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
  32 #include <asm/unaligned.h>
  33
  34 /* Registers */
  35 #define BPF_R0  regs[BPF_REG_0]
  36 #define BPF_R1  regs[BPF_REG_1]
  37 #define BPF_R2  regs[BPF_REG_2]
  38 #define BPF_R3  regs[BPF_REG_3]
  39 #define BPF_R4  regs[BPF_REG_4]
  40 #define BPF_R5  regs[BPF_REG_5]
  41 #define BPF_R6  regs[BPF_REG_6]
  42 #define BPF_R7  regs[BPF_REG_7]
  43 #define BPF_R8  regs[BPF_REG_8]
  44 #define BPF_R9  regs[BPF_REG_9]
  45 #define BPF_R10 regs[BPF_REG_10]
  46
  47 /* Named registers */
  48 #define DST     regs[insn->dst_reg]
  49 #define SRC     regs[insn->src_reg]
  50 #define FP      regs[BPF_REG_FP]
  51 #define ARG1    regs[BPF_REG_ARG1]
  52 #define CTX     regs[BPF_REG_CTX]
  53 #define IMM     insn->imm
  54
  55 /* No hurry in this branch
  56  *
  57  * Exported for the bpf jit load helper.
  58  */
  59 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
  60 {
  61         u8 *ptr = NULL;
  62
  63         if (k >= SKF_NET_OFF)
  64                 ptr = skb_network_header(skb) + k - SKF_NET_OFF;
  65         else if (k >= SKF_LL_OFF)
  66                 ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
  67
  68         if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
  69                 return ptr;
  70
  71         return NULL;
  72 }
  73
  74 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
  75 {
  76         gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO |
  77                           gfp_extra_flags;
  78         struct bpf_prog_aux *aux;
  79         struct bpf_prog *fp;
  80
  81         size = round_up(size, PAGE_SIZE);
  82         fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
  83         if (fp == NULL)
  84                 return NULL;
  85
  86         kmemcheck_annotate_bitfield(fp, meta);
  87
  88         aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags);
  89         if (aux == NULL) {
  90                 vfree(fp);
  91                 return NULL;
  92         }
  93
  94         fp->pages = size / PAGE_SIZE;
  95         fp->aux = aux;
  96         fp->aux->prog = fp;
  97
  98         return fp;
  99 }
 100 EXPORT_SYMBOL_GPL(bpf_prog_alloc);
 101
 102 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 103                                   gfp_t gfp_extra_flags)
 104 {
 105         gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO |
 106                           gfp_extra_flags;
 107         struct bpf_prog *fp;
 108         u32 pages, delta;
 109         int ret;
 110
 111         BUG_ON(fp_old == NULL);
 112
 113         size = round_up(size, PAGE_SIZE);
 114         pages = size / PAGE_SIZE;
 115         if (pages <= fp_old->pages)
 116                 return fp_old;
 117
 118         delta = pages - fp_old->pages;
 119         ret = __bpf_prog_charge(fp_old->aux->user, delta);
 120         if (ret)
 121                 return NULL;
 122
 123         fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
 124         if (fp == NULL) {
 125                 __bpf_prog_uncharge(fp_old->aux->user, delta);
 126         } else {
 127                 kmemcheck_annotate_bitfield(fp, meta);
 128
 129                 memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
 130                 fp->pages = pages;
 131                 fp->aux->prog = fp;
 132
 133                 /* We keep fp->aux from fp_old around in the new
 134                  * reallocated structure.
 135                  */
 136                 fp_old->aux = NULL;
 137                 __bpf_prog_free(fp_old);
 138         }
 139
 140         return fp;
 141 }
 142
 143 void __bpf_prog_free(struct bpf_prog *fp)
 144 {
 145         kfree(fp->aux);
 146         vfree(fp);
 147 }
 148
 149 int bpf_prog_calc_digest(struct bpf_prog *fp)
 150 {
 151         const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64);
 152         u32 raw_size = bpf_prog_digest_scratch_size(fp);
 153         u32 ws[SHA_WORKSPACE_WORDS];
 154         u32 i, bsize, psize, blocks;
 155         struct bpf_insn *dst;
 156         bool was_ld_map;
 157         u8 *raw, *todo;
 158         __be32 *result;
 159         __be64 *bits;
 160
 161         raw = vmalloc(raw_size);
 162         if (!raw)
 163                 return -ENOMEM;
 164
 165         sha_init(fp->digest);
 166         memset(ws, 0, sizeof(ws));
 167
 168         /* We need to take out the map fd for the digest calculation
 169          * since they are unstable from user space side.
