LXR linux/arch/x86/include/asm/insn.h

   1#ifndef _ASM_X86_INSN_H
   2#define _ASM_X86_INSN_H
   3/*
   4 * x86 instruction analysis
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19 *
  20 * Copyright (C) IBM Corporation, 2009
  21 */
  22
  23/* insn_attr_t is defined in inat.h */
  24#include <asm/inat.h>
  25
  26struct insn_field {
  27        union {
  28                insn_value_t value;
  29                insn_byte_t bytes[4];
  30        };
  31        /* !0 if we've run insn_get_xxx() for this field */
  32        unsigned char got;
  33        unsigned char nbytes;
  34};
  35
  36struct insn {
  37        struct insn_field prefixes;     /*
  38                                         * Prefixes
  39                                         * prefixes.bytes[3]: last prefix
  40                                         */
  41        struct insn_field rex_prefix;   /* REX prefix */
  42        struct insn_field vex_prefix;   /* VEX prefix */
  43        struct insn_field opcode;       /*
  44                                         * opcode.bytes[0]: opcode1
  45                                         * opcode.bytes[1]: opcode2
  46                                         * opcode.bytes[2]: opcode3
  47                                         */
  48        struct insn_field modrm;
  49        struct insn_field sib;
  50        struct insn_field displacement;
  51        union {
  52                struct insn_field immediate;
  53                struct insn_field moffset1;     /* for 64bit MOV */
  54                struct insn_field immediate1;   /* for 64bit imm or off16/32 */
  55        };
  56        union {
  57                struct insn_field moffset2;     /* for 64bit MOV */
  58                struct insn_field immediate2;   /* for 64bit imm or seg16 */
  59        };
  60
  61        insn_attr_t attr;
  62        unsigned char opnd_bytes;
  63        unsigned char addr_bytes;
  64        unsigned char length;
  65        unsigned char x86_64;
  66
  67        const insn_byte_t *kaddr;       /* kernel address of insn to analyze */
  68        const insn_byte_t *end_kaddr;   /* kernel address of last insn in buffer */
  69        const insn_byte_t *next_byte;
  70};
  71
  72#define MAX_INSN_SIZE   15
  73
  74#define X86_MODRM_MOD(modrm) (((modrm) & 0xc0) >> 6)
  75#define X86_MODRM_REG(modrm) (((modrm) & 0x38) >> 3)
  76#define X86_MODRM_RM(modrm) ((modrm) & 0x07)
  77
  78#define X86_SIB_SCALE(sib) (((sib) & 0xc0) >> 6)
  79#define X86_SIB_INDEX(sib) (((sib) & 0x38) >> 3)
  80#define X86_SIB_BASE(sib) ((sib) & 0x07)
  81
  82#define X86_REX_W(rex) ((rex) & 8)
  83#define X86_REX_R(rex) ((rex) & 4)
  84#define X86_REX_X(rex) ((rex) & 2)
  85#define X86_REX_B(rex) ((rex) & 1)
  86
  87/* VEX bit flags  */
  88#define X86_VEX_W(vex)  ((vex) & 0x80)  /* VEX3 Byte2 */
  89#define X86_VEX_R(vex)  ((vex) & 0x80)  /* VEX2/3 Byte1 */
  90#define X86_VEX_X(vex)  ((vex) & 0x40)  /* VEX3 Byte1 */
  91#define X86_VEX_B(vex)  ((vex) & 0x20)  /* VEX3 Byte1 */
  92#define X86_VEX_L(vex)  ((vex) & 0x04)  /* VEX3 Byte2, VEX2 Byte1 */
  93/* VEX bit fields */
  94#define X86_VEX3_M(vex) ((vex) & 0x1f)          /* VEX3 Byte1 */
  95#define X86_VEX2_M      1                       /* VEX2.M always 1 */
  96#define X86_VEX_V(vex)  (((vex) & 0x78) >> 3)   /* VEX3 Byte2, VEX2 Byte1 */
  97#define X86_VEX_P(vex)  ((vex) & 0x03)          /* VEX3 Byte2, VEX2 Byte1 */
  98#define X86_VEX_M_MAX   0x1f                    /* VEX3.M Maximum value */
  99
 100extern void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64);
