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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] | |
1ead6876 | 54 | #define AX regs[BPF_REG_AX] |
f5bffecd AS |
55 | #define ARG1 regs[BPF_REG_ARG1] |
56 | #define CTX regs[BPF_REG_CTX] | |
57 | #define IMM insn->imm | |
58 | ||
59 | /* No hurry in this branch | |
60 | * | |
61 | * Exported for the bpf jit load helper. | |
62 | */ | |
63 | void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) | |
64 | { | |
65 | u8 *ptr = NULL; | |
66 | ||
67 | if (k >= SKF_NET_OFF) | |
68 | ptr = skb_network_header(skb) + k - SKF_NET_OFF; | |
69 | else if (k >= SKF_LL_OFF) | |
70 | ptr = skb_mac_header(skb) + k - SKF_LL_OFF; | |
3324b584 | 71 | |
f5bffecd AS |
72 | if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) |
73 | return ptr; | |
74 | ||
75 | return NULL; | |
76 | } | |
77 | ||
60a3b225 DB |
78 | struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) |
79 | { | |
19809c2d | 80 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
09756af4 | 81 | struct bpf_prog_aux *aux; |
60a3b225 DB |
82 | struct bpf_prog *fp; |
83 | ||
84 | size = round_up(size, PAGE_SIZE); | |
85 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); | |
86 | if (fp == NULL) | |
87 | return NULL; | |
88 | ||
09756af4 AS |
89 | aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags); |
90 | if (aux == NULL) { | |
60a3b225 DB |
91 | vfree(fp); |
92 | return NULL; | |
93 | } | |
94 | ||
95 | fp->pages = size / PAGE_SIZE; | |
09756af4 | 96 | fp->aux = aux; |
e9d8afa9 | 97 | fp->aux->prog = fp; |
60a3b225 | 98 | |
74451e66 DB |
99 | INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode); |
100 | ||
60a3b225 DB |
101 | return fp; |
102 | } | |
103 | EXPORT_SYMBOL_GPL(bpf_prog_alloc); | |
104 | ||
105 | struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, | |
106 | gfp_t gfp_extra_flags) | |
107 | { | |
19809c2d | 108 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
60a3b225 | 109 | struct bpf_prog *fp; |
5ccb071e DB |
110 | u32 pages, delta; |
111 | int ret; | |
60a3b225 DB |
112 | |
113 | BUG_ON(fp_old == NULL); | |
114 | ||
115 | size = round_up(size, PAGE_SIZE); | |
5ccb071e DB |
116 | pages = size / PAGE_SIZE; |
117 | if (pages <= fp_old->pages) | |
60a3b225 DB |
118 | return fp_old; |
119 | ||
5ccb071e DB |
120 | delta = pages - fp_old->pages; |
121 | ret = __bpf_prog_charge(fp_old->aux->user, delta); | |
122 | if (ret) | |
123 | return NULL; | |
124 | ||
60a3b225 | 125 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); |
5ccb071e DB |
126 | if (fp == NULL) { |
127 | __bpf_prog_uncharge(fp_old->aux->user, delta); | |
128 | } else { | |
60a3b225 | 129 | memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); |
5ccb071e | 130 | fp->pages = pages; |
e9d8afa9 | 131 | fp->aux->prog = fp; |
60a3b225 | 132 | |
09756af4 | 133 | /* We keep fp->aux from fp_old around in the new |
60a3b225 DB |
134 | * reallocated structure. |
135 | */ | |
09756af4 | 136 | fp_old->aux = NULL; |
60a3b225 DB |
137 | __bpf_prog_free(fp_old); |
138 | } | |
139 | ||
140 | return fp; | |
141 | } | |
60a3b225 DB |
142 | |
143 | void __bpf_prog_free(struct bpf_prog *fp) | |
144 | { | |
09756af4 | 145 | kfree(fp->aux); |
60a3b225 DB |
146 | vfree(fp); |
147 | } | |
60a3b225 | 148 | |
f1f7714e | 149 | int bpf_prog_calc_tag(struct bpf_prog *fp) |
7bd509e3 DB |
150 | { |
151 | const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64); | |
f1f7714e DB |
152 | u32 raw_size = bpf_prog_tag_scratch_size(fp); |
153 | u32 digest[SHA_DIGEST_WORDS]; | |
aafe6ae9 | 154 | u32 ws[SHA_WORKSPACE_WORDS]; |
7bd509e3 | 155 | u32 i, bsize, psize, blocks; |
aafe6ae9 | 156 | struct bpf_insn *dst; |
7bd509e3 | 157 | bool was_ld_map; |
aafe6ae9 | 158 | u8 *raw, *todo; |
7bd509e3 DB |
159 | __be32 *result; |
160 | __be64 *bits; | |
161 | ||
aafe6ae9 DB |
162 | raw = vmalloc(raw_size); |
163 | if (!raw) | |
164 | return -ENOMEM; | |
165 | ||
f1f7714e | 166 | sha_init(digest); |
7bd509e3 DB |
167 | memset(ws, 0, sizeof(ws)); |
168 | ||
169 | /* We need to take out the map fd for the digest calculation | |
170 | * since they are unstable from user space side. | |
171 | */ | |
aafe6ae9 | 172 | dst = (void *)raw; |
7bd509e3 DB |
173 | for (i = 0, was_ld_map = false; i < fp->len; i++) { |
174 | dst[i] = fp->insnsi[i]; | |
175 | if (!was_ld_map && | |
176 | dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
177 | dst[i].src_reg == BPF_PSEUDO_MAP_FD) { | |
178 | was_ld_map = true; | |
179 | dst[i].imm = 0; | |
180 | } else if (was_ld_map && | |
181 | dst[i].code == 0 && | |
182 | dst[i].dst_reg == 0 && | |
183 | dst[i].src_reg == 0 && | |
184 | dst[i].off == 0) { | |
185 | was_ld_map = false; | |
186 | dst[i].imm = 0; | |
187 | } else { | |
188 | was_ld_map = false; | |
189 | } | |
190 | } | |
191 | ||
aafe6ae9 DB |
192 | psize = bpf_prog_insn_size(fp); |
193 | memset(&raw[psize], 0, raw_size - psize); | |
7bd509e3 DB |
194 | raw[psize++] = 0x80; |
195 | ||
196 | bsize = round_up(psize, SHA_MESSAGE_BYTES); | |
197 | blocks = bsize / SHA_MESSAGE_BYTES; | |
aafe6ae9 | 198 | todo = raw; |
7bd509e3 DB |
199 | if (bsize - psize >= sizeof(__be64)) { |
200 | bits = (__be64 *)(todo + bsize - sizeof(__be64)); | |
201 | } else { | |
202 | bits = (__be64 *)(todo + bsize + bits_offset); | |
203 | blocks++; | |
204 | } | |
205 | *bits = cpu_to_be64((psize - 1) << 3); | |
206 | ||
207 | while (blocks--) { | |
f1f7714e | 208 | sha_transform(digest, todo, ws); |
7bd509e3 DB |
209 | todo += SHA_MESSAGE_BYTES; |
210 | } | |
211 | ||
f1f7714e | 212 | result = (__force __be32 *)digest; |
7bd509e3 | 213 | for (i = 0; i < SHA_DIGEST_WORDS; i++) |
f1f7714e DB |
214 | result[i] = cpu_to_be32(digest[i]); |
215 | memcpy(fp->tag, result, sizeof(fp->tag)); | |
aafe6ae9 DB |
216 | |
217 | vfree(raw); | |
218 | return 0; | |
7bd509e3 DB |
219 | } |
220 | ||
c237ee5e DB |
221 | static bool bpf_is_jmp_and_has_target(const struct bpf_insn *insn) |
222 | { | |
223 | return BPF_CLASS(insn->code) == BPF_JMP && | |
224 | /* Call and Exit are both special jumps with no | |
225 | * target inside the BPF instruction image. | |
226 | */ | |
227 | BPF_OP(insn->code) != BPF_CALL && | |
228 | BPF_OP(insn->code) != BPF_EXIT; | |
229 | } | |
230 | ||
231 | static void bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta) | |
232 | { | |
233 | struct bpf_insn *insn = prog->insnsi; | |
234 | u32 i, insn_cnt = prog->len; | |
235 | ||
236 | for (i = 0; i < insn_cnt; i++, insn++) { | |
237 | if (!bpf_is_jmp_and_has_target(insn)) | |
238 | continue; | |
239 | ||
240 | /* Adjust offset of jmps if we cross boundaries. */ | |
241 | if (i < pos && i + insn->off + 1 > pos) | |
242 | insn->off += delta; | |
243 | else if (i > pos + delta && i + insn->off + 1 <= pos + delta) | |
244 | insn->off -= delta; | |
245 | } | |
246 | } | |
247 | ||
248 | struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, | |
249 | const struct bpf_insn *patch, u32 len) | |
250 | { | |
251 | u32 insn_adj_cnt, insn_rest, insn_delta = len - 1; | |
252 | struct bpf_prog *prog_adj; | |
253 | ||
254 | /* Since our patchlet doesn't expand the image, we're done. */ | |
255 | if (insn_delta == 0) { | |
256 | memcpy(prog->insnsi + off, patch, sizeof(*patch)); | |
257 | return prog; | |
258 | } | |
259 | ||
260 | insn_adj_cnt = prog->len + insn_delta; | |
261 | ||
262 | /* Several new instructions need to be inserted. Make room | |
263 | * for them. Likely, there's no need for a new allocation as | |
264 | * last page could have large enough tailroom. | |
265 | */ | |
266 | prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt), | |
267 | GFP_USER); | |
268 | if (!prog_adj) | |
269 | return NULL; | |
270 | ||
271 | prog_adj->len = insn_adj_cnt; | |
272 | ||
273 | /* Patching happens in 3 steps: | |
274 | * | |
275 | * 1) Move over tail of insnsi from next instruction onwards, | |
276 | * so we can patch the single target insn with one or more | |
277 | * new ones (patching is always from 1 to n insns, n > 0). | |