 170          */
 171         dst = (void *)raw;
 172         for (i = 0, was_ld_map = false; i < fp->len; i++) {
 173                 dst[i] = fp->insnsi[i];
 174                 if (!was_ld_map &&
 175                     dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
 176                     dst[i].src_reg == BPF_PSEUDO_MAP_FD) {
 177                         was_ld_map = true;
 178                         dst[i].imm = 0;
 179                 } else if (was_ld_map &&
 180                            dst[i].code == 0 &&
 181                            dst[i].dst_reg == 0 &&
 182                            dst[i].src_reg == 0 &&
 183                            dst[i].off == 0) {
 184                         was_ld_map = false;
 185                         dst[i].imm = 0;
 186                 } else {
 187                         was_ld_map = false;
 188                 }
 189         }
 190
 191         psize = bpf_prog_insn_size(fp);
 192         memset(&raw[psize], 0, raw_size - psize);
 193         raw[psize++] = 0x80;
 194
 195         bsize  = round_up(psize, SHA_MESSAGE_BYTES);
 196         blocks = bsize / SHA_MESSAGE_BYTES;
 197         todo   = raw;
 198         if (bsize - psize >= sizeof(__be64)) {
 199                 bits = (__be64 *)(todo + bsize - sizeof(__be64));
 200         } else {
 201                 bits = (__be64 *)(todo + bsize + bits_offset);
 202                 blocks++;
 203         }
 204         *bits = cpu_to_be64((psize - 1) << 3);
 205
 206         while (blocks--) {
 207                 sha_transform(fp->digest, todo, ws);
 208                 todo += SHA_MESSAGE_BYTES;
 209         }
 210
 211         result = (__force __be32 *)fp->digest;
 212         for (i = 0; i < SHA_DIGEST_WORDS; i++)
 213                 result[i] = cpu_to_be32(fp->digest[i]);
 214
 215         vfree(raw);
 216         return 0;
 217 }
 218
 219 static bool bpf_is_jmp_and_has_target(const struct bpf_insn *insn)
 220 {
 221         return BPF_CLASS(insn->code) == BPF_JMP  &&
 222                /* Call and Exit are both special jumps with no
 223                 * target inside the BPF instruction image.
 224                 */
 225                BPF_OP(insn->code) != BPF_CALL &&
 226                BPF_OP(insn->code) != BPF_EXIT;
 227 }
 228
 229 static void bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta)
 230 {
 231         struct bpf_insn *insn = prog->insnsi;
 232         u32 i, insn_cnt = prog->len;
 233
 234         for (i = 0; i < insn_cnt; i++, insn++) {
 235                 if (!bpf_is_jmp_and_has_target(insn))
 236                         continue;
 237
 238                 /* Adjust offset of jmps if we cross boundaries. */
 239                 if (i < pos && i + insn->off + 1 > pos)
 240                         insn->off += delta;
 241                 else if (i > pos + delta && i + insn->off + 1 <= pos + delta)
 242                         insn->off -= delta;
 243         }
 244 }
 245
 246 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
 247                                        const struct bpf_insn *patch, u32 len)
 248 {
 249         u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
 250         struct bpf_prog *prog_adj;
 251
 252         /* Since our patchlet doesn't expand the image, we're done. */
 253         if (insn_delta == 0) {
 254                 memcpy(prog->insnsi + off, patch, sizeof(*patch));
 255                 return prog;
 256         }
 257
 258         insn_adj_cnt = prog->len + insn_delta;
 259
 260         /* Several new instructions need to be inserted. Make room
 261          * for them. Likely, there's no need for a new allocation as
 262          * last page could have large enough tailroom.
 263          */
 264         prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
 265                                     GFP_USER);
 266         if (!prog_adj)
 267                 return NULL;
 268
 269         prog_adj->len = insn_adj_cnt;
 270
 271         /* Patching happens in 3 steps:
 272          *
 273          * 1) Move over tail of insnsi from next instruction onwards,
 274          *    so we can patch the single target insn with one or more
 275          *    new ones (patching is always from 1 to n insns, n > 0).
 276          * 2) Inject new instructions at the target location.
 277          * 3) Adjust branch offsets if necessary.
 278          */
 279         insn_rest = insn_adj_cnt - off - len;
 280
 281         memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
 282                 sizeof(*patch) * insn_rest);
 283         memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
 284
 285         bpf_adj_branches(prog_adj, off, insn_delta);
 286
 287         return prog_adj;
 288 }
 289
 290 #ifdef CONFIG_BPF_JIT
 291 struct bpf_binary_header *
 292 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
 293                      unsigned int alignment,
 294                      bpf_jit_fill_hole_t bpf_fill_ill_insns)
 295 {
 296         struct bpf_binary_header *hdr;
 297         unsigned int size, hole, start;
 298
 299         /* Most of BPF filters are really small, but if some of them
 300          * fill a page, allow at least 128 extra bytes to insert a
 301          * random section of illegal instructions.
