sys/i386/i386/bpf_jit_machdep.h

   1 /*-
   2  * Copyright (C) 2002-2003 NetGroup, Politecnico di Torino (Italy)
   3  * Copyright (C) 2005-2009 Jung-uk Kim <jkim@FreeBSD.org>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  * notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  * notice, this list of conditions and the following disclaimer in the
  14  * documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the Politecnico di Torino nor the names of its
  16  * contributors may be used to endorse or promote products derived from
  17  * this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  23  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  *
  31  * $FreeBSD$
  32  */
  33
  34 #ifndef _BPF_JIT_MACHDEP_H_
  35 #define _BPF_JIT_MACHDEP_H_
  36
  37 /*
  38  * Registers
  39  */
  40 #define EAX     0
  41 #define ECX     1
  42 #define EDX     2
  43 #define EBX     3
  44 #define ESP     4
  45 #define EBP     5
  46 #define ESI     6
  47 #define EDI     7
  48
  49 #define AX      0
  50 #define CX      1
  51 #define DX      2
  52 #define BX      3
  53 #define SP      4
  54 #define BP      5
  55 #define SI      6
  56 #define DI      7
  57
  58 #define AL      0
  59 #define CL      1
  60 #define DL      2
  61 #define BL      3
  62
  63 /* Optimization flags */
  64 #define BPF_JIT_FRET    0x01
  65 #define BPF_JIT_FPKT    0x02
  66 #define BPF_JIT_FMEM    0x04
  67 #define BPF_JIT_FJMP    0x08
  68 #define BPF_JIT_FADK    0x10
  69
  70 #define BPF_JIT_FLAG_ALL        \
  71     (BPF_JIT_FPKT | BPF_JIT_FMEM | BPF_JIT_FJMP | BPF_JIT_FADK)
  72
  73 /* A stream of native binary code */
  74 typedef struct bpf_bin_stream {
  75         /* Current native instruction pointer. */
  76         int             cur_ip;
  77
  78         /*
  79          * Current BPF instruction pointer, i.e. position in
  80          * the BPF program reached by the jitter.
  81          */
  82         int             bpf_pc;
  83
  84         /* Instruction buffer, contains the generated native code. */
  85         char            *ibuf;
  86
  87         /* Jumps reference table. */
  88         u_int           *refs;
  89 } bpf_bin_stream;
  90
  91 /*
  92  * Prototype of the emit functions.
  93  *
  94  * Different emit functions are used to create the reference table and
  95  * to generate the actual filtering code. This allows to have simpler
  96  * instruction macros.
  97  * The first parameter is the stream that will receive the data.
  98  * The second one is a variable containing the data.
  99  * The third one is the length, that can be 1, 2, or 4 since it is possible
 100  * to emit a byte, a short, or a word at a time.
 101  */
 102 typedef void (*emit_func)(bpf_bin_stream *stream, u_int value, u_int n);
 103
 104 /*
 105  * Native instruction macros
 106  */
 107
 108 /* movl i32,r32 */
 109 #define MOVid(i32, r32) do {                                            \
 110         emitm(&stream, (11 << 4) | (1 << 3) | (r32 & 0x7), 1);          \
 111         emitm(&stream, i32, 4);                                         \
 112 } while (0)
 113
 114 /* movl sr32,dr32 */
 115 #define MOVrd(sr32, dr32) do {                                          \
 116         emitm(&stream, 0x89, 1);                                        \
 117         emitm(&stream,                                                  \
 118             (3 << 6) | ((sr32 & 0x7) << 3) | (dr32 & 0x7), 1);          \
 119 } while (0)
 120
 121 /* movl off(sr32),dr32 */
 122 #define MOVodd(off, sr32, dr32) do {                                    \
 123         emitm(&stream, 0x8b, 1);                                        \
 124         emitm(&stream,                                                  \
 125             (1 << 6) | ((dr32 & 0x7) << 3) | (sr32 & 0x7), 1);          \
 126         emitm(&stream, off, 1);                                         \
 127 } while (0)
 128
 129 /* movl (sr32,or32,1),dr32 */
 130 #define MOVobd(sr32, or32, dr32) do {                                   \
 131         emitm(&stream, 0x8b, 1);                                        \
 132         emitm(&stream, ((dr32 & 0x7) << 3) | 4, 1);                     \
 133         emitm(&stream, ((or32 & 0x7) << 3) | (sr32 & 0x7), 1);          \
 134 } while (0)
 135
 136 /* movw (sr32,or32,1),dr16 */
 137 #define MOVobw(sr32, or32, dr16) do {                                   \
 138         emitm(&stream, 0x8b66, 2);                                      \
 139         emitm(&stream, ((dr16 & 0x7) << 3) | 4, 1);                     \
 140         emitm(&stream, ((or32 & 0x7) << 3) | (sr32 & 0x7), 1);          \
 141 } while (0)
 142
 143 /* movb (sr32,or32,1),dr8 */
 144 #define MOVobb(sr32, or32, dr8) do {                                    \
 145         emitm(&stream, 0x8a, 1);                                        \