278 | * 2) Inject new instructions at the target location. | |
279 | * 3) Adjust branch offsets if necessary. | |
280 | */ | |
281 | insn_rest = insn_adj_cnt - off - len; | |
282 | ||
283 | memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1, | |
284 | sizeof(*patch) * insn_rest); | |
285 | memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len); | |
286 | ||
287 | bpf_adj_branches(prog_adj, off, insn_delta); | |
288 | ||
289 | return prog_adj; | |
290 | } | |
291 | ||
b954d834 | 292 | #ifdef CONFIG_BPF_JIT |
69e97d45 DB |
293 | /* All BPF JIT sysctl knobs here. */ |
294 | int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON); | |
295 | int bpf_jit_harden __read_mostly; | |
296 | int bpf_jit_kallsyms __read_mostly; | |
ce873e76 | 297 | long bpf_jit_limit __read_mostly; |
69e97d45 | 298 | |
74451e66 DB |
299 | static __always_inline void |
300 | bpf_get_prog_addr_region(const struct bpf_prog *prog, | |
301 | unsigned long *symbol_start, | |
302 | unsigned long *symbol_end) | |
303 | { | |
304 | const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog); | |
305 | unsigned long addr = (unsigned long)hdr; | |
306 | ||
307 | WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog)); | |
308 | ||
309 | *symbol_start = addr; | |
310 | *symbol_end = addr + hdr->pages * PAGE_SIZE; | |
311 | } | |
312 | ||
313 | static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) | |
314 | { | |
368211fb MKL |
315 | const char *end = sym + KSYM_NAME_LEN; |
316 | ||
74451e66 | 317 | BUILD_BUG_ON(sizeof("bpf_prog_") + |
368211fb MKL |
318 | sizeof(prog->tag) * 2 + |
319 | /* name has been null terminated. | |
320 | * We should need +1 for the '_' preceding | |
321 | * the name. However, the null character | |
322 | * is double counted between the name and the | |
323 | * sizeof("bpf_prog_") above, so we omit | |
324 | * the +1 here. | |
325 | */ | |
326 | sizeof(prog->aux->name) > KSYM_NAME_LEN); | |
74451e66 DB |
327 | |
328 | sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_"); | |
329 | sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); | |
368211fb MKL |
330 | if (prog->aux->name[0]) |
331 | snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name); | |
332 | else | |
333 | *sym = 0; | |
74451e66 DB |
334 | } |
335 | ||
336 | static __always_inline unsigned long | |
337 | bpf_get_prog_addr_start(struct latch_tree_node *n) | |
338 | { | |
339 | unsigned long symbol_start, symbol_end; | |
340 | const struct bpf_prog_aux *aux; | |
341 | ||
342 | aux = container_of(n, struct bpf_prog_aux, ksym_tnode); | |
343 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
344 | ||
345 | return symbol_start; | |
346 | } | |
347 | ||
348 | static __always_inline bool bpf_tree_less(struct latch_tree_node *a, | |
349 | struct latch_tree_node *b) | |
350 | { | |
351 | return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b); | |
352 | } | |
353 | ||
354 | static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n) | |
355 | { | |
356 | unsigned long val = (unsigned long)key; | |
357 | unsigned long symbol_start, symbol_end; | |
358 | const struct bpf_prog_aux *aux; | |
359 | ||
360 | aux = container_of(n, struct bpf_prog_aux, ksym_tnode); | |
361 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
362 | ||
363 | if (val < symbol_start) | |
364 | return -1; | |
365 | if (val >= symbol_end) | |
366 | return 1; | |
367 | ||
368 | return 0; | |
369 | } | |
370 | ||
371 | static const struct latch_tree_ops bpf_tree_ops = { | |
372 | .less = bpf_tree_less, | |
373 | .comp = bpf_tree_comp, | |
374 | }; | |
375 | ||
376 | static DEFINE_SPINLOCK(bpf_lock); | |
377 | static LIST_HEAD(bpf_kallsyms); | |
378 | static struct latch_tree_root bpf_tree __cacheline_aligned; | |
379 | ||
74451e66 DB |
380 | static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux) |
381 | { | |
382 | WARN_ON_ONCE(!list_empty(&aux->ksym_lnode)); | |
383 | list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms); | |
384 | latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); | |
385 | } | |
386 | ||
387 | static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux) | |
388 | { | |
389 | if (list_empty(&aux->ksym_lnode)) | |
390 | return; | |
391 | ||
392 | latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); | |
393 | list_del_rcu(&aux->ksym_lnode); | |
394 | } | |
395 | ||
396 | static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp) | |
397 | { | |
398 | return fp->jited && !bpf_prog_was_classic(fp); | |
399 | } | |
400 | ||
401 | static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp) | |
402 | { | |
403 | return list_empty(&fp->aux->ksym_lnode) || | |
404 | fp->aux->ksym_lnode.prev == LIST_POISON2; | |
405 | } | |
406 | ||
407 | void bpf_prog_kallsyms_add(struct bpf_prog *fp) | |
408 | { | |
74451e66 DB |
409 | if (!bpf_prog_kallsyms_candidate(fp) || |
410 | !capable(CAP_SYS_ADMIN)) | |
411 | return; | |
412 | ||
d24f7c7f | 413 | spin_lock_bh(&bpf_lock); |
74451e66 | 414 | bpf_prog_ksym_node_add(fp->aux); |
d24f7c7f | 415 | spin_unlock_bh(&bpf_lock); |
74451e66 DB |
416 | } |
417 | ||
418 | void bpf_prog_kallsyms_del(struct bpf_prog *fp) | |
419 | { | |
74451e66 DB |
420 | if (!bpf_prog_kallsyms_candidate(fp)) |
421 | return; | |
422 | ||
d24f7c7f | 423 | spin_lock_bh(&bpf_lock); |
74451e66 | 424 | bpf_prog_ksym_node_del(fp->aux); |
d24f7c7f | 425 | spin_unlock_bh(&bpf_lock); |
74451e66 DB |
426 | } |
427 | ||
428 | static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr) | |
429 | { | |
430 | struct latch_tree_node *n; | |
431 | ||
432 | if (!bpf_jit_kallsyms_enabled()) | |
433 | return NULL; | |
434 | ||
435 | n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops); | |
436 | return n ? | |
437 | container_of(n, struct bpf_prog_aux, ksym_tnode)->prog : | |
438 | NULL; | |
439 | } | |
440 | ||
441 | const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, | |
442 | unsigned long *off, char *sym) | |
443 | { | |
444 | unsigned long symbol_start, symbol_end; | |
445 | struct bpf_prog *prog; | |
446 | char *ret = NULL; | |
447 | ||
448 | rcu_read_lock(); | |
449 | prog = bpf_prog_kallsyms_find(addr); | |
450 | if (prog) { | |
451 | bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end); | |
452 | bpf_get_prog_name(prog, sym); | |
453 | ||
454 | ret = sym; | |
455 | if (size) | |
456 | *size = symbol_end - symbol_start; | |
457 | if (off) | |
458 | *off = addr - symbol_start; | |
459 | } | |
460 | rcu_read_unlock(); | |
461 | ||
462 | return ret; | |
463 | } | |
464 | ||
465 | bool is_bpf_text_address(unsigned long addr) | |
466 | { | |
467 | bool ret; | |
468 | ||
469 | rcu_read_lock(); | |
470 | ret = bpf_prog_kallsyms_find(addr) != NULL; | |
471 | rcu_read_unlock(); | |
472 | ||
473 | return ret; | |
474 | } | |
475 | ||
476 | int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, | |
477 | char *sym) | |
478 | { | |
479 | unsigned long symbol_start, symbol_end; | |
480 | struct bpf_prog_aux *aux; | |
481 | unsigned int it = 0; | |
482 | int ret = -ERANGE; | |
483 | ||
484 | if (!bpf_jit_kallsyms_enabled()) | |
485 | return ret; | |
486 | ||
487 | rcu_read_lock(); | |
488 | list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) { | |
489 | if (it++ != symnum) | |
490 | continue; | |
491 | ||
492 | bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); | |
493 | bpf_get_prog_name(aux->prog, sym); | |
494 | ||
495 | *value = symbol_start; | |
496 | *type = BPF_SYM_ELF_TYPE; | |
497 | ||
498 | ret = 0; | |
499 | break; | |
500 | } | |
501 | rcu_read_unlock(); | |
502 | ||
503 | return ret; | |
504 | } | |
505 | ||
409a37eb DB |
506 | static atomic_long_t bpf_jit_current; |
507 | ||
ce873e76 DB |
508 | /* Can be overridden by an arch's JIT compiler if it has a custom, |
509 | * dedicated BPF backend memory area, or if neither of the two | |
510 | * below apply. | |
511 | */ | |
512 | u64 __weak bpf_jit_alloc_exec_limit(void) | |
513 | { | |
