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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 | ||
a10423b8 AS |
22 | static void bpf_array_free_percpu(struct bpf_array *array) |
23 | { | |
24 | int i; | |
25 | ||
26 | for (i = 0; i < array->map.max_entries; i++) | |
27 | free_percpu(array->pptrs[i]); | |
28 | } | |
29 | ||
30 | static int bpf_array_alloc_percpu(struct bpf_array *array) | |
31 | { | |
32 | void __percpu *ptr; | |
33 | int i; | |
34 | ||
35 | for (i = 0; i < array->map.max_entries; i++) { | |
36 | ptr = __alloc_percpu_gfp(array->elem_size, 8, | |
37 | GFP_USER | __GFP_NOWARN); | |
38 | if (!ptr) { | |
39 | bpf_array_free_percpu(array); | |
40 | return -ENOMEM; | |
41 | } | |
42 | array->pptrs[i] = ptr; | |
43 | } | |
44 | ||
45 | return 0; | |
46 | } | |
47 | ||
28fbcfa0 AS |
48 | /* Called from syscall */ |
49 | static struct bpf_map *array_map_alloc(union bpf_attr *attr) | |
50 | { | |
a10423b8 | 51 | bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; |
96eabe7a | 52 | int numa_node = bpf_map_attr_numa_node(attr); |
28fbcfa0 | 53 | struct bpf_array *array; |
a10423b8 AS |
54 | u64 array_size; |
55 | u32 elem_size; | |
28fbcfa0 AS |
56 | |
57 | /* check sanity of attributes */ | |
58 | if (attr->max_entries == 0 || attr->key_size != 4 || | |
96eabe7a MKL |
59 | attr->value_size == 0 || attr->map_flags & ~BPF_F_NUMA_NODE || |
60 | (percpu && numa_node != NUMA_NO_NODE)) | |
28fbcfa0 AS |
61 | return ERR_PTR(-EINVAL); |
62 | ||
7984c27c | 63 | if (attr->value_size > KMALLOC_MAX_SIZE) |
01b3f521 AS |
64 | /* if value_size is bigger, the user space won't be able to |
65 | * access the elements. | |
66 | */ | |
67 | return ERR_PTR(-E2BIG); | |
68 | ||
28fbcfa0 AS |
69 | elem_size = round_up(attr->value_size, 8); |
70 | ||
a10423b8 AS |
71 | array_size = sizeof(*array); |
72 | if (percpu) | |
73 | array_size += (u64) attr->max_entries * sizeof(void *); | |
74 | else | |
75 | array_size += (u64) attr->max_entries * elem_size; | |
76 | ||
77 | /* make sure there is no u32 overflow later in round_up() */ | |
78 | if (array_size >= U32_MAX - PAGE_SIZE) | |
daaf427c AS |
79 | return ERR_PTR(-ENOMEM); |
80 | ||
28fbcfa0 | 81 | /* allocate all map elements and zero-initialize them */ |
96eabe7a | 82 | array = bpf_map_area_alloc(array_size, numa_node); |
d407bd25 DB |
83 | if (!array) |
84 | return ERR_PTR(-ENOMEM); | |
28fbcfa0 AS |
85 | |
86 | /* copy mandatory map attributes */ | |
a10423b8 | 87 | array->map.map_type = attr->map_type; |
28fbcfa0 AS |
88 | array->map.key_size = attr->key_size; |
89 | array->map.value_size = attr->value_size; | |
90 | array->map.max_entries = attr->max_entries; | |
a316338c | 91 | array->map.map_flags = attr->map_flags; |
96eabe7a | 92 | array->map.numa_node = numa_node; |
28fbcfa0 AS |
93 | array->elem_size = elem_size; |
94 | ||
a10423b8 AS |
95 | if (!percpu) |
96 | goto out; | |
97 | ||
98 | array_size += (u64) attr->max_entries * elem_size * num_possible_cpus(); | |
99 | ||
100 | if (array_size >= U32_MAX - PAGE_SIZE || | |
bc6d5031 | 101 | bpf_array_alloc_percpu(array)) { |
d407bd25 | 102 | bpf_map_area_free(array); |
a10423b8 AS |
103 | return ERR_PTR(-ENOMEM); |
104 | } | |
105 | out: | |
106 | array->map.pages = round_up(array_size, PAGE_SIZE) >> PAGE_SHIFT; | |
107 | ||
