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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#define HTAB_CREATE_FLAG_MASK \
22 (BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU | BPF_F_NUMA_NODE | \
23 BPF_F_RDONLY | BPF_F_WRONLY)
24
25struct bucket {
26 struct hlist_nulls_head head;
27 raw_spinlock_t lock;
28};
29
30struct bpf_htab {
31 struct bpf_map map;
32 struct bucket *buckets;
33 void *elems;
34 union {
35 struct pcpu_freelist freelist;
36 struct bpf_lru lru;
37 };
38 struct htab_elem *__percpu *extra_elems;
39 atomic_t count; /* number of elements in this hashtable */
40 u32 n_buckets; /* number of hash buckets */
41 u32 elem_size; /* size of each element in bytes */
42};
43
44/* each htab element is struct htab_elem + key + value */
45struct htab_elem {
46 union {
47 struct hlist_nulls_node hash_node;
48 struct {
49 void *padding;
50 union {
51 struct bpf_htab *htab;
52 struct pcpu_freelist_node fnode;
53 };
54 };
55 };
56 union {
57 struct rcu_head rcu;
58 struct bpf_lru_node lru_node;
59 };
60 u32 hash;
61 char key[0] __aligned(8);
62};
63
64static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node);
65
66static bool htab_is_lru(const struct bpf_htab *htab)
67{
68 return htab->map.map_type == BPF_MAP_TYPE_LRU_HASH ||
69 htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
70}
71
72static bool htab_is_percpu(const struct bpf_htab *htab)
73{
74 return htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH ||
75 htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
76}
77
78static bool htab_is_prealloc(const struct bpf_htab *htab)
79{
80 return !(htab->map.map_flags & BPF_F_NO_PREALLOC);
81}
82
83static inline void htab_elem_set_ptr(struct htab_elem *l, u32 key_size,
84 void __percpu *pptr)
85{
86 *(void __percpu **)(l->key + key_size) = pptr;
87}
88
89static inline void __percpu *htab_elem_get_ptr(struct htab_elem *l, u32 key_size)
90{
91 return *(void __percpu **)(l->key + key_size);
92}
93
94static void *fd_htab_map_get_ptr(const struct bpf_map *map, struct htab_elem *l)
95{
96 return *(void **)(l->key + roundup(map->key_size, 8));
97}
98
99static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i)
100{
101 return (struct htab_elem *) (htab->elems + i * htab->elem_size);
102}
103
104static void htab_free_elems(struct bpf_htab *htab)
105{
106 int i;
107
108 if (!htab_is_percpu(htab))
109 goto free_elems;
110
111 for (i = 0; i < htab->map.max_entries; i++) {
112 void __percpu *pptr;
113
114 pptr = htab_elem_get_ptr(get_htab_elem(htab, i),
115 htab->map.key_size);
116 free_percpu(pptr);
117 cond_resched();
118 }
119free_elems:
120 bpf_map_area_free(htab->elems);
121}
122
123static struct htab_elem *prealloc_lru_pop(struct bpf_htab *htab, void *key,
124 u32 hash)
125{
126 struct bpf_lru_node *node = bpf_lru_pop_free(&htab->lru, hash);
127 struct htab_elem *l;
128
129 if (node) {
130 l = container_of(node, struct htab_elem, lru_node);
131 memcpy(l->key, key, htab->map.key_size);
132 return l;
133 }
134
135 return NULL;
136}
137
138static int prealloc_init(struct bpf_htab *htab)
139{
140 u32 num_entries = htab->map.max_entries;
141 int err = -ENOMEM, i;
142
143 if (!htab_is_percpu(htab) && !htab_is_lru(htab))
144 num_entries += num_possible_cpus();
145
146 htab->elems = bpf_map_area_alloc(htab->elem_size * num_entries,
147 htab->map.numa_node);
148 if (!htab->elems)
149 return -ENOMEM;
150
151 if (!htab_is_percpu(htab))
152 goto skip_percpu_elems;
153
154 for (i = 0; i < num_entries; i++) {
155 u32 size = round_up(htab->map.value_size, 8);
156 void __percpu *pptr;
157
158 pptr = __alloc_percpu_gfp(size, 8, GFP_USER | __GFP_NOWARN);
159 if (!pptr)
160 goto free_elems;
161 htab_elem_set_ptr(get_htab_elem(htab, i), htab->map.key_size,
162 pptr);
163 cond_resched();
164 }
165
166skip_percpu_elems:
167 if (htab_is_lru(htab))
168 err = bpf_lru_init(&htab->lru,
169 htab->map.map_flags & BPF_F_NO_COMMON_LRU,
170 offsetof(struct htab_elem, hash) -
171 offsetof(struct htab_elem, lru_node),
172 htab_lru_map_delete_node,
173 htab);
174 else
175 err = pcpu_freelist_init(&htab->freelist);
176
177 if (err)
178 goto free_elems;
179
180 if (htab_is_lru(htab))
181 bpf_lru_populate(&htab->lru, htab->elems,
182 offsetof(struct htab_elem, lru_node),
183 htab->elem_size, num_entries);
184 else
185 pcpu_freelist_populate(&htab->freelist,
186 htab->elems + offsetof(struct htab_elem, fnode),
187 htab->elem_size, num_entries);
188
189 return 0;
190
191free_elems:
192 htab_free_elems(htab);
193 return err;
194}
195
196static void prealloc_destroy(struct bpf_htab *htab)
197{
198 htab_free_elems(htab);
199
200 if (htab_is_lru(htab))
201 bpf_lru_destroy(&htab->lru);
202 else
203 pcpu_freelist_destroy(&htab->freelist);
204}
205
206static int alloc_extra_elems(struct bpf_htab *htab)
207{
208 struct htab_elem *__percpu *pptr, *l_new;
209 struct pcpu_freelist_node *l;
210 int cpu;
211
212 pptr = __alloc_percpu_gfp(sizeof(struct htab_elem *), 8,
213 GFP_USER | __GFP_NOWARN);
214 if (!pptr)
215 return -ENOMEM;
216
217 for_each_possible_cpu(cpu) {
218 l = pcpu_freelist_pop(&htab->freelist);
219 /* pop will succeed, since prealloc_init()
220 * preallocated extra num_possible_cpus elements
221 */
222 l_new = container_of(l, struct htab_elem, fnode);
223 *per_cpu_ptr(pptr, cpu) = l_new;
224 }
225 htab->extra_elems = pptr;
226 return 0;
227}
228
229/* Called from syscall */
230static int htab_map_alloc_check(union bpf_attr *attr)
231{
232 bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
233 attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
234 bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH ||
235 attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
236 /* percpu_lru means each cpu has its own LRU list.
237 * it is different from BPF_MAP_TYPE_PERCPU_HASH where
238 * the map's value itself is percpu. percpu_lru has
239 * nothing to do with the map's value.
240 */
241 bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU);
242 bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC);
243 int numa_node = bpf_map_attr_numa_node(attr);
244
245 BUILD_BUG_ON(offsetof(struct htab_elem, htab) !=
246 offsetof(struct htab_elem, hash_node.pprev));
247 BUILD_BUG_ON(offsetof(struct htab_elem, fnode.next) !=
248 offsetof(struct htab_elem, hash_node.pprev));
249
250 if (lru && !capable(CAP_SYS_ADMIN))
251 /* LRU implementation is much complicated than other
252 * maps. Hence, limit to CAP_SYS_ADMIN for now.
253 */
254 return -EPERM;
255
256 if (attr->map_flags & ~HTAB_CREATE_FLAG_MASK)
257 /* reserved bits should not be used */
258 return -EINVAL;
259
260 if (!lru && percpu_lru)
261 return -EINVAL;
262
263 if (lru && !prealloc)
264 return -ENOTSUPP;
265
266 if (numa_node != NUMA_NO_NODE && (percpu || percpu_lru))
267 return -EINVAL;
268
269 /* check sanity of attributes.
270 * value_size == 0 may be allowed in the future to use map as a set
271 */
272 if (attr->max_entries == 0 || attr->key_size == 0 ||
273 attr->value_size == 0)
274 return -EINVAL;
275
276 if (attr->key_size > MAX_BPF_STACK)
277 /* eBPF programs initialize keys on stack, so they cannot be
278 * larger than max stack size
279 */
280 return -E2BIG;
281
282 if (attr->value_size >= KMALLOC_MAX_SIZE -
283 MAX_BPF_STACK - sizeof(struct htab_elem))
284 /* if value_size is bigger, the user space won't be able to
285 * access the elements via bpf syscall. This check also makes
286 * sure that the elem_size doesn't overflow and it's
287 * kmalloc-able later in htab_map_update_elem()
288 */
289 return -E2BIG;
290
291 return 0;
292}
293
294static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
295{
296 bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
297 attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
298 bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH ||
299 attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
300 /* percpu_lru means each cpu has its own LRU list.
301 * it is different from BPF_MAP_TYPE_PERCPU_HASH where
302 * the map's value itself is percpu. percpu_lru has
303 * nothing to do with the map's value.
304 */
305 bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU);
306 bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC);
307 struct bpf_htab *htab;
308 int err, i;
309 u64 cost;
310
311 htab = kzalloc(sizeof(*htab), GFP_USER);
312 if (!htab)
313 return ERR_PTR(-ENOMEM);
314
315 bpf_map_init_from_attr(&htab->map, attr);
316
317 if (percpu_lru) {
318 /* ensure each CPU's lru list has >=1 elements.
319 * since we are at it, make each lru list has the same
320 * number of elements.
321 */
322 htab->map.max_entries = roundup(attr->max_entries,
323 num_possible_cpus());
324 if (htab->map.max_entries < attr->max_entries)
325 htab->map.max_entries = rounddown(attr->max_entries,
326 num_possible_cpus());
327 }
328
329 /* hash table size must be power of 2 */
330 htab->n_buckets = roundup_pow_of_two(htab->map.max_entries);
331
332 htab->elem_size = sizeof(struct htab_elem) +
333 round_up(htab->map.key_size, 8);
334 if (percpu)
335 htab->elem_size += sizeof(void *);
336 else
337 htab->elem_size += round_up(htab->map.value_size, 8);
338
339 err = -E2BIG;
340 /* prevent zero size kmalloc and check for u32 overflow */
341 if (htab->n_buckets == 0 ||
342 htab->n_buckets > U32_MAX / sizeof(struct bucket))
343 goto free_htab;
344
345 cost = (u64) htab->n_buckets * sizeof(struct bucket) +
346 (u64) htab->elem_size * htab->map.max_entries;
347
348 if (percpu)
349 cost += (u64) round_up(htab->map.value_size, 8) *
350 num_possible_cpus() * htab->map.max_entries;
351 else
352 cost += (u64) htab->elem_size * num_possible_cpus();
353
354 if (cost >= U32_MAX - PAGE_SIZE)
355 /* make sure page count doesn't overflow */
356 goto free_htab;
357
358 htab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
359
360 /* if map size is larger than memlock limit, reject it early */
361 err = bpf_map_precharge_memlock(htab->map.pages);
362 if (err)
363 goto free_htab;
364
365 err = -ENOMEM;
366 htab->buckets = bpf_map_area_alloc(htab->n_buckets *
367 sizeof(struct bucket),
368 htab->map.numa_node);
369 if (!htab->buckets)
370 goto free_htab;
371
372 for (i = 0; i < htab->n_buckets; i++) {
373 INIT_HLIST_NULLS_HEAD(&htab->buckets[i].head, i);
374 raw_spin_lock_init(&htab->buckets[i].lock);
375 }
376
377 if (prealloc) {
378 err = prealloc_init(htab);
379 if (err)
380 goto free_buckets;
381
382 if (!percpu && !lru) {
383 /* lru itself can remove the least used element, so
384 * there is no need for an extra elem during map_update.
385 */
386 err = alloc_extra_elems(htab);
387 if (err)
388 goto free_prealloc;
389 }
390 }
391
392 return &htab->map;
393
394free_prealloc:
395 prealloc_destroy(htab);
396free_buckets:
397 bpf_map_area_free(htab->buckets);
398free_htab:
399 kfree(htab);
400 return ERR_PTR(err);
401}
402
403static inline u32 htab_map_hash(const void *key, u32 key_len)
404{
405 return jhash(key, key_len, 0);
406}
407
408static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash)
409{
410 return &htab->buckets[hash & (htab->n_buckets - 1)];
411}
412
413static inline struct hlist_nulls_head *select_bucket(struct bpf_htab *htab, u32 hash)
414{
415 return &__select_bucket(htab, hash)->head;
416}
417
418/* this lookup function can only be called with bucket lock taken */
419static struct htab_elem *lookup_elem_raw(struct hlist_nulls_head *head, u32 hash,
420 void *key, u32 key_size)
421{
422 struct hlist_nulls_node *n;
423 struct htab_elem *l;
424
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 return NULL;
430}
431
432/* can be called without bucket lock. it will repeat the loop in
433 * the unlikely event when elements moved from one bucket into another
434 * while link list is being walked
435 */
436static struct htab_elem *lookup_nulls_elem_raw(struct hlist_nulls_head *head,
437 u32 hash, void *key,
438 u32 key_size, u32 n_buckets)
439{
440 struct hlist_nulls_node *n;
441 struct htab_elem *l;
442
443again:
444 hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
445 if (l->hash == hash && !memcmp(&l->key, key, key_size))
446 return l;
447
448 if (unlikely(get_nulls_value(n) != (hash & (n_buckets - 1))))
449 goto again;
450
451 return NULL;
452}
453
454/* Called from syscall or from eBPF program directly, so
455 * arguments have to match bpf_map_lookup_elem() exactly.
456 * The return value is adjusted by BPF instructions
457 * in htab_map_gen_lookup().
458 */
459static void *__htab_map_lookup_elem(struct bpf_map *map, void *key)
460{
461 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
462 struct hlist_nulls_head *head;
463 struct htab_elem *l;
464 u32 hash, key_size;
465
466 /* Must be called with rcu_read_lock. */
467 WARN_ON_ONCE(!rcu_read_lock_held());
468
469 key_size = map->key_size;
470
471 hash = htab_map_hash(key, key_size);
472
473 head = select_bucket(htab, hash);
474
475 l = lookup_nulls_elem_raw(head, hash, key, key_size, htab->n_buckets);
476
477 return l;
478}
479
480static void *htab_map_lookup_elem(struct bpf_map *map, void *key)
481{
482 struct htab_elem *l = __htab_map_lookup_elem(map, key);
483
484 if (l)
485 return l->key + round_up(map->key_size, 8);
486
487 return NULL;
488}
489
490/* inline bpf_map_lookup_elem() call.
491 * Instead of:
492 * bpf_prog
493 * bpf_map_lookup_elem
494 * map->ops->map_lookup_elem
495 * htab_map_lookup_elem
496 * __htab_map_lookup_elem
497 * do:
498 * bpf_prog
499 * __htab_map_lookup_elem
500 */
501static u32 htab_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
502{
503 struct bpf_insn *insn = insn_buf;
504 const int ret = BPF_REG_0;
505
506 *insn++ = BPF_EMIT_CALL((u64 (*)(u64, u64, u64, u64, u64))__htab_map_lookup_elem);
507 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1);
508 *insn++ = BPF_ALU64_IMM(BPF_ADD, ret,
509 offsetof(struct htab_elem, key) +
510 round_up(map->key_size, 8));
511 return insn - insn_buf;
512}
513
514static void *htab_lru_map_lookup_elem(struct bpf_map *map, void *key)
515{
516 struct htab_elem *l = __htab_map_lookup_elem(map, key);
517
518 if (l) {
519 bpf_lru_node_set_ref(&l->lru_node);
520 return l->key + round_up(map->key_size, 8);
521 }
522
523 return NULL;
524}
525
526static u32 htab_lru_map_gen_lookup(struct bpf_map *map,
527 struct bpf_insn *insn_buf)
528{
529 struct bpf_insn *insn = insn_buf;
530 const int ret = BPF_REG_0;
531 const int ref_reg = BPF_REG_1;
532
533 *insn++ = BPF_EMIT_CALL((u64 (*)(u64, u64, u64, u64, u64))__htab_map_lookup_elem);
534 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 4);
535 *insn++ = BPF_LDX_MEM(BPF_B, ref_reg, ret,
536 offsetof(struct htab_elem, lru_node) +
537 offsetof(struct bpf_lru_node, ref));
538 *insn++ = BPF_JMP_IMM(BPF_JNE, ref_reg, 0, 1);
539 *insn++ = BPF_ST_MEM(BPF_B, ret,
540 offsetof(struct htab_elem, lru_node) +
541 offsetof(struct bpf_lru_node, ref),
542 1);
543 *insn++ = BPF_ALU64_IMM(BPF_ADD, ret,
544 offsetof(struct htab_elem, key) +
545 round_up(map->key_size, 8));
546 return insn - insn_buf;
547}
548
549/* It is called from the bpf_lru_list when the LRU needs to delete
550 * older elements from the htab.
