kernel/bpf/hashtab.c

   1 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
   2  * Copyright (c) 2016 Facebook
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of version 2 of the GNU General Public
   6  * License as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11  * General Public License for more details.
  12  */
  13 #include <linux/bpf.h>
  14 #include <linux/jhash.h>
  15 #include <linux/filter.h>
  16 #include <linux/rculist_nulls.h>
  17 #include "percpu_freelist.h"
  18 #include "bpf_lru_list.h"
  19 #include "map_in_map.h"
  20
  21 struct bucket {
  22         struct hlist_nulls_head head;
  23         raw_spinlock_t lock;
  24 };
  25
  26 struct bpf_htab {
  27         struct bpf_map map;
  28         struct bucket *buckets;
  29         void *elems;
  30         union {
  31                 struct pcpu_freelist freelist;
  32                 struct bpf_lru lru;
  33         };
  34         struct htab_elem *__percpu *extra_elems;
  35         atomic_t count; /* number of elements in this hashtable */
  36         u32 n_buckets;  /* number of hash buckets */
  37         u32 elem_size;  /* size of each element in bytes */
  38 };
  39
  40 /* each htab element is struct htab_elem + key + value */
  41 struct htab_elem {
  42         union {
  43                 struct hlist_nulls_node hash_node;
  44                 struct {
  45                         void *padding;
  46                         union {
  47                                 struct bpf_htab *htab;
  48                                 struct pcpu_freelist_node fnode;
  49                         };
  50                 };
  51         };
  52         union {
  53                 struct rcu_head rcu;
  54                 struct bpf_lru_node lru_node;
  55         };
  56         u32 hash;
  57         char key[0] __aligned(8);
  58 };
  59
  60 static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node);
  61
  62 static bool htab_is_lru(const struct bpf_htab *htab)
  63 {
  64         return htab->map.map_type == BPF_MAP_TYPE_LRU_HASH ||
  65                 htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
  66 }
  67
  68 static bool htab_is_percpu(const struct bpf_htab *htab)
  69 {
  70         return htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH ||
  71                 htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
  72 }
  73
  74 static bool htab_is_prealloc(const struct bpf_htab *htab)
  75 {
  76         return !(htab->map.map_flags & BPF_F_NO_PREALLOC);
  77 }
  78
  79 static inline void htab_elem_set_ptr(struct htab_elem *l, u32 key_size,
  80                                      void __percpu *pptr)
  81 {
  82         *(void __percpu **)(l->key + key_size) = pptr;
  83 }
  84
  85 static inline void __percpu *htab_elem_get_ptr(struct htab_elem *l, u32 key_size)
  86 {
  87         return *(void __percpu **)(l->key + key_size);
  88 }
  89
  90 static void *fd_htab_map_get_ptr(const struct bpf_map *map, struct htab_elem *l)
  91 {
  92         return *(void **)(l->key + roundup(map->key_size, 8));
  93 }
  94
  95 static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i)
  96 {
  97         return (struct htab_elem *) (htab->elems + i * htab->elem_size);
  98 }
  99
 100 static void htab_free_elems(struct bpf_htab *htab)
 101 {
 102         int i;
 103
 104         if (!htab_is_percpu(htab))
 105                 goto free_elems;
 106
 107         for (i = 0; i < htab->map.max_entries; i++) {
 108                 void __percpu *pptr;
 109
 110                 pptr = htab_elem_get_ptr(get_htab_elem(htab, i),
 111                                          htab->map.key_size);
 112                 free_percpu(pptr);
 113         }
 114 free_elems:
 115         bpf_map_area_free(htab->elems);
 116 }
 117
 118 static struct htab_elem *prealloc_lru_pop(struct bpf_htab *htab, void *key,
 119                                           u32 hash)
 120 {
 121         struct bpf_lru_node *node = bpf_lru_pop_free(&htab->lru, hash);
 122         struct htab_elem *l;
 123
 124         if (node) {
 125                 l = container_of(node, struct htab_elem, lru_node);
 126                 memcpy(l->key, key, htab->map.key_size);
 127                 return l;
 128         }
 129
 130         return NULL;
 131 }
 132
 133 static int prealloc_init(struct bpf_htab *htab)
 134 {
 135         u32 num_entries = htab->map.max_entries;
 136         int err = -ENOMEM, i;
 137
 138         if (!htab_is_percpu(htab) && !htab_is_lru(htab))
 139                 num_entries += num_possible_cpus();
 140
 141         htab->elems = bpf_map_area_alloc(htab->elem_size * num_entries);
 142         if (!htab->elems)
 143                 return -ENOMEM;
 144
 145         if (!htab_is_percpu(htab))
 146                 goto skip_percpu_elems;
 147
 148         for (i = 0; i < num_entries; i++) {
 149                 u32 size = round_up(htab->map.value_size, 8);
 150                 void __percpu *pptr;
 151
 152                 pptr = __alloc_percpu_gfp(size, 8, GFP_USER | __GFP_NOWARN);
 153                 if (!pptr)
 154                         goto free_elems;
 155                 htab_elem_set_ptr(get_htab_elem(htab, i), htab->map.key_size,
 156                                   pptr);
 157         }
 158
 159 skip_percpu_elems:
 160         if (htab_is_lru(htab))
 161                 err = bpf_lru_init(&htab->lru,
 162                                    htab->map.map_flags & BPF_F_NO_COMMON_LRU,
 163                                    offsetof(struct htab_elem, hash) -
 164                                    offsetof(struct htab_elem, lru_node),
 165                                    htab_lru_map_delete_node,
 166                                    htab);
 167         else
 168                 err = pcpu_freelist_init(&htab->freelist);
 169
 170         if (err)
 171                 goto free_elems;
 172
 173         if (htab_is_lru(htab))
 174                 bpf_lru_populate(&htab->lru, htab->elems,
 175                                  offsetof(struct htab_elem, lru_node),
 176                                  htab->elem_size, num_entries);
 177         else
 178                 pcpu_freelist_populate(&htab->freelist,
 179                                        htab->elems + offsetof(struct htab_elem, fnode),
 180                                        htab->elem_size, num_entries);
 181
 182         return 0;
 183
 184 free_elems:
 185         htab_free_elems(htab);
 186         return err;
 187 }
 188
 189 static void prealloc_destroy(struct bpf_htab *htab)
 190 {
 191         htab_free_elems(htab);
 192
 193         if (htab_is_lru(htab))
 194                 bpf_lru_destroy(&htab->lru);
 195         else
 196                 pcpu_freelist_destroy(&htab->freelist);
 197 }
 198
 199 static int alloc_extra_elems(struct bpf_htab *htab)
 200 {
 201         struct htab_elem *__percpu *pptr, *l_new;
 202         struct pcpu_freelist_node *l;
 203         int cpu;
 204
 205         pptr = __alloc_percpu_gfp(sizeof(struct htab_elem *), 8,
 206                                   GFP_USER | __GFP_NOWARN);
