Commit | Line | Data |
---|---|---|
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 | ||
29 | for (i = 0; i < array->map.max_entries; i++) | |
30 | free_percpu(array->pptrs[i]); | |
31 | } | |
32 | ||
33 | static int bpf_array_alloc_percpu(struct bpf_array *array) | |
34 | { | |
35 | void __percpu *ptr; | |
36 | int i; | |
37 | ||
38 | for (i = 0; i < array->map.max_entries; i++) { | |
39 | ptr = __alloc_percpu_gfp(array->elem_size, 8, | |
40 | GFP_USER | __GFP_NOWARN); | |
41 | if (!ptr) { | |
42 | bpf_array_free_percpu(array); | |
43 | return -ENOMEM; | |
44 | } | |
45 | array->pptrs[i] = ptr; | |
46 | } | |
47 | ||
48 | return 0; | |
49 | } | |
50 | ||
28fbcfa0 AS |
51 | /* Called from syscall */ |
52 | static struct bpf_map *array_map_alloc(union bpf_attr *attr) | |
53 | { | |
a10423b8 | 54 | bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; |
96eabe7a | 55 | int numa_node = bpf_map_attr_numa_node(attr); |
b2157399 AS |
56 | u32 elem_size, index_mask, max_entries; |
57 | bool unpriv = !capable(CAP_SYS_ADMIN); | |
28fbcfa0 | 58 | struct bpf_array *array; |
bbeb6e43 | 59 | u64 array_size, mask64; |
28fbcfa0 AS |
60 | |
61 | /* check sanity of attributes */ | |
62 | if (attr->max_entries == 0 || attr->key_size != 4 || | |
6e71b04a CF |
63 | attr->value_size == 0 || |
64 | attr->map_flags & ~ARRAY_CREATE_FLAG_MASK || | |
96eabe7a | 65 | (percpu && numa_node != NUMA_NO_NODE)) |
28fbcfa0 AS |
66 | return ERR_PTR(-EINVAL); |
67 | ||
7984c27c | 68 | if (attr->value_size > KMALLOC_MAX_SIZE) |
01b3f521 AS |
69 | /* if value_size is bigger, the user space won't be able to |
70 | * access the elements. | |
71 | */ | |
72 | return ERR_PTR(-E2BIG); | |
73 | ||
28fbcfa0 AS |
74 | elem_size = round_up(attr->value_size, 8); |
75 | ||
b2157399 | 76 | max_entries = attr->max_entries; |
b2157399 | 77 | |
bbeb6e43 DB |
78 | /* On 32 bit archs roundup_pow_of_two() with max_entries that has |
79 | * upper most bit set in u32 space is undefined behavior due to | |
80 | * resulting 1U << 32, so do it manually here in u64 space. | |
81 | */ | |
82 | mask64 = fls_long(max_entries - 1); | |
83 | mask64 = 1ULL << mask64; | |
84 | mask64 -= 1; | |
85 | ||
86 | index_mask = mask64; | |
87 | if (unpriv) { | |
b2157399 AS |
88 | /* round up array size to nearest power of 2, |
89 | * since cpu will speculate within index_mask limits | |
90 | */ | |
91 | max_entries = index_mask + 1; | |
bbeb6e43 DB |
92 | /* Check for overflows. */ |
93 | if (max_entries < attr->max_entries) | |
94 | return ERR_PTR(-E2BIG); | |
95 | } | |
b2157399 | 96 | |
a10423b8 AS |
97 | array_size = sizeof(*array); |
98 | if (percpu) | |
b2157399 | 99 | array_size += (u64) max_entries * sizeof(void *); |
a10423b8 | 100 | else |
b2157399 | 101 | array_size += (u64) max_entries * elem_size; |
a10423b8 AS |
102 | |
103 | /* make sure there is no u32 overflow later in round_up() */ | |
104 | if (array_size >= U32_MAX - PAGE_SIZE) | |
daaf427c AS |
105 | return ERR_PTR(-ENOMEM); |
106 | ||
28fbcfa0 | 107 | /* allocate all map elements and zero-initialize them */ |
96eabe7a | 108 | array = bpf_map_area_alloc(array_size, numa_node); |
d407bd25 DB |
109 | if (!array) |
110 | return ERR_PTR(-ENOMEM); | |
b2157399 AS |
111 | array->index_mask = index_mask; |
112 | array->map.unpriv_array = unpriv; | |
28fbcfa0 AS |
113 | |
114 | /* copy mandatory map attributes */ | |
a10423b8 | 115 | array->map.map_type = attr->map_type; |
28fbcfa0 AS |
116 | array->map.key_size = attr->key_size; |
117 | array->map.value_size = attr->value_size; | |
