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. 21 * Kris Katterjohn - Added many additional checks in bpf_check_classic() 22 */ 23 24 #include <linux/filter.h> 25 #include <linux/skbuff.h> 26 #include <linux/vmalloc.h> 27 #include <linux/random.h> 28 #include <linux/moduleloader.h> 29 #include <linux/bpf.h> 30 #include <linux/frame.h> 31 32 #include <asm/unaligned.h> 33 34 /* Registers */ 35 #define BPF_R0 regs[BPF_REG_0] 36 #define BPF_R1 regs[BPF_REG_1] 37 #define BPF_R2 regs[BPF_REG_2] 38 #define BPF_R3 regs[BPF_REG_3] 39 #define BPF_R4 regs[BPF_REG_4] 40 #define BPF_R5 regs[BPF_REG_5] 41 #define BPF_R6 regs[BPF_REG_6] 42 #define BPF_R7 regs[BPF_REG_7] 43 #define BPF_R8 regs[BPF_REG_8] 44 #define BPF_R9 regs[BPF_REG_9] 45 #define BPF_R10 regs[BPF_REG_10] 46 47 /* Named registers */ 48 #define DST regs[insn->dst_reg] 49 #define SRC regs[insn->src_reg] 50 #define FP regs[BPF_REG_FP] 51 #define ARG1 regs[BPF_REG_ARG1] 52 #define CTX regs[BPF_REG_CTX] 53 #define IMM insn->imm 54 55 /* No hurry in this branch 56 * 57 * Exported for the bpf jit load helper. 58 */ 59 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) 60 { 61 u8 *ptr = NULL; 62 63 if (k >= SKF_NET_OFF) 64 ptr = skb_network_header(skb) + k - SKF_NET_OFF; 65 else if (k >= SKF_LL_OFF) 66 ptr = skb_mac_header(skb) + k - SKF_LL_OFF; 67 68 if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) 69 return ptr; 70 71 return NULL; 72 } 73 74 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) 75 { 76 gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | 77 gfp_extra_flags; 78 struct bpf_prog_aux *aux; 79 struct bpf_prog *fp; 80 81 size = round_up(size, PAGE_SIZE); 82 fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); 83 if (fp == NULL) 84 return NULL; 85 86 kmemcheck_annotate_bitfield(fp, meta); 87 88 aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags); 89 if (aux == NULL) { 90 vfree(fp); 91 return NULL; 92 } 93 94 fp->pages = size / PAGE_SIZE; 95 fp->aux = aux; 96 fp->aux->prog = fp; 97 98 return fp; 99 } 100 EXPORT_SYMBOL_GPL(bpf_prog_alloc); 101 102 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, 103 gfp_t gfp_extra_flags) 104 { 105 gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | 106 gfp_extra_flags; 107 struct bpf_prog *fp; 108 u32 pages, delta; 109 int ret; 110 111 BUG_ON(fp_old == NULL); 112 113 size = round_up(size, PAGE_SIZE); 114 pages = size / PAGE_SIZE; 115 if (pages <= fp_old->pages) 116 return fp_old; 117 118 delta = pages - fp_old->pages; 119 ret = __bpf_prog_charge(fp_old->aux->user, delta); 120 if (ret) 121 return NULL; 122 123 fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); 124 if (fp == NULL) { 125 __bpf_prog_uncharge(fp_old->aux->user, delta); 126 } else { 127 kmemcheck_annotate_bitfield(fp, meta); 128 129 memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); 130 fp->pages = pages; 131 fp->aux->prog = fp; 132 133 /* We keep fp->aux from fp_old around in the new 134 * reallocated structure. 135 */ 136 fp_old->aux = NULL; 137 __bpf_prog_free(fp_old); 138 } 139 140 return fp; 141 } 142 143 void __bpf_prog_free(struct bpf_prog *fp) 144 { 145 kfree(fp->aux); 146 vfree(fp); 147 } 148 149 int bpf_prog_calc_digest(struct bpf_prog *fp) 150 { 151 const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64); 152 u32 raw_size = bpf_prog_digest_scratch_size(fp); 153 u32 ws[SHA_WORKSPACE_WORDS]; 154 u32 i, bsize, psize, blocks; 155 struct bpf_insn *dst; 156 bool was_ld_map; 157 u8 *raw, *todo; 158 __be32 *result; 159 __be64 *bits; 160 161 raw = vmalloc(raw_size); 162 if (!raw) 163 return -ENOMEM; 164 165 sha_init(fp->digest); 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 */ 171 dst = (void *)raw; 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 } 190 191 psize = bpf_prog_insn_size(fp); 192 memset(&raw[psize], 0, raw_size - psize); 193 raw[psize++] = 0x80; 194 195 bsize = round_up(psize, SHA_MESSAGE_BYTES); 196 blocks = bsize / SHA_MESSAGE_BYTES; 197 todo = raw; 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--) { 207 sha_transform(fp->digest, todo, ws); 208 todo += SHA_MESSAGE_BYTES; 209 } 210 211 result = (__force __be32 *)fp->digest; 212 for (i = 0; i < SHA_DIGEST_WORDS; i++) 213 result[i] = cpu_to_be32(fp->digest[i]); 214 215 vfree(raw); 216 return 0; 217 } 218 219 static bool bpf_is_jmp_and_has_target(const struct bpf_insn *insn) 220 { 221 return BPF_CLASS(insn->code) == BPF_JMP && 222 /* Call and Exit are both special jumps with no 223 * target inside the BPF instruction image. 