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