#!/usr/bin/perl -w
# SPDX-License-Identifier: GPL-2.0-only
#
# Copyright 2015 - Steven Rostedt, Red Hat Inc.
# Copyright 2017 - Steven Rostedt, VMware, Inc.
#
# usage:
# config-bisect.pl [options] good-config bad-config [good|bad]
#
# Compares a good config to a bad config, then takes half of the diffs
# and produces a config that is somewhere between the good config and
# the bad config. That is, the resulting config will start with the
# good config and will try to make half of the differences of between
# the good and bad configs match the bad config. It tries because of
# dependencies between the two configs it may not be able to change
# exactly half of the configs that are different between the two config
# files.
# Here's a normal way to use it:
#
# $ cd /path/to/linux/kernel
# $ config-bisect.pl /path/to/good/config /path/to/bad/config
# This will now pull in good config (blowing away .config in that directory
# so do not make that be one of the good or bad configs), and then
# build the config with "make oldconfig" to make sure it matches the
# current kernel. It will then store the configs in that result for
# the good config. It does the same for the bad config as well.
# The algorithm will run, merging half of the differences between
# the two configs and building them with "make oldconfig" to make sure
# the result changes (dependencies may reset changes the tool had made).
# It then copies the result of its good config to /path/to/good/config.tmp
# and the bad config to /path/to/bad/config.tmp (just appends ".tmp" to the
# files passed in). And the ".config" that you should test will be in
# directory
# After the first run, determine if the result is good or bad then
# run the same command appending the result
# For good results:
# $ config-bisect.pl /path/to/good/config /path/to/bad/config good
# For bad results:
# $ config-bisect.pl /path/to/good/config /path/to/bad/config bad
# Do not change the good-config or bad-config, config-bisect.pl will
# copy the good-config to a temp file with the same name as good-config
# but with a ".tmp" after it. It will do the same with the bad-config.
# If "good" or "bad" is not stated at the end, it will copy the good and
# bad configs to the .tmp versions. If a .tmp version already exists, it will
# warn before writing over them (-r will not warn, and just write over them).
# If the last config is labeled "good", then it will copy it to the good .tmp
# version. If the last config is labeled "bad", it will copy it to the bad
# .tmp version. It will continue this until it can not merge the two any more
# without the result being equal to either the good or bad .tmp configs.
my $start = 0;
my $val = "";
my $pwd = `pwd`;
chomp $pwd;
my $tree = $pwd;
my $build;
my $output_config;
my $reset_bisect;
sub usage {
print << "EOF"
usage: config-bisect.pl [-l linux-tree][-b build-dir] good-config bad-config [good|bad]
-l [optional] define location of linux-tree (default is current directory)
-b [optional] define location to build (O=build-dir) (default is linux-tree)
good-config the config that is considered good
bad-config the config that does not work
"good" add this if the last run produced a good config
"bad" add this if the last run produced a bad config
If "good" or "bad" is not specified, then it is the start of a new bisect
Note, each run will create copy of good and bad configs with ".tmp" appended.
EOF
;
exit(-1);
}
sub doprint {
print @_;
}
sub dodie {
doprint "CRITICAL FAILURE... ", @_, "\n";
die @_, "\n";
}
sub expand_path {
my ($file) = @_;
if ($file =~ m,^/,) {
return $file;
}
return "$pwd/$file";
}
sub read_prompt {
my ($cancel, $prompt) = @_;
my $ans;
for (;;) {
if ($cancel) {
print "$prompt [y/n/C] ";
} else {
print "$prompt [y/N] ";
}
$ans = <STDIN>;
chomp $ans;
if ($ans =~ /^\s*$/) {
if ($cancel) {
$ans = "c";
} else {
$ans = "n";
}
}
last if ($ans =~ /^y$/i || $ans =~ /^n$/i);
if ($cancel) {
last if ($ans =~ /^c$/i);
print "Please answer either 'y', 'n' or 'c'.\n";
} else {
print "Please answer either 'y' or 'n'.\n";
}
}
if ($ans =~ /^c/i) {
exit;
}
if ($ans !~ /^y$/i) {
return 0;
}
return 1;
}
sub read_yn {
my ($prompt) = @_;
return read_prompt 0, $prompt;
}
sub read_ync {
my ($prompt) = @_;
return read_prompt 1, $prompt;
}
sub run_command {
my ($command, $redirect) = @_;
my $start_time;
my $end_time;
my $dord = 0;
my $pid;
$start_time = time;
doprint("$command ... ");
$pid = open(CMD, "$command 2>&1 |") or
dodie "unable to exec $command";
if (defined($redirect)) {
open (RD, ">$redirect") or
dodie "failed to write to redirect $redirect";
$dord = 1;
}
while (<CMD>) {
print RD if ($dord);
}
waitpid($pid, 0);
my $failed = $?;
close(CMD);
close(RD) if ($dord);
$end_time = time;
my $delta = $end_time - $start_time;
if ($delta == 1) {
doprint "[1 second] ";
} else {
doprint "[$delta seconds] ";
}
if ($failed) {
doprint "FAILED!\n";
} else {
doprint "SUCCESS\n";
}
return !$failed;
