Index: sandbox/linux/seccomp/x86_decode.cc |
=================================================================== |
--- sandbox/linux/seccomp/x86_decode.cc (revision 57969) |
+++ sandbox/linux/seccomp/x86_decode.cc (working copy) |
@@ -1,310 +0,0 @@ |
-// Copyright (c) 2010 The Chromium Authors. All rights reserved. |
-// Use of this source code is governed by a BSD-style license that can be |
-// found in the LICENSE file. |
- |
-#include "x86_decode.h" |
- |
-namespace playground { |
- |
-#if defined(__x86_64__) || defined(__i386__) |
-unsigned short next_inst(const char **ip, bool is64bit, bool *has_prefix, |
- char **rex_ptr, char **mod_rm_ptr, char **sib_ptr, |
- bool *is_group) { |
- enum { |
- BYTE_OP = (1<<1), // 0x02 |
- IMM = (1<<2), // 0x04 |
- IMM_BYTE = (2<<2), // 0x08 |
- MEM_ABS = (3<<2), // 0x0C |
- MODE_MASK = (7<<2), // 0x1C |
- MOD_RM = (1<<5), // 0x20 |
- STACK = (1<<6), // 0x40 |
- GROUP = (1<<7), // 0x80 |
- GROUP_MASK = 0x7F, |
- }; |
- |
- static unsigned char opcode_types[512] = { |
- 0x23, 0x21, 0x23, 0x21, 0x09, 0x05, 0x01, 0x01, // 0x00 - 0x07 |
- 0x23, 0x21, 0x23, 0x21, 0x09, 0x05, 0x01, 0x00, // 0x08 - 0x0F |
- 0x23, 0x21, 0x23, 0x21, 0x09, 0x05, 0x01, 0x01, // 0x10 - 0x17 |
- 0x23, 0x21, 0x23, 0x21, 0x09, 0x05, 0x01, 0x01, // 0x18 - 0x1F |
- 0x23, 0x21, 0x23, 0x21, 0x09, 0x05, 0x00, 0x01, // 0x20 - 0x27 |
- 0x23, 0x21, 0x23, 0x21, 0x09, 0x05, 0x00, 0x01, // 0x28 - 0x2F |
- 0x23, 0x21, 0x23, 0x21, 0x09, 0x05, 0x00, 0x01, // 0x30 - 0x37 |
- 0x23, 0x21, 0x23, 0x21, 0x09, 0x05, 0x00, 0x01, // 0x38 - 0x3F |
- 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, // 0x40 - 0x47 |
- 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, // 0x48 - 0x4F |
- 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, // 0x50 - 0x57 |
- 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, 0x41, // 0x58 - 0x5F |
- 0x01, 0x01, 0x21, 0x21, 0x00, 0x00, 0x00, 0x00, // 0x60 - 0x67 |
- 0x45, 0x25, 0x49, 0x29, 0x03, 0x01, 0x03, 0x01, // 0x68 - 0x6F |
- 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, // 0x70 - 0x77 |
- 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, // 0x78 - 0x7F |
- 0x27, 0x25, 0x27, 0x29, 0x23, 0x21, 0x23, 0x21, // 0x80 - 0x87 |
- 0x23, 0x21, 0x23, 0x21, 0x21, 0x21, 0x21, 0x80, // 0x88 - 0x8F |
- 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, // 0x90 - 0x97 |
- 0x01, 0x01, 0x05, 0x01, 0x41, 0x41, 0x01, 0x01, // 0x98 - 0x9F |
- 0x0F, 0x0D, 0x0F, 0x0D, 0x03, 0x01, 0x03, 0x01, // 0xA0 - 0xA7 |
- 0x09, 0x05, 0x03, 0x01, 0x03, 0x01, 0x03, 0x01, // 0xA8 - 0xAF |
- 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, // 0xB0 - 0xB7 |
- 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, // 0xB8 - 0xBF |
- 0x27, 0x29, 0x01, 0x01, 0x21, 0x21, 0x27, 0x25, // 0xC0 - 0xC7 |
- 0x01, 0x01, 0x01, 0x01, 0x01, 0x09, 0x01, 0x01, // 0xC8 - 0xCF |
- 0x23, 0x21, 0x23, 0x21, 0x09, 0x09, 0x01, 0x01, // 0xD0 - 0xD7 |
- 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, // 0xD8 - 0xDF |
- 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, // 0xE0 - 0xE7 |
- 0x05, 0x05, 0x05, 0x09, 0x03, 0x01, 0x03, 0x01, // 0xE8 - 0xEF |
- 0x00, 0x01, 0x00, 0x00, 0x01, 0x01, 0x88, 0x90, // 0xF0 - 0xF7 |
- 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x98, 0xA0, // 0xF8 - 0xFF |
- 0x00, 0xA8, 0x00, 0x00, 0x00, 0x01, 0x01, 0x01, // 0xF00 - 0xF07 |
- 0x01, 0x01, 0x00, 0x01, 0x00, 0x21, 0x01, 0x00, // 0xF08 - 0xF0F |
- 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, // 0xF10 - 0xF17 |
- 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, // 0xF18 - 0xF1F |
- 0x21, 0x21, 0x21, 0x21, 0x00, 0x00, 0x00, 0x00, // 0xF20 - 0xF27 |
- 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, // 0xF28 - 0xF2F |
