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