 302          */
 303         size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
 304         hdr = module_alloc(size);
 305         if (hdr == NULL)
 306                 return NULL;
 307
 308         /* Fill space with illegal/arch-dep instructions. */
 309         bpf_fill_ill_insns(hdr, size);
 310
 311         hdr->pages = size / PAGE_SIZE;
 312         hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
 313                      PAGE_SIZE - sizeof(*hdr));
 314         start = (get_random_int() % hole) & ~(alignment - 1);
 315
 316         /* Leave a random number of instructions before BPF code. */
 317         *image_ptr = &hdr->image[start];
 318
 319         return hdr;
 320 }
 321
 322 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
 323 {
 324         module_memfree(hdr);
 325 }
 326
 327 int bpf_jit_harden __read_mostly;
 328
 329 static int bpf_jit_blind_insn(const struct bpf_insn *from,
 330                               const struct bpf_insn *aux,
 331                               struct bpf_insn *to_buff)
 332 {
 333         struct bpf_insn *to = to_buff;
 334         u32 imm_rnd = get_random_int();
 335         s16 off;
 336
 337         BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
 338         BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
 339
 340         if (from->imm == 0 &&
 341             (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
 342              from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
 343                 *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
 344                 goto out;
 345         }
 346
 347         switch (from->code) {
 348         case BPF_ALU | BPF_ADD | BPF_K:
 349         case BPF_ALU | BPF_SUB | BPF_K:
 350         case BPF_ALU | BPF_AND | BPF_K:
 351         case BPF_ALU | BPF_OR  | BPF_K:
 352         case BPF_ALU | BPF_XOR | BPF_K:
 353         case BPF_ALU | BPF_MUL | BPF_K:
 354         case BPF_ALU | BPF_MOV | BPF_K:
 355         case BPF_ALU | BPF_DIV | BPF_K:
 356         case BPF_ALU | BPF_MOD | BPF_K:
 357                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
 358                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 359                 *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
 360                 break;
 361
 362         case BPF_ALU64 | BPF_ADD | BPF_K:
 363         case BPF_ALU64 | BPF_SUB | BPF_K:
 364         case BPF_ALU64 | BPF_AND | BPF_K:
 365         case BPF_ALU64 | BPF_OR  | BPF_K:
 366         case BPF_ALU64 | BPF_XOR | BPF_K:
 367         case BPF_ALU64 | BPF_MUL | BPF_K:
 368         case BPF_ALU64 | BPF_MOV | BPF_K:
 369         case BPF_ALU64 | BPF_DIV | BPF_K:
 370         case BPF_ALU64 | BPF_MOD | BPF_K:
 371                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
 372                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 373                 *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
 374                 break;
 375
 376         case BPF_JMP | BPF_JEQ  | BPF_K:
 377         case BPF_JMP | BPF_JNE  | BPF_K:
 378         case BPF_JMP | BPF_JGT  | BPF_K:
 379         case BPF_JMP | BPF_JGE  | BPF_K:
 380         case BPF_JMP | BPF_JSGT | BPF_K:
 381         case BPF_JMP | BPF_JSGE | BPF_K:
 382         case BPF_JMP | BPF_JSET | BPF_K:
 383                 /* Accommodate for extra offset in case of a backjump. */
 384                 off = from->off;
 385                 if (off < 0)
 386                         off -= 2;
 387                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
 388                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 389                 *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
 390                 break;
 391
 392         case BPF_LD | BPF_ABS | BPF_W:
 393         case BPF_LD | BPF_ABS | BPF_H:
 394         case BPF_LD | BPF_ABS | BPF_B:
 395                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
 396                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 397                 *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0);
 398                 break;
 399
 400         case BPF_LD | BPF_IND | BPF_W:
 401         case BPF_LD | BPF_IND | BPF_H:
 402         case BPF_LD | BPF_IND | BPF_B:
 403                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
 404                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 405                 *to++ = BPF_ALU32_REG(BPF_ADD, BPF_REG_AX, from->src_reg);
 406                 *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0);
 407                 break;
 408
 409         case BPF_LD | BPF_IMM | BPF_DW:
 410                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
 411                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 412                 *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
 413                 *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
 414                 break;
 415         case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
 416                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
 417                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 418                 *to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
 419                 break;
 420
 421         case BPF_ST | BPF_MEM | BPF_DW:
 422         case BPF_ST | BPF_MEM | BPF_W:
 423         case BPF_ST | BPF_MEM | BPF_H:
 424         case BPF_ST | BPF_MEM | BPF_B:
 425                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
 426                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 427                 *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
 428                 break;
 429         }
 430 out:
 431         return to - to_buff;
 432 }
 433
 434 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
 435                                               gfp_t gfp_extra_flags)
 436 {
 437         gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO |
 438                           gfp_extra_flags;
 439         struct bpf_prog *fp;
 440
 441         fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL);
 442         if (fp != NULL) {
 443                 kmemcheck_annotate_bitfield(fp, meta);
 444
 445                 /* aux->prog still points to the fp_other one, so
 446                  * when promoting the clone to the real program,
 447                  * this still needs to be adapted.
