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28fbcfa0 1/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
81ed18ab 2 * Copyright (c) 2016,2017 Facebook
28fbcfa0
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>
a26ca7c9 14#include <linux/btf.h>
28fbcfa0 15#include <linux/err.h>
28fbcfa0
AS
16#include <linux/slab.h>
17#include <linux/mm.h>
04fd61ab 18#include <linux/filter.h>
0cdf5640 19#include <linux/perf_event.h>
a26ca7c9 20#include <uapi/linux/btf.h>
28fbcfa0 21
56f668df
MKL
22#include "map_in_map.h"
23
6e71b04a
CF
24#define ARRAY_CREATE_FLAG_MASK \
25 (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
26
a10423b8
AS
27static void bpf_array_free_percpu(struct bpf_array *array)
28{
29 int i;
30
32fff239 31 for (i = 0; i < array->map.max_entries; i++) {
a10423b8 32 free_percpu(array->pptrs[i]);
32fff239
ED
33 cond_resched();
34 }
a10423b8
AS
35}
36
37static int bpf_array_alloc_percpu(struct bpf_array *array)
38{
39 void __percpu *ptr;
40 int i;
41
42 for (i = 0; i < array->map.max_entries; i++) {
43 ptr = __alloc_percpu_gfp(array->elem_size, 8,
44 GFP_USER | __GFP_NOWARN);
45 if (!ptr) {
46 bpf_array_free_percpu(array);
47 return -ENOMEM;
48 }
49 array->pptrs[i] = ptr;
32fff239 50 cond_resched();
a10423b8
AS
51 }
52
53 return 0;
54}
55
28fbcfa0 56/* Called from syscall */
ad46061f 57static int array_map_alloc_check(union bpf_attr *attr)
28fbcfa0 58{
a10423b8 59 bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
96eabe7a 60 int numa_node = bpf_map_attr_numa_node(attr);
28fbcfa0
AS
61
62 /* check sanity of attributes */
63 if (attr->max_entries == 0 || attr->key_size != 4 ||
6e71b04a
CF
64 attr->value_size == 0 ||
65 attr->map_flags & ~ARRAY_CREATE_FLAG_MASK ||
96eabe7a 66 (percpu && numa_node != NUMA_NO_NODE))
ad46061f 67 return -EINVAL;
28fbcfa0 68
7984c27c 69 if (attr->value_size > KMALLOC_MAX_SIZE)
01b3f521
AS
70 /* if value_size is bigger, the user space won't be able to
71 * access the elements.
72 */
ad46061f
JK
73 return -E2BIG;
74
75 return 0;
76}
77
78static struct bpf_map *array_map_alloc(union bpf_attr *attr)
79{
80 bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY;
9c2d63b8 81 int ret, numa_node = bpf_map_attr_numa_node(attr);
ad46061f
JK
82 u32 elem_size, index_mask, max_entries;
83 bool unpriv = !capable(CAP_SYS_ADMIN);
9c2d63b8 84 u64 cost, array_size, mask64;
ad46061f 85 struct bpf_array *array;
01b3f521 86
28fbcfa0
AS
87 elem_size = round_up(attr->value_size, 8);
88
b2157399 89 max_entries = attr->max_entries;
b2157399 90
bbeb6e43
DB
91 /* On 32 bit archs roundup_pow_of_two() with max_entries that has
92 * upper most bit set in u32 space is undefined behavior due to
93 * resulting 1U << 32, so do it manually here in u64 space.
