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5b497af4 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
28fbcfa0 | 2 | /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com |
81ed18ab | 3 | * Copyright (c) 2016,2017 Facebook |
28fbcfa0 AS |
4 | */ |
5 | #include <linux/bpf.h> | |
a26ca7c9 | 6 | #include <linux/btf.h> |
28fbcfa0 | 7 | #include <linux/err.h> |
28fbcfa0 AS |
8 | #include <linux/slab.h> |
9 | #include <linux/mm.h> | |
04fd61ab | 10 | #include <linux/filter.h> |
0cdf5640 | 11 | #include <linux/perf_event.h> |
a26ca7c9 | 12 | #include <uapi/linux/btf.h> |
1e6c62a8 | 13 | #include <linux/rcupdate_trace.h> |
c317ab71 | 14 | #include <linux/btf_ids.h> |
28fbcfa0 | 15 | |
56f668df MKL |
16 | #include "map_in_map.h" |
17 | ||
6e71b04a | 18 | #define ARRAY_CREATE_FLAG_MASK \ |
792caccc | 19 | (BPF_F_NUMA_NODE | BPF_F_MMAPABLE | BPF_F_ACCESS_MASK | \ |
4a8f87e6 | 20 | BPF_F_PRESERVE_ELEMS | BPF_F_INNER_MAP) |
6e71b04a | 21 | |
a10423b8 AS |
22 | static void bpf_array_free_percpu(struct bpf_array *array) |
23 | { | |
24 | int i; | |
25 | ||
32fff239 | 26 | for (i = 0; i < array->map.max_entries; i++) { |
a10423b8 | 27 | free_percpu(array->pptrs[i]); |
32fff239 ED |
28 | cond_resched(); |
29 | } | |
a10423b8 AS |
30 | } |
31 | ||
32 | static int bpf_array_alloc_percpu(struct bpf_array *array) | |
33 | { | |
34 | void __percpu *ptr; | |
35 | int i; | |
36 | ||
37 | for (i = 0; i < array->map.max_entries; i++) { | |
6d192c79 RG |
38 | ptr = bpf_map_alloc_percpu(&array->map, array->elem_size, 8, |
39 | GFP_USER | __GFP_NOWARN); | |
a10423b8 AS |
40 | if (!ptr) { |
41 | bpf_array_free_percpu(array); | |
42 | return -ENOMEM; | |
43 | } | |
44 | array->pptrs[i] = ptr; | |
32fff239 | 45 | cond_resched(); |
a10423b8 AS |
46 | } |
47 | ||
48 | return 0; | |
49 | } | |
50 | ||
28fbcfa0 | 51 | /* Called from syscall */ |
5dc4c4b7 | 52 | int array_map_alloc_check(union bpf_attr *attr) |
28fbcfa0 | 53 | { |
a10423b8 | 54 | bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; |
96eabe7a | 55 | int numa_node = bpf_map_attr_numa_node(attr); |
28fbcfa0 AS |
56 | |
57 | /* check sanity of attributes */ | |
58 | if (attr->max_entries == 0 || attr->key_size != 4 || | |
6e71b04a CF |
59 | attr->value_size == 0 || |
60 | attr->map_flags & ~ARRAY_CREATE_FLAG_MASK || | |
591fe988 | 61 | !bpf_map_flags_access_ok(attr->map_flags) || |
96eabe7a | 62 | (percpu && numa_node != NUMA_NO_NODE)) |
ad46061f | 63 | return -EINVAL; |
28fbcfa0 | 64 | |
fc970227 | 65 | if (attr->map_type != BPF_MAP_TYPE_ARRAY && |
4a8f87e6 | 66 | attr->map_flags & (BPF_F_MMAPABLE | BPF_F_INNER_MAP)) |
fc970227 AN |
67 | return -EINVAL; |
68 | ||
792caccc SL |
69 | if (attr->map_type != BPF_MAP_TYPE_PERF_EVENT_ARRAY && |
70 | attr->map_flags & BPF_F_PRESERVE_ELEMS) | |
71 | return -EINVAL; | |
72 | ||
63b8ce77 AN |
73 | /* avoid overflow on round_up(map->value_size) */ |
74 | if (attr->value_size > INT_MAX) | |
ad46061f JK |
75 | return -E2BIG; |
76 | ||
77 | return 0; | |
78 | } | |
79 | ||
80 | static struct bpf_map *array_map_alloc(union bpf_attr *attr) | |
81 | { | |
82 | bool percpu = attr->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; | |
1bc59756 | 83 | int numa_node = bpf_map_attr_numa_node(attr); |
ad46061f | 84 | u32 elem_size, index_mask, max_entries; |
2c78ee89 | 85 | bool bypass_spec_v1 = bpf_bypass_spec_v1(); |
1bc59756 | 86 | u64 array_size, mask64; |
ad46061f | 87 | struct bpf_array *array; |
01b3f521 | 88 | |
28fbcfa0 AS |
89 | elem_size = round_up(attr->value_size, 8); |
90 | ||
b2157399 | 91 | max_entries = attr->max_entries; |
b2157399 | 92 | |
bbeb6e43 DB |
93 | /* On 32 bit archs roundup_pow_of_two() with max_entries that has |
94 | * upper most bit set in u32 space is undefined behavior due to | |
95 | * resulting 1U << 32, so do it manually here in u64 space. | |
96 | */ | |
97 | mask64 = fls_long(max_entries - 1); | |
98 | mask64 = 1ULL << mask64; | |
99 | mask64 -= 1; | |
100 | ||
101 | index_mask = mask64; | |
2c78ee89 | 102 | if (!bypass_spec_v1) { |
b2157399 AS |
103 | /* round up array size to nearest power of 2, |
104 | * since cpu will speculate within index_mask limits | |
105 | */ | |
106 | max_entries = index_mask + 1; | |
bbeb6e43 DB |
107 | /* Check for overflows. */ |
108 | if (max_entries < attr->max_entries) | |
109 | return ERR_PTR(-E2BIG); | |
110 | } | |
b2157399 | 111 | |
a10423b8 | 112 | array_size = sizeof(*array); |
fc970227 | 113 | if (percpu) { |
b2157399 | 114 | array_size += (u64) max_entries * sizeof(void *); |
fc970227 AN |
115 | } else { |
116 | /* rely on vmalloc() to return page-aligned memory and | |
117 | * ensure array->value is exactly page-aligned | |
118 | */ | |
119 | if (attr->map_flags & BPF_F_MMAPABLE) { | |
120 | array_size = PAGE_ALIGN(array_size); | |
121 | array_size += PAGE_ALIGN((u64) max_entries * elem_size); | |
122 | } else { | |
123 | array_size += (u64) max_entries * elem_size; | |
124 | } | |
125 | } | |
a10423b8 | 126 | |
28fbcfa0 | 127 | /* allocate all map elements and zero-initialize them */ |
fc970227 AN |
128 | if (attr->map_flags & BPF_F_MMAPABLE) { |
129 | void *data; | |
130 | ||
131 | /* kmalloc'ed memory can't be mmap'ed, use explicit vmalloc */ | |
132 | data = bpf_map_area_mmapable_alloc(array_size, numa_node); | |
1bc59756 | 133 | if (!data) |
fc970227 | 134 | return ERR_PTR(-ENOMEM); |
fc970227 AN |
135 | array = data + PAGE_ALIGN(sizeof(struct bpf_array)) |
136 | - offsetof(struct bpf_array, value); | |
137 | } else { | |
138 | array = bpf_map_area_alloc(array_size, numa_node); | |
139 | } | |
1bc59756 | 140 | if (!array) |
d407bd25 | 141 | return ERR_PTR(-ENOMEM); |
b2157399 | 142 | array->index_mask = index_mask; |
2c78ee89 | 143 | array->map.bypass_spec_v1 = bypass_spec_v1; |
28fbcfa0 AS |
144 | |
145 | /* copy mandatory map attributes */ | |
32852649 | 146 | bpf_map_init_from_attr(&array->map, attr); |
28fbcfa0 AS |
147 | array->elem_size = elem_size; |
148 | ||
9c2d63b8 | 149 | if (percpu && bpf_array_alloc_percpu(array)) { |
d407bd25 | 150 | bpf_map_area_free(array); |
a10423b8 AS |
151 | return ERR_PTR(-ENOMEM); |
152 | } | |
a10423b8 | 153 | |
28fbcfa0 | 154 | return &array->map; |
28fbcfa0 AS |
155 | } |
156 | ||
87ac0d60 AN |
157 | static void *array_map_elem_ptr(struct bpf_array* array, u32 index) |
158 | { | |
159 | return array->value + (u64)array->elem_size * index; | |
160 | } | |
161 | ||
28fbcfa0 AS |
162 | /* Called from syscall or from eBPF program */ |
163 | static void *array_map_lookup_elem(struct bpf_map *map, void *key) | |
164 | { | |
165 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
166 | u32 index = *(u32 *)key; | |
167 | ||
a10423b8 | 168 | if (unlikely(index >= array->map.max_entries)) |
28fbcfa0 AS |
169 | return NULL; |
170 | ||
87ac0d60 | 171 | return array->value + (u64)array->elem_size * (index & array->index_mask); |
