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1#!/usr/bin/perl -w2# SPDX-License-Identifier: GPL-2.0-only3#4# Copyright 2015 - Steven Rostedt, Red Hat Inc.5# Copyright 2017 - Steven Rostedt, VMware, Inc.6#7 8# usage:9# config-bisect.pl [options] good-config bad-config [good|bad]10#11 12# Compares a good config to a bad config, then takes half of the diffs13# and produces a config that is somewhere between the good config and14# the bad config. That is, the resulting config will start with the15# good config and will try to make half of the differences of between16# the good and bad configs match the bad config. It tries because of17# dependencies between the two configs it may not be able to change18# exactly half of the configs that are different between the two config19# files.20 21# Here's a normal way to use it:22#23# $ cd /path/to/linux/kernel24# $ config-bisect.pl /path/to/good/config /path/to/bad/config25 26# This will now pull in good config (blowing away .config in that directory27# so do not make that be one of the good or bad configs), and then28# build the config with "make oldconfig" to make sure it matches the29# current kernel. It will then store the configs in that result for30# the good config. It does the same for the bad config as well.31# The algorithm will run, merging half of the differences between32# the two configs and building them with "make oldconfig" to make sure33# the result changes (dependencies may reset changes the tool had made).34# It then copies the result of its good config to /path/to/good/config.tmp35# and the bad config to /path/to/bad/config.tmp (just appends ".tmp" to the36# files passed in). And the ".config" that you should test will be in37# directory38 39# After the first run, determine if the result is good or bad then40# run the same command appending the result41 42# For good results:43# $ config-bisect.pl /path/to/good/config /path/to/bad/config good44 45# For bad results:46# $ config-bisect.pl /path/to/good/config /path/to/bad/config bad47 48# Do not change the good-config or bad-config, config-bisect.pl will49# copy the good-config to a temp file with the same name as good-config50# but with a ".tmp" after it. It will do the same with the bad-config.51 52# If "good" or "bad" is not stated at the end, it will copy the good and53# bad configs to the .tmp versions. If a .tmp version already exists, it will54# warn before writing over them (-r will not warn, and just write over them).55# If the last config is labeled "good", then it will copy it to the good .tmp56# version. If the last config is labeled "bad", it will copy it to the bad57# .tmp version. It will continue this until it can not merge the two any more58# without the result being equal to either the good or bad .tmp configs.59 60my $start = 0;61my $val = "";62 63my $pwd = `pwd`;64chomp $pwd;65my $tree = $pwd;66my $build;67 68my $output_config;69my $reset_bisect;70 71sub usage {72 print << "EOF"73 74usage: config-bisect.pl [-l linux-tree][-b build-dir] good-config bad-config [good|bad]75 -l [optional] define location of linux-tree (default is current directory)76 -b [optional] define location to build (O=build-dir) (default is linux-tree)77 good-config the config that is considered good78 bad-config the config that does not work79 "good" add this if the last run produced a good config80 "bad" add this if the last run produced a bad config81 If "good" or "bad" is not specified, then it is the start of a new bisect82 83 Note, each run will create copy of good and bad configs with ".tmp" appended.84 85EOF86;87 88 exit(-1);89}90 91sub doprint {92 print @_;93}94 95sub dodie {96 doprint "CRITICAL FAILURE... ", @_, "\n";97 98 die @_, "\n";99}100 101sub expand_path {102 my ($file) = @_;103 104 if ($file =~ m,^/,) {105 return $file;106 }107 return "$pwd/$file";108}109 110sub read_prompt {111 my ($cancel, $prompt) = @_;112 113 my $ans;114 115 for (;;) {116 if ($cancel) {117 print "$prompt [y/n/C] ";118 } else {119 print "$prompt [y/N] ";120 }121 $ans = <STDIN>;122 chomp $ans;123 if ($ans =~ /^\s*$/) {124 if ($cancel) {125 $ans = "c";126 } else {127 $ans = "n";128 }129 }130 last if ($ans =~ /^y$/i || $ans =~ /^n$/i);131 if ($cancel) {132 last if ($ans =~ /^c$/i);133 print "Please answer either 'y', 'n' or 'c'.