- 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x00, 0x00, // 0xF30 - 0xF37 |
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 0xF38 - 0xF3F |
- 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, // 0xF40 - 0xF47 |
- 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, // 0xF48 - 0xF4F |
- 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, // 0xF50 - 0xF57 |
- 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, // 0xF58 - 0xF5F |
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 0xF60 - 0xF67 |
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 0xF68 - 0xF6F |
- 0x21, 0x00, 0x00, 0x00, 0x21, 0x21, 0x21, 0x00, // 0xF70 - 0xF77 |
- 0x21, 0x21, 0x00, 0x00, 0x21, 0x21, 0x21, 0x21, // 0xF78 - 0xF7F |
- 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, // 0xF80 - 0xF87 |
- 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, // 0xF88 - 0xF8F |
- 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, // 0xF90 - 0xF97 |
- 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, // 0xF98 - 0xF9F |
- 0x01, 0x01, 0x01, 0x21, 0x29, 0x21, 0x00, 0x00, // 0xFA0 - 0xFA7 |
- 0x01, 0x01, 0x01, 0x21, 0x29, 0x21, 0x21, 0x21, // 0xFA8 - 0xFAF |
- 0x23, 0x21, 0x00, 0x21, 0x00, 0x00, 0x23, 0x21, // 0xFB0 - 0xFB7 |
- 0x21, 0x00, 0x29, 0x21, 0x21, 0x21, 0x21, 0x21, // 0xFB8 - 0xFBF |
- 0x21, 0x21, 0x00, 0x21, 0x00, 0x00, 0x00, 0x21, // 0xFC0 - 0xFC7 |
- 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, // 0xFC8 - 0xFCF |
- 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, // 0xFD0 - 0xFD7 |
- 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, // 0xFD8 - 0xFDF |
- 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, // 0xFE0 - 0xFE7 |
- 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, // 0xFE8 - 0xFEF |
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 0xFF0 - 0xFF7 |
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 0xFF8 - 0xFFF |
- }; |
- |
- static unsigned char group_table[56] = { |
- 0x61, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Group 1A |
- 0x27, 0x27, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23, // Group 3 (Byte) |
- 0x25, 0x25, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, // Group 3 |
- 0x23, 0x23, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Group 4 |
- 0x21, 0x21, 0x61, 0x21, 0x61, 0x21, 0x61, 0x00, // Group 5 |
- 0x00, 0x00, 0x21, 0x21, 0x21, 0x00, 0x21, 0x23, // Group 7 |
- 0x21, 0x00, 0x00, 0x21, 0x21, 0x00, 0x21, 0x00, // Group 7 (Alternate) |
- }; |
- |
- const unsigned char *insn_ptr = reinterpret_cast<const unsigned char *>(*ip); |
- int operand_width = 4; |
- int address_width = 4; |
- if (is64bit) { |
- address_width = 8; |
- } |
- unsigned char byte, rex = 0; |
- bool found_prefix = false; |
- if (rex_ptr) { |
- *rex_ptr = 0; |
- } |
- if (mod_rm_ptr) { |
- *mod_rm_ptr = 0; |
- } |
- if (sib_ptr) { |
- *sib_ptr = 0; |
- } |
- for (;; ++insn_ptr) { |
- switch (byte = *insn_ptr) { |
- case 0x66: // Operand width prefix |
- operand_width ^= 6; |
- break; |
- case 0x67: // Address width prefix |
- address_width ^= is64bit ? 12 : 6; |
- break; |
- case 0x26: // Segment selector prefixes |
- case 0x2e: |
- case 0x36: |
- case 0x3e: |
- case 0x64: |
- case 0x65: |
- case 0xF0: |
- case 0xF2: |
- case 0xF3: |
- break; |
- case 0x40: case 0x41: case 0x42: case 0x43: // 64 bit REX prefixes |
- case 0x44: case 0x45: case 0x46: case 0x47: |
- case 0x48: case 0x49: case 0x4A: case 0x4B: |
- case 0x4C: case 0x4D: case 0x4E: case 0x4F: |
- if (is64bit) { |
- if (rex_ptr) { |
- *rex_ptr = (char *)insn_ptr; |
- } |
- rex = byte; |
- found_prefix = true; |
- continue; |
- } |
- // fall through |
- default: |
- ++insn_ptr; |
- goto no_more_prefixes; |
- } |
- rex = 0; |
- found_prefix = true; |
- } |