28fbcfa0 | 108 | return &array->map; |
28fbcfa0 AS |
109 | } |
110 | ||
111 | /* Called from syscall or from eBPF program */ | |
112 | static void *array_map_lookup_elem(struct bpf_map *map, void *key) | |
113 | { | |
114 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
115 | u32 index = *(u32 *)key; | |
116 | ||
a10423b8 | 117 | if (unlikely(index >= array->map.max_entries)) |
28fbcfa0 AS |
118 | return NULL; |
119 | ||
120 | return array->value + array->elem_size * index; | |
121 | } | |
122 | ||
81ed18ab AS |
123 | /* emit BPF instructions equivalent to C code of array_map_lookup_elem() */ |
124 | static u32 array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) | |
125 | { | |
81ed18ab | 126 | struct bpf_insn *insn = insn_buf; |
fad73a1a | 127 | u32 elem_size = round_up(map->value_size, 8); |
81ed18ab AS |
128 | const int ret = BPF_REG_0; |
129 | const int map_ptr = BPF_REG_1; | |
130 | const int index = BPF_REG_2; | |
131 | ||
132 | *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value)); | |
133 | *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0); | |
fad73a1a MKL |
134 | *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 3); |
135 | ||
136 | if (is_power_of_2(elem_size)) { | |
81ed18ab AS |
137 | *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size)); |
138 | } else { | |
139 | *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size); | |
140 | } | |
141 | *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr); | |
142 | *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1); | |
143 | *insn++ = BPF_MOV64_IMM(ret, 0); | |
144 | return insn - insn_buf; | |
145 | } | |
146 | ||
a10423b8 AS |
147 | /* Called from eBPF program */ |
148 | static void *percpu_array_map_lookup_elem(struct bpf_map *map, void *key) | |
149 | { | |
150 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
151 | u32 index = *(u32 *)key; | |
152 | ||
153 | if (unlikely(index >= array->map.max_entries)) | |
154 | return NULL; | |
155 | ||
156 | return this_cpu_ptr(array->pptrs[index]); | |
157 | } | |
158 | ||
15a07b33 AS |
159 | int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value) |
160 | { | |
161 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
162 | u32 index = *(u32 *)key; | |
163 | void __percpu *pptr; | |
164 | int cpu, off = 0; | |
165 | u32 size; | |
166 | ||
167 | if (unlikely(index >= array->map.max_entries)) | |
168 | return -ENOENT; | |
169 | ||
170 | /* per_cpu areas are zero-filled and bpf programs can only | |
171 | * access 'value_size' of them, so copying rounded areas | |
172 | * will not leak any kernel data | |
173 | */ | |
174 | size = round_up(map->value_size, 8); | |
175 | rcu_read_lock(); | |
176 | pptr = array->pptrs[index]; | |
177 | for_each_possible_cpu(cpu) { | |
178 | bpf_long_memcpy(value + off, per_cpu_ptr(pptr, cpu), size); | |
179 | off += size; | |
180 | } | |
181 | rcu_read_unlock(); | |
182 | return 0; | |
183 | } | |
184 | ||
28fbcfa0 AS |
185 | /* Called from syscall */ |
186 | static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key) | |
187 | { | |
188 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
8fe45924 | 189 | u32 index = key ? *(u32 *)key : U32_MAX; |
28fbcfa0 AS |
190 | u32 *next = (u32 *)next_key; |
191 | ||
192 | if (index >= array->map.max_entries) { | |