94 */
95 mask64 = fls_long(max_entries - 1);
96 mask64 = 1ULL << mask64;
97 mask64 -= 1;
98
99 index_mask = mask64;
100 if (unpriv) {
b2157399
AS
101 /* round up array size to nearest power of 2,
102 * since cpu will speculate within index_mask limits
103 */
104 max_entries = index_mask + 1;
bbeb6e43
DB
105 /* Check for overflows. */
106 if (max_entries < attr->max_entries)
107 return ERR_PTR(-E2BIG);
108 }
b2157399 109
a10423b8
AS
110 array_size = sizeof(*array);
111 if (percpu)
b2157399 112 array_size += (u64) max_entries * sizeof(void *);
a10423b8 113 else
b2157399 114 array_size += (u64) max_entries * elem_size;
a10423b8
AS
115
116 /* make sure there is no u32 overflow later in round_up() */
9c2d63b8
DB
117 cost = array_size;
118 if (cost >= U32_MAX - PAGE_SIZE)
daaf427c 119 return ERR_PTR(-ENOMEM);
9c2d63b8
DB
120 if (percpu) {
121 cost += (u64)attr->max_entries * elem_size * num_possible_cpus();
122 if (cost >= U32_MAX - PAGE_SIZE)
123 return ERR_PTR(-ENOMEM);
124 }
125 cost = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
126
127 ret = bpf_map_precharge_memlock(cost);
128 if (ret < 0)
129 return ERR_PTR(ret);
daaf427c 130
28fbcfa0 131 /* allocate all map elements and zero-initialize them */
96eabe7a 132 array = bpf_map_area_alloc(array_size, numa_node);
d407bd25
DB
133 if (!array)
134 return ERR_PTR(-ENOMEM);
b2157399
AS
135 array->index_mask = index_mask;
136 array->map.unpriv_array = unpriv;
28fbcfa0
AS
137
138 /* copy mandatory map attributes */
32852649 139 bpf_map_init_from_attr(&array->map, attr);
9c2d63b8 140 array->map.pages = cost;
28fbcfa0
AS
141 array->elem_size = elem_size;
142
9c2d63b8 143 if (percpu && bpf_array_alloc_percpu(array)) {
d407bd25 144 bpf_map_area_free(array);
a10423b8
AS
145 return ERR_PTR(-ENOMEM);
146 }
a10423b8 147
28fbcfa0 148 return &array->map;
28fbcfa0
AS
149}
150
151/* Called from syscall or from eBPF program */
152static void *array_map_lookup_elem(struct bpf_map *map, void *key)
153{
154 struct bpf_array *array = container_of(map, struct bpf_array, map);
155 u32 index = *(u32 *)key;
156
a10423b8 157 if (unlikely(index >= array->map.max_entries))
28fbcfa0
AS
158 return NULL;
159
b2157399 160 return array->value + array->elem_size * (index & array->index_mask);
28fbcfa0
AS
161}
162
81ed18ab
AS
163/* emit BPF instructions equivalent to C code of array_map_lookup_elem() */
164static u32 array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
165{
b2157399 166 struct bpf_array *array = container_of(map, struct bpf_array, map);
81ed18ab 167 struct bpf_insn *insn = insn_buf;
fad73a1a 168 u32 elem_size = round_up(map->value_size, 8);
81ed18ab
AS
169 const int ret = BPF_REG_0;
170 const int map_ptr = BPF_REG_1;
171 const int index = BPF_REG_2;
172
173 *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
174 *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
b2157399
AS
175 if (map->unpriv_array) {
176 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 4);
177 *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
178 } else {
179 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 3);
180 }
fad73a1a
MKL
181
182 if (is_power_of_2(elem_size)) {
81ed18ab
AS
183 *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));
184 } else {
185 *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);
186 }
187 *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);
188 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
189 *insn++ = BPF_MOV64_IMM(ret, 0);
190 return insn - insn_buf;
191}
192
a10423b8
AS
193/* Called from eBPF program */
