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1 | #!/usr/bin/python3 |
2 | # Helpers for glibc system call list processing. | |
2b778ceb | 3 | # Copyright (C) 2018-2021 Free Software Foundation, Inc. |
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4 | # This file is part of the GNU C Library. |
5 | # | |
6 | # The GNU C Library is free software; you can redistribute it and/or | |
7 | # modify it under the terms of the GNU Lesser General Public | |
8 | # License as published by the Free Software Foundation; either | |
9 | # version 2.1 of the License, or (at your option) any later version. | |
10 | # | |
11 | # The GNU C Library is distributed in the hope that it will be useful, | |
12 | # but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | # Lesser General Public License for more details. | |
15 | # | |
16 | # You should have received a copy of the GNU Lesser General Public | |
17 | # License along with the GNU C Library; if not, see | |
18 | # <http://www.gnu.org/licenses/>. | |
19 | ||
6fcb0272 | 20 | import os |
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21 | import re |
22 | ||
6fcb0272 FW |
23 | if __name__ != '__main__': |
24 | # When called as a main program, this is not needed. | |
25 | import glibcextract | |
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26 | |
27 | def extract_system_call_name(macro): | |
28 | """Convert the macro name (with __NR_) to a system call name.""" | |
29 | prefix = '__NR_' | |
30 | if macro.startswith(prefix): | |
31 | return macro[len(prefix):] | |
32 | else: | |
33 | raise ValueError('invalid system call name: {!r}'.format(macro)) | |
34 | ||
35 | # Matches macros for systme call names. | |
36 | RE_SYSCALL = re.compile('__NR_.*') | |
37 | ||
38 | # Some __NR_ constants are not real | |
39 | RE_PSEUDO_SYSCALL = re.compile(r"""__NR_( | |
40 | # Reserved system call. | |
41 | (unused|reserved)[0-9]+ | |
42 | ||
43 | # Pseudo-system call which describes a range. | |
44 | |(syscalls|arch_specific_syscall|(OABI_)?SYSCALL_BASE) | |
45 | |(|64_|[NO]32_)Linux(_syscalls)? | |
46 | )""", re.X) | |
47 | ||
48 | def kernel_constants(cc): | |
49 | """Return a dictionary with the kernel-defined system call numbers. | |
50 | ||
51 | This comes from <asm/unistd.h>. | |
52 | ||
53 | """ | |
54 | return {extract_system_call_name(name) : int(value) | |
55 | for name, value in glibcextract.compute_macro_consts( | |
56 | '#include <asm/unistd.h>\n' | |
57 | # Regularlize the kernel definitions if necessary. | |
58 | '#include <fixup-asm-unistd.h>', | |
59 | cc, macro_re=RE_SYSCALL, exclude_re=RE_PSEUDO_SYSCALL) | |
60 | .items()} | |
61 | ||
62 | class SyscallNamesList: | |
63 | """The list of known system call names. | |
64 | ||
65 | glibc keeps a list of system call names. The <sys/syscall.h> | |
66 | header needs to provide a SYS_ name for each __NR_ macro, | |
67 | and the generated <bits/syscall.h> header uses an | |
68 | architecture-independent list, so that there is a chance that | |
69 | system calls arriving late on certain architectures will automatically | |
70 | get the expected SYS_ macro. | |
71 | ||
72 | syscalls: list of strings with system call names | |
73 | kernel_version: tuple of integers; the kernel version given in the file | |
74 | ||
75 | """ | |
76 | def __init__(self, lines): | |
77 | self.syscalls = [] | |
78 | old_name = None | |
79 | self.kernel_version = None | |
80 | self.__lines = tuple(lines) | |
81 | for line in self.__lines: | |
82 | line = line.strip() | |
83 | if (not line) or line[0] == '#': | |
84 | continue | |
85 | comps = line.split() | |
86 | if len(comps) == 1: | |
87 | self.syscalls.append(comps[0]) | |
88 | if old_name is not None: | |
89 | if comps[0] < old_name: | |
90 | raise ValueError( | |
91 | 'name list is not sorted: {!r} < {!r}'.format( | |
92 | comps[0], old_name)) | |
93 | old_name = comps[0] | |
94 | continue | |
95 | if len(comps) == 2 and comps[0] == "kernel": | |
96 | if self.kernel_version is not None: | |
97 | raise ValueError( | |
98 | "multiple kernel versions: {!r} and !{r}".format( | |
99 | kernel_version, comps[1])) | |
100 | self.kernel_version = tuple(map(int, comps[1].split("."))) | |
101 | continue | |
102 | raise ValueError("invalid line: !r".format(line)) | |
103 | if self.kernel_version is None: | |
104 | raise ValueError("missing kernel version") | |
105 | ||
106 | def merge(self, names): | |
107 | """Merge sequence NAMES and return the lines of the new file.""" | |
108 | names = list(set(names) - set(self.syscalls)) | |
109 | names.sort() | |
110 | names.reverse() | |
111 | result = [] | |
112 | def emit_name(): | |
113 | result.append(names[-1] + "\n") | |
114 | del names[-1] | |
115 | ||
116 | for line in self.__lines: | |
117 | comps = line.strip().split() | |
118 | if len(comps) == 1 and not comps[0].startswith("#"): | |
119 | # File has a system call at this position. Insert all | |