224 */ 225 BPF_OP(insn->code) != BPF_CALL && 226 BPF_OP(insn->code) != BPF_EXIT; 227 } 228 229 static void bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta) 230 { 231 struct bpf_insn *insn = prog->insnsi; 232 u32 i, insn_cnt = prog->len; 233 234 for (i = 0; i < insn_cnt; i++, insn++) { 235 if (!bpf_is_jmp_and_has_target(insn)) 236 continue; 237 238 /* Adjust offset of jmps if we cross boundaries. */ 239 if (i < pos && i + insn->off + 1 > pos) 240 insn->off += delta; 241 else if (i > pos + delta && i + insn->off + 1 <= pos + delta) 242 insn->off -= delta; 243 } 244 } 245 246 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, 247 const struct bpf_insn *patch, u32 len) 248 { 249 u32 insn_adj_cnt, insn_rest, insn_delta = len - 1; 250 struct bpf_prog *prog_adj; 251 252 /* Since our patchlet doesn't expand the image, we're done. */ 253 if (insn_delta == 0) { 254 memcpy(prog->insnsi + off, patch, sizeof(*patch)); 255 return prog; 256 } 257 258 insn_adj_cnt = prog->len + insn_delta; 259 260 /* Several new instructions need to be inserted. Make room 261 * for them. Likely, there's no need for a new allocation as 262 * last page could have large enough tailroom. 263 */ 264 prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt), 265 GFP_USER); 266 if (!prog_adj) 267 return NULL; 268 269 prog_adj->len = insn_adj_cnt; 270 271 /* Patching happens in 3 steps: 272 * 273 * 1) Move over tail of insnsi from next instruction onwards, 274 * so we can patch the single target insn with one or more 275 * new ones (patching is always from 1 to n insns, n > 0). 276 * 2) Inject new instructions at the target location. 277 * 3) Adjust branch offsets if necessary. 278 */ 279 insn_rest = insn_adj_cnt - off - len; 280 281 memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1, 282 sizeof(*patch) * insn_rest); 283 memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len); 284 285 bpf_adj_branches(prog_adj, off, insn_delta); 286 287 return prog_adj; 288 } 289 290 #ifdef CONFIG_BPF_JIT 291 struct bpf_binary_header * 292 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, 293 unsigned int alignment, 294 bpf_jit_fill_hole_t bpf_fill_ill_insns) 295 { 296 struct bpf_binary_header *hdr; 297 unsigned int size, hole, start; 298 299 /* Most of BPF filters are really small, but if some of them 300 * fill a page, allow at least 128 extra bytes to insert a 301 * random section of illegal instructions. 302 */ 303 size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE); 304 hdr = module_alloc(size); 305 if (hdr == NULL) 306 return NULL; 307 308 /* Fill space with illegal/arch-dep instructions. */ 309 bpf_fill_ill_insns(hdr, size); 310 311 hdr->pages = size / PAGE_SIZE; 312 hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)), 313 PAGE_SIZE - sizeof(*hdr)); 314 start = (get_random_int() % hole) & ~(alignment - 1); 315 316 /* Leave a random number of instructions before BPF code. */ 317 *image_ptr = &hdr->image[start]; 318 319 return hdr; 320 } 321 322 void bpf_jit_binary_free(struct bpf_binary_header *hdr) 323 { 324 module_memfree(hdr); 325 } 326 327 int bpf_jit_harden __read_mostly; 328 329 static int bpf_jit_blind_insn(const struct bpf_insn *from, 330 const struct bpf_insn *aux, 331 struct bpf_insn *to_buff) 332 { 333 struct bpf_insn *to = to_buff; 334 u32 imm_rnd = get_random_int(); 335 s16 off; 336 337 BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG); 338 BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG); 339 340 if (from->imm == 0 && 341 (from->code == (BPF_ALU | BPF_MOV | BPF_K) || 342 from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) { 343 *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg); 344 goto out; 345 } 346 347 switch (from->code) { 348 case BPF_ALU | BPF_ADD | BPF_K: 349 case BPF_ALU | BPF_SUB | BPF_K: 350 case BPF_ALU | BPF_AND | BPF_K: 351 case BPF_ALU | BPF_OR | BPF_K: 