28fbcfa0 AS |
172 | } |
173 | ||
d8eca5bb DB |
174 | static int array_map_direct_value_addr(const struct bpf_map *map, u64 *imm, |
175 | u32 off) | |
176 | { | |
177 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
178 | ||
179 | if (map->max_entries != 1) | |
180 | return -ENOTSUPP; | |
181 | if (off >= map->value_size) | |
182 | return -EINVAL; | |
183 | ||
184 | *imm = (unsigned long)array->value; | |
185 | return 0; | |
186 | } | |
187 | ||
188 | static int array_map_direct_value_meta(const struct bpf_map *map, u64 imm, | |
189 | u32 *off) | |
190 | { | |
191 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
192 | u64 base = (unsigned long)array->value; | |
193 | u64 range = array->elem_size; | |
194 | ||
195 | if (map->max_entries != 1) | |
196 | return -ENOTSUPP; | |
197 | if (imm < base || imm >= base + range) | |
198 | return -ENOENT; | |
199 | ||
200 | *off = imm - base; | |
201 | return 0; | |
202 | } | |
203 | ||
81ed18ab | 204 | /* emit BPF instructions equivalent to C code of array_map_lookup_elem() */ |
4a8f87e6 | 205 | static int array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) |
81ed18ab | 206 | { |
b2157399 | 207 | struct bpf_array *array = container_of(map, struct bpf_array, map); |
81ed18ab | 208 | struct bpf_insn *insn = insn_buf; |
d937bc34 | 209 | u32 elem_size = array->elem_size; |
81ed18ab AS |
210 | const int ret = BPF_REG_0; |
211 | const int map_ptr = BPF_REG_1; | |
212 | const int index = BPF_REG_2; | |
213 | ||
4a8f87e6 DB |
214 | if (map->map_flags & BPF_F_INNER_MAP) |
215 | return -EOPNOTSUPP; | |
216 | ||
81ed18ab AS |
217 | *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value)); |
218 | *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0); | |
2c78ee89 | 219 | if (!map->bypass_spec_v1) { |
b2157399 AS |
220 | *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 4); |
221 | *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask); | |
222 | } else { | |
223 | *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 3); | |
224 | } | |
fad73a1a MKL |
225 | |
226 | if (is_power_of_2(elem_size)) { | |
81ed18ab AS |
227 | *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size)); |
228 | } else { | |
229 | *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size); | |
230 | } | |
231 | *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr); | |
232 | *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1); | |
233 | *insn++ = BPF_MOV64_IMM(ret, 0); | |
234 | return insn - insn_buf; | |
235 | } | |
236 | ||
a10423b8 AS |
237 | /* Called from eBPF program */ |
238 | static void *percpu_array_map_lookup_elem(struct bpf_map *map, void *key) | |
239 | { | |
240 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
241 | u32 index = *(u32 *)key; | |
242 | ||
243 | if (unlikely(index >= array->map.max_entries)) | |
244 | return NULL; | |
245 | ||
b2157399 | 246 | return this_cpu_ptr(array->pptrs[index & array->index_mask]); |
a10423b8 AS |
247 | } |
248 | ||
07343110 FZ |
249 | static void *percpu_array_map_lookup_percpu_elem(struct bpf_map *map, void *key, u32 cpu) |
250 | { | |
251 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
252 | u32 index = *(u32 *)key; | |
253 | ||
254 | if (cpu >= nr_cpu_ids) | |
255 | return NULL; | |
256 | ||
257 | if (unlikely(index >= array->map.max_entries)) | |
258 | return NULL; | |
259 | ||
260 | return per_cpu_ptr(array->pptrs[index & array->index_mask], cpu); | |
261 | } | |
262 | ||
15a07b33 AS |
263 | int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value) |
264 | { | |
265 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
266 | u32 index = *(u32 *)key; | |
267 | void __percpu *pptr; | |
268 | int cpu, off = 0; | |
269 | u32 size; | |
270 | ||
271 | if (unlikely(index >= array->map.max_entries)) | |
272 | return -ENOENT; | |
273 | ||
274 | /* per_cpu areas are zero-filled and bpf programs can only | |
275 | * access 'value_size' of them, so copying rounded areas | |
276 | * will not leak any kernel data | |
277 | */ | |
d937bc34 | 278 | size = array->elem_size; |
15a07b33 | 279 | rcu_read_lock(); |
b2157399 | 280 | pptr = array->pptrs[index & array->index_mask]; |
15a07b33 | 281 | for_each_possible_cpu(cpu) { |
6df4ea1f KKD |
282 | copy_map_value_long(map, value + off, per_cpu_ptr(pptr, cpu)); |
283 | check_and_init_map_value(map, value + off); | |
15a07b33 AS |
284 | off += size; |
285 | } | |
286 | rcu_read_unlock(); | |
287 | return 0; | |
288 | } | |
289 | ||
28fbcfa0 AS |
290 | /* Called from syscall */ |
291 | static int array_map_get_next_key(struct bpf_map *map, void *key, void *next_key) | |
292 | { | |
293 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
8fe45924 | 294 | u32 index = key ? *(u32 *)key : U32_MAX; |
28fbcfa0 AS |
295 | u32 *next = (u32 *)next_key; |
296 | ||
297 | if (index >= array->map.max_entries) { | |
298 | *next = 0; | |
299 | return 0; | |
300 | } | |
301 | ||
302 | if (index == array->map.max_entries - 1) | |
303 | return -ENOENT; | |
304 | ||
305 | *next = index + 1; | |
306 | return 0; | |
307 | } | |
308 | ||
309 | /* Called from syscall or from eBPF program */ | |
d7ba4cc9 JK |
310 | static long array_map_update_elem(struct bpf_map *map, void *key, void *value, |
311 | u64 map_flags) | |
28fbcfa0 AS |
312 | { |
313 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
314 | u32 index = *(u32 *)key; | |
96049f3a | 315 | char *val; |
28fbcfa0 | 316 | |
96049f3a | 317 | if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST)) |
28fbcfa0 AS |
318 | /* unknown flags */ |
319 | return -EINVAL; | |
320 | ||
a10423b8 | 321 | if (unlikely(index >= array->map.max_entries)) |
28fbcfa0 AS |
322 | /* all elements were pre-allocated, cannot insert a new one */ |
323 | return -E2BIG; | |
324 | ||
96049f3a | 325 | if (unlikely(map_flags & BPF_NOEXIST)) |
daaf427c | 326 | /* all elements already exist */ |
28fbcfa0 AS |
327 | return -EEXIST; |
328 | ||
96049f3a | 329 | if (unlikely((map_flags & BPF_F_LOCK) && |
db559117 | 330 | !btf_record_has_field(map->record, BPF_SPIN_LOCK))) |
96049f3a AS |
331 | return -EINVAL; |
332 | ||
333 | if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { | |
6df4ea1f KKD |
334 | val = this_cpu_ptr(array->pptrs[index & array->index_mask]); |
335 | copy_map_value(map, val, value); | |
db559117 | 336 | bpf_obj_free_fields(array->map.record, val); |
96049f3a AS |
337 | } else { |
338 | val = array->value + | |
87ac0d60 | 339 | (u64)array->elem_size * (index & array->index_mask); |
96049f3a AS |
340 | if (map_flags & BPF_F_LOCK) |
341 | copy_map_value_locked(map, val, value, false); | |
342 | else | |
343 | copy_map_value(map, val, value); | |
db559117 | 344 | bpf_obj_free_fields(array->map.record, val); |
96049f3a | 345 | } |
28fbcfa0 AS |
346 | return 0; |
347 | } | |
348 | ||
15a07b33 AS |