551 */
552static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node)
553{
554 struct bpf_htab *htab = (struct bpf_htab *)arg;
555 struct htab_elem *l = NULL, *tgt_l;
556 struct hlist_nulls_head *head;
557 struct hlist_nulls_node *n;
558 unsigned long flags;
559 struct bucket *b;
560
561 tgt_l = container_of(node, struct htab_elem, lru_node);
562 b = __select_bucket(htab, tgt_l->hash);
563 head = &b->head;
564
565 raw_spin_lock_irqsave(&b->lock, flags);
566
567 hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
568 if (l == tgt_l) {
569 hlist_nulls_del_rcu(&l->hash_node);
570 break;
571 }
572
573 raw_spin_unlock_irqrestore(&b->lock, flags);
574
575 return l == tgt_l;
576}
577
578/* Called from syscall */
579static int htab_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
580{
581 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
582 struct hlist_nulls_head *head;
583 struct htab_elem *l, *next_l;
584 u32 hash, key_size;
585 int i = 0;
586
587 WARN_ON_ONCE(!rcu_read_lock_held());
588
589 key_size = map->key_size;
590
591 if (!key)
592 goto find_first_elem;
593
594 hash = htab_map_hash(key, key_size);
595
596 head = select_bucket(htab, hash);
597
598 /* lookup the key */
599 l = lookup_nulls_elem_raw(head, hash, key, key_size, htab->n_buckets);
600
601 if (!l)
602 goto find_first_elem;
603
604 /* key was found, get next key in the same bucket */
605 next_l = hlist_nulls_entry_safe(rcu_dereference_raw(hlist_nulls_next_rcu(&l->hash_node)),
606 struct htab_elem, hash_node);
607
608 if (next_l) {
609 /* if next elem in this hash list is non-zero, just return it */
610 memcpy(next_key, next_l->key, key_size);
611 return 0;
612 }
613
614 /* no more elements in this hash list, go to the next bucket */
615 i = hash & (htab->n_buckets - 1);
616 i++;
617
618find_first_elem:
619 /* iterate over buckets */
620 for (; i < htab->n_buckets; i++) {
621 head = select_bucket(htab, i);
622
623 /* pick first element in the bucket */
624 next_l = hlist_nulls_entry_safe(rcu_dereference_raw(hlist_nulls_first_rcu(head)),
625 struct htab_elem, hash_node);
626 if (next_l) {
627 /* if it's not empty, just return it */
628 memcpy(next_key, next_l->key, key_size);
629 return 0;
630 }
631 }
632
633 /* iterated over all buckets and all elements */
634 return -ENOENT;
635}
636
637static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l)
638{
639 if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH)
640 free_percpu(htab_elem_get_ptr(l, htab->map.key_size));
641 kfree(l);
642}
643
644static void htab_elem_free_rcu(struct rcu_head *head)
645{
646 struct htab_elem *l = container_of(head, struct htab_elem, rcu);
647 struct bpf_htab *htab = l->htab;
648
649 /* must increment bpf_prog_active to avoid kprobe+bpf triggering while
650 * we're calling kfree, otherwise deadlock is possible if kprobes
651 * are placed somewhere inside of slub
652 */
653 preempt_disable();
654 __this_cpu_inc(bpf_prog_active);
655 htab_elem_free(htab, l);
656 __this_cpu_dec(bpf_prog_active);
657 preempt_enable();
658}
659
660static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
661{
662 struct bpf_map *map = &htab->map;
663
664 if (map->ops->map_fd_put_ptr) {
665 void *ptr = fd_htab_map_get_ptr(map, l);
666
667 map->ops->map_fd_put_ptr(ptr);
668 }
669
670 if (htab_is_prealloc(htab)) {
671 pcpu_freelist_push(&htab->freelist, &l->fnode);
672 } else {
673 atomic_dec(&htab->count);
674 l->htab = htab;
675 call_rcu(&l->rcu, htab_elem_free_rcu);
676 }
677}
678
679static void pcpu_copy_value(struct bpf_htab *htab, void __percpu *pptr,
680 void *value, bool onallcpus)
681{
682 if (!onallcpus) {
683 /* copy true value_size bytes */
684 memcpy(this_cpu_ptr(pptr), value, htab->map.value_size);
685 } else {
686 u32 size = round_up(htab->map.value_size, 8);
687 int off = 0, cpu;
688
689 for_each_possible_cpu(cpu) {
690 bpf_long_memcpy(per_cpu_ptr(pptr, cpu),
691 value + off, size);
692 off += size;
693 }
694 }
695}
696
697static bool fd_htab_map_needs_adjust(const struct bpf_htab *htab)
698{
699 return htab->map.map_type == BPF_MAP_TYPE_HASH_OF_MAPS &&
700 BITS_PER_LONG == 64;
701}
702
703static u32 htab_size_value(const struct bpf_htab *htab, bool percpu)
704{
705 u32 size = htab->map.value_size;
706
707 if (percpu || fd_htab_map_needs_adjust(htab))
708 size = round_up(size, 8);
709 return size;
710}
711
712static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
713 void *value, u32 key_size, u32 hash,
714 bool percpu, bool onallcpus,
715 struct htab_elem *old_elem)
716{
717 u32 size = htab_size_value(htab, percpu);
718 bool prealloc = htab_is_prealloc(htab);
719 struct htab_elem *l_new, **pl_new;
720 void __percpu *pptr;
721
722 if (prealloc) {
723 if (old_elem) {
724 /* if we're updating the existing element,
725 * use per-cpu extra elems to avoid freelist_pop/push
726 */
727 pl_new = this_cpu_ptr(htab->extra_elems);
728 l_new = *pl_new;
729 *pl_new = old_elem;
730 } else {
731 struct pcpu_freelist_node *l;
732
733 l = pcpu_freelist_pop(&htab->freelist);
734 if (!l)
735 return ERR_PTR(-E2BIG);
736 l_new = container_of(l, struct htab_elem, fnode);
737 }
738 } else {
739 if (atomic_inc_return(&htab->count) > htab->map.max_entries)
740 if (!old_elem) {
741 /* when map is full and update() is replacing
742 * old element, it's ok to allocate, since
743 * old element will be freed immediately.
744 * Otherwise return an error
745 */
746 atomic_dec(&htab->count);
747 return ERR_PTR(-E2BIG);
748 }
749 l_new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN,
750 htab->map.numa_node);
751 if (!l_new)
752 return ERR_PTR(-ENOMEM);
753 }
754
755 memcpy(l_new->key, key, key_size);
756 if (percpu) {
757 if (prealloc) {
758 pptr = htab_elem_get_ptr(l_new, key_size);
759 } else {
760 /* alloc_percpu zero-fills */
761 pptr = __alloc_percpu_gfp(size, 8,
762 GFP_ATOMIC | __GFP_NOWARN);
763 if (!pptr) {
764 kfree(l_new);
765 return ERR_PTR(-ENOMEM);
766 }
767 }
768
769 pcpu_copy_value(htab, pptr, value, onallcpus);
770
771 if (!prealloc)
772 htab_elem_set_ptr(l_new, key_size, pptr);
773 } else {
774 memcpy(l_new->key + round_up(key_size, 8), value, size);
775 }
776
777 l_new->hash = hash;
778 return l_new;
779}
780
781static int check_flags(struct bpf_htab *htab, struct htab_elem *l_old,
782 u64 map_flags)
783{
784 if (l_old && map_flags == BPF_NOEXIST)
785 /* elem already exists */
786 return -EEXIST;
787
788 if (!l_old && map_flags == BPF_EXIST)
789 /* elem doesn't exist, cannot update it */
790 return -ENOENT;
791
792 return 0;
793}
794
795/* Called from syscall or from eBPF program */
796static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
797 u64 map_flags)
798{
799 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
800 struct htab_elem *l_new = NULL, *l_old;
801 struct hlist_nulls_head *head;
802 unsigned long flags;
803 struct bucket *b;
804 u32 key_size, hash;
805 int ret;
806
807 if (unlikely(map_flags > BPF_EXIST))
808 /* unknown flags */
809 return -EINVAL;
810
811 WARN_ON_ONCE(!rcu_read_lock_held());
812
813 key_size = map->key_size;
814
815 hash = htab_map_hash(key, key_size);
816
817 b = __select_bucket(htab, hash);
818 head = &b->head;
819
820 /* bpf_map_update_elem() can be called in_irq() */
821 raw_spin_lock_irqsave(&b->lock, flags);
822
823 l_old = lookup_elem_raw(head, hash, key, key_size);
824
825 ret = check_flags(htab, l_old, map_flags);
826 if (ret)
827 goto err;
828
829 l_new = alloc_htab_elem(htab, key, value, key_size, hash, false, false,
830 l_old);
831 if (IS_ERR(l_new)) {
832 /* all pre-allocated elements are in use or memory exhausted */
833 ret = PTR_ERR(l_new);
834 goto err;
835 }
836
837 /* add new element to the head of the list, so that
838 * concurrent search will find it before old elem
839 */
840 hlist_nulls_add_head_rcu(&l_new->hash_node, head);
841 if (l_old) {
842 hlist_nulls_del_rcu(&l_old->hash_node);
843 if (!htab_is_prealloc(htab))
844 free_htab_elem(htab, l_old);
845 }
846 ret = 0;
847err:
848 raw_spin_unlock_irqrestore(&b->lock, flags);
849 return ret;
850}
851
852static int htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value,
853 u64 map_flags)
854{
855 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
856 struct htab_elem *l_new, *l_old = NULL;
857 struct hlist_nulls_head *head;
858 unsigned long flags;
859 struct bucket *b;
860 u32 key_size, hash;
861 int ret;
862
863 if (unlikely(map_flags > BPF_EXIST))
864 /* unknown flags */
865 return -EINVAL;
866
867 WARN_ON_ONCE(!rcu_read_lock_held());
868
869 key_size = map->key_size;
870
871 hash = htab_map_hash(key, key_size);
872
873 b = __select_bucket(htab, hash);
874 head = &b->head;
875
876 /* For LRU, we need to alloc before taking bucket's
877 * spinlock because getting free nodes from LRU may need
878 * to remove older elements from htab and this removal
879 * operation will need a bucket lock.
880 */
881 l_new = prealloc_lru_pop(htab, key, hash);
882 if (!l_new)
883 return -ENOMEM;
884 memcpy(l_new->key + round_up(map->key_size, 8), value, map->value_size);
885
886 /* bpf_map_update_elem() can be called in_irq() */
887 raw_spin_lock_irqsave(&b->lock, flags);
888
889 l_old = lookup_elem_raw(head, hash, key, key_size);
890
891 ret = check_flags(htab, l_old, map_flags);
892 if (ret)
893 goto err;
894
895 /* add new element to the head of the list, so that
896 * concurrent search will find it before old elem
897 */
898 hlist_nulls_add_head_rcu(&l_new->hash_node, head);
899 if (l_old) {
900 bpf_lru_node_set_ref(&l_new->lru_node);
901 hlist_nulls_del_rcu(&l_old->hash_node);
902 }
903 ret = 0;
904
905err:
906 raw_spin_unlock_irqrestore(&b->lock, flags);
907
908 if (ret)
909 bpf_lru_push_free(&htab->lru, &l_new->lru_node);
910 else if (l_old)
911 bpf_lru_push_free(&htab->lru, &l_old->lru_node);
912
913 return ret;
914}
915
916static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key,
917 void *value, u64 map_flags,
918 bool onallcpus)
919{
920 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
921 struct htab_elem *l_new = NULL, *l_old;
922 struct hlist_nulls_head *head;
923 unsigned long flags;
924 struct bucket *b;
925 u32 key_size, hash;
926 int ret;
927
928 if (unlikely(map_flags > BPF_EXIST))
929 /* unknown flags */
930 return -EINVAL;
931
932 WARN_ON_ONCE(!rcu_read_lock_held());
933
934 key_size = map->key_size;
935
936 hash = htab_map_hash(key, key_size);
937
938 b = __select_bucket(htab, hash);
939 head = &b->head;
940
941 /* bpf_map_update_elem() can be called in_irq() */
942 raw_spin_lock_irqsave(&b->lock, flags);
943
944 l_old = lookup_elem_raw(head, hash, key, key_size);
945
946 ret = check_flags(htab, l_old, map_flags);
947 if (ret)
948 goto err;
949
950 if (l_old) {
951 /* per-cpu hash map can update value in-place */
952 pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
953 value, onallcpus);
954 } else {
955 l_new = alloc_htab_elem(htab, key, value, key_size,
956 hash, true, onallcpus, NULL);
957 if (IS_ERR(l_new)) {
958 ret = PTR_ERR(l_new);
959 goto err;
960 }
961 hlist_nulls_add_head_rcu(&l_new->hash_node, head);
962 }
963 ret = 0;
964err:
965 raw_spin_unlock_irqrestore(&b->lock, flags);
966 return ret;
967}
968
969static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
970 void *value, u64 map_flags,
971 bool onallcpus)
972{
973 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
974 struct htab_elem *l_new = NULL, *l_old;
975 struct hlist_nulls_head *head;
976 unsigned long flags;
977 struct bucket *b;
978 u32 key_size, hash;
979 int ret;
980
981 if (unlikely(map_flags > BPF_EXIST))
982 /* unknown flags */
983 return -EINVAL;
984
985 WARN_ON_ONCE(!rcu_read_lock_held());
986
987 key_size = map->key_size;
988
989 hash = htab_map_hash(key, key_size);
990
991 b = __select_bucket(htab, hash);
992 head = &b->head;
993
994 /* For LRU, we need to alloc before taking bucket's
995 * spinlock because LRU's elem alloc may need
996 * to remove older elem from htab and this removal
997 * operation will need a bucket lock.
998 */
999 if (map_flags != BPF_EXIST) {
1000 l_new = prealloc_lru_pop(htab, key, hash);
1001 if (!l_new)
1002 return -ENOMEM;
1003 }
1004
1005 /* bpf_map_update_elem() can be called in_irq() */
1006 raw_spin_lock_irqsave(&b->lock, flags);
1007
1008 l_old = lookup_elem_raw(head, hash, key, key_size);
1009
1010 ret = check_flags(htab, l_old, map_flags);
1011 if (ret)
1012 goto err;
1013
1014 if (l_old) {
1015 bpf_lru_node_set_ref(&l_old->lru_node);
1016
1017 /* per-cpu hash map can update value in-place */
1018 pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
1019 value, onallcpus);
1020 } else {
1021 pcpu_copy_value(htab, htab_elem_get_ptr(l_new, key_size),
1022 value, onallcpus);
1023 hlist_nulls_add_head_rcu(&l_new->hash_node, head);
1024 l_new = NULL;
1025 }
1026 ret = 0;
1027err:
1028 raw_spin_unlock_irqrestore(&b->lock, flags);
1029 if (l_new)
1030 bpf_lru_push_free(&htab->lru, &l_new->lru_node);
1031 return ret;
1032}
1033
1034static int htab_percpu_map_update_elem(struct bpf_map *map, void *key,
1035 void *value, u64 map_flags)
1036{
1037 return __htab_percpu_map_update_elem(map, key, value, map_flags, false);
1038}
1039
1040static int htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
1041 void *value, u64 map_flags)
1042{
1043 return __htab_lru_percpu_map_update_elem(map, key, value, map_flags,
1044 false);
1045}
1046
1047/* Called from syscall or from eBPF program */
1048static int htab_map_delete_elem(struct bpf_map *map, void *key)
1049{
1050 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1051 struct hlist_nulls_head *head;
1052 struct bucket *b;
1053 struct htab_elem *l;
1054 unsigned long flags;
1055 u32 hash, key_size;
1056 int ret = -ENOENT;
1057
1058 WARN_ON_ONCE(!rcu_read_lock_held());
1059
1060 key_size = map->key_size;
1061
1062 hash = htab_map_hash(key, key_size);
1063 b = __select_bucket(htab, hash);
1064 head = &b->head;
1065
1066 raw_spin_lock_irqsave(&b->lock, flags);
1067
1068 l = lookup_elem_raw(head, hash, key, key_size);
1069
1070 if (l) {
1071 hlist_nulls_del_rcu(&l->hash_node);
1072 free_htab_elem(htab, l);
1073 ret = 0;
1074 }
1075
1076 raw_spin_unlock_irqrestore(&b->lock, flags);
1077 return ret;
1078}
1079
1080static int htab_lru_map_delete_elem(struct bpf_map *map, void *key)
1081{
1082 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1083 struct hlist_nulls_head *head;
1084 struct bucket *b;
1085 struct htab_elem *l;
1086 unsigned long flags;
1087 u32 hash, key_size;
1088 int ret = -ENOENT;
1089
1090 WARN_ON_ONCE(!rcu_read_lock_held());
1091
1092 key_size = map->key_size;
1093
1094 hash = htab_map_hash(key, key_size);
1095 b = __select_bucket(htab, hash);
1096 head = &b->head;
1097
1098 raw_spin_lock_irqsave(&b->lock, flags);
1099
1100 l = lookup_elem_raw(head, hash, key, key_size);
1101
1102 if (l) {
1103 hlist_nulls_del_rcu(&l->hash_node);
1104 ret = 0;
1105 }
1106
1107 raw_spin_unlock_irqrestore(&b->lock, flags);
1108 if (l)
1109 bpf_lru_push_free(&htab->lru, &l->lru_node);
1110 return ret;
1111}
1112
1113static void delete_all_elements(struct bpf_htab *htab)
1114{
1115 int i;
1116
1117 for (i = 0; i < htab->n_buckets; i++) {
1118 struct hlist_nulls_head *head = select_bucket(htab, i);
1119 struct hlist_nulls_node *n;
1120 struct htab_elem *l;
1121
1122 hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
1123 hlist_nulls_del_rcu(&l->hash_node);
1124 htab_elem_free(htab, l);
1125 }
1126 }
1127}
1128
1129/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
1130static void htab_map_free(struct bpf_map *map)
1131{
1132 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1133
1134 /* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0,
1135 * so the programs (can be more than one that used this map) were
1136 * disconnected from events. Wait for outstanding critical sections in
1137 * these programs to complete
1138 */
1139 synchronize_rcu();
1140
1141 /* some of free_htab_elem() callbacks for elements of this map may
1142 * not have executed. Wait for them.
