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
  26 struct 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
  36 struct 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 *next_byte;
  69 };
  70
  71 #define MAX_INSN_SIZE   16
  72
  73 #define X86_MODRM_MOD(modrm) (((modrm) & 0xc0) >> 6)
  74 #define X86_MODRM_REG(modrm) (((modrm) & 0x38) >> 3)
  75 #define X86_MODRM_RM(modrm) ((modrm) & 0x07)
  76
  77 #define X86_SIB_SCALE(sib) (((sib) & 0xc0) >> 6)
  78 #define X86_SIB_INDEX(sib) (((sib) & 0x38) >> 3)
  79 #define X86_SIB_BASE(sib) ((sib) & 0x07)
  80
  81 #define X86_REX_W(rex) ((rex) & 8)
  82 #define X86_REX_R(rex) ((rex) & 4)
  83 #define X86_REX_X(rex) ((rex) & 2)
  84 #define X86_REX_B(rex) ((rex) & 1)
  85
  86 /* VEX bit flags  */
  87 #define X86_VEX_W(vex)  ((vex) & 0x80)  /* VEX3 Byte2 */
  88 #define X86_VEX_R(vex)  ((vex) & 0x80)  /* VEX2/3 Byte1 */
  89 #define X86_VEX_X(vex)  ((vex) & 0x40)  /* VEX3 Byte1 */
  90 #define X86_VEX_B(vex)  ((vex) & 0x20)  /* VEX3 Byte1 */
  91 #define X86_VEX_L(vex)  ((vex) & 0x04)  /* VEX3 Byte2, VEX2 Byte1 */
  92 /* VEX bit fields */
  93 #define X86_VEX3_M(vex) ((vex) & 0x1f)          /* VEX3 Byte1 */
  94 #define X86_VEX2_M      1                       /* VEX2.M always 1 */
  95 #define X86_VEX_V(vex)  (((vex) & 0x78) >> 3)   /* VEX3 Byte2, VEX2 Byte1 */
  96 #define X86_VEX_P(vex)  ((vex) & 0x03)          /* VEX3 Byte2, VEX2 Byte1 */
  97 #define X86_VEX_M_MAX   0x1f                    /* VEX3.M Maximum value */
  98
  99 extern void insn_init(struct insn *insn, const void *kaddr, int x86_64);
 100 extern void insn_get_prefixes(struct insn *insn);
 101 extern void insn_get_opcode(struct insn *insn);
 102 extern void insn_get_modrm(struct insn *insn);
 103 extern void insn_get_sib(struct insn *insn);
 104 extern void insn_get_displacement(struct insn *insn);
 105 extern void insn_get_immediate(struct insn *insn);
 106 extern void insn_get_length(struct insn *insn);
 107
 108 /* Attribute will be determined after getting ModRM (for opcode groups) */
 109 static inline void insn_get_attribute(struct insn *insn)
 110 {
 111         insn_get_modrm(insn);
 112 }
 113
 114 /* Instruction uses RIP-relative addressing */
 115 extern int insn_rip_relative(struct insn *insn);
 116
 117 /* Init insn for kernel text */
 118 static inline void kernel_insn_init(struct insn *insn, const void *kaddr)
 119 {
 120 #ifdef CONFIG_X86_64
 121         insn_init(insn, kaddr, 1);
 122 #else /* CONFIG_X86_32 */
 123         insn_init(insn, kaddr, 0);
 124 #endif
 125 }
 126
 127 static inline int insn_is_avx(struct insn *insn)
 128 {
 129         if (!insn->prefixes.got)
 130                 insn_get_prefixes(insn);
 131         return (insn->vex_prefix.value != 0);
 132 }
 133
 134 /* Ensure this instruction is decoded completely */
 135 static inline int insn_complete(struct insn *insn)
 136 {
 137         return insn->opcode.got && insn->modrm.got && insn->sib.got &&
 138                 insn->displacement.got && insn->immediate.got;
 139 }
 140
 141 static inline insn_byte_t insn_vex_m_bits(struct insn *insn)
 142 {
 143         if (insn->vex_prefix.nbytes == 2)       /* 2 bytes VEX */
 144                 return X86_VEX2_M;
 145         else
 146                 return X86_VEX3_M(insn->vex_prefix.bytes[1]);
 147 }
 148
 149 static inline insn_byte_t insn_vex_p_bits(struct insn *insn)
 150 {
 151         if (insn->vex_prefix.nbytes == 2)       /* 2 bytes VEX */
 152                 return X86_VEX_P(insn->vex_prefix.bytes[1]);
 153         else
 154                 return X86_VEX_P(insn->vex_prefix.bytes[2]);
 155 }
 156
 157 /* Get the last prefix id from last prefix or VEX prefix */
 158 static inline int insn_last_prefix_id(struct insn *insn)
 159 {
 160         if (insn_is_avx(insn))
 161                 return insn_vex_p_bits(insn);   /* VEX_p is a SIMD prefix id */
 162
 163         if (insn->prefixes.bytes[3])
 164                 return inat_get_last_prefix_id(insn->prefixes.bytes[3]);
 165
 166         return 0;
 167 }
 168
 169 /* Offset of each field from kaddr */
 170 static inline int insn_offset_rex_prefix(struct insn *insn)
 171 {
 172         return insn->prefixes.nbytes;
 173 }
 174 static inline int insn_offset_vex_prefix(struct insn *insn)
 175 {
 176         return insn_offset_rex_prefix(insn) + insn->rex_prefix.nbytes;
 177 }
 178 static inline int insn_offset_opcode(struct insn *insn)
 179 {
 180         return insn_offset_vex_prefix(insn) + insn->vex_prefix.nbytes;
 181 }
 182 static inline int insn_offset_modrm(struct insn *insn)
 183 {
 184         return insn_offset_opcode(insn) + insn->opcode.nbytes;
 185 }
 186 static inline int insn_offset_sib(struct insn *insn)
 187 {
 188         return insn_offset_modrm(insn) + insn->modrm.nbytes;
 189 }
 190 static inline int insn_offset_displacement(struct insn *insn)
 191 {
 192         return insn_offset_sib(insn) + insn->sib.nbytes;
 193 }
 194 static inline int insn_offset_immediate(struct insn *insn)
 195 {
 196         return insn_offset_displacement(insn) + insn->displacement.nbytes;
 197 }
 198
 199 #endif /* _ASM_X86_INSN_H */