352 case BPF_ALU | BPF_XOR | BPF_K: 353 case BPF_ALU | BPF_MUL | BPF_K: 354 case BPF_ALU | BPF_MOV | BPF_K: 355 case BPF_ALU | BPF_DIV | BPF_K: 356 case BPF_ALU | BPF_MOD | BPF_K: 357 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 358 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 359 *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX); 360 break; 361 362 case BPF_ALU64 | BPF_ADD | BPF_K: 363 case BPF_ALU64 | BPF_SUB | BPF_K: 364 case BPF_ALU64 | BPF_AND | BPF_K: 365 case BPF_ALU64 | BPF_OR | BPF_K: 366 case BPF_ALU64 | BPF_XOR | BPF_K: 367 case BPF_ALU64 | BPF_MUL | BPF_K: 368 case BPF_ALU64 | BPF_MOV | BPF_K: 369 case BPF_ALU64 | BPF_DIV | BPF_K: 370 case BPF_ALU64 | BPF_MOD | BPF_K: 371 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 372 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 373 *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX); 374 break; 375 376 case BPF_JMP | BPF_JEQ | BPF_K: 377 case BPF_JMP | BPF_JNE | BPF_K: 378 case BPF_JMP | BPF_JGT | BPF_K: 379 case BPF_JMP | BPF_JGE | BPF_K: 380 case BPF_JMP | BPF_JSGT | BPF_K: 381 case BPF_JMP | BPF_JSGE | BPF_K: 382 case BPF_JMP | BPF_JSET | BPF_K: 383 /* Accommodate for extra offset in case of a backjump. */ 384 off = from->off; 385 if (off < 0) 386 off -= 2; 387 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 388 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 389 *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off); 390 break; 391 392 case BPF_LD | BPF_ABS | BPF_W: 393 case BPF_LD | BPF_ABS | BPF_H: 394 case BPF_LD | BPF_ABS | BPF_B: 395 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 396 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 397 *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0); 398 break; 399 400 case BPF_LD | BPF_IND | BPF_W: 401 case BPF_LD | BPF_IND | BPF_H: 402 case BPF_LD | BPF_IND | BPF_B: 403 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 404 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 405 *to++ = BPF_ALU32_REG(BPF_ADD, BPF_REG_AX, from->src_reg); 406 *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0); 407 break; 408 409 case BPF_LD | BPF_IMM | BPF_DW: 410 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm); 411 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 412 *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32); 413 *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX); 414 break; 415 case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */ 416 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm); 417 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 418 *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX); 419 break; 420 421 case BPF_ST | BPF_MEM | BPF_DW: 422 case BPF_ST | BPF_MEM | BPF_W: 423 case BPF_ST | BPF_MEM | BPF_H: 424 case BPF_ST | BPF_MEM | BPF_B: 425 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 426 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 427 *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off); 428 break; 429 } 430 out: 431 return to - to_buff; 432 } 433 434 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other, 435 gfp_t gfp_extra_flags) 436 { 437 gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | 438 gfp_extra_flags; 439 struct bpf_prog *fp; 440 441 fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL); 442 if (fp != NULL) { 443 kmemcheck_annotate_bitfield(fp, meta); 444 445 /* aux->prog still points to the fp_other one, so 446 * when promoting the clone to the real program, 447 * this still needs to be adapted. 448 */ 449 memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE); 450 } 451 452 return fp; 453 } 454 455 static void bpf_prog_clone_free(struct bpf_prog *fp) 456 { 457 /* aux was stolen by the other clone, so we cannot free 458 * it from this path! It will be freed eventually by the 459 * other program on release. 460 * 461 * At this point, we don't need a deferred release since 462 * clone is guaranteed to not be locked. 463 */ 464 fp->aux = NULL; 465 __bpf_prog_free(fp); 466 } 467 468 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other) 469 { 470 /* We have to repoint aux->prog to self, as we don't 471 * know whether fp here is the clone or the original. 