]>
Commit | Line | Data |
---|---|---|
28fbcfa0 AS |
1 | /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com |
2 | * | |
3 | * This program is free software; you can redistribute it and/or | |
4 | * modify it under the terms of version 2 of the GNU General Public | |
5 | * License as published by the Free Software Foundation. | |
6 | * | |
7 | * This program is distributed in the hope that it will be useful, but | |
8 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
10 | * General Public License for more details. | |
11 | */ | |
12 | #include <linux/bpf.h> | |
13 | #include <linux/err.h> | |
14 | #include <linux/vmalloc.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/mm.h> | |
04fd61ab | 17 | #include <linux/filter.h> |
0cdf5640 | 18 | #include <linux/perf_event.h> |
28fbcfa0 AS |
19 | |
20 | /* Called from syscall */ | |
21 | static struct bpf_map *array_map_alloc(union bpf_attr *attr) | |
22 | { | |
23 | struct bpf_array *array; | |
daaf427c | 24 | u32 elem_size, array_size; |
28fbcfa0 AS |
25 | |
26 | /* check sanity of attributes */ | |
27 | if (attr->max_entries == 0 || attr->key_size != 4 || | |
28 | attr->value_size == 0) | |
29 | return ERR_PTR(-EINVAL); | |
30 | ||
01b3f521 AS |
31 | if (attr->value_size >= 1 << (KMALLOC_SHIFT_MAX - 1)) |
32 | /* if value_size is bigger, the user space won't be able to | |
33 | * access the elements. | |
34 | */ | |
35 | return ERR_PTR(-E2BIG); | |
36 | ||
28fbcfa0 AS |
37 | elem_size = round_up(attr->value_size, 8); |
38 | ||
daaf427c AS |
39 | /* check round_up into zero and u32 overflow */ |
40 | if (elem_size == 0 || | |
01b3f521 | 41 | attr->max_entries > (U32_MAX - PAGE_SIZE - sizeof(*array)) / elem_size) |
daaf427c AS |
42 | return ERR_PTR(-ENOMEM); |
43 | ||
44 | array_size = sizeof(*array) + attr->max_entries * elem_size; | |
45 | ||
28fbcfa0 | 46 | /* allocate all map elements and zero-initialize them */ |
daaf427c | 47 | array = kzalloc(array_size, GFP_USER | __GFP_NOWARN); |
28fbcfa0 | 48 | if (!array) { |
daaf427c | 49 | array = vzalloc(array_size); |
28fbcfa0 AS |
50 | if (!array) |
51 | return ERR_PTR(-ENOMEM); | |
52 | } | |
53 | ||
54 | /* copy mandatory map attributes */ | |
55 | array->map.key_size = attr->key_size; | |
56 | array->map.value_size = attr->value_size; | |
57 | array->map.max_entries = attr->max_entries; | |
aaac3ba9 | 58 | array->map.pages = round_up(array_size, PAGE_SIZE) >> PAGE_SHIFT; |
28fbcfa0 AS |
59 | array->elem_size = elem_size; |
60 | ||
61 | return &array->map; | |
28fbcfa0 AS |
62 | } |
63 | ||
64 | /* Called from syscall or from eBPF program */ | |
65 | static void *array_map_lookup_elem(struct bpf_map *map, void *key) | |
66 | { | |
67 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
68 | u32 index = *(u32 *)key; | |
69 | ||
70 | if (index >= array->map.max_entries) | |
71 | return NULL; | |
72 | ||
73 | return array->value + array->elem_size * index; | |
74 | } | |
75 | ||
76 | /* Called from syscall */ | |
77 | static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key) | |
78 | { | |
79 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
