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Eugeniu Roscae91610d2018-05-19 14:13:50 +02001#!/usr/bin/env perl
Masahiro Yamada0a9064f2014-07-30 14:08:13 +09002#
3# Copyright 2005-2009 - Steven Rostedt
4# Licensed under the terms of the GNU GPL License version 2
5#
6# It's simple enough to figure out how this works.
7# If not, then you can ask me at stripconfig@goodmis.org
8#
9# What it does?
10#
11# If you have installed a Linux kernel from a distribution
12# that turns on way too many modules than you need, and
13# you only want the modules you use, then this program
14# is perfect for you.
15#
16# It gives you the ability to turn off all the modules that are
17# not loaded on your system.
18#
19# Howto:
20#
21# 1. Boot up the kernel that you want to stream line the config on.
22# 2. Change directory to the directory holding the source of the
23# kernel that you just booted.
24# 3. Copy the configuraton file to this directory as .config
25# 4. Have all your devices that you need modules for connected and
26# operational (make sure that their corresponding modules are loaded)
27# 5. Run this script redirecting the output to some other file
28# like config_strip.
29# 6. Back up your old config (if you want too).
30# 7. copy the config_strip file to .config
31# 8. Run "make oldconfig"
32#
33# Now your kernel is ready to be built with only the modules that
34# are loaded.
35#
36# Here's what I did with my Debian distribution.
37#
38# cd /usr/src/linux-2.6.10
39# cp /boot/config-2.6.10-1-686-smp .config
40# ~/bin/streamline_config > config_strip
41# mv .config config_sav
42# mv config_strip .config
43# make oldconfig
44#
Eugeniu Roscae91610d2018-05-19 14:13:50 +020045use warnings;
Masahiro Yamada0a9064f2014-07-30 14:08:13 +090046use strict;
47use Getopt::Long;
48
49# set the environment variable LOCALMODCONFIG_DEBUG to get
50# debug output.
51my $debugprint = 0;
52$debugprint = 1 if (defined($ENV{LOCALMODCONFIG_DEBUG}));
53
54sub dprint {
55 return if (!$debugprint);
56 print STDERR @_;
57}
58
59my $config = ".config";
60
61my $uname = `uname -r`;
62chomp $uname;
63
64my @searchconfigs = (
65 {
66 "file" => ".config",
67 "exec" => "cat",
68 },
69 {
70 "file" => "/proc/config.gz",
71 "exec" => "zcat",
72 },
73 {
74 "file" => "/boot/config-$uname",
75 "exec" => "cat",
76 },
77 {
78 "file" => "/boot/vmlinuz-$uname",
79 "exec" => "scripts/extract-ikconfig",
80 "test" => "scripts/extract-ikconfig",
81 },
82 {
83 "file" => "vmlinux",
84 "exec" => "scripts/extract-ikconfig",
85 "test" => "scripts/extract-ikconfig",
86 },
87 {
88 "file" => "/lib/modules/$uname/kernel/kernel/configs.ko",
89 "exec" => "scripts/extract-ikconfig",
90 "test" => "scripts/extract-ikconfig",
91 },
92 {
93 "file" => "kernel/configs.ko",
94 "exec" => "scripts/extract-ikconfig",
95 "test" => "scripts/extract-ikconfig",
96 },
97 {
98 "file" => "kernel/configs.o",
99 "exec" => "scripts/extract-ikconfig",
100 "test" => "scripts/extract-ikconfig",
101 },
102);
103
104sub read_config {
105 foreach my $conf (@searchconfigs) {
106 my $file = $conf->{"file"};
107
108 next if ( ! -f "$file");
109
110 if (defined($conf->{"test"})) {
111 `$conf->{"test"} $conf->{"file"} 2>/dev/null`;
112 next if ($?);
113 }
114
115 my $exec = $conf->{"exec"};
116
117 print STDERR "using config: '$file'\n";
118
119 open(my $infile, '-|', "$exec $file") || die "Failed to run $exec $file";
120 my @x = <$infile>;
121 close $infile;
122 return @x;
