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drm/panfrost: Remove set but not used variable 'bo'
[linux/fpc-iii.git] / kernel / bpf / hashtab.c
blob2d182c4ee9d9964a6ec55ea102a5de9c7b6fc811
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/random.h>
11 #include <uapi/linux/btf.h>
12 #include "percpu_freelist.h"
13 #include "bpf_lru_list.h"
14 #include "map_in_map.h"
15
16 #define HTAB_CREATE_FLAG_MASK \
17 (BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU | BPF_F_NUMA_NODE | \
18 BPF_F_ACCESS_MASK | BPF_F_ZERO_SEED)
19
20 #define BATCH_OPS(_name) \
21 .map_lookup_batch = \
22 _name##_map_lookup_batch, \
23 .map_lookup_and_delete_batch = \
24 _name##_map_lookup_and_delete_batch, \
25 .map_update_batch = \
26 generic_map_update_batch, \
27 .map_delete_batch = \
28 generic_map_delete_batch
29
30 struct bucket {
31 struct hlist_nulls_head head;
32 raw_spinlock_t lock;
33 };
34
35 struct bpf_htab {
36 struct bpf_map map;
37 struct bucket *buckets;
38 void *elems;
39 union {
40 struct pcpu_freelist freelist;
41 struct bpf_lru lru;
42 };
43 struct htab_elem *__percpu *extra_elems;
44 atomic_t count; /* number of elements in this hashtable */
45 u32 n_buckets; /* number of hash buckets */
46 u32 elem_size; /* size of each element in bytes */
47 u32 hashrnd;
48 };
49
50 /* each htab element is struct htab_elem + key + value */
51 struct htab_elem {
52 union {
53 struct hlist_nulls_node hash_node;
54 struct {
55 void *padding;
56 union {
57 struct bpf_htab *htab;
58 struct pcpu_freelist_node fnode;
59 };
60 };
61 };
62 union {
63 struct rcu_head rcu;
64 struct bpf_lru_node lru_node;
65 };
66 u32 hash;
67 char key[0] __aligned(8);
68 };
69
70 static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node);
71
72 static bool htab_is_lru(const struct bpf_htab *htab)
73 {
74 return htab->map.map_type == BPF_MAP_TYPE_LRU_HASH ||
75 htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
76 }
77
78 static bool htab_is_percpu(const struct bpf_htab *htab)
79 {
80 return htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH ||
81 htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH;
82 }
83
84 static bool htab_is_prealloc(const struct bpf_htab *htab)
85 {
86 return !(htab->map.map_flags & BPF_F_NO_PREALLOC);
87 }
88
89 static inline void htab_elem_set_ptr(struct htab_elem *l, u32 key_size,
90 void __percpu *pptr)
91 {
92 *(void __percpu **)(l->key + key_size) = pptr;
93 }
94
95 static inline void __percpu *htab_elem_get_ptr(struct htab_elem *l, u32 key_size)
96 {
97 return *(void __percpu **)(l->key + key_size);
98 }
99
100 static void *fd_htab_map_get_ptr(const struct bpf_map *map, struct htab_elem *l)
101 {
102 return *(void **)(l->key + roundup(map->key_size, 8));
103 }
104
105 static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i)
106 {
107 return (struct htab_elem *) (htab->elems + i * htab->elem_size);
108 }
109
110 static void htab_free_elems(struct bpf_htab *htab)
111 {
112 int i;
113
114 if (!htab_is_percpu(htab))
115 goto free_elems;
116
117 for (i = 0; i < htab->map.max_entries; i++) {
118 void __percpu *pptr;
119
120 pptr = htab_elem_get_ptr(get_htab_elem(htab, i),
121 htab->map.key_size);
122 free_percpu(pptr);
123 cond_resched();
124 }
125 free_elems:
126 bpf_map_area_free(htab->elems);
127 }
128
129 static struct htab_elem *prealloc_lru_pop(struct bpf_htab *htab, void *key,
130 u32 hash)
131 {
132 struct bpf_lru_node *node = bpf_lru_pop_free(&htab->lru, hash);
133 struct htab_elem *l;
134
135 if (node) {
136 l = container_of(node, struct htab_elem, lru_node);
137 memcpy(l->key, key, htab->map.key_size);
138 return l;
139 }
140
141 return NULL;
142 }
143
144 static int prealloc_init(struct bpf_htab *htab)
145 {
146 u32 num_entries = htab->map.max_entries;
147 int err = -ENOMEM, i;
148
149 if (!htab_is_percpu(htab) && !htab_is_lru(htab))
150 num_entries += num_possible_cpus();
151
152 htab->elems = bpf_map_area_alloc(htab->elem_size * num_entries,
153 htab->map.numa_node);
154 if (!htab->elems)
155 return -ENOMEM;
156
157 if (!htab_is_percpu(htab))
158 goto skip_percpu_elems;
159
160 for (i = 0; i < num_entries; i++) {
161 u32 size = round_up(htab->map.value_size, 8);
162 void __percpu *pptr;
163
164 pptr = __alloc_percpu_gfp(size, 8, GFP_USER | __GFP_NOWARN);
165 if (!pptr)
166 goto free_elems;
167 htab_elem_set_ptr(get_htab_elem(htab, i), htab->map.key_size,
168 pptr);
169 cond_resched();
170 }
171
172 skip_percpu_elems:
173 if (htab_is_lru(htab))
174 err = bpf_lru_init(&htab->lru,
175 htab->map.map_flags & BPF_F_NO_COMMON_LRU,
176 offsetof(struct htab_elem, hash) -
177 offsetof(struct htab_elem, lru_node),
178 htab_lru_map_delete_node,
179 htab);
180 else
181 err = pcpu_freelist_init(&htab->freelist);
182
183 if (err)
184 goto free_elems;
185
186 if (htab_is_lru(htab))
187 bpf_lru_populate(&htab->lru, htab->elems,
188 offsetof(struct htab_elem, lru_node),
189 htab->elem_size, num_entries);
190 else
191 pcpu_freelist_populate(&htab->freelist,
192 htab->elems + offsetof(struct htab_elem, fnode),
193 htab->elem_size, num_entries);
194
195 return 0;
196
197 free_elems:
198 htab_free_elems(htab);
199 return err;
200 }
201
202 static void prealloc_destroy(struct bpf_htab *htab)
203 {
204 htab_free_elems(htab);
205
206 if (htab_is_lru(htab))
207 bpf_lru_destroy(&htab->lru);
208 else
209 pcpu_freelist_destroy(&htab->freelist);
210 }
211
212 static int alloc_extra_elems(struct bpf_htab *htab)
213 {
214 struct htab_elem *__percpu *pptr, *l_new;
215 struct pcpu_freelist_node *l;
216 int cpu;
217
218 pptr = __alloc_percpu_gfp(sizeof(struct htab_elem *), 8,
219 GFP_USER | __GFP_NOWARN);
220 if (!pptr)
221 return -ENOMEM;
222
223 for_each_possible_cpu(cpu) {
224 l = pcpu_freelist_pop(&htab->freelist);
225 /* pop will succeed, since prealloc_init()
226 * preallocated extra num_possible_cpus elements
227 */
228 l_new = container_of(l, struct htab_elem, fnode);
229 *per_cpu_ptr(pptr, cpu) = l_new;
230 }
231 htab->extra_elems = pptr;
232 return 0;
233 }
234
235 /* Called from syscall */
236 static int htab_map_alloc_check(union bpf_attr *attr)
237 {
238 bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
239 attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
240 bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH ||
241 attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
242 /* percpu_lru means each cpu has its own LRU list.
