1
0
forked from pool/kernel-source
kernel-source/symsets.pl

537 lines
15 KiB
Perl

#!/usr/bin/env perl
=head1 NAME
symsets.pl - tool to generate symsets for the kernel packages
=head1 SYNOPSIS
symsets.pl --list-exported-symbols modules...
symsets.pl --generate-symsets [--reference=DIR] --output-dir=DIR modules...
symsets.pl --list-symsets [--reference=DIR] modules...
symsets.pl --check-kabi --reference=DIR modules...
=head1 OPTIONS
=head3 MODE OPTIONS
One of the following options has to be selected:
=over
=item B<--list-exported-symbols>
List symbols exported by modules in a Module.symvers style format.
=item B<--generate-symsets>
Group exported symbols into symsets. Symbols from modules from the same
directory end up in one symset. This option requires B<--output-dir>.
=item B<--list-symsets>
Like B<--generate-symsets>, but only print the symset names on stdout.
=item B<--check-kabi>
Check for kabi changes. This requires B<--reference>.
=back
=head3 OTHER OPTIONS
=over
=item B<-v, --verbose>
Increase verbosity.
=item B<--symvers-file=Module.symvers>
Load built-in symbols from Module.symvers. Only symbols provided by the main
kernel image (marked as vmlinux or built-in) are read from this file.
=item B<--modules=FILE>
Read list of modules from FILE instead of command line. This option can be used
multiple times to read modules from multiple files.
=item B<--required-modules=FILE>
List of modules that are installed by packages required by this package. If
a module moves from subpackage A to subpackage B, this can result in a changed
symset checksum in A. Together with B<--reference>, this option ensures that
the old checksum is provided in the subpackage that installs or requires
all modules from the symset.
=item B<--reference=DIR>
Load symsets of a previous kernel package from DIR and add them to the output
if the symbols are still provided by this kernel package.
=item B<--output-dir=DIR>
Write symsets into DIR (B<--generate-symsets> only).
=item B<--max-badness=NUM>
Set maximum allowed badness to NUM. Meaningful values are 4, 6, 8, 15 or 31
(B<--check-kabi> only).
=item B<--commonsyms=FILE>
Read common symbols from FILE. Badness for changes to common symbols is
incremented by 8 (the resulting badness is 16 by default). (B<--check-kabi>
only).
=item B<--usedsyms=FILE>
Read used symbols from FILE. Badness for changes to used symbols is incremented
by 16 (the resulting badness is 24 by default). (B<--check-kabi> only).
=item B<--severities=FILE>
Read a table of kabi change severities from FILE. Each line consists of a
GLOB-SEVERITY pair separated by whitespace. Changes in modules matching GLOB
will have severity SEVERITY instead of the default 8. (B<--check-kabi> only).
=back
=cut
use strict;
use warnings;
#use diagnostics;
use Digest::MD5 qw(md5_hex);
use Getopt::Long;
eval { require Pod::Usage; };
if ($@) {
sub pod2usage {
my %opts = @_;
print STDERR
"Usage:
symsets.pl --list-exported-symbols ...
symsets.pl --generate-symsets [--reference=DIR] --output-dir=DIR ...
symsets.pl --list-symsets [--reference=DIR] ...
symsets.pl --check-kabi --reference=DIR ...
Install Pod::Usage for a better help message.
