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 #include <linux/rbtree_latch.h> 32 #include <linux/kallsyms.h> 33 #include <linux/rcupdate.h> 34 35 #include <asm/unaligned.h> 36 37 /* Registers */ 38 #define BPF_R0 regs[BPF_REG_0] 39 #define BPF_R1 regs[BPF_REG_1] 40 #define BPF_R2 regs[BPF_REG_2] 41 #define BPF_R3 regs[BPF_REG_3] 42 #define BPF_R4 regs[BPF_REG_4] 43 #define BPF_R5 regs[BPF_REG_5] 44 #define BPF_R6 regs[BPF_REG_6] 45 #define BPF_R7 regs[BPF_REG_7] 46 #define BPF_R8 regs[BPF_REG_8] 47 #define BPF_R9 regs[BPF_REG_9] 48 #define BPF_R10 regs[BPF_REG_10] 49 50 /* Named registers */ 51 #define DST regs[insn->dst_reg] 52 #define SRC regs[insn->src_reg] 53 #define FP regs[BPF_REG_FP] 54 #define ARG1 regs[BPF_REG_ARG1] 55 #define CTX regs[BPF_REG_CTX] 56 #define IMM insn->imm 57 58 /* No hurry in this branch 59 * 60 * Exported for the bpf jit load helper. 61 */ 62 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) 63 { 64 u8 *ptr = NULL; 65 66 if (k >= SKF_NET_OFF) 67 ptr = skb_network_header(skb) + k - SKF_NET_OFF; 68 else if (k >= SKF_LL_OFF) 69 ptr = skb_mac_header(skb) + k - SKF_LL_OFF; 70 71 if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) 72 return ptr; 73 74 return NULL; 75 } 76 77 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) 78 { 79 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; 80 struct bpf_prog_aux *aux; 81 struct bpf_prog *fp; 82 83 size = round_up(size, PAGE_SIZE); 84 fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); 85 if (fp == NULL) 86 return NULL; 87 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 fp->jit_requested = ebpf_jit_enabled(); 98 99 INIT_LIST_HEAD_RCU(&fp->aux->ksym_lnode); 100 101 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 { 108 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; 109 struct bpf_prog *fp; 110 u32 pages, delta; 111 int ret; 112 113 BUG_ON(fp_old == NULL); 114 115 size = round_up(size, PAGE_SIZE); 116 pages = size / PAGE_SIZE; 117 if (pages <= fp_old->pages) 118 return fp_old; 119 120 delta = pages - fp_old->pages; 121 ret = __bpf_prog_charge(fp_old->aux->user, delta); 122 if (ret) 123 return NULL; 124 125 fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); 126 if (fp == NULL) { 127 __bpf_prog_uncharge(fp_old->aux->user, delta); 128 } else { 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_tag(struct bpf_prog *fp) 150 { 151 const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64); 152 u32 raw_size = bpf_prog_tag_scratch_size(fp); 153 u32 digest[SHA_DIGEST_WORDS]; 154 u32 ws[SHA_WORKSPACE_WORDS]; 155 u32 i, bsize, psize, blocks; 156 struct bpf_insn *dst; 157 bool was_ld_map; 158 u8 *raw, *todo; 159 __be32 *result; 160 __be64 *bits; 161 162 raw = vmalloc(raw_size); 163 if (!raw) 164 return -ENOMEM; 165 166 sha_init(digest); 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 */ 172 dst = (void *)raw; 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 } 191 192 psize = bpf_prog_insn_size(fp); 193 memset(&raw[psize], 0, raw_size - psize); 194 raw[psize++] = 0x80; 195 196 bsize = round_up(psize, SHA_MESSAGE_BYTES); 197 blocks = bsize / SHA_MESSAGE_BYTES; 198 todo = raw; 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--) { 208 sha_transform(digest, todo, ws); 209 todo += SHA_MESSAGE_BYTES; 210 } 211 212 result = (__force __be32 *)digest; 213 for (i = 0; i < SHA_DIGEST_WORDS; i++) 214 result[i] = cpu_to_be32(digest[i]); 215 memcpy(fp->tag, result, sizeof(fp->tag)); 216 217 vfree(raw); 218 return 0; 219 } 220 221 static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, u32 delta, 222 u32 curr, const bool probe_pass) 223 { 224 const s64 imm_min = S32_MIN, imm_max = S32_MAX; 225 s64 imm = insn->imm; 226 227 if (curr < pos && curr + imm + 1 > pos) 228 imm += delta; 229 else if (curr > pos + delta && curr + imm + 1 <= pos + delta) 230 imm -= delta; 231 if (imm < imm_min || imm > imm_max) 232 return -ERANGE; 233 if (!probe_pass) 234 insn->imm = imm; 235 return 0; 236 } 237 238 static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, u32 delta, 239 u32 curr, const bool probe_pass) 240 { 241 const s32 off_min = S16_MIN, off_max = S16_MAX; 242 s32 off = insn->off; 243 244 if (curr < pos && curr + off + 1 > pos) 245 off += delta; 246 else if (curr > pos + delta && curr + off + 1 <= pos + delta) 247 off -= delta; 248 if (off < off_min || off > off_max) 249 return -ERANGE; 250 if (!probe_pass) 251 insn->off = off; 252 return 0; 253 } 254 255 static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta, 256 const bool probe_pass) 257 { 258 u32 i, insn_cnt = prog->len + (probe_pass ? delta : 0); 259 struct bpf_insn *insn = prog->insnsi; 260 int ret = 0; 261 262 for (i = 0; i < insn_cnt; i++, insn++) { 263 u8 code; 264 265 /* In the probing pass we still operate on the original, 266 * unpatched image in order to check overflows before we 267 * do any other adjustments. Therefore skip the patchlet. 268 */ 269 if (probe_pass && i == pos) { 270 i += delta + 1; 271 insn++; 272 } 273 code = insn->code; 274 if (BPF_CLASS(code) != BPF_JMP || 275 BPF_OP(code) == BPF_EXIT) 276 continue; 277 /* Adjust offset of jmps if we cross patch boundaries. */ 278 if (BPF_OP(code) == BPF_CALL) { 279 if (insn->src_reg != BPF_PSEUDO_CALL) 280 continue; 281 ret = bpf_adj_delta_to_imm(insn, pos, delta, i, 282 probe_pass); 283 } else { 284 ret = bpf_adj_delta_to_off(insn, pos, delta, i, 285 probe_pass); 286 } 287 if (ret) 288 break; 289 } 290 291 return ret; 292 } 293 294 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, 295 const struct bpf_insn *patch, u32 len) 296 { 297 u32 insn_adj_cnt, insn_rest, insn_delta = len - 1; 298 const u32 cnt_max = S16_MAX; 299 struct bpf_prog *prog_adj; 300 301 /* Since our patchlet doesn't expand the image, we're done. */ 302 if (insn_delta == 0) { 303 memcpy(prog->insnsi + off, patch, sizeof(*patch)); 304 return prog; 305 } 306 307 insn_adj_cnt = prog->len + insn_delta; 308 309 /* Reject anything that would potentially let the insn->off 310 * target overflow when we have excessive program expansions. 311 * We need to probe here before we do any reallocation where 312 * we afterwards may not fail anymore. 313 */ 314 if (insn_adj_cnt > cnt_max && 315 bpf_adj_branches(prog, off, insn_delta, true)) 316 return NULL; 317 318 /* Several new instructions need to be inserted. Make room 319 * for them. Likely, there's no need for a new allocation as 320 * last page could have large enough tailroom. 