bpfjit.c revision 1.2.2.3
1 1.2.2.3 tls /* $NetBSD: bpfjit.c,v 1.2.2.3 2014/08/20 00:04:34 tls Exp $ */ 2 1.2.2.3 tls 3 1.2.2.2 tls /*- 4 1.2.2.3 tls * Copyright (c) 2011-2014 Alexander Nasonov. 5 1.2.2.2 tls * All rights reserved. 6 1.2.2.2 tls * 7 1.2.2.2 tls * Redistribution and use in source and binary forms, with or without 8 1.2.2.2 tls * modification, are permitted provided that the following conditions 9 1.2.2.2 tls * are met: 10 1.2.2.2 tls * 11 1.2.2.2 tls * 1. Redistributions of source code must retain the above copyright 12 1.2.2.2 tls * notice, this list of conditions and the following disclaimer. 13 1.2.2.2 tls * 2. Redistributions in binary form must reproduce the above copyright 14 1.2.2.2 tls * notice, this list of conditions and the following disclaimer in 15 1.2.2.2 tls * the documentation and/or other materials provided with the 16 1.2.2.2 tls * distribution. 17 1.2.2.2 tls * 18 1.2.2.2 tls * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 1.2.2.2 tls * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 1.2.2.2 tls * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 21 1.2.2.2 tls * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 22 1.2.2.2 tls * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 23 1.2.2.2 tls * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 24 1.2.2.2 tls * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 25 1.2.2.2 tls * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 26 1.2.2.2 tls * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 27 1.2.2.2 tls * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 28 1.2.2.2 tls * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 1.2.2.2 tls * SUCH DAMAGE. 30 1.2.2.2 tls */ 31 1.2.2.2 tls 32 1.2.2.2 tls #include <sys/cdefs.h> 33 1.2.2.2 tls #ifdef _KERNEL 34 1.2.2.3 tls __KERNEL_RCSID(0, "$NetBSD: bpfjit.c,v 1.2.2.3 2014/08/20 00:04:34 tls Exp $"); 35 1.2.2.2 tls #else 36 1.2.2.3 tls __RCSID("$NetBSD: bpfjit.c,v 1.2.2.3 2014/08/20 00:04:34 tls Exp $"); 37 1.2.2.2 tls #endif 38 1.2.2.2 tls 39 1.2.2.3 tls #include <sys/types.h> 40 1.2.2.3 tls #include <sys/queue.h> 41 1.2.2.2 tls 42 1.2.2.2 tls #ifndef _KERNEL 43 1.2.2.2 tls #include <assert.h> 44 1.2.2.3 tls #define BJ_ASSERT(c) assert(c) 45 1.2.2.2 tls #else 46 1.2.2.3 tls #define BJ_ASSERT(c) KASSERT(c) 47 1.2.2.2 tls #endif 48 1.2.2.2 tls 49 1.2.2.2 tls #ifndef _KERNEL 50 1.2.2.2 tls #include <stdlib.h> 51 1.2.2.3 tls #define BJ_ALLOC(sz) malloc(sz) 52 1.2.2.3 tls #define BJ_FREE(p, sz) free(p) 53 1.2.2.2 tls #else 54 1.2.2.3 tls #include <sys/kmem.h> 55 1.2.2.3 tls #define BJ_ALLOC(sz) kmem_alloc(sz, KM_SLEEP) 56 1.2.2.3 tls #define BJ_FREE(p, sz) kmem_free(p, sz) 57 1.2.2.2 tls #endif 58 1.2.2.2 tls 59 1.2.2.2 tls #ifndef _KERNEL 60 1.2.2.2 tls #include <limits.h> 61 1.2.2.2 tls #include <stdbool.h> 62 1.2.2.2 tls #include <stddef.h> 63 1.2.2.2 tls #include <stdint.h> 64 1.2.2.2 tls #else 65 1.2.2.2 tls #include <sys/atomic.h> 66 1.2.2.2 tls #include <sys/module.h> 67 1.2.2.2 tls #endif 68 1.2.2.2 tls 69 1.2.2.3 tls #define __BPF_PRIVATE 70 1.2.2.3 tls #include <net/bpf.h> 71 1.2.2.3 tls #include <net/bpfjit.h> 72 1.2.2.2 tls #include <sljitLir.h> 73 1.2.2.2 tls 74 1.2.2.2 tls #if !defined(_KERNEL) && defined(SLJIT_VERBOSE) && SLJIT_VERBOSE 75 1.2.2.2 tls #include <stdio.h> /* for stderr */ 76 1.2.2.2 tls #endif 77 1.2.2.2 tls 78 1.2.2.3 tls /* 79 1.2.2.3 tls * Arguments of generated bpfjit_func_t. 80 1.2.2.3 tls * The first argument is reassigned upon entry 81 1.2.2.3 tls * to a more frequently used buf argument. 82 1.2.2.3 tls */ 83 1.2.2.3 tls #define BJ_CTX_ARG SLJIT_SAVED_REG1 84 1.2.2.3 tls #define BJ_ARGS SLJIT_SAVED_REG2 85 1.2.2.3 tls 86 1.2.2.3 tls /* 87 1.2.2.3 tls * Permanent register assignments. 88 1.2.2.3 tls */ 89 1.2.2.3 tls #define BJ_BUF SLJIT_SAVED_REG1 90 1.2.2.3 tls //#define BJ_ARGS SLJIT_SAVED_REG2 91 1.2.2.3 tls #define BJ_BUFLEN SLJIT_SAVED_REG3 92 1.2.2.3 tls #define BJ_AREG SLJIT_SCRATCH_REG1 93 1.2.2.3 tls #define BJ_TMP1REG SLJIT_SCRATCH_REG2 94 1.2.2.3 tls #define BJ_TMP2REG SLJIT_SCRATCH_REG3 95 1.2.2.3 tls #define BJ_XREG SLJIT_TEMPORARY_EREG1 96 1.2.2.3 tls #define BJ_TMP3REG SLJIT_TEMPORARY_EREG2 97 1.2.2.3 tls 98 1.2.2.3 tls #ifdef _KERNEL 99 1.2.2.3 tls #define MAX_MEMWORDS BPF_MAX_MEMWORDS 100 1.2.2.3 tls #else 101 1.2.2.3 tls #define MAX_MEMWORDS BPF_MEMWORDS 102 1.2.2.3 tls #endif 103 1.2.2.2 tls 104 1.2.2.3 tls #define BJ_INIT_NOBITS ((bpf_memword_init_t)0) 105 1.2.2.3 tls #define BJ_INIT_MBIT(k) BPF_MEMWORD_INIT(k) 106 1.2.2.3 tls #define BJ_INIT_ABIT BJ_INIT_MBIT(MAX_MEMWORDS) 107 1.2.2.3 tls #define BJ_INIT_XBIT BJ_INIT_MBIT(MAX_MEMWORDS + 1) 108 1.2.2.2 tls 109 1.2.2.3 tls /* 110 1.2.2.3 tls * Get a number of memwords and external memwords from a bpf_ctx object. 111 1.2.2.2 tls */ 112 1.2.2.3 tls #define GET_EXTWORDS(bc) ((bc) ? (bc)->extwords : 0) 113 1.2.2.3 tls #define GET_MEMWORDS(bc) (GET_EXTWORDS(bc) ? GET_EXTWORDS(bc) : BPF_MEMWORDS) 114 1.2.2.2 tls 115 1.2.2.3 tls /* 116 1.2.2.3 tls * Optimization hints. 117 1.2.2.3 tls */ 118 1.2.2.3 tls typedef unsigned int bpfjit_hint_t; 119 1.2.2.3 tls #define BJ_HINT_ABS 0x01 /* packet read at absolute offset */ 120 1.2.2.3 tls #define BJ_HINT_IND 0x02 /* packet read at variable offset */ 121 1.2.2.3 tls #define BJ_HINT_MSH 0x04 /* BPF_MSH instruction */ 122 1.2.2.3 tls #define BJ_HINT_COP 0x08 /* BPF_COP or BPF_COPX instruction */ 123 1.2.2.3 tls #define BJ_HINT_COPX 0x10 /* BPF_COPX instruction */ 124 1.2.2.3 tls #define BJ_HINT_XREG 0x20 /* BJ_XREG is needed */ 125 1.2.2.3 tls #define BJ_HINT_LDX 0x40 /* BPF_LDX instruction */ 126 1.2.2.3 tls #define BJ_HINT_PKT (BJ_HINT_ABS|BJ_HINT_IND|BJ_HINT_MSH) 127 1.2.2.2 tls 128 1.2.2.2 tls /* 129 1.2.2.3 tls * Datatype for Array Bounds Check Elimination (ABC) pass. 130 1.2.2.2 tls */ 131 1.2.2.3 tls typedef uint64_t bpfjit_abc_length_t; 132 1.2.2.3 tls #define MAX_ABC_LENGTH (UINT32_MAX + UINT64_C(4)) /* max. width is 4 */ 133 1.2.2.3 tls 134 1.2.2.3 tls struct bpfjit_stack 135 1.2.2.2 tls { 136 1.2.2.3 tls bpf_ctx_t *ctx; 137 1.2.2.3 tls uint32_t *extmem; /* pointer to external memory store */ 138 1.2.2.3 tls uint32_t reg; /* saved A or X register */ 139 1.2.2.3 tls #ifdef _KERNEL 140 1.2.2.3 tls int err; /* 3rd argument for m_xword/m_xhalf/m_xbyte function call */ 141 1.2.2.3 tls #endif 142 1.2.2.3 tls uint32_t mem[BPF_MEMWORDS]; /* internal memory store */ 143 1.2.2.2 tls }; 144 1.2.2.2 tls 145 1.2.2.2 tls /* 146 1.2.2.2 tls * Data for BPF_JMP instruction. 147 1.2.2.3 tls * Forward declaration for struct bpfjit_jump. 148 1.2.2.2 tls */ 149 1.2.2.3 tls struct bpfjit_jump_data; 150 1.2.2.3 tls 151 1.2.2.3 tls /* 152 1.2.2.3 tls * Node of bjumps list. 153 1.2.2.3 tls */ 154 1.2.2.3 tls struct bpfjit_jump { 155 1.2.2.3 tls struct sljit_jump *sjump; 156 1.2.2.3 tls SLIST_ENTRY(bpfjit_jump) entries; 157 1.2.2.3 tls struct bpfjit_jump_data *jdata; 158 1.2.2.3 tls }; 159 1.2.2.3 tls 160 1.2.2.3 tls /* 161 1.2.2.3 tls * Data for BPF_JMP instruction. 162 1.2.2.3 tls */ 163 1.2.2.3 tls struct bpfjit_jump_data { 164 1.2.2.3 tls /* 165 1.2.2.3 tls * These entries make up bjumps list: 166 1.2.2.3 tls * jtf[0] - when coming from jt path, 167 1.2.2.3 tls * jtf[1] - when coming from jf path. 168 1.2.2.3 tls */ 169 1.2.2.3 tls struct bpfjit_jump jtf[2]; 170 1.2.2.3 tls /* 171 1.2.2.3 tls * Length calculated by Array Bounds Check Elimination (ABC) pass. 172 1.2.2.3 tls */ 173 1.2.2.3 tls bpfjit_abc_length_t abc_length; 174 1.2.2.2 tls /* 175 1.2.2.3 tls * Length checked by the last out-of-bounds check. 176 1.2.2.2 tls */ 177 1.2.2.3 tls bpfjit_abc_length_t checked_length; 178 1.2.2.2 tls }; 179 1.2.2.2 tls 180 1.2.2.2 tls /* 181 1.2.2.2 tls * Data for "read from packet" instructions. 182 1.2.2.2 tls * See also read_pkt_insn() function below. 183 1.2.2.2 tls */ 184 1.2.2.3 tls struct bpfjit_read_pkt_data { 185 1.2.2.3 tls /* 186 1.2.2.3 tls * Length calculated by Array Bounds Check Elimination (ABC) pass. 187 1.2.2.3 tls */ 188 1.2.2.3 tls bpfjit_abc_length_t abc_length; 189 1.2.2.2 tls /* 190 1.2.2.3 tls * If positive, emit "if (buflen < check_length) return 0" 191 1.2.2.3 tls * out-of-bounds check. 192 1.2.2.3 tls * Values greater than UINT32_MAX generate unconditional "return 0". 193 1.2.2.2 tls */ 194 1.2.2.3 tls bpfjit_abc_length_t check_length; 195 1.2.2.2 tls }; 196 1.2.2.2 tls 197 1.2.2.2 tls /* 198 1.2.2.2 tls * Additional (optimization-related) data for bpf_insn. 199 1.2.2.2 tls */ 200 1.2.2.3 tls struct bpfjit_insn_data { 201 1.2.2.2 tls /* List of jumps to this insn. */ 202 1.2.2.3 tls SLIST_HEAD(, bpfjit_jump) bjumps; 203 1.2.2.2 tls 204 1.2.2.2 tls union { 205 1.2.2.3 tls struct bpfjit_jump_data jdata; 206 1.2.2.3 tls struct bpfjit_read_pkt_data rdata; 207 1.2.2.3 tls } u; 208 1.2.2.2 tls 209 1.2.2.3 tls bpf_memword_init_t invalid; 210 1.2.2.3 tls bool unreachable; 211 1.2.2.2 tls }; 212 1.2.2.2 tls 213 1.2.2.2 tls #ifdef _KERNEL 214 1.2.2.2 tls 215 1.2.2.2 tls uint32_t m_xword(const struct mbuf *, uint32_t, int *); 216 1.2.2.2 tls uint32_t m_xhalf(const struct mbuf *, uint32_t, int *); 217 1.2.2.2 tls uint32_t m_xbyte(const struct mbuf *, uint32_t, int *); 218 1.2.2.2 tls 219 1.2.2.2 tls MODULE(MODULE_CLASS_MISC, bpfjit, "sljit") 220 1.2.2.2 tls 221 1.2.2.2 tls static int 222 1.2.2.2 tls bpfjit_modcmd(modcmd_t cmd, void *arg) 223 1.2.2.2 tls { 224 1.2.2.2 tls 225 1.2.2.2 tls switch (cmd) { 226 1.2.2.2 tls case MODULE_CMD_INIT: 227 1.2.2.2 tls bpfjit_module_ops.bj_free_code = &bpfjit_free_code; 228 1.2.2.2 tls membar_producer(); 229 1.2.2.2 tls bpfjit_module_ops.bj_generate_code = &bpfjit_generate_code; 230 1.2.2.2 tls membar_producer(); 231 1.2.2.2 tls return 0; 232 1.2.2.2 tls 233 1.2.2.2 tls case MODULE_CMD_FINI: 234 1.2.2.2 tls return EOPNOTSUPP; 235 1.2.2.2 tls 236 1.2.2.2 tls default: 237 1.2.2.2 tls return ENOTTY; 238 1.2.2.2 tls } 239 1.2.2.2 tls } 240 1.2.2.2 tls #endif 241 1.2.2.2 tls 242 1.2.2.3 tls /* 243 1.2.2.3 tls * Return a number of scratch registers to pass 244 1.2.2.3 tls * to sljit_emit_enter() function. 