 448                  */
 449                 memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
 450         }
 451
 452         return fp;
 453 }
 454
 455 static void bpf_prog_clone_free(struct bpf_prog *fp)
 456 {
 457         /* aux was stolen by the other clone, so we cannot free
 458          * it from this path! It will be freed eventually by the
 459          * other program on release.
 460          *
 461          * At this point, we don't need a deferred release since
 462          * clone is guaranteed to not be locked.
 463          */
 464         fp->aux = NULL;
 465         __bpf_prog_free(fp);
 466 }
 467
 468 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
 469 {
 470         /* We have to repoint aux->prog to self, as we don't
 471          * know whether fp here is the clone or the original.
 472          */
 473         fp->aux->prog = fp;
 474         bpf_prog_clone_free(fp_other);
 475 }
 476
 477 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
 478 {
 479         struct bpf_insn insn_buff[16], aux[2];
 480         struct bpf_prog *clone, *tmp;
 481         int insn_delta, insn_cnt;
 482         struct bpf_insn *insn;
 483         int i, rewritten;
 484
 485         if (!bpf_jit_blinding_enabled())
 486                 return prog;
 487
 488         clone = bpf_prog_clone_create(prog, GFP_USER);
 489         if (!clone)
 490                 return ERR_PTR(-ENOMEM);
 491
 492         insn_cnt = clone->len;
 493         insn = clone->insnsi;
 494
 495         for (i = 0; i < insn_cnt; i++, insn++) {
 496                 /* We temporarily need to hold the original ld64 insn
 497                  * so that we can still access the first part in the
 498                  * second blinding run.
 499                  */
 500                 if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
 501                     insn[1].code == 0)
 502                         memcpy(aux, insn, sizeof(aux));
 503
 504                 rewritten = bpf_jit_blind_insn(insn, aux, insn_buff);
 505                 if (!rewritten)
 506                         continue;
 507
 508                 tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
 509                 if (!tmp) {
 510                         /* Patching may have repointed aux->prog during
 511                          * realloc from the original one, so we need to
 512                          * fix it up here on error.
 513                          */
 514                         bpf_jit_prog_release_other(prog, clone);
 515                         return ERR_PTR(-ENOMEM);
 516                 }
 517
 518                 clone = tmp;
 519                 insn_delta = rewritten - 1;
 520
 521                 /* Walk new program and skip insns we just inserted. */
 522                 insn = clone->insnsi + i + insn_delta;
 523                 insn_cnt += insn_delta;
 524                 i        += insn_delta;
 525         }
 526
 527         return clone;
 528 }
 529 #endif /* CONFIG_BPF_JIT */
 530
 531 /* Base function for offset calculation. Needs to go into .text section,
 532  * therefore keeping it non-static as well; will also be used by JITs
 533  * anyway later on, so do not let the compiler omit it.
 534  */
 535 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
 536 {
 537         return 0;
 538 }
 539 EXPORT_SYMBOL_GPL(__bpf_call_base);
 540
 541 /**
 542  *      __bpf_prog_run - run eBPF program on a given context
 543  *      @ctx: is the data we are operating on
 544  *      @insn: is the array of eBPF instructions
 545  *
 546  * Decode and execute eBPF instructions.
