#!/usr/bin/perl
#
# Copyright (c) 2006-2014 Apple Inc. All rights reserved.
#
# @APPLE_OSREFERENCE_LICENSE_HEADER_START@
#
# This file contains Original Code and/or Modifications of Original Code
# as defined in and that are subject to the Apple Public Source License
# Version 2.0 (the 'License'). You may not use this file except in
# compliance with the License. Please obtain a copy of the License at
# http://www.opensource.apple.com/apsl/ and read it before using this
# file.
#
# The Original Code and all software distributed under the License are
# distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
# EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
# INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
# Please see the License for the specific language governing rights and
# limitations under the License.
#
# @APPLE_OSREFERENCE_LICENSE_HEADER_END@
#
##########################################################################
#
# % create-syscalls.pl syscalls.master custom-directory platforms-directory platform-name out-directory
#
# This script fills the the out-directory with a Makefile.inc and *.s
# files to create the double-underbar syscall stubs. It reads the
# syscall.master file to get the symbol names and number of arguments,
# and whether Libsystem should automatically create the (non-double-underbar)
# stubs if Libc doesn't provide a wrapper. Which system calls will get
# the automatic treatment is writen to the libsyscall.list file, also
# written to the out-directory.
#
# The custom-directory contains:
# 1. SYS.h - used by the automatically created *.s and custom files
# 2. custom.s - contains architecture specific additional system calls and
# auxilliary routines (like cerror)
# 3. special case double-underbar stub files - which are copied into
# the out-directory
#
##########################################################################
use strict;
use File::Basename ();
use File::Copy ();
use File::Spec;
use IO::File;
my $MyName = File::Basename::basename($0);
my @CustomSrc = qw(custom.s);
my @Architectures = split /\s/, $ENV{"ARCHS"};
my @Copy = (qw(SYS.h), @CustomSrc);
my $CustomDir;
my $PlatformsDir;
my $PlatformName;
my $OutDir;
# size in bytes of known types (only used for i386)
my %TypeBytes = (
'au_asid_t' => 4,
'sae_associd_t' => 4,
'caddr_t' => 4,
'caddr_ut' => 4,
'sae_connid_t' => 4,
'gid_t' => 4,
'id_t' => 4,
'idtype_t' => 4,
'int' => 4,
'int32_t' => 4,
'int64_t' => 8,
'key_t' => 4,
'long' => 4,
'mach_port_name_t' => 4,
'mode_t' => 4,
'off_t' => 8,
'pid_t' => 4,
'semun_t' => 4,
'sigset_t' => 4,
'size_t' => 4,
'size_ut' => 4,
'socklen_t' => 4,
'ssize_t' => 4,
'u_int' => 4,
'u_long' => 4,
'uid_t' => 4,
'uint32_t' => 4,
'uint64_t' => 8,
'user_addr_t' => 4,
'user_addr_ut' => 4,
'user_long_t' => 4,
'user_size_t' => 4,
'user_size_ut' => 4,
'user_ssize_t' => 4,
'user_ulong_t' => 4,
'uuid_t' => 4,
);
# Types that potentially have different sizes in user-space compared to
# kernel-space as well as whether the value should be sign/zero-extended when
# passing the user/kernel boundary.
my %UserKernelMismatchTypes = (
'long' => 'SIGN_EXTEND',
'size_t' => 'ZERO_EXTEND',
'size_ut' => 'ZERO_EXTEND',
'u_long' => 'ZERO_EXTEND',
'user_size_t' => 'ZERO_EXTEND',
'user_size_ut' => 'ZERO_EXTEND',
'user_ssize_t' => 'SIGN_EXTEND'
);
# Moving towards storing all data in this hash, then we always know
# if data is aliased or not, or promoted or not.
my %Symbols = (
"syscall" => {
c_sym => "syscall",
syscall => "syscall",
asm_sym => "_syscall",
is_private => undef,
is_custom => undef,
nargs => 0,
bytes => 0,
aliases => {},
mismatch_args => {}, # Arguments that might need to be zero/sign-extended
},
);
# An explicit list of cancelable syscalls. For creating stubs that call the
# cancellable version of cerror.
my @Cancelable = qw/
accept access aio_suspend
close connect connectx
disconnectx
faccessat fcntl fdatasync fpathconf fstat fstatat fsync
getlogin
ioctl
link linkat lseek lstat
msgrcv msgsnd msync
open openat
pathconf peeloff poll posix_spawn pread preadv pselect pwrite pwritev
read readv recvfrom recvmsg rename renameat
rename_ext
__semwait_signal __sigwait
select sem_wait semop sendmsg sendto sigsuspend stat symlink symlinkat sync
unlink unlinkat
wait4 waitid write writev
/;
sub usage {
die "Usage: $MyName syscalls.master custom-directory platforms-directory platform-name out-directory\n";