80 | u32 index = *(u32 *)key; | |
81 | u32 *next = (u32 *)next_key; | |
82 | ||
83 | if (index >= array->map.max_entries) { | |
84 | *next = 0; | |
85 | return 0; | |
86 | } | |
87 | ||
88 | if (index == array->map.max_entries - 1) | |
89 | return -ENOENT; | |
90 | ||
91 | *next = index + 1; | |
92 | return 0; | |
93 | } | |
94 | ||
95 | /* Called from syscall or from eBPF program */ | |
96 | static int array_map_update_elem(struct bpf_map *map, void *key, void *value, | |
97 | u64 map_flags) | |
98 | { | |
99 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
100 | u32 index = *(u32 *)key; | |
101 | ||
102 | if (map_flags > BPF_EXIST) | |
103 | /* unknown flags */ | |
104 | return -EINVAL; | |
105 | ||
106 | if (index >= array->map.max_entries) | |
107 | /* all elements were pre-allocated, cannot insert a new one */ | |
108 | return -E2BIG; | |
109 | ||
110 | if (map_flags == BPF_NOEXIST) | |
daaf427c | 111 | /* all elements already exist */ |
28fbcfa0 AS |
112 | return -EEXIST; |
113 | ||
fbca9d2d | 114 | memcpy(array->value + array->elem_size * index, value, map->value_size); |
28fbcfa0 AS |
115 | return 0; |
116 | } | |
117 | ||
118 | /* Called from syscall or from eBPF program */ | |
119 | static int array_map_delete_elem(struct bpf_map *map, void *key) | |
120 | { | |
121 | return -EINVAL; | |
122 | } | |
123 | ||
124 | /* Called when map->refcnt goes to zero, either from workqueue or from syscall */ | |
125 | static void array_map_free(struct bpf_map *map) | |
126 | { | |
127 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
128 | ||
129 | /* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0, | |
130 | * so the programs (can be more than one that used this map) were | |
131 | * disconnected from events. Wait for outstanding programs to complete | |
132 | * and free the array | |
133 | */ | |
134 | synchronize_rcu(); | |
135 | ||
136 | kvfree(array); | |
137 | } | |
138 | ||
a2c83fff | 139 | static const struct bpf_map_ops array_ops = { |
28fbcfa0 AS |
140 | .map_alloc = array_map_alloc, |
141 | .map_free = array_map_free, | |
142 | .map_get_next_key = array_map_get_next_key, | |
143 | .map_lookup_elem = array_map_lookup_elem, | |
144 | .map_update_elem = array_map_update_elem, | |
145 | .map_delete_elem = array_map_delete_elem, | |
146 | }; | |
147 | ||
a2c83fff | 148 | static struct bpf_map_type_list array_type __read_mostly = { |
28fbcfa0 AS |
149 | .ops = &array_ops, |
150 | .type = BPF_MAP_TYPE_ARRAY, | |
151 | }; | |
152 | ||
153 | static int __init register_array_map(void) | |
154 | { | |
a2c83fff | 155 | bpf_register_map_type(&array_type); |
28fbcfa0 AS |
156 | return 0; |
157 | } | |
158 | late_initcall(register_array_map); | |
04fd61ab | 159 | |
2a36f0b9 | 160 | static struct bpf_map *fd_array_map_alloc(union bpf_attr *attr) |
04fd61ab | 161 | { |
2a36f0b9 | 162 | /* only file descriptors can be stored in this type of map */ |
04fd61ab AS |
163 | if (attr->value_size != sizeof(u32)) |
164 | return ERR_PTR(-EINVAL); | |
165 | return array_map_alloc(attr); | |
166 | } | |
167 | ||
2a36f0b9 | 168 | static void fd_array_map_free(struct bpf_map *map) |