243 * it is different from BPF_MAP_TYPE_PERCPU_HASH where
244 * the map's value itself is percpu. percpu_lru has
245 * nothing to do with the map's value.
246 */
247 bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU);
248 bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC);
249 bool zero_seed = (attr->map_flags & BPF_F_ZERO_SEED);
250 int numa_node = bpf_map_attr_numa_node(attr);
251
252 BUILD_BUG_ON(offsetof(struct htab_elem, htab) !=
253 offsetof(struct htab_elem, hash_node.pprev));
254 BUILD_BUG_ON(offsetof(struct htab_elem, fnode.next) !=
255 offsetof(struct htab_elem, hash_node.pprev));
256
257 if (lru && !capable(CAP_SYS_ADMIN))
258 /* LRU implementation is much complicated than other
259 * maps. Hence, limit to CAP_SYS_ADMIN for now.
260 */
261 return -EPERM;
262
263 if (zero_seed && !capable(CAP_SYS_ADMIN))
264 /* Guard against local DoS, and discourage production use. */
265 return -EPERM;
266
267 if (attr->map_flags & ~HTAB_CREATE_FLAG_MASK ||
268 !bpf_map_flags_access_ok(attr->map_flags))
269 return -EINVAL;
270
271 if (!lru && percpu_lru)
272 return -EINVAL;
273
274 if (lru && !prealloc)
275 return -ENOTSUPP;
276
277 if (numa_node != NUMA_NO_NODE && (percpu || percpu_lru))
278 return -EINVAL;
279
280 /* check sanity of attributes.
281 * value_size == 0 may be allowed in the future to use map as a set
282 */
283 if (attr->max_entries == 0 || attr->key_size == 0 ||
284 attr->value_size == 0)
285 return -EINVAL;
286
287 if (attr->key_size > MAX_BPF_STACK)
288 /* eBPF programs initialize keys on stack, so they cannot be
289 * larger than max stack size
290 */
291 return -E2BIG;
292
293 if (attr->value_size >= KMALLOC_MAX_SIZE -
294 MAX_BPF_STACK - sizeof(struct htab_elem))
295 /* if value_size is bigger, the user space won't be able to
296 * access the elements via bpf syscall. This check also makes
297 * sure that the elem_size doesn't overflow and it's
298 * kmalloc-able later in htab_map_update_elem()
299 */
300 return -E2BIG;
301
302 return 0;
303 }
304
305 static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
306 {
307 bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
308 attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
309 bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH ||
310 attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH);
311 /* percpu_lru means each cpu has its own LRU list.
312 * it is different from BPF_MAP_TYPE_PERCPU_HASH where
313 * the map's value itself is percpu. percpu_lru has
314 * nothing to do with the map's value.
315 */
316 bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU);
317 bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC);
318 struct bpf_htab *htab;
319 int err, i;
320 u64 cost;
321
322 htab = kzalloc(sizeof(*htab), GFP_USER);
323 if (!htab)
324 return ERR_PTR(-ENOMEM);
325
326 bpf_map_init_from_attr(&htab->map, attr);
327
328 if (percpu_lru) {
329 /* ensure each CPU's lru list has >=1 elements.
330 * since we are at it, make each lru list has the same
331 * number of elements.
332 */
333 htab->map.max_entries = roundup(attr->max_entries,
334 num_possible_cpus());
335 if (htab->map.max_entries < attr->max_entries)
336 htab->map.max_entries = rounddown(attr->max_entries,
337 num_possible_cpus());
338 }
339
340 /* hash table size must be power of 2 */
341 htab->n_buckets = roundup_pow_of_two(htab->map.max_entries);
342
343 htab->elem_size = sizeof(struct htab_elem) +
344 round_up(htab->map.key_size, 8);
345 if (percpu)
346 htab->elem_size += sizeof(void *);
347 else
348 htab->elem_size += round_up(htab->map.value_size, 8);
349
350 err = -E2BIG;
351 /* prevent zero size kmalloc and check for u32 overflow */
352 if (htab->n_buckets == 0 ||
353 htab->n_buckets > U32_MAX / sizeof(struct bucket))
354 goto free_htab;
355
356 cost = (u64) htab->n_buckets * sizeof(struct bucket) +
357 (u64) htab->elem_size * htab->map.max_entries;
358
359 if (percpu)
360 cost += (u64) round_up(htab->map.value_size, 8) *
361 num_possible_cpus() * htab->map.max_entries;
362 else
363 cost += (u64) htab->elem_size * num_possible_cpus();
364
365 /* if map size is larger than memlock limit, reject it */
366 err = bpf_map_charge_init(&htab->map.memory, cost);
367 if (err)
368 goto free_htab;
369
370 err = -ENOMEM;
371 htab->buckets = bpf_map_area_alloc(htab->n_buckets *
372 sizeof(struct bucket),
373 htab->map.numa_node);
374 if (!htab->buckets)
375 goto free_charge;
376
377 if (htab->map.map_flags & BPF_F_ZERO_SEED)
378 htab->hashrnd = 0;
379 else
380 htab->hashrnd = get_random_int();
381
382 for (i = 0; i < htab->n_buckets; i++) {
383 INIT_HLIST_NULLS_HEAD(&htab->buckets[i].head, i);
384 raw_spin_lock_init(&htab->buckets[i].lock);
385 }
386
387 if (prealloc) {
388 err = prealloc_init(htab);
389 if (err)
390 goto free_buckets;
391
392 if (!percpu && !lru) {
393 /* lru itself can remove the least used element, so
394 * there is no need for an extra elem during map_update.
395 */
396 err = alloc_extra_elems(htab);
397 if (err)
398 goto free_prealloc;
399 }
400 }
401
402 return &htab->map;
403
404 free_prealloc:
405 prealloc_destroy(htab);
406 free_buckets:
407 bpf_map_area_free(htab->buckets);
408 free_charge:
409 bpf_map_charge_finish(&htab->map.memory);
410 free_htab:
411 kfree(htab);
412 return ERR_PTR(err);
413 }
414
415 static inline u32 htab_map_hash(const void *key, u32 key_len, u32 hashrnd)
416 {
417 return jhash(key, key_len, hashrnd);
418 }
419
420 static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash)
421 {
422 return &htab->buckets[hash & (htab->n_buckets - 1)];
423 }
424
425 static inline struct hlist_nulls_head *select_bucket(struct bpf_htab *htab, u32 hash)
426 {
427 return &__select_bucket(htab, hash)->head;
428 }
429
430 /* this lookup function can only be called with bucket lock taken */
431 static struct htab_elem *lookup_elem_raw(struct hlist_nulls_head *head, u32 hash,
432 void *key, u32 key_size)
433 {
434 struct hlist_nulls_node *n;
435 struct htab_elem *l;
436
437 hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
438 if (l->hash == hash && !memcmp(&l->key, key, key_size))
439 return l;
440
441 return NULL;
442 }
443
444 /* can be called without bucket lock. it will repeat the loop in
445 * the unlikely event when elements moved from one bucket into another
446 * while link list is being walked
447 */
448 static struct htab_elem *lookup_nulls_elem_raw(struct hlist_nulls_head *head,
449 u32 hash, void *key,
450 u32 key_size, u32 n_buckets)
451 {
452 struct hlist_nulls_node *n;
453 struct htab_elem *l;
454
455 again:
456 hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
457 if (l->hash == hash && !memcmp(&l->key, key, key_size))
458 return l;
459
460 if (unlikely(get_nulls_value(n) != (hash & (n_buckets - 1))))
461 goto again;
462
463 return NULL;
464 }
465
466 /* Called from syscall or from eBPF program directly, so
467 * arguments have to match bpf_map_lookup_elem() exactly.