118 | array->map.max_entries = attr->max_entries; | |
a316338c | 119 | array->map.map_flags = attr->map_flags; |
96eabe7a | 120 | array->map.numa_node = numa_node; |
28fbcfa0 AS |
121 | array->elem_size = elem_size; |
122 | ||
a10423b8 AS |
123 | if (!percpu) |
124 | goto out; | |
125 | ||
126 | array_size += (u64) attr->max_entries * elem_size * num_possible_cpus(); | |
127 | ||
128 | if (array_size >= U32_MAX - PAGE_SIZE || | |
bc6d5031 | 129 | bpf_array_alloc_percpu(array)) { |
d407bd25 | 130 | bpf_map_area_free(array); |
a10423b8 AS |
131 | return ERR_PTR(-ENOMEM); |
132 | } | |
133 | out: | |
134 | array->map.pages = round_up(array_size, PAGE_SIZE) >> PAGE_SHIFT; | |
135 | ||
28fbcfa0 | 136 | return &array->map; |
28fbcfa0 AS |
137 | } |
138 | ||
139 | /* Called from syscall or from eBPF program */ | |
140 | static void *array_map_lookup_elem(struct bpf_map *map, void *key) | |
141 | { | |
142 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
143 | u32 index = *(u32 *)key; | |
144 | ||
a10423b8 | 145 | if (unlikely(index >= array->map.max_entries)) |
28fbcfa0 AS |
146 | return NULL; |
147 | ||
b2157399 | 148 | return array->value + array->elem_size * (index & array->index_mask); |
28fbcfa0 AS |
149 | } |
150 | ||
81ed18ab AS |
151 | /* emit BPF instructions equivalent to C code of array_map_lookup_elem() */ |
152 | static u32 array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) | |
153 | { | |
b2157399 | 154 | struct bpf_array *array = container_of(map, struct bpf_array, map); |
81ed18ab | 155 | struct bpf_insn *insn = insn_buf; |
fad73a1a | 156 | u32 elem_size = round_up(map->value_size, 8); |
81ed18ab AS |
157 | const int ret = BPF_REG_0; |
158 | const int map_ptr = BPF_REG_1; | |
159 | const int index = BPF_REG_2; | |
160 | ||
161 | *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value)); | |
162 | *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0); | |
b2157399 AS |
163 | if (map->unpriv_array) { |
164 | *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 4); | |
165 | *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask); | |
166 | } else { | |
167 | *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 3); | |
168 | } | |
fad73a1a MKL |
169 | |
170 | if (is_power_of_2(elem_size)) { | |
81ed18ab AS |
171 | *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size)); |
172 | } else { | |
173 | *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size); | |
174 | } | |
175 | *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr); | |
176 | *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1); | |
177 | *insn++ = BPF_MOV64_IMM(ret, 0); | |
178 | return insn - insn_buf; | |
179 | } | |
180 | ||
a10423b8 AS |
181 | /* Called from eBPF program */ |
182 | static void *percpu_array_map_lookup_elem(struct bpf_map *map, void *key) | |
183 | { | |
184 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
185 | u32 index = *(u32 *)key; | |
186 | ||
187 | if (unlikely(index >= array->map.max_entries)) | |
188 | return NULL; | |
189 | ||
b2157399 | 190 | return this_cpu_ptr(array->pptrs[index & array->index_mask]); |
a10423b8 AS |
191 | } |
192 | ||
15a07b33 AS |
193 | int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value) |
194 | { | |
195 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
196 | u32 index = *(u32 *)key; | |
197 | void __percpu *pptr; | |
198 | int cpu, off = 0; | |
199 | u32 size; | |
200 | ||
201 | if (unlikely(index >= array->map.max_entries)) | |
202 | return -ENOENT; | |
203 | ||
204 | /* per_cpu areas are zero-filled and bpf programs can only | |