472 */ 473 fp->aux->prog = fp; 474 bpf_prog_clone_free(fp_other); 475 } 476 477 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog) 478 { 479 struct bpf_insn insn_buff[16], aux[2]; 480 struct bpf_prog *clone, *tmp; 481 int insn_delta, insn_cnt; 482 struct bpf_insn *insn; 483 int i, rewritten; 484 485 if (!bpf_jit_blinding_enabled()) 486 return prog; 487 488 clone = bpf_prog_clone_create(prog, GFP_USER); 489 if (!clone) 490 return ERR_PTR(-ENOMEM); 491 492 insn_cnt = clone->len; 493 insn = clone->insnsi; 494 495 for (i = 0; i < insn_cnt; i++, insn++) { 496 /* We temporarily need to hold the original ld64 insn 497 * so that we can still access the first part in the 498 * second blinding run. 499 */ 500 if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) && 501 insn[1].code == 0) 502 memcpy(aux, insn, sizeof(aux)); 503 504 rewritten = bpf_jit_blind_insn(insn, aux, insn_buff); 505 if (!rewritten) 506 continue; 507 508 tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten); 509 if (!tmp) { 510 /* Patching may have repointed aux->prog during 511 * realloc from the original one, so we need to 512 * fix it up here on error. 513 */ 514 bpf_jit_prog_release_other(prog, clone); 515 return ERR_PTR(-ENOMEM); 516 } 517 518 clone = tmp; 519 insn_delta = rewritten - 1; 520 521 /* Walk new program and skip insns we just inserted. */ 522 insn = clone->insnsi + i + insn_delta; 523 insn_cnt += insn_delta; 524 i += insn_delta; 525 } 526 527 return clone; 528 } 529 #endif /* CONFIG_BPF_JIT */ 530 531 /* Base function for offset calculation. Needs to go into .text section, 532 * therefore keeping it non-static as well; will also be used by JITs 533 * anyway later on, so do not let the compiler omit it. 534 */ 535 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) 536 { 537 return 0; 538 } 539 EXPORT_SYMBOL_GPL(__bpf_call_base); 540 541 /** 542 * __bpf_prog_run - run eBPF program on a given context 543 * @ctx: is the data we are operating on 544 * @insn: is the array of eBPF instructions 545 * 546 * Decode and execute eBPF instructions. 547 */ 548 static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn) 549 { 550 u64 stack[MAX_BPF_STACK / sizeof(u64)]; 551 u64 regs[MAX_BPF_REG], tmp; 552 static const void *jumptable[256] = { 553 [0 ... 255] = &&default_label, 554 /* Now overwrite non-defaults ... */ 555 /* 32 bit ALU operations */ 556 [BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X, 557 [BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K, 558 [BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X, 559 [BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K, 560 [BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X, 561 [BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K, 562 [BPF_ALU | BPF_OR | BPF_X] = &&ALU_OR_X, 563 [BPF_ALU | BPF_OR | BPF_K] = &&ALU_OR_K, 564 [BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X, 565 [BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K, 566 [BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X, 567 [BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K, 568 [BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X, 569 [BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K, 570 [BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X, 571 [BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K, 572 [BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X, 573 [BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K, 574 [BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X, 575 [BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K, 576 [BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X, 577 [BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K, 578 [BPF_ALU | BPF_NEG] = &&ALU_NEG, 579 [BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE, 580 [BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE, 581 /* 64 bit ALU operations */ 582 [BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X, 583 [BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K, 584 [BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X, 585 [BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K, 586 [BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X, 587 [BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K, 588 [BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X, 589 [BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K, 590 [BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X, 591 [BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K, 592 [BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X, 593 [BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K, 594 [BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X, 595 [BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K, 596 [BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X, 597 [BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K, 598 [BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X, 599 [BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K, 600 [BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X, 601 [BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K, 602 [BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X, 603 [BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K, 604 [BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X, 605 [BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K, 606 [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG, 607 /* Call instruction */ 608 [BPF_JMP | BPF_CALL] = &&JMP_CALL, 609 [BPF_JMP | BPF_CALL | BPF_X] = &&JMP_TAIL_CALL, 610 /* Jumps */ 611 [BPF_JMP | BPF_JA] = &&JMP_JA, 612 [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X, 613 [BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K, 614 [BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X, 615 [BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K, 616 [BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X, 617 [BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K, 618 [BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X, 619 [BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K, 620 [BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X, 621 [BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K, 622 [BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X, 623 [BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K, 624 [BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X, 625 [BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K, 626 /* Program return */ 627 [BPF_JMP | BPF_EXIT] = &&JMP_EXIT, 628 /* Store instructions */ 629 [BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B, 630 [BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H, 631 [BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W, 632 [BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW, 633 [BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W, 634 [BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW, 635 [BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B, 636 [BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H, 637 [BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W, 638 [BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW, 639 /* Load instructions */ 640 [BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B, 641 [BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H, 642 [BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W, 643 [BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW, 644 [BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W, 645 [BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H, 646 [BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B, 647 [BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W, 648 [BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H, 649 [BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B, 650 [BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW, 651 }; 652 u32 tail_call_cnt = 0; 653 void *ptr; 654 int off; 655 656 #define CONT ({ insn++; goto select_insn; }) 657 #define CONT_JMP ({ insn++; goto select_insn; }) 658 659 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; 660 ARG1 = (u64) (unsigned long) ctx; 661 662 select_insn: 663 goto *jumptable[insn->code]; 664 665 /* ALU */ 666 #define ALU(OPCODE, OP) \ 667 ALU64_##OPCODE##_X: \ 668 DST = DST OP SRC; \ 669 CONT; \ 670 