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1// SPDX-License-Identifier: GPL-2.0
2#include <linux/bpf-cgroup.h>
3#include <linux/bpf.h>
4#include <linux/bpf_local_storage.h>
5#include <linux/btf.h>
6#include <linux/bug.h>
7#include <linux/filter.h>
8#include <linux/mm.h>
9#include <linux/rbtree.h>
10#include <linux/slab.h>
11#include <uapi/linux/btf.h>
12#include <linux/btf_ids.h>
13
14#ifdef CONFIG_CGROUP_BPF
15
16#include "../cgroup/cgroup-internal.h"
17
18#define LOCAL_STORAGE_CREATE_FLAG_MASK \
19 (BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)
20
21struct bpf_cgroup_storage_map {
22 struct bpf_map map;
23
24 spinlock_t lock;
25 struct rb_root root;
26 struct list_head list;
27};
28
29static struct bpf_cgroup_storage_map *map_to_storage(struct bpf_map *map)
30{
31 return container_of(map, struct bpf_cgroup_storage_map, map);
32}
33
34static bool attach_type_isolated(const struct bpf_map *map)
35{
36 return map->key_size == sizeof(struct bpf_cgroup_storage_key);
37}
38
39static int bpf_cgroup_storage_key_cmp(const struct bpf_cgroup_storage_map *map,
40 const void *_key1, const void *_key2)
41{
42 if (attach_type_isolated(&map->map)) {
43 const struct bpf_cgroup_storage_key *key1 = _key1;
44 const struct bpf_cgroup_storage_key *key2 = _key2;
45
46 if (key1->cgroup_inode_id < key2->cgroup_inode_id)
47 return -1;
48 else if (key1->cgroup_inode_id > key2->cgroup_inode_id)
49 return 1;
50 else if (key1->attach_type < key2->attach_type)
51 return -1;
52 else if (key1->attach_type > key2->attach_type)
53 return 1;
54 } else {
55 const __u64 *cgroup_inode_id1 = _key1;
56 const __u64 *cgroup_inode_id2 = _key2;
57
58 if (*cgroup_inode_id1 < *cgroup_inode_id2)
59 return -1;
60 else if (*cgroup_inode_id1 > *cgroup_inode_id2)
61 return 1;
62 }
63 return 0;
64}
65
66struct bpf_cgroup_storage *
67cgroup_storage_lookup(struct bpf_cgroup_storage_map *map,
68 void *key, bool locked)
69{
70 struct rb_root *root = &map->root;
71 struct rb_node *node;
72
73 if (!locked)
74 spin_lock_bh(&map->lock);
75
76 node = root->rb_node;
77 while (node) {
78 struct bpf_cgroup_storage *storage;
79
80 storage = container_of(node, struct bpf_cgroup_storage, node);
81
82 switch (bpf_cgroup_storage_key_cmp(map, key, &storage->key)) {
83 case -1:
84 node = node->rb_left;
85 break;
86 case 1:
87 node = node->rb_right;
88 break;
89 default:
90 if (!locked)
91 spin_unlock_bh(&map->lock);
92 return storage;
93 }
94 }
95
96 if (!locked)
97 spin_unlock_bh(&map->lock);
98
99 return NULL;
100}
101
102static int cgroup_storage_insert(struct bpf_cgroup_storage_map *map,
103 struct bpf_cgroup_storage *storage)
104{
105 struct rb_root *root = &map->root;
106 struct rb_node **new = &(root->rb_node), *parent = NULL;
107
108 while (*new) {
109 struct bpf_cgroup_storage *this;
110
111 this = container_of(*new, struct bpf_cgroup_storage, node);
112
113 parent = *new;
114 switch (bpf_cgroup_storage_key_cmp(map, &storage->key, &this->key)) {
115 case -1:
116 new = &((*new)->rb_left);
117 break;
118 case 1:
119 new = &((*new)->rb_right);
120 break;
121 default:
122 return -EEXIST;
123 }
124 }
125
126 rb_link_node(&storage->node, parent, new);
127 rb_insert_color(&storage->node, root);
128
129 return 0;
130}
131
132static void *cgroup_storage_lookup_elem(struct bpf_map *_map, void *key)
133{
134 struct bpf_cgroup_storage_map *map = map_to_storage(_map);
135 struct bpf_cgroup_storage *storage;
136
137 storage = cgroup_storage_lookup(map, key, false);
138 if (!storage)
139 return NULL;
140
141 return &READ_ONCE(storage->buf)->data[0];
142}
143
144static int cgroup_storage_update_elem(struct bpf_map *map, void *key,
145 void *value, u64 flags)
146{
147 struct bpf_cgroup_storage *storage;
148 struct bpf_storage_buffer *new;
149
150 if (unlikely(flags & ~(BPF_F_LOCK | BPF_EXIST)))