\n";134 } else {135 print "Please answer either 'y' or 'n'.\n";136 }137 }138 if ($ans =~ /^c/i) {139 exit;140 }141 if ($ans !~ /^y$/i) {142 return 0;143 }144 return 1;145}146 147sub read_yn {148 my ($prompt) = @_;149 150 return read_prompt 0, $prompt;151}152 153sub read_ync {154 my ($prompt) = @_;155 156 return read_prompt 1, $prompt;157}158 159sub run_command {160 my ($command, $redirect) = @_;161 my $start_time;162 my $end_time;163 my $dord = 0;164 my $pid;165 166 $start_time = time;167 168 doprint("$command ... ");169 170 $pid = open(CMD, "$command 2>&1 |") or171 dodie "unable to exec $command";172 173 if (defined($redirect)) {174 open (RD, ">$redirect") or175 dodie "failed to write to redirect $redirect";176 $dord = 1;177 }178 179 while (<CMD>) {180 print RD if ($dord);181 }182 183 waitpid($pid, 0);184 my $failed = $?;185 186 close(CMD);187 close(RD) if ($dord);188 189 $end_time = time;190 my $delta = $end_time - $start_time;191 192 if ($delta == 1) {193 doprint "[1 second] ";194 } else {195 doprint "[$delta seconds] ";196 }197 198 if ($failed) {199 doprint "FAILED!\n";200 } else {201 doprint "SUCCESS\n";202 }203 204 return !$failed;205}206 207###### CONFIG BISECT ######208 209# config_ignore holds the configs that were set (or unset) for210# a good config and we will ignore these configs for the rest211# of a config bisect. These configs stay as they were.212my %config_ignore;213 214# config_set holds what all configs were set as.215my %config_set;216 217# config_off holds the set of configs that the bad config had disabled.218# We need to record them and set them in the .config when running219# olddefconfig, because olddefconfig keeps the defaults.220my %config_off;221 222# config_off_tmp holds a set of configs to turn off for now223my @config_off_tmp;224 225# config_list is the set of configs that are being tested226my %config_list;227my %null_config;228 229my %dependency;230 231my $make;232 233sub make_oldconfig {234 235 if (!run_command "$make olddefconfig") {236 # Perhaps olddefconfig doesn't exist in this version of the kernel237 # try oldnoconfig238 doprint "olddefconfig failed, trying make oldnoconfig\n";239 if (!run_command "$make oldnoconfig") {240 doprint "oldnoconfig failed, trying yes '' | make oldconfig\n";241 # try a yes '' | oldconfig242 run_command "yes '' | $make oldconfig" or243 dodie "failed make config oldconfig";244 }245 }246}247 248sub assign_configs {249 my ($hash, $config) = @_;250 251 doprint "Reading configs from $config\n";252 253 open (IN, $config)254 or dodie "Failed to read $config";255 256 while (<IN>) {257 chomp;258 if (/^((CONFIG\S*)=.*)/) {259 ${$hash}{$2} = $1;260 } elsif (/^(# (CONFIG\S*) is not set)/) {261 ${$hash}{$2} = $1;262 }263 }264 265 close(IN);266}267 268sub process_config_ignore {269 my ($config) = @_;270 271 assign_configs \%config_ignore, $config;272}273 274sub get_dependencies {275 my ($config) = @_;276 277 my $arr = $dependency{$config};278 if (!defined($arr)) {279 return ();280 }281 282 my @deps = @{$arr};283 284 foreach my $dep (@{$arr}) {285 print "ADD DEP $dep\n";286 @deps = (@deps, get_dependencies $dep);287 }288 289 return @deps;290}291 292sub save_config {293 my ($pc, $file) = @_;294 295 my %configs = %{$pc};296 