ALU_##OPCODE##_X: \ 671 DST = (u32) DST OP (u32) SRC; \ 672 CONT; \ 673 ALU64_##OPCODE##_K: \ 674 DST = DST OP IMM; \ 675 CONT; \ 676 ALU_##OPCODE##_K: \ 677 DST = (u32) DST OP (u32) IMM; \ 678 CONT; 679 680 ALU(ADD, +) 681 ALU(SUB, -) 682 ALU(AND, &) 683 ALU(OR, |) 684 ALU(LSH, <<) 685 ALU(RSH, >>) 686 ALU(XOR, ^) 687 ALU(MUL, *) 688 #undef ALU 689 ALU_NEG: 690 DST = (u32) -DST; 691 CONT; 692 ALU64_NEG: 693 DST = -DST; 694 CONT; 695 ALU_MOV_X: 696 DST = (u32) SRC; 697 CONT; 698 ALU_MOV_K: 699 DST = (u32) IMM; 700 CONT; 701 ALU64_MOV_X: 702 DST = SRC; 703 CONT; 704 ALU64_MOV_K: 705 DST = IMM; 706 CONT; 707 LD_IMM_DW: 708 DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; 709 insn++; 710 CONT; 711 ALU64_ARSH_X: 712 (*(s64 *) &DST) >>= SRC; 713 CONT; 714 ALU64_ARSH_K: 715 (*(s64 *) &DST) >>= IMM; 716 CONT; 717 ALU64_MOD_X: 718 if (unlikely(SRC == 0)) 719 return 0; 720 div64_u64_rem(DST, SRC, &tmp); 721 DST = tmp; 722 CONT; 723 ALU_MOD_X: 724 if (unlikely(SRC == 0)) 725 return 0; 726 tmp = (u32) DST; 727 DST = do_div(tmp, (u32) SRC); 728 CONT; 729 ALU64_MOD_K: 730 div64_u64_rem(DST, IMM, &tmp); 731 DST = tmp; 732 CONT; 733 ALU_MOD_K: 734 tmp = (u32) DST; 735 DST = do_div(tmp, (u32) IMM); 736 CONT; 737 ALU64_DIV_X: 738 if (unlikely(SRC == 0)) 739 return 0; 740 DST = div64_u64(DST, SRC); 741 CONT; 742 ALU_DIV_X: 743 if (unlikely(SRC == 0)) 744 return 0; 745 tmp = (u32) DST; 746 do_div(tmp, (u32) SRC); 747 DST = (u32) tmp; 748 CONT; 749 ALU64_DIV_K: 750 DST = div64_u64(DST, IMM); 751 CONT; 752 ALU_DIV_K: 753 tmp = (u32) DST; 754 do_div(tmp, (u32) IMM); 755 DST = (u32) tmp; 756 CONT; 757 ALU_END_TO_BE: 758 switch (IMM) { 759 case 16: 760 DST = (__force u16) cpu_to_be16(DST); 761 break; 762 case 32: 763 DST = (__force u32) cpu_to_be32(DST); 764 break; 765 case 64: 766 DST = (__force u64) cpu_to_be64(DST); 767 break; 768 } 769 CONT; 770 ALU_END_TO_LE: 771 switch (IMM) { 772 case 16: 773 DST = (__force u16) cpu_to_le16(DST); 774 break; 775 case 32: 776 DST = (__force u32) cpu_to_le32(DST); 777 break; 778 case 64: 779 DST = (__force u64) cpu_to_le64(DST); 780 break; 781 } 782 CONT; 783 784 /* CALL */ 785 JMP_CALL: 786 /* Function call scratches BPF_R1-BPF_R5 registers, 787 * preserves BPF_R6-BPF_R9, and stores return value 788 * into BPF_R0. 789 */ 790 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, 791 BPF_R4, BPF_R5); 792 CONT; 793 794 JMP_TAIL_CALL: { 795 struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2; 796 struct bpf_array *array = container_of(map, struct bpf_array, map); 797 struct bpf_prog *prog; 798 u64 index = BPF_R3; 799 800 if (unlikely(index >= array->map.max_entries)) 801 goto out; 802 if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT)) 803 goto out; 804 805 tail_call_cnt++; 806 807 prog = READ_ONCE(array->ptrs[index]); 808 if (!prog) 809 goto out; 810 811 /* ARG1 at this point is guaranteed to point to CTX from 812 * the verifier side due to the fact that the tail call is 813 * handeled like a helper, that is, bpf_tail_call_proto, 814 * where arg1_type is ARG_PTR_TO_CTX. 815 */ 816 insn = prog->insnsi; 817 goto select_insn; 818 out: 819 CONT; 820 } 821 /* JMP */ 822 JMP_JA: 823 insn += insn->off; 824 CONT; 825 JMP_JEQ_X: 826 if (DST == SRC) { 827 insn += insn->off; 828 CONT_JMP; 829 } 830 CONT; 831 JMP_JEQ_K: 832 if (DST == IMM) { 833 insn += insn->off; 834 CONT_JMP; 835 } 836 CONT; 837 JMP_JNE_X: 838 if (DST != SRC) { 839 insn += insn->off; 840 CONT_JMP; 841 } 842 CONT; 843 JMP_JNE_K: 844 if (DST != IMM) { 845 insn += insn->off; 846 CONT_JMP; 847 } 848 CONT; 849 JMP_JGT_X: 850 if (DST > SRC) { 851 insn += insn->off; 852 CONT_JMP; 853 } 854 CONT; 855 JMP_JGT_K: 856 if (DST > IMM) { 857 insn += insn->off; 858 CONT_JMP; 859 } 860 CONT; 861 JMP_JGE_X: 862 if (DST >= SRC) { 863 insn += insn->off; 864 CONT_JMP; 865 } 866 CONT; 867 JMP_JGE_K: 868 if (DST >= IMM) { 869 insn += insn->off; 870 CONT_JMP; 871 } 872 CONT; 873 JMP_JSGT_X: 874 if (((s64) DST) > ((s64) SRC)) { 875 insn += insn->off; 876 CONT_JMP; 877 } 878 CONT; 879 JMP_JSGT_K: 880 if (((s64) DST) > ((s64) IMM)) { 881 insn += insn->off; 882 CONT_JMP; 883 } 884 CONT; 885 JMP_JSGE_X: 886 if (((s64) DST) >= ((s64) SRC)) { 887 insn += insn->off; 888 CONT_JMP; 889 } 890 CONT; 891 JMP_JSGE_K: 892 if (((s64) DST) >= ((s64) IMM)) { 893 insn += insn->off; 894 CONT_JMP; 895 } 896 CONT; 897 JMP_JSET_X: 898 if (DST & SRC) { 899 insn += insn->off; 900 CONT_JMP; 901 } 902 CONT; 903 JMP_JSET_K: 904 if (DST & IMM) { 905 insn += insn->off; 906 CONT_JMP; 907 } 908 CONT; 909 JMP_EXIT: 910 return BPF_R0; 911 912 /* STX and ST and LDX*/ 913 #define LDST(SIZEOP, SIZE) \ 914 STX_MEM_##SIZEOP: \ 915 *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ 916 CONT; \ 917 ST_MEM_##SIZEOP: \ 918 *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ 919 CONT; \ 920 LDX_MEM_##SIZEOP: \ 921 DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ 922 CONT; 923 924 LDST(B, u8) 925 LDST(H, u16) 926 LDST(W, u32) 927 LDST(DW, u64) 928 #undef LDST 929 STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ 930 atomic_add((u32) SRC, (atomic_t *)(unsigned long) 931 (DST + insn->off)); 932 CONT; 933 STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ 934 atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) 935 (DST + insn->off)); 936 CONT; 937 LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */ 938 off = IMM; 939 load_word: 940 /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are 941 * only appearing in the programs where ctx == 942 * skb. All programs keep 'ctx' in regs[BPF_REG_CTX] 943 * == BPF_R6, bpf_convert_filter() saves it in BPF_R6, 944 * internal BPF verifier will check that BPF_R6 == 945 * ctx. 946 * 947 * BPF_ABS and BPF_IND are wrappers of function calls, 948 * so they scratch BPF_R1-BPF_R5 registers, preserve 949 * BPF_R6-BPF_R9, and store return value into BPF_R0. 950 * 951 * Implicit input: 952 * ctx == skb == BPF_R6 == CTX 953 * 954 * Explicit input: 955 * SRC == any register 956 * IMM == 32-bit immediate 957 * 958 * Output: 959 * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness 960 */ 961 962 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp); 963 if (likely(ptr != NULL)) { 964 BPF_R0 = get_unaligned_be32(ptr); 965 CONT; 966 } 967 968 return 0; 969 LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */ 970 off = IMM; 971 load_half: 972 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp); 973 if (likely(ptr != NULL)) { 974 BPF_R0 = get_unaligned_be16(ptr); 975 CONT; 976 } 977 978 return 0; 979 LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */ 980 off = IMM; 981 load_byte: 982 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp); 983 if (likely(ptr != NULL)) { 984 BPF_R0 = *(u8 *)ptr; 985 CONT; 986 } 987 988 return 0; 989 LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */ 990 off = IMM + SRC; 991 goto load_word; 992 LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */ 993 off = IMM + SRC; 994 goto load_half; 995 LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */ 996 off = IMM + SRC; 997 goto load_byte; 998 999 default_label: 1000 /* If we ever reach this, we have a bug somewhere. */ 1001 WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code); 1002 return 0; 1003 } 1004 STACK_FRAME_NON_STANDARD(__bpf_prog_run); /* jump table */ 1005 1006 bool bpf_prog_array_compatible(struct bpf_array *array, 1007 const struct bpf_prog *fp) 1008 { 1009 if (!array->owner_prog_type) { 1010 /* There's no owner yet where we could check for 1011 * compatibility. 1012 */ 1013 array->owner_prog_type = fp->type; 1014 array->owner_jited = fp->jited; 1015 1016 return true; 1017 } 1018 1019 return array->owner_prog_type == fp->type && 1020 array->owner_jited == fp->jited; 1021 } 1022 1023 static int bpf_check_tail_call(const struct bpf_prog *fp) 1024 { 1025 struct bpf_prog_aux *aux = fp->aux; 1026 int i; 1027 1028 for (i = 0; i < aux->used_map_cnt; i++) { 1029 struct bpf_map *map = aux->used_maps[i]; 1030 struct bpf_array *array; 1031 1032 if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY) 1033 continue; 1034 1035 array = container_of(map, struct bpf_array, map); 1036 if (!bpf_prog_array_compatible(array, fp)) 1037 return -EINVAL; 1038 } 1039 1040 return 0; 1041 } 1042 1043 /** 1044 * bpf_prog_select_runtime - select exec runtime for BPF program 1045 * @fp: bpf_prog populated with internal BPF program 1046 * @err: pointer to error variable 1047 * 1048 * Try to JIT eBPF program, if JIT is not available, use interpreter. 