321 */ 322 prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt), 323 GFP_USER); 324 if (!prog_adj) 325 return NULL; 326 327 prog_adj->len = insn_adj_cnt; 328 329 /* Patching happens in 3 steps: 330 * 331 * 1) Move over tail of insnsi from next instruction onwards, 332 * so we can patch the single target insn with one or more 333 * new ones (patching is always from 1 to n insns, n > 0). 334 * 2) Inject new instructions at the target location. 335 * 3) Adjust branch offsets if necessary. 336 */ 337 insn_rest = insn_adj_cnt - off - len; 338 339 memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1, 340 sizeof(*patch) * insn_rest); 341 memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len); 342 343 /* We are guaranteed to not fail at this point, otherwise 344 * the ship has sailed to reverse to the original state. An 345 * overflow cannot happen at this point. 346 */ 347 BUG_ON(bpf_adj_branches(prog_adj, off, insn_delta, false)); 348 349 return prog_adj; 350 } 351 352 #ifdef CONFIG_BPF_JIT 353 /* All BPF JIT sysctl knobs here. */ 354 int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON); 355 int bpf_jit_harden __read_mostly; 356 int bpf_jit_kallsyms __read_mostly; 357 358 static __always_inline void 359 bpf_get_prog_addr_region(const struct bpf_prog *prog, 360 unsigned long *symbol_start, 361 unsigned long *symbol_end) 362 { 363 const struct bpf_binary_header *hdr = bpf_jit_binary_hdr(prog); 364 unsigned long addr = (unsigned long)hdr; 365 366 WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog)); 367 368 *symbol_start = addr; 369 *symbol_end = addr + hdr->pages * PAGE_SIZE; 370 } 371 372 static void bpf_get_prog_name(const struct bpf_prog *prog, char *sym) 373 { 374 const char *end = sym + KSYM_NAME_LEN; 375 376 BUILD_BUG_ON(sizeof("bpf_prog_") + 377 sizeof(prog->tag) * 2 + 378 /* name has been null terminated. 379 * We should need +1 for the '_' preceding 380 * the name. However, the null character 381 * is double counted between the name and the 382 * sizeof("bpf_prog_") above, so we omit 383 * the +1 here. 384 */ 385 sizeof(prog->aux->name) > KSYM_NAME_LEN); 386 387 sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_"); 388 sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); 389 if (prog->aux->name[0]) 390 snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name); 391 else 392 *sym = 0; 393 } 394 395 static __always_inline unsigned long 396 bpf_get_prog_addr_start(struct latch_tree_node *n) 397 { 398 unsigned long symbol_start, symbol_end; 399 const struct bpf_prog_aux *aux; 400 401 aux = container_of(n, struct bpf_prog_aux, ksym_tnode); 402 bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); 403 404 return symbol_start; 405 } 406 407 static __always_inline bool bpf_tree_less(struct latch_tree_node *a, 408 struct latch_tree_node *b) 409 { 410 return bpf_get_prog_addr_start(a) < bpf_get_prog_addr_start(b); 411 } 412 413 static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n) 414 { 415 unsigned long val = (unsigned long)key; 416 unsigned long symbol_start, symbol_end; 417 const struct bpf_prog_aux *aux; 418 419 aux = container_of(n, struct bpf_prog_aux, ksym_tnode); 420 bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); 421 422 if (val < symbol_start) 423 return -1; 424 if (val >= symbol_end) 425 return 1; 426 427 return 0; 428 } 429 430 static const struct latch_tree_ops bpf_tree_ops = { 431 .less = bpf_tree_less, 432 .comp = bpf_tree_comp, 433 }; 434 435 static DEFINE_SPINLOCK(bpf_lock); 436 static LIST_HEAD(bpf_kallsyms); 437 static struct latch_tree_root bpf_tree __cacheline_aligned; 438 439 static void bpf_prog_ksym_node_add(struct bpf_prog_aux *aux) 440 { 441 WARN_ON_ONCE(!list_empty(&aux->ksym_lnode)); 442 list_add_tail_rcu(&aux->ksym_lnode, &bpf_kallsyms); 443 latch_tree_insert(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); 444 } 445 446 static void bpf_prog_ksym_node_del(struct bpf_prog_aux *aux) 447 { 448 if (list_empty(&aux->ksym_lnode)) 449 return; 450 451 latch_tree_erase(&aux->ksym_tnode, &bpf_tree, &bpf_tree_ops); 452 list_del_rcu(&aux->ksym_lnode); 453 } 454 455 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp) 456 { 457 return fp->jited && !bpf_prog_was_classic(fp); 458 } 459 460 static bool bpf_prog_kallsyms_verify_off(const struct bpf_prog *fp) 461 { 462 return list_empty(&fp->aux->ksym_lnode) || 463 fp->aux->ksym_lnode.prev == LIST_POISON2; 464 } 465 466 void bpf_prog_kallsyms_add(struct bpf_prog *fp) 467 { 468 if (!bpf_prog_kallsyms_candidate(fp) || 469 !capable(CAP_SYS_ADMIN)) 470 return; 471 472 spin_lock_bh(&bpf_lock); 473 bpf_prog_ksym_node_add(fp->aux); 474 spin_unlock_bh(&bpf_lock); 475 } 476 477 void bpf_prog_kallsyms_del(struct bpf_prog *fp) 478 { 479 if (!bpf_prog_kallsyms_candidate(fp)) 480 return; 481 482 spin_lock_bh(&bpf_lock); 483 bpf_prog_ksym_node_del(fp->aux); 484 spin_unlock_bh(&bpf_lock); 485 } 486 487 static struct bpf_prog *bpf_prog_kallsyms_find(unsigned long addr) 488 { 489 struct latch_tree_node *n; 490 491 if (!bpf_jit_kallsyms_enabled()) 492 return NULL; 493 494 n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops); 495 return n ? 496 container_of(n, struct bpf_prog_aux, ksym_tnode)->prog : 497 NULL; 498 } 499 500 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, 501 unsigned long *off, char *sym) 502 { 503 unsigned long symbol_start, symbol_end; 504 struct bpf_prog *prog; 505 char *ret = NULL; 506 507 rcu_read_lock(); 508 prog = bpf_prog_kallsyms_find(addr); 509 if (prog) { 510 bpf_get_prog_addr_region(prog, &symbol_start, &symbol_end); 511 bpf_get_prog_name(prog, sym); 512 513 ret = sym; 514 if (size) 515 *size = symbol_end - symbol_start; 516 if (off) 517 *off = addr - symbol_start; 518 } 519 rcu_read_unlock(); 520 521 return ret; 522 } 523 524 bool is_bpf_text_address(unsigned long addr) 525 { 526 bool ret; 527 528 rcu_read_lock(); 529 ret = bpf_prog_kallsyms_find(addr) != NULL; 530 rcu_read_unlock(); 531 532 return ret; 533 } 534 535 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, 536 char *sym) 537 { 538 unsigned long symbol_start, symbol_end; 539 struct bpf_prog_aux *aux; 540 unsigned int it = 0; 541 int ret = -ERANGE; 542 543 if (!bpf_jit_kallsyms_enabled()) 544 return ret; 545 546 rcu_read_lock(); 547 list_for_each_entry_rcu(aux, &bpf_kallsyms, ksym_lnode) { 548 if (it++ != symnum) 549 continue; 550 551 bpf_get_prog_addr_region(aux->prog, &symbol_start, &symbol_end); 552 bpf_get_prog_name(aux->prog, sym); 553 554 *value = symbol_start; 555 *type = BPF_SYM_ELF_TYPE; 556 557 ret = 0; 558 break; 559 } 560 rcu_read_unlock(); 561 562 return ret; 563 } 564 565 struct bpf_binary_header * 566 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, 567 unsigned int alignment, 568 bpf_jit_fill_hole_t bpf_fill_ill_insns) 569 { 570 struct bpf_binary_header *hdr; 571 unsigned int size, hole, start; 572 573 /* Most of BPF filters are really small, but if some of them 574 * fill a page, allow at least 128 extra bytes to insert a 575 * random section of illegal instructions. 