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 <jschlst@samba.org>
  12  *      Alexei Starovoitov <ast@plumgrid.com>
  13  *      Daniel Borkmann <dborkman@redhat.com>
  14  *
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License
  17  * as published by the Free Software Foundation; either version
  18  * 2 of the License, or (at your option) any later version.
  19  *
  20  * Andi Kleen - Fix a few bad bugs and races.
  21  * Kris Katterjohn - Added many additional checks in bpf_check_classic()
  22  */
  23
  24 #include <linux/filter.h>
  25 #include <linux/skbuff.h>
  26 #include <linux/vmalloc.h>
  27 #include <linux/random.h>
  28 #include <linux/moduleloader.h>
  29 #include <linux/bpf.h>
  30 #include <linux/frame.h>
  31
  32 #include <asm/unaligned.h>
  33
  34 /* Registers */
  35 #define BPF_R0  regs[BPF_REG_0]
  36 #define BPF_R1  regs[BPF_REG_1]
  37 #define BPF_R2  regs[BPF_REG_2]
  38 #define BPF_R3  regs[BPF_REG_3]
  39 #define BPF_R4  regs[BPF_REG_4]
  40 #define BPF_R5  regs[BPF_REG_5]
  41 #define BPF_R6  regs[BPF_REG_6]
  42 #define BPF_R7  regs[BPF_REG_7]
  43 #define BPF_R8  regs[BPF_REG_8]
  44 #define BPF_R9  regs[BPF_REG_9]
  45 #define BPF_R10 regs[BPF_REG_10]
  46
  47 /* Named registers */
  48 #define DST     regs[insn->dst_reg]
  49 #define SRC     regs[insn->src_reg]
  50 #define FP      regs[BPF_REG_FP]
  51 #define ARG1    regs[BPF_REG_ARG1]
  52 #define CTX     regs[BPF_REG_CTX]
  53 #define IMM     insn->imm
  54
  55 /* No hurry in this branch
  56  *
  57  * Exported for the bpf jit load helper.
  58  */
  59 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
  60 {
  61         u8 *ptr = NULL;
  62
  63         if (k >= SKF_NET_OFF)
  64                 ptr = skb_network_header(skb) + k - SKF_NET_OFF;
  65         else if (k >= SKF_LL_OFF)
  66                 ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
  67
  68         if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
  69                 return ptr;
  70
  71         return NULL;
  72 }
  73
  74 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
  75 {
  76         gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO |
  77                           gfp_extra_flags;
  78         struct bpf_prog_aux *aux;
  79         struct bpf_prog *fp;
  80
  81         size = round_up(size, PAGE_SIZE);
  82         fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
  83         if (fp == NULL)
  84                 return NULL;
  85
  86         kmemcheck_annotate_bitfield(fp, meta);
  87
  88         aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags);
  89         if (aux == NULL) {
  90                 vfree(fp);
  91                 return NULL;
  92         }
  93
  94         fp->pages = size / PAGE_SIZE;
  95         fp->aux = aux;
  96         fp->aux->prog = fp;
  97
  98         return fp;
  99 }
 100 EXPORT_SYMBOL_GPL(bpf_prog_alloc);
 101
 102 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 103                                   gfp_t gfp_extra_flags)
 104 {
 105         gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO |
 106                           gfp_extra_flags;
 107         struct bpf_prog *fp;
 108
 109         BUG_ON(fp_old == NULL);
 110
 111         size = round_up(size, PAGE_SIZE);
 112         if (size <= fp_old->pages * PAGE_SIZE)
 113                 return fp_old;
 114
 115         fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
 116         if (fp != NULL) {
 117                 kmemcheck_annotate_bitfield(fp, meta);
 118
 119                 memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
 120                 fp->pages = size / PAGE_SIZE;
 121                 fp->aux->prog = fp;
 122
 123                 /* We keep fp->aux from fp_old around in the new
 124                  * reallocated structure.
 125                  */
 126                 fp_old->aux = NULL;
 127                 __bpf_prog_free(fp_old);
 128         }
 129
 130         return fp;
 131 }
 132
 133 void __bpf_prog_free(struct bpf_prog *fp)
 134 {
 135         kfree(fp->aux);
 136         vfree(fp);
 137 }
 138
 139 #define SHA_BPF_RAW_SIZE                                                \
 140         round_up(MAX_BPF_SIZE + sizeof(__be64) + 1, SHA_MESSAGE_BYTES)
 141
 142 /* Called under verifier mutex. */
 143 void bpf_prog_calc_digest(struct bpf_prog *fp)
 144 {
 145         const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64);
 146         static u32 ws[SHA_WORKSPACE_WORDS];
 147         static u8 raw[SHA_BPF_RAW_SIZE];
 148         struct bpf_insn *dst = (void *)raw;
 149         u32 i, bsize, psize, blocks;
 150         bool was_ld_map;
 151         u8 *todo = raw;
 152         __be32 *result;
 153         __be64 *bits;
 154
 155         sha_init(fp->digest);
 156         memset(ws, 0, sizeof(ws));
 157
 158         /* We need to take out the map fd for the digest calculation
 159          * since they are unstable from user space side.
