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0f8e4bd8 | 1 | /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com |
6c905981 | 2 | * Copyright (c) 2016 Facebook |
0f8e4bd8 AS |
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> | |
6c905981 | 16 | #include "percpu_freelist.h" |
29ba732a | 17 | #include "bpf_lru_list.h" |
0f8e4bd8 | 18 | |
688ecfe6 | 19 | struct bucket { |
20 | struct hlist_head head; | |
21 | raw_spinlock_t lock; | |
22 | }; | |
23 | ||
0f8e4bd8 AS |
24 | struct bpf_htab { |
25 | struct bpf_map map; | |
688ecfe6 | 26 | struct bucket *buckets; |
6c905981 | 27 | void *elems; |
29ba732a MKL |
28 | union { |
29 | struct pcpu_freelist freelist; | |
30 | struct bpf_lru lru; | |
31 | }; | |
a6ed3ea6 | 32 | void __percpu *extra_elems; |
6591f1e6 | 33 | atomic_t count; /* number of elements in this hashtable */ |
0f8e4bd8 AS |
34 | u32 n_buckets; /* number of hash buckets */ |
35 | u32 elem_size; /* size of each element in bytes */ | |
36 | }; | |
37 | ||
a6ed3ea6 AS |
38 | enum extra_elem_state { |
39 | HTAB_NOT_AN_EXTRA_ELEM = 0, | |
40 | HTAB_EXTRA_ELEM_FREE, | |
41 | HTAB_EXTRA_ELEM_USED | |
42 | }; | |
43 | ||
0f8e4bd8 AS |
44 | /* each htab element is struct htab_elem + key + value */ |
45 | struct htab_elem { | |
824bd0ce | 46 | union { |
6c905981 | 47 | struct hlist_node hash_node; |
9f691549 AS |
48 | struct { |
49 | void *padding; | |
50 | union { | |
51 | struct bpf_htab *htab; | |
52 | struct pcpu_freelist_node fnode; | |
53 | }; | |
54 | }; | |
824bd0ce | 55 | }; |
a6ed3ea6 AS |
56 | union { |
57 | struct rcu_head rcu; | |
58 | enum extra_elem_state state; | |
29ba732a | 59 | struct bpf_lru_node lru_node; |
a6ed3ea6 | 60 | }; |
6c905981 | 61 | u32 hash; |
0f8e4bd8 AS |
62 | char key[0] __aligned(8); |
63 | }; | |
64 | ||
29ba732a MKL |
65 | static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node); |
66 | ||
67 | static bool htab_is_lru(const struct bpf_htab *htab) | |
68 | { | |
8f844938 MKL |
69 | return htab->map.map_type == BPF_MAP_TYPE_LRU_HASH || |
70 | htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH; | |
71 | } | |
72 | ||
73 | static bool htab_is_percpu(const struct bpf_htab *htab) | |
74 | { | |
75 | return htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH || | |
76 | htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH; | |
29ba732a MKL |
77 | } |
78 | ||
6c905981 AS |
79 | static inline void htab_elem_set_ptr(struct htab_elem *l, u32 key_size, |
80 | void __percpu *pptr) | |
81 | { | |
82 | *(void __percpu **)(l->key + key_size) = pptr; | |
83 | } | |
84 | ||
85 | static inline void __percpu *htab_elem_get_ptr(struct htab_elem *l, u32 key_size) | |
86 | { | |
87 | return *(void __percpu **)(l->key + key_size); | |
88 | } | |
89 | ||
90 | static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i) | |
91 | { | |
92 | return (struct htab_elem *) (htab->elems + i * htab->elem_size); | |
93 | } | |
94 | ||
95 | static void htab_free_elems(struct bpf_htab *htab) | |
96 | { | |
97 | int i; | |
98 | ||
8f844938 | 99 | if (!htab_is_percpu(htab)) |
6c905981 AS |
100 | goto free_elems; |
101 | ||
102 | for (i = 0; i < htab->map.max_entries; i++) { | |
103 | void __percpu *pptr; | |
104 | ||
105 | pptr = htab_elem_get_ptr(get_htab_elem(htab, i), | |
106 | htab->map.key_size); | |
107 | free_percpu(pptr); | |
108 | } | |
109 | free_elems: | |
d407bd25 | 110 | bpf_map_area_free(htab->elems); |
6c905981 AS |
111 | } |
112 | ||
29ba732a MKL |
113 | static struct htab_elem *prealloc_lru_pop(struct bpf_htab *htab, void *key, |
114 | u32 hash) | |
115 | { | |
116 | struct bpf_lru_node *node = bpf_lru_pop_free(&htab->lru, hash); | |
117 | struct htab_elem *l; | |
118 | ||
119 | if (node) { | |
120 | l = container_of(node, struct htab_elem, lru_node); | |
121 | memcpy(l->key, key, htab->map.key_size); | |
122 | return l; | |
123 | } | |
124 | ||
125 | return NULL; | |
126 | } | |
127 | ||
128 | static int prealloc_init(struct bpf_htab *htab) | |
6c905981 AS |
129 | { |
130 | int err = -ENOMEM, i; | |
131 | ||
d407bd25 DB |
132 | htab->elems = bpf_map_area_alloc(htab->elem_size * |
133 | htab->map.max_entries); | |
6c905981 AS |
134 | if (!htab->elems) |
135 | return -ENOMEM; | |
136 | ||
8f844938 | 137 | if (!htab_is_percpu(htab)) |
6c905981 AS |
138 | goto skip_percpu_elems; |
139 | ||
140 | for (i = 0; i < htab->map.max_entries; i++) { | |
141 | u32 size = round_up(htab->map.value_size, 8); | |
142 | void __percpu *pptr; | |
143 | ||
144 | pptr = __alloc_percpu_gfp(size, 8, GFP_USER | __GFP_NOWARN); | |
145 | if (!pptr) | |
146 | goto free_elems; | |
147 | htab_elem_set_ptr(get_htab_elem(htab, i), htab->map.key_size, | |
148 | pptr); | |
149 | } | |
150 | ||
151 | skip_percpu_elems: | |
29ba732a MKL |
152 | if (htab_is_lru(htab)) |
153 | err = bpf_lru_init(&htab->lru, | |
154 | htab->map.map_flags & BPF_F_NO_COMMON_LRU, | |
155 | offsetof(struct htab_elem, hash) - | |
156 | offsetof(struct htab_elem, lru_node), | |
157 | htab_lru_map_delete_node, | |
158 | htab); | |
159 | else | |
160 | err = pcpu_freelist_init(&htab->freelist); | |
161 | ||
6c905981 AS |
162 | if (err) |
163 | goto free_elems; | |
