1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Linux Socket Filter - Kernel level socket filtering 4 * 5 * Based on the design of the Berkeley Packet Filter. The new 6 * internal format has been designed by PLUMgrid: 7 * 8 * Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com 9 * 10 * Authors: 11 * 12 * Jay Schulist <jschlst@samba.org> 13 * Alexei Starovoitov <ast@plumgrid.com> 14 * Daniel Borkmann <dborkman@redhat.com> 15 * 16 * Andi Kleen - Fix a few bad bugs and races. 17 * Kris Katterjohn - Added many additional checks in bpf_check_classic() 18 */ 19 20 #include <uapi/linux/btf.h> 21 #include <linux/filter.h> 22 #include <linux/skbuff.h> 23 #include <linux/vmalloc.h> 24 #include <linux/random.h> 25 #include <linux/moduleloader.h> 26 #include <linux/bpf.h> 27 #include <linux/btf.h> 28 #include <linux/objtool.h> 29 #include <linux/rbtree_latch.h> 30 #include <linux/kallsyms.h> 31 #include <linux/rcupdate.h> 32 #include <linux/perf_event.h> 33 #include <linux/extable.h> 34 #include <linux/log2.h> 35 #include <linux/bpf_verifier.h> 36 #include <linux/nodemask.h> 37 #include <linux/nospec.h> 38 #include <linux/bpf_mem_alloc.h> 39 #include <linux/memcontrol.h> 40 41 #include <asm/barrier.h> 42 #include <asm/unaligned.h> 43 44 /* Registers */ 45 #define BPF_R0 regs[BPF_REG_0] 46 #define BPF_R1 regs[BPF_REG_1] 47 #define BPF_R2 regs[BPF_REG_2] 48 #define BPF_R3 regs[BPF_REG_3] 49 #define BPF_R4 regs[BPF_REG_4] 50 #define BPF_R5 regs[BPF_REG_5] 51 #define BPF_R6 regs[BPF_REG_6] 52 #define BPF_R7 regs[BPF_REG_7] 53 #define BPF_R8 regs[BPF_REG_8] 54 #define BPF_R9 regs[BPF_REG_9] 55 #define BPF_R10 regs[BPF_REG_10] 56 57 /* Named registers */ 58 #define DST regs[insn->dst_reg] 59 #define SRC regs[insn->src_reg] 60 #define FP regs[BPF_REG_FP] 61 #define AX regs[BPF_REG_AX] 62 #define ARG1 regs[BPF_REG_ARG1] 63 #define CTX regs[BPF_REG_CTX] 64 #define OFF insn->off 65 #define IMM insn->imm 66 67 struct bpf_mem_alloc bpf_global_ma; 68 bool bpf_global_ma_set; 69 70 /* No hurry in this branch 71 * 72 * Exported for the bpf jit load helper. 73 */ 74 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) 75 { 76 u8 *ptr = NULL; 77 78 if (k >= SKF_NET_OFF) { 79 ptr = skb_network_header(skb) + k - SKF_NET_OFF; 80 } else if (k >= SKF_LL_OFF) { 81 if (unlikely(!skb_mac_header_was_set(skb))) 82 return NULL; 83 ptr = skb_mac_header(skb) + k - SKF_LL_OFF; 84 } 85 if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) 86 return ptr; 87 88 return NULL; 89 } 90 91 struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags) 92 { 93 gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags); 94 struct bpf_prog_aux *aux; 95 struct bpf_prog *fp; 96 97 size = round_up(size, PAGE_SIZE); 98 fp = __vmalloc(size, gfp_flags); 99 if (fp == NULL) 100 return NULL; 101 102 aux = kzalloc(sizeof(*aux), bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags)); 103 if (aux == NULL) { 104 vfree(fp); 105 return NULL; 106 } 107 fp->active = alloc_percpu_gfp(int, bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags)); 108 if (!fp->active) { 109 vfree(fp); 110 kfree(aux); 111 return NULL; 112 } 113 114 fp->pages = size / PAGE_SIZE; 115 fp->aux = aux; 116 fp->aux->prog = fp; 117 fp->jit_requested = ebpf_jit_enabled(); 118 fp->blinding_requested = bpf_jit_blinding_enabled(fp); 119 #ifdef CONFIG_CGROUP_BPF 120 aux->cgroup_atype = CGROUP_BPF_ATTACH_TYPE_INVALID; 121 #endif 122 123 INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode); 124 mutex_init(&fp->aux->used_maps_mutex); 125 mutex_init(&fp->aux->dst_mutex); 126 127 return fp; 128 } 129 130 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) 131 { 132 gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags); 133 struct bpf_prog *prog; 134 int cpu; 135 136 prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags); 137 if (!prog) 138 return NULL; 139 140 prog->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags); 141 if (!prog->stats) { 142 free_percpu(prog->active); 143 kfree(prog->aux); 144 vfree(prog); 145 return NULL; 146 } 147 148 for_each_possible_cpu(cpu) { 149 struct bpf_prog_stats *pstats; 150 151 pstats = per_cpu_ptr(prog->stats, cpu); 152 u64_stats_init(&pstats->syncp); 153 } 154 return prog; 155 } 156 EXPORT_SYMBOL_GPL(bpf_prog_alloc); 157 158 int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog) 159 { 160 if (!prog->aux->nr_linfo || !prog->jit_requested) 161 return 0; 162 163 prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo, 164 sizeof(*prog->aux->jited_linfo), 165 bpf_memcg_flags(GFP_KERNEL | __GFP_NOWARN)); 166 if (!prog->aux->jited_linfo) 167 return -ENOMEM; 168 169 return 0; 170 } 171 172 void bpf_prog_jit_attempt_done(struct bpf_prog *prog) 173 { 174 if (prog->aux->jited_linfo && 175 (!prog->jited || !prog->aux->jited_linfo[0])) { 176 kvfree(prog->aux->jited_linfo); 177 prog->aux->jited_linfo = NULL; 178 } 179 180 kfree(prog->aux->kfunc_tab); 181 prog->aux->kfunc_tab = NULL; 182 } 183 184 /* The jit engine is responsible to provide an array 185 * for insn_off to the jited_off mapping (insn_to_jit_off). 186 * 187 * The idx to this array is the insn_off. Hence, the insn_off 188 * here is relative to the prog itself instead of the main prog. 189 * This array has one entry for each xlated bpf insn. 190 * 191 * jited_off is the byte off to the end of the jited insn. 192 * 193 * Hence, with 194 * insn_start: 195 * The first bpf insn off of the prog. The insn off 196 * here is relative to the main prog. 197 * e.g. if prog is a subprog, insn_start > 0 198 * linfo_idx: 199 * The prog's idx to prog->aux->linfo and jited_linfo 200 * 201 * jited_linfo[linfo_idx] = prog->bpf_func 202 * 203 * For i > linfo_idx, 204 * 205 * jited_linfo[i] = prog->bpf_func + 206 * insn_to_jit_off[linfo[i].insn_off - insn_start - 1] 207 */ 208 void bpf_prog_fill_jited_linfo(struct bpf_prog *prog, 209 const u32 *insn_to_jit_off) 210 { 211 u32 linfo_idx, insn_start, insn_end, nr_linfo, i; 212 const struct bpf_line_info *linfo; 213 void **jited_linfo; 214 215 if (!prog->aux->jited_linfo || prog->aux->func_idx > prog->aux->func_cnt) 216 /* Userspace did not provide linfo */ 217 return; 218 219 linfo_idx = prog->aux->linfo_idx; 220 linfo = &prog->aux->linfo[linfo_idx]; 221 insn_start = linfo[0].insn_off; 222 insn_end = insn_start + prog->len; 223 224 jited_linfo = &prog->aux->jited_linfo[linfo_idx]; 225 jited_linfo[0] = prog->bpf_func; 226 227 nr_linfo = prog->aux->nr_linfo - linfo_idx; 228 229 for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++) 230 /* The verifier ensures that linfo[i].insn_off is 231 * strictly increasing 232 */ 233 jited_linfo[i] = prog->bpf_func + 234 insn_to_jit_off[linfo[i].insn_off - insn_start - 1]; 235 } 236 237 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, 238 gfp_t gfp_extra_flags) 239 { 240 gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags); 241 struct bpf_prog *fp; 242 u32 pages; 243 244 size = round_up(size, PAGE_SIZE); 245 pages = size / PAGE_SIZE; 246 if (pages <= fp_old->pages) 247 return fp_old; 248 249 fp = __vmalloc(size, gfp_flags); 250 if (fp) { 251 memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); 252 fp->pages = pages; 253 fp->aux->prog = fp; 254 255 /* We keep fp->aux from fp_old around in the new 256 * reallocated structure. 257 */ 258 fp_old->aux = NULL; 259 fp_old->stats = NULL; 260 fp_old->active = NULL; 261 __bpf_prog_free(fp_old); 262 } 263 264 return fp; 265 } 266 267 void __bpf_prog_free(struct bpf_prog *fp) 268 { 269 if (fp->aux) { 270 mutex_destroy(&fp->aux->used_maps_mutex); 271 mutex_destroy(&fp->aux->dst_mutex); 272 kfree(fp->aux->poke_tab); 273 kfree(fp->aux); 274 } 275 free_percpu(fp->stats); 276 free_percpu(fp->active); 277 vfree(fp); 278 } 279 280 int bpf_prog_calc_tag(struct bpf_prog *fp) 281 { 282 const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64); 283 u32 raw_size = bpf_prog_tag_scratch_size(fp); 284 u32 digest[SHA1_DIGEST_WORDS]; 285 u32 ws[SHA1_WORKSPACE_WORDS]; 286 u32 i, bsize, psize, blocks; 287 struct bpf_insn *dst; 288 bool was_ld_map; 289 u8 *raw, *todo; 290 __be32 *result; 291 __be64 *bits; 292 293 raw = vmalloc(raw_size); 294 if (!raw) 295 return -ENOMEM; 296 297 sha1_init(digest); 298 memset(ws, 0, sizeof(ws)); 299 300 /* We need to take out the map fd for the digest calculation 301 * since they are unstable from user space side. 302 */ 303 dst = (void *)raw; 304 for (i = 0, was_ld_map = false; i < fp->len; i++) { 305 dst[i] = fp->insnsi[i]; 306 if (!was_ld_map && 307 dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) && 308 (dst[i].src_reg == BPF_PSEUDO_MAP_FD || 309 dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) { 310 was_ld_map = true; 311 dst[i].imm = 0; 312 } else if (was_ld_map && 313 dst[i].code == 0 && 314 dst[i].dst_reg == 0 && 315 dst[i].src_reg == 0 && 316 dst[i].off == 0) { 317 was_ld_map = false; 318 dst[i].imm = 0; 319 } else { 320 was_ld_map = false; 321 } 322 } 323 324 psize = bpf_prog_insn_size(fp); 325 memset(&raw[psize], 0, raw_size - psize); 326 raw[psize++] = 0x80; 327 328 bsize = round_up(psize, SHA1_BLOCK_SIZE); 329 blocks = bsize / SHA1_BLOCK_SIZE; 330 todo = raw; 331 if (bsize - psize >= sizeof(__be64)) { 332 bits = (__be64 *)(todo + bsize - sizeof(__be64)); 333 } else { 334 bits = (__be64 *)(todo + bsize + bits_offset); 335 blocks++; 336 } 337 *bits = cpu_to_be64((psize - 1) << 3); 338 339 while (blocks--) { 340 sha1_transform(digest, todo, ws); 341 todo += SHA1_BLOCK_SIZE; 342 } 343 344 result = (__force __be32 *)digest; 345 for (i = 0; i < SHA1_DIGEST_WORDS; i++) 346 result[i] = cpu_to_be32(digest[i]); 347 memcpy(fp->tag, result, sizeof(fp->tag)); 348 349 vfree(raw); 350 return 0; 351 } 352 353 static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old, 354 s32 end_new, s32 curr, const bool probe_pass) 355 { 356 const s64 imm_min = S32_MIN, imm_max = S32_MAX; 357 s32 delta = end_new - end_old; 358 s64 imm = insn->imm; 359 360 if (curr < pos && curr + imm + 1 >= end_old) 361 imm += delta; 362 else if (curr >= end_new && curr + imm + 1 < end_new) 363 imm -= delta; 364 if (imm < imm_min || imm > imm_max) 365 return -ERANGE; 366 if (!probe_pass) 367 insn->imm = imm; 368 return 0; 369 } 370 371 static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old, 372 s32 end_new, s32 curr, const bool probe_pass) 373 { 374 s64 off_min, off_max, off; 375 s32 delta = end_new - end_old; 376 377 if (insn->code == (BPF_JMP32 | BPF_JA)) { 378 off = insn->imm; 379 off_min = S32_MIN; 380 off_max = S32_MAX; 381 } else { 382 off = insn->off; 383 off_min = S16_MIN; 384 off_max = S16_MAX; 385 } 386 387 if (curr < pos && curr + off + 1 >= end_old) 388 off += delta; 389 else if (curr >= end_new && curr + off + 1 < end_new) 390 off -= delta; 391 if (off < off_min || off > off_max) 392 return -ERANGE; 393 if (!probe_pass) { 394 if (insn->code == (BPF_JMP32 | BPF_JA)) 395 insn->imm = off; 396 else 397 insn->off = off; 398 } 399 return 0; 400 } 401 402 static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old, 403 s32 end_new, const bool probe_pass) 404 { 405 u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0); 406 struct bpf_insn *insn = prog->insnsi; 407 int ret = 0; 408 409 for (i = 0; i < insn_cnt; i++, insn++) { 410 u8 code; 411 412 /* In the probing pass we still operate on the original, 413 * unpatched image in order to check overflows before we 414 * do any other adjustments. Therefore skip the patchlet. 