409a37eb | 514 | #if defined(MODULES_VADDR) |
ce873e76 DB |
515 | return MODULES_END - MODULES_VADDR; |
516 | #else | |
517 | return VMALLOC_END - VMALLOC_START; | |
518 | #endif | |
519 | } | |
520 | ||
409a37eb DB |
521 | static int __init bpf_jit_charge_init(void) |
522 | { | |
523 | /* Only used as heuristic here to derive limit. */ | |
ce873e76 DB |
524 | bpf_jit_limit = min_t(u64, round_up(bpf_jit_alloc_exec_limit() >> 2, |
525 | PAGE_SIZE), LONG_MAX); | |
409a37eb DB |
526 | return 0; |
527 | } | |
528 | pure_initcall(bpf_jit_charge_init); | |
409a37eb DB |
529 | |
530 | static int bpf_jit_charge_modmem(u32 pages) | |
531 | { | |
532 | if (atomic_long_add_return(pages, &bpf_jit_current) > | |
533 | (bpf_jit_limit >> PAGE_SHIFT)) { | |
534 | if (!capable(CAP_SYS_ADMIN)) { | |
535 | atomic_long_sub(pages, &bpf_jit_current); | |
536 | return -EPERM; | |
537 | } | |
538 | } | |
539 | ||
540 | return 0; | |
541 | } | |
542 | ||
543 | static void bpf_jit_uncharge_modmem(u32 pages) | |
544 | { | |
545 | atomic_long_sub(pages, &bpf_jit_current); | |
546 | } | |
547 | ||
738cbe72 DB |
548 | struct bpf_binary_header * |
549 | bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, | |
550 | unsigned int alignment, | |
551 | bpf_jit_fill_hole_t bpf_fill_ill_insns) | |
552 | { | |
553 | struct bpf_binary_header *hdr; | |
409a37eb | 554 | u32 size, hole, start, pages; |
738cbe72 DB |
555 | |
556 | /* Most of BPF filters are really small, but if some of them | |
557 | * fill a page, allow at least 128 extra bytes to insert a | |
558 | * random section of illegal instructions. | |
559 | */ | |
560 | size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE); | |
409a37eb DB |
561 | pages = size / PAGE_SIZE; |
562 | ||
563 | if (bpf_jit_charge_modmem(pages)) | |
564 | return NULL; | |
738cbe72 | 565 | hdr = module_alloc(size); |
409a37eb DB |
566 | if (!hdr) { |
567 | bpf_jit_uncharge_modmem(pages); | |
738cbe72 | 568 | return NULL; |
409a37eb | 569 | } |
738cbe72 DB |
570 | |
571 | /* Fill space with illegal/arch-dep instructions. */ | |
572 | bpf_fill_ill_insns(hdr, size); | |
573 | ||
409a37eb | 574 | hdr->pages = pages; |
738cbe72 DB |
575 | hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)), |
576 | PAGE_SIZE - sizeof(*hdr)); | |
b7552e1b | 577 | start = (get_random_int() % hole) & ~(alignment - 1); |
738cbe72 DB |
578 | |
579 | /* Leave a random number of instructions before BPF code. */ | |
580 | *image_ptr = &hdr->image[start]; | |
581 | ||
582 | return hdr; | |
583 | } | |
584 | ||
585 | void bpf_jit_binary_free(struct bpf_binary_header *hdr) | |
586 | { | |
409a37eb DB |
587 | u32 pages = hdr->pages; |
588 | ||
be1f221c | 589 | module_memfree(hdr); |
409a37eb | 590 | bpf_jit_uncharge_modmem(pages); |
738cbe72 | 591 | } |
4f3446bb | 592 | |
74451e66 DB |
593 | /* This symbol is only overridden by archs that have different |
594 | * requirements than the usual eBPF JITs, f.e. when they only | |
595 | * implement cBPF JIT, do not set images read-only, etc. | |
596 | */ | |
597 | void __weak bpf_jit_free(struct bpf_prog *fp) | |
598 | { | |
599 | if (fp->jited) { | |
600 | struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp); | |
601 | ||
602 | bpf_jit_binary_unlock_ro(hdr); | |
603 | bpf_jit_binary_free(hdr); | |
604 | ||
605 | WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp)); | |
606 | } | |
607 | ||
608 | bpf_prog_unlock_free(fp); | |
609 | } | |
610 | ||
4f3446bb DB |
611 | static int bpf_jit_blind_insn(const struct bpf_insn *from, |
612 | const struct bpf_insn *aux, | |
613 | struct bpf_insn *to_buff) | |
614 | { | |
615 | struct bpf_insn *to = to_buff; | |
b7552e1b | 616 | u32 imm_rnd = get_random_int(); |
4f3446bb DB |
617 | s16 off; |
618 | ||
619 | BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG); | |
620 | BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG); | |
621 | ||
92c22ad6 DB |
622 | /* Constraints on AX register: |
623 | * | |
624 | * AX register is inaccessible from user space. It is mapped in | |
625 | * all JITs, and used here for constant blinding rewrites. It is | |
626 | * typically "stateless" meaning its contents are only valid within | |
627 | * the executed instruction, but not across several instructions. | |
628 | * There are a few exceptions however which are further detailed | |
629 | * below. | |
630 | * | |
631 | * Constant blinding is only used by JITs, not in the interpreter. | |
632 | * The interpreter uses AX in some occasions as a local temporary | |
633 | * register e.g. in DIV or MOD instructions. | |
634 | * | |
635 | * In restricted circumstances, the verifier can also use the AX | |
636 | * register for rewrites as long as they do not interfere with | |
637 | * the above cases! | |
638 | */ | |
639 | if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX) | |
640 | goto out; | |
641 | ||
4f3446bb DB |
642 | if (from->imm == 0 && |
643 | (from->code == (BPF_ALU | BPF_MOV | BPF_K) || | |
644 | from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) { | |
645 | *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg); | |
646 | goto out; | |
647 | } | |
648 | ||
649 | switch (from->code) { | |
650 | case BPF_ALU | BPF_ADD | BPF_K: | |
651 | case BPF_ALU | BPF_SUB | BPF_K: | |
652 | case BPF_ALU | BPF_AND | BPF_K: | |
653 | case BPF_ALU | BPF_OR | BPF_K: | |
654 | case BPF_ALU | BPF_XOR | BPF_K: | |
655 | case BPF_ALU | BPF_MUL | BPF_K: | |
656 | case BPF_ALU | BPF_MOV | BPF_K: | |
657 | case BPF_ALU | BPF_DIV | BPF_K: | |
658 | case BPF_ALU | BPF_MOD | BPF_K: | |
659 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
660 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
661 | *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX); | |
662 | break; | |
663 | ||
664 | case BPF_ALU64 | BPF_ADD | BPF_K: | |
665 | case BPF_ALU64 | BPF_SUB | BPF_K: | |
666 | case BPF_ALU64 | BPF_AND | BPF_K: | |
667 | case BPF_ALU64 | BPF_OR | BPF_K: | |
668 | case BPF_ALU64 | BPF_XOR | BPF_K: | |
669 | case BPF_ALU64 | BPF_MUL | BPF_K: | |
670 | case BPF_ALU64 | BPF_MOV | BPF_K: | |
671 | case BPF_ALU64 | BPF_DIV | BPF_K: | |
672 | case BPF_ALU64 | BPF_MOD | BPF_K: | |
673 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
674 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
675 | *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX); | |
676 | break; | |
677 | ||
678 | case BPF_JMP | BPF_JEQ | BPF_K: | |
679 | case BPF_JMP | BPF_JNE | BPF_K: | |
680 | case BPF_JMP | BPF_JGT | BPF_K: | |
92b31a9a | 681 | case BPF_JMP | BPF_JLT | BPF_K: |
4f3446bb | 682 | case BPF_JMP | BPF_JGE | BPF_K: |
92b31a9a | 683 | case BPF_JMP | BPF_JLE | BPF_K: |
4f3446bb | 684 | case BPF_JMP | BPF_JSGT | BPF_K: |
92b31a9a | 685 | case BPF_JMP | BPF_JSLT | BPF_K: |
4f3446bb | 686 | case BPF_JMP | BPF_JSGE | BPF_K: |
92b31a9a | 687 | case BPF_JMP | BPF_JSLE | BPF_K: |
4f3446bb DB |
688 | case BPF_JMP | BPF_JSET | BPF_K: |
689 | /* Accommodate for extra offset in case of a backjump. */ | |
690 | off = from->off; | |
691 | if (off < 0) | |
692 | off -= 2; | |
693 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
694 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
695 | *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off); | |
696 | break; | |
697 | ||
698 | case BPF_LD | BPF_ABS | BPF_W: | |
699 | case BPF_LD | BPF_ABS | BPF_H: | |
700 | case BPF_LD | BPF_ABS | BPF_B: | |
701 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
702 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
703 | *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0); | |
704 | break; | |
705 | ||
706 | case BPF_LD | BPF_IND | BPF_W: | |
707 | case BPF_LD | BPF_IND | BPF_H: | |
708 | case BPF_LD | BPF_IND | BPF_B: | |
709 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
710 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
711 | *to++ = BPF_ALU32_REG(BPF_ADD, BPF_REG_AX, from->src_reg); | |
712 | *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0); | |
713 | break; | |
714 | ||