164 | ||
29ba732a MKL |
165 | if (htab_is_lru(htab)) |
166 | bpf_lru_populate(&htab->lru, htab->elems, | |
167 | offsetof(struct htab_elem, lru_node), | |
168 | htab->elem_size, htab->map.max_entries); | |
169 | else | |
9f691549 AS |
170 | pcpu_freelist_populate(&htab->freelist, |
171 | htab->elems + offsetof(struct htab_elem, fnode), | |
29ba732a MKL |
172 | htab->elem_size, htab->map.max_entries); |
173 | ||
6c905981 AS |
174 | return 0; |
175 | ||
176 | free_elems: | |
177 | htab_free_elems(htab); | |
178 | return err; | |
179 | } | |
180 | ||
29ba732a MKL |
181 | static void prealloc_destroy(struct bpf_htab *htab) |
182 | { | |
183 | htab_free_elems(htab); | |
184 | ||
185 | if (htab_is_lru(htab)) | |
186 | bpf_lru_destroy(&htab->lru); | |
187 | else | |
188 | pcpu_freelist_destroy(&htab->freelist); | |
189 | } | |
190 | ||
a6ed3ea6 AS |
191 | static int alloc_extra_elems(struct bpf_htab *htab) |
192 | { | |
193 | void __percpu *pptr; | |
194 | int cpu; | |
195 | ||
196 | pptr = __alloc_percpu_gfp(htab->elem_size, 8, GFP_USER | __GFP_NOWARN); | |
197 | if (!pptr) | |
198 | return -ENOMEM; | |
199 | ||
200 | for_each_possible_cpu(cpu) { | |
201 | ((struct htab_elem *)per_cpu_ptr(pptr, cpu))->state = | |
202 | HTAB_EXTRA_ELEM_FREE; | |
203 | } | |
204 | htab->extra_elems = pptr; | |
205 | return 0; | |
206 | } | |
207 | ||
0f8e4bd8 AS |
208 | /* Called from syscall */ |
209 | static struct bpf_map *htab_map_alloc(union bpf_attr *attr) | |
210 | { | |
8f844938 MKL |
211 | bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH || |
212 | attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH); | |
213 | bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH || | |
214 | attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH); | |
29ba732a MKL |
215 | /* percpu_lru means each cpu has its own LRU list. |
216 | * it is different from BPF_MAP_TYPE_PERCPU_HASH where | |
217 | * the map's value itself is percpu. percpu_lru has | |
218 | * nothing to do with the map's value. | |
219 | */ | |
220 | bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU); | |
221 | bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC); | |
0f8e4bd8 AS |
222 | struct bpf_htab *htab; |
223 | int err, i; | |
824bd0ce | 224 | u64 cost; |
0f8e4bd8 | 225 | |
9f691549 AS |
226 | BUILD_BUG_ON(offsetof(struct htab_elem, htab) != |
227 | offsetof(struct htab_elem, hash_node.pprev)); | |
228 | BUILD_BUG_ON(offsetof(struct htab_elem, fnode.next) != | |
229 | offsetof(struct htab_elem, hash_node.pprev)); | |
230 | ||
29ba732a MKL |
231 | if (lru && !capable(CAP_SYS_ADMIN)) |
232 | /* LRU implementation is much complicated than other | |
233 | * maps. Hence, limit to CAP_SYS_ADMIN for now. | |
234 | */ | |
235 | return ERR_PTR(-EPERM); | |
236 | ||
237 | if (attr->map_flags & ~(BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU)) | |
6c905981 AS |
238 | /* reserved bits should not be used */ |
239 | return ERR_PTR(-EINVAL); | |
240 | ||
29ba732a MKL |
241 | if (!lru && percpu_lru) |
242 | return ERR_PTR(-EINVAL); | |
243 | ||
244 | if (lru && !prealloc) | |
245 | return ERR_PTR(-ENOTSUPP); | |
246 | ||
0f8e4bd8 AS |
247 | htab = kzalloc(sizeof(*htab), GFP_USER); |
248 | if (!htab) | |
249 | return ERR_PTR(-ENOMEM); | |
250 | ||
251 | /* mandatory map attributes */ | |
824bd0ce | 252 | htab->map.map_type = attr->map_type; |
0f8e4bd8 AS |
253 | htab->map.key_size = attr->key_size; |
254 | htab->map.value_size = attr->value_size; | |
255 | htab->map.max_entries = attr->max_entries; | |
6c905981 | 256 | htab->map.map_flags = attr->map_flags; |
0f8e4bd8 AS |
257 | |
258 | /* check sanity of attributes. | |
259 | * value_size == 0 may be allowed in the future to use map as a set | |
260 | */ | |
261 | err = -EINVAL; | |
262 | if (htab->map.max_entries == 0 || htab->map.key_size == 0 || | |
263 | htab->map.value_size == 0) | |
264 | goto free_htab; | |
265 | ||
29ba732a MKL |
266 | if (percpu_lru) { |
267 | /* ensure each CPU's lru list has >=1 elements. | |
268 | * since we are at it, make each lru list has the same | |
269 | * number of elements. | |
270 | */ | |
271 | htab->map.max_entries = roundup(attr->max_entries, | |
272 | num_possible_cpus()); | |
273 | if (htab->map.max_entries < attr->max_entries) | |
274 | htab->map.max_entries = rounddown(attr->max_entries, | |
275 | num_possible_cpus()); | |
276 | } | |
277 | ||
0f8e4bd8 AS |
278 | /* hash table size must be power of 2 */ |
279 | htab->n_buckets = roundup_pow_of_two(htab->map.max_entries); | |
280 | ||
281 | err = -E2BIG; | |
282 | if (htab->map.key_size > MAX_BPF_STACK) | |
283 | /* eBPF programs initialize keys on stack, so they cannot be | |
284 | * larger than max stack size | |
285 | */ | |
286 | goto free_htab; | |
287 | ||
7984c27c | 288 | if (htab->map.value_size >= KMALLOC_MAX_SIZE - |
01b3f521 AS |
289 | MAX_BPF_STACK - sizeof(struct htab_elem)) |
290 | /* if value_size is bigger, the user space won't be able to | |
291 | * access the elements via bpf syscall. This check also makes | |
292 | * sure that the elem_size doesn't overflow and it's | |
293 | * kmalloc-able later in htab_map_update_elem() | |