 547  */
 548 static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn)
 549 {
 550         u64 stack[MAX_BPF_STACK / sizeof(u64)];
 551         u64 regs[MAX_BPF_REG], tmp;
 552         static const void *jumptable[256] = {
 553                 [0 ... 255] = &&default_label,
 554                 /* Now overwrite non-defaults ... */
 555                 /* 32 bit ALU operations */
 556                 [BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X,
 557                 [BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K,
 558                 [BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X,
 559                 [BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K,
 560                 [BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X,
 561                 [BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K,
 562                 [BPF_ALU | BPF_OR | BPF_X]  = &&ALU_OR_X,
 563                 [BPF_ALU | BPF_OR | BPF_K]  = &&ALU_OR_K,
 564                 [BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X,
 565                 [BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K,
 566                 [BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X,
 567                 [BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K,
 568                 [BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X,
 569                 [BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K,
 570                 [BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X,
 571                 [BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K,
 572                 [BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X,
 573                 [BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K,
 574                 [BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X,
 575                 [BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K,
 576                 [BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X,
 577                 [BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K,
 578                 [BPF_ALU | BPF_NEG] = &&ALU_NEG,
 579                 [BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE,
 580                 [BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE,
 581                 /* 64 bit ALU operations */
 582                 [BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X,
 583                 [BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K,
 584                 [BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X,
 585                 [BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K,
 586                 [BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X,
 587                 [BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K,
 588                 [BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X,
 589                 [BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K,
 590                 [BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X,
 591                 [BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K,
 592                 [BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X,
 593                 [BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K,
 594                 [BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X,
 595                 [BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K,
 596                 [BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X,
 597                 [BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K,
 598                 [BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X,
 599                 [BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K,
 600                 [BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X,
 601                 [BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K,
 602                 [BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X,
 603                 [BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K,
 604                 [BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X,
 605                 [BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K,
 606                 [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG,
 607                 /* Call instruction */
 608                 [BPF_JMP | BPF_CALL] = &&JMP_CALL,
 609                 [BPF_JMP | BPF_CALL | BPF_X] = &&JMP_TAIL_CALL,
 610                 /* Jumps */
 611                 [BPF_JMP | BPF_JA] = &&JMP_JA,
 612                 [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X,
 613                 [BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K,
 614                 [BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X,
 615                 [BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K,
 616                 [BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X,
 617                 [BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K,
 618                 [BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X,
 619                 [BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K,
 620                 [BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X,
 621                 [BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K,
 622                 [BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X,
 623                 [BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K,
 624                 [BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X,
 625                 [BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K,
 626                 /* Program return */
 627                 [BPF_JMP | BPF_EXIT] = &&JMP_EXIT,
 628                 /* Store instructions */
 629                 [BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B,
 630                 [BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H,
 631                 [BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W,
 632                 [BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW,
 633                 [BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W,
 634                 [BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW,
 635                 [BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B,
 636                 [BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H,
 637                 [BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W,
 638                 [BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW,
 639                 /* Load instructions */
 640                 [BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B,
 641                 [BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H,
 642                 [BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W,
 643                 [BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW,
 644                 [BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W,
 645                 [BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H,