415 */ 416 if (probe_pass && i == pos) { 417 i = end_new; 418 insn = prog->insnsi + end_old; 419 } 420 if (bpf_pseudo_func(insn)) { 421 ret = bpf_adj_delta_to_imm(insn, pos, end_old, 422 end_new, i, probe_pass); 423 if (ret) 424 return ret; 425 continue; 426 } 427 code = insn->code; 428 if ((BPF_CLASS(code) != BPF_JMP && 429 BPF_CLASS(code) != BPF_JMP32) || 430 BPF_OP(code) == BPF_EXIT) 431 continue; 432 /* Adjust offset of jmps if we cross patch boundaries. */ 433 if (BPF_OP(code) == BPF_CALL) { 434 if (insn->src_reg != BPF_PSEUDO_CALL) 435 continue; 436 ret = bpf_adj_delta_to_imm(insn, pos, end_old, 437 end_new, i, probe_pass); 438 } else { 439 ret = bpf_adj_delta_to_off(insn, pos, end_old, 440 end_new, i, probe_pass); 441 } 442 if (ret) 443 break; 444 } 445 446 return ret; 447 } 448 449 static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta) 450 { 451 struct bpf_line_info *linfo; 452 u32 i, nr_linfo; 453 454 nr_linfo = prog->aux->nr_linfo; 455 if (!nr_linfo || !delta) 456 return; 457 458 linfo = prog->aux->linfo; 459 460 for (i = 0; i < nr_linfo; i++) 461 if (off < linfo[i].insn_off) 462 break; 463 464 /* Push all off < linfo[i].insn_off by delta */ 465 for (; i < nr_linfo; i++) 466 linfo[i].insn_off += delta; 467 } 468 469 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, 470 const struct bpf_insn *patch, u32 len) 471 { 472 u32 insn_adj_cnt, insn_rest, insn_delta = len - 1; 473 const u32 cnt_max = S16_MAX; 474 struct bpf_prog *prog_adj; 475 int err; 476 477 /* Since our patchlet doesn't expand the image, we're done. */ 478 if (insn_delta == 0) { 479 memcpy(prog->insnsi + off, patch, sizeof(*patch)); 480 return prog; 481 } 482 483 insn_adj_cnt = prog->len + insn_delta; 484 485 /* Reject anything that would potentially let the insn->off 486 * target overflow when we have excessive program expansions. 487 * We need to probe here before we do any reallocation where 488 * we afterwards may not fail anymore. 489 */ 490 if (insn_adj_cnt > cnt_max && 491 (err = bpf_adj_branches(prog, off, off + 1, off + len, true))) 492 return ERR_PTR(err); 493 494 /* Several new instructions need to be inserted. Make room 495 * for them. Likely, there's no need for a new allocation as 496 * last page could have large enough tailroom. 497 */ 498 prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt), 499 GFP_USER); 500 if (!prog_adj) 501 return ERR_PTR(-ENOMEM); 502 503 prog_adj->len = insn_adj_cnt; 504 505 /* Patching happens in 3 steps: 506 * 507 * 1) Move over tail of insnsi from next instruction onwards, 508 * so we can patch the single target insn with one or more 509 * new ones (patching is always from 1 to n insns, n > 0). 510 * 2) Inject new instructions at the target location. 511 * 3) Adjust branch offsets if necessary. 512 */ 513 insn_rest = insn_adj_cnt - off - len; 514 515 memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1, 516 sizeof(*patch) * insn_rest); 517 memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len); 518 519 /* We are guaranteed to not fail at this point, otherwise 520 * the ship has sailed to reverse to the original state. An 521 * overflow cannot happen at this point. 522 */ 523 BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false)); 524 525 bpf_adj_linfo(prog_adj, off, insn_delta); 526 527 return prog_adj; 528 } 529 530 int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt) 531 { 532 /* Branch offsets can't overflow when program is shrinking, no need 533 * to call bpf_adj_branches(..., true) here 534 */ 535 memmove(prog->insnsi + off, prog->insnsi + off + cnt, 536 sizeof(struct bpf_insn) * (prog->len - off - cnt)); 537 prog->len -= cnt; 538 539 return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false)); 540 } 541 542 static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp) 543 { 544 int i; 545 546 for (i = 0; i < fp->aux->real_func_cnt; i++) 547 bpf_prog_kallsyms_del(fp->aux->func[i]); 548 } 549 550 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp) 551 { 552 bpf_prog_kallsyms_del_subprogs(fp); 553 bpf_prog_kallsyms_del(fp); 554 } 555 556 #ifdef CONFIG_BPF_JIT 557 /* All BPF JIT sysctl knobs here. */ 558 int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON); 559 int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON); 560 int bpf_jit_harden __read_mostly; 561 long bpf_jit_limit __read_mostly; 562 long bpf_jit_limit_max __read_mostly; 563 564 static void 565 bpf_prog_ksym_set_addr(struct bpf_prog *prog) 566 { 567 WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog)); 568 569 prog->aux->ksym.start = (unsigned long) prog->bpf_func; 570 prog->aux->ksym.end = prog->aux->ksym.start + prog->jited_len; 571 } 572 573 static void 574 bpf_prog_ksym_set_name(struct bpf_prog *prog) 575 { 576 char *sym = prog->aux->ksym.name; 577 const char *end = sym + KSYM_NAME_LEN; 578 const struct btf_type *type; 579 const char *func_name; 580 581 BUILD_BUG_ON(sizeof("bpf_prog_") + 582 sizeof(prog->tag) * 2 + 583 /* name has been null terminated. 584 * We should need +1 for the '_' preceding 585 * the name. However, the null character 586 * is double counted between the name and the 587 * sizeof("bpf_prog_") above, so we omit 588 * the +1 here. 589 */ 590 sizeof(prog->aux->name) > KSYM_NAME_LEN); 591 592 sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_"); 593 sym = bin2hex(sym, prog->tag, sizeof(prog->tag)); 594 595 /* prog->aux->name will be ignored if full btf name is available */ 596 if (prog->aux->func_info_cnt && prog->aux->func_idx < prog->aux->func_info_cnt) { 597 type = btf_type_by_id(prog->aux->btf, 598 prog->aux->func_info[prog->aux->func_idx].type_id); 599 func_name = btf_name_by_offset(prog->aux->btf, type->name_off); 600 snprintf(sym, (size_t)(end - sym), "_%s", func_name); 601 return; 602 } 603 604 if (prog->aux->name[0]) 605 snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name); 606 else 607 *sym = 0; 608 } 609 610 static unsigned long bpf_get_ksym_start(struct latch_tree_node *n) 611 { 612 return container_of(n, struct bpf_ksym, tnode)->start; 613 } 614 615 static __always_inline bool bpf_tree_less(struct latch_tree_node *a, 616 struct latch_tree_node *b) 617 { 618 return bpf_get_ksym_start(a) < bpf_get_ksym_start(b); 619 } 620 621 static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n) 622 { 623 unsigned long val = (unsigned long)key; 624 const struct bpf_ksym *ksym; 625 626 ksym = container_of(n, struct bpf_ksym, tnode); 627 628 if (val < ksym->start) 629 return -1; 630 /* Ensure that we detect return addresses as part of the program, when 631 * the final instruction is a call for a program part of the stack 632 * trace. Therefore, do val > ksym->end instead of val >= ksym->end. 633 */ 634 if (val > ksym->end) 635 return 1; 636 637 return 0; 638 } 639 640 static const struct latch_tree_ops bpf_tree_ops = { 641 .less = bpf_tree_less, 642 .comp = bpf_tree_comp, 643 }; 644 645 static DEFINE_SPINLOCK(bpf_lock); 646 static LIST_HEAD(bpf_kallsyms); 647 static struct latch_tree_root bpf_tree __cacheline_aligned; 648 649 void bpf_ksym_add(struct bpf_ksym *ksym) 650 { 651 spin_lock_bh(&bpf_lock); 652 WARN_ON_ONCE(!list_empty(&ksym->lnode)); 653 list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms); 654 latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops); 655 spin_unlock_bh(&bpf_lock); 656 } 657 658 static void __bpf_ksym_del(struct bpf_ksym *ksym) 659 { 660 if (list_empty(&ksym->lnode)) 661 return; 662 663 latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops); 664 list_del_rcu(&ksym->lnode); 665 } 666 667 void bpf_ksym_del(struct bpf_ksym *ksym) 668 { 669 spin_lock_bh(&bpf_lock); 670 __bpf_ksym_del(ksym); 671 spin_unlock_bh(&bpf_lock); 672 } 673 674 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp) 675 { 676 return fp->jited && !bpf_prog_was_classic(fp); 677 } 678 679 void bpf_prog_kallsyms_add(struct bpf_prog *fp) 680 { 681 if (!bpf_prog_kallsyms_candidate(fp) || 682 !bpf_capable()) 683 return; 684 685 bpf_prog_ksym_set_addr(fp); 686 bpf_prog_ksym_set_name(fp); 687 fp->aux->ksym.prog = true; 688 689 bpf_ksym_add(&fp->aux->ksym); 690 } 691 692 void bpf_prog_kallsyms_del(struct bpf_prog *fp) 693 { 694 if (!bpf_prog_kallsyms_candidate(fp)) 695 return; 696 697 bpf_ksym_del(&fp->aux->ksym); 698 } 699 700 static struct bpf_ksym *bpf_ksym_find(unsigned long addr) 701 { 702 struct latch_tree_node *n; 703 704 n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops); 705 return n ? container_of(n, struct bpf_ksym, tnode) : NULL; 706 } 707 708 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, 709 unsigned long *off, char *sym) 710 { 711 struct bpf_ksym *ksym; 712 char *ret = NULL; 713 714 rcu_read_lock(); 715 ksym = bpf_ksym_find(addr); 716 if (ksym) { 717 unsigned long symbol_start = ksym->start; 718 unsigned long symbol_end = ksym->end; 719 720 strncpy(sym, ksym->name, KSYM_NAME_LEN); 721 722 ret = sym; 723 if (size) 724 *size = symbol_end - symbol_start; 725 if (off) 726 *off = addr - symbol_start; 727 } 728 rcu_read_unlock(); 729 730 return ret; 731 } 732 733 bool is_bpf_text_address(unsigned long addr) 734 { 735 bool ret; 736 737 rcu_read_lock(); 738 ret = bpf_ksym_find(addr) != NULL; 739 rcu_read_unlock(); 740 741 return ret; 742 } 743 744 struct bpf_prog *bpf_prog_ksym_find(unsigned long addr) 745 { 746 struct bpf_ksym *ksym = bpf_ksym_find(addr); 747 748 return ksym && ksym->prog ? 