 160          */
 161         for (i = 0, was_ld_map = false; i < fp->len; i++) {
 162                 dst[i] = fp->insnsi[i];
 163                 if (!was_ld_map &&
 164                     dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
 165                     dst[i].src_reg == BPF_PSEUDO_MAP_FD) {
 166                         was_ld_map = true;
 167                         dst[i].imm = 0;
 168                 } else if (was_ld_map &&
 169                            dst[i].code == 0 &&
 170                            dst[i].dst_reg == 0 &&
 171                            dst[i].src_reg == 0 &&
 172                            dst[i].off == 0) {
 173                         was_ld_map = false;
 174                         dst[i].imm = 0;
 175                 } else {
 176                         was_ld_map = false;
 177                 }
 178         }
 179
 180         psize = fp->len * sizeof(struct bpf_insn);
 181         memset(&raw[psize], 0, sizeof(raw) - psize);
 182         raw[psize++] = 0x80;
 183
 184         bsize  = round_up(psize, SHA_MESSAGE_BYTES);
 185         blocks = bsize / SHA_MESSAGE_BYTES;
 186         if (bsize - psize >= sizeof(__be64)) {
 187                 bits = (__be64 *)(todo + bsize - sizeof(__be64));
 188         } else {
 189                 bits = (__be64 *)(todo + bsize + bits_offset);
 190                 blocks++;
 191         }
 192         *bits = cpu_to_be64((psize - 1) << 3);
 193
 194         while (blocks--) {
 195                 sha_transform(fp->digest, todo, ws);
 196                 todo += SHA_MESSAGE_BYTES;
 197         }
 198
 199         result = (__force __be32 *)fp->digest;
 200         for (i = 0; i < SHA_DIGEST_WORDS; i++)
 201                 result[i] = cpu_to_be32(fp->digest[i]);
 202 }
 203
 204 static bool bpf_is_jmp_and_has_target(const struct bpf_insn *insn)
 205 {
 206         return BPF_CLASS(insn->code) == BPF_JMP  &&
 207                /* Call and Exit are both special jumps with no
 208                 * target inside the BPF instruction image.
 209                 */
 210                BPF_OP(insn->code) != BPF_CALL &&
 211                BPF_OP(insn->code) != BPF_EXIT;
 212 }
 213
 214 static void bpf_adj_branches(struct bpf_prog *prog, u32 pos, u32 delta)
 215 {
 216         struct bpf_insn *insn = prog->insnsi;
 217         u32 i, insn_cnt = prog->len;
 218
 219         for (i = 0; i < insn_cnt; i++, insn++) {
 220                 if (!bpf_is_jmp_and_has_target(insn))
 221                         continue;
 222
 223                 /* Adjust offset of jmps if we cross boundaries. */
 224                 if (i < pos && i + insn->off + 1 > pos)
 225                         insn->off += delta;
 226                 else if (i > pos + delta && i + insn->off + 1 <= pos + delta)
 227                         insn->off -= delta;
 228         }
 229 }
 230
 231 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
 232                                        const struct bpf_insn *patch, u32 len)
 233 {
 234         u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
 235         struct bpf_prog *prog_adj;
 236
 237         /* Since our patchlet doesn't expand the image, we're done. */
 238         if (insn_delta == 0) {
 239                 memcpy(prog->insnsi + off, patch, sizeof(*patch));
 240                 return prog;
 241         }
 242
 243         insn_adj_cnt = prog->len + insn_delta;
 244
 245         /* Several new instructions need to be inserted. Make room
 246          * for them. Likely, there's no need for a new allocation as
 247          * last page could have large enough tailroom.
 248          */
 249         prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
 250                                     GFP_USER);
 251         if (!prog_adj)
 252                 return NULL;
 253
 254         prog_adj->len = insn_adj_cnt;
 255
 256         /* Patching happens in 3 steps:
 257          *
 258          * 1) Move over tail of insnsi from next instruction onwards,
 259          *    so we can patch the single target insn with one or more
 260          *    new ones (patching is always from 1 to n insns, n > 0).
 261          * 2) Inject new instructions at the target location.
 262          * 3) Adjust branch offsets if necessary.
 263          */
 264         insn_rest = insn_adj_cnt - off - len;
 265
 266         memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
 267                 sizeof(*patch) * insn_rest);
 268         memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
 269
 270         bpf_adj_branches(prog_adj, off, insn_delta);
 271
 272         return prog_adj;
 273 }
 274
 275 #ifdef CONFIG_BPF_JIT
 276 struct bpf_binary_header *
 277 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
 278                      unsigned int alignment,
 279                      bpf_jit_fill_hole_t bpf_fill_ill_insns)
 280 {
 281         struct bpf_binary_header *hdr;
 282         unsigned int size, hole, start;
 283
 284         /* Most of BPF filters are really small, but if some of them
 285          * fill a page, allow at least 128 extra bytes to insert a
 286          * random section of illegal instructions.
