ksplice-create.in

   1 #!/usr/bin/perl
   2
   3 # Copyright (C) 2007-2008  Jeffrey Brian Arnold <jbarnold@mit.edu>
   4 # Copyright (C) 2008  Anders Kaseorg <andersk@mit.edu>,
   5 #                     Tim Abbott <tabbott@mit.edu>
   6 #
   7 # This program is free software; you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License, version 2.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program; if not, write to the Free Software
  17 # Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
  18 # 02110-1301, USA.
  19
  20 use strict;
  21 use warnings;
  22 use lib 'KSPLICE_DATA_DIR';
  23 use Ksplice;
  24
  25 my ($patchfile, $diffext, $orig_config_dir, $jobs, $kid);
  26 my $description;
  27 my $series = 0;
  28 my $build_modules = 0;
  29 my @only_targets;
  30 my @extra_match;
  31 my $standalone;
  32 my ($prebuild, $skip_prebuild) = (0, 0);
  33 my @patch_opt = "-p1";
  34 GetOptions(@common_options,
  35         "id=s" => \$kid,
  36         "patch=s" => \$patchfile,
  37         "description=s" => \$description,
  38         "diffext=s" => \$diffext,
  39         "prebuild" => \$prebuild,
  40         "series!" => \$series,
  41         "build-modules!" => \$build_modules,
  42         "only-targets=s" => \@only_targets,
  43         "extra-match=s" => \@extra_match,
  44         "standalone!" => \$standalone,
  45         "skip-prebuild" => \$skip_prebuild,
  46         "jobs|j:i" => \$jobs,
  47         "config=s" => \$orig_config_dir,
  48         "patch-opt=s" => \@patch_opt) or pod2usage(1);
  49
  50 pod2usage(1) if($help || scalar(@ARGV) != 1);
  51 my $actions = (defined $patchfile) + (defined $diffext) + ($prebuild);
  52 pod2usage(1) if($actions != 1);
  53
  54 my ($linuxtree) = (abs_path($ARGV[0]));
  55
  56 if(!defined $orig_config_dir) {
  57         $orig_config_dir = "$linuxtree/ksplice";
  58 }
  59 else {
  60         $orig_config_dir = abs_path($orig_config_dir);
  61         if($orig_config_dir =~ $linuxtree) {
  62                 die "Aborting: User-specified ORIG_CONFIG cannot be KERNEL_SOURCE or a subdirectory";
  63         }
  64 }
  65 if(!defined $orig_config_dir || ! -d $orig_config_dir) {
  66         die "Failed to find ORIG_CONFIG directory ($orig_config_dir)";
  67 }
  68 if(! -e "$orig_config_dir/System.map") {
  69         die "Failed to find System.map file in ORIG_CONFIG directory";
  70 }
  71
  72 my $kernel_headers_dir = "$orig_config_dir/build";
  73 $kernel_headers_dir = $linuxtree unless(-d $kernel_headers_dir);
  74
  75 my @kbuild_flags = ();
  76 if(-e "$orig_config_dir/flags") {
  77         open(FLAGS, '<', "$orig_config_dir/flags") or die;
  78         local $/;
  79         @kbuild_flags = shellwords(scalar <FLAGS>);
  80         close(FLAGS);
  81 }
  82
  83 $ENV{KSPLICE_VERBOSE} = $Verbose::level;
  84 $ENV{KSPLICE_CONFIG_DIR} = $orig_config_dir;
  85
  86 my @chars = ('a'..'z', 0..9);
  87 $kid = join '', map { $chars[int(rand(36))] } 0..7 if(!defined $kid);
  88 my $ksplice = "ksplice-$kid";
  89 $ENV{KSPLICE_KID} = $kid;
  90
  91 # Some versions of Fedora have System.map files whose symbol addresses disagree
  92 # with the running kernel by a constant address offset.  Here, Ksplice notes the
  93 # System.map address for printk so that it can later compare this address against
  94 # the kernel's address for printk.  This comparison helps Ksplice work around
  95 # this Fedora problem, and this comparison also helps Ksplice detect whether
  96 # the user has provided an incorrect System.map file.
