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 #include <linux/filter.h>
  24 #include <linux/skbuff.h>
  25 #include <asm/unaligned.h>
  26
  27 /* Registers */
  28 #define BPF_R0  regs[BPF_REG_0]
  29 #define BPF_R1  regs[BPF_REG_1]
  30 #define BPF_R2  regs[BPF_REG_2]
  31 #define BPF_R3  regs[BPF_REG_3]
  32 #define BPF_R4  regs[BPF_REG_4]
  33 #define BPF_R5  regs[BPF_REG_5]
  34 #define BPF_R6  regs[BPF_REG_6]
  35 #define BPF_R7  regs[BPF_REG_7]
  36 #define BPF_R8  regs[BPF_REG_8]
  37 #define BPF_R9  regs[BPF_REG_9]
  38 #define BPF_R10 regs[BPF_REG_10]
  39
  40 /* Named registers */
  41 #define DST     regs[insn->dst_reg]
  42 #define SRC     regs[insn->src_reg]
  43 #define FP      regs[BPF_REG_FP]
  44 #define ARG1    regs[BPF_REG_ARG1]
  45 #define CTX     regs[BPF_REG_CTX]
  46 #define IMM     insn->imm
  47
  48 /* No hurry in this branch
  49  *
  50  * Exported for the bpf jit load helper.
  51  */
  52 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
  53 {
  54         u8 *ptr = NULL;
  55
  56         if (k >= SKF_NET_OFF)
  57                 ptr = skb_network_header(skb) + k - SKF_NET_OFF;
  58         else if (k >= SKF_LL_OFF)
  59                 ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
  60         if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
  61                 return ptr;
  62
  63         return NULL;
  64 }
  65
  66 /* Base function for offset calculation. Needs to go into .text section,
  67  * therefore keeping it non-static as well; will also be used by JITs
  68  * anyway later on, so do not let the compiler omit it.
  69  */
  70 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
  71 {
  72         return 0;
  73 }
  74
  75 /**
  76  *      __sk_run_filter - run a filter on a given context
  77  *      @ctx: buffer to run the filter on
  78  *      @insn: filter to apply
  79  *
  80  * Decode and apply filter instructions to the skb->data. Return length to
  81  * keep, 0 for none. @ctx is the data we are operating on, @insn is the
  82  * array of filter instructions.
  83  */
  84 static unsigned int __sk_run_filter(void *ctx, const struct bpf_insn *insn)
  85 {
  86         u64 stack[MAX_BPF_STACK / sizeof(u64)];
  87         u64 regs[MAX_BPF_REG], tmp;
  88         static const void *jumptable[256] = {
  89                 [0 ... 255] = &&default_label,
  90                 /* Now overwrite non-defaults ... */
  91                 /* 32 bit ALU operations */
  92                 [BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X,
  93                 [BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K,
  94                 [BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X,
  95                 [BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K,
  96                 [BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X,
  97                 [BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K,
  98                 [BPF_ALU | BPF_OR | BPF_X]  = &&ALU_OR_X,
  99                 [BPF_ALU | BPF_OR | BPF_K]  = &&ALU_OR_K,
 100                 [BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X,
 101                 [BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K,
 102                 [BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X,
 103                 [BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K,
 104                 [BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X,
 105                 [BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K,
 106                 [BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X,
 107                 [BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K,
 108                 [BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X,
 109                 [BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K,
 110                 [BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X,
 111                 [BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K,
 112                 [BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X,
 113                 [BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K,
 114                 [BPF_ALU | BPF_NEG] = &&ALU_NEG,
 115                 [BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE,
 116                 [BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE,
 117                 /* 64 bit ALU operations */
 118                 [BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X,
 119                 [BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K,
 120                 [BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X,
 121                 [BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K,
 122                 [BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X,
 123                 [BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K,
 124                 [BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X,
 125                 [BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K,
 126                 [BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X,
 127                 [BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K,
 128                 [BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X,
 129                 [BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K,
 130                 [BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X,
 131                 [BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K,
 132                 [BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X,