151 return -EINVAL;
152
153 if (unlikely((flags & BPF_F_LOCK) &&
154 !btf_record_has_field(map->record, BPF_SPIN_LOCK)))
155 return -EINVAL;
156
157 storage = cgroup_storage_lookup((struct bpf_cgroup_storage_map *)map,
158 key, false);
159 if (!storage)
160 return -ENOENT;
161
162 if (flags & BPF_F_LOCK) {
163 copy_map_value_locked(map, storage->buf->data, value, false);
164 return 0;
165 }
166
167 new = bpf_map_kmalloc_node(map, struct_size(new, data, map->value_size),
168 __GFP_ZERO | GFP_NOWAIT | __GFP_NOWARN,
169 map->numa_node);
170 if (!new)
171 return -ENOMEM;
172
173 memcpy(&new->data[0], value, map->value_size);
174 check_and_init_map_value(map, new->data);
175
176 new = xchg(&storage->buf, new);
177 kfree_rcu(new, rcu);
178
179 return 0;
180}
181
182int bpf_percpu_cgroup_storage_copy(struct bpf_map *_map, void *key,
183 void *value)
184{
185 struct bpf_cgroup_storage_map *map = map_to_storage(_map);
186 struct bpf_cgroup_storage *storage;
187 int cpu, off = 0;
188 u32 size;
189
190 rcu_read_lock();
191 storage = cgroup_storage_lookup(map, key, false);
192 if (!storage) {
193 rcu_read_unlock();
194 return -ENOENT;
195 }
196
197 /* per_cpu areas are zero-filled and bpf programs can only
198 * access 'value_size' of them, so copying rounded areas
199 * will not leak any kernel data
200 */
201 size = round_up(_map->value_size, 8);
202 for_each_possible_cpu(cpu) {
203 bpf_long_memcpy(value + off,
204 per_cpu_ptr(storage->percpu_buf, cpu), size);
205 off += size;
206 }
207 rcu_read_unlock();
208 return 0;
209}
210
211int bpf_percpu_cgroup_storage_update(struct bpf_map *_map, void *key,
212 void *value, u64 map_flags)
213{
214 struct bpf_cgroup_storage_map *map = map_to_storage(_map);
215 struct bpf_cgroup_storage *storage;
216 int cpu, off = 0;
217 u32 size;
218
219 if (map_flags != BPF_ANY && map_flags != BPF_EXIST)
220 return -EINVAL;
221
222 rcu_read_lock();
223 storage = cgroup_storage_lookup(map, key, false);
224 if (!storage) {
225 rcu_read_unlock();
226 return -ENOENT;
227 }
228
229 /* the user space will provide round_up(value_size, 8) bytes that
230 * will be copied into per-cpu area. bpf programs can only access
231 * value_size of it. During lookup the same extra bytes will be
232 * returned or zeros which were zero-filled by percpu_alloc,
233 * so no kernel data leaks possible
234 */
235 size = round_up(_map->value_size, 8);
236 for_each_possible_cpu(cpu) {
237 bpf_long_memcpy(per_cpu_ptr(storage->percpu_buf, cpu),
238 value + off, size);
239 off += size;
240 }
241 rcu_read_unlock();
242 return 0;
243}
244
245static int cgroup_storage_get_next_key(struct bpf_map *_map, void *key,
246 void *_next_key)
247{
248 struct bpf_cgroup_storage_map *map = map_to_storage(_map);
249 struct bpf_cgroup_storage *storage;
250
251 spin_lock_bh(&map->lock);
252
253 if (list_empty(&map->list))
254 goto enoent;
255
256 if (key) {
257 storage = cgroup_storage_lookup(map, key, true);
258 if (!storage)
259 goto enoent;
260
261 storage = list_next_entry(storage, list_map);
262 if (!storage)
263 goto enoent;
264 } else {
265 storage = list_first_entry(&map->list,
266 struct bpf_cgroup_storage, list_map);
267 }
268
269 spin_unlock_bh(&map->lock);
270
271 if (attach_type_isolated(&map->map)) {
272 struct bpf_cgroup_storage_key *next = _next_key;
273 *next = storage->key;
274 } else {
275 __u64 *next = _next_key;
276 *next = storage->key.cgroup_inode_id;
277 }
278 return 0;
279
280enoent:
281 spin_unlock_bh(&map->lock);
282 return -ENOENT;
283}
284
285static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
286{
287 __u32 max_value_size = BPF_LOCAL_STORAGE_MAX_VALUE_SIZE;
288 int numa_node = bpf_map_attr_numa_node(attr);
289 struct bpf_cgroup_storage_map *map;
290
291 /* percpu is bound by PCPU_MIN_UNIT_SIZE, non-percu
292 * is the same as other local storages.