";
exit $opts{-exitval};
}
} else {
Pod::Usage->import('pod2usage');
}
our ($opt_verbose);
our $kabi_badness = 0;
our (%commonsyms, %usedsyms, @severities);
our ($opt_list_exp, $opt_gen_sets, $opt_list_sets, $opt_check_kabi) = (0,0,0,0);
our ($opt_max_badness, $opt_commonsyms, $opt_usedsyms, $opt_severities);
our ($opt_symvers_file, $opt_reference);
our ($opt_output_dir);
sub main {
my (@modules, @pulled_modules);
my $res = GetOptions(
'verbose|v' => \$opt_verbose,
'list-exported-symbols' => \$opt_list_exp,
'generate-symsets' => \$opt_gen_sets,
'list-symsets' => \$opt_list_sets,
'check-kabi' => \$opt_check_kabi,
'max-badness=i' => \$opt_max_badness,
'commonsyms|common-syms=s' => \$opt_commonsyms,
'usedsyms|used-syms=s' => \$opt_usedsyms,
'severities=s' => \$opt_severities,
'symvers-file=s' => \$opt_symvers_file,
'modules=s' => sub { push(@modules, load_list($_[1])); },
'required-modules=s' => sub { push(@pulled_modules, load_list($_[1])); },
'reference=s' => \$opt_reference,
'output-dir=s' => \$opt_output_dir,
'usage' => sub { pod2usage(-exitval => 0, -verbose => 0); },
'help' => sub { pod2usage(-exitval => 0, -verbose => 1); },
);
# boring option checking
my $opt_err = sub {
print STDERR "ERROR: @_\n";
$res = 0;
};
&$opt_err("Please choose one of --list-exported-symbols, --generate-symsets, --list-symsets or --check-kabi")
if ($opt_list_exp + $opt_gen_sets + $opt_list_sets > 1 ||
!($opt_list_exp + $opt_gen_sets + $opt_list_sets + $opt_check_kabi));
&$opt_err("--check-kabi doesn't work with --list-exported-symbols")
if ($opt_list_exp && $opt_check_kabi);
&$opt_err("--check-kabi requires --reference")
if ($opt_check_kabi && !$opt_reference);
&$opt_err("--output-dir only makes sense with --generate-symsets")
if ($opt_output_dir && !$opt_gen_sets);
&$opt_err("--generate-symsets requires --output-dir")
if ($opt_gen_sets && !$opt_output_dir);
if (!$opt_check_kabi) {
for my $opt qw(max-badness commonsyms usedsyms severities) {
no strict 'refs';
my $var = "opt_$opt";
$var =~ s/-/_/g;
if (defined(${$var})) {
&$opt_err("--$opt only makes sense with --check-kabi");
}
}
}
# get list of modules
if (@modules == 0) {
@modules = @ARGV;
}
if (@modules == 0 && !defined($opt_symvers_file)) {
&$opt_err("No modules supplied");
}
if (!$res) {
pod2usage(-exitval => 1, -verbose => 0, -output => ">&2");
}
# get list of exports
my (@exports, @pulled_exports);
for my $file (@modules) {
push(@exports, module_exports($file));
}
if (defined($opt_symvers_file)) {
push(@exports, builtin_exports(parse_symset($opt_symvers_file)));
}
if ($opt_list_exp) {
print format_exports(@exports);
exit 0;
}
for my $file (@pulled_modules) {
push(@pulled_exports, module_exports($file));
}
# generate symsets and optionally check kabi
my (@ref, @sets);
@sets = split_into_symsets(@exports);
if (defined($opt_reference)) {
@ref = load_symsets($opt_reference);
if ($opt_check_kabi) {
load_kabi_files($opt_commonsyms, $opt_usedsyms, $opt_severities);
}
# records kabi breakage if $opt_check_kabi is set
preserve_symsets(\@sets, \@ref, \@pulled_exports);
}
if ($opt_gen_sets) {
write_symsets($opt_output_dir, @sets);
} elsif ($opt_list_sets) {
write_symsets(undef, @sets);
}
if ($kabi_badness) {
print STDERR "KABI: badness is $kabi_badness";
if (!defined($opt_max_badness) || $kabi_badness <= $opt_max_badness) {
print STDERR " (tolerated)\n";
} else {
print STDERR " (exceeds threshold $opt_max_badness), aborting\n";
exit 1;
}
}
exit 0;
