sysdeps/unix/sysv/linux/update-syscall-lists.py

   1 #!/usr/bin/python3
   2 # Regenerate <arch-syscall.h> and update syscall-names.list.
   3 # Copyright (C) 2020-2023 Free Software Foundation, Inc.
   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
  20 import argparse
  21 import io
  22 import os
  23 import sys
  24
  25 import glibcextract
  26 import glibcsyscalls
  27
  28 def atomic_replace(path, contents):
  29     """Atomically replace PATH with CONTENTS, via a temporary file.
  30
  31     The name of the temporary file is predictable, so locking is
  32     required to avoid corruption.
  33
  34     """
  35     path_tmp = path + 'T'
  36     with open(path_tmp, 'w') as tmp:
  37         tmp.write(contents)
  38     ok = False
  39     try:
  40         os.rename(path_tmp, path)
  41         ok = True
  42     finally:
  43         # On error, try to delete the temporary file.
  44         if not ok:
  45             try:
  46                 os.unlink(path_tmp)
  47             except:
  48                 pass
  49
  50 def main():
  51     """The main entry point."""
  52     parser = argparse.ArgumentParser(
  53         description='System call list consistency checks')
  54     parser.add_argument('--cc', metavar='CC', required=True,
  55                         help='C compiler (including options) to use')
  56     parser.add_argument('--lock', metavar='PATH', required=True,
  57                         help='file to lock during the updates')
  58     parser.add_argument('arch_syscall', metavar='ARCH-SYSCALL-H',
  59                         help='The <arch-syscall.h> file to update')
  60     parser.add_argument('names_list', metavar='SYSCALL-NAMES-LIST',
  61                         help='The syscall name list to update ')
  62
  63     args = parser.parse_args()
  64
  65     kernel_constants = glibcsyscalls.kernel_constants(args.cc)
  66
  67     with open(args.lock, 'r+') as lockfile:
  68         os.lockf(lockfile.fileno(), os.F_LOCK, 0)
  69
  70         # Replace <arch-syscall.h> with data derived from kernel headers.
  71         # No merging is necessary here.  Arch-specific changes should go
  72         # into <fixup-unistd-asm.h>.
  73         out = io.StringIO()
  74         out.write('/* AUTOGENERATED by update-syscall-lists.py.  */\n')
  75         for name, value in sorted(kernel_constants.items()):
  76             out.write('#define __NR_{} {}\n'.format(name, value))
  77         atomic_replace(args.arch_syscall, out.getvalue())
  78
  79         # Merge the architecture-specific system call names into the
  80         # global names list, syscall-names.list.  This file contains names
  81         # from other architectures (and comments), so it is necessary to
  82         # merge the existing files with the names obtained from the
  83         # kernel.
  84         with open(args.names_list, 'r') as list_file:
  85             names_list = glibcsyscalls.SyscallNamesList(list_file)
  86         merged = names_list.merge(kernel_constants.keys())
  87         out = io.StringIO()
  88         for line in merged:
  89             out.write(line)
  90         atomic_replace(args.names_list, out.getvalue())
  91
  92 if __name__ == '__main__':
  93     main()