749 container_of(ksym, struct bpf_prog_aux, ksym)->prog : 750 NULL; 751 } 752 753 const struct exception_table_entry *search_bpf_extables(unsigned long addr) 754 { 755 const struct exception_table_entry *e = NULL; 756 struct bpf_prog *prog; 757 758 rcu_read_lock(); 759 prog = bpf_prog_ksym_find(addr); 760 if (!prog) 761 goto out; 762 if (!prog->aux->num_exentries) 763 goto out; 764 765 e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr); 766 out: 767 rcu_read_unlock(); 768 return e; 769 } 770 771 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, 772 char *sym) 773 { 774 struct bpf_ksym *ksym; 775 unsigned int it = 0; 776 int ret = -ERANGE; 777 778 if (!bpf_jit_kallsyms_enabled()) 779 return ret; 780 781 rcu_read_lock(); 782 list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) { 783 if (it++ != symnum) 784 continue; 785 786 strncpy(sym, ksym->name, KSYM_NAME_LEN); 787 788 *value = ksym->start; 789 *type = BPF_SYM_ELF_TYPE; 790 791 ret = 0; 792 break; 793 } 794 rcu_read_unlock(); 795 796 return ret; 797 } 798 799 int bpf_jit_add_poke_descriptor(struct bpf_prog *prog, 800 struct bpf_jit_poke_descriptor *poke) 801 { 802 struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab; 803 static const u32 poke_tab_max = 1024; 804 u32 slot = prog->aux->size_poke_tab; 805 u32 size = slot + 1; 806 807 if (size > poke_tab_max) 808 return -ENOSPC; 809 if (poke->tailcall_target || poke->tailcall_target_stable || 810 poke->tailcall_bypass || poke->adj_off || poke->bypass_addr) 811 return -EINVAL; 812 813 switch (poke->reason) { 814 case BPF_POKE_REASON_TAIL_CALL: 815 if (!poke->tail_call.map) 816 return -EINVAL; 817 break; 818 default: 819 return -EINVAL; 820 } 821 822 tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL); 823 if (!tab) 824 return -ENOMEM; 825 826 memcpy(&tab[slot], poke, sizeof(*poke)); 827 prog->aux->size_poke_tab = size; 828 prog->aux->poke_tab = tab; 829 830 return slot; 831 } 832 833 /* 834 * BPF program pack allocator. 835 * 836 * Most BPF programs are pretty small. Allocating a hole page for each 837 * program is sometime a waste. Many small bpf program also adds pressure 838 * to instruction TLB. To solve this issue, we introduce a BPF program pack 839 * allocator. The prog_pack allocator uses HPAGE_PMD_SIZE page (2MB on x86) 840 * to host BPF programs. 841 */ 842 #define BPF_PROG_CHUNK_SHIFT 6 843 #define BPF_PROG_CHUNK_SIZE (1 << BPF_PROG_CHUNK_SHIFT) 844 #define BPF_PROG_CHUNK_MASK (~(BPF_PROG_CHUNK_SIZE - 1)) 845 846 struct bpf_prog_pack { 847 struct list_head list; 848 void *ptr; 849 unsigned long bitmap[]; 850 }; 851 852 void bpf_jit_fill_hole_with_zero(void *area, unsigned int size) 853 { 854 memset(area, 0, size); 855 } 856 857 #define BPF_PROG_SIZE_TO_NBITS(size) (round_up(size, BPF_PROG_CHUNK_SIZE) / BPF_PROG_CHUNK_SIZE) 858 859 static DEFINE_MUTEX(pack_mutex); 860 static LIST_HEAD(pack_list); 861 862 /* PMD_SIZE is not available in some special config, e.g. ARCH=arm with 863 * CONFIG_MMU=n. Use PAGE_SIZE in these cases. 864 */ 865 #ifdef PMD_SIZE 866 #define BPF_PROG_PACK_SIZE (PMD_SIZE * num_possible_nodes()) 867 #else 868 #define BPF_PROG_PACK_SIZE PAGE_SIZE 869 #endif 870 871 #define BPF_PROG_CHUNK_COUNT (BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE) 872 873 static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns) 874 { 875 struct bpf_prog_pack *pack; 876 877 pack = kzalloc(struct_size(pack, bitmap, BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)), 878 GFP_KERNEL); 879 if (!pack) 880 return NULL; 881 pack->ptr = bpf_jit_alloc_exec(BPF_PROG_PACK_SIZE); 882 if (!pack->ptr) { 883 kfree(pack); 884 return NULL; 885 } 886 bpf_fill_ill_insns(pack->ptr, BPF_PROG_PACK_SIZE); 887 bitmap_zero(pack->bitmap, BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE); 888 list_add_tail(&pack->list, &pack_list); 889 890 set_vm_flush_reset_perms(pack->ptr); 891 set_memory_rox((unsigned long)pack->ptr, BPF_PROG_PACK_SIZE / PAGE_SIZE); 892 return pack; 893 } 894 895 void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns) 896 { 897 unsigned int nbits = BPF_PROG_SIZE_TO_NBITS(size); 898 struct bpf_prog_pack *pack; 899 unsigned long pos; 900 void *ptr = NULL; 901 902 mutex_lock(&pack_mutex); 903 if (size > BPF_PROG_PACK_SIZE) { 904 size = round_up(size, PAGE_SIZE); 905 ptr = bpf_jit_alloc_exec(size); 906 if (ptr) { 907 bpf_fill_ill_insns(ptr, size); 908 set_vm_flush_reset_perms(ptr); 909 set_memory_rox((unsigned long)ptr, size / PAGE_SIZE); 910 } 911 goto out; 912 } 913 list_for_each_entry(pack, &pack_list, list) { 914 pos = bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0, 915 nbits, 0); 916 if (pos < BPF_PROG_CHUNK_COUNT) 917 goto found_free_area; 918 } 919 920 pack = alloc_new_pack(bpf_fill_ill_insns); 921 if (!pack) 922 goto out; 923 924 pos = 0; 925 926 found_free_area: 927 bitmap_set(pack->bitmap, pos, nbits); 928 ptr = (void *)(pack->ptr) + (pos << BPF_PROG_CHUNK_SHIFT); 929 930 out: 931 mutex_unlock(&pack_mutex); 932 return ptr; 933 } 934 935 void bpf_prog_pack_free(struct bpf_binary_header *hdr) 936 { 937 struct bpf_prog_pack *pack = NULL, *tmp; 938 unsigned int nbits; 939 unsigned long pos; 940 941 mutex_lock(&pack_mutex); 942 if (hdr->size > BPF_PROG_PACK_SIZE) { 943 bpf_jit_free_exec(hdr); 944 goto out; 945 } 946 947 list_for_each_entry(tmp, &pack_list, list) { 948 if ((void *)hdr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > (void *)hdr) { 949 pack = tmp; 950 break; 951 } 952 } 953 954 if (WARN_ONCE(!pack, "bpf_prog_pack bug\n")) 955 goto out; 956 957 nbits = BPF_PROG_SIZE_TO_NBITS(hdr->size); 958 pos = ((unsigned long)hdr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT; 959 960 WARN_ONCE(bpf_arch_text_invalidate(hdr, hdr->size), 961 "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n"); 962 963 bitmap_clear(pack->bitmap, pos, nbits); 964 if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0, 965 BPF_PROG_CHUNK_COUNT, 0) == 0) { 966 list_del(&pack->list); 967 bpf_jit_free_exec(pack->ptr); 968 kfree(pack); 969 } 970 out: 971 mutex_unlock(&pack_mutex); 972 } 973 974 static atomic_long_t bpf_jit_current; 975 976 /* Can be overridden by an arch's JIT compiler if it has a custom, 977 * dedicated BPF backend memory area, or if neither of the two 978 * below apply. 979 */ 980 u64 __weak bpf_jit_alloc_exec_limit(void) 981 { 982 #if defined(MODULES_VADDR) 983 return MODULES_END - MODULES_VADDR; 984 #else 985 return VMALLOC_END - VMALLOC_START; 986 #endif 987 } 988 989 static int __init bpf_jit_charge_init(void) 990 { 991 /* Only used as heuristic here to derive limit. */ 992 bpf_jit_limit_max = bpf_jit_alloc_exec_limit(); 993 bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 1, 994 PAGE_SIZE), LONG_MAX); 995 return 0; 996 } 997 pure_initcall(bpf_jit_charge_init); 998 999 int bpf_jit_charge_modmem(u32 size) 1000 { 1001 if (atomic_long_add_return(size, &bpf_jit_current) > READ_ONCE(bpf_jit_limit)) { 1002 if (!bpf_capable()) { 1003 atomic_long_sub(size, &bpf_jit_current); 1004 return -EPERM; 1005 } 1006 } 1007 1008 return 0; 1009 } 1010 1011 void bpf_jit_uncharge_modmem(u32 size) 1012 { 1013 atomic_long_sub(size, &bpf_jit_current); 1014 } 1015 1016 void *__weak bpf_jit_alloc_exec(unsigned long size) 1017 { 1018 return module_alloc(size); 1019 } 1020 1021 void __weak bpf_jit_free_exec(void *addr) 1022 { 1023 module_memfree(addr); 1024 } 1025 1026 struct bpf_binary_header * 1027 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, 1028 unsigned int alignment, 1029 bpf_jit_fill_hole_t bpf_fill_ill_insns) 1030 { 1031 struct bpf_binary_header *hdr; 1032 u32 size, hole, start; 1033 1034 WARN_ON_ONCE(!is_power_of_2(alignment) || 1035 alignment > BPF_IMAGE_ALIGNMENT); 1036 1037 /* Most of BPF filters are really small, but if some of them 1038 * fill a page, allow at least 128 extra bytes to insert a 1039 * random section of illegal instructions. 1040 */ 1041 size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE); 1042 1043 if (bpf_jit_charge_modmem(size)) 1044 return NULL; 1045 hdr = bpf_jit_alloc_exec(size); 1046 if (!hdr) { 1047 bpf_jit_uncharge_modmem(size); 1048 return NULL; 1049 } 1050 1051 /* Fill space with illegal/arch-dep instructions. */ 1052 bpf_fill_ill_insns(hdr, size); 1053 1054 hdr->size = size; 1055 hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)), 1056 PAGE_SIZE - sizeof(*hdr)); 1057 start = get_random_u32_below(hole) & ~(alignment - 1); 1058 1059 /* Leave a random number of instructions before BPF code. */ 1060 *image_ptr = &hdr->image[start]; 1061 1062 return hdr; 1063 } 1064 1065 void bpf_jit_binary_free(struct bpf_binary_header *hdr) 1066 { 1067 u32 size = hdr->size; 1068 1069 bpf_jit_free_exec(hdr); 1070 bpf_jit_uncharge_modmem(size); 1071 } 1072 1073 /* Allocate jit binary from bpf_prog_pack allocator. 1074 * Since the allocated memory is RO+X, the JIT engine cannot write directly 1075 * to the memory. To solve this problem, a RW buffer is also allocated at 1076 * as the same time. The JIT engine should calculate offsets based on the 1077 * RO memory address, but write JITed program to the RW buffer. Once the 1078 * JIT engine finishes, it calls bpf_jit_binary_pack_finalize, which copies 1079 * the JITed program to the RO memory. 1080 */ 1081 struct bpf_binary_header * 1082 bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr, 1083 unsigned int alignment, 1084 struct bpf_binary_header **rw_header, 1085 u8 **rw_image, 1086 bpf_jit_fill_hole_t bpf_fill_ill_insns) 1087 { 1088 struct bpf_binary_header *ro_header; 1089 u32 size, hole, start; 1090 1091 WARN_ON_ONCE(!is_power_of_2(alignment) || 1092 alignment > BPF_IMAGE_ALIGNMENT); 1093 1094 /* add 16 bytes for a random section of illegal instructions */ 1095 size = round_up(proglen + sizeof(*ro_header) + 16, BPF_PROG_CHUNK_SIZE); 1096 1097 if (bpf_jit_charge_modmem(size)) 1098 return NULL; 1099 ro_header = bpf_prog_pack_alloc(size, bpf_fill_ill_insns); 1100 if (!ro_header) { 1101 bpf_jit_uncharge_modmem(size); 1102 return NULL; 1103 } 1104 1105 *rw_header = kvmalloc(size, GFP_KERNEL); 1106 if (!*rw_header) { 1107 bpf_arch_text_copy(&ro_header->size, &size, sizeof(size)); 1108 bpf_prog_pack_free(ro_header); 1109 bpf_jit_uncharge_modmem(size); 1110 return NULL; 1111 } 1112 1113 /* Fill space with illegal/arch-dep instructions. */ 1114 bpf_fill_ill_insns(*rw_header, size); 1115 (*rw_header)->size = size; 1116 1117 hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)), 1118 BPF_PROG_CHUNK_SIZE - sizeof(*ro_header)); 1119 start = get_random_u32_below(hole) & ~(alignment - 1); 1120 1121 *image_ptr = &ro_header->image[start]; 1122 *rw_image = &(*rw_header)->image[start]; 1123 1124 return ro_header; 1125 } 1126 1127 /* Copy JITed text from rw_header to its final location, the ro_header. */ 1128 int bpf_jit_binary_pack_finalize(struct bpf_prog *prog, 1129 struct bpf_binary_header *ro_header, 1130 struct bpf_binary_header *rw_header) 1131 { 1132 void *ptr; 1133 1134 ptr = bpf_arch_text_copy(ro_header, rw_header, rw_header->size); 1135 1136 kvfree(rw_header); 1137 1138 if (IS_ERR(ptr)) { 1139 bpf_prog_pack_free(ro_header); 1140 return PTR_ERR(ptr); 1141 } 1142 return 0; 1143 } 1144 1145 /* bpf_jit_binary_pack_free is called in two different scenarios: 1146 * 1) when the program is freed after; 1147 * 2) when the JIT engine fails (before bpf_jit_binary_pack_finalize). 