293 */
294 if (attr->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
295 max_value_size = min_t(__u32, max_value_size,
296 PCPU_MIN_UNIT_SIZE);
297
298 if (attr->key_size != sizeof(struct bpf_cgroup_storage_key) &&
299 attr->key_size != sizeof(__u64))
300 return ERR_PTR(-EINVAL);
301
302 if (attr->value_size == 0)
303 return ERR_PTR(-EINVAL);
304
305 if (attr->value_size > max_value_size)
306 return ERR_PTR(-E2BIG);
307
308 if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK ||
309 !bpf_map_flags_access_ok(attr->map_flags))
310 return ERR_PTR(-EINVAL);
311
312 if (attr->max_entries)
313 /* max_entries is not used and enforced to be 0 */
314 return ERR_PTR(-EINVAL);
315
316 map = bpf_map_area_alloc(sizeof(struct bpf_cgroup_storage_map), numa_node);
317 if (!map)
318 return ERR_PTR(-ENOMEM);
319
320 /* copy mandatory map attributes */
321 bpf_map_init_from_attr(&map->map, attr);
322
323 spin_lock_init(&map->lock);
324 map->root = RB_ROOT;
325 INIT_LIST_HEAD(&map->list);
326
327 return &map->map;
328}
329
330static void cgroup_storage_map_free(struct bpf_map *_map)
331{
332 struct bpf_cgroup_storage_map *map = map_to_storage(_map);
333 struct list_head *storages = &map->list;
334 struct bpf_cgroup_storage *storage, *stmp;
335
336 mutex_lock(&cgroup_mutex);
337
338 list_for_each_entry_safe(storage, stmp, storages, list_map) {
339 bpf_cgroup_storage_unlink(storage);
340 bpf_cgroup_storage_free(storage);
341 }
342
343 mutex_unlock(&cgroup_mutex);
344
345 WARN_ON(!RB_EMPTY_ROOT(&map->root));
346 WARN_ON(!list_empty(&map->list));
347
348 bpf_map_area_free(map);
349}
350
351static int cgroup_storage_delete_elem(struct bpf_map *map, void *key)
352{
353 return -EINVAL;
354}
355
356static int cgroup_storage_check_btf(const struct bpf_map *map,
357 const struct btf *btf,
358 const struct btf_type *key_type,
359 const struct btf_type *value_type)
360{
361 if (attach_type_isolated(map)) {
362 struct btf_member *m;
363 u32 offset, size;
364
365 /* Key is expected to be of struct bpf_cgroup_storage_key type,
366 * which is:
367 * struct bpf_cgroup_storage_key {
368 * __u64 cgroup_inode_id;
369 * __u32 attach_type;
370 * };
371 */
372
373 /*
374 * Key_type must be a structure with two fields.
375 */
376 if (BTF_INFO_KIND(key_type->info) != BTF_KIND_STRUCT ||
377 BTF_INFO_VLEN(key_type->info) != 2)
378 return -EINVAL;
379
380 /*
381 * The first field must be a 64 bit integer at 0 offset.
382 */
383 m = (struct btf_member *)(key_type + 1);
384 size = sizeof_field(struct bpf_cgroup_storage_key, cgroup_inode_id);
385 if (!btf_member_is_reg_int(btf, key_type, m, 0, size))
386 return -EINVAL;
387
388 /*
389 * The second field must be a 32 bit integer at 64 bit offset.
390 */
391 m++;
392 offset = offsetof(struct bpf_cgroup_storage_key, attach_type);
393 size = sizeof_field(struct bpf_cgroup_storage_key, attach_type);
394 if (!btf_member_is_reg_int(btf, key_type, m, offset, size))
395 return -EINVAL;
396 } else {
397 u32 int_data;
398
399 /*
400 * Key is expected to be u64, which stores the cgroup_inode_id
401 */
402
403 if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
404 return -EINVAL;
405
406 int_data = *(u32 *)(key_type + 1);
407 if (BTF_INT_BITS(int_data) != 64 || BTF_INT_OFFSET(int_data))
408 return -EINVAL;
409 }
410
411 return 0;
412}
413
414static void cgroup_storage_seq_show_elem(struct bpf_map *map, void *key,
415 struct seq_file *m)
416{
417 enum bpf_cgroup_storage_type stype;
418 struct bpf_cgroup_storage *storage;
419 int cpu;
420
421 rcu_read_lock();
422 storage = cgroup_storage_lookup(map_to_storage(map), key, false);
423 if (!storage) {
424 rcu_read_unlock();
425 return;
426 }
427
428 btf_type_seq_show(map->btf, map->btf_key_type_id, key, m);
429 stype = cgroup_storage_type(map);
430 if (stype == BPF_CGROUP_STORAGE_SHARED) {
431 seq_puts(m, ": ");
432 btf_type_seq_show(map->btf, map->btf_value_type_id,
433 &READ_ONCE(storage->buf)->data[0], m);
434 seq_puts(m, "\n");
435 } else {
436 seq_puts(m, ": {\n");
437 for_each_possible_cpu(cpu) {
438 seq_printf(m, "\tcpu%d: ", cpu);
439 btf_type_seq_show(map->btf, map->btf_value_type_id,
440 per_cpu_ptr(storage->percpu_buf, cpu),
441 m);