 101extern void insn_get_prefixes(struct insn *insn);
 102extern void insn_get_opcode(struct insn *insn);
 103extern void insn_get_modrm(struct insn *insn);
 104extern void insn_get_sib(struct insn *insn);
 105extern void insn_get_displacement(struct insn *insn);
 106extern void insn_get_immediate(struct insn *insn);
 107extern void insn_get_length(struct insn *insn);
 108
 109/* Attribute will be determined after getting ModRM (for opcode groups) */
 110static inline void insn_get_attribute(struct insn *insn)
 111{
 112        insn_get_modrm(insn);
 113}
 114
 115/* Instruction uses RIP-relative addressing */
 116extern int insn_rip_relative(struct insn *insn);
 117
 118/* Init insn for kernel text */
 119static inline void kernel_insn_init(struct insn *insn,
 120                                    const void *kaddr, int buf_len)
 121{
 122#ifdef CONFIG_X86_64
 123        insn_init(insn, kaddr, buf_len, 1);
 124#else /* CONFIG_X86_32 */
 125        insn_init(insn, kaddr, buf_len, 0);
 126#endif
 127}
 128
 129static inline int insn_is_avx(struct insn *insn)
 130{
 131        if (!insn->prefixes.got)
 132                insn_get_prefixes(insn);
 133        return (insn->vex_prefix.value != 0);
 134}
 135
 136/* Ensure this instruction is decoded completely */
 137static inline int insn_complete(struct insn *insn)
 138{
 139        return insn->opcode.got && insn->modrm.got && insn->sib.got &&
 140                insn->displacement.got && insn->immediate.got;
 141}
 142
 143static inline insn_byte_t insn_vex_m_bits(struct insn *insn)
 144{
 145        if (insn->vex_prefix.nbytes == 2)       /* 2 bytes VEX */
 146                return X86_VEX2_M;
 147        else
 148                return X86_VEX3_M(insn->vex_prefix.bytes[1]);
 149}
 150
 151static inline insn_byte_t insn_vex_p_bits(struct insn *insn)
 152{
 153        if (insn->vex_prefix.nbytes == 2)       /* 2 bytes VEX */
 154                return X86_VEX_P(insn->vex_prefix.bytes[1]);
 155        else
 156                return X86_VEX_P(insn->vex_prefix.bytes[2]);
 157}
 158
 159/* Get the last prefix id from last prefix or VEX prefix */
 160static inline int insn_last_prefix_id(struct insn *insn)
 161{
 162        if (insn_is_avx(insn))
 163                return insn_vex_p_bits(insn);   /* VEX_p is a SIMD prefix id */
 164
 165        if (insn->prefixes.bytes[3])
 166                return inat_get_last_prefix_id(insn->prefixes.bytes[3]);
 167
 168        return 0;
 169}
 170
 171/* Offset of each field from kaddr */
 172static inline int insn_offset_rex_prefix(struct insn *insn)
 173{
 174        return insn->prefixes.nbytes;
 175}
 176static inline int insn_offset_vex_prefix(struct insn *insn)
 177{
 178        return insn_offset_rex_prefix(insn) + insn->rex_prefix.nbytes;
 179}
 180static inline int insn_offset_opcode(struct insn *insn)
 181{
 182        return insn_offset_vex_prefix(insn) + insn->vex_prefix.nbytes;
 183}
 184static inline int insn_offset_modrm(struct insn *insn)
 185{
 186        return insn_offset_opcode(insn) + insn->opcode.nbytes;
 187}
 188static inline int insn_offset_sib(struct insn *insn)
 189{
 190        return insn_offset_modrm(insn) + insn->modrm.nbytes;
 191}
 192static inline int insn_offset_displacement(struct insn *insn)
 193{
 194        return insn_offset_sib(insn) + insn->sib.nbytes;
 195}
 196static inline int insn_offset_immediate(struct insn *insn)
 197{
 198        return insn_offset_displacement(insn) + insn->displacement.nbytes;
 199}
 200
 201#endif /* _ASM_X86_INSN_H */
 202