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Commit | Line | Data |
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f5bffecd AS |
1 | /* |
2 | * Linux Socket Filter - Kernel level socket filtering | |
3 | * | |
4 | * Based on the design of the Berkeley Packet Filter. The new | |
5 | * internal format has been designed by PLUMgrid: | |
6 | * | |
7 | * Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com | |
8 | * | |
9 | * Authors: | |
10 | * | |
11 | * Jay Schulist <jschlst@samba.org> | |
12 | * Alexei Starovoitov <ast@plumgrid.com> | |
13 | * Daniel Borkmann <dborkman@redhat.com> | |
14 | * | |
15 | * This program is free software; you can redistribute it and/or | |
16 | * modify it under the terms of the GNU General Public License | |
17 | * as published by the Free Software Foundation; either version | |
18 | * 2 of the License, or (at your option) any later version. | |
19 | * | |
20 | * Andi Kleen - Fix a few bad bugs and races. | |
4df95ff4 | 21 | * Kris Katterjohn - Added many additional checks in bpf_check_classic() |
f5bffecd | 22 | */ |
738cbe72 | 23 | |
f5bffecd AS |
24 | #include <linux/filter.h> |
25 | #include <linux/skbuff.h> | |
60a3b225 | 26 | #include <linux/vmalloc.h> |
738cbe72 DB |
27 | #include <linux/random.h> |
28 | #include <linux/moduleloader.h> | |
09756af4 | 29 | #include <linux/bpf.h> |
39853cc0 | 30 | #include <linux/frame.h> |
74451e66 DB |
31 | #include <linux/rbtree_latch.h> |
32 | #include <linux/kallsyms.h> | |
33 | #include <linux/rcupdate.h> | |
f5bffecd | 34 | |
3324b584 DB |
35 | #include <asm/unaligned.h> |
36 | ||
f5bffecd AS |
37 | /* Registers */ |
38 | #define BPF_R0 regs[BPF_REG_0] | |
39 | #define BPF_R1 regs[BPF_REG_1] | |
40 | #define BPF_R2 regs[BPF_REG_2] | |
41 | #define BPF_R3 regs[BPF_REG_3] | |
42 | #define BPF_R4 regs[BPF_REG_4] | |
43 | #define BPF_R5 regs[BPF_REG_5] | |
44 | #define BPF_R6 regs[BPF_REG_6] | |
45 | #define BPF_R7 regs[BPF_REG_7] | |
46 | #define BPF_R8 regs[BPF_REG_8] | |
47 | #define BPF_R9 regs[BPF_REG_9] | |
48 | #define BPF_R10 regs[BPF_REG_10] | |
49 | ||
50 | /* Named registers */ | |
51 | #define DST regs[insn->dst_reg] | |
52 | #define SRC regs[insn->src_reg] | |
53 | #define FP regs[BPF_REG_FP] | |
54 | #define ARG1 regs[BPF_REG_ARG1] | |
55 | #define CTX regs[BPF_REG_CTX] | |
56 | #define IMM insn->imm | |
57 | ||
58 | /* No hurry in this branch | |
59 | * | |
60 | * Exported for the bpf jit load helper. | |
61 | */ | |
62 | void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) | |
63 | { | |
64 | u8 *ptr = NULL; | |
65 | ||
66 | if (k >= SKF_NET_OFF) | |
67 | ptr = skb_network_header(skb) + k - SKF_NET_OFF; | |
68 | else if (k >= SKF_LL_OFF) | |
69 | ptr = skb_mac_header(skb) + k - SKF_LL_OFF; | |
3324b584 | 70 | |
f5bffecd AS |
71 | if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) |
72 | return ptr; | |
73 | ||
74 | return NULL; | |
75 | } | |
76 | ||
60a3b225 DB |
77 | struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) |
78 | { | |
19809c2d | 79 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
09756af4 | 80 | struct bpf_prog_aux *aux; |
60a3b225 DB |
81 | struct bpf_prog *fp; |
82 | ||
83 | size = round_up(size, PAGE_SIZE); | |
84 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); | |
85 | if (fp == NULL) | |
86 | return NULL; | |
87 | ||
09756af4 AS |
88 | aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags); |
89 | if (aux == NULL) { | |
60a3b225 DB |
90 | vfree(fp); |
91 | return NULL; | |
92 | } | |
93 | ||
94 | fp->pages = size / PAGE_SIZE; | |
09756af4 | 95 | fp->aux = aux; |
e9d8afa9 | 96 | fp->aux->prog = fp; |
60a3b225 | 97 | |
74451e66 DB |
98 | INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode); |
99 | ||
60a3b225 DB |
100 | return fp; |
101 | } | |
102 | EXPORT_SYMBOL_GPL(bpf_prog_alloc); | |
103 | ||
104 | struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, | |
105 | gfp_t gfp_extra_flags) | |
106 | { | |
19809c2d | 107 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
60a3b225 | 108 | struct bpf_prog *fp; |
5ccb071e DB |
109 | u32 pages, delta; |
110 | int ret; | |
60a3b225 DB |
111 | |
112 | BUG_ON(fp_old == NULL); | |
113 | ||
114 | size = round_up(size, PAGE_SIZE); | |
5ccb071e DB |
115 | pages = size / PAGE_SIZE; |
116 | if (pages <= fp_old->pages) | |
60a3b225 DB |
117 | return fp_old; |
118 | ||
5ccb071e DB |
119 | delta = pages - fp_old->pages; |
120 | ret = __bpf_prog_charge(fp_old->aux->user, delta); | |
121 | if (ret) | |
122 | return NULL; | |
123 | ||
60a3b225 | 124 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); |
5ccb071e DB |
125 | if (fp == NULL) { |
126 | __bpf_prog_uncharge(fp_old->aux->user, delta); | |
127 | } else { | |
60a3b225 | 128 | memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); |
5ccb071e | 129 | fp->pages = pages; |
e9d8afa9 | 130 | fp->aux->prog = fp; |
60a3b225 | 131 | |
09756af4 | 132 | /* We keep fp->aux from fp_old around in the new |
60a3b225 DB |
133 | * reallocated structure. |
134 | */ | |
09756af4 | 135 | fp_old->aux = NULL; |
60a3b225 DB |
136 | __bpf_prog_free(fp_old); |
137 | } | |
138 | ||
139 | return fp; | |
140 | } | |
60a3b225 DB |
141 | |
142 | void __bpf_prog_free(struct bpf_prog *fp) | |
143 | { | |
09756af4 | 144 | kfree(fp->aux); |
60a3b225 DB |
145 | vfree(fp); |
146 | } | |
60a3b225 | 147 | |
f1f7714e | 148 | int bpf_prog_calc_tag(struct bpf_prog *fp) |
7bd509e3 DB |
149 | { |
150 | const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64); | |
f1f7714e DB |
151 | u32 raw_size = bpf_prog_tag_scratch_size(fp); |
152 | u32 digest[SHA_DIGEST_WORDS]; | |
aafe6ae9 | 153 | u32 ws[SHA_WORKSPACE_WORDS]; |
7bd509e3 | 154 | u32 i, bsize, psize, blocks; |
aafe6ae9 | 155 | struct bpf_insn *dst; |
7bd509e3 | 156 | bool was_ld_map; |
aafe6ae9 | 157 | u8 *raw, *todo; |
7bd509e3 DB |
158 | __be32 *result; |
159 | __be64 *bits; | |
160 | ||
aafe6ae9 DB |
161 | raw = vmalloc(raw_size); |
162 | if (!raw) | |
163 | return -ENOMEM; | |
164 | ||
f1f7714e | 165 | sha_init(digest); |
7bd509e3 DB |
166 | memset(ws, 0, sizeof(ws)); |
167 | ||
168 | /* We need to take out the map fd for the digest calculation | |
169 | * since they are unstable from user space side. | |
170 | */ | |
aafe6ae9 | 171 | dst = (void *)raw; |
7bd509e3 DB |
172 | for (i = 0, was_ld_map = false; i < fp->len; i++) { |
173 | dst[i] = fp->insnsi[i]; | |
174 | if (!was_ld_map && | |
175 | dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
176 | dst[i].src_reg == BPF_PSEUDO_MAP_FD) { | |
177 | was_ld_map = true; | |
178 | dst[i].imm = 0; | |
179 | } else if (was_ld_map && | |
180 | dst[i].code == 0 && | |
181 | dst[i].dst_reg == 0 && | |
182 | dst[i].src_reg == 0 && | |
183 | dst[i].off == 0) { | |
184 | was_ld_map = false; | |
185 | dst[i].imm = 0; | |
186 | } else { | |
187 | was_ld_map = false; | |
188 | } | |
189 | } | |
190 | ||
aafe6ae9 DB |
191 | psize = bpf_prog_insn_size(fp); |
192 | memset(&raw[psize], 0, raw_size - psize); | |
7bd509e3 DB |
193 | raw[psize++] = 0x80; |
194 | ||
195 | bsize = round_up(psize, SHA_MESSAGE_BYTES); | |
196 | blocks = bsize / SHA_MESSAGE_BYTES; | |
aafe6ae9 | 197 | todo = raw; |
7bd509e3 DB |
198 | if (bsize - psize >= sizeof(__be64)) { |
199 | bits = (__be64 *)(todo + bsize - sizeof(__be64)); | |
200 | } else { | |
201 | bits = (__be64 *)(todo + bsize + bits_offset); | |
202 | blocks++; | |
203 | } | |
204 | *bits = cpu_to_be64((psize - 1) << 3); | |
205 | ||
206 | while (blocks--) { | |
f1f7714e | 207 | sha_transform(digest, todo, ws); |
7bd509e3 DB |
208 | todo += SHA_MESSAGE_BYTES; |
209 | } | |
210 | ||
f1f7714e | 211 | result = (__force __be32 *)digest; |
7bd509e3 | 212 | for (i = 0; i < SHA_DIGEST_WORDS; i++) |
f1f7714e DB |
213 | result[i] = cpu_to_be32(digest[i]); |
214 | memcpy(fp->tag, result, sizeof(fp->tag)); | |
aafe6ae9 DB |