294 | */ | |
295 | goto free_htab; | |
296 | ||
824bd0ce AS |
297 | if (percpu && round_up(htab->map.value_size, 8) > PCPU_MIN_UNIT_SIZE) |
298 | /* make sure the size for pcpu_alloc() is reasonable */ | |
299 | goto free_htab; | |
300 | ||
01b3f521 | 301 | htab->elem_size = sizeof(struct htab_elem) + |
824bd0ce AS |
302 | round_up(htab->map.key_size, 8); |
303 | if (percpu) | |
304 | htab->elem_size += sizeof(void *); | |
305 | else | |
6c905981 | 306 | htab->elem_size += round_up(htab->map.value_size, 8); |
01b3f521 | 307 | |
daaf427c AS |
308 | /* prevent zero size kmalloc and check for u32 overflow */ |
309 | if (htab->n_buckets == 0 || | |
688ecfe6 | 310 | htab->n_buckets > U32_MAX / sizeof(struct bucket)) |
daaf427c AS |
311 | goto free_htab; |
312 | ||
824bd0ce AS |
313 | cost = (u64) htab->n_buckets * sizeof(struct bucket) + |
314 | (u64) htab->elem_size * htab->map.max_entries; | |
315 | ||
316 | if (percpu) | |
317 | cost += (u64) round_up(htab->map.value_size, 8) * | |
318 | num_possible_cpus() * htab->map.max_entries; | |
a6ed3ea6 AS |
319 | else |
320 | cost += (u64) htab->elem_size * num_possible_cpus(); | |
824bd0ce AS |
321 | |
322 | if (cost >= U32_MAX - PAGE_SIZE) | |
01b3f521 AS |
323 | /* make sure page count doesn't overflow */ |
324 | goto free_htab; | |
325 | ||
824bd0ce | 326 | htab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT; |
01b3f521 | 327 | |
6c905981 AS |
328 | /* if map size is larger than memlock limit, reject it early */ |
329 | err = bpf_map_precharge_memlock(htab->map.pages); | |
330 | if (err) | |
331 | goto free_htab; | |
332 | ||
01b3f521 | 333 | err = -ENOMEM; |
d407bd25 DB |
334 | htab->buckets = bpf_map_area_alloc(htab->n_buckets * |
335 | sizeof(struct bucket)); | |
336 | if (!htab->buckets) | |
337 | goto free_htab; | |
0f8e4bd8 | 338 | |
688ecfe6 | 339 | for (i = 0; i < htab->n_buckets; i++) { |
340 | INIT_HLIST_HEAD(&htab->buckets[i].head); | |
341 | raw_spin_lock_init(&htab->buckets[i].lock); | |
342 | } | |
0f8e4bd8 | 343 | |
29ba732a MKL |
344 | if (!percpu && !lru) { |
345 | /* lru itself can remove the least used element, so | |
346 | * there is no need for an extra elem during map_update. | |
347 | */ | |
a6ed3ea6 AS |
348 | err = alloc_extra_elems(htab); |
349 | if (err) | |
350 | goto free_buckets; | |
351 | } | |
352 | ||
29ba732a MKL |
353 | if (prealloc) { |
354 | err = prealloc_init(htab); | |
6c905981 | 355 | if (err) |
a6ed3ea6 | 356 | goto free_extra_elems; |
6c905981 | 357 | } |
0f8e4bd8 | 358 | |
0f8e4bd8 AS |
359 | return &htab->map; |
360 | ||
a6ed3ea6 AS |
361 | free_extra_elems: |
362 | free_percpu(htab->extra_elems); | |
6c905981 | 363 | free_buckets: |
d407bd25 | 364 | bpf_map_area_free(htab->buckets); |
0f8e4bd8 AS |
365 | free_htab: |
366 | kfree(htab); | |
367 | return ERR_PTR(err); | |
368 | } | |
369 | ||
370 | static inline u32 htab_map_hash(const void *key, u32 key_len) | |
371 | { | |
372 | return jhash(key, key_len, 0); | |
373 | } | |
374 | ||
688ecfe6 | 375 | static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash) |
0f8e4bd8 AS |
376 | { |
377 | return &htab->buckets[hash & (htab->n_buckets - 1)]; | |
378 | } | |
379 | ||
688ecfe6 | 380 | static inline struct hlist_head *select_bucket(struct bpf_htab *htab, u32 hash) |
381 | { | |
382 | return &__select_bucket(htab, hash)->head; | |
383 | } | |
384 | ||
0f8e4bd8 AS |
385 | static struct htab_elem *lookup_elem_raw(struct hlist_head *head, u32 hash, |
386 | void *key, u32 key_size) | |
387 | { | |
388 | struct htab_elem *l; | |
389 | ||
390 | hlist_for_each_entry_rcu(l, head, hash_node) | |
391 | if (l->hash == hash && !memcmp(&l->key, key, key_size)) | |
392 | return l; | |
393 | ||
394 | return NULL; | |
395 | } | |
396 | ||
397 | /* Called from syscall or from eBPF program */ | |
824bd0ce | 398 | static void *__htab_map_lookup_elem(struct bpf_map *map, void *key) |
0f8e4bd8 AS |
399 | { |
400 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | |
401 | struct hlist_head *head; | |
402 | struct htab_elem *l; | |
403 | u32 hash, key_size; | |
404 | ||
405 | /* Must be called with rcu_read_lock. */ | |
406 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
407 | ||
408 | key_size = map->key_size; | |
409 | ||
410 | hash = htab_map_hash(key, key_size); | |
411 | ||
412 | head = select_bucket(htab, hash); | |
413 | ||
414 | l = lookup_elem_raw(head, hash, key, key_size); | |
415 | ||
824bd0ce AS |
416 | return l; |
417 | } | |
418 | ||
419 | static void *htab_map_lookup_elem(struct bpf_map *map, void *key) | |
420 | { | |
421 | struct htab_elem *l = __htab_map_lookup_elem(map, key); | |
422 | ||
0f8e4bd8 AS |
423 | if (l) |
424 | return l->key + round_up(map->key_size, 8); | |
425 | ||
426 | return NULL; | |
427 | } | |
428 | ||
29ba732a MKL |
429 | static void *htab_lru_map_lookup_elem(struct bpf_map *map, void *key) |
430 | { | |
431 | struct htab_elem *l = __htab_map_lookup_elem(map, key); | |
432 | ||
433 | if (l) { | |
434 | bpf_lru_node_set_ref(&l->lru_node); | |
435 | return l->key + round_up(map->key_size, 8); | |
436 | } | |
437 | ||
438 | return NULL; | |
439 | } | |
440 | ||