193 | *next = 0; | |
194 | return 0; | |
195 | } | |
196 | ||
197 | if (index == array->map.max_entries - 1) | |
198 | return -ENOENT; | |
199 | ||
200 | *next = index + 1; | |
201 | return 0; | |
202 | } | |
203 | ||
204 | /* Called from syscall or from eBPF program */ | |
205 | static int array_map_update_elem(struct bpf_map *map, void *key, void *value, | |
206 | u64 map_flags) | |
207 | { | |
208 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
209 | u32 index = *(u32 *)key; | |
210 | ||
a10423b8 | 211 | if (unlikely(map_flags > BPF_EXIST)) |
28fbcfa0 AS |
212 | /* unknown flags */ |
213 | return -EINVAL; | |
214 | ||
a10423b8 | 215 | if (unlikely(index >= array->map.max_entries)) |
28fbcfa0 AS |
216 | /* all elements were pre-allocated, cannot insert a new one */ |
217 | return -E2BIG; | |
218 | ||
a10423b8 | 219 | if (unlikely(map_flags == BPF_NOEXIST)) |
daaf427c | 220 | /* all elements already exist */ |
28fbcfa0 AS |
221 | return -EEXIST; |
222 | ||
a10423b8 AS |
223 | if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) |
224 | memcpy(this_cpu_ptr(array->pptrs[index]), | |
225 | value, map->value_size); | |
226 | else | |
227 | memcpy(array->value + array->elem_size * index, | |
228 | value, map->value_size); | |
28fbcfa0 AS |
229 | return 0; |
230 | } | |
231 | ||
15a07b33 AS |
232 | int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, |
233 | u64 map_flags) | |
234 | { | |
235 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
236 | u32 index = *(u32 *)key; | |
237 | void __percpu *pptr; | |
238 | int cpu, off = 0; | |
239 | u32 size; | |
240 | ||
241 | if (unlikely(map_flags > BPF_EXIST)) | |
242 | /* unknown flags */ | |
243 | return -EINVAL; | |
244 | ||
245 | if (unlikely(index >= array->map.max_entries)) | |
246 | /* all elements were pre-allocated, cannot insert a new one */ | |
247 | return -E2BIG; | |
248 | ||
249 | if (unlikely(map_flags == BPF_NOEXIST)) | |
250 | /* all elements already exist */ | |
251 | return -EEXIST; | |
252 | ||
253 | /* the user space will provide round_up(value_size, 8) bytes that | |
254 | * will be copied into per-cpu area. bpf programs can only access | |
255 | * value_size of it. During lookup the same extra bytes will be | |
256 | * returned or zeros which were zero-filled by percpu_alloc, | |
257 | * so no kernel data leaks possible | |
258 | */ | |
259 | size = round_up(map->value_size, 8); | |
260 | rcu_read_lock(); | |
261 | pptr = array->pptrs[index]; | |
262 | for_each_possible_cpu(cpu) { | |
263 | bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value + off, size); | |
264 | off += size; | |
265 | } | |
266 | rcu_read_unlock(); | |
267 | return 0; | |
268 | } | |
269 | ||
28fbcfa0 AS |
270 | /* Called from syscall or from eBPF program */ |
271 | static int array_map_delete_elem(struct bpf_map *map, void *key) | |
272 | { | |
273 | return -EINVAL; | |
274 | } | |
275 | ||
276 | /* Called when map->refcnt goes to zero, either from workqueue or from syscall */ | |
277 | static void array_map_free(struct bpf_map *map) | |
278 | { | |
279 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
280 | ||
281 | /* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0, | |
282 | * so the programs (can be more than one that used this map) were | |