715 | case BPF_LD | BPF_IMM | BPF_DW: | |
716 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm); | |
717 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
718 | *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32); | |
719 | *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX); | |
720 | break; | |
721 | case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */ | |
722 | *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm); | |
723 | *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
724 | *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX); | |
725 | break; | |
726 | ||
727 | case BPF_ST | BPF_MEM | BPF_DW: | |
728 | case BPF_ST | BPF_MEM | BPF_W: | |
729 | case BPF_ST | BPF_MEM | BPF_H: | |
730 | case BPF_ST | BPF_MEM | BPF_B: | |
731 | *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); | |
732 | *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); | |
733 | *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off); | |
734 | break; | |
735 | } | |
736 | out: | |
737 | return to - to_buff; | |
738 | } | |
739 | ||
740 | static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other, | |
741 | gfp_t gfp_extra_flags) | |
742 | { | |
19809c2d | 743 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; |
4f3446bb DB |
744 | struct bpf_prog *fp; |
745 | ||
746 | fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL); | |
747 | if (fp != NULL) { | |
4f3446bb DB |
748 | /* aux->prog still points to the fp_other one, so |
749 | * when promoting the clone to the real program, | |
750 | * this still needs to be adapted. | |
751 | */ | |
752 | memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE); | |
753 | } | |
754 | ||
755 | return fp; | |
756 | } | |
757 | ||
758 | static void bpf_prog_clone_free(struct bpf_prog *fp) | |
759 | { | |
760 | /* aux was stolen by the other clone, so we cannot free | |
761 | * it from this path! It will be freed eventually by the | |
762 | * other program on release. | |
763 | * | |
764 | * At this point, we don't need a deferred release since | |
765 | * clone is guaranteed to not be locked. | |
766 | */ | |
767 | fp->aux = NULL; | |
768 | __bpf_prog_free(fp); | |
769 | } | |
770 | ||
771 | void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other) | |
772 | { | |
773 | /* We have to repoint aux->prog to self, as we don't | |
774 | * know whether fp here is the clone or the original. | |
775 | */ | |
776 | fp->aux->prog = fp; | |
777 | bpf_prog_clone_free(fp_other); | |
778 | } | |
779 | ||
780 | struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog) | |
781 | { | |
782 | struct bpf_insn insn_buff[16], aux[2]; | |
783 | struct bpf_prog *clone, *tmp; | |
784 | int insn_delta, insn_cnt; | |
785 | struct bpf_insn *insn; | |
786 | int i, rewritten; | |
787 | ||
788 | if (!bpf_jit_blinding_enabled()) | |
789 | return prog; | |
790 | ||
791 | clone = bpf_prog_clone_create(prog, GFP_USER); | |
792 | if (!clone) | |
793 | return ERR_PTR(-ENOMEM); | |
794 | ||
795 | insn_cnt = clone->len; | |
796 | insn = clone->insnsi; | |
797 | ||
798 | for (i = 0; i < insn_cnt; i++, insn++) { | |
799 | /* We temporarily need to hold the original ld64 insn | |
800 | * so that we can still access the first part in the | |
801 | * second blinding run. | |
802 | */ | |
803 | if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) && | |
804 | insn[1].code == 0) | |
805 | memcpy(aux, insn, sizeof(aux)); | |
806 | ||
807 | rewritten = bpf_jit_blind_insn(insn, aux, insn_buff); | |
808 | if (!rewritten) | |
809 | continue; | |
810 | ||
811 | tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten); | |
812 | if (!tmp) { | |
813 | /* Patching may have repointed aux->prog during | |
814 | * realloc from the original one, so we need to | |
815 | * fix it up here on error. | |
816 | */ | |
817 | bpf_jit_prog_release_other(prog, clone); | |
818 | return ERR_PTR(-ENOMEM); | |
819 | } | |
820 | ||
821 | clone = tmp; | |
822 | insn_delta = rewritten - 1; | |
823 | ||
824 | /* Walk new program and skip insns we just inserted. */ | |
825 | insn = clone->insnsi + i + insn_delta; | |
826 | insn_cnt += insn_delta; | |
827 | i += insn_delta; | |
828 | } | |
829 | ||
830 | return clone; | |
831 | } | |
b954d834 | 832 | #endif /* CONFIG_BPF_JIT */ |
738cbe72 | 833 | |
f5bffecd AS |
834 | /* Base function for offset calculation. Needs to go into .text section, |
835 | * therefore keeping it non-static as well; will also be used by JITs | |
836 | * anyway later on, so do not let the compiler omit it. | |
837 | */ | |
838 | noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) | |
839 | { | |
840 | return 0; | |
841 | } | |
4d9c5c53 | 842 | EXPORT_SYMBOL_GPL(__bpf_call_base); |
f5bffecd | 843 | |
290af866 | 844 | #ifndef CONFIG_BPF_JIT_ALWAYS_ON |
f5bffecd | 845 | /** |
7ae457c1 AS |
846 | * __bpf_prog_run - run eBPF program on a given context |
847 | * @ctx: is the data we are operating on | |
848 | * @insn: is the array of eBPF instructions | |
f5bffecd | 849 | * |
7ae457c1 | 850 | * Decode and execute eBPF instructions. |
f5bffecd | 851 | */ |
f696b8f4 AS |
852 | static unsigned int ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, |
853 | u64 *stack) | |
f5bffecd | 854 | { |
f5bffecd AS |
855 | static const void *jumptable[256] = { |
856 | [0 ... 255] = &&default_label, | |
857 | /* Now overwrite non-defaults ... */ | |
858 | /* 32 bit ALU operations */ | |
859 | [BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X, | |
860 | [BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K, | |
861 | [BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X, | |
862 | [BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K, | |
863 | [BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X, | |
864 | [BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K, | |
865 | [BPF_ALU | BPF_OR | BPF_X] = &&ALU_OR_X, | |
866 | [BPF_ALU | BPF_OR | BPF_K] = &&ALU_OR_K, | |
867 | [BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X, | |
868 | [BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K, | |
869 | [BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X, | |
870 | [BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K, | |
871 | [BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X, | |
872 | [BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K, | |
873 | [BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X, | |
874 | [BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K, | |
875 | [BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X, | |
876 | [BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K, | |
877 | [BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X, | |
878 | [BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K, | |
879 | [BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X, | |
880 | [BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K, | |
881 | [BPF_ALU | BPF_NEG] = &&ALU_NEG, | |
882 | [BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE, | |
883 | [BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE, | |
884 | /* 64 bit ALU operations */ | |
885 | [BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X, | |
886 | [BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K, | |
887 | [BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X, | |
888 | [BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K, | |
889 | [BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X, | |
890 | [BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K, | |
891 | [BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X, | |
892 | [BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K, | |
893 | [BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X, | |
894 | [BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K, | |
895 | [BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X, | |
896 | [BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K, | |
897 | [BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X, | |