349 | int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, |
350 | u64 map_flags) | |
351 | { | |
352 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
353 | u32 index = *(u32 *)key; | |
354 | void __percpu *pptr; | |
355 | int cpu, off = 0; | |
356 | u32 size; | |
357 | ||
358 | if (unlikely(map_flags > BPF_EXIST)) | |
359 | /* unknown flags */ | |
360 | return -EINVAL; | |
361 | ||
362 | if (unlikely(index >= array->map.max_entries)) | |
363 | /* all elements were pre-allocated, cannot insert a new one */ | |
364 | return -E2BIG; | |
365 | ||
366 | if (unlikely(map_flags == BPF_NOEXIST)) | |
367 | /* all elements already exist */ | |
368 | return -EEXIST; | |
369 | ||
370 | /* the user space will provide round_up(value_size, 8) bytes that | |
371 | * will be copied into per-cpu area. bpf programs can only access | |
372 | * value_size of it. During lookup the same extra bytes will be | |
373 | * returned or zeros which were zero-filled by percpu_alloc, | |
374 | * so no kernel data leaks possible | |
375 | */ | |
d937bc34 | 376 | size = array->elem_size; |
15a07b33 | 377 | rcu_read_lock(); |
b2157399 | 378 | pptr = array->pptrs[index & array->index_mask]; |
15a07b33 | 379 | for_each_possible_cpu(cpu) { |
6df4ea1f | 380 | copy_map_value_long(map, per_cpu_ptr(pptr, cpu), value + off); |
db559117 | 381 | bpf_obj_free_fields(array->map.record, per_cpu_ptr(pptr, cpu)); |
15a07b33 AS |
382 | off += size; |
383 | } | |
384 | rcu_read_unlock(); | |
385 | return 0; | |
386 | } | |
387 | ||
28fbcfa0 | 388 | /* Called from syscall or from eBPF program */ |
d7ba4cc9 | 389 | static long array_map_delete_elem(struct bpf_map *map, void *key) |
28fbcfa0 AS |
390 | { |
391 | return -EINVAL; | |
392 | } | |
393 | ||
fc970227 AN |
394 | static void *array_map_vmalloc_addr(struct bpf_array *array) |
395 | { | |
396 | return (void *)round_down((unsigned long)array, PAGE_SIZE); | |
397 | } | |
398 | ||
68134668 AS |
399 | static void array_map_free_timers(struct bpf_map *map) |
400 | { | |
401 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
402 | int i; | |
403 | ||
aa3496ac | 404 | /* We don't reset or free fields other than timer on uref dropping to zero. */ |
db559117 | 405 | if (!btf_record_has_field(map->record, BPF_TIMER)) |
68134668 AS |
406 | return; |
407 | ||
408 | for (i = 0; i < array->map.max_entries; i++) | |
db559117 | 409 | bpf_obj_free_timer(map->record, array_map_elem_ptr(array, i)); |
68134668 AS |
410 | } |
411 | ||
28fbcfa0 AS |
412 | /* Called when map->refcnt goes to zero, either from workqueue or from syscall */ |
413 | static void array_map_free(struct bpf_map *map) | |
414 | { | |
415 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
14a324f6 KKD |
416 | int i; |
417 | ||
aa3496ac | 418 | if (!IS_ERR_OR_NULL(map->record)) { |
6df4ea1f KKD |
419 | if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { |
420 | for (i = 0; i < array->map.max_entries; i++) { | |
421 | void __percpu *pptr = array->pptrs[i & array->index_mask]; | |
422 | int cpu; | |
423 | ||
424 | for_each_possible_cpu(cpu) { | |
aa3496ac | 425 | bpf_obj_free_fields(map->record, per_cpu_ptr(pptr, cpu)); |
6df4ea1f KKD |
426 | cond_resched(); |
427 | } | |
428 | } | |
429 | } else { | |
430 | for (i = 0; i < array->map.max_entries; i++) | |
aa3496ac | 431 | bpf_obj_free_fields(map->record, array_map_elem_ptr(array, i)); |
6df4ea1f | 432 | } |
14a324f6 | 433 | } |
28fbcfa0 | 434 | |
a10423b8 AS |
435 | if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) |
436 | bpf_array_free_percpu(array); | |
437 | ||
fc970227 AN |
438 | if (array->map.map_flags & BPF_F_MMAPABLE) |
439 | bpf_map_area_free(array_map_vmalloc_addr(array)); | |
440 | else | |
441 | bpf_map_area_free(array); | |
28fbcfa0 AS |
442 | } |
443 | ||
a26ca7c9 MKL |
444 | static void array_map_seq_show_elem(struct bpf_map *map, void *key, |
445 | struct seq_file *m) | |
446 | { | |
447 | void *value; | |
448 | ||
449 | rcu_read_lock(); | |
450 | ||
451 | value = array_map_lookup_elem(map, key); | |
452 | if (!value) { | |
453 | rcu_read_unlock(); | |
454 | return; | |
455 | } | |
456 | ||
2824ecb7 DB |
457 | if (map->btf_key_type_id) |
458 | seq_printf(m, "%u: ", *(u32 *)key); | |
9b2cf328 | 459 | btf_type_seq_show(map->btf, map->btf_value_type_id, value, m); |
a26ca7c9 MKL |
460 | seq_puts(m, "\n"); |
461 | ||
462 | rcu_read_unlock(); | |
463 | } | |
464 | ||
c7b27c37 YS |
465 | static void percpu_array_map_seq_show_elem(struct bpf_map *map, void *key, |
466 | struct seq_file *m) | |
467 | { | |
468 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
469 | u32 index = *(u32 *)key; | |
470 | void __percpu *pptr; | |
471 | int cpu; | |
472 | ||
473 | rcu_read_lock(); | |
474 | ||
475 | seq_printf(m, "%u: {\n", *(u32 *)key); | |
476 | pptr = array->pptrs[index & array->index_mask]; | |
477 | for_each_possible_cpu(cpu) { | |
478 | seq_printf(m, "\tcpu%d: ", cpu); | |
479 | btf_type_seq_show(map->btf, map->btf_value_type_id, | |
480 | per_cpu_ptr(pptr, cpu), m); | |
481 | seq_puts(m, "\n"); | |
482 | } | |
483 | seq_puts(m, "}\n"); | |
484 | ||
485 | rcu_read_unlock(); | |
486 | } | |
487 | ||
e8d2bec0 | 488 | static int array_map_check_btf(const struct bpf_map *map, |
1b2b234b | 489 | const struct btf *btf, |
e8d2bec0 DB |
490 | const struct btf_type *key_type, |
491 | const struct btf_type *value_type) | |
a26ca7c9 | 492 | { |
a26ca7c9 MKL |
493 | u32 int_data; |
494 | ||
2824ecb7 DB |
495 | /* One exception for keyless BTF: .bss/.data/.rodata map */ |
496 | if (btf_type_is_void(key_type)) { | |
497 | if (map->map_type != BPF_MAP_TYPE_ARRAY || | |
498 | map->max_entries != 1) | |
499 | return -EINVAL; | |
500 | ||
501 | if (BTF_INFO_KIND(value_type->info) != BTF_KIND_DATASEC) | |
502 | return -EINVAL; | |
503 | ||
504 | return 0; | |
505 | } | |
506 | ||
e8d2bec0 | 507 | if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT) |
a26ca7c9 MKL |
508 | return -EINVAL; |
509 | ||
510 | int_data = *(u32 *)(key_type + 1); | |
e8d2bec0 DB |
511 | /* bpf array can only take a u32 key. This check makes sure |
512 | * that the btf matches the attr used during map_create. | |
a26ca7c9 | 513 | */ |
e8d2bec0 | 514 | if (BTF_INT_BITS(int_data) != 32 || BTF_INT_OFFSET(int_data)) |
a26ca7c9 MKL |
515 | return -EINVAL; |
516 | ||
517 | return 0; | |
518 | } | |
519 | ||
b2e2f0e6 | 520 | static int array_map_mmap(struct bpf_map *map, struct vm_area_struct *vma) |
fc970227 AN |
521 | { |
522 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
523 | pgoff_t pgoff = PAGE_ALIGN(sizeof(*array)) >> PAGE_SHIFT; | |
524 | ||
525 | if (!(map->map_flags & BPF_F_MMAPABLE)) | |
526 | return -EINVAL; | |
527 | ||
333291ce AN |
528 | if (vma->vm_pgoff * PAGE_SIZE + (vma->vm_end - vma->vm_start) > |
529 | PAGE_ALIGN((u64)array->map.max_entries * array->elem_size)) | |
530 | return -EINVAL; | |
531 | ||