120 | # the names that come before the name in the file | |
121 | # lexicographically. | |
122 | while names and names[-1] < comps[0]: | |
123 | emit_name() | |
124 | result.append(line) | |
125 | while names: | |
126 | emit_name() | |
127 | ||
128 | return result | |
129 | ||
130 | def load_arch_syscall_header(path): | |
131 | """"Load the system call header form the file PATH. | |
132 | ||
133 | The file must consist of lines of this form: | |
134 | ||
135 | #define __NR_exit 1 | |
136 | ||
137 | The file is parsed verbatim, without running it through a C | |
138 | preprocessor or parser. The intent is that the file can be | |
139 | readily processed by tools. | |
140 | ||
141 | """ | |
142 | with open(path) as inp: | |
143 | result = {} | |
144 | old_name = None | |
145 | for line in inp: | |
146 | line = line.strip() | |
147 | ||
148 | # Ignore the initial comment line. | |
149 | if line.startswith("/*") and line.endswith("*/"): | |
150 | continue | |
151 | ||
152 | define, name, number = line.split(' ', 2) | |
153 | if define != '#define': | |
154 | raise ValueError("invalid syscall header line: {!r}".format( | |
155 | line)) | |
156 | result[extract_system_call_name(name)] = int(number) | |
157 | ||
158 | # Check list order. | |
159 | if old_name is not None: | |
160 | if name < old_name: | |
161 | raise ValueError( | |
162 | 'system call list is not sorted: {!r} < {!r}'.format( | |
163 | name, old_name)) | |
164 | old_name = name | |
165 | return result | |
166 | ||
167 | def linux_kernel_version(cc): | |
168 | """Return the (major, minor) version of the Linux kernel headers.""" | |
169 | sym_data = ['#include <linux/version.h>', 'START', | |
170 | ('LINUX_VERSION_CODE', 'LINUX_VERSION_CODE')] | |
171 | val = glibcextract.compute_c_consts(sym_data, cc)['LINUX_VERSION_CODE'] | |
172 | val = int(val) | |
173 | return ((val & 0xff0000) >> 16, (val & 0xff00) >> 8) | |
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174 | |
175 | class ArchSyscall: | |
176 | """Canonical name and location of a syscall header.""" | |
177 | ||
178 | def __init__(self, name, path): | |
179 | self.name = name | |
180 | self.path = path | |
181 | ||
182 | def __repr__(self): | |
183 | return 'ArchSyscall(name={!r}, patch={!r})'.format( | |
184 | self.name, self.path) | |
185 | ||
186 | def list_arch_syscall_headers(topdir): | |
187 | """A generator which returns all the ArchSyscall objects in a tree.""" | |
188 | ||
189 | sysdeps = os.path.join(topdir, 'sysdeps', 'unix', 'sysv', 'linux') | |
190 | for root, dirs, files in os.walk(sysdeps): | |
191 | if root != sysdeps: | |
192 | for filename in files: | |
193 | if filename == 'arch-syscall.h': | |
194 | yield ArchSyscall( | |
195 | name=os.path.relpath(root, sysdeps), | |
196 | path=os.path.join(root, filename)) | |
197 | ||
198 | def __main(): | |
199 | """Entry point when called as the main program.""" | |
200 | ||
201 | import argparse | |
202 | import sys | |
203 | ||
204 | # Top-level directory of the source tree. | |
205 | topdir = os.path.realpath(os.path.join( | |
206 | os.path.dirname(os.path.realpath(__file__)), *('..',) * 4)) | |
207 | ||
208 | def get_parser(): | |
209 | parser = argparse.ArgumentParser(description=__doc__) | |
210 | subparsers = parser.add_subparsers(dest='command', required=True) | |
211 | subparsers.add_parser('list-headers', | |
212 | help='Print the absolute paths of all arch-syscall.h header files') | |
213 | subparser = subparsers.add_parser('query-syscall', | |
214 | help='Summarize the implementation status of system calls') | |
215 | subparser.add_argument('syscalls', help='Which syscalls to check', | |
216 | nargs='+') | |
217 | return parser | |
218 | parser = get_parser() | |
219 | args = parser.parse_args() | |
220 | ||
221 | if args.command == 'list-headers': | |
222 | for header in sorted([syscall.path for syscall | |
223 | in list_arch_syscall_headers(topdir)]): | |
224 | print(header) | |
225 | ||
226 | elif args.command == 'query-syscall': | |
227 | # List of system call tables. | |
228 | tables = sorted(list_arch_syscall_headers(topdir), | |
229 | key=lambda syscall: syscall.name) | |
230 | for table in tables: | |
231 | table.numbers = load_arch_syscall_header(table.path) | |
232 | ||
233 | for nr in args.syscalls: | |
234 | defined = [table.name for table in tables | |
235 | if nr in table.numbers] | |
236 | undefined = [table.name for table in tables | |
237 | if nr not in table.numbers] | |
238 | if not defined: | |
239 | print('{}: not defined on any architecture'.format(nr)) | |
240 | elif not undefined: | |
241 | print('{}: defined on all architectures'.format(nr)) | |
242 | else: | |
243 | print('{}:'.format(nr)) | |
244 | print(' defined: {}'.format(' '.join(defined))) | |
245 | print(' undefined: {}'.format(' '.join(undefined))) | |
246 | ||
247 | else: | |
248 | # Unrecognized command. | |
249 | usage(1) | |
250 | ||
251 | if __name__ == '__main__': | |
252 | __main() |