297 doprint "Saving configs into $file\n";298 299 open(OUT, ">$file") or dodie "Can not write to $file";300 301 foreach my $config (keys %configs) {302 print OUT "$configs{$config}\n";303 }304 close(OUT);305}306 307sub create_config {308 my ($name, $pc) = @_;309 310 doprint "Creating old config from $name configs\n";311 312 save_config $pc, $output_config;313 314 make_oldconfig;315}316 317# compare two config hashes, and return configs with different vals.318# It returns B's config values, but you can use A to see what A was.319sub diff_config_vals {320 my ($pa, $pb) = @_;321 322 # crappy Perl way to pass in hashes.323 my %a = %{$pa};324 my %b = %{$pb};325 326 my %ret;327 328 foreach my $item (keys %a) {329 if (defined($b{$item}) && $b{$item} ne $a{$item}) {330 $ret{$item} = $b{$item};331 }332 }333 334 return %ret;335}336 337# compare two config hashes and return the configs in B but not A338sub diff_configs {339 my ($pa, $pb) = @_;340 341 my %ret;342 343 # crappy Perl way to pass in hashes.344 my %a = %{$pa};345 my %b = %{$pb};346 347 foreach my $item (keys %b) {348 if (!defined($a{$item})) {349 $ret{$item} = $b{$item};350 }351 }352 353 return %ret;354}355 356# return if two configs are equal or not357# 0 is equal +1 b has something a does not358# +1 if a and b have a different item.359# -1 if a has something b does not360sub compare_configs {361 my ($pa, $pb) = @_;362 363 my %ret;364 365 # crappy Perl way to pass in hashes.366 my %a = %{$pa};367 my %b = %{$pb};368 369 foreach my $item (keys %b) {370 if (!defined($a{$item})) {371 return 1;372 }373 if ($a{$item} ne $b{$item}) {374 return 1;375 }376 }377 378 foreach my $item (keys %a) {379 if (!defined($b{$item})) {380 return -1;381 }382 }383 384 return 0;385}386 387sub process_failed {388 my ($config) = @_;389 390 doprint "\n\n***************************************\n";391 doprint "Found bad config: $config\n";392 doprint "***************************************\n\n";393}394 395sub process_new_config {396 my ($tc, $nc, $gc, $bc) = @_;397 398 my %tmp_config = %{$tc};399 my %good_configs = %{$gc};400 my %bad_configs = %{$bc};401 402 my %new_configs;403 404 my $runtest = 1;405 my $ret;406 407 create_config "tmp_configs", \%tmp_config;408 assign_configs \%new_configs, $output_config;409 410 $ret = compare_configs \%new_configs, \%bad_configs;411 if (!$ret) {412 doprint "New config equals bad config, try next test\n";413 $runtest = 0;414 }415 416 if ($runtest) {417 $ret = compare_configs \%new_configs, \%good_configs;418 if (!$ret) {419 doprint "New config equals good config, try next test\n";420 $runtest = 0;421 }422 }423 424 %{$nc} = %new_configs;425 426 return $runtest;427}428 429sub convert_config {430 my ($config) = @_;431 432 if ($config =~ /^# (.*) is not set/) {433 $config = "$1=n";434 }435 436 $config =~ s/^CONFIG_//;437 return $config;438}439 440sub print_config {441 my ($sym, $config) = @_;442 443 $config = convert_config $config;444 doprint "$sym$config\n";445}446 447sub print_config_compare {448 my ($good_config, $bad_config) = @_;449 450 $good_config = convert_config $good_config;451 $bad_config = convert_config $bad_config;452 453 my $good_value = $good_config;454 my $bad_value = $bad_config;455 $good_value =~ s/(.*)=//;456 my $config = $1;457 458 $bad_value =~ s/.