532 | return remap_vmalloc_range(vma, array_map_vmalloc_addr(array), | |
533 | vma->vm_pgoff + pgoff); | |
fc970227 AN |
534 | } |
535 | ||
134fede4 MKL |
536 | static bool array_map_meta_equal(const struct bpf_map *meta0, |
537 | const struct bpf_map *meta1) | |
538 | { | |
4a8f87e6 DB |
539 | if (!bpf_map_meta_equal(meta0, meta1)) |
540 | return false; | |
541 | return meta0->map_flags & BPF_F_INNER_MAP ? true : | |
542 | meta0->max_entries == meta1->max_entries; | |
134fede4 MKL |
543 | } |
544 | ||
d3cc2ab5 YS |
545 | struct bpf_iter_seq_array_map_info { |
546 | struct bpf_map *map; | |
547 | void *percpu_value_buf; | |
548 | u32 index; | |
549 | }; | |
550 | ||
551 | static void *bpf_array_map_seq_start(struct seq_file *seq, loff_t *pos) | |
552 | { | |
553 | struct bpf_iter_seq_array_map_info *info = seq->private; | |
554 | struct bpf_map *map = info->map; | |
555 | struct bpf_array *array; | |
556 | u32 index; | |
557 | ||
558 | if (info->index >= map->max_entries) | |
559 | return NULL; | |
560 | ||
561 | if (*pos == 0) | |
562 | ++*pos; | |
563 | array = container_of(map, struct bpf_array, map); | |
564 | index = info->index & array->index_mask; | |
565 | if (info->percpu_value_buf) | |
566 | return array->pptrs[index]; | |
87ac0d60 | 567 | return array_map_elem_ptr(array, index); |
d3cc2ab5 YS |
568 | } |
569 | ||
570 | static void *bpf_array_map_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
571 | { | |
572 | struct bpf_iter_seq_array_map_info *info = seq->private; | |
573 | struct bpf_map *map = info->map; | |
574 | struct bpf_array *array; | |
575 | u32 index; | |
576 | ||
577 | ++*pos; | |
578 | ++info->index; | |
579 | if (info->index >= map->max_entries) | |
580 | return NULL; | |
581 | ||
582 | array = container_of(map, struct bpf_array, map); | |
583 | index = info->index & array->index_mask; | |
584 | if (info->percpu_value_buf) | |
585 | return array->pptrs[index]; | |
87ac0d60 | 586 | return array_map_elem_ptr(array, index); |
d3cc2ab5 YS |
587 | } |
588 | ||
589 | static int __bpf_array_map_seq_show(struct seq_file *seq, void *v) | |
590 | { | |
591 | struct bpf_iter_seq_array_map_info *info = seq->private; | |
592 | struct bpf_iter__bpf_map_elem ctx = {}; | |
593 | struct bpf_map *map = info->map; | |
d937bc34 | 594 | struct bpf_array *array = container_of(map, struct bpf_array, map); |
d3cc2ab5 YS |
595 | struct bpf_iter_meta meta; |
596 | struct bpf_prog *prog; | |
597 | int off = 0, cpu = 0; | |
598 | void __percpu **pptr; | |
599 | u32 size; | |
600 | ||
601 | meta.seq = seq; | |
602 | prog = bpf_iter_get_info(&meta, v == NULL); | |
603 | if (!prog) | |
604 | return 0; | |
605 | ||
606 | ctx.meta = &meta; | |
607 | ctx.map = info->map; | |
608 | if (v) { | |
609 | ctx.key = &info->index; | |
610 | ||
611 | if (!info->percpu_value_buf) { | |
612 | ctx.value = v; | |
613 | } else { | |
614 | pptr = v; | |
d937bc34 | 615 | size = array->elem_size; |
d3cc2ab5 | 616 | for_each_possible_cpu(cpu) { |
6df4ea1f KKD |
617 | copy_map_value_long(map, info->percpu_value_buf + off, |
618 | per_cpu_ptr(pptr, cpu)); | |
619 | check_and_init_map_value(map, info->percpu_value_buf + off); | |
d3cc2ab5 YS |
620 | off += size; |
621 | } | |
622 | ctx.value = info->percpu_value_buf; | |
623 | } | |
624 | } | |
625 | ||
626 | return bpf_iter_run_prog(prog, &ctx); | |
627 | } | |
628 | ||
629 | static int bpf_array_map_seq_show(struct seq_file *seq, void *v) | |
630 | { | |
631 | return __bpf_array_map_seq_show(seq, v); | |
632 | } | |
633 | ||
634 | static void bpf_array_map_seq_stop(struct seq_file *seq, void *v) | |
635 | { | |
636 | if (!v) | |
637 | (void)__bpf_array_map_seq_show(seq, NULL); | |
638 | } | |
639 | ||
640 | static int bpf_iter_init_array_map(void *priv_data, | |
641 | struct bpf_iter_aux_info *aux) | |
642 | { | |
643 | struct bpf_iter_seq_array_map_info *seq_info = priv_data; | |
644 | struct bpf_map *map = aux->map; | |
d937bc34 | 645 | struct bpf_array *array = container_of(map, struct bpf_array, map); |
d3cc2ab5 YS |
646 | void *value_buf; |
647 | u32 buf_size; | |
648 | ||
649 | if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { | |
d937bc34 | 650 | buf_size = array->elem_size * num_possible_cpus(); |
d3cc2ab5 YS |
651 | value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN); |
652 | if (!value_buf) | |
653 | return -ENOMEM; | |
654 | ||
655 | seq_info->percpu_value_buf = value_buf; | |
656 | } | |
657 | ||
f76fa6b3 HT |
658 | /* bpf_iter_attach_map() acquires a map uref, and the uref may be |
659 | * released before or in the middle of iterating map elements, so | |
660 | * acquire an extra map uref for iterator. | |
661 | */ | |
662 | bpf_map_inc_with_uref(map); | |
d3cc2ab5 YS |
663 | seq_info->map = map; |
664 | return 0; | |
665 | } | |
666 | ||
667 | static void bpf_iter_fini_array_map(void *priv_data) | |
668 | { | |
669 | struct bpf_iter_seq_array_map_info *seq_info = priv_data; | |
670 | ||
f76fa6b3 | 671 | bpf_map_put_with_uref(seq_info->map); |
d3cc2ab5 YS |
672 | kfree(seq_info->percpu_value_buf); |
673 | } | |
674 | ||
675 | static const struct seq_operations bpf_array_map_seq_ops = { | |
676 | .start = bpf_array_map_seq_start, | |
677 | .next = bpf_array_map_seq_next, | |
678 | .stop = bpf_array_map_seq_stop, | |
679 | .show = bpf_array_map_seq_show, | |
680 | }; | |
681 | ||
682 | static const struct bpf_iter_seq_info iter_seq_info = { | |
683 | .seq_ops = &bpf_array_map_seq_ops, | |
684 | .init_seq_private = bpf_iter_init_array_map, | |
685 | .fini_seq_private = bpf_iter_fini_array_map, | |
686 | .seq_priv_size = sizeof(struct bpf_iter_seq_array_map_info), | |
687 | }; | |
688 | ||
d7ba4cc9 JK |
689 | static long bpf_for_each_array_elem(struct bpf_map *map, bpf_callback_t callback_fn, |
690 | void *callback_ctx, u64 flags) | |
06dcdcd4 YS |
691 | { |
692 | u32 i, key, num_elems = 0; | |
693 | struct bpf_array *array; | |
694 | bool is_percpu; | |
695 | u64 ret = 0; | |
696 | void *val; | |
697 | ||
698 | if (flags != 0) | |
699 | return -EINVAL; | |
700 | ||
701 | is_percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; | |
702 | array = container_of(map, struct bpf_array, map); | |
703 | if (is_percpu) | |
704 | migrate_disable(); | |
705 | for (i = 0; i < map->max_entries; i++) { | |
706 | if (is_percpu) | |
707 | val = this_cpu_ptr(array->pptrs[i]); | |
708 | else | |
87ac0d60 | 709 | val = array_map_elem_ptr(array, i); |
06dcdcd4 YS |
710 | num_elems++; |
711 | key = i; | |
102acbac KC |
712 | ret = callback_fn((u64)(long)map, (u64)(long)&key, |
713 | (u64)(long)val, (u64)(long)callback_ctx, 0); | |
06dcdcd4 YS |
714 | /* return value: 0 - continue, 1 - stop and return */ |
715 | if (ret) | |
716 | break; | |
717 | } | |
718 | ||
719 | if (is_percpu) | |
720 | migrate_enable(); | |
721 | return num_elems; | |
722 | } | |
723 | ||