 133                 [BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K,
 134                 [BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X,
 135                 [BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K,
 136                 [BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X,
 137                 [BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K,
 138                 [BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X,
 139                 [BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K,
 140                 [BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X,
 141                 [BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K,
 142                 [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG,
 143                 /* Call instruction */
 144                 [BPF_JMP | BPF_CALL] = &&JMP_CALL,
 145                 /* Jumps */
 146                 [BPF_JMP | BPF_JA] = &&JMP_JA,
 147                 [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X,
 148                 [BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K,
 149                 [BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X,
 150                 [BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K,
 151                 [BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X,
 152                 [BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K,
 153                 [BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X,
 154                 [BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K,
 155                 [BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X,
 156                 [BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K,
 157                 [BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X,
 158                 [BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K,
 159                 [BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X,
 160                 [BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K,
 161                 /* Program return */
 162                 [BPF_JMP | BPF_EXIT] = &&JMP_EXIT,
 163                 /* Store instructions */
 164                 [BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B,
 165                 [BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H,
 166                 [BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W,
 167                 [BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW,
 168                 [BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W,
 169                 [BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW,
 170                 [BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B,
 171                 [BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H,
 172                 [BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W,
 173                 [BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW,
 174                 /* Load instructions */
 175                 [BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B,
 176                 [BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H,
 177                 [BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W,
 178                 [BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW,
 179                 [BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W,
 180                 [BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H,
 181                 [BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B,
 182                 [BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W,
 183                 [BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H,
 184                 [BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B,
 185         };
 186         void *ptr;
 187         int off;
 188
 189 #define CONT     ({ insn++; goto select_insn; })
 190 #define CONT_JMP ({ insn++; goto select_insn; })
 191
 192         FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)];
 193         ARG1 = (u64) (unsigned long) ctx;
 194
 195         /* Registers used in classic BPF programs need to be reset first. */
 196         regs[BPF_REG_A] = 0;
 197         regs[BPF_REG_X] = 0;
 198
 199 select_insn:
 200         goto *jumptable[insn->code];
 201
 202         /* ALU */
 203 #define ALU(OPCODE, OP)                 \
 204         ALU64_##OPCODE##_X:             \
 205                 DST = DST OP SRC;       \
 206                 CONT;                   \
 207         ALU_##OPCODE##_X:               \
 208                 DST = (u32) DST OP (u32) SRC;   \
 209                 CONT;                   \
 210         ALU64_##OPCODE##_K:             \
 211                 DST = DST OP IMM;               \
 212                 CONT;                   \
 213         ALU_##OPCODE##_K:               \
 214                 DST = (u32) DST OP (u32) IMM;   \
 215                 CONT;
 216
 217         ALU(ADD,  +)
 218         ALU(SUB,  -)
 219         ALU(AND,  &)
 220         ALU(OR,   |)
 221         ALU(LSH, <<)
 222         ALU(RSH, >>)
 223         ALU(XOR,  ^)
 224         ALU(MUL,  *)
 225 #undef ALU
 226         ALU_NEG:
 227                 DST = (u32) -DST;
 228                 CONT;
 229         ALU64_NEG:
 230                 DST = -DST;
 231                 CONT;
 232         ALU_MOV_X:
 233                 DST = (u32) SRC;
 234                 CONT;
 235         ALU_MOV_K:
 236                 DST = (u32) IMM;
 237                 CONT;
 238         ALU64_MOV_X:
 239                 DST = SRC;
 240                 CONT;
 241         ALU64_MOV_K:
 242                 DST = IMM;
 243                 CONT;
 244         ALU64_ARSH_X:
 245                 (*(s64 *) &DST) >>= SRC;
 246                 CONT;
 247         ALU64_ARSH_K:
 248                 (*(s64 *) &DST) >>= IMM;
 249                 CONT;
 250         ALU64_MOD_X:
 251                 if (unlikely(SRC == 0))
 252                         return 0;
 253                 tmp = DST;
 254                 DST = do_div(tmp, SRC);
 255                 CONT;
 256         ALU_MOD_X:
 257                 if (unlikely(SRC == 0))
 258                         return 0;
 259                 tmp = (u32) DST;
 260                 DST = do_div(tmp, (u32) SRC);
 261                 CONT;
 262         ALU64_MOD_K:
 263                 tmp = DST;
 264                 DST = do_div(tmp, IMM);
 265                 CONT;
 266         ALU_MOD_K:
 267                 tmp = (u32) DST;
 268                 DST = do_div(tmp, (u32) IMM);
 269                 CONT;
 270         ALU64_DIV_X:
 271                 if (unlikely(SRC == 0))
 272                         return 0;
 273                 do_div(DST, SRC);
 274                 CONT;
 275         ALU_DIV_X:
 276                 if (unlikely(SRC == 0))
 277                         return 0;
 278                 tmp = (u32) DST;
 279                 do_div(tmp, (u32) SRC);
 280                 DST = (u32) tmp;
 281                 CONT;
 282         ALU64_DIV_K:
 283                 do_div(DST, IMM);
 284                 CONT;
 285         ALU_DIV_K:
 286                 tmp = (u32) DST;
 287                 do_div(tmp, (u32) IMM);
 288                 DST = (u32) tmp;
 289                 CONT;
 290         ALU_END_TO_BE:
 291                 switch (IMM) {
 292                 case 16:
 293                         DST = (__force u16) cpu_to_be16(DST);
 294                         break;
 295                 case 32:
 296                         DST = (__force u32) cpu_to_be32(DST);
 297                         break;
 298                 case 64:
 299                         DST = (__force u64) cpu_to_be64(DST);
 300                         break;
 301                 }
 302                 CONT;
 303         ALU_END_TO_LE:
 304                 switch (IMM) {
 305                 case 16:
 306                         DST = (__force u16) cpu_to_le16(DST);
 307                         break;
 308                 case 32:
 309                         DST = (__force u32) cpu_to_le32(DST);
 310                         break;
 311                 case 64:
 312                         DST = (__force u64) cpu_to_le64(DST);
 313                         break;
 314                 }
 315                 CONT;
 316
 317         /* CALL */
 318         JMP_CALL:
 319                 /* Function call scratches BPF_R1-BPF_R5 registers,
 320                  * preserves BPF_R6-BPF_R9, and stores return value
 321                  * into BPF_R0.
 322                  */
 323                 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
 324                                                        BPF_R4, BPF_R5);
 325                 CONT;
 326
 327         /* JMP */
 328         JMP_JA:
 329                 insn += insn->off;
 330                 CONT;
 331         JMP_JEQ_X:
 332                 if (DST == SRC) {
 333                         insn += insn->off;
 334                         CONT_JMP;
 335                 }
 336                 CONT;
 337         JMP_JEQ_K:
 338                 if (DST == IMM) {
 339                         insn += insn->off;
 340                         CONT_JMP;
 341                 }
 342                 CONT;
 343         JMP_JNE_X:
 344                 if (DST != SRC) {
 345                         insn += insn->off;
 346                         CONT_JMP;
 347                 }
 348                 CONT;
 349         JMP_JNE_K:
 350                 if (DST != IMM) {
 351                         insn += insn->off;
 352                         CONT_JMP;
 353                 }
 354                 CONT;
 355         JMP_JGT_X:
 356                 if (DST > SRC) {
 357                         insn += insn->off;
 358                         CONT_JMP;
 359                 }
 360                 CONT;
 361         JMP_JGT_K:
 362                 if (DST > IMM) {
 363                         insn += insn->off;
 364                         CONT_JMP;
 365                 }
 366                 CONT;
 367         JMP_JGE_X:
 368                 if (DST >= SRC) {
 369                         insn += insn->off;
 370                         CONT_JMP;
 371                 }
 372                 CONT;
 373         JMP_JGE_K:
 374                 if (DST >= IMM) {
 375                         insn += insn->off;
 376                         CONT_JMP;
 377                 }
 378                 CONT;
 379         JMP_JSGT_X:
 380                 if (((s64) DST) > ((s64) SRC)) {
 381                         insn += insn->off;
 382                         CONT_JMP;
 383                 }
 384                 CONT;
 385         JMP_JSGT_K:
 386                 if (((s64) DST) > ((s64) IMM)) {
 387                         insn += insn->off;
 388                         CONT_JMP;
 389                 }
 390                 CONT;
 391         JMP_JSGE_X:
 392                 if (((s64) DST) >= ((s64) SRC)) {
 393                         insn += insn->off;
 394                         CONT_JMP;
 395                 }
 396                 CONT;
 397         JMP_JSGE_K:
 398                 if (((s64) DST) >= ((s64) IMM)) {
 399                         insn += insn->off;
 400                         CONT_JMP;
