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 /* The last prefix is needed for two-byte and three-byte opcodes */
insn_last_prefix(struct insn * insn)100 static inline insn_byte_t insn_last_prefix(struct insn *insn)
101 {
102 return insn->prefixes.bytes[3];
103 }
104
105 extern void insn_init(struct insn *insn, const void *kaddr, int x86_64);
106 extern void insn_get_prefixes(struct insn *insn);
107 extern void insn_get_opcode(struct insn *insn);
108 extern void insn_get_modrm(struct insn *insn);
109 extern void insn_get_sib(struct insn *insn);
110 extern void insn_get_displacement(struct insn *insn);
111 extern void insn_get_immediate(struct insn *insn);
112 extern void insn_get_length(struct insn *insn);
113
114 /* Attribute will be determined after getting ModRM (for opcode groups) */
insn_get_attribute(struct insn * insn)115 static inline void insn_get_attribute(struct insn *insn)
116 {
117 insn_get_modrm(insn);
118 }
119
120 /* Instruction uses RIP-relative addressing */
121 extern int insn_rip_relative(struct insn *insn);
122
123 /* Init insn for kernel text */
kernel_insn_init(struct insn * insn,const void * kaddr)124 static inline void kernel_insn_init(struct insn *insn, const void *kaddr)
125 {
126 #ifdef CONFIG_X86_64
127 insn_init(insn, kaddr, 1);
128 #else /* CONFIG_X86_32 */
129 insn_init(insn, kaddr, 0);
130 #endif
131 }
132
insn_is_avx(struct insn * insn)133 static inline int insn_is_avx(struct insn *insn)
134 {
135 if (!insn->prefixes.got)
136 insn_get_prefixes(insn);
137 return (insn->vex_prefix.value != 0);
138 }
139
insn_vex_m_bits(struct insn * insn)140 static inline insn_byte_t insn_vex_m_bits(struct insn *insn)
141 {
142 if (insn->vex_prefix.nbytes == 2) /* 2 bytes VEX */
143 return X86_VEX2_M;
144 else
145 return X86_VEX3_M(insn->vex_prefix.bytes[1]);
146 }
147
insn_vex_p_bits(struct insn * insn)148 static inline insn_byte_t insn_vex_p_bits(struct insn *insn)
149 {
150 if (insn->vex_prefix.nbytes == 2) /* 2 bytes VEX */
151 return X86_VEX_P(insn->vex_prefix.bytes[1]);
152 else
153 return X86_VEX_P(insn->vex_prefix.bytes[2]);
154 }
155
156 /* Offset of each field from kaddr */
insn_offset_rex_prefix(struct insn * insn)157 static inline int insn_offset_rex_prefix(struct insn *insn)
158 {
159 return insn->prefixes.nbytes;
160 }
insn_offset_vex_prefix(struct insn * insn)161 static inline int insn_offset_vex_prefix(struct insn *insn)
162 {
163 return insn_offset_rex_prefix(insn) + insn->rex_prefix.nbytes;
164 }
insn_offset_opcode(struct insn * insn)165 static inline int insn_offset_opcode(struct insn *insn)
166 {
167 return insn_offset_vex_prefix(insn) + insn->vex_prefix.nbytes;
168 }
insn_offset_modrm(struct insn * insn)169 static inline int insn_offset_modrm(struct insn *insn)
170 {
171 return insn_offset_opcode(insn) + insn->opcode.nbytes;
172 }
insn_offset_sib(struct insn * insn)173 static inline int insn_offset_sib(struct insn *insn)
174 {
175 return insn_offset_modrm(insn) + insn->modrm.nbytes;
176 }
insn_offset_displacement(struct insn * insn)177 static inline int insn_offset_displacement(struct insn *insn)
178 {
179 return insn_offset_sib(insn) + insn->sib.nbytes;
180 }
insn_offset_immediate(struct insn * insn)181 static inline int insn_offset_immediate(struct insn *insn)
182 {
183 return insn_offset_displacement(insn) + insn->displacement.nbytes;
184 }
185
186 #endif /* _ASM_X86_INSN_H */
187