215 | |
216 | vfree(raw); | |
217 | return 0; | |
7bd509e3 DB |
218 | } |
219 | ||
c237ee5e DB |
220 | static bool bpf_is_jmp_and_has_target(const struct bpf_insn *insn) |
221 | { | |
222 | return BPF_CLASS(insn->code) == BPF_JMP && | |
223 | /* Call and Exit are both special jumps with no | |
224 | * target inside the BPF instruction image. | |
225 | */ | |
226 | BPF_OP(insn->code) != BPF_CALL && | |
227 | BPF_OP(insn->code) != BPF_EXIT; | |
228 | } | |
229 | ||
230 | static void bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta) | |
231 | { | |
232 | struct bpf_insn *insn = prog->insnsi; | |
233 | u32 i, insn_cnt = prog->len; | |
234 | ||
235 | for (i = 0; i < insn_cnt; i++, insn++) { | |
236 | if (!bpf_is_jmp_and_has_target(insn)) | |
237 | continue; | |
238 | ||
239 | /* Adjust offset of jmps if we cross boundaries. */ | |
240 | if (i < pos && i + insn->off + 1 > pos) | |
241 | insn->off += delta; | |
242 | else if (i > pos + delta && i + insn->off + 1 <= pos + delta) | |
243 | insn->off -= delta; | |
244 | } | |
245 | } | |
246 | ||
247 | struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, | |
248 | const struct bpf_insn *patch, u32 len) | |
249 | { | |
250 | u32 insn_adj_cnt, insn_rest, insn_delta = len - 1; | |
251 | struct bpf_prog *prog_adj; | |
252 | ||
253 | /* Since our patchlet doesn't expand the image, we're done. */ | |
254 | if (insn_delta == 0) { | |
255 | memcpy(prog->insnsi + off, patch, sizeof(*patch)); | |
256 | return prog; | |
257 | } | |
258 | ||
259 | insn_adj_cnt = prog->len + insn_delta; | |
260 | ||
261 | /* Several new instructions need to be inserted. Make room | |
262 | * for them. Likely, there's no need for a new allocation as | |
263 | * last page could have large enough tailroom. | |
264 | */ | |
265 | prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt), | |
266 | GFP_USER); | |
267 | if (!prog_adj) | |
268 | return NULL; | |
269 | ||
270 | prog_adj->len = insn_adj_cnt; | |
271 | ||
272 | /* Patching happens in 3 steps: | |
273 | * | |
274 | * 1) Move over tail of insnsi from next instruction onwards, | |
275 | * so we can patch the single target insn with one or more | |
276 | * new ones (patching is always from 1 to n insns, n > 0). | |
277 | * 2) Inject new instructions at the target location. | |
278 | * 3) Adjust branch offsets if necessary. | |
279 | */ | |
280 | insn_rest = insn_adj_cnt - off - len; | |
281 | ||
282 | memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1, | |
283 | sizeof(*patch) * insn_rest); | |
284 | memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len); | |
285 | ||
286 | bpf_adj_branches(prog_adj, off, insn_delta); | |
287 | ||
288 | return prog_adj; | |
289 | } | |
290 | ||
b954d834 | 291 | #ifdef CONFIG_BPF_JIT |
74451e66 DB |
292 | static __always_inline void |
293 | bpf_get_prog_addr_region(const struct bpf_prog *prog, | |
294 | unsigned long *symbol_start, | |
295 | unsigned long *symbol_end) | |
296 | { | |
297 | const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog); | |
298 | unsigned long addr = (unsigned long)hdr; | |
299 | ||
300 | WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog)); | |
301 | ||
302 | *symbol_start = addr; | |
303 | *symbol_end = addr + hdr->pages * PAGE_SIZE; | |
304 | } | |
305 | ||
306 | static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) | |
307 | { | |
368211fb MKL |
308 | const char *end = sym + KSYM_NAME_LEN; |
309 | ||
74451e66 | 310 | BUILD_BUG_ON(sizeof("bpf_prog_") + |
368211fb MKL |
311 | sizeof(prog->tag) * 2 + |
312 | /* name has been null terminated. | |
313 | * We should need +1 for the '_' preceding | |
314 | * the name. However, the null character | |
315 | * is double counted between the name and the | |
316 | * sizeof("bpf_prog_") above, so we omit | |
317 | * the +1 here. | |
318 | */ | |
319 | sizeof(prog->aux->name) > KSYM_NAME_LEN); | |
74451e66 DB |
320 | |
321 | sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_"); | |
322 | sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); | |
368211fb MKL |
323 | if (prog->aux->name[0]) |
324 | snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name); | |
325 | else | |
326 | *sym = 0; | |
74451e66 DB |
327 | } |
328 | ||
329 | static __always_inline unsigned long | |
330 | bpf_get_prog_addr_start(struct latch_tree_node *n) | |
331 | { | |
332 | unsigned long symbol_start, symbol_end; | |
333 | const struct bpf_prog_aux *aux; | |
334 | ||
335 | aux = container_of(n, struct bpf_prog_aux, ksym_tnode); | |
336 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
337 | ||
338 | return symbol_start; | |
339 | } | |
340 | ||
341 | static __always_inline bool bpf_tree_less(struct latch_tree_node *a, | |
342 | struct latch_tree_node *b) | |
343 | { | |
344 | return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b); | |
345 | } | |
346 | ||
347 | static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n) | |
348 | { | |
349 | unsigned long val = (unsigned long)key; | |
350 | unsigned long symbol_start, symbol_end; | |
351 | const struct bpf_prog_aux *aux; | |
352 | ||
353 | aux = container_of(n, struct bpf_prog_aux, ksym_tnode); | |
354 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
355 | ||
356 | if (val < symbol_start) | |
357 | return -1; | |
358 | if (val >= symbol_end) | |
359 | return 1; | |
360 | ||
361 | return 0; | |
362 | } | |
363 | ||
364 | static const struct latch_tree_ops bpf_tree_ops = { | |
365 | .less = bpf_tree_less, | |
366 | .comp = bpf_tree_comp, | |
367 | }; | |
368 | ||
369 | static DEFINE_SPINLOCK(bpf_lock); | |
370 | static LIST_HEAD(bpf_kallsyms); | |
371 | static struct latch_tree_root bpf_tree __cacheline_aligned; | |
372 | ||
373 | int bpf_jit_kallsyms __read_mostly; | |
374 | ||
375 | static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux) | |
376 | { | |
377 | WARN_ON_ONCE(!list_empty(&aux->ksym_lnode)); | |
378 | list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms); | |
379 | latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); | |
380 | } | |
381 | ||
382 | static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux) | |
383 | { | |
384 | if (list_empty(&aux->ksym_lnode)) | |
385 | return; | |
386 | ||
387 | latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); | |
388 | list_del_rcu(&aux->ksym_lnode); | |
389 | } | |
390 | ||
391 | static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp) | |
392 | { | |
393 | return fp->jited && !bpf_prog_was_classic(fp); | |
394 | } | |
395 | ||
396 | static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp) | |
397 | { | |
398 | return list_empty(&fp->aux->ksym_lnode) || | |
399 | fp->aux->ksym_lnode.prev == LIST_POISON2; | |
400 | } | |
401 | ||
402 | void bpf_prog_kallsyms_add(struct bpf_prog *fp) | |
403 | { | |
74451e66 DB |
404 | if (!bpf_prog_kallsyms_candidate(fp) || |
405 | !capable(CAP_SYS_ADMIN)) | |
406 | return; | |
407 | ||
d24f7c7f | 408 | spin_lock_bh(&bpf_lock); |
74451e66 | 409 | bpf_prog_ksym_node_add(fp->aux); |
d24f7c7f | 410 | spin_unlock_bh(&bpf_lock); |
74451e66 DB |
411 | } |
412 | ||
413 | void bpf_prog_kallsyms_del(struct bpf_prog *fp) | |
414 | { | |
74451e66 DB |
415 | if (!bpf_prog_kallsyms_candidate(fp)) |
416 | return; | |
417 | ||
d24f7c7f | 418 | spin_lock_bh(&bpf_lock); |
74451e66 | 419 | bpf_prog_ksym_node_del(fp->aux); |
d24f7c7f | 420 | spin_unlock_bh(&bpf_lock); |
74451e66 DB |
421 | } |
422 | ||
423 | static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr) | |
424 | { | |
425 | struct latch_tree_node *n; | |
426 | ||
427 | if (!bpf_jit_kallsyms_enabled()) | |
428 | return NULL; | |
429 | ||
430 | n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops); | |
431 | return n ? | |
432 | container_of(n, struct bpf_prog_aux, ksym_tnode)->prog : | |
433 | NULL; | |
434 | } | |
435 | ||