 146         emitm(&stream, ((dr8 & 0x7) << 3) | 4, 1);                      \
 147         emitm(&stream, ((or32 & 0x7) << 3) | (sr32 & 0x7), 1);          \
 148 } while (0)
 149
 150 /* movl sr32,(dr32,or32,1) */
 151 #define MOVomd(sr32, dr32, or32) do {                                   \
 152         emitm(&stream, 0x89, 1);                                        \
 153         emitm(&stream, ((sr32 & 0x7) << 3) | 4, 1);                     \
 154         emitm(&stream, ((or32 & 0x7) << 3) | (dr32 & 0x7), 1);          \
 155 } while (0)
 156
 157 /* bswapl dr32 */
 158 #define BSWAP(dr32) do {                                                \
 159         emitm(&stream, 0xf, 1);                                         \
 160         emitm(&stream, (0x19 << 3) | dr32, 1);                          \
 161 } while (0)
 162
 163 /* xchgb %al,%ah */
 164 #define SWAP_AX() do {                                                  \
 165         emitm(&stream, 0xc486, 2);                                      \
 166 } while (0)
 167
 168 /* pushl r32 */
 169 #define PUSH(r32) do {                                                  \
 170         emitm(&stream, (5 << 4) | (0 << 3) | (r32 & 0x7), 1);           \
 171 } while (0)
 172
 173 /* popl r32 */
 174 #define POP(r32) do {                                                   \
 175         emitm(&stream, (5 << 4) | (1 << 3) | (r32 & 0x7), 1);           \
 176 } while (0)
 177
 178 /* leave */
 179 #define LEAVE() do {                                                    \
 180         emitm(&stream, 0xc9, 1);                                        \
 181 } while (0)
 182
 183 /* ret */
 184 #define RET() do {                                                      \
 185         emitm(&stream, 0xc3, 1);                                        \
 186 } while (0)
 187
 188 /* addl sr32,dr32 */
 189 #define ADDrd(sr32, dr32) do {                                          \
 190         emitm(&stream, 0x01, 1);                                        \
 191         emitm(&stream,                                                  \
 192             (3 << 6) | ((sr32 & 0x7) << 3) | (dr32 & 0x7), 1);          \
 193 } while (0)
 194
 195 /* addl i32,%eax */
 196 #define ADD_EAXi(i32) do {                                              \
 197         emitm(&stream, 0x05, 1);                                        \
 198         emitm(&stream, i32, 4);                                         \
 199 } while (0)
 200
 201 /* addl i8,r32 */
 202 #define ADDib(i8, r32) do {                                             \
 203         emitm(&stream, 0x83, 1);                                        \
 204         emitm(&stream, (24 << 3) | r32, 1);                             \
 205         emitm(&stream, i8, 1);                                          \
 206 } while (0)
 207
 208 /* subl sr32,dr32 */
 209 #define SUBrd(sr32, dr32) do {                                          \
 210         emitm(&stream, 0x29, 1);                                        \
 211         emitm(&stream,                                                  \
 212             (3 << 6) | ((sr32 & 0x7) << 3) | (dr32 & 0x7), 1);          \
 213 } while (0)
 214
 215 /* subl i32,%eax */
 216 #define SUB_EAXi(i32) do {                                              \
 217         emitm(&stream, 0x2d, 1);                                        \
 218         emitm(&stream, i32, 4);                                         \
 219 } while (0)
 220
 221 /* subl i8,r32 */
 222 #define SUBib(i8, r32) do {                                             \
 223         emitm(&stream, 0x83, 1);                                        \
 224         emitm(&stream, (29 << 3) | (r32 & 0x7), 1);                     \
 225         emitm(&stream, i8, 1);                                          \
 226 } while (0)
 227
 228 /* mull r32 */
 229 #define MULrd(r32) do {                                                 \
 230         emitm(&stream, 0xf7, 1);                                        \
 231         emitm(&stream, (7 << 5) | (r32 & 0x7), 1);                      \
 232 } while (0)
 233
 234 /* divl r32 */
 235 #define DIVrd(r32) do {                                                 \
 236         emitm(&stream, 0xf7, 1);                                        \
 237         emitm(&stream, (15 << 4) | (r32 & 0x7), 1);                     \
 238 } while (0)
 239
 240 /* andb i8,r8 */
 241 #define ANDib(i8, r8) do {                                              \
 242         if (r8 == AL) {                                                 \
 243                 emitm(&stream, 0x24, 1);                                \
 244         } else {                                                        \
 245                 emitm(&stream, 0x80, 1);                                \