205 | * access 'value_size' of them, so copying rounded areas | |
206 | * will not leak any kernel data | |
207 | */ | |
208 | size = round_up(map->value_size, 8); | |
209 | rcu_read_lock(); | |
b2157399 | 210 | pptr = array->pptrs[index & array->index_mask]; |
15a07b33 AS |
211 | for_each_possible_cpu(cpu) { |
212 | bpf_long_memcpy(value + off, per_cpu_ptr(pptr, cpu), size); | |
213 | off += size; | |
214 | } | |
215 | rcu_read_unlock(); | |
216 | return 0; | |
217 | } | |
218 | ||
28fbcfa0 AS |
219 | /* Called from syscall */ |
220 | static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key) | |
221 | { | |
222 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
8fe45924 | 223 | u32 index = key ? *(u32 *)key : U32_MAX; |
28fbcfa0 AS |
224 | u32 *next = (u32 *)next_key; |
225 | ||
226 | if (index >= array->map.max_entries) { | |
227 | *next = 0; | |
228 | return 0; | |
229 | } | |
230 | ||
231 | if (index == array->map.max_entries - 1) | |
232 | return -ENOENT; | |
233 | ||
234 | *next = index + 1; | |
235 | return 0; | |
236 | } | |
237 | ||
238 | /* Called from syscall or from eBPF program */ | |
239 | static int array_map_update_elem(struct bpf_map *map, void *key, void *value, | |
240 | u64 map_flags) | |
241 | { | |
242 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
243 | u32 index = *(u32 *)key; | |
244 | ||
a10423b8 | 245 | if (unlikely(map_flags > BPF_EXIST)) |
28fbcfa0 AS |
246 | /* unknown flags */ |
247 | return -EINVAL; | |
248 | ||
a10423b8 | 249 | if (unlikely(index >= array->map.max_entries)) |
28fbcfa0 AS |
250 | /* all elements were pre-allocated, cannot insert a new one */ |
251 | return -E2BIG; | |
252 | ||
a10423b8 | 253 | if (unlikely(map_flags == BPF_NOEXIST)) |
daaf427c | 254 | /* all elements already exist */ |
28fbcfa0 AS |
255 | return -EEXIST; |
256 | ||
a10423b8 | 257 | if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) |
b2157399 | 258 | memcpy(this_cpu_ptr(array->pptrs[index & array->index_mask]), |
a10423b8 AS |
259 | value, map->value_size); |
260 | else | |
b2157399 AS |
261 | memcpy(array->value + |
262 | array->elem_size * (index & array->index_mask), | |
a10423b8 | 263 | value, map->value_size); |
28fbcfa0 AS |
264 | return 0; |
265 | } | |
266 | ||
15a07b33 AS |
267 | int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, |
268 | u64 map_flags) | |
269 | { | |
270 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
271 | u32 index = *(u32 *)key; | |
272 | void __percpu *pptr; | |
273 | int cpu, off = 0; | |
274 | u32 size; | |
275 | ||
276 | if (unlikely(map_flags > BPF_EXIST)) | |
277 | /* unknown flags */ | |
278 | return -EINVAL; | |
279 | ||
280 | if (unlikely(index >= array->map.max_entries)) | |
281 | /* all elements were pre-allocated, cannot insert a new one */ | |
282 | return -E2BIG; | |
283 | ||
284 | if (unlikely(map_flags == BPF_NOEXIST)) | |
285 | /* all elements already exist */ | |
286 | return -EEXIST; | |
287 | ||
288 | /* the user space will provide round_up(value_size, 8) bytes that | |
289 | * will be copied into per-cpu area. bpf programs can only access | |
290 | * value_size of it. During lookup the same extra bytes will be | |
291 | * returned or zeros which were zero-filled by percpu_alloc, | |
292 | * so no kernel data leaks possible | |
293 | */ | |
294 | size = round_up(map->value_size, 8); | |
295 | rcu_read_lock(); | |
b2157399 | 296 | pptr = array->pptrs[index & array->index_mask]; |
15a07b33 AS |
297 | for_each_possible_cpu(cpu) { |
298 | bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value + off, size); | |