436 | const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, | |
437 | unsigned long *off, char *sym) | |
438 | { | |
439 | unsigned long symbol_start, symbol_end; | |
440 | struct bpf_prog *prog; | |
441 | char *ret = NULL; | |
442 | ||
443 | rcu_read_lock(); | |
444 | prog = bpf_prog_kallsyms_find(addr); | |
445 | if (prog) { | |
446 | bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end); | |
447 | bpf_get_prog_name(prog, sym); | |
448 | ||
449 | ret = sym; | |
450 | if (size) | |
451 | *size = symbol_end - symbol_start; | |
452 | if (off) | |
453 | *off = addr - symbol_start; | |
454 | } | |
455 | rcu_read_unlock(); | |
456 | ||
457 | return ret; | |
458 | } | |
459 | ||
460 | bool is_bpf_text_address(unsigned long addr) | |
461 | { | |
462 | bool ret; | |
463 | ||
464 | rcu_read_lock(); | |
465 | ret = bpf_prog_kallsyms_find(addr) != NULL; | |
466 | rcu_read_unlock(); | |
467 | ||
468 | return ret; | |
469 | } | |
470 | ||
471 | int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, | |
472 | char *sym) | |
473 | { | |
474 | unsigned long symbol_start, symbol_end; | |
475 | struct bpf_prog_aux *aux; | |
476 | unsigned int it = 0; | |
477 | int ret = -ERANGE; | |
478 | ||
479 | if (!bpf_jit_kallsyms_enabled()) | |
480 | return ret; | |
481 | ||
482 | rcu_read_lock(); | |
483 | list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) { | |
484 | if (it++ != symnum) | |
485 | continue; | |
486 | ||
487 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
488 | bpf_get_prog_name(aux->prog, sym); | |
489 | ||
490 | *value = symbol_start; | |
491 | *type = BPF_SYM_ELF_TYPE; | |
492 | ||
493 | ret = 0; | |
494 | break; | |
495 | } | |
496 | rcu_read_unlock(); | |
497 | ||
498 | return ret; | |
499 | } | |
500 | ||
738cbe72 DB |
501 | struct bpf_binary_header * |
502 | bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, | |
503 | unsigned int alignment, | |
504 | bpf_jit_fill_hole_t bpf_fill_ill_insns) | |
505 | { | |
506 | struct bpf_binary_header *hdr; | |
507 | unsigned int size, hole, start; | |
508 | ||
509 | /* Most of BPF filters are really small, but if some of them | |
510 | * fill a page, allow at least 128 extra bytes to insert a | |
511 | * random section of illegal instructions. | |
512 | */ | |
513 | size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE); | |
514 | hdr = module_alloc(size); | |
515 | if (hdr == NULL) | |
516 | return NULL; | |
517 | ||
518 | /* Fill space with illegal/arch-dep instructions. */ | |
519 | bpf_fill_ill_insns(hdr, size); | |
520 | ||
521 | hdr->pages = size / PAGE_SIZE; | |
522 | hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)), | |
523 | PAGE_SIZE - sizeof(*hdr)); | |
b7552e1b | 524 | start = (get_random_int() % hole) & ~(alignment - 1); |
738cbe72 DB |
525 | |
526 | /* Leave a random number of instructions before BPF code. */ | |
527 | *image_ptr = &hdr->image[start]; | |
528 | ||
529 | return hdr; | |
530 | } | |
531 | ||
532 | void bpf_jit_binary_free(struct bpf_binary_header *hdr) | |
533 | { | |
be1f221c | 534 | module_memfree(hdr); |
738cbe72 | 535 | } |
4f3446bb | 536 | |
74451e66 DB |
537 | /* This symbol is only overridden by archs that have different |
538 | * requirements than the usual eBPF JITs, f.e. when they only | |
539 | * implement cBPF JIT, do not set images read-only, etc. | |
540 | */ | |
541 | void __weak bpf_jit_free(struct bpf_prog *fp) | |
542 | { | |
543 | if (fp->jited) { | |
544 | struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp); | |
545 | ||
546 | bpf_jit_binary_unlock_ro(hdr); | |
547 | bpf_jit_binary_free(hdr); | |
548 | ||
549 | WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp)); | |
550 | } | |
551 | ||
552 | bpf_prog_unlock_free(fp); | |
553 | } | |
554 | ||
4f3446bb DB |
555 | int bpf_jit_harden __read_mostly; |
556 | ||
557 | static int bpf_jit_blind_insn(const struct bpf_insn *from, | |
558 | const struct bpf_insn *aux, | |
559 | struct bpf_insn *to_buff) | |
560 | { | |
561 | struct bpf_insn *to = to_buff; | |
b7552e1b | 562 | u32 imm_rnd = get_random_int(); |
4f3446bb DB |
563 | s16 off; |
564 | ||
565 | BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG); | |
566 | BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG); | |
567 | ||
568 | if (from->imm == 0 && | |
569 | (from->code == (BPF_ALU | BPF_MOV | BPF_K) || | |
570 | from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) { | |
571 | *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg); | |
572 | goto out; | |
573 | } | |
574 | ||
575 | switch (from->code) { | |
576 | case BPF_ALU | BPF_ADD | BPF_K: | |
577 | case BPF_ALU | BPF_SUB | BPF_K: | |
578 | case BPF_ALU | BPF_AND | BPF_K: | |
579 | case BPF_ALU | BPF_OR | BPF_K: | |
580 | case BPF_ALU | BPF_XOR | BPF_K: | |
581 | case BPF_ALU | BPF_MUL | BPF_K: | |
582 | case BPF_ALU | BPF_MOV | BPF_K: | |
583 | case BPF_ALU | BPF_DIV | BPF_K: | |
584 | case BPF_ALU | BPF_MOD | BPF_K: | |
585 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
586 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
587 | *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX); | |
588 | break; | |
589 | ||
590 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
591 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
592 | case BPF_ALU64 | BPF_AND | BPF_K: | |
593 | case BPF_ALU64 | BPF_OR | BPF_K: | |
594 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
595 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
596 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
597 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
598 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
599 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
600 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
601 | *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX); | |
602 | break; | |
603 | ||
604 | case BPF_JMP | BPF_JEQ | BPF_K: | |
605 | case BPF_JMP | BPF_JNE | BPF_K: | |
606 | case BPF_JMP | BPF_JGT | BPF_K: | |
92b31a9a | 607 | case BPF_JMP | BPF_JLT | BPF_K: |
4f3446bb | 608 | case BPF_JMP | BPF_JGE | BPF_K: |
92b31a9a | 609 | case BPF_JMP | BPF_JLE | BPF_K: |
4f3446bb | 610 | case BPF_JMP | BPF_JSGT | BPF_K: |
92b31a9a | 611 | case BPF_JMP | BPF_JSLT | BPF_K: |
4f3446bb | 612 | case BPF_JMP | BPF_JSGE | BPF_K: |
92b31a9a | 613 | case BPF_JMP | BPF_JSLE | BPF_K: |
4f3446bb DB |
614 | case BPF_JMP | BPF_JSET | BPF_K: |
615 | /* Accommodate for extra offset in case of a backjump. */ | |
616 | off = from->off; | |
617 | if (off < 0) | |
618 | off -= 2; | |
619 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
620 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
621 | *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off); | |
622 | break; | |
623 | ||
624 | case BPF_LD | BPF_ABS | BPF_W: | |
625 | case BPF_LD | BPF_ABS | BPF_H: | |
626 | case BPF_LD | BPF_ABS | BPF_B: | |
627 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
628 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
629 | *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0); | |
630 | break; | |
631 | ||
632 | case BPF_LD | BPF_IND | BPF_W: | |
633 | case BPF_LD | BPF_IND | BPF_H: | |
634 | case BPF_LD | BPF_IND | BPF_B: | |
635 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
636 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
637 | *to++ = BPF_ALU32_REG(BPF_ADD, BPF_REG_AX, from->src_reg); | |
638 | *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0); | |
639 | break; | |
640 | ||
641 | case BPF_LD | BPF_IMM | BPF_DW: | |
642 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm); | |
643 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
644 | *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32); | |
645 | *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX); | |
646 | break; | |
647 | case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */ | |
648 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm); | |
649 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
650 | *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX); | |
651 | break; | |
652 | ||
653 | case BPF_ST | BPF_MEM | BPF_DW: | |
654 | case BPF_ST | BPF_MEM | BPF_W: | |
655 | case BPF_ST | BPF_MEM | BPF_H: | |
656 | case BPF_ST | BPF_MEM | BPF_B: | |
657 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
658 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
659 | *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off); | |
660 | break; | |
661 | } | |
662 | out: | |
663 | return to - to_buff; | |
664 | } | |
665 | ||
666 | static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other, | |
667 | gfp_t gfp_extra_flags) | |
668 | { | |
19809c2d | 669 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
4f3446bb DB |
670 | struct bpf_prog *fp; |
671 | ||
672 | fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL); | |
673 | if (fp != NULL) { | |
4f3446bb DB |
674 | /* aux->prog still points to the fp_other one, so |
675 | * when promoting the clone to the real program, | |
676 | * this still needs to be adapted. | |
677 | */ | |
678 | memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE); | |
679 | } | |
680 | ||
681 | return fp; | |
682 | } | |
683 | ||
684 | static void bpf_prog_clone_free(struct bpf_prog *fp) | |
685 | { | |
686 | /* aux was stolen by the other clone, so we cannot free | |
687 | * it from this path! It will be freed eventually by the | |
688 | * other program on release. | |
689 | * | |
690 | * At this point, we don't need a deferred release since | |
691 | * clone is guaranteed to not be locked. | |
692 | */ | |
693 | fp->aux = NULL; | |
694 | __bpf_prog_free(fp); | |
695 | } | |
696 | ||
697 | void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other) | |
698 | { | |
699 | /* We have to repoint aux->prog to self, as we don't | |
700 | * know whether fp here is the clone or the original. | |
701 | */ | |
702 | fp->aux->prog = fp; | |
703 | bpf_prog_clone_free(fp_other); | |
704 | } | |
705 | ||
706 | struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog) | |
707 | { | |
708 | struct bpf_insn insn_buff[16], aux[2]; | |
709 | struct bpf_prog *clone, *tmp; | |
710 | int insn_delta, insn_cnt; | |
711 | struct bpf_insn *insn; | |
712 | int i, rewritten; | |
713 | ||
714 | if (!bpf_jit_blinding_enabled()) | |
715 | return prog; | |
716 | ||
717 | clone = bpf_prog_clone_create(prog, GFP_USER); | |
718 | if (!clone) | |
719 | return ERR_PTR(-ENOMEM); | |
720 | ||
721 | insn_cnt = clone->len; | |
722 | insn = clone->insnsi; | |
723 | ||
724 | for (i = 0; i < insn_cnt; i++, insn++) { | |
725 | /* We temporarily need to hold the original ld64 insn | |
726 | * so that we can still access the first part in the | |
727 | * second blinding run. | |
728 | */ | |
729 | if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
730 | insn[1].code == 0) | |
731 | memcpy(aux, insn, sizeof(aux)); | |
732 | ||
733 | rewritten = bpf_jit_blind_insn(insn, aux, insn_buff); | |
734 | if (!rewritten) | |
735 | continue; | |
736 | ||
737 | tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten); | |
738 | if (!tmp) { | |
739 | /* Patching may have repointed aux->prog during | |
740 | * realloc from the original one, so we need to | |
741 | * fix it up here on error. | |
742 | */ | |
743 | bpf_jit_prog_release_other(prog, clone); | |
744 | return ERR_PTR(-ENOMEM); | |
745 | } | |
746 | ||
747 | clone = tmp; | |
748 | insn_delta = rewritten - 1; | |
749 | ||
750 | /* Walk new program and skip insns we just inserted. */ | |
751 | insn = clone->insnsi + i + insn_delta; | |
752 | insn_cnt += insn_delta; | |
753 | i += insn_delta; | |
754 | } | |
755 | ||
756 | return clone; | |
757 | } | |
b954d834 | 758 | #endif /* CONFIG_BPF_JIT */ |
738cbe72 | 759 | |
f5bffecd AS |
760 | /* Base function for offset calculation. Needs to go into .text section, |
761 | * therefore keeping it non-static as well; will also be used by JITs | |
762 | * anyway later on, so do not let the compiler omit it. | |
763 | */ | |
764 | noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) | |
765 | { | |
766 | return 0; | |
767 | } | |
4d9c5c53 | 768 | EXPORT_SYMBOL_GPL(__bpf_call_base); |
f5bffecd AS |
769 | |
770 | /** | |
7ae457c1 AS |
771 | * __bpf_prog_run - run eBPF program on a given context |
772 | * @ctx: is the data we are operating on | |
773 | * @insn: is the array of eBPF instructions | |
f5bffecd | 774 | * |
7ae457c1 | 775 | * Decode and execute eBPF instructions. |
f5bffecd | 776 | */ |
f696b8f4 AS |
777 | static unsigned int ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, |
778 | u64 *stack) | |
f5bffecd | 779 | { |
f696b8f4 | 780 | u64 tmp; |
f5bffecd AS |
781 | static const void *jumptable[256] = { |
782 | [0 ... 255] = &&default_label, | |
783 | /* Now overwrite non-defaults ... */ | |
784 | /* 32 bit ALU operations */ | |
785 | [BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X, | |
786 | [BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K, | |
787 | [BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X, | |
788 | [BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K, | |
789 | [BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X, | |
790 | [BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K, | |
791 | [BPF_ALU | BPF_OR | BPF_X] = &&ALU_OR_X, | |
792 | [BPF_ALU | BPF_OR | BPF_K] = &&ALU_OR_K, | |
793 | [BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X, | |
794 | [BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K, | |
795 | [BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X, | |
796 | [BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K, | |
797 | [BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X, | |
798 | [BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K, | |
799 | [BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X, | |
800 | [BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K, | |
801 | [BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X, | |
802 | [BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K, | |
803 | [BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X, | |
804 | [BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K, | |
805 | [BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X, | |
806 | [BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K, | |
807 | [BPF_ALU | BPF_NEG] = &&ALU_NEG, | |
808 | [BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE, | |
809 | [BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE, | |
810 | /* 64 bit ALU operations */ | |
811 | [BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X, | |
812 | [BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K, | |
813 | [BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X, | |
814 | [BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K, | |
815 | [BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X, | |
816 | [BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K, | |
817 | [BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X, | |
818 | [BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K, | |
819 | [BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X, | |
820 | [BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K, | |
821 | [BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X, | |
822 | [BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K, | |
823 | [BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X, | |
824 | [BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K, | |
825 | [BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X, | |
826 | [BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K, | |
827 | [BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X, | |
