kernel/bpf/core.c

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