468 * The return value is adjusted by BPF instructions
469 * in htab_map_gen_lookup().
470 */
471 static void *__htab_map_lookup_elem(struct bpf_map *map, void *key)
472 {
473 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
474 struct hlist_nulls_head *head;
475 struct htab_elem *l;
476 u32 hash, key_size;
477
478 /* Must be called with rcu_read_lock. */
479 WARN_ON_ONCE(!rcu_read_lock_held());
480
481 key_size = map->key_size;
482
483 hash = htab_map_hash(key, key_size, htab->hashrnd);
484
485 head = select_bucket(htab, hash);
486
487 l = lookup_nulls_elem_raw(head, hash, key, key_size, htab->n_buckets);
488
489 return l;
490 }
491
492 static void *htab_map_lookup_elem(struct bpf_map *map, void *key)
493 {
494 struct htab_elem *l = __htab_map_lookup_elem(map, key);
495
496 if (l)
497 return l->key + round_up(map->key_size, 8);
498
499 return NULL;
500 }
501
502 /* inline bpf_map_lookup_elem() call.
503 * Instead of:
504 * bpf_prog
505 * bpf_map_lookup_elem
506 * map->ops->map_lookup_elem
507 * htab_map_lookup_elem
508 * __htab_map_lookup_elem
509 * do:
510 * bpf_prog
511 * __htab_map_lookup_elem
512 */
513 static u32 htab_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
514 {
515 struct bpf_insn *insn = insn_buf;
516 const int ret = BPF_REG_0;
517
518 BUILD_BUG_ON(!__same_type(&__htab_map_lookup_elem,
519 (void *(*)(struct bpf_map *map, void *key))NULL));
520 *insn++ = BPF_EMIT_CALL(BPF_CAST_CALL(__htab_map_lookup_elem));
521 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1);
522 *insn++ = BPF_ALU64_IMM(BPF_ADD, ret,
523 offsetof(struct htab_elem, key) +
524 round_up(map->key_size, 8));
525 return insn - insn_buf;
526 }
527
528 static __always_inline void *__htab_lru_map_lookup_elem(struct bpf_map *map,
529 void *key, const bool mark)
530 {
531 struct htab_elem *l = __htab_map_lookup_elem(map, key);
532
533 if (l) {
534 if (mark)
535 bpf_lru_node_set_ref(&l->lru_node);
536 return l->key + round_up(map->key_size, 8);
537 }
538
539 return NULL;
540 }
541
542 static void *htab_lru_map_lookup_elem(struct bpf_map *map, void *key)
543 {
544 return __htab_lru_map_lookup_elem(map, key, true);
545 }
546
547 static void *htab_lru_map_lookup_elem_sys(struct bpf_map *map, void *key)
548 {
549 return __htab_lru_map_lookup_elem(map, key, false);
550 }
551
552 static u32 htab_lru_map_gen_lookup(struct bpf_map *map,
553 struct bpf_insn *insn_buf)
554 {
555 struct bpf_insn *insn = insn_buf;
556 const int ret = BPF_REG_0;
557 const int ref_reg = BPF_REG_1;
558
559 BUILD_BUG_ON(!__same_type(&__htab_map_lookup_elem,
560 (void *(*)(struct bpf_map *map, void *key))NULL));
561 *insn++ = BPF_EMIT_CALL(BPF_CAST_CALL(__htab_map_lookup_elem));
562 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 4);
563 *insn++ = BPF_LDX_MEM(BPF_B, ref_reg, ret,
564 offsetof(struct htab_elem, lru_node) +
565 offsetof(struct bpf_lru_node, ref));
566 *insn++ = BPF_JMP_IMM(BPF_JNE, ref_reg, 0, 1);
567 *insn++ = BPF_ST_MEM(BPF_B, ret,
568 offsetof(struct htab_elem, lru_node) +
569 offsetof(struct bpf_lru_node, ref),
570 1);
571 *insn++ = BPF_ALU64_IMM(BPF_ADD, ret,
572 offsetof(struct htab_elem, key) +
573 round_up(map->key_size, 8));
574 return insn - insn_buf;
575 }
576
577 /* It is called from the bpf_lru_list when the LRU needs to delete
578 * older elements from the htab.
579 */
580 static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node)
581 {
582 struct bpf_htab *htab = (struct bpf_htab *)arg;
583 struct htab_elem *l = NULL, *tgt_l;
584 struct hlist_nulls_head *head;
585 struct hlist_nulls_node *n;
586 unsigned long flags;
587 struct bucket *b;
588
589 tgt_l = container_of(node, struct htab_elem, lru_node);
590 b = __select_bucket(htab, tgt_l->hash);
591 head = &b->head;
592
593 raw_spin_lock_irqsave(&b->lock, flags);
594
595 hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
596 if (l == tgt_l) {
597 hlist_nulls_del_rcu(&l->hash_node);
598 break;
599 }
600
601 raw_spin_unlock_irqrestore(&b->lock, flags);
602
603 return l == tgt_l;
604 }
605
606 /* Called from syscall */
607 static int htab_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
608 {
609 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
610 struct hlist_nulls_head *head;
611 struct htab_elem *l, *next_l;
612 u32 hash, key_size;
613 int i = 0;
614
615 WARN_ON_ONCE(!rcu_read_lock_held());
616
617 key_size = map->key_size;
618
619 if (!key)
620 goto find_first_elem;
621
622 hash = htab_map_hash(key, key_size, htab->hashrnd);
623
624 head = select_bucket(htab, hash);
625
626 /* lookup the key */
627 l = lookup_nulls_elem_raw(head, hash, key, key_size, htab->n_buckets);
628
629 if (!l)
630 goto find_first_elem;
631
632 /* key was found, get next key in the same bucket */
633 next_l = hlist_nulls_entry_safe(rcu_dereference_raw(hlist_nulls_next_rcu(&l->hash_node)),
634 struct htab_elem, hash_node);
635
636 if (next_l) {
637 /* if next elem in this hash list is non-zero, just return it */
638 memcpy(next_key, next_l->key, key_size);
639 return 0;
640 }
641
642 /* no more elements in this hash list, go to the next bucket */
643 i = hash & (htab->n_buckets - 1);
644 i++;
645
646 find_first_elem:
647 /* iterate over buckets */
648 for (; i < htab->n_buckets; i++) {
649 head = select_bucket(htab, i);
650
651 /* pick first element in the bucket */
652 next_l = hlist_nulls_entry_safe(rcu_dereference_raw(hlist_nulls_first_rcu(head)),
653 struct htab_elem, hash_node);
654 if (next_l) {
655 /* if it's not empty, just return it */
656 memcpy(next_key, next_l->key, key_size);
657 return 0;
658 }
659 }
660
661 /* iterated over all buckets and all elements */
662 return -ENOENT;
663 }
664
665 static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l)
666 {
667 if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH)
668 free_percpu(htab_elem_get_ptr(l, htab->map.key_size));
669 kfree(l);
670 }
671
672 static void htab_elem_free_rcu(struct rcu_head *head)
673 {