04fd61ab AS |
169 | { |
170 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
171 | int i; | |
172 | ||
173 | synchronize_rcu(); | |
174 | ||
175 | /* make sure it's empty */ | |
176 | for (i = 0; i < array->map.max_entries; i++) | |
2a36f0b9 | 177 | BUG_ON(array->ptrs[i] != NULL); |
04fd61ab AS |
178 | kvfree(array); |
179 | } | |
180 | ||
2a36f0b9 | 181 | static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key) |
04fd61ab AS |
182 | { |
183 | return NULL; | |
184 | } | |
185 | ||
186 | /* only called from syscall */ | |
2a36f0b9 WN |
187 | static int fd_array_map_update_elem(struct bpf_map *map, void *key, |
188 | void *value, u64 map_flags) | |
04fd61ab AS |
189 | { |
190 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
2a36f0b9 | 191 | void *new_ptr, *old_ptr; |
04fd61ab AS |
192 | u32 index = *(u32 *)key, ufd; |
193 | ||
194 | if (map_flags != BPF_ANY) | |
195 | return -EINVAL; | |
196 | ||
197 | if (index >= array->map.max_entries) | |
198 | return -E2BIG; | |
199 | ||
200 | ufd = *(u32 *)value; | |
2a36f0b9 WN |
201 | new_ptr = map->ops->map_fd_get_ptr(map, ufd); |
202 | if (IS_ERR(new_ptr)) | |
203 | return PTR_ERR(new_ptr); | |
04fd61ab | 204 | |
2a36f0b9 WN |
205 | old_ptr = xchg(array->ptrs + index, new_ptr); |
206 | if (old_ptr) | |
207 | map->ops->map_fd_put_ptr(old_ptr); | |
04fd61ab AS |
208 | |
209 | return 0; | |
210 | } | |
211 | ||
2a36f0b9 | 212 | static int fd_array_map_delete_elem(struct bpf_map *map, void *key) |
04fd61ab AS |
213 | { |
214 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
2a36f0b9 | 215 | void *old_ptr; |
04fd61ab AS |
216 | u32 index = *(u32 *)key; |
217 | ||
218 | if (index >= array->map.max_entries) | |
219 | return -E2BIG; | |
220 | ||
2a36f0b9 WN |
221 | old_ptr = xchg(array->ptrs + index, NULL); |
222 | if (old_ptr) { | |
223 | map->ops->map_fd_put_ptr(old_ptr); | |
04fd61ab AS |
224 | return 0; |
225 | } else { | |
226 | return -ENOENT; | |
227 | } | |
228 | } | |
229 | ||
2a36f0b9 WN |
230 | static void *prog_fd_array_get_ptr(struct bpf_map *map, int fd) |
231 | { | |
232 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
233 | struct bpf_prog *prog = bpf_prog_get(fd); | |
234 | if (IS_ERR(prog)) | |
235 | return prog; | |
236 | ||
237 | if (!bpf_prog_array_compatible(array, prog)) { | |
238 | bpf_prog_put(prog); | |
239 | return ERR_PTR(-EINVAL); | |
240 | } | |
241 | return prog; | |
242 | } | |
243 | ||
244 | static void prog_fd_array_put_ptr(void *ptr) | |
245 | { | |
246 | struct bpf_prog *prog = ptr; | |
247 | ||
248 | bpf_prog_put_rcu(prog); | |
249 | } | |
250 | ||
04fd61ab | 251 | /* decrement refcnt of all bpf_progs that are stored in this map */ |
2a36f0b9 | 252 | void bpf_fd_array_map_clear(struct bpf_map *map) |
04fd61ab AS |
253 | { |
254 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
255 | int i; | |
256 | ||
257 | for (i = 0; i < array->map.max_entries; i++) | |
2a36f0b9 | 258 | fd_array_map_delete_elem(map, &i); |
04fd61ab AS |
259 | } |
260 | ||
261 | static const struct bpf_map_ops prog_array_ops = { | |
2a36f0b9 WN |
262 | .map_alloc = fd_array_map_alloc, |
