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) */
insn_get_attribute(struct insn * insn)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 */
kernel_insn_init(struct insn * insn,const void * kaddr)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
insn_is_avx(struct insn * insn)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 */
insn_complete(struct insn * insn)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
insn_vex_m_bits(struct insn * insn)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
insn_vex_p_bits(struct insn * insn)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 */
insn_last_prefix_id(struct insn * insn)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 */
insn_offset_rex_prefix(struct insn * insn)170 static inline int insn_offset_rex_prefix(struct insn *insn)
171 {
172 return insn->prefixes.nbytes;
173 }
insn_offset_vex_prefix(struct insn * insn)174 static inline int insn_offset_vex_prefix(struct insn *insn)
175 {
176 return insn_offset_rex_prefix(insn) + insn->rex_prefix.nbytes;
177 }
insn_offset_opcode(struct insn * insn)178 static inline int insn_offset_opcode(struct insn *insn)
179 {
180 return insn_offset_vex_prefix(insn) + insn->vex_prefix.nbytes;
181 }
insn_offset_modrm(struct insn * insn)182 static inline int insn_offset_modrm(struct insn *insn)
183 {
184 return insn_offset_opcode(insn) + insn->opcode.nbytes;
185 }
insn_offset_sib(struct insn * insn)186 static inline int insn_offset_sib(struct insn *insn)
187 {
188 return insn_offset_modrm(insn) + insn->modrm.nbytes;
189 }
insn_offset_displacement(struct insn * insn)190 static inline int insn_offset_displacement(struct insn *insn)
191 {
192 return insn_offset_sib(insn) + insn->sib.nbytes;
193 }
insn_offset_immediate(struct insn * insn)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 */
200