 246                 emitm(&stream, (7 << 5) | r8, 1);                       \
 247         }                                                               \
 248         emitm(&stream, i8, 1);                                          \
 249 } while (0)
 250
 251 /* andl i32,r32 */
 252 #define ANDid(i32, r32) do {                                            \
 253         if (r32 == EAX) {                                               \
 254                 emitm(&stream, 0x25, 1);                                \
 255         } else {                                                        \
 256                 emitm(&stream, 0x81, 1);                                \
 257                 emitm(&stream, (7 << 5) | r32, 1);                      \
 258         }                                                               \
 259         emitm(&stream, i32, 4);                                         \
 260 } while (0)
 261
 262 /* andl sr32,dr32 */
 263 #define ANDrd(sr32, dr32) do {                                          \
 264         emitm(&stream, 0x21, 1);                                        \
 265         emitm(&stream,                                                  \
 266             (3 << 6) | ((sr32 & 0x7) << 3) | (dr32 & 0x7), 1);          \
 267 } while (0)
 268
 269 /* testl i32,r32 */
 270 #define TESTid(i32, r32) do {                                           \
 271         if (r32 == EAX) {                                               \
 272                 emitm(&stream, 0xa9, 1);                                \
 273         } else {                                                        \
 274                 emitm(&stream, 0xf7, 1);                                \
 275                 emitm(&stream, (3 << 6) | r32, 1);                      \
 276         }                                                               \
 277         emitm(&stream, i32, 4);                                         \
 278 } while (0)
 279
 280 /* testl sr32,dr32 */
 281 #define TESTrd(sr32, dr32) do {                                         \
 282         emitm(&stream, 0x85, 1);                                        \
 283         emitm(&stream,                                                  \
 284             (3 << 6) | ((sr32 & 0x7) << 3) | (dr32 & 0x7), 1);          \
 285 } while (0)
 286
 287 /* orl sr32,dr32 */
 288 #define ORrd(sr32, dr32) do {                                           \
 289         emitm(&stream, 0x09, 1);                                        \
 290         emitm(&stream,                                                  \
 291             (3 << 6) | ((sr32 & 0x7) << 3) | (dr32 & 0x7), 1);          \
 292 } while (0)
 293
 294 /* orl i32,r32 */
 295 #define ORid(i32, r32) do {                                             \
 296         if (r32 == EAX) {                                               \
 297                 emitm(&stream, 0x0d, 1);                                \
 298         } else {                                                        \
 299                 emitm(&stream, 0x81, 1);                                \
 300                 emitm(&stream, (25 << 3) | r32, 1);                     \
 301         }                                                               \
 302         emitm(&stream, i32, 4);                                         \
 303 } while (0)
 304
 305 /* shll i8,r32 */
 306 #define SHLib(i8, r32) do {                                             \
 307         emitm(&stream, 0xc1, 1);                                        \
 308         emitm(&stream, (7 << 5) | (r32 & 0x7), 1);                      \
 309         emitm(&stream, i8, 1);                                          \
 310 } while (0)
 311
 312 /* shll %cl,dr32 */
 313 #define SHL_CLrb(dr32) do {                                             \
 314         emitm(&stream, 0xd3, 1);                                        \
 315         emitm(&stream, (7 << 5) | (dr32 & 0x7), 1);                     \
 316 } while (0)
 317
 318 /* shrl i8,r32 */
 319 #define SHRib(i8, r32) do {                                             \
 320         emitm(&stream, 0xc1, 1);                                        \
 321         emitm(&stream, (29 << 3) | (r32 & 0x7), 1);                     \
 322         emitm(&stream, i8, 1);                                          \
 323 } while (0)
 324
 325 /* shrl %cl,dr32 */
 326 #define SHR_CLrb(dr32) do {                                             \
 327         emitm(&stream, 0xd3, 1);                                        \
 328         emitm(&stream, (29 << 3) | (dr32 & 0x7), 1);                    \
 329 } while (0)
 330
 331 /* negl r32 */
 332 #define NEGd(r32) do {                                                  \
 333         emitm(&stream, 0xf7, 1);                                        \