299 | off += size; | |
300 | } | |
301 | rcu_read_unlock(); | |
302 | return 0; | |
303 | } | |
304 | ||
28fbcfa0 AS |
305 | /* Called from syscall or from eBPF program */ |
306 | static int array_map_delete_elem(struct bpf_map *map, void *key) | |
307 | { | |
308 | return -EINVAL; | |
309 | } | |
310 | ||
311 | /* Called when map->refcnt goes to zero, either from workqueue or from syscall */ | |
312 | static void array_map_free(struct bpf_map *map) | |
313 | { | |
314 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
315 | ||
316 | /* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0, | |
317 | * so the programs (can be more than one that used this map) were | |
318 | * disconnected from events. Wait for outstanding programs to complete | |
319 | * and free the array | |
320 | */ | |
321 | synchronize_rcu(); | |
322 | ||
a10423b8 AS |
323 | if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) |
324 | bpf_array_free_percpu(array); | |
325 | ||
d407bd25 | 326 | bpf_map_area_free(array); |
28fbcfa0 AS |
327 | } |
328 | ||
40077e0c | 329 | const struct bpf_map_ops array_map_ops = { |
28fbcfa0 AS |
330 | .map_alloc = array_map_alloc, |
331 | .map_free = array_map_free, | |
332 | .map_get_next_key = array_map_get_next_key, | |
333 | .map_lookup_elem = array_map_lookup_elem, | |
334 | .map_update_elem = array_map_update_elem, | |
335 | .map_delete_elem = array_map_delete_elem, | |
81ed18ab | 336 | .map_gen_lookup = array_map_gen_lookup, |
28fbcfa0 AS |
337 | }; |
338 | ||
40077e0c | 339 | const struct bpf_map_ops percpu_array_map_ops = { |
a10423b8 AS |
340 | .map_alloc = array_map_alloc, |
341 | .map_free = array_map_free, | |
342 | .map_get_next_key = array_map_get_next_key, | |
343 | .map_lookup_elem = percpu_array_map_lookup_elem, | |
344 | .map_update_elem = array_map_update_elem, | |
345 | .map_delete_elem = array_map_delete_elem, | |
346 | }; | |
347 | ||
2a36f0b9 | 348 | static struct bpf_map *fd_array_map_alloc(union bpf_attr *attr) |
04fd61ab | 349 | { |
2a36f0b9 | 350 | /* only file descriptors can be stored in this type of map */ |
04fd61ab AS |
351 | if (attr->value_size != sizeof(u32)) |
352 | return ERR_PTR(-EINVAL); | |
353 | return array_map_alloc(attr); | |
354 | } | |
355 | ||
2a36f0b9 | 356 | static void fd_array_map_free(struct bpf_map *map) |
04fd61ab AS |
357 | { |
358 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
359 | int i; | |
360 | ||
361 | synchronize_rcu(); | |
362 | ||
363 | /* make sure it's empty */ | |
364 | for (i = 0; i < array->map.max_entries; i++) | |
2a36f0b9 | 365 | BUG_ON(array->ptrs[i] != NULL); |
d407bd25 DB |
366 | |
367 | bpf_map_area_free(array); | |
04fd61ab AS |
368 | } |
369 | ||
2a36f0b9 | 370 | static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key) |
04fd61ab AS |
371 | { |
372 | return NULL; | |
373 | } | |
374 | ||
14dc6f04 MKL |
375 | /* only called from syscall */ |
376 | int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value) | |
377 | { | |
378 | void **elem, *ptr; | |
379 | int ret = 0; | |
380 | ||
381 | if (!map->ops->map_fd_sys_lookup_elem) | |
382 | return -ENOTSUPP; | |
383 | ||
384 | rcu_read_lock(); | |
385 | elem = array_map_lookup_elem(map, key); | |
386 | if (elem && (ptr = READ_ONCE(*elem))) | |
387 | *value = map->ops->map_fd_sys_lookup_elem(ptr); | |
388 | else | |
389 | ret = -ENOENT; | |
390 | rcu_read_unlock(); | |
391 | ||
392 | return ret; | |
393 | } | |
394 | ||
04fd61ab | 395 | /* only called from syscall */ |
d056a788 DB |
396 | int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file, |