-no_more_prefixes: |
- if (has_prefix) { |
- *has_prefix = found_prefix; |
- } |
- if (rex & REX_W) { |
- operand_width = 8; |
- } |
- unsigned char type; |
- unsigned short insn = byte; |
- unsigned int idx = 0; |
- if (byte == 0x0F) { |
- byte = *insn_ptr++; |
- insn = (insn << 8) | byte; |
- idx = 256; |
- } |
- type = opcode_types[idx + byte]; |
- bool found_mod_rm = false; |
- bool found_group = false; |
- bool found_sib = false; |
- unsigned char mod_rm = 0; |
- unsigned char sib = 0; |
- if (type & GROUP) { |
- found_mod_rm = true; |
- found_group = true; |
- mod_rm = *insn_ptr; |
- if (mod_rm_ptr) { |
- *mod_rm_ptr = (char *)insn_ptr; |
- } |
- unsigned char group = (type & GROUP_MASK) + ((mod_rm >> 3) & 0x7); |
- if ((type & GROUP_MASK) == 40 && (mod_rm >> 6) == 3) { |
- group += 8; |
- } |
- type = group_table[group]; |
- } |
- if (!type) { |
- // We know that we still don't decode some of the more obscure |
- // instructions, but for all practical purposes that doesn't matter. |
- // Compilers are unlikely to output them, and even if we encounter |
- // hand-coded assembly, we will soon synchronize to the instruction |
- // stream again. |
- // |
- // std::cerr << "Unsupported instruction at 0x" << std::hex << |
- // std::uppercase << reinterpret_cast<long>(*ip) << " [ "; |
- // for (const unsigned char *ptr = |
- // reinterpret_cast<const unsigned char *>(*ip); |
- // ptr < insn_ptr; ) { |
- // std::cerr << std::hex << std::uppercase << std::setw(2) << |
- // std::setfill('0') << (unsigned int)*ptr++ << ' '; |
- // } |
- // std::cerr << "]" << std::endl; |
- } else { |
- if (is64bit && (type & STACK)) { |
- operand_width = 8; |
- } |
- if (type & MOD_RM) { |
- found_mod_rm = true; |
- if (mod_rm_ptr) { |
- *mod_rm_ptr = (char *)insn_ptr; |
- } |
- mod_rm = *insn_ptr++; |
- int mod = (mod_rm >> 6) & 0x3; |
- int rm = 8*(rex & REX_B) + (mod_rm & 0x7); |
- if (mod != 3) { |
- if (address_width == 2) { |
- switch (mod) { |
- case 0: |
- if (rm != 6 /* SI */) { |
- break; |
- } |
- // fall through |
- case 2: |
- insn_ptr++; |
- // fall through |
- case 1: |
- insn_ptr++; |
- break; |
- } |
- } else { |
- if ((rm & 0x7) == 4) { |
- found_sib = true; |
- if (sib_ptr) { |
- *sib_ptr = (char *)insn_ptr; |
- } |
- sib = *insn_ptr++; |
- if (!mod && (sib & 0x7) == 5 /* BP */) { |
- insn_ptr += 4; |
- } |
- } |
- switch (mod) { |
- case 0: |
- if (rm != 5 /* BP */) { |
- break; |
- } |
- // fall through |
- case 2: |
- insn_ptr += 3; |
- // fall through |
- case 1: |
- insn_ptr++; |
- break; |
- } |
- } |
- } |
- } |
- switch (insn) { |
- case 0xC8: // ENTER |
- insn_ptr++; |
- // fall through |
- case 0x9A: // CALL (far) |
- case 0xC2: // RET (near) |
- case 0xCA: // LRET |
- case 0xEA: // JMP (far) |
- insn_ptr += 2; |
- break; |
- case 0xF80: case 0xF81: case 0xF82: case 0xF83: // Jcc (rel) |
- case 0xF84: case 0xF85: case 0xF86: case 0xF87: |
- case 0xF88: case 0xF89: case 0xF8A: case 0xF8B: |
- case 0xF8C: case 0xF8D: case 0xF8E: case 0xF8F: |
- insn_ptr += operand_width; |
- break; |
- } |
- switch (type & MODE_MASK) { |
- case IMM: |
- if (!(type & BYTE_OP)) { |
- switch (insn) { |
- case 0xB8: case 0xB9: case 0xBA: case 0xBB: |
- case 0xBC: case 0xBD: case 0xBE: case 0xBF: |
- // Allow MOV to/from 64bit addresses |
- insn_ptr += operand_width; |
- break; |
- default: |
- insn_ptr += (operand_width == 8) ? 4 : operand_width; |
- break; |
- } |
- break; |
- } |
- // fall through |
- case IMM_BYTE: |
- insn_ptr++; |
- break; |
- case MEM_ABS: |
- insn_ptr += address_width; |
- break; |
- } |
- } |
- if (is_group) { |
- *is_group = found_group; |
- } |
- *ip = reinterpret_cast<const char *>(insn_ptr); |
- return insn; |
-} |
-#endif |
- |
-} // namespace |