828 | [BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K, | |
829 | [BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X, | |
830 | [BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K, | |
831 | [BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X, | |
832 | [BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K, | |
833 | [BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X, | |
834 | [BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K, | |
835 | [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG, | |
836 | /* Call instruction */ | |
837 | [BPF_JMP | BPF_CALL] = &&JMP_CALL, | |
71189fa9 | 838 | [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL, |
f5bffecd AS |
839 | /* Jumps */ |
840 | [BPF_JMP | BPF_JA] = &&JMP_JA, | |
841 | [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X, | |
842 | [BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K, | |
843 | [BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X, | |
844 | [BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K, | |
845 | [BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X, | |
846 | [BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K, | |
92b31a9a DB |
847 | [BPF_JMP | BPF_JLT | BPF_X] = &&JMP_JLT_X, |
848 | [BPF_JMP | BPF_JLT | BPF_K] = &&JMP_JLT_K, | |
f5bffecd AS |
849 | [BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X, |
850 | [BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K, | |
92b31a9a DB |
851 | [BPF_JMP | BPF_JLE | BPF_X] = &&JMP_JLE_X, |
852 | [BPF_JMP | BPF_JLE | BPF_K] = &&JMP_JLE_K, | |
f5bffecd AS |
853 | [BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X, |
854 | [BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K, | |
92b31a9a DB |
855 | [BPF_JMP | BPF_JSLT | BPF_X] = &&JMP_JSLT_X, |
856 | [BPF_JMP | BPF_JSLT | BPF_K] = &&JMP_JSLT_K, | |
f5bffecd AS |
857 | [BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X, |
858 | [BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K, | |
92b31a9a DB |
859 | [BPF_JMP | BPF_JSLE | BPF_X] = &&JMP_JSLE_X, |
860 | [BPF_JMP | BPF_JSLE | BPF_K] = &&JMP_JSLE_K, | |
f5bffecd AS |
861 | [BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X, |
862 | [BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K, | |
863 | /* Program return */ | |
864 | [BPF_JMP | BPF_EXIT] = &&JMP_EXIT, | |
865 | /* Store instructions */ | |
866 | [BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B, | |
867 | [BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H, | |
868 | [BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W, | |
869 | [BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW, | |
870 | [BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W, | |
871 | [BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW, | |
872 | [BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B, | |
873 | [BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H, | |
874 | [BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W, | |
875 | [BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW, | |
876 | /* Load instructions */ | |
877 | [BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B, | |
878 | [BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H, | |
879 | [BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W, | |
880 | [BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW, | |
881 | [BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W, | |
882 | [BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H, | |
883 | [BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B, | |
884 | [BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W, | |
885 | [BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H, | |
886 | [BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B, | |
02ab695b | 887 | [BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW, |
f5bffecd | 888 | }; |
04fd61ab | 889 | u32 tail_call_cnt = 0; |
f5bffecd AS |
890 | void *ptr; |
891 | int off; | |
892 | ||
893 | #define CONT ({ insn++; goto select_insn; }) | |
894 | #define CONT_JMP ({ insn++; goto select_insn; }) | |
895 | ||
f5bffecd AS |
896 | select_insn: |
897 | goto *jumptable[insn->code]; | |
898 | ||
899 | /* ALU */ | |
900 | #define ALU(OPCODE, OP) \ | |
901 | ALU64_##OPCODE##_X: \ | |
902 | DST = DST OP SRC; \ | |
903 | CONT; \ | |
904 | ALU_##OPCODE##_X: \ | |
905 | DST = (u32) DST OP (u32) SRC; \ | |
906 | CONT; \ | |
907 | ALU64_##OPCODE##_K: \ | |
908 | DST = DST OP IMM; \ | |
909 | CONT; \ | |
910 | ALU_##OPCODE##_K: \ | |
911 | DST = (u32) DST OP (u32) IMM; \ | |
912 | CONT; | |
913 | ||
914 | ALU(ADD, +) | |
915 | ALU(SUB, -) | |
916 | ALU(AND, &) | |
917 | ALU(OR, |) | |
918 | ALU(LSH, <<) | |
919 | ALU(RSH, >>) | |
920 | ALU(XOR, ^) | |
921 | ALU(MUL, *) | |
922 | #undef ALU | |
923 | ALU_NEG: | |
924 | DST = (u32) -DST; | |
925 | CONT; | |
926 | ALU64_NEG: | |
927 | DST = -DST; | |
928 | CONT; | |
929 | ALU_MOV_X: | |
930 | DST = (u32) SRC; | |
931 | CONT; | |
932 | ALU_MOV_K: | |
933 | DST = (u32) IMM; | |
934 | CONT; | |
935 | ALU64_MOV_X: | |
936 | DST = SRC; | |
937 | CONT; | |
938 | ALU64_MOV_K: | |
939 | DST = IMM; | |
940 | CONT; | |
02ab695b AS |
941 | LD_IMM_DW: |
942 | DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; | |
943 | insn++; | |
944 | CONT; | |
f5bffecd AS |
945 | ALU64_ARSH_X: |
946 | (*(s64 *) &DST) >>= SRC; | |
947 | CONT; | |
948 | ALU64_ARSH_K: | |
949 | (*(s64 *) &DST) >>= IMM; | |
950 | CONT; | |
951 | ALU64_MOD_X: | |
952 | if (unlikely(SRC == 0)) | |
953 | return 0; | |
876a7ae6 AS |
954 | div64_u64_rem(DST, SRC, &tmp); |
955 | DST = tmp; | |
f5bffecd AS |
956 | CONT; |
957 | ALU_MOD_X: | |
958 | if (unlikely(SRC == 0)) | |
959 | return 0; | |
960 | tmp = (u32) DST; | |
961 | DST = do_div(tmp, (u32) SRC); | |
962 | CONT; | |
963 | ALU64_MOD_K: | |
876a7ae6 AS |
964 | div64_u64_rem(DST, IMM, &tmp); |
965 | DST = tmp; | |
f5bffecd AS |
966 | CONT; |
967 | ALU_MOD_K: | |
968 | tmp = (u32) DST; | |
969 | DST = do_div(tmp, (u32) IMM); | |
970 | CONT; | |
971 | ALU64_DIV_X: | |
972 | if (unlikely(SRC == 0)) | |
973 | return 0; | |
876a7ae6 | 974 | DST = div64_u64(DST, SRC); |
f5bffecd AS |
975 | CONT; |
976 | ALU_DIV_X: | |
977 | if (unlikely(SRC == 0)) | |
978 | return 0; | |
979 | tmp = (u32) DST; | |
980 | do_div(tmp, (u32) SRC); | |
981 | DST = (u32) tmp; | |
982 | CONT; | |
983 | ALU64_DIV_K: | |
876a7ae6 | 984 | DST = div64_u64(DST, IMM); |
f5bffecd AS |
985 | CONT; |
986 | ALU_DIV_K: | |
987 | tmp = (u32) DST; | |
988 | do_div(tmp, (u32) IMM); | |
989 | DST = (u32) tmp; | |
990 | CONT; | |
991 | ALU_END_TO_BE: | |
992 | switch (IMM) { | |
993 | case 16: | |
994 | DST = (__force u16) cpu_to_be16(DST); | |
995 | break; | |
996 | case 32: | |
997 | DST = (__force u32) cpu_to_be32(DST); | |
998 | break; | |
999 | case 64: | |
1000 | DST = (__force u64) cpu_to_be64(DST); | |
1001 | break; | |
1002 | } | |
1003 | CONT; | |
1004 | ALU_END_TO_LE: | |
1005 | switch (IMM) { | |
1006 | case 16: | |
1007 | DST = (__force u16) cpu_to_le16(DST); | |
1008 | break; | |
1009 | case 32: | |
1010 | DST = (__force u32) cpu_to_le32(DST); | |
1011 | break; | |
1012 | case 64: | |
1013 | DST = (__force u64) cpu_to_le64(DST); | |
1014 | break; | |
1015 | } | |
1016 | CONT; | |
1017 | ||
1018 | /* CALL */ | |
1019 | JMP_CALL: | |
1020 | /* Function call scratches BPF_R1-BPF_R5 registers, | |
1021 | * preserves BPF_R6-BPF_R9, and stores return value | |
1022 | * into BPF_R0. | |
1023 | */ | |
1024 | BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, | |
1025 | BPF_R4, BPF_R5); | |
1026 | CONT; | |
1027 | ||
04fd61ab AS |
1028 | JMP_TAIL_CALL: { |
1029 | struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2; | |
1030 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
1031 | struct bpf_prog *prog; | |
90caccdd | 1032 | u32 index = BPF_R3; |
