs_cmd_verbs(struct ib_uverbs_file *ufile,
 525                                struct ib_uverbs_ioctl_hdr *hdr,
 526                                struct ib_uverbs_attr __user *user_attrs)
 527 {
 528         const struct uverbs_api_ioctl_method *method_elm;
 529         struct uverbs_api *uapi = ufile->device->uapi;
 530         struct radix_tree_iter attrs_iter;
 531         struct bundle_priv *pbundle;
 532         struct bundle_priv onstack;
 533         void __rcu **slot;
 534         int destroy_ret;
 535         int ret;
 536
 537         if (unlikely(hdr->driver_id != uapi->driver_id))
 538                 return -EINVAL;
 539
 540         slot = radix_tree_iter_lookup(
 541                 &uapi->radix, &attrs_iter,
 542                 uapi_key_obj(hdr->object_id) |
 543                         uapi_key_ioctl_method(hdr->method_id));
 544         if (unlikely(!slot))
 545                 return -EPROTONOSUPPORT;
 546         method_elm = rcu_dereference_protected(*slot, true);
 547
 548         if (!method_elm->use_stack) {
 549                 pbundle = kmalloc(method_elm->bundle_size, GFP_KERNEL);
 550                 if (!pbundle)
 551                         return -ENOMEM;
 552                 pbundle->internal_avail =
 553                         method_elm->bundle_size -
 554                         offsetof(struct bundle_priv, internal_buffer);
 555                 pbundle->alloc_head.next = NULL;
 556                 pbundle->allocated_mem = &pbundle->alloc_head;
 557         } else {
 558                 pbundle = &onstack;
 559                 pbundle->internal_avail = sizeof(pbundle->internal_buffer);
 560                 pbundle->allocated_mem = NULL;
 561         }
 562
 563         /* Space for the pbundle->bundle.attrs flex array */
 564         pbundle->method_elm = method_elm;
 565         pbundle->method_key = attrs_iter.index;
 566         pbundle->bundle.ufile = ufile;
 567         pbundle->radix = &uapi->radix;
 568         pbundle->radix_slots = slot;
 569         pbundle->radix_slots_len = radix_tree_chunk_size(&attrs_iter);
 570         pbundle->user_attrs = user_attrs;
 571
 572         pbundle->internal_used = ALIGN(pbundle->method_elm->key_bitmap_len *
 573                                                sizeof(*pbundle->bundle.attrs),
 574                                        sizeof(*pbundle->internal_buffer));
 575         memset(pbundle->bundle.attr_present, 0,
 576                sizeof(pbundle->bundle.attr_present));
 577         memset(pbundle->uobj_finalize, 0, sizeof(pbundle->uobj_finalize));
 578         memset(pbundle->spec_finalize, 0, sizeof(pbundle->spec_finalize));
 579
 580         ret = ib_uverbs_run_method(pbundle, hdr->num_attrs);
 581         destroy_ret = bundle_destroy(pbundle, ret == 0);
 582         if (unlikely(destroy_ret && !ret))
 583                 return destroy_ret;
 584
 585         return ret;
 586 }
 587
 588 long ib_uverbs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 589 {
 590         struct ib_uverbs_file *file = filp->private_data;
 591         struct ib_uverbs_ioctl_hdr __user *user_hdr =
 592                 (struct ib_uverbs_ioctl_hdr __user *)arg;
 593         struct ib_uverbs_ioctl_hdr hdr;
 594         int srcu_key;
 595         int err;
 596
 597         if (unlikely(cmd != RDMA_VERBS_IOCTL))
 598                 return -ENOIOCTLCMD;
 599
 600         err = copy_from_user(&hdr, user_hdr, sizeof(hdr));
 601         if (err)
 602                 return -EFAULT;
 603
 604         if (hdr.length > PAGE_SIZE ||
 605             hdr.length != struct_size(&hdr, attrs, hdr.num_attrs))
 606                 return -EINVAL;
 607
 608         if (hdr.reserved1 || hdr.reserved2)
 609                 return -EPROTONOSUPPORT;
 610
 611         srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
 612         err = ib_uverbs_cmd_verbs(file, &hdr, user_hdr->attrs);
 613         srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
 614         return err;
 615 }
 616
 617 int uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
 618                        size_t idx, u64 allowed_bits)
 619 {
 620         const struct uverbs_attr *attr;
 621         u64 flags;
 622
 623         attr = uverbs_attr_get(attrs_bundle, idx);
 624         /* Missing attribute means 0 flags */
 625         if (IS_ERR(attr)) {
 626                 *to = 0;
 627                 return 0;
 628         }
 629
 630         /*
 631          * New userspace code should use 8 bytes to pass flags, but we
 632          * transparently support old userspaces that were using 4 bytes as
 633          * well.
