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> | |
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 |
27 | static 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 | ||
37 | static 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 | 57 | static 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 | ||
78 | static 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 */ | |
152 | static 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() */ |
164 | static 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 */ |
194 | static 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 |
205 | int 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 */ |
232 | static 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 */ | |
251 | static 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 |
279 | int 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 */ |
318 | static 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 */ | |
324 | static 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 |
341 | static 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 | ||
361 | static 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 | 387 | const 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 | 400 | const 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 | 410 | static 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 | 418 | static 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 | 432 | static 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 */ |
438 | int 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 |
458 | int 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 | 483 | static 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 |
501 | static 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 | ||
518 | static void prog_fd_array_put_ptr(void *ptr) | |
519 | { | |
1aacde3d | 520 | bpf_prog_put(ptr); |
2a36f0b9 WN |
521 | } |
522 | ||
14dc6f04 MKL |
523 | static 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 | 529 | static 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 | 538 | const 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 |
551 | static 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 | ||
566 | static 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 | ||
575 | static 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 |
580 | static 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 | |
3b1efb19 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) |
3b1efb19 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); | |
3b1efb19 DB |
601 | err_out: |
602 | fput(perf_file); | |
603 | return ee; | |
ea317b26 KX |
604 | } |
605 | ||
606 | static void perf_event_fd_array_put_ptr(void *ptr) | |
607 | { | |
3b1efb19 DB |
608 | bpf_event_entry_free_rcu(ptr); |
609 | } | |
610 | ||
611 | static 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(); | |
ea317b26 KX |
625 | } |
626 | ||
40077e0c | 627 | const 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, |
ea317b26 KX |
631 | .map_get_next_key = array_map_get_next_key, |
632 | .map_lookup_elem = fd_array_map_lookup_elem, | |
ea317b26 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 |
640 | static 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 | ||
647 | static 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 | ||
653 | static 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 | 659 | const 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 | |
671 | static 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 | ||
690 | static 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 | ||
700 | static 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 | ||
7b0c2a05 DB |
710 | static 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 | 741 | const 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 | }; |