441 | /* It is called from the bpf_lru_list when the LRU needs to delete | |
442 | * older elements from the htab. | |
443 | */ | |
444 | static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node) | |
445 | { | |
446 | struct bpf_htab *htab = (struct bpf_htab *)arg; | |
447 | struct htab_elem *l, *tgt_l; | |
448 | struct hlist_head *head; | |
449 | unsigned long flags; | |
450 | struct bucket *b; | |
451 | ||
452 | tgt_l = container_of(node, struct htab_elem, lru_node); | |
453 | b = __select_bucket(htab, tgt_l->hash); | |
454 | head = &b->head; | |
455 | ||
456 | raw_spin_lock_irqsave(&b->lock, flags); | |
457 | ||
458 | hlist_for_each_entry_rcu(l, head, hash_node) | |
459 | if (l == tgt_l) { | |
460 | hlist_del_rcu(&l->hash_node); | |
461 | break; | |
462 | } | |
463 | ||
464 | raw_spin_unlock_irqrestore(&b->lock, flags); | |
465 | ||
466 | return l == tgt_l; | |
467 | } | |
468 | ||
0f8e4bd8 AS |
469 | /* Called from syscall */ |
470 | static int htab_map_get_next_key(struct bpf_map *map, void *key, void *next_key) | |
471 | { | |
472 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | |
473 | struct hlist_head *head; | |
474 | struct htab_elem *l, *next_l; | |
475 | u32 hash, key_size; | |
476 | int i; | |
477 | ||
478 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
479 | ||
480 | key_size = map->key_size; | |
481 | ||
482 | hash = htab_map_hash(key, key_size); | |
483 | ||
484 | head = select_bucket(htab, hash); | |
485 | ||
486 | /* lookup the key */ | |
487 | l = lookup_elem_raw(head, hash, key, key_size); | |
488 | ||
489 | if (!l) { | |
490 | i = 0; | |
491 | goto find_first_elem; | |
492 | } | |
493 | ||
494 | /* key was found, get next key in the same bucket */ | |
495 | next_l = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(&l->hash_node)), | |
496 | struct htab_elem, hash_node); | |
497 | ||
498 | if (next_l) { | |
499 | /* if next elem in this hash list is non-zero, just return it */ | |
500 | memcpy(next_key, next_l->key, key_size); | |
501 | return 0; | |
502 | } | |
503 | ||
504 | /* no more elements in this hash list, go to the next bucket */ | |
505 | i = hash & (htab->n_buckets - 1); | |
506 | i++; | |
507 | ||
508 | find_first_elem: | |
509 | /* iterate over buckets */ | |
510 | for (; i < htab->n_buckets; i++) { | |
511 | head = select_bucket(htab, i); | |
512 | ||
513 | /* pick first element in the bucket */ | |
514 | next_l = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)), | |
515 | struct htab_elem, hash_node); | |
516 | if (next_l) { | |
517 | /* if it's not empty, just return it */ | |
518 | memcpy(next_key, next_l->key, key_size); | |
519 | return 0; | |
520 | } | |
521 | } | |
522 | ||
6c905981 | 523 | /* iterated over all buckets and all elements */ |
0f8e4bd8 AS |
524 | return -ENOENT; |
525 | } | |
526 | ||
6c905981 | 527 | static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l) |
824bd0ce | 528 | { |
6c905981 AS |
529 | if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH) |
530 | free_percpu(htab_elem_get_ptr(l, htab->map.key_size)); | |
824bd0ce AS |
531 | kfree(l); |
532 | } | |
533 | ||
6c905981 | 534 | static void htab_elem_free_rcu(struct rcu_head *head) |
824bd0ce AS |
535 | { |
536 | struct htab_elem *l = container_of(head, struct htab_elem, rcu); | |
6c905981 | 537 | struct bpf_htab *htab = l->htab; |
824bd0ce | 538 | |
6c905981 AS |
539 | /* must increment bpf_prog_active to avoid kprobe+bpf triggering while |
540 | * we're calling kfree, otherwise deadlock is possible if kprobes | |
541 | * are placed somewhere inside of slub | |
542 | */ | |
543 | preempt_disable(); | |
544 | __this_cpu_inc(bpf_prog_active); | |
545 | htab_elem_free(htab, l); | |
546 | __this_cpu_dec(bpf_prog_active); | |
547 | preempt_enable(); | |
824bd0ce AS |
548 | } |
549 | ||
6c905981 | 550 | static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l) |
824bd0ce | 551 | { |
a6ed3ea6 AS |
552 | if (l->state == HTAB_EXTRA_ELEM_USED) { |
553 | l->state = HTAB_EXTRA_ELEM_FREE; | |
554 | return; | |
555 | } | |
556 | ||
6c905981 AS |
557 | if (!(htab->map.map_flags & BPF_F_NO_PREALLOC)) { |
558 | pcpu_freelist_push(&htab->freelist, &l->fnode); | |
824bd0ce | 559 | } else { |
6c905981 AS |
560 | atomic_dec(&htab->count); |
561 | l->htab = htab; | |
562 | call_rcu(&l->rcu, htab_elem_free_rcu); | |
824bd0ce AS |
563 | } |
564 | } | |
565 | ||
fd91de7b MKL |
566 | static void pcpu_copy_value(struct bpf_htab *htab, void __percpu *pptr, |
567 | void *value, bool onallcpus) | |
568 | { | |
569 | if (!onallcpus) { | |
570 | /* copy true value_size bytes */ | |
571 | memcpy(this_cpu_ptr(pptr), value, htab->map.value_size); | |
572 | } else { | |
573 | u32 size = round_up(htab->map.value_size, 8); | |
574 | int off = 0, cpu; | |
575 | ||
576 | for_each_possible_cpu(cpu) { | |
577 | bpf_long_memcpy(per_cpu_ptr(pptr, cpu), | |
578 | value + off, size); | |
579 | off += size; | |
580 | } | |
581 | } | |
582 | } | |
583 | ||
824bd0ce AS |
584 | static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key, |
585 | void *value, u32 key_size, u32 hash, | |
a6ed3ea6 AS |
586 | bool percpu, bool onallcpus, |