123 }
124 die "No config file found";
125}
126
127my @config_file = read_config;
128
129# Parse options
130my $localmodconfig = 0;
131my $localyesconfig = 0;
132
133GetOptions("localmodconfig" => \$localmodconfig,
134 "localyesconfig" => \$localyesconfig);
135
136# Get the build source and top level Kconfig file (passed in)
137my $ksource = ($ARGV[0] ? $ARGV[0] : '.');
138my $kconfig = $ARGV[1];
139my $lsmod_file = $ENV{'LSMOD'};
140
Masahiro Yamadabf7ab1e2017-02-11 12:39:54 +0900141my @makefiles = `find $ksource -name Makefile -or -name Kbuild 2>/dev/null`;
Masahiro Yamada0a9064f2014-07-30 14:08:13 +0900142chomp @makefiles;
143
144my %depends;
145my %selects;
146my %prompts;
147my %objects;
148my $var;
149my $iflevel = 0;
150my @ifdeps;
151
152# prevent recursion
153my %read_kconfigs;
154
155sub read_kconfig {
156 my ($kconfig) = @_;
157
158 my $state = "NONE";
159 my $config;
160
161 my $cont = 0;
162 my $line;
163
164 my $source = "$ksource/$kconfig";
165 my $last_source = "";
166
167 # Check for any environment variables used
Tom Rini5972ff02020-03-11 18:11:17 -0400168 while ($source =~ /\$\((\w+)\)/ && $last_source ne $source) {
Masahiro Yamada0a9064f2014-07-30 14:08:13 +0900169 my $env = $1;
170 $last_source = $source;
Tom Rini5972ff02020-03-11 18:11:17 -0400171 $source =~ s/\$\($env\)/$ENV{$env}/;
Masahiro Yamada0a9064f2014-07-30 14:08:13 +0900172 }
173
174 open(my $kinfile, '<', $source) || die "Can't open $kconfig";
175 while (<$kinfile>) {
176 chomp;
177
178 # Make sure that lines ending with \ continue
179 if ($cont) {
180 $_ = $line . " " . $_;
181 }
182
183 if (s/\\$//) {
184 $cont = 1;
185 $line = $_;
186 next;
187 }
188
189 $cont = 0;
190
191 # collect any Kconfig sources
Masahiro Yamadabf7ab1e2017-02-11 12:39:54 +0900192 if (/^source\s+"?([^"]+)/) {
Masahiro Yamada0a9064f2014-07-30 14:08:13 +0900193 my $kconfig = $1;
194 # prevent reading twice.
195 if (!defined($read_kconfigs{$kconfig})) {
196 $read_kconfigs{$kconfig} = 1;
197 read_kconfig($kconfig);
198 }
199 next;
200 }
201
202 # configs found
203 if (/^\s*(menu)?config\s+(\S+)\s*$/) {
204 $state = "NEW";
205 $config = $2;
206
207 # Add depends for 'if' nesting
208 for (my $i = 0; $i < $iflevel; $i++) {
209 if ($i) {
210 $depends{$config} .= " " . $ifdeps[$i];
211 } else {
212 $depends{$config} = $ifdeps[$i];
213 }
214 $state = "DEP";
215 }
216
217 # collect the depends for the config
218 } elsif ($state eq "NEW" && /^\s*depends\s+on\s+(.*)$/) {
219 $state = "DEP";
220 $depends{$config} = $1;
221 } elsif ($state eq "DEP" && /^\s*depends\s+on\s+(.*)$/) {
222 $depends{$config} .= " " . $1;
223 } elsif ($state eq "DEP" && /^\s*def(_(bool|tristate)|ault)\s+(\S.*)$/) {
224 my $dep = $3;
225 if ($dep !~ /^\s*(y|m|n)\s*$/) {
226 $dep =~ s/.*\sif\s+//;
227 $depends{$config} .= " " . $dep;
228 dprint "Added default depends $dep to $config\n";
229 }
230
231 # Get the configs that select this config
232 } elsif ($state ne "NONE" && /^\s*select\s+(\S+)/) {
233 my $conf = $1;
234 if (defined($selects{$conf})) {
235 $selects{$conf} .= " " . $config;
236 } else {
237 $selects{$conf} = $config;
238 }
239
240 # configs without prompts must be selected
Masahiro Yamadabf7ab1e2017-02-11 12:39:54 +0900241 } elsif ($state ne "NONE" && /^\s*(tristate\s+\S|prompt\b)/) {
Masahiro Yamada0a9064f2014-07-30 14:08:13 +0900242 # note if the config has a prompt
243 $prompts{$config} = 1;
244
245 # Check for if statements
246 } elsif (/^if\s+(.*\S)\s*$/) {