898 | [BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K, | |
899 | [BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X, | |
900 | [BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K, | |
901 | [BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X, | |
902 | [BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K, | |
903 | [BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X, | |
904 | [BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K, | |
905 | [BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X, | |
906 | [BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K, | |
907 | [BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X, | |
908 | [BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K, | |
909 | [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG, | |
910 | /* Call instruction */ | |
911 | [BPF_JMP | BPF_CALL] = &&JMP_CALL, | |
71189fa9 | 912 | [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL, |
f5bffecd AS |
913 | /* Jumps */ |
914 | [BPF_JMP | BPF_JA] = &&JMP_JA, | |
915 | [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X, | |
916 | [BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K, | |
917 | [BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X, | |
918 | [BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K, | |
919 | [BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X, | |
920 | [BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K, | |
92b31a9a DB |
921 | [BPF_JMP | BPF_JLT | BPF_X] = &&JMP_JLT_X, |
922 | [BPF_JMP | BPF_JLT | BPF_K] = &&JMP_JLT_K, | |
f5bffecd AS |
923 | [BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X, |
924 | [BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K, | |
92b31a9a DB |
925 | [BPF_JMP | BPF_JLE | BPF_X] = &&JMP_JLE_X, |
926 | [BPF_JMP | BPF_JLE | BPF_K] = &&JMP_JLE_K, | |
f5bffecd AS |
927 | [BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X, |
928 | [BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K, | |
92b31a9a DB |
929 | [BPF_JMP | BPF_JSLT | BPF_X] = &&JMP_JSLT_X, |
930 | [BPF_JMP | BPF_JSLT | BPF_K] = &&JMP_JSLT_K, | |
f5bffecd AS |
931 | [BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X, |
932 | [BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K, | |
92b31a9a DB |
933 | [BPF_JMP | BPF_JSLE | BPF_X] = &&JMP_JSLE_X, |
934 | [BPF_JMP | BPF_JSLE | BPF_K] = &&JMP_JSLE_K, | |
f5bffecd AS |
935 | [BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X, |
936 | [BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K, | |
937 | /* Program return */ | |
938 | [BPF_JMP | BPF_EXIT] = &&JMP_EXIT, | |
939 | /* Store instructions */ | |
940 | [BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B, | |
941 | [BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H, | |
942 | [BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W, | |
943 | [BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW, | |
944 | [BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W, | |
945 | [BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW, | |
946 | [BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B, | |
947 | [BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H, | |
948 | [BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W, | |
949 | [BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW, | |
950 | /* Load instructions */ | |
951 | [BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B, | |
952 | [BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H, | |
953 | [BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W, | |
954 | [BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW, | |
955 | [BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W, | |
956 | [BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H, | |
957 | [BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B, | |
958 | [BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W, | |
959 | [BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H, | |
960 | [BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B, | |
02ab695b | 961 | [BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW, |
f5bffecd | 962 | }; |
04fd61ab | 963 | u32 tail_call_cnt = 0; |
f5bffecd AS |
964 | void *ptr; |
965 | int off; | |
966 | ||
967 | #define CONT ({ insn++; goto select_insn; }) | |
968 | #define CONT_JMP ({ insn++; goto select_insn; }) | |
969 | ||
f5bffecd AS |
970 | select_insn: |
971 | goto *jumptable[insn->code]; | |
972 | ||
973 | /* ALU */ | |
974 | #define ALU(OPCODE, OP) \ | |
975 | ALU64_##OPCODE##_X: \ | |
976 | DST = DST OP SRC; \ | |
977 | CONT; \ | |
978 | ALU_##OPCODE##_X: \ | |
979 | DST = (u32) DST OP (u32) SRC; \ | |
980 | CONT; \ | |
981 | ALU64_##OPCODE##_K: \ | |
982 | DST = DST OP IMM; \ | |
983 | CONT; \ | |
984 | ALU_##OPCODE##_K: \ | |
985 | DST = (u32) DST OP (u32) IMM; \ | |
986 | CONT; | |
987 | ||
988 | ALU(ADD, +) | |
989 | ALU(SUB, -) | |
990 | ALU(AND, &) | |
991 | ALU(OR, |) | |
992 | ALU(LSH, <<) | |
993 | ALU(RSH, >>) | |
994 | ALU(XOR, ^) | |
995 | ALU(MUL, *) | |
996 | #undef ALU | |
997 | ALU_NEG: | |
998 | DST = (u32) -DST; | |
999 | CONT; | |
1000 | ALU64_NEG: | |
1001 | DST = -DST; | |
1002 | CONT; | |
1003 | ALU_MOV_X: | |
1004 | DST = (u32) SRC; | |
1005 | CONT; | |
1006 | ALU_MOV_K: | |
1007 | DST = (u32) IMM; | |
1008 | CONT; | |
1009 | ALU64_MOV_X: | |
1010 | DST = SRC; | |
1011 | CONT; | |
1012 | ALU64_MOV_K: | |
1013 | DST = IMM; | |
1014 | CONT; | |
02ab695b AS |
1015 | LD_IMM_DW: |
1016 | DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; | |
1017 | insn++; | |
1018 | CONT; | |
f5bffecd AS |
1019 | ALU64_ARSH_X: |
1020 | (*(s64 *) &DST) >>= SRC; | |
1021 | CONT; | |
1022 | ALU64_ARSH_K: | |
1023 | (*(s64 *) &DST) >>= IMM; | |
1024 | CONT; | |
1025 | ALU64_MOD_X: | |
1026 | if (unlikely(SRC == 0)) | |
1027 | return 0; | |
1ead6876 DB |
1028 | div64_u64_rem(DST, SRC, &AX); |
1029 | DST = AX; | |
f5bffecd AS |
1030 | CONT; |
1031 | ALU_MOD_X: | |
c366287e | 1032 | if (unlikely((u32)SRC == 0)) |
f5bffecd | 1033 | return 0; |
1ead6876 DB |
1034 | AX = (u32) DST; |
1035 | DST = do_div(AX, (u32) SRC); | |
f5bffecd AS |
1036 | CONT; |
1037 | ALU64_MOD_K: | |
1ead6876 DB |
1038 | div64_u64_rem(DST, IMM, &AX); |
1039 | DST = AX; | |
f5bffecd AS |
1040 | CONT; |
1041 | ALU_MOD_K: | |
1ead6876 DB |
1042 | AX = (u32) DST; |
1043 | DST = do_div(AX, (u32) IMM); | |
f5bffecd AS |
1044 | CONT; |
1045 | ALU64_DIV_X: | |
1046 | if (unlikely(SRC == 0)) | |
1047 | return 0; | |
876a7ae6 | 1048 | DST = div64_u64(DST, SRC); |
f5bffecd AS |
1049 | CONT; |
1050 | ALU_DIV_X: | |
c366287e | 1051 | if (unlikely((u32)SRC == 0)) |
f5bffecd | 1052 | return 0; |
1ead6876 DB |
1053 | AX = (u32) DST; |
1054 | do_div(AX, (u32) SRC); | |
1055 | DST = (u32) AX; | |
f5bffecd AS |
1056 | CONT; |
1057 | ALU64_DIV_K: | |
876a7ae6 | 1058 | DST = div64_u64(DST, IMM); |
f5bffecd AS |
1059 | CONT; |
1060 | ALU_DIV_K: | |
1ead6876 DB |
1061 | AX = (u32) DST; |
1062 | do_div(AX, (u32) IMM); | |
1063 | DST = (u32) AX; | |
f5bffecd AS |
1064 | CONT; |
1065 | ALU_END_TO_BE: | |
1066 | switch (IMM) { | |
1067 | case 16: | |
1068 | DST = (__force u16) cpu_to_be16(DST); | |
1069 | break; | |
1070 | case 32: | |
1071 | DST = (__force u32) cpu_to_be32(DST); | |
1072 | break; | |
1073 | case 64: | |
1074 | DST = (__force u64) cpu_to_be64(DST); | |
1075 | break; | |
1076 | } | |
1077 | CONT; | |
1078 | ALU_END_TO_LE: | |
1079 | switch (IMM) { | |
1080 | case 16: | |
1081 | DST = (__force u16) cpu_to_le16(DST); | |
1082 | break; | |
1083 | case 32: | |
1084 | DST = (__force u32) cpu_to_le32(DST); | |
1085 | break; | |
1086 | case 64: | |
1087 | DST = (__force u64) cpu_to_le64(DST); | |
1088 | break; | |
1089 | } | |
1090 | CONT; | |
1091 | ||
1092 | /* CALL */ | |
1093 | JMP_CALL: | |
1094 | /* Function call scratches BPF_R1-BPF_R5 registers, | |
1095 | * preserves BPF_R6-BPF_R9, and stores return value | |
1096 | * into BPF_R0. | |
1097 | */ | |
1098 | BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, | |