 287          */
 288         size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
 289         hdr = module_alloc(size);
 290         if (hdr == NULL)
 291                 return NULL;
 292
 293         /* Fill space with illegal/arch-dep instructions. */
 294         bpf_fill_ill_insns(hdr, size);
 295
 296         hdr->pages = size / PAGE_SIZE;
 297         hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
 298                      PAGE_SIZE - sizeof(*hdr));
 299         start = (get_random_int() % hole) & ~(alignment - 1);
 300
 301         /* Leave a random number of instructions before BPF code. */
 302         *image_ptr = &hdr->image[start];
 303
 304         return hdr;
 305 }
 306
 307 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
 308 {
 309         module_memfree(hdr);
 310 }
 311
 312 int bpf_jit_harden __read_mostly;
 313
 314 static int bpf_jit_blind_insn(const struct bpf_insn *from,
 315                               const struct bpf_insn *aux,
 316                               struct bpf_insn *to_buff)
 317 {
 318         struct bpf_insn *to = to_buff;
 319         u32 imm_rnd = get_random_int();
 320         s16 off;
 321
 322         BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
 323         BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
 324
 325         if (from->imm == 0 &&
 326             (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
 327              from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
 328                 *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
 329                 goto out;
 330         }
 331
 332         switch (from->code) {
 333         case BPF_ALU | BPF_ADD | BPF_K:
 334         case BPF_ALU | BPF_SUB | BPF_K:
 335         case BPF_ALU | BPF_AND | BPF_K:
 336         case BPF_ALU | BPF_OR  | BPF_K:
 337         case BPF_ALU | BPF_XOR | BPF_K:
 338         case BPF_ALU | BPF_MUL | BPF_K:
 339         case BPF_ALU | BPF_MOV | BPF_K:
 340         case BPF_ALU | BPF_DIV | BPF_K:
 341         case BPF_ALU | BPF_MOD | BPF_K:
 342                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
 343                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 344                 *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
 345                 break;
 346
 347         case BPF_ALU64 | BPF_ADD | BPF_K:
 348         case BPF_ALU64 | BPF_SUB | BPF_K:
 349         case BPF_ALU64 | BPF_AND | BPF_K:
 350         case BPF_ALU64 | BPF_OR  | BPF_K:
 351         case BPF_ALU64 | BPF_XOR | BPF_K:
 352         case BPF_ALU64 | BPF_MUL | BPF_K:
 353         case BPF_ALU64 | BPF_MOV | BPF_K:
 354         case BPF_ALU64 | BPF_DIV | BPF_K:
 355         case BPF_ALU64 | BPF_MOD | BPF_K:
 356                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
 357                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 358                 *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
 359                 break;
 360
 361         case BPF_JMP | BPF_JEQ  | BPF_K:
 362         case BPF_JMP | BPF_JNE  | BPF_K:
 363         case BPF_JMP | BPF_JGT  | BPF_K:
 364         case BPF_JMP | BPF_JGE  | BPF_K:
 365         case BPF_JMP | BPF_JSGT | BPF_K:
 366         case BPF_JMP | BPF_JSGE | BPF_K:
 367         case BPF_JMP | BPF_JSET | BPF_K:
 368                 /* Accommodate for extra offset in case of a backjump. */
 369                 off = from->off;
 370                 if (off < 0)
 371                         off -= 2;
 372                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
 373                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 374                 *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
 375                 break;
 376
 377         case BPF_LD | BPF_ABS | BPF_W:
 378         case BPF_LD | BPF_ABS | BPF_H:
 379         case BPF_LD | BPF_ABS | BPF_B:
 380                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
 381                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 382                 *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0);
 383                 break;
 384
 385         case BPF_LD | BPF_IND | BPF_W:
 386         case BPF_LD | BPF_IND | BPF_H:
 387         case BPF_LD | BPF_IND | BPF_B:
 388                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
 389                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 390                 *to++ = BPF_ALU32_REG(BPF_ADD, BPF_REG_AX, from->src_reg);
 391                 *to++ = BPF_LD_IND(from->code, BPF_REG_AX, 0);
 392                 break;
 393
 394         case BPF_LD | BPF_IMM | BPF_DW:
 395                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
 396                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 397                 *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
 398                 *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
 399                 break;
 400         case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
 401                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
 402                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 403                 *to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
 404                 break;
 405
 406         case BPF_ST | BPF_MEM | BPF_DW:
 407         case BPF_ST | BPF_MEM | BPF_W:
 408         case BPF_ST | BPF_MEM | BPF_H:
 409         case BPF_ST | BPF_MEM | BPF_B:
 410                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
 411                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
 412                 *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
 413                 break;
 414         }
 415 out:
 416         return to - to_buff;
 417 }
 418
 419 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
 420                                               gfp_t gfp_extra_flags)
 421 {
 422         gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO |
 423                           gfp_extra_flags;
 424         struct bpf_prog *fp;
 425
 426         fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags, PAGE_KERNEL);
 427         if (fp != NULL) {
 428                 kmemcheck_annotate_bitfield(fp, meta);
 429
 430                 /* aux->prog still points to the fp_other one, so
 431                  * when promoting the clone to the real program,
 432                  * this still needs to be adapted.