1143 */
1144 rcu_barrier();
1145 if (!htab_is_prealloc(htab))
1146 delete_all_elements(htab);
1147 else
1148 prealloc_destroy(htab);
1149
1150 free_percpu(htab->extra_elems);
1151 bpf_map_area_free(htab->buckets);
1152 kfree(htab);
1153}
1154
1155const struct bpf_map_ops htab_map_ops = {
1156 .map_alloc_check = htab_map_alloc_check,
1157 .map_alloc = htab_map_alloc,
1158 .map_free = htab_map_free,
1159 .map_get_next_key = htab_map_get_next_key,
1160 .map_lookup_elem = htab_map_lookup_elem,
1161 .map_update_elem = htab_map_update_elem,
1162 .map_delete_elem = htab_map_delete_elem,
1163 .map_gen_lookup = htab_map_gen_lookup,
1164};
1165
1166const struct bpf_map_ops htab_lru_map_ops = {
1167 .map_alloc_check = htab_map_alloc_check,
1168 .map_alloc = htab_map_alloc,
1169 .map_free = htab_map_free,
1170 .map_get_next_key = htab_map_get_next_key,
1171 .map_lookup_elem = htab_lru_map_lookup_elem,
1172 .map_update_elem = htab_lru_map_update_elem,
1173 .map_delete_elem = htab_lru_map_delete_elem,
1174 .map_gen_lookup = htab_lru_map_gen_lookup,
1175};
1176
1177/* Called from eBPF program */
1178static void *htab_percpu_map_lookup_elem(struct bpf_map *map, void *key)
1179{
1180 struct htab_elem *l = __htab_map_lookup_elem(map, key);
1181
1182 if (l)
1183 return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
1184 else
1185 return NULL;
1186}
1187
1188static void *htab_lru_percpu_map_lookup_elem(struct bpf_map *map, void *key)
1189{
1190 struct htab_elem *l = __htab_map_lookup_elem(map, key);
1191
1192 if (l) {
1193 bpf_lru_node_set_ref(&l->lru_node);
1194 return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
1195 }
1196
1197 return NULL;
1198}
1199
1200int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value)
1201{
1202 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1203 struct htab_elem *l;
1204 void __percpu *pptr;
1205 int ret = -ENOENT;
1206 int cpu, off = 0;
1207 u32 size;
1208
1209 /* per_cpu areas are zero-filled and bpf programs can only
1210 * access 'value_size' of them, so copying rounded areas
1211 * will not leak any kernel data
1212 */
1213 size = round_up(map->value_size, 8);
1214 rcu_read_lock();
1215 l = __htab_map_lookup_elem(map, key);
1216 if (!l)
1217 goto out;
1218 if (htab_is_lru(htab))
1219 bpf_lru_node_set_ref(&l->lru_node);
1220 pptr = htab_elem_get_ptr(l, map->key_size);
1221 for_each_possible_cpu(cpu) {
1222 bpf_long_memcpy(value + off,
1223 per_cpu_ptr(pptr, cpu), size);
1224 off += size;
1225 }
1226 ret = 0;
1227out:
1228 rcu_read_unlock();
1229 return ret;
1230}
1231
1232int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
1233 u64 map_flags)
1234{
1235 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1236 int ret;
1237
1238 rcu_read_lock();
1239 if (htab_is_lru(htab))
1240 ret = __htab_lru_percpu_map_update_elem(map, key, value,
1241 map_flags, true);
1242 else
1243 ret = __htab_percpu_map_update_elem(map, key, value, map_flags,
1244 true);
1245 rcu_read_unlock();
1246
1247 return ret;
1248}
1249
1250const struct bpf_map_ops htab_percpu_map_ops = {
1251 .map_alloc_check = htab_map_alloc_check,
1252 .map_alloc = htab_map_alloc,
1253 .map_free = htab_map_free,
1254 .map_get_next_key = htab_map_get_next_key,
1255 .map_lookup_elem = htab_percpu_map_lookup_elem,
1256 .map_update_elem = htab_percpu_map_update_elem,
1257 .map_delete_elem = htab_map_delete_elem,
1258};
1259
1260const struct bpf_map_ops htab_lru_percpu_map_ops = {
1261 .map_alloc_check = htab_map_alloc_check,
1262 .map_alloc = htab_map_alloc,
1263 .map_free = htab_map_free,
1264 .map_get_next_key = htab_map_get_next_key,
1265 .map_lookup_elem = htab_lru_percpu_map_lookup_elem,
1266 .map_update_elem = htab_lru_percpu_map_update_elem,
1267 .map_delete_elem = htab_lru_map_delete_elem,
1268};
1269
1270static int fd_htab_map_alloc_check(union bpf_attr *attr)
1271{
1272 if (attr->value_size != sizeof(u32))
1273 return -EINVAL;
1274 return htab_map_alloc_check(attr);
1275}
1276
1277static void fd_htab_map_free(struct bpf_map *map)
1278{
1279 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1280 struct hlist_nulls_node *n;
1281 struct hlist_nulls_head *head;
1282 struct htab_elem *l;
1283 int i;
1284
1285 for (i = 0; i < htab->n_buckets; i++) {
1286 head = select_bucket(htab, i);
1287
1288 hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
1289 void *ptr = fd_htab_map_get_ptr(map, l);
1290
1291 map->ops->map_fd_put_ptr(ptr);
1292 }
1293 }
1294
1295 htab_map_free(map);
1296}
1297
1298/* only called from syscall */
1299int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value)
1300{
1301 void **ptr;
1302 int ret = 0;
1303
1304 if (!map->ops->map_fd_sys_lookup_elem)
1305 return -ENOTSUPP;
1306
1307 rcu_read_lock();
1308 ptr = htab_map_lookup_elem(map, key);
1309 if (ptr)
1310 *value = map->ops->map_fd_sys_lookup_elem(READ_ONCE(*ptr));
1311 else
1312 ret = -ENOENT;
1313 rcu_read_unlock();
1314
1315 return ret;
1316}
1317
1318/* only called from syscall */
1319int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file,
1320 void *key, void *value, u64 map_flags)
1321{
1322 void *ptr;
1323 int ret;
1324 u32 ufd = *(u32 *)value;
1325
1326 ptr = map->ops->map_fd_get_ptr(map, map_file, ufd);
1327 if (IS_ERR(ptr))
1328 return PTR_ERR(ptr);
1329
1330 ret = htab_map_update_elem(map, key, &ptr, map_flags);
1331 if (ret)
1332 map->ops->map_fd_put_ptr(ptr);
1333
1334 return ret;
1335}
1336
1337static struct bpf_map *htab_of_map_alloc(union bpf_attr *attr)
1338{
1339 struct bpf_map *map, *inner_map_meta;
1340
1341 inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd);
1342 if (IS_ERR(inner_map_meta))
1343 return inner_map_meta;
1344
1345 map = htab_map_alloc(attr);
1346 if (IS_ERR(map)) {
1347 bpf_map_meta_free(inner_map_meta);
1348 return map;
1349 }
1350
1351 map->inner_map_meta = inner_map_meta;
1352
1353 return map;
1354}
1355
1356static void *htab_of_map_lookup_elem(struct bpf_map *map, void *key)
1357{
1358 struct bpf_map **inner_map = htab_map_lookup_elem(map, key);
1359
1360 if (!inner_map)
1361 return NULL;
1362
1363 return READ_ONCE(*inner_map);
1364}
1365
1366static u32 htab_of_map_gen_lookup(struct bpf_map *map,
1367 struct bpf_insn *insn_buf)
1368{
1369 struct bpf_insn *insn = insn_buf;
1370 const int ret = BPF_REG_0;
1371
1372 *insn++ = BPF_EMIT_CALL((u64 (*)(u64, u64, u64, u64, u64))__htab_map_lookup_elem);
1373 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 2);
1374 *insn++ = BPF_ALU64_IMM(BPF_ADD, ret,
1375 offsetof(struct htab_elem, key) +
1376 round_up(map->key_size, 8));
1377 *insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0);
1378
1379 return insn - insn_buf;
1380}
1381
1382static void htab_of_map_free(struct bpf_map *map)
1383{
1384 bpf_map_meta_free(map->inner_map_meta);
1385 fd_htab_map_free(map);
1386}
1387
1388const struct bpf_map_ops htab_of_maps_map_ops = {
1389 .map_alloc_check = fd_htab_map_alloc_check,
1390 .map_alloc = htab_of_map_alloc,
1391 .map_free = htab_of_map_free,
1392 .map_get_next_key = htab_map_get_next_key,
1393 .map_lookup_elem = htab_of_map_lookup_elem,
1394 .map_delete_elem = htab_map_delete_elem,
1395 .map_fd_get_ptr = bpf_map_fd_get_ptr,
1396 .map_fd_put_ptr = bpf_map_fd_put_ptr,
1397 .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
1398 .map_gen_lookup = htab_of_map_gen_lookup,
1399};
1// SPDX-License-Identifier: GPL-2.0-only
2/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3 * Copyright (c) 2016 Facebook
4 */
5#include <linux/bpf.h>
6#include <linux/btf.h>
7#include <linux/jhash.h>
8#include <linux/filter.h>
9#include <linux/rculist_nulls.h>
10#include <linux/rcupdate_wait.h>
11#include <linux/random.h>
12#include <uapi/linux/btf.h>
13#include <linux/rcupdate_trace.h>
14#include <linux/btf_ids.h>
15#include "percpu_freelist.h"
16#include "bpf_lru_list.h"
17#include "map_in_map.h"
18#include <linux/bpf_mem_alloc.h>
19
20#define HTAB_CREATE_FLAG_MASK \
21 (BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU | BPF_F_NUMA_NODE | \
22 BPF_F_ACCESS_MASK | BPF_F_ZERO_SEED)
23
24#define BATCH_OPS(_name) \
25 .map_lookup_batch = \
26 _name##_map_lookup_batch, \
27 .map_lookup_and_delete_batch = \
28 _name##_map_lookup_and_delete_batch, \
29 .map_update_batch = \
30 generic_map_update_batch, \
31 .map_delete_batch = \
32 generic_map_delete_batch
33
34/*
35 * The bucket lock has two protection scopes:
36 *
37 * 1) Serializing concurrent operations from BPF programs on different
38 * CPUs
39 *
40 * 2) Serializing concurrent operations from BPF programs and sys_bpf()
41 *
42 * BPF programs can execute in any context including perf, kprobes and
43 * tracing. As there are almost no limits where perf, kprobes and tracing
44 * can be invoked from the lock operations need to be protected against
45 * deadlocks. Deadlocks can be caused by recursion and by an invocation in
46 * the lock held section when functions which acquire this lock are invoked
47 * from sys_bpf(). BPF recursion is prevented by incrementing the per CPU
48 * variable bpf_prog_active, which prevents BPF programs attached to perf
49 * events, kprobes and tracing to be invoked before the prior invocation
50 * from one of these contexts completed. sys_bpf() uses the same mechanism
51 * by pinning the task to the current CPU and incrementing the recursion
52 * protection across the map operation.
53 *
54 * This has subtle implications on PREEMPT_RT. PREEMPT_RT forbids certain
55 * operations like memory allocations (even with GFP_ATOMIC) from atomic
56 * contexts. This is required because even with GFP_ATOMIC the memory
57 * allocator calls into code paths which acquire locks with long held lock
58 * sections. To ensure the deterministic behaviour these locks are regular
59 * spinlocks, which are converted to 'sleepable' spinlocks on RT. The only
60 * true atomic contexts on an RT kernel are the low level hardware
61 * handling, scheduling, low level interrupt handling, NMIs etc. None of
62 * these contexts should ever do memory allocations.
63 *
64 * As regular device interrupt handlers and soft interrupts are forced into
65 * thread context, the existing code which does
66 * spin_lock*(); alloc(GFP_ATOMIC); spin_unlock*();
67 * just works.
68 *
69 * In theory the BPF locks could be converted to regular spinlocks as well,
70 * but the bucket locks and percpu_freelist locks can be taken from
71 * arbitrary contexts (perf, kprobes, tracepoints) which are required to be
72 * atomic contexts even on RT. Before the introduction of bpf_mem_alloc,
73 * it is only safe to use raw spinlock for preallocated hash map on a RT kernel,
74 * because there is no memory allocation within the lock held sections. However
75 * after hash map was fully converted to use bpf_mem_alloc, there will be
76 * non-synchronous memory allocation for non-preallocated hash map, so it is
77 * safe to always use raw spinlock for bucket lock.
78 */
79struct bucket {
80 struct hlist_nulls_head head;
81 raw_spinlock_t raw_lock;
82};
83
84#define HASHTAB_MAP_LOCK_COUNT 8
85#define HASHTAB_MAP_LOCK_MASK (HASHTAB_MAP_LOCK_COUNT - 1)
86
87struct bpf_htab {
88 struct bpf_map map;
89 struct bpf_mem_alloc ma;
90 struct bpf_mem_alloc pcpu_ma;
91 struct bucket *buckets;
92 void *elems;
93 union {
94 struct pcpu_freelist freelist;
95 struct bpf_lru lru;
96 };
97 struct htab_elem *__percpu *extra_elems;
98 /* number of elements in non-preallocated hashtable are kept
99 * in either pcount or count
100 */
101 struct percpu_counter pcount;
102 atomic_t count;
103 bool use_percpu_counter;
104 u32 n_buckets; /* number of hash buckets */
105 u32 elem_size; /* size of each element in bytes */
106 u32 hashrnd;
107 struct lock_class_key lockdep_key;
108 int __percpu *map_locked[HASHTAB_MAP_LOCK_COUNT];
109};
110
111/* each htab element is struct htab_elem + key + value */
112struct htab_elem {
113 union {
114 struct hlist_nulls_node hash_node;
115 struct {
116 void *padding;
117 union {
118 struct pcpu_freelist_node fnode;
119 struct htab_elem *batch_flink;
120 };
121 };
122 };
123 union {
124 /* pointer to per-cpu pointer */
125 void *ptr_to_pptr;
126 struct bpf_lru_node lru_node;
127 };
128 u32 hash;
129 char key[] __aligned(8);
130};
131
132static inline bool htab_is_prealloc(const struct bpf_htab *htab)
133{
134 return !(htab->map.map_flags & BPF_F_NO_PREALLOC);
135}
136
137static void htab_init_buckets(struct bpf_htab *htab)
138{
139 unsigned int i;
140
141 for (i = 0; i < htab->n_buckets; i++) {
142 INIT_HLIST_NULLS_HEAD(&htab->buckets[i].head, i);
143 raw_spin_lock_init(&htab->buckets[i].raw_lock);
144 lockdep_set_class(&htab->buckets[i].raw_lock,
145 &htab->lockdep_key);
146 cond_resched();
147 }
148}
149
150static inline int htab_lock_bucket(const struct bpf_htab *htab,
151 struct bucket *b, u32 hash,
152 unsigned long *pflags)
153{
154 unsigned long flags;
155
156 hash = hash & min_t(u32, HASHTAB_MAP_LOCK_MASK, htab->n_buckets - 1);
157
158 preempt_disable();
159 local_irq_save(flags);
160 if (unlikely(__this_cpu_inc_return(*(htab->map_locked[hash])) != 1)) {
161 __this_cpu_dec(*(htab->map_locked[hash]));
162 local_irq_restore(flags);
163 preempt_enable();
164 return -EBUSY;
165 }
166
167 raw_spin_lock(&b->raw_lock);
168 *pflags = flags;
169
170 return 0;
171}
172
173static inline void htab_unlock_bucket(const struct bpf_htab *htab,
174 struct bucket *b, u32 hash,
175 unsigned long flags)
176{
177 hash = hash & min_t(u32, HASHTAB_MAP_LOCK_MASK, htab->n_buckets - 1);
178 raw_spin_unlock(&b->raw_lock);
179 __this_cpu_dec(*(htab->map_locked[hash]));
180 local_irq_restore(flags);
181 preempt_enable();
182}
183
184static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node);
185
186static bool htab_is_lru(const struct bpf_htab *htab)
187{
188 return htab->map.map_type == BPF_MAP_TYPE_LRU_HASH ||
189 htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
190}
191
192static bool htab_is_percpu(const struct bpf_htab *htab)
193{
194 return htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH ||
195 htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
196}
197
198static inline void htab_elem_set_ptr(struct htab_elem *l, u32 key_size,
199 void __percpu *pptr)
200{
201 *(void __percpu **)(l->key + key_size) = pptr;
202}
203
204static inline void __percpu *htab_elem_get_ptr(struct htab_elem *l, u32 key_size)
205{
206 return *(void __percpu **)(l->key + key_size);
207}
208
209static void *fd_htab_map_get_ptr(const struct bpf_map *map, struct htab_elem *l)
210{
211 return *(void **)(l->key + roundup(map->key_size, 8));
212}
213
214static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i)
215{
216 return (struct htab_elem *) (htab->elems + i * (u64)htab->elem_size);
217}
218
219static bool htab_has_extra_elems(struct bpf_htab *htab)
220{
221 return !htab_is_percpu(htab) && !htab_is_lru(htab);
222}
223
224static void htab_free_prealloced_timers_and_wq(struct bpf_htab *htab)
225{
226 u32 num_entries = htab->map.max_entries;
227 int i;
228
229 if (htab_has_extra_elems(htab))
230 num_entries += num_possible_cpus();
231
232 for (i = 0; i < num_entries; i++) {
233 struct htab_elem *elem;
234
235 elem = get_htab_elem(htab, i);
236 if (btf_record_has_field(htab->map.record, BPF_TIMER))
237 bpf_obj_free_timer(htab->map.record,
238 elem->key + round_up(htab->map.key_size, 8));
239 if (btf_record_has_field(htab->map.record, BPF_WORKQUEUE))
240 bpf_obj_free_workqueue(htab->map.record,
241 elem->key + round_up(htab->map.key_size, 8));
242 cond_resched();
243 }
244}
245
246static void htab_free_prealloced_fields(struct bpf_htab *htab)
247{
248 u32 num_entries = htab->map.max_entries;
249 int i;
250
251 if (IS_ERR_OR_NULL(htab->map.record))
252 return;
253 if (htab_has_extra_elems(htab))
254 num_entries += num_possible_cpus();
255 for (i = 0; i < num_entries; i++) {
256 struct htab_elem *elem;
257
258 elem = get_htab_elem(htab, i);
259 if (htab_is_percpu(htab)) {
260 void __percpu *pptr = htab_elem_get_ptr(elem, htab->map.key_size);
261 int cpu;
262
263 for_each_possible_cpu(cpu) {
264 bpf_obj_free_fields(htab->map.record, per_cpu_ptr(pptr, cpu));
265 cond_resched();
266 }
267 } else {
268 bpf_obj_free_fields(htab->map.record, elem->key + round_up(htab->map.key_size, 8));
269 cond_resched();
270 }
271 cond_resched();
272 }
273}
274
275static void htab_free_elems(struct bpf_htab *htab)
276{
277 int i;
278
279 if (!htab_is_percpu(htab))
280 goto free_elems;
281
282 for (i = 0; i < htab->map.max_entries; i++) {
283 void __percpu *pptr;
284
285 pptr = htab_elem_get_ptr(get_htab_elem(htab, i),
286 htab->map.key_size);
287 free_percpu(pptr);
288 cond_resched();
289 }
290free_elems:
291 bpf_map_area_free(htab->elems);
292}
293
294/* The LRU list has a lock (lru_lock). Each htab bucket has a lock
295 * (bucket_lock). If both locks need to be acquired together, the lock
296 * order is always lru_lock -> bucket_lock and this only happens in
297 * bpf_lru_list.c logic. For example, certain code path of
298 * bpf_lru_pop_free(), which is called by function prealloc_lru_pop(),
299 * will acquire lru_lock first followed by acquiring bucket_lock.