247 my $deps = $1;
248 # remove beginning and ending non text
249 $deps =~ s/^[^a-zA-Z0-9_]*//;
250 $deps =~ s/[^a-zA-Z0-9_]*$//;
251
252 my @deps = split /[^a-zA-Z0-9_]+/, $deps;
253
254 $ifdeps[$iflevel++] = join ':', @deps;
255
256 } elsif (/^endif/) {
257
258 $iflevel-- if ($iflevel);
259
Masahiro Yamadabf7ab1e2017-02-11 12:39:54 +0900260 # stop on "help" and keywords that end a menu entry
261 } elsif (/^\s*(---)?help(---)?\s*$/ || /^(comment|choice|menu)\b/) {
Masahiro Yamada0a9064f2014-07-30 14:08:13 +0900262 $state = "NONE";
263 }
264 }
265 close($kinfile);
266}
267
268if ($kconfig) {
269 read_kconfig($kconfig);
270}
271
272# Makefiles can use variables to define their dependencies
273sub convert_vars {
274 my ($line, %vars) = @_;
275
276 my $process = "";
277
278 while ($line =~ s/^(.*?)(\$\((.*?)\))//) {
279 my $start = $1;
280 my $variable = $2;
281 my $var = $3;
282
283 if (defined($vars{$var})) {
284 $process .= $start . $vars{$var};
285 } else {
286 $process .= $start . $variable;
287 }
288 }
289
290 $process .= $line;
291
292 return $process;
293}
294
295# Read all Makefiles to map the configs to the objects
296foreach my $makefile (@makefiles) {
297
298 my $line = "";
299 my %make_vars;
300
301 open(my $infile, '<', $makefile) || die "Can't open $makefile";
302 while (<$infile>) {
303 # if this line ends with a backslash, continue
304 chomp;
305 if (/^(.*)\\$/) {
306 $line .= $1;
307 next;
308 }
309
310 $line .= $_;
311 $_ = $line;
312 $line = "";
313
314 my $objs;
315
316 # Convert variables in a line (could define configs)
317 $_ = convert_vars($_, %make_vars);
318
319 # collect objects after obj-$(CONFIG_FOO_BAR)
320 if (/obj-\$\((CONFIG_[^\)]*)\)\s*[+:]?=\s*(.*)/) {
321 $var = $1;
322 $objs = $2;
323
324 # check if variables are set
325 } elsif (/^\s*(\S+)\s*[:]?=\s*(.*\S)/) {
326 $make_vars{$1} = $2;
327 }
328 if (defined($objs)) {
329 foreach my $obj (split /\s+/,$objs) {
330 $obj =~ s/-/_/g;
331 if ($obj =~ /(.*)\.o$/) {
332 # Objects may be enabled by more than one config.
333 # Store configs in an array.
334 my @arr;
335
336 if (defined($objects{$1})) {
337 @arr = @{$objects{$1}};
338 }
339
340 $arr[$#arr+1] = $var;
341
342 # The objects have a hash mapping to a reference
343 # of an array of configs.
344 $objects{$1} = \@arr;
345 }
346 }
347 }
348 }
349 close($infile);
350}
351
352my %modules;
353my $linfile;
354
355if (defined($lsmod_file)) {
356 if ( ! -f $lsmod_file) {
357 if ( -f $ENV{'objtree'}."/".$lsmod_file) {
358 $lsmod_file = $ENV{'objtree'}."/".$lsmod_file;
359 } else {
360 die "$lsmod_file not found";
361 }
362 }
363
364 my $otype = ( -x $lsmod_file) ? '-|' : '<';
365 open($linfile, $otype, $lsmod_file);
366
367} else {
368
369 # see what modules are loaded on this system
370 my $lsmod;
371
372 foreach my $dir ( ("/sbin", "/bin", "/usr/sbin", "/usr/bin") ) {
373 if ( -x "$dir/lsmod" ) {
374 $lsmod = "$dir/lsmod";
375 last;
376 }
377}
378 if (!defined($lsmod)) {
379 # try just the path
380 $lsmod = "lsmod";
381 }
382
383 open($linfile, '-|', $lsmod) || die "Can not call lsmod with $lsmod";
384}
385
386while (<$linfile>) {
387 next if (/^Module/); # Skip the first line.
388 if (/^(\S+)/) {
389 $modules{$1} = 1;
390 }
391}
392close ($linfile);
393
394# add to the configs hash all configs that are needed to enable
395# a loaded module. This is a direct obj-${CONFIG_FOO} += bar.o
396# where we know we need bar.o so we add FOO to the list.
