projects / mirror_ubuntu-kernels.git / blame
| Commit | Line | Data |
|---|---|---|
| 442f04c3 JP |
1 | /* |
| 2 | * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com> | |
| 3 | * | |
| 4 | * This program is free software; you can redistribute it and/or | |
| 5 | * modify it under the terms of the GNU General Public License | |
| 6 | * as published by the Free Software Foundation; either version 2 | |
| 7 | * of the License, or (at your option) any later version. | |
| 8 | * | |
| 9 | * This program is distributed in the hope that it will be useful, | |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 12 | * GNU General Public License for more details. | |
| 13 | * | |
| 14 | * You should have received a copy of the GNU General Public License | |
| 15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
| 16 | */ | |
| 17 | ||
| 18 | #include <stdio.h> | |
| 19 | #include <stdlib.h> | |
| 20 | ||
| 21 | #define unlikely(cond) (cond) | |
| 22 | #include "insn/insn.h" | |
| 23 | #include "insn/inat.c" | |
| 24 | #include "insn/insn.c" | |
| 25 | ||
| 26 | #include "../../elf.h" | |
| 27 | #include "../../arch.h" | |
| 28 | #include "../../warn.h" | |
| 29 | ||
| 30 | static int is_x86_64(struct elf *elf) | |
| 31 | { | |
| 32 | switch (elf->ehdr.e_machine) { | |
| 33 | case EM_X86_64: | |
| 34 | return 1; | |
| 35 | case EM_386: | |
| 36 | return 0; | |
| 37 | default: | |
| 38 | WARN("unexpected ELF machine type %d", elf->ehdr.e_machine); | |
| 39 | return -1; | |
| 40 | } | |
| 41 | } | |
| 42 | ||
| 43 | int arch_decode_instruction(struct elf *elf, struct section *sec, | |
| 44 | unsigned long offset, unsigned int maxlen, | |
| 45 | unsigned int *len, unsigned char *type, | |
| 46 | unsigned long *immediate) | |
| 47 | { | |
| 48 | struct insn insn; | |
| 49 | int x86_64; | |
| 50 | unsigned char op1, op2, ext; | |
| 51 | ||
| 52 | x86_64 = is_x86_64(elf); | |
| 53 | if (x86_64 == -1) | |
| 54 | return -1; | |
| 55 | ||
| 56 | insn_init(&insn, (void *)(sec->data + offset), maxlen, x86_64); | |
| 57 | insn_get_length(&insn); | |
| 58 | insn_get_opcode(&insn); | |
| 59 | insn_get_modrm(&insn); | |
| 60 | insn_get_immediate(&insn); | |
| 61 | ||
| 62 | if (!insn_complete(&insn)) { | |
| 63 | WARN_FUNC("can't decode instruction", sec, offset); | |
| 64 | return -1; | |
| 65 | } | |
| 66 | ||
| 67 | *len = insn.length; | |
| 68 | *type = INSN_OTHER; | |
| 69 | ||
| 70 | if (insn.vex_prefix.nbytes) | |
| 71 | return 0; | |
| 72 | ||
| 73 | op1 = insn.opcode.bytes[0]; | |
| 74 | op2 = insn.opcode.bytes[1]; | |
| 75 | ||
| 76 | switch (op1) { | |
| 77 | case 0x55: | |
| 78 | if (!insn.rex_prefix.nbytes) | |
| 79 | /* push rbp */ | |
| 80 | *type = INSN_FP_SAVE; | |
| 81 | break; | |
| 82 | ||
| 83 | case 0x5d: | |
| 84 | if (!insn.rex_prefix.nbytes) | |
| 85 | /* pop rbp */ | |
| 86 | *type = INSN_FP_RESTORE; | |
| 87 | break; | |
| 88 | ||
| 89 | case 0x70 ... 0x7f: | |
| 90 | *type = INSN_JUMP_CONDITIONAL; | |
| 91 | break; | |
| 92 | ||
| 93 | case 0x89: | |
| 94 | if (insn.rex_prefix.nbytes == 1 && | |
| 95 | insn.rex_prefix.bytes[0] == 0x48 && | |
| 96 | insn.modrm.nbytes && insn.modrm.bytes[0] == 0xe5) | |
| 97 | /* mov rsp, rbp */ | |
| 98 | *type = INSN_FP_SETUP; | |
| 99 | break; | |
| 100 | ||
| 101 | case 0x90: | |
| 102 | *type = INSN_NOP; | |
| 103 | break; | |
| 104 | ||
| 105 | case 0x0f: | |
| 106 | if (op2 >= 0x80 && op2 <= 0x8f) | |
| 107 | *type = INSN_JUMP_CONDITIONAL; | |
| 108 | else if (op2 == 0x05 || op2 == 0x07 || op2 == 0x34 || | |
| 109 | op2 == 0x35) | |
| 110 | /* sysenter, sysret */ | |
| 111 | *type = INSN_CONTEXT_SWITCH; | |
| 112 | else if (op2 == 0x0b || op2 == 0xb9) | |
| 113 | /* ud2 */ | |
| 114 | *type = INSN_BUG; | |
| 115 | else if (op2 == 0x0d || op2 == 0x1f) | |
| 116 | /* nopl/nopw */ | |
| 117 | *type = INSN_NOP; | |
| 118 | else if (op2 == 0x01 && insn.modrm.nbytes && | |
| 119 | (insn.modrm.bytes[0] == 0xc2 || | |
| 120 | insn.modrm.bytes[0] == 0xd8)) | |
| 121 | /* vmlaunch, vmrun */ | |
| 122 | *type = INSN_CONTEXT_SWITCH; | |
| 123 | ||
| 124 | break; | |
| 125 | ||
| 126 | case 0xc9: /* leave */ | |
| 127 | *type = INSN_FP_RESTORE; | |
| 128 | break; | |
| 129 | ||
| 130 | case 0xe3: /* jecxz/jrcxz */ | |
| 131 | *type = INSN_JUMP_CONDITIONAL; | |
| 132 | break; | |
| 133 | ||
| 134 | case 0xe9: | |
| 135 | case 0xeb: | |
| 136 | *type = INSN_JUMP_UNCONDITIONAL; | |
| 137 | break; | |
| 138 | ||
| 139 | case 0xc2: | |
| 140 | case 0xc3: | |
| 141 | *type = INSN_RETURN; | |
| 142 | break; | |
| 143 | ||
| 144 | case 0xc5: /* iret */ | |
| 145 | case 0xca: /* retf */ | |
| 146 | case 0xcb: /* retf */ | |
| 147 | *type = INSN_CONTEXT_SWITCH; | |
| 148 | break; | |
| 149 | ||
| 150 | case 0xe8: | |
| 151 | *type = INSN_CALL; | |
| 152 | break; | |
| 153 | ||
| 154 | case 0xff: | |
| 155 | ext = X86_MODRM_REG(insn.modrm.bytes[0]); | |
| 156 | if (ext == 2 || ext == 3) | |
| 157 | *type = INSN_CALL_DYNAMIC; | |
| 158 | else if (ext == 4) | |
| 159 | *type = INSN_JUMP_DYNAMIC; | |
| 160 | else if (ext == 5) /*jmpf */ | |
| 161 | *type = INSN_CONTEXT_SWITCH; | |
| 162 | ||
| 163 | break; | |
| 164 | ||
| 165 | default: | |
| 166 | break; | |
| 167 | } | |
| 168 | ||
| 169 | *immediate = insn.immediate.nbytes ? insn.immediate.value : 0; | |
| 170 | ||
| 171 | return 0; | |
| 172 | } |