674 struct htab_elem *l = container_of(head, struct htab_elem, rcu);
675 struct bpf_htab *htab = l->htab;
676
677 /* must increment bpf_prog_active to avoid kprobe+bpf triggering while
678 * we're calling kfree, otherwise deadlock is possible if kprobes
679 * are placed somewhere inside of slub
680 */
681 preempt_disable();
682 __this_cpu_inc(bpf_prog_active);
683 htab_elem_free(htab, l);
684 __this_cpu_dec(bpf_prog_active);
685 preempt_enable();
686 }
687
688 static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
689 {
690 struct bpf_map *map = &htab->map;
691
692 if (map->ops->map_fd_put_ptr) {
693 void *ptr = fd_htab_map_get_ptr(map, l);
694
695 map->ops->map_fd_put_ptr(ptr);
696 }
697
698 if (htab_is_prealloc(htab)) {
699 __pcpu_freelist_push(&htab->freelist, &l->fnode);
700 } else {
701 atomic_dec(&htab->count);
702 l->htab = htab;
703 call_rcu(&l->rcu, htab_elem_free_rcu);
704 }
705 }
706
707 static void pcpu_copy_value(struct bpf_htab *htab, void __percpu *pptr,
708 void *value, bool onallcpus)
709 {
710 if (!onallcpus) {
711 /* copy true value_size bytes */
712 memcpy(this_cpu_ptr(pptr), value, htab->map.value_size);
713 } else {
714 u32 size = round_up(htab->map.value_size, 8);
715 int off = 0, cpu;
716
717 for_each_possible_cpu(cpu) {
718 bpf_long_memcpy(per_cpu_ptr(pptr, cpu),
719 value + off, size);
720 off += size;
721 }
722 }
723 }
724
725 static bool fd_htab_map_needs_adjust(const struct bpf_htab *htab)
726 {
727 return htab->map.map_type == BPF_MAP_TYPE_HASH_OF_MAPS &&
728 BITS_PER_LONG == 64;
729 }
730
731 static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key,
732 void *value, u32 key_size, u32 hash,
733 bool percpu, bool onallcpus,
734 struct htab_elem *old_elem)
735 {
736 u32 size = htab->map.value_size;
737 bool prealloc = htab_is_prealloc(htab);
738 struct htab_elem *l_new, **pl_new;
739 void __percpu *pptr;
740
741 if (prealloc) {
742 if (old_elem) {
743 /* if we're updating the existing element,
744 * use per-cpu extra elems to avoid freelist_pop/push
745 */
746 pl_new = this_cpu_ptr(htab->extra_elems);
747 l_new = *pl_new;
748 *pl_new = old_elem;
749 } else {
750 struct pcpu_freelist_node *l;
751
752 l = __pcpu_freelist_pop(&htab->freelist);
753 if (!l)
754 return ERR_PTR(-E2BIG);
755 l_new = container_of(l, struct htab_elem, fnode);
756 }
757 } else {
758 if (atomic_inc_return(&htab->count) > htab->map.max_entries)
759 if (!old_elem) {
760 /* when map is full and update() is replacing
761 * old element, it's ok to allocate, since
762 * old element will be freed immediately.
763 * Otherwise return an error
764 */
765 l_new = ERR_PTR(-E2BIG);
766 goto dec_count;
767 }
768 l_new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN,
769 htab->map.numa_node);
770 if (!l_new) {
771 l_new = ERR_PTR(-ENOMEM);
772 goto dec_count;
773 }
774 check_and_init_map_lock(&htab->map,
775 l_new->key + round_up(key_size, 8));
776 }
777
778 memcpy(l_new->key, key, key_size);
779 if (percpu) {
780 size = round_up(size, 8);
781 if (prealloc) {
782 pptr = htab_elem_get_ptr(l_new, key_size);
783 } else {
784 /* alloc_percpu zero-fills */
785 pptr = __alloc_percpu_gfp(size, 8,
786 GFP_ATOMIC | __GFP_NOWARN);
787 if (!pptr) {
788 kfree(l_new);
789 l_new = ERR_PTR(-ENOMEM);
790 goto dec_count;
791 }
792 }
793
794 pcpu_copy_value(htab, pptr, value, onallcpus);
795
796 if (!prealloc)
797 htab_elem_set_ptr(l_new, key_size, pptr);
798 } else if (fd_htab_map_needs_adjust(htab)) {
799 size = round_up(size, 8);
800 memcpy(l_new->key + round_up(key_size, 8), value, size);
801 } else {
802 copy_map_value(&htab->map,
803 l_new->key + round_up(key_size, 8),
804 value);
805 }
806
807 l_new->hash = hash;
808 return l_new;
809 dec_count:
810 atomic_dec(&htab->count);
811 return l_new;
812 }
813
814 static int check_flags(struct bpf_htab *htab, struct htab_elem *l_old,
815 u64 map_flags)
816 {
817 if (l_old && (map_flags & ~BPF_F_LOCK) == BPF_NOEXIST)
818 /* elem already exists */
819 return -EEXIST;
820
821 if (!l_old && (map_flags & ~BPF_F_LOCK) == BPF_EXIST)
822 /* elem doesn't exist, cannot update it */
823 return -ENOENT;
824
825 return 0;
826 }
827
828 /* Called from syscall or from eBPF program */
829 static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
830 u64 map_flags)
831 {
832 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
833 struct htab_elem *l_new = NULL, *l_old;
834 struct hlist_nulls_head *head;
835 unsigned long flags;
836 struct bucket *b;
837 u32 key_size, hash;
838 int ret;
839
840 if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST))
841 /* unknown flags */
842 return -EINVAL;
843
844 WARN_ON_ONCE(!rcu_read_lock_held());
845
846 key_size = map->key_size;
847
848 hash = htab_map_hash(key, key_size, htab->hashrnd);
849
850 b = __select_bucket(htab, hash);
851 head = &b->head;
852
853 if (unlikely(map_flags & BPF_F_LOCK)) {
854 if (unlikely(!map_value_has_spin_lock(map)))
855 return -EINVAL;
856 /* find an element without taking the bucket lock */
857 l_old = lookup_nulls_elem_raw(head, hash, key, key_size,
858 htab->n_buckets);
859 ret = check_flags(htab, l_old, map_flags);
860 if (ret)
861 return ret;
862 if (l_old) {
863 /* grab the element lock and update value in place */
864 copy_map_value_locked(map,
865 l_old->key + round_up(key_size, 8),
866 value, false);
867 return 0;
868 }
869 /* fall through, grab the bucket lock and lookup again.
870 * 99.9% chance that the element won't be found,
871 * but second lookup under lock has to be done.
872 */
873 }
874
875 /* bpf_map_update_elem() can be called in_irq() */
876 raw_spin_lock_irqsave(&b->lock, flags);
877
878 l_old = lookup_elem_raw(head, hash, key, key_size);
879
880 ret = check_flags(htab, l_old, map_flags);
881 if (ret)
882 goto err;
883
884 if (unlikely(l_old && (map_flags & BPF_F_LOCK))) {
885 /* first lookup without the bucket lock didn't find the element,
886 * but second lookup with the bucket lock found it.