 207         if (!pptr)
 208                 return -ENOMEM;
 209
 210         for_each_possible_cpu(cpu) {
 211                 l = pcpu_freelist_pop(&htab->freelist);
 212                 /* pop will succeed, since prealloc_init()
 213                  * preallocated extra num_possible_cpus elements
 214                  */
 215                 l_new = container_of(l, struct htab_elem, fnode);
 216                 *per_cpu_ptr(pptr, cpu) = l_new;
 217         }
 218         htab->extra_elems = pptr;
 219         return 0;
 220 }
 221
 222 /* Called from syscall */
 223 static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 224 {
 225         bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
 226                        attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
 227         bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH ||
 228                     attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
 229         /* percpu_lru means each cpu has its own LRU list.
 230          * it is different from BPF_MAP_TYPE_PERCPU_HASH where
 231          * the map's value itself is percpu.  percpu_lru has
 232          * nothing to do with the map's value.
 233          */
 234         bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU);
 235         bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC);
 236         struct bpf_htab *htab;
 237         int err, i;
 238         u64 cost;
 239
 240         BUILD_BUG_ON(offsetof(struct htab_elem, htab) !=
 241                      offsetof(struct htab_elem, hash_node.pprev));
 242         BUILD_BUG_ON(offsetof(struct htab_elem, fnode.next) !=
 243                      offsetof(struct htab_elem, hash_node.pprev));
 244
 245         if (lru && !capable(CAP_SYS_ADMIN))
 246                 /* LRU implementation is much complicated than other
 247                  * maps.  Hence, limit to CAP_SYS_ADMIN for now.
 248                  */
 249                 return ERR_PTR(-EPERM);
 250
 251         if (attr->map_flags & ~(BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU))
 252                 /* reserved bits should not be used */
 253                 return ERR_PTR(-EINVAL);
 254
 255         if (!lru && percpu_lru)
 256                 return ERR_PTR(-EINVAL);
 257
 258         if (lru && !prealloc)
 259                 return ERR_PTR(-ENOTSUPP);
 260
 261         htab = kzalloc(sizeof(*htab), GFP_USER);
 262         if (!htab)
 263                 return ERR_PTR(-ENOMEM);
 264
 265         /* mandatory map attributes */
 266         htab->map.map_type = attr->map_type;
 267         htab->map.key_size = attr->key_size;
 268         htab->map.value_size = attr->value_size;
 269         htab->map.max_entries = attr->max_entries;
 270         htab->map.map_flags = attr->map_flags;
 271
 272         /* check sanity of attributes.
 273          * value_size == 0 may be allowed in the future to use map as a set
 274          */
 275         err = -EINVAL;
 276         if (htab->map.max_entries == 0 || htab->map.key_size == 0 ||
 277             htab->map.value_size == 0)
 278                 goto free_htab;
 279
 280         if (percpu_lru) {
 281                 /* ensure each CPU's lru list has >=1 elements.
 282                  * since we are at it, make each lru list has the same
 283                  * number of elements.
 284                  */
 285                 htab->map.max_entries = roundup(attr->max_entries,
 286                                                 num_possible_cpus());
 287                 if (htab->map.max_entries < attr->max_entries)
 288                         htab->map.max_entries = rounddown(attr->max_entries,
 289                                                           num_possible_cpus());
 290         }
 291
 292         /* hash table size must be power of 2 */
 293         htab->n_buckets = roundup_pow_of_two(htab->map.max_entries);
 294
 295         err = -E2BIG;
 296         if (htab->map.key_size > MAX_BPF_STACK)
 297                 /* eBPF programs initialize keys on stack, so they cannot be
 298                  * larger than max stack size
 299                  */
 300                 goto free_htab;
 301
 302         if (htab->map.value_size >= KMALLOC_MAX_SIZE -
 303             MAX_BPF_STACK - sizeof(struct htab_elem))
 304                 /* if value_size is bigger, the user space won't be able to
 305                  * access the elements via bpf syscall. This check also makes
 306                  * sure that the elem_size doesn't overflow and it's
 307                  * kmalloc-able later in htab_map_update_elem()
 308                  */
 309                 goto free_htab;
 310
 311         if (percpu && round_up(htab->map.value_size, 8) > PCPU_MIN_UNIT_SIZE)
 312                 /* make sure the size for pcpu_alloc() is reasonable */
 313                 goto free_htab;
 314
 315         htab->elem_size = sizeof(struct htab_elem) +
 316                           round_up(htab->map.key_size, 8);
 317         if (percpu)
 318                 htab->elem_size += sizeof(void *);
 319         else
 320                 htab->elem_size += round_up(htab->map.value_size, 8);
 321
 322         /* prevent zero size kmalloc and check for u32 overflow */
 323         if (htab->n_buckets == 0 ||
 324             htab->n_buckets > U32_MAX / sizeof(struct bucket))
 325                 goto free_htab;
 326
 327         cost = (u64) htab->n_buckets * sizeof(struct bucket) +
 328                (u64) htab->elem_size * htab->map.max_entries;
 329
 330         if (percpu)
 331                 cost += (u64) round_up(htab->map.value_size, 8) *
 332                         num_possible_cpus() * htab->map.max_entries;
 333         else
 334                cost += (u64) htab->elem_size * num_possible_cpus();
 335
 336         if (cost >= U32_MAX - PAGE_SIZE)
 337                 /* make sure page count doesn't overflow */
 338                 goto free_htab;
 339
 340         htab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
 341
 342         /* if map size is larger than memlock limit, reject it early */
 343         err = bpf_map_precharge_memlock(htab->map.pages);
 344         if (err)
 345                 goto free_htab;
 346
 347         err = -ENOMEM;
 348         htab->buckets = bpf_map_area_alloc(htab->n_buckets *
 349                                            sizeof(struct bucket));
 350         if (!htab->buckets)
 351                 goto free_htab;
 352
 353         for (i = 0; i < htab->n_buckets; i++) {
 354                 INIT_HLIST_NULLS_HEAD(&htab->buckets[i].head, i);
 355                 raw_spin_lock_init(&htab->buckets[i].lock);
 356         }
 357
 358         if (prealloc) {
 359                 err = prealloc_init(htab);
 360                 if (err)
 361                         goto free_buckets;
 362
 363                 if (!percpu && !lru) {
 364                         /* lru itself can remove the least used element, so
 365                          * there is no need for an extra elem during map_update.