  97 my $map_printk = runstr("$datadir/ksplice-obj.pl", "system_map_lookup", "printk");
  98
  99 print "Starting kernel builds (this process might take a long time)...\n"
 100     if($Verbose::level >= 0);
 101
 102 $patchfile = abs_path($patchfile) if(defined $patchfile);
 103
 104 my $origdir = getcwd();
 105 chdir($linuxtree);
 106
 107 my @make = ("make", "-rR");
 108 if(defined $jobs) {
 109         push @make, "-j$jobs";
 110 } elsif(defined $ENV{CONCURRENCY_LEVEL}) {
 111         push @make, "-j$ENV{CONCURRENCY_LEVEL}";
 112 }
 113
 114 if($Verbose::level >= 2) {
 115         push @make, "V=1";
 116 } elsif($Verbose::level < 0) {
 117         push @make, "-s";
 118 }
 119
 120 $ENV{PATH} = "$datadir:$ENV{PATH}";
 121 my @make_ksplice = (@make, "-f", "$datadir/Makefile.ksplice", @kbuild_flags);
 122
 123 push(@make_ksplice, "KSPLICE_BUILD_MODULES=1") if ($build_modules);
 124 if(-e "include/config/kernel.release") {
 125         push(@make_ksplice, "-o", "include/config/kernel.release");
 126 }
 127
 128 my @revert_flags = ("KSPLICE_MODE=revert");
 129 push(@revert_flags, "KSPLICE_SERIES=y") if ($series);
 130
 131 sub revert_orig() {
 132         for(split(/\0/, runstr(qw(find -name *.KSPLICE_presrc -print0)))) {
 133                 my ($file) = m/^(.*)\.KSPLICE_presrc$/;
 134                 if ($series) {
 135                         unlink($_);
 136                 } else {
 137                         rename($_, $file);
 138                 }
 139         }
 140         runval(@make_ksplice, @revert_flags);
 141 }
 142 revert_orig();
 143
 144 if(!$skip_prebuild) {
 145         if(-e "$orig_config_dir/.config") {
 146                 copy("$orig_config_dir/.config", "$linuxtree/.config");
 147                 utime((stat("$orig_config_dir/.config"))[8, 9],
 148                       "$linuxtree/.config");
 149         }
 150         my @snap_flags = ("KSPLICE_MODE=snap");
 151         runval_raw(@make_ksplice, @snap_flags) == 0 or
 152             die "Aborting: Prebuild failed";
 153         sleep(1);
 154 }
 155 exit(0) if($prebuild);
 156
 157 my $tmpdir = tempdir('ksplice-tmp-XXXXXX', TMPDIR => 1, CLEANUP => 1);
 158 copy($patchfile, "$tmpdir/patch") if(defined $patchfile);
 159 $patchfile = "$tmpdir/patch";
 160
 161 if(defined $diffext) {
 162         open(PATCH, '>', $patchfile) or die;
 163         for(split(/\0/, runstr("find", "-name", "*$diffext", "-print0"))) {
 164                 my ($file) = /^(.*)\Q$diffext\E/ or die;
 165                 print PATCH runstr("diff", "-u", "--", $file, $_);
 166         }
 167         close(PATCH) or die;
 168         @patch_opt = ("-p0");
 169 }
 170
 171 my $kmodsrc = "$tmpdir/kmodsrc";
 172 runval("cp", "-a", "--", "$datadir/kmodsrc", $kmodsrc);
 173 $ENV{KSPLICE_KMODSRC} = $kmodsrc;
 174
 175 my @make_kmodsrc = (@make, "-C", $kernel_headers_dir, "M=$kmodsrc", "KSPLICE_KID=$kid", "KSPLICE_VERSION=PACKAGE_VERSION", "map_printk=$map_printk");
 176
 177 if (!defined($standalone)) {
 178         $standalone = (runval_raw(qw(grep -q ^CONFIG_KSPLICE=[ym]$), "$linuxtree/.config") != 0);
 179 }
 180 push(@make_kmodsrc, "KSPLICE_STANDALONE=1") if ($standalone);
 181
 182 runval(@make_kmodsrc);
 183
 184 @patch_opt = ("-s", @patch_opt) if ($Verbose::level < 0);
 185