}
# structures used:
# %export:
# (crc => $crc, sym => $sym, mod => $module, type => $type)
# @exportlist
# ({crc => $crc, sym => $sym, mod => $module, type => $type}, ...)
# @symset:
# ($name, [{crc => $crc, sym => $sym, mod => $module, type => $type}, ...])
# @symsetlist:
# (
# [$name, [{crc => $crc, sym => $sym, mod => $module, type => $type}, ...],
# ...
# )
#
# parse a Modules.symvers-style file
# returns an exportlist
sub parse_symset {
my ($file) = @_;
my @res;
open(my $fh, '<', $file) or die "Error opening $file: $!\n";
while (<$fh>) {
my @l = split(/\s+/);
if (@l < 4) {
print STDERR "$file:$.: unknown line\n";
next;
}
$l[0] =~ s/^0x//;
push(@res, {crc => $l[0], sym => $l[1], mod => $l[2], type => $l[3]});
}
close($fh);
return @res;
}
# greps an exportlist for built-in symbols
sub builtin_exports {
return grep { $_->{mod} =~ /(^vmlinux$)|(\/built-in$)/ } @_;
}
my %export_types = (
__ksymtab => "EXPORT_SYMBOL",
__ksymtab_unused => "EXPORT_UNUSED_SYMBOL",
__ksymtab_gpl => "EXPORT_SYMBOL_GPL",
__ksymtab_unused_gpl => "EXPORT_UNUSED_SYMBOL_GPL",
__ksymtab_gpl_future => "EXPORT_SYMBOL_GPL_FUTURE"
);
# returns an exportlist for a given module
sub module_exports {
my ($file) = @_;
my (%crcs, %types, @res);
my $mod = $file;
$mod =~ s/.*\/lib\/modules\/[^\/]*\/kernel\///;
$mod =~ s/\.(k?o|a)$//;
open(my $pipe, '-|', 'objdump', '-t', $file) or die "objdump -t $file: $!\n";
while (<$pipe>) {
my $l = $_;
my @l = split(/\s+/);
next if (@l < 3);
next if ($l =~ /^[^ ]* .....d/); # debug symbol
my $sym = $l[$#l];
my $sec = $l[$#l - 2];
if ($sym =~ /^__crc_(.*)/) {
$crcs{$1} = $l[0];
$crcs{$1} =~ s/^0{8}//;
} elsif ($sym =~ /^__ksymtab_(.*)/ && exists($export_types{$sec})) {
$types{$1} = $export_types{$sec};
}
}
close($pipe);
if ($? != 0) {
die "objdump returned an error\n";
}
for my $sym (keys(%types)) {
push(@res, {sym => $sym, crc => $crcs{$sym} || "0"x8, mod => $mod,
type => $types{$sym}});
}
return @res;
}
# format an exportlist for output
sub format_exports {
my $res = "";
for my $exp (sort { $a->{sym} cmp $b->{sym} } @_) {
$res .= "0x$exp->{crc}\t$exp->{sym}\t$exp->{mod}\t$exp->{type}\n";
}
return $res;
}
# splits exports by directories, returns a symsetlist
sub split_into_symsets {
my %sets;
for my $exp (@_) {
my $set = $exp->{mod};
$set =~ s/\/[^\/]+$//;
$set =~ s/\//_/g;
$sets{$set} ||= [];
push(@{$sets{$set}}, $exp);
}
return map { [$_, $sets{$_}] } keys(%sets)
}
# loads symsets from a directory created by write_symsets
# returns symsetlist
# FIXME: multiple versions of a symset
sub load_symsets {
my ($dir) = @_;
my @sets;
opendir(my $dh, $dir) or die "Error reading directory $dir: $!\n";
for my $file (readdir($dh)) {
next if $file =~ /^\.\.?$/;
if (!-f "$dir/$file" || $file !~ /^([\w-]+)\.[0-9a-f]{16}$/) {
print STDERR "Ignoring unknown file $dir/$file\n";
next;
}
my $set = $1;
push(@sets, [$set, [parse_symset("$dir/$file")]]);
}
closedir($dh);
return @sets;
}
sub hash {
return substr(md5_hex(@_), 0, 16);
}
# writes symsets as returned by split_into_symsets/load_symsets into $dir
sub write_symsets {
my $dir = shift;
my @sets = @_;
my $print_only = (!defined($dir));
for my $set (@sets) {
my $name = $set->[0];
my $exports = $set->[1];
my $data = format_exports(@$exports);
my $hash = hash($data);
if ($print_only) {