263 | .map_free = fd_array_map_free, | |
04fd61ab | 264 | .map_get_next_key = array_map_get_next_key, |
2a36f0b9 WN |
265 | .map_lookup_elem = fd_array_map_lookup_elem, |
266 | .map_update_elem = fd_array_map_update_elem, | |
267 | .map_delete_elem = fd_array_map_delete_elem, | |
268 | .map_fd_get_ptr = prog_fd_array_get_ptr, | |
269 | .map_fd_put_ptr = prog_fd_array_put_ptr, | |
04fd61ab AS |
270 | }; |
271 | ||
272 | static struct bpf_map_type_list prog_array_type __read_mostly = { | |
273 | .ops = &prog_array_ops, | |
274 | .type = BPF_MAP_TYPE_PROG_ARRAY, | |
275 | }; | |
276 | ||
277 | static int __init register_prog_array_map(void) | |
278 | { | |
279 | bpf_register_map_type(&prog_array_type); | |
280 | return 0; | |
281 | } | |
282 | late_initcall(register_prog_array_map); | |
ea317b26 KX |
283 | |
284 | static void perf_event_array_map_free(struct bpf_map *map) | |
285 | { | |
286 | bpf_fd_array_map_clear(map); | |
287 | fd_array_map_free(map); | |
288 | } | |
289 | ||
290 | static void *perf_event_fd_array_get_ptr(struct bpf_map *map, int fd) | |
291 | { | |
292 | struct perf_event *event; | |
293 | const struct perf_event_attr *attr; | |
e03e7ee3 | 294 | struct file *file; |
ea317b26 | 295 | |
e03e7ee3 AS |
296 | file = perf_event_get(fd); |
297 | if (IS_ERR(file)) | |
298 | return file; | |
299 | ||
300 | event = file->private_data; | |
ea317b26 KX |
301 | |
302 | attr = perf_event_attrs(event); | |
303 | if (IS_ERR(attr)) | |
62544ce8 | 304 | goto err; |
ea317b26 | 305 | |
62544ce8 AS |
306 | if (attr->inherit) |
307 | goto err; | |
308 | ||
309 | if (attr->type == PERF_TYPE_RAW) | |
e03e7ee3 | 310 | return file; |
62544ce8 AS |
311 | |
312 | if (attr->type == PERF_TYPE_HARDWARE) | |
e03e7ee3 | 313 | return file; |
62544ce8 AS |
314 | |
315 | if (attr->type == PERF_TYPE_SOFTWARE && | |
316 | attr->config == PERF_COUNT_SW_BPF_OUTPUT) | |
e03e7ee3 | 317 | return file; |
62544ce8 | 318 | err: |
e03e7ee3 | 319 | fput(file); |
62544ce8 | 320 | return ERR_PTR(-EINVAL); |
ea317b26 KX |
321 | } |
322 | ||
323 | static void perf_event_fd_array_put_ptr(void *ptr) | |
324 | { | |
e03e7ee3 | 325 | fput((struct file *)ptr); |
ea317b26 KX |
326 | } |
327 | ||
328 | static const struct bpf_map_ops perf_event_array_ops = { | |
329 | .map_alloc = fd_array_map_alloc, | |
330 | .map_free = perf_event_array_map_free, | |
331 | .map_get_next_key = array_map_get_next_key, | |
332 | .map_lookup_elem = fd_array_map_lookup_elem, | |
333 | .map_update_elem = fd_array_map_update_elem, | |
334 | .map_delete_elem = fd_array_map_delete_elem, | |
335 | .map_fd_get_ptr = perf_event_fd_array_get_ptr, | |
336 | .map_fd_put_ptr = perf_event_fd_array_put_ptr, | |
337 | }; | |
338 | ||
339 | static struct bpf_map_type_list perf_event_array_type __read_mostly = { | |
340 | .ops = &perf_event_array_ops, | |
341 | .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY, | |
342 | }; | |
343 | ||
344 | static int __init register_perf_event_array_map(void) | |
345 | { | |
346 | bpf_register_map_type(&perf_event_array_type); | |
347 | return 0; | |
348 | } | |
349 | late_initcall(register_perf_event_array_map); |