194static void *percpu_array_map_lookup_elem(struct bpf_map *map, void *key)
195{
196 struct bpf_array *array = container_of(map, struct bpf_array, map);
197 u32 index = *(u32 *)key;
198
199 if (unlikely(index >= array->map.max_entries))
200 return NULL;
201
b2157399 202 return this_cpu_ptr(array->pptrs[index & array->index_mask]);
a10423b8
AS
203}
204
15a07b33
AS
205int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value)
206{
207 struct bpf_array *array = container_of(map, struct bpf_array, map);
208 u32 index = *(u32 *)key;
209 void __percpu *pptr;
210 int cpu, off = 0;
211 u32 size;
212
213 if (unlikely(index >= array->map.max_entries))
214 return -ENOENT;
215
216 /* per_cpu areas are zero-filled and bpf programs can only
217 * access 'value_size' of them, so copying rounded areas
218 * will not leak any kernel data
219 */
220 size = round_up(map->value_size, 8);
221 rcu_read_lock();
b2157399 222 pptr = array->pptrs[index & array->index_mask];
15a07b33
AS
223 for_each_possible_cpu(cpu) {
224 bpf_long_memcpy(value + off, per_cpu_ptr(pptr, cpu), size);
225 off += size;
226 }
227 rcu_read_unlock();
228 return 0;
229}
230
28fbcfa0
AS
231/* Called from syscall */
232static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
233{
234 struct bpf_array *array = container_of(map, struct bpf_array, map);
8fe45924 235 u32 index = key ? *(u32 *)key : U32_MAX;
28fbcfa0
AS
236 u32 *next = (u32 *)next_key;
237
238 if (index >= array->map.max_entries) {
239 *next = 0;
240 return 0;
241 }
242
243 if (index == array->map.max_entries - 1)
244 return -ENOENT;
245
246 *next = index + 1;
247 return 0;
248}
249
250/* Called from syscall or from eBPF program */
251static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
252 u64 map_flags)
253{
254 struct bpf_array *array = container_of(map, struct bpf_array, map);
255 u32 index = *(u32 *)key;
256
a10423b8 257 if (unlikely(map_flags > BPF_EXIST))
28fbcfa0
AS
258 /* unknown flags */
259 return -EINVAL;
260
a10423b8 261 if (unlikely(index >= array->map.max_entries))
28fbcfa0
AS
262 /* all elements were pre-allocated, cannot insert a new one */
263 return -E2BIG;
264
a10423b8 265 if (unlikely(map_flags == BPF_NOEXIST))
daaf427c 266 /* all elements already exist */
28fbcfa0
AS
267 return -EEXIST;
268
a10423b8 269 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
b2157399 270 memcpy(this_cpu_ptr(array->pptrs[index & array->index_mask]),
a10423b8
AS
271 value, map->value_size);
272 else
b2157399
AS
273 memcpy(array->value +
274 array->elem_size * (index & array->index_mask),
a10423b8 275 value, map->value_size);
28fbcfa0
AS
276 return 0;
277}
278
15a07b33
AS
279int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
280 u64 map_flags)
281{
282 struct bpf_array *array = container_of(map, struct bpf_array, map);
283 u32 index = *(u32 *)key;
284 void __percpu *pptr;
285 int cpu, off = 0;
286 u32 size;
287
288 if (unlikely(map_flags > BPF_EXIST))
289 /* unknown flags */
290 return -EINVAL;
291
292 if (unlikely(index >= array->map.max_entries))
293 /* all elements were pre-allocated, cannot insert a new one */
294 return -E2BIG;
295
296 if (unlikely(map_flags == BPF_NOEXIST))
297 /* all elements already exist */
298 return -EEXIST;
299
300 /* the user space will provide round_up(value_size, 8) bytes that
301 * will be copied into per-cpu area. bpf programs can only access
302 * value_size of it. During lookup the same extra bytes will be
303 * returned or zeros which were zero-filled by percpu_alloc,
304 * so no kernel data leaks possible
305 */
306 size = round_up(map->value_size, 8);