1148 * For case 2), we need to free both the RO memory and the RW buffer. 1149 * 1150 * bpf_jit_binary_pack_free requires proper ro_header->size. However, 1151 * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size 1152 * must be set with either bpf_jit_binary_pack_finalize (normal path) or 1153 * bpf_arch_text_copy (when jit fails). 1154 */ 1155 void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header, 1156 struct bpf_binary_header *rw_header) 1157 { 1158 u32 size = ro_header->size; 1159 1160 bpf_prog_pack_free(ro_header); 1161 kvfree(rw_header); 1162 bpf_jit_uncharge_modmem(size); 1163 } 1164 1165 struct bpf_binary_header * 1166 bpf_jit_binary_pack_hdr(const struct bpf_prog *fp) 1167 { 1168 unsigned long real_start = (unsigned long)fp->bpf_func; 1169 unsigned long addr; 1170 1171 addr = real_start & BPF_PROG_CHUNK_MASK; 1172 return (void *)addr; 1173 } 1174 1175 static inline struct bpf_binary_header * 1176 bpf_jit_binary_hdr(const struct bpf_prog *fp) 1177 { 1178 unsigned long real_start = (unsigned long)fp->bpf_func; 1179 unsigned long addr; 1180 1181 addr = real_start & PAGE_MASK; 1182 return (void *)addr; 1183 } 1184 1185 /* This symbol is only overridden by archs that have different 1186 * requirements than the usual eBPF JITs, f.e. when they only 1187 * implement cBPF JIT, do not set images read-only, etc. 1188 */ 1189 void __weak bpf_jit_free(struct bpf_prog *fp) 1190 { 1191 if (fp->jited) { 1192 struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp); 1193 1194 bpf_jit_binary_free(hdr); 1195 WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp)); 1196 } 1197 1198 bpf_prog_unlock_free(fp); 1199 } 1200 1201 int bpf_jit_get_func_addr(const struct bpf_prog *prog, 1202 const struct bpf_insn *insn, bool extra_pass, 1203 u64 *func_addr, bool *func_addr_fixed) 1204 { 1205 s16 off = insn->off; 1206 s32 imm = insn->imm; 1207 u8 *addr; 1208 int err; 1209 1210 *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL; 1211 if (!*func_addr_fixed) { 1212 /* Place-holder address till the last pass has collected 1213 * all addresses for JITed subprograms in which case we 1214 * can pick them up from prog->aux. 1215 */ 1216 if (!extra_pass) 1217 addr = NULL; 1218 else if (prog->aux->func && 1219 off >= 0 && off < prog->aux->real_func_cnt) 1220 addr = (u8 *)prog->aux->func[off]->bpf_func; 1221 else 1222 return -EINVAL; 1223 } else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL && 1224 bpf_jit_supports_far_kfunc_call()) { 1225 err = bpf_get_kfunc_addr(prog, insn->imm, insn->off, &addr); 1226 if (err) 1227 return err; 1228 } else { 1229 /* Address of a BPF helper call. Since part of the core 1230 * kernel, it's always at a fixed location. __bpf_call_base 1231 * and the helper with imm relative to it are both in core 1232 * kernel. 1233 */ 1234 addr = (u8 *)__bpf_call_base + imm; 1235 } 1236 1237 *func_addr = (unsigned long)addr; 1238 return 0; 1239 } 1240 1241 static int bpf_jit_blind_insn(const struct bpf_insn *from, 1242 const struct bpf_insn *aux, 1243 struct bpf_insn *to_buff, 1244 bool emit_zext) 1245 { 1246 struct bpf_insn *to = to_buff; 1247 u32 imm_rnd = get_random_u32(); 1248 s16 off; 1249 1250 BUILD_BUG_ON(BPF_REG_AX + 1 != MAX_BPF_JIT_REG); 1251 BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG); 1252 1253 /* Constraints on AX register: 1254 * 1255 * AX register is inaccessible from user space. It is mapped in 1256 * all JITs, and used here for constant blinding rewrites. It is 1257 * typically "stateless" meaning its contents are only valid within 1258 * the executed instruction, but not across several instructions. 1259 * There are a few exceptions however which are further detailed 1260 * below. 1261 * 1262 * Constant blinding is only used by JITs, not in the interpreter. 1263 * The interpreter uses AX in some occasions as a local temporary 1264 * register e.g. in DIV or MOD instructions. 1265 * 1266 * In restricted circumstances, the verifier can also use the AX 1267 * register for rewrites as long as they do not interfere with 1268 * the above cases! 1269 */ 1270 if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX) 1271 goto out; 1272 1273 if (from->imm == 0 && 1274 (from->code == (BPF_ALU | BPF_MOV | BPF_K) || 1275 from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) { 1276 *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg); 1277 goto out; 1278 } 1279 1280 switch (from->code) { 1281 case BPF_ALU | BPF_ADD | BPF_K: 1282 case BPF_ALU | BPF_SUB | BPF_K: 1283 case BPF_ALU | BPF_AND | BPF_K: 1284 case BPF_ALU | BPF_OR | BPF_K: 1285 case BPF_ALU | BPF_XOR | BPF_K: 1286 case BPF_ALU | BPF_MUL | BPF_K: 1287 case BPF_ALU | BPF_MOV | BPF_K: 1288 case BPF_ALU | BPF_DIV | BPF_K: 1289 case BPF_ALU | BPF_MOD | BPF_K: 1290 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 1291 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 1292 *to++ = BPF_ALU32_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off); 1293 break; 1294 1295 case BPF_ALU64 | BPF_ADD | BPF_K: 1296 case BPF_ALU64 | BPF_SUB | BPF_K: 1297 case BPF_ALU64 | BPF_AND | BPF_K: 1298 case BPF_ALU64 | BPF_OR | BPF_K: 1299 case BPF_ALU64 | BPF_XOR | BPF_K: 1300 case BPF_ALU64 | BPF_MUL | BPF_K: 1301 case BPF_ALU64 | BPF_MOV | BPF_K: 1302 case BPF_ALU64 | BPF_DIV | BPF_K: 1303 case BPF_ALU64 | BPF_MOD | BPF_K: 1304 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 1305 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 1306 *to++ = BPF_ALU64_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off); 1307 break; 1308 1309 case BPF_JMP | BPF_JEQ | BPF_K: 1310 case BPF_JMP | BPF_JNE | BPF_K: 1311 case BPF_JMP | BPF_JGT | BPF_K: 1312 case BPF_JMP | BPF_JLT | BPF_K: 1313 case BPF_JMP | BPF_JGE | BPF_K: 1314 case BPF_JMP | BPF_JLE | BPF_K: 1315 case BPF_JMP | BPF_JSGT | BPF_K: 1316 case BPF_JMP | BPF_JSLT | BPF_K: 1317 case BPF_JMP | BPF_JSGE | BPF_K: 1318 case BPF_JMP | BPF_JSLE | BPF_K: 1319 case BPF_JMP | BPF_JSET | BPF_K: 1320 /* Accommodate for extra offset in case of a backjump. */ 1321 off = from->off; 1322 if (off < 0) 1323 off -= 2; 1324 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 1325 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 1326 *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off); 1327 break; 1328 1329 case BPF_JMP32 | BPF_JEQ | BPF_K: 1330 case BPF_JMP32 | BPF_JNE | BPF_K: 1331 case BPF_JMP32 | BPF_JGT | BPF_K: 1332 case BPF_JMP32 | BPF_JLT | BPF_K: 1333 case BPF_JMP32 | BPF_JGE | BPF_K: 1334 case BPF_JMP32 | BPF_JLE | BPF_K: 1335 case BPF_JMP32 | BPF_JSGT | BPF_K: 1336 case BPF_JMP32 | BPF_JSLT | BPF_K: 1337 case BPF_JMP32 | BPF_JSGE | BPF_K: 1338 case BPF_JMP32 | BPF_JSLE | BPF_K: 1339 case BPF_JMP32 | BPF_JSET | BPF_K: 1340 /* Accommodate for extra offset in case of a backjump. */ 1341 off = from->off; 1342 if (off < 0) 1343 off -= 2; 1344 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 1345 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 1346 *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX, 1347 off); 1348 break; 1349 1350 case BPF_LD | BPF_IMM | BPF_DW: 1351 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm); 1352 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 1353 *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32); 1354 *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX); 1355 break; 1356 case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */ 1357 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm); 1358 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 1359 if (emit_zext) 1360 *to++ = BPF_ZEXT_REG(BPF_REG_AX); 1361 *to++ = BPF_ALU64_REG(BPF_OR, aux[0].dst_reg, BPF_REG_AX); 1362 break; 1363 1364 case BPF_ST | BPF_MEM | BPF_DW: 1365 case BPF_ST | BPF_MEM | BPF_W: 1366 case BPF_ST | BPF_MEM | BPF_H: 1367 case BPF_ST | BPF_MEM | BPF_B: 1368 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm); 1369 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd); 1370 *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off); 1371 break; 1372 } 1373 out: 1374 return to - to_buff; 1375 } 1376 1377 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other, 1378 gfp_t gfp_extra_flags) 1379 { 1380 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags; 1381 struct bpf_prog *fp; 1382 1383 fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags); 1384 if (fp != NULL) { 1385 /* aux->prog still points to the fp_other one, so 1386 * when promoting the clone to the real program, 1387 * this still needs to be adapted. 1388 */ 1389 memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE); 1390 } 1391 1392 return fp; 1393 } 1394 1395 static void bpf_prog_clone_free(struct bpf_prog *fp) 1396 { 1397 /* aux was stolen by the other clone, so we cannot free 1398 * it from this path! It will be freed eventually by the 1399 * other program on release. 1400 * 1401 * At this point, we don't need a deferred release since 1402 * clone is guaranteed to not be locked. 1403 */ 1404 fp->aux = NULL; 1405 fp->stats = NULL; 1406 fp->active = NULL; 1407 __bpf_prog_free(fp); 1408 } 1409 1410 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other) 1411 { 1412 /* We have to repoint aux->prog to self, as we don't 1413 * know whether fp here is the clone or the original. 1414 */ 1415 fp->aux->prog = fp; 1416 bpf_prog_clone_free(fp_other); 1417 } 1418 1419 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog) 1420 { 1421 struct bpf_insn insn_buff[16], aux[2]; 1422 struct bpf_prog *clone, *tmp; 1423 int insn_delta, insn_cnt; 1424 struct bpf_insn *insn; 1425 int i, rewritten; 1426 1427 if (!prog->blinding_requested || prog->blinded) 1428 return prog; 1429 1430 clone = bpf_prog_clone_create(prog, GFP_USER); 1431 if (!clone) 1432 return ERR_PTR(-ENOMEM); 1433 1434 insn_cnt = clone->len; 1435 insn = clone->insnsi; 1436 1437 for (i = 0; i < insn_cnt; i++, insn++) { 1438 if (bpf_pseudo_func(insn)) { 1439 /* ld_imm64 with an address of bpf subprog is not 1440 * a user controlled constant. Don't randomize it, 1441 * since it will conflict with jit_subprogs() logic. 1442 */ 1443 insn++; 1444 i++; 1445 continue; 1446 } 1447 1448 /* We temporarily need to hold the original ld64 insn 1449 * so that we can still access the first part in the 1450 * second blinding run. 1451 */ 1452 if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) && 1453 insn[1].code == 0) 1454 memcpy(aux, insn, sizeof(aux)); 1455 1456 rewritten = bpf_jit_blind_insn(insn, aux, insn_buff, 1457 clone->aux->verifier_zext); 1458 if (!rewritten) 1459 continue; 1460 1461 tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten); 1462 if (IS_ERR(tmp)) { 1463 /* Patching may have repointed aux->prog during 1464 * realloc from the original one, so we need to 1465 * fix it up here on error. 