587 | bool old_elem_exists) | |
824bd0ce AS |
588 | { |
589 | u32 size = htab->map.value_size; | |
6c905981 | 590 | bool prealloc = !(htab->map.map_flags & BPF_F_NO_PREALLOC); |
824bd0ce AS |
591 | struct htab_elem *l_new; |
592 | void __percpu *pptr; | |
a6ed3ea6 | 593 | int err = 0; |
824bd0ce | 594 | |
6c905981 | 595 | if (prealloc) { |
9f691549 AS |
596 | struct pcpu_freelist_node *l; |
597 | ||
598 | l = pcpu_freelist_pop(&htab->freelist); | |
599 | if (!l) | |
a6ed3ea6 | 600 | err = -E2BIG; |
9f691549 AS |
601 | else |
602 | l_new = container_of(l, struct htab_elem, fnode); | |
6c905981 AS |
603 | } else { |
604 | if (atomic_inc_return(&htab->count) > htab->map.max_entries) { | |
605 | atomic_dec(&htab->count); | |
a6ed3ea6 AS |
606 | err = -E2BIG; |
607 | } else { | |
608 | l_new = kmalloc(htab->elem_size, | |
609 | GFP_ATOMIC | __GFP_NOWARN); | |
610 | if (!l_new) | |
611 | return ERR_PTR(-ENOMEM); | |
6c905981 | 612 | } |
a6ed3ea6 AS |
613 | } |
614 | ||
615 | if (err) { | |
616 | if (!old_elem_exists) | |
617 | return ERR_PTR(err); | |
618 | ||
619 | /* if we're updating the existing element and the hash table | |
620 | * is full, use per-cpu extra elems | |
621 | */ | |
622 | l_new = this_cpu_ptr(htab->extra_elems); | |
623 | if (l_new->state != HTAB_EXTRA_ELEM_FREE) | |
624 | return ERR_PTR(-E2BIG); | |
625 | l_new->state = HTAB_EXTRA_ELEM_USED; | |
626 | } else { | |
627 | l_new->state = HTAB_NOT_AN_EXTRA_ELEM; | |
6c905981 | 628 | } |
824bd0ce AS |
629 | |
630 | memcpy(l_new->key, key, key_size); | |
631 | if (percpu) { | |
632 | /* round up value_size to 8 bytes */ | |
633 | size = round_up(size, 8); | |
634 | ||
6c905981 AS |
635 | if (prealloc) { |
636 | pptr = htab_elem_get_ptr(l_new, key_size); | |
637 | } else { | |
638 | /* alloc_percpu zero-fills */ | |
639 | pptr = __alloc_percpu_gfp(size, 8, | |
640 | GFP_ATOMIC | __GFP_NOWARN); | |
641 | if (!pptr) { | |
642 | kfree(l_new); | |
643 | return ERR_PTR(-ENOMEM); | |
644 | } | |
824bd0ce AS |
645 | } |
646 | ||
fd91de7b | 647 | pcpu_copy_value(htab, pptr, value, onallcpus); |
15a07b33 | 648 | |
6c905981 AS |
649 | if (!prealloc) |
650 | htab_elem_set_ptr(l_new, key_size, pptr); | |
824bd0ce AS |
651 | } else { |
652 | memcpy(l_new->key + round_up(key_size, 8), value, size); | |
653 | } | |
654 | ||
655 | l_new->hash = hash; | |
656 | return l_new; | |
657 | } | |
658 | ||
659 | static int check_flags(struct bpf_htab *htab, struct htab_elem *l_old, | |
660 | u64 map_flags) | |
661 | { | |
824bd0ce AS |
662 | if (l_old && map_flags == BPF_NOEXIST) |
663 | /* elem already exists */ | |
664 | return -EEXIST; | |
665 | ||
666 | if (!l_old && map_flags == BPF_EXIST) | |
667 | /* elem doesn't exist, cannot update it */ | |
668 | return -ENOENT; | |
669 | ||
670 | return 0; | |
671 | } | |
672 | ||
0f8e4bd8 AS |
673 | /* Called from syscall or from eBPF program */ |
674 | static int htab_map_update_elem(struct bpf_map *map, void *key, void *value, | |
675 | u64 map_flags) | |
676 | { | |
677 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | |
824bd0ce | 678 | struct htab_elem *l_new = NULL, *l_old; |
0f8e4bd8 AS |
679 | struct hlist_head *head; |
680 | unsigned long flags; | |
824bd0ce AS |
681 | struct bucket *b; |
682 | u32 key_size, hash; | |
0f8e4bd8 AS |
683 | int ret; |
684 | ||
824bd0ce | 685 | if (unlikely(map_flags > BPF_EXIST)) |
0f8e4bd8 AS |
686 | /* unknown flags */ |
687 | return -EINVAL; | |
688 | ||
689 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
690 | ||
0f8e4bd8 AS |
691 | key_size = map->key_size; |
692 | ||
824bd0ce AS |
693 | hash = htab_map_hash(key, key_size); |
694 | ||
824bd0ce | 695 | b = __select_bucket(htab, hash); |
688ecfe6 | 696 | head = &b->head; |
0f8e4bd8 AS |
697 | |
698 | /* bpf_map_update_elem() can be called in_irq() */ | |
688ecfe6 | 699 | raw_spin_lock_irqsave(&b->lock, flags); |
0f8e4bd8 | 700 | |
824bd0ce | 701 | l_old = lookup_elem_raw(head, hash, key, key_size); |
0f8e4bd8 | 702 | |
824bd0ce AS |
703 | ret = check_flags(htab, l_old, map_flags); |
704 | if (ret) | |
0f8e4bd8 | 705 | goto err; |
0f8e4bd8 | 706 | |
a6ed3ea6 AS |
707 | l_new = alloc_htab_elem(htab, key, value, key_size, hash, false, false, |
708 | !!l_old); | |
6c905981 AS |
709 | if (IS_ERR(l_new)) { |
710 | /* all pre-allocated elements are in use or memory exhausted */ | |
711 | ret = PTR_ERR(l_new); | |
712 | goto err; | |
713 | } | |
714 | ||
824bd0ce AS |
715 | /* add new element to the head of the list, so that |
716 | * concurrent search will find it before old elem | |
0f8e4bd8 AS |
717 | */ |
718 | hlist_add_head_rcu(&l_new->hash_node, head); | |
719 | if (l_old) { | |
720 | hlist_del_rcu(&l_old->hash_node); | |
6c905981 | 721 | free_htab_elem(htab, l_old); |
0f8e4bd8 | 722 | } |
6c905981 | 723 | ret = 0; |
0f8e4bd8 | 724 | err: |
688ecfe6 | 725 | raw_spin_unlock_irqrestore(&b->lock, flags); |
0f8e4bd8 AS |
726 | return ret; |
727 | } | |
728 | ||
29ba732a MKL |
729 | static int htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value, |
730 | u64 map_flags) | |
731 | { | |
732 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | |
733 | struct htab_elem *l_new, *l_old = NULL; | |