887 * This case is highly unlikely, but has to be dealt with:
888 * grab the element lock in addition to the bucket lock
889 * and update element in place
890 */
891 copy_map_value_locked(map,
892 l_old->key + round_up(key_size, 8),
893 value, false);
894 ret = 0;
895 goto err;
896 }
897
898 l_new = alloc_htab_elem(htab, key, value, key_size, hash, false, false,
899 l_old);
900 if (IS_ERR(l_new)) {
901 /* all pre-allocated elements are in use or memory exhausted */
902 ret = PTR_ERR(l_new);
903 goto err;
904 }
905
906 /* add new element to the head of the list, so that
907 * concurrent search will find it before old elem
908 */
909 hlist_nulls_add_head_rcu(&l_new->hash_node, head);
910 if (l_old) {
911 hlist_nulls_del_rcu(&l_old->hash_node);
912 if (!htab_is_prealloc(htab))
913 free_htab_elem(htab, l_old);
914 }
915 ret = 0;
916 err:
917 raw_spin_unlock_irqrestore(&b->lock, flags);
918 return ret;
919 }
920
921 static int htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value,
922 u64 map_flags)
923 {
924 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
925 struct htab_elem *l_new, *l_old = NULL;
926 struct hlist_nulls_head *head;
927 unsigned long flags;
928 struct bucket *b;
929 u32 key_size, hash;
930 int ret;
931
932 if (unlikely(map_flags > BPF_EXIST))
933 /* unknown flags */
934 return -EINVAL;
935
936 WARN_ON_ONCE(!rcu_read_lock_held());
937
938 key_size = map->key_size;
939
940 hash = htab_map_hash(key, key_size, htab->hashrnd);
941
942 b = __select_bucket(htab, hash);
943 head = &b->head;
944
945 /* For LRU, we need to alloc before taking bucket's
946 * spinlock because getting free nodes from LRU may need
947 * to remove older elements from htab and this removal
948 * operation will need a bucket lock.
949 */
950 l_new = prealloc_lru_pop(htab, key, hash);
951 if (!l_new)
952 return -ENOMEM;
953 memcpy(l_new->key + round_up(map->key_size, 8), value, map->value_size);
954
955 /* bpf_map_update_elem() can be called in_irq() */
956 raw_spin_lock_irqsave(&b->lock, flags);
957
958 l_old = lookup_elem_raw(head, hash, key, key_size);
959
960 ret = check_flags(htab, l_old, map_flags);
961 if (ret)
962 goto err;
963
964 /* add new element to the head of the list, so that
965 * concurrent search will find it before old elem
966 */
967 hlist_nulls_add_head_rcu(&l_new->hash_node, head);
968 if (l_old) {
969 bpf_lru_node_set_ref(&l_new->lru_node);
970 hlist_nulls_del_rcu(&l_old->hash_node);
971 }
972 ret = 0;
973
974 err:
975 raw_spin_unlock_irqrestore(&b->lock, flags);
976
977 if (ret)
978 bpf_lru_push_free(&htab->lru, &l_new->lru_node);
979 else if (l_old)
980 bpf_lru_push_free(&htab->lru, &l_old->lru_node);
981
982 return ret;
983 }
984
985 static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key,
986 void *value, u64 map_flags,
987 bool onallcpus)
988 {
989 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
990 struct htab_elem *l_new = NULL, *l_old;
991 struct hlist_nulls_head *head;
992 unsigned long flags;
993 struct bucket *b;
994 u32 key_size, hash;
995 int ret;
996
997 if (unlikely(map_flags > BPF_EXIST))
998 /* unknown flags */
999 return -EINVAL;
1000
1001 WARN_ON_ONCE(!rcu_read_lock_held());
1002
1003 key_size = map->key_size;
1004
1005 hash = htab_map_hash(key, key_size, htab->hashrnd);
1006
1007 b = __select_bucket(htab, hash);
1008 head = &b->head;
1009
1010 /* bpf_map_update_elem() can be called in_irq() */
1011 raw_spin_lock_irqsave(&b->lock, flags);
1012
1013 l_old = lookup_elem_raw(head, hash, key, key_size);
1014
1015 ret = check_flags(htab, l_old, map_flags);
1016 if (ret)
1017 goto err;
1018
1019 if (l_old) {
1020 /* per-cpu hash map can update value in-place */
1021 pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
1022 value, onallcpus);
1023 } else {
1024 l_new = alloc_htab_elem(htab, key, value, key_size,
1025 hash, true, onallcpus, NULL);
1026 if (IS_ERR(l_new)) {
1027 ret = PTR_ERR(l_new);
1028 goto err;
1029 }
1030 hlist_nulls_add_head_rcu(&l_new->hash_node, head);
1031 }
1032 ret = 0;
1033 err:
1034 raw_spin_unlock_irqrestore(&b->lock, flags);
1035 return ret;
1036 }
1037
1038 static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
1039 void *value, u64 map_flags,
1040 bool onallcpus)
1041 {
1042 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1043 struct htab_elem *l_new = NULL, *l_old;
1044 struct hlist_nulls_head *head;
1045 unsigned long flags;
1046 struct bucket *b;
1047 u32 key_size, hash;
1048 int ret;
1049
1050 if (unlikely(map_flags > BPF_EXIST))
1051 /* unknown flags */
1052 return -EINVAL;
1053
1054 WARN_ON_ONCE(!rcu_read_lock_held());
1055
1056 key_size = map->key_size;
1057
1058 hash = htab_map_hash(key, key_size, htab->hashrnd);
1059
1060 b = __select_bucket(htab, hash);
1061 head = &b->head;
1062
1063 /* For LRU, we need to alloc before taking bucket's
1064 * spinlock because LRU's elem alloc may need
1065 * to remove older elem from htab and this removal
1066 * operation will need a bucket lock.
1067 */
1068 if (map_flags != BPF_EXIST) {
1069 l_new = prealloc_lru_pop(htab, key, hash);
1070 if (!l_new)
1071 return -ENOMEM;
1072 }
1073
1074 /* bpf_map_update_elem() can be called in_irq() */
1075 raw_spin_lock_irqsave(&b->lock, flags);
1076
1077 l_old = lookup_elem_raw(head, hash, key, key_size);
1078
1079 ret = check_flags(htab, l_old, map_flags);
1080 if (ret)
1081 goto err;
1082
1083 if (l_old) {
1084 bpf_lru_node_set_ref(&l_old->lru_node);
1085
1086 /* per-cpu hash map can update value in-place */
1087 pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size),
1088 value, onallcpus);
1089 } else {
1090 pcpu_copy_value(htab, htab_elem_get_ptr(l_new, key_size),
1091 value, onallcpus);
1092 hlist_nulls_add_head_rcu(&l_new->hash_node, head);
1093 l_new = NULL;
1094 }
1095 ret = 0;
1096 err:
1097 raw_spin_unlock_irqrestore(&b->lock, flags);
1098 if (l_new)
1099 bpf_lru_push_free(&htab->lru, &l_new->lru_node);
1100 return ret;
1101 }
1102
1103 static int htab_percpu_map_update_elem(struct bpf_map *map, void *key,
1104 void *value, u64 map_flags)
1105 {
1106 return __htab_percpu_map_update_elem(map, key, value, map_flags, false);
1107 }
1108
1109 static int htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key,
1110 void *value, u64 map_flags)
1111 {
1112 return __htab_lru_percpu_map_update_elem(map, key, value, map_flags,
1113 false);
1114 }
1115
1116 /* Called from syscall or from eBPF program */
1117 static int htab_map_delete_elem(struct bpf_map *map, void *key)
1118 {
1119 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1120 struct hlist_nulls_head *head;
1121 struct bucket *b;
1122 struct htab_elem *l;
1123 unsigned long flags;
1124 u32 hash, key_size;
1125 int ret = -ENOENT;
1126
1127 WARN_ON_ONCE(!rcu_read_lock_held());
1128
1129 key_size = map->key_size;
1130
1131 hash = htab_map_hash(key, key_size, htab->hashrnd);
1132 b = __select_bucket(htab, hash);
1133 head = &b->head;
1134
1135 raw_spin_lock_irqsave(&b->lock, flags);