 401                 }
 402                 CONT;
 403         JMP_JSET_X:
 404                 if (DST & SRC) {
 405                         insn += insn->off;
 406                         CONT_JMP;
 407                 }
 408                 CONT;
 409         JMP_JSET_K:
 410                 if (DST & IMM) {
 411                         insn += insn->off;
 412                         CONT_JMP;
 413                 }
 414                 CONT;
 415         JMP_EXIT:
 416                 return BPF_R0;
 417
 418         /* STX and ST and LDX*/
 419 #define LDST(SIZEOP, SIZE)                                              \
 420         STX_MEM_##SIZEOP:                                               \
 421                 *(SIZE *)(unsigned long) (DST + insn->off) = SRC;       \
 422                 CONT;                                                   \
 423         ST_MEM_##SIZEOP:                                                \
 424                 *(SIZE *)(unsigned long) (DST + insn->off) = IMM;       \
 425                 CONT;                                                   \
 426         LDX_MEM_##SIZEOP:                                               \
 427                 DST = *(SIZE *)(unsigned long) (SRC + insn->off);       \
 428                 CONT;
 429
 430         LDST(B,   u8)
 431         LDST(H,  u16)
 432         LDST(W,  u32)
 433         LDST(DW, u64)
 434 #undef LDST
 435         STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */
 436                 atomic_add((u32) SRC, (atomic_t *)(unsigned long)
 437                            (DST + insn->off));
 438                 CONT;
 439         STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */
 440                 atomic64_add((u64) SRC, (atomic64_t *)(unsigned long)
 441                              (DST + insn->off));
 442                 CONT;
 443         LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */
 444                 off = IMM;
 445 load_word:
 446                 /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are
 447                  * only appearing in the programs where ctx ==
 448                  * skb. All programs keep 'ctx' in regs[BPF_REG_CTX]
 449                  * == BPF_R6, sk_convert_filter() saves it in BPF_R6,
 450                  * internal BPF verifier will check that BPF_R6 ==
 451                  * ctx.
 452                  *
 453                  * BPF_ABS and BPF_IND are wrappers of function calls,
 454                  * so they scratch BPF_R1-BPF_R5 registers, preserve
 455                  * BPF_R6-BPF_R9, and store return value into BPF_R0.
 456                  *
 457                  * Implicit input:
 458                  *   ctx == skb == BPF_R6 == CTX
 459                  *
 460                  * Explicit input:
 461                  *   SRC == any register
 462                  *   IMM == 32-bit immediate
 463                  *
 464                  * Output:
 465                  *   BPF_R0 - 8/16/32-bit skb data converted to cpu endianness
 466                  */
 467
 468                 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp);
 469                 if (likely(ptr != NULL)) {
 470                         BPF_R0 = get_unaligned_be32(ptr);
 471                         CONT;
 472                 }
 473
 474                 return 0;
 475         LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */
 476                 off = IMM;
 477 load_half:
 478                 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp);
 479                 if (likely(ptr != NULL)) {
 480                         BPF_R0 = get_unaligned_be16(ptr);
 481                         CONT;
 482                 }
 483
 484                 return 0;
 485         LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */
 486                 off = IMM;
 487 load_byte:
 488                 ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp);
 489                 if (likely(ptr != NULL)) {
 490                         BPF_R0 = *(u8 *)ptr;
 491                         CONT;
 492                 }
 493
 494                 return 0;
 495         LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */
 496                 off = IMM + SRC;
 497                 goto load_word;
 498         LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */
 499                 off = IMM + SRC;
 500                 goto load_half;
 501         LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */
 502                 off = IMM + SRC;
 503                 goto load_byte;
 504
 505         default_label:
 506                 /* If we ever reach this, we have a bug somewhere. */
 507                 WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code);
 508                 return 0;
 509 }
 510
 511 void __weak bpf_int_jit_compile(struct sk_filter *prog)
 512 {
 513 }
 514
 515 /**
 516  *      sk_filter_select_runtime - select execution runtime for BPF program
 517  *      @fp: sk_filter populated with internal BPF program
 518  *
 519  * try to JIT internal BPF program, if JIT is not available select interpreter
 520  * BPF program will be executed via SK_RUN_FILTER() macro
 521  */
 522 void sk_filter_select_runtime(struct sk_filter *fp)
 523 {
 524         fp->bpf_func = (void *) __sk_run_filter;
 525
 526         /* Probe if internal BPF can be JITed */
 527         bpf_int_jit_compile(fp);
 528 }
 529 EXPORT_SYMBOL_GPL(sk_filter_select_runtime);
 530
 531 /* free internal BPF program */
 532 void sk_filter_free(struct sk_filter *fp)
 533 {
 534         bpf_jit_free(fp);
 535 }
 536 EXPORT_SYMBOL_GPL(sk_filter_free);