1466 */ 1467 bpf_jit_prog_release_other(prog, clone); 1468 return tmp; 1469 } 1470 1471 clone = tmp; 1472 insn_delta = rewritten - 1; 1473 1474 /* Walk new program and skip insns we just inserted. */ 1475 insn = clone->insnsi + i + insn_delta; 1476 insn_cnt += insn_delta; 1477 i += insn_delta; 1478 } 1479 1480 clone->blinded = 1; 1481 return clone; 1482 } 1483 #endif /* CONFIG_BPF_JIT */ 1484 1485 /* Base function for offset calculation. Needs to go into .text section, 1486 * therefore keeping it non-static as well; will also be used by JITs 1487 * anyway later on, so do not let the compiler omit it. This also needs 1488 * to go into kallsyms for correlation from e.g. bpftool, so naming 1489 * must not change. 1490 */ 1491 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) 1492 { 1493 return 0; 1494 } 1495 EXPORT_SYMBOL_GPL(__bpf_call_base); 1496 1497 /* All UAPI available opcodes. */ 1498 #define BPF_INSN_MAP(INSN_2, INSN_3) \ 1499 /* 32 bit ALU operations. */ \ 1500 /* Register based. */ \ 1501 INSN_3(ALU, ADD, X), \ 1502 INSN_3(ALU, SUB, X), \ 1503 INSN_3(ALU, AND, X), \ 1504 INSN_3(ALU, OR, X), \ 1505 INSN_3(ALU, LSH, X), \ 1506 INSN_3(ALU, RSH, X), \ 1507 INSN_3(ALU, XOR, X), \ 1508 INSN_3(ALU, MUL, X), \ 1509 INSN_3(ALU, MOV, X), \ 1510 INSN_3(ALU, ARSH, X), \ 1511 INSN_3(ALU, DIV, X), \ 1512 INSN_3(ALU, MOD, X), \ 1513 INSN_2(ALU, NEG), \ 1514 INSN_3(ALU, END, TO_BE), \ 1515 INSN_3(ALU, END, TO_LE), \ 1516 /* Immediate based. */ \ 1517 INSN_3(ALU, ADD, K), \ 1518 INSN_3(ALU, SUB, K), \ 1519 INSN_3(ALU, AND, K), \ 1520 INSN_3(ALU, OR, K), \ 1521 INSN_3(ALU, LSH, K), \ 1522 INSN_3(ALU, RSH, K), \ 1523 INSN_3(ALU, XOR, K), \ 1524 INSN_3(ALU, MUL, K), \ 1525 INSN_3(ALU, MOV, K), \ 1526 INSN_3(ALU, ARSH, K), \ 1527 INSN_3(ALU, DIV, K), \ 1528 INSN_3(ALU, MOD, K), \ 1529 /* 64 bit ALU operations. */ \ 1530 /* Register based. */ \ 1531 INSN_3(ALU64, ADD, X), \ 1532 INSN_3(ALU64, SUB, X), \ 1533 INSN_3(ALU64, AND, X), \ 1534 INSN_3(ALU64, OR, X), \ 1535 INSN_3(ALU64, LSH, X), \ 1536 INSN_3(ALU64, RSH, X), \ 1537 INSN_3(ALU64, XOR, X), \ 1538 INSN_3(ALU64, MUL, X), \ 1539 INSN_3(ALU64, MOV, X), \ 1540 INSN_3(ALU64, ARSH, X), \ 1541 INSN_3(ALU64, DIV, X), \ 1542 INSN_3(ALU64, MOD, X), \ 1543 INSN_2(ALU64, NEG), \ 1544 INSN_3(ALU64, END, TO_LE), \ 1545 /* Immediate based. */ \ 1546 INSN_3(ALU64, ADD, K), \ 1547 INSN_3(ALU64, SUB, K), \ 1548 INSN_3(ALU64, AND, K), \ 1549 INSN_3(ALU64, OR, K), \ 1550 INSN_3(ALU64, LSH, K), \ 1551 INSN_3(ALU64, RSH, K), \ 1552 INSN_3(ALU64, XOR, K), \ 1553 INSN_3(ALU64, MUL, K), \ 1554 INSN_3(ALU64, MOV, K), \ 1555 INSN_3(ALU64, ARSH, K), \ 1556 INSN_3(ALU64, DIV, K), \ 1557 INSN_3(ALU64, MOD, K), \ 1558 /* Call instruction. */ \ 1559 INSN_2(JMP, CALL), \ 1560 /* Exit instruction. */ \ 1561 INSN_2(JMP, EXIT), \ 1562 /* 32-bit Jump instructions. */ \ 1563 /* Register based. */ \ 1564 INSN_3(JMP32, JEQ, X), \ 1565 INSN_3(JMP32, JNE, X), \ 1566 INSN_3(JMP32, JGT, X), \ 1567 INSN_3(JMP32, JLT, X), \ 1568 INSN_3(JMP32, JGE, X), \ 1569 INSN_3(JMP32, JLE, X), \ 1570 INSN_3(JMP32, JSGT, X), \ 1571 INSN_3(JMP32, JSLT, X), \ 1572 INSN_3(JMP32, JSGE, X), \ 1573 INSN_3(JMP32, JSLE, X), \ 1574 INSN_3(JMP32, JSET, X), \ 1575 /* Immediate based. */ \ 1576 INSN_3(JMP32, JEQ, K), \ 1577 INSN_3(JMP32, JNE, K), \ 1578 INSN_3(JMP32, JGT, K), \ 1579 INSN_3(JMP32, JLT, K), \ 1580 INSN_3(JMP32, JGE, K), \ 1581 INSN_3(JMP32, JLE, K), \ 1582 INSN_3(JMP32, JSGT, K), \ 1583 INSN_3(JMP32, JSLT, K), \ 1584 INSN_3(JMP32, JSGE, K), \ 1585 INSN_3(JMP32, JSLE, K), \ 1586 INSN_3(JMP32, JSET, K), \ 1587 /* Jump instructions. */ \ 1588 /* Register based. */ \ 1589 INSN_3(JMP, JEQ, X), \ 1590 INSN_3(JMP, JNE, X), \ 1591 INSN_3(JMP, JGT, X), \ 1592 INSN_3(JMP, JLT, X), \ 1593 INSN_3(JMP, JGE, X), \ 1594 INSN_3(JMP, JLE, X), \ 1595 INSN_3(JMP, JSGT, X), \ 1596 INSN_3(JMP, JSLT, X), \ 1597 INSN_3(JMP, JSGE, X), \ 1598 INSN_3(JMP, JSLE, X), \ 1599 INSN_3(JMP, JSET, X), \ 1600 /* Immediate based. */ \ 1601 INSN_3(JMP, JEQ, K), \ 1602 INSN_3(JMP, JNE, K), \ 1603 INSN_3(JMP, JGT, K), \ 1604 INSN_3(JMP, JLT, K), \ 1605 INSN_3(JMP, JGE, K), \ 1606 INSN_3(JMP, JLE, K), \ 1607 INSN_3(JMP, JSGT, K), \ 1608 INSN_3(JMP, JSLT, K), \ 1609 INSN_3(JMP, JSGE, K), \ 1610 INSN_3(JMP, JSLE, K), \ 1611 INSN_3(JMP, JSET, K), \ 1612 INSN_2(JMP, JA), \ 1613 INSN_2(JMP32, JA), \ 1614 /* Store instructions. */ \ 1615 /* Register based. */ \ 1616 INSN_3(STX, MEM, B), \ 1617 INSN_3(STX, MEM, H), \ 1618 INSN_3(STX, MEM, W), \ 1619 INSN_3(STX, MEM, DW), \ 1620 INSN_3(STX, ATOMIC, W), \ 1621 INSN_3(STX, ATOMIC, DW), \ 1622 /* Immediate based. */ \ 1623 INSN_3(ST, MEM, B), \ 1624 INSN_3(ST, MEM, H), \ 1625 INSN_3(ST, MEM, W), \ 1626 INSN_3(ST, MEM, DW), \ 1627 /* Load instructions. */ \ 1628 /* Register based. */ \ 1629 INSN_3(LDX, MEM, B), \ 1630 INSN_3(LDX, MEM, H), \ 1631 INSN_3(LDX, MEM, W), \ 1632 INSN_3(LDX, MEM, DW), \ 1633 INSN_3(LDX, MEMSX, B), \ 1634 INSN_3(LDX, MEMSX, H), \ 1635 INSN_3(LDX, MEMSX, W), \ 1636 /* Immediate based. */ \ 1637 INSN_3(LD, IMM, DW) 1638 1639 bool bpf_opcode_in_insntable(u8 code) 1640 { 1641 #define BPF_INSN_2_TBL(x, y) [BPF_##x | BPF_##y] = true 1642 #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true 1643 static const bool public_insntable[256] = { 1644 [0 ... 255] = false, 1645 /* Now overwrite non-defaults ... */ 1646 BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL), 1647 /* UAPI exposed, but rewritten opcodes. cBPF carry-over. */ 1648 [BPF_LD | BPF_ABS | BPF_B] = true, 1649 [BPF_LD | BPF_ABS | BPF_H] = true, 1650 [BPF_LD | BPF_ABS | BPF_W] = true, 1651 [BPF_LD | BPF_IND | BPF_B] = true, 1652 [BPF_LD | BPF_IND | BPF_H] = true, 1653 [BPF_LD | BPF_IND | BPF_W] = true, 1654 }; 1655 #undef BPF_INSN_3_TBL 1656 #undef BPF_INSN_2_TBL 1657 return public_insntable[code]; 1658 } 1659 1660 #ifndef CONFIG_BPF_JIT_ALWAYS_ON 1661 /** 1662 * ___bpf_prog_run - run eBPF program on a given context 1663 * @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers 1664 * @insn: is the array of eBPF instructions 1665 * 1666 * Decode and execute eBPF instructions. 1667 * 1668 * Return: whatever value is in %BPF_R0 at program exit 1669 */ 1670 static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn) 1671 { 1672 #define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y 1673 #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z 1674 static const void * const jumptable[256] __annotate_jump_table = { 1675 [0 ... 255] = &&default_label, 1676 /* Now overwrite non-defaults ... */ 1677 BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL), 1678 /* Non-UAPI available opcodes. */ 1679 [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS, 1680 [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL, 1681 [BPF_ST | BPF_NOSPEC] = &&ST_NOSPEC, 1682 [BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B, 1683 [BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H, 1684 [BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W, 1685 [BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW, 1686 [BPF_LDX | BPF_PROBE_MEMSX | BPF_B] = &&LDX_PROBE_MEMSX_B, 1687 [BPF_LDX | BPF_PROBE_MEMSX | BPF_H] = &&LDX_PROBE_MEMSX_H, 1688 [BPF_LDX | BPF_PROBE_MEMSX | BPF_W] = &&LDX_PROBE_MEMSX_W, 1689 }; 1690 #undef BPF_INSN_3_LBL 1691 #undef BPF_INSN_2_LBL 1692 u32 tail_call_cnt = 0; 1693 1694 #define CONT ({ insn++; goto select_insn; }) 1695 #define CONT_JMP ({ insn++; goto select_insn; }) 1696 1697 select_insn: 1698 goto *jumptable[insn->code]; 1699 1700 /* Explicitly mask the register-based shift amounts with 63 or 31 1701 * to avoid undefined behavior. Normally this won't affect the 1702 * generated code, for example, in case of native 64 bit archs such 1703 * as x86-64 or arm64, the compiler is optimizing the AND away for 1704 * the interpreter. In case of JITs, each of the JIT backends compiles 1705 * the BPF shift operations to machine instructions which produce 1706 * implementation-defined results in such a case; the resulting 1707 * contents of the register may be arbitrary, but program behaviour 1708 * as a whole remains defined. In other words, in case of JIT backends, 1709 * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation. 1710 */ 1711 /* ALU (shifts) */ 1712 #define SHT(OPCODE, OP) \ 1713 ALU64_##OPCODE##_X: \ 1714 DST = DST OP (SRC & 63); \ 1715 CONT; \ 1716 ALU_##OPCODE##_X: \ 1717 DST = (u32) DST OP ((u32) SRC & 31); \ 1718 CONT; \ 1719 ALU64_##OPCODE##_K: \ 1720 DST = DST OP IMM; \ 1721 CONT; \ 1722 ALU_##OPCODE##_K: \ 1723 DST = (u32) DST OP (u32) IMM; \ 1724 CONT; 1725 /* ALU (rest) */ 1726 #define ALU(OPCODE, OP) \ 1727 ALU64_##OPCODE##_X: \ 1728 DST = DST OP SRC; \ 1729 CONT; \ 1730 ALU_##OPCODE##_X: \ 1731 DST = (u32) DST OP (u32) SRC; \ 1732 CONT; \ 1733 ALU64_##OPCODE##_K: \ 1734 DST = DST OP IMM; \ 1735 CONT; \ 1736 ALU_##OPCODE##_K: \ 1737 DST = (u32) DST OP (u32) IMM; \ 1738 CONT; 1739 ALU(ADD, +) 1740 ALU(SUB, -) 1741 ALU(AND, &) 1742 ALU(OR, |) 1743 ALU(XOR, ^) 1744 ALU(MUL, *) 1745 SHT(LSH, <<) 1746 SHT(RSH, >>) 1747 #undef SHT 1748 #undef ALU 1749 ALU_NEG: 1750 DST = (u32) -DST; 1751 CONT; 1752 ALU64_NEG: 1753 DST = -DST; 1754 CONT; 1755 ALU_MOV_X: 1756 switch (OFF) { 1757 case 0: 1758 DST = (u32) SRC; 1759 break; 1760 case 8: 1761 DST = (u32)(s8) SRC; 1762 break; 1763 case 16: 1764 DST = (u32)(s16) SRC; 1765 break; 1766 } 1767 CONT; 1768 ALU_MOV_K: 1769 DST = (u32) IMM; 1770 CONT; 1771 ALU64_MOV_X: 1772 switch (OFF) { 1773 case 0: 1774 DST = SRC; 1775 break; 1776 case 8: 1777 DST = (s8) SRC; 1778 break; 1779 case 16: 1780 DST = (s16) SRC; 1781 break; 1782 case 32: 1783 DST = (s32) SRC; 1784 break; 1785 } 1786 CONT; 1787 ALU64_MOV_K: 1788 DST = IMM; 1789 CONT; 1790 LD_IMM_DW: 1791 DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; 1792 insn++; 1793 CONT; 1794 ALU_ARSH_X: 1795 DST = (u64) (u32) (((s32) DST) >> (SRC & 31)); 1796 CONT; 1797 ALU_ARSH_K: 1798 DST = (u64) (u32) (((s32) DST) >> IMM); 1799 CONT; 1800 ALU64_ARSH_X: 1801 (*(s64 *) &DST) >>= (SRC & 63); 1802 CONT; 1803 ALU64_ARSH_K: 1804 (*(s64 *) &DST) >>= IMM; 1805 CONT; 1806 ALU64_MOD_X: 1807 switch (OFF) { 1808 case 0: 1809 div64_u64_rem(DST, SRC, &AX); 1810 DST = AX; 1811 break; 1812 case 1: 1813 AX = div64_s64(DST, SRC); 1814 DST = DST - AX * SRC; 1815 break; 1816 } 1817 CONT; 1818 ALU_MOD_X: 1819 switch (OFF) { 1820 case 0: 1821 AX = (u32) DST; 1822 DST = do_div(AX, (u32) SRC); 1823 break; 1824 case 1: 1825 AX = abs((s32)DST); 1826 AX = do_div(AX, abs((s32)SRC)); 1827 if ((s32)DST < 0) 1828 DST = (u32)-AX; 