1746d055 YS |
724 | static u64 array_map_mem_usage(const struct bpf_map *map) |
725 | { | |
726 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
727 | bool percpu = map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY; | |
728 | u32 elem_size = array->elem_size; | |
729 | u64 entries = map->max_entries; | |
730 | u64 usage = sizeof(*array); | |
731 | ||
732 | if (percpu) { | |
733 | usage += entries * sizeof(void *); | |
734 | usage += entries * elem_size * num_possible_cpus(); | |
735 | } else { | |
736 | if (map->map_flags & BPF_F_MMAPABLE) { | |
737 | usage = PAGE_ALIGN(usage); | |
738 | usage += PAGE_ALIGN(entries * elem_size); | |
739 | } else { | |
740 | usage += entries * elem_size; | |
741 | } | |
742 | } | |
743 | return usage; | |
744 | } | |
745 | ||
c317ab71 | 746 | BTF_ID_LIST_SINGLE(array_map_btf_ids, struct, bpf_array) |
40077e0c | 747 | const struct bpf_map_ops array_map_ops = { |
134fede4 | 748 | .map_meta_equal = array_map_meta_equal, |
ad46061f | 749 | .map_alloc_check = array_map_alloc_check, |
28fbcfa0 AS |
750 | .map_alloc = array_map_alloc, |
751 | .map_free = array_map_free, | |
752 | .map_get_next_key = array_map_get_next_key, | |
68134668 | 753 | .map_release_uref = array_map_free_timers, |
28fbcfa0 AS |
754 | .map_lookup_elem = array_map_lookup_elem, |
755 | .map_update_elem = array_map_update_elem, | |
756 | .map_delete_elem = array_map_delete_elem, | |
81ed18ab | 757 | .map_gen_lookup = array_map_gen_lookup, |
d8eca5bb DB |
758 | .map_direct_value_addr = array_map_direct_value_addr, |
759 | .map_direct_value_meta = array_map_direct_value_meta, | |
fc970227 | 760 | .map_mmap = array_map_mmap, |
a26ca7c9 MKL |
761 | .map_seq_show_elem = array_map_seq_show_elem, |
762 | .map_check_btf = array_map_check_btf, | |
c60f2d28 BV |
763 | .map_lookup_batch = generic_map_lookup_batch, |
764 | .map_update_batch = generic_map_update_batch, | |
06dcdcd4 YS |
765 | .map_set_for_each_callback_args = map_set_for_each_callback_args, |
766 | .map_for_each_callback = bpf_for_each_array_elem, | |
1746d055 | 767 | .map_mem_usage = array_map_mem_usage, |
c317ab71 | 768 | .map_btf_id = &array_map_btf_ids[0], |
d3cc2ab5 | 769 | .iter_seq_info = &iter_seq_info, |
28fbcfa0 AS |
770 | }; |
771 | ||
40077e0c | 772 | const struct bpf_map_ops percpu_array_map_ops = { |
f4d05259 | 773 | .map_meta_equal = bpf_map_meta_equal, |
ad46061f | 774 | .map_alloc_check = array_map_alloc_check, |
a10423b8 AS |
775 | .map_alloc = array_map_alloc, |
776 | .map_free = array_map_free, | |
777 | .map_get_next_key = array_map_get_next_key, | |
778 | .map_lookup_elem = percpu_array_map_lookup_elem, | |
779 | .map_update_elem = array_map_update_elem, | |
780 | .map_delete_elem = array_map_delete_elem, | |
07343110 | 781 | .map_lookup_percpu_elem = percpu_array_map_lookup_percpu_elem, |
c7b27c37 | 782 | .map_seq_show_elem = percpu_array_map_seq_show_elem, |
e8d2bec0 | 783 | .map_check_btf = array_map_check_btf, |
f008d732 PT |
784 | .map_lookup_batch = generic_map_lookup_batch, |
785 | .map_update_batch = generic_map_update_batch, | |
06dcdcd4 YS |
786 | .map_set_for_each_callback_args = map_set_for_each_callback_args, |
787 | .map_for_each_callback = bpf_for_each_array_elem, | |
1746d055 | 788 | .map_mem_usage = array_map_mem_usage, |
c317ab71 | 789 | .map_btf_id = &array_map_btf_ids[0], |
d3cc2ab5 | 790 | .iter_seq_info = &iter_seq_info, |
a10423b8 AS |
791 | }; |
792 | ||
ad46061f | 793 | static int fd_array_map_alloc_check(union bpf_attr *attr) |
04fd61ab | 794 | { |
2a36f0b9 | 795 | /* only file descriptors can be stored in this type of map */ |
04fd61ab | 796 | if (attr->value_size != sizeof(u32)) |
ad46061f | 797 | return -EINVAL; |
591fe988 DB |
798 | /* Program read-only/write-only not supported for special maps yet. */ |
799 | if (attr->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) | |
800 | return -EINVAL; | |
ad46061f | 801 | return array_map_alloc_check(attr); |
04fd61ab AS |
802 | } |
803 | ||
2a36f0b9 | 804 | static void fd_array_map_free(struct bpf_map *map) |
04fd61ab AS |
805 | { |
806 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
807 | int i; | |
808 | ||
04fd61ab AS |
809 | /* make sure it's empty */ |
810 | for (i = 0; i < array->map.max_entries; i++) | |
2a36f0b9 | 811 | BUG_ON(array->ptrs[i] != NULL); |
d407bd25 DB |
812 | |
813 | bpf_map_area_free(array); | |
04fd61ab AS |
814 | } |
815 | ||
2a36f0b9 | 816 | static void *fd_array_map_lookup_elem(struct bpf_map *map, void *key) |
04fd61ab | 817 | { |
3b4a63f6 | 818 | return ERR_PTR(-EOPNOTSUPP); |
04fd61ab AS |
819 | } |
820 | ||
14dc6f04 MKL |
821 | /* only called from syscall */ |
822 | int bpf_fd_array_map_lookup_elem(struct bpf_map *map, void *key, u32 *value) | |
823 | { | |
824 | void **elem, *ptr; | |
825 | int ret = 0; | |
826 | ||
827 | if (!map->ops->map_fd_sys_lookup_elem) | |
828 | return -ENOTSUPP; | |
829 | ||
830 | rcu_read_lock(); | |
831 | elem = array_map_lookup_elem(map, key); | |
832 | if (elem && (ptr = READ_ONCE(*elem))) | |
833 | *value = map->ops->map_fd_sys_lookup_elem(ptr); | |
834 | else | |
835 | ret = -ENOENT; | |
836 | rcu_read_unlock(); | |
837 | ||
838 | return ret; | |
839 | } | |
840 | ||
04fd61ab | 841 | /* only called from syscall */ |
d056a788 DB |
842 | int bpf_fd_array_map_update_elem(struct bpf_map *map, struct file *map_file, |
843 | void *key, void *value, u64 map_flags) | |
04fd61ab AS |
844 | { |
845 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
2a36f0b9 | 846 | void *new_ptr, *old_ptr; |
04fd61ab AS |
847 | u32 index = *(u32 *)key, ufd; |
848 | ||
849 | if (map_flags != BPF_ANY) | |
850 | return -EINVAL; | |
851 | ||
852 | if (index >= array->map.max_entries) | |
853 | return -E2BIG; | |
854 | ||
855 | ufd = *(u32 *)value; | |
d056a788 | 856 | new_ptr = map->ops->map_fd_get_ptr(map, map_file, ufd); |
2a36f0b9 WN |
857 | if (IS_ERR(new_ptr)) |
858 | return PTR_ERR(new_ptr); | |
04fd61ab | 859 | |
da765a2f DB |
860 | if (map->ops->map_poke_run) { |
861 | mutex_lock(&array->aux->poke_mutex); | |
862 | old_ptr = xchg(array->ptrs + index, new_ptr); | |
863 | map->ops->map_poke_run(map, index, old_ptr, new_ptr); | |
864 | mutex_unlock(&array->aux->poke_mutex); | |
865 | } else { | |
866 | old_ptr = xchg(array->ptrs + index, new_ptr); | |
867 | } | |
868 | ||
2a36f0b9 WN |
869 | if (old_ptr) |
870 | map->ops->map_fd_put_ptr(old_ptr); | |
04fd61ab AS |
871 | return 0; |
872 | } | |
873 | ||
d7ba4cc9 | 874 | static long fd_array_map_delete_elem(struct bpf_map *map, void *key) |
04fd61ab AS |
875 | { |
876 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
2a36f0b9 | 877 | void *old_ptr; |
04fd61ab AS |
878 | u32 index = *(u32 *)key; |
879 | ||
880 | if (index >= array->map.max_entries) | |
881 | return -E2BIG; | |
882 | ||
da765a2f DB |
883 | if (map->ops->map_poke_run) { |