283 | * disconnected from events. Wait for outstanding programs to complete | |
284 | * and free the array | |
285 | */ | |
286 | synchronize_rcu(); | |
287 | ||
a10423b8 AS |
288 | if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) |
289 | bpf_array_free_percpu(array); | |
290 | ||
d407bd25 | 291 | bpf_map_area_free(array); |
28fbcfa0 AS |
292 | } |
293 | ||
40077e0c | 294 | const struct bpf_map_ops array_map_ops = { |
28fbcfa0 AS |
295 | .map_alloc = array_map_alloc, |
296 | .map_free = array_map_free, | |
297 | .map_get_next_key = array_map_get_next_key, | |
298 | .map_lookup_elem = array_map_lookup_elem, | |
299 | .map_update_elem = array_map_update_elem, | |
300 | .map_delete_elem = array_map_delete_elem, | |
81ed18ab | 301 | .map_gen_lookup = array_map_gen_lookup, |
28fbcfa0 AS |
302 | }; |
303 | ||
40077e0c | 304 | const struct bpf_map_ops percpu_array_map_ops = { |
a10423b8 AS |
305 | .map_alloc = array_map_alloc, |
306 | .map_free = array_map_free, | |
307 | .map_get_next_key = array_map_get_next_key, | |
308 | .map_lookup_elem = percpu_array_map_lookup_elem, | |
309 | .map_update_elem = array_map_update_elem, | |
310 | .map_delete_elem = array_map_delete_elem, | |
311 | }; | |
312 | ||
2a36f0b9 | 313 | static struct bpf_map *fd_array_map_alloc(union bpf_attr *attr) |
04fd61ab | 314 | { |
2a36f0b9 | 315 | /* only file descriptors can be stored in this type of map */ |
04fd61ab AS |
316 | if (attr->value_size != sizeof(u32)) |
317 | return ERR_PTR(-EINVAL); | |
318 | return array_map_alloc(attr); | |
319 | } | |
320 | ||
2a36f0b9 | 321 | static void fd_array_map_free(struct bpf_map *map) |
04fd61ab AS |
322 | { |
323 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
324 | int i; | |
325 | ||
326 | synchronize_rcu(); | |
327 | ||
328 | /* make sure it's empty */ | |
329 | for (i = 0; i < array->map.max_entries; i++) | |
2a36f0b9 | 330 | BUG_ON(array->ptrs[i] != NULL); |
d407bd25 DB |
331 | |
332 | bpf_map_area_free(array); | |
04fd61ab AS |
333 | } |
334 | ||
2a36f0b9 | 335 | static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key) |
04fd61ab AS |
336 | { |
337 | return NULL; | |
338 | } | |
339 | ||
14dc6f04 MKL |
340 | /* only called from syscall */ |
341 | int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value) | |
342 | { | |
343 | void **elem, *ptr; | |
344 | int ret = 0; | |
345 | ||
346 | if (!map->ops->map_fd_sys_lookup_elem) | |
347 | return -ENOTSUPP; | |
348 | ||
349 | rcu_read_lock(); | |
350 | elem = array_map_lookup_elem(map, key); | |
351 | if (elem && (ptr = READ_ONCE(*elem))) | |
352 | *value = map->ops->map_fd_sys_lookup_elem(ptr); | |
353 | else | |
354 | ret = -ENOENT; | |
355 | rcu_read_unlock(); | |
356 | ||
357 | return ret; | |
358 | } | |
359 | ||
04fd61ab | 360 | /* only called from syscall */ |
d056a788 DB |
361 | int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file, |
362 | void *key, void *value, u64 map_flags) | |
04fd61ab AS |
363 | { |
364 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
2a36f0b9 | 365 | void *new_ptr, *old_ptr; |
04fd61ab AS |
366 | u32 index = *(u32 *)key, ufd; |
367 | ||
368 | if (map_flags != BPF_ANY) | |
369 | return -EINVAL; | |
370 | ||
371 | if (index >= array->map.max_entries) | |
372 | return -E2BIG; | |
373 | ||
374 | ufd = *(u32 *)value; | |
