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 "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 */