}
##########################################################################
# Read the syscall.master file and collect the system call names and number
# of arguments. It looks for the NO_SYSCALL_STUB quailifier following the
# prototype to determine if no automatic stub should be created by Libsystem.
#
# The `sys_` prefix is stripped from syscall names, and is only kept for
# the kernel symbol in order to avoid namespace clashes and identify
# syscalls more easily.
#
# For the #if lines in syscall.master, all macros are assumed to be defined,
# except COMPAT_GETFSSTAT (assumed undefined).
##########################################################################
sub readMaster {
my $file = shift;
local $_;
my $f = IO::File->new($file, 'r');
die "$MyName: $file: $!\n" unless defined($f);
my $line = 0;
my $skip = 0;
my $allow_missing = 0;
while(<$f>) {
$line++;
if(/^#\s*endif/) {
$skip = 0;
$allow_missing = 0;
next;
}
if(/^#\s*else/) {
$skip = -$skip;
$allow_missing = 0;
next;
}
chomp;
if(/^#\s*ifndef\s+(RC_HIDE\S+)$/) {
$skip = 1;
$allow_missing = 1;
}
if(/^#\s*if\s+(\S+)$/) {
$skip = ($1 eq 'COMPAT_GETFSSTAT') ? -1 : 1;
next;
}
next if $skip < 0;
next unless /^\d/;
s/^[^{]*{\s*//;
s/\s*}.*$//; # }
die "$MyName: no function prototype on line $line\n" unless length($_) > 0 && /;$/;
my $no_syscall_stub = /\)\s*NO_SYSCALL_STUB\s*;/;
my($name, $args) = /\s(\S+)\s*\(([^)]*)\)/;
next if $name =~ /e?nosys/;
$name =~ s/^sys_//;
$args =~ s/^\s+//;
$args =~ s/\s+$//;
my $argbytes = 0;
my $nargs = 0;
my %mismatch_args;
if($args ne '' && $args ne 'void') {
my @a = split(',', $args);
$nargs = scalar(@a);
my $index = 0;
for my $type (@a) {
$type =~ s/\s*\w+$//; # remove the argument name
# Calculate the size of all the arguments (only used for i386)
if($type =~ /\*$/) {
$argbytes += 4; # a pointer type
} else {
$type =~ s/^.*\s//; # remove any type qualifier, like unsigned
my $b = $TypeBytes{$type};
die "$MyName: $name: unknown type '$type'\n" unless defined($b);
$argbytes += $b;
}
# Determine which arguments might need to be zero/sign-extended
if(exists $UserKernelMismatchTypes{$type}) {
$mismatch_args{$index} = $UserKernelMismatchTypes{$type};
}
$index++;
}
}
$Symbols{$name} = {
c_sym => $name,
syscall => $name,
asm_sym => $no_syscall_stub ? "___$name" : "_$name",
is_private => $no_syscall_stub,
is_custom => undef,
nargs => $nargs,
bytes => $argbytes,
aliases => {},
mismatch_args => \%mismatch_args, # Arguments that might need to be zero/sign-extended
except => [],
allow_missing => $allow_missing,
};
}
}
sub checkForCustomStubs {
my ($dir) = @_;
my ($c_sym_name, $sym);
while (($c_sym_name, $sym) = each %Symbols) {
my $source = "__".$$sym{c_sym}.".s";
my $custom = File::Spec->join($dir, $source);
next unless -f $custom;
$$sym{is_custom} = $source;
if (!$$sym{is_private}) {
foreach my $subarch (@Architectures) {
(my $arch = $subarch) =~ s/arm(v.*)/arm/;
$arch =~ s/x86_64(.*)/x86_64/;
$arch =~ s/arm64(.*)/arm64/;
$$sym{aliases}{$arch} = [] unless $$sym{aliases}{$arch};
push(@{$$sym{aliases}{$arch}}, $$sym{asm_sym});
}
$$sym{asm_sym} = "__".$$sym{asm_sym};
$$sym{is_private} = 1;
}
}
}
sub readAliases {
my ($platformDir, $platformName) = @_;
my $genericMap = File::Spec->join($platformDir, "syscall.map");
my %sym_to_c;
foreach my $k (keys %Symbols) {
$sym_to_c{$Symbols{$k}{asm_sym}} = $k;
}
my @a = ();
for my $arch (@Architectures) {
(my $new_arch = $arch) =~ s/arm(v.*)/arm/g;
$new_arch =~ s/x86_64(.*)/x86_64/g;