}
###### CONFIG BISECT ######
# config_ignore holds the configs that were set (or unset) for
# a good config and we will ignore these configs for the rest
# of a config bisect. These configs stay as they were.
my %config_ignore;
# config_set holds what all configs were set as.
my %config_set;
# config_off holds the set of configs that the bad config had disabled.
# We need to record them and set them in the .config when running
# olddefconfig, because olddefconfig keeps the defaults.
my %config_off;
# config_off_tmp holds a set of configs to turn off for now
my @config_off_tmp;
# config_list is the set of configs that are being tested
my %config_list;
my %null_config;
my %dependency;
my $make;
sub make_oldconfig {
if (!run_command "$make olddefconfig") {
# Perhaps olddefconfig doesn't exist in this version of the kernel
# try oldnoconfig
doprint "olddefconfig failed, trying make oldnoconfig\n";
if (!run_command "$make oldnoconfig") {
doprint "oldnoconfig failed, trying yes '' | make oldconfig\n";
# try a yes '' | oldconfig
run_command "yes '' | $make oldconfig" or
dodie "failed make config oldconfig";
}
}
}
sub assign_configs {
my ($hash, $config) = @_;
doprint "Reading configs from $config\n";
open (IN, $config)
or dodie "Failed to read $config";
while (<IN>) {
chomp;
if (/^((CONFIG\S*)=.*)/) {
${$hash}{$2} = $1;
} elsif (/^(# (CONFIG\S*) is not set)/) {
${$hash}{$2} = $1;
}
}
close(IN);
}
sub process_config_ignore {
my ($config) = @_;
assign_configs \%config_ignore, $config;
}
sub get_dependencies {
my ($config) = @_;
my $arr = $dependency{$config};
if (!defined($arr)) {
return ();
}
my @deps = @{$arr};
foreach my $dep (@{$arr}) {
print "ADD DEP $dep\n";
@deps = (@deps, get_dependencies $dep);
}
return @deps;
}
sub save_config {
my ($pc, $file) = @_;
my %configs = %{$pc};
doprint "Saving configs into $file\n";
open(OUT, ">$file") or dodie "Can not write to $file";
foreach my $config (keys %configs) {
print OUT "$configs{$config}\n";
}
close(OUT);
}
sub create_config {
my ($name, $pc) = @_;
doprint "Creating old config from $name configs\n";
save_config $pc, $output_config;
make_oldconfig;
}
# compare two config hashes, and return configs with different vals.
# It returns B's config values, but you can use A to see what A was.
sub diff_config_vals {
my ($pa, $pb) = @_;
# crappy Perl way to pass in hashes.
my %a = %{$pa};
my %b = %{$pb};
my %ret;
foreach my $item (keys %a) {
if (defined($b{$item}) && $b{$item} ne $a{$item}) {
$ret{$item} = $b{$item};
}
}
return %ret;
}
# compare two config hashes and return the configs in B but not A
sub diff_configs {
my ($pa, $pb) = @_;
my %ret;
# crappy Perl way to pass in hashes.
my %a = %{$pa};
my %b = %{$pb};
foreach my $item (keys %b) {
if (!defined($a{$item})) {
$ret{$item} = $b{$item};
}
}
return %ret;
}
# return if two configs are equal or not
# 0 is equal +1 b has something a does not
# +1 if a and b have a different item.
# -1 if a has something b does not
sub compare_configs {
my ($pa, $pb) = @_;
my %ret;