 366                          */
 367                         err = alloc_extra_elems(htab);
 368                         if (err)
 369                                 goto free_prealloc;
 370                 }
 371         }
 372
 373         return &htab->map;
 374
 375 free_prealloc:
 376         prealloc_destroy(htab);
 377 free_buckets:
 378         bpf_map_area_free(htab->buckets);
 379 free_htab:
 380         kfree(htab);
 381         return ERR_PTR(err);
 382 }
 383
 384 static inline u32 htab_map_hash(const void *key, u32 key_len)
 385 {
 386         return jhash(key, key_len, 0);
 387 }
 388
 389 static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash)
 390 {
 391         return &htab->buckets[hash & (htab->n_buckets - 1)];
 392 }
 393
 394 static inline struct hlist_nulls_head *select_bucket(struct bpf_htab *htab, u32 hash)
 395 {
 396         return &__select_bucket(htab, hash)->head;
 397 }
 398
 399 /* this lookup function can only be called with bucket lock taken */
 400 static struct htab_elem *lookup_elem_raw(struct hlist_nulls_head *head, u32 hash,
 401                                          void *key, u32 key_size)
 402 {
 403         struct hlist_nulls_node *n;
 404         struct htab_elem *l;
 405
 406         hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
 407                 if (l->hash == hash && !memcmp(&l->key, key, key_size))
 408                         return l;
 409
 410         return NULL;
 411 }
 412
 413 /* can be called without bucket lock. it will repeat the loop in
 414  * the unlikely event when elements moved from one bucket into another
 415  * while link list is being walked
 416  */
 417 static struct htab_elem *lookup_nulls_elem_raw(struct hlist_nulls_head *head,
 418                                                u32 hash, void *key,
 419                                                u32 key_size, u32 n_buckets)
 420 {
 421         struct hlist_nulls_node *n;
 422         struct htab_elem *l;
 423
 424 again:
 425         hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
 426                 if (l->hash == hash && !memcmp(&l->key, key, key_size))
 427                         return l;
 428
 429         if (unlikely(get_nulls_value(n) != (hash & (n_buckets - 1))))
 430                 goto again;
 431
 432         return NULL;
 433 }
 434
 435 /* Called from syscall or from eBPF program directly, so
 436  * arguments have to match bpf_map_lookup_elem() exactly.
 437  * The return value is adjusted by BPF instructions
 438  * in htab_map_gen_lookup().
 439  */
 440 static void *__htab_map_lookup_elem(struct bpf_map *map, void *key)
 441 {
 442         struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
 443         struct hlist_nulls_head *head;
 444         struct htab_elem *l;
 445         u32 hash, key_size;
 446
 447         /* Must be called with rcu_read_lock. */
 448         WARN_ON_ONCE(!rcu_read_lock_held());
 449
 450         key_size = map->key_size;
 451
 452         hash = htab_map_hash(key, key_size);
 453
 454         head = select_bucket(htab, hash);
 455
 456         l = lookup_nulls_elem_raw(head, hash, key, key_size, htab->n_buckets);
 457
 458         return l;
 459 }
 460
 461 static void *htab_map_lookup_elem(struct bpf_map *map, void *key)
 462 {
 463         struct htab_elem *l = __htab_map_lookup_elem(map, key);
 464
 465         if (l)
 466                 return l->key + round_up(map->key_size, 8);
 467
 468         return NULL;
 469 }
 470
 471 /* inline bpf_map_lookup_elem() call.
 472  * Instead of:
 473  * bpf_prog
 474  *   bpf_map_lookup_elem
 475  *     map->ops->map_lookup_elem
 476  *       htab_map_lookup_elem
 477  *         __htab_map_lookup_elem
 478  * do:
 479  * bpf_prog
 480  *   __htab_map_lookup_elem
 481  */
 482 static u32 htab_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
 483 {
 484         struct bpf_insn *insn = insn_buf;
 485         const int ret = BPF_REG_0;
 486
 487         *insn++ = BPF_EMIT_CALL((u64 (*)(u64, u64, u64, u64, u64))__htab_map_lookup_elem);
 488         *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1);
 489         *insn++ = BPF_ALU64_IMM(BPF_ADD, ret,
 490                                 offsetof(struct htab_elem, key) +
 491                                 round_up(map->key_size, 8));
 492         return insn - insn_buf;
 493 }
 494
 495 static void *htab_lru_map_lookup_elem(struct bpf_map *map, void *key)
 496 {
 497         struct htab_elem *l = __htab_map_lookup_elem(map, key);
 498
 499         if (l) {
 500                 bpf_lru_node_set_ref(&l->lru_node);
 501                 return l->key + round_up(map->key_size, 8);
 502         }
 503
 504         return NULL;
 505 }
 506
 507 /* It is called from the bpf_lru_list when the LRU needs to delete
 508  * older elements from the htab.