04fd61ab AS |
1033 | |
1034 | if (unlikely(index >= array->map.max_entries)) | |
1035 | goto out; | |
04fd61ab AS |
1036 | if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT)) |
1037 | goto out; | |
1038 | ||
1039 | tail_call_cnt++; | |
1040 | ||
2a36f0b9 | 1041 | prog = READ_ONCE(array->ptrs[index]); |
1ca1cc98 | 1042 | if (!prog) |
04fd61ab AS |
1043 | goto out; |
1044 | ||
c4675f93 DB |
1045 | /* ARG1 at this point is guaranteed to point to CTX from |
1046 | * the verifier side due to the fact that the tail call is | |
1047 | * handeled like a helper, that is, bpf_tail_call_proto, | |
1048 | * where arg1_type is ARG_PTR_TO_CTX. | |
1049 | */ | |
04fd61ab AS |
1050 | insn = prog->insnsi; |
1051 | goto select_insn; | |
1052 | out: | |
1053 | CONT; | |
1054 | } | |
f5bffecd AS |
1055 | /* JMP */ |
1056 | JMP_JA: | |
1057 | insn += insn->off; | |
1058 | CONT; | |
1059 | JMP_JEQ_X: | |
1060 | if (DST == SRC) { | |
1061 | insn += insn->off; | |
1062 | CONT_JMP; | |
1063 | } | |
1064 | CONT; | |
1065 | JMP_JEQ_K: | |
1066 | if (DST == IMM) { | |
1067 | insn += insn->off; | |
1068 | CONT_JMP; | |
1069 | } | |
1070 | CONT; | |
1071 | JMP_JNE_X: | |
1072 | if (DST != SRC) { | |
1073 | insn += insn->off; | |
1074 | CONT_JMP; | |
1075 | } | |
1076 | CONT; | |
1077 | JMP_JNE_K: | |
1078 | if (DST != IMM) { | |
1079 | insn += insn->off; | |
1080 | CONT_JMP; | |
1081 | } | |
1082 | CONT; | |
1083 | JMP_JGT_X: | |
1084 | if (DST > SRC) { | |
1085 | insn += insn->off; | |
1086 | CONT_JMP; | |
1087 | } | |
1088 | CONT; | |
1089 | JMP_JGT_K: | |
1090 | if (DST > IMM) { | |
1091 | insn += insn->off; | |
1092 | CONT_JMP; | |
1093 | } | |
1094 | CONT; | |
92b31a9a DB |
1095 | JMP_JLT_X: |
1096 | if (DST < SRC) { | |
1097 | insn += insn->off; | |
1098 | CONT_JMP; | |
1099 | } | |
1100 | CONT; | |
1101 | JMP_JLT_K: | |
1102 | if (DST < IMM) { | |
1103 | insn += insn->off; | |
1104 | CONT_JMP; | |
1105 | } | |
1106 | CONT; | |
f5bffecd AS |
1107 | JMP_JGE_X: |
1108 | if (DST >= SRC) { | |
1109 | insn += insn->off; | |
1110 | CONT_JMP; | |
1111 | } | |
1112 | CONT; | |
1113 | JMP_JGE_K: | |
1114 | if (DST >= IMM) { | |
1115 | insn += insn->off; | |
1116 | CONT_JMP; | |
1117 | } | |
1118 | CONT; | |
92b31a9a DB |
1119 | JMP_JLE_X: |
1120 | if (DST <= SRC) { | |
1121 | insn += insn->off; | |
1122 | CONT_JMP; | |
1123 | } | |
1124 | CONT; | |
1125 | JMP_JLE_K: | |
1126 | if (DST <= IMM) { | |
1127 | insn += insn->off; | |
1128 | CONT_JMP; | |
1129 | } | |
1130 | CONT; | |
f5bffecd AS |
1131 | JMP_JSGT_X: |
1132 | if (((s64) DST) > ((s64) SRC)) { | |
1133 | insn += insn->off; | |
1134 | CONT_JMP; | |
1135 | } | |
1136 | CONT; | |
1137 | JMP_JSGT_K: | |
1138 | if (((s64) DST) > ((s64) IMM)) { | |
1139 | insn += insn->off; | |
1140 | CONT_JMP; | |
1141 | } | |
1142 | CONT; | |
92b31a9a DB |
1143 | JMP_JSLT_X: |
1144 | if (((s64) DST) < ((s64) SRC)) { | |
1145 | insn += insn->off; | |
1146 | CONT_JMP; | |
1147 | } | |
1148 | CONT; | |
1149 | JMP_JSLT_K: | |
1150 | if (((s64) DST) < ((s64) IMM)) { | |
1151 | insn += insn->off; | |
1152 | CONT_JMP; | |
1153 | } | |
1154 | CONT; | |
f5bffecd AS |
1155 | JMP_JSGE_X: |
1156 | if (((s64) DST) >= ((s64) SRC)) { | |
1157 | insn += insn->off; | |
1158 | CONT_JMP; | |
1159 | } | |
1160 | CONT; | |
1161 | JMP_JSGE_K: | |
1162 | if (((s64) DST) >= ((s64) IMM)) { | |
1163 | insn += insn->off; | |
1164 | CONT_JMP; | |
1165 | } | |
1166 | CONT; | |
92b31a9a DB |
1167 | JMP_JSLE_X: |
1168 | if (((s64) DST) <= ((s64) SRC)) { | |
1169 | insn += insn->off; | |
1170 | CONT_JMP; | |
1171 | } | |
1172 | CONT; | |
1173 | JMP_JSLE_K: | |
1174 | if (((s64) DST) <= ((s64) IMM)) { | |
1175 | insn += insn->off; | |
1176 | CONT_JMP; | |
1177 | } | |
1178 | CONT; | |
f5bffecd AS |
1179 | JMP_JSET_X: |
1180 | if (DST & SRC) { | |
1181 | insn += insn->off; | |
1182 | CONT_JMP; | |
1183 | } | |
1184 | CONT; | |
1185 | JMP_JSET_K: | |
1186 | if (DST & IMM) { | |
1187 | insn += insn->off; | |
1188 | CONT_JMP; | |
1189 | } | |
1190 | CONT; | |
1191 | JMP_EXIT: | |
1192 | return BPF_R0; | |
1193 | ||
1194 | /* STX and ST and LDX*/ | |
1195 | #define LDST(SIZEOP, SIZE) \ | |
1196 | STX_MEM_##SIZEOP: \ | |
1197 | *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ | |
1198 | CONT; \ | |
1199 | ST_MEM_##SIZEOP: \ | |
1200 | *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ | |
1201 | CONT; \ | |
1202 | LDX_MEM_##SIZEOP: \ | |
1203 | DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ | |
1204 | CONT; | |
1205 | ||
1206 | LDST(B, u8) | |
1207 | LDST(H, u16) | |
1208 | LDST(W, u32) | |
1209 | LDST(DW, u64) | |
1210 | #undef LDST | |
1211 | STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ | |
1212 | atomic_add((u32) SRC, (atomic_t *)(unsigned long) | |
1213 | (DST + insn->off)); | |
1214 | CONT; | |
1215 | STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ | |
1216 | atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) | |
1217 | (DST + insn->off)); | |
1218 | CONT; | |
1219 | LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */ | |
1220 | off = IMM; | |
1221 | load_word: | |
96a94cc5 JB |
1222 | /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are only |
1223 | * appearing in the programs where ctx == skb | |
1224 | * (see may_access_skb() in the verifier). All programs | |
1225 | * keep 'ctx' in regs[BPF_REG_CTX] == BPF_R6, | |
1226 | * bpf_convert_filter() saves it in BPF_R6, internal BPF | |
1227 | * verifier will check that BPF_R6 == ctx. | |
f5bffecd AS |
1228 | * |
1229 | * BPF_ABS and BPF_IND are wrappers of function calls, | |
1230 | * so they scratch BPF_R1-BPF_R5 registers, preserve | |
1231 | * BPF_R6-BPF_R9, and store return value into BPF_R0. | |
1232 | * | |
1233 | * Implicit input: | |
1234 | * ctx == skb == BPF_R6 == CTX | |
1235 | * | |
1236 | * Explicit input: | |
1237 | * SRC == any register | |
1238 | * IMM == 32-bit immediate | |
1239 | * | |
1240 | * Output: | |
1241 | * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness | |
1242 | */ | |
1243 | ||
1244 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp); | |
1245 | if (likely(ptr != NULL)) { | |
1246 | BPF_R0 = get_unaligned_be32(ptr); | |
1247 | CONT; | |
1248 | } | |
1249 | ||
1250 | return 0; | |
1251 | LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */ | |
1252 | off = IMM; | |
1253 | load_half: | |
1254 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp); | |
1255 | if (likely(ptr != NULL)) { | |
1256 | BPF_R0 = get_unaligned_be16(ptr); | |
1257 | CONT; | |
1258 | } | |
1259 | ||
1260 | return 0; | |
1261 | LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */ | |
1262 | off = IMM; | |
1263 | load_byte: | |
1264 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp); | |
1265 | if (likely(ptr != NULL)) { | |
1266 | BPF_R0 = *(u8 *)ptr; | |
1267 | CONT; | |
1268 | } | |
1269 | ||
1270 | return 0; | |
1271 | LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */ | |
1272 | off = IMM + SRC; | |
1273 | goto load_word; | |
1274 | LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */ | |
1275 | off = IMM + SRC; | |
1276 | goto load_half; | |
1277 | LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */ | |
1278 | off = IMM + SRC; | |
1279 | goto load_byte; | |
1280 | ||
1281 | default_label: | |
1282 | /* If we ever reach this, we have a bug somewhere. */ | |
1283 | WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code); | |
1284 | return 0; | |
1285 | } | |
f696b8f4 AS |
1286 | STACK_FRAME_NON_STANDARD(___bpf_prog_run); /* jump table */ |
1287 | ||
b870aa90 AS |
1288 | #define PROG_NAME(stack_size) __bpf_prog_run##stack_size |
1289 | #define DEFINE_BPF_PROG_RUN(stack_size) \ | |
1290 | static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \ | |
1291 | { \ | |
1292 | u64 stack[stack_size / sizeof(u64)]; \ | |
1293 | u64 regs[MAX_BPF_REG]; \ | |