300 *
301 * In hashtab.c, to avoid deadlock, lock acquisition of
302 * bucket_lock followed by lru_lock is not allowed. In such cases,
303 * bucket_lock needs to be released first before acquiring lru_lock.
304 */
305static struct htab_elem *prealloc_lru_pop(struct bpf_htab *htab, void *key,
306 u32 hash)
307{
308 struct bpf_lru_node *node = bpf_lru_pop_free(&htab->lru, hash);
309 struct htab_elem *l;
310
311 if (node) {
312 bpf_map_inc_elem_count(&htab->map);
313 l = container_of(node, struct htab_elem, lru_node);
314 memcpy(l->key, key, htab->map.key_size);
315 return l;
316 }
317
318 return NULL;
319}
320
321static int prealloc_init(struct bpf_htab *htab)
322{
323 u32 num_entries = htab->map.max_entries;
324 int err = -ENOMEM, i;
325
326 if (htab_has_extra_elems(htab))
327 num_entries += num_possible_cpus();
328
329 htab->elems = bpf_map_area_alloc((u64)htab->elem_size * num_entries,
330 htab->map.numa_node);
331 if (!htab->elems)
332 return -ENOMEM;
333
334 if (!htab_is_percpu(htab))
335 goto skip_percpu_elems;
336
337 for (i = 0; i < num_entries; i++) {
338 u32 size = round_up(htab->map.value_size, 8);
339 void __percpu *pptr;
340
341 pptr = bpf_map_alloc_percpu(&htab->map, size, 8,
342 GFP_USER | __GFP_NOWARN);
343 if (!pptr)
344 goto free_elems;
345 htab_elem_set_ptr(get_htab_elem(htab, i), htab->map.key_size,
346 pptr);
347 cond_resched();
348 }
349
350skip_percpu_elems:
351 if (htab_is_lru(htab))
352 err = bpf_lru_init(&htab->lru,
353 htab->map.map_flags & BPF_F_NO_COMMON_LRU,
354 offsetof(struct htab_elem, hash) -
355 offsetof(struct htab_elem, lru_node),
356 htab_lru_map_delete_node,
357 htab);
358 else
359 err = pcpu_freelist_init(&htab->freelist);
360
361 if (err)
362 goto free_elems;
363
364 if (htab_is_lru(htab))
365 bpf_lru_populate(&htab->lru, htab->elems,
366 offsetof(struct htab_elem, lru_node),
367 htab->elem_size, num_entries);
368 else
369 pcpu_freelist_populate(&htab->freelist,
370 htab->elems + offsetof(struct htab_elem, fnode),
371 htab->elem_size, num_entries);
372
373 return 0;
374
375free_elems:
376 htab_free_elems(htab);
377 return err;
378}
379
380static void prealloc_destroy(struct bpf_htab *htab)
381{
382 htab_free_elems(htab);
383
384 if (htab_is_lru(htab))
385 bpf_lru_destroy(&htab->lru);
386 else
387 pcpu_freelist_destroy(&htab->freelist);
388}
389
390static int alloc_extra_elems(struct bpf_htab *htab)
391{
392 struct htab_elem *__percpu *pptr, *l_new;
393 struct pcpu_freelist_node *l;
394 int cpu;
395
396 pptr = bpf_map_alloc_percpu(&htab->map, sizeof(struct htab_elem *), 8,
397 GFP_USER | __GFP_NOWARN);
398 if (!pptr)
399 return -ENOMEM;
400
401 for_each_possible_cpu(cpu) {
402 l = pcpu_freelist_pop(&htab->freelist);
403 /* pop will succeed, since prealloc_init()
404 * preallocated extra num_possible_cpus elements
405 */
406 l_new = container_of(l, struct htab_elem, fnode);
407 *per_cpu_ptr(pptr, cpu) = l_new;
408 }
409 htab->extra_elems = pptr;
410 return 0;
411}
412
413/* Called from syscall */
414static int htab_map_alloc_check(union bpf_attr *attr)
415{
416 bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
417 attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
418 bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH ||
419 attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
420 /* percpu_lru means each cpu has its own LRU list.
421 * it is different from BPF_MAP_TYPE_PERCPU_HASH where
422 * the map's value itself is percpu. percpu_lru has
423 * nothing to do with the map's value.
424 */
425 bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU);
426 bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC);
427 bool zero_seed = (attr->map_flags & BPF_F_ZERO_SEED);
428 int numa_node = bpf_map_attr_numa_node(attr);
429
430 BUILD_BUG_ON(offsetof(struct htab_elem, fnode.next) !=
431 offsetof(struct htab_elem, hash_node.pprev));
432
433 if (zero_seed && !capable(CAP_SYS_ADMIN))
434 /* Guard against local DoS, and discourage production use. */
435 return -EPERM;
436
437 if (attr->map_flags & ~HTAB_CREATE_FLAG_MASK ||
438 !bpf_map_flags_access_ok(attr->map_flags))
439 return -EINVAL;
440
441 if (!lru && percpu_lru)
442 return -EINVAL;
443
444 if (lru && !prealloc)
445 return -ENOTSUPP;
446
447 if (numa_node != NUMA_NO_NODE && (percpu || percpu_lru))
448 return -EINVAL;
449
450 /* check sanity of attributes.
451 * value_size == 0 may be allowed in the future to use map as a set
452 */
453 if (attr->max_entries == 0 || attr->key_size == 0 ||
454 attr->value_size == 0)
455 return -EINVAL;
456
457 if ((u64)attr->key_size + attr->value_size >= KMALLOC_MAX_SIZE -
458 sizeof(struct htab_elem))
459 /* if key_size + value_size is bigger, the user space won't be
460 * able to access the elements via bpf syscall. This check
461 * also makes sure that the elem_size doesn't overflow and it's
462 * kmalloc-able later in htab_map_update_elem()
463 */
464 return -E2BIG;
465 /* percpu map value size is bound by PCPU_MIN_UNIT_SIZE */
466 if (percpu && round_up(attr->value_size, 8) > PCPU_MIN_UNIT_SIZE)
467 return -E2BIG;
468
469 return 0;
470}
471
472static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
473{
474 bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
475 attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
476 bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH ||
477 attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
478 /* percpu_lru means each cpu has its own LRU list.
479 * it is different from BPF_MAP_TYPE_PERCPU_HASH where
480 * the map's value itself is percpu. percpu_lru has
481 * nothing to do with the map's value.
482 */
483 bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU);
484 bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC);
485 struct bpf_htab *htab;
486 int err, i;
487
488 htab = bpf_map_area_alloc(sizeof(*htab), NUMA_NO_NODE);
489 if (!htab)
490 return ERR_PTR(-ENOMEM);
491
492 lockdep_register_key(&htab->lockdep_key);
493
494 bpf_map_init_from_attr(&htab->map, attr);
495
496 if (percpu_lru) {
497 /* ensure each CPU's lru list has >=1 elements.
498 * since we are at it, make each lru list has the same
499 * number of elements.
500 */
501 htab->map.max_entries = roundup(attr->max_entries,
502 num_possible_cpus());
503 if (htab->map.max_entries < attr->max_entries)
504 htab->map.max_entries = rounddown(attr->max_entries,
505 num_possible_cpus());
506 }
507
508 /* hash table size must be power of 2; roundup_pow_of_two() can overflow
509 * into UB on 32-bit arches, so check that first
510 */
511 err = -E2BIG;
512 if (htab->map.max_entries > 1UL << 31)
513 goto free_htab;
514
515 htab->n_buckets = roundup_pow_of_two(htab->map.max_entries);
516
517 htab->elem_size = sizeof(struct htab_elem) +
518 round_up(htab->map.key_size, 8);
519 if (percpu)
520 htab->elem_size += sizeof(void *);
521 else
522 htab->elem_size += round_up(htab->map.value_size, 8);
523
524 /* check for u32 overflow */
525 if (htab->n_buckets > U32_MAX / sizeof(struct bucket))
526 goto free_htab;
527
528 err = bpf_map_init_elem_count(&htab->map);
529 if (err)
530 goto free_htab;
531
532 err = -ENOMEM;
533 htab->buckets = bpf_map_area_alloc(htab->n_buckets *
534 sizeof(struct bucket),
535 htab->map.numa_node);
536 if (!htab->buckets)
537 goto free_elem_count;
538
539 for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++) {
540 htab->map_locked[i] = bpf_map_alloc_percpu(&htab->map,
541 sizeof(int),
542 sizeof(int),
543 GFP_USER);
544 if (!htab->map_locked[i])
545 goto free_map_locked;
546 }
547
548 if (htab->map.map_flags & BPF_F_ZERO_SEED)
549 htab->hashrnd = 0;
550 else
551 htab->hashrnd = get_random_u32();
552
553 htab_init_buckets(htab);
554
555/* compute_batch_value() computes batch value as num_online_cpus() * 2
556 * and __percpu_counter_compare() needs
557 * htab->max_entries - cur_number_of_elems to be more than batch * num_online_cpus()
558 * for percpu_counter to be faster than atomic_t. In practice the average bpf
559 * hash map size is 10k, which means that a system with 64 cpus will fill
560 * hashmap to 20% of 10k before percpu_counter becomes ineffective. Therefore
561 * define our own batch count as 32 then 10k hash map can be filled up to 80%:
562 * 10k - 8k > 32 _batch_ * 64 _cpus_
563 * and __percpu_counter_compare() will still be fast. At that point hash map
564 * collisions will dominate its performance anyway. Assume that hash map filled
565 * to 50+% isn't going to be O(1) and use the following formula to choose
566 * between percpu_counter and atomic_t.
567 */
568#define PERCPU_COUNTER_BATCH 32
569 if (attr->max_entries / 2 > num_online_cpus() * PERCPU_COUNTER_BATCH)
570 htab->use_percpu_counter = true;
571
572 if (htab->use_percpu_counter) {
573 err = percpu_counter_init(&htab->pcount, 0, GFP_KERNEL);
574 if (err)
575 goto free_map_locked;
576 }
577
578 if (prealloc) {
579 err = prealloc_init(htab);
580 if (err)
581 goto free_map_locked;
582
583 if (!percpu && !lru) {
584 /* lru itself can remove the least used element, so
585 * there is no need for an extra elem during map_update.
586 */
587 err = alloc_extra_elems(htab);
588 if (err)
589 goto free_prealloc;
590 }
591 } else {
592 err = bpf_mem_alloc_init(&htab->ma, htab->elem_size, false);
593 if (err)
594 goto free_map_locked;
595 if (percpu) {
596 err = bpf_mem_alloc_init(&htab->pcpu_ma,
597 round_up(htab->map.value_size, 8), true);
598 if (err)
599 goto free_map_locked;
600 }
601 }
602
603 return &htab->map;
604
605free_prealloc:
606 prealloc_destroy(htab);
607free_map_locked:
608 if (htab->use_percpu_counter)
609 percpu_counter_destroy(&htab->pcount);
610 for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++)
611 free_percpu(htab->map_locked[i]);
612 bpf_map_area_free(htab->buckets);
613 bpf_mem_alloc_destroy(&htab->pcpu_ma);
614 bpf_mem_alloc_destroy(&htab->ma);
615free_elem_count:
616 bpf_map_free_elem_count(&htab->map);
617free_htab:
618 lockdep_unregister_key(&htab->lockdep_key);
619 bpf_map_area_free(htab);
620 return ERR_PTR(err);
621}
622
623static inline u32 htab_map_hash(const void *key, u32 key_len, u32 hashrnd)
624{
625 if (likely(key_len % 4 == 0))
626 return jhash2(key, key_len / 4, hashrnd);
627 return jhash(key, key_len, hashrnd);
628}
629
630static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash)
631{
632 return &htab->buckets[hash & (htab->n_buckets - 1)];
633}
634
635static inline struct hlist_nulls_head *select_bucket(struct bpf_htab *htab, u32 hash)
636{
637 return &__select_bucket(htab, hash)->head;
638}
639
640/* this lookup function can only be called with bucket lock taken */
641static struct htab_elem *lookup_elem_raw(struct hlist_nulls_head *head, u32 hash,
642 void *key, u32 key_size)
643{
644 struct hlist_nulls_node *n;
645 struct htab_elem *l;
646
647 hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
648 if (l->hash == hash && !memcmp(&l->key, key, key_size))
649 return l;
650
651 return NULL;
652}
653
654/* can be called without bucket lock. it will repeat the loop in
655 * the unlikely event when elements moved from one bucket into another
656 * while link list is being walked
657 */
658static struct htab_elem *lookup_nulls_elem_raw(struct hlist_nulls_head *head,
659 u32 hash, void *key,
660 u32 key_size, u32 n_buckets)
661{
662 struct hlist_nulls_node *n;
663 struct htab_elem *l;
664
665again:
666 hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
667 if (l->hash == hash && !memcmp(&l->key, key, key_size))
668 return l;
669
670 if (unlikely(get_nulls_value(n) != (hash & (n_buckets - 1))))
671 goto again;
672
673 return NULL;
674}
675
676/* Called from syscall or from eBPF program directly, so
677 * arguments have to match bpf_map_lookup_elem() exactly.
678 * The return value is adjusted by BPF instructions
679 * in htab_map_gen_lookup().
680 */
681static void *__htab_map_lookup_elem(struct bpf_map *map, void *key)
682{
683 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
684 struct hlist_nulls_head *head;
685 struct htab_elem *l;
686 u32 hash, key_size;
687
688 WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
689 !rcu_read_lock_bh_held());
690
691 key_size = map->key_size;
692
693 hash = htab_map_hash(key, key_size, htab->hashrnd);
694
695 head = select_bucket(htab, hash);
696
697 l = lookup_nulls_elem_raw(head, hash, key, key_size, htab->n_buckets);
698
699 return l;
700}
701
702static void *htab_map_lookup_elem(struct bpf_map *map, void *key)
703{
704 struct htab_elem *l = __htab_map_lookup_elem(map, key);
705
706 if (l)
707 return l->key + round_up(map->key_size, 8);
708
709 return NULL;
710}
711
712/* inline bpf_map_lookup_elem() call.