576 */ 577 size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE); 578 hdr = module_alloc(size); 579 if (hdr == NULL) 580 return NULL; 581 582 /* Fill space with illegal/arch-dep instructions. */ 583 bpf_fill_ill_insns(hdr, size); 584 585 hdr->pages = size / PAGE_SIZE; 586 hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)), 587 PAGE_SIZE - sizeof(*hdr)); 588 start = (get_random_int() % hole) & ~(alignment - 1); 589 590 /* Leave a random number of instructions before BPF code. */ 591 *image_ptr = &hdr->image[start]; 592 593 return hdr; 594 } 595 596 void bpf_jit_binary_free(struct bpf_binary_header *hdr) 597 { 598 module_memfree(hdr); 599 } 600 601 /* This symbol is only overridden by archs that have different 602 * requirements than the usual eBPF JITs, f.e. when they only 603 * implement cBPF JIT, do not set images read-only, etc. 604 */ 605 void __weak bpf_jit_free(struct bpf_prog *fp) 606 { 607 if (fp->jited) { 608 struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp); 609 610 bpf_jit_binary_unlock_ro(hdr); 611 bpf_jit_binary_free(hdr); 612 613 WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp)); 614 } 615 616 bpf_prog_unlock_free(fp); 617 } 618 619 static int bpf_jit_blind_insn(const struct bpf_insn *from, 620 const struct bpf_insn *aux, 621 struct bpf_insn *to_buff) 622 { 623 struct bpf_insn *to = to_buff; 624 u32 imm_rnd = get_random_int(); 625 s16 off; 626 627 BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG); 628 BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG); 629 630 if (from->imm == 0 && 631 (from->code == (BPF_ALU | BPF_MOV | BPF_K) || 632 from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) { 633 *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg); 634 goto out; 635 } 636 637 switch (from->code) { 638 case BPF_ALU | BPF_ADD | BPF_K: 639 case BPF_ALU | BPF_SUB | BPF_K: 640 case BPF_ALU | BPF_AND | BPF_K: 641 case BPF_ALU | BPF_OR | BPF_K: 642 case BPF_ALU | BPF_XOR | BPF_K: 643 case BPF_ALU | BPF_MUL | BPF_K: 644 case BPF_ALU | BPF_MOV | BPF_K: 645 case BPF_ALU | BPF_DIV | BPF_K: 646 case BPF_ALU | BPF_MOD | BPF_K: 647 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 648 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 649 *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX); 650 break; 651 652 case BPF_ALU64 | BPF_ADD | BPF_K: 653 case BPF_ALU64 | BPF_SUB | BPF_K: 654 case BPF_ALU64 | BPF_AND | BPF_K: 655 case BPF_ALU64 | BPF_OR | BPF_K: 656 case BPF_ALU64 | BPF_XOR | BPF_K: 657 case BPF_ALU64 | BPF_MUL | BPF_K: 658 case BPF_ALU64 | BPF_MOV | BPF_K: 659 case BPF_ALU64 | BPF_DIV | BPF_K: 660 case BPF_ALU64 | BPF_MOD | BPF_K: 661 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 662 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 663 *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX); 664 break; 665 666 case BPF_JMP | BPF_JEQ | BPF_K: 667 case BPF_JMP | BPF_JNE | BPF_K: 668 case BPF_JMP | BPF_JGT | BPF_K: 669 case BPF_JMP | BPF_JLT | BPF_K: 670 case BPF_JMP | BPF_JGE | BPF_K: 671 case BPF_JMP | BPF_JLE | BPF_K: 672 case BPF_JMP | BPF_JSGT | BPF_K: 673 case BPF_JMP | BPF_JSLT | BPF_K: 674 case BPF_JMP | BPF_JSGE | BPF_K: 675 case BPF_JMP | BPF_JSLE | BPF_K: 676 case BPF_JMP | BPF_JSET | BPF_K: 677 /* Accommodate for extra offset in case of a backjump. */ 678 off = from->off; 679 if (off < 0) 680 off -= 2; 681 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 682 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 683 *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off); 684 break; 685 686 case BPF_LD | BPF_ABS | BPF_W: 687 case BPF_LD | BPF_ABS | BPF_H: 688 case BPF_LD | BPF_ABS | BPF_B: 689 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 690 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 691 *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0); 692 break; 693 694 case BPF_LD | BPF_IND | BPF_W: 695 case BPF_LD | BPF_IND | BPF_H: 696 case BPF_LD | BPF_IND | BPF_B: 697 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 698 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 699 *to++ = BPF_ALU32_REG(BPF_ADD, BPF_REG_AX, from->src_reg); 700 *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0); 701 break; 702 703 case BPF_LD | BPF_IMM | BPF_DW: 704 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm); 705 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 706 *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32); 707 *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX); 708 break; 709 case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */ 710 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm); 711 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 712 *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX); 713 break; 714 715 case BPF_ST | BPF_MEM | BPF_DW: 716 case BPF_ST | BPF_MEM | BPF_W: 717 case BPF_ST | BPF_MEM | BPF_H: 718 case BPF_ST | BPF_MEM | BPF_B: 719 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 720 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 721 *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off); 722 break; 723 } 724 out: 725 return to - to_buff; 726 } 727 728 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other, 729 gfp_t gfp_extra_flags) 730 { 731 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; 732 struct bpf_prog *fp; 733 734 fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL); 735 if (fp != NULL) { 736 /* aux->prog still points to the fp_other one, so 737 * when promoting the clone to the real program, 738 * this still needs to be adapted. 