442 seq_puts(m, "\n");
443 }
444 seq_puts(m, "}\n");
445 }
446 rcu_read_unlock();
447}
448
449BTF_ID_LIST_SINGLE(cgroup_storage_map_btf_ids, struct,
450 bpf_cgroup_storage_map)
451const struct bpf_map_ops cgroup_storage_map_ops = {
452 .map_alloc = cgroup_storage_map_alloc,
453 .map_free = cgroup_storage_map_free,
454 .map_get_next_key = cgroup_storage_get_next_key,
455 .map_lookup_elem = cgroup_storage_lookup_elem,
456 .map_update_elem = cgroup_storage_update_elem,
457 .map_delete_elem = cgroup_storage_delete_elem,
458 .map_check_btf = cgroup_storage_check_btf,
459 .map_seq_show_elem = cgroup_storage_seq_show_elem,
460 .map_btf_id = &cgroup_storage_map_btf_ids[0],
461};
462
463int bpf_cgroup_storage_assign(struct bpf_prog_aux *aux, struct bpf_map *_map)
464{
465 enum bpf_cgroup_storage_type stype = cgroup_storage_type(_map);
466
467 if (aux->cgroup_storage[stype] &&
468 aux->cgroup_storage[stype] != _map)
469 return -EBUSY;
470
471 aux->cgroup_storage[stype] = _map;
472 return 0;
473}
474
475static size_t bpf_cgroup_storage_calculate_size(struct bpf_map *map, u32 *pages)
476{
477 size_t size;
478
479 if (cgroup_storage_type(map) == BPF_CGROUP_STORAGE_SHARED) {
480 size = sizeof(struct bpf_storage_buffer) + map->value_size;
481 *pages = round_up(sizeof(struct bpf_cgroup_storage) + size,
482 PAGE_SIZE) >> PAGE_SHIFT;
483 } else {
484 size = map->value_size;
485 *pages = round_up(round_up(size, 8) * num_possible_cpus(),
486 PAGE_SIZE) >> PAGE_SHIFT;
487 }
488
489 return size;
490}
491
492struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(struct bpf_prog *prog,
493 enum bpf_cgroup_storage_type stype)
494{
495 const gfp_t gfp = __GFP_ZERO | GFP_USER;
496 struct bpf_cgroup_storage *storage;
497 struct bpf_map *map;
498 size_t size;
499 u32 pages;
500
501 map = prog->aux->cgroup_storage[stype];
502 if (!map)
503 return NULL;
504
505 size = bpf_cgroup_storage_calculate_size(map, &pages);
506
507 storage = bpf_map_kmalloc_node(map, sizeof(struct bpf_cgroup_storage),
508 gfp, map->numa_node);
509 if (!storage)
510 goto enomem;
511
512 if (stype == BPF_CGROUP_STORAGE_SHARED) {
513 storage->buf = bpf_map_kmalloc_node(map, size, gfp,
514 map->numa_node);
515 if (!storage->buf)
516 goto enomem;
517 check_and_init_map_value(map, storage->buf->data);
518 } else {
519 storage->percpu_buf = bpf_map_alloc_percpu(map, size, 8, gfp);
520 if (!storage->percpu_buf)
521 goto enomem;
522 }
523
524 storage->map = (struct bpf_cgroup_storage_map *)map;
525
526 return storage;
527
528enomem:
529 kfree(storage);
530 return ERR_PTR(-ENOMEM);
531}
532
533static void free_shared_cgroup_storage_rcu(struct rcu_head *rcu)
534{
535 struct bpf_cgroup_storage *storage =
536 container_of(rcu, struct bpf_cgroup_storage, rcu);
537
538 kfree(storage->buf);
539 kfree(storage);
540}
541
542static void free_percpu_cgroup_storage_rcu(struct rcu_head *rcu)
543{
544 struct bpf_cgroup_storage *storage =
545 container_of(rcu, struct bpf_cgroup_storage, rcu);
546
547 free_percpu(storage->percpu_buf);
548 kfree(storage);
549}
550
551void bpf_cgroup_storage_free(struct bpf_cgroup_storage *storage)
552{
553 enum bpf_cgroup_storage_type stype;
554 struct bpf_map *map;
555
556 if (!storage)
557 return;
558
559 map = &storage->map->map;
560 stype = cgroup_storage_type(map);
561 if (stype == BPF_CGROUP_STORAGE_SHARED)
562 call_rcu(&storage->rcu, free_shared_cgroup_storage_rcu);
563 else
564 call_rcu(&storage->rcu, free_percpu_cgroup_storage_rcu);
565}
566
567void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage,
568 struct cgroup *cgroup,
569 enum bpf_attach_type type)
570{
571 struct bpf_cgroup_storage_map *map;
572
573 if (!storage)
574 return;
575
576 storage->key.attach_type = type;
577 storage->key.cgroup_inode_id = cgroup_id(cgroup);
578
579 map = storage->map;
580
581 spin_lock_bh(&map->lock);
582 WARN_ON(cgroup_storage_insert(map, storage));
583 list_add(&storage->list_map, &map->list);
584 list_add(&storage->list_cg, &cgroup->bpf.storages);
585 spin_unlock_bh(&map->lock);
586}
587
588void bpf_cgroup_storage_unlink(struct bpf_cgroup_storage *storage)
589{
590 struct bpf_cgroup_storage_map *map;
591 struct rb_root *root;
592
