1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
|
#!/usr/bin/env python3
#
# Copyright (C) 2019 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
"""Common APIs related to symbol extractions.
extract_exported_symbols(): Extracts the ksymtab exported symbols from an ELF
binary.
extract_undefined_symbols(): Extracts the undefined symbols from an ELF file at
binary_path.
is_signature_present(): Checks whether a kernel module file has a PKCS#7
signature appended.
read_symbol_list(): Reads a previously created libabigail format symbol list
into a list of symbols.
"""
import subprocess
def extract_exported_symbols(binary):
"""Extracts the ksymtab exported symbols from an ELF binary."""
symbols = []
out = subprocess.check_output(["llvm-nm", "--defined-only", binary],
stderr=subprocess.DEVNULL).decode("ascii")
for line in out.splitlines():
pos = line.find(" __ksymtab_")
if pos != -1:
symbols.append(line[pos + len(" __ksymtab_"):])
return symbols
def extract_undefined_symbols(binary_path):
"""Extracts the undefined symbols from an ELF file at binary_path."""
symbols = []
out = subprocess.check_output(["llvm-nm", "--undefined-only", binary_path],
stderr=subprocess.DEVNULL).decode("ascii")
for line in out.splitlines():
symbols.append(line.strip().split()[1])
return symbols
def is_signature_present(module):
"""Checks whether module has a signature appended (GKI) or not (vendor)"""
out = subprocess.check_output(["modinfo", "-F", "sig_id", module],
stderr=subprocess.STDOUT).decode("ascii")
return out == "PKCS#7\n"
def read_symbol_list(symbol_list):
"""Reads a previously created libabigail symbol symbol list."""
symbols = []
with open(symbol_list) as symbol_list_file:
for line in [l.strip() for l in symbol_list_file]:
if not line or line.startswith("#") or line.startswith("["):
continue
symbols.append(line)
return symbols
|