1136
1137 l = lookup_elem_raw(head, hash, key, key_size);
1138
1139 if (l) {
1140 hlist_nulls_del_rcu(&l->hash_node);
1141 free_htab_elem(htab, l);
1142 ret = 0;
1143 }
1144
1145 raw_spin_unlock_irqrestore(&b->lock, flags);
1146 return ret;
1147 }
1148
1149 static int htab_lru_map_delete_elem(struct bpf_map *map, void *key)
1150 {
1151 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1152 struct hlist_nulls_head *head;
1153 struct bucket *b;
1154 struct htab_elem *l;
1155 unsigned long flags;
1156 u32 hash, key_size;
1157 int ret = -ENOENT;
1158
1159 WARN_ON_ONCE(!rcu_read_lock_held());
1160
1161 key_size = map->key_size;
1162
1163 hash = htab_map_hash(key, key_size, htab->hashrnd);
1164 b = __select_bucket(htab, hash);
1165 head = &b->head;
1166
1167 raw_spin_lock_irqsave(&b->lock, flags);
1168
1169 l = lookup_elem_raw(head, hash, key, key_size);
1170
1171 if (l) {
1172 hlist_nulls_del_rcu(&l->hash_node);
1173 ret = 0;
1174 }
1175
1176 raw_spin_unlock_irqrestore(&b->lock, flags);
1177 if (l)
1178 bpf_lru_push_free(&htab->lru, &l->lru_node);
1179 return ret;
1180 }
1181
1182 static void delete_all_elements(struct bpf_htab *htab)
1183 {
1184 int i;
1185
1186 for (i = 0; i < htab->n_buckets; i++) {
1187 struct hlist_nulls_head *head = select_bucket(htab, i);
1188 struct hlist_nulls_node *n;
1189 struct htab_elem *l;
1190
1191 hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
1192 hlist_nulls_del_rcu(&l->hash_node);
1193 htab_elem_free(htab, l);
1194 }
1195 }
1196 }
1197
1198 /* Called when map->refcnt goes to zero, either from workqueue or from syscall */
1199 static void htab_map_free(struct bpf_map *map)
1200 {
1201 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1202
1203 /* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0,
1204 * so the programs (can be more than one that used this map) were
1205 * disconnected from events. Wait for outstanding critical sections in
1206 * these programs to complete
1207 */
1208 synchronize_rcu();
1209
1210 /* some of free_htab_elem() callbacks for elements of this map may
1211 * not have executed. Wait for them.
1212 */
1213 rcu_barrier();
1214 if (!htab_is_prealloc(htab))
1215 delete_all_elements(htab);
1216 else
1217 prealloc_destroy(htab);
1218
1219 free_percpu(htab->extra_elems);
1220 bpf_map_area_free(htab->buckets);
1221 kfree(htab);
1222 }
1223
1224 static void htab_map_seq_show_elem(struct bpf_map *map, void *key,
1225 struct seq_file *m)
1226 {
1227 void *value;
1228
1229 rcu_read_lock();
1230
1231 value = htab_map_lookup_elem(map, key);
1232 if (!value) {
1233 rcu_read_unlock();
1234 return;
1235 }
1236
1237 btf_type_seq_show(map->btf, map->btf_key_type_id, key, m);
1238 seq_puts(m, ": ");
1239 btf_type_seq_show(map->btf, map->btf_value_type_id, value, m);
1240 seq_puts(m, "\n");
1241
1242 rcu_read_unlock();
1243 }
1244
1245 static int
1246 __htab_map_lookup_and_delete_batch(struct bpf_map *map,
1247 const union bpf_attr *attr,
1248 union bpf_attr __user *uattr,
1249 bool do_delete, bool is_lru_map,
1250 bool is_percpu)
1251 {
1252 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1253 u32 bucket_cnt, total, key_size, value_size, roundup_key_size;
1254 void *keys = NULL, *values = NULL, *value, *dst_key, *dst_val;
1255 void __user *uvalues = u64_to_user_ptr(attr->batch.values);
1256 void __user *ukeys = u64_to_user_ptr(attr->batch.keys);
1257 void *ubatch = u64_to_user_ptr(attr->batch.in_batch);
1258 u32 batch, max_count, size, bucket_size;
1259 u64 elem_map_flags, map_flags;
1260 struct hlist_nulls_head *head;
1261 struct hlist_nulls_node *n;
1262 unsigned long flags;
1263 struct htab_elem *l;
1264 struct bucket *b;
1265 int ret = 0;
1266
1267 elem_map_flags = attr->batch.elem_flags;
1268 if ((elem_map_flags & ~BPF_F_LOCK) ||
1269 ((elem_map_flags & BPF_F_LOCK) && !map_value_has_spin_lock(map)))
1270 return -EINVAL;
1271
1272 map_flags = attr->batch.flags;
1273 if (map_flags)
1274 return -EINVAL;
1275
1276 max_count = attr->batch.count;
1277 if (!max_count)
1278 return 0;
1279
1280 if (put_user(0, &uattr->batch.count))
1281 return -EFAULT;
1282
1283 batch = 0;
1284 if (ubatch && copy_from_user(&batch, ubatch, sizeof(batch)))
1285 return -EFAULT;
1286
1287 if (batch >= htab->n_buckets)
1288 return -ENOENT;
1289
1290 key_size = htab->map.key_size;
1291 roundup_key_size = round_up(htab->map.key_size, 8);
1292 value_size = htab->map.value_size;
1293 size = round_up(value_size, 8);
1294 if (is_percpu)
1295 value_size = size * num_possible_cpus();
1296 total = 0;
1297 /* while experimenting with hash tables with sizes ranging from 10 to
1298 * 1000, it was observed that a bucket can have upto 5 entries.
1299 */
1300 bucket_size = 5;
1301
1302 alloc:
1303 /* We cannot do copy_from_user or copy_to_user inside
1304 * the rcu_read_lock. Allocate enough space here.
1305 */
1306 keys = kvmalloc(key_size * bucket_size, GFP_USER | __GFP_NOWARN);
1307 values = kvmalloc(value_size * bucket_size, GFP_USER | __GFP_NOWARN);
1308 if (!keys || !values) {
1309 ret = -ENOMEM;
1310 goto after_loop;
1311 }
1312
1313 again:
1314 preempt_disable();
1315 this_cpu_inc(bpf_prog_active);
1316 rcu_read_lock();
1317 again_nocopy:
1318 dst_key = keys;
1319 dst_val = values;
1320 b = &htab->buckets[batch];
1321 head = &b->head;
1322 raw_spin_lock_irqsave(&b->lock, flags);
1323
1324 bucket_cnt = 0;
1325 hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
1326 bucket_cnt++;
1327
1328 if (bucket_cnt > (max_count - total)) {
1329 if (total == 0)
1330 ret = -ENOSPC;
1331 raw_spin_unlock_irqrestore(&b->lock, flags);
1332 rcu_read_unlock();
1333 this_cpu_dec(bpf_prog_active);
1334 preempt_enable();
1335 goto after_loop;
1336 }
1337
1338 if (bucket_cnt > bucket_size) {
1339 bucket_size = bucket_cnt;
1340 raw_spin_unlock_irqrestore(&b->lock, flags);
1341 rcu_read_unlock();
1342 this_cpu_dec(bpf_prog_active);
1343 preempt_enable();
1344 kvfree(keys);
1345 kvfree(values);
1346 goto alloc;
1347 }
1348
1349 hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
1350 memcpy(dst_key, l->key, key_size);
1351
1352 if (is_percpu) {
1353 int off = 0, cpu;
1354 void __percpu *pptr;
1355
1356 pptr = htab_elem_get_ptr(l, map->key_size);
1357 for_each_possible_cpu(cpu) {
1358 bpf_long_memcpy(dst_val + off,
1359 per_cpu_ptr(pptr, cpu), size);
1360 off += size;
1361 }
1362 } else {
1363 value = l->key + roundup_key_size;
1364 if (elem_map_flags & BPF_F_LOCK)
1365 copy_map_value_locked(map, dst_val, value,
1366 true);
1367 else
1368 copy_map_value(map, dst_val, value);
1369 check_and_init_map_lock(map, dst_val);
1370 }
1371 if (do_delete) {
1372 hlist_nulls_del_rcu(&l->hash_node);
1373 if (is_lru_map)
1374 bpf_lru_push_free(&htab->lru, &l->lru_node);
1375 else
1376 free_htab_elem(htab, l);
1377 }
1378 dst_key += key_size;
1379 dst_val += value_size;
1380 }
1381
1382 raw_spin_unlock_irqrestore(&b->lock, flags);
1383 /* If we are not copying data, we can go to next bucket and avoid
1384 * unlocking the rcu.