d056a788 | 375 | new_ptr = map->ops->map_fd_get_ptr(map, map_file, ufd); |
2a36f0b9 WN |
376 | if (IS_ERR(new_ptr)) |
377 | return PTR_ERR(new_ptr); | |
04fd61ab | 378 | |
2a36f0b9 WN |
379 | old_ptr = xchg(array->ptrs + index, new_ptr); |
380 | if (old_ptr) | |
381 | map->ops->map_fd_put_ptr(old_ptr); | |
04fd61ab AS |
382 | |
383 | return 0; | |
384 | } | |
385 | ||
2a36f0b9 | 386 | static int fd_array_map_delete_elem(struct bpf_map *map, void *key) |
04fd61ab AS |
387 | { |
388 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
2a36f0b9 | 389 | void *old_ptr; |
04fd61ab AS |
390 | u32 index = *(u32 *)key; |
391 | ||
392 | if (index >= array->map.max_entries) | |
393 | return -E2BIG; | |
394 | ||
2a36f0b9 WN |
395 | old_ptr = xchg(array->ptrs + index, NULL); |
396 | if (old_ptr) { | |
397 | map->ops->map_fd_put_ptr(old_ptr); | |
04fd61ab AS |
398 | return 0; |
399 | } else { | |
400 | return -ENOENT; | |
401 | } | |
402 | } | |
403 | ||
d056a788 DB |
404 | static void *prog_fd_array_get_ptr(struct bpf_map *map, |
405 | struct file *map_file, int fd) | |
2a36f0b9 WN |
406 | { |
407 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
408 | struct bpf_prog *prog = bpf_prog_get(fd); | |
d056a788 | 409 | |
2a36f0b9 WN |
410 | if (IS_ERR(prog)) |
411 | return prog; | |
412 | ||
413 | if (!bpf_prog_array_compatible(array, prog)) { | |
414 | bpf_prog_put(prog); | |
415 | return ERR_PTR(-EINVAL); | |
416 | } | |
d056a788 | 417 | |
2a36f0b9 WN |
418 | return prog; |
419 | } | |
420 | ||
421 | static void prog_fd_array_put_ptr(void *ptr) | |
422 | { | |
1aacde3d | 423 | bpf_prog_put(ptr); |
2a36f0b9 WN |
424 | } |
425 | ||
14dc6f04 MKL |
426 | static u32 prog_fd_array_sys_lookup_elem(void *ptr) |
427 | { | |
428 | return ((struct bpf_prog *)ptr)->aux->id; | |
429 | } | |
430 | ||
04fd61ab | 431 | /* decrement refcnt of all bpf_progs that are stored in this map */ |
2a36f0b9 | 432 | void bpf_fd_array_map_clear(struct bpf_map *map) |
04fd61ab AS |
433 | { |
434 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
435 | int i; | |
436 | ||
437 | for (i = 0; i < array->map.max_entries; i++) | |
2a36f0b9 | 438 | fd_array_map_delete_elem(map, &i); |
04fd61ab AS |
439 | } |
440 | ||
40077e0c | 441 | const struct bpf_map_ops prog_array_map_ops = { |
2a36f0b9 WN |
442 | .map_alloc = fd_array_map_alloc, |
443 | .map_free = fd_array_map_free, | |
04fd61ab | 444 | .map_get_next_key = array_map_get_next_key, |
2a36f0b9 | 445 | .map_lookup_elem = fd_array_map_lookup_elem, |
2a36f0b9 WN |
446 | .map_delete_elem = fd_array_map_delete_elem, |
447 | .map_fd_get_ptr = prog_fd_array_get_ptr, | |
448 | .map_fd_put_ptr = prog_fd_array_put_ptr, | |
14dc6f04 | 449 | .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem, |
04fd61ab AS |
450 | }; |
451 | ||
3b1efb19 DB |
452 | static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file, |
453 | struct file *map_file) | |
ea317b26 | 454 | { |
3b1efb19 DB |
455 | struct bpf_event_entry *ee; |
456 | ||
858d68f1 | 457 | ee = kzalloc(sizeof(*ee), GFP_ATOMIC); |
3b1efb19 DB |
458 | if (ee) { |
459 | ee->event = perf_file->private_data; | |
460 | ee->perf_file = perf_file; | |
461 | ee->map_file = map_file; | |
462 | } | |
463 | ||
464 | return ee; | |
465 | } | |
466 | ||
467 | static void __bpf_event_entry_free(struct rcu_head *rcu) | |