734 | struct hlist_head *head; | |
735 | unsigned long flags; | |
736 | struct bucket *b; | |
737 | u32 key_size, hash; | |
738 | int ret; | |
739 | ||
740 | if (unlikely(map_flags > BPF_EXIST)) | |
741 | /* unknown flags */ | |
742 | return -EINVAL; | |
743 | ||
744 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
745 | ||
746 | key_size = map->key_size; | |
747 | ||
748 | hash = htab_map_hash(key, key_size); | |
749 | ||
750 | b = __select_bucket(htab, hash); | |
751 | head = &b->head; | |
752 | ||
753 | /* For LRU, we need to alloc before taking bucket's | |
754 | * spinlock because getting free nodes from LRU may need | |
755 | * to remove older elements from htab and this removal | |
756 | * operation will need a bucket lock. | |
757 | */ | |
758 | l_new = prealloc_lru_pop(htab, key, hash); | |
759 | if (!l_new) | |
760 | return -ENOMEM; | |
761 | memcpy(l_new->key + round_up(map->key_size, 8), value, map->value_size); | |
762 | ||
763 | /* bpf_map_update_elem() can be called in_irq() */ | |
764 | raw_spin_lock_irqsave(&b->lock, flags); | |
765 | ||
766 | l_old = lookup_elem_raw(head, hash, key, key_size); | |
767 | ||
768 | ret = check_flags(htab, l_old, map_flags); | |
769 | if (ret) | |
770 | goto err; | |
771 | ||
772 | /* add new element to the head of the list, so that | |
773 | * concurrent search will find it before old elem | |
774 | */ | |
775 | hlist_add_head_rcu(&l_new->hash_node, head); | |
776 | if (l_old) { | |
777 | bpf_lru_node_set_ref(&l_new->lru_node); | |
778 | hlist_del_rcu(&l_old->hash_node); | |
779 | } | |
780 | ret = 0; | |
781 | ||
782 | err: | |
783 | raw_spin_unlock_irqrestore(&b->lock, flags); | |
784 | ||
785 | if (ret) | |
786 | bpf_lru_push_free(&htab->lru, &l_new->lru_node); | |
787 | else if (l_old) | |
788 | bpf_lru_push_free(&htab->lru, &l_old->lru_node); | |
789 | ||
790 | return ret; | |
791 | } | |
792 | ||
15a07b33 AS |
793 | static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key, |
794 | void *value, u64 map_flags, | |
795 | bool onallcpus) | |
824bd0ce AS |
796 | { |
797 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | |
798 | struct htab_elem *l_new = NULL, *l_old; | |
799 | struct hlist_head *head; | |
800 | unsigned long flags; | |
801 | struct bucket *b; | |
802 | u32 key_size, hash; | |
803 | int ret; | |
804 | ||
805 | if (unlikely(map_flags > BPF_EXIST)) | |
806 | /* unknown flags */ | |
807 | return -EINVAL; | |
808 | ||
809 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
810 | ||
811 | key_size = map->key_size; | |
812 | ||
813 | hash = htab_map_hash(key, key_size); | |
814 | ||
815 | b = __select_bucket(htab, hash); | |
816 | head = &b->head; | |
817 | ||
818 | /* bpf_map_update_elem() can be called in_irq() */ | |
819 | raw_spin_lock_irqsave(&b->lock, flags); | |
820 | ||
821 | l_old = lookup_elem_raw(head, hash, key, key_size); | |
822 | ||
823 | ret = check_flags(htab, l_old, map_flags); | |
824 | if (ret) | |
825 | goto err; | |
826 | ||
827 | if (l_old) { | |
828 | /* per-cpu hash map can update value in-place */ | |
fd91de7b MKL |
829 | pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size), |
830 | value, onallcpus); | |
824bd0ce AS |
831 | } else { |
832 | l_new = alloc_htab_elem(htab, key, value, key_size, | |
a6ed3ea6 | 833 | hash, true, onallcpus, false); |
6c905981 AS |
834 | if (IS_ERR(l_new)) { |
835 | ret = PTR_ERR(l_new); | |
824bd0ce AS |
836 | goto err; |
837 | } | |
838 | hlist_add_head_rcu(&l_new->hash_node, head); | |
824bd0ce AS |
839 | } |
840 | ret = 0; | |
841 | err: | |
842 | raw_spin_unlock_irqrestore(&b->lock, flags); | |
843 | return ret; | |
844 | } | |
845 | ||
8f844938 MKL |
846 | static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key, |
847 | void *value, u64 map_flags, | |
848 | bool onallcpus) | |
849 | { | |
850 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | |
851 | struct htab_elem *l_new = NULL, *l_old; | |
852 | struct hlist_head *head; | |
853 | unsigned long flags; | |
854 | struct bucket *b; | |
855 | u32 key_size, hash; | |
856 | int ret; | |
857 | ||
858 | if (unlikely(map_flags > BPF_EXIST)) | |
859 | /* unknown flags */ | |
860 | return -EINVAL; | |
861 | ||
862 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
863 | ||
864 | key_size = map->key_size; | |
865 | ||
866 | hash = htab_map_hash(key, key_size); | |
867 | ||
868 | b = __select_bucket(htab, hash); | |
869 | head = &b->head; | |
870 | ||
871 | /* For LRU, we need to alloc before taking bucket's | |
872 | * spinlock because LRU's elem alloc may need | |
873 | * to remove older elem from htab and this removal | |
874 | * operation will need a bucket lock. | |
875 | */ | |
876 | if (map_flags != BPF_EXIST) { | |
877 | l_new = prealloc_lru_pop(htab, key, hash); | |
878 | if (!l_new) | |
879 | return -ENOMEM; | |
880 | } | |
881 | ||
882 | /* bpf_map_update_elem() can be called in_irq() */ | |
883 | raw_spin_lock_irqsave(&b->lock, flags); | |
884 | ||
885 | l_old = lookup_elem_raw(head, hash, key, key_size); | |
886 | ||
887 | ret = check_flags(htab, l_old, map_flags); | |
888 | if (ret) | |
889 | goto err; | |
890 | ||