 509  */
 510 static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node)
 511 {
 512         struct bpf_htab *htab = (struct bpf_htab *)arg;
 513         struct htab_elem *l = NULL, *tgt_l;
 514         struct hlist_nulls_head *head;
 515         struct hlist_nulls_node *n;
 516         unsigned long flags;
 517         struct bucket *b;
 518
 519         tgt_l = container_of(node, struct htab_elem, lru_node);
 520         b = __select_bucket(htab, tgt_l->hash);
 521         head = &b->head;
 522
 523         raw_spin_lock_irqsave(&b->lock, flags);
 524
 525         hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
 526                 if (l == tgt_l) {
 527                         hlist_nulls_del_rcu(&l->hash_node);
 528                         break;
 529                 }
 530
 531         raw_spin_unlock_irqrestore(&b->lock, flags);
 532
 533         return l == tgt_l;
 534 }
 535
 536 /* Called from syscall */
 537 static int htab_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
 538 {
 539         struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
 540         struct hlist_nulls_head *head;
 541         struct htab_elem *l, *next_l;
 542         u32 hash, key_size;
 543         int i = 0;
 544
 545         WARN_ON_ONCE(!rcu_read_lock_held());
 546
 547         key_size = map->key_size;
 548
 549         if (!key)
 550                 goto find_first_elem;
 551
 552         hash = htab_map_hash(key, key_size);
 553
 554         head = select_bucket(htab, hash);
 555
 556         /* lookup the key */
 557         l = lookup_nulls_elem_raw(head, hash, key, key_size, htab->n_buckets);
 558
 559         if (!l)
 560                 goto find_first_elem;
 561
 562         /* key was found, get next key in the same bucket */
 563         next_l = hlist_nulls_entry_safe(rcu_dereference_raw(hlist_nulls_next_rcu(&l->hash_node)),
 564                                   struct htab_elem, hash_node);
 565
 566         if (next_l) {
 567                 /* if next elem in this hash list is non-zero, just return it */
 568                 memcpy(next_key, next_l->key, key_size);
 569                 return 0;
 570         }
 571
 572         /* no more elements in this hash list, go to the next bucket */
 573         i = hash & (htab->n_buckets - 1);
 574         i++;
 575
 576 find_first_elem:
 577         /* iterate over buckets */
 578         for (; i < htab->n_buckets; i++) {
 579                 head = select_bucket(htab, i);
 580
 581                 /* pick first element in the bucket */
 582                 next_l = hlist_nulls_entry_safe(rcu_dereference_raw(hlist_nulls_first_rcu(head)),
 583                                           struct htab_elem, hash_node);
 584                 if (next_l) {
 585                         /* if it's not empty, just return it */
 586                         memcpy(next_key, next_l->key, key_size);
 587                         return 0;
 588                 }
 589         }
 590
 591         /* iterated over all buckets and all elements */
 592         return -ENOENT;
 593 }
 594
 595 static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l)
 596 {
 597         if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH)
 598                 free_percpu(htab_elem_get_ptr(l, htab->map.key_size));
 599         kfree(l);
 600 }
 601
 602 static void htab_elem_free_rcu(struct rcu_head *head)
 603 {
 604         struct htab_elem *l = container_of(head, struct htab_elem, rcu);
 605         struct bpf_htab *htab = l->htab;
 606
 607         /* must increment bpf_prog_active to avoid kprobe+bpf triggering while
 608          * we're calling kfree, otherwise deadlock is possible if kprobes
 609          * are placed somewhere inside of slub
 610          */
 611         preempt_disable();
 612         __this_cpu_inc(bpf_prog_active);
 613         htab_elem_free(htab, l);
 614         __this_cpu_dec(bpf_prog_active);
 615         preempt_enable();
 616 }
 617
 618 static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
 619 {
 620         struct bpf_map *map = &htab->map;
 621
 622         if (map->ops->map_fd_put_ptr) {
 623                 void *ptr = fd_htab_map_get_ptr(map, l);
 624
 625                 map->ops->map_fd_put_ptr(ptr);
 626         }
 627
 628         if (htab_is_prealloc(htab)) {
 629                 pcpu_freelist_push(&htab->freelist, &l->fnode);
 630         } else {
 631                 atomic_dec(&htab->count);
 632                 l->htab = htab;
 633                 call_rcu(&l->rcu, htab_elem_free_rcu);
 634         }
 635 }
 636
 637 static void pcpu_copy_value(struct bpf_htab *htab, void __percpu *pptr,
 638                             void *value, bool onallcpus)
 639 {
 640         if (!onallcpus) {
 641                 /* copy true value_size bytes */
 642                 memcpy(this_cpu_ptr(pptr), value, htab->map.value_size);
 643         } else {
 644                 u32 size = round_up(htab->map.value_size, 8);
 645                 int off = 0, cpu;
 646
 647                 for_each_possible_cpu(cpu) {
 648                         bpf_long_memcpy(per_cpu_ptr(pptr, cpu),
 649                                         value + off, size);
 650                         off += size;
 651                 }
 652         }
 653 }
 654
 655 static bool fd_htab_map_needs_adjust(const struct bpf_htab *htab)
 656 {
 657         return htab->map.map_type == BPF_MAP_TYPE_HASH_OF_MAPS &&
 658                BITS_PER_LONG == 64;
 659 }
 660
 661 static u32 htab_size_value(const struct bpf_htab *htab, bool percpu)
 662 {
 663         u32 size = htab->map.value_size;
 664
 665         if (percpu || fd_htab_map_needs_adjust(htab))
 666                 size = round_up(size, 8);
 667         return size;
 668 }
 669
 670 static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
 671                                          void *value, u32 key_size, u32 hash,
 672                                          bool percpu, bool onallcpus,
 673                                          struct htab_elem *old_elem)
 674 {
 675         u32 size = htab_size_value(htab, percpu);
 676         bool prealloc = htab_is_prealloc(htab);
 677         struct htab_elem *l_new, **pl_new;
 678         void __percpu *pptr;
 679
 680         if (prealloc) {
 681                 if (old_elem) {
 682                         /* if we're updating the existing element,
 683                          * use per-cpu extra elems to avoid freelist_pop/push
 684                          */
 685                         pl_new = this_cpu_ptr(htab->extra_elems);
 686                         l_new = *pl_new;
 687                         *pl_new = old_elem;
 688                 } else {
 689                         struct pcpu_freelist_node *l;
 690
 691                         l = pcpu_freelist_pop(&htab->freelist);
 692                         if (!l)
 693                                 return ERR_PTR(-E2BIG);
 694                         l_new = container_of(l, struct htab_elem, fnode);
 695                 }
 696         } else {
 697                 if (atomic_inc_return(&htab->count) > htab->map.max_entries)
 698                         if (!old_elem) {
 699                                 /* when map is full and update() is replacing
 700                                  * old element, it's ok to allocate, since
 701                                  * old element will be freed immediately.