1385 */
1386 if (!bucket_cnt && (batch + 1 < htab->n_buckets)) {
1387 batch++;
1388 goto again_nocopy;
1389 }
1390
1391 rcu_read_unlock();
1392 this_cpu_dec(bpf_prog_active);
1393 preempt_enable();
1394 if (bucket_cnt && (copy_to_user(ukeys + total * key_size, keys,
1395 key_size * bucket_cnt) ||
1396 copy_to_user(uvalues + total * value_size, values,
1397 value_size * bucket_cnt))) {
1398 ret = -EFAULT;
1399 goto after_loop;
1400 }
1401
1402 total += bucket_cnt;
1403 batch++;
1404 if (batch >= htab->n_buckets) {
1405 ret = -ENOENT;
1406 goto after_loop;
1407 }
1408 goto again;
1409
1410 after_loop:
1411 if (ret == -EFAULT)
1412 goto out;
1413
1414 /* copy # of entries and next batch */
1415 ubatch = u64_to_user_ptr(attr->batch.out_batch);
1416 if (copy_to_user(ubatch, &batch, sizeof(batch)) ||
1417 put_user(total, &uattr->batch.count))
1418 ret = -EFAULT;
1419
1420 out:
1421 kvfree(keys);
1422 kvfree(values);
1423 return ret;
1424 }
1425
1426 static int
1427 htab_percpu_map_lookup_batch(struct bpf_map *map, const union bpf_attr *attr,
1428 union bpf_attr __user *uattr)
1429 {
1430 return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
1431 false, true);
1432 }
1433
1434 static int
1435 htab_percpu_map_lookup_and_delete_batch(struct bpf_map *map,
1436 const union bpf_attr *attr,
1437 union bpf_attr __user *uattr)
1438 {
1439 return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
1440 false, true);
1441 }
1442
1443 static int
1444 htab_map_lookup_batch(struct bpf_map *map, const union bpf_attr *attr,
1445 union bpf_attr __user *uattr)
1446 {
1447 return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
1448 false, false);
1449 }
1450
1451 static int
1452 htab_map_lookup_and_delete_batch(struct bpf_map *map,
1453 const union bpf_attr *attr,
1454 union bpf_attr __user *uattr)
1455 {
1456 return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
1457 false, false);
1458 }
1459
1460 static int
1461 htab_lru_percpu_map_lookup_batch(struct bpf_map *map,
1462 const union bpf_attr *attr,
1463 union bpf_attr __user *uattr)
1464 {
1465 return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
1466 true, true);
1467 }
1468
1469 static int
1470 htab_lru_percpu_map_lookup_and_delete_batch(struct bpf_map *map,
1471 const union bpf_attr *attr,
1472 union bpf_attr __user *uattr)
1473 {
1474 return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
1475 true, true);
1476 }
1477
1478 static int
1479 htab_lru_map_lookup_batch(struct bpf_map *map, const union bpf_attr *attr,
1480 union bpf_attr __user *uattr)
1481 {
1482 return __htab_map_lookup_and_delete_batch(map, attr, uattr, false,
1483 true, false);
1484 }
1485
1486 static int
1487 htab_lru_map_lookup_and_delete_batch(struct bpf_map *map,
1488 const union bpf_attr *attr,
1489 union bpf_attr __user *uattr)
1490 {
1491 return __htab_map_lookup_and_delete_batch(map, attr, uattr, true,
1492 true, false);
1493 }
1494
1495 const struct bpf_map_ops htab_map_ops = {
1496 .map_alloc_check = htab_map_alloc_check,
1497 .map_alloc = htab_map_alloc,
1498 .map_free = htab_map_free,
1499 .map_get_next_key = htab_map_get_next_key,
1500 .map_lookup_elem = htab_map_lookup_elem,
1501 .map_update_elem = htab_map_update_elem,
1502 .map_delete_elem = htab_map_delete_elem,
1503 .map_gen_lookup = htab_map_gen_lookup,
1504 .map_seq_show_elem = htab_map_seq_show_elem,
1505 BATCH_OPS(htab),
1506 };
1507
1508 const struct bpf_map_ops htab_lru_map_ops = {
1509 .map_alloc_check = htab_map_alloc_check,
1510 .map_alloc = htab_map_alloc,
1511 .map_free = htab_map_free,
1512 .map_get_next_key = htab_map_get_next_key,
1513 .map_lookup_elem = htab_lru_map_lookup_elem,
1514 .map_lookup_elem_sys_only = htab_lru_map_lookup_elem_sys,
1515 .map_update_elem = htab_lru_map_update_elem,
1516 .map_delete_elem = htab_lru_map_delete_elem,
1517 .map_gen_lookup = htab_lru_map_gen_lookup,
1518 .map_seq_show_elem = htab_map_seq_show_elem,
1519 BATCH_OPS(htab_lru),
1520 };
1521
1522 /* Called from eBPF program */
1523 static void *htab_percpu_map_lookup_elem(struct bpf_map *map, void *key)
1524 {
1525 struct htab_elem *l = __htab_map_lookup_elem(map, key);
1526
1527 if (l)
1528 return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
1529 else
1530 return NULL;
1531 }
1532
1533 static void *htab_lru_percpu_map_lookup_elem(struct bpf_map *map, void *key)
1534 {
1535 struct htab_elem *l = __htab_map_lookup_elem(map, key);
1536
1537 if (l) {
1538 bpf_lru_node_set_ref(&l->lru_node);
1539 return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size));
1540 }
1541
1542 return NULL;
1543 }
1544
1545 int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value)
1546 {
1547 struct htab_elem *l;
1548 void __percpu *pptr;
1549 int ret = -ENOENT;
1550 int cpu, off = 0;
1551 u32 size;
1552
1553 /* per_cpu areas are zero-filled and bpf programs can only
1554 * access 'value_size' of them, so copying rounded areas
1555 * will not leak any kernel data
1556 */
1557 size = round_up(map->value_size, 8);
1558 rcu_read_lock();
1559 l = __htab_map_lookup_elem(map, key);
1560 if (!l)
1561 goto out;
1562 /* We do not mark LRU map element here in order to not mess up
1563 * eviction heuristics when user space does a map walk.