 433                  */
 434                 memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
 435         }
 436
 437         return fp;
 438 }
 439
 440 static void bpf_prog_clone_free(struct bpf_prog *fp)
 441 {
 442         /* aux was stolen by the other clone, so we cannot free
 443          * it from this path! It will be freed eventually by the
 444          * other program on release.
 445          *
 446          * At this point, we don't need a deferred release since
 447          * clone is guaranteed to not be locked.
 448          */
 449         fp->aux = NULL;
 450         __bpf_prog_free(fp);
 451 }
 452
 453 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
 454 {
 455         /* We have to repoint aux->prog to self, as we don't
 456          * know whether fp here is the clone or the original.
 457          */
 458         fp->aux->prog = fp;
 459         bpf_prog_clone_free(fp_other);
 460 }
 461
 462 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
 463 {
 464         struct bpf_insn insn_buff[16], aux[2];
 465         struct bpf_prog *clone, *tmp;
 466         int insn_delta, insn_cnt;
 467         struct bpf_insn *insn;
 468         int i, rewritten;
 469
 470         if (!bpf_jit_blinding_enabled())
 471                 return prog;
 472
 473         clone = bpf_prog_clone_create(prog, GFP_USER);
 474         if (!clone)
 475                 return ERR_PTR(-ENOMEM);
 476
 477         insn_cnt = clone->len;
 478         insn = clone->insnsi;
 479
 480         for (i = 0; i < insn_cnt; i++, insn++) {
 481                 /* We temporarily need to hold the original ld64 insn
 482                  * so that we can still access the first part in the
 483                  * second blinding run.
 484                  */
 485                 if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
 486                     insn[1].code == 0)
 487                         memcpy(aux, insn, sizeof(aux));
 488
 489                 rewritten = bpf_jit_blind_insn(insn, aux, insn_buff);
 490                 if (!rewritten)
 491                         continue;
 492
 493                 tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
 494                 if (!tmp) {
 495                         /* Patching may have repointed aux->prog during
 496                          * realloc from the original one, so we need to
 497                          * fix it up here on error.
 498                          */
 499                         bpf_jit_prog_release_other(prog, clone);
 500                         return ERR_PTR(-ENOMEM);
 501                 }
 502
 503                 clone = tmp;
 504                 insn_delta = rewritten - 1;
 505
 506                 /* Walk new program and skip insns we just inserted. */
 507                 insn = clone->insnsi + i + insn_delta;
 508                 insn_cnt += insn_delta;
 509                 i        += insn_delta;
 510         }
 511
 512         return clone;
 513 }
 514 #endif /* CONFIG_BPF_JIT */
 515
 516 /* Base function for offset calculation. Needs to go into .text section,
 517  * therefore keeping it non-static as well; will also be used by JITs
 518  * anyway later on, so do not let the compiler omit it.
 519  */
 520 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
 521 {
 522         return 0;
 523 }
 524 EXPORT_SYMBOL_GPL(__bpf_call_base);
 525
 526 /**
 527  *      __bpf_prog_run - run eBPF program on a given context
 528  *      @ctx: is the data we are operating on
 529  *      @insn: is the array of eBPF instructions
 530  *
 531  * Decode and execute eBPF instructions.