 702                                  * Otherwise return an error
 703                                  */
 704                                 atomic_dec(&htab->count);
 705                                 return ERR_PTR(-E2BIG);
 706                         }
 707                 l_new = kmalloc(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN);
 708                 if (!l_new)
 709                         return ERR_PTR(-ENOMEM);
 710         }
 711
 712         memcpy(l_new->key, key, key_size);
 713         if (percpu) {
 714                 if (prealloc) {
 715                         pptr = htab_elem_get_ptr(l_new, key_size);
 716                 } else {
 717                         /* alloc_percpu zero-fills */
 718                         pptr = __alloc_percpu_gfp(size, 8,
 719                                                   GFP_ATOMIC | __GFP_NOWARN);
 720                         if (!pptr) {
 721                                 kfree(l_new);
 722                                 return ERR_PTR(-ENOMEM);
 723                         }
 724                 }
 725
 726                 pcpu_copy_value(htab, pptr, value, onallcpus);
 727
 728                 if (!prealloc)
 729                         htab_elem_set_ptr(l_new, key_size, pptr);
 730         } else {
 731                 memcpy(l_new->key + round_up(key_size, 8), value, size);
 732         }
 733
 734         l_new->hash = hash;
 735         return l_new;
 736 }
 737
 738 static int check_flags(struct bpf_htab *htab, struct htab_elem *l_old,
 739                        u64 map_flags)
 740 {
 741         if (l_old && map_flags == BPF_NOEXIST)
 742                 /* elem already exists */
 743                 return -EEXIST;
 744
 745         if (!l_old && map_flags == BPF_EXIST)
 746                 /* elem doesn't exist, cannot update it */
 747                 return -ENOENT;
 748
 749         return 0;
 750 }
 751
 752 /* Called from syscall or from eBPF program */
 753 static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
 754                                 u64 map_flags)
 755 {
 756         struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
 757         struct htab_elem *l_new = NULL, *l_old;
 758         struct hlist_nulls_head *head;
 759         unsigned long flags;
 760         struct bucket *b;
 761         u32 key_size, hash;
 762         int ret;
 763
 764         if (unlikely(map_flags > BPF_EXIST))
 765                 /* unknown flags */
 766                 return -EINVAL;
 767
 768         WARN_ON_ONCE(!rcu_read_lock_held());
 769
 770         key_size = map->key_size;
 771
 772         hash = htab_map_hash(key, key_size);
 773
 774         b = __select_bucket(htab, hash);
 775         head = &b->head;
 776
 777         /* bpf_map_update_elem() can be called in_irq() */
 778         raw_spin_lock_irqsave(&b->lock, flags);
 779
 780         l_old = lookup_elem_raw(head, hash, key, key_size);
 781
 782         ret = check_flags(htab, l_old, map_flags);
 783         if (ret)
 784                 goto err;
 785
 786         l_new = alloc_htab_elem(htab, key, value, key_size, hash, false, false,
 787                                 l_old);
 788         if (IS_ERR(l_new)) {
 789                 /* all pre-allocated elements are in use or memory exhausted */
 790                 ret = PTR_ERR(l_new);
 791                 goto err;
 792         }
 793
 794         /* add new element to the head of the list, so that
 795          * concurrent search will find it before old elem
 796          */
 797         hlist_nulls_add_head_rcu(&l_new->hash_node, head);
 798         if (l_old) {
 799                 hlist_nulls_del_rcu(&l_old->hash_node);
 800                 if (!htab_is_prealloc(htab))
 801                         free_htab_elem(htab, l_old);
 802         }
 803         ret = 0;
 804 err:
 805         raw_spin_unlock_irqrestore(&b->lock, flags);
 806         return ret;
 807 }
 808
 809 static int htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value,
 810                                     u64 map_flags)
 811 {
 812         struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
 813         struct htab_elem *l_new, *l_old = NULL;
 814         struct hlist_nulls_head *head;
 815         unsigned long flags;
 816         struct bucket *b;
 817         u32 key_size, hash;
 818         int ret;
 819
 820         if (unlikely(map_flags > BPF_EXIST))
 821                 /* unknown flags */
 822                 return -EINVAL;
 823
 824         WARN_ON_ONCE(!rcu_read_lock_held());
 825
 826         key_size = map->key_size;
 827
 828         hash = htab_map_hash(key, key_size);
 829
 830         b = __select_bucket(htab, hash);
 831         head = &b->head;
 832
 833         /* For LRU, we need to alloc before taking bucket's
 834          * spinlock because getting free nodes from LRU may need
 835          * to remove older elements from htab and this removal
 836          * operation will need a bucket lock.