884 | mutex_lock(&array->aux->poke_mutex); | |
885 | old_ptr = xchg(array->ptrs + index, NULL); | |
886 | map->ops->map_poke_run(map, index, old_ptr, NULL); | |
887 | mutex_unlock(&array->aux->poke_mutex); | |
888 | } else { | |
889 | old_ptr = xchg(array->ptrs + index, NULL); | |
890 | } | |
891 | ||
2a36f0b9 WN |
892 | if (old_ptr) { |
893 | map->ops->map_fd_put_ptr(old_ptr); | |
04fd61ab AS |
894 | return 0; |
895 | } else { | |
896 | return -ENOENT; | |
897 | } | |
898 | } | |
899 | ||
d056a788 DB |
900 | static void *prog_fd_array_get_ptr(struct bpf_map *map, |
901 | struct file *map_file, int fd) | |
2a36f0b9 | 902 | { |
2a36f0b9 | 903 | struct bpf_prog *prog = bpf_prog_get(fd); |
d056a788 | 904 | |
2a36f0b9 WN |
905 | if (IS_ERR(prog)) |
906 | return prog; | |
907 | ||
f45d5b6c | 908 | if (!bpf_prog_map_compatible(map, prog)) { |
2a36f0b9 WN |
909 | bpf_prog_put(prog); |
910 | return ERR_PTR(-EINVAL); | |
911 | } | |
d056a788 | 912 | |
2a36f0b9 WN |
913 | return prog; |
914 | } | |
915 | ||
916 | static void prog_fd_array_put_ptr(void *ptr) | |
917 | { | |
1aacde3d | 918 | bpf_prog_put(ptr); |
2a36f0b9 WN |
919 | } |
920 | ||
14dc6f04 MKL |
921 | static u32 prog_fd_array_sys_lookup_elem(void *ptr) |
922 | { | |
923 | return ((struct bpf_prog *)ptr)->aux->id; | |
924 | } | |
925 | ||
04fd61ab | 926 | /* decrement refcnt of all bpf_progs that are stored in this map */ |
ba6b8de4 | 927 | static void bpf_fd_array_map_clear(struct bpf_map *map) |
04fd61ab AS |
928 | { |
929 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
930 | int i; | |
931 | ||
932 | for (i = 0; i < array->map.max_entries; i++) | |
2a36f0b9 | 933 | fd_array_map_delete_elem(map, &i); |
04fd61ab AS |
934 | } |
935 | ||
a7c19db3 YS |
936 | static void prog_array_map_seq_show_elem(struct bpf_map *map, void *key, |
937 | struct seq_file *m) | |
938 | { | |
939 | void **elem, *ptr; | |
940 | u32 prog_id; | |
941 | ||
942 | rcu_read_lock(); | |
943 | ||
944 | elem = array_map_lookup_elem(map, key); | |
945 | if (elem) { | |
946 | ptr = READ_ONCE(*elem); | |
947 | if (ptr) { | |
948 | seq_printf(m, "%u: ", *(u32 *)key); | |
949 | prog_id = prog_fd_array_sys_lookup_elem(ptr); | |
950 | btf_type_seq_show(map->btf, map->btf_value_type_id, | |
951 | &prog_id, m); | |
952 | seq_puts(m, "\n"); | |
953 | } | |
954 | } | |
955 | ||
956 | rcu_read_unlock(); | |
957 | } | |
958 | ||
da765a2f DB |
959 | struct prog_poke_elem { |
960 | struct list_head list; | |
961 | struct bpf_prog_aux *aux; | |
962 | }; | |
963 | ||
964 | static int prog_array_map_poke_track(struct bpf_map *map, | |
965 | struct bpf_prog_aux *prog_aux) | |
966 | { | |
967 | struct prog_poke_elem *elem; | |
968 | struct bpf_array_aux *aux; | |
969 | int ret = 0; | |
970 | ||
971 | aux = container_of(map, struct bpf_array, map)->aux; | |
972 | mutex_lock(&aux->poke_mutex); | |
973 | list_for_each_entry(elem, &aux->poke_progs, list) { | |
974 | if (elem->aux == prog_aux) | |
975 | goto out; | |
976 | } | |
977 | ||
978 | elem = kmalloc(sizeof(*elem), GFP_KERNEL); | |
979 | if (!elem) { | |
980 | ret = -ENOMEM; | |
981 | goto out; | |
982 | } | |
983 | ||
984 | INIT_LIST_HEAD(&elem->list); | |
985 | /* We must track the program's aux info at this point in time | |
986 | * since the program pointer itself may not be stable yet, see | |
987 | * also comment in prog_array_map_poke_run(). | |
988 | */ | |
989 | elem->aux = prog_aux; | |
990 | ||
991 | list_add_tail(&elem->list, &aux->poke_progs); | |
992 | out: | |
993 | mutex_unlock(&aux->poke_mutex); | |
994 | return ret; | |
995 | } | |
996 | ||
997 | static void prog_array_map_poke_untrack(struct bpf_map *map, | |
998 | struct bpf_prog_aux *prog_aux) | |
999 | { | |
1000 | struct prog_poke_elem *elem, *tmp; | |
1001 | struct bpf_array_aux *aux; | |
1002 | ||
1003 | aux = container_of(map, struct bpf_array, map)->aux; | |
1004 | mutex_lock(&aux->poke_mutex); | |
1005 | list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) { | |
1006 | if (elem->aux == prog_aux) { | |
1007 | list_del_init(&elem->list); | |
1008 | kfree(elem); | |
1009 | break; | |
1010 | } | |
1011 | } | |
1012 | mutex_unlock(&aux->poke_mutex); | |
1013 | } | |
1014 | ||
1015 | static void prog_array_map_poke_run(struct bpf_map *map, u32 key, | |
1016 | struct bpf_prog *old, | |
1017 | struct bpf_prog *new) | |
1018 | { | |
ebf7d1f5 | 1019 | u8 *old_addr, *new_addr, *old_bypass_addr; |
da765a2f DB |
1020 | struct prog_poke_elem *elem; |
1021 | struct bpf_array_aux *aux; | |
1022 | ||
da765a2f DB |
1023 | aux = container_of(map, struct bpf_array, map)->aux; |
1024 | WARN_ON_ONCE(!mutex_is_locked(&aux->poke_mutex)); | |
1025 | ||
1026 | list_for_each_entry(elem, &aux->poke_progs, list) { | |
1027 | struct bpf_jit_poke_descriptor *poke; | |
1028 | int i, ret; | |
1029 | ||
1030 | for (i = 0; i < elem->aux->size_poke_tab; i++) { | |
1031 | poke = &elem->aux->poke_tab[i]; | |
1032 | ||
1033 | /* Few things to be aware of: | |
1034 | * | |
1035 | * 1) We can only ever access aux in this context, but | |
1036 | * not aux->prog since it might not be stable yet and | |
1037 | * there could be danger of use after free otherwise. | |
1038 | * 2) Initially when we start tracking aux, the program | |
1039 | * is not JITed yet and also does not have a kallsyms | |
cf71b174 MF |
1040 | * entry. We skip these as poke->tailcall_target_stable |
1041 | * is not active yet. The JIT will do the final fixup | |
1042 | * before setting it stable. The various | |
1043 | * poke->tailcall_target_stable are successively | |
1044 | * activated, so tail call updates can arrive from here | |
1045 | * while JIT is still finishing its final fixup for | |
1046 | * non-activated poke entries. | |
da765a2f DB |
1047 | * 3) On program teardown, the program's kallsym entry gets |
1048 | * removed out of RCU callback, but we can only untrack | |
1049 | * from sleepable context, therefore bpf_arch_text_poke() | |
1050 | * might not see that this is in BPF text section and | |
1051 | * bails out with -EINVAL. As these are unreachable since | |
1052 | * RCU grace period already passed, we simply skip them. | |
1053 | * 4) Also programs reaching refcount of zero while patching | |
1054 | * is in progress is okay since we're protected under | |
1055 | * poke_mutex and untrack the programs before the JIT | |
1056 | * buffer is freed. When we're still in the middle of | |
1057 | * patching and suddenly kallsyms entry of the program | |
1058 | * gets evicted, we just skip the rest which is fine due | |
1059 | * to point 3). | |
1060 | * 5) Any other error happening below from bpf_arch_text_poke() | |
1061 | * is a unexpected bug. | |
1062 | */ | |
cf71b174 | 1063 | if (!READ_ONCE(poke->tailcall_target_stable)) |
da765a2f DB |
1064 | continue; |
1065 | if (poke->reason != BPF_POKE_REASON_TAIL_CALL) | |
1066 | continue; | |