$new_arch =~ s/arm64(.*)/arm64/g;
push(@a, $new_arch) unless grep { $_ eq $new_arch } @a;
}
foreach my $arch (@a) {
my $syscallFile = File::Spec->join($platformDir, $platformName, $arch, "syscall.map");
my @files = ();
push(@files, IO::File->new($syscallFile, 'r'));
die "$MyName: $syscallFile: $!\n" unless defined($files[$#files]);
push(@files, IO::File->new($genericMap, 'r'));
die "$MyName: $genericMap: $!\n" unless defined($files[$#files]);
foreach my $f (@files) {
while (<$f>) {
next if /^#/;
chomp;
my ($alias, $target_symbol) = split;
if (defined($target_symbol)) {
foreach my $sym (values %Symbols) {
# I've eliminated most of the ugly from this script except
# the need to try stripping underbars here.
if ($$sym{is_private}) {
next unless $$sym{asm_sym} eq $target_symbol;
} else {
(my $target = $target_symbol) =~ s/^__//;
next unless ($$sym{asm_sym} eq $target || $$sym{asm_sym} eq $target_symbol);
}
$$sym{aliases}{$arch} = [] unless $$sym{aliases}{$arch};
die "$MyName: $arch $$sym{asm_sym} -> $alias: Duplicate alias.\n" if grep { $_ eq $alias } @{$$sym{aliases}{$arch}};
push(@{$$sym{aliases}{$arch}}, $alias);
# last thing to do, if we aliased over a first class symbol, we need
# to mark it
my $c = $sym_to_c{$alias};
if ($Symbols{$c}) {
push(@{$Symbols{$c}{except}}, $arch);
}
}
}
}
}
}
}
##########################################################################
# Make a __xxx.s file: if it exists in the $CustomDir, just copy it, otherwise
# create one. We define the macro __SYSCALL_32BIT_ARG_BYTES so that SYS.h could
# use that to define __SYSCALL dependent on the arguments' total size.
##########################################################################
sub writeStubForSymbol {
my ($f, $symbol) = @_;
my @conditions;
my $has_arm64 = 0;
for my $subarch (@Architectures) {
(my $arch = $subarch) =~ s/arm(v.*)/arm/;
$arch =~ s/x86_64(.*)/x86_64/;
$arch =~ s/arm64(.*)/arm64/;
push(@conditions, "defined(__${arch}__)") unless grep { $_ eq $arch } @{$$symbol{except}};
if($arch eq "arm64") {
$has_arm64 = 1 unless grep { $_ eq $arch } @{$$symbol{except}};
}
}
my %is_cancel;
for (@Cancelable) { $is_cancel{$_} = 1 };
print $f "#define __SYSCALL_32BIT_ARG_BYTES $$symbol{bytes}\n";
print $f "#include \"SYS.h\"\n\n";
if ($$symbol{allow_missing}) {
printf $f "#ifdef SYS_%s\n", $$symbol{syscall};
}
if (scalar(@conditions)) {
printf $f "#ifndef SYS_%s\n", $$symbol{syscall};
printf $f "#error \"SYS_%s not defined. The header files libsyscall is building against do not match syscalls.master.\"\n", $$symbol{syscall};
printf $f "#endif\n\n";
}
my $nc = ($is_cancel{$$symbol{syscall}} ? "cerror" : "cerror_nocancel");
if($has_arm64) {
printf $f "#if defined(__arm64__)\n";
printf $f "MI_ENTRY_POINT(%s)\n", $$symbol{asm_sym};
if(keys %{$$symbol{mismatch_args}}) {
while(my($argnum, $extend) = each %{$$symbol{mismatch_args}}) {
printf $f "%s(%d)\n", $extend, $argnum;
}
}
printf $f "SYSCALL_NONAME(%s, %d, %s)\n", $$symbol{syscall}, $$symbol{nargs}, $nc;
printf $f "ret\n";
printf $f "#else\n";
}
if (scalar(@conditions)) {
printf $f "#if " . join(" || ", @conditions) . "\n";
printf $f "__SYSCALL2(%s, %s, %d, %s)\n", $$symbol{asm_sym}, $$symbol{syscall}, $$symbol{nargs}, $nc;
if (!$$symbol{is_private} && (scalar(@conditions) < scalar(@Architectures))) {
printf $f "#else\n";
printf $f "__SYSCALL2(%s, %s, %d, %s)\n", "__".$$symbol{asm_sym}, $$symbol{syscall}, $$symbol{nargs}, $nc;
}
printf $f "#endif\n\n";