 634          */
 635         if (attr->ptr_attr.len == 8)
 636                 flags = attr->ptr_attr.data;
 637         else if (attr->ptr_attr.len == 4)
 638                 flags = *(u32 *)&attr->ptr_attr.data;
 639         else
 640                 return -EINVAL;
 641
 642         if (flags & ~allowed_bits)
 643                 return -EINVAL;
 644
 645         *to = flags;
 646         return 0;
 647 }
 648 EXPORT_SYMBOL(uverbs_get_flags64);
 649
 650 int uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
 651                        size_t idx, u64 allowed_bits)
 652 {
 653         u64 flags;
 654         int ret;
 655
 656         ret = uverbs_get_flags64(&flags, attrs_bundle, idx, allowed_bits);
 657         if (ret)
 658                 return ret;
 659
 660         if (flags > U32_MAX)
 661                 return -EINVAL;
 662         *to = flags;
 663
 664         return 0;
 665 }
 666 EXPORT_SYMBOL(uverbs_get_flags32);
 667
 668 /*
 669  * Fill a ib_udata struct (core or uhw) using the given attribute IDs.
 670  * This is primarily used to convert the UVERBS_ATTR_UHW() into the
 671  * ib_udata format used by the drivers.
 672  */
 673 void uverbs_fill_udata(struct uverbs_attr_bundle *bundle,
 674                        struct ib_udata *udata, unsigned int attr_in,
 675                        unsigned int attr_out)
 676 {
 677         struct bundle_priv *pbundle =
 678                 container_of(bundle, struct bundle_priv, bundle);
 679         const struct uverbs_attr *in =
 680                 uverbs_attr_get(&pbundle->bundle, attr_in);
 681         const struct uverbs_attr *out =
 682                 uverbs_attr_get(&pbundle->bundle, attr_out);
 683
 684         if (!IS_ERR(in)) {
 685                 udata->inlen = in->ptr_attr.len;
 686                 if (uverbs_attr_ptr_is_inline(in))
 687                         udata->inbuf =
 688                                 &pbundle->user_attrs[in->ptr_attr.uattr_idx]
 689                                          .data;
 690                 else
 691                         udata->inbuf = u64_to_user_ptr(in->ptr_attr.data);
 692         } else {
 693                 udata->inbuf = NULL;
 694                 udata->inlen = 0;
 695         }
 696
 697         if (!IS_ERR(out)) {
 698                 udata->outbuf = u64_to_user_ptr(out->ptr_attr.data);
 699                 udata->outlen = out->ptr_attr.len;
 700         } else {
 701                 udata->outbuf = NULL;
 702                 udata->outlen = 0;
 703         }
 704 }
 705
 706 int uverbs_copy_to(const struct uverbs_attr_bundle *bundle, size_t idx,
 707                    const void *from, size_t size)
 708 {
 709         struct bundle_priv *pbundle =
 710                 container_of(bundle, struct bundle_priv, bundle);
 711         const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
 712         u16 flags;
 713         size_t min_size;
 714
 715         if (IS_ERR(attr))
 716                 return PTR_ERR(attr);
 717
 718         min_size = min_t(size_t, attr->ptr_attr.len, size);
 719         if (copy_to_user(u64_to_user_ptr(attr->ptr_attr.data), from, min_size))
 720                 return -EFAULT;
 721
 722         flags = pbundle->uattrs[attr->ptr_attr.uattr_idx].flags |
 723                 UVERBS_ATTR_F_VALID_OUTPUT;
 724         if (put_user(flags,
 725                      &pbundle->user_attrs[attr->ptr_attr.uattr_idx].flags))
 726                 return -EFAULT;
 727
 728         return 0;
 729 }
 730 EXPORT_SYMBOL(uverbs_copy_to);
 731
 732 int _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle,
 733                       size_t idx, s64 lower_bound, u64 upper_bound,
 734                       s64  *def_val)
 735 {
 736         const struct uverbs_attr *attr;
 737
 738         attr = uverbs_attr_get(attrs_bundle, idx);
 739         if (IS_ERR(attr)) {
 740                 if ((PTR_ERR(attr) != -ENOENT) || !def_val)
 741                         return PTR_ERR(attr);
 742
 743                 *to = *def_val;
 744         } else {
 745                 *to = attr->ptr_attr.data;
 746         }
 747
 748         if (*to < lower_bound || (*to > 0 && (u64)*to > upper_bound))
 749                 return -EINVAL;
 750
 751         return 0;
 752 }
 753 EXPORT_SYMBOL(_uverbs_get_const);
 754
 755 int uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle,
 756                                   size_t idx, const void *from, size_t size)
 757 {
 758         const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
 759
 760         if (clear_user(u64_to_user_ptr(attr->ptr_attr.data),
 761                        attr->ptr_attr.len))
 762                 return -EFAULT;
 763         return uverbs_copy_to(bundle, idx, from, size);
 764 }