1049 * The BPF program will be executed via BPF_PROG_RUN() macro. 1050 */ 1051 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) 1052 { 1053 fp->bpf_func = (void *) __bpf_prog_run; 1054 1055 /* eBPF JITs can rewrite the program in case constant 1056 * blinding is active. However, in case of error during 1057 * blinding, bpf_int_jit_compile() must always return a 1058 * valid program, which in this case would simply not 1059 * be JITed, but falls back to the interpreter. 1060 */ 1061 fp = bpf_int_jit_compile(fp); 1062 bpf_prog_lock_ro(fp); 1063 1064 /* The tail call compatibility check can only be done at 1065 * this late stage as we need to determine, if we deal 1066 * with JITed or non JITed program concatenations and not 1067 * all eBPF JITs might immediately support all features. 1068 */ 1069 *err = bpf_check_tail_call(fp); 1070 1071 return fp; 1072 } 1073 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); 1074 1075 static void bpf_prog_free_deferred(struct work_struct *work) 1076 { 1077 struct bpf_prog_aux *aux; 1078 1079 aux = container_of(work, struct bpf_prog_aux, work); 1080 bpf_jit_free(aux->prog); 1081 } 1082 1083 /* Free internal BPF program */ 1084 void bpf_prog_free(struct bpf_prog *fp) 1085 { 1086 struct bpf_prog_aux *aux = fp->aux; 1087 1088 INIT_WORK(&aux->work, bpf_prog_free_deferred); 1089 schedule_work(&aux->work); 1090 } 1091 EXPORT_SYMBOL_GPL(bpf_prog_free); 1092 1093 /* RNG for unpriviledged user space with separated state from prandom_u32(). */ 1094 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state); 1095 1096 void bpf_user_rnd_init_once(void) 1097 { 1098 prandom_init_once(&bpf_user_rnd_state); 1099 } 1100 1101 BPF_CALL_0(bpf_user_rnd_u32) 1102 { 1103 /* Should someone ever have the rather unwise idea to use some 1104 * of the registers passed into this function, then note that 1105 * this function is called from native eBPF and classic-to-eBPF 1106 * transformations. Register assignments from both sides are 1107 * different, f.e. classic always sets fn(ctx, A, X) here. 1108 */ 1109 struct rnd_state *state; 1110 u32 res; 1111 1112 state = &get_cpu_var(bpf_user_rnd_state); 1113 res = prandom_u32_state(state); 1114 put_cpu_var(bpf_user_rnd_state); 1115 1116 return res; 1117 } 1118 1119 /* Weak definitions of helper functions in case we don't have bpf syscall. */ 1120 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak; 1121 const struct bpf_func_proto bpf_map_update_elem_proto __weak; 1122 const struct bpf_func_proto bpf_map_delete_elem_proto __weak; 1123 1124 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; 1125 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; 1126 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; 1127 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; 1128 1129 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; 1130 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; 1131 const struct bpf_func_proto bpf_get_current_comm_proto __weak; 1132 1133 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) 1134 { 1135 return NULL; 1136 } 1137 1138 u64 __weak 1139 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 1140 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 1141 { 1142 return -ENOTSUPP; 1143 } 1144 1145 /* Always built-in helper functions. */ 1146 const struct bpf_func_proto bpf_tail_call_proto = { 1147 .func = NULL, 1148 .gpl_only = false, 1149 .ret_type = RET_VOID, 1150 .arg1_type = ARG_PTR_TO_CTX, 1151 .arg2_type = ARG_CONST_MAP_PTR, 1152 .arg3_type = ARG_ANYTHING, 1153 }; 1154 1155 /* For classic BPF JITs that don't implement bpf_int_jit_compile(). */ 1156 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog) 1157 { 1158 return prog; 1159 } 1160 1161 bool __weak bpf_helper_changes_pkt_data(void *func) 1162 { 1163 return false; 1164 } 1165 1166 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call 1167 * skb_copy_bits(), so provide a weak definition of it for NET-less config. 1168 */ 1169 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, 1170 int len) 1171 { 1172 return -EFAULT; 1173 } 1174