739 */ 740 memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE); 741 } 742 743 return fp; 744 } 745 746 static void bpf_prog_clone_free(struct bpf_prog *fp) 747 { 748 /* aux was stolen by the other clone, so we cannot free 749 * it from this path! It will be freed eventually by the 750 * other program on release. 751 * 752 * At this point, we don't need a deferred release since 753 * clone is guaranteed to not be locked. 754 */ 755 fp->aux = NULL; 756 __bpf_prog_free(fp); 757 } 758 759 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other) 760 { 761 /* We have to repoint aux->prog to self, as we don't 762 * know whether fp here is the clone or the original. 763 */ 764 fp->aux->prog = fp; 765 bpf_prog_clone_free(fp_other); 766 } 767 768 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog) 769 { 770 struct bpf_insn insn_buff[16], aux[2]; 771 struct bpf_prog *clone, *tmp; 772 int insn_delta, insn_cnt; 773 struct bpf_insn *insn; 774 int i, rewritten; 775 776 if (!bpf_jit_blinding_enabled(prog) || prog->blinded) 777 return prog; 778 779 clone = bpf_prog_clone_create(prog, GFP_USER); 780 if (!clone) 781 return ERR_PTR(-ENOMEM); 782 783 insn_cnt = clone->len; 784 insn = clone->insnsi; 785 786 for (i = 0; i < insn_cnt; i++, insn++) { 787 /* We temporarily need to hold the original ld64 insn 788 * so that we can still access the first part in the 789 * second blinding run. 790 */ 791 if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) && 792 insn[1].code == 0) 793 memcpy(aux, insn, sizeof(aux)); 794 795 rewritten = bpf_jit_blind_insn(insn, aux, insn_buff); 796 if (!rewritten) 797 continue; 798 799 tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten); 800 if (!tmp) { 801 /* Patching may have repointed aux->prog during 802 * realloc from the original one, so we need to 803 * fix it up here on error. 804 */ 805 bpf_jit_prog_release_other(prog, clone); 806 return ERR_PTR(-ENOMEM); 807 } 808 809 clone = tmp; 810 insn_delta = rewritten - 1; 811 812 /* Walk new program and skip insns we just inserted. */ 813 insn = clone->insnsi + i + insn_delta; 814 insn_cnt += insn_delta; 815 i += insn_delta; 816 } 817 818 clone->blinded = 1; 819 return clone; 820 } 821 #endif /* CONFIG_BPF_JIT */ 822 823 /* Base function for offset calculation. Needs to go into .text section, 824 * therefore keeping it non-static as well; will also be used by JITs 825 * anyway later on, so do not let the compiler omit it. This also needs 826 * to go into kallsyms for correlation from e.g. bpftool, so naming 827 * must not change. 828 */ 829 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) 830 { 831 return 0; 832 } 833 EXPORT_SYMBOL_GPL(__bpf_call_base); 834 835 /* All UAPI available opcodes. */ 836 #define BPF_INSN_MAP(INSN_2, INSN_3) \ 837 /* 32 bit ALU operations. */ \ 838 /* Register based. */ \ 839 INSN_3(ALU, ADD, X), \ 840 INSN_3(ALU, SUB, X), \ 841 INSN_3(ALU, AND, X), \ 842 INSN_3(ALU, OR, X), \ 843 INSN_3(ALU, LSH, X), \ 844 INSN_3(ALU, RSH, X), \ 845 INSN_3(ALU, XOR, X), \ 846 INSN_3(ALU, MUL, X), \ 847 INSN_3(ALU, MOV, X), \ 848 INSN_3(ALU, DIV, X), \ 849 INSN_3(ALU, MOD, X), \ 850 INSN_2(ALU, NEG), \ 851 INSN_3(ALU, END, TO_BE), \ 852 INSN_3(ALU, END, TO_LE), \ 853 /* Immediate based. */ \ 854 INSN_3(ALU, ADD, K), \ 855 INSN_3(ALU, SUB, K), \ 856 INSN_3(ALU, AND, K), \ 857 INSN_3(ALU, OR, K), \ 858 INSN_3(ALU, LSH, K), \ 859 INSN_3(ALU, RSH, K), \ 860 INSN_3(ALU, XOR, K), \ 861 INSN_3(ALU, MUL, K), \ 862 INSN_3(ALU, MOV, K), \ 863 INSN_3(ALU, DIV, K), \ 864 INSN_3(ALU, MOD, K), \ 865 /* 64 bit ALU operations. */ \ 866 /* Register based. */ \ 867 INSN_3(ALU64, ADD, X), \ 868 INSN_3(ALU64, SUB, X), \ 869 INSN_3(ALU64, AND, X), \ 870 INSN_3(ALU64, OR, X), \ 871 INSN_3(ALU64, LSH, X), \ 872 INSN_3(ALU64, RSH, X), \ 873 INSN_3(ALU64, XOR, X), \ 874 INSN_3(ALU64, MUL, X), \ 875 INSN_3(ALU64, MOV, X), \ 876 INSN_3(ALU64, ARSH, X), \ 877 INSN_3(ALU64, DIV, X), \ 878 INSN_3(ALU64, MOD, X), \ 879 INSN_2(ALU64, NEG), \ 880 /* Immediate based. */ \ 881 INSN_3(ALU64, ADD, K), \ 882 INSN_3(ALU64, SUB, K), \ 883 INSN_3(ALU64, AND, K), \ 884 INSN_3(ALU64, OR, K), \ 885 INSN_3(ALU64, LSH, K), \ 886 INSN_3(ALU64, RSH, K), \ 887 INSN_3(ALU64, XOR, K), \ 888 INSN_3(ALU64, MUL, K), \ 889 INSN_3(ALU64, MOV, K), \ 890 INSN_3(ALU64, ARSH, K), \ 891 INSN_3(ALU64, DIV, K), \ 892 INSN_3(ALU64, MOD, K), \ 893 /* Call instruction. */ \ 894 INSN_2(JMP, CALL), \ 895 /* Exit instruction. */ \ 896 INSN_2(JMP, EXIT), \ 897 /* Jump instructions. */ \ 898 /* Register based. */ \ 899 INSN_3(JMP, JEQ, X), \ 900 INSN_3(JMP, JNE, X), \ 901 INSN_3(JMP, JGT, X), \ 902 INSN_3(JMP, JLT, X), \ 903 INSN_3(JMP, JGE, X), \ 904 INSN_3(JMP, JLE, X), \ 905 INSN_3(JMP, JSGT, X), \ 906 INSN_3(JMP, JSLT, X), \ 907 INSN_3(JMP, JSGE, X), \ 908 INSN_3(JMP, JSLE, X), \ 909 INSN_3(JMP, JSET, X), \ 910 /* Immediate based. */ \ 911 INSN_3(JMP, JEQ, K), \ 912 INSN_3(JMP, JNE, K), \ 913 INSN_3(JMP, JGT, K), \ 914 INSN_3(JMP, JLT, K), \ 915 INSN_3(JMP, JGE, K), \ 916 INSN_3(JMP, JLE, K), \ 917 INSN_3(JMP, JSGT, K), \ 918 INSN_3(JMP, JSLT, K), \ 919 INSN_3(JMP, JSGE, K), \ 920 INSN_3(JMP, JSLE, K), \ 921 INSN_3(JMP, JSET, K), \ 922 INSN_2(JMP, JA), \ 923 /* Store instructions. */ \ 924 /* Register based. */ \ 925 INSN_3(STX, MEM, B), \ 926 INSN_3(STX, MEM, H), \ 927 INSN_3(STX, MEM, W), \ 928 INSN_3(STX, MEM, DW), \ 929 INSN_3(STX, XADD, W), \ 930 INSN_3(STX, XADD, DW), \ 931 /* Immediate based. */ \ 932 INSN_3(ST, MEM, B), \ 933 INSN_3(ST, MEM, H), \ 934 INSN_3(ST, MEM, W), \ 935 INSN_3(ST, MEM, DW), \ 936 /* Load instructions. */ \ 937 /* Register based. */ \ 938 INSN_3(LDX, MEM, B), \ 939 INSN_3(LDX, MEM, H), \ 940 INSN_3(LDX, MEM, W), \ 941 INSN_3(LDX, MEM, DW), \ 942 /* Immediate based. */ \ 943 INSN_3(LD, IMM, DW), \ 944 /* Misc (old cBPF carry-over). */ \ 945 INSN_3(LD, ABS, B), \ 946 INSN_3(LD, ABS, H), \ 947 INSN_3(LD, ABS, W), \ 948 INSN_3(LD, IND, B), \ 949 INSN_3(LD, IND, H), \ 950 INSN_3(LD, IND, W) 951 952 bool bpf_opcode_in_insntable(u8 code) 953 { 954 #define BPF_INSN_2_TBL(x, y) [BPF_##x | BPF_##y] = true 955 #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true 956 static const bool public_insntable[256] = { 957 [0 ... 255] = false, 958 /* Now overwrite non-defaults ... */ 959 BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL), 960 }; 961 #undef BPF_INSN_3_TBL 962 #undef BPF_INSN_2_TBL 963 return public_insntable[code]; 964 } 965 966 #ifndef CONFIG_BPF_JIT_ALWAYS_ON 967 /** 968 * __bpf_prog_run - run eBPF program on a given context 969 * @ctx: is the data we are operating on 970 * @insn: is the array of eBPF instructions 971 * 972 * Decode and execute eBPF instructions. 