} else {
# actually this isnt an inconsistency. kernel can expose what it wants but if all our arches
# override it we need to honour that.
}
if ($$symbol{allow_missing}) {
printf $f "#endif\n";
}
if($has_arm64) {
printf $f "#endif\n\n";
}
}
sub writeAliasesForSymbol {
my ($f, $symbol) = @_;
if ($$symbol{allow_missing}) {
printf $f "#ifdef SYS_%s\n", $$symbol{syscall};
}
foreach my $subarch (@Architectures) {
(my $arch = $subarch) =~ s/arm(v.*)/arm/;
$arch =~ s/x86_64(.*)/x86_64/;
$arch =~ s/arm64(.*)/arm64/;
next unless scalar($$symbol{aliases}{$arch});
printf $f "#if defined(__${arch}__)\n";
foreach my $alias_sym (@{$$symbol{aliases}{$arch}}) {
my $sym = (grep { $_ eq $arch } @{$$symbol{except}}) ? "__".$$symbol{asm_sym} : $$symbol{asm_sym};
printf $f "\t.globl\t$alias_sym\n";
printf $f "\t.set\t$alias_sym, $sym\n";
}
printf $f "#endif\n\n";
}
if ($$symbol{allow_missing}) {
printf $f "#endif\n";
}
}
usage() unless scalar(@ARGV) == 5;
$CustomDir = $ARGV[1];
die "$MyName: $CustomDir: No such directory\n" unless -d $CustomDir;
$PlatformsDir = $ARGV[2];
die "$MyName: $PlatformsDir: No such directory\n" unless -d $PlatformsDir;
$PlatformName = $ARGV[3];
die "$MyName: $PlatformsDir/$PlatformName: No such directory\n" unless -d "$PlatformsDir/$PlatformName";
$OutDir = $ARGV[4];
die "$MyName: $OutDir: No such directory\n" unless -d $OutDir;
readMaster($ARGV[0]);
checkForCustomStubs($CustomDir);
readAliases($PlatformsDir, $PlatformName);
##########################################################################
# copy the files specified in @Copy from the $CustomDir to $OutDir
##########################################################################
for(@Copy) {
my $custom = File::Spec->join($CustomDir, $_);
my $path = File::Spec->join($OutDir, $_);
print "Copy $custom -> $path\n";
File::Copy::copy($custom, $path) || die "$MyName: copy($custom, $path): $!\n";
}
##########################################################################
# make all the *.s files
##########################################################################
my @src;
my($k, $sym);
while (($k, $sym) = each %Symbols)
{
my $srcname = $$sym{asm_sym} . ".s";
my $outpath = File::Spec->join($OutDir, $srcname);
if ($$sym{is_custom}) {
my $custom = File::Spec->join($CustomDir, $$sym{is_custom});
File::Copy::copy($custom, $outpath);
print "Copied $outpath\n";
print "Writing aliases for $srcname\n";
my $f = IO::File->new($outpath, 'a');
die "$MyName: $outpath: $!\n" unless defined($f);
writeAliasesForSymbol($f, $sym);
undef $f;
} else {
my $f = IO::File->new($outpath, 'w');
die "$MyName: $outpath: $!\n" unless defined($f);
printf "Creating $outpath\n";
writeStubForSymbol($f, $sym);
writeAliasesForSymbol($f, $sym);
undef $f;
}
push(@src, $srcname);
}
##########################################################################
# create the Makefile.inc file from the list for files in @src and @CustomSrc
##########################################################################
my $path = File::Spec->join($OutDir, 'stubs.list');
my $f = IO::File->new($path, 'w');
my @sources = sort(@src, @CustomSrc);
for my $s (@sources) {
printf $f File::Spec->join($OutDir, $s) . "\n";
}
undef $f;
undef $path;