1099 | BPF_R4, BPF_R5); | |
1100 | CONT; | |
1101 | ||
04fd61ab AS |
1102 | JMP_TAIL_CALL: { |
1103 | struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2; | |
1104 | struct bpf_array *array = container_of(map, struct bpf_array, map); | |
1105 | struct bpf_prog *prog; | |
90caccdd | 1106 | u32 index = BPF_R3; |
04fd61ab AS |
1107 | |
1108 | if (unlikely(index >= array->map.max_entries)) | |
1109 | goto out; | |
04fd61ab AS |
1110 | if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT)) |
1111 | goto out; | |
1112 | ||
1113 | tail_call_cnt++; | |
1114 | ||
2a36f0b9 | 1115 | prog = READ_ONCE(array->ptrs[index]); |
1ca1cc98 | 1116 | if (!prog) |
04fd61ab AS |
1117 | goto out; |
1118 | ||
c4675f93 DB |
1119 | /* ARG1 at this point is guaranteed to point to CTX from |
1120 | * the verifier side due to the fact that the tail call is | |
1121 | * handeled like a helper, that is, bpf_tail_call_proto, | |
1122 | * where arg1_type is ARG_PTR_TO_CTX. | |
1123 | */ | |
04fd61ab AS |
1124 | insn = prog->insnsi; |
1125 | goto select_insn; | |
1126 | out: | |
1127 | CONT; | |
1128 | } | |
f5bffecd AS |
1129 | /* JMP */ |
1130 | JMP_JA: | |
1131 | insn += insn->off; | |
1132 | CONT; | |
1133 | JMP_JEQ_X: | |
1134 | if (DST == SRC) { | |
1135 | insn += insn->off; | |
1136 | CONT_JMP; | |
1137 | } | |
1138 | CONT; | |
1139 | JMP_JEQ_K: | |
1140 | if (DST == IMM) { | |
1141 | insn += insn->off; | |
1142 | CONT_JMP; | |
1143 | } | |
1144 | CONT; | |
1145 | JMP_JNE_X: | |
1146 | if (DST != SRC) { | |
1147 | insn += insn->off; | |
1148 | CONT_JMP; | |
1149 | } | |
1150 | CONT; | |
1151 | JMP_JNE_K: | |
1152 | if (DST != IMM) { | |
1153 | insn += insn->off; | |
1154 | CONT_JMP; | |
1155 | } | |
1156 | CONT; | |
1157 | JMP_JGT_X: | |
1158 | if (DST > SRC) { | |
1159 | insn += insn->off; | |
1160 | CONT_JMP; | |
1161 | } | |
1162 | CONT; | |
1163 | JMP_JGT_K: | |
1164 | if (DST > IMM) { | |
1165 | insn += insn->off; | |
1166 | CONT_JMP; | |
1167 | } | |
1168 | CONT; | |
92b31a9a DB |
1169 | JMP_JLT_X: |
1170 | if (DST < SRC) { | |
1171 | insn += insn->off; | |
1172 | CONT_JMP; | |
1173 | } | |
1174 | CONT; | |
1175 | JMP_JLT_K: | |
1176 | if (DST < IMM) { | |
1177 | insn += insn->off; | |
1178 | CONT_JMP; | |
1179 | } | |
1180 | CONT; | |
f5bffecd AS |
1181 | JMP_JGE_X: |
1182 | if (DST >= SRC) { | |
1183 | insn += insn->off; | |
1184 | CONT_JMP; | |
1185 | } | |
1186 | CONT; | |
1187 | JMP_JGE_K: | |
1188 | if (DST >= IMM) { | |
1189 | insn += insn->off; | |
1190 | CONT_JMP; | |
1191 | } | |
1192 | CONT; | |
92b31a9a DB |
1193 | JMP_JLE_X: |
1194 | if (DST <= SRC) { | |
1195 | insn += insn->off; | |
1196 | CONT_JMP; | |
1197 | } | |
1198 | CONT; | |
1199 | JMP_JLE_K: | |
1200 | if (DST <= IMM) { | |
1201 | insn += insn->off; | |
1202 | CONT_JMP; | |
1203 | } | |
1204 | CONT; | |
f5bffecd AS |
1205 | JMP_JSGT_X: |
1206 | if (((s64) DST) > ((s64) SRC)) { | |
1207 | insn += insn->off; | |
1208 | CONT_JMP; | |
1209 | } | |
1210 | CONT; | |
1211 | JMP_JSGT_K: | |
1212 | if (((s64) DST) > ((s64) IMM)) { | |
1213 | insn += insn->off; | |
1214 | CONT_JMP; | |
1215 | } | |
1216 | CONT; | |
92b31a9a DB |
1217 | JMP_JSLT_X: |
1218 | if (((s64) DST) < ((s64) SRC)) { | |
1219 | insn += insn->off; | |
1220 | CONT_JMP; | |
1221 | } | |
1222 | CONT; | |
1223 | JMP_JSLT_K: | |
1224 | if (((s64) DST) < ((s64) IMM)) { | |
1225 | insn += insn->off; | |
1226 | CONT_JMP; | |
1227 | } | |
1228 | CONT; | |
f5bffecd AS |
1229 | JMP_JSGE_X: |
1230 | if (((s64) DST) >= ((s64) SRC)) { | |
1231 | insn += insn->off; | |
1232 | CONT_JMP; | |
1233 | } | |
1234 | CONT; | |
1235 | JMP_JSGE_K: | |
1236 | if (((s64) DST) >= ((s64) IMM)) { | |
1237 | insn += insn->off; | |
1238 | CONT_JMP; | |
1239 | } | |
1240 | CONT; | |
92b31a9a DB |
1241 | JMP_JSLE_X: |
1242 | if (((s64) DST) <= ((s64) SRC)) { | |
1243 | insn += insn->off; | |
1244 | CONT_JMP; | |
1245 | } | |
1246 | CONT; | |
1247 | JMP_JSLE_K: | |
1248 | if (((s64) DST) <= ((s64) IMM)) { | |
1249 | insn += insn->off; | |
1250 | CONT_JMP; | |
1251 | } | |
1252 | CONT; | |
f5bffecd AS |
1253 | JMP_JSET_X: |
1254 | if (DST & SRC) { | |
1255 | insn += insn->off; | |
1256 | CONT_JMP; | |
1257 | } | |
1258 | CONT; | |
1259 | JMP_JSET_K: | |
1260 | if (DST & IMM) { | |
1261 | insn += insn->off; | |
1262 | CONT_JMP; | |
1263 | } | |
1264 | CONT; | |
1265 | JMP_EXIT: | |
1266 | return BPF_R0; | |
1267 | ||
1268 | /* STX and ST and LDX*/ | |
1269 | #define LDST(SIZEOP, SIZE) \ | |
1270 | STX_MEM_##SIZEOP: \ | |
1271 | *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ | |
1272 | CONT; \ | |
1273 | ST_MEM_##SIZEOP: \ | |
1274 | *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ | |
1275 | CONT; \ | |
1276 | LDX_MEM_##SIZEOP: \ | |
1277 | DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ | |
1278 | CONT; | |
1279 | ||
1280 | LDST(B, u8) | |
1281 | LDST(H, u16) | |
1282 | LDST(W, u32) | |
1283 | LDST(DW, u64) | |
1284 | #undef LDST | |
1285 | STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ | |
1286 | atomic_add((u32) SRC, (atomic_t *)(unsigned long) | |
1287 | (DST + insn->off)); | |
1288 | CONT; | |
1289 | STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ | |
1290 | atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) | |
1291 | (DST + insn->off)); | |
1292 | CONT; | |
1293 | LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */ | |
1294 | off = IMM; | |
1295 | load_word: | |
96a94cc5 JB |
1296 | /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are only |
1297 | * appearing in the programs where ctx == skb | |
1298 | * (see may_access_skb() in the verifier). All programs | |
1299 | * keep 'ctx' in regs[BPF_REG_CTX] == BPF_R6, | |
1300 | * bpf_convert_filter() saves it in BPF_R6, internal BPF | |
1301 | * verifier will check that BPF_R6 == ctx. | |
f5bffecd AS |
1302 | * |
1303 | * BPF_ABS and BPF_IND are wrappers of function calls, | |
1304 | * so they scratch BPF_R1-BPF_R5 registers, preserve | |
1305 | * BPF_R6-BPF_R9, and store return value into BPF_R0. | |
1306 | * | |
1307 | * Implicit input: | |
1308 | * ctx == skb == BPF_R6 == CTX | |
1309 | * | |
1310 | * Explicit input: | |
1311 | * SRC == any register | |
1312 | * IMM == 32-bit immediate | |
1313 | * | |
1314 | * Output: | |
1315 | * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness | |
1316 | */ | |
1317 | ||
1ead6876 | 1318 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &AX); |
f5bffecd AS |
1319 | if (likely(ptr != NULL)) { |
1320 | BPF_R0 = get_unaligned_be32(ptr); | |
1321 | CONT; | |
1322 | } | |
1323 | ||
1324 | return 0; | |
1325 | LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */ | |
1326 | off = IMM; | |
1327 | load_half: | |
1ead6876 | 1328 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &AX); |
f5bffecd AS |
1329 | if (likely(ptr != NULL)) { |
1330 | BPF_R0 = get_unaligned_be16(ptr); | |
1331 | CONT; | |
1332 | } | |
1333 | ||
1334 | return 0; | |
1335 | LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */ | |
1336 | off = IMM; | |
1337 | load_byte: | |
1ead6876 | 1338 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &AX); |
f5bffecd AS |
1339 | if (likely(ptr != NULL)) { |
1340 | BPF_R0 = *(u8 *)ptr; | |
1341 | CONT; | |
1342 | } | |
1343 | ||
1344 | return 0; | |
1345 | LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */ | |
1346 | off = IMM + SRC; | |
1347 | goto load_word; | |
1348 | LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */ | |
1349 | off = IMM + SRC; | |
1350 | goto load_half; | |
1351 | LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */ | |
1352 | off = IMM + SRC; | |
1353 | goto load_byte; | |
1354 | ||
1355 | default_label: | |
1356 | /* If we ever reach this, we have a bug somewhere. */ | |
1357 | WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code); | |
1358 | return 0; | |
1359 | } | |
f696b8f4 AS |
1360 | STACK_FRAME_NON_STANDARD(___bpf_prog_run); /* jump table */ |
1361 | ||
b870aa90 AS |