397my %configs;
398foreach my $module (keys(%modules)) {
399 if (defined($objects{$module})) {
400 my @arr = @{$objects{$module}};
401 foreach my $conf (@arr) {
402 $configs{$conf} = $module;
403 dprint "$conf added by direct ($module)\n";
404 if ($debugprint) {
405 my $c=$conf;
406 $c =~ s/^CONFIG_//;
407 if (defined($depends{$c})) {
408 dprint " deps = $depends{$c}\n";
409 } else {
410 dprint " no deps\n";
411 }
412 }
413 }
414 } else {
415 # Most likely, someone has a custom (binary?) module loaded.
416 print STDERR "$module config not found!!\n";
417 }
418}
419
420# Read the current config, and see what is enabled. We want to
421# ignore configs that we would not enable anyway.
422
423my %orig_configs;
424my $valid = "A-Za-z_0-9";
425
426foreach my $line (@config_file) {
427 $_ = $line;
428
429 if (/(CONFIG_[$valid]*)=(m|y)/) {
430 $orig_configs{$1} = $2;
431 }
432}
433
434my $repeat = 1;
435
436my $depconfig;
437
438#
439# Note, we do not care about operands (like: &&, ||, !) we want to add any
440# config that is in the depend list of another config. This script does
441# not enable configs that are not already enabled. If we come across a
442# config A that depends on !B, we can still add B to the list of depends
443# to keep on. If A was on in the original config, B would not have been
444# and B would not be turned on by this script.
445#
446sub parse_config_depends
447{
448 my ($p) = @_;
449
450 while ($p =~ /[$valid]/) {
451
452 if ($p =~ /^[^$valid]*([$valid]+)/) {
453 my $conf = "CONFIG_" . $1;
454
455 $p =~ s/^[^$valid]*[$valid]+//;
456
457 # We only need to process if the depend config is a module
Masahiro Yamadabf7ab1e2017-02-11 12:39:54 +0900458 if (!defined($orig_configs{$conf}) || $orig_configs{$conf} eq "y") {
Masahiro Yamada0a9064f2014-07-30 14:08:13 +0900459 next;
460 }
461
462 if (!defined($configs{$conf})) {
463 # We must make sure that this config has its
464 # dependencies met.
465 $repeat = 1; # do again
466 dprint "$conf selected by depend $depconfig\n";
467 $configs{$conf} = 1;
468 }
469 } else {
470 die "this should never happen";
471 }
472 }
473}
474
475# Select is treated a bit differently than depends. We call this
476# when a config has no prompt and requires another config to be
477# selected. We use to just select all configs that selected this
478# config, but found that that can balloon into enabling hundreds
479# of configs that we do not care about.
480#
481# The idea is we look at all the configs that select it. If one
482# is already in our list of configs to enable, then there's nothing
483# else to do. If there isn't, we pick the first config that was
484# enabled in the orignal config and use that.
485sub parse_config_selects
486{
487 my ($config, $p) = @_;
488
489 my $next_config;
490
491 while ($p =~ /[$valid]/) {
492
493 if ($p =~ /^[^$valid]*([$valid]+)/) {
494 my $conf = "CONFIG_" . $1;
495
496 $p =~ s/^[^$valid]*[$valid]+//;
497
498 # Make sure that this config exists in the current .config file
499 if (!defined($orig_configs{$conf})) {
500 dprint "$conf not set for $config select\n";
501 next;
502 }
503
504 # Check if something other than a module selects this config
505 if (defined($orig_configs{$conf}) && $orig_configs{$conf} ne "m") {
506 dprint "$conf (non module) selects config, we are good\n";
507 # we are good with this
508 return;
509 }
510 if (defined($configs{$conf})) {
511 dprint "$conf selects $config so we are good\n";
512 # A set config selects this config, we are good
513 return;
514 }
515 # Set this config to be selected
516 if (!defined($next_config)) {
517 $next_config = $conf;
518 }
519 } else {
520 die "this should never happen";
521 }
522 }
523
524 # If no possible config selected this, then something happened.
525 if (!defined($next_config)) {
526 print STDERR "WARNING: $config is required, but nothing in the\n";
527 print STDERR " current config selects it.\n";
528 return;
529 }
530
531 # If we are here, then we found no config that is set and
532 # selects this config. Repeat.
533 $repeat = 1;
534 # Make this config need to be selected
535 $configs{$next_config} = 1;
536 dprint "$next_config selected by select $config\n";
537}
538
539my %process_selects;
540
541# loop through all configs, select their dependencies.