245 1.2.2.3 tls */ 246 1.2.2.3 tls static sljit_si 247 1.2.2.3 tls nscratches(bpfjit_hint_t hints) 248 1.2.2.3 tls { 249 1.2.2.3 tls sljit_si rv = 2; 250 1.2.2.3 tls 251 1.2.2.3 tls #ifdef _KERNEL 252 1.2.2.3 tls if (hints & BJ_HINT_PKT) 253 1.2.2.3 tls rv = 3; /* xcall with three arguments */ 254 1.2.2.3 tls #endif 255 1.2.2.3 tls 256 1.2.2.3 tls if (hints & BJ_HINT_IND) 257 1.2.2.3 tls rv = 3; /* uses BJ_TMP2REG */ 258 1.2.2.3 tls 259 1.2.2.3 tls if (hints & BJ_HINT_COP) 260 1.2.2.3 tls rv = 3; /* calls copfunc with three arguments */ 261 1.2.2.3 tls 262 1.2.2.3 tls if (hints & BJ_HINT_XREG) 263 1.2.2.3 tls rv = 4; /* uses BJ_XREG */ 264 1.2.2.3 tls 265 1.2.2.3 tls #ifdef _KERNEL 266 1.2.2.3 tls if (hints & BJ_HINT_LDX) 267 1.2.2.3 tls rv = 5; /* uses BJ_TMP3REG */ 268 1.2.2.3 tls #endif 269 1.2.2.3 tls 270 1.2.2.3 tls if (hints & BJ_HINT_COPX) 271 1.2.2.3 tls rv = 5; /* uses BJ_TMP3REG */ 272 1.2.2.3 tls 273 1.2.2.3 tls return rv; 274 1.2.2.3 tls } 275 1.2.2.3 tls 276 1.2.2.3 tls /* 277 1.2.2.3 tls * Return a number of saved registers to pass 278 1.2.2.3 tls * to sljit_emit_enter() function. 279 1.2.2.3 tls */ 280 1.2.2.3 tls static sljit_si 281 1.2.2.3 tls nsaveds(bpfjit_hint_t hints) 282 1.2.2.3 tls { 283 1.2.2.3 tls sljit_si rv = 3; 284 1.2.2.3 tls 285 1.2.2.3 tls return rv; 286 1.2.2.3 tls } 287 1.2.2.3 tls 288 1.2.2.2 tls static uint32_t 289 1.2.2.3 tls read_width(const struct bpf_insn *pc) 290 1.2.2.2 tls { 291 1.2.2.2 tls 292 1.2.2.2 tls switch (BPF_SIZE(pc->code)) { 293 1.2.2.2 tls case BPF_W: 294 1.2.2.2 tls return 4; 295 1.2.2.2 tls case BPF_H: 296 1.2.2.2 tls return 2; 297 1.2.2.2 tls case BPF_B: 298 1.2.2.2 tls return 1; 299 1.2.2.2 tls default: 300 1.2.2.3 tls BJ_ASSERT(false); 301 1.2.2.2 tls return 0; 302 1.2.2.2 tls } 303 1.2.2.2 tls } 304 1.2.2.2 tls 305 1.2.2.2 tls /* 306 1.2.2.3 tls * Copy buf and buflen members of bpf_args from BJ_ARGS 307 1.2.2.3 tls * pointer to BJ_BUF and BJ_BUFLEN registers. 308 1.2.2.2 tls */ 309 1.2.2.3 tls static int 310 1.2.2.3 tls load_buf_buflen(struct sljit_compiler *compiler) 311 1.2.2.2 tls { 312 1.2.2.3 tls int status; 313 1.2.2.2 tls 314 1.2.2.3 tls status = sljit_emit_op1(compiler, 315 1.2.2.3 tls SLJIT_MOV_P, 316 1.2.2.3 tls BJ_BUF, 0, 317 1.2.2.3 tls SLJIT_MEM1(BJ_ARGS), 318 1.2.2.3 tls offsetof(struct bpf_args, pkt)); 319 1.2.2.3 tls if (status != SLJIT_SUCCESS) 320 1.2.2.3 tls return status; 321 1.2.2.3 tls 322 1.2.2.3 tls status = sljit_emit_op1(compiler, 323 1.2.2.3 tls SLJIT_MOV, /* size_t source */ 324 1.2.2.3 tls BJ_BUFLEN, 0, 325 1.2.2.3 tls SLJIT_MEM1(BJ_ARGS), 326 1.2.2.3 tls offsetof(struct bpf_args, buflen)); 327 1.2.2.3 tls 328 1.2.2.3 tls return status; 329 1.2.2.3 tls } 330 1.2.2.3 tls 331 1.2.2.3 tls static bool 332 1.2.2.3 tls grow_jumps(struct sljit_jump ***jumps, size_t *size) 333 1.2.2.3 tls { 334 1.2.2.3 tls struct sljit_jump **newptr; 335 1.2.2.3 tls const size_t elemsz = sizeof(struct sljit_jump *); 336 1.2.2.3 tls size_t old_size = *size; 337 1.2.2.3 tls size_t new_size = 2 * old_size; 338 1.2.2.3 tls 339 1.2.2.3 tls if (new_size < old_size || new_size > SIZE_MAX / elemsz) 340 1.2.2.3 tls return false; 341 1.2.2.3 tls 342 1.2.2.3 tls newptr = BJ_ALLOC(new_size * elemsz); 343 1.2.2.3 tls if (newptr == NULL) 344 1.2.2.3 tls return false; 345 1.2.2.3 tls 346 1.2.2.3 tls memcpy(newptr, *jumps, old_size * elemsz); 347 1.2.2.3 tls BJ_FREE(*jumps, old_size * elemsz); 348 1.2.2.3 tls 349 1.2.2.3 tls *jumps = newptr; 350 1.2.2.3 tls *size = new_size; 351 1.2.2.3 tls return true; 352 1.2.2.3 tls } 353 1.2.2.3 tls 354 1.2.2.3 tls static bool 355 1.2.2.3 tls append_jump(struct sljit_jump *jump, struct sljit_jump ***jumps, 356 1.2.2.3 tls size_t *size, size_t *max_size) 357 1.2.2.3 tls { 358 1.2.2.3 tls if (*size == *max_size && !grow_jumps(jumps, max_size)) 359 1.2.2.3 tls return false; 360 1.2.2.3 tls 361 1.2.2.3 tls (*jumps)[(*size)++] = jump; 362 1.2.2.3 tls return true; 363 1.2.2.2 tls } 364 1.2.2.2 tls 365 1.2.2.2 tls /* 366 1.2.2.3 tls * Emit code for BPF_LD+BPF_B+BPF_ABS A <- P[k:1]. 367 1.2.2.2 tls */ 368 1.2.2.2 tls static int 369 1.2.2.3 tls emit_read8(struct sljit_compiler *compiler, sljit_si src, uint32_t k) 370 1.2.2.2 tls { 371 1.2.2.2 tls 372 1.2.2.2 tls return sljit_emit_op1(compiler, 373 1.2.2.2 tls SLJIT_MOV_UB, 374 1.2.2.3 tls BJ_AREG, 0, 375 1.2.2.3 tls SLJIT_MEM1(src), k); 376 1.2.2.2 tls } 377 1.2.2.2 tls 378 1.2.2.2 tls /* 379 1.2.2.3 tls * Emit code for BPF_LD+BPF_H+BPF_ABS A <- P[k:2]. 380 1.2.2.2 tls */ 381 1.2.2.2 tls static int 382 1.2.2.3 tls emit_read16(struct sljit_compiler *compiler, sljit_si src, uint32_t k) 383 1.2.2.2 tls { 384 1.2.2.2 tls int status; 385 1.2.2.2 tls 386 1.2.2.3 tls BJ_ASSERT(k <= UINT32_MAX - 1); 387 1.2.2.3 tls 388 1.2.2.3 tls /* A = buf[k]; */ 389 1.2.2.2 tls status = sljit_emit_op1(compiler, 390 1.2.2.2 tls SLJIT_MOV_UB, 391 1.2.2.3 tls BJ_AREG, 0, 392 1.2.2.3 tls SLJIT_MEM1(src), k); 393 1.2.2.2 tls if (status != SLJIT_SUCCESS) 394 1.2.2.2 tls return status; 395 1.2.2.2 tls 396 1.2.2.3 tls /* tmp1 = buf[k+1]; */ 397 1.2.2.2 tls status = sljit_emit_op1(compiler, 398 1.2.2.2 tls SLJIT_MOV_UB, 399 1.2.2.3 tls BJ_TMP1REG, 0, 400 1.2.2.3 tls SLJIT_MEM1(src), k+1); 401 1.2.2.2 tls if (status != SLJIT_SUCCESS) 402 1.2.2.2 tls return status; 403 1.2.2.2 tls 404 1.2.2.3 tls /* A = A << 8; */ 405 1.2.2.2 tls status = sljit_emit_op2(compiler, 406 1.2.2.2 tls SLJIT_SHL, 407 1.2.2.3 tls BJ_AREG, 0, 408 1.2.2.3 tls BJ_AREG, 0, 409 1.2.2.2 tls SLJIT_IMM, 8); 410 1.2.2.2 tls if (status != SLJIT_SUCCESS) 411 1.2.2.2 tls return status; 412 1.2.2.2 tls 413 1.2.2.2 tls /* A = A + tmp1; */ 414 1.2.2.2 tls status = sljit_emit_op2(compiler, 415 1.2.2.2 tls SLJIT_ADD, 416 1.2.2.3 tls BJ_AREG, 0, 417 1.2.2.3 tls BJ_AREG, 0, 418 1.2.2.3 tls BJ_TMP1REG, 0); 419 1.2.2.2 tls return status; 420 1.2.2.2 tls } 421 1.2.2.2 tls 422 1.2.2.2 tls /* 423 1.2.2.3 tls * Emit code for BPF_LD+BPF_W+BPF_ABS A <- P[k:4]. 424 1.2.2.2 tls */ 425 1.2.2.2 tls static int 426 1.2.2.3 tls emit_read32(struct sljit_compiler *compiler, sljit_si src, uint32_t k) 427 1.2.2.2 tls { 428 1.2.2.2 tls int status; 429 1.2.2.2 tls 430 1.2.2.3 tls BJ_ASSERT(k <= UINT32_MAX - 3); 431 1.2.2.2 tls 432 1.2.2.3 tls /* A = buf[k]; */ 433 1.2.2.2 tls status = sljit_emit_op1(compiler, 434 1.2.2.2 tls SLJIT_MOV_UB, 435 1.2.2.3 tls BJ_AREG, 0, 436 1.2.2.3 tls SLJIT_MEM1(src), k); 437 1.2.2.2 tls if (status != SLJIT_SUCCESS) 438 1.2.2.2 tls return status; 439 1.2.2.2 tls 440 1.2.2.3 tls /* tmp1 = buf[k+1]; */ 441 1.2.2.2 tls status = sljit_emit_op1(compiler, 442 1.2.2.2 tls SLJIT_MOV_UB, 443 1.2.2.3 tls BJ_TMP1REG, 0, 444 1.2.2.3 tls SLJIT_MEM1(src), k+1); 445 1.2.2.2 tls if (status != SLJIT_SUCCESS) 446 1.2.2.2 tls return status; 447 1.2.2.2 tls 448 1.2.2.3 tls /* A = A << 8; */ 449 1.2.2.2 tls status = sljit_emit_op2(compiler, 450 1.2.2.2 tls SLJIT_SHL, 451 1.2.2.3 tls BJ_AREG, 0, 452 1.2.2.3 tls BJ_AREG, 0, 453 1.2.2.3 tls SLJIT_IMM, 8); 454 1.2.2.2 tls if (status != SLJIT_SUCCESS) 455 1.2.2.2 tls return status; 456 1.2.2.2 tls 457 1.2.2.2 tls /* A = A + tmp1; */ 458 1.2.2.2 tls status = sljit_emit_op2(compiler, 459 1.2.2.2 tls SLJIT_ADD, 460 1.2.2.3 tls BJ_AREG, 0, 461 1.2.2.3 tls BJ_AREG, 0, 462 1.2.2.3 tls BJ_TMP1REG, 0); 463 1.2.2.2 tls if (status != SLJIT_SUCCESS) 464 1.2.2.2 tls return status; 465 1.2.2.2 tls 466 1.2.2.2 tls /* tmp1 = buf[k+2]; */ 467 1.2.2.2 tls status = sljit_emit_op1(compiler, 468 1.2.2.2 tls SLJIT_MOV_UB, 469 1.2.2.3 tls BJ_TMP1REG, 0, 470 1.2.2.3 tls SLJIT_MEM1(src), k+2); 471 1.2.2.2 tls if (status != SLJIT_SUCCESS) 472 1.2.2.2 tls return status; 473 1.2.2.2 tls 474 1.2.2.3 tls /* A = A << 8; */ 475 1.2.2.2 tls status = sljit_emit_op2(compiler, 476 1.2.2.2 tls SLJIT_SHL, 477 1.2.2.3 tls BJ_AREG, 0, 478 1.2.2.3 tls BJ_AREG, 0, 479 1.2.2.3 tls SLJIT_IMM, 8); 480 1.2.2.2 tls if (status != SLJIT_SUCCESS) 481 1.2.2.2 tls return status; 482 1.2.2.2 tls 483 1.2.2.3 tls /* A = A + tmp1; */ 484 1.2.2.2 tls status = sljit_emit_op2(compiler, 485 1.2.2.2 tls SLJIT_ADD, 486 1.2.2.3 tls BJ_AREG, 0, 487 1.2.2.3 tls BJ_AREG, 0, 488 1.2.2.3 tls BJ_TMP1REG, 0); 489 1.2.2.3 tls if (status != SLJIT_SUCCESS) 490 1.2.2.3 tls return status; 491 1.2.2.3 tls 492 1.2.2.3 tls /* tmp1 = buf[k+3]; */ 493 1.2.2.3 tls status = sljit_emit_op1(compiler, 494 1.2.2.3 tls SLJIT_MOV_UB, 495 1.2.2.3 tls BJ_TMP1REG, 0, 496 1.2.2.3 tls SLJIT_MEM1(src), k+3); 497 1.2.2.2 tls if (status != SLJIT_SUCCESS) 498 1.2.2.2 tls return status; 499 1.2.2.2 tls 500 1.2.2.3 tls /* A = A << 8; */ 501 1.2.2.2 tls status = sljit_emit_op2(compiler, 502 1.2.2.2 tls SLJIT_SHL, 503 1.2.2.3 tls BJ_AREG, 0, 504 1.2.2.3 tls BJ_AREG, 0, 505 1.2.2.2 tls SLJIT_IMM, 8); 506 1.2.2.2 tls if (status != SLJIT_SUCCESS) 507 1.2.2.2 tls return status; 508 1.2.2.2 tls 509 1.2.2.2 tls /* A = A + tmp1; */ 510 1.2.2.2 tls status = sljit_emit_op2(compiler, 511 1.2.2.2 tls SLJIT_ADD, 512 1.2.2.3 tls BJ_AREG, 0, 513 1.2.2.3 tls BJ_AREG, 0, 514 1.2.2.3 tls BJ_TMP1REG, 0); 515 1.2.2.2 tls return status; 516 1.2.2.2 tls } 517 1.2.2.2 tls 518 1.2.2.2 tls #ifdef _KERNEL 519 1.2.2.2 tls /* 520 1.2.2.3 tls * Emit code for m_xword/m_xhalf/m_xbyte call. 521 1.2.2.2 tls * 522 1.2.2.3 tls * @pc BPF_LD+BPF_W+BPF_ABS A <- P[k:4] 523 1.2.2.3 tls * BPF_LD+BPF_H+BPF_ABS A <- P[k:2] 524 1.2.2.3 tls * BPF_LD+BPF_B+BPF_ABS A <- P[k:1] 525 1.2.2.3 tls * BPF_LD+BPF_W+BPF_IND A <- P[X+k:4] 526 1.2.2.3 tls * BPF_LD+BPF_H+BPF_IND A <- P[X+k:2] 527 1.2.2.3 tls * BPF_LD+BPF_B+BPF_IND A <- P[X+k:1] 528 1.2.2.3 tls * BPF_LDX+BPF_B+BPF_MSH X <- 4*(P[k:1]&0xf) 529 1.2.2.2 tls */ 530 1.2.2.2 tls static int 531 1.2.2.3 tls emit_xcall(struct sljit_compiler *compiler, bpfjit_hint_t hints, 532 1.2.2.3 tls const struct bpf_insn *pc, int dst, struct sljit_jump ***ret0, 533 1.2.2.3 tls size_t *ret0_size, size_t *ret0_maxsize, 534 1.2.2.2 tls uint32_t (*fn)(const struct mbuf *, uint32_t, int *)) 535 1.2.2.2 tls { 536 1.2.2.3 tls #if BJ_XREG == SLJIT_RETURN_REG || \ 537 1.2.2.3 tls BJ_XREG == SLJIT_SCRATCH_REG1 || \ 538 1.2.2.3 tls BJ_XREG == SLJIT_SCRATCH_REG2 || \ 539 1.2.2.3 tls BJ_XREG == SLJIT_SCRATCH_REG3 540 1.2.2.2 tls #error "Not supported assignment of registers." 