 837          */
 838         l_new = prealloc_lru_pop(htab, key, hash);
 839         if (!l_new)
 840                 return -ENOMEM;
 841         memcpy(l_new->key + round_up(map->key_size, 8), value, map->value_size);
 842
 843         /* bpf_map_update_elem() can be called in_irq() */
 844         raw_spin_lock_irqsave(&b->lock, flags);
 845
 846         l_old = lookup_elem_raw(head, hash, key, key_size);
 847
 848         ret = check_flags(htab, l_old, map_flags);
 849         if (ret)
 850                 goto err;
 851
 852         /* add new element to the head of the list, so that
 853          * concurrent search will find it before old elem
 854          */
 855         hlist_nulls_add_head_rcu(&l_new->hash_node, head);
 856         if (l_old) {
 857                 bpf_lru_node_set_ref(&l_new->lru_node);
 858                 hlist_nulls_del_rcu(&l_old->hash_node);
 859         }
 860         ret = 0;
 861
 862 err:
 863         raw_spin_unlock_irqrestore(&b->lock, flags);
 864
 865         if (ret)
 866                 bpf_lru_push_free(&htab->lru, &l_new->lru_node);
 867         else if (l_old)
 868                 bpf_lru_push_free(&htab->lru, &l_old->lru_node);
 869
 870         return ret;
 871 }
 872
 873 static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key,
 874                                          void *value, u64 map_flags,
 875                                          bool onallcpus)
 876 {
 877         struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
 878         struct htab_elem *l_new = NULL, *l_old;
 879         struct hlist_nulls_head *head;
 880         unsigned long flags;
 881         struct bucket *b;
 882         u32 key_size, hash;
 883         int ret;
 884
 885         if (unlikely(map_flags > BPF_EXIST))
 886                 /* unknown flags */
 887                 return -EINVAL;
 888
 889         WARN_ON_ONCE(!rcu_read_lock_held());
 890
 891         key_size = map->key_size;
 892
 893         hash = htab_map_hash(key, key_size);
 894
 895         b = __select_bucket(htab, hash);
 896         head = &b->head;
 897
 898         /* bpf_map_update_elem() can be called in_irq() */
 899         raw_spin_lock_irqsave(&b->lock, flags);
 900
 901         l_old = lookup_elem_raw(head, hash, key, key_size);
 902
 903         ret = check_flags(htab, l_old, map_flags);
 904         if (ret)
 905                 goto err;
 906
 907         if (l_old) {
 908                 /* per-cpu hash map can update value in-place */
 909                 pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
 910                                 value, onallcpus);
 911         } else {
 912                 l_new = alloc_htab_elem(htab, key, value, key_size,
 913                                         hash, true, onallcpus, NULL);
 914                 if (IS_ERR(l_new)) {
 915                         ret = PTR_ERR(l_new);
 916                         goto err;
 917                 }
 918                 hlist_nulls_add_head_rcu(&l_new->hash_node, head);
 919         }
 920         ret = 0;
 921 err:
 922         raw_spin_unlock_irqrestore(&b->lock, flags);
 923         return ret;
 924 }
 925
 926 static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
 927                                              void *value, u64 map_flags,
 928                                              bool onallcpus)
 929 {
 930         struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
 931         struct htab_elem *l_new = NULL, *l_old;
 932         struct hlist_nulls_head *head;
 933         unsigned long flags;
 934         struct bucket *b;
 935         u32 key_size, hash;
 936         int ret;
 937
 938         if (unlikely(map_flags > BPF_EXIST))
 939                 /* unknown flags */
 940                 return -EINVAL;
 941
 942         WARN_ON_ONCE(!rcu_read_lock_held());
 943
 944         key_size = map->key_size;
 945
 946         hash = htab_map_hash(key, key_size);
 947
 948         b = __select_bucket(htab, hash);
 949         head = &b->head;
 950
 951         /* For LRU, we need to alloc before taking bucket's
 952          * spinlock because LRU's elem alloc may need
 953          * to remove older elem from htab and this removal
 954          * operation will need a bucket lock.