*=//;459 460 doprint " $config $good_value -> $bad_value\n";461}462 463# Pass in:464# $phalf: half of the configs names you want to add465# $oconfigs: The orginial configs to start with466# $sconfigs: The source to update $oconfigs with (from $phalf)467# $which: The name of which half that is updating (top / bottom)468# $type: The name of the source type (good / bad)469sub make_half {470 my ($phalf, $oconfigs, $sconfigs, $which, $type) = @_;471 472 my @half = @{$phalf};473 my %orig_configs = %{$oconfigs};474 my %source_configs = %{$sconfigs};475 476 my %tmp_config = %orig_configs;477 478 doprint "Settings bisect with $which half of $type configs:\n";479 foreach my $item (@half) {480 doprint "Updating $item to $source_configs{$item}\n";481 $tmp_config{$item} = $source_configs{$item};482 }483 484 return %tmp_config;485}486 487sub run_config_bisect {488 my ($pgood, $pbad) = @_;489 490 my %good_configs = %{$pgood};491 my %bad_configs = %{$pbad};492 493 my %diff_configs = diff_config_vals \%good_configs, \%bad_configs;494 my %b_configs = diff_configs \%good_configs, \%bad_configs;495 my %g_configs = diff_configs \%bad_configs, \%good_configs;496 497 # diff_arr is what is in both good and bad but are different (y->n)498 my @diff_arr = keys %diff_configs;499 my $len_diff = $#diff_arr + 1;500 501 # b_arr is what is in bad but not in good (has depends)502 my @b_arr = keys %b_configs;503 my $len_b = $#b_arr + 1;504 505 # g_arr is what is in good but not in bad506 my @g_arr = keys %g_configs;507 my $len_g = $#g_arr + 1;508 509 my $runtest = 0;510 my %new_configs;511 my $ret;512 513 # Look at the configs that are different between good and bad.514 # This does not include those that depend on other configs515 # (configs depending on other configs that are not set would516 # not show up even as a "# CONFIG_FOO is not set"517 518 519 doprint "# of configs to check: $len_diff\n";520 doprint "# of configs showing only in good: $len_g\n";521 doprint "# of configs showing only in bad: $len_b\n";522 523 if ($len_diff > 0) {524 # Now test for different values525 526 doprint "Configs left to check:\n";527 doprint " Good Config\t\t\tBad Config\n";528 doprint " -----------\t\t\t----------\n";529 foreach my $item (@diff_arr) {530 doprint " $good_configs{$item}\t$bad_configs{$item}\n";531 }532 533 my $half = int($#diff_arr / 2);534 my @tophalf = @diff_arr[0 .. $half];535 536 doprint "Set tmp config to be good config with some bad config values\n";537 538 my %tmp_config = make_half \@tophalf, \%good_configs,539 \%bad_configs, "top", "bad";540 541 $runtest = process_new_config \%tmp_config, \%new_configs,542 \%good_configs, \%bad_configs;543 544 if (!$runtest) {545 doprint "Set tmp config to be bad config with some good config values\n";546 547 my %tmp_config = make_half \@tophalf, \%bad_configs,548 \%good_configs, "top", "good";549 550 $runtest = process_new_config \%tmp_config, \%new_configs,551 \%good_configs, \%bad_configs;552 }553 }554 555 if (!$runtest && $len_diff > 0) {556 # do the same thing, but this time with bottom half557 558 my $half = int($#diff_arr / 2);559 my @bottomhalf = @diff_arr[$half+1 .. $#diff_arr];560 561 doprint "Set tmp config to be good config with some bad config values\n";562 563 my %tmp_config = make_half \@bottomhalf, \%good_configs,564 \%bad_configs, "bottom", "bad";565 566 $runtest = process_new_config \%tmp_config, \%new_configs,567 \%good_configs, \%bad_configs;568 569 if (!$runtest) {570 doprint "Set tmp config to be bad config with some good config values\n";571 572 my %tmp_config = make_half \@bottomhalf, \%bad_configs,573 \%good_configs, "bottom", "good";574 575 $runtest = process_new_config \%tmp_config, \%new_configs,576 \%good_configs, \%bad_configs;577 }578 }579 580 if ($runtest) {581 make_oldconfig;582 doprint "READY TO TEST .config IN $build\n";583 return 0;584 }585 586 doprint "\n%%%%%%%% FAILED TO FIND SINGLE BAD CONFIG %%%%%%%%\n";587 doprint "Hmm, can't make any more changes without making good == bad?