593 if (!storage)
594 return;
595
596 map = storage->map;
597
598 spin_lock_bh(&map->lock);
599 root = &map->root;
600 rb_erase(&storage->node, root);
601
602 list_del(&storage->list_map);
603 list_del(&storage->list_cg);
604 spin_unlock_bh(&map->lock);
605}
606
607#endif
1//SPDX-License-Identifier: GPL-2.0
2#include <linux/bpf-cgroup.h>
3#include <linux/bpf.h>
4#include <linux/btf.h>
5#include <linux/bug.h>
6#include <linux/filter.h>
7#include <linux/mm.h>
8#include <linux/rbtree.h>
9#include <linux/slab.h>
10#include <uapi/linux/btf.h>
11
12DEFINE_PER_CPU(struct bpf_cgroup_storage*, bpf_cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]);
13
14#ifdef CONFIG_CGROUP_BPF
15
16#include "../cgroup/cgroup-internal.h"
17
18#define LOCAL_STORAGE_CREATE_FLAG_MASK \
19 (BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)
20
21struct bpf_cgroup_storage_map {
22 struct bpf_map map;
23
24 spinlock_t lock;
25 struct rb_root root;
26 struct list_head list;
27};
28
29static struct bpf_cgroup_storage_map *map_to_storage(struct bpf_map *map)
30{
31 return container_of(map, struct bpf_cgroup_storage_map, map);
32}
33
34static bool attach_type_isolated(const struct bpf_map *map)
35{
36 return map->key_size == sizeof(struct bpf_cgroup_storage_key);
37}
38
39static int bpf_cgroup_storage_key_cmp(const struct bpf_cgroup_storage_map *map,
40 const void *_key1, const void *_key2)
41{
42 if (attach_type_isolated(&map->map)) {
43 const struct bpf_cgroup_storage_key *key1 = _key1;
44 const struct bpf_cgroup_storage_key *key2 = _key2;
45
46 if (key1->cgroup_inode_id < key2->cgroup_inode_id)
47 return -1;
48 else if (key1->cgroup_inode_id > key2->cgroup_inode_id)
49 return 1;
50 else if (key1->attach_type < key2->attach_type)
51 return -1;
52 else if (key1->attach_type > key2->attach_type)
53 return 1;
54 } else {
55 const __u64 *cgroup_inode_id1 = _key1;
56 const __u64 *cgroup_inode_id2 = _key2;
57
58 if (*cgroup_inode_id1 < *cgroup_inode_id2)
59 return -1;
60 else if (*cgroup_inode_id1 > *cgroup_inode_id2)
61 return 1;
62 }
63 return 0;
64}
65
66struct bpf_cgroup_storage *
67cgroup_storage_lookup(struct bpf_cgroup_storage_map *map,
68 void *key, bool locked)
69{
70 struct rb_root *root = &map->root;
71 struct rb_node *node;
72
73 if (!locked)
74 spin_lock_bh(&map->lock);
75
76 node = root->rb_node;
77 while (node) {
78 struct bpf_cgroup_storage *storage;
79
80 storage = container_of(node, struct bpf_cgroup_storage, node);
81
82 switch (bpf_cgroup_storage_key_cmp(map, key, &storage->key)) {
83 case -1:
84 node = node->rb_left;
85 break;
86 case 1:
87 node = node->rb_right;
88 break;
89 default:
90 if (!locked)
91 spin_unlock_bh(&map->lock);
92 return storage;
93 }
94 }
95
96 if (!locked)
97 spin_unlock_bh(&map->lock);
98
99 return NULL;
100}
101
102static int cgroup_storage_insert(struct bpf_cgroup_storage_map *map,
103 struct bpf_cgroup_storage *storage)
104{
105 struct rb_root *root = &map->root;
106 struct rb_node **new = &(root->rb_node), *parent = NULL;
107
108 while (*new) {
109 struct bpf_cgroup_storage *this;
110
111 this = container_of(*new, struct bpf_cgroup_storage, node);
112
113 parent = *new;
114 switch (bpf_cgroup_storage_key_cmp(map, &storage->key, &this->key)) {
115 case -1:
116 new = &((*new)->rb_left);
117 break;
118 case 1:
119 new = &((*new)->rb_right);
120 break;
121 default:
122 return -EEXIST;
123 }
124 }
125
126 rb_link_node(&storage->node, parent, new);
127 rb_insert_color(&storage->node, root);
128
129 return 0;
130}
131
132static void *cgroup_storage_lookup_elem(struct bpf_map *_map, void *key)
133{
134 struct bpf_cgroup_storage_map *map = map_to_storage(_map);
135 struct bpf_cgroup_storage *storage;
136
137 storage = cgroup_storage_lookup(map, key, false);
138 if (!storage)
139 return NULL;
140
141 return &READ_ONCE(storage->buf)->data[0];
142}
143
144static int cgroup_storage_update_elem(struct bpf_map *map, void *key,
145 void *value, u64 flags)
146{
147 struct bpf_cgroup_storage *storage;
148 struct bpf_storage_buffer *new;
149
150 if (unlikely(flags & ~(BPF_F_LOCK | BPF_EXIST)))
151 return -EINVAL;
152
153 if (unlikely((flags & BPF_F_LOCK) &&
154 !map_value_has_spin_lock(map)))