 532  */
 533 static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn)
 534 {
 535         u64 stack[MAX_BPF_STACK / sizeof(u64)];
 536         u64 regs[MAX_BPF_REG], tmp;
 537         static const void *jumptable[256] = {
 538                 [0 ... 255] = &&default_label,
 539                 /* Now overwrite non-defaults ... */
 540                 /* 32 bit ALU operations */
 541                 [BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X,
 542                 [BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K,
 543                 [BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X,
 544                 [BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K,
 545                 [BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X,
 546                 [BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K,
 547                 [BPF_ALU | BPF_OR | BPF_X]  = &&ALU_OR_X,
 548                 [BPF_ALU | BPF_OR | BPF_K]  = &&ALU_OR_K,
 549                 [BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X,
 550                 [BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K,
 551                 [BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X,
 552                 [BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K,
 553                 [BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X,
 554                 [BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K,
 555                 [BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X,
 556                 [BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K,
 557                 [BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X,
 558                 [BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K,
 559                 [BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X,
 560                 [BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K,
 561                 [BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X,
 562                 [BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K,
 563                 [BPF_ALU | BPF_NEG] = &&ALU_NEG,
 564                 [BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE,
 565                 [BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE,
 566                 /* 64 bit ALU operations */
 567                 [BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X,
 568                 [BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K,
 569                 [BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X,
 570                 [BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K,
 571                 [BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X,
 572                 [BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K,
 573                 [BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X,
 574                 [BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K,
 575                 [BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X,
 576                 [BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K,
 577                 [BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X,
 578                 [BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K,
 579                 [BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X,
 580                 [BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K,
 581                 [BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X,
 582                 [BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K,
 583                 [BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X,
 584                 [BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K,
 585                 [BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X,
 586                 [BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K,
 587                 [BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X,
 588                 [BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K,
 589                 [BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X,
 590                 [BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K,
 591                 [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG,
 592                 /* Call instruction */
 593                 [BPF_JMP | BPF_CALL] = &&JMP_CALL,
 594                 [BPF_JMP | BPF_CALL | BPF_X] = &&JMP_TAIL_CALL,
 595                 /* Jumps */
 596                 [BPF_JMP | BPF_JA] = &&JMP_JA,
 597                 [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X,
 598                 [BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K,
 599                 [BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X,
 600                 [BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K,
 601                 [BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X,
 602                 [BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K,
 603                 [BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X,
 604                 [BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K,
 605                 [BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X,
 606                 [BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K,
 607                 [BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X,
 608                 [BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K,
 609                 [BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X,
 610                 [BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K,
 611                 /* Program return */
 612                 [BPF_JMP | BPF_EXIT] = &&JMP_EXIT,
 613                 /* Store instructions */
 614                 [BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B,
 615                 [BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H,
 616                 [BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W,
 617                 [BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW,
 618                 [BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W,
 619                 [BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW,
 620                 [BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B,
 621                 [BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H,
 622                 [BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W,
 623                 [BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW,
 624                 /* Load instructions */
 625                 [BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B,
 626                 [BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H,
 627                 [BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W,
 628                 [BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW,
 629                 [BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W,
 630                 [BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H,