713 * Instead of:
714 * bpf_prog
715 * bpf_map_lookup_elem
716 * map->ops->map_lookup_elem
717 * htab_map_lookup_elem
718 * __htab_map_lookup_elem
719 * do:
720 * bpf_prog
721 * __htab_map_lookup_elem
722 */
723static int htab_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
724{
725 struct bpf_insn *insn = insn_buf;
726 const int ret = BPF_REG_0;
727
728 BUILD_BUG_ON(!__same_type(&__htab_map_lookup_elem,
729 (void *(*)(struct bpf_map *map, void *key))NULL));
730 *insn++ = BPF_EMIT_CALL(__htab_map_lookup_elem);
731 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1);
732 *insn++ = BPF_ALU64_IMM(BPF_ADD, ret,
733 offsetof(struct htab_elem, key) +
734 round_up(map->key_size, 8));
735 return insn - insn_buf;
736}
737
738static __always_inline void *__htab_lru_map_lookup_elem(struct bpf_map *map,
739 void *key, const bool mark)
740{
741 struct htab_elem *l = __htab_map_lookup_elem(map, key);
742
743 if (l) {
744 if (mark)
745 bpf_lru_node_set_ref(&l->lru_node);
746 return l->key + round_up(map->key_size, 8);
747 }
748
749 return NULL;
750}
751
752static void *htab_lru_map_lookup_elem(struct bpf_map *map, void *key)
753{
754 return __htab_lru_map_lookup_elem(map, key, true);
755}
756
757static void *htab_lru_map_lookup_elem_sys(struct bpf_map *map, void *key)
758{
759 return __htab_lru_map_lookup_elem(map, key, false);
760}
761
762static int htab_lru_map_gen_lookup(struct bpf_map *map,
763 struct bpf_insn *insn_buf)
764{
765 struct bpf_insn *insn = insn_buf;
766 const int ret = BPF_REG_0;
767 const int ref_reg = BPF_REG_1;
768
769 BUILD_BUG_ON(!__same_type(&__htab_map_lookup_elem,
770 (void *(*)(struct bpf_map *map, void *key))NULL));
771 *insn++ = BPF_EMIT_CALL(__htab_map_lookup_elem);
772 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 4);
773 *insn++ = BPF_LDX_MEM(BPF_B, ref_reg, ret,
774 offsetof(struct htab_elem, lru_node) +
775 offsetof(struct bpf_lru_node, ref));
776 *insn++ = BPF_JMP_IMM(BPF_JNE, ref_reg, 0, 1);
777 *insn++ = BPF_ST_MEM(BPF_B, ret,
778 offsetof(struct htab_elem, lru_node) +
779 offsetof(struct bpf_lru_node, ref),
780 1);
781 *insn++ = BPF_ALU64_IMM(BPF_ADD, ret,
782 offsetof(struct htab_elem, key) +
783 round_up(map->key_size, 8));
784 return insn - insn_buf;
785}
786
787static void check_and_free_fields(struct bpf_htab *htab,
788 struct htab_elem *elem)
789{
790 if (htab_is_percpu(htab)) {
791 void __percpu *pptr = htab_elem_get_ptr(elem, htab->map.key_size);
792 int cpu;
793
794 for_each_possible_cpu(cpu)
795 bpf_obj_free_fields(htab->map.record, per_cpu_ptr(pptr, cpu));
796 } else {
797 void *map_value = elem->key + round_up(htab->map.key_size, 8);
798
799 bpf_obj_free_fields(htab->map.record, map_value);
800 }
801}
802
803/* It is called from the bpf_lru_list when the LRU needs to delete
804 * older elements from the htab.
805 */
806static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node)
807{
808 struct bpf_htab *htab = arg;
809 struct htab_elem *l = NULL, *tgt_l;
810 struct hlist_nulls_head *head;
811 struct hlist_nulls_node *n;
812 unsigned long flags;
813 struct bucket *b;
814 int ret;
815
816 tgt_l = container_of(node, struct htab_elem, lru_node);
817 b = __select_bucket(htab, tgt_l->hash);
818 head = &b->head;
819
820 ret = htab_lock_bucket(htab, b, tgt_l->hash, &flags);
821 if (ret)
822 return false;
823
824 hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
825 if (l == tgt_l) {
826 hlist_nulls_del_rcu(&l->hash_node);
827 check_and_free_fields(htab, l);
828 bpf_map_dec_elem_count(&htab->map);
829 break;
830 }
831
832 htab_unlock_bucket(htab, b, tgt_l->hash, flags);
833
834 return l == tgt_l;
835}
836
837/* Called from syscall */
838static int htab_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
839{
840 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
841 struct hlist_nulls_head *head;
842 struct htab_elem *l, *next_l;
843 u32 hash, key_size;
844 int i = 0;
845
846 WARN_ON_ONCE(!rcu_read_lock_held());
847
848 key_size = map->key_size;
849
850 if (!key)
851 goto find_first_elem;
852
853 hash = htab_map_hash(key, key_size, htab->hashrnd);
854
855 head = select_bucket(htab, hash);
856
857 /* lookup the key */
858 l = lookup_nulls_elem_raw(head, hash, key, key_size, htab->n_buckets);
859
860 if (!l)
861 goto find_first_elem;
862
863 /* key was found, get next key in the same bucket */
864 next_l = hlist_nulls_entry_safe(rcu_dereference_raw(hlist_nulls_next_rcu(&l->hash_node)),
865 struct htab_elem, hash_node);
866
867 if (next_l) {
868 /* if next elem in this hash list is non-zero, just return it */
869 memcpy(next_key, next_l->key, key_size);
870 return 0;
871 }
872
873 /* no more elements in this hash list, go to the next bucket */
874 i = hash & (htab->n_buckets - 1);
875 i++;
876
877find_first_elem:
878 /* iterate over buckets */
879 for (; i < htab->n_buckets; i++) {
880 head = select_bucket(htab, i);
881
882 /* pick first element in the bucket */
883 next_l = hlist_nulls_entry_safe(rcu_dereference_raw(hlist_nulls_first_rcu(head)),
884 struct htab_elem, hash_node);
885 if (next_l) {
886 /* if it's not empty, just return it */
887 memcpy(next_key, next_l->key, key_size);
888 return 0;
889 }
890 }
891
892 /* iterated over all buckets and all elements */
893 return -ENOENT;
894}
895
896static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l)
897{
898 check_and_free_fields(htab, l);
899
900 migrate_disable();
901 if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH)
902 bpf_mem_cache_free(&htab->pcpu_ma, l->ptr_to_pptr);
903 bpf_mem_cache_free(&htab->ma, l);
904 migrate_enable();
905}
906
907static void htab_put_fd_value(struct bpf_htab *htab, struct htab_elem *l)
908{
909 struct bpf_map *map = &htab->map;
910 void *ptr;
911
912 if (map->ops->map_fd_put_ptr) {
913 ptr = fd_htab_map_get_ptr(map, l);
914 map->ops->map_fd_put_ptr(map, ptr, true);
915 }
916}
917
918static bool is_map_full(struct bpf_htab *htab)
919{
920 if (htab->use_percpu_counter)
921 return __percpu_counter_compare(&htab->pcount, htab->map.max_entries,
922 PERCPU_COUNTER_BATCH) >= 0;
923 return atomic_read(&htab->count) >= htab->map.max_entries;
924}
925
926static void inc_elem_count(struct bpf_htab *htab)
927{
928 bpf_map_inc_elem_count(&htab->map);
929
930 if (htab->use_percpu_counter)
931 percpu_counter_add_batch(&htab->pcount, 1, PERCPU_COUNTER_BATCH);
932 else
933 atomic_inc(&htab->count);
934}
935
936static void dec_elem_count(struct bpf_htab *htab)
937{
938 bpf_map_dec_elem_count(&htab->map);
939
940 if (htab->use_percpu_counter)
941 percpu_counter_add_batch(&htab->pcount, -1, PERCPU_COUNTER_BATCH);
942 else
943 atomic_dec(&htab->count);
944}
945
946
947static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
948{
949 htab_put_fd_value(htab, l);
950
951 if (htab_is_prealloc(htab)) {
952 bpf_map_dec_elem_count(&htab->map);
953 check_and_free_fields(htab, l);
954 pcpu_freelist_push(&htab->freelist, &l->fnode);
955 } else {
956 dec_elem_count(htab);
957 htab_elem_free(htab, l);
958 }
959}
960
961static void pcpu_copy_value(struct bpf_htab *htab, void __percpu *pptr,
962 void *value, bool onallcpus)
963{
964 if (!onallcpus) {
965 /* copy true value_size bytes */
966 copy_map_value(&htab->map, this_cpu_ptr(pptr), value);
967 } else {
968 u32 size = round_up(htab->map.value_size, 8);
969 int off = 0, cpu;
970
971 for_each_possible_cpu(cpu) {
972 copy_map_value_long(&htab->map, per_cpu_ptr(pptr, cpu), value + off);
973 off += size;
974 }
975 }
976}
977
978static void pcpu_init_value(struct bpf_htab *htab, void __percpu *pptr,
979 void *value, bool onallcpus)
980{
981 /* When not setting the initial value on all cpus, zero-fill element
982 * values for other cpus. Otherwise, bpf program has no way to ensure
983 * known initial values for cpus other than current one
984 * (onallcpus=false always when coming from bpf prog).
985 */
986 if (!onallcpus) {
987 int current_cpu = raw_smp_processor_id();
988 int cpu;
989
990 for_each_possible_cpu(cpu) {
991 if (cpu == current_cpu)
992 copy_map_value_long(&htab->map, per_cpu_ptr(pptr, cpu), value);
993 else /* Since elem is preallocated, we cannot touch special fields */
994 zero_map_value(&htab->map, per_cpu_ptr(pptr, cpu));
995 }
996 } else {
997 pcpu_copy_value(htab, pptr, value, onallcpus);
998 }
999}
1000
1001static bool fd_htab_map_needs_adjust(const struct bpf_htab *htab)
1002{
1003 return htab->map.map_type == BPF_MAP_TYPE_HASH_OF_MAPS &&
1004 BITS_PER_LONG == 64;
1005}
1006
1007static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
1008 void *value, u32 key_size, u32 hash,
1009 bool percpu, bool onallcpus,
1010 struct htab_elem *old_elem)
1011{
1012 u32 size = htab->map.value_size;
1013 bool prealloc = htab_is_prealloc(htab);
1014 struct htab_elem *l_new, **pl_new;
1015 void __percpu *pptr;
1016
1017 if (prealloc) {
1018 if (old_elem) {
1019 /* if we're updating the existing element,
1020 * use per-cpu extra elems to avoid freelist_pop/push
1021 */
1022 pl_new = this_cpu_ptr(htab->extra_elems);
1023 l_new = *pl_new;
1024 *pl_new = old_elem;
1025 } else {
1026 struct pcpu_freelist_node *l;
1027
1028 l = __pcpu_freelist_pop(&htab->freelist);
1029 if (!l)
1030 return ERR_PTR(-E2BIG);
1031 l_new = container_of(l, struct htab_elem, fnode);
1032 bpf_map_inc_elem_count(&htab->map);
1033 }
1034 } else {
1035 if (is_map_full(htab))
1036 if (!old_elem)
1037 /* when map is full and update() is replacing
1038 * old element, it's ok to allocate, since
1039 * old element will be freed immediately.
1040 * Otherwise return an error
1041 */
1042 return ERR_PTR(-E2BIG);
1043 inc_elem_count(htab);
1044 l_new = bpf_mem_cache_alloc(&htab->ma);
1045 if (!l_new) {
1046 l_new = ERR_PTR(-ENOMEM);
1047 goto dec_count;
1048 }
1049 }
1050
1051 memcpy(l_new->key, key, key_size);
1052 if (percpu) {
1053 if (prealloc) {
1054 pptr = htab_elem_get_ptr(l_new, key_size);
1055 } else {
1056 /* alloc_percpu zero-fills */
1057 void *ptr = bpf_mem_cache_alloc(&htab->pcpu_ma);
1058
1059 if (!ptr) {
1060 bpf_mem_cache_free(&htab->ma, l_new);
1061 l_new = ERR_PTR(-ENOMEM);
1062 goto dec_count;
1063 }
1064 l_new->ptr_to_pptr = ptr;
1065 pptr = *(void __percpu **)ptr;
1066 }
1067
1068 pcpu_init_value(htab, pptr, value, onallcpus);
1069
1070 if (!prealloc)
1071 htab_elem_set_ptr(l_new, key_size, pptr);
1072 } else if (fd_htab_map_needs_adjust(htab)) {
1073 size = round_up(size, 8);
1074 memcpy(l_new->key + round_up(key_size, 8), value, size);
1075 } else {
1076 copy_map_value(&htab->map,
1077 l_new->key + round_up(key_size, 8),
1078 value);
1079 }
1080
1081 l_new->hash = hash;
1082 return l_new;
1083dec_count:
1084 dec_elem_count(htab);
1085 return l_new;
1086}
1087
1088static int check_flags(struct bpf_htab *htab, struct htab_elem *l_old,
1089 u64 map_flags)
1090{
1091 if (l_old && (map_flags & ~BPF_F_LOCK) == BPF_NOEXIST)
1092 /* elem already exists */
1093 return -EEXIST;
1094
1095 if (!l_old && (map_flags & ~BPF_F_LOCK) == BPF_EXIST)
1096 /* elem doesn't exist, cannot update it */
1097 return -ENOENT;
1098
1099 return 0;
1100}
1101
1102/* Called from syscall or from eBPF program */
1103static long htab_map_update_elem(struct bpf_map *map, void *key, void *value,
1104 u64 map_flags)
1105{
1106 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1107 struct htab_elem *l_new = NULL, *l_old;
1108 struct hlist_nulls_head *head;
1109 unsigned long flags;
1110 void *old_map_ptr;
1111 struct bucket *b;
1112 u32 key_size, hash;
1113 int ret;
1114
1115 if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST))
1116 /* unknown flags */
1117 return -EINVAL;
1118
1119 WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
1120 !rcu_read_lock_bh_held());
1121
1122 key_size = map->key_size;
1123
1124 hash = htab_map_hash(key, key_size, htab->hashrnd);
1125
1126 b = __select_bucket(htab, hash);
1127 head = &b->head;
1128
1129 if (unlikely(map_flags & BPF_F_LOCK)) {
1130 if (unlikely(!btf_record_has_field(map->record, BPF_SPIN_LOCK)))
1131 return -EINVAL;
1132 /* find an element without taking the bucket lock */
1133 l_old = lookup_nulls_elem_raw(head, hash, key, key_size,
1134 htab->n_buckets);
1135 ret = check_flags(htab, l_old, map_flags);
1136 if (ret)
1137 return ret;
1138 if (l_old) {
1139 /* grab the element lock and update value in place */
1140 copy_map_value_locked(map,
1141 l_old->key + round_up(key_size, 8),
1142 value, false);
1143 return 0;
1144 }
1145 /* fall through, grab the bucket lock and lookup again.
1146 * 99.9% chance that the element won't be found,
1147 * but second lookup under lock has to be done.
1148 */
1149 }
1150
1151 ret = htab_lock_bucket(htab, b, hash, &flags);
1152 if (ret)
1153 return ret;
1154
1155 l_old = lookup_elem_raw(head, hash, key, key_size);
1156
1157 ret = check_flags(htab, l_old, map_flags);
1158 if (ret)
1159 goto err;
1160
1161 if (unlikely(l_old && (map_flags & BPF_F_LOCK))) {
1162 /* first lookup without the bucket lock didn't find the element,
1163 * but second lookup with the bucket lock found it.
1164 * This case is highly unlikely, but has to be dealt with:
1165 * grab the element lock in addition to the bucket lock
1166 * and update element in place
1167 */
1168 copy_map_value_locked(map,
1169 l_old->key + round_up(key_size, 8),
1170 value, false);
1171 ret = 0;
1172 goto err;
1173 }
1174
1175 l_new = alloc_htab_elem(htab, key, value, key_size, hash, false, false,
1176 l_old);
1177 if (IS_ERR(l_new)) {
1178 /* all pre-allocated elements are in use or memory exhausted */
1179 ret = PTR_ERR(l_new);
1180 goto err;
1181 }
1182
1183 /* add new element to the head of the list, so that
1184 * concurrent search will find it before old elem
1185 */
1186 hlist_nulls_add_head_rcu(&l_new->hash_node, head);
1187 if (l_old) {
1188 hlist_nulls_del_rcu(&l_old->hash_node);
1189
1190 /* l_old has already been stashed in htab->extra_elems, free
1191 * its special fields before it is available for reuse. Also
1192 * save the old map pointer in htab of maps before unlock
1193 * and release it after unlock.