\n";588 doprint "Difference between good (+) and bad (-)\n";589 590 foreach my $item (keys %bad_configs) {591 if (!defined($good_configs{$item})) {592 print_config "-", $bad_configs{$item};593 }594 }595 596 foreach my $item (keys %good_configs) {597 next if (!defined($bad_configs{$item}));598 if ($good_configs{$item} ne $bad_configs{$item}) {599 print_config_compare $good_configs{$item}, $bad_configs{$item};600 }601 }602 603 foreach my $item (keys %good_configs) {604 if (!defined($bad_configs{$item})) {605 print_config "+", $good_configs{$item};606 }607 }608 return -1;609}610 611sub config_bisect {612 my ($good_config, $bad_config) = @_;613 my $ret;614 615 my %good_configs;616 my %bad_configs;617 my %tmp_configs;618 619 doprint "Run good configs through make oldconfig\n";620 assign_configs \%tmp_configs, $good_config;621 create_config "$good_config", \%tmp_configs;622 assign_configs \%good_configs, $output_config;623 624 doprint "Run bad configs through make oldconfig\n";625 assign_configs \%tmp_configs, $bad_config;626 create_config "$bad_config", \%tmp_configs;627 assign_configs \%bad_configs, $output_config;628 629 save_config \%good_configs, $good_config;630 save_config \%bad_configs, $bad_config;631 632 return run_config_bisect \%good_configs, \%bad_configs;633}634 635while ($#ARGV >= 0) {636 if ($ARGV[0] !~ m/^-/) {637 last;638 }639 my $opt = shift @ARGV;640 641 if ($opt eq "-b") {642 $val = shift @ARGV;643 if (!defined($val)) {644 die "-b requires value\n";645 }646 $build = $val;647 }648 649 elsif ($opt eq "-l") {650 $val = shift @ARGV;651 if (!defined($val)) {652 die "-l requires value\n";653 }654 $tree = $val;655 }656 657 elsif ($opt eq "-r") {658 $reset_bisect = 1;659 }660 661 elsif ($opt eq "-h") {662 usage;663 }664 665 else {666 die "Unknown option $opt\n";667 }668}669 670$build = $tree if (!defined($build));671 672$tree = expand_path $tree;673$build = expand_path $build;674 675if ( ! -d $tree ) {676 die "$tree not a directory\n";677}678 679if ( ! -d $build ) {680 die "$build not a directory\n";681}682 683usage if $#ARGV < 1;684 685if ($#ARGV == 1) {686 $start = 1;687} elsif ($#ARGV == 2) {688 $val = $ARGV[2];689 if ($val ne "good" && $val ne "bad") {690 die "Unknown command '$val', bust be either \"good\" or \"bad\"\n";691 }692} else {693 usage;694}695 696my $good_start = expand_path $ARGV[0];697my $bad_start = expand_path $ARGV[1];698 699my $good = "$good_start.tmp";700my $bad = "$bad_start.tmp";701 702$make = "make";703 704if ($build ne $tree) {705 $make = "make O=$build"706}707 708$output_config = "$build/.config";709 710if ($start) {711 if ( ! -f $good_start ) {712 die "$good_start not found\n";713 }714 if ( ! -f $bad_start ) {715 die "$bad_start not found\n";716 }717 if ( -f $good || -f $bad ) {718 my $p = "";719 720 if ( -f $good ) {721 $p = "$good exists\n";722 }723 724 if ( -f $bad ) {725 $p = "$p$bad exists\n";726 }727 728 if (!defined($reset_bisect)) {729 if (!read_yn "${p}Overwrite and start new bisect anyway?") {730 exit (-1);731 }732 }733 }734 run_command "cp $good_start $good" or die "failed to copy to $good\n";735 run_command "cp $bad_start $bad" or die "failed to copy to $bad\n";736} else {737 if ( ! -f $good ) {738 die "Can not find file $good\n";739 }740 if ( ! -f $bad ) {741 die "Can not find file $bad\n";742 }743 if ($val eq "good") {744 run_command "cp $output_config $good" or die "failed to copy $config to $good\n";745 } elsif ($val eq "bad") {746 run_command "cp $output_config $bad" or die "failed to copy $config to $bad\n";747 }748}749 750chdir $tree || die "can't change directory to $tree";751 752my $ret = config_bisect $good, $bad;753 754if (!$ret) {755 exit(0);756}757 758if ($ret > 0) {759 doprint "Cleaning temp files\n";760 run_command "rm $good";761 run_command "rm $bad";762 exit(1);763} else {764 doprint "See good and bad configs for details:\n";765 doprint "good: $good\n";766 doprint "bad: $bad\n";767 doprint "%%%%%%%% FAILED TO FIND SINGLE BAD CONFIG %%%%%%%%\n";768}769exit(2);770