397 | void *key, void *value, u64 map_flags) | |
04fd61ab AS |
398 | { |
399 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
2a36f0b9 | 400 | void *new_ptr, *old_ptr; |
04fd61ab AS |
401 | u32 index = *(u32 *)key, ufd; |
402 | ||
403 | if (map_flags != BPF_ANY) | |
404 | return -EINVAL; | |
405 | ||
406 | if (index >= array->map.max_entries) | |
407 | return -E2BIG; | |
408 | ||
409 | ufd = *(u32 *)value; | |
d056a788 | 410 | new_ptr = map->ops->map_fd_get_ptr(map, map_file, ufd); |
2a36f0b9 WN |
411 | if (IS_ERR(new_ptr)) |
412 | return PTR_ERR(new_ptr); | |
04fd61ab | 413 | |
2a36f0b9 WN |
414 | old_ptr = xchg(array->ptrs + index, new_ptr); |
415 | if (old_ptr) | |
416 | map->ops->map_fd_put_ptr(old_ptr); | |
04fd61ab AS |
417 | |
418 | return 0; | |
419 | } | |
420 | ||
2a36f0b9 | 421 | static int fd_array_map_delete_elem(struct bpf_map *map, void *key) |
04fd61ab AS |
422 | { |
423 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
2a36f0b9 | 424 | void *old_ptr; |
04fd61ab AS |
425 | u32 index = *(u32 *)key; |
426 | ||
427 | if (index >= array->map.max_entries) | |
428 | return -E2BIG; | |
429 | ||
2a36f0b9 WN |
430 | old_ptr = xchg(array->ptrs + index, NULL); |
431 | if (old_ptr) { | |
432 | map->ops->map_fd_put_ptr(old_ptr); | |
04fd61ab AS |
433 | return 0; |
434 | } else { | |
435 | return -ENOENT; | |
436 | } | |
437 | } | |
438 | ||
d056a788 DB |
439 | static void *prog_fd_array_get_ptr(struct bpf_map *map, |
440 | struct file *map_file, int fd) | |
2a36f0b9 WN |
441 | { |
442 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
443 | struct bpf_prog *prog = bpf_prog_get(fd); | |
d056a788 | 444 | |
2a36f0b9 WN |
445 | if (IS_ERR(prog)) |
446 | return prog; | |
447 | ||
448 | if (!bpf_prog_array_compatible(array, prog)) { | |
449 | bpf_prog_put(prog); | |
450 | return ERR_PTR(-EINVAL); | |
451 | } | |
d056a788 | 452 | |
2a36f0b9 WN |
453 | return prog; |
454 | } | |
455 | ||
456 | static void prog_fd_array_put_ptr(void *ptr) | |
457 | { | |
1aacde3d | 458 | bpf_prog_put(ptr); |
2a36f0b9 WN |
459 | } |
460 | ||
14dc6f04 MKL |
461 | static u32 prog_fd_array_sys_lookup_elem(void *ptr) |
462 | { | |
463 | return ((struct bpf_prog *)ptr)->aux->id; | |
464 | } | |
465 | ||
04fd61ab | 466 | /* decrement refcnt of all bpf_progs that are stored in this map */ |
2a36f0b9 | 467 | void bpf_fd_array_map_clear(struct bpf_map *map) |
04fd61ab AS |
468 | { |
469 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
470 | int i; | |
471 | ||
472 | for (i = 0; i < array->map.max_entries; i++) | |
2a36f0b9 | 473 | fd_array_map_delete_elem(map, &i); |
04fd61ab AS |
474 | } |
475 | ||
40077e0c | 476 | const struct bpf_map_ops prog_array_map_ops = { |
2a36f0b9 WN |
477 | .map_alloc = fd_array_map_alloc, |
478 | .map_free = fd_array_map_free, | |
04fd61ab | 479 | .map_get_next_key = array_map_get_next_key, |
2a36f0b9 | 480 | .map_lookup_elem = fd_array_map_lookup_elem, |
2a36f0b9 WN |
481 | .map_delete_elem = fd_array_map_delete_elem, |
482 | .map_fd_get_ptr = prog_fd_array_get_ptr, | |
483 | .map_fd_put_ptr = prog_fd_array_put_ptr, | |
14dc6f04 | 484 | .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem, |
04fd61ab AS |
485 | }; |
486 | ||
3b1efb19 DB |
487 | static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file, |
488 | struct file *map_file) | |
ea317b26 | 489 | { |
3b1efb19 DB |
490 | struct bpf_event_entry *ee; |
491 | ||
858d68f1 | 492 | ee = kzalloc(sizeof(*ee), GFP_ATOMIC); |
3b1efb19 DB |
493 | if (ee) { |
494 | ee->event = perf_file->private_data; | |