973 */ 974 static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack) 975 { 976 u64 tmp; 977 #define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y 978 #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z 979 static const void *jumptable[256] = { 980 [0 ... 255] = &&default_label, 981 /* Now overwrite non-defaults ... */ 982 BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL), 983 /* Non-UAPI available opcodes. */ 984 [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS, 985 [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL, 986 }; 987 #undef BPF_INSN_3_LBL 988 #undef BPF_INSN_2_LBL 989 u32 tail_call_cnt = 0; 990 void *ptr; 991 int off; 992 993 #define CONT ({ insn++; goto select_insn; }) 994 #define CONT_JMP ({ insn++; goto select_insn; }) 995 996 select_insn: 997 goto *jumptable[insn->code]; 998 999 /* ALU */ 1000 #define ALU(OPCODE, OP) \ 1001 ALU64_##OPCODE##_X: \ 1002 DST = DST OP SRC; \ 1003 CONT; \ 1004 ALU_##OPCODE##_X: \ 1005 DST = (u32) DST OP (u32) SRC; \ 1006 CONT; \ 1007 ALU64_##OPCODE##_K: \ 1008 DST = DST OP IMM; \ 1009 CONT; \ 1010 ALU_##OPCODE##_K: \ 1011 DST = (u32) DST OP (u32) IMM; \ 1012 CONT; 1013 1014 ALU(ADD, +) 1015 ALU(SUB, -) 1016 ALU(AND, &) 1017 ALU(OR, |) 1018 ALU(LSH, <<) 1019 ALU(RSH, >>) 1020 ALU(XOR, ^) 1021 ALU(MUL, *) 1022 #undef ALU 1023 ALU_NEG: 1024 DST = (u32) -DST; 1025 CONT; 1026 ALU64_NEG: 1027 DST = -DST; 1028 CONT; 1029 ALU_MOV_X: 1030 DST = (u32) SRC; 1031 CONT; 1032 ALU_MOV_K: 1033 DST = (u32) IMM; 1034 CONT; 1035 ALU64_MOV_X: 1036 DST = SRC; 1037 CONT; 1038 ALU64_MOV_K: 1039 DST = IMM; 1040 CONT; 1041 LD_IMM_DW: 1042 DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; 1043 insn++; 1044 CONT; 1045 ALU64_ARSH_X: 1046 (*(s64 *) &DST) >>= SRC; 1047 CONT; 1048 ALU64_ARSH_K: 1049 (*(s64 *) &DST) >>= IMM; 1050 CONT; 1051 ALU64_MOD_X: 1052 div64_u64_rem(DST, SRC, &tmp); 1053 DST = tmp; 1054 CONT; 1055 ALU_MOD_X: 1056 tmp = (u32) DST; 1057 DST = do_div(tmp, (u32) SRC); 1058 CONT; 1059 ALU64_MOD_K: 1060 div64_u64_rem(DST, IMM, &tmp); 1061 DST = tmp; 1062 CONT; 1063 ALU_MOD_K: 1064 tmp = (u32) DST; 1065 DST = do_div(tmp, (u32) IMM); 1066 CONT; 1067 ALU64_DIV_X: 1068 DST = div64_u64(DST, SRC); 1069 CONT; 1070 ALU_DIV_X: 1071 tmp = (u32) DST; 1072 do_div(tmp, (u32) SRC); 1073 DST = (u32) tmp; 1074 CONT; 1075 ALU64_DIV_K: 1076 DST = div64_u64(DST, IMM); 1077 CONT; 1078 ALU_DIV_K: 1079 tmp = (u32) DST; 1080 do_div(tmp, (u32) IMM); 1081 DST = (u32) tmp; 1082 CONT; 1083 ALU_END_TO_BE: 1084 switch (IMM) { 1085 case 16: 1086 DST = (__force u16) cpu_to_be16(DST); 1087 break; 1088 case 32: 1089 DST = (__force u32) cpu_to_be32(DST); 1090 break; 1091 case 64: 1092 DST = (__force u64) cpu_to_be64(DST); 1093 break; 1094 } 1095 CONT; 1096 ALU_END_TO_LE: 1097 switch (IMM) { 1098 case 16: 1099 DST = (__force u16) cpu_to_le16(DST); 1100 break; 1101 case 32: 1102 DST = (__force u32) cpu_to_le32(DST); 1103 break; 1104 case 64: 1105 DST = (__force u64) cpu_to_le64(DST); 1106 break; 1107 } 1108 CONT; 1109 1110 /* CALL */ 1111 JMP_CALL: 1112 /* Function call scratches BPF_R1-BPF_R5 registers, 1113 * preserves BPF_R6-BPF_R9, and stores return value 1114 * into BPF_R0. 1115 */ 1116 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, 1117 BPF_R4, BPF_R5); 1118 CONT; 1119 1120 JMP_CALL_ARGS: 1121 BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2, 1122 BPF_R3, BPF_R4, 1123 BPF_R5, 1124 insn + insn->off + 1); 1125 CONT; 1126 1127 JMP_TAIL_CALL: { 1128 struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2; 1129 struct bpf_array *array = container_of(map, struct bpf_array, map); 1130 struct bpf_prog *prog; 1131 u32 index = BPF_R3; 1132 1133 if (unlikely(index >= array->map.max_entries)) 1134 goto out; 1135 if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT)) 1136 goto out; 1137 1138 tail_call_cnt++; 1139 1140 prog = READ_ONCE(array->ptrs[index]); 1141 if (!prog) 1142 goto out; 1143 1144 /* ARG1 at this point is guaranteed to point to CTX from 1145 * the verifier side due to the fact that the tail call is 1146 * handeled like a helper, that is, bpf_tail_call_proto, 1147 * where arg1_type is ARG_PTR_TO_CTX. 1148 */ 1149 insn = prog->insnsi; 1150 goto select_insn; 1151 out: 1152 CONT; 1153 } 1154 /* JMP */ 1155 JMP_JA: 1156 insn += insn->off; 1157 CONT; 1158 JMP_JEQ_X: 1159 if (DST == SRC) { 1160 insn += insn->off; 1161 CONT_JMP; 1162 } 1163 CONT; 1164 JMP_JEQ_K: 1165 if (DST == IMM) { 1166 insn += insn->off; 1167 CONT_JMP; 1168 } 1169 CONT; 1170 JMP_JNE_X: 1171 if (DST != SRC) { 1172 insn += insn->off; 1173 CONT_JMP; 1174 } 1175 CONT; 1176 JMP_JNE_K: 1177 if (DST != IMM) { 1178 insn += insn->off; 1179 CONT_JMP; 1180 } 1181 CONT; 1182 JMP_JGT_X: 1183 if (DST > SRC) { 1184 insn += insn->off; 1185 CONT_JMP; 1186 } 1187 CONT; 1188 JMP_JGT_K: 1189 if (DST > IMM) { 1190 insn += insn->off; 1191 CONT_JMP; 1192 } 1193 CONT; 1194 JMP_JLT_X: 1195 if (DST < SRC) { 1196 insn += insn->off; 1197 CONT_JMP; 1198 } 1199 CONT; 1200 JMP_JLT_K: 1201 if (DST < IMM) { 1202 insn += insn->off; 1203 CONT_JMP; 1204 } 1205 CONT; 1206 JMP_JGE_X: 1207 if (DST >= SRC) { 1208 insn += insn->off; 1209 CONT_JMP; 1210 } 1211 CONT; 1212 JMP_JGE_K: 1213 if (DST >= IMM) { 1214 insn += insn->off; 1215 CONT_JMP; 1216 } 1217 CONT; 1218 JMP_JLE_X: 1219 if (DST <= SRC) { 1220 insn += insn->off; 1221 CONT_JMP; 1222 } 1223 CONT; 1224 JMP_JLE_K: 1225 if (DST <= IMM) { 1226 insn += insn->off; 1227 CONT_JMP; 1228 } 1229 CONT; 1230 JMP_JSGT_X: 1231 if (((s64) DST) > ((s64) SRC)) { 1232 insn += insn->off; 1233 CONT_JMP; 1234 } 1235 CONT; 1236 JMP_JSGT_K: 1237 if (((s64) DST) > ((s64) IMM)) { 1238 insn += insn->off; 1239 CONT_JMP; 1240 } 1241 CONT; 1242 JMP_JSLT_X: 1243 if (((s64) DST) < ((s64) SRC)) { 1244 insn += insn->off; 1245 CONT_JMP; 1246 } 1247 CONT; 1248 JMP_JSLT_K: 1249 if (((s64) DST) < ((s64) IMM)) { 1250 insn += insn->off; 1251 CONT_JMP; 1252 } 1253 CONT; 1254 JMP_JSGE_X: 1255 if (((s64) DST) >= ((s64) SRC)) { 1256 insn += insn->off; 1257 CONT_JMP; 1258 } 1259 CONT; 1260 JMP_JSGE_K: 1261 if (((s64) DST) >= ((s64) IMM)) { 1262 insn += insn->off; 1263 CONT_JMP; 1264 } 1265 CONT; 1266 JMP_JSLE_X: 1267 if (((s64) DST) <= ((s64) SRC)) { 1268 insn += insn->off; 1269 CONT_JMP; 1270 } 1271 CONT; 1272 JMP_JSLE_K: 1273 if (((s64) DST) <= ((s64) IMM)) { 1274 insn += insn->off; 1275 CONT_JMP; 1276 } 1277 CONT; 1278 JMP_JSET_X: 1279 if (DST & SRC) { 1280 insn += insn->off; 1281 CONT_JMP; 1282 } 1283 CONT; 1284 JMP_JSET_K: 1285 if (DST & IMM) { 1286 insn += insn->off; 1287 CONT_JMP; 1288 } 1289 CONT; 1290 JMP_EXIT: 1291 return BPF_R0; 1292 1293 /* STX and ST and LDX*/ 1294 #define LDST(SIZEOP, SIZE) \ 1295 STX_MEM_##SIZEOP: \ 1296 *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ 1297 CONT; \ 1298 ST_MEM_##SIZEOP: \ 1299 *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ 1300 CONT; \ 1301 LDX_MEM_##SIZEOP: \ 1302 DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ 1303 CONT; 1304 1305 LDST(B, u8) 1306 LDST(H, u16) 1307 LDST(W, u32) 1308 LDST(DW, u64) 1309 #undef LDST 1310 STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ 1311 atomic_add((u32) SRC, (atomic_t *)(unsigned long) 1312 (DST + insn->off)); 1313 CONT; 1314 STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ 1315 atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) 1316 (DST + insn->off)); 1317 CONT; 1318 LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */ 1319 off = IMM; 1320 load_word: 1321 /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are only 1322 * appearing in the programs where ctx == skb 1323 * (see may_access_skb() in the verifier). All programs 1324 * keep 'ctx' in regs[BPF_REG_CTX] == BPF_R6, 1325 * bpf_convert_filter() saves it in BPF_R6, internal BPF 1326 * verifier will check that BPF_R6 == ctx. 1327 * 1328 * BPF_ABS and BPF_IND are wrappers of function calls, 1329 * so they scratch BPF_R1-BPF_R5 registers, preserve 1330 * BPF_R6-BPF_R9, and store return value into BPF_R0. 1331 * 1332 * Implicit input: 1333 * ctx == skb == BPF_R6 == CTX 1334 * 1335 * Explicit input: 1336 * SRC == any register 1337 * IMM == 32-bit immediate 1338 * 1339 * Output: 1340 * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness 1341 */ 1342 1343 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp); 1344 if (likely(ptr != NULL)) { 1345 BPF_R0 = get_unaligned_be32(ptr); 1346 CONT; 1347 } 1348 1349 return 0; 1350 LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */ 1351 off = IMM; 1352 load_half: 1353 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp); 1354 if (likely(ptr != NULL)) { 1355 BPF_R0 = get_unaligned_be16(ptr); 1356 CONT; 1357 } 1358 1359 return 0; 1360 LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */ 1361 off = IMM; 1362 load_byte: 1363 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp); 1364 if (likely(ptr != NULL)) { 1365 BPF_R0 = *(u8 *)ptr; 1366 CONT; 1367 } 1368 1369 return 0; 1370 LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */ 1371 off = IMM + SRC; 1372 goto load_word; 1373 LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */ 1374 off = IMM + SRC; 1375 goto load_half; 1376 LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */ 1377 off = IMM + SRC; 1378 goto load_byte; 1379 1380 default_label: 1381 /* If we ever reach this, we have a bug somewhere. Die hard here 1382 * instead of just returning 0; we could be somewhere in a subprog, 1383 * so execution could continue otherwise which we do /not/ want. 1384 * 1385 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable(). 1386 */ 1387 pr_warn("BPF interpreter: unknown opcode %02x\n", insn->code); 1388 BUG_ON(1); 1389 return 0; 1390 } 1391 STACK_FRAME_NON_STANDARD(___bpf_prog_run); /* jump table */ 1392 1393 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size 1394 #define DEFINE_BPF_PROG_RUN(stack_size) \ 1395 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \ 1396 { \ 1397 u64 stack[stack_size / sizeof(u64)]; \ 1398 u64 regs[MAX_BPF_REG]; \ 1399 \ 1400 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ 1401 ARG1 = (u64) (unsigned long) ctx; \ 1402 return ___bpf_prog_run(regs, insn, stack); \ 1403 } 1404 1405 #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size 1406 #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \ 1407 static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \ 1408 const struct bpf_insn *insn) \ 1409 { \ 1410 u64 stack[stack_size / sizeof(u64)]; \ 1411 u64 regs[MAX_BPF_REG]; \ 1412 \ 1413 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ 1414 BPF_R1 = r1; \ 1415 BPF_R2 = r2; \ 1416 BPF_R3 = r3; \ 1417 BPF_R4 = r4; \ 1418 BPF_R5 = r5; \ 1419 return ___bpf_prog_run(regs, insn, stack); \ 1420 } 1421 1422 #define EVAL1(FN, X) FN(X) 1423 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y) 1424 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y) 1425 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y) 1426 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y) 1427 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y) 1428 1429 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192); 1430 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384); 1431 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512); 1432 1433 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192); 1434 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384); 1435 EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512); 1436 1437 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size), 1438 1439 static unsigned int (*interpreters[])(const void *ctx, 1440 const struct bpf_insn *insn) = { 1441 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) 1442 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) 1443 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) 1444 }; 1445 #undef PROG_NAME_LIST 1446 #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size), 1447 static u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, 1448 const struct bpf_insn *insn) = { 1449 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) 1450 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) 1451 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) 1452 }; 1453 #undef PROG_NAME_LIST 1454 1455 void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth) 1456 { 1457 stack_depth = max_t(u32, stack_depth, 1); 1458 insn->off = (s16) insn->imm; 1459 insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] - 1460 __bpf_call_base_args; 1461 insn->code = BPF_JMP | BPF_CALL_ARGS; 1462 } 1463 1464 #else 1465 static unsigned int __bpf_prog_ret0_warn(const void *ctx, 1466 const struct bpf_insn *insn) 1467 { 1468 /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON 1469 * is not working properly, so warn about it! 1470 */ 1471 WARN_ON_ONCE(1); 1472 return 0; 1473 } 1474 #endif 1475 1476 bool bpf_prog_array_compatible(struct bpf_array *array, 1477 const struct bpf_prog *fp) 1478 { 1479 if (fp->kprobe_override) 1480 return false; 1481 1482 if (!array->owner_prog_type) { 1483 /* There's no owner yet where we could check for 1484 * compatibility. 