1829 else 1830 DST = (u32)AX; 1831 break; 1832 } 1833 CONT; 1834 ALU64_MOD_K: 1835 switch (OFF) { 1836 case 0: 1837 div64_u64_rem(DST, IMM, &AX); 1838 DST = AX; 1839 break; 1840 case 1: 1841 AX = div64_s64(DST, IMM); 1842 DST = DST - AX * IMM; 1843 break; 1844 } 1845 CONT; 1846 ALU_MOD_K: 1847 switch (OFF) { 1848 case 0: 1849 AX = (u32) DST; 1850 DST = do_div(AX, (u32) IMM); 1851 break; 1852 case 1: 1853 AX = abs((s32)DST); 1854 AX = do_div(AX, abs((s32)IMM)); 1855 if ((s32)DST < 0) 1856 DST = (u32)-AX; 1857 else 1858 DST = (u32)AX; 1859 break; 1860 } 1861 CONT; 1862 ALU64_DIV_X: 1863 switch (OFF) { 1864 case 0: 1865 DST = div64_u64(DST, SRC); 1866 break; 1867 case 1: 1868 DST = div64_s64(DST, SRC); 1869 break; 1870 } 1871 CONT; 1872 ALU_DIV_X: 1873 switch (OFF) { 1874 case 0: 1875 AX = (u32) DST; 1876 do_div(AX, (u32) SRC); 1877 DST = (u32) AX; 1878 break; 1879 case 1: 1880 AX = abs((s32)DST); 1881 do_div(AX, abs((s32)SRC)); 1882 if (((s32)DST < 0) == ((s32)SRC < 0)) 1883 DST = (u32)AX; 1884 else 1885 DST = (u32)-AX; 1886 break; 1887 } 1888 CONT; 1889 ALU64_DIV_K: 1890 switch (OFF) { 1891 case 0: 1892 DST = div64_u64(DST, IMM); 1893 break; 1894 case 1: 1895 DST = div64_s64(DST, IMM); 1896 break; 1897 } 1898 CONT; 1899 ALU_DIV_K: 1900 switch (OFF) { 1901 case 0: 1902 AX = (u32) DST; 1903 do_div(AX, (u32) IMM); 1904 DST = (u32) AX; 1905 break; 1906 case 1: 1907 AX = abs((s32)DST); 1908 do_div(AX, abs((s32)IMM)); 1909 if (((s32)DST < 0) == ((s32)IMM < 0)) 1910 DST = (u32)AX; 1911 else 1912 DST = (u32)-AX; 1913 break; 1914 } 1915 CONT; 1916 ALU_END_TO_BE: 1917 switch (IMM) { 1918 case 16: 1919 DST = (__force u16) cpu_to_be16(DST); 1920 break; 1921 case 32: 1922 DST = (__force u32) cpu_to_be32(DST); 1923 break; 1924 case 64: 1925 DST = (__force u64) cpu_to_be64(DST); 1926 break; 1927 } 1928 CONT; 1929 ALU_END_TO_LE: 1930 switch (IMM) { 1931 case 16: 1932 DST = (__force u16) cpu_to_le16(DST); 1933 break; 1934 case 32: 1935 DST = (__force u32) cpu_to_le32(DST); 1936 break; 1937 case 64: 1938 DST = (__force u64) cpu_to_le64(DST); 1939 break; 1940 } 1941 CONT; 1942 ALU64_END_TO_LE: 1943 switch (IMM) { 1944 case 16: 1945 DST = (__force u16) __swab16(DST); 1946 break; 1947 case 32: 1948 DST = (__force u32) __swab32(DST); 1949 break; 1950 case 64: 1951 DST = (__force u64) __swab64(DST); 1952 break; 1953 } 1954 CONT; 1955 1956 /* CALL */ 1957 JMP_CALL: 1958 /* Function call scratches BPF_R1-BPF_R5 registers, 1959 * preserves BPF_R6-BPF_R9, and stores return value 1960 * into BPF_R0. 1961 */ 1962 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, 1963 BPF_R4, BPF_R5); 1964 CONT; 1965 1966 JMP_CALL_ARGS: 1967 BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2, 1968 BPF_R3, BPF_R4, 1969 BPF_R5, 1970 insn + insn->off + 1); 1971 CONT; 1972 1973 JMP_TAIL_CALL: { 1974 struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2; 1975 struct bpf_array *array = container_of(map, struct bpf_array, map); 1976 struct bpf_prog *prog; 1977 u32 index = BPF_R3; 1978 1979 if (unlikely(index >= array->map.max_entries)) 1980 goto out; 1981 1982 if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT)) 1983 goto out; 1984 1985 tail_call_cnt++; 1986 1987 prog = READ_ONCE(array->ptrs[index]); 1988 if (!prog) 1989 goto out; 1990 1991 /* ARG1 at this point is guaranteed to point to CTX from 1992 * the verifier side due to the fact that the tail call is 1993 * handled like a helper, that is, bpf_tail_call_proto, 1994 * where arg1_type is ARG_PTR_TO_CTX. 1995 */ 1996 insn = prog->insnsi; 1997 goto select_insn; 1998 out: 1999 CONT; 2000 } 2001 JMP_JA: 2002 insn += insn->off; 2003 CONT; 2004 JMP32_JA: 2005 insn += insn->imm; 2006 CONT; 2007 JMP_EXIT: 2008 return BPF_R0; 2009 /* JMP */ 2010 #define COND_JMP(SIGN, OPCODE, CMP_OP) \ 2011 JMP_##OPCODE##_X: \ 2012 if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) { \ 2013 insn += insn->off; \ 2014 CONT_JMP; \ 2015 } \ 2016 CONT; \ 2017 JMP32_##OPCODE##_X: \ 2018 if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) { \ 2019 insn += insn->off; \ 2020 CONT_JMP; \ 2021 } \ 2022 CONT; \ 2023 JMP_##OPCODE##_K: \ 2024 if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) { \ 2025 insn += insn->off; \ 2026 CONT_JMP; \ 2027 } \ 2028 CONT; \ 2029 JMP32_##OPCODE##_K: \ 2030 if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) { \ 2031 insn += insn->off; \ 2032 CONT_JMP; \ 2033 } \ 2034 CONT; 2035 COND_JMP(u, JEQ, ==) 2036 COND_JMP(u, JNE, !=) 2037 COND_JMP(u, JGT, >) 2038 COND_JMP(u, JLT, <) 2039 COND_JMP(u, JGE, >=) 2040 COND_JMP(u, JLE, <=) 2041 COND_JMP(u, JSET, &) 2042 COND_JMP(s, JSGT, >) 2043 COND_JMP(s, JSLT, <) 2044 COND_JMP(s, JSGE, >=) 2045 COND_JMP(s, JSLE, <=) 2046 #undef COND_JMP 2047 /* ST, STX and LDX*/ 2048 ST_NOSPEC: 2049 /* Speculation barrier for mitigating Speculative Store Bypass. 2050 * In case of arm64, we rely on the firmware mitigation as 2051 * controlled via the ssbd kernel parameter. Whenever the 2052 * mitigation is enabled, it works for all of the kernel code 2053 * with no need to provide any additional instructions here. 2054 * In case of x86, we use 'lfence' insn for mitigation. We 2055 * reuse preexisting logic from Spectre v1 mitigation that 2056 * happens to produce the required code on x86 for v4 as well. 2057 */ 2058 barrier_nospec(); 2059 CONT; 2060 #define LDST(SIZEOP, SIZE) \ 2061 STX_MEM_##SIZEOP: \ 2062 *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ 2063 CONT; \ 2064 ST_MEM_##SIZEOP: \ 2065 *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ 2066 CONT; \ 2067 LDX_MEM_##SIZEOP: \ 2068 DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ 2069 CONT; \ 2070 LDX_PROBE_MEM_##SIZEOP: \ 2071 bpf_probe_read_kernel_common(&DST, sizeof(SIZE), \ 2072 (const void *)(long) (SRC + insn->off)); \ 2073 DST = *((SIZE *)&DST); \ 2074 CONT; 2075 2076 LDST(B, u8) 2077 LDST(H, u16) 2078 LDST(W, u32) 2079 LDST(DW, u64) 2080 #undef LDST 2081 2082 #define LDSX(SIZEOP, SIZE) \ 2083 LDX_MEMSX_##SIZEOP: \ 2084 DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ 2085 CONT; \ 2086 LDX_PROBE_MEMSX_##SIZEOP: \ 2087 bpf_probe_read_kernel_common(&DST, sizeof(SIZE), \ 2088 (const void *)(long) (SRC + insn->off)); \ 2089 DST = *((SIZE *)&DST); \ 2090 CONT; 2091 2092 LDSX(B, s8) 2093 LDSX(H, s16) 2094 LDSX(W, s32) 2095 #undef LDSX 2096 2097 #define ATOMIC_ALU_OP(BOP, KOP) \ 2098 case BOP: \ 2099 if (BPF_SIZE(insn->code) == BPF_W) \ 2100 atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \ 2101 (DST + insn->off)); \ 2102 else \ 2103 atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \ 2104 (DST + insn->off)); \ 2105 break; \ 2106 case BOP | BPF_FETCH: \ 2107 if (BPF_SIZE(insn->code) == BPF_W) \ 2108 SRC = (u32) atomic_fetch_##KOP( \ 2109 (u32) SRC, \ 2110 (atomic_t *)(unsigned long) (DST + insn->off)); \ 2111 else \ 2112 SRC = (u64) atomic64_fetch_##KOP( \ 2113 (u64) SRC, \ 2114 (atomic64_t *)(unsigned long) (DST + insn->off)); \ 2115 break; 2116 2117 STX_ATOMIC_DW: 2118 STX_ATOMIC_W: 2119 switch (IMM) { 2120 ATOMIC_ALU_OP(BPF_ADD, add) 2121 ATOMIC_ALU_OP(BPF_AND, and) 2122 ATOMIC_ALU_OP(BPF_OR, or) 2123 ATOMIC_ALU_OP(BPF_XOR, xor) 2124 #undef ATOMIC_ALU_OP 2125 2126 case BPF_XCHG: 2127 if (BPF_SIZE(insn->code) == BPF_W) 2128 SRC = (u32) atomic_xchg( 2129 (atomic_t *)(unsigned long) (DST + insn->off), 2130 (u32) SRC); 2131 else 2132 SRC = (u64) atomic64_xchg( 2133 (atomic64_t *)(unsigned long) (DST + insn->off), 2134 (u64) SRC); 2135 break; 2136 case BPF_CMPXCHG: 2137 if (BPF_SIZE(insn->code) == BPF_W) 2138 BPF_R0 = (u32) atomic_cmpxchg( 2139 (atomic_t *)(unsigned long) (DST + insn->off), 2140 (u32) BPF_R0, (u32) SRC); 2141 else 2142 BPF_R0 = (u64) atomic64_cmpxchg( 2143 (atomic64_t *)(unsigned long) (DST + insn->off), 2144 (u64) BPF_R0, (u64) SRC); 2145 break; 2146 2147 default: 2148 goto default_label; 2149 } 2150 CONT; 2151 2152 default_label: 2153 /* If we ever reach this, we have a bug somewhere. Die hard here 2154 * instead of just returning 0; we could be somewhere in a subprog, 2155 * so execution could continue otherwise which we do /not/ want. 2156 * 2157 * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable(). 2158 */ 2159 pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n", 2160 insn->code, insn->imm); 2161 BUG_ON(1); 2162 return 0; 2163 } 2164 2165 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size 2166 #define DEFINE_BPF_PROG_RUN(stack_size) \ 2167 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \ 2168 { \ 2169 u64 stack[stack_size / sizeof(u64)]; \ 2170 u64 regs[MAX_BPF_EXT_REG] = {}; \ 2171 \ 2172 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ 2173 ARG1 = (u64) (unsigned long) ctx; \ 2174 return ___bpf_prog_run(regs, insn); \ 2175 } 2176 2177 #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size 2178 #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \ 2179 static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \ 2180 const struct bpf_insn *insn) \ 2181 { \ 2182 u64 stack[stack_size / sizeof(u64)]; \ 2183 u64 regs[MAX_BPF_EXT_REG]; \ 2184 \ 2185 FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \ 2186 BPF_R1 = r1; \ 2187 BPF_R2 = r2; \ 2188 BPF_R3 = r3; \ 2189 BPF_R4 = r4; \ 2190 BPF_R5 = r5; \ 2191 return ___bpf_prog_run(regs, insn); \ 2192 } 2193 2194 #define EVAL1(FN, X) FN(X) 2195 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y) 2196 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y) 2197 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y) 2198 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y) 2199 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y) 2200 2201 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192); 2202 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384); 2203 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512); 2204 2205 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192); 2206 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384); 2207 EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512); 2208 2209 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size), 2210 2211 static unsigned int (*interpreters[])(const void *ctx, 2212 const struct bpf_insn *insn) = { 2213 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) 2214 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) 2215 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) 2216 }; 2217 #undef PROG_NAME_LIST 2218 #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size), 2219 static __maybe_unused 2220 u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, 2221 const struct bpf_insn *insn) = { 2222 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) 2223 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) 2224 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) 2225 }; 2226 #undef PROG_NAME_LIST 2227 2228 #ifdef CONFIG_BPF_SYSCALL 2229 void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth) 2230 { 2231 stack_depth = max_t(u32, stack_depth, 1); 2232 insn->off = (s16) insn->imm; 2233 insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] - 2234 __bpf_call_base_args; 2235 insn->code = BPF_JMP | BPF_CALL_ARGS; 2236 } 2237 #endif 2238 #else 2239 static unsigned int __bpf_prog_ret0_warn(const void *ctx, 2240 const struct bpf_insn *insn) 2241 { 2242 /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON 2243 * is not working properly, so warn about it! 2244 */ 2245 WARN_ON_ONCE(1); 2246 return 0; 2247 } 2248 #endif 2249 2250 bool bpf_prog_map_compatible(struct bpf_map *map, 2251 const struct bpf_prog *fp) 2252 { 2253 enum bpf_prog_type prog_type = resolve_prog_type(fp); 2254 bool ret; 2255 2256 if (fp->kprobe_override) 2257 return false; 2258 2259 /* XDP programs inserted into maps are not guaranteed to run on 2260 * a particular netdev (and can run outside driver context entirely 2261 * in the case of devmap and cpumap). Until device checks 2262 * are implemented, prohibit adding dev-bound programs to program maps. 2263 */ 2264 if (bpf_prog_is_dev_bound(fp->aux)) 2265 return false; 2266 2267 spin_lock(&map->owner.lock); 2268 if (!map->owner.type) { 2269 /* There's no owner yet where we could check for 2270 * compatibility. 