# crappy Perl way to pass in hashes.
my %a = %{$pa};
my %b = %{$pb};
foreach my $item (keys %b) {
if (!defined($a{$item})) {
return 1;
}
if ($a{$item} ne $b{$item}) {
return 1;
}
}
foreach my $item (keys %a) {
if (!defined($b{$item})) {
return -1;
}
}
return 0;
}
sub process_failed {
my ($config) = @_;
doprint "\n\n***************************************\n";
doprint "Found bad config: $config\n";
doprint "***************************************\n\n";
}
sub process_new_config {
my ($tc, $nc, $gc, $bc) = @_;
my %tmp_config = %{$tc};
my %good_configs = %{$gc};
my %bad_configs = %{$bc};
my %new_configs;
my $runtest = 1;
my $ret;
create_config "tmp_configs", \%tmp_config;
assign_configs \%new_configs, $output_config;
$ret = compare_configs \%new_configs, \%bad_configs;
if (!$ret) {
doprint "New config equals bad config, try next test\n";
$runtest = 0;
}
if ($runtest) {
$ret = compare_configs \%new_configs, \%good_configs;
if (!$ret) {
doprint "New config equals good config, try next test\n";
$runtest = 0;
}
}
%{$nc} = %new_configs;
return $runtest;
}
sub convert_config {
my ($config) = @_;
if ($config =~ /^# (.*) is not set/) {
$config = "$1=n";
}
$config =~ s/^CONFIG_//;
return $config;
}
sub print_config {
my ($sym, $config) = @_;
$config = convert_config $config;
doprint "$sym$config\n";
}
sub print_config_compare {
my ($good_config, $bad_config) = @_;
$good_config = convert_config $good_config;
$bad_config = convert_config $bad_config;
my $good_value = $good_config;
my $bad_value = $bad_config;
$good_value =~ s/(.*)=//;
my $config = $1;
$bad_value =~ s/.*=//;
doprint " $config $good_value -> $bad_value\n";
}
# Pass in:
# $phalf: half of the configs names you want to add
# $oconfigs: The orginial configs to start with
# $sconfigs: The source to update $oconfigs with (from $phalf)
# $which: The name of which half that is updating (top / bottom)
# $type: The name of the source type (good / bad)
sub make_half {
my ($phalf, $oconfigs, $sconfigs, $which, $type) = @_;
my @half = @{$phalf};
my %orig_configs = %{$oconfigs};
my %source_configs = %{$sconfigs};
my %tmp_config = %orig_configs;
doprint "Settings bisect with $which half of $type configs:\n";
foreach my $item (@half) {
doprint "Updating $item to $source_configs{$item}\n";
$tmp_config{$item} = $source_configs{$item};
}
return %tmp_config;
}
sub run_config_bisect {
my ($pgood, $pbad) = @_;
my %good_configs = %{$pgood};
my %bad_configs = %{$pbad};
my %diff_configs = diff_config_vals \%good_configs, \%bad_configs;
my %b_configs = diff_configs \%good_configs, \%bad_configs;
my %g_configs = diff_configs \%bad_configs, \%good_configs;
# diff_arr is what is in both good and bad but are different (y->n)
my @diff_arr = keys %diff_configs;
my $len_diff = $#diff_arr + 1;
# b_arr is what is in bad but not in good (has depends)
my @b_arr = keys %b_configs;
my $len_b = $#b_arr + 1;
# g_arr is what is in good but not in bad
my @g_arr = keys %g_configs;
my $len_g = $#g_arr + 1;
my $runtest = 0;
my %new_configs;
my $ret;
# Look at the configs that are different between good and bad.
# This does not include those that depend on other configs
# (configs depending on other configs that are not set would
# not show up even as a "# CONFIG_FOO is not set"
doprint "# of configs to check: $len_diff\n";
doprint "# of configs showing only in good: $len_g\n";
doprint "# of configs showing only in bad: $len_b\n";
if ($len_diff > 0) {
# Now test for different values
doprint "Configs left to check:\n";
doprint " Good Config\t\t\tBad Config\n";
doprint " -----------\t\t\t----------\n";
foreach my $item (@diff_arr) {
doprint " $good_configs{$item}\t$bad_configs{$item}\n";
}
my $half = int($#diff_arr / 2);
my @tophalf = @diff_arr[0 .. $half];
doprint "Set tmp config to be good config with some bad config values\n";
my %tmp_config = make_half \@tophalf, \%good_configs,
\%bad_configs, "top", "bad";
$runtest = process_new_config \%tmp_config, \%new_configs,
\%good_configs, \%bad_configs;
if (!$runtest) {
doprint "Set tmp config to be bad config with some good config values\n";
my %tmp_config = make_half \@tophalf, \%bad_configs,
\%good_configs, "top", "good";
$runtest = process_new_config \%tmp_config, \%new_configs,
\%good_configs, \%bad_configs;
}
}
if (!$runtest && $len_diff > 0) {
# do the same thing, but this time with bottom half
my $half = int($#diff_arr / 2);