542sub loop_depend {
543 $repeat = 1;
544
545 while ($repeat) {
546 $repeat = 0;
547
548 forloop:
549 foreach my $config (keys %configs) {
550
551 # If this config is not a module, we do not need to process it
552 if (defined($orig_configs{$config}) && $orig_configs{$config} ne "m") {
553 next forloop;
554 }
555
556 $config =~ s/^CONFIG_//;
557 $depconfig = $config;
558
559 if (defined($depends{$config})) {
560 # This config has dependencies. Make sure they are also included
561 parse_config_depends $depends{$config};
562 }
563
564 # If the config has no prompt, then we need to check if a config
565 # that is enabled selected it. Or if we need to enable one.
566 if (!defined($prompts{$config}) && defined($selects{$config})) {
567 $process_selects{$config} = 1;
568 }
569 }
570 }
571}
572
573sub loop_select {
574
575 foreach my $config (keys %process_selects) {
576 $config =~ s/^CONFIG_//;
577
578 dprint "Process select $config\n";
579
580 # config has no prompt and must be selected.
581 parse_config_selects $config, $selects{$config};
582 }
583}
584
585while ($repeat) {
586 # Get the first set of configs and their dependencies.
587 loop_depend;
588
589 $repeat = 0;
590
591 # Now we need to see if we have to check selects;
592 loop_select;
593}
594
595my %setconfigs;
596
597# Finally, read the .config file and turn off any module enabled that
598# we could not find a reason to keep enabled.
599foreach my $line (@config_file) {
600 $_ = $line;
601
602 if (/CONFIG_IKCONFIG/) {
603 if (/# CONFIG_IKCONFIG is not set/) {
604 # enable IKCONFIG at least as a module
605 print "CONFIG_IKCONFIG=m\n";
606 # don't ask about PROC
607 print "# CONFIG_IKCONFIG_PROC is not set\n";
608 } else {
609 print;
610 }
611 next;
612 }
613
Masahiro Yamadabf7ab1e2017-02-11 12:39:54 +0900614 if (/CONFIG_MODULE_SIG_KEY="(.+)"/) {
615 my $orig_cert = $1;
616 my $default_cert = "certs/signing_key.pem";
617
618 # Check that the logic in this script still matches the one in Kconfig
619 if (!defined($depends{"MODULE_SIG_KEY"}) ||
620 $depends{"MODULE_SIG_KEY"} !~ /"\Q$default_cert\E"/) {
621 print STDERR "WARNING: MODULE_SIG_KEY assertion failure, ",
622 "update needed to ", __FILE__, " line ", __LINE__, "\n";
623 print;
624 } elsif ($orig_cert ne $default_cert && ! -f $orig_cert) {
625 print STDERR "Module signature verification enabled but ",
626 "module signing key \"$orig_cert\" not found. Resetting ",
627 "signing key to default value.\n";
628 print "CONFIG_MODULE_SIG_KEY=\"$default_cert\"\n";
629 } else {
630 print;
631 }
632 next;
633 }
634
635 if (/CONFIG_SYSTEM_TRUSTED_KEYS="(.+)"/) {
636 my $orig_keys = $1;
637
638 if (! -f $orig_keys) {
639 print STDERR "System keyring enabled but keys \"$orig_keys\" ",
640 "not found. Resetting keys to default value.\n";
641 print "CONFIG_SYSTEM_TRUSTED_KEYS=\"\"\n";
642 } else {
643 print;
644 }
645 next;
646 }
647
Masahiro Yamada0a9064f2014-07-30 14:08:13 +0900648 if (/^(CONFIG.*)=(m|y)/) {
649 if (defined($configs{$1})) {
650 if ($localyesconfig) {
651 $setconfigs{$1} = 'y';
652 print "$1=y\n";
653 next;
654 } else {
655 $setconfigs{$1} = $2;
656 }
657 } elsif ($2 eq "m") {
658 print "# $1 is not set\n";
659 next;
660 }
661 }
662 print;
663}
664
665# Integrity check, make sure all modules that we want enabled do
666# indeed have their configs set.
667loop:
668foreach my $module (keys(%modules)) {
669 if (defined($objects{$module})) {
670 my @arr = @{$objects{$module}};
671 foreach my $conf (@arr) {
672 if (defined($setconfigs{$conf})) {
673 next loop;
674 }
675 }
676 print STDERR "module $module did not have configs";
677 foreach my $conf (@arr) {
678 print STDERR " " , $conf;
679 }
680 print STDERR "\n";
681 }
682}