307 rcu_read_lock();
b2157399 308 pptr = array->pptrs[index & array->index_mask];
15a07b33
AS
309 for_each_possible_cpu(cpu) {
310 bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value + off, size);
311 off += size;
312 }
313 rcu_read_unlock();
314 return 0;
315}
316
28fbcfa0
AS
317/* Called from syscall or from eBPF program */
318static int array_map_delete_elem(struct bpf_map *map, void *key)
319{
320 return -EINVAL;
321}
322
323/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
324static void array_map_free(struct bpf_map *map)
325{
326 struct bpf_array *array = container_of(map, struct bpf_array, map);
327
328 /* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0,
329 * so the programs (can be more than one that used this map) were
330 * disconnected from events. Wait for outstanding programs to complete
331 * and free the array
332 */
333 synchronize_rcu();
334
a10423b8
AS
335 if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
336 bpf_array_free_percpu(array);
337
d407bd25 338 bpf_map_area_free(array);
28fbcfa0
AS
339}
340
a26ca7c9
MKL
341static void array_map_seq_show_elem(struct bpf_map *map, void *key,
342 struct seq_file *m)
343{
344 void *value;
345
346 rcu_read_lock();
347
348 value = array_map_lookup_elem(map, key);
349 if (!value) {
350 rcu_read_unlock();
351 return;
352 }
353
354 seq_printf(m, "%u: ", *(u32 *)key);
355 btf_type_seq_show(map->btf, map->btf_value_id, value, m);
356 seq_puts(m, "\n");
357
358 rcu_read_unlock();
359}
360
361static int array_map_check_btf(const struct bpf_map *map, const struct btf *btf,
362 u32 btf_key_id, u32 btf_value_id)
363{
364 const struct btf_type *key_type, *value_type;
365 u32 key_size, value_size;
366 u32 int_data;
367
368 key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
369 if (!key_type || BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
370 return -EINVAL;
371
372 int_data = *(u32 *)(key_type + 1);
373 /* bpf array can only take a u32 key. This check makes
374 * sure that the btf matches the attr used during map_create.
375 */
376 if (BTF_INT_BITS(int_data) != 32 || key_size != 4 ||
377 BTF_INT_OFFSET(int_data))
378 return -EINVAL;
379
380 value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
381 if (!value_type || value_size > map->value_size)
382 return -EINVAL;
383
384 return 0;
385}
386
40077e0c 387const struct bpf_map_ops array_map_ops = {
ad46061f 388 .map_alloc_check = array_map_alloc_check,
28fbcfa0
AS
389 .map_alloc = array_map_alloc,
390 .map_free = array_map_free,
391 .map_get_next_key = array_map_get_next_key,
392 .map_lookup_elem = array_map_lookup_elem,
393 .map_update_elem = array_map_update_elem,
394 .map_delete_elem = array_map_delete_elem,
81ed18ab 395 .map_gen_lookup = array_map_gen_lookup,
a26ca7c9
MKL
396 .map_seq_show_elem = array_map_seq_show_elem,
397 .map_check_btf = array_map_check_btf,
28fbcfa0
AS
398};
399
40077e0c 400const struct bpf_map_ops percpu_array_map_ops = {
ad46061f 401 .map_alloc_check = array_map_alloc_check,
a10423b8
AS
402 .map_alloc = array_map_alloc,
403 .map_free = array_map_free,
404 .map_get_next_key = array_map_get_next_key,
405 .map_lookup_elem = percpu_array_map_lookup_elem,
406 .map_update_elem = array_map_update_elem,
407 .map_delete_elem = array_map_delete_elem,
408};
409
ad46061f 410static int fd_array_map_alloc_check(union bpf_attr *attr)
04fd61ab 411{
2a36f0b9 412 /* only file descriptors can be stored in this type of map */
04fd61ab 413 if (attr->value_size != sizeof(u32))
ad46061f
JK
414 return -EINVAL;
415 return array_map_alloc_check(attr);
04fd61ab