 186 runval_infile($patchfile, "patch", @patch_opt, "-bz", ".KSPLICE_presrc");
 187 my @diff_flags = ("KSPLICE_MODE=diff");
 188 push @diff_flags, "KSPLICE_EXTRA_MATCH=@extra_match" if (@extra_match);
 189 push @diff_flags, "KSPLICE_ONLY_TARGETS=@only_targets" if (@only_targets);
 190 if(runval_raw(@make_ksplice, @diff_flags) != 0) {
 191         revert_orig() if(defined($diffext));
 192         die "Aborting: Applying the patch appears to break the kernel build";
 193 }
 194
 195 sub copy_debug {
 196         my ($file) = @_;
 197         my ($dir, $base) = (dirname($file), basename($file));
 198         -d "$tmpdir/objects/$dir" or mkpath("$tmpdir/objects/$dir");
 199         copy($file, "$tmpdir/objects/$file");
 200         my $cmdfile = "$dir/.$base.cmd";
 201         copy($cmdfile, "$tmpdir/objects/$cmdfile") if(-e $cmdfile);
 202 }
 203
 204 mkdir("$tmpdir/objects");
 205 for (split(/\0/, runstr(qw(find -name *.KSPLICE* ! ( -name *.KSPLICE -empty ) ! -name .*.KSPLICE.cmd -print0)))) {
 206         copy_debug($_);
 207         copy_debug($1) if (m/^(.*)\.KSPLICE_pre(?:src)$/);
 208 }
 209
 210 my @modulepaths = ();
 211 my @modules = ();
 212 foreach(glob("$kmodsrc/*.mod.KSPLICE")) {
 213         open MOD, '<', $_;
 214         chomp(my $mod = <MOD>);
 215         close MOD;
 216         push @modulepaths, "$mod.ko" if ($mod ne "vmlinux");
 217         push @modules, basename($mod);
 218 }
 219
 220 if(!@modules) {
 221         revert_orig() if(defined($diffext));
 222         die "Aborting: No changes detected";
 223 }
 224
 225 if ($build_modules) {
 226         mkdir("$tmpdir/modules");
 227         runval(@make_ksplice, "KSPLICE_MODE=modinst", "MODLIB=$tmpdir/modules", "modules=@modulepaths");
 228 }
 229
 230 revert_orig() if(defined($diffext));
 231
 232 runval(@make_kmodsrc, "modules", "KSPLICE_MODULES=@modules");
 233
 234 chdir($tmpdir);
 235 mkdir($ksplice);
 236 move($patchfile, $ksplice);
 237 if ($description) {
 238         write_file("$ksplice/description", "$description\n");
 239 }
 240 write_file("$ksplice/api-version", "KSPLICE_API_VERSION\n");
 241 write_file("$ksplice/timestamp", time() . "\n");
 242 runval_outfile("$ksplice/utsname", "/usr/local/libexec/ksplice-kernel-utsname", "$kmodsrc/offsets.o");
 243 open(CONTENTS, ">", "$ksplice/contents");
 244 foreach my $mod (@modules) {
 245         (my $target = $mod) =~ s/-/_/g;
 246         my $mid = "${kid}_$target";
 247         my $module = "ksplice-$mid";
 248         rename("$kmodsrc/$module.ko", "$ksplice/$module.ko");
 249         print CONTENTS "primary $target ksplice_$mid $module.ko\n";
 250         rename("$kmodsrc/$module-helper.ko", "$ksplice/$module-helper.ko");
 251         print CONTENTS "helper $target ksplice_$mid $module-helper.ko\n";
 252 }
 253 if ($standalone) {
 254         rename("$kmodsrc/ksplice-$kid.ko", "$ksplice/ksplice-$kid.ko");
 255         print CONTENTS "core ksplice_$kid ksplice-$kid.ko\n";
 256 }
 257 if ($build_modules) {
 258         foreach my $mod (@modulepaths) {
 259                 (my $target = basename($mod)) =~ s/-/_/g;
 260                 print CONTENTS "target $target $mod\n";
 261         }
 262 }
 263
 264 mkdir("$ksplice/debug");
 265 rename("objects", "$ksplice/debug/objects");
 266 rename("modules", "$ksplice/modules") if ($build_modules);
