projects/linux·blob uaccess-cleanups · refs

107 lines · 3.3 KiB

1#!/usr/bin/env python
2# SPDX-License-Identifier: GPL-2.0
3# libxed.py: Python wrapper for libxed.so
4# Copyright (c) 2014-2021, Intel Corporation.
5
6# To use Intel XED, libxed.so must be present. To build and install
7# libxed.so:
8# git clone https://github.com/intelxed/mbuild.git mbuild
9# git clone https://github.com/intelxed/xed
10# cd xed
11# ./mfile.py --share
12# sudo ./mfile.py --prefix=/usr/local install
13# sudo ldconfig
14#
15
16import sys
17
18from ctypes import CDLL, Structure, create_string_buffer, addressof, sizeof, \
19 c_void_p, c_bool, c_byte, c_char, c_int, c_uint, c_longlong, c_ulonglong
20
21# XED Disassembler
22
23class xed_state_t(Structure):
24
25 _fields_ = [
26 ("mode", c_int),
27 ("width", c_int)
28 ]
29
30class XEDInstruction():
31
32 def __init__(self, libxed):
33 # Current xed_decoded_inst_t structure is 192 bytes. Use 512 to allow for future expansion
34 xedd_t = c_byte * 512
35 self.xedd = xedd_t()
36 self.xedp = addressof(self.xedd)
37 libxed.xed_decoded_inst_zero(self.xedp)
38 self.state = xed_state_t()
39 self.statep = addressof(self.state)
40 # Buffer for disassembled instruction text
41 self.buffer = create_string_buffer(256)
42 self.bufferp = addressof(self.buffer)
43
44class LibXED():
45
46 def __init__(self):
47 try:
48 self.libxed = CDLL("libxed.so")
49 except:
50 self.libxed = None
51 if not self.libxed:
52 self.libxed = CDLL("/usr/local/lib/libxed.so")
53
54 self.xed_tables_init = self.libxed.xed_tables_init
55 self.xed_tables_init.restype = None
56 self.xed_tables_init.argtypes = []
57
58 self.xed_decoded_inst_zero = self.libxed.xed_decoded_inst_zero
59 self.xed_decoded_inst_zero.restype = None
60 self.xed_decoded_inst_zero.argtypes = [ c_void_p ]
61
62 self.xed_operand_values_set_mode = self.libxed.xed_operand_values_set_mode
63 self.xed_operand_values_set_mode.restype = None
64 self.xed_operand_values_set_mode.argtypes = [ c_void_p, c_void_p ]
65
66 self.xed_decoded_inst_zero_keep_mode = self.libxed.xed_decoded_inst_zero_keep_mode
67 self.xed_decoded_inst_zero_keep_mode.restype = None
68 self.xed_decoded_inst_zero_keep_mode.argtypes = [ c_void_p ]
69
70 self.xed_decode = self.libxed.xed_decode
71 self.xed_decode.restype = c_int
72 self.xed_decode.argtypes = [ c_void_p, c_void_p, c_uint ]
73
74 self.xed_format_context = self.libxed.xed_format_context
75 self.xed_format_context.restype = c_uint
76 self.xed_format_context.argtypes = [ c_int, c_void_p, c_void_p, c_int, c_ulonglong, c_void_p, c_void_p ]
77
78 self.xed_tables_init()
79
80 def Instruction(self):
81 return XEDInstruction(self)
82
83 def SetMode(self, inst, mode):
84 if mode:
85 inst.state.mode = 4 # 32-bit
86 inst.state.width = 4 # 4 bytes
87 else:
88 inst.state.mode = 1 # 64-bit
89 inst.state.width = 8 # 8 bytes
90 self.xed_operand_values_set_mode(inst.xedp, inst.statep)
91
92 def DisassembleOne(self, inst, bytes_ptr, bytes_cnt, ip):
93 self.xed_decoded_inst_zero_keep_mode(inst.xedp)
94 err = self.xed_decode(inst.xedp, bytes_ptr, bytes_cnt)
95 if err:
96 return 0, ""
97 # Use AT&T mode (2), alternative is Intel (3)
98 ok = self.xed_format_context(2, inst.xedp, inst.bufferp, sizeof(inst.buffer), ip, 0, 0)
99 if not ok:
100 return 0, ""
101 if sys.version_info[0] == 2:
102 result = inst.buffer.value
103 else:
104 result = inst.buffer.value.decode()
105 # Return instruction length and the disassembled instruction text
106 # For now, assume the length is in byte 166
107 return inst.xedd[166], result