891 | if (l_old) { | |
892 | bpf_lru_node_set_ref(&l_old->lru_node); | |
893 | ||
894 | /* per-cpu hash map can update value in-place */ | |
895 | pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size), | |
896 | value, onallcpus); | |
897 | } else { | |
898 | pcpu_copy_value(htab, htab_elem_get_ptr(l_new, key_size), | |
899 | value, onallcpus); | |
900 | hlist_add_head_rcu(&l_new->hash_node, head); | |
901 | l_new = NULL; | |
902 | } | |
903 | ret = 0; | |
904 | err: | |
905 | raw_spin_unlock_irqrestore(&b->lock, flags); | |
906 | if (l_new) | |
907 | bpf_lru_push_free(&htab->lru, &l_new->lru_node); | |
908 | return ret; | |
909 | } | |
910 | ||
15a07b33 AS |
911 | static int htab_percpu_map_update_elem(struct bpf_map *map, void *key, |
912 | void *value, u64 map_flags) | |
913 | { | |
914 | return __htab_percpu_map_update_elem(map, key, value, map_flags, false); | |
915 | } | |
916 | ||
8f844938 MKL |
917 | static int htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key, |
918 | void *value, u64 map_flags) | |
919 | { | |
920 | return __htab_lru_percpu_map_update_elem(map, key, value, map_flags, | |
921 | false); | |
922 | } | |
923 | ||
0f8e4bd8 AS |
924 | /* Called from syscall or from eBPF program */ |
925 | static int htab_map_delete_elem(struct bpf_map *map, void *key) | |
926 | { | |
927 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | |
928 | struct hlist_head *head; | |
688ecfe6 | 929 | struct bucket *b; |
0f8e4bd8 AS |
930 | struct htab_elem *l; |
931 | unsigned long flags; | |
932 | u32 hash, key_size; | |
933 | int ret = -ENOENT; | |
934 | ||
935 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
936 | ||
937 | key_size = map->key_size; | |
938 | ||
939 | hash = htab_map_hash(key, key_size); | |
688ecfe6 | 940 | b = __select_bucket(htab, hash); |
941 | head = &b->head; | |
0f8e4bd8 | 942 | |
688ecfe6 | 943 | raw_spin_lock_irqsave(&b->lock, flags); |
0f8e4bd8 | 944 | |
0f8e4bd8 AS |
945 | l = lookup_elem_raw(head, hash, key, key_size); |
946 | ||
947 | if (l) { | |
948 | hlist_del_rcu(&l->hash_node); | |
6c905981 | 949 | free_htab_elem(htab, l); |
0f8e4bd8 AS |
950 | ret = 0; |
951 | } | |
952 | ||
688ecfe6 | 953 | raw_spin_unlock_irqrestore(&b->lock, flags); |
0f8e4bd8 AS |
954 | return ret; |
955 | } | |
956 | ||
29ba732a MKL |
957 | static int htab_lru_map_delete_elem(struct bpf_map *map, void *key) |
958 | { | |
959 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | |
960 | struct hlist_head *head; | |
961 | struct bucket *b; | |
962 | struct htab_elem *l; | |
963 | unsigned long flags; | |
964 | u32 hash, key_size; | |
965 | int ret = -ENOENT; | |
966 | ||
967 | WARN_ON_ONCE(!rcu_read_lock_held()); | |
968 | ||
969 | key_size = map->key_size; | |
970 | ||
971 | hash = htab_map_hash(key, key_size); | |
972 | b = __select_bucket(htab, hash); | |
973 | head = &b->head; | |
974 | ||
975 | raw_spin_lock_irqsave(&b->lock, flags); | |
976 | ||
977 | l = lookup_elem_raw(head, hash, key, key_size); | |
978 | ||
979 | if (l) { | |
980 | hlist_del_rcu(&l->hash_node); | |
981 | ret = 0; | |
982 | } | |
983 | ||
984 | raw_spin_unlock_irqrestore(&b->lock, flags); | |
985 | if (l) | |
986 | bpf_lru_push_free(&htab->lru, &l->lru_node); | |
987 | return ret; | |
988 | } | |
989 | ||
0f8e4bd8 AS |
990 | static void delete_all_elements(struct bpf_htab *htab) |
991 | { | |
992 | int i; | |
993 | ||
994 | for (i = 0; i < htab->n_buckets; i++) { | |
995 | struct hlist_head *head = select_bucket(htab, i); | |
996 | struct hlist_node *n; | |
997 | struct htab_elem *l; | |
998 | ||
999 | hlist_for_each_entry_safe(l, n, head, hash_node) { | |
1000 | hlist_del_rcu(&l->hash_node); | |
483bed2b DB |
1001 | if (l->state != HTAB_EXTRA_ELEM_USED) |
1002 | htab_elem_free(htab, l); | |
0f8e4bd8 AS |
1003 | } |
1004 | } | |
1005 | } | |
0f8e4bd8 AS |
1006 | /* Called when map->refcnt goes to zero, either from workqueue or from syscall */ |
1007 | static void htab_map_free(struct bpf_map *map) | |
1008 | { | |
1009 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | |
1010 | ||
1011 | /* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0, | |
1012 | * so the programs (can be more than one that used this map) were | |
1013 | * disconnected from events. Wait for outstanding critical sections in | |
1014 | * these programs to complete | |
1015 | */ | |
1016 | synchronize_rcu(); | |
1017 | ||
6c905981 AS |
1018 | /* some of free_htab_elem() callbacks for elements of this map may |
1019 | * not have executed. Wait for them. | |
0f8e4bd8 | 1020 | */ |
6c905981 | 1021 | rcu_barrier(); |
29ba732a | 1022 | if (htab->map.map_flags & BPF_F_NO_PREALLOC) |
6c905981 | 1023 | delete_all_elements(htab); |
29ba732a MKL |
1024 | else |
1025 | prealloc_destroy(htab); | |
1026 | ||
a6ed3ea6 | 1027 | free_percpu(htab->extra_elems); |
d407bd25 | 1028 | bpf_map_area_free(htab->buckets); |
0f8e4bd8 AS |
1029 | kfree(htab); |
1030 | } | |
1031 | ||
a2c83fff | 1032 | static const struct bpf_map_ops htab_ops = { |
0f8e4bd8 AS |
1033 | .map_alloc = htab_map_alloc, |
1034 | .map_free = htab_map_free, | |
1035 | .map_get_next_key = htab_map_get_next_key, | |