 631                 [BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B,
 632                 [BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W,
 633                 [BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H,
 634                 [BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B,
 635                 [BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW,
 636         };
 637         u32 tail_call_cnt = 0;
 638         void *ptr;
 639         int off;
 640
 641 #define CONT     ({ insn++; goto select_insn; })
 642 #define CONT_JMP ({ insn++; goto select_insn; })
 643
 644         FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)];
 645         ARG1 = (u64) (unsigned long) ctx;
 646
 647 select_insn:
 648         goto *jumptable[insn->code];
 649
 650         /* ALU */
 651 #define ALU(OPCODE, OP)                 \
 652         ALU64_##OPCODE##_X:             \
 653                 DST = DST OP SRC;       \
 654                 CONT;                   \
 655         ALU_##OPCODE##_X:               \
 656                 DST = (u32) DST OP (u32) SRC;   \
 657                 CONT;                   \
 658         ALU64_##OPCODE##_K:             \
 659                 DST = DST OP IMM;               \
 660                 CONT;                   \
 661         ALU_##OPCODE##_K:               \
 662                 DST = (u32) DST OP (u32) IMM;   \
 663                 CONT;
 664
 665         ALU(ADD,  +)
 666         ALU(SUB,  -)
 667         ALU(AND,  &)
 668         ALU(OR,   |)
 669         ALU(LSH, <<)
 670         ALU(RSH, >>)
 671         ALU(XOR,  ^)
 672         ALU(MUL,  *)
 673 #undef ALU
 674         ALU_NEG:
 675                 DST = (u32) -DST;
 676                 CONT;
 677         ALU64_NEG:
 678                 DST = -DST;
 679                 CONT;
 680         ALU_MOV_X:
 681                 DST = (u32) SRC;
 682                 CONT;
 683         ALU_MOV_K:
 684                 DST = (u32) IMM;
 685                 CONT;
 686         ALU64_MOV_X:
 687                 DST = SRC;
 688                 CONT;
 689         ALU64_MOV_K:
 690                 DST = IMM;
 691                 CONT;
 692         LD_IMM_DW:
 693                 DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
 694                 insn++;
 695                 CONT;
 696         ALU64_ARSH_X:
 697                 (*(s64 *) &DST) >>= SRC;
 698                 CONT;
 699         ALU64_ARSH_K:
 700                 (*(s64 *) &DST) >>= IMM;
 701                 CONT;
 702         ALU64_MOD_X:
 703                 if (unlikely(SRC == 0))
 704                         return 0;
 705                 div64_u64_rem(DST, SRC, &tmp);
 706                 DST = tmp;
 707                 CONT;
 708         ALU_MOD_X:
 709                 if (unlikely(SRC == 0))
 710                         return 0;
 711                 tmp = (u32) DST;
 712                 DST = do_div(tmp, (u32) SRC);
 713                 CONT;
 714         ALU64_MOD_K:
 715                 div64_u64_rem(DST, IMM, &tmp);
 716                 DST = tmp;
 717                 CONT;
 718         ALU_MOD_K:
 719                 tmp = (u32) DST;
 720                 DST = do_div(tmp, (u32) IMM);
 721                 CONT;
 722         ALU64_DIV_X:
 723                 if (unlikely(SRC == 0))
 724                         return 0;
 725                 DST = div64_u64(DST, SRC);
 726                 CONT;
 727         ALU_DIV_X:
 728                 if (unlikely(SRC == 0))
 729                         return 0;
 730                 tmp = (u32) DST;
 731                 do_div(tmp, (u32) SRC);
 732                 DST = (u32) tmp;
 733                 CONT;
 734         ALU64_DIV_K:
 735                 DST = div64_u64(DST, IMM);
 736                 CONT;
 737         ALU_DIV_K:
 738                 tmp = (u32) DST;
 739                 do_div(tmp, (u32) IMM);
 740                 DST = (u32) tmp;
 741                 CONT;
 742         ALU_END_TO_BE:
 743                 switch (IMM) {
 744                 case 16:
 745                         DST = (__force u16) cpu_to_be16(DST);
 746                         break;
 747                 case 32:
 748                         DST = (__force u32) cpu_to_be32(DST);
 749                         break;
 750                 case 64:
 751                         DST = (__force u64) cpu_to_be64(DST);
 752                         break;
 753                 }
 754                 CONT;
 755         ALU_END_TO_LE:
 756                 switch (IMM) {
 757                 case 16:
 758                         DST = (__force u16) cpu_to_le16(DST);
 759                         break;
 760                 case 32:
 761                         DST = (__force u32) cpu_to_le32(DST);
 762                         break;
 763                 case 64:
 764                         DST = (__force u64) cpu_to_le64(DST);
 765                         break;
 766                 }
 767                 CONT;
 768
 769         /* CALL */
 770         JMP_CALL:
 771                 /* Function call scratches BPF_R1-BPF_R5 registers,
 772                  * preserves BPF_R6-BPF_R9, and stores return value
 773                  * into BPF_R0.
 774                  */
 775                 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
 776                                                        BPF_R4, BPF_R5);
 777                 CONT;
 778
 779         JMP_TAIL_CALL: {
 780                 struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
 781                 struct bpf_array *array = container_of(map, struct bpf_array, map);
 782                 struct bpf_prog *prog;
 783                 u64 index = BPF_R3;
 784
 785                 if (unlikely(index >= array->map.max_entries))
 786                         goto out;
 787                 if (unlikely(tail_call_cnt > MAX_TAIL_CALL_CNT))
 788                         goto out;
 789
 790                 tail_call_cnt++;
 791
 792                 prog = READ_ONCE(array->ptrs[index]);
 793                 if (!prog)
 794                         goto out;
 795
 796                 /* ARG1 at this point is guaranteed to point to CTX from
 797                  * the verifier side due to the fact that the tail call is
 798                  * handeled like a helper, that is, bpf_tail_call_proto,
 799                  * where arg1_type is ARG_PTR_TO_CTX.
 800                  */
 801                 insn = prog->insnsi;
 802                 goto select_insn;
 803 out:
 804                 CONT;
 805         }
 806         /* JMP */
 807         JMP_JA:
 808                 insn += insn->off;
 809                 CONT;
 810         JMP_JEQ_X:
 811                 if (DST == SRC) {
 812                         insn += insn->off;
 813                         CONT_JMP;
 814                 }
 815                 CONT;
 816         JMP_JEQ_K:
 817                 if (DST == IMM) {
 818                         insn += insn->off;
 819                         CONT_JMP;
 820                 }
 821                 CONT;
 822         JMP_JNE_X:
 823                 if (DST != SRC) {
 824                         insn += insn->off;
 825                         CONT_JMP;
 826                 }
 827                 CONT;
 828         JMP_JNE_K:
 829                 if (DST != IMM) {
 830                         insn += insn->off;
 831                         CONT_JMP;
 832                 }
 833                 CONT;
 834         JMP_JGT_X:
 835                 if (DST > SRC) {
 836                         insn += insn->off;
 837                         CONT_JMP;
 838                 }
 839                 CONT;
 840         JMP_JGT_K:
 841                 if (DST > IMM) {
 842                         insn += insn->off;
 843                         CONT_JMP;
 844                 }
 845                 CONT;
 846         JMP_JGE_X:
 847                 if (DST >= SRC) {
 848                         insn += insn->off;
 849                         CONT_JMP;
 850                 }
 851                 CONT;
 852         JMP_JGE_K:
 853                 if (DST >= IMM) {
 854                         insn += insn->off;
 855                         CONT_JMP;
 856                 }
 857                 CONT;
 858         JMP_JSGT_X:
 859                 if (((s64) DST) > ((s64) SRC)) {
 860                         insn += insn->off;
 861                         CONT_JMP;
 862                 }
 863                 CONT;
 864         JMP_JSGT_K:
 865                 if (((s64) DST) > ((s64) IMM)) {
 866                         insn += insn->off;
 867                         CONT_JMP;
 868                 }
 869                 CONT;
 870         JMP_JSGE_X:
 871                 if (((s64) DST) >= ((s64) SRC)) {
 872                         insn += insn->off;
 873                         CONT_JMP;
 874                 }
 875                 CONT;
 876         JMP_JSGE_K:
 877                 if (((s64) DST) >= ((s64) IMM)) {
 878                         insn += insn->off;
 879                         CONT_JMP;
 880                 }
 881                 CONT;
 882         JMP_JSET_X:
 883                 if (DST & SRC) {
 884                         insn += insn->off;
 885                         CONT_JMP;
 886                 }
 887                 CONT;
 888         JMP_JSET_K:
 889                 if (DST & IMM) {
 890                         insn += insn->off;
 891                         CONT_JMP;
 892                 }
 893                 CONT;
 894         JMP_EXIT:
 895                 return BPF_R0;
 896
 897         /* STX and ST and LDX*/
 898 #define LDST(SIZEOP, SIZE)                                              \
 899         STX_MEM_##SIZEOP:                                               \
 900                 *(SIZE *)(unsigned long) (DST + insn->off) = SRC;       \
 901                 CONT;                                                   \
 902         ST_MEM_##SIZEOP:                                                \
 903                 *(SIZE *)(unsigned long) (DST + insn->off) = IMM;       \
 904                 CONT;                                                   \
 905         LDX_MEM_##SIZEOP:                                               \
 906                 DST = *(SIZE *)(unsigned long) (SRC + insn->off);       \
 907                 CONT;
 908
 909         LDST(B,   u8)
 910         LDST(H,  u16)
 911         LDST(W,  u32)
 912         LDST(DW, u64)
 913 #undef LDST
 914         STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */
 915                 atomic_add((u32) SRC, (atomic_t *)(unsigned long)
 916                            (DST + insn->off));
 917                 CONT;
 918         STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */
 919                 atomic64_add((u64) SRC, (atomic64_t *)(unsigned long)
 920                              (DST + insn->off));
 921                 CONT;
 922         LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */
 923                 off = IMM;
 924 load_word:
 925                 /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are
 926                  * only appearing in the programs where ctx ==
 927                  * skb. All programs keep 'ctx' in regs[BPF_REG_CTX]
 928                  * == BPF_R6, bpf_convert_filter() saves it in BPF_R6,
 929                  * internal BPF verifier will check that BPF_R6 ==
 930                  * ctx.
 931                  *
 932                  * BPF_ABS and BPF_IND are wrappers of function calls,
 933                  * so they scratch BPF_R1-BPF_R5 registers, preserve
 934                  * BPF_R6-BPF_R9, and store return value into BPF_R0.
 935                  *
 936                  * Implicit input:
 937                  *   ctx == skb == BPF_R6 == CTX
 938                  *
 939                  * Explicit input:
 940                  *   SRC == any register
 941                  *   IMM == 32-bit immediate
 942                  *
 943                  * Output:
 944                  *   BPF_R0 - 8/16/32-bit skb data converted to cpu endianness
 945                  */
 946
 947                 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp);
 948                 if (likely(ptr != NULL)) {
 949                         BPF_R0 = get_unaligned_be32(ptr);
 950                         CONT;
 951                 }
 952
 953                 return 0;
 954         LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */
 955                 off = IMM;
 956 load_half:
 957                 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp);
 958                 if (likely(ptr != NULL)) {
 959                         BPF_R0 = get_unaligned_be16(ptr);
 960                         CONT;
 961                 }
 962
 963                 return 0;
 964         LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */
 965                 off = IMM;
 966 load_byte:
 967                 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp);
 968                 if (likely(ptr != NULL)) {
 969                         BPF_R0 = *(u8 *)ptr;
 970                         CONT;
 971                 }
 972
 973                 return 0;
 974         LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */
 975                 off = IMM + SRC;
 976                 goto load_word;
 977         LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */
 978                 off = IMM + SRC;
 979                 goto load_half;
 980         LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */
 981                 off = IMM + SRC;
 982                 goto load_byte;
 983
 984         default_label:
 985                 /* If we ever reach this, we have a bug somewhere. */
 986                 WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code);
 987                 return 0;
 988 }
 989 STACK_FRAME_NON_STANDARD(__bpf_prog_run); /* jump table */
 990
 991 bool bpf_prog_array_compatible(struct bpf_array *array,
 992                                const struct bpf_prog *fp)
 993 {
 994         if (!array->owner_prog_type) {
 995                 /* There's no owner yet where we could check for
 996                  * compatibility.