468 | { | |
469 | struct bpf_event_entry *ee; | |
470 | ||
471 | ee = container_of(rcu, struct bpf_event_entry, rcu); | |
472 | fput(ee->perf_file); | |
473 | kfree(ee); | |
474 | } | |
475 | ||
476 | static void bpf_event_entry_free_rcu(struct bpf_event_entry *ee) | |
477 | { | |
478 | call_rcu(&ee->rcu, __bpf_event_entry_free); | |
ea317b26 KX |
479 | } |
480 | ||
d056a788 DB |
481 | static void *perf_event_fd_array_get_ptr(struct bpf_map *map, |
482 | struct file *map_file, int fd) | |
ea317b26 | 483 | { |
3b1efb19 DB |
484 | struct bpf_event_entry *ee; |
485 | struct perf_event *event; | |
486 | struct file *perf_file; | |
f91840a3 | 487 | u64 value; |
ea317b26 | 488 | |
3b1efb19 DB |
489 | perf_file = perf_event_get(fd); |
490 | if (IS_ERR(perf_file)) | |
491 | return perf_file; | |
e03e7ee3 | 492 | |
f91840a3 | 493 | ee = ERR_PTR(-EOPNOTSUPP); |
3b1efb19 | 494 | event = perf_file->private_data; |
f91840a3 | 495 | if (perf_event_read_local(event, &value) == -EOPNOTSUPP) |
3b1efb19 DB |
496 | goto err_out; |
497 | ||
f91840a3 AS |
498 | ee = bpf_event_entry_gen(perf_file, map_file); |
499 | if (ee) | |
500 | return ee; | |
501 | ee = ERR_PTR(-ENOMEM); | |
3b1efb19 DB |
502 | err_out: |
503 | fput(perf_file); | |
504 | return ee; | |
ea317b26 KX |
505 | } |
506 | ||
507 | static void perf_event_fd_array_put_ptr(void *ptr) | |
508 | { | |
3b1efb19 DB |
509 | bpf_event_entry_free_rcu(ptr); |
510 | } | |
511 | ||
512 | static void perf_event_fd_array_release(struct bpf_map *map, | |
513 | struct file *map_file) | |
514 | { | |
515 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
516 | struct bpf_event_entry *ee; | |
517 | int i; | |
518 | ||
519 | rcu_read_lock(); | |
520 | for (i = 0; i < array->map.max_entries; i++) { | |
521 | ee = READ_ONCE(array->ptrs[i]); | |
522 | if (ee && ee->map_file == map_file) | |
523 | fd_array_map_delete_elem(map, &i); | |
524 | } | |
525 | rcu_read_unlock(); | |
ea317b26 KX |
526 | } |
527 | ||
40077e0c | 528 | const struct bpf_map_ops perf_event_array_map_ops = { |
ea317b26 | 529 | .map_alloc = fd_array_map_alloc, |
3b1efb19 | 530 | .map_free = fd_array_map_free, |
ea317b26 KX |
531 | .map_get_next_key = array_map_get_next_key, |
532 | .map_lookup_elem = fd_array_map_lookup_elem, | |
ea317b26 KX |
533 | .map_delete_elem = fd_array_map_delete_elem, |
534 | .map_fd_get_ptr = perf_event_fd_array_get_ptr, | |
535 | .map_fd_put_ptr = perf_event_fd_array_put_ptr, | |
3b1efb19 | 536 | .map_release = perf_event_fd_array_release, |
ea317b26 KX |
537 | }; |
538 | ||
60d20f91 | 539 | #ifdef CONFIG_CGROUPS |
4ed8ec52 MKL |
540 | static void *cgroup_fd_array_get_ptr(struct bpf_map *map, |
541 | struct file *map_file /* not used */, | |
542 | int fd) | |
543 | { | |
544 | return cgroup_get_from_fd(fd); | |
545 | } | |
546 | ||
547 | static void cgroup_fd_array_put_ptr(void *ptr) | |
548 | { | |
549 | /* cgroup_put free cgrp after a rcu grace period */ | |
550 | cgroup_put(ptr); | |
551 | } | |
552 | ||
553 | static void cgroup_fd_array_free(struct bpf_map *map) | |
554 | { | |
555 | bpf_fd_array_map_clear(map); | |
556 | fd_array_map_free(map); | |
557 | } | |
558 | ||
40077e0c | 559 | const struct bpf_map_ops cgroup_array_map_ops = { |
4ed8ec52 MKL |
560 | .map_alloc = fd_array_map_alloc, |