AS
416}
417
2a36f0b9 418static void fd_array_map_free(struct bpf_map *map)
04fd61ab
AS
419{
420 struct bpf_array *array = container_of(map, struct bpf_array, map);
421 int i;
422
423 synchronize_rcu();
424
425 /* make sure it's empty */
426 for (i = 0; i < array->map.max_entries; i++)
2a36f0b9 427 BUG_ON(array->ptrs[i] != NULL);
d407bd25
DB
428
429 bpf_map_area_free(array);
04fd61ab
AS
430}
431
2a36f0b9 432static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key)
04fd61ab
AS
433{
434 return NULL;
435}
436
14dc6f04
MKL
437/* only called from syscall */
438int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value)
439{
440 void **elem, *ptr;
441 int ret = 0;
442
443 if (!map->ops->map_fd_sys_lookup_elem)
444 return -ENOTSUPP;
445
446 rcu_read_lock();
447 elem = array_map_lookup_elem(map, key);
448 if (elem && (ptr = READ_ONCE(*elem)))
449 *value = map->ops->map_fd_sys_lookup_elem(ptr);
450 else
451 ret = -ENOENT;
452 rcu_read_unlock();
453
454 return ret;
455}
456
04fd61ab 457/* only called from syscall */
d056a788
DB
458int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file,
459 void *key, void *value, u64 map_flags)
04fd61ab
AS
460{
461 struct bpf_array *array = container_of(map, struct bpf_array, map);
2a36f0b9 462 void *new_ptr, *old_ptr;
04fd61ab
AS
463 u32 index = *(u32 *)key, ufd;
464
465 if (map_flags != BPF_ANY)
466 return -EINVAL;
467
468 if (index >= array->map.max_entries)
469 return -E2BIG;
470
471 ufd = *(u32 *)value;
d056a788 472 new_ptr = map->ops->map_fd_get_ptr(map, map_file, ufd);
2a36f0b9
WN
473 if (IS_ERR(new_ptr))
474 return PTR_ERR(new_ptr);
04fd61ab 475
2a36f0b9
WN
476 old_ptr = xchg(array->ptrs + index, new_ptr);
477 if (old_ptr)
478 map->ops->map_fd_put_ptr(old_ptr);
04fd61ab
AS
479
480 return 0;
481}
482
2a36f0b9 483static int fd_array_map_delete_elem(struct bpf_map *map, void *key)
04fd61ab
AS
484{
485 struct bpf_array *array = container_of(map, struct bpf_array, map);
2a36f0b9 486 void *old_ptr;
04fd61ab
AS
487 u32 index = *(u32 *)key;
488
489 if (index >= array->map.max_entries)
490 return -E2BIG;
491
2a36f0b9
WN
492 old_ptr = xchg(array->ptrs + index, NULL);
493 if (old_ptr) {
494 map->ops->map_fd_put_ptr(old_ptr);
04fd61ab
AS
495 return 0;
496 } else {
497 return -ENOENT;
498 }
499}
500
d056a788
DB
501static void *prog_fd_array_get_ptr(struct bpf_map *map,
502 struct file *map_file, int fd)
2a36f0b9
WN
503{
504 struct bpf_array *array = container_of(map, struct bpf_array, map);
505 struct bpf_prog *prog = bpf_prog_get(fd);
d056a788 506
2a36f0b9
WN
507 if (IS_ERR(prog))
508 return prog;
509
510 if (!bpf_prog_array_compatible(array, prog)) {
511 bpf_prog_put(prog);
512 return ERR_PTR(-EINVAL);
513 }
d056a788 514
2a36f0b9
WN
515 return prog;
516}
517
518static void prog_fd_array_put_ptr(void *ptr)
519{
1aacde3d 520 bpf_prog_put(ptr);
2a36f0b9
WN
521}
522
14dc6f04
MKL
523static u32 prog_fd_array_sys_lookup_elem(void *ptr)
524{
525 return ((struct bpf_prog *)ptr)->aux->id;
526}
527
04fd61ab 528/* decrement refcnt of all bpf_progs that are stored in this map */
ba6b8de4 529static void bpf_fd_array_map_clear(struct bpf_map *map)
04fd61ab
AS
530{
531 struct bpf_array *array = container_of(map, struct bpf_array, map);
532 int i;
533
534 for (i = 0; i < array->map.max_entries; i++)
2a36f0b9 535 fd_array_map_delete_elem(map, &i);
04fd61ab
AS
536}
537
40077e0c 538const struct bpf_map_ops prog_array_map_ops = {
ad46061f
JK
539 .map_alloc_check = fd_array_map_alloc_check,
540 .map_alloc = array_map_alloc,
2a36f0b9 541 .map_free = fd_array_map_free,