495 | ee->perf_file = perf_file; | |
496 | ee->map_file = map_file; | |
497 | } | |
498 | ||
499 | return ee; | |
500 | } | |
501 | ||
502 | static void __bpf_event_entry_free(struct rcu_head *rcu) | |
503 | { | |
504 | struct bpf_event_entry *ee; | |
505 | ||
506 | ee = container_of(rcu, struct bpf_event_entry, rcu); | |
507 | fput(ee->perf_file); | |
508 | kfree(ee); | |
509 | } | |
510 | ||
511 | static void bpf_event_entry_free_rcu(struct bpf_event_entry *ee) | |
512 | { | |
513 | call_rcu(&ee->rcu, __bpf_event_entry_free); | |
ea317b26 KX |
514 | } |
515 | ||
d056a788 DB |
516 | static void *perf_event_fd_array_get_ptr(struct bpf_map *map, |
517 | struct file *map_file, int fd) | |
ea317b26 | 518 | { |
3b1efb19 DB |
519 | struct bpf_event_entry *ee; |
520 | struct perf_event *event; | |
521 | struct file *perf_file; | |
f91840a3 | 522 | u64 value; |
ea317b26 | 523 | |
3b1efb19 DB |
524 | perf_file = perf_event_get(fd); |
525 | if (IS_ERR(perf_file)) | |
526 | return perf_file; | |
e03e7ee3 | 527 | |
f91840a3 | 528 | ee = ERR_PTR(-EOPNOTSUPP); |
3b1efb19 | 529 | event = perf_file->private_data; |
97562633 | 530 | if (perf_event_read_local(event, &value, NULL, NULL) == -EOPNOTSUPP) |
3b1efb19 DB |
531 | goto err_out; |
532 | ||
f91840a3 AS |
533 | ee = bpf_event_entry_gen(perf_file, map_file); |
534 | if (ee) | |
535 | return ee; | |
536 | ee = ERR_PTR(-ENOMEM); | |
3b1efb19 DB |
537 | err_out: |
538 | fput(perf_file); | |
539 | return ee; | |
ea317b26 KX |
540 | } |
541 | ||
542 | static void perf_event_fd_array_put_ptr(void *ptr) | |
543 | { | |
3b1efb19 DB |
544 | bpf_event_entry_free_rcu(ptr); |
545 | } | |
546 | ||
547 | static void perf_event_fd_array_release(struct bpf_map *map, | |
548 | struct file *map_file) | |
549 | { | |
550 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
551 | struct bpf_event_entry *ee; | |
552 | int i; | |
553 | ||
554 | rcu_read_lock(); | |
555 | for (i = 0; i < array->map.max_entries; i++) { | |
556 | ee = READ_ONCE(array->ptrs[i]); | |
557 | if (ee && ee->map_file == map_file) | |
558 | fd_array_map_delete_elem(map, &i); | |
559 | } | |
560 | rcu_read_unlock(); | |
ea317b26 KX |
561 | } |
562 | ||
40077e0c | 563 | const struct bpf_map_ops perf_event_array_map_ops = { |
ea317b26 | 564 | .map_alloc = fd_array_map_alloc, |
3b1efb19 | 565 | .map_free = fd_array_map_free, |
ea317b26 KX |
566 | .map_get_next_key = array_map_get_next_key, |
567 | .map_lookup_elem = fd_array_map_lookup_elem, | |
ea317b26 KX |
568 | .map_delete_elem = fd_array_map_delete_elem, |
569 | .map_fd_get_ptr = perf_event_fd_array_get_ptr, | |
570 | .map_fd_put_ptr = perf_event_fd_array_put_ptr, | |
3b1efb19 | 571 | .map_release = perf_event_fd_array_release, |
ea317b26 KX |
572 | }; |
573 | ||
60d20f91 | 574 | #ifdef CONFIG_CGROUPS |
4ed8ec52 MKL |
575 | static void *cgroup_fd_array_get_ptr(struct bpf_map *map, |
576 | struct file *map_file /* not used */, | |
577 | int fd) | |
578 | { | |
579 | return cgroup_get_from_fd(fd); | |
580 | } | |
581 | ||
582 | static void cgroup_fd_array_put_ptr(void *ptr) | |
583 | { | |
584 | /* cgroup_put free cgrp after a rcu grace period */ | |
585 | cgroup_put(ptr); | |
586 | } | |
587 | ||
588 | static void cgroup_fd_array_free(struct bpf_map *map) | |
589 | { | |
590 | bpf_fd_array_map_clear(map); | |
591 | fd_array_map_free(map); | |
592 | } | |
593 | ||
40077e0c | 594 | const struct bpf_map_ops cgroup_array_map_ops = { |
4ed8ec52 MKL |
595 | .map_alloc = fd_array_map_alloc, |
596 | .map_free = cgroup_fd_array_free, | |