1036 | .map_lookup_elem = htab_map_lookup_elem, | |
1037 | .map_update_elem = htab_map_update_elem, | |
1038 | .map_delete_elem = htab_map_delete_elem, | |
1039 | }; | |
1040 | ||
c78f8bdf | 1041 | static struct bpf_map_type_list htab_type __ro_after_init = { |
0f8e4bd8 AS |
1042 | .ops = &htab_ops, |
1043 | .type = BPF_MAP_TYPE_HASH, | |
1044 | }; | |
1045 | ||
29ba732a MKL |
1046 | static const struct bpf_map_ops htab_lru_ops = { |
1047 | .map_alloc = htab_map_alloc, | |
1048 | .map_free = htab_map_free, | |
1049 | .map_get_next_key = htab_map_get_next_key, | |
1050 | .map_lookup_elem = htab_lru_map_lookup_elem, | |
1051 | .map_update_elem = htab_lru_map_update_elem, | |
1052 | .map_delete_elem = htab_lru_map_delete_elem, | |
1053 | }; | |
1054 | ||
c78f8bdf | 1055 | static struct bpf_map_type_list htab_lru_type __ro_after_init = { |
29ba732a MKL |
1056 | .ops = &htab_lru_ops, |
1057 | .type = BPF_MAP_TYPE_LRU_HASH, | |
1058 | }; | |
1059 | ||
824bd0ce AS |
1060 | /* Called from eBPF program */ |
1061 | static void *htab_percpu_map_lookup_elem(struct bpf_map *map, void *key) | |
1062 | { | |
1063 | struct htab_elem *l = __htab_map_lookup_elem(map, key); | |
1064 | ||
1065 | if (l) | |
1066 | return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size)); | |
1067 | else | |
1068 | return NULL; | |
1069 | } | |
1070 | ||
8f844938 MKL |
1071 | static void *htab_lru_percpu_map_lookup_elem(struct bpf_map *map, void *key) |
1072 | { | |
1073 | struct htab_elem *l = __htab_map_lookup_elem(map, key); | |
1074 | ||
1075 | if (l) { | |
1076 | bpf_lru_node_set_ref(&l->lru_node); | |
1077 | return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size)); | |
1078 | } | |
1079 | ||
1080 | return NULL; | |
1081 | } | |
1082 | ||
15a07b33 AS |
1083 | int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value) |
1084 | { | |
8f844938 | 1085 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
15a07b33 AS |
1086 | struct htab_elem *l; |
1087 | void __percpu *pptr; | |
1088 | int ret = -ENOENT; | |
1089 | int cpu, off = 0; | |
1090 | u32 size; | |
1091 | ||
1092 | /* per_cpu areas are zero-filled and bpf programs can only | |
1093 | * access 'value_size' of them, so copying rounded areas | |
1094 | * will not leak any kernel data | |
1095 | */ | |
1096 | size = round_up(map->value_size, 8); | |
1097 | rcu_read_lock(); | |
1098 | l = __htab_map_lookup_elem(map, key); | |
1099 | if (!l) | |
1100 | goto out; | |
8f844938 MKL |
1101 | if (htab_is_lru(htab)) |
1102 | bpf_lru_node_set_ref(&l->lru_node); | |
15a07b33 AS |
1103 | pptr = htab_elem_get_ptr(l, map->key_size); |
1104 | for_each_possible_cpu(cpu) { | |
1105 | bpf_long_memcpy(value + off, | |
1106 | per_cpu_ptr(pptr, cpu), size); | |
1107 | off += size; | |
1108 | } | |
1109 | ret = 0; | |
1110 | out: | |
1111 | rcu_read_unlock(); | |
1112 | return ret; | |
1113 | } | |
1114 | ||
1115 | int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value, | |
1116 | u64 map_flags) | |
1117 | { | |
8f844938 | 1118 | struct bpf_htab *htab = container_of(map, struct bpf_htab, map); |
6bbd9a05 SL |
1119 | int ret; |
1120 | ||
1121 | rcu_read_lock(); | |
8f844938 MKL |
1122 | if (htab_is_lru(htab)) |
1123 | ret = __htab_lru_percpu_map_update_elem(map, key, value, | |
1124 | map_flags, true); | |
1125 | else | |
1126 | ret = __htab_percpu_map_update_elem(map, key, value, map_flags, | |
1127 | true); | |
6bbd9a05 SL |
1128 | rcu_read_unlock(); |
1129 | ||
1130 | return ret; | |
15a07b33 AS |
1131 | } |
1132 | ||
824bd0ce AS |
1133 | static const struct bpf_map_ops htab_percpu_ops = { |
1134 | .map_alloc = htab_map_alloc, | |
1135 | .map_free = htab_map_free, | |
1136 | .map_get_next_key = htab_map_get_next_key, | |
1137 | .map_lookup_elem = htab_percpu_map_lookup_elem, | |
1138 | .map_update_elem = htab_percpu_map_update_elem, | |
1139 | .map_delete_elem = htab_map_delete_elem, | |
1140 | }; | |
1141 | ||
c78f8bdf | 1142 | static struct bpf_map_type_list htab_percpu_type __ro_after_init = { |
824bd0ce AS |
1143 | .ops = &htab_percpu_ops, |
1144 | .type = BPF_MAP_TYPE_PERCPU_HASH, | |
1145 | }; | |
1146 | ||
8f844938 MKL |
1147 | static const struct bpf_map_ops htab_lru_percpu_ops = { |
1148 | .map_alloc = htab_map_alloc, | |
1149 | .map_free = htab_map_free, | |
1150 | .map_get_next_key = htab_map_get_next_key, | |
1151 | .map_lookup_elem = htab_lru_percpu_map_lookup_elem, | |
1152 | .map_update_elem = htab_lru_percpu_map_update_elem, | |
1153 | .map_delete_elem = htab_lru_map_delete_elem, | |
1154 | }; | |
1155 | ||
c78f8bdf | 1156 | static struct bpf_map_type_list htab_lru_percpu_type __ro_after_init = { |
8f844938 MKL |
1157 | .ops = &htab_lru_percpu_ops, |
1158 | .type = BPF_MAP_TYPE_LRU_PERCPU_HASH, | |
1159 | }; | |
1160 | ||
0f8e4bd8 AS |
1161 | static int __init register_htab_map(void) |
1162 | { | |
a2c83fff | 1163 | bpf_register_map_type(&htab_type); |
824bd0ce | 1164 | bpf_register_map_type(&htab_percpu_type); |
29ba732a | 1165 | bpf_register_map_type(&htab_lru_type); |
8f844938 | 1166 | bpf_register_map_type(&htab_lru_percpu_type); |
0f8e4bd8 AS |
1167 | return 0; |
1168 | } | |
1169 | late_initcall(register_htab_map); |