04fd61ab 542 .map_get_next_key = array_map_get_next_key,
2a36f0b9 543 .map_lookup_elem = fd_array_map_lookup_elem,
2a36f0b9
WN
544 .map_delete_elem = fd_array_map_delete_elem,
545 .map_fd_get_ptr = prog_fd_array_get_ptr,
546 .map_fd_put_ptr = prog_fd_array_put_ptr,
14dc6f04 547 .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem,
ba6b8de4 548 .map_release_uref = bpf_fd_array_map_clear,
04fd61ab
AS
549};
550
3b1efb19
DB
551static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file,
552 struct file *map_file)
ea317b26 553{
3b1efb19
DB
554 struct bpf_event_entry *ee;
555
858d68f1 556 ee = kzalloc(sizeof(*ee), GFP_ATOMIC);
3b1efb19
DB
557 if (ee) {
558 ee->event = perf_file->private_data;
559 ee->perf_file = perf_file;
560 ee->map_file = map_file;
561 }
562
563 return ee;
564}
565
566static void __bpf_event_entry_free(struct rcu_head *rcu)
567{
568 struct bpf_event_entry *ee;
569
570 ee = container_of(rcu, struct bpf_event_entry, rcu);
571 fput(ee->perf_file);
572 kfree(ee);
573}
574
575static void bpf_event_entry_free_rcu(struct bpf_event_entry *ee)
576{
577 call_rcu(&ee->rcu, __bpf_event_entry_free);
ea317b26
KX
578}
579
d056a788
DB
580static void *perf_event_fd_array_get_ptr(struct bpf_map *map,
581 struct file *map_file, int fd)
ea317b26 582{
3b1efb19
DB
583 struct bpf_event_entry *ee;
584 struct perf_event *event;
585 struct file *perf_file;
f91840a3 586 u64 value;
ea317b26 587
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DB
588 perf_file = perf_event_get(fd);
589 if (IS_ERR(perf_file))
590 return perf_file;
e03e7ee3 591
f91840a3 592 ee = ERR_PTR(-EOPNOTSUPP);
3b1efb19 593 event = perf_file->private_data;
97562633 594 if (perf_event_read_local(event, &value, NULL, NULL) == -EOPNOTSUPP)
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DB
595 goto err_out;
596
f91840a3
AS
597 ee = bpf_event_entry_gen(perf_file, map_file);
598 if (ee)
599 return ee;
600 ee = ERR_PTR(-ENOMEM);
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DB
601err_out:
602 fput(perf_file);
603 return ee;
ea317b26
KX
604}
605
606static void perf_event_fd_array_put_ptr(void *ptr)
607{
3b1efb19
DB
608 bpf_event_entry_free_rcu(ptr);
609}
610
611static void perf_event_fd_array_release(struct bpf_map *map,
612 struct file *map_file)
613{
614 struct bpf_array *array = container_of(map, struct bpf_array, map);
615 struct bpf_event_entry *ee;
616 int i;
617
618 rcu_read_lock();
619 for (i = 0; i < array->map.max_entries; i++) {
620 ee = READ_ONCE(array->ptrs[i]);
621 if (ee && ee->map_file == map_file)
622 fd_array_map_delete_elem(map, &i);
623 }
624 rcu_read_unlock();
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KX
625}
626
40077e0c 627const struct bpf_map_ops perf_event_array_map_ops = {
ad46061f
JK
628 .map_alloc_check = fd_array_map_alloc_check,
629 .map_alloc = array_map_alloc,
3b1efb19 630 .map_free = fd_array_map_free,
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KX
631 .map_get_next_key = array_map_get_next_key,
632 .map_lookup_elem = fd_array_map_lookup_elem,
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KX
633 .map_delete_elem = fd_array_map_delete_elem,
634 .map_fd_get_ptr = perf_event_fd_array_get_ptr,
635 .map_fd_put_ptr = perf_event_fd_array_put_ptr,
3b1efb19 636 .map_release = perf_event_fd_array_release,
ea317b26
KX
637};
638
60d20f91 639#ifdef CONFIG_CGROUPS
4ed8ec52
MKL
640static void *cgroup_fd_array_get_ptr(struct bpf_map *map,
641 struct file *map_file /* not used */,
642 int fd)
643{
644 return cgroup_get_from_fd(fd);
645}
646
647static void cgroup_fd_array_put_ptr(void *ptr)
648{