561 | .map_free = cgroup_fd_array_free, | |
562 | .map_get_next_key = array_map_get_next_key, | |
563 | .map_lookup_elem = fd_array_map_lookup_elem, | |
564 | .map_delete_elem = fd_array_map_delete_elem, | |
565 | .map_fd_get_ptr = cgroup_fd_array_get_ptr, | |
566 | .map_fd_put_ptr = cgroup_fd_array_put_ptr, | |
567 | }; | |
4ed8ec52 | 568 | #endif |
56f668df MKL |
569 | |
570 | static struct bpf_map *array_of_map_alloc(union bpf_attr *attr) | |
571 | { | |
572 | struct bpf_map *map, *inner_map_meta; | |
573 | ||
574 | inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd); | |
575 | if (IS_ERR(inner_map_meta)) | |
576 | return inner_map_meta; | |
577 | ||
578 | map = fd_array_map_alloc(attr); | |
579 | if (IS_ERR(map)) { | |
580 | bpf_map_meta_free(inner_map_meta); | |
581 | return map; | |
582 | } | |
583 | ||
584 | map->inner_map_meta = inner_map_meta; | |
585 | ||
586 | return map; | |
587 | } | |
588 | ||
589 | static void array_of_map_free(struct bpf_map *map) | |
590 | { | |
591 | /* map->inner_map_meta is only accessed by syscall which | |
592 | * is protected by fdget/fdput. | |
593 | */ | |
594 | bpf_map_meta_free(map->inner_map_meta); | |
595 | bpf_fd_array_map_clear(map); | |
596 | fd_array_map_free(map); | |
597 | } | |
598 | ||
599 | static void *array_of_map_lookup_elem(struct bpf_map *map, void *key) | |
600 | { | |
601 | struct bpf_map **inner_map = array_map_lookup_elem(map, key); | |
602 | ||
603 | if (!inner_map) | |
604 | return NULL; | |
605 | ||
606 | return READ_ONCE(*inner_map); | |
607 | } | |
608 | ||
7b0c2a05 DB |
609 | static u32 array_of_map_gen_lookup(struct bpf_map *map, |
610 | struct bpf_insn *insn_buf) | |
611 | { | |
612 | u32 elem_size = round_up(map->value_size, 8); | |
613 | struct bpf_insn *insn = insn_buf; | |
614 | const int ret = BPF_REG_0; | |
615 | const int map_ptr = BPF_REG_1; | |
616 | const int index = BPF_REG_2; | |
617 | ||
618 | *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value)); | |
619 | *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0); | |
620 | *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5); | |
621 | if (is_power_of_2(elem_size)) | |
622 | *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size)); | |
623 | else | |
624 | *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size); | |
625 | *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr); | |
626 | *insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0); | |
627 | *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1); | |
628 | *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1); | |
629 | *insn++ = BPF_MOV64_IMM(ret, 0); | |
630 | ||
631 | return insn - insn_buf; | |
632 | } | |
633 | ||
40077e0c | 634 | const struct bpf_map_ops array_of_maps_map_ops = { |
56f668df MKL |
635 | .map_alloc = array_of_map_alloc, |
636 | .map_free = array_of_map_free, | |
637 | .map_get_next_key = array_map_get_next_key, | |
638 | .map_lookup_elem = array_of_map_lookup_elem, | |
639 | .map_delete_elem = fd_array_map_delete_elem, | |
640 | .map_fd_get_ptr = bpf_map_fd_get_ptr, | |
641 | .map_fd_put_ptr = bpf_map_fd_put_ptr, | |
14dc6f04 | 642 | .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem, |
7b0c2a05 | 643 | .map_gen_lookup = array_of_map_gen_lookup, |
56f668df | 644 | }; |