 646                 [BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B,
 647                 [BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W,
 648                 [BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H,
 649                 [BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B,
 650                 [BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW,
 651         };
 652         u32 tail_call_cnt = 0;
 653         void *ptr;
 654         int off;
 655
 656 #define CONT     ({ insn++; goto select_insn; })
 657 #define CONT_JMP ({ insn++; goto select_insn; })
 658
 659         FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)];
 660         ARG1 = (u64) (unsigned long) ctx;
 661
 662 select_insn:
 663         goto *jumptable[insn->code];
 664
 665         /* ALU */
 666 #define ALU(OPCODE, OP)                 \
 667         ALU64_##OPCODE##_X:             \
 668                 DST = DST OP SRC;       \
 669                 CONT;                   \
 670         ALU_##OPCODE##_X:               \
 671                 DST = (u32) DST OP (u32) SRC;   \
 672                 CONT;                   \
 673         ALU64_##OPCODE##_K:             \
 674                 DST = DST OP IMM;               \
 675                 CONT;                   \
 676         ALU_##OPCODE##_K:               \
 677                 DST = (u32) DST OP (u32) IMM;   \
 678                 CONT;
 679
 680         ALU(ADD,  +)
 681         ALU(SUB,  -)
 682         ALU(AND,  &)
 683         ALU(OR,   |)
 684         ALU(LSH, <<)
 685         ALU(RSH, >>)
 686         ALU(XOR,  ^)
 687         ALU(MUL,  *)
 688 #undef ALU
 689         ALU_NEG:
 690                 DST = (u32) -DST;
 691                 CONT;
 692         ALU64_NEG:
 693                 DST = -DST;
 694                 CONT;
 695         ALU_MOV_X:
 696                 DST = (u32) SRC;
 697                 CONT;
 698         ALU_MOV_K:
 699                 DST = (u32) IMM;
 700                 CONT;
 701         ALU64_MOV_X:
 702                 DST = SRC;
 703                 CONT;
 704         ALU64_MOV_K:
 705                 DST = IMM;
 706                 CONT;
 707         LD_IMM_DW:
 708                 DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
 709                 insn++;
 710                 CONT;
 711         ALU64_ARSH_X:
 712                 (*(s64 *) &DST) >>= SRC;
 713                 CONT;
 714         ALU64_ARSH_K:
 715                 (*(s64 *) &DST) >>= IMM;
 716                 CONT;
 717         ALU64_MOD_X:
 718                 if (unlikely(SRC == 0))
 719                         return 0;
 720                 div64_u64_rem(DST, SRC, &tmp);
 721                 DST = tmp;
 722                 CONT;
 723         ALU_MOD_X:
 724                 if (unlikely(SRC == 0))
 725                         return 0;
 726                 tmp = (u32) DST;
 727                 DST = do_div(tmp, (u32) SRC);
 728                 CONT;
 729         ALU64_MOD_K:
 730                 div64_u64_rem(DST, IMM, &tmp);
 731                 DST = tmp;
 732                 CONT;
 733         ALU_MOD_K:
 734                 tmp = (u32) DST;
 735                 DST = do_div(tmp, (u32) IMM);
 736                 CONT;
 737         ALU64_DIV_X:
 738                 if (unlikely(SRC == 0))
 739                         return 0;
 740                 DST = div64_u64(DST, SRC);
 741                 CONT;
 742         ALU_DIV_X:
 743                 if (unlikely(SRC == 0))
 744                         return 0;
 745                 tmp = (u32) DST;
 746                 do_div(tmp, (u32) SRC);
 747                 DST = (u32) tmp;
 748                 CONT;
 749         ALU64_DIV_K:
 750                 DST = div64_u64(DST, IMM);
 751                 CONT;
 752         ALU_DIV_K:
 753                 tmp = (u32) DST;
 754                 do_div(tmp, (u32) IMM);
 755                 DST = (u32) tmp;
 756                 CONT;
 757         ALU_END_TO_BE:
 758                 switch (IMM) {
 759                 case 16:
 760                         DST = (__force u16) cpu_to_be16(DST);
 761                         break;
 762                 case 32:
 763                         DST = (__force u32) cpu_to_be32(DST);
 764                         break;
 765                 case 64:
 766                         DST = (__force u64) cpu_to_be64(DST);
 767                         break;
 768                 }
 769                 CONT;
 770         ALU_END_TO_LE:
 771                 switch (IMM) {
 772                 case 16:
 773                         DST = (__force u16) cpu_to_le16(DST);
 774                         break;
 775                 case 32:
 776                         DST = (__force u32) cpu_to_le32(DST);
 777                         break;
 778                 case 64:
 779                         DST = (__force u64) cpu_to_le64(DST);
 780                         break;
 781                 }
 782                 CONT;
 783
 784         /* CALL */
 785         JMP_CALL:
 786                 /* Function call scratches BPF_R1-BPF_R5 registers,
 787                  * preserves BPF_R6-BPF_R9, and stores return value
 788                  * into BPF_R0.
 789                  */
 790                 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
 791                                                        BPF_R4, BPF_R5);
 792                 CONT;
 793
 794         JMP_TAIL_CALL: {
 795                 struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
 796                 struct bpf_array *array = container_of(map, struct bpf_array, map);
 797                 struct bpf_prog *prog;
 798                 u64 index = BPF_R3;
 799
 800                 if (unlikely(index >= array->map.max_entries))
 801                         goto out;
 802                 if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT))
 803                         goto out;
 804
 805                 tail_call_cnt++;
 806
 807                 prog = READ_ONCE(array->ptrs[index]);
 808                 if (!prog)
 809                         goto out;
 810
 811                 /* ARG1 at this point is guaranteed to point to CTX from
 812                  * the verifier side due to the fact that the tail call is
 813                  * handeled like a helper, that is, bpf_tail_call_proto,
 814                  * where arg1_type is ARG_PTR_TO_CTX.
 815                  */
 816                 insn = prog->insnsi;
 817                 goto select_insn;
 818 out:
 819                 CONT;
 820         }
 821         /* JMP */
 822         JMP_JA:
 823                 insn += insn->off;
 824                 CONT;
 825         JMP_JEQ_X:
 826                 if (DST == SRC) {
 827                         insn += insn->off;
 828                         CONT_JMP;
 829                 }
 830                 CONT;
 831         JMP_JEQ_K:
 832                 if (DST == IMM) {
 833                         insn += insn->off;
 834                         CONT_JMP;
 835                 }
 836                 CONT;
 837         JMP_JNE_X:
 838                 if (DST != SRC) {
 839                         insn += insn->off;
 840                         CONT_JMP;
 841                 }
 842                 CONT;
 843         JMP_JNE_K:
 844                 if (DST != IMM) {
 845                         insn += insn->off;
 846                         CONT_JMP;
 847                 }
 848                 CONT;
 849         JMP_JGT_X:
 850                 if (DST > SRC) {
 851                         insn += insn->off;
 852                         CONT_JMP;
 853                 }
 854                 CONT;
 855         JMP_JGT_K:
 856                 if (DST > IMM) {
 857                         insn += insn->off;
 858                         CONT_JMP;
 859                 }
 860                 CONT;
 861         JMP_JGE_X:
 862                 if (DST >= SRC) {
 863                         insn += insn->off;
 864                         CONT_JMP;
 865                 }
 866                 CONT;
 867         JMP_JGE_K:
 868                 if (DST >= IMM) {
 869                         insn += insn->off;
 870                         CONT_JMP;
 871                 }
 872                 CONT;
 873         JMP_JSGT_X:
 874                 if (((s64) DST) > ((s64) SRC)) {
 875                         insn += insn->off;
 876                         CONT_JMP;
 877                 }
 878                 CONT;
 879         JMP_JSGT_K:
 880                 if (((s64) DST) > ((s64) IMM)) {
 881                         insn += insn->off;
 882                         CONT_JMP;
 883                 }
 884                 CONT;
 885         JMP_JSGE_X:
 886                 if (((s64) DST) >= ((s64) SRC)) {
 887                         insn += insn->off;
 888                         CONT_JMP;
 889                 }
 890                 CONT;
 891         JMP_JSGE_K:
 892                 if (((s64) DST) >= ((s64) IMM)) {
 893                         insn += insn->off;
 894                         CONT_JMP;
 895                 }
 896                 CONT;
 897         JMP_JSET_X:
 898                 if (DST & SRC) {
 899                         insn += insn->off;
 900                         CONT_JMP;
 901                 }
 902                 CONT;
 903         JMP_JSET_K:
 904                 if (DST & IMM) {
 905                         insn += insn->off;
 906                         CONT_JMP;
 907                 }
 908                 CONT;
 909         JMP_EXIT:
 910                 return BPF_R0;
 911
 912         /* STX and ST and LDX*/
 913 #define LDST(SIZEOP, SIZE)                                              \
 914         STX_MEM_##SIZEOP:                                               \
 915                 *(SIZE *)(unsigned long) (DST + insn->off) = SRC;       \
 916                 CONT;                                                   \
 917         ST_MEM_##SIZEOP:                                                \
 918                 *(SIZE *)(unsigned long) (DST + insn->off) = IMM;       \
 919                 CONT;                                                   \
 920         LDX_MEM_##SIZEOP:                                               \
 921                 DST = *(SIZE *)(unsigned long) (SRC + insn->off);       \
 922                 CONT;
 923
 924         LDST(B,   u8)
 925         LDST(H,  u16)
 926         LDST(W,  u32)
 927         LDST(DW, u64)
 928 #undef LDST
 929         STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */
 930                 atomic_add((u32) SRC, (atomic_t *)(unsigned long)
 931                            (DST + insn->off));
 932                 CONT;
 933         STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */
 934                 atomic64_add((u64) SRC, (atomic64_t *)(unsigned long)
 935                              (DST + insn->off));
 936                 CONT;
 937         LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */
 938                 off = IMM;
 939 load_word:
 940                 /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are
 941                  * only appearing in the programs where ctx ==
 942                  * skb. All programs keep 'ctx' in regs[BPF_REG_CTX]
 943                  * == BPF_R6, bpf_convert_filter() saves it in BPF_R6,
 944                  * internal BPF verifier will check that BPF_R6 ==
 945                  * ctx.
 946                  *
 947                  * BPF_ABS and BPF_IND are wrappers of function calls,
 948                  * so they scratch BPF_R1-BPF_R5 registers, preserve
 949                  * BPF_R6-BPF_R9, and store return value into BPF_R0.
 950                  *
 951                  * Implicit input:
 952                  *   ctx == skb == BPF_R6 == CTX
 953                  *
 954                  * Explicit input:
 955                  *   SRC == any register
 956                  *   IMM == 32-bit immediate
 957                  *
 958                  * Output:
 959                  *   BPF_R0 - 8/16/32-bit skb data converted to cpu endianness
 960                  */
 961
 962                 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp);
 963                 if (likely(ptr != NULL)) {
 964                         BPF_R0 = get_unaligned_be32(ptr);
 965                         CONT;
 966                 }
 967
 968                 return 0;
 969         LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */
 970                 off = IMM;
 971 load_half:
 972                 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp);
 973                 if (likely(ptr != NULL)) {
 974                         BPF_R0 = get_unaligned_be16(ptr);
 975                         CONT;
 976                 }
 977
 978                 return 0;
 979         LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */
 980                 off = IMM;
 981 load_byte:
 982                 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp);
 983                 if (likely(ptr != NULL)) {
 984                         BPF_R0 = *(u8 *)ptr;
 985                         CONT;
 986                 }
 987
 988                 return 0;
 989         LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */
 990                 off = IMM + SRC;
 991                 goto load_word;
 992         LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */
 993                 off = IMM + SRC;
 994                 goto load_half;
 995         LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */
 996                 off = IMM + SRC;
 997                 goto load_byte;
 998
 999         default_label:
1000                 /* If we ever reach this, we have a bug somewhere. */
1001                 WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code);
1002                 return 0;
1003 }
1004 STACK_FRAME_NON_STANDARD(__bpf_prog_run); /* jump table */
1005
1006 bool bpf_prog_array_compatible(struct bpf_array *array,
1007                                const struct bpf_prog *fp)
1008 {
1009         if (!array->owner_prog_type) {
1010                 /* There's no owner yet where we could check for
1011                  * compatibility.