1294 | \ | |
1295 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ | |
1296 | ARG1 = (u64) (unsigned long) ctx; \ | |
1297 | return ___bpf_prog_run(regs, insn, stack); \ | |
f696b8f4 | 1298 | } |
f5bffecd | 1299 | |
b870aa90 AS |
1300 | #define EVAL1(FN, X) FN(X) |
1301 | #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y) | |
1302 | #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y) | |
1303 | #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y) | |
1304 | #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y) | |
1305 | #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y) | |
1306 | ||
1307 | EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192); | |
1308 | EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384); | |
1309 | EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512); | |
1310 | ||
1311 | #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size), | |
1312 | ||
1313 | static unsigned int (*interpreters[])(const void *ctx, | |
1314 | const struct bpf_insn *insn) = { | |
1315 | EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) | |
1316 | EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) | |
1317 | EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) | |
1318 | }; | |
1319 | ||
3324b584 DB |
1320 | bool bpf_prog_array_compatible(struct bpf_array *array, |
1321 | const struct bpf_prog *fp) | |
04fd61ab | 1322 | { |
3324b584 DB |
1323 | if (!array->owner_prog_type) { |
1324 | /* There's no owner yet where we could check for | |
1325 | * compatibility. | |
1326 | */ | |
04fd61ab AS |
1327 | array->owner_prog_type = fp->type; |
1328 | array->owner_jited = fp->jited; | |
3324b584 DB |
1329 | |
1330 | return true; | |
04fd61ab | 1331 | } |
3324b584 DB |
1332 | |
1333 | return array->owner_prog_type == fp->type && | |
1334 | array->owner_jited == fp->jited; | |
04fd61ab AS |
1335 | } |
1336 | ||
3324b584 | 1337 | static int bpf_check_tail_call(const struct bpf_prog *fp) |
04fd61ab AS |
1338 | { |
1339 | struct bpf_prog_aux *aux = fp->aux; | |
1340 | int i; | |
1341 | ||
1342 | for (i = 0; i < aux->used_map_cnt; i++) { | |
3324b584 | 1343 | struct bpf_map *map = aux->used_maps[i]; |
04fd61ab | 1344 | struct bpf_array *array; |
04fd61ab | 1345 | |
04fd61ab AS |
1346 | if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY) |
1347 | continue; | |
3324b584 | 1348 | |
04fd61ab AS |
1349 | array = container_of(map, struct bpf_array, map); |
1350 | if (!bpf_prog_array_compatible(array, fp)) | |
1351 | return -EINVAL; | |
1352 | } | |
1353 | ||
1354 | return 0; | |
1355 | } | |
1356 | ||
f5bffecd | 1357 | /** |
3324b584 | 1358 | * bpf_prog_select_runtime - select exec runtime for BPF program |
7ae457c1 | 1359 | * @fp: bpf_prog populated with internal BPF program |
d1c55ab5 | 1360 | * @err: pointer to error variable |
f5bffecd | 1361 | * |
3324b584 DB |
1362 | * Try to JIT eBPF program, if JIT is not available, use interpreter. |
1363 | * The BPF program will be executed via BPF_PROG_RUN() macro. | |
f5bffecd | 1364 | */ |
d1c55ab5 | 1365 | struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) |
f5bffecd | 1366 | { |
8007e40a MKL |
1367 | u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1); |
1368 | ||
1369 | fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1]; | |
f5bffecd | 1370 | |
d1c55ab5 DB |
1371 | /* eBPF JITs can rewrite the program in case constant |
1372 | * blinding is active. However, in case of error during | |
1373 | * blinding, bpf_int_jit_compile() must always return a | |
1374 | * valid program, which in this case would simply not | |
1375 | * be JITed, but falls back to the interpreter. | |
1376 | */ | |
ab3f0063 JK |
1377 | if (!bpf_prog_is_dev_bound(fp->aux)) { |
1378 | fp = bpf_int_jit_compile(fp); | |
1379 | } else { | |
1380 | *err = bpf_prog_offload_compile(fp); | |
1381 | if (*err) | |
1382 | return fp; | |
1383 | } | |
60a3b225 | 1384 | bpf_prog_lock_ro(fp); |
04fd61ab | 1385 | |
3324b584 DB |
1386 | /* The tail call compatibility check can only be done at |
1387 | * this late stage as we need to determine, if we deal | |
1388 | * with JITed or non JITed program concatenations and not | |
1389 | * all eBPF JITs might immediately support all features. | |
1390 | */ | |
d1c55ab5 DB |
1391 | *err = bpf_check_tail_call(fp); |
1392 | ||
1393 | return fp; | |
f5bffecd | 1394 | } |
7ae457c1 | 1395 | EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); |
f5bffecd | 1396 | |
e87c6bc3 YS |
1397 | static unsigned int __bpf_prog_ret1(const void *ctx, |
1398 | const struct bpf_insn *insn) | |
1399 | { | |
1400 | return 1; | |
1401 | } | |
1402 | ||
1403 | static struct bpf_prog_dummy { | |
1404 | struct bpf_prog prog; | |
1405 | } dummy_bpf_prog = { | |
1406 | .prog = { | |
1407 | .bpf_func = __bpf_prog_ret1, | |
1408 | }, | |
1409 | }; | |
1410 | ||
324bda9e AS |
1411 | /* to avoid allocating empty bpf_prog_array for cgroups that |
1412 | * don't have bpf program attached use one global 'empty_prog_array' | |
1413 | * It will not be modified the caller of bpf_prog_array_alloc() | |
1414 | * (since caller requested prog_cnt == 0) | |
1415 | * that pointer should be 'freed' by bpf_prog_array_free() | |
1416 | */ | |
1417 | static struct { | |
1418 | struct bpf_prog_array hdr; | |
1419 | struct bpf_prog *null_prog; | |
1420 | } empty_prog_array = { | |
1421 | .null_prog = NULL, | |
1422 | }; | |
1423 | ||
1424 | struct bpf_prog_array __rcu *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags) | |
1425 | { | |
1426 | if (prog_cnt) | |
1427 | return kzalloc(sizeof(struct bpf_prog_array) + | |
1428 | sizeof(struct bpf_prog *) * (prog_cnt + 1), | |
1429 | flags); | |
1430 | ||
1431 | return &empty_prog_array.hdr; | |
1432 | } | |
1433 | ||
1434 | void bpf_prog_array_free(struct bpf_prog_array __rcu *progs) | |
1435 | { | |
1436 | if (!progs || | |
1437 | progs == (struct bpf_prog_array __rcu *)&empty_prog_array.hdr) | |
1438 | return; | |
1439 | kfree_rcu(progs, rcu); | |
1440 | } | |
1441 | ||
468e2f64 AS |
1442 | int bpf_prog_array_length(struct bpf_prog_array __rcu *progs) |
1443 | { | |
1444 | struct bpf_prog **prog; | |
1445 | u32 cnt = 0; | |
1446 | ||
1447 | rcu_read_lock(); | |
1448 | prog = rcu_dereference(progs)->progs; | |
1449 | for (; *prog; prog++) | |
c8c088ba YS |
1450 | if (*prog != &dummy_bpf_prog.prog) |
1451 | cnt++; | |
468e2f64 AS |
1452 | rcu_read_unlock(); |
1453 | return cnt; | |
1454 | } | |
1455 | ||
1456 | int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs, | |
1457 | __u32 __user *prog_ids, u32 cnt) | |
1458 | { | |
1459 | struct bpf_prog **prog; | |
1460 | u32 i = 0, id; | |
1461 | ||
1462 | rcu_read_lock(); | |
1463 | prog = rcu_dereference(progs)->progs; | |
1464 | for (; *prog; prog++) { | |
f371b304 YS |
1465 | if (*prog == &dummy_bpf_prog.prog) |
1466 | continue; | |
468e2f64 AS |
1467 | id = (*prog)->aux->id; |
1468 | if (copy_to_user(prog_ids + i, &id, sizeof(id))) { | |
1469 | rcu_read_unlock(); | |
1470 | return -EFAULT; | |
1471 | } | |
1472 | if (++i == cnt) { | |
1473 | prog++; | |
1474 | break; | |
1475 | } | |
1476 | } | |
1477 | rcu_read_unlock(); | |
1478 | if (*prog) | |
1479 | return -ENOSPC; | |
1480 | return 0; | |
1481 | } | |
1482 | ||
e87c6bc3 YS |
1483 | void bpf_prog_array_delete_safe(struct bpf_prog_array __rcu *progs, |
1484 | struct bpf_prog *old_prog) | |
1485 | { | |
1486 | struct bpf_prog **prog = progs->progs; | |
1487 | ||
1488 | for (; *prog; prog++) | |
1489 | if (*prog == old_prog) { | |
1490 | WRITE_ONCE(*prog, &dummy_bpf_prog.prog); | |
1491 | break; | |
1492 | } | |
1493 | } | |
1494 | ||
1495 | int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array, | |
1496 | struct bpf_prog *exclude_prog, | |
1497 | struct bpf_prog *include_prog, | |
1498 | struct bpf_prog_array **new_array) | |
1499 | { | |