1362 | #define PROG_NAME(stack_size) __bpf_prog_run##stack_size |
1363 | #define DEFINE_BPF_PROG_RUN(stack_size) \ | |
1364 | static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \ | |
1365 | { \ | |
1366 | u64 stack[stack_size / sizeof(u64)]; \ | |
1ead6876 | 1367 | u64 regs[MAX_BPF_EXT_REG]; \ |
b870aa90 AS |
1368 | \ |
1369 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ | |
1370 | ARG1 = (u64) (unsigned long) ctx; \ | |
1371 | return ___bpf_prog_run(regs, insn, stack); \ | |
f696b8f4 | 1372 | } |
f5bffecd | 1373 | |
b870aa90 AS |
1374 | #define EVAL1(FN, X) FN(X) |
1375 | #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y) | |
1376 | #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y) | |
1377 | #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y) | |
1378 | #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y) | |
1379 | #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y) | |
1380 | ||
1381 | EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192); | |
1382 | EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384); | |
1383 | EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512); | |
1384 | ||
1385 | #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size), | |
1386 | ||
1387 | static unsigned int (*interpreters[])(const void *ctx, | |
1388 | const struct bpf_insn *insn) = { | |
1389 | EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) | |
1390 | EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) | |
1391 | EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) | |
1392 | }; | |
1393 | ||
290af866 | 1394 | #else |
69e97d45 DB |
1395 | static unsigned int __bpf_prog_ret0_warn(const void *ctx, |
1396 | const struct bpf_insn *insn) | |
290af866 | 1397 | { |
69e97d45 DB |
1398 | /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON |
1399 | * is not working properly, so warn about it! | |
1400 | */ | |
1401 | WARN_ON_ONCE(1); | |
290af866 AS |
1402 | return 0; |
1403 | } | |
1404 | #endif | |
1405 | ||
3324b584 DB |
1406 | bool bpf_prog_array_compatible(struct bpf_array *array, |
1407 | const struct bpf_prog *fp) | |
04fd61ab | 1408 | { |
3324b584 DB |
1409 | if (!array->owner_prog_type) { |
1410 | /* There's no owner yet where we could check for | |
1411 | * compatibility. | |
1412 | */ | |
04fd61ab AS |
1413 | array->owner_prog_type = fp->type; |
1414 | array->owner_jited = fp->jited; | |
3324b584 DB |
1415 | |
1416 | return true; | |
04fd61ab | 1417 | } |
3324b584 DB |
1418 | |
1419 | return array->owner_prog_type == fp->type && | |
1420 | array->owner_jited == fp->jited; | |
04fd61ab AS |
1421 | } |
1422 | ||
3324b584 | 1423 | static int bpf_check_tail_call(const struct bpf_prog *fp) |
04fd61ab AS |
1424 | { |
1425 | struct bpf_prog_aux *aux = fp->aux; | |
1426 | int i; | |
1427 | ||
1428 | for (i = 0; i < aux->used_map_cnt; i++) { | |
3324b584 | 1429 | struct bpf_map *map = aux->used_maps[i]; |
04fd61ab | 1430 | struct bpf_array *array; |
04fd61ab | 1431 | |
04fd61ab AS |
1432 | if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY) |
1433 | continue; | |
3324b584 | 1434 | |
04fd61ab AS |
1435 | array = container_of(map, struct bpf_array, map); |
1436 | if (!bpf_prog_array_compatible(array, fp)) | |
1437 | return -EINVAL; | |
1438 | } | |
1439 | ||
1440 | return 0; | |
1441 | } | |
1442 | ||
f5bffecd | 1443 | /** |
3324b584 | 1444 | * bpf_prog_select_runtime - select exec runtime for BPF program |
7ae457c1 | 1445 | * @fp: bpf_prog populated with internal BPF program |
d1c55ab5 | 1446 | * @err: pointer to error variable |
f5bffecd | 1447 | * |
3324b584 DB |
1448 | * Try to JIT eBPF program, if JIT is not available, use interpreter. |
1449 | * The BPF program will be executed via BPF_PROG_RUN() macro. | |
f5bffecd | 1450 | */ |
d1c55ab5 | 1451 | struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) |
f5bffecd | 1452 | { |
290af866 | 1453 | #ifndef CONFIG_BPF_JIT_ALWAYS_ON |
8007e40a MKL |
1454 | u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1); |
1455 | ||
1456 | fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1]; | |
290af866 | 1457 | #else |
69e97d45 | 1458 | fp->bpf_func = __bpf_prog_ret0_warn; |
290af866 | 1459 | #endif |
f5bffecd | 1460 | |
d1c55ab5 DB |
1461 | /* eBPF JITs can rewrite the program in case constant |
1462 | * blinding is active. However, in case of error during | |
1463 | * blinding, bpf_int_jit_compile() must always return a | |
1464 | * valid program, which in this case would simply not | |
1465 | * be JITed, but falls back to the interpreter. | |
1466 | */ | |
ab3f0063 JK |
1467 | if (!bpf_prog_is_dev_bound(fp->aux)) { |
1468 | fp = bpf_int_jit_compile(fp); | |
290af866 AS |
1469 | #ifdef CONFIG_BPF_JIT_ALWAYS_ON |
1470 | if (!fp->jited) { | |
1471 | *err = -ENOTSUPP; | |
1472 | return fp; | |
1473 | } | |
1474 | #endif | |
ab3f0063 JK |
1475 | } else { |
1476 | *err = bpf_prog_offload_compile(fp); | |
1477 | if (*err) | |
1478 | return fp; | |
1479 | } | |
60a3b225 | 1480 | bpf_prog_lock_ro(fp); |
04fd61ab | 1481 | |
3324b584 DB |
1482 | /* The tail call compatibility check can only be done at |
1483 | * this late stage as we need to determine, if we deal | |
1484 | * with JITed or non JITed program concatenations and not | |
1485 | * all eBPF JITs might immediately support all features. | |
1486 | */ | |
d1c55ab5 DB |
1487 | *err = bpf_check_tail_call(fp); |
1488 | ||
1489 | return fp; | |
f5bffecd | 1490 | } |
7ae457c1 | 1491 | EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); |
f5bffecd | 1492 | |
e87c6bc3 YS |
1493 | static unsigned int __bpf_prog_ret1(const void *ctx, |
1494 | const struct bpf_insn *insn) | |
1495 | { | |
1496 | return 1; | |
1497 | } | |
1498 | ||
1499 | static struct bpf_prog_dummy { | |
1500 | struct bpf_prog prog; | |
1501 | } dummy_bpf_prog = { | |
1502 | .prog = { | |
1503 | .bpf_func = __bpf_prog_ret1, | |
1504 | }, | |
1505 | }; | |
1506 | ||
324bda9e AS |
1507 | /* to avoid allocating empty bpf_prog_array for cgroups that |
1508 | * don't have bpf program attached use one global 'empty_prog_array' | |
1509 | * It will not be modified the caller of bpf_prog_array_alloc() | |
1510 | * (since caller requested prog_cnt == 0) | |
1511 | * that pointer should be 'freed' by bpf_prog_array_free() | |
1512 | */ | |
1513 | static struct { | |
1514 | struct bpf_prog_array hdr; | |
1515 | struct bpf_prog *null_prog; | |
1516 | } empty_prog_array = { | |
1517 | .null_prog = NULL, | |
1518 | }; | |
1519 | ||
1520 | struct bpf_prog_array __rcu *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags) | |
1521 | { | |
1522 | if (prog_cnt) | |
1523 | return kzalloc(sizeof(struct bpf_prog_array) + | |
1524 | sizeof(struct bpf_prog *) * (prog_cnt + 1), | |
1525 | flags); | |
1526 | ||
1527 | return &empty_prog_array.hdr; | |
1528 | } | |
1529 | ||
1530 | void bpf_prog_array_free(struct bpf_prog_array __rcu *progs) | |
1531 | { | |
1532 | if (!progs || | |
1533 | progs == (struct bpf_prog_array __rcu *)&empty_prog_array.hdr) | |
1534 | return; | |
1535 | kfree_rcu(progs, rcu); | |
1536 | } | |
1537 | ||
468e2f64 AS |
1538 | int bpf_prog_array_length(struct bpf_prog_array __rcu *progs) |
1539 | { | |
1540 | struct bpf_prog **prog; | |
1541 | u32 cnt = 0; | |
1542 | ||
1543 | rcu_read_lock(); | |
1544 | prog = rcu_dereference(progs)->progs; | |
1545 | for (; *prog; prog++) | |
c8c088ba YS |
1546 | if (*prog != &dummy_bpf_prog.prog) |
1547 | cnt++; | |
468e2f64 AS |
1548 | rcu_read_unlock(); |
1549 | return cnt; | |
1550 | } | |
1551 | ||
1552 | int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs, | |
1553 | __u32 __user *prog_ids, u32 cnt) | |
1554 | { | |
1555 | struct bpf_prog **prog; | |
1556 | u32 i = 0, id; | |
1557 | ||
1558 | rcu_read_lock(); | |
1559 | prog = rcu_dereference(progs)->progs; | |
1560 | for (; *prog; prog++) { | |
1561 | id = (*prog)->aux->id; | |
1562 | if (copy_to_user(prog_ids + i, &id, sizeof(id))) { | |
1563 | rcu_read_unlock(); | |
1564 | return -EFAULT; | |
1565 | } | |