541 1.2.2.2 tls #endif 542 1.2.2.3 tls struct sljit_jump *jump; 543 1.2.2.3 tls sljit_si save_reg; 544 1.2.2.2 tls int status; 545 1.2.2.2 tls 546 1.2.2.3 tls save_reg = (BPF_CLASS(pc->code) == BPF_LDX) ? BJ_AREG : BJ_XREG; 547 1.2.2.2 tls 548 1.2.2.3 tls if (save_reg == BJ_AREG || (hints & BJ_HINT_XREG)) { 549 1.2.2.3 tls /* save A or X */ 550 1.2.2.2 tls status = sljit_emit_op1(compiler, 551 1.2.2.3 tls SLJIT_MOV_UI, /* uint32_t destination */ 552 1.2.2.3 tls SLJIT_MEM1(SLJIT_LOCALS_REG), 553 1.2.2.3 tls offsetof(struct bpfjit_stack, reg), 554 1.2.2.3 tls save_reg, 0); 555 1.2.2.2 tls if (status != SLJIT_SUCCESS) 556 1.2.2.2 tls return status; 557 1.2.2.2 tls } 558 1.2.2.2 tls 559 1.2.2.2 tls /* 560 1.2.2.3 tls * Prepare registers for fn(mbuf, k, &err) call. 561 1.2.2.2 tls */ 562 1.2.2.2 tls status = sljit_emit_op1(compiler, 563 1.2.2.2 tls SLJIT_MOV, 564 1.2.2.3 tls SLJIT_SCRATCH_REG1, 0, 565 1.2.2.3 tls BJ_BUF, 0); 566 1.2.2.2 tls if (status != SLJIT_SUCCESS) 567 1.2.2.2 tls return status; 568 1.2.2.2 tls 569 1.2.2.2 tls if (BPF_CLASS(pc->code) == BPF_LD && BPF_MODE(pc->code) == BPF_IND) { 570 1.2.2.3 tls if (pc->k == 0) { 571 1.2.2.3 tls /* k = X; */ 572 1.2.2.3 tls status = sljit_emit_op1(compiler, 573 1.2.2.3 tls SLJIT_MOV, 574 1.2.2.3 tls SLJIT_SCRATCH_REG2, 0, 575 1.2.2.3 tls BJ_XREG, 0); 576 1.2.2.3 tls if (status != SLJIT_SUCCESS) 577 1.2.2.3 tls return status; 578 1.2.2.3 tls } else { 579 1.2.2.3 tls /* if (X > UINT32_MAX - pc->k) return 0; */ 580 1.2.2.3 tls jump = sljit_emit_cmp(compiler, 581 1.2.2.3 tls SLJIT_C_GREATER, 582 1.2.2.3 tls BJ_XREG, 0, 583 1.2.2.3 tls SLJIT_IMM, UINT32_MAX - pc->k); 584 1.2.2.3 tls if (jump == NULL) 585 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 586 1.2.2.3 tls if (!append_jump(jump, ret0, ret0_size, ret0_maxsize)) 587 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 588 1.2.2.3 tls 589 1.2.2.3 tls /* k = X + pc->k; */ 590 1.2.2.3 tls status = sljit_emit_op2(compiler, 591 1.2.2.3 tls SLJIT_ADD, 592 1.2.2.3 tls SLJIT_SCRATCH_REG2, 0, 593 1.2.2.3 tls BJ_XREG, 0, 594 1.2.2.3 tls SLJIT_IMM, (uint32_t)pc->k); 595 1.2.2.3 tls if (status != SLJIT_SUCCESS) 596 1.2.2.3 tls return status; 597 1.2.2.3 tls } 598 1.2.2.2 tls } else { 599 1.2.2.3 tls /* k = pc->k */ 600 1.2.2.2 tls status = sljit_emit_op1(compiler, 601 1.2.2.2 tls SLJIT_MOV, 602 1.2.2.3 tls SLJIT_SCRATCH_REG2, 0, 603 1.2.2.2 tls SLJIT_IMM, (uint32_t)pc->k); 604 1.2.2.3 tls if (status != SLJIT_SUCCESS) 605 1.2.2.3 tls return status; 606 1.2.2.2 tls } 607 1.2.2.2 tls 608 1.2.2.3 tls /* 609 1.2.2.3 tls * The third argument of fn is an address on stack. 610 1.2.2.3 tls */ 611 1.2.2.2 tls status = sljit_get_local_base(compiler, 612 1.2.2.3 tls SLJIT_SCRATCH_REG3, 0, 613 1.2.2.3 tls offsetof(struct bpfjit_stack, err)); 614 1.2.2.2 tls if (status != SLJIT_SUCCESS) 615 1.2.2.2 tls return status; 616 1.2.2.2 tls 617 1.2.2.2 tls /* fn(buf, k, &err); */ 618 1.2.2.2 tls status = sljit_emit_ijump(compiler, 619 1.2.2.2 tls SLJIT_CALL3, 620 1.2.2.2 tls SLJIT_IMM, SLJIT_FUNC_OFFSET(fn)); 621 1.2.2.3 tls if (status != SLJIT_SUCCESS) 622 1.2.2.3 tls return status; 623 1.2.2.2 tls 624 1.2.2.3 tls if (dst != SLJIT_RETURN_REG) { 625 1.2.2.2 tls /* move return value to dst */ 626 1.2.2.2 tls status = sljit_emit_op1(compiler, 627 1.2.2.2 tls SLJIT_MOV, 628 1.2.2.3 tls dst, 0, 629 1.2.2.2 tls SLJIT_RETURN_REG, 0); 630 1.2.2.2 tls if (status != SLJIT_SUCCESS) 631 1.2.2.2 tls return status; 632 1.2.2.3 tls } 633 1.2.2.3 tls 634 1.2.2.3 tls /* if (*err != 0) return 0; */ 635 1.2.2.3 tls jump = sljit_emit_cmp(compiler, 636 1.2.2.3 tls SLJIT_C_NOT_EQUAL|SLJIT_INT_OP, 637 1.2.2.3 tls SLJIT_MEM1(SLJIT_LOCALS_REG), 638 1.2.2.3 tls offsetof(struct bpfjit_stack, err), 639 1.2.2.3 tls SLJIT_IMM, 0); 640 1.2.2.3 tls if (jump == NULL) 641 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 642 1.2.2.3 tls 643 1.2.2.3 tls if (!append_jump(jump, ret0, ret0_size, ret0_maxsize)) 644 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 645 1.2.2.2 tls 646 1.2.2.3 tls if (save_reg == BJ_AREG || (hints & BJ_HINT_XREG)) { 647 1.2.2.3 tls /* restore A or X */ 648 1.2.2.2 tls status = sljit_emit_op1(compiler, 649 1.2.2.3 tls SLJIT_MOV_UI, /* uint32_t source */ 650 1.2.2.3 tls save_reg, 0, 651 1.2.2.3 tls SLJIT_MEM1(SLJIT_LOCALS_REG), 652 1.2.2.3 tls offsetof(struct bpfjit_stack, reg)); 653 1.2.2.3 tls if (status != SLJIT_SUCCESS) 654 1.2.2.3 tls return status; 655 1.2.2.3 tls } 656 1.2.2.3 tls 657 1.2.2.3 tls return SLJIT_SUCCESS; 658 1.2.2.3 tls } 659 1.2.2.3 tls #endif 660 1.2.2.3 tls 661 1.2.2.3 tls /* 662 1.2.2.3 tls * Emit code for BPF_COP and BPF_COPX instructions. 663 1.2.2.3 tls */ 664 1.2.2.3 tls static int 665 1.2.2.3 tls emit_cop(struct sljit_compiler *compiler, bpfjit_hint_t hints, 666 1.2.2.3 tls const bpf_ctx_t *bc, const struct bpf_insn *pc, 667 1.2.2.3 tls struct sljit_jump ***ret0, size_t *ret0_size, size_t *ret0_maxsize) 668 1.2.2.3 tls { 669 1.2.2.3 tls #if BJ_XREG == SLJIT_RETURN_REG || \ 670 1.2.2.3 tls BJ_XREG == SLJIT_SCRATCH_REG1 || \ 671 1.2.2.3 tls BJ_XREG == SLJIT_SCRATCH_REG2 || \ 672 1.2.2.3 tls BJ_XREG == SLJIT_SCRATCH_REG3 || \ 673 1.2.2.3 tls BJ_TMP3REG == SLJIT_SCRATCH_REG1 || \ 674 1.2.2.3 tls BJ_TMP3REG == SLJIT_SCRATCH_REG2 || \ 675 1.2.2.3 tls BJ_TMP3REG == SLJIT_SCRATCH_REG3 676 1.2.2.3 tls #error "Not supported assignment of registers." 677 1.2.2.3 tls #endif 678 1.2.2.3 tls 679 1.2.2.3 tls struct sljit_jump *jump; 680 1.2.2.3 tls sljit_si call_reg; 681 1.2.2.3 tls sljit_sw call_off; 682 1.2.2.3 tls int status; 683 1.2.2.3 tls 684 1.2.2.3 tls BJ_ASSERT(bc != NULL && bc->copfuncs != NULL); 685 1.2.2.3 tls 686 1.2.2.3 tls if (hints & BJ_HINT_LDX) { 687 1.2.2.3 tls /* save X */ 688 1.2.2.3 tls status = sljit_emit_op1(compiler, 689 1.2.2.3 tls SLJIT_MOV_UI, /* uint32_t destination */ 690 1.2.2.3 tls SLJIT_MEM1(SLJIT_LOCALS_REG), 691 1.2.2.3 tls offsetof(struct bpfjit_stack, reg), 692 1.2.2.3 tls BJ_XREG, 0); 693 1.2.2.3 tls if (status != SLJIT_SUCCESS) 694 1.2.2.3 tls return status; 695 1.2.2.3 tls } 696 1.2.2.3 tls 697 1.2.2.3 tls if (BPF_MISCOP(pc->code) == BPF_COP) { 698 1.2.2.3 tls call_reg = SLJIT_IMM; 699 1.2.2.3 tls call_off = SLJIT_FUNC_OFFSET(bc->copfuncs[pc->k]); 700 1.2.2.3 tls } else { 701 1.2.2.3 tls /* if (X >= bc->nfuncs) return 0; */ 702 1.2.2.3 tls jump = sljit_emit_cmp(compiler, 703 1.2.2.3 tls SLJIT_C_GREATER_EQUAL, 704 1.2.2.3 tls BJ_XREG, 0, 705 1.2.2.3 tls SLJIT_IMM, bc->nfuncs); 706 1.2.2.3 tls if (jump == NULL) 707 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 708 1.2.2.3 tls if (!append_jump(jump, ret0, ret0_size, ret0_maxsize)) 709 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 710 1.2.2.3 tls 711 1.2.2.3 tls /* tmp1 = ctx; */ 712 1.2.2.3 tls status = sljit_emit_op1(compiler, 713 1.2.2.3 tls SLJIT_MOV_P, 714 1.2.2.3 tls BJ_TMP1REG, 0, 715 1.2.2.3 tls SLJIT_MEM1(SLJIT_LOCALS_REG), 716 1.2.2.3 tls offsetof(struct bpfjit_stack, ctx)); 717 1.2.2.3 tls if (status != SLJIT_SUCCESS) 718 1.2.2.3 tls return status; 719 1.2.2.3 tls 720 1.2.2.3 tls /* tmp1 = ctx->copfuncs; */ 721 1.2.2.3 tls status = sljit_emit_op1(compiler, 722 1.2.2.3 tls SLJIT_MOV_P, 723 1.2.2.3 tls BJ_TMP1REG, 0, 724 1.2.2.3 tls SLJIT_MEM1(BJ_TMP1REG), 725 1.2.2.3 tls offsetof(struct bpf_ctx, copfuncs)); 726 1.2.2.2 tls if (status != SLJIT_SUCCESS) 727 1.2.2.2 tls return status; 728 1.2.2.2 tls 729 1.2.2.3 tls /* tmp2 = X; */ 730 1.2.2.2 tls status = sljit_emit_op1(compiler, 731 1.2.2.2 tls SLJIT_MOV, 732 1.2.2.3 tls BJ_TMP2REG, 0, 733 1.2.2.3 tls BJ_XREG, 0); 734 1.2.2.3 tls if (status != SLJIT_SUCCESS) 735 1.2.2.3 tls return status; 736 1.2.2.3 tls 737 1.2.2.3 tls /* tmp3 = ctx->copfuncs[tmp2]; */ 738 1.2.2.3 tls call_reg = BJ_TMP3REG; 739 1.2.2.3 tls call_off = 0; 740 1.2.2.3 tls status = sljit_emit_op1(compiler, 741 1.2.2.3 tls SLJIT_MOV_P, 742 1.2.2.3 tls call_reg, call_off, 743 1.2.2.3 tls SLJIT_MEM2(BJ_TMP1REG, BJ_TMP2REG), 744 1.2.2.3 tls SLJIT_WORD_SHIFT); 745 1.2.2.2 tls if (status != SLJIT_SUCCESS) 746 1.2.2.2 tls return status; 747 1.2.2.2 tls } 748 1.2.2.2 tls 749 1.2.2.3 tls /* 750 1.2.2.3 tls * Copy bpf_copfunc_t arguments to registers. 751 1.2.2.3 tls */ 752 1.2.2.3 tls #if BJ_AREG != SLJIT_SCRATCH_REG3 753 1.2.2.2 tls status = sljit_emit_op1(compiler, 754 1.2.2.2 tls SLJIT_MOV_UI, 755 1.2.2.3 tls SLJIT_SCRATCH_REG3, 0, 756 1.2.2.3 tls BJ_AREG, 0); 757 1.2.2.2 tls if (status != SLJIT_SUCCESS) 758 1.2.2.2 tls return status; 759 1.2.2.3 tls #endif 760 1.2.2.2 tls 761 1.2.2.3 tls status = sljit_emit_op1(compiler, 762 1.2.2.3 tls SLJIT_MOV_P, 763 1.2.2.3 tls SLJIT_SCRATCH_REG1, 0, 764 1.2.2.3 tls SLJIT_MEM1(SLJIT_LOCALS_REG), 765 1.2.2.3 tls offsetof(struct bpfjit_stack, ctx)); 766 1.2.2.3 tls if (status != SLJIT_SUCCESS) 767 1.2.2.3 tls return status; 768 1.2.2.2 tls 769 1.2.2.3 tls status = sljit_emit_op1(compiler, 770 1.2.2.3 tls SLJIT_MOV_P, 771 1.2.2.3 tls SLJIT_SCRATCH_REG2, 0, 772 1.2.2.3 tls BJ_ARGS, 0); 773 1.2.2.3 tls if (status != SLJIT_SUCCESS) 774 1.2.2.3 tls return status; 775 1.2.2.3 tls 776 1.2.2.3 tls status = sljit_emit_ijump(compiler, 777 1.2.2.3 tls SLJIT_CALL3, call_reg, call_off); 778 1.2.2.3 tls if (status != SLJIT_SUCCESS) 779 1.2.2.3 tls return status; 780 1.2.2.3 tls 781 1.2.2.3 tls #if BJ_AREG != SLJIT_RETURN_REG 782 1.2.2.3 tls status = sljit_emit_op1(compiler, 783 1.2.2.3 tls SLJIT_MOV, 784 1.2.2.3 tls BJ_AREG, 0, 785 1.2.2.3 tls SLJIT_RETURN_REG, 0); 786 1.2.2.3 tls if (status != SLJIT_SUCCESS) 787 1.2.2.3 tls return status; 788 1.2.2.2 tls #endif 789 1.2.2.2 tls 790 1.2.2.3 tls if (hints & BJ_HINT_LDX) { 791 1.2.2.3 tls /* restore X */ 792 1.2.2.3 tls status = sljit_emit_op1(compiler, 793 1.2.2.3 tls SLJIT_MOV_UI, /* uint32_t source */ 794 1.2.2.3 tls BJ_XREG, 0, 795 1.2.2.3 tls SLJIT_MEM1(SLJIT_LOCALS_REG), 796 1.2.2.3 tls offsetof(struct bpfjit_stack, reg)); 797 1.2.2.3 tls if (status != SLJIT_SUCCESS) 798 1.2.2.3 tls return status; 799 1.2.2.3 tls } 800 1.2.2.3 tls 801 1.2.2.3 tls return SLJIT_SUCCESS; 802 1.2.2.3 tls } 803 1.2.2.3 tls 804 1.2.2.2 tls /* 805 1.2.2.2 tls * Generate code for 806 1.2.2.2 tls * BPF_LD+BPF_W+BPF_ABS A <- P[k:4] 807 1.2.2.2 tls * BPF_LD+BPF_H+BPF_ABS A <- P[k:2] 808 1.2.2.2 tls * BPF_LD+BPF_B+BPF_ABS A <- P[k:1] 809 1.2.2.2 tls * BPF_LD+BPF_W+BPF_IND A <- P[X+k:4] 810 1.2.2.2 tls * BPF_LD+BPF_H+BPF_IND A <- P[X+k:2] 811 1.2.2.2 tls * BPF_LD+BPF_B+BPF_IND A <- P[X+k:1] 812 1.2.2.2 tls */ 813 1.2.2.2 tls static int 814 1.2.2.3 tls emit_pkt_read(struct sljit_compiler *compiler, bpfjit_hint_t hints, 815 1.2.2.3 tls const struct bpf_insn *pc, struct sljit_jump *to_mchain_jump, 816 1.2.2.3 tls struct sljit_jump ***ret0, size_t *ret0_size, size_t *ret0_maxsize) 817 1.2.2.2 tls { 818 1.2.2.3 tls int status = SLJIT_ERR_ALLOC_FAILED; 819 1.2.2.2 tls uint32_t width; 820 1.2.2.3 tls sljit_si ld_reg; 821 1.2.2.2 tls struct sljit_jump *jump; 822 1.2.2.2 tls #ifdef _KERNEL 823 1.2.2.2 tls struct sljit_label *label; 824 1.2.2.2 tls struct sljit_jump *over_mchain_jump; 825 1.2.2.2 tls const bool check_zero_buflen = (to_mchain_jump != NULL); 826 1.2.2.2 tls #endif 827 1.2.2.2 tls const uint32_t k = pc->k; 828 1.2.2.2 tls 829 1.2.2.2 tls #ifdef _KERNEL 830 1.2.2.2 tls if (to_mchain_jump == NULL) { 831 1.2.2.2 tls to_mchain_jump = sljit_emit_cmp(compiler, 832 1.2.2.2 tls SLJIT_C_EQUAL, 833 1.2.2.3 tls BJ_BUFLEN, 0, 834 1.2.2.2 tls SLJIT_IMM, 0); 835 1.2.2.2 tls if (to_mchain_jump == NULL) 836 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 837 1.2.2.2 tls } 838 1.2.2.2 tls #endif 839 1.2.2.2 tls 840 1.2.2.3 tls ld_reg = BJ_BUF; 841 1.2.2.2 tls width = read_width(pc); 842 1.2.2.2 tls 843 1.2.2.2 tls if (BPF_MODE(pc->code) == BPF_IND) { 844 1.2.2.2 tls /* tmp1 = buflen - (pc->k + width); */ 845 1.2.2.2 tls status = sljit_emit_op2(compiler, 846 1.2.2.2 tls SLJIT_SUB, 847 1.2.2.3 tls BJ_TMP1REG, 0, 848 1.2.2.3 tls BJ_BUFLEN, 0, 849 1.2.2.2 tls SLJIT_IMM, k + width); 850 1.2.2.2 tls if (status != SLJIT_SUCCESS) 851 1.2.2.2 tls return status; 852 1.2.2.2 tls 853 1.2.2.3 tls /* ld_reg = buf + X; */ 854 1.2.2.3 tls ld_reg = BJ_TMP2REG; 855 1.2.2.2 tls status = sljit_emit_op2(compiler, 856 1.2.2.2 tls SLJIT_ADD, 857 1.2.2.3 tls ld_reg, 0, 858 1.2.2.3 tls BJ_BUF, 0, 859 1.2.2.3 tls BJ_XREG, 0); 860 1.2.2.2 tls if (status != SLJIT_SUCCESS) 861 1.2.2.2 tls return status; 862 1.2.2.2 tls 863 1.2.2.2 tls /* if (tmp1 < X) return 0; */ 864 1.2.2.2 tls jump = sljit_emit_cmp(compiler, 865 1.2.2.2 tls SLJIT_C_LESS, 866 1.2.2.3 tls BJ_TMP1REG, 0, 867 1.2.2.3 tls BJ_XREG, 0); 868 1.2.2.2 tls if (jump == NULL) 869 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 870 1.2.2.3 tls if (!append_jump(jump, ret0, ret0_size, ret0_maxsize)) 871 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 872 1.2.2.2 tls } 873 1.2.2.2 tls 874 1.2.2.2 tls switch (width) { 875 1.2.2.2 tls case 4: 876 1.2.2.3 tls status = emit_read32(compiler, ld_reg, k); 877 1.2.2.2 tls break; 878 1.2.2.2 tls case 2: 879 1.2.2.3 tls status = emit_read16(compiler, ld_reg, k); 880 1.2.2.2 tls break; 881 1.2.2.2 tls case 1: 882 1.2.2.3 tls status = emit_read8(compiler, ld_reg, k); 883 1.2.2.2 tls break; 884 1.2.2.2 tls } 885 1.2.2.2 tls 886 1.2.2.2 tls if (status != SLJIT_SUCCESS) 887 1.2.2.2 tls return status; 888 1.2.2.2 tls 889 1.2.2.2 tls #ifdef _KERNEL 890 1.2.2.2 tls over_mchain_jump = sljit_emit_jump(compiler, SLJIT_JUMP); 891 1.2.2.2 tls if (over_mchain_jump == NULL) 892 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 893 1.2.2.2 tls 894 1.2.2.2 tls /* entry point to mchain handler */ 895 1.2.2.2 tls label = sljit_emit_label(compiler); 896 1.2.2.2 tls if (label == NULL) 897 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 898 1.2.2.2 tls sljit_set_label(to_mchain_jump, label); 899 1.2.2.2 tls 900 1.2.2.2 tls if (check_zero_buflen) { 901 1.2.2.2 tls /* if (buflen != 0) return 0; */ 902 1.2.2.2 tls jump = sljit_emit_cmp(compiler, 903 1.2.2.2 tls SLJIT_C_NOT_EQUAL, 904 1.2.2.3 tls BJ_BUFLEN, 0, 905 1.2.2.2 tls SLJIT_IMM, 0); 906 1.2.2.2 tls if (jump == NULL) 907 1.2.2.2 tls return SLJIT_ERR_ALLOC_FAILED; 908 1.2.2.3 tls if (!append_jump(jump, ret0, ret0_size, ret0_maxsize)) 909 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 910 1.2.2.2 tls } 911 1.2.2.2 tls 912 1.2.2.2 tls switch (width) { 913 1.2.2.2 tls case 4: 914 1.2.2.3 tls status = emit_xcall(compiler, hints, pc, BJ_AREG, 915 1.2.2.3 tls ret0, ret0_size, ret0_maxsize, &m_xword); 916 1.2.2.2 tls break; 917 1.2.2.2 tls case 2: 918 1.2.2.3 tls status = emit_xcall(compiler, hints, pc, BJ_AREG, 919 1.2.2.3 tls ret0, ret0_size, ret0_maxsize, &m_xhalf); 920 1.2.2.2 tls break; 921 1.2.2.2 tls case 1: 922 1.2.2.3 tls status = emit_xcall(compiler, hints, pc, BJ_AREG, 923 1.2.2.3 tls ret0, ret0_size, ret0_maxsize, &m_xbyte); 924 1.2.2.2 tls break; 925 1.2.2.2 tls } 926 1.2.2.2 tls 927 1.2.2.2 tls if (status != SLJIT_SUCCESS) 928 1.2.2.2 tls return status; 929 1.2.2.2 tls 930 1.2.2.2 tls label = sljit_emit_label(compiler); 931 1.2.2.2 tls if (label == NULL) 932 1.2.2.2 tls return SLJIT_ERR_ALLOC_FAILED; 933 1.2.2.2 tls sljit_set_label(over_mchain_jump, label); 934 1.2.2.2 tls #endif 935 1.2.2.2 tls 936 1.2.2.3 tls return SLJIT_SUCCESS; 937 1.2.2.3 tls } 938 1.2.2.3 tls 939 1.2.2.3 tls static int 940 1.2.2.3 tls emit_memload(struct sljit_compiler *compiler, 941 1.2.2.3 tls sljit_si dst, uint32_t k, size_t extwords) 942 1.2.2.3 tls { 943 1.2.2.3 tls int status; 944 1.2.2.3 tls sljit_si src; 945 1.2.2.3 tls sljit_sw srcw; 946 1.2.2.3 tls 947 1.2.2.3 tls srcw = k * sizeof(uint32_t); 948 1.2.2.3 tls 949 1.2.2.3 tls if (extwords == 0) { 950 1.2.2.3 tls src = SLJIT_MEM1(SLJIT_LOCALS_REG); 951 1.2.2.3 tls srcw += offsetof(struct bpfjit_stack, mem); 952 1.2.2.3 tls } else { 953 1.2.2.3 tls /* copy extmem pointer to the tmp1 register */ 954 1.2.2.3 tls status = sljit_emit_op1(compiler, 955 1.2.2.3 tls SLJIT_MOV_P, 956 1.2.2.3 tls BJ_TMP1REG, 0, 957 1.2.2.3 tls SLJIT_MEM1(SLJIT_LOCALS_REG), 958 1.2.2.3 tls offsetof(struct bpfjit_stack, extmem)); 959 1.2.2.3 tls if (status != SLJIT_SUCCESS) 960 1.2.2.3 tls return status; 961 1.2.2.3 tls src = SLJIT_MEM1(BJ_TMP1REG); 962 1.2.2.3 tls } 963 1.2.2.3 tls 964 1.2.2.3 tls return sljit_emit_op1(compiler, SLJIT_MOV_UI, dst, 0, src, srcw); 965 1.2.2.3 tls } 966 1.2.2.3 tls 967 1.2.2.3 tls static int 968 1.2.2.3 tls emit_memstore(struct sljit_compiler *compiler, 969 1.2.2.3 tls sljit_si src, uint32_t k, size_t extwords) 970 1.2.2.3 tls { 971 1.2.2.3 tls int status; 972 1.2.2.3 tls sljit_si dst; 973 1.2.2.3 tls sljit_sw dstw; 974 1.2.2.3 tls 975 1.2.2.3 tls dstw = k * sizeof(uint32_t); 976 1.2.2.3 tls 977 1.2.2.3 tls if (extwords == 0) { 978 1.2.2.3 tls dst = SLJIT_MEM1(SLJIT_LOCALS_REG); 979 1.2.2.3 tls dstw += offsetof(struct bpfjit_stack, mem); 980 1.2.2.3 tls } else { 981 1.2.2.3 tls /* copy extmem pointer to the tmp1 register */ 982 1.2.2.3 tls status = sljit_emit_op1(compiler, 983 1.2.2.3 tls SLJIT_MOV_P, 984 1.2.2.3 tls BJ_TMP1REG, 0, 985 1.2.2.3 tls SLJIT_MEM1(SLJIT_LOCALS_REG), 986 1.2.2.3 tls offsetof(struct bpfjit_stack, extmem)); 987 1.2.2.3 tls if (status != SLJIT_SUCCESS) 988 1.2.2.3 tls return status; 989 1.2.2.3 tls dst = SLJIT_MEM1(BJ_TMP1REG); 990 1.2.2.3 tls } 991 1.2.2.3 tls 992 1.2.2.3 tls return sljit_emit_op1(compiler, SLJIT_MOV_UI, dst, dstw, src, 0); 993 1.2.2.2 tls } 994 1.2.2.2 tls 995 1.2.2.2 tls /* 996 1.2.2.3 tls * Emit code for BPF_LDX+BPF_B+BPF_MSH X <- 4*(P[k:1]&0xf). 997 1.2.2.2 tls */ 998 1.2.2.2 tls static int 999 1.2.2.3 tls emit_msh(struct sljit_compiler *compiler, bpfjit_hint_t hints, 1000 1.2.2.3 tls const struct bpf_insn *pc, struct sljit_jump *to_mchain_jump, 1001 1.2.2.3 tls struct sljit_jump ***ret0, size_t *ret0_size, size_t *ret0_maxsize) 1002 1.2.2.2 tls { 1003 1.2.2.2 tls int status; 1004 1.2.2.2 tls #ifdef _KERNEL 1005 1.2.2.2 tls struct sljit_label *label; 1006 1.2.2.2 tls struct sljit_jump *jump, *over_mchain_jump; 1007 1.2.2.2 tls const bool check_zero_buflen = (to_mchain_jump != NULL); 1008 1.2.2.2 tls #endif 1009 1.2.2.2 tls const uint32_t k = pc->k; 1010 1.2.2.2 tls 1011 1.2.2.2 tls #ifdef _KERNEL 1012 1.2.2.2 tls if (to_mchain_jump == NULL) { 1013 1.2.2.2 tls to_mchain_jump = sljit_emit_cmp(compiler, 1014 1.2.2.2 tls SLJIT_C_EQUAL, 1015 1.2.2.3 tls BJ_BUFLEN, 0, 1016 1.2.2.2 tls SLJIT_IMM, 0); 1017 1.2.2.2 tls if (to_mchain_jump == NULL) 1018 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 1019 1.2.2.2 tls } 1020 1.2.2.2 tls #endif 1021 1.2.2.2 tls 1022 1.2.2.2 tls /* tmp1 = buf[k] */ 1023 1.2.2.2 tls status = sljit_emit_op1(compiler, 1024 1.2.2.2 tls SLJIT_MOV_UB, 1025 1.2.2.3 tls BJ_TMP1REG, 0, 1026 1.2.2.3 tls SLJIT_MEM1(BJ_BUF), k); 1027 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1028 1.2.2.2 tls return status; 1029 1.2.2.2 tls 1030 1.2.2.2 tls #ifdef _KERNEL 1031 1.2.2.2 tls over_mchain_jump = sljit_emit_jump(compiler, SLJIT_JUMP); 1032 1.2.2.2 tls if (over_mchain_jump == NULL) 1033 1.2.2.2 tls return SLJIT_ERR_ALLOC_FAILED; 1034 1.2.2.2 tls 1035 1.2.2.2 tls /* entry point to mchain handler */ 1036 1.2.2.2 tls label = sljit_emit_label(compiler); 1037 1.2.2.2 tls if (label == NULL) 1038 1.2.2.2 tls return SLJIT_ERR_ALLOC_FAILED; 1039 1.2.2.2 tls sljit_set_label(to_mchain_jump, label); 1040 1.2.2.2 tls 1041 1.2.2.2 tls if (check_zero_buflen) { 1042 1.2.2.2 tls /* if (buflen != 0) return 0; */ 1043 1.2.2.2 tls jump = sljit_emit_cmp(compiler, 1044 1.2.2.2 tls SLJIT_C_NOT_EQUAL, 1045 1.2.2.3 tls BJ_BUFLEN, 0, 1046 1.2.2.2 tls SLJIT_IMM, 0); 1047 1.2.2.2 tls if (jump == NULL) 1048 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 1049 1.2.2.3 tls if (!append_jump(jump, ret0, ret0_size, ret0_maxsize)) 1050 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 1051 1.2.2.2 tls } 1052 1.2.2.2 tls 1053 1.2.2.3 tls status = emit_xcall(compiler, hints, pc, BJ_TMP1REG, 1054 1.2.2.3 tls ret0, ret0_size, ret0_maxsize, &m_xbyte); 1055 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1056 1.2.2.2 tls return status; 1057 1.2.2.3 tls 1058 1.2.2.3 tls label = sljit_emit_label(compiler); 1059 1.2.2.3 tls if (label == NULL) 1060 1.2.2.3 tls return SLJIT_ERR_ALLOC_FAILED; 1061 1.2.2.3 tls sljit_set_label(over_mchain_jump, label); 1062 1.2.2.3 tls #endif 1063 1.2.2.2 tls 1064 1.2.2.2 tls /* tmp1 &= 0xf */ 1065 1.2.2.2 tls status = sljit_emit_op2(compiler, 1066 1.2.2.2 tls SLJIT_AND, 1067 1.2.2.3 tls BJ_TMP1REG, 0, 1068 1.2.2.3 tls BJ_TMP1REG, 0, 1069 1.2.2.2 tls SLJIT_IMM, 0xf); 1070 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1071 1.2.2.2 tls return status; 1072 1.2.2.2 tls 1073 1.2.2.3 tls /* X = tmp1 << 2 */ 1074 1.2.2.2 tls status = sljit_emit_op2(compiler, 1075 1.2.2.2 tls SLJIT_SHL, 1076 1.2.2.3 tls BJ_XREG, 0, 1077 1.2.2.3 tls BJ_TMP1REG, 0, 1078 1.2.2.2 tls SLJIT_IMM, 2); 1079 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1080 1.2.2.2 tls return status; 1081 1.2.2.2 tls 1082 1.2.2.3 tls return SLJIT_SUCCESS; 1083 1.2.2.2 tls } 1084 1.2.2.2 tls 1085 1.2.2.2 tls static int 1086 1.2.2.3 tls emit_pow2_division(struct sljit_compiler *compiler, uint32_t k) 1087 1.2.2.2 tls { 1088 1.2.2.2 tls int shift = 0; 1089 1.2.2.2 tls int status = SLJIT_SUCCESS; 1090 1.2.2.2 tls 1091 1.2.2.2 tls while (k > 1) { 1092 1.2.2.2 tls k >>= 1; 1093 1.2.2.2 tls shift++; 1094 1.2.2.2 tls } 1095 1.2.2.2 tls 1096 1.2.2.3 tls BJ_ASSERT(k == 1 && shift < 32); 1097 1.2.2.2 tls 1098 1.2.2.2 tls if (shift != 0) { 1099 1.2.2.2 tls status = sljit_emit_op2(compiler, 1100 1.2.2.2 tls SLJIT_LSHR|SLJIT_INT_OP, 1101 1.2.2.3 tls BJ_AREG, 0, 1102 1.2.2.3 tls BJ_AREG, 0, 1103 1.2.2.2 tls SLJIT_IMM, shift); 1104 1.2.2.2 tls } 1105 1.2.2.2 tls 1106 1.2.2.2 tls return status; 1107 1.2.2.2 tls } 1108 1.2.2.2 tls 1109 1.2.2.2 tls #if !defined(BPFJIT_USE_UDIV) 1110 1.2.2.2 tls static sljit_uw 1111 1.2.2.2 tls divide(sljit_uw x, sljit_uw y) 1112 1.2.2.2 tls { 1113 1.2.2.2 tls 1114 1.2.2.2 tls return (uint32_t)x / (uint32_t)y; 1115 1.2.2.2 tls } 1116 1.2.2.2 tls #endif 1117 1.2.2.2 tls 1118 1.2.2.2 tls /* 1119 1.2.2.3 tls * Emit code for A = A / div. 1120 1.2.2.3 tls * divt,divw are either SLJIT_IMM,pc->k or BJ_XREG,0. 