print "$name.$hash\n";
} else {
my $f = "$dir/$name.$hash";
open(my $fh, '>', $f) or die "error creating $f: $!\n";
print $fh $data;
close($fh);
}
}
}
# loads kabi check configurations into %commonsyms, %usedsyms and %severities
sub load_kabi_files {
my ($csfile, $usfile, $sevfile) = @_;
if (defined($csfile)) {
open(my $fh, '<', $csfile) or die "Can't open $csfile: $!\n";
%commonsyms = map { s/\s+//g; ; $_ => 1 } <$fh>;
close($fh);
}
if (defined($usfile)) {
open(my $fh, '<', $usfile) or die "Can't open $usfile: $!\n";
%usedsyms = map { s/\s+//g; $_ => 1 } <$fh>;
close($fh);
}
if (defined($sevfile)) {
open(my $fh, '<', $sevfile) or die "Can't open $sevfile: $!\n";
while (<$fh>) {
chomp;
s/#.*//;
next if /^\s*$/;
my @f = split(/\s+/);
if (@f != 2) {
print STDERR "$sevfile:$.: unknown line\n";
next;
}
if ($f[1] !~ /^\d+$/) {
print STDERR "$sevfile:$.: invalid severity $f[1]\n";
next;
}
# simple glob -> regexp conversion
$f[0] =~ s/\*/.*/g;
$f[0] =~ s/\?/./g;
$f[0] =~ s/.*/^$&\$/;
push(@severities, [@f]);
}
close($fh);
}
}
# loads a list of filenames from file
sub load_list {
my ($file) = @_;
my ($fh, @res);
if ($file eq '-') {
open($fh, '<&STDIN');
} else {
open($fh, '<', $file) or die "Error opening $file: $!\n";
}
@res = <$fh>;
chomp(@res);
close($fh);
return @res;
}
# record kabi changes
sub kabi_change {
my $exp = shift;
my $sev;
return if !$opt_check_kabi;
$sev = 8;
for my $rule (@severities) {
if ($exp->{mod} =~ $rule->[0]) {
$sev = $rule->[1];
last;
}
}
if (exists($usedsyms{$exp->{sym}})) {
$sev += 16;
} elsif (exists($commonsyms{$exp->{sym}})) {
$sev += 8;
}
print STDERR "KABI: symbol $exp->{sym}.$exp->{crc} (badness $sev): @_\n";
$kabi_badness = $sev if ($sev > $kabi_badness);
}
# check if all symbols from $old symsetlist are provided by $new symsetlist,
# add compatible symsets to $new
# $pulled_exports is a exportlist of modules, that are pulled as dependencies
# of this package (thus also "provided" by this package).
sub preserve_symsets {
my ($new, $old, $pulled_exports) = @_;
my (%symcrcs, %pulled_symcrcs, %symsethashes);
for my $set (@$new) {
my $name = $set->[0];
my $exports = $set->[1];
$symsethashes{$name} = hash(format_exports(@$exports));
for my $exp (@$exports) {
$symcrcs{$exp->{sym}} = $exp->{crc};
}
}
for my $exp (@$pulled_exports) {
$pulled_symcrcs{$exp->{sym}} = $exp->{crc};
}
for my $set (@$old) {
my $name = $set->[0];
my $exports = $set->[1];
my $hash = hash(format_exports(@$exports));
if (exists($symsethashes{$name}) && $symsethashes{$name} eq $hash) {
next;
}
my $compatible = 1;
my $oursyms = 0;
for my $exp (@$exports) {
my $crc;
if (exists($symcrcs{$exp->{sym}})) {
$oursyms++;
$crc = $symcrcs{$exp->{sym}};
} elsif (exists($pulled_symcrcs{$exp->{sym}})) {
$crc = $pulled_symcrcs{$exp->{sym}};
} else {
kabi_change($exp, "missing");
$compatible = 0;
next;
}
if ($crc ne $exp->{crc}) {
kabi_change($exp, "crc changed to $crc\n");
$compatible = 0;
}
}
if ($compatible) {
if ($oursyms == 0) {
# this symset is fully provided by a package we require,
# so do not duplicate it in our symsets
next;
}
print STDERR "KABI: symset $name.$hash preserved\n"
if $opt_verbose && $opt_check_kabi;
push(@$new, $set);
} else {
print STDERR "KABI: symset $name.$hash NOT preserved\n"
if $opt_check_kabi;
}
}
}
main();
# vim: sw=4:et:sts=4