1566 | if (++i == cnt) { | |
1567 | prog++; | |
1568 | break; | |
1569 | } | |
1570 | } | |
1571 | rcu_read_unlock(); | |
1572 | if (*prog) | |
1573 | return -ENOSPC; | |
1574 | return 0; | |
1575 | } | |
1576 | ||
e87c6bc3 YS |
1577 | void bpf_prog_array_delete_safe(struct bpf_prog_array __rcu *progs, |
1578 | struct bpf_prog *old_prog) | |
1579 | { | |
1580 | struct bpf_prog **prog = progs->progs; | |
1581 | ||
1582 | for (; *prog; prog++) | |
1583 | if (*prog == old_prog) { | |
1584 | WRITE_ONCE(*prog, &dummy_bpf_prog.prog); | |
1585 | break; | |
1586 | } | |
1587 | } | |
1588 | ||
1589 | int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array, | |
1590 | struct bpf_prog *exclude_prog, | |
1591 | struct bpf_prog *include_prog, | |
1592 | struct bpf_prog_array **new_array) | |
1593 | { | |
1594 | int new_prog_cnt, carry_prog_cnt = 0; | |
1595 | struct bpf_prog **existing_prog; | |
1596 | struct bpf_prog_array *array; | |
1597 | int new_prog_idx = 0; | |
1598 | ||
1599 | /* Figure out how many existing progs we need to carry over to | |
1600 | * the new array. | |
1601 | */ | |
1602 | if (old_array) { | |
1603 | existing_prog = old_array->progs; | |
1604 | for (; *existing_prog; existing_prog++) { | |
1605 | if (*existing_prog != exclude_prog && | |
1606 | *existing_prog != &dummy_bpf_prog.prog) | |
1607 | carry_prog_cnt++; | |
1608 | if (*existing_prog == include_prog) | |
1609 | return -EEXIST; | |
1610 | } | |
1611 | } | |
1612 | ||
1613 | /* How many progs (not NULL) will be in the new array? */ | |
1614 | new_prog_cnt = carry_prog_cnt; | |
1615 | if (include_prog) | |
1616 | new_prog_cnt += 1; | |
1617 | ||
1618 | /* Do we have any prog (not NULL) in the new array? */ | |
1619 | if (!new_prog_cnt) { | |
1620 | *new_array = NULL; | |
1621 | return 0; | |
1622 | } | |
1623 | ||
1624 | /* +1 as the end of prog_array is marked with NULL */ | |
1625 | array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL); | |
1626 | if (!array) | |
1627 | return -ENOMEM; | |
1628 | ||
1629 | /* Fill in the new prog array */ | |
1630 | if (carry_prog_cnt) { | |
1631 | existing_prog = old_array->progs; | |
1632 | for (; *existing_prog; existing_prog++) | |
1633 | if (*existing_prog != exclude_prog && | |
1634 | *existing_prog != &dummy_bpf_prog.prog) | |
1635 | array->progs[new_prog_idx++] = *existing_prog; | |
1636 | } | |
1637 | if (include_prog) | |
1638 | array->progs[new_prog_idx++] = include_prog; | |
1639 | array->progs[new_prog_idx] = NULL; | |
1640 | *new_array = array; | |
1641 | return 0; | |
1642 | } | |
1643 | ||
60a3b225 DB |
1644 | static void bpf_prog_free_deferred(struct work_struct *work) |
1645 | { | |
09756af4 | 1646 | struct bpf_prog_aux *aux; |
60a3b225 | 1647 | |
09756af4 | 1648 | aux = container_of(work, struct bpf_prog_aux, work); |
ab3f0063 JK |
1649 | if (bpf_prog_is_dev_bound(aux)) |
1650 | bpf_prog_offload_destroy(aux->prog); | |
09756af4 | 1651 | bpf_jit_free(aux->prog); |
60a3b225 DB |
1652 | } |
1653 | ||
1654 | /* Free internal BPF program */ | |
7ae457c1 | 1655 | void bpf_prog_free(struct bpf_prog *fp) |
f5bffecd | 1656 | { |
09756af4 | 1657 | struct bpf_prog_aux *aux = fp->aux; |
60a3b225 | 1658 | |
09756af4 | 1659 | INIT_WORK(&aux->work, bpf_prog_free_deferred); |
09756af4 | 1660 | schedule_work(&aux->work); |
f5bffecd | 1661 | } |
7ae457c1 | 1662 | EXPORT_SYMBOL_GPL(bpf_prog_free); |
f89b7755 | 1663 | |
3ad00405 DB |
1664 | /* RNG for unpriviledged user space with separated state from prandom_u32(). */ |
1665 | static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state); | |
1666 | ||
1667 | void bpf_user_rnd_init_once(void) | |
1668 | { | |
1669 | prandom_init_once(&bpf_user_rnd_state); | |
1670 | } | |
1671 | ||
f3694e00 | 1672 | BPF_CALL_0(bpf_user_rnd_u32) |
3ad00405 DB |
1673 | { |
1674 | /* Should someone ever have the rather unwise idea to use some | |
1675 | * of the registers passed into this function, then note that | |
1676 | * this function is called from native eBPF and classic-to-eBPF | |
1677 | * transformations. Register assignments from both sides are | |
1678 | * different, f.e. classic always sets fn(ctx, A, X) here. | |
1679 | */ | |
1680 | struct rnd_state *state; | |
1681 | u32 res; | |
1682 | ||
1683 | state = &get_cpu_var(bpf_user_rnd_state); | |
1684 | res = prandom_u32_state(state); | |
b761fe22 | 1685 | put_cpu_var(bpf_user_rnd_state); |
3ad00405 DB |
1686 | |
1687 | return res; | |
1688 | } | |
1689 | ||
3ba67dab DB |
1690 | /* Weak definitions of helper functions in case we don't have bpf syscall. */ |
1691 | const struct bpf_func_proto bpf_map_lookup_elem_proto __weak; | |
1692 | const struct bpf_func_proto bpf_map_update_elem_proto __weak; | |
1693 | const struct bpf_func_proto bpf_map_delete_elem_proto __weak; | |
1694 | ||
03e69b50 | 1695 | const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; |
c04167ce | 1696 | const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; |
2d0e30c3 | 1697 | const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; |
17ca8cbf | 1698 | const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; |
bd570ff9 | 1699 | |
ffeedafb AS |
1700 | const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; |
1701 | const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; | |
1702 | const struct bpf_func_proto bpf_get_current_comm_proto __weak; | |
6bdc9c4c | 1703 | const struct bpf_func_proto bpf_sock_map_update_proto __weak; |
bd570ff9 | 1704 | |
0756ea3e AS |
1705 | const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) |
1706 | { | |
1707 | return NULL; | |
1708 | } | |
03e69b50 | 1709 | |
555c8a86 DB |
1710 | u64 __weak |
1711 | bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, | |
1712 | void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) | |
bd570ff9 | 1713 | { |
555c8a86 | 1714 | return -ENOTSUPP; |
bd570ff9 DB |
1715 | } |
1716 | ||
3324b584 DB |
1717 | /* Always built-in helper functions. */ |
1718 | const struct bpf_func_proto bpf_tail_call_proto = { | |
1719 | .func = NULL, | |
1720 | .gpl_only = false, | |
1721 | .ret_type = RET_VOID, | |
1722 | .arg1_type = ARG_PTR_TO_CTX, | |
1723 | .arg2_type = ARG_CONST_MAP_PTR, | |
1724 | .arg3_type = ARG_ANYTHING, | |
1725 | }; | |
1726 | ||
9383191d DB |
1727 | /* Stub for JITs that only support cBPF. eBPF programs are interpreted. |
1728 | * It is encouraged to implement bpf_int_jit_compile() instead, so that | |
1729 | * eBPF and implicitly also cBPF can get JITed! | |
1730 | */ | |
d1c55ab5 | 1731 | struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog) |
3324b584 | 1732 | { |
d1c55ab5 | 1733 | return prog; |
3324b584 DB |
1734 | } |
1735 | ||
9383191d DB |
1736 | /* Stub for JITs that support eBPF. All cBPF code gets transformed into |
1737 | * eBPF by the kernel and is later compiled by bpf_int_jit_compile(). | |
1738 | */ | |
1739 | void __weak bpf_jit_compile(struct bpf_prog *prog) | |
1740 | { | |
1741 | } | |
1742 | ||
17bedab2 | 1743 | bool __weak bpf_helper_changes_pkt_data(void *func) |
969bf05e AS |
1744 | { |
1745 | return false; | |
1746 | } | |
1747 | ||
f89b7755 AS |
1748 | /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call |
1749 | * skb_copy_bits(), so provide a weak definition of it for NET-less config. | |
1750 | */ | |
1751 | int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, | |
1752 | int len) | |
1753 | { | |
1754 | return -EFAULT; | |
1755 | } | |
a67edbf4 DB |
1756 | |
1757 | /* All definitions of tracepoints related to BPF. */ | |
1758 | #define CREATE_TRACE_POINTS | |
1759 | #include <linux/bpf_trace.h> | |
1760 | ||
1761 | EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception); | |
1762 | ||
9185a610 SRV |
1763 | /* These are only used within the BPF_SYSCALL code */ |
1764 | #ifdef CONFIG_BPF_SYSCALL | |
a67edbf4 DB |
1765 | EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_get_type); |
1766 | EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_put_rcu); | |
9185a610 | 1767 | #endif |