my @bottomhalf = @diff_arr[$half+1 .. $#diff_arr];
doprint "Set tmp config to be good config with some bad config values\n";
my %tmp_config = make_half \@bottomhalf, \%good_configs,
\%bad_configs, "bottom", "bad";
$runtest = process_new_config \%tmp_config, \%new_configs,
\%good_configs, \%bad_configs;
if (!$runtest) {
doprint "Set tmp config to be bad config with some good config values\n";
my %tmp_config = make_half \@bottomhalf, \%bad_configs,
\%good_configs, "bottom", "good";
$runtest = process_new_config \%tmp_config, \%new_configs,
\%good_configs, \%bad_configs;
}
}
if ($runtest) {
make_oldconfig;
doprint "READY TO TEST .config IN $build\n";
return 0;
}
doprint "\n%%%%%%%% FAILED TO FIND SINGLE BAD CONFIG %%%%%%%%\n";
doprint "Hmm, can't make any more changes without making good == bad?\n";
doprint "Difference between good (+) and bad (-)\n";
foreach my $item (keys %bad_configs) {
if (!defined($good_configs{$item})) {
print_config "-", $bad_configs{$item};
}
}
foreach my $item (keys %good_configs) {
next if (!defined($bad_configs{$item}));
if ($good_configs{$item} ne $bad_configs{$item}) {
print_config_compare $good_configs{$item}, $bad_configs{$item};
}
}
foreach my $item (keys %good_configs) {
if (!defined($bad_configs{$item})) {
print_config "+", $good_configs{$item};
}
}
return -1;
}
sub config_bisect {
my ($good_config, $bad_config) = @_;
my $ret;
my %good_configs;
my %bad_configs;
my %tmp_configs;
doprint "Run good configs through make oldconfig\n";
assign_configs \%tmp_configs, $good_config;
create_config "$good_config", \%tmp_configs;
assign_configs \%good_configs, $output_config;
doprint "Run bad configs through make oldconfig\n";
assign_configs \%tmp_configs, $bad_config;
create_config "$bad_config", \%tmp_configs;
assign_configs \%bad_configs, $output_config;
save_config \%good_configs, $good_config;
save_config \%bad_configs, $bad_config;
return run_config_bisect \%good_configs, \%bad_configs;
}
while ($#ARGV >= 0) {
if ($ARGV[0] !~ m/^-/) {
last;
}
my $opt = shift @ARGV;
if ($opt eq "-b") {
$val = shift @ARGV;
if (!defined($val)) {
die "-b requires value\n";
}
$build = $val;
}
elsif ($opt eq "-l") {
$val = shift @ARGV;
if (!defined($val)) {
die "-l requires value\n";
}
$tree = $val;
}
elsif ($opt eq "-r") {
$reset_bisect = 1;
}
elsif ($opt eq "-h") {
usage;
}
else {
die "Unknown option $opt\n";
}
}
$build = $tree if (!defined($build));
$tree = expand_path $tree;
$build = expand_path $build;
if ( ! -d $tree ) {
die "$tree not a directory\n";
}
if ( ! -d $build ) {
die "$build not a directory\n";
}
usage if $#ARGV < 1;
if ($#ARGV == 1) {
$start = 1;
} elsif ($#ARGV == 2) {
$val = $ARGV[2];
if ($val ne "good" && $val ne "bad") {
die "Unknown command '$val', bust be either \"good\" or \"bad\"\n";
}
} else {
usage;
}
my $good_start = expand_path $ARGV[0];
my $bad_start = expand_path $ARGV[1];
my $good = "$good_start.tmp";
my $bad = "$bad_start.tmp";
$make = "make";
if ($build ne $tree) {
$make = "make O=$build"
}
$output_config = "$build/.config";
if ($start) {
if ( ! -f $good_start ) {
die "$good_start not found\n";
}
if ( ! -f $bad_start ) {
die "$bad_start not found\n";
}
if ( -f $good || -f $bad ) {
my $p = "";
if ( -f $good ) {
$p = "$good exists\n";
}
if ( -f $bad ) {
$p = "$p$bad exists\n";
}
if (!defined($reset_bisect)) {
if (!read_yn "${p}Overwrite and start new bisect anyway?") {
exit (-1);
}
}
}
run_command "cp $good_start $good" or die "failed to copy to $good\n";
run_command "cp $bad_start $bad" or die "failed to copy to $bad\n";
} else {
if ( ! -f $good ) {
die "Can not find file $good\n";
}
if ( ! -f $bad ) {
die "Can not find file $bad\n";
}
if ($val eq "good") {
run_command "cp $output_config $good" or die "failed to copy $config to $good\n";
} elsif ($val eq "bad") {
run_command "cp $output_config $bad" or die "failed to copy $config to $bad\n";
}
}
chdir $tree || die "can't change directory to $tree";
my $ret = config_bisect $good, $bad;
if (!$ret) {
exit(0);
}
if ($ret > 0) {
doprint "Cleaning temp files\n";
run_command "rm $good";
run_command "rm $bad";
exit(1);
} else {
doprint "See good and bad configs for details:\n";
doprint "good: $good\n";
doprint "bad: $bad\n";
doprint "%%%%%%%% FAILED TO FIND SINGLE BAD CONFIG %%%%%%%%\n";
}
exit(2);
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