 955          */
 956         if (map_flags != BPF_EXIST) {
 957                 l_new = prealloc_lru_pop(htab, key, hash);
 958                 if (!l_new)
 959                         return -ENOMEM;
 960         }
 961
 962         /* bpf_map_update_elem() can be called in_irq() */
 963         raw_spin_lock_irqsave(&b->lock, flags);
 964
 965         l_old = lookup_elem_raw(head, hash, key, key_size);
 966
 967         ret = check_flags(htab, l_old, map_flags);
 968         if (ret)
 969                 goto err;
 970
 971         if (l_old) {
 972                 bpf_lru_node_set_ref(&l_old->lru_node);
 973
 974                 /* per-cpu hash map can update value in-place */
 975                 pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
 976                                 value, onallcpus);
 977         } else {
 978                 pcpu_copy_value(htab, htab_elem_get_ptr(l_new, key_size),
 979                                 value, onallcpus);
 980                 hlist_nulls_add_head_rcu(&l_new->hash_node, head);
 981                 l_new = NULL;
 982         }
 983         ret = 0;
 984 err:
 985         raw_spin_unlock_irqrestore(&b->lock, flags);
 986         if (l_new)
 987                 bpf_lru_push_free(&htab->lru, &l_new->lru_node);
 988         return ret;
 989 }
 990
 991 static int htab_percpu_map_update_elem(struct bpf_map *map, void *key,
 992                                        void *value, u64 map_flags)
 993 {
 994         return __htab_percpu_map_update_elem(map, key, value, map_flags, false);
 995 }
 996
 997 static int htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
 998                                            void *value, u64 map_flags)
 999 {
1000         return __htab_lru_percpu_map_update_elem(map, key, value, map_flags,
1001                                                  false);
1002 }
1003
1004 /* Called from syscall or from eBPF program */
1005 static int htab_map_delete_elem(struct bpf_map *map, void *key)
1006 {
1007         struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1008         struct hlist_nulls_head *head;
1009         struct bucket *b;
1010         struct htab_elem *l;
1011         unsigned long flags;
1012         u32 hash, key_size;
1013         int ret = -ENOENT;
1014
1015         WARN_ON_ONCE(!rcu_read_lock_held());
1016
1017         key_size = map->key_size;
1018
1019         hash = htab_map_hash(key, key_size);
1020         b = __select_bucket(htab, hash);
1021         head = &b->head;
1022
1023         raw_spin_lock_irqsave(&b->lock, flags);
1024
1025         l = lookup_elem_raw(head, hash, key, key_size);
1026
1027         if (l) {
1028                 hlist_nulls_del_rcu(&l->hash_node);
1029                 free_htab_elem(htab, l);
1030                 ret = 0;
1031         }
1032
1033         raw_spin_unlock_irqrestore(&b->lock, flags);
1034         return ret;
1035 }
1036
1037 static int htab_lru_map_delete_elem(struct bpf_map *map, void *key)
1038 {
1039         struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1040         struct hlist_nulls_head *head;
1041         struct bucket *b;
1042         struct htab_elem *l;
1043         unsigned long flags;
1044         u32 hash, key_size;
1045         int ret = -ENOENT;
1046
1047         WARN_ON_ONCE(!rcu_read_lock_held());
1048
1049         key_size = map->key_size;
1050
1051         hash = htab_map_hash(key, key_size);
1052         b = __select_bucket(htab, hash);
1053         head = &b->head;
1054
1055         raw_spin_lock_irqsave(&b->lock, flags);
1056
1057         l = lookup_elem_raw(head, hash, key, key_size);
1058
1059         if (l) {
1060                 hlist_nulls_del_rcu(&l->hash_node);
1061                 ret = 0;
1062         }
1063
1064         raw_spin_unlock_irqrestore(&b->lock, flags);
1065         if (l)
1066                 bpf_lru_push_free(&htab->lru, &l->lru_node);
1067         return ret;
1068 }
1069
1070 static void delete_all_elements(struct bpf_htab *htab)
1071 {
1072         int i;
1073
1074         for (i = 0; i < htab->n_buckets; i++) {
1075                 struct hlist_nulls_head *head = select_bucket(htab, i);
1076                 struct hlist_nulls_node *n;
1077                 struct htab_elem *l;
1078
1079                 hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
1080                         hlist_nulls_del_rcu(&l->hash_node);
1081                         htab_elem_free(htab, l);
1082                 }
1083         }
1084 }
1085
1086 /* Called when map->refcnt goes to zero, either from workqueue or from syscall */
1087 static void htab_map_free(struct bpf_map *map)
1088 {
1089         struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1090
1091         /* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0,
1092          * so the programs (can be more than one that used this map) were
1093          * disconnected from events. Wait for outstanding critical sections in
1094          * these programs to complete
1095          */
1096         synchronize_rcu();
1097
1098         /* some of free_htab_elem() callbacks for elements of this map may
1099          * not have executed. Wait for them.
1100          */
1101         rcu_barrier();
1102         if (!htab_is_prealloc(htab))
1103                 delete_all_elements(htab);
1104         else
1105                 prealloc_destroy(htab);
1106
1107         free_percpu(htab->extra_elems);
1108         bpf_map_area_free(htab->buckets);
1109         kfree(htab);
1110 }
1111
1112 const struct bpf_map_ops htab_map_ops = {
1113         .map_alloc = htab_map_alloc,
1114         .map_free = htab_map_free,
1115         .map_get_next_key = htab_map_get_next_key,
1116         .map_lookup_elem = htab_map_lookup_elem,
1117         .map_update_elem = htab_map_update_elem,
1118         .map_delete_elem = htab_map_delete_elem,
1119         .map_gen_lookup = htab_map_gen_lookup,
1120 };
1121
1122 const struct bpf_map_ops htab_lru_map_ops = {
1123         .map_alloc = htab_map_alloc,
1124         .map_free = htab_map_free,
1125         .map_get_next_key = htab_map_get_next_key,
1126         .map_lookup_elem = htab_lru_map_lookup_elem,
1127         .map_update_elem = htab_lru_map_update_elem,
1128         .map_delete_elem = htab_lru_map_delete_elem,
1129 };
1130
1131 /* Called from eBPF program */
1132 static void *htab_percpu_map_lookup_elem(struct bpf_map *map, void *key)
1133 {
1134         struct htab_elem *l = __htab_map_lookup_elem(map, key);
1135
1136         if (l)
1137                 return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
1138         else