1194 */
1195 old_map_ptr = NULL;
1196 if (htab_is_prealloc(htab)) {
1197 if (map->ops->map_fd_put_ptr)
1198 old_map_ptr = fd_htab_map_get_ptr(map, l_old);
1199 check_and_free_fields(htab, l_old);
1200 }
1201 }
1202 htab_unlock_bucket(htab, b, hash, flags);
1203 if (l_old) {
1204 if (old_map_ptr)
1205 map->ops->map_fd_put_ptr(map, old_map_ptr, true);
1206 if (!htab_is_prealloc(htab))
1207 free_htab_elem(htab, l_old);
1208 }
1209 return 0;
1210err:
1211 htab_unlock_bucket(htab, b, hash, flags);
1212 return ret;
1213}
1214
1215static void htab_lru_push_free(struct bpf_htab *htab, struct htab_elem *elem)
1216{
1217 check_and_free_fields(htab, elem);
1218 bpf_map_dec_elem_count(&htab->map);
1219 bpf_lru_push_free(&htab->lru, &elem->lru_node);
1220}
1221
1222static long htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value,
1223 u64 map_flags)
1224{
1225 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1226 struct htab_elem *l_new, *l_old = NULL;
1227 struct hlist_nulls_head *head;
1228 unsigned long flags;
1229 struct bucket *b;
1230 u32 key_size, hash;
1231 int ret;
1232
1233 if (unlikely(map_flags > BPF_EXIST))
1234 /* unknown flags */
1235 return -EINVAL;
1236
1237 WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
1238 !rcu_read_lock_bh_held());
1239
1240 key_size = map->key_size;
1241
1242 hash = htab_map_hash(key, key_size, htab->hashrnd);
1243
1244 b = __select_bucket(htab, hash);
1245 head = &b->head;
1246
1247 /* For LRU, we need to alloc before taking bucket's
1248 * spinlock because getting free nodes from LRU may need
1249 * to remove older elements from htab and this removal
1250 * operation will need a bucket lock.
1251 */
1252 l_new = prealloc_lru_pop(htab, key, hash);
1253 if (!l_new)
1254 return -ENOMEM;
1255 copy_map_value(&htab->map,
1256 l_new->key + round_up(map->key_size, 8), value);
1257
1258 ret = htab_lock_bucket(htab, b, hash, &flags);
1259 if (ret)
1260 goto err_lock_bucket;
1261
1262 l_old = lookup_elem_raw(head, hash, key, key_size);
1263
1264 ret = check_flags(htab, l_old, map_flags);
1265 if (ret)
1266 goto err;
1267
1268 /* add new element to the head of the list, so that
1269 * concurrent search will find it before old elem
1270 */
1271 hlist_nulls_add_head_rcu(&l_new->hash_node, head);
1272 if (l_old) {
1273 bpf_lru_node_set_ref(&l_new->lru_node);
1274 hlist_nulls_del_rcu(&l_old->hash_node);
1275 }
1276 ret = 0;
1277
1278err:
1279 htab_unlock_bucket(htab, b, hash, flags);
1280
1281err_lock_bucket:
1282 if (ret)
1283 htab_lru_push_free(htab, l_new);
1284 else if (l_old)
1285 htab_lru_push_free(htab, l_old);
1286
1287 return ret;
1288}
1289
1290static long __htab_percpu_map_update_elem(struct bpf_map *map, void *key,
1291 void *value, u64 map_flags,
1292 bool onallcpus)
1293{
1294 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1295 struct htab_elem *l_new = NULL, *l_old;
1296 struct hlist_nulls_head *head;
1297 unsigned long flags;
1298 struct bucket *b;
1299 u32 key_size, hash;
1300 int ret;
1301
1302 if (unlikely(map_flags > BPF_EXIST))
1303 /* unknown flags */
1304 return -EINVAL;
1305
1306 WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
1307 !rcu_read_lock_bh_held());
1308
1309 key_size = map->key_size;
1310
1311 hash = htab_map_hash(key, key_size, htab->hashrnd);
1312
1313 b = __select_bucket(htab, hash);
1314 head = &b->head;
1315
1316 ret = htab_lock_bucket(htab, b, hash, &flags);
1317 if (ret)
1318 return ret;
1319
1320 l_old = lookup_elem_raw(head, hash, key, key_size);
1321
1322 ret = check_flags(htab, l_old, map_flags);
1323 if (ret)
1324 goto err;
1325
1326 if (l_old) {
1327 /* per-cpu hash map can update value in-place */
1328 pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
1329 value, onallcpus);
1330 } else {
1331 l_new = alloc_htab_elem(htab, key, value, key_size,
1332 hash, true, onallcpus, NULL);
1333 if (IS_ERR(l_new)) {
1334 ret = PTR_ERR(l_new);
1335 goto err;
1336 }
1337 hlist_nulls_add_head_rcu(&l_new->hash_node, head);
1338 }
1339 ret = 0;
1340err:
1341 htab_unlock_bucket(htab, b, hash, flags);
1342 return ret;
1343}
1344
1345static long __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
1346 void *value, u64 map_flags,
1347 bool onallcpus)
1348{
1349 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1350 struct htab_elem *l_new = NULL, *l_old;
1351 struct hlist_nulls_head *head;
1352 unsigned long flags;
1353 struct bucket *b;
1354 u32 key_size, hash;
1355 int ret;
1356
1357 if (unlikely(map_flags > BPF_EXIST))
1358 /* unknown flags */
1359 return -EINVAL;
1360
1361 WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
1362 !rcu_read_lock_bh_held());
1363
1364 key_size = map->key_size;
1365
1366 hash = htab_map_hash(key, key_size, htab->hashrnd);
1367
1368 b = __select_bucket(htab, hash);
1369 head = &b->head;
1370
1371 /* For LRU, we need to alloc before taking bucket's
1372 * spinlock because LRU's elem alloc may need
1373 * to remove older elem from htab and this removal
1374 * operation will need a bucket lock.
1375 */
1376 if (map_flags != BPF_EXIST) {
1377 l_new = prealloc_lru_pop(htab, key, hash);
1378 if (!l_new)
1379 return -ENOMEM;
1380 }
1381
1382 ret = htab_lock_bucket(htab, b, hash, &flags);
1383 if (ret)
1384 goto err_lock_bucket;
1385
1386 l_old = lookup_elem_raw(head, hash, key, key_size);
1387
1388 ret = check_flags(htab, l_old, map_flags);
1389 if (ret)
1390 goto err;
1391
1392 if (l_old) {
1393 bpf_lru_node_set_ref(&l_old->lru_node);
1394
1395 /* per-cpu hash map can update value in-place */
1396 pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
1397 value, onallcpus);
1398 } else {
1399 pcpu_init_value(htab, htab_elem_get_ptr(l_new, key_size),
1400 value, onallcpus);
1401 hlist_nulls_add_head_rcu(&l_new->hash_node, head);
1402 l_new = NULL;
1403 }
1404 ret = 0;
1405err:
1406 htab_unlock_bucket(htab, b, hash, flags);
1407err_lock_bucket:
1408 if (l_new) {
1409 bpf_map_dec_elem_count(&htab->map);
1410 bpf_lru_push_free(&htab->lru, &l_new->lru_node);
1411 }
1412 return ret;
1413}
1414
1415static long htab_percpu_map_update_elem(struct bpf_map *map, void *key,
1416 void *value, u64 map_flags)
1417{
1418 return __htab_percpu_map_update_elem(map, key, value, map_flags, false);
1419}
1420
1421static long htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
1422 void *value, u64 map_flags)
1423{
1424 return __htab_lru_percpu_map_update_elem(map, key, value, map_flags,
1425 false);
1426}
1427
1428/* Called from syscall or from eBPF program */
1429static long htab_map_delete_elem(struct bpf_map *map, void *key)
1430{
1431 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1432 struct hlist_nulls_head *head;
1433 struct bucket *b;
1434 struct htab_elem *l;
1435 unsigned long flags;
1436 u32 hash, key_size;
1437 int ret;
1438
1439 WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
1440 !rcu_read_lock_bh_held());
1441
1442 key_size = map->key_size;
1443
1444 hash = htab_map_hash(key, key_size, htab->hashrnd);
1445 b = __select_bucket(htab, hash);
1446 head = &b->head;
1447
1448 ret = htab_lock_bucket(htab, b, hash, &flags);
1449 if (ret)
1450 return ret;
1451
1452 l = lookup_elem_raw(head, hash, key, key_size);
1453 if (l)
1454 hlist_nulls_del_rcu(&l->hash_node);
1455 else
1456 ret = -ENOENT;
1457
1458 htab_unlock_bucket(htab, b, hash, flags);
1459
1460 if (l)
1461 free_htab_elem(htab, l);
1462 return ret;
1463}
1464
1465static long htab_lru_map_delete_elem(struct bpf_map *map, void *key)
1466{
1467 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1468 struct hlist_nulls_head *head;
1469 struct bucket *b;
1470 struct htab_elem *l;
1471 unsigned long flags;
1472 u32 hash, key_size;
1473 int ret;
1474
1475 WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held() &&
1476 !rcu_read_lock_bh_held());
1477
1478 key_size = map->key_size;
1479
1480 hash = htab_map_hash(key, key_size, htab->hashrnd);
1481 b = __select_bucket(htab, hash);
1482 head = &b->head;
1483
1484 ret = htab_lock_bucket(htab, b, hash, &flags);
1485 if (ret)
1486 return ret;
1487
1488 l = lookup_elem_raw(head, hash, key, key_size);
1489
1490 if (l)
1491 hlist_nulls_del_rcu(&l->hash_node);
1492 else
1493 ret = -ENOENT;
1494
1495 htab_unlock_bucket(htab, b, hash, flags);
1496 if (l)
1497 htab_lru_push_free(htab, l);
1498 return ret;
1499}
1500
1501static void delete_all_elements(struct bpf_htab *htab)
1502{
1503 int i;
1504
1505 /* It's called from a worker thread, so disable migration here,
1506 * since bpf_mem_cache_free() relies on that.
1507 */
1508 migrate_disable();
1509 for (i = 0; i < htab->n_buckets; i++) {
1510 struct hlist_nulls_head *head = select_bucket(htab, i);
1511 struct hlist_nulls_node *n;
1512 struct htab_elem *l;
1513
1514 hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
1515 hlist_nulls_del_rcu(&l->hash_node);
1516 htab_elem_free(htab, l);
1517 }
1518 cond_resched();
1519 }
1520 migrate_enable();
1521}
1522
1523static void htab_free_malloced_timers_and_wq(struct bpf_htab *htab)
1524{
1525 int i;
1526
1527 rcu_read_lock();
1528 for (i = 0; i < htab->n_buckets; i++) {
1529 struct hlist_nulls_head *head = select_bucket(htab, i);
1530 struct hlist_nulls_node *n;
1531 struct htab_elem *l;
1532
1533 hlist_nulls_for_each_entry(l, n, head, hash_node) {
1534 /* We only free timer on uref dropping to zero */
1535 if (btf_record_has_field(htab->map.record, BPF_TIMER))
1536 bpf_obj_free_timer(htab->map.record,
1537 l->key + round_up(htab->map.key_size, 8));
1538 if (btf_record_has_field(htab->map.record, BPF_WORKQUEUE))
1539 bpf_obj_free_workqueue(htab->map.record,
1540 l->key + round_up(htab->map.key_size, 8));
1541 }
1542 cond_resched_rcu();
1543 }
1544 rcu_read_unlock();
1545}
1546
1547static void htab_map_free_timers_and_wq(struct bpf_map *map)
1548{
1549 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1550
1551 /* We only free timer and workqueue on uref dropping to zero */
1552 if (btf_record_has_field(htab->map.record, BPF_TIMER | BPF_WORKQUEUE)) {
1553 if (!htab_is_prealloc(htab))
1554 htab_free_malloced_timers_and_wq(htab);
1555 else
1556 htab_free_prealloced_timers_and_wq(htab);
1557 }
1558}
1559
1560/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
1561static void htab_map_free(struct bpf_map *map)
1562{
1563 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1564 int i;
1565
1566 /* bpf_free_used_maps() or close(map_fd) will trigger this map_free callback.
1567 * bpf_free_used_maps() is called after bpf prog is no longer executing.
1568 * There is no need to synchronize_rcu() here to protect map elements.
1569 */
1570
1571 /* htab no longer uses call_rcu() directly. bpf_mem_alloc does it
1572 * underneath and is responsible for waiting for callbacks to finish
1573 * during bpf_mem_alloc_destroy().
1574 */
1575 if (!htab_is_prealloc(htab)) {
1576 delete_all_elements(htab);
1577 } else {
1578 htab_free_prealloced_fields(htab);
1579 prealloc_destroy(htab);
1580 }
1581
1582 bpf_map_free_elem_count(map);
1583 free_percpu(htab->extra_elems);
1584 bpf_map_area_free(htab->buckets);
1585 bpf_mem_alloc_destroy(&htab->pcpu_ma);
1586 bpf_mem_alloc_destroy(&htab->ma);
1587 if (htab->use_percpu_counter)
1588 percpu_counter_destroy(&htab->pcount);
1589 for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++)
1590 free_percpu(htab->map_locked[i]);
1591 lockdep_unregister_key(&htab->lockdep_key);
1592 bpf_map_area_free(htab);
1593}
1594
1595static void htab_map_seq_show_elem(struct bpf_map *map, void *key,
1596 struct seq_file *m)
1597{
1598 void *value;
1599
1600 rcu_read_lock();
1601
1602 value = htab_map_lookup_elem(map, key);
1603 if (!value) {
1604 rcu_read_unlock();
1605 return;
1606 }
1607
1608 btf_type_seq_show(map->btf, map->btf_key_type_id, key, m);
1609 seq_puts(m, ": ");
1610 btf_type_seq_show(map->btf, map->btf_value_type_id, value, m);
1611 seq_putc(m, '\n');
1612
1613 rcu_read_unlock();
1614}
1615
1616static int __htab_map_lookup_and_delete_elem(struct bpf_map *map, void *key,
1617 void *value, bool is_lru_map,
1618 bool is_percpu, u64 flags)
1619{
1620 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1621 struct hlist_nulls_head *head;
1622 unsigned long bflags;
1623 struct htab_elem *l;
1624 u32 hash, key_size;
1625 struct bucket *b;
1626 int ret;
1627
1628 key_size = map->key_size;
1629
1630 hash = htab_map_hash(key, key_size, htab->hashrnd);
1631 b = __select_bucket(htab, hash);
1632 head = &b->head;
1633
1634 ret = htab_lock_bucket(htab, b, hash, &bflags);
1635 if (ret)
1636 return ret;
1637
1638 l = lookup_elem_raw(head, hash, key, key_size);
1639 if (!l) {
1640 ret = -ENOENT;
1641 } else {
1642 if (is_percpu) {
1643 u32 roundup_value_size = round_up(map->value_size, 8);
1644 void __percpu *pptr;
1645 int off = 0, cpu;
1646
1647 pptr = htab_elem_get_ptr(l, key_size);
1648 for_each_possible_cpu(cpu) {
1649 copy_map_value_long(&htab->map, value + off, per_cpu_ptr(pptr, cpu));
1650 check_and_init_map_value(&htab->map, value + off);
1651 off += roundup_value_size;
1652 }
1653 } else {
1654 u32 roundup_key_size = round_up(map->key_size, 8);
1655
1656 if (flags & BPF_F_LOCK)
1657 copy_map_value_locked(map, value, l->key +
1658 roundup_key_size,
1659 true);
1660 else
1661 copy_map_value(map, value, l->key +
1662 roundup_key_size);
1663 /* Zeroing special fields in the temp buffer */
1664 check_and_init_map_value(map, value);
1665 }
1666
1667 hlist_nulls_del_rcu(&l->hash_node);
1668 if (!is_lru_map)
1669 free_htab_elem(htab, l);
1670 }
1671
1672 htab_unlock_bucket(htab, b, hash, bflags);
1673
1674 if (is_lru_map && l)
1675 htab_lru_push_free(htab, l);
1676
1677 return ret;
1678}
1679
1680static int htab_map_lookup_and_delete_elem(struct bpf_map *map, void *key,
1681 void *value, u64 flags)
1682{
1683 return __htab_map_lookup_and_delete_elem(map, key, value, false, false,
1684 flags);
1685}
1686
1687static int htab_percpu_map_lookup_and_delete_elem(struct bpf_map *map,
1688 void *key, void *value,
1689 u64 flags)
1690{
1691 return __htab_map_lookup_and_delete_elem(map, key, value, false, true,
1692 flags);
1693}
1694
1695static int htab_lru_map_lookup_and_delete_elem(struct bpf_map *map, void *key,
1696 void *value, u64 flags)
1697{
1698 return __htab_map_lookup_and_delete_elem(map, key, value, true, false,
1699 flags);
1700}
1701
1702static int htab_lru_percpu_map_lookup_and_delete_elem(struct bpf_map *map,
1703 void *key, void *value,
1704 u64 flags)
1705{
1706 return __htab_map_lookup_and_delete_elem(map, key, value, true, true,
1707 flags);
1708}
1709
1710static int
1711__htab_map_lookup_and_delete_batch(struct bpf_map *map,
1712 const union bpf_attr *attr,
1713 union bpf_attr __user *uattr,
1714 bool do_delete, bool is_lru_map,
1715 bool is_percpu)
1716{
1717 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1718 u32 bucket_cnt, total, key_size, value_size, roundup_key_size;
1719 void *keys = NULL, *values = NULL, *value, *dst_key, *dst_val;
1720 void __user *uvalues = u64_to_user_ptr(attr->batch.values);
1721 void __user *ukeys = u64_to_user_ptr(attr->batch.keys);
1722 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
1723 u32 batch, max_count, size, bucket_size, map_id;
1724 struct htab_elem *node_to_free = NULL;
1725 u64 elem_map_flags, map_flags;
1726 struct hlist_nulls_head *head;
1727 struct hlist_nulls_node *n;
1728 unsigned long flags = 0;
1729 bool locked = false;
1730 struct htab_elem *l;
1731 struct bucket *b;
1732 int ret = 0;
1733
1734 elem_map_flags = attr->batch.elem_flags;
1735 if ((elem_map_flags & ~BPF_F_LOCK) ||
1736 ((elem_map_flags & BPF_F_LOCK) && !btf_record_has_field(map->record, BPF_SPIN_LOCK)))
1737 return -EINVAL;
1738
1739 map_flags = attr->batch.flags;
1740 if (map_flags)
1741 return -EINVAL;
1742
1743 max_count = attr->batch.count;
1744 if (!max_count)
1745 return 0;
1746
1747 if (put_user(0, &uattr->batch.count))
1748 return -EFAULT;
1749
1750 batch = 0;
1751 if (ubatch && copy_from_user(&batch, ubatch, sizeof(batch)))
1752 return -EFAULT;
1753
1754 if (batch >= htab->n_buckets)
1755 return -ENOENT;
1756
1757 key_size = htab->map.key_size;
1758 roundup_key_size = round_up(htab->map.key_size, 8);
1759 value_size = htab->map.value_size;
1760 size = round_up(value_size, 8);
1761 if (is_percpu)
1762 value_size = size * num_possible_cpus();
1763 total = 0;
1764 /* while experimenting with hash tables with sizes ranging from 10 to
1765 * 1000, it was observed that a bucket can have up to 5 entries.