1500 | int new_prog_cnt, carry_prog_cnt = 0; | |
1501 | struct bpf_prog **existing_prog; | |
1502 | struct bpf_prog_array *array; | |
1503 | int new_prog_idx = 0; | |
1504 | ||
1505 | /* Figure out how many existing progs we need to carry over to | |
1506 | * the new array. | |
1507 | */ | |
1508 | if (old_array) { | |
1509 | existing_prog = old_array->progs; | |
1510 | for (; *existing_prog; existing_prog++) { | |
1511 | if (*existing_prog != exclude_prog && | |
1512 | *existing_prog != &dummy_bpf_prog.prog) | |
1513 | carry_prog_cnt++; | |
1514 | if (*existing_prog == include_prog) | |
1515 | return -EEXIST; | |
1516 | } | |
1517 | } | |
1518 | ||
1519 | /* How many progs (not NULL) will be in the new array? */ | |
1520 | new_prog_cnt = carry_prog_cnt; | |
1521 | if (include_prog) | |
1522 | new_prog_cnt += 1; | |
1523 | ||
1524 | /* Do we have any prog (not NULL) in the new array? */ | |
1525 | if (!new_prog_cnt) { | |
1526 | *new_array = NULL; | |
1527 | return 0; | |
1528 | } | |
1529 | ||
1530 | /* +1 as the end of prog_array is marked with NULL */ | |
1531 | array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL); | |
1532 | if (!array) | |
1533 | return -ENOMEM; | |
1534 | ||
1535 | /* Fill in the new prog array */ | |
1536 | if (carry_prog_cnt) { | |
1537 | existing_prog = old_array->progs; | |
1538 | for (; *existing_prog; existing_prog++) | |
1539 | if (*existing_prog != exclude_prog && | |
1540 | *existing_prog != &dummy_bpf_prog.prog) | |
1541 | array->progs[new_prog_idx++] = *existing_prog; | |
1542 | } | |
1543 | if (include_prog) | |
1544 | array->progs[new_prog_idx++] = include_prog; | |
1545 | array->progs[new_prog_idx] = NULL; | |
1546 | *new_array = array; | |
1547 | return 0; | |
1548 | } | |
1549 | ||
f371b304 YS |
1550 | int bpf_prog_array_copy_info(struct bpf_prog_array __rcu *array, |
1551 | __u32 __user *prog_ids, u32 request_cnt, | |
1552 | __u32 __user *prog_cnt) | |
1553 | { | |
1554 | u32 cnt = 0; | |
1555 | ||
1556 | if (array) | |
1557 | cnt = bpf_prog_array_length(array); | |
1558 | ||
1559 | if (copy_to_user(prog_cnt, &cnt, sizeof(cnt))) | |
1560 | return -EFAULT; | |
1561 | ||
1562 | /* return early if user requested only program count or nothing to copy */ | |
1563 | if (!request_cnt || !cnt) | |
1564 | return 0; | |
1565 | ||
1566 | return bpf_prog_array_copy_to_user(array, prog_ids, request_cnt); | |
1567 | } | |
1568 | ||
60a3b225 DB |
1569 | static void bpf_prog_free_deferred(struct work_struct *work) |
1570 | { | |
09756af4 | 1571 | struct bpf_prog_aux *aux; |
60a3b225 | 1572 | |
09756af4 | 1573 | aux = container_of(work, struct bpf_prog_aux, work); |
ab3f0063 JK |
1574 | if (bpf_prog_is_dev_bound(aux)) |
1575 | bpf_prog_offload_destroy(aux->prog); | |
09756af4 | 1576 | bpf_jit_free(aux->prog); |
60a3b225 DB |
1577 | } |
1578 | ||
1579 | /* Free internal BPF program */ | |
7ae457c1 | 1580 | void bpf_prog_free(struct bpf_prog *fp) |
f5bffecd | 1581 | { |
09756af4 | 1582 | struct bpf_prog_aux *aux = fp->aux; |
60a3b225 | 1583 | |
09756af4 | 1584 | INIT_WORK(&aux->work, bpf_prog_free_deferred); |
09756af4 | 1585 | schedule_work(&aux->work); |
f5bffecd | 1586 | } |
7ae457c1 | 1587 | EXPORT_SYMBOL_GPL(bpf_prog_free); |
f89b7755 | 1588 | |
3ad00405 DB |
1589 | /* RNG for unpriviledged user space with separated state from prandom_u32(). */ |
1590 | static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state); | |
1591 | ||
1592 | void bpf_user_rnd_init_once(void) | |
1593 | { | |
1594 | prandom_init_once(&bpf_user_rnd_state); | |
1595 | } | |
1596 | ||
f3694e00 | 1597 | BPF_CALL_0(bpf_user_rnd_u32) |
3ad00405 DB |
1598 | { |
1599 | /* Should someone ever have the rather unwise idea to use some | |
1600 | * of the registers passed into this function, then note that | |
1601 | * this function is called from native eBPF and classic-to-eBPF | |
1602 | * transformations. Register assignments from both sides are | |
1603 | * different, f.e. classic always sets fn(ctx, A, X) here. | |
1604 | */ | |
1605 | struct rnd_state *state; | |
1606 | u32 res; | |
1607 | ||
1608 | state = &get_cpu_var(bpf_user_rnd_state); | |
1609 | res = prandom_u32_state(state); | |
b761fe22 | 1610 | put_cpu_var(bpf_user_rnd_state); |
3ad00405 DB |
1611 | |
1612 | return res; | |
1613 | } | |
1614 | ||
3ba67dab DB |
1615 | /* Weak definitions of helper functions in case we don't have bpf syscall. */ |
1616 | const struct bpf_func_proto bpf_map_lookup_elem_proto __weak; | |
1617 | const struct bpf_func_proto bpf_map_update_elem_proto __weak; | |
1618 | const struct bpf_func_proto bpf_map_delete_elem_proto __weak; | |
1619 | ||
03e69b50 | 1620 | const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; |
c04167ce | 1621 | const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; |
2d0e30c3 | 1622 | const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; |
17ca8cbf | 1623 | const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; |
bd570ff9 | 1624 | |
ffeedafb AS |
1625 | const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; |
1626 | const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; | |
1627 | const struct bpf_func_proto bpf_get_current_comm_proto __weak; | |
6bdc9c4c | 1628 | const struct bpf_func_proto bpf_sock_map_update_proto __weak; |
bd570ff9 | 1629 | |
0756ea3e AS |
1630 | const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) |
1631 | { | |
1632 | return NULL; | |
1633 | } | |
03e69b50 | 1634 | |
555c8a86 DB |
1635 | u64 __weak |
1636 | bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, | |
1637 | void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) | |
bd570ff9 | 1638 | { |
555c8a86 | 1639 | return -ENOTSUPP; |
bd570ff9 DB |
1640 | } |
1641 | ||
3324b584 DB |
1642 | /* Always built-in helper functions. */ |
1643 | const struct bpf_func_proto bpf_tail_call_proto = { | |
1644 | .func = NULL, | |
1645 | .gpl_only = false, | |
1646 | .ret_type = RET_VOID, | |
1647 | .arg1_type = ARG_PTR_TO_CTX, | |
1648 | .arg2_type = ARG_CONST_MAP_PTR, | |
1649 | .arg3_type = ARG_ANYTHING, | |
1650 | }; | |
1651 | ||
9383191d DB |
1652 | /* Stub for JITs that only support cBPF. eBPF programs are interpreted. |
1653 | * It is encouraged to implement bpf_int_jit_compile() instead, so that | |
1654 | * eBPF and implicitly also cBPF can get JITed! | |
1655 | */ | |
d1c55ab5 | 1656 | struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog) |
3324b584 | 1657 | { |
d1c55ab5 | 1658 | return prog; |
3324b584 DB |
1659 | } |
1660 | ||
9383191d DB |
1661 | /* Stub for JITs that support eBPF. All cBPF code gets transformed into |
1662 | * eBPF by the kernel and is later compiled by bpf_int_jit_compile(). | |
1663 | */ | |
1664 | void __weak bpf_jit_compile(struct bpf_prog *prog) | |
1665 | { | |
1666 | } | |
1667 | ||
17bedab2 | 1668 | bool __weak bpf_helper_changes_pkt_data(void *func) |
969bf05e AS |
1669 | { |
1670 | return false; | |
1671 | } | |
1672 | ||
f89b7755 AS |
1673 | /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call |
1674 | * skb_copy_bits(), so provide a weak definition of it for NET-less config. | |
1675 | */ | |
1676 | int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, | |
1677 | int len) | |
1678 | { | |
1679 | return -EFAULT; | |
1680 | } | |
a67edbf4 DB |
1681 | |
1682 | /* All definitions of tracepoints related to BPF. */ | |
1683 | #define CREATE_TRACE_POINTS | |
1684 | #include <linux/bpf_trace.h> | |
1685 | ||
1686 | EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception); | |
1687 | ||
9185a610 SRV |
1688 | /* These are only used within the BPF_SYSCALL code */ |
1689 | #ifdef CONFIG_BPF_SYSCALL | |
a67edbf4 DB |
1690 | EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_get_type); |
1691 | EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_put_rcu); | |
9185a610 | 1692 | #endif |