155 return -EINVAL;
156
157 storage = cgroup_storage_lookup((struct bpf_cgroup_storage_map *)map,
158 key, false);
159 if (!storage)
160 return -ENOENT;
161
162 if (flags & BPF_F_LOCK) {
163 copy_map_value_locked(map, storage->buf->data, value, false);
164 return 0;
165 }
166
167 new = kmalloc_node(sizeof(struct bpf_storage_buffer) +
168 map->value_size,
169 __GFP_ZERO | GFP_ATOMIC | __GFP_NOWARN,
170 map->numa_node);
171 if (!new)
172 return -ENOMEM;
173
174 memcpy(&new->data[0], value, map->value_size);
175 check_and_init_map_lock(map, new->data);
176
177 new = xchg(&storage->buf, new);
178 kfree_rcu(new, rcu);
179
180 return 0;
181}
182
183int bpf_percpu_cgroup_storage_copy(struct bpf_map *_map, void *key,
184 void *value)
185{
186 struct bpf_cgroup_storage_map *map = map_to_storage(_map);
187 struct bpf_cgroup_storage *storage;
188 int cpu, off = 0;
189 u32 size;
190
191 rcu_read_lock();
192 storage = cgroup_storage_lookup(map, key, false);
193 if (!storage) {
194 rcu_read_unlock();
195 return -ENOENT;
196 }
197
198 /* per_cpu areas are zero-filled and bpf programs can only
199 * access 'value_size' of them, so copying rounded areas
200 * will not leak any kernel data
201 */
202 size = round_up(_map->value_size, 8);
203 for_each_possible_cpu(cpu) {
204 bpf_long_memcpy(value + off,
205 per_cpu_ptr(storage->percpu_buf, cpu), size);
206 off += size;
207 }
208 rcu_read_unlock();
209 return 0;
210}
211
212int bpf_percpu_cgroup_storage_update(struct bpf_map *_map, void *key,
213 void *value, u64 map_flags)
214{
215 struct bpf_cgroup_storage_map *map = map_to_storage(_map);
216 struct bpf_cgroup_storage *storage;
217 int cpu, off = 0;
218 u32 size;
219
220 if (map_flags != BPF_ANY && map_flags != BPF_EXIST)
221 return -EINVAL;
222
223 rcu_read_lock();
224 storage = cgroup_storage_lookup(map, key, false);
225 if (!storage) {
226 rcu_read_unlock();
227 return -ENOENT;
228 }
229
230 /* the user space will provide round_up(value_size, 8) bytes that
231 * will be copied into per-cpu area. bpf programs can only access
232 * value_size of it. During lookup the same extra bytes will be
233 * returned or zeros which were zero-filled by percpu_alloc,
234 * so no kernel data leaks possible
235 */
236 size = round_up(_map->value_size, 8);
237 for_each_possible_cpu(cpu) {
238 bpf_long_memcpy(per_cpu_ptr(storage->percpu_buf, cpu),
239 value + off, size);
240 off += size;
241 }
242 rcu_read_unlock();
243 return 0;
244}
245
246static int cgroup_storage_get_next_key(struct bpf_map *_map, void *key,
247 void *_next_key)
248{
249 struct bpf_cgroup_storage_map *map = map_to_storage(_map);
250 struct bpf_cgroup_storage *storage;
251
252 spin_lock_bh(&map->lock);
253
254 if (list_empty(&map->list))
255 goto enoent;
256
257 if (key) {
258 storage = cgroup_storage_lookup(map, key, true);
259 if (!storage)
260 goto enoent;
261
262 storage = list_next_entry(storage, list_map);
263 if (!storage)
264 goto enoent;
265 } else {
266 storage = list_first_entry(&map->list,
267 struct bpf_cgroup_storage, list_map);
268 }
269
270 spin_unlock_bh(&map->lock);
271
272 if (attach_type_isolated(&map->map)) {
273 struct bpf_cgroup_storage_key *next = _next_key;
274 *next = storage->key;
275 } else {
276 __u64 *next = _next_key;
277 *next = storage->key.cgroup_inode_id;
278 }
279 return 0;
280
281enoent:
282 spin_unlock_bh(&map->lock);
283 return -ENOENT;
284}
285
286static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
287{
288 int numa_node = bpf_map_attr_numa_node(attr);
289 struct bpf_cgroup_storage_map *map;
290 struct bpf_map_memory mem;
291 int ret;
292
293 if (attr->key_size != sizeof(struct bpf_cgroup_storage_key) &&
294 attr->key_size != sizeof(__u64))
295 return ERR_PTR(-EINVAL);
296
297 if (attr->value_size == 0)
298 return ERR_PTR(-EINVAL);
299
300 if (attr->value_size > PAGE_SIZE)
301 return ERR_PTR(-E2BIG);
302
303 if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK ||
304 !bpf_map_flags_access_ok(attr->map_flags))
305 return ERR_PTR(-EINVAL);
306
307 if (attr->max_entries)
308 /* max_entries is not used and enforced to be 0 */
309 return ERR_PTR(-EINVAL);
310
311 ret = bpf_map_charge_init(&mem, sizeof(struct bpf_cgroup_storage_map));