1485 */ 1486 array->owner_prog_type = fp->type; 1487 array->owner_jited = fp->jited; 1488 1489 return true; 1490 } 1491 1492 return array->owner_prog_type == fp->type && 1493 array->owner_jited == fp->jited; 1494 } 1495 1496 static int bpf_check_tail_call(const struct bpf_prog *fp) 1497 { 1498 struct bpf_prog_aux *aux = fp->aux; 1499 int i; 1500 1501 for (i = 0; i < aux->used_map_cnt; i++) { 1502 struct bpf_map *map = aux->used_maps[i]; 1503 struct bpf_array *array; 1504 1505 if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY) 1506 continue; 1507 1508 array = container_of(map, struct bpf_array, map); 1509 if (!bpf_prog_array_compatible(array, fp)) 1510 return -EINVAL; 1511 } 1512 1513 return 0; 1514 } 1515 1516 /** 1517 * bpf_prog_select_runtime - select exec runtime for BPF program 1518 * @fp: bpf_prog populated with internal BPF program 1519 * @err: pointer to error variable 1520 * 1521 * Try to JIT eBPF program, if JIT is not available, use interpreter. 1522 * The BPF program will be executed via BPF_PROG_RUN() macro. 1523 */ 1524 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) 1525 { 1526 #ifndef CONFIG_BPF_JIT_ALWAYS_ON 1527 u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1); 1528 1529 fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1]; 1530 #else 1531 fp->bpf_func = __bpf_prog_ret0_warn; 1532 #endif 1533 1534 /* eBPF JITs can rewrite the program in case constant 1535 * blinding is active. However, in case of error during 1536 * blinding, bpf_int_jit_compile() must always return a 1537 * valid program, which in this case would simply not 1538 * be JITed, but falls back to the interpreter. 1539 */ 1540 if (!bpf_prog_is_dev_bound(fp->aux)) { 1541 fp = bpf_int_jit_compile(fp); 1542 #ifdef CONFIG_BPF_JIT_ALWAYS_ON 1543 if (!fp->jited) { 1544 *err = -ENOTSUPP; 1545 return fp; 1546 } 1547 #endif 1548 } else { 1549 *err = bpf_prog_offload_compile(fp); 1550 if (*err) 1551 return fp; 1552 } 1553 bpf_prog_lock_ro(fp); 1554 1555 /* The tail call compatibility check can only be done at 1556 * this late stage as we need to determine, if we deal 1557 * with JITed or non JITed program concatenations and not 1558 * all eBPF JITs might immediately support all features. 1559 */ 1560 *err = bpf_check_tail_call(fp); 1561 1562 return fp; 1563 } 1564 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); 1565 1566 static unsigned int __bpf_prog_ret1(const void *ctx, 1567 const struct bpf_insn *insn) 1568 { 1569 return 1; 1570 } 1571 1572 static struct bpf_prog_dummy { 1573 struct bpf_prog prog; 1574 } dummy_bpf_prog = { 1575 .prog = { 1576 .bpf_func = __bpf_prog_ret1, 1577 }, 1578 }; 1579 1580 /* to avoid allocating empty bpf_prog_array for cgroups that 1581 * don't have bpf program attached use one global 'empty_prog_array' 1582 * It will not be modified the caller of bpf_prog_array_alloc() 1583 * (since caller requested prog_cnt == 0) 1584 * that pointer should be 'freed' by bpf_prog_array_free() 1585 */ 1586 static struct { 1587 struct bpf_prog_array hdr; 1588 struct bpf_prog *null_prog; 1589 } empty_prog_array = { 1590 .null_prog = NULL, 1591 }; 1592 1593 struct bpf_prog_array __rcu *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags) 1594 { 1595 if (prog_cnt) 1596 return kzalloc(sizeof(struct bpf_prog_array) + 1597 sizeof(struct bpf_prog *) * (prog_cnt + 1), 1598 flags); 1599 1600 return &empty_prog_array.hdr; 1601 } 1602 1603 void bpf_prog_array_free(struct bpf_prog_array __rcu *progs) 1604 { 1605 if (!progs || 1606 progs == (struct bpf_prog_array __rcu *)&empty_prog_array.hdr) 1607 return; 1608 kfree_rcu(progs, rcu); 1609 } 1610 1611 int bpf_prog_array_length(struct bpf_prog_array __rcu *progs) 1612 { 1613 struct bpf_prog **prog; 1614 u32 cnt = 0; 1615 1616 rcu_read_lock(); 1617 prog = rcu_dereference(progs)->progs; 1618 for (; *prog; prog++) 1619 if (*prog != &dummy_bpf_prog.prog) 1620 cnt++; 1621 rcu_read_unlock(); 1622 return cnt; 1623 } 1624 1625 static bool bpf_prog_array_copy_core(struct bpf_prog **prog, 1626 u32 *prog_ids, 1627 u32 request_cnt) 1628 { 1629 int i = 0; 1630 1631 for (; *prog; prog++) { 1632 if (*prog == &dummy_bpf_prog.prog) 1633 continue; 1634 prog_ids[i] = (*prog)->aux->id; 1635 if (++i == request_cnt) { 1636 prog++; 1637 break; 1638 } 1639 } 1640 1641 return !!(*prog); 1642 } 1643 1644 int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs, 1645 __u32 __user *prog_ids, u32 cnt) 1646 { 1647 struct bpf_prog **prog; 1648 unsigned long err = 0; 1649 bool nospc; 1650 u32 *ids; 1651 1652 /* users of this function are doing: 1653 * cnt = bpf_prog_array_length(); 1654 * if (cnt > 0) 1655 * bpf_prog_array_copy_to_user(..., cnt); 1656 * so below kcalloc doesn't need extra cnt > 0 check, but 1657 * bpf_prog_array_length() releases rcu lock and 1658 * prog array could have been swapped with empty or larger array, 1659 * so always copy 'cnt' prog_ids to the user. 1660 * In a rare race the user will see zero prog_ids 1661 */ 1662 ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN); 1663 if (!ids) 1664 return -ENOMEM; 1665 rcu_read_lock(); 1666 prog = rcu_dereference(progs)->progs; 1667 nospc = bpf_prog_array_copy_core(prog, ids, cnt); 1668 rcu_read_unlock(); 1669 err = copy_to_user(prog_ids, ids, cnt * sizeof(u32)); 1670 kfree(ids); 1671 if (err) 1672 return -EFAULT; 1673 if (nospc) 1674 return -ENOSPC; 1675 return 0; 1676 } 1677 1678 void bpf_prog_array_delete_safe(struct bpf_prog_array __rcu *progs, 1679 struct bpf_prog *old_prog) 1680 { 1681 struct bpf_prog **prog = progs->progs; 1682 1683 for (; *prog; prog++) 1684 if (*prog == old_prog) { 1685 WRITE_ONCE(*prog, &dummy_bpf_prog.prog); 1686 break; 1687 } 1688 } 1689 1690 int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array, 1691 struct bpf_prog *exclude_prog, 1692 struct bpf_prog *include_prog, 1693 struct bpf_prog_array **new_array) 1694 { 1695 int new_prog_cnt, carry_prog_cnt = 0; 1696 struct bpf_prog **existing_prog; 1697 struct bpf_prog_array *array; 1698 int new_prog_idx = 0; 1699 1700 /* Figure out how many existing progs we need to carry over to 1701 * the new array. 