1067 | if (poke->tail_call.map != map || | |
1068 | poke->tail_call.key != key) | |
1069 | continue; | |
1070 | ||
ebf7d1f5 MF |
1071 | old_bypass_addr = old ? NULL : poke->bypass_addr; |
1072 | old_addr = old ? (u8 *)old->bpf_func + poke->adj_off : NULL; | |
1073 | new_addr = new ? (u8 *)new->bpf_func + poke->adj_off : NULL; | |
1074 | ||
1075 | if (new) { | |
1076 | ret = bpf_arch_text_poke(poke->tailcall_target, | |
1077 | BPF_MOD_JUMP, | |
1078 | old_addr, new_addr); | |
1079 | BUG_ON(ret < 0 && ret != -EINVAL); | |
1080 | if (!old) { | |
1081 | ret = bpf_arch_text_poke(poke->tailcall_bypass, | |
1082 | BPF_MOD_JUMP, | |
1083 | poke->bypass_addr, | |
1084 | NULL); | |
1085 | BUG_ON(ret < 0 && ret != -EINVAL); | |
1086 | } | |
1087 | } else { | |
1088 | ret = bpf_arch_text_poke(poke->tailcall_bypass, | |
1089 | BPF_MOD_JUMP, | |
1090 | old_bypass_addr, | |
1091 | poke->bypass_addr); | |
1092 | BUG_ON(ret < 0 && ret != -EINVAL); | |
1093 | /* let other CPUs finish the execution of program | |
1094 | * so that it will not possible to expose them | |
1095 | * to invalid nop, stack unwind, nop state | |
1096 | */ | |
1097 | if (!ret) | |
1098 | synchronize_rcu(); | |
1099 | ret = bpf_arch_text_poke(poke->tailcall_target, | |
1100 | BPF_MOD_JUMP, | |
1101 | old_addr, NULL); | |
1102 | BUG_ON(ret < 0 && ret != -EINVAL); | |
1103 | } | |
da765a2f DB |
1104 | } |
1105 | } | |
1106 | } | |
1107 | ||
1108 | static void prog_array_map_clear_deferred(struct work_struct *work) | |
1109 | { | |
1110 | struct bpf_map *map = container_of(work, struct bpf_array_aux, | |
1111 | work)->map; | |
1112 | bpf_fd_array_map_clear(map); | |
1113 | bpf_map_put(map); | |
1114 | } | |
1115 | ||
1116 | static void prog_array_map_clear(struct bpf_map *map) | |
1117 | { | |
1118 | struct bpf_array_aux *aux = container_of(map, struct bpf_array, | |
1119 | map)->aux; | |
1120 | bpf_map_inc(map); | |
1121 | schedule_work(&aux->work); | |
1122 | } | |
1123 | ||
2beee5f5 DB |
1124 | static struct bpf_map *prog_array_map_alloc(union bpf_attr *attr) |
1125 | { | |
1126 | struct bpf_array_aux *aux; | |
1127 | struct bpf_map *map; | |
1128 | ||
6d192c79 | 1129 | aux = kzalloc(sizeof(*aux), GFP_KERNEL_ACCOUNT); |
2beee5f5 DB |
1130 | if (!aux) |
1131 | return ERR_PTR(-ENOMEM); | |
1132 | ||
da765a2f DB |
1133 | INIT_WORK(&aux->work, prog_array_map_clear_deferred); |
1134 | INIT_LIST_HEAD(&aux->poke_progs); | |
1135 | mutex_init(&aux->poke_mutex); | |
1136 | ||
2beee5f5 DB |
1137 | map = array_map_alloc(attr); |
1138 | if (IS_ERR(map)) { | |
1139 | kfree(aux); | |
1140 | return map; | |
1141 | } | |
1142 | ||
1143 | container_of(map, struct bpf_array, map)->aux = aux; | |
da765a2f DB |
1144 | aux->map = map; |
1145 | ||
2beee5f5 DB |
1146 | return map; |
1147 | } | |
1148 | ||
1149 | static void prog_array_map_free(struct bpf_map *map) | |
1150 | { | |
da765a2f | 1151 | struct prog_poke_elem *elem, *tmp; |
2beee5f5 DB |
1152 | struct bpf_array_aux *aux; |
1153 | ||
1154 | aux = container_of(map, struct bpf_array, map)->aux; | |
da765a2f DB |
1155 | list_for_each_entry_safe(elem, tmp, &aux->poke_progs, list) { |
1156 | list_del_init(&elem->list); | |
1157 | kfree(elem); | |
1158 | } | |
2beee5f5 DB |
1159 | kfree(aux); |
1160 | fd_array_map_free(map); | |
1161 | } | |
1162 | ||
f4d05259 MKL |
1163 | /* prog_array->aux->{type,jited} is a runtime binding. |
1164 | * Doing static check alone in the verifier is not enough. | |
1165 | * Thus, prog_array_map cannot be used as an inner_map | |
1166 | * and map_meta_equal is not implemented. | |
1167 | */ | |
40077e0c | 1168 | const struct bpf_map_ops prog_array_map_ops = { |
ad46061f | 1169 | .map_alloc_check = fd_array_map_alloc_check, |
2beee5f5 DB |
1170 | .map_alloc = prog_array_map_alloc, |
1171 | .map_free = prog_array_map_free, | |
da765a2f DB |
1172 | .map_poke_track = prog_array_map_poke_track, |
1173 | .map_poke_untrack = prog_array_map_poke_untrack, | |
1174 | .map_poke_run = prog_array_map_poke_run, | |
04fd61ab | 1175 | .map_get_next_key = array_map_get_next_key, |
2a36f0b9 | 1176 | .map_lookup_elem = fd_array_map_lookup_elem, |
2a36f0b9 WN |
1177 | .map_delete_elem = fd_array_map_delete_elem, |
1178 | .map_fd_get_ptr = prog_fd_array_get_ptr, | |
1179 | .map_fd_put_ptr = prog_fd_array_put_ptr, | |
14dc6f04 | 1180 | .map_fd_sys_lookup_elem = prog_fd_array_sys_lookup_elem, |
da765a2f | 1181 | .map_release_uref = prog_array_map_clear, |
a7c19db3 | 1182 | .map_seq_show_elem = prog_array_map_seq_show_elem, |
1746d055 | 1183 | .map_mem_usage = array_map_mem_usage, |
c317ab71 | 1184 | .map_btf_id = &array_map_btf_ids[0], |
04fd61ab AS |
1185 | }; |
1186 | ||
3b1efb19 DB |
1187 | static struct bpf_event_entry *bpf_event_entry_gen(struct file *perf_file, |
1188 | struct file *map_file) | |
ea317b26 | 1189 | { |
3b1efb19 DB |
1190 | struct bpf_event_entry *ee; |
1191 | ||
858d68f1 | 1192 | ee = kzalloc(sizeof(*ee), GFP_ATOMIC); |
3b1efb19 DB |
1193 | if (ee) { |
1194 | ee->event = perf_file->private_data; | |
1195 | ee->perf_file = perf_file; | |
1196 | ee->map_file = map_file; | |
1197 | } | |
1198 | ||
1199 | return ee; | |
1200 | } | |
1201 | ||
1202 | static void __bpf_event_entry_free(struct rcu_head *rcu) | |
1203 | { | |
1204 | struct bpf_event_entry *ee; | |
1205 | ||
1206 | ee = container_of(rcu, struct bpf_event_entry, rcu); | |
1207 | fput(ee->perf_file); | |
1208 | kfree(ee); | |
1209 | } | |
1210 | ||
1211 | static void bpf_event_entry_free_rcu(struct bpf_event_entry *ee) | |
1212 | { | |
1213 | call_rcu(&ee->rcu, __bpf_event_entry_free); | |
ea317b26 KX |
1214 | } |
1215 | ||
d056a788 DB |
1216 | static void *perf_event_fd_array_get_ptr(struct bpf_map *map, |
1217 | struct file *map_file, int fd) | |
ea317b26 | 1218 | { |
3b1efb19 DB |
1219 | struct bpf_event_entry *ee; |
1220 | struct perf_event *event; | |
1221 | struct file *perf_file; | |
f91840a3 | 1222 | u64 value; |
ea317b26 | 1223 | |
3b1efb19 DB |
1224 | perf_file = perf_event_get(fd); |
1225 | if (IS_ERR(perf_file)) | |
1226 | return perf_file; | |
e03e7ee3 | 1227 | |
f91840a3 | 1228 | ee = ERR_PTR(-EOPNOTSUPP); |
3b1efb19 | 1229 | event = perf_file->private_data; |
97562633 | 1230 | if (perf_event_read_local(event, &value, NULL, NULL) == -EOPNOTSUPP) |
3b1efb19 DB |
1231 | goto err_out; |
1232 | ||
f91840a3 AS |
1233 | ee = bpf_event_entry_gen(perf_file, map_file); |
1234 | if (ee) | |
1235 | return ee; | |
1236 | ee = ERR_PTR(-ENOMEM); | |
3b1efb19 DB |
1237 | err_out: |
1238 | fput(perf_file); | |
1239 | return ee; | |
ea317b26 KX |
1240 | } |
1241 | ||
1242 | static void perf_event_fd_array_put_ptr(void *ptr) | |
1243 | { | |
3b1efb19 DB |
1244 | bpf_event_entry_free_rcu(ptr); |
1245 | } | |
1246 | ||
1247 | static void perf_event_fd_array_release(struct bpf_map *map, | |
1248 | struct file *map_file) | |
1249 | { | |