312 if (ret < 0)
313 return ERR_PTR(ret);
314
315 map = kmalloc_node(sizeof(struct bpf_cgroup_storage_map),
316 __GFP_ZERO | GFP_USER, numa_node);
317 if (!map) {
318 bpf_map_charge_finish(&mem);
319 return ERR_PTR(-ENOMEM);
320 }
321
322 bpf_map_charge_move(&map->map.memory, &mem);
323
324 /* copy mandatory map attributes */
325 bpf_map_init_from_attr(&map->map, attr);
326
327 spin_lock_init(&map->lock);
328 map->root = RB_ROOT;
329 INIT_LIST_HEAD(&map->list);
330
331 return &map->map;
332}
333
334static void cgroup_storage_map_free(struct bpf_map *_map)
335{
336 struct bpf_cgroup_storage_map *map = map_to_storage(_map);
337 struct list_head *storages = &map->list;
338 struct bpf_cgroup_storage *storage, *stmp;
339
340 mutex_lock(&cgroup_mutex);
341
342 list_for_each_entry_safe(storage, stmp, storages, list_map) {
343 bpf_cgroup_storage_unlink(storage);
344 bpf_cgroup_storage_free(storage);
345 }
346
347 mutex_unlock(&cgroup_mutex);
348
349 WARN_ON(!RB_EMPTY_ROOT(&map->root));
350 WARN_ON(!list_empty(&map->list));
351
352 kfree(map);
353}
354
355static int cgroup_storage_delete_elem(struct bpf_map *map, void *key)
356{
357 return -EINVAL;
358}
359
360static int cgroup_storage_check_btf(const struct bpf_map *map,
361 const struct btf *btf,
362 const struct btf_type *key_type,
363 const struct btf_type *value_type)
364{
365 if (attach_type_isolated(map)) {
366 struct btf_member *m;
367 u32 offset, size;
368
369 /* Key is expected to be of struct bpf_cgroup_storage_key type,
370 * which is:
371 * struct bpf_cgroup_storage_key {
372 * __u64 cgroup_inode_id;
373 * __u32 attach_type;
374 * };
375 */
376
377 /*
378 * Key_type must be a structure with two fields.
379 */
380 if (BTF_INFO_KIND(key_type->info) != BTF_KIND_STRUCT ||
381 BTF_INFO_VLEN(key_type->info) != 2)
382 return -EINVAL;
383
384 /*
385 * The first field must be a 64 bit integer at 0 offset.
386 */
387 m = (struct btf_member *)(key_type + 1);
388 size = sizeof_field(struct bpf_cgroup_storage_key, cgroup_inode_id);
389 if (!btf_member_is_reg_int(btf, key_type, m, 0, size))
390 return -EINVAL;
391
392 /*
393 * The second field must be a 32 bit integer at 64 bit offset.
394 */
395 m++;
396 offset = offsetof(struct bpf_cgroup_storage_key, attach_type);
397 size = sizeof_field(struct bpf_cgroup_storage_key, attach_type);
398 if (!btf_member_is_reg_int(btf, key_type, m, offset, size))
399 return -EINVAL;
400 } else {
401 u32 int_data;
402
403 /*
404 * Key is expected to be u64, which stores the cgroup_inode_id
405 */
406
407 if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
408 return -EINVAL;
409
410 int_data = *(u32 *)(key_type + 1);
411 if (BTF_INT_BITS(int_data) != 64 || BTF_INT_OFFSET(int_data))
412 return -EINVAL;
413 }
414
415 return 0;
416}
417
418static void cgroup_storage_seq_show_elem(struct bpf_map *map, void *key,
419 struct seq_file *m)
420{
421 enum bpf_cgroup_storage_type stype = cgroup_storage_type(map);
422 struct bpf_cgroup_storage *storage;
423 int cpu;
424
425 rcu_read_lock();
426 storage = cgroup_storage_lookup(map_to_storage(map), key, false);
427 if (!storage) {
428 rcu_read_unlock();
429 return;
430 }
431
432 btf_type_seq_show(map->btf, map->btf_key_type_id, key, m);
433 stype = cgroup_storage_type(map);
434 if (stype == BPF_CGROUP_STORAGE_SHARED) {
435 seq_puts(m, ": ");
436 btf_type_seq_show(map->btf, map->btf_value_type_id,
437 &READ_ONCE(storage->buf)->data[0], m);
438 seq_puts(m, "\n");
439 } else {
440 seq_puts(m, ": {\n");
441 for_each_possible_cpu(cpu) {
442 seq_printf(m, "\tcpu%d: ", cpu);
443 btf_type_seq_show(map->btf, map->btf_value_type_id,
444 per_cpu_ptr(storage->percpu_buf, cpu),
445 m);
446 seq_puts(m, "\n");
447 }
448 seq_puts(m, "}\n");
449 }
450 rcu_read_unlock();
451}
452
453static int cgroup_storage_map_btf_id;
454const struct bpf_map_ops cgroup_storage_map_ops = {
455 .map_alloc = cgroup_storage_map_alloc,
456 .map_free = cgroup_storage_map_free,
457 .map_get_next_key = cgroup_storage_get_next_key,
458 .map_lookup_elem = cgroup_storage_lookup_elem,
459 .map_update_elem = cgroup_storage_update_elem,
460 .map_delete_elem = cgroup_storage_delete_elem,