1121 1.2.2.2 tls */ 1122 1.2.2.2 tls static int 1123 1.2.2.3 tls emit_division(struct sljit_compiler *compiler, int divt, sljit_sw divw) 1124 1.2.2.2 tls { 1125 1.2.2.2 tls int status; 1126 1.2.2.2 tls 1127 1.2.2.3 tls #if BJ_XREG == SLJIT_RETURN_REG || \ 1128 1.2.2.3 tls BJ_XREG == SLJIT_SCRATCH_REG1 || \ 1129 1.2.2.3 tls BJ_XREG == SLJIT_SCRATCH_REG2 || \ 1130 1.2.2.3 tls BJ_AREG == SLJIT_SCRATCH_REG2 1131 1.2.2.2 tls #error "Not supported assignment of registers." 1132 1.2.2.2 tls #endif 1133 1.2.2.2 tls 1134 1.2.2.3 tls #if BJ_AREG != SLJIT_SCRATCH_REG1 1135 1.2.2.2 tls status = sljit_emit_op1(compiler, 1136 1.2.2.2 tls SLJIT_MOV, 1137 1.2.2.3 tls SLJIT_SCRATCH_REG1, 0, 1138 1.2.2.3 tls BJ_AREG, 0); 1139 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1140 1.2.2.2 tls return status; 1141 1.2.2.2 tls #endif 1142 1.2.2.2 tls 1143 1.2.2.2 tls status = sljit_emit_op1(compiler, 1144 1.2.2.2 tls SLJIT_MOV, 1145 1.2.2.3 tls SLJIT_SCRATCH_REG2, 0, 1146 1.2.2.2 tls divt, divw); 1147 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1148 1.2.2.2 tls return status; 1149 1.2.2.2 tls 1150 1.2.2.2 tls #if defined(BPFJIT_USE_UDIV) 1151 1.2.2.2 tls status = sljit_emit_op0(compiler, SLJIT_UDIV|SLJIT_INT_OP); 1152 1.2.2.2 tls 1153 1.2.2.3 tls #if BJ_AREG != SLJIT_SCRATCH_REG1 1154 1.2.2.2 tls status = sljit_emit_op1(compiler, 1155 1.2.2.2 tls SLJIT_MOV, 1156 1.2.2.3 tls BJ_AREG, 0, 1157 1.2.2.3 tls SLJIT_SCRATCH_REG1, 0); 1158 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1159 1.2.2.2 tls return status; 1160 1.2.2.2 tls #endif 1161 1.2.2.2 tls #else 1162 1.2.2.2 tls status = sljit_emit_ijump(compiler, 1163 1.2.2.2 tls SLJIT_CALL2, 1164 1.2.2.2 tls SLJIT_IMM, SLJIT_FUNC_OFFSET(divide)); 1165 1.2.2.2 tls 1166 1.2.2.3 tls #if BJ_AREG != SLJIT_RETURN_REG 1167 1.2.2.2 tls status = sljit_emit_op1(compiler, 1168 1.2.2.2 tls SLJIT_MOV, 1169 1.2.2.3 tls BJ_AREG, 0, 1170 1.2.2.2 tls SLJIT_RETURN_REG, 0); 1171 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1172 1.2.2.2 tls return status; 1173 1.2.2.2 tls #endif 1174 1.2.2.2 tls #endif 1175 1.2.2.2 tls 1176 1.2.2.2 tls return status; 1177 1.2.2.2 tls } 1178 1.2.2.2 tls 1179 1.2.2.2 tls /* 1180 1.2.2.2 tls * Return true if pc is a "read from packet" instruction. 1181 1.2.2.2 tls * If length is not NULL and return value is true, *length will 1182 1.2.2.2 tls * be set to a safe length required to read a packet. 1183 1.2.2.2 tls */ 1184 1.2.2.2 tls static bool 1185 1.2.2.3 tls read_pkt_insn(const struct bpf_insn *pc, bpfjit_abc_length_t *length) 1186 1.2.2.2 tls { 1187 1.2.2.2 tls bool rv; 1188 1.2.2.3 tls bpfjit_abc_length_t width; 1189 1.2.2.2 tls 1190 1.2.2.2 tls switch (BPF_CLASS(pc->code)) { 1191 1.2.2.2 tls default: 1192 1.2.2.2 tls rv = false; 1193 1.2.2.2 tls break; 1194 1.2.2.2 tls 1195 1.2.2.2 tls case BPF_LD: 1196 1.2.2.2 tls rv = BPF_MODE(pc->code) == BPF_ABS || 1197 1.2.2.2 tls BPF_MODE(pc->code) == BPF_IND; 1198 1.2.2.2 tls if (rv) 1199 1.2.2.2 tls width = read_width(pc); 1200 1.2.2.2 tls break; 1201 1.2.2.2 tls 1202 1.2.2.2 tls case BPF_LDX: 1203 1.2.2.2 tls rv = pc->code == (BPF_LDX|BPF_B|BPF_MSH); 1204 1.2.2.2 tls width = 1; 1205 1.2.2.2 tls break; 1206 1.2.2.2 tls } 1207 1.2.2.2 tls 1208 1.2.2.2 tls if (rv && length != NULL) { 1209 1.2.2.3 tls /* 1210 1.2.2.3 tls * Values greater than UINT32_MAX will generate 1211 1.2.2.3 tls * unconditional "return 0". 1212 1.2.2.3 tls */ 1213 1.2.2.3 tls *length = (uint32_t)pc->k + width; 1214 1.2.2.2 tls } 1215 1.2.2.2 tls 1216 1.2.2.2 tls return rv; 1217 1.2.2.2 tls } 1218 1.2.2.2 tls 1219 1.2.2.2 tls static void 1220 1.2.2.3 tls optimize_init(struct bpfjit_insn_data *insn_dat, size_t insn_count) 1221 1.2.2.2 tls { 1222 1.2.2.3 tls size_t i; 1223 1.2.2.2 tls 1224 1.2.2.3 tls for (i = 0; i < insn_count; i++) { 1225 1.2.2.3 tls SLIST_INIT(&insn_dat[i].bjumps); 1226 1.2.2.3 tls insn_dat[i].invalid = BJ_INIT_NOBITS; 1227 1.2.2.2 tls } 1228 1.2.2.2 tls } 1229 1.2.2.2 tls 1230 1.2.2.2 tls /* 1231 1.2.2.2 tls * The function divides instructions into blocks. Destination of a jump 1232 1.2.2.2 tls * instruction starts a new block. BPF_RET and BPF_JMP instructions 1233 1.2.2.2 tls * terminate a block. Blocks are linear, that is, there are no jumps out 1234 1.2.2.2 tls * from the middle of a block and there are no jumps in to the middle of 1235 1.2.2.2 tls * a block. 1236 1.2.2.3 tls * 1237 1.2.2.3 tls * The function also sets bits in *initmask for memwords that 1238 1.2.2.3 tls * need to be initialized to zero. Note that this set should be empty 1239 1.2.2.3 tls * for any valid kernel filter program. 1240 1.2.2.2 tls */ 1241 1.2.2.3 tls static bool 1242 1.2.2.3 tls optimize_pass1(const bpf_ctx_t *bc, const struct bpf_insn *insns, 1243 1.2.2.3 tls struct bpfjit_insn_data *insn_dat, size_t insn_count, 1244 1.2.2.3 tls bpf_memword_init_t *initmask, bpfjit_hint_t *hints) 1245 1.2.2.2 tls { 1246 1.2.2.3 tls struct bpfjit_jump *jtf; 1247 1.2.2.2 tls size_t i; 1248 1.2.2.2 tls uint32_t jt, jf; 1249 1.2.2.3 tls bpfjit_abc_length_t length; 1250 1.2.2.3 tls bpf_memword_init_t invalid; /* borrowed from bpf_filter() */ 1251 1.2.2.3 tls bool unreachable; 1252 1.2.2.3 tls 1253 1.2.2.3 tls const size_t memwords = GET_MEMWORDS(bc); 1254 1.2.2.2 tls 1255 1.2.2.3 tls *hints = 0; 1256 1.2.2.3 tls *initmask = BJ_INIT_NOBITS; 1257 1.2.2.2 tls 1258 1.2.2.2 tls unreachable = false; 1259 1.2.2.3 tls invalid = ~BJ_INIT_NOBITS; 1260 1.2.2.2 tls 1261 1.2.2.2 tls for (i = 0; i < insn_count; i++) { 1262 1.2.2.3 tls if (!SLIST_EMPTY(&insn_dat[i].bjumps)) 1263 1.2.2.2 tls unreachable = false; 1264 1.2.2.3 tls insn_dat[i].unreachable = unreachable; 1265 1.2.2.2 tls 1266 1.2.2.2 tls if (unreachable) 1267 1.2.2.2 tls continue; 1268 1.2.2.2 tls 1269 1.2.2.3 tls invalid |= insn_dat[i].invalid; 1270 1.2.2.3 tls 1271 1.2.2.3 tls if (read_pkt_insn(&insns[i], &length) && length > UINT32_MAX) 1272 1.2.2.3 tls unreachable = true; 1273 1.2.2.2 tls 1274 1.2.2.2 tls switch (BPF_CLASS(insns[i].code)) { 1275 1.2.2.2 tls case BPF_RET: 1276 1.2.2.3 tls if (BPF_RVAL(insns[i].code) == BPF_A) 1277 1.2.2.3 tls *initmask |= invalid & BJ_INIT_ABIT; 1278 1.2.2.3 tls 1279 1.2.2.2 tls unreachable = true; 1280 1.2.2.2 tls continue; 1281 1.2.2.2 tls 1282 1.2.2.3 tls case BPF_LD: 1283 1.2.2.3 tls if (BPF_MODE(insns[i].code) == BPF_ABS) 1284 1.2.2.3 tls *hints |= BJ_HINT_ABS; 1285 1.2.2.3 tls 1286 1.2.2.3 tls if (BPF_MODE(insns[i].code) == BPF_IND) { 1287 1.2.2.3 tls *hints |= BJ_HINT_IND | BJ_HINT_XREG; 1288 1.2.2.3 tls *initmask |= invalid & BJ_INIT_XBIT; 1289 1.2.2.3 tls } 1290 1.2.2.3 tls 1291 1.2.2.3 tls if (BPF_MODE(insns[i].code) == BPF_MEM && 1292 1.2.2.3 tls (uint32_t)insns[i].k < memwords) { 1293 1.2.2.3 tls *initmask |= invalid & BJ_INIT_MBIT(insns[i].k); 1294 1.2.2.3 tls } 1295 1.2.2.3 tls 1296 1.2.2.3 tls invalid &= ~BJ_INIT_ABIT; 1297 1.2.2.3 tls continue; 1298 1.2.2.3 tls 1299 1.2.2.3 tls case BPF_LDX: 1300 1.2.2.3 tls *hints |= BJ_HINT_XREG | BJ_HINT_LDX; 1301 1.2.2.3 tls 1302 1.2.2.3 tls if (BPF_MODE(insns[i].code) == BPF_MEM && 1303 1.2.2.3 tls (uint32_t)insns[i].k < memwords) { 1304 1.2.2.3 tls *initmask |= invalid & BJ_INIT_MBIT(insns[i].k); 1305 1.2.2.3 tls } 1306 1.2.2.3 tls 1307 1.2.2.3 tls if (BPF_MODE(insns[i].code) == BPF_MSH && 1308 1.2.2.3 tls BPF_SIZE(insns[i].code) == BPF_B) { 1309 1.2.2.3 tls *hints |= BJ_HINT_MSH; 1310 1.2.2.3 tls } 1311 1.2.2.3 tls 1312 1.2.2.3 tls invalid &= ~BJ_INIT_XBIT; 1313 1.2.2.3 tls continue; 1314 1.2.2.3 tls 1315 1.2.2.3 tls case BPF_ST: 1316 1.2.2.3 tls *initmask |= invalid & BJ_INIT_ABIT; 1317 1.2.2.3 tls 1318 1.2.2.3 tls if ((uint32_t)insns[i].k < memwords) 1319 1.2.2.3 tls invalid &= ~BJ_INIT_MBIT(insns[i].k); 1320 1.2.2.3 tls 1321 1.2.2.3 tls continue; 1322 1.2.2.3 tls 1323 1.2.2.3 tls case BPF_STX: 1324 1.2.2.3 tls *hints |= BJ_HINT_XREG; 1325 1.2.2.3 tls *initmask |= invalid & BJ_INIT_XBIT; 1326 1.2.2.3 tls 1327 1.2.2.3 tls if ((uint32_t)insns[i].k < memwords) 1328 1.2.2.3 tls invalid &= ~BJ_INIT_MBIT(insns[i].k); 1329 1.2.2.3 tls 1330 1.2.2.3 tls continue; 1331 1.2.2.3 tls 1332 1.2.2.3 tls case BPF_ALU: 1333 1.2.2.3 tls *initmask |= invalid & BJ_INIT_ABIT; 1334 1.2.2.3 tls 1335 1.2.2.3 tls if (insns[i].code != (BPF_ALU|BPF_NEG) && 1336 1.2.2.3 tls BPF_SRC(insns[i].code) == BPF_X) { 1337 1.2.2.3 tls *hints |= BJ_HINT_XREG; 1338 1.2.2.3 tls *initmask |= invalid & BJ_INIT_XBIT; 1339 1.2.2.3 tls } 1340 1.2.2.3 tls 1341 1.2.2.3 tls invalid &= ~BJ_INIT_ABIT; 1342 1.2.2.3 tls continue; 1343 1.2.2.3 tls 1344 1.2.2.3 tls case BPF_MISC: 1345 1.2.2.3 tls switch (BPF_MISCOP(insns[i].code)) { 1346 1.2.2.3 tls case BPF_TAX: // X <- A 1347 1.2.2.3 tls *hints |= BJ_HINT_XREG; 1348 1.2.2.3 tls *initmask |= invalid & BJ_INIT_ABIT; 1349 1.2.2.3 tls invalid &= ~BJ_INIT_XBIT; 1350 1.2.2.3 tls continue; 1351 1.2.2.3 tls 1352 1.2.2.3 tls case BPF_TXA: // A <- X 1353 1.2.2.3 tls *hints |= BJ_HINT_XREG; 1354 1.2.2.3 tls *initmask |= invalid & BJ_INIT_XBIT; 1355 1.2.2.3 tls invalid &= ~BJ_INIT_ABIT; 1356 1.2.2.3 tls continue; 1357 1.2.2.3 tls 1358 1.2.2.3 tls case BPF_COPX: 1359 1.2.2.3 tls *hints |= BJ_HINT_XREG | BJ_HINT_COPX; 1360 1.2.2.3 tls /* FALLTHROUGH */ 1361 1.2.2.3 tls 1362 1.2.2.3 tls case BPF_COP: 1363 1.2.2.3 tls *hints |= BJ_HINT_COP; 1364 1.2.2.3 tls *initmask |= invalid & BJ_INIT_ABIT; 1365 1.2.2.3 tls invalid &= ~BJ_INIT_ABIT; 1366 1.2.2.3 tls continue; 1367 1.2.2.3 tls } 1368 1.2.2.3 tls 1369 1.2.2.3 tls continue; 1370 1.2.2.3 tls 1371 1.2.2.2 tls case BPF_JMP: 1372 1.2.2.3 tls /* Initialize abc_length for ABC pass. */ 1373 1.2.2.3 tls insn_dat[i].u.jdata.abc_length = MAX_ABC_LENGTH; 1374 1.2.2.3 tls 1375 1.2.2.3 tls if (BPF_OP(insns[i].code) == BPF_JA) { 1376 1.2.2.2 tls jt = jf = insns[i].k; 1377 1.2.2.2 tls } else { 1378 1.2.2.2 tls jt = insns[i].jt; 1379 1.2.2.2 tls jf = insns[i].jf; 1380 1.2.2.2 tls } 1381 1.2.2.2 tls 1382 1.2.2.2 tls if (jt >= insn_count - (i + 1) || 1383 1.2.2.2 tls jf >= insn_count - (i + 1)) { 1384 1.2.2.3 tls return false; 1385 1.2.2.2 tls } 1386 1.2.2.2 tls 1387 1.2.2.2 tls if (jt > 0 && jf > 0) 1388 1.2.2.2 tls unreachable = true; 1389 