1250 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
1251 | struct bpf_event_entry *ee; | |
1252 | int i; | |
1253 | ||
792caccc SL |
1254 | if (map->map_flags & BPF_F_PRESERVE_ELEMS) |
1255 | return; | |
1256 | ||
3b1efb19 DB |
1257 | rcu_read_lock(); |
1258 | for (i = 0; i < array->map.max_entries; i++) { | |
1259 | ee = READ_ONCE(array->ptrs[i]); | |
1260 | if (ee && ee->map_file == map_file) | |
1261 | fd_array_map_delete_elem(map, &i); | |
1262 | } | |
1263 | rcu_read_unlock(); | |
ea317b26 KX |
1264 | } |
1265 | ||
792caccc SL |
1266 | static void perf_event_fd_array_map_free(struct bpf_map *map) |
1267 | { | |
1268 | if (map->map_flags & BPF_F_PRESERVE_ELEMS) | |
1269 | bpf_fd_array_map_clear(map); | |
1270 | fd_array_map_free(map); | |
1271 | } | |
1272 | ||
40077e0c | 1273 | const struct bpf_map_ops perf_event_array_map_ops = { |
f4d05259 | 1274 | .map_meta_equal = bpf_map_meta_equal, |
ad46061f JK |
1275 | .map_alloc_check = fd_array_map_alloc_check, |
1276 | .map_alloc = array_map_alloc, | |
792caccc | 1277 | .map_free = perf_event_fd_array_map_free, |
ea317b26 KX |
1278 | .map_get_next_key = array_map_get_next_key, |
1279 | .map_lookup_elem = fd_array_map_lookup_elem, | |
ea317b26 KX |
1280 | .map_delete_elem = fd_array_map_delete_elem, |
1281 | .map_fd_get_ptr = perf_event_fd_array_get_ptr, | |
1282 | .map_fd_put_ptr = perf_event_fd_array_put_ptr, | |
3b1efb19 | 1283 | .map_release = perf_event_fd_array_release, |
e8d2bec0 | 1284 | .map_check_btf = map_check_no_btf, |
1746d055 | 1285 | .map_mem_usage = array_map_mem_usage, |
c317ab71 | 1286 | .map_btf_id = &array_map_btf_ids[0], |
ea317b26 KX |
1287 | }; |
1288 | ||
60d20f91 | 1289 | #ifdef CONFIG_CGROUPS |
4ed8ec52 MKL |
1290 | static void *cgroup_fd_array_get_ptr(struct bpf_map *map, |
1291 | struct file *map_file /* not used */, | |
1292 | int fd) | |
1293 | { | |
1294 | return cgroup_get_from_fd(fd); | |
1295 | } | |
1296 | ||
1297 | static void cgroup_fd_array_put_ptr(void *ptr) | |
1298 | { | |
1299 | /* cgroup_put free cgrp after a rcu grace period */ | |
1300 | cgroup_put(ptr); | |
1301 | } | |
1302 | ||
1303 | static void cgroup_fd_array_free(struct bpf_map *map) | |
1304 | { | |
1305 | bpf_fd_array_map_clear(map); | |
1306 | fd_array_map_free(map); | |
1307 | } | |
1308 | ||
40077e0c | 1309 | const struct bpf_map_ops cgroup_array_map_ops = { |
f4d05259 | 1310 | .map_meta_equal = bpf_map_meta_equal, |
ad46061f JK |
1311 | .map_alloc_check = fd_array_map_alloc_check, |
1312 | .map_alloc = array_map_alloc, | |
4ed8ec52 MKL |
1313 | .map_free = cgroup_fd_array_free, |
1314 | .map_get_next_key = array_map_get_next_key, | |
1315 | .map_lookup_elem = fd_array_map_lookup_elem, | |
1316 | .map_delete_elem = fd_array_map_delete_elem, | |
1317 | .map_fd_get_ptr = cgroup_fd_array_get_ptr, | |
1318 | .map_fd_put_ptr = cgroup_fd_array_put_ptr, | |
e8d2bec0 | 1319 | .map_check_btf = map_check_no_btf, |
1746d055 | 1320 | .map_mem_usage = array_map_mem_usage, |
c317ab71 | 1321 | .map_btf_id = &array_map_btf_ids[0], |
4ed8ec52 | 1322 | }; |
4ed8ec52 | 1323 | #endif |
56f668df MKL |
1324 | |
1325 | static struct bpf_map *array_of_map_alloc(union bpf_attr *attr) | |
1326 | { | |
1327 | struct bpf_map *map, *inner_map_meta; | |
1328 | ||
1329 | inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd); | |
1330 | if (IS_ERR(inner_map_meta)) | |
1331 | return inner_map_meta; | |
1332 | ||
ad46061f | 1333 | map = array_map_alloc(attr); |
56f668df MKL |
1334 | if (IS_ERR(map)) { |
1335 | bpf_map_meta_free(inner_map_meta); | |
1336 | return map; | |
1337 | } | |
1338 | ||
1339 | map->inner_map_meta = inner_map_meta; | |
1340 | ||
1341 | return map; | |
1342 | } | |
1343 | ||
1344 | static void array_of_map_free(struct bpf_map *map) | |
1345 | { | |
1346 | /* map->inner_map_meta is only accessed by syscall which | |
1347 | * is protected by fdget/fdput. | |
1348 | */ | |
1349 | bpf_map_meta_free(map->inner_map_meta); | |
1350 | bpf_fd_array_map_clear(map); | |
1351 | fd_array_map_free(map); | |
1352 | } | |
1353 | ||
1354 | static void *array_of_map_lookup_elem(struct bpf_map *map, void *key) | |
1355 | { | |
1356 | struct bpf_map **inner_map = array_map_lookup_elem(map, key); | |
1357 | ||
1358 | if (!inner_map) | |
1359 | return NULL; | |
1360 | ||
1361 | return READ_ONCE(*inner_map); | |
1362 | } | |
1363 | ||
4a8f87e6 | 1364 | static int array_of_map_gen_lookup(struct bpf_map *map, |
7b0c2a05 DB |
1365 | struct bpf_insn *insn_buf) |
1366 | { | |
b2157399 | 1367 | struct bpf_array *array = container_of(map, struct bpf_array, map); |
d937bc34 | 1368 | u32 elem_size = array->elem_size; |
7b0c2a05 DB |
1369 | struct bpf_insn *insn = insn_buf; |
1370 | const int ret = BPF_REG_0; | |
1371 | const int map_ptr = BPF_REG_1; | |
1372 | const int index = BPF_REG_2; | |
1373 | ||
1374 | *insn++ = BPF_ALU64_IMM(BPF_ADD, map_ptr, offsetof(struct bpf_array, value)); | |
1375 | *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0); | |
2c78ee89 | 1376 | if (!map->bypass_spec_v1) { |
b2157399 AS |
1377 | *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 6); |
1378 | *insn++ = BPF_ALU32_IMM(BPF_AND, ret, array->index_mask); | |
1379 | } else { | |
1380 | *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5); | |
1381 | } | |
7b0c2a05 DB |
1382 | if (is_power_of_2(elem_size)) |
1383 | *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(elem_size)); | |
1384 | else | |
1385 | *insn++ = BPF_ALU64_IMM(BPF_MUL, ret, elem_size); | |
1386 | *insn++ = BPF_ALU64_REG(BPF_ADD, ret, map_ptr); | |
1387 | *insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0); | |
1388 | *insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1); | |
1389 | *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1); | |
1390 | *insn++ = BPF_MOV64_IMM(ret, 0); | |
1391 | ||
1392 | return insn - insn_buf; | |
1393 | } | |
1394 | ||
40077e0c | 1395 | const struct bpf_map_ops array_of_maps_map_ops = { |
ad46061f | 1396 | .map_alloc_check = fd_array_map_alloc_check, |
56f668df MKL |
1397 | .map_alloc = array_of_map_alloc, |
1398 | .map_free = array_of_map_free, | |
1399 | .map_get_next_key = array_map_get_next_key, | |
1400 | .map_lookup_elem = array_of_map_lookup_elem, | |
1401 | .map_delete_elem = fd_array_map_delete_elem, | |
1402 | .map_fd_get_ptr = bpf_map_fd_get_ptr, | |
1403 | .map_fd_put_ptr = bpf_map_fd_put_ptr, | |
14dc6f04 | 1404 | .map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem, |
7b0c2a05 | 1405 | .map_gen_lookup = array_of_map_gen_lookup, |
9263dddc TC |
1406 | .map_lookup_batch = generic_map_lookup_batch, |
1407 | .map_update_batch = generic_map_update_batch, | |
e8d2bec0 | 1408 | .map_check_btf = map_check_no_btf, |
1746d055 | 1409 | .map_mem_usage = array_map_mem_usage, |
c317ab71 | 1410 | .map_btf_id = &array_map_btf_ids[0], |
56f668df | 1411 | }; |