2271 */ 2272 map->owner.type = prog_type; 2273 map->owner.jited = fp->jited; 2274 map->owner.xdp_has_frags = fp->aux->xdp_has_frags; 2275 ret = true; 2276 } else { 2277 ret = map->owner.type == prog_type && 2278 map->owner.jited == fp->jited && 2279 map->owner.xdp_has_frags == fp->aux->xdp_has_frags; 2280 } 2281 spin_unlock(&map->owner.lock); 2282 2283 return ret; 2284 } 2285 2286 static int bpf_check_tail_call(const struct bpf_prog *fp) 2287 { 2288 struct bpf_prog_aux *aux = fp->aux; 2289 int i, ret = 0; 2290 2291 mutex_lock(&aux->used_maps_mutex); 2292 for (i = 0; i < aux->used_map_cnt; i++) { 2293 struct bpf_map *map = aux->used_maps[i]; 2294 2295 if (!map_type_contains_progs(map)) 2296 continue; 2297 2298 if (!bpf_prog_map_compatible(map, fp)) { 2299 ret = -EINVAL; 2300 goto out; 2301 } 2302 } 2303 2304 out: 2305 mutex_unlock(&aux->used_maps_mutex); 2306 return ret; 2307 } 2308 2309 static void bpf_prog_select_func(struct bpf_prog *fp) 2310 { 2311 #ifndef CONFIG_BPF_JIT_ALWAYS_ON 2312 u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1); 2313 2314 fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1]; 2315 #else 2316 fp->bpf_func = __bpf_prog_ret0_warn; 2317 #endif 2318 } 2319 2320 /** 2321 * bpf_prog_select_runtime - select exec runtime for BPF program 2322 * @fp: bpf_prog populated with BPF program 2323 * @err: pointer to error variable 2324 * 2325 * Try to JIT eBPF program, if JIT is not available, use interpreter. 2326 * The BPF program will be executed via bpf_prog_run() function. 2327 * 2328 * Return: the &fp argument along with &err set to 0 for success or 2329 * a negative errno code on failure 2330 */ 2331 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err) 2332 { 2333 /* In case of BPF to BPF calls, verifier did all the prep 2334 * work with regards to JITing, etc. 2335 */ 2336 bool jit_needed = false; 2337 2338 if (fp->bpf_func) 2339 goto finalize; 2340 2341 if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) || 2342 bpf_prog_has_kfunc_call(fp)) 2343 jit_needed = true; 2344 2345 bpf_prog_select_func(fp); 2346 2347 /* eBPF JITs can rewrite the program in case constant 2348 * blinding is active. However, in case of error during 2349 * blinding, bpf_int_jit_compile() must always return a 2350 * valid program, which in this case would simply not 2351 * be JITed, but falls back to the interpreter. 2352 */ 2353 if (!bpf_prog_is_offloaded(fp->aux)) { 2354 *err = bpf_prog_alloc_jited_linfo(fp); 2355 if (*err) 2356 return fp; 2357 2358 fp = bpf_int_jit_compile(fp); 2359 bpf_prog_jit_attempt_done(fp); 2360 if (!fp->jited && jit_needed) { 2361 *err = -ENOTSUPP; 2362 return fp; 2363 } 2364 } else { 2365 *err = bpf_prog_offload_compile(fp); 2366 if (*err) 2367 return fp; 2368 } 2369 2370 finalize: 2371 bpf_prog_lock_ro(fp); 2372 2373 /* The tail call compatibility check can only be done at 2374 * this late stage as we need to determine, if we deal 2375 * with JITed or non JITed program concatenations and not 2376 * all eBPF JITs might immediately support all features. 2377 */ 2378 *err = bpf_check_tail_call(fp); 2379 2380 return fp; 2381 } 2382 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); 2383 2384 static unsigned int __bpf_prog_ret1(const void *ctx, 2385 const struct bpf_insn *insn) 2386 { 2387 return 1; 2388 } 2389 2390 static struct bpf_prog_dummy { 2391 struct bpf_prog prog; 2392 } dummy_bpf_prog = { 2393 .prog = { 2394 .bpf_func = __bpf_prog_ret1, 2395 }, 2396 }; 2397 2398 struct bpf_empty_prog_array bpf_empty_prog_array = { 2399 .null_prog = NULL, 2400 }; 2401 EXPORT_SYMBOL(bpf_empty_prog_array); 2402 2403 struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags) 2404 { 2405 if (prog_cnt) 2406 return kzalloc(sizeof(struct bpf_prog_array) + 2407 sizeof(struct bpf_prog_array_item) * 2408 (prog_cnt + 1), 2409 flags); 2410 2411 return &bpf_empty_prog_array.hdr; 2412 } 2413 2414 void bpf_prog_array_free(struct bpf_prog_array *progs) 2415 { 2416 if (!progs || progs == &bpf_empty_prog_array.hdr) 2417 return; 2418 kfree_rcu(progs, rcu); 2419 } 2420 2421 static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu) 2422 { 2423 struct bpf_prog_array *progs; 2424 2425 /* If RCU Tasks Trace grace period implies RCU grace period, there is 2426 * no need to call kfree_rcu(), just call kfree() directly. 2427 */ 2428 progs = container_of(rcu, struct bpf_prog_array, rcu); 2429 if (rcu_trace_implies_rcu_gp()) 2430 kfree(progs); 2431 else 2432 kfree_rcu(progs, rcu); 2433 } 2434 2435 void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs) 2436 { 2437 if (!progs || progs == &bpf_empty_prog_array.hdr) 2438 return; 2439 call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb); 2440 } 2441 2442 int bpf_prog_array_length(struct bpf_prog_array *array) 2443 { 2444 struct bpf_prog_array_item *item; 2445 u32 cnt = 0; 2446 2447 for (item = array->items; item->prog; item++) 2448 if (item->prog != &dummy_bpf_prog.prog) 2449 cnt++; 2450 return cnt; 2451 } 2452 2453 bool bpf_prog_array_is_empty(struct bpf_prog_array *array) 2454 { 2455 struct bpf_prog_array_item *item; 2456 2457 for (item = array->items; item->prog; item++) 2458 if (item->prog != &dummy_bpf_prog.prog) 2459 return false; 2460 return true; 2461 } 2462 2463 static bool bpf_prog_array_copy_core(struct bpf_prog_array *array, 2464 u32 *prog_ids, 2465 u32 request_cnt) 2466 { 2467 struct bpf_prog_array_item *item; 2468 int i = 0; 2469 2470 for (item = array->items; item->prog; item++) { 2471 if (item->prog == &dummy_bpf_prog.prog) 2472 continue; 2473 prog_ids[i] = item->prog->aux->id; 2474 if (++i == request_cnt) { 2475 item++; 2476 break; 2477 } 2478 } 2479 2480 return !!(item->prog); 2481 } 2482 2483 int bpf_prog_array_copy_to_user(struct bpf_prog_array *array, 2484 __u32 __user *prog_ids, u32 cnt) 2485 { 2486 unsigned long err = 0; 2487 bool nospc; 2488 u32 *ids; 2489 2490 /* users of this function are doing: 2491 * cnt = bpf_prog_array_length(); 2492 * if (cnt > 0) 2493 * bpf_prog_array_copy_to_user(..., cnt); 2494 * so below kcalloc doesn't need extra cnt > 0 check. 2495 */ 2496 ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN); 2497 if (!ids) 2498 return -ENOMEM; 2499 nospc = bpf_prog_array_copy_core(array, ids, cnt); 2500 err = copy_to_user(prog_ids, ids, cnt * sizeof(u32)); 2501 kfree(ids); 2502 if (err) 2503 return -EFAULT; 2504 if (nospc) 2505 return -ENOSPC; 2506 return 0; 2507 } 2508 2509 void bpf_prog_array_delete_safe(struct bpf_prog_array *array, 2510 struct bpf_prog *old_prog) 2511 { 2512 struct bpf_prog_array_item *item; 2513 2514 for (item = array->items; item->prog; item++) 2515 if (item->prog == old_prog) { 2516 WRITE_ONCE(item->prog, &dummy_bpf_prog.prog); 2517 break; 2518 } 2519 } 2520 2521 /** 2522 * bpf_prog_array_delete_safe_at() - Replaces the program at the given 2523 * index into the program array with 2524 * a dummy no-op program. 2525 * @array: a bpf_prog_array 2526 * @index: the index of the program to replace 2527 * 2528 * Skips over dummy programs, by not counting them, when calculating 2529 * the position of the program to replace. 2530 * 2531 * Return: 2532 * * 0 - Success 2533 * * -EINVAL - Invalid index value. Must be a non-negative integer. 2534 * * -ENOENT - Index out of range 2535 */ 2536 int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index) 2537 { 2538 return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog); 2539 } 2540 2541 /** 2542 * bpf_prog_array_update_at() - Updates the program at the given index 2543 * into the program array. 2544 * @array: a bpf_prog_array 2545 * @index: the index of the program to update 2546 * @prog: the program to insert into the array 2547 * 2548 * Skips over dummy programs, by not counting them, when calculating 2549 * the position of the program to update. 2550 * 2551 * Return: 2552 * * 0 - Success 2553 * * -EINVAL - Invalid index value. Must be a non-negative integer. 2554 * * -ENOENT - Index out of range 2555 */ 2556 int bpf_prog_array_update_at(struct bpf_prog_array *array, int index, 2557 struct bpf_prog *prog) 2558 { 2559 struct bpf_prog_array_item *item; 2560 2561 if (unlikely(index < 0)) 2562 return -EINVAL; 2563 2564 for (item = array->items; item->prog; item++) { 2565 if (item->prog == &dummy_bpf_prog.prog) 2566 continue; 2567 if (!index) { 2568 WRITE_ONCE(item->prog, prog); 2569 return 0; 2570 } 2571 index--; 2572 } 2573 return -ENOENT; 2574 } 2575 2576 int bpf_prog_array_copy(struct bpf_prog_array *old_array, 2577 struct bpf_prog *exclude_prog, 2578 struct bpf_prog *include_prog, 2579 u64 bpf_cookie, 2580 struct bpf_prog_array **new_array) 2581 { 2582 int new_prog_cnt, carry_prog_cnt = 0; 2583 struct bpf_prog_array_item *existing, *new; 2584 struct bpf_prog_array *array; 2585 bool found_exclude = false; 2586 2587 /* Figure out how many existing progs we need to carry over to 2588 * the new array. 