1564 */
1565 pptr = htab_elem_get_ptr(l, map->key_size);
1566 for_each_possible_cpu(cpu) {
1567 bpf_long_memcpy(value + off,
1568 per_cpu_ptr(pptr, cpu), size);
1569 off += size;
1570 }
1571 ret = 0;
1572 out:
1573 rcu_read_unlock();
1574 return ret;
1575 }
1576
1577 int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
1578 u64 map_flags)
1579 {
1580 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1581 int ret;
1582
1583 rcu_read_lock();
1584 if (htab_is_lru(htab))
1585 ret = __htab_lru_percpu_map_update_elem(map, key, value,
1586 map_flags, true);
1587 else
1588 ret = __htab_percpu_map_update_elem(map, key, value, map_flags,
1589 true);
1590 rcu_read_unlock();
1591
1592 return ret;
1593 }
1594
1595 static void htab_percpu_map_seq_show_elem(struct bpf_map *map, void *key,
1596 struct seq_file *m)
1597 {
1598 struct htab_elem *l;
1599 void __percpu *pptr;
1600 int cpu;
1601
1602 rcu_read_lock();
1603
1604 l = __htab_map_lookup_elem(map, key);
1605 if (!l) {
1606 rcu_read_unlock();
1607 return;
1608 }
1609
1610 btf_type_seq_show(map->btf, map->btf_key_type_id, key, m);
1611 seq_puts(m, ": {\n");
1612 pptr = htab_elem_get_ptr(l, map->key_size);
1613 for_each_possible_cpu(cpu) {
1614 seq_printf(m, "\tcpu%d: ", cpu);
1615 btf_type_seq_show(map->btf, map->btf_value_type_id,
1616 per_cpu_ptr(pptr, cpu), m);
1617 seq_puts(m, "\n");
1618 }
1619 seq_puts(m, "}\n");
1620
1621 rcu_read_unlock();
1622 }
1623
1624 const struct bpf_map_ops htab_percpu_map_ops = {
1625 .map_alloc_check = htab_map_alloc_check,
1626 .map_alloc = htab_map_alloc,
1627 .map_free = htab_map_free,
1628 .map_get_next_key = htab_map_get_next_key,
1629 .map_lookup_elem = htab_percpu_map_lookup_elem,
1630 .map_update_elem = htab_percpu_map_update_elem,
1631 .map_delete_elem = htab_map_delete_elem,
1632 .map_seq_show_elem = htab_percpu_map_seq_show_elem,
1633 BATCH_OPS(htab_percpu),
1634 };
1635
1636 const struct bpf_map_ops htab_lru_percpu_map_ops = {
1637 .map_alloc_check = htab_map_alloc_check,
1638 .map_alloc = htab_map_alloc,
1639 .map_free = htab_map_free,
1640 .map_get_next_key = htab_map_get_next_key,
1641 .map_lookup_elem = htab_lru_percpu_map_lookup_elem,
1642 .map_update_elem = htab_lru_percpu_map_update_elem,
1643 .map_delete_elem = htab_lru_map_delete_elem,
1644 .map_seq_show_elem = htab_percpu_map_seq_show_elem,
1645 BATCH_OPS(htab_lru_percpu),
1646 };
1647
1648 static int fd_htab_map_alloc_check(union bpf_attr *attr)
1649 {
1650 if (attr->value_size != sizeof(u32))
1651 return -EINVAL;
1652 return htab_map_alloc_check(attr);
1653 }
1654
1655 static void fd_htab_map_free(struct bpf_map *map)
1656 {
1657 struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
1658 struct hlist_nulls_node *n;
1659 struct hlist_nulls_head *head;
1660 struct htab_elem *l;
1661 int i;
1662
1663 for (i = 0; i < htab->n_buckets; i++) {
1664 head = select_bucket(htab, i);
1665
1666 hlist_nulls_for_each_entry_safe(l, n, head, hash_node) {
1667 void *ptr = fd_htab_map_get_ptr(map, l);
1668
1669 map->ops->map_fd_put_ptr(ptr);
1670 }
1671 }
1672
1673 htab_map_free(map);
1674 }
1675
1676 /* only called from syscall */
1677 int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value)
1678 {
1679 void **ptr;
1680 int ret = 0;
1681
1682 if (!map->ops->map_fd_sys_lookup_elem)
1683 return -ENOTSUPP;
1684
1685 rcu_read_lock();
1686 ptr = htab_map_lookup_elem(map, key);
1687 if (ptr)
1688 *value = map->ops->map_fd_sys_lookup_elem(READ_ONCE(*ptr));
1689 else
1690 ret = -ENOENT;
1691 rcu_read_unlock();
1692
1693 return ret;
1694 }
1695
1696 /* only called from syscall */
1697 int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file,
1698 void *key, void *value, u64 map_flags)
1699 {
1700 void *ptr;
1701 int ret;
1702 u32 ufd = *(u32 *)value;
1703
1704 ptr = map->ops->map_fd_get_ptr(map, map_file, ufd);
1705 if (IS_ERR(ptr))
1706 return PTR_ERR(ptr);
1707
1708 ret = htab_map_update_elem(map, key, &ptr, map_flags);
1709 if (ret)
1710 map->ops->map_fd_put_ptr(ptr);
1711
1712 return ret;
1713 }
1714
1715 static struct bpf_map *htab_of_map_alloc(union bpf_attr *attr)
1716 {
1717 struct bpf_map *map, *inner_map_meta;
1718
1719 inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd);
1720 if (IS_ERR(inner_map_meta))
1721 return inner_map_meta;
1722
1723 map = htab_map_alloc(attr);
1724 if (IS_ERR(map)) {
1725 bpf_map_meta_free(inner_map_meta);
1726 return map;
1727 }
1728
1729 map->inner_map_meta = inner_map_meta;
1730
1731 return map;
1732 }
1733
1734 static void *htab_of_map_lookup_elem(struct bpf_map *map, void *key)
1735 {
1736 struct bpf_map **inner_map = htab_map_lookup_elem(map, key);
1737
1738 if (!inner_map)
1739 return NULL;
1740
1741 return READ_ONCE(*inner_map);
1742 }
1743
1744 static u32 htab_of_map_gen_lookup(struct bpf_map *map,
1745 struct bpf_insn *insn_buf)
1746 {
1747 struct bpf_insn *insn = insn_buf;
1748 const int ret = BPF_REG_0;
1749
1750 BUILD_BUG_ON(!__same_type(&__htab_map_lookup_elem,
1751 (void *(*)(struct bpf_map *map, void *key))NULL));
1752 *insn++ = BPF_EMIT_CALL(BPF_CAST_CALL(__htab_map_lookup_elem));
1753 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 2);
1754 *insn++ = BPF_ALU64_IMM(BPF_ADD, ret,
1755 offsetof(struct htab_elem, key) +
1756 round_up(map->key_size, 8));
1757 *insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0);
1758
1759 return insn - insn_buf;
1760 }
1761
1762 static void htab_of_map_free(struct bpf_map *map)
1763 {
1764 bpf_map_meta_free(map->inner_map_meta);
1765 fd_htab_map_free(map);
1766 }
1767
1768 const struct bpf_map_ops htab_of_maps_map_ops = {
1769 .map_alloc_check = fd_htab_map_alloc_check,
1770 .map_alloc = htab_of_map_alloc,
1771 .map_free = htab_of_map_free,
1772 .map_get_next_key = htab_map_get_next_key,
1773 .map_lookup_elem = htab_of_map_lookup_elem,
1774 .map_delete_elem = htab_map_delete_elem,
1775 .map_fd_get_ptr = bpf_map_fd_get_ptr,
1776 .map_fd_put_ptr = bpf_map_fd_put_ptr,
1777 .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
1778 .map_gen_lookup = htab_of_map_gen_lookup,
1779 .map_check_btf = map_check_no_btf,
1780 };
Linux with added FPC-III support