 334         emitm(&stream, (27 << 3) | (r32 & 0x7), 1);                     \
 335 } while (0)
 336
 337 /* cmpl sr32,dr32 */
 338 #define CMPrd(sr32, dr32) do {                                          \
 339         emitm(&stream, 0x39, 1);                                        \
 340         emitm(&stream,                                                  \
 341             (3 << 6) | ((sr32 & 0x7) << 3) | (dr32 & 0x7), 1);          \
 342 } while (0)
 343
 344 /* cmpl i32,dr32 */
 345 #define CMPid(i32, dr32) do {                                           \
 346         if (dr32 == EAX){                                               \
 347                 emitm(&stream, 0x3d, 1);                                \
 348                 emitm(&stream, i32, 4);                                 \
 349         } else {                                                        \
 350                 emitm(&stream, 0x81, 1);                                \
 351                 emitm(&stream, (0x1f << 3) | (dr32 & 0x7), 1);          \
 352                 emitm(&stream, i32, 4);                                 \
 353         }                                                               \
 354 } while (0)
 355
 356 /* jb off8 */
 357 #define JBb(off8) do {                                                  \
 358         emitm(&stream, 0x72, 1);                                        \
 359         emitm(&stream, off8, 1);                                        \
 360 } while (0)
 361
 362 /* jae off8 */
 363 #define JAEb(off8) do {                                                 \
 364         emitm(&stream, 0x73, 1);                                        \
 365         emitm(&stream, off8, 1);                                        \
 366 } while (0)
 367
 368 /* jne off8 */
 369 #define JNEb(off8) do {                                                 \
 370         emitm(&stream, 0x75, 1);                                        \
 371         emitm(&stream, off8, 1);                                        \
 372 } while (0)
 373
 374 /* ja off8 */
 375 #define JAb(off8) do {                                                  \
 376         emitm(&stream, 0x77, 1);                                        \
 377         emitm(&stream, off8, 1);                                        \
 378 } while (0)
 379
 380 /* jmp off32 */
 381 #define JMP(off32) do {                                                 \
 382         emitm(&stream, 0xe9, 1);                                        \
 383         emitm(&stream, off32, 4);                                       \
 384 } while (0)
 385
 386 /* xorl r32,r32 */
 387 #define ZEROrd(r32) do {                                                \
 388         emitm(&stream, 0x31, 1);                                        \
 389         emitm(&stream, (3 << 6) | ((r32 & 0x7) << 3) | (r32 & 0x7), 1); \
 390 } while (0)
 391
 392 /*
 393  * Conditional long jumps
 394  */
 395 #define JB      0x82
 396 #define JAE     0x83
 397 #define JE      0x84
 398 #define JNE     0x85
 399 #define JBE     0x86
 400 #define JA      0x87
 401
 402 #define JCC(t, f) do {                                                  \
 403         if (ins->jt != 0 && ins->jf != 0) {                             \
 404                 /* 5 is the size of the following jmp */                \
 405                 emitm(&stream, ((t) << 8) | 0x0f, 2);                   \
 406                 emitm(&stream, stream.refs[stream.bpf_pc + ins->jt] -   \
 407                     stream.refs[stream.bpf_pc] + 5, 4);                 \
 408                 JMP(stream.refs[stream.bpf_pc + ins->jf] -              \
 409                     stream.refs[stream.bpf_pc]);                        \
 410         } else if (ins->jt != 0) {                                      \
 411                 emitm(&stream, ((t) << 8) | 0x0f, 2);                   \
 412                 emitm(&stream, stream.refs[stream.bpf_pc + ins->jt] -   \
 413                     stream.refs[stream.bpf_pc], 4);                     \
 414         } else {                                                        \
 415                 emitm(&stream, ((f) << 8) | 0x0f, 2);                   \
 416                 emitm(&stream, stream.refs[stream.bpf_pc + ins->jf] -   \
 417                     stream.refs[stream.bpf_pc], 4);                     \
 418         }                                                               \
 419 } while (0)
 420
 421 #define JUMP(off) do {                                                  \
 422         if ((off) != 0)                                                 \
 423                 JMP(stream.refs[stream.bpf_pc + (off)] -                \
 424                     stream.refs[stream.bpf_pc]);                        \
 425 } while (0)
 426
 427 #endif  /* _BPF_JIT_MACHDEP_H_ */