1.2.2.2 tls 1390 1.2.2.3 tls jt += i + 1; 1391 1.2.2.3 tls jf += i + 1; 1392 1.2.2.3 tls 1393 1.2.2.3 tls jtf = insn_dat[i].u.jdata.jtf; 1394 1.2.2.2 tls 1395 1.2.2.3 tls jtf[0].jdata = &insn_dat[i].u.jdata; 1396 1.2.2.3 tls SLIST_INSERT_HEAD(&insn_dat[jt].bjumps, 1397 1.2.2.3 tls &jtf[0], entries); 1398 1.2.2.2 tls 1399 1.2.2.2 tls if (jf != jt) { 1400 1.2.2.3 tls jtf[1].jdata = &insn_dat[i].u.jdata; 1401 1.2.2.3 tls SLIST_INSERT_HEAD(&insn_dat[jf].bjumps, 1402 1.2.2.3 tls &jtf[1], entries); 1403 1.2.2.2 tls } 1404 1.2.2.2 tls 1405 1.2.2.3 tls insn_dat[jf].invalid |= invalid; 1406 1.2.2.3 tls insn_dat[jt].invalid |= invalid; 1407 1.2.2.3 tls invalid = 0; 1408 1.2.2.3 tls 1409 1.2.2.2 tls continue; 1410 1.2.2.2 tls } 1411 1.2.2.2 tls } 1412 1.2.2.2 tls 1413 1.2.2.3 tls return true; 1414 1.2.2.2 tls } 1415 1.2.2.2 tls 1416 1.2.2.2 tls /* 1417 1.2.2.3 tls * Array Bounds Check Elimination (ABC) pass. 1418 1.2.2.2 tls */ 1419 1.2.2.3 tls static void 1420 1.2.2.3 tls optimize_pass2(const bpf_ctx_t *bc, const struct bpf_insn *insns, 1421 1.2.2.3 tls struct bpfjit_insn_data *insn_dat, size_t insn_count) 1422 1.2.2.2 tls { 1423 1.2.2.3 tls struct bpfjit_jump *jmp; 1424 1.2.2.3 tls const struct bpf_insn *pc; 1425 1.2.2.3 tls struct bpfjit_insn_data *pd; 1426 1.2.2.2 tls size_t i; 1427 1.2.2.3 tls bpfjit_abc_length_t length, abc_length = 0; 1428 1.2.2.2 tls 1429 1.2.2.3 tls const size_t extwords = GET_EXTWORDS(bc); 1430 1.2.2.2 tls 1431 1.2.2.3 tls for (i = insn_count; i != 0; i--) { 1432 1.2.2.3 tls pc = &insns[i-1]; 1433 1.2.2.3 tls pd = &insn_dat[i-1]; 1434 1.2.2.3 tls 1435 1.2.2.3 tls if (pd->unreachable) 1436 1.2.2.3 tls continue; 1437 1.2.2.3 tls 1438 1.2.2.3 tls switch (BPF_CLASS(pc->code)) { 1439 1.2.2.3 tls case BPF_RET: 1440 1.2.2.3 tls /* 1441 1.2.2.3 tls * It's quite common for bpf programs to 1442 1.2.2.3 tls * check packet bytes in increasing order 1443 1.2.2.3 tls * and return zero if bytes don't match 1444 1.2.2.3 tls * specified critetion. Such programs disable 1445 1.2.2.3 tls * ABC optimization completely because for 1446 1.2.2.3 tls * every jump there is a branch with no read 1447 1.2.2.3 tls * instruction. 1448 1.2.2.3 tls * With no side effects, BPF_STMT(BPF_RET+BPF_K, 0) 1449 1.2.2.3 tls * is indistinguishable from out-of-bound load. 1450 1.2.2.3 tls * Therefore, abc_length can be set to 1451 1.2.2.3 tls * MAX_ABC_LENGTH and enable ABC for many 1452 1.2.2.3 tls * bpf programs. 1453 1.2.2.3 tls * If this optimization encounters any 1454 1.2.2.3 tls * instruction with a side effect, it will 1455 1.2.2.3 tls * reset abc_length. 1456 1.2.2.3 tls */ 1457 1.2.2.3 tls if (BPF_RVAL(pc->code) == BPF_K && pc->k == 0) 1458 1.2.2.3 tls abc_length = MAX_ABC_LENGTH; 1459 1.2.2.3 tls else 1460 1.2.2.3 tls abc_length = 0; 1461 1.2.2.3 tls break; 1462 1.2.2.3 tls 1463 1.2.2.3 tls case BPF_MISC: 1464 1.2.2.3 tls if (BPF_MISCOP(pc->code) == BPF_COP || 1465 1.2.2.3 tls BPF_MISCOP(pc->code) == BPF_COPX) { 1466 1.2.2.3 tls /* COP instructions can have side effects. */ 1467 1.2.2.3 tls abc_length = 0; 1468 1.2.2.3 tls } 1469 1.2.2.3 tls break; 1470 1.2.2.3 tls 1471 1.2.2.3 tls case BPF_ST: 1472 1.2.2.3 tls case BPF_STX: 1473 1.2.2.3 tls if (extwords != 0) { 1474 1.2.2.3 tls /* Write to memory is visible after a call. */ 1475 1.2.2.3 tls abc_length = 0; 1476 1.2.2.3 tls } 1477 1.2.2.3 tls break; 1478 1.2.2.3 tls 1479 1.2.2.3 tls case BPF_JMP: 1480 1.2.2.3 tls abc_length = pd->u.jdata.abc_length; 1481 1.2.2.3 tls break; 1482 1.2.2.3 tls 1483 1.2.2.3 tls default: 1484 1.2.2.3 tls if (read_pkt_insn(pc, &length)) { 1485 1.2.2.3 tls if (abc_length < length) 1486 1.2.2.3 tls abc_length = length; 1487 1.2.2.3 tls pd->u.rdata.abc_length = abc_length; 1488 1.2.2.3 tls } 1489 1.2.2.3 tls break; 1490 1.2.2.2 tls } 1491 1.2.2.2 tls 1492 1.2.2.3 tls SLIST_FOREACH(jmp, &pd->bjumps, entries) { 1493 1.2.2.3 tls if (jmp->jdata->abc_length > abc_length) 1494 1.2.2.3 tls jmp->jdata->abc_length = abc_length; 1495 1.2.2.2 tls } 1496 1.2.2.3 tls } 1497 1.2.2.3 tls } 1498 1.2.2.2 tls 1499 1.2.2.3 tls static void 1500 1.2.2.3 tls optimize_pass3(const struct bpf_insn *insns, 1501 1.2.2.3 tls struct bpfjit_insn_data *insn_dat, size_t insn_count) 1502 1.2.2.3 tls { 1503 1.2.2.3 tls struct bpfjit_jump *jmp; 1504 1.2.2.3 tls size_t i; 1505 1.2.2.3 tls bpfjit_abc_length_t checked_length = 0; 1506 1.2.2.3 tls 1507 1.2.2.3 tls for (i = 0; i < insn_count; i++) { 1508 1.2.2.3 tls if (insn_dat[i].unreachable) 1509 1.2.2.3 tls continue; 1510 1.2.2.2 tls 1511 1.2.2.3 tls SLIST_FOREACH(jmp, &insn_dat[i].bjumps, entries) { 1512 1.2.2.3 tls if (jmp->jdata->checked_length < checked_length) 1513 1.2.2.3 tls checked_length = jmp->jdata->checked_length; 1514 1.2.2.3 tls } 1515 1.2.2.3 tls 1516 1.2.2.3 tls if (BPF_CLASS(insns[i].code) == BPF_JMP) { 1517 1.2.2.3 tls insn_dat[i].u.jdata.checked_length = checked_length; 1518 1.2.2.3 tls } else if (read_pkt_insn(&insns[i], NULL)) { 1519 1.2.2.3 tls struct bpfjit_read_pkt_data *rdata = 1520 1.2.2.3 tls &insn_dat[i].u.rdata; 1521 1.2.2.3 tls rdata->check_length = 0; 1522 1.2.2.3 tls if (checked_length < rdata->abc_length) { 1523 1.2.2.3 tls checked_length = rdata->abc_length; 1524 1.2.2.3 tls rdata->check_length = checked_length; 1525 1.2.2.3 tls } 1526 1.2.2.2 tls } 1527 1.2.2.2 tls } 1528 1.2.2.3 tls } 1529 1.2.2.2 tls 1530 1.2.2.3 tls static bool 1531 1.2.2.3 tls optimize(const bpf_ctx_t *bc, const struct bpf_insn *insns, 1532 1.2.2.3 tls struct bpfjit_insn_data *insn_dat, size_t insn_count, 1533 1.2.2.3 tls bpf_memword_init_t *initmask, bpfjit_hint_t *hints) 1534 1.2.2.3 tls { 1535 1.2.2.3 tls 1536 1.2.2.3 tls optimize_init(insn_dat, insn_count); 1537 1.2.2.3 tls 1538 1.2.2.3 tls if (!optimize_pass1(bc, insns, insn_dat, insn_count, initmask, hints)) 1539 1.2.2.3 tls return false; 1540 1.2.2.3 tls 1541 1.2.2.3 tls optimize_pass2(bc, insns, insn_dat, insn_count); 1542 1.2.2.3 tls optimize_pass3(insns, insn_dat, insn_count); 1543 1.2.2.3 tls 1544 1.2.2.3 tls return true; 1545 1.2.2.2 tls } 1546 1.2.2.2 tls 1547 1.2.2.2 tls /* 1548 1.2.2.2 tls * Convert BPF_ALU operations except BPF_NEG and BPF_DIV to sljit operation. 1549 1.2.2.2 tls */ 1550 1.2.2.2 tls static int 1551 1.2.2.3 tls bpf_alu_to_sljit_op(const struct bpf_insn *pc) 1552 1.2.2.2 tls { 1553 1.2.2.2 tls 1554 1.2.2.2 tls /* 1555 1.2.2.2 tls * Note: all supported 64bit arches have 32bit multiply 1556 1.2.2.2 tls * instruction so SLJIT_INT_OP doesn't have any overhead. 1557 1.2.2.2 tls */ 1558 1.2.2.2 tls switch (BPF_OP(pc->code)) { 1559 1.2.2.2 tls case BPF_ADD: return SLJIT_ADD; 1560 1.2.2.2 tls case BPF_SUB: return SLJIT_SUB; 1561 1.2.2.2 tls case BPF_MUL: return SLJIT_MUL|SLJIT_INT_OP; 1562 1.2.2.2 tls case BPF_OR: return SLJIT_OR; 1563 1.2.2.2 tls case BPF_AND: return SLJIT_AND; 1564 1.2.2.2 tls case BPF_LSH: return SLJIT_SHL; 1565 1.2.2.2 tls case BPF_RSH: return SLJIT_LSHR|SLJIT_INT_OP; 1566 1.2.2.2 tls default: 1567 1.2.2.3 tls BJ_ASSERT(false); 1568 1.2.2.2 tls return 0; 1569 1.2.2.2 tls } 1570 1.2.2.2 tls } 1571 1.2.2.2 tls 1572 1.2.2.2 tls /* 1573 1.2.2.2 tls * Convert BPF_JMP operations except BPF_JA to sljit condition. 1574 1.2.2.2 tls */ 1575 1.2.2.2 tls static int 1576 1.2.2.3 tls bpf_jmp_to_sljit_cond(const struct bpf_insn *pc, bool negate) 1577 1.2.2.2 tls { 1578 1.2.2.2 tls /* 1579 1.2.2.2 tls * Note: all supported 64bit arches have 32bit comparison 1580 1.2.2.2 tls * instructions so SLJIT_INT_OP doesn't have any overhead. 1581 1.2.2.2 tls */ 1582 1.2.2.2 tls int rv = SLJIT_INT_OP; 1583 1.2.2.2 tls 1584 1.2.2.2 tls switch (BPF_OP(pc->code)) { 1585 1.2.2.2 tls case BPF_JGT: 1586 1.2.2.2 tls rv |= negate ? SLJIT_C_LESS_EQUAL : SLJIT_C_GREATER; 1587 1.2.2.2 tls break; 1588 1.2.2.2 tls case BPF_JGE: 1589 1.2.2.2 tls rv |= negate ? SLJIT_C_LESS : SLJIT_C_GREATER_EQUAL; 1590 1.2.2.2 tls break; 1591 1.2.2.2 tls case BPF_JEQ: 1592 1.2.2.2 tls rv |= negate ? SLJIT_C_NOT_EQUAL : SLJIT_C_EQUAL; 1593 1.2.2.2 tls break; 1594 1.2.2.2 tls case BPF_JSET: 1595 1.2.2.2 tls rv |= negate ? SLJIT_C_EQUAL : SLJIT_C_NOT_EQUAL; 1596 1.2.2.2 tls break; 1597 1.2.2.2 tls default: 1598 1.2.2.3 tls BJ_ASSERT(false); 1599 1.2.2.2 tls } 1600 1.2.2.2 tls 1601 1.2.2.2 tls return rv; 1602 1.2.2.2 tls } 1603 1.2.2.2 tls 1604 1.2.2.2 tls /* 1605 1.2.2.2 tls * Convert BPF_K and BPF_X to sljit register. 1606 1.2.2.2 tls */ 1607 1.2.2.2 tls static int 1608 1.2.2.3 tls kx_to_reg(const struct bpf_insn *pc) 1609 1.2.2.2 tls { 1610 1.2.2.2 tls 1611 1.2.2.2 tls switch (BPF_SRC(pc->code)) { 1612 1.2.2.2 tls case BPF_K: return SLJIT_IMM; 1613 1.2.2.3 tls case BPF_X: return BJ_XREG; 1614 1.2.2.2 tls default: 1615 1.2.2.3 tls BJ_ASSERT(false); 1616 1.2.2.2 tls return 0; 1617 1.2.2.2 tls } 1618 1.2.2.2 tls } 1619 1.2.2.2 tls 1620 1.2.2.3 tls static sljit_sw 1621 1.2.2.3 tls kx_to_reg_arg(const struct bpf_insn *pc) 1622 1.2.2.2 tls { 1623 1.2.2.2 tls 1624 1.2.2.2 tls switch (BPF_SRC(pc->code)) { 1625 1.2.2.2 tls case BPF_K: return (uint32_t)pc->k; /* SLJIT_IMM, pc->k, */ 1626 1.2.2.3 tls case BPF_X: return 0; /* BJ_XREG, 0, */ 1627 1.2.2.2 tls default: 1628 1.2.2.3 tls BJ_ASSERT(false); 1629 1.2.2.2 tls return 0; 1630 1.2.2.2 tls } 1631 1.2.2.2 tls } 1632 1.2.2.2 tls 1633 1.2.2.3 tls static bool 1634 1.2.2.3 tls generate_insn_code(struct sljit_compiler *compiler, bpfjit_hint_t hints, 1635 1.2.2.3 tls const bpf_ctx_t *bc, const struct bpf_insn *insns, 1636 1.2.2.3 tls struct bpfjit_insn_data *insn_dat, size_t insn_count) 1637 1.2.2.2 tls { 1638 1.2.2.2 tls /* a list of jumps to out-of-bound return from a generated function */ 1639 1.2.2.2 tls struct sljit_jump **ret0; 1640 1.2.2.2 tls size_t ret0_size, ret0_maxsize; 1641 1.2.2.2 tls 1642 1.2.2.2 tls struct sljit_jump *jump; 1643 1.2.2.3 tls struct sljit_label *label; 1644 1.2.2.3 tls const struct bpf_insn *pc; 1645 1.2.2.2 tls struct bpfjit_jump *bjump, *jtf; 1646 1.2.2.2 tls struct sljit_jump *to_mchain_jump; 1647 1.2.2.2 tls 1648 1.2.2.3 tls size_t i; 1649 1.2.2.3 tls int status; 1650 1.2.2.3 tls int branching, negate; 1651 1.2.2.3 tls unsigned int rval, mode, src; 1652 1.2.2.2 tls uint32_t jt, jf; 1653 1.2.2.2 tls 1654 1.2.2.3 tls bool unconditional_ret; 1655 1.2.2.3 tls bool rv; 1656 1.2.2.2 tls 1657 1.2.2.3 tls const size_t extwords = GET_EXTWORDS(bc); 1658 1.2.2.3 tls const size_t memwords = GET_MEMWORDS(bc); 1659 1.2.2.2 tls 1660 1.2.2.3 tls ret0 = NULL; 1661 1.2.2.3 tls rv = false; 1662 1.2.2.2 tls 1663 1.2.2.2 tls ret0_size = 0; 1664 1.2.2.3 tls ret0_maxsize = 64; 