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 *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 */ 99 100 extern void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64); 101 extern void insn_get_prefixes(struct insn *insn); 102 extern void insn_get_opcode(struct insn *insn); 103 extern void insn_get_modrm(struct insn *insn); 104 extern void insn_get_sib(struct insn *insn); 105 extern void insn_get_displacement(struct insn *insn); 106 extern void insn_get_immediate(struct insn *insn); 107 extern void insn_get_length(struct insn *insn); 108 109 /* Attribute will be determined after getting ModRM (for opcode groups) */ 110 static inline void insn_get_attribute(struct insn *insn) 111 { 112 insn_get_modrm(insn); 113 } 114 115 /* Instruction uses RIP-relative addressing */ 116 extern int insn_rip_relative(struct insn *insn); 117 118 /* Init insn for kernel text */ 119 static 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 } 128 129 static 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 */ 137 static 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 } 142 143 static 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 } 150 151 static 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 */ 160 static 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 */ 172 static inline int insn_offset_rex_prefix(struct insn *insn) 173 { 174 return insn->prefixes.nbytes; 175 } 176 static inline int insn_offset_vex_prefix(struct insn *insn) 177 { 178 return insn_offset_rex_prefix(insn) + insn->rex_prefix.nbytes; 179 } 180 static inline int insn_offset_opcode(struct insn *insn) 181 { 182 return insn_offset_vex_prefix(insn) + insn->vex_prefix.nbytes; 183 } 184 static inline int insn_offset_modrm(struct insn *insn) 185 { 186 return insn_offset_opcode(insn) + insn->opcode.nbytes; 187 } 188 static inline int insn_offset_sib(struct insn *insn) 189 { 190 return insn_offset_modrm(insn) + insn->modrm.nbytes; 191 } 192 static inline int insn_offset_displacement(struct insn *insn) 193 { 194 return insn_offset_sib(insn) + insn->sib.nbytes; 195 } 196 static 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