1702 */ 1703 if (old_array) { 1704 existing_prog = old_array->progs; 1705 for (; *existing_prog; existing_prog++) { 1706 if (*existing_prog != exclude_prog && 1707 *existing_prog != &dummy_bpf_prog.prog) 1708 carry_prog_cnt++; 1709 if (*existing_prog == include_prog) 1710 return -EEXIST; 1711 } 1712 } 1713 1714 /* How many progs (not NULL) will be in the new array? */ 1715 new_prog_cnt = carry_prog_cnt; 1716 if (include_prog) 1717 new_prog_cnt += 1; 1718 1719 /* Do we have any prog (not NULL) in the new array? */ 1720 if (!new_prog_cnt) { 1721 *new_array = NULL; 1722 return 0; 1723 } 1724 1725 /* +1 as the end of prog_array is marked with NULL */ 1726 array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL); 1727 if (!array) 1728 return -ENOMEM; 1729 1730 /* Fill in the new prog array */ 1731 if (carry_prog_cnt) { 1732 existing_prog = old_array->progs; 1733 for (; *existing_prog; existing_prog++) 1734 if (*existing_prog != exclude_prog && 1735 *existing_prog != &dummy_bpf_prog.prog) 1736 array->progs[new_prog_idx++] = *existing_prog; 1737 } 1738 if (include_prog) 1739 array->progs[new_prog_idx++] = include_prog; 1740 array->progs[new_prog_idx] = NULL; 1741 *new_array = array; 1742 return 0; 1743 } 1744 1745 int bpf_prog_array_copy_info(struct bpf_prog_array __rcu *array, 1746 u32 *prog_ids, u32 request_cnt, 1747 u32 *prog_cnt) 1748 { 1749 struct bpf_prog **prog; 1750 u32 cnt = 0; 1751 1752 if (array) 1753 cnt = bpf_prog_array_length(array); 1754 1755 *prog_cnt = cnt; 1756 1757 /* return early if user requested only program count or nothing to copy */ 1758 if (!request_cnt || !cnt) 1759 return 0; 1760 1761 /* this function is called under trace/bpf_trace.c: bpf_event_mutex */ 1762 prog = rcu_dereference_check(array, 1)->progs; 1763 return bpf_prog_array_copy_core(prog, prog_ids, request_cnt) ? -ENOSPC 1764 : 0; 1765 } 1766 1767 static void bpf_prog_free_deferred(struct work_struct *work) 1768 { 1769 struct bpf_prog_aux *aux; 1770 int i; 1771 1772 aux = container_of(work, struct bpf_prog_aux, work); 1773 if (bpf_prog_is_dev_bound(aux)) 1774 bpf_prog_offload_destroy(aux->prog); 1775 for (i = 0; i < aux->func_cnt; i++) 1776 bpf_jit_free(aux->func[i]); 1777 if (aux->func_cnt) { 1778 kfree(aux->func); 1779 bpf_prog_unlock_free(aux->prog); 1780 } else { 1781 bpf_jit_free(aux->prog); 1782 } 1783 } 1784 1785 /* Free internal BPF program */ 1786 void bpf_prog_free(struct bpf_prog *fp) 1787 { 1788 struct bpf_prog_aux *aux = fp->aux; 1789 1790 INIT_WORK(&aux->work, bpf_prog_free_deferred); 1791 schedule_work(&aux->work); 1792 } 1793 EXPORT_SYMBOL_GPL(bpf_prog_free); 1794 1795 /* RNG for unpriviledged user space with separated state from prandom_u32(). */ 1796 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state); 1797 1798 void bpf_user_rnd_init_once(void) 1799 { 1800 prandom_init_once(&bpf_user_rnd_state); 1801 } 1802 1803 BPF_CALL_0(bpf_user_rnd_u32) 1804 { 1805 /* Should someone ever have the rather unwise idea to use some 1806 * of the registers passed into this function, then note that 1807 * this function is called from native eBPF and classic-to-eBPF 1808 * transformations. Register assignments from both sides are 1809 * different, f.e. classic always sets fn(ctx, A, X) here. 1810 */ 1811 struct rnd_state *state; 1812 u32 res; 1813 1814 state = &get_cpu_var(bpf_user_rnd_state); 1815 res = prandom_u32_state(state); 1816 put_cpu_var(bpf_user_rnd_state); 1817 1818 return res; 1819 } 1820 1821 /* Weak definitions of helper functions in case we don't have bpf syscall. */ 1822 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak; 1823 const struct bpf_func_proto bpf_map_update_elem_proto __weak; 1824 const struct bpf_func_proto bpf_map_delete_elem_proto __weak; 1825 1826 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; 1827 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; 1828 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; 1829 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; 1830 1831 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; 1832 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; 1833 const struct bpf_func_proto bpf_get_current_comm_proto __weak; 1834 const struct bpf_func_proto bpf_sock_map_update_proto __weak; 1835 1836 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) 1837 { 1838 return NULL; 1839 } 1840 1841 u64 __weak 1842 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 1843 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 1844 { 1845 return -ENOTSUPP; 1846 } 1847 1848 /* Always built-in helper functions. */ 1849 const struct bpf_func_proto bpf_tail_call_proto = { 1850 .func = NULL, 1851 .gpl_only = false, 1852 .ret_type = RET_VOID, 1853 .arg1_type = ARG_PTR_TO_CTX, 1854 .arg2_type = ARG_CONST_MAP_PTR, 1855 .arg3_type = ARG_ANYTHING, 1856 }; 1857 1858 /* Stub for JITs that only support cBPF. eBPF programs are interpreted. 1859 * It is encouraged to implement bpf_int_jit_compile() instead, so that 1860 * eBPF and implicitly also cBPF can get JITed! 1861 */ 1862 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog) 1863 { 1864 return prog; 1865 } 1866 1867 /* Stub for JITs that support eBPF. All cBPF code gets transformed into 1868 * eBPF by the kernel and is later compiled by bpf_int_jit_compile(). 1869 */ 1870 void __weak bpf_jit_compile(struct bpf_prog *prog) 1871 { 1872 } 1873 1874 bool __weak bpf_helper_changes_pkt_data(void *func) 1875 { 1876 return false; 1877 } 1878 1879 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call 1880 * skb_copy_bits(), so provide a weak definition of it for NET-less config. 1881 */ 1882 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, 1883 int len) 1884 { 1885 return -EFAULT; 1886 } 1887 1888 /* All definitions of tracepoints related to BPF. */ 1889 #define CREATE_TRACE_POINTS 1890 #include <linux/bpf_trace.h> 1891 1892 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception); 1893 1894 /* These are only used within the BPF_SYSCALL code */ 1895 #ifdef CONFIG_BPF_SYSCALL 1896 EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_get_type); 1897 EXPORT_TRACEPOINT_SYMBOL_GPL(bpf_prog_put_rcu); 1898 #endif 1899