461 .map_check_btf = cgroup_storage_check_btf,
462 .map_seq_show_elem = cgroup_storage_seq_show_elem,
463 .map_btf_name = "bpf_cgroup_storage_map",
464 .map_btf_id = &cgroup_storage_map_btf_id,
465};
466
467int bpf_cgroup_storage_assign(struct bpf_prog_aux *aux, struct bpf_map *_map)
468{
469 enum bpf_cgroup_storage_type stype = cgroup_storage_type(_map);
470
471 if (aux->cgroup_storage[stype] &&
472 aux->cgroup_storage[stype] != _map)
473 return -EBUSY;
474
475 aux->cgroup_storage[stype] = _map;
476 return 0;
477}
478
479static size_t bpf_cgroup_storage_calculate_size(struct bpf_map *map, u32 *pages)
480{
481 size_t size;
482
483 if (cgroup_storage_type(map) == BPF_CGROUP_STORAGE_SHARED) {
484 size = sizeof(struct bpf_storage_buffer) + map->value_size;
485 *pages = round_up(sizeof(struct bpf_cgroup_storage) + size,
486 PAGE_SIZE) >> PAGE_SHIFT;
487 } else {
488 size = map->value_size;
489 *pages = round_up(round_up(size, 8) * num_possible_cpus(),
490 PAGE_SIZE) >> PAGE_SHIFT;
491 }
492
493 return size;
494}
495
496struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(struct bpf_prog *prog,
497 enum bpf_cgroup_storage_type stype)
498{
499 struct bpf_cgroup_storage *storage;
500 struct bpf_map *map;
501 gfp_t flags;
502 size_t size;
503 u32 pages;
504
505 map = prog->aux->cgroup_storage[stype];
506 if (!map)
507 return NULL;
508
509 size = bpf_cgroup_storage_calculate_size(map, &pages);
510
511 if (bpf_map_charge_memlock(map, pages))
512 return ERR_PTR(-EPERM);
513
514 storage = kmalloc_node(sizeof(struct bpf_cgroup_storage),
515 __GFP_ZERO | GFP_USER, map->numa_node);
516 if (!storage)
517 goto enomem;
518
519 flags = __GFP_ZERO | GFP_USER;
520
521 if (stype == BPF_CGROUP_STORAGE_SHARED) {
522 storage->buf = kmalloc_node(size, flags, map->numa_node);
523 if (!storage->buf)
524 goto enomem;
525 check_and_init_map_lock(map, storage->buf->data);
526 } else {
527 storage->percpu_buf = __alloc_percpu_gfp(size, 8, flags);
528 if (!storage->percpu_buf)
529 goto enomem;
530 }
531
532 storage->map = (struct bpf_cgroup_storage_map *)map;
533
534 return storage;
535
536enomem:
537 bpf_map_uncharge_memlock(map, pages);
538 kfree(storage);
539 return ERR_PTR(-ENOMEM);
540}
541
542static void free_shared_cgroup_storage_rcu(struct rcu_head *rcu)
543{
544 struct bpf_cgroup_storage *storage =
545 container_of(rcu, struct bpf_cgroup_storage, rcu);
546
547 kfree(storage->buf);
548 kfree(storage);
549}
550
551static void free_percpu_cgroup_storage_rcu(struct rcu_head *rcu)
552{
553 struct bpf_cgroup_storage *storage =
554 container_of(rcu, struct bpf_cgroup_storage, rcu);
555
556 free_percpu(storage->percpu_buf);
557 kfree(storage);
558}
559
560void bpf_cgroup_storage_free(struct bpf_cgroup_storage *storage)
561{
562 enum bpf_cgroup_storage_type stype;
563 struct bpf_map *map;
564 u32 pages;
565
566 if (!storage)
567 return;
568
569 map = &storage->map->map;
570
571 bpf_cgroup_storage_calculate_size(map, &pages);
572 bpf_map_uncharge_memlock(map, pages);
573
574 stype = cgroup_storage_type(map);
575 if (stype == BPF_CGROUP_STORAGE_SHARED)
576 call_rcu(&storage->rcu, free_shared_cgroup_storage_rcu);
577 else
578 call_rcu(&storage->rcu, free_percpu_cgroup_storage_rcu);
579}
580
581void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage,
582 struct cgroup *cgroup,
583 enum bpf_attach_type type)
584{
585 struct bpf_cgroup_storage_map *map;
586
587 if (!storage)
588 return;
589
590 storage->key.attach_type = type;
591 storage->key.cgroup_inode_id = cgroup_id(cgroup);
592
593 map = storage->map;
594
595 spin_lock_bh(&map->lock);
596 WARN_ON(cgroup_storage_insert(map, storage));
597 list_add(&storage->list_map, &map->list);
598 list_add(&storage->list_cg, &cgroup->bpf.storages);
599 spin_unlock_bh(&map->lock);
600}
601
602void bpf_cgroup_storage_unlink(struct bpf_cgroup_storage *storage)
603{
604 struct bpf_cgroup_storage_map *map;
605 struct rb_root *root;
606
607 if (!storage)
608 return;
609
610 map = storage->map;
611
612 spin_lock_bh(&map->lock);
613 root = &map->root;
614 rb_erase(&storage->node, root);
615
616 list_del(&storage->list_map);
617 list_del(&storage->list_cg);
618 spin_unlock_bh(&map->lock);
619}
620
621#endif