1665 1.2.2.3 tls ret0 = BJ_ALLOC(ret0_maxsize * sizeof(ret0[0])); 1666 1.2.2.3 tls if (ret0 == NULL) 1667 1.2.2.2 tls goto fail; 1668 1.2.2.2 tls 1669 1.2.2.3 tls /* reset sjump members of jdata */ 1670 1.2.2.3 tls for (i = 0; i < insn_count; i++) { 1671 1.2.2.3 tls if (insn_dat[i].unreachable || 1672 1.2.2.3 tls BPF_CLASS(insns[i].code) != BPF_JMP) { 1673 1.2.2.3 tls continue; 1674 1.2.2.3 tls } 1675 1.2.2.2 tls 1676 1.2.2.3 tls jtf = insn_dat[i].u.jdata.jtf; 1677 1.2.2.3 tls jtf[0].sjump = jtf[1].sjump = NULL; 1678 1.2.2.2 tls } 1679 1.2.2.2 tls 1680 1.2.2.3 tls /* main loop */ 1681 1.2.2.2 tls for (i = 0; i < insn_count; i++) { 1682 1.2.2.3 tls if (insn_dat[i].unreachable) 1683 1.2.2.2 tls continue; 1684 1.2.2.2 tls 1685 1.2.2.2 tls /* 1686 1.2.2.2 tls * Resolve jumps to the current insn. 1687 1.2.2.2 tls */ 1688 1.2.2.2 tls label = NULL; 1689 1.2.2.3 tls SLIST_FOREACH(bjump, &insn_dat[i].bjumps, entries) { 1690 1.2.2.3 tls if (bjump->sjump != NULL) { 1691 1.2.2.2 tls if (label == NULL) 1692 1.2.2.2 tls label = sljit_emit_label(compiler); 1693 1.2.2.2 tls if (label == NULL) 1694 1.2.2.2 tls goto fail; 1695 1.2.2.3 tls sljit_set_label(bjump->sjump, label); 1696 1.2.2.2 tls } 1697 1.2.2.2 tls } 1698 1.2.2.2 tls 1699 1.2.2.3 tls to_mchain_jump = NULL; 1700 1.2.2.3 tls unconditional_ret = false; 1701 1.2.2.3 tls 1702 1.2.2.3 tls if (read_pkt_insn(&insns[i], NULL)) { 1703 1.2.2.3 tls if (insn_dat[i].u.rdata.check_length > UINT32_MAX) { 1704 1.2.2.3 tls /* Jump to "return 0" unconditionally. */ 1705 1.2.2.3 tls unconditional_ret = true; 1706 1.2.2.3 tls jump = sljit_emit_jump(compiler, SLJIT_JUMP); 1707 1.2.2.3 tls if (jump == NULL) 1708 1.2.2.3 tls goto fail; 1709 1.2.2.3 tls if (!append_jump(jump, &ret0, 1710 1.2.2.3 tls &ret0_size, &ret0_maxsize)) 1711 1.2.2.3 tls goto fail; 1712 1.2.2.3 tls } else if (insn_dat[i].u.rdata.check_length > 0) { 1713 1.2.2.3 tls /* if (buflen < check_length) return 0; */ 1714 1.2.2.3 tls jump = sljit_emit_cmp(compiler, 1715 1.2.2.3 tls SLJIT_C_LESS, 1716 1.2.2.3 tls BJ_BUFLEN, 0, 1717 1.2.2.3 tls SLJIT_IMM, 1718 1.2.2.3 tls insn_dat[i].u.rdata.check_length); 1719 1.2.2.3 tls if (jump == NULL) 1720 1.2.2.3 tls goto fail; 1721 1.2.2.2 tls #ifdef _KERNEL 1722 1.2.2.3 tls to_mchain_jump = jump; 1723 1.2.2.2 tls #else 1724 1.2.2.3 tls if (!append_jump(jump, &ret0, 1725 1.2.2.3 tls &ret0_size, &ret0_maxsize)) 1726 1.2.2.3 tls goto fail; 1727 1.2.2.2 tls #endif 1728 1.2.2.3 tls } 1729 1.2.2.2 tls } 1730 1.2.2.2 tls 1731 1.2.2.2 tls pc = &insns[i]; 1732 1.2.2.2 tls switch (BPF_CLASS(pc->code)) { 1733 1.2.2.2 tls 1734 1.2.2.2 tls default: 1735 1.2.2.2 tls goto fail; 1736 1.2.2.2 tls 1737 1.2.2.2 tls case BPF_LD: 1738 1.2.2.2 tls /* BPF_LD+BPF_IMM A <- k */ 1739 1.2.2.2 tls if (pc->code == (BPF_LD|BPF_IMM)) { 1740 1.2.2.2 tls status = sljit_emit_op1(compiler, 1741 1.2.2.2 tls SLJIT_MOV, 1742 1.2.2.3 tls BJ_AREG, 0, 1743 1.2.2.2 tls SLJIT_IMM, (uint32_t)pc->k); 1744 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1745 1.2.2.2 tls goto fail; 1746 1.2.2.2 tls 1747 1.2.2.2 tls continue; 1748 1.2.2.2 tls } 1749 1.2.2.2 tls 1750 1.2.2.2 tls /* BPF_LD+BPF_MEM A <- M[k] */ 1751 1.2.2.2 tls if (pc->code == (BPF_LD|BPF_MEM)) { 1752 1.2.2.3 tls if ((uint32_t)pc->k >= memwords) 1753 1.2.2.2 tls goto fail; 1754 1.2.2.3 tls status = emit_memload(compiler, 1755 1.2.2.3 tls BJ_AREG, pc->k, extwords); 1756 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1757 1.2.2.2 tls goto fail; 1758 1.2.2.2 tls 1759 1.2.2.2 tls continue; 1760 1.2.2.2 tls } 1761 1.2.2.2 tls 1762 1.2.2.2 tls /* BPF_LD+BPF_W+BPF_LEN A <- len */ 1763 1.2.2.2 tls if (pc->code == (BPF_LD|BPF_W|BPF_LEN)) { 1764 1.2.2.2 tls status = sljit_emit_op1(compiler, 1765 1.2.2.3 tls SLJIT_MOV, /* size_t source */ 1766 1.2.2.3 tls BJ_AREG, 0, 1767 1.2.2.3 tls SLJIT_MEM1(BJ_ARGS), 1768 1.2.2.3 tls offsetof(struct bpf_args, wirelen)); 1769 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1770 1.2.2.2 tls goto fail; 1771 1.2.2.2 tls 1772 1.2.2.2 tls continue; 1773 1.2.2.2 tls } 1774 1.2.2.2 tls 1775 1.2.2.2 tls mode = BPF_MODE(pc->code); 1776 1.2.2.2 tls if (mode != BPF_ABS && mode != BPF_IND) 1777 1.2.2.2 tls goto fail; 1778 1.2.2.2 tls 1779 1.2.2.3 tls if (unconditional_ret) 1780 1.2.2.3 tls continue; 1781 1.2.2.3 tls 1782 1.2.2.3 tls status = emit_pkt_read(compiler, hints, pc, 1783 1.2.2.3 tls to_mchain_jump, &ret0, &ret0_size, &ret0_maxsize); 1784 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1785 1.2.2.2 tls goto fail; 1786 1.2.2.2 tls 1787 1.2.2.2 tls continue; 1788 1.2.2.2 tls 1789 1.2.2.2 tls case BPF_LDX: 1790 1.2.2.2 tls mode = BPF_MODE(pc->code); 1791 1.2.2.2 tls 1792 1.2.2.2 tls /* BPF_LDX+BPF_W+BPF_IMM X <- k */ 1793 1.2.2.2 tls if (mode == BPF_IMM) { 1794 1.2.2.2 tls if (BPF_SIZE(pc->code) != BPF_W) 1795 1.2.2.2 tls goto fail; 1796 1.2.2.2 tls status = sljit_emit_op1(compiler, 1797 1.2.2.2 tls SLJIT_MOV, 1798 1.2.2.3 tls BJ_XREG, 0, 1799 1.2.2.2 tls SLJIT_IMM, (uint32_t)pc->k); 1800 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1801 1.2.2.2 tls goto fail; 1802 1.2.2.2 tls 1803 1.2.2.2 tls continue; 1804 1.2.2.2 tls } 1805 1.2.2.2 tls 1806 1.2.2.2 tls /* BPF_LDX+BPF_W+BPF_LEN X <- len */ 1807 1.2.2.2 tls if (mode == BPF_LEN) { 1808 1.2.2.2 tls if (BPF_SIZE(pc->code) != BPF_W) 1809 1.2.2.2 tls goto fail; 1810 1.2.2.2 tls status = sljit_emit_op1(compiler, 1811 1.2.2.3 tls SLJIT_MOV, /* size_t source */ 1812 1.2.2.3 tls BJ_XREG, 0, 1813 1.2.2.3 tls SLJIT_MEM1(BJ_ARGS), 1814 1.2.2.3 tls offsetof(struct bpf_args, wirelen)); 1815 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1816 1.2.2.2 tls goto fail; 1817 1.2.2.2 tls 1818 1.2.2.2 tls continue; 1819 1.2.2.2 tls } 1820 1.2.2.2 tls 1821 1.2.2.2 tls /* BPF_LDX+BPF_W+BPF_MEM X <- M[k] */ 1822 1.2.2.2 tls if (mode == BPF_MEM) { 1823 1.2.2.2 tls if (BPF_SIZE(pc->code) != BPF_W) 1824 1.2.2.2 tls goto fail; 1825 1.2.2.3 tls if ((uint32_t)pc->k >= memwords) 1826 1.2.2.2 tls goto fail; 1827 1.2.2.3 tls status = emit_memload(compiler, 1828 1.2.2.3 tls BJ_XREG, pc->k, extwords); 1829 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1830 1.2.2.2 tls goto fail; 1831 1.2.2.2 tls 1832 1.2.2.2 tls continue; 1833 1.2.2.2 tls } 1834 1.2.2.2 tls 1835 1.2.2.2 tls /* BPF_LDX+BPF_B+BPF_MSH X <- 4*(P[k:1]&0xf) */ 1836 1.2.2.2 tls if (mode != BPF_MSH || BPF_SIZE(pc->code) != BPF_B) 1837 1.2.2.2 tls goto fail; 1838 1.2.2.2 tls 1839 1.2.2.3 tls if (unconditional_ret) 1840 1.2.2.3 tls continue; 1841 1.2.2.3 tls 1842 1.2.2.3 tls status = emit_msh(compiler, hints, pc, 1843 1.2.2.3 tls to_mchain_jump, &ret0, &ret0_size, &ret0_maxsize); 1844 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1845 1.2.2.2 tls goto fail; 1846 1.2.2.2 tls 1847 1.2.2.2 tls continue; 1848 1.2.2.2 tls 1849 1.2.2.2 tls case BPF_ST: 1850 1.2.2.3 tls if (pc->code != BPF_ST || 1851 1.2.2.3 tls (uint32_t)pc->k >= memwords) { 1852 1.2.2.2 tls goto fail; 1853 1.2.2.3 tls } 1854 1.2.2.2 tls 1855 1.2.2.3 tls status = emit_memstore(compiler, 1856 1.2.2.3 tls BJ_AREG, pc->k, extwords); 1857 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1858 1.2.2.2 tls goto fail; 1859 1.2.2.2 tls 1860 1.2.2.2 tls continue; 1861 1.2.2.2 tls 1862 1.2.2.2 tls case BPF_STX: 1863 1.2.2.3 tls if (pc->code != BPF_STX || 1864 1.2.2.3 tls (uint32_t)pc->k >= memwords) { 1865 1.2.2.2 tls goto fail; 1866 1.2.2.3 tls } 1867 1.2.2.2 tls 1868 1.2.2.3 tls status = emit_memstore(compiler, 1869 1.2.2.3 tls BJ_XREG, pc->k, extwords); 1870 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1871 1.2.2.2 tls goto fail; 1872 1.2.2.2 tls 1873 1.2.2.2 tls continue; 1874 1.2.2.2 tls 1875 1.2.2.2 tls case BPF_ALU: 1876 1.2.2.2 tls if (pc->code == (BPF_ALU|BPF_NEG)) { 1877 1.2.2.2 tls status = sljit_emit_op1(compiler, 1878 1.2.2.2 tls SLJIT_NEG, 1879 1.2.2.3 tls BJ_AREG, 0, 1880 1.2.2.3 tls BJ_AREG, 0); 1881 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1882 1.2.2.2 tls goto fail; 1883 1.2.2.2 tls 1884 1.2.2.2 tls continue; 1885 1.2.2.2 tls } 1886 1.2.2.2 tls 1887 1.2.2.2 tls if (BPF_OP(pc->code) != BPF_DIV) { 1888 1.2.2.2 tls status = sljit_emit_op2(compiler, 1889 1.2.2.2 tls bpf_alu_to_sljit_op(pc), 1890 1.2.2.3 tls BJ_AREG, 0, 1891 1.2.2.3 tls BJ_AREG, 0, 1892 1.2.2.2 tls kx_to_reg(pc), kx_to_reg_arg(pc)); 1893 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1894 1.2.2.2 tls goto fail; 1895 1.2.2.2 tls 1896 1.2.2.2 tls continue; 1897 1.2.2.2 tls } 1898 1.2.2.2 tls 1899 1.2.2.2 tls /* BPF_DIV */ 1900 1.2.2.2 tls 1901 1.2.2.2 tls src = BPF_SRC(pc->code); 1902 1.2.2.2 tls if (src != BPF_X && src != BPF_K) 1903 1.2.2.2 tls goto fail; 1904 1.2.2.2 tls 1905 1.2.2.2 tls /* division by zero? */ 1906 1.2.2.2 tls if (src == BPF_X) { 1907 1.2.2.2 tls jump = sljit_emit_cmp(compiler, 1908 1.2.2.2 tls SLJIT_C_EQUAL|SLJIT_INT_OP, 1909 1.2.2.3 tls BJ_XREG, 0, 1910 1.2.2.2 tls SLJIT_IMM, 0); 1911 1.2.2.2 tls if (jump == NULL) 1912 1.2.2.2 tls goto fail; 1913 1.2.2.3 tls if (!append_jump(jump, &ret0, 1914 1.2.2.3 tls &ret0_size, &ret0_maxsize)) 1915 1.2.2.3 tls goto fail; 1916 1.2.2.2 tls } else if (pc->k == 0) { 1917 1.2.2.2 tls jump = sljit_emit_jump(compiler, SLJIT_JUMP); 1918 1.2.2.2 tls if (jump == NULL) 1919 1.2.2.2 tls goto fail; 1920 1.2.2.3 tls if (!append_jump(jump, &ret0, 1921 1.2.2.3 tls &ret0_size, &ret0_maxsize)) 1922 1.2.2.3 tls goto fail; 1923 1.2.2.2 tls } 1924 1.2.2.2 tls 1925 1.2.2.2 tls if (src == BPF_X) { 1926 1.2.2.3 tls status = emit_division(compiler, BJ_XREG, 0); 1927 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1928 1.2.2.2 tls goto fail; 1929 1.2.2.2 tls } else if (pc->k != 0) { 1930 1.2.2.2 tls if (pc->k & (pc->k - 1)) { 1931 1.2.2.2 tls status = emit_division(compiler, 1932 1.2.2.2 tls SLJIT_IMM, (uint32_t)pc->k); 1933 1.2.2.2 tls } else { 1934 1.2.2.3 tls status = emit_pow2_division(compiler, 1935 1.2.2.2 tls (uint32_t)pc->k); 1936 1.2.2.2 tls } 1937 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1938 1.2.2.2 tls goto fail; 1939 1.2.2.2 tls } 1940 1.2.2.2 tls 1941 1.2.2.2 tls continue; 1942 1.2.2.2 tls 1943 1.2.2.2 tls case BPF_JMP: 1944 1.2.2.3 tls if (BPF_OP(pc->code) == BPF_JA) { 1945 1.2.2.2 tls jt = jf = pc->k; 1946 1.2.2.2 tls } else { 1947 1.2.2.2 tls jt = pc->jt; 1948 1.2.2.2 tls jf = pc->jf; 1949 1.2.2.2 tls } 1950 1.2.2.2 tls 1951 1.2.2.2 tls negate = (jt == 0) ? 1 : 0; 1952 1.2.2.2 tls branching = (jt == jf) ? 