1766 */
1767 bucket_size = 5;
1768
1769alloc:
1770 /* We cannot do copy_from_user or copy_to_user inside
1771 * the rcu_read_lock. Allocate enough space here.
1772 */
1773 keys = kvmalloc_array(key_size, bucket_size, GFP_USER | __GFP_NOWARN);
1774 values = kvmalloc_array(value_size, bucket_size, GFP_USER | __GFP_NOWARN);
1775 if (!keys || !values) {
1776 ret = -ENOMEM;
1777 goto after_loop;
1778 }
1779
1780again:
1781 bpf_disable_instrumentation();
1782 rcu_read_lock();
1783again_nocopy:
1784 dst_key = keys;
1785 dst_val = values;
1786 b = &htab->buckets[batch];
1787 head = &b->head;
1788 /* do not grab the lock unless need it (bucket_cnt > 0). */
1789 if (locked) {
1790 ret = htab_lock_bucket(htab, b, batch, &flags);
1791 if (ret) {
1792 rcu_read_unlock();
1793 bpf_enable_instrumentation();
1794 goto after_loop;
1795 }
1796 }
1797
1798 bucket_cnt = 0;
1799 hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
1800 bucket_cnt++;
1801
1802 if (bucket_cnt && !locked) {
1803 locked = true;
1804 goto again_nocopy;
1805 }
1806
1807 if (bucket_cnt > (max_count - total)) {
1808 if (total == 0)
1809 ret = -ENOSPC;
1810 /* Note that since bucket_cnt > 0 here, it is implicit
1811 * that the locked was grabbed, so release it.
1812 */
1813 htab_unlock_bucket(htab, b, batch, flags);
1814 rcu_read_unlock();
1815 bpf_enable_instrumentation();
1816 goto after_loop;
1817 }
1818
1819 if (bucket_cnt > bucket_size) {
1820 bucket_size = bucket_cnt;
1821 /* Note that since bucket_cnt > 0 here, it is implicit
1822 * that the locked was grabbed, so release it.
1823 */
1824 htab_unlock_bucket(htab, b, batch, flags);
1825 rcu_read_unlock();
1826 bpf_enable_instrumentation();
1827 kvfree(keys);
1828 kvfree(values);
1829 goto alloc;
1830 }
1831
1832 /* Next block is only safe to run if you have grabbed the lock */
1833 if (!locked)
1834 goto next_batch;
1835
1836 hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
1837 memcpy(dst_key, l->key, key_size);
1838
1839 if (is_percpu) {
1840 int off = 0, cpu;
1841 void __percpu *pptr;
1842
1843 pptr = htab_elem_get_ptr(l, map->key_size);
1844 for_each_possible_cpu(cpu) {
1845 copy_map_value_long(&htab->map, dst_val + off, per_cpu_ptr(pptr, cpu));
1846 check_and_init_map_value(&htab->map, dst_val + off);
1847 off += size;
1848 }
1849 } else {
1850 value = l->key + roundup_key_size;
1851 if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
1852 struct bpf_map **inner_map = value;
1853
1854 /* Actual value is the id of the inner map */
1855 map_id = map->ops->map_fd_sys_lookup_elem(*inner_map);
1856 value = &map_id;
1857 }
1858
1859 if (elem_map_flags & BPF_F_LOCK)
1860 copy_map_value_locked(map, dst_val, value,
1861 true);
1862 else
1863 copy_map_value(map, dst_val, value);
1864 /* Zeroing special fields in the temp buffer */
1865 check_and_init_map_value(map, dst_val);
1866 }
1867 if (do_delete) {
1868 hlist_nulls_del_rcu(&l->hash_node);
1869
1870 /* bpf_lru_push_free() will acquire lru_lock, which
1871 * may cause deadlock. See comments in function
1872 * prealloc_lru_pop(). Let us do bpf_lru_push_free()
1873 * after releasing the bucket lock.
1874 *
1875 * For htab of maps, htab_put_fd_value() in
1876 * free_htab_elem() may acquire a spinlock with bucket
1877 * lock being held and it violates the lock rule, so
1878 * invoke free_htab_elem() after unlock as well.
1879 */
1880 l->batch_flink = node_to_free;
1881 node_to_free = l;
1882 }
1883 dst_key += key_size;
1884 dst_val += value_size;
1885 }
1886
1887 htab_unlock_bucket(htab, b, batch, flags);
1888 locked = false;
1889
1890 while (node_to_free) {
1891 l = node_to_free;
1892 node_to_free = node_to_free->batch_flink;
1893 if (is_lru_map)
1894 htab_lru_push_free(htab, l);
1895 else
1896 free_htab_elem(htab, l);
1897 }
1898
1899next_batch:
1900 /* If we are not copying data, we can go to next bucket and avoid
1901 * unlocking the rcu.
1902 */
1903 if (!bucket_cnt && (batch + 1 < htab->n_buckets)) {
1904 batch++;
1905 goto again_nocopy;
1906 }
1907
1908 rcu_read_unlock();
1909 bpf_enable_instrumentation();
1910 if (bucket_cnt && (copy_to_user(ukeys + total * key_size, keys,
1911 key_size * bucket_cnt) ||
1912 copy_to_user(uvalues + total * value_size, values,
1913 value_size * bucket_cnt))) {
1914 ret = -EFAULT;
1915 goto after_loop;
1916 }
1917
1918 total += bucket_cnt;
1919 batch++;
1920 if (batch >= htab->n_buckets) {
1921 ret = -ENOENT;
1922 goto after_loop;
1923 }
1924 goto again;
1925
1926after_loop:
1927 if (ret == -EFAULT)
1928 goto out;
1929
1930 /* copy # of entries and next batch */
1931 ubatch = u64_to_user_ptr(attr->batch.out_batch);
1932 if (copy_to_user(ubatch, &batch, sizeof(batch)) ||
1933 put_user(total, &uattr->batch.count))
1934 ret = -EFAULT;
1935
1936out:
1937 kvfree(keys);
1938 kvfree(values);
1939 return ret;
1940}
1941
1942static int
1943htab_percpu_map_lookup_batch(struct bpf_map *map, const union bpf_attr *attr,
1944 union bpf_attr __user *uattr)
1945{
1946 return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
1947 false, true);
1948}
1949
1950static int
1951htab_percpu_map_lookup_and_delete_batch(struct bpf_map *map,
1952 const union bpf_attr *attr,
1953 union bpf_attr __user *uattr)
1954{
1955 return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
1956 false, true);
1957}
1958
1959static int
1960htab_map_lookup_batch(struct bpf_map *map, const union bpf_attr *attr,
1961 union bpf_attr __user *uattr)
1962{
1963 return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
1964 false, false);
1965}
1966
1967static int
1968htab_map_lookup_and_delete_batch(struct bpf_map *map,
1969 const union bpf_attr *attr,
1970 union bpf_attr __user *uattr)
1971{
1972 return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
1973 false, false);
1974}
1975
1976static int
1977htab_lru_percpu_map_lookup_batch(struct bpf_map *map,
1978 const union bpf_attr *attr,
1979 union bpf_attr __user *uattr)
1980{
1981 return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
1982 true, true);
1983}
1984
1985static int
1986htab_lru_percpu_map_lookup_and_delete_batch(struct bpf_map *map,
1987 const union bpf_attr *attr,
1988 union bpf_attr __user *uattr)
1989{
1990 return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
1991 true, true);
1992}
1993
1994static int
1995htab_lru_map_lookup_batch(struct bpf_map *map, const union bpf_attr *attr,
1996 union bpf_attr __user *uattr)
1997{
1998 return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
1999 true, false);
2000}
2001
2002static int
2003htab_lru_map_lookup_and_delete_batch(struct bpf_map *map,
2004 const union bpf_attr *attr,
2005 union bpf_attr __user *uattr)
2006{
2007 return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
2008 true, false);
2009}
2010
2011struct bpf_iter_seq_hash_map_info {
2012 struct bpf_map *map;
2013 struct bpf_htab *htab;
2014 void *percpu_value_buf; // non-zero means percpu hash
2015 u32 bucket_id;
2016 u32 skip_elems;
2017};
2018
2019static struct htab_elem *
2020bpf_hash_map_seq_find_next(struct bpf_iter_seq_hash_map_info *info,
2021 struct htab_elem *prev_elem)
2022{
2023 const struct bpf_htab *htab = info->htab;
2024 u32 skip_elems = info->skip_elems;
2025 u32 bucket_id = info->bucket_id;
2026 struct hlist_nulls_head *head;
2027 struct hlist_nulls_node *n;
2028 struct htab_elem *elem;
2029 struct bucket *b;
2030 u32 i, count;
2031
2032 if (bucket_id >= htab->n_buckets)
2033 return NULL;
2034
2035 /* try to find next elem in the same bucket */
2036 if (prev_elem) {
2037 /* no update/deletion on this bucket, prev_elem should be still valid
2038 * and we won't skip elements.
2039 */
2040 n = rcu_dereference_raw(hlist_nulls_next_rcu(&prev_elem->hash_node));
2041 elem = hlist_nulls_entry_safe(n, struct htab_elem, hash_node);
2042 if (elem)
2043 return elem;
2044
2045 /* not found, unlock and go to the next bucket */
2046 b = &htab->buckets[bucket_id++];
2047 rcu_read_unlock();
2048 skip_elems = 0;
2049 }
2050
2051 for (i = bucket_id; i < htab->n_buckets; i++) {
2052 b = &htab->buckets[i];
2053 rcu_read_lock();
2054
2055 count = 0;
2056 head = &b->head;
2057 hlist_nulls_for_each_entry_rcu(elem, n, head, hash_node) {
2058 if (count >= skip_elems) {
2059 info->bucket_id = i;
2060 info->skip_elems = count;
2061 return elem;
2062 }
2063 count++;
2064 }
2065
2066 rcu_read_unlock();
2067 skip_elems = 0;
2068 }
2069
2070 info->bucket_id = i;
2071 info->skip_elems = 0;
2072 return NULL;
2073}
2074
2075static void *bpf_hash_map_seq_start(struct seq_file *seq, loff_t *pos)
2076{
2077 struct bpf_iter_seq_hash_map_info *info = seq->private;
2078 struct htab_elem *elem;
2079
2080 elem = bpf_hash_map_seq_find_next(info, NULL);
2081 if (!elem)
2082 return NULL;
2083
2084 if (*pos == 0)
2085 ++*pos;
2086 return elem;
2087}
2088
2089static void *bpf_hash_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2090{
2091 struct bpf_iter_seq_hash_map_info *info = seq->private;
2092
2093 ++*pos;
2094 ++info->skip_elems;
2095 return bpf_hash_map_seq_find_next(info, v);
2096}
2097
2098static int __bpf_hash_map_seq_show(struct seq_file *seq, struct htab_elem *elem)
2099{
2100 struct bpf_iter_seq_hash_map_info *info = seq->private;
2101 u32 roundup_key_size, roundup_value_size;
2102 struct bpf_iter__bpf_map_elem ctx = {};
2103 struct bpf_map *map = info->map;
2104 struct bpf_iter_meta meta;
2105 int ret = 0, off = 0, cpu;
2106 struct bpf_prog *prog;
2107 void __percpu *pptr;
2108
2109 meta.seq = seq;
2110 prog = bpf_iter_get_info(&meta, elem == NULL);
2111 if (prog) {
2112 ctx.meta = &meta;
2113 ctx.map = info->map;
2114 if (elem) {
2115 roundup_key_size = round_up(map->key_size, 8);
2116 ctx.key = elem->key;
2117 if (!info->percpu_value_buf) {
2118 ctx.value = elem->key + roundup_key_size;
2119 } else {
2120 roundup_value_size = round_up(map->value_size, 8);
2121 pptr = htab_elem_get_ptr(elem, map->key_size);
2122 for_each_possible_cpu(cpu) {
2123 copy_map_value_long(map, info->percpu_value_buf + off,
2124 per_cpu_ptr(pptr, cpu));
2125 check_and_init_map_value(map, info->percpu_value_buf + off);
2126 off += roundup_value_size;
2127 }
2128 ctx.value = info->percpu_value_buf;
2129 }
2130 }
2131 ret = bpf_iter_run_prog(prog, &ctx);
2132 }
2133
2134 return ret;
2135}
2136
2137static int bpf_hash_map_seq_show(struct seq_file *seq, void *v)
2138{
2139 return __bpf_hash_map_seq_show(seq, v);
2140}
2141
2142static void bpf_hash_map_seq_stop(struct seq_file *seq, void *v)
2143{
2144 if (!v)
2145 (void)__bpf_hash_map_seq_show(seq, NULL);
2146 else
2147 rcu_read_unlock();
2148}
2149
2150static int bpf_iter_init_hash_map(void *priv_data,
2151 struct bpf_iter_aux_info *aux)
2152{
2153 struct bpf_iter_seq_hash_map_info *seq_info = priv_data;
2154 struct bpf_map *map = aux->map;
2155 void *value_buf;
2156 u32 buf_size;
2157
2158 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
2159 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
2160 buf_size = round_up(map->value_size, 8) * num_possible_cpus();
2161 value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN);
2162 if (!value_buf)
2163 return -ENOMEM;
2164
2165 seq_info->percpu_value_buf = value_buf;
2166 }
2167
2168 bpf_map_inc_with_uref(map);
2169 seq_info->map = map;
2170 seq_info->htab = container_of(map, struct bpf_htab, map);
2171 return 0;
2172}
2173
2174static void bpf_iter_fini_hash_map(void *priv_data)
2175{
2176 struct bpf_iter_seq_hash_map_info *seq_info = priv_data;
2177
2178 bpf_map_put_with_uref(seq_info->map);
2179 kfree(seq_info->percpu_value_buf);
2180}
2181
2182static const struct seq_operations bpf_hash_map_seq_ops = {
2183 .start = bpf_hash_map_seq_start,
2184 .next = bpf_hash_map_seq_next,
2185 .stop = bpf_hash_map_seq_stop,
2186 .show = bpf_hash_map_seq_show,
2187};
2188
2189static const struct bpf_iter_seq_info iter_seq_info = {
2190 .seq_ops = &bpf_hash_map_seq_ops,
2191 .init_seq_private = bpf_iter_init_hash_map,
2192 .fini_seq_private = bpf_iter_fini_hash_map,
2193 .seq_priv_size = sizeof(struct bpf_iter_seq_hash_map_info),
2194};
2195
2196static long bpf_for_each_hash_elem(struct bpf_map *map, bpf_callback_t callback_fn,
2197 void *callback_ctx, u64 flags)
2198{
2199 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
2200 struct hlist_nulls_head *head;
2201 struct hlist_nulls_node *n;
2202 struct htab_elem *elem;
2203 u32 roundup_key_size;
2204 int i, num_elems = 0;
2205 void __percpu *pptr;
2206 struct bucket *b;
2207 void *key, *val;
2208 bool is_percpu;
2209 u64 ret = 0;
2210
2211 if (flags != 0)
2212 return -EINVAL;
2213
2214 is_percpu = htab_is_percpu(htab);
2215
2216 roundup_key_size = round_up(map->key_size, 8);
2217 /* disable migration so percpu value prepared here will be the
2218 * same as the one seen by the bpf program with bpf_map_lookup_elem().