 997                  */
 998                 array->owner_prog_type = fp->type;
 999                 array->owner_jited = fp->jited;
1000
1001                 return true;
1002         }
1003
1004         return array->owner_prog_type == fp->type &&
1005                array->owner_jited == fp->jited;
1006 }
1007
1008 static int bpf_check_tail_call(const struct bpf_prog *fp)
1009 {
1010         struct bpf_prog_aux *aux = fp->aux;
1011         int i;
1012
1013         for (i = 0; i < aux->used_map_cnt; i++) {
1014                 struct bpf_map *map = aux->used_maps[i];
1015                 struct bpf_array *array;
1016
1017                 if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
1018                         continue;
1019
1020                 array = container_of(map, struct bpf_array, map);
1021                 if (!bpf_prog_array_compatible(array, fp))
1022                         return -EINVAL;
1023         }
1024
1025         return 0;
1026 }
1027
1028 /**
1029  *      bpf_prog_select_runtime - select exec runtime for BPF program
1030  *      @fp: bpf_prog populated with internal BPF program
1031  *      @err: pointer to error variable
1032  *
1033  * Try to JIT eBPF program, if JIT is not available, use interpreter.
1034  * The BPF program will be executed via BPF_PROG_RUN() macro.
1035  */
1036 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
1037 {
1038         fp->bpf_func = (void *) __bpf_prog_run;
1039
1040         /* eBPF JITs can rewrite the program in case constant
1041          * blinding is active. However, in case of error during
1042          * blinding, bpf_int_jit_compile() must always return a
1043          * valid program, which in this case would simply not
1044          * be JITed, but falls back to the interpreter.
1045          */
1046         fp = bpf_int_jit_compile(fp);
1047         bpf_prog_lock_ro(fp);
1048
1049         /* The tail call compatibility check can only be done at
1050          * this late stage as we need to determine, if we deal
1051          * with JITed or non JITed program concatenations and not
1052          * all eBPF JITs might immediately support all features.
1053          */
1054         *err = bpf_check_tail_call(fp);
1055
1056         return fp;
1057 }
1058 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
1059
1060 static void bpf_prog_free_deferred(struct work_struct *work)
1061 {
1062         struct bpf_prog_aux *aux;
1063
1064         aux = container_of(work, struct bpf_prog_aux, work);
1065         bpf_jit_free(aux->prog);
1066 }
1067
1068 /* Free internal BPF program */
1069 void bpf_prog_free(struct bpf_prog *fp)
1070 {
1071         struct bpf_prog_aux *aux = fp->aux;
1072
1073         INIT_WORK(&aux->work, bpf_prog_free_deferred);
1074         schedule_work(&aux->work);
1075 }
1076 EXPORT_SYMBOL_GPL(bpf_prog_free);
1077
1078 /* RNG for unpriviledged user space with separated state from prandom_u32(). */
1079 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
1080
1081 void bpf_user_rnd_init_once(void)
1082 {
1083         prandom_init_once(&bpf_user_rnd_state);
1084 }
1085
1086 BPF_CALL_0(bpf_user_rnd_u32)
1087 {
1088         /* Should someone ever have the rather unwise idea to use some
1089          * of the registers passed into this function, then note that
1090          * this function is called from native eBPF and classic-to-eBPF
1091          * transformations. Register assignments from both sides are
1092          * different, f.e. classic always sets fn(ctx, A, X) here.
1093          */
1094         struct rnd_state *state;
1095         u32 res;
1096
1097         state = &get_cpu_var(bpf_user_rnd_state);
1098         res = prandom_u32_state(state);
1099         put_cpu_var(bpf_user_rnd_state);
1100
1101         return res;
1102 }
1103
1104 /* Weak definitions of helper functions in case we don't have bpf syscall. */
1105 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
1106 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
1107 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
1108
1109 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
1110 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
1111 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
1112 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
1113
1114 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
1115 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
1116 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
1117
1118 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
1119 {
1120         return NULL;
1121 }
1122
1123 u64 __weak
1124 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
1125                  void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
1126 {
1127         return -ENOTSUPP;
1128 }
1129
1130 /* Always built-in helper functions. */
1131 const struct bpf_func_proto bpf_tail_call_proto = {
1132         .func           = NULL,
1133         .gpl_only       = false,
1134         .ret_type       = RET_VOID,
1135         .arg1_type      = ARG_PTR_TO_CTX,
1136         .arg2_type      = ARG_CONST_MAP_PTR,
1137         .arg3_type      = ARG_ANYTHING,
1138 };
1139
1140 /* For classic BPF JITs that don't implement bpf_int_jit_compile(). */
1141 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
1142 {
1143         return prog;
1144 }
1145
1146 bool __weak bpf_helper_changes_skb_data(void *func)
1147 {
1148         return false;
1149 }
1150
1151 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
1152  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
1153  */
1154 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
1155                          int len)
1156 {
1157         return -EFAULT;
1158 }