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
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
#!/usr/bin/python3
# Move symbols from other shared objects into libc.so.
# Copyright (C) 2020-2021 Free Software Foundation, Inc.
# This file is part of the GNU C Library.
#
# The GNU C Library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# The GNU C Library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with the GNU C Library; if not, see
# <https://www.gnu.org/licenses/>.
"""Move symbols from other shared objects into libc.so.
This script moves ABI symbols from non-libc abilists in to
libc.abilist. Symbol versions are preserved. The script must be
called from the top of the glibc source tree.
"""
import argparse
import os.path
import sys
def replace_file(path, new_contents):
"""Atomically replace PATH with lines from NEW_CONTENTS.
NEW_CONTENTS must be a sequence of strings.
"""
temppath = path + 'T'
with open(temppath, 'w') as out:
for line in new_contents:
out.write(line)
os.rename(temppath, path)
class VersionedSymbol:
"""A combination of a symbol and its version."""
def __init__(self, symbol, version):
"""Construct a new versioned symbol."""
assert symbol
assert version
self.symbol = symbol
self.version = version
def __str__(self):
return self.symbol + '@' + self.version
def __eq__(self, other):
return self.symbol == other.symbol and self.version == other.version
def __hash__(self):
return hash(self.symbol) ^ hash(self.version)
def read_abilist(path):
"""Read the abilist file at PATH.
Return a dictionary from VersionedSymbols to their flags (as
strings).
"""
result = {}
with open(path) as inp:
for line in inp:
version, symbol, flags = line.strip().split(' ', 2)
result[VersionedSymbol(symbol, version)] = flags
return result
def abilist_lines(symbols):
"""Build the abilist file contents (as a list of lines).
SYMBOLS is a dictionary from VersionedSymbols to their flags.
"""
result = []
for versym, flags in symbols.items():
result.append('{} {} {}\n'.format(
versym.version, versym.symbol, flags))
result.sort()
return result
def add_to_libc_path(path, new_symbols):
"""Add SYMBOLS to the abilist file PATH.
NEW_SYMBOLS is a dictionary from VersionedSymbols to their flags.
"""
original_symbols = read_abilist(path)
updated_symbols = original_symbols.copy()
updated_symbols.update(new_symbols)
if updated_symbols != original_symbols:
sys.stdout.write('updating libc abilist {}\n'.format(path))
replace_file(path, abilist_lines(updated_symbols))
# The name of the libc.so abilist file.
libc_abilist = 'libc.abilist'
def add_to_libc_fallback(directory, subdirs, symbol_lines):
"""Add SYMBOL_LINES to the libc.abilist files in SUBDIRS in DIRECTORY.
All subdirectories must exist. If they do, return True. If not,
skip processing and return False.
"""
abilists = [os.path.join(directory, subdir, libc_abilist)
for subdir in subdirs]
for abilist in abilists:
if not os.path.exists(abilist):
return False
for abilist in abilists:
add_to_libc_path(abilist, symbol_lines)
return True
def add_to_libc(directory, symbol_lines):
"""Add SYMBOL_LINES (a list of strings) to libc.abilist in DIRECTORY.
Try specific subdirectories as well if libc.abilist is not found
in DIRECTORY.
"""
libc_path = os.path.join(directory, libc_abilist)
if os.path.exists(libc_path):
add_to_libc_path(libc_path, symbol_lines)
return
# Special case for powerpc32 and mips32 variants.
if add_to_libc_fallback(directory, ('fpu', 'nofpu'), symbol_lines):
return
# Special case for mips64.
if add_to_libc_fallback(directory, ('n32', 'n64'), symbol_lines):
return
raise IOError('No libc.abilist found for: {}'.format(directory))
def move_symbols_1(path, to_move, moved_symbols):
"""Move SYMBOLS from the abilist file PATH to MOVED_SYMBOLS.
TO_MOVE must be a set of strings. MOVED_SYMBOLS is a dictionary.
"""
suffix = '.abilist'
assert path.endswith('.abilist')
library = os.path.basename(path)[:-len(suffix)]
placeholder = '__{}_version_placeholder'.format(library)
new_lines = []
changed = False
old_symbols = read_abilist(path)
old_versions = set(versym.version for versym in old_symbols.keys())
matching_symbols = dict(e for e in old_symbols.items()
if e[0].symbol in to_move)
if matching_symbols:
sys.stdout.write('updating {} abilist {}\n'.format(library, path))
new_symbols = dict(e for e in old_symbols.items()
if e[0].symbol not in to_move)
# Add placeholder symbols to prevent symbol versions from
# going away completely.
new_versions = set(versym.version for versym in new_symbols.keys())
for missing_version in old_versions - new_versions:
new_symbols[VersionedSymbol(placeholder, missing_version)] = 'F'
replace_file(path, abilist_lines(new_symbols))
moved_symbols.update(matching_symbols)
def move_symbols(directory, files, symbols):
"""Move SYMBOLS from FILES (a list of abilist file names) in DIRECTORY.
SYMBOLS must be a set of strings.
"""
moved_symbols = {}
for filename in files:
move_symbols_1(os.path.join(directory, filename), symbols,
moved_symbols)
if moved_symbols:
add_to_libc(directory, moved_symbols)
def get_parser():
"""Return an argument parser for this module."""
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument('--only-linux', action='store_true',
help='Restrict the operation to Linux abilists')
parser.add_argument('symbols', help='name of the symbol to move',
nargs='+')
return parser
def main(argv):
"""The main entry point."""
parser = get_parser()
opts = parser.parse_args(argv)
if opts.only_linux:
sysdeps = 'sysdeps/unix/sysv/linux'
else:
sysdeps = 'sysdeps'
symbols = frozenset(opts.symbols)
for directory, dirs, files in os.walk(sysdeps):
move_symbols(directory, [name for name in files
if name != 'libc.abilist'
and name.endswith('.abilist')], symbols)
if __name__ == '__main__':
main(sys.argv[1:])
|