2219 */
2220 if (is_percpu)
2221 migrate_disable();
2222 for (i = 0; i < htab->n_buckets; i++) {
2223 b = &htab->buckets[i];
2224 rcu_read_lock();
2225 head = &b->head;
2226 hlist_nulls_for_each_entry_rcu(elem, n, head, hash_node) {
2227 key = elem->key;
2228 if (is_percpu) {
2229 /* current cpu value for percpu map */
2230 pptr = htab_elem_get_ptr(elem, map->key_size);
2231 val = this_cpu_ptr(pptr);
2232 } else {
2233 val = elem->key + roundup_key_size;
2234 }
2235 num_elems++;
2236 ret = callback_fn((u64)(long)map, (u64)(long)key,
2237 (u64)(long)val, (u64)(long)callback_ctx, 0);
2238 /* return value: 0 - continue, 1 - stop and return */
2239 if (ret) {
2240 rcu_read_unlock();
2241 goto out;
2242 }
2243 }
2244 rcu_read_unlock();
2245 }
2246out:
2247 if (is_percpu)
2248 migrate_enable();
2249 return num_elems;
2250}
2251
2252static u64 htab_map_mem_usage(const struct bpf_map *map)
2253{
2254 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
2255 u32 value_size = round_up(htab->map.value_size, 8);
2256 bool prealloc = htab_is_prealloc(htab);
2257 bool percpu = htab_is_percpu(htab);
2258 bool lru = htab_is_lru(htab);
2259 u64 num_entries;
2260 u64 usage = sizeof(struct bpf_htab);
2261
2262 usage += sizeof(struct bucket) * htab->n_buckets;
2263 usage += sizeof(int) * num_possible_cpus() * HASHTAB_MAP_LOCK_COUNT;
2264 if (prealloc) {
2265 num_entries = map->max_entries;
2266 if (htab_has_extra_elems(htab))
2267 num_entries += num_possible_cpus();
2268
2269 usage += htab->elem_size * num_entries;
2270
2271 if (percpu)
2272 usage += value_size * num_possible_cpus() * num_entries;
2273 else if (!lru)
2274 usage += sizeof(struct htab_elem *) * num_possible_cpus();
2275 } else {
2276#define LLIST_NODE_SZ sizeof(struct llist_node)
2277
2278 num_entries = htab->use_percpu_counter ?
2279 percpu_counter_sum(&htab->pcount) :
2280 atomic_read(&htab->count);
2281 usage += (htab->elem_size + LLIST_NODE_SZ) * num_entries;
2282 if (percpu) {
2283 usage += (LLIST_NODE_SZ + sizeof(void *)) * num_entries;
2284 usage += value_size * num_possible_cpus() * num_entries;
2285 }
2286 }
2287 return usage;
2288}
2289
2290BTF_ID_LIST_SINGLE(htab_map_btf_ids, struct, bpf_htab)
2291const struct bpf_map_ops htab_map_ops = {
2292 .map_meta_equal = bpf_map_meta_equal,
2293 .map_alloc_check = htab_map_alloc_check,
2294 .map_alloc = htab_map_alloc,
2295 .map_free = htab_map_free,
2296 .map_get_next_key = htab_map_get_next_key,
2297 .map_release_uref = htab_map_free_timers_and_wq,
2298 .map_lookup_elem = htab_map_lookup_elem,
2299 .map_lookup_and_delete_elem = htab_map_lookup_and_delete_elem,
2300 .map_update_elem = htab_map_update_elem,
2301 .map_delete_elem = htab_map_delete_elem,
2302 .map_gen_lookup = htab_map_gen_lookup,
2303 .map_seq_show_elem = htab_map_seq_show_elem,
2304 .map_set_for_each_callback_args = map_set_for_each_callback_args,
2305 .map_for_each_callback = bpf_for_each_hash_elem,
2306 .map_mem_usage = htab_map_mem_usage,
2307 BATCH_OPS(htab),
2308 .map_btf_id = &htab_map_btf_ids[0],
2309 .iter_seq_info = &iter_seq_info,
2310};
2311
2312const struct bpf_map_ops htab_lru_map_ops = {
2313 .map_meta_equal = bpf_map_meta_equal,
2314 .map_alloc_check = htab_map_alloc_check,
2315 .map_alloc = htab_map_alloc,
2316 .map_free = htab_map_free,
2317 .map_get_next_key = htab_map_get_next_key,
2318 .map_release_uref = htab_map_free_timers_and_wq,
2319 .map_lookup_elem = htab_lru_map_lookup_elem,
2320 .map_lookup_and_delete_elem = htab_lru_map_lookup_and_delete_elem,
2321 .map_lookup_elem_sys_only = htab_lru_map_lookup_elem_sys,
2322 .map_update_elem = htab_lru_map_update_elem,
2323 .map_delete_elem = htab_lru_map_delete_elem,
2324 .map_gen_lookup = htab_lru_map_gen_lookup,
2325 .map_seq_show_elem = htab_map_seq_show_elem,
2326 .map_set_for_each_callback_args = map_set_for_each_callback_args,
2327 .map_for_each_callback = bpf_for_each_hash_elem,
2328 .map_mem_usage = htab_map_mem_usage,
2329 BATCH_OPS(htab_lru),
2330 .map_btf_id = &htab_map_btf_ids[0],
2331 .iter_seq_info = &iter_seq_info,
2332};
2333
2334/* Called from eBPF program */
2335static void *htab_percpu_map_lookup_elem(struct bpf_map *map, void *key)
2336{
2337 struct htab_elem *l = __htab_map_lookup_elem(map, key);
2338
2339 if (l)
2340 return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
2341 else
2342 return NULL;
2343}
2344
2345/* inline bpf_map_lookup_elem() call for per-CPU hashmap */
2346static int htab_percpu_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
2347{
2348 struct bpf_insn *insn = insn_buf;
2349
2350 if (!bpf_jit_supports_percpu_insn())
2351 return -EOPNOTSUPP;
2352
2353 BUILD_BUG_ON(!__same_type(&__htab_map_lookup_elem,
2354 (void *(*)(struct bpf_map *map, void *key))NULL));
2355 *insn++ = BPF_EMIT_CALL(__htab_map_lookup_elem);
2356 *insn++ = BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3);
2357 *insn++ = BPF_ALU64_IMM(BPF_ADD, BPF_REG_0,
2358 offsetof(struct htab_elem, key) + map->key_size);
2359 *insn++ = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0);
2360 *insn++ = BPF_MOV64_PERCPU_REG(BPF_REG_0, BPF_REG_0);
2361
2362 return insn - insn_buf;
2363}
2364
2365static void *htab_percpu_map_lookup_percpu_elem(struct bpf_map *map, void *key, u32 cpu)
2366{
2367 struct htab_elem *l;
2368
2369 if (cpu >= nr_cpu_ids)
2370 return NULL;
2371
2372 l = __htab_map_lookup_elem(map, key);
2373 if (l)
2374 return per_cpu_ptr(htab_elem_get_ptr(l, map->key_size), cpu);
2375 else
2376 return NULL;
2377}
2378
2379static void *htab_lru_percpu_map_lookup_elem(struct bpf_map *map, void *key)
2380{
2381 struct htab_elem *l = __htab_map_lookup_elem(map, key);
2382
2383 if (l) {
2384 bpf_lru_node_set_ref(&l->lru_node);
2385 return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
2386 }
2387
2388 return NULL;
2389}
2390
2391static void *htab_lru_percpu_map_lookup_percpu_elem(struct bpf_map *map, void *key, u32 cpu)
2392{
2393 struct htab_elem *l;
2394
2395 if (cpu >= nr_cpu_ids)
2396 return NULL;
2397
2398 l = __htab_map_lookup_elem(map, key);
2399 if (l) {
2400 bpf_lru_node_set_ref(&l->lru_node);
2401 return per_cpu_ptr(htab_elem_get_ptr(l, map->key_size), cpu);
2402 }
2403
2404 return NULL;
2405}
2406
2407int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value)
2408{
2409 struct htab_elem *l;
2410 void __percpu *pptr;
2411 int ret = -ENOENT;
2412 int cpu, off = 0;
2413 u32 size;
2414
2415 /* per_cpu areas are zero-filled and bpf programs can only
2416 * access 'value_size' of them, so copying rounded areas
2417 * will not leak any kernel data
2418 */
2419 size = round_up(map->value_size, 8);
2420 rcu_read_lock();
2421 l = __htab_map_lookup_elem(map, key);
2422 if (!l)
2423 goto out;
2424 /* We do not mark LRU map element here in order to not mess up
2425 * eviction heuristics when user space does a map walk.
2426 */
2427 pptr = htab_elem_get_ptr(l, map->key_size);
2428 for_each_possible_cpu(cpu) {
2429 copy_map_value_long(map, value + off, per_cpu_ptr(pptr, cpu));
2430 check_and_init_map_value(map, value + off);
2431 off += size;
2432 }
2433 ret = 0;
2434out:
2435 rcu_read_unlock();
2436 return ret;
2437}
2438
2439int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
2440 u64 map_flags)
2441{
2442 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
2443 int ret;
2444
2445 rcu_read_lock();
2446 if (htab_is_lru(htab))
2447 ret = __htab_lru_percpu_map_update_elem(map, key, value,
2448 map_flags, true);
2449 else
2450 ret = __htab_percpu_map_update_elem(map, key, value, map_flags,
2451 true);
2452 rcu_read_unlock();
2453
2454 return ret;
2455}
2456
2457static void htab_percpu_map_seq_show_elem(struct bpf_map *map, void *key,
2458 struct seq_file *m)
2459{
2460 struct htab_elem *l;
2461 void __percpu *pptr;
2462 int cpu;
2463
2464 rcu_read_lock();
2465
2466 l = __htab_map_lookup_elem(map, key);
2467 if (!l) {
2468 rcu_read_unlock();
2469 return;
2470 }
2471
2472 btf_type_seq_show(map->btf, map->btf_key_type_id, key, m);
2473 seq_puts(m, ": {\n");
2474 pptr = htab_elem_get_ptr(l, map->key_size);
2475 for_each_possible_cpu(cpu) {
2476 seq_printf(m, "\tcpu%d: ", cpu);
2477 btf_type_seq_show(map->btf, map->btf_value_type_id,
2478 per_cpu_ptr(pptr, cpu), m);
2479 seq_putc(m, '\n');
2480 }
2481 seq_puts(m, "}\n");
2482
2483 rcu_read_unlock();
2484}
2485
2486const struct bpf_map_ops htab_percpu_map_ops = {
2487 .map_meta_equal = bpf_map_meta_equal,
2488 .map_alloc_check = htab_map_alloc_check,
2489 .map_alloc = htab_map_alloc,
2490 .map_free = htab_map_free,
2491 .map_get_next_key = htab_map_get_next_key,
2492 .map_lookup_elem = htab_percpu_map_lookup_elem,
2493 .map_gen_lookup = htab_percpu_map_gen_lookup,
2494 .map_lookup_and_delete_elem = htab_percpu_map_lookup_and_delete_elem,
2495 .map_update_elem = htab_percpu_map_update_elem,
2496 .map_delete_elem = htab_map_delete_elem,
2497 .map_lookup_percpu_elem = htab_percpu_map_lookup_percpu_elem,
2498 .map_seq_show_elem = htab_percpu_map_seq_show_elem,
2499 .map_set_for_each_callback_args = map_set_for_each_callback_args,
2500 .map_for_each_callback = bpf_for_each_hash_elem,
2501 .map_mem_usage = htab_map_mem_usage,
2502 BATCH_OPS(htab_percpu),
2503 .map_btf_id = &htab_map_btf_ids[0],
2504 .iter_seq_info = &iter_seq_info,
2505};
2506
2507const struct bpf_map_ops htab_lru_percpu_map_ops = {
2508 .map_meta_equal = bpf_map_meta_equal,
2509 .map_alloc_check = htab_map_alloc_check,
2510 .map_alloc = htab_map_alloc,
2511 .map_free = htab_map_free,
2512 .map_get_next_key = htab_map_get_next_key,
2513 .map_lookup_elem = htab_lru_percpu_map_lookup_elem,
2514 .map_lookup_and_delete_elem = htab_lru_percpu_map_lookup_and_delete_elem,
2515 .map_update_elem = htab_lru_percpu_map_update_elem,
2516 .map_delete_elem = htab_lru_map_delete_elem,
2517 .map_lookup_percpu_elem = htab_lru_percpu_map_lookup_percpu_elem,
2518 .map_seq_show_elem = htab_percpu_map_seq_show_elem,
2519 .map_set_for_each_callback_args = map_set_for_each_callback_args,
2520 .map_for_each_callback = bpf_for_each_hash_elem,
2521 .map_mem_usage = htab_map_mem_usage,
2522 BATCH_OPS(htab_lru_percpu),
2523 .map_btf_id = &htab_map_btf_ids[0],
2524 .iter_seq_info = &iter_seq_info,
2525};
2526
2527static int fd_htab_map_alloc_check(union bpf_attr *attr)
2528{
2529 if (attr->value_size != sizeof(u32))
2530 return -EINVAL;
2531 return htab_map_alloc_check(attr);
2532}
2533
2534static void fd_htab_map_free(struct bpf_map *map)
2535{
2536 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
2537 struct hlist_nulls_node *n;
2538 struct hlist_nulls_head *head;
2539 struct htab_elem *l;
2540 int i;
2541
2542 for (i = 0; i < htab->n_buckets; i++) {
2543 head = select_bucket(htab, i);
2544
2545 hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
2546 void *ptr = fd_htab_map_get_ptr(map, l);
2547
2548 map->ops->map_fd_put_ptr(map, ptr, false);
2549 }
2550 }
2551
2552 htab_map_free(map);
2553}
2554
2555/* only called from syscall */
2556int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value)
2557{
2558 void **ptr;
2559 int ret = 0;
2560
2561 if (!map->ops->map_fd_sys_lookup_elem)
2562 return -ENOTSUPP;
2563
2564 rcu_read_lock();
2565 ptr = htab_map_lookup_elem(map, key);
2566 if (ptr)
2567 *value = map->ops->map_fd_sys_lookup_elem(READ_ONCE(*ptr));
2568 else
2569 ret = -ENOENT;
2570 rcu_read_unlock();
2571
2572 return ret;
2573}
2574
2575/* only called from syscall */
2576int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file,
2577 void *key, void *value, u64 map_flags)
2578{
2579 void *ptr;
2580 int ret;
2581 u32 ufd = *(u32 *)value;
2582
2583 ptr = map->ops->map_fd_get_ptr(map, map_file, ufd);
2584 if (IS_ERR(ptr))
2585 return PTR_ERR(ptr);
2586
2587 /* The htab bucket lock is always held during update operations in fd
2588 * htab map, and the following rcu_read_lock() is only used to avoid
2589 * the WARN_ON_ONCE in htab_map_update_elem().
2590 */
2591 rcu_read_lock();
2592 ret = htab_map_update_elem(map, key, &ptr, map_flags);
2593 rcu_read_unlock();
2594 if (ret)
2595 map->ops->map_fd_put_ptr(map, ptr, false);
2596
2597 return ret;
2598}
2599
2600static struct bpf_map *htab_of_map_alloc(union bpf_attr *attr)
2601{
2602 struct bpf_map *map, *inner_map_meta;
2603
2604 inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd);
2605 if (IS_ERR(inner_map_meta))
2606 return inner_map_meta;
2607
2608 map = htab_map_alloc(attr);
2609 if (IS_ERR(map)) {
2610 bpf_map_meta_free(inner_map_meta);
2611 return map;
2612 }
2613
2614 map->inner_map_meta = inner_map_meta;
2615
2616 return map;
2617}
2618
2619static void *htab_of_map_lookup_elem(struct bpf_map *map, void *key)
2620{
2621 struct bpf_map **inner_map = htab_map_lookup_elem(map, key);
2622
2623 if (!inner_map)
2624 return NULL;
2625
2626 return READ_ONCE(*inner_map);
2627}
2628
2629static int htab_of_map_gen_lookup(struct bpf_map *map,
2630 struct bpf_insn *insn_buf)
2631{
2632 struct bpf_insn *insn = insn_buf;
2633 const int ret = BPF_REG_0;
2634
2635 BUILD_BUG_ON(!__same_type(&__htab_map_lookup_elem,
2636 (void *(*)(struct bpf_map *map, void *key))NULL));
2637 *insn++ = BPF_EMIT_CALL(__htab_map_lookup_elem);
2638 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 2);
2639 *insn++ = BPF_ALU64_IMM(BPF_ADD, ret,
2640 offsetof(struct htab_elem, key) +
2641 round_up(map->key_size, 8));
2642 *insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0);
2643
2644 return insn - insn_buf;
2645}
2646
2647static void htab_of_map_free(struct bpf_map *map)
2648{
2649 bpf_map_meta_free(map->inner_map_meta);
2650 fd_htab_map_free(map);
2651}
2652
2653const struct bpf_map_ops htab_of_maps_map_ops = {
2654 .map_alloc_check = fd_htab_map_alloc_check,
2655 .map_alloc = htab_of_map_alloc,
2656 .map_free = htab_of_map_free,
2657 .map_get_next_key = htab_map_get_next_key,
2658 .map_lookup_elem = htab_of_map_lookup_elem,
2659 .map_delete_elem = htab_map_delete_elem,
2660 .map_fd_get_ptr = bpf_map_fd_get_ptr,
2661 .map_fd_put_ptr = bpf_map_fd_put_ptr,
2662 .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
2663 .map_gen_lookup = htab_of_map_gen_lookup,
2664 .map_check_btf = map_check_no_btf,
2665 .map_mem_usage = htab_map_mem_usage,
2666 BATCH_OPS(htab),
2667 .map_btf_id = &htab_map_btf_ids[0],
2668};