1139                 return NULL;
1140 }
1141
1142 static void *htab_lru_percpu_map_lookup_elem(struct bpf_map *map, void *key)
1143 {
1144         struct htab_elem *l = __htab_map_lookup_elem(map, key);
1145
1146         if (l) {
1147                 bpf_lru_node_set_ref(&l->lru_node);
1148                 return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
1149         }
1150
1151         return NULL;
1152 }
1153
1154 int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value)
1155 {
1156         struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1157         struct htab_elem *l;
1158         void __percpu *pptr;
1159         int ret = -ENOENT;
1160         int cpu, off = 0;
1161         u32 size;
1162
1163         /* per_cpu areas are zero-filled and bpf programs can only
1164          * access 'value_size' of them, so copying rounded areas
1165          * will not leak any kernel data
1166          */
1167         size = round_up(map->value_size, 8);
1168         rcu_read_lock();
1169         l = __htab_map_lookup_elem(map, key);
1170         if (!l)
1171                 goto out;
1172         if (htab_is_lru(htab))
1173                 bpf_lru_node_set_ref(&l->lru_node);
1174         pptr = htab_elem_get_ptr(l, map->key_size);
1175         for_each_possible_cpu(cpu) {
1176                 bpf_long_memcpy(value + off,
1177                                 per_cpu_ptr(pptr, cpu), size);
1178                 off += size;
1179         }
1180         ret = 0;
1181 out:
1182         rcu_read_unlock();
1183         return ret;
1184 }
1185
1186 int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
1187                            u64 map_flags)
1188 {
1189         struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1190         int ret;
1191
1192         rcu_read_lock();
1193         if (htab_is_lru(htab))
1194                 ret = __htab_lru_percpu_map_update_elem(map, key, value,
1195                                                         map_flags, true);
1196         else
1197                 ret = __htab_percpu_map_update_elem(map, key, value, map_flags,
1198                                                     true);
1199         rcu_read_unlock();
1200
1201         return ret;
1202 }
1203
1204 const struct bpf_map_ops htab_percpu_map_ops = {
1205         .map_alloc = htab_map_alloc,
1206         .map_free = htab_map_free,
1207         .map_get_next_key = htab_map_get_next_key,
1208         .map_lookup_elem = htab_percpu_map_lookup_elem,
1209         .map_update_elem = htab_percpu_map_update_elem,
1210         .map_delete_elem = htab_map_delete_elem,
1211 };
1212
1213 const struct bpf_map_ops htab_lru_percpu_map_ops = {
1214         .map_alloc = htab_map_alloc,
1215         .map_free = htab_map_free,
1216         .map_get_next_key = htab_map_get_next_key,
1217         .map_lookup_elem = htab_lru_percpu_map_lookup_elem,
1218         .map_update_elem = htab_lru_percpu_map_update_elem,
1219         .map_delete_elem = htab_lru_map_delete_elem,
1220 };
1221
1222 static struct bpf_map *fd_htab_map_alloc(union bpf_attr *attr)
1223 {
1224         if (attr->value_size != sizeof(u32))
1225                 return ERR_PTR(-EINVAL);
1226         return htab_map_alloc(attr);
1227 }
1228
1229 static void fd_htab_map_free(struct bpf_map *map)
1230 {
1231         struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1232         struct hlist_nulls_node *n;
1233         struct hlist_nulls_head *head;
1234         struct htab_elem *l;
1235         int i;
1236
1237         for (i = 0; i < htab->n_buckets; i++) {
1238                 head = select_bucket(htab, i);
1239
1240                 hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
1241                         void *ptr = fd_htab_map_get_ptr(map, l);
1242
1243                         map->ops->map_fd_put_ptr(ptr);
1244                 }
1245         }
1246
1247         htab_map_free(map);
1248 }
1249
1250 /* only called from syscall */
1251 int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value)
1252 {
1253         void **ptr;
1254         int ret = 0;
1255
1256         if (!map->ops->map_fd_sys_lookup_elem)
1257                 return -ENOTSUPP;
1258
1259         rcu_read_lock();
1260         ptr = htab_map_lookup_elem(map, key);
1261         if (ptr)
1262                 *value = map->ops->map_fd_sys_lookup_elem(READ_ONCE(*ptr));
1263         else
1264                 ret = -ENOENT;
1265         rcu_read_unlock();
1266
1267         return ret;
1268 }
1269
1270 /* only called from syscall */
1271 int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file,
1272                                 void *key, void *value, u64 map_flags)
1273 {
1274         void *ptr;
1275         int ret;
1276         u32 ufd = *(u32 *)value;
1277
1278         ptr = map->ops->map_fd_get_ptr(map, map_file, ufd);
1279         if (IS_ERR(ptr))
1280                 return PTR_ERR(ptr);
1281
1282         ret = htab_map_update_elem(map, key, &ptr, map_flags);
1283         if (ret)
1284                 map->ops->map_fd_put_ptr(ptr);
1285
1286         return ret;
1287 }
1288
1289 static struct bpf_map *htab_of_map_alloc(union bpf_attr *attr)
1290 {
1291         struct bpf_map *map, *inner_map_meta;
1292
1293         inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd);
1294         if (IS_ERR(inner_map_meta))
1295                 return inner_map_meta;
1296
1297         map = fd_htab_map_alloc(attr);
1298         if (IS_ERR(map)) {
1299                 bpf_map_meta_free(inner_map_meta);
1300                 return map;
1301         }
1302
1303         map->inner_map_meta = inner_map_meta;
1304
1305         return map;
1306 }
1307
1308 static void *htab_of_map_lookup_elem(struct bpf_map *map, void *key)
1309 {
1310         struct bpf_map **inner_map  = htab_map_lookup_elem(map, key);
1311
1312         if (!inner_map)
1313                 return NULL;
1314
1315         return READ_ONCE(*inner_map);
1316 }
1317
1318 static void htab_of_map_free(struct bpf_map *map)
1319 {
1320         bpf_map_meta_free(map->inner_map_meta);
1321         fd_htab_map_free(map);
1322 }
1323
1324 const struct bpf_map_ops htab_of_maps_map_ops = {
1325         .map_alloc = htab_of_map_alloc,
1326         .map_free = htab_of_map_free,
1327         .map_get_next_key = htab_map_get_next_key,
1328         .map_lookup_elem = htab_of_map_lookup_elem,
1329         .map_delete_elem = htab_map_delete_elem,
1330         .map_fd_get_ptr = bpf_map_fd_get_ptr,
1331         .map_fd_put_ptr = bpf_map_fd_put_ptr,
1332         .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
1333 };