597 | .map_get_next_key = array_map_get_next_key, | |
598 | .map_lookup_elem = fd_array_map_lookup_elem, | |
599 | .map_delete_elem = fd_array_map_delete_elem, | |
600 | .map_fd_get_ptr = cgroup_fd_array_get_ptr, | |
601 | .map_fd_put_ptr = cgroup_fd_array_put_ptr, | |
602 | }; | |
4ed8ec52 | 603 | #endif |
56f668df MKL |
604 | |
605 | static struct bpf_map *array_of_map_alloc(union bpf_attr *attr) | |
606 | { | |
607 | struct bpf_map *map, *inner_map_meta; | |
608 | ||
609 | inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd); | |
610 | if (IS_ERR(inner_map_meta)) | |
611 | return inner_map_meta; | |
612 | ||
613 | map = fd_array_map_alloc(attr); | |
614 | if (IS_ERR(map)) { | |
615 | bpf_map_meta_free(inner_map_meta); | |
616 | return map; | |
617 | } | |
618 | ||
619 | map->inner_map_meta = inner_map_meta; | |
620 | ||
621 | return map; | |
622 | } | |
623 | ||
624 | static void array_of_map_free(struct bpf_map *map) | |
625 | { | |
626 | /* map->inner_map_meta is only accessed by syscall which | |
627 | * is protected by fdget/fdput. | |
628 | */ | |
629 | bpf_map_meta_free(map->inner_map_meta); | |
630 | bpf_fd_array_map_clear(map); | |
631 | fd_array_map_free(map); | |
632 | } | |
633 | ||
634 | static void *array_of_map_lookup_elem(struct bpf_map *map, void *key) | |
635 | { | |
636 | struct bpf_map **inner_map = array_map_lookup_elem(map, key); | |
637 | ||
638 | if (!inner_map) | |
639 | return NULL; | |
640 | ||
641 | return READ_ONCE(*inner_map); | |
642 | } | |
643 | ||
7b0c2a05 DB |
644 | static u32 array_of_map_gen_lookup(struct bpf_map *map, |
645 | struct bpf_insn *insn_buf) | |
646 | { | |
b2157399 | 647 | struct bpf_array *array = container_of(map, struct bpf_array, map); |
7b0c2a05 DB |
648 | u32 elem_size = round_up(map->value_size, 8); |
649 | struct bpf_insn *insn = insn_buf; | |
650 | const int ret = BPF_REG_0; | |
651 | const int map_ptr = BPF_REG_1; | |
652 | const int index = BPF_REG_2; | |
653 | ||
654 | *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value)); | |
655 | *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0); | |
b2157399 AS |
656 | if (map->unpriv_array) { |
657 | *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 6); | |
658 | *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask); | |
659 | } else { | |
660 | *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5); | |
661 | } | |
7b0c2a05 DB |
662 | if (is_power_of_2(elem_size)) |
663 | *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size)); | |
664 | else | |
665 | *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size); | |
666 | *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr); | |
667 | *insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0); | |
668 | *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1); | |
669 | *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1); | |
670 | *insn++ = BPF_MOV64_IMM(ret, 0); | |
671 | ||
672 | return insn - insn_buf; | |
673 | } | |
674 | ||
40077e0c | 675 | const struct bpf_map_ops array_of_maps_map_ops = { |
56f668df MKL |
676 | .map_alloc = array_of_map_alloc, |
677 | .map_free = array_of_map_free, | |
678 | .map_get_next_key = array_map_get_next_key, | |
679 | .map_lookup_elem = array_of_map_lookup_elem, | |
680 | .map_delete_elem = fd_array_map_delete_elem, | |
681 | .map_fd_get_ptr = bpf_map_fd_get_ptr, | |
682 | .map_fd_put_ptr = bpf_map_fd_put_ptr, | |
14dc6f04 | 683 | .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem, |
7b0c2a05 | 684 | .map_gen_lookup = array_of_map_gen_lookup, |
56f668df | 685 | }; |