0 : 1; 1953 1.2.2.3 tls jtf = insn_dat[i].u.jdata.jtf; 1954 1.2.2.2 tls 1955 1.2.2.2 tls if (branching) { 1956 1.2.2.2 tls if (BPF_OP(pc->code) != BPF_JSET) { 1957 1.2.2.2 tls jump = sljit_emit_cmp(compiler, 1958 1.2.2.2 tls bpf_jmp_to_sljit_cond(pc, negate), 1959 1.2.2.3 tls BJ_AREG, 0, 1960 1.2.2.2 tls kx_to_reg(pc), kx_to_reg_arg(pc)); 1961 1.2.2.2 tls } else { 1962 1.2.2.2 tls status = sljit_emit_op2(compiler, 1963 1.2.2.2 tls SLJIT_AND, 1964 1.2.2.3 tls BJ_TMP1REG, 0, 1965 1.2.2.3 tls BJ_AREG, 0, 1966 1.2.2.2 tls kx_to_reg(pc), kx_to_reg_arg(pc)); 1967 1.2.2.2 tls if (status != SLJIT_SUCCESS) 1968 1.2.2.2 tls goto fail; 1969 1.2.2.2 tls 1970 1.2.2.2 tls jump = sljit_emit_cmp(compiler, 1971 1.2.2.2 tls bpf_jmp_to_sljit_cond(pc, negate), 1972 1.2.2.3 tls BJ_TMP1REG, 0, 1973 1.2.2.2 tls SLJIT_IMM, 0); 1974 1.2.2.2 tls } 1975 1.2.2.2 tls 1976 1.2.2.2 tls if (jump == NULL) 1977 1.2.2.2 tls goto fail; 1978 1.2.2.2 tls 1979 1.2.2.3 tls BJ_ASSERT(jtf[negate].sjump == NULL); 1980 1.2.2.3 tls jtf[negate].sjump = jump; 1981 1.2.2.2 tls } 1982 1.2.2.2 tls 1983 1.2.2.2 tls if (!branching || (jt != 0 && jf != 0)) { 1984 1.2.2.2 tls jump = sljit_emit_jump(compiler, SLJIT_JUMP); 1985 1.2.2.2 tls if (jump == NULL) 1986 1.2.2.2 tls goto fail; 1987 1.2.2.2 tls 1988 1.2.2.3 tls BJ_ASSERT(jtf[branching].sjump == NULL); 1989 1.2.2.3 tls jtf[branching].sjump = jump; 1990 1.2.2.2 tls } 1991 1.2.2.2 tls 1992 1.2.2.2 tls continue; 1993 1.2.2.2 tls 1994 1.2.2.2 tls case BPF_RET: 1995 1.2.2.2 tls rval = BPF_RVAL(pc->code); 1996 1.2.2.2 tls if (rval == BPF_X) 1997 1.2.2.2 tls goto fail; 1998 1.2.2.2 tls 1999 1.2.2.2 tls /* BPF_RET+BPF_K accept k bytes */ 2000 1.2.2.2 tls if (rval == BPF_K) { 2001 1.2.2.3 tls status = sljit_emit_return(compiler, 2002 1.2.2.3 tls SLJIT_MOV_UI, 2003 1.2.2.2 tls SLJIT_IMM, (uint32_t)pc->k); 2004 1.2.2.2 tls if (status != SLJIT_SUCCESS) 2005 1.2.2.2 tls goto fail; 2006 1.2.2.2 tls } 2007 1.2.2.2 tls 2008 1.2.2.2 tls /* BPF_RET+BPF_A accept A bytes */ 2009 1.2.2.2 tls if (rval == BPF_A) { 2010 1.2.2.3 tls status = sljit_emit_return(compiler, 2011 1.2.2.3 tls SLJIT_MOV_UI, 2012 1.2.2.3 tls BJ_AREG, 0); 2013 1.2.2.2 tls if (status != SLJIT_SUCCESS) 2014 1.2.2.2 tls goto fail; 2015 1.2.2.2 tls } 2016 1.2.2.2 tls 2017 1.2.2.2 tls continue; 2018 1.2.2.2 tls 2019 1.2.2.2 tls case BPF_MISC: 2020 1.2.2.3 tls switch (BPF_MISCOP(pc->code)) { 2021 1.2.2.3 tls case BPF_TAX: 2022 1.2.2.2 tls status = sljit_emit_op1(compiler, 2023 1.2.2.2 tls SLJIT_MOV_UI, 2024 1.2.2.3 tls BJ_XREG, 0, 2025 1.2.2.3 tls BJ_AREG, 0); 2026 1.2.2.2 tls if (status != SLJIT_SUCCESS) 2027 1.2.2.2 tls goto fail; 2028 1.2.2.2 tls 2029 1.2.2.2 tls continue; 2030 1.2.2.2 tls 2031 1.2.2.3 tls case BPF_TXA: 2032 1.2.2.2 tls status = sljit_emit_op1(compiler, 2033 1.2.2.2 tls SLJIT_MOV, 2034 1.2.2.3 tls BJ_AREG, 0, 2035 1.2.2.3 tls BJ_XREG, 0); 2036 1.2.2.3 tls if (status != SLJIT_SUCCESS) 2037 1.2.2.3 tls goto fail; 2038 1.2.2.3 tls 2039 1.2.2.3 tls continue; 2040 1.2.2.3 tls 2041 1.2.2.3 tls case BPF_COP: 2042 1.2.2.3 tls case BPF_COPX: 2043 1.2.2.3 tls if (bc == NULL || bc->copfuncs == NULL) 2044 1.2.2.3 tls goto fail; 2045 1.2.2.3 tls if (BPF_MISCOP(pc->code) == BPF_COP && 2046 1.2.2.3 tls (uint32_t)pc->k >= bc->nfuncs) { 2047 1.2.2.3 tls goto fail; 2048 1.2.2.3 tls } 2049 1.2.2.3 tls 2050 1.2.2.3 tls status = emit_cop(compiler, hints, bc, pc, 2051 1.2.2.3 tls &ret0, &ret0_size, &ret0_maxsize); 2052 1.2.2.2 tls if (status != SLJIT_SUCCESS) 2053 1.2.2.2 tls goto fail; 2054 1.2.2.2 tls 2055 1.2.2.2 tls continue; 2056 1.2.2.2 tls } 2057 1.2.2.2 tls 2058 1.2.2.2 tls goto fail; 2059 1.2.2.2 tls } /* switch */ 2060 1.2.2.2 tls } /* main loop */ 2061 1.2.2.2 tls 2062 1.2.2.3 tls BJ_ASSERT(ret0_size <= ret0_maxsize); 2063 1.2.2.2 tls 2064 1.2.2.3 tls if (ret0_size > 0) { 2065 1.2.2.2 tls label = sljit_emit_label(compiler); 2066 1.2.2.2 tls if (label == NULL) 2067 1.2.2.2 tls goto fail; 2068 1.2.2.3 tls for (i = 0; i < ret0_size; i++) 2069 1.2.2.3 tls sljit_set_label(ret0[i], label); 2070 1.2.2.2 tls } 2071 1.2.2.2 tls 2072 1.2.2.2 tls status = sljit_emit_return(compiler, 2073 1.2.2.2 tls SLJIT_MOV_UI, 2074 1.2.2.3 tls SLJIT_IMM, 0); 2075 1.2.2.2 tls if (status != SLJIT_SUCCESS) 2076 1.2.2.2 tls goto fail; 2077 1.2.2.2 tls 2078 1.2.2.3 tls rv = true; 2079 1.2.2.3 tls 2080 1.2.2.3 tls fail: 2081 1.2.2.3 tls if (ret0 != NULL) 2082 1.2.2.3 tls BJ_FREE(ret0, ret0_maxsize * sizeof(ret0[0])); 2083 1.2.2.3 tls 2084 1.2.2.3 tls return rv; 2085 1.2.2.3 tls } 2086 1.2.2.3 tls 2087 1.2.2.3 tls bpfjit_func_t 2088 1.2.2.3 tls bpfjit_generate_code(const bpf_ctx_t *bc, 2089 1.2.2.3 tls const struct bpf_insn *insns, size_t insn_count) 2090 1.2.2.3 tls { 2091 1.2.2.3 tls void *rv; 2092 1.2.2.3 tls struct sljit_compiler *compiler; 2093 1.2.2.3 tls 2094 1.2.2.3 tls size_t i; 2095 1.2.2.3 tls int status; 2096 1.2.2.3 tls 2097 1.2.2.3 tls /* optimization related */ 2098 1.2.2.3 tls bpf_memword_init_t initmask; 2099 1.2.2.3 tls bpfjit_hint_t hints; 2100 1.2.2.3 tls 2101 1.2.2.3 tls /* memory store location for initial zero initialization */ 2102 1.2.2.3 tls sljit_si mem_reg; 2103 1.2.2.3 tls sljit_sw mem_off; 2104 1.2.2.3 tls 2105 1.2.2.3 tls struct bpfjit_insn_data *insn_dat; 2106 1.2.2.3 tls 2107 1.2.2.3 tls const size_t extwords = GET_EXTWORDS(bc); 2108 1.2.2.3 tls const size_t memwords = GET_MEMWORDS(bc); 2109 1.2.2.3 tls const bpf_memword_init_t preinited = extwords ? bc->preinited : 0; 2110 1.2.2.3 tls 2111 1.2.2.3 tls rv = NULL; 2112 1.2.2.3 tls compiler = NULL; 2113 1.2.2.3 tls insn_dat = NULL; 2114 1.2.2.3 tls 2115 1.2.2.3 tls if (memwords > MAX_MEMWORDS) 2116 1.2.2.3 tls goto fail; 2117 1.2.2.3 tls 2118 1.2.2.3 tls if (insn_count == 0 || insn_count > SIZE_MAX / sizeof(insn_dat[0])) 2119 1.2.2.3 tls goto fail; 2120 1.2.2.3 tls 2121 1.2.2.3 tls insn_dat = BJ_ALLOC(insn_count * sizeof(insn_dat[0])); 2122 1.2.2.3 tls if (insn_dat == NULL) 2123 1.2.2.3 tls goto fail; 2124 1.2.2.3 tls 2125 1.2.2.3 tls if (!optimize(bc, insns, insn_dat, insn_count, &initmask, &hints)) 2126 1.2.2.3 tls goto fail; 2127 1.2.2.3 tls 2128 1.2.2.3 tls compiler = sljit_create_compiler(); 2129 1.2.2.3 tls if (compiler == NULL) 2130 1.2.2.3 tls goto fail; 2131 1.2.2.3 tls 2132 1.2.2.3 tls #if !defined(_KERNEL) && defined(SLJIT_VERBOSE) && SLJIT_VERBOSE 2133 1.2.2.3 tls sljit_compiler_verbose(compiler, stderr); 2134 1.2.2.3 tls #endif 2135 1.2.2.3 tls 2136 1.2.2.3 tls status = sljit_emit_enter(compiler, 2137 1.2.2.3 tls 2, nscratches(hints), nsaveds(hints), sizeof(struct bpfjit_stack)); 2138 1.2.2.3 tls if (status != SLJIT_SUCCESS) 2139 1.2.2.3 tls goto fail; 2140 1.2.2.3 tls 2141 1.2.2.3 tls if (hints & BJ_HINT_COP) { 2142 1.2.2.3 tls /* save ctx argument */ 2143 1.2.2.3 tls status = sljit_emit_op1(compiler, 2144 1.2.2.3 tls SLJIT_MOV_P, 2145 1.2.2.3 tls SLJIT_MEM1(SLJIT_LOCALS_REG), 2146 1.2.2.3 tls offsetof(struct bpfjit_stack, ctx), 2147 1.2.2.3 tls BJ_CTX_ARG, 0); 2148 1.2.2.3 tls if (status != SLJIT_SUCCESS) 2149 1.2.2.2 tls goto fail; 2150 1.2.2.3 tls } 2151 1.2.2.2 tls 2152 1.2.2.3 tls if (extwords == 0) { 2153 1.2.2.3 tls mem_reg = SLJIT_MEM1(SLJIT_LOCALS_REG); 2154 1.2.2.3 tls mem_off = offsetof(struct bpfjit_stack, mem); 2155 1.2.2.3 tls } else { 2156 1.2.2.3 tls /* copy "mem" argument from bpf_args to bpfjit_stack */ 2157 1.2.2.3 tls status = sljit_emit_op1(compiler, 2158 1.2.2.3 tls SLJIT_MOV_P, 2159 1.2.2.3 tls BJ_TMP1REG, 0, 2160 1.2.2.3 tls SLJIT_MEM1(BJ_ARGS), offsetof(struct bpf_args, mem)); 2161 1.2.2.3 tls if (status != SLJIT_SUCCESS) 2162 1.2.2.3 tls goto fail; 2163 1.2.2.3 tls 2164 1.2.2.3 tls status = sljit_emit_op1(compiler, 2165 1.2.2.3 tls SLJIT_MOV_P, 2166 1.2.2.3 tls SLJIT_MEM1(SLJIT_LOCALS_REG), 2167 1.2.2.3 tls offsetof(struct bpfjit_stack, extmem), 2168 1.2.2.3 tls BJ_TMP1REG, 0); 2169 1.2.2.3 tls if (status != SLJIT_SUCCESS) 2170 1.2.2.3 tls goto fail; 2171 1.2.2.3 tls 2172 1.2.2.3 tls mem_reg = SLJIT_MEM1(BJ_TMP1REG); 2173 1.2.2.3 tls mem_off = 0; 2174 1.2.2.3 tls } 2175 1.2.2.3 tls 2176 1.2.2.3 tls /* 2177 1.2.2.3 tls * Exclude pre-initialised external memory words but keep 2178 1.2.2.3 tls * initialization statuses of A and X registers in case 2179 1.2.2.3 tls * bc->preinited wrongly sets those two bits. 2180 1.2.2.3 tls */ 2181 1.2.2.3 tls initmask &= ~preinited | BJ_INIT_ABIT | BJ_INIT_XBIT; 2182 1.2.2.2 tls 2183 1.2.2.3 tls #if defined(_KERNEL) 2184 1.2.2.3 tls /* bpf_filter() checks initialization of memwords. */ 2185 1.2.2.3 tls BJ_ASSERT((initmask & (BJ_INIT_MBIT(memwords) - 1)) == 0); 2186 1.2.2.3 tls #endif 2187 1.2.2.3 tls for (i = 0; i < memwords; i++) { 2188 1.2.2.3 tls if (initmask & BJ_INIT_MBIT(i)) { 2189 1.2.2.3 tls /* M[i] = 0; */ 2190 1.2.2.3 tls status = sljit_emit_op1(compiler, 2191 1.2.2.3 tls SLJIT_MOV_UI, 2192 1.2.2.3 tls mem_reg, mem_off + i * sizeof(uint32_t), 2193 1.2.2.3 tls SLJIT_IMM, 0); 2194 1.2.2.3 tls if (status != SLJIT_SUCCESS) 2195 1.2.2.3 tls goto fail; 2196 1.2.2.3 tls } 2197 1.2.2.3 tls } 2198 1.2.2.3 tls 2199 1.2.2.3 tls if (initmask & BJ_INIT_ABIT) { 2200 1.2.2.3 tls /* A = 0; */ 2201 1.2.2.2 tls status = sljit_emit_op1(compiler, 2202 1.2.2.2 tls SLJIT_MOV, 2203 1.2.2.3 tls BJ_AREG, 0, 2204 1.2.2.2 tls SLJIT_IMM, 0); 2205 1.2.2.2 tls if (status != SLJIT_SUCCESS) 2206 1.2.2.2 tls goto fail; 2207 1.2.2.3 tls } 2208 1.2.2.2 tls 2209 1.2.2.3 tls if (initmask & BJ_INIT_XBIT) { 2210 1.2.2.3 tls /* X = 0; */ 2211 1.2.2.3 tls status = sljit_emit_op1(compiler, 2212 1.2.2.3 tls SLJIT_MOV, 2213 1.2.2.3 tls BJ_XREG, 0, 2214 1.2.2.3 tls SLJIT_IMM, 0); 2215 1.2.2.2 tls if (status != SLJIT_SUCCESS) 2216 1.2.2.2 tls goto fail; 2217 1.2.2.2 tls } 2218 1.2.2.2 tls 2219 1.2.2.3 tls status = load_buf_buflen(compiler); 2220 1.2.2.3 tls if (status != SLJIT_SUCCESS) 2221 1.2.2.3 tls goto fail; 2222 1.2.2.3 tls 2223 1.2.2.3 tls if (!generate_insn_code(compiler, hints, 2224 1.2.2.3 tls bc, insns, insn_dat, insn_count)) { 2225 1.2.2.3 tls goto fail; 2226 1.2.2.3 tls } 2227 1.2.2.3 tls 2228 1.2.2.2 tls rv = sljit_generate_code(compiler); 2229 1.2.2.2 tls 2230 1.2.2.2 tls fail: 2231 1.2.2.2 tls if (compiler != NULL) 2232 1.2.2.2 tls sljit_free_compiler(compiler); 2233 1.2.2.2 tls 2234 1.2.2.2 tls if (insn_dat != NULL) 2235 1.2.2.3 tls BJ_FREE(insn_dat, insn_count * sizeof(insn_dat[0])); 2236 1.2.2.2 tls 2237 1.2.2.3 tls return (bpfjit_func_t)rv; 2238 1.2.2.2 tls } 2239 1.2.2.2 tls 2240 1.2.2.2 tls void 2241 1.2.2.3 tls bpfjit_free_code(bpfjit_func_t code) 2242 1.2.2.2 tls { 2243 1.2.2.2 tls 2244 1.2.2.2 tls sljit_free_code((void *)code); 2245 1.2.2.2 tls } 2246
Indexes created Thu Oct 02 10:09:58 GMT 2025