649 /* cgroup_put free cgrp after a rcu grace period */
650 cgroup_put(ptr);
651}
652
653static void cgroup_fd_array_free(struct bpf_map *map)
654{
655 bpf_fd_array_map_clear(map);
656 fd_array_map_free(map);
657}
658
40077e0c 659const struct bpf_map_ops cgroup_array_map_ops = {
ad46061f
JK
660 .map_alloc_check = fd_array_map_alloc_check,
661 .map_alloc = array_map_alloc,
4ed8ec52
MKL
662 .map_free = cgroup_fd_array_free,
663 .map_get_next_key = array_map_get_next_key,
664 .map_lookup_elem = fd_array_map_lookup_elem,
665 .map_delete_elem = fd_array_map_delete_elem,
666 .map_fd_get_ptr = cgroup_fd_array_get_ptr,
667 .map_fd_put_ptr = cgroup_fd_array_put_ptr,
668};
4ed8ec52 669#endif
56f668df
MKL
670
671static struct bpf_map *array_of_map_alloc(union bpf_attr *attr)
672{
673 struct bpf_map *map, *inner_map_meta;
674
675 inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd);
676 if (IS_ERR(inner_map_meta))
677 return inner_map_meta;
678
ad46061f 679 map = array_map_alloc(attr);
56f668df
MKL
680 if (IS_ERR(map)) {
681 bpf_map_meta_free(inner_map_meta);
682 return map;
683 }
684
685 map->inner_map_meta = inner_map_meta;
686
687 return map;
688}
689
690static void array_of_map_free(struct bpf_map *map)
691{
692 /* map->inner_map_meta is only accessed by syscall which
693 * is protected by fdget/fdput.
694 */
695 bpf_map_meta_free(map->inner_map_meta);
696 bpf_fd_array_map_clear(map);
697 fd_array_map_free(map);
698}
699
700static void *array_of_map_lookup_elem(struct bpf_map *map, void *key)
701{
702 struct bpf_map **inner_map = array_map_lookup_elem(map, key);
703
704 if (!inner_map)
705 return NULL;
706
707 return READ_ONCE(*inner_map);
708}
709
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DB
710static u32 array_of_map_gen_lookup(struct bpf_map *map,
711 struct bpf_insn *insn_buf)
712{
b2157399 713 struct bpf_array *array = container_of(map, struct bpf_array, map);
7b0c2a05
DB
714 u32 elem_size = round_up(map->value_size, 8);
715 struct bpf_insn *insn = insn_buf;
716 const int ret = BPF_REG_0;
717 const int map_ptr = BPF_REG_1;
718 const int index = BPF_REG_2;
719
720 *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value));
721 *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
b2157399
AS
722 if (map->unpriv_array) {
723 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 6);
724 *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask);
725 } else {
726 *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5);
727 }
7b0c2a05
DB
728 if (is_power_of_2(elem_size))
729 *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size));
730 else
731 *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size);
732 *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr);
733 *insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0);
734 *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1);
735 *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
736 *insn++ = BPF_MOV64_IMM(ret, 0);
737
738 return insn - insn_buf;
739}
740
40077e0c 741const struct bpf_map_ops array_of_maps_map_ops = {
ad46061f 742 .map_alloc_check = fd_array_map_alloc_check,
56f668df
MKL
743 .map_alloc = array_of_map_alloc,
744 .map_free = array_of_map_free,
745 .map_get_next_key = array_map_get_next_key,
746 .map_lookup_elem = array_of_map_lookup_elem,
747 .map_delete_elem = fd_array_map_delete_elem,
748 .map_fd_get_ptr = bpf_map_fd_get_ptr,
749 .map_fd_put_ptr = bpf_map_fd_put_ptr,
14dc6f04 750 .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem,
7b0c2a05 751 .map_gen_lookup = array_of_map_gen_lookup,
56f668df 752};