1012                  */
1013                 array->owner_prog_type = fp->type;
1014                 array->owner_jited = fp->jited;
1015
1016                 return true;
1017         }
1018
1019         return array->owner_prog_type == fp->type &&
1020                array->owner_jited == fp->jited;
1021 }
1022
1023 static int bpf_check_tail_call(const struct bpf_prog *fp)
1024 {
1025         struct bpf_prog_aux *aux = fp->aux;
1026         int i;
1027
1028         for (i = 0; i < aux->used_map_cnt; i++) {
1029                 struct bpf_map *map = aux->used_maps[i];
1030                 struct bpf_array *array;
1031
1032                 if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
1033                         continue;
1034
1035                 array = container_of(map, struct bpf_array, map);
1036                 if (!bpf_prog_array_compatible(array, fp))
1037                         return -EINVAL;
1038         }
1039
1040         return 0;
1041 }
1042
1043 /**
1044  *      bpf_prog_select_runtime - select exec runtime for BPF program
1045  *      @fp: bpf_prog populated with internal BPF program
1046  *      @err: pointer to error variable
1047  *
1048  * Try to JIT eBPF program, if JIT is not available, use interpreter.
1049  * The BPF program will be executed via BPF_PROG_RUN() macro.
1050  */
1051 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
1052 {
1053         fp->bpf_func = (void *) __bpf_prog_run;
1054
1055         /* eBPF JITs can rewrite the program in case constant
1056          * blinding is active. However, in case of error during
1057          * blinding, bpf_int_jit_compile() must always return a
1058          * valid program, which in this case would simply not
1059          * be JITed, but falls back to the interpreter.
1060          */
1061         fp = bpf_int_jit_compile(fp);
1062         bpf_prog_lock_ro(fp);
1063
1064         /* The tail call compatibility check can only be done at
1065          * this late stage as we need to determine, if we deal
1066          * with JITed or non JITed program concatenations and not
1067          * all eBPF JITs might immediately support all features.
1068          */
1069         *err = bpf_check_tail_call(fp);
1070
1071         return fp;
1072 }
1073 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
1074
1075 static void bpf_prog_free_deferred(struct work_struct *work)
1076 {
1077         struct bpf_prog_aux *aux;
1078
1079         aux = container_of(work, struct bpf_prog_aux, work);
1080         bpf_jit_free(aux->prog);
1081 }
1082
1083 /* Free internal BPF program */
1084 void bpf_prog_free(struct bpf_prog *fp)
1085 {
1086         struct bpf_prog_aux *aux = fp->aux;
1087
1088         INIT_WORK(&aux->work, bpf_prog_free_deferred);
1089         schedule_work(&aux->work);
1090 }
1091 EXPORT_SYMBOL_GPL(bpf_prog_free);
1092
1093 /* RNG for unpriviledged user space with separated state from prandom_u32(). */
1094 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
1095
1096 void bpf_user_rnd_init_once(void)
1097 {
1098         prandom_init_once(&bpf_user_rnd_state);
1099 }
1100
1101 BPF_CALL_0(bpf_user_rnd_u32)
1102 {
1103         /* Should someone ever have the rather unwise idea to use some
1104          * of the registers passed into this function, then note that
1105          * this function is called from native eBPF and classic-to-eBPF
1106          * transformations. Register assignments from both sides are
1107          * different, f.e. classic always sets fn(ctx, A, X) here.
1108          */
1109         struct rnd_state *state;
1110         u32 res;
1111
1112         state = &get_cpu_var(bpf_user_rnd_state);
1113         res = prandom_u32_state(state);
1114         put_cpu_var(bpf_user_rnd_state);
1115
1116         return res;
1117 }
1118
1119 /* Weak definitions of helper functions in case we don't have bpf syscall. */
1120 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
1121 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
1122 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
1123
1124 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
1125 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
1126 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
1127 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
1128
1129 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
1130 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
1131 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
1132
1133 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
1134 {
1135         return NULL;
1136 }
1137
1138 u64 __weak
1139 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
1140                  void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
1141 {
1142         return -ENOTSUPP;
1143 }
1144
1145 /* Always built-in helper functions. */
1146 const struct bpf_func_proto bpf_tail_call_proto = {
1147         .func           = NULL,
1148         .gpl_only       = false,
1149         .ret_type       = RET_VOID,
1150         .arg1_type      = ARG_PTR_TO_CTX,
1151         .arg2_type      = ARG_CONST_MAP_PTR,
1152         .arg3_type      = ARG_ANYTHING,
1153 };
1154
1155 /* For classic BPF JITs that don't implement bpf_int_jit_compile(). */
1156 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
1157 {
1158         return prog;
1159 }
1160
1161 bool __weak bpf_helper_changes_pkt_data(void *func)
1162 {
1163         return false;
1164 }
1165
1166 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
1167  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
1168  */
1169 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
1170                          int len)
1171 {
1172         return -EFAULT;
1173 }