2589 */ 2590 if (old_array) { 2591 existing = old_array->items; 2592 for (; existing->prog; existing++) { 2593 if (existing->prog == exclude_prog) { 2594 found_exclude = true; 2595 continue; 2596 } 2597 if (existing->prog != &dummy_bpf_prog.prog) 2598 carry_prog_cnt++; 2599 if (existing->prog == include_prog) 2600 return -EEXIST; 2601 } 2602 } 2603 2604 if (exclude_prog && !found_exclude) 2605 return -ENOENT; 2606 2607 /* How many progs (not NULL) will be in the new array? */ 2608 new_prog_cnt = carry_prog_cnt; 2609 if (include_prog) 2610 new_prog_cnt += 1; 2611 2612 /* Do we have any prog (not NULL) in the new array? */ 2613 if (!new_prog_cnt) { 2614 *new_array = NULL; 2615 return 0; 2616 } 2617 2618 /* +1 as the end of prog_array is marked with NULL */ 2619 array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL); 2620 if (!array) 2621 return -ENOMEM; 2622 new = array->items; 2623 2624 /* Fill in the new prog array */ 2625 if (carry_prog_cnt) { 2626 existing = old_array->items; 2627 for (; existing->prog; existing++) { 2628 if (existing->prog == exclude_prog || 2629 existing->prog == &dummy_bpf_prog.prog) 2630 continue; 2631 2632 new->prog = existing->prog; 2633 new->bpf_cookie = existing->bpf_cookie; 2634 new++; 2635 } 2636 } 2637 if (include_prog) { 2638 new->prog = include_prog; 2639 new->bpf_cookie = bpf_cookie; 2640 new++; 2641 } 2642 new->prog = NULL; 2643 *new_array = array; 2644 return 0; 2645 } 2646 2647 int bpf_prog_array_copy_info(struct bpf_prog_array *array, 2648 u32 *prog_ids, u32 request_cnt, 2649 u32 *prog_cnt) 2650 { 2651 u32 cnt = 0; 2652 2653 if (array) 2654 cnt = bpf_prog_array_length(array); 2655 2656 *prog_cnt = cnt; 2657 2658 /* return early if user requested only program count or nothing to copy */ 2659 if (!request_cnt || !cnt) 2660 return 0; 2661 2662 /* this function is called under trace/bpf_trace.c: bpf_event_mutex */ 2663 return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC 2664 : 0; 2665 } 2666 2667 void __bpf_free_used_maps(struct bpf_prog_aux *aux, 2668 struct bpf_map **used_maps, u32 len) 2669 { 2670 struct bpf_map *map; 2671 u32 i; 2672 2673 for (i = 0; i < len; i++) { 2674 map = used_maps[i]; 2675 if (map->ops->map_poke_untrack) 2676 map->ops->map_poke_untrack(map, aux); 2677 bpf_map_put(map); 2678 } 2679 } 2680 2681 static void bpf_free_used_maps(struct bpf_prog_aux *aux) 2682 { 2683 __bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt); 2684 kfree(aux->used_maps); 2685 } 2686 2687 void __bpf_free_used_btfs(struct bpf_prog_aux *aux, 2688 struct btf_mod_pair *used_btfs, u32 len) 2689 { 2690 #ifdef CONFIG_BPF_SYSCALL 2691 struct btf_mod_pair *btf_mod; 2692 u32 i; 2693 2694 for (i = 0; i < len; i++) { 2695 btf_mod = &used_btfs[i]; 2696 if (btf_mod->module) 2697 module_put(btf_mod->module); 2698 btf_put(btf_mod->btf); 2699 } 2700 #endif 2701 } 2702 2703 static void bpf_free_used_btfs(struct bpf_prog_aux *aux) 2704 { 2705 __bpf_free_used_btfs(aux, aux->used_btfs, aux->used_btf_cnt); 2706 kfree(aux->used_btfs); 2707 } 2708 2709 static void bpf_prog_free_deferred(struct work_struct *work) 2710 { 2711 struct bpf_prog_aux *aux; 2712 int i; 2713 2714 aux = container_of(work, struct bpf_prog_aux, work); 2715 #ifdef CONFIG_BPF_SYSCALL 2716 bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab); 2717 #endif 2718 #ifdef CONFIG_CGROUP_BPF 2719 if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID) 2720 bpf_cgroup_atype_put(aux->cgroup_atype); 2721 #endif 2722 bpf_free_used_maps(aux); 2723 bpf_free_used_btfs(aux); 2724 if (bpf_prog_is_dev_bound(aux)) 2725 bpf_prog_dev_bound_destroy(aux->prog); 2726 #ifdef CONFIG_PERF_EVENTS 2727 if (aux->prog->has_callchain_buf) 2728 put_callchain_buffers(); 2729 #endif 2730 if (aux->dst_trampoline) 2731 bpf_trampoline_put(aux->dst_trampoline); 2732 for (i = 0; i < aux->real_func_cnt; i++) { 2733 /* We can just unlink the subprog poke descriptor table as 2734 * it was originally linked to the main program and is also 2735 * released along with it. 2736 */ 2737 aux->func[i]->aux->poke_tab = NULL; 2738 bpf_jit_free(aux->func[i]); 2739 } 2740 if (aux->real_func_cnt) { 2741 kfree(aux->func); 2742 bpf_prog_unlock_free(aux->prog); 2743 } else { 2744 bpf_jit_free(aux->prog); 2745 } 2746 } 2747 2748 void bpf_prog_free(struct bpf_prog *fp) 2749 { 2750 struct bpf_prog_aux *aux = fp->aux; 2751 2752 if (aux->dst_prog) 2753 bpf_prog_put(aux->dst_prog); 2754 INIT_WORK(&aux->work, bpf_prog_free_deferred); 2755 schedule_work(&aux->work); 2756 } 2757 EXPORT_SYMBOL_GPL(bpf_prog_free); 2758 2759 /* RNG for unpriviledged user space with separated state from prandom_u32(). */ 2760 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state); 2761 2762 void bpf_user_rnd_init_once(void) 2763 { 2764 prandom_init_once(&bpf_user_rnd_state); 2765 } 2766 2767 BPF_CALL_0(bpf_user_rnd_u32) 2768 { 2769 /* Should someone ever have the rather unwise idea to use some 2770 * of the registers passed into this function, then note that 2771 * this function is called from native eBPF and classic-to-eBPF 2772 * transformations. Register assignments from both sides are 2773 * different, f.e. classic always sets fn(ctx, A, X) here. 2774 */ 2775 struct rnd_state *state; 2776 u32 res; 2777 2778 state = &get_cpu_var(bpf_user_rnd_state); 2779 res = prandom_u32_state(state); 2780 put_cpu_var(bpf_user_rnd_state); 2781 2782 return res; 2783 } 2784 2785 BPF_CALL_0(bpf_get_raw_cpu_id) 2786 { 2787 return raw_smp_processor_id(); 2788 } 2789 2790 /* Weak definitions of helper functions in case we don't have bpf syscall. */ 2791 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak; 2792 const struct bpf_func_proto bpf_map_update_elem_proto __weak; 2793 const struct bpf_func_proto bpf_map_delete_elem_proto __weak; 2794 const struct bpf_func_proto bpf_map_push_elem_proto __weak; 2795 const struct bpf_func_proto bpf_map_pop_elem_proto __weak; 2796 const struct bpf_func_proto bpf_map_peek_elem_proto __weak; 2797 const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto __weak; 2798 const struct bpf_func_proto bpf_spin_lock_proto __weak; 2799 const struct bpf_func_proto bpf_spin_unlock_proto __weak; 2800 const struct bpf_func_proto bpf_jiffies64_proto __weak; 2801 2802 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; 2803 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; 2804 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; 2805 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; 2806 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak; 2807 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak; 2808 const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak; 2809 2810 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; 2811 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; 2812 const struct bpf_func_proto bpf_get_current_comm_proto __weak; 2813 const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak; 2814 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak; 2815 const struct bpf_func_proto bpf_get_local_storage_proto __weak; 2816 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak; 2817 const struct bpf_func_proto bpf_snprintf_btf_proto __weak; 2818 const struct bpf_func_proto bpf_seq_printf_btf_proto __weak; 2819 const struct bpf_func_proto bpf_set_retval_proto __weak; 2820 const struct bpf_func_proto bpf_get_retval_proto __weak; 2821 2822 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) 2823 { 2824 return NULL; 2825 } 2826 2827 const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void) 2828 { 2829 return NULL; 2830 } 2831 2832 u64 __weak 2833 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size, 2834 void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy) 2835 { 2836 return -ENOTSUPP; 2837 } 2838 EXPORT_SYMBOL_GPL(bpf_event_output); 2839 2840 /* Always built-in helper functions. */ 2841 const struct bpf_func_proto bpf_tail_call_proto = { 2842 .func = NULL, 2843 .gpl_only = false, 2844 .ret_type = RET_VOID, 2845 .arg1_type = ARG_PTR_TO_CTX, 2846 .arg2_type = ARG_CONST_MAP_PTR, 2847 .arg3_type = ARG_ANYTHING, 2848 }; 2849 2850 /* Stub for JITs that only support cBPF. eBPF programs are interpreted. 2851 * It is encouraged to implement bpf_int_jit_compile() instead, so that 2852 * eBPF and implicitly also cBPF can get JITed! 2853 */ 2854 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog) 2855 { 2856 return prog; 2857 } 2858 2859 /* Stub for JITs that support eBPF. All cBPF code gets transformed into 2860 * eBPF by the kernel and is later compiled by bpf_int_jit_compile(). 2861 */ 2862 void __weak bpf_jit_compile(struct bpf_prog *prog) 2863 { 2864 } 2865 2866 bool __weak bpf_helper_changes_pkt_data(void *func) 2867 { 2868 return false; 2869 } 2870 2871 /* Return TRUE if the JIT backend wants verifier to enable sub-register usage 2872 * analysis code and wants explicit zero extension inserted by verifier. 2873 * Otherwise, return FALSE. 2874 * 2875 * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if 2876 * you don't override this. JITs that don't want these extra insns can detect 2877 * them using insn_is_zext. 2878 */ 2879 bool __weak bpf_jit_needs_zext(void) 2880 { 2881 return false; 2882 } 2883 2884 /* Return TRUE if the JIT backend supports mixing bpf2bpf and tailcalls. */ 2885 bool __weak bpf_jit_supports_subprog_tailcalls(void) 2886 { 2887 return false; 2888 } 2889 2890 bool __weak bpf_jit_supports_kfunc_call(void) 2891 { 2892 return false; 2893 } 2894 2895 bool __weak bpf_jit_supports_far_kfunc_call(void) 2896 { 2897 return false; 2898 } 2899 2900 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call 2901 * skb_copy_bits(), so provide a weak definition of it for NET-less config. 2902 */ 2903 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, 2904 int len) 2905 { 2906 return -EFAULT; 2907 } 2908 2909 int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t, 2910 void *addr1, void *addr2) 2911 { 2912 return -ENOTSUPP; 2913 } 2914 2915 void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len) 2916 { 2917 return ERR_PTR(-ENOTSUPP); 2918 } 2919 2920 int __weak bpf_arch_text_invalidate(void *dst, size_t len) 2921 { 2922 return -ENOTSUPP; 2923 } 2924 2925 bool __weak bpf_jit_supports_exceptions(void) 2926 { 2927 return false; 2928 } 2929 2930 void __weak arch_bpf_stack_walk(bool (*consume_fn)(void *cookie, u64 ip, u64 sp, u64 bp), void *cookie) 2931 { 2932 } 2933 2934 #ifdef CONFIG_BPF_SYSCALL 2935 static int __init bpf_global_ma_init(void) 2936 { 2937 int ret; 2938 2939 ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false); 2940 bpf_global_ma_set = !ret; 2941 return ret; 2942 } 2943 late_initcall(bpf_global_ma_init); 2944 #endif 2945 2946 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key); 2947 EXPORT_SYMBOL(bpf_stats_enabled_key); 2948 2949 /* All definitions of tracepoints related to BPF. */ 2950 #define CREATE_TRACE_POINTS 2951 #include <linux/bpf_trace.h> 2952 2953 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception); 2954 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx); 2955