src/basic/missing_syscalls.py

   1 #!/usr/bin/env python3
   2 # SPDX-License-Identifier: LGPL-2.1-or-later
   3
   4 import sys
   5 import functools
   6
   7 # We only generate numbers for a dozen or so syscalls
   8 SYSCALLS = [
   9     'bpf',
  10     'close_range',
  11     'copy_file_range',
  12     'epoll_pwait2',
  13     'getrandom',
  14     'memfd_create',
  15     'mount_setattr',
  16     'move_mount',
  17     'name_to_handle_at',
  18     'open_tree',
  19     'pidfd_open',
  20     'pidfd_send_signal',
  21     'pkey_mprotect',
  22     'renameat2',
  23     'setns',
  24     'statx',
  25 ]
  26
  27 def dictify(f):
  28     def wrap(*args, **kwargs):
  29         return dict(f(*args, **kwargs))
  30     return functools.update_wrapper(wrap, f)
  31
  32 @dictify
  33 def parse_syscall_table(filename):
  34     print(f'Reading {filename}…')
  35     for line in open(filename):
  36         items = line.split()
  37         if len(items) >= 2:
  38             yield items[0], int(items[1])
  39
  40 def parse_syscall_tables(filenames):
  41     return {filename.split('-')[-1][:-4]: parse_syscall_table(filename)
  42             for filename in filenames}
  43
  44 DEF_TEMPLATE_A = '''\
  45
  46 #ifndef __IGNORE_{syscall}
  47 '''
  48
  49 DEF_TEMPLATE_B = '''\
  50 #  if defined(__aarch64__)
  51 #    define systemd_NR_{syscall} {nr_arm64}
  52 #  elif defined(__alpha__)
  53 #    define systemd_NR_{syscall} {nr_alpha}
  54 #  elif defined(__arc__) || defined(__tilegx__)
  55 #    define systemd_NR_{syscall} {nr_arc}
  56 #  elif defined(__arm__)
  57 #    define systemd_NR_{syscall} {nr_arm}
  58 #  elif defined(__i386__)
  59 #    define systemd_NR_{syscall} {nr_i386}
  60 #  elif defined(__ia64__)
  61 #    define systemd_NR_{syscall} {nr_ia64}
  62 #  elif defined(__m68k__)
  63 #    define systemd_NR_{syscall} {nr_m68k}
  64 #  elif defined(_MIPS_SIM)
  65 #    if _MIPS_SIM == _MIPS_SIM_ABI32
  66 #      define systemd_NR_{syscall} {nr_mipso32}
  67 #    elif _MIPS_SIM == _MIPS_SIM_NABI32
  68 #      define systemd_NR_{syscall} {nr_mips64n32}
  69 #    elif _MIPS_SIM == _MIPS_SIM_ABI64
  70 #      define systemd_NR_{syscall} {nr_mips64}
  71 #    else
  72 #      error "Unknown MIPS ABI"
  73 #    endif
  74 #  elif defined(__powerpc__)
  75 #    define systemd_NR_{syscall} {nr_powerpc}
  76 #  elif defined(__riscv)
  77 #    if __riscv_xlen == 32
  78 #      define systemd_NR_{syscall} {nr_riscv32}
  79 #    elif __riscv_xlen == 64
  80 #      define systemd_NR_{syscall} {nr_riscv64}
  81 #    else
  82 #      error "Unknown RISC-V ABI"
  83 #    endif
  84 #  elif defined(__s390__)
  85 #    define systemd_NR_{syscall} {nr_s390}
  86 #  elif defined(__sparc__)
  87 #    define systemd_NR_{syscall} {nr_sparc}
  88 #  elif defined(__x86_64__)
  89 #    if defined(__ILP32__)
  90 #      define systemd_NR_{syscall} ({nr_x86_64} | /* __X32_SYSCALL_BIT */ 0x40000000)
  91 #    else
  92 #      define systemd_NR_{syscall} {nr_x86_64}
  93 #    endif
  94 #  elif !defined(missing_arch_template)
  95 %s
  96 #  endif
  97 '''
  98
  99 DEF_TEMPLATE_C = '''\
 100
 101 /* may be an (invalid) negative number due to libseccomp, see PR 13319 */
 102 #  if defined __NR_{syscall} && __NR_{syscall} >= 0
 103 #    if defined systemd_NR_{syscall}
 104 assert_cc(__NR_{syscall} == systemd_NR_{syscall});
 105 #    endif
 106 #  else
 107 #    if defined __NR_{syscall}
 108 #      undef __NR_{syscall}
 109 #    endif
 110 #    if defined systemd_NR_{syscall} && systemd_NR_{syscall} >= 0
 111 #      define __NR_{syscall} systemd_NR_{syscall}
 112 #    endif
 113 #  endif
 114 #endif'''
 115
 116 DEF_TEMPLATE = (DEF_TEMPLATE_A +
 117                 DEF_TEMPLATE_B % '#    warning "{syscall}() syscall number is unknown for your architecture"' +
 118                 DEF_TEMPLATE_C)
 119
 120 ARCH_CHECK = '''\
 121 /* Note: if this code looks strange, this is because it is derived from the same
 122  * template as the per-syscall blocks below. */
 123 ''' + '\n'.join(line for line in DEF_TEMPLATE_B.splitlines()
 124                        if ' define ' not in line) % '''\
 125 #    warning "Current architecture is missing from the template"
 126 #    define missing_arch_template 1'''
 127
 128 def print_syscall_def(syscall, tables, out):
 129     mappings = {f'nr_{arch}':t.get(syscall, -1)
 130                 for arch, t in tables.items()}
 131     print(DEF_TEMPLATE.format(syscall=syscall, **mappings),
 132           file=out)
 133
 134 def print_syscall_defs(syscalls, tables, out):
 135     print('''\
 136 /* SPDX-License-Identifier: LGPL-2.1-or-later
 137  * This file is generated by src/basic/missing_syscalls.py. Do not edit!
 138  *
 139  * Use 'ninja -C build update-syscall-tables' to download new syscall tables,
 140  * and 'ninja -C build update-syscall-header' to regenerate this file.
 141  */
 142 ''',
 143           file=out)
 144     print(ARCH_CHECK, file=out)
 145     for syscall in syscalls:
 146         print_syscall_def(syscall, tables, out)
 147
 148 if __name__ == '__main__':
 149     output_file = sys.argv[1]
 150     arch_files = sys.argv[2:]
 151     out = open(output_file, 'wt')
 152
 153     tables = parse_syscall_tables(arch_files)
 154     print_syscall_defs(SYSCALLS, tables, out)
 155
 156     print(f'Wrote {output_file}')