 267 rename("$kmodsrc", "$ksplice/debug/kmodsrc");
 268
 269 close(CONTENTS);
 270 runval("tar", "czf", "$ksplice.tar.gz", "--", $ksplice);
 271 copy("$ksplice.tar.gz", "$origdir/$ksplice.tar.gz");
 272 print "Ksplice update tarball written to $ksplice.tar.gz\n";
 273 exit(0);
 274
 275 =head1 NAME
 276
 277 ksplice-create - Create a set of kernel modules for a rebootless kernel update
 278
 279 =head1 SYNOPSIS
 280
 281 B<ksplice-create> [B<--config=>I<ORIG_CONFIG>] B<--patch=>I<PATCH_FILE> I<KERNEL_SOURCE>
 282
 283 B<ksplice-create> [B<--config=>I<ORIG_CONFIG>] B<--diffext=>I<EXTENSION> I<KERNEL_SOURCE>
 284
 285 B<ksplice-create> [B<--config=>I<ORIG_CONFIG>] B<--prebuild> I<KERNEL_SOURCE>
 286
 287 =head1 DESCRIPTION
 288
 289 B<ksplice-create> creates a set of Ksplice kernel modules that, when loaded,
 290 will apply a user-specified source code patch to the running binary kernel.
 291
 292 Before you use B<ksplice-create> on a patch, you should confirm that the
 293 desired source code change does not make any semantic changes to kernel data
 294 structures--that is, changes that would require existing instances of kernel
 295 data structures to be transformed (e.g., a patch that adds a field to a global
 296 data structure would require the existing data structures to change).  If you
 297 use Ksplice on a patch that changes data structure semantics, Ksplice will not
 298 detect the problem and you could experience kernel problems as a result.
 299
 300 The to-be-applied source code patch can be specified by providing a L<patch(1)>
 301 file (B<--patch=>I<PATCH_FILE>) or by providing a file extension
 302 (B<--diffext=>I<EXTENSION>).
 303
 304 If a file extension is specified, then the desired source code patch will be
 305 determined by comparing all of the files in the I<KERNEL_SOURCE> directory tree
 306 whose names end with the extra extension I<EXTENSION> against the corresponding
 307 files without the extra extension.  Only the new files containing the extra
 308 extension in their filenames should be modified.
 309
 310 Here is an example of using a file extension to specify a patch:
 311
 312  $ cp KERNEL_SOURCE/kernel/sys.c KERNEL_SOURCE/kernel/sys.c.prctl_fixed
 313  [edit sys.c.prctl_fixed to include the desired changes]
 314  $ ksplice-create --diffext=.prctl_fixed KERNEL_SOURCE
 315
 316 KERNEL_SOURCE must be a directory containing the to-be-updated kernel's
 317 original source code.  If your Linux distribution applies patches to the Linux
 318 kernel during the kernel build process, then those patches must be applied to
 319 the I<KERNEL_SOURCE> directory before invoking B<ksplice-create> on that
 320 directory.  B<ksplice-create> will not modify the source code in the
 321 I<KERNEL_SOURCE> directory tree, but it will perform a kernel build in that
 322 directory tree.
 323
 324 I<ORIG_CONFIG> can be used to specify the directory containing the
 325 to-be-updated kernel's original F<.config> file and original F<System.map> file
 326 (the files should have exactly those names).  I<ORIG_CONFIG> defaults to
 327 I<KERNEL_SOURCE>B</ksplice>.
 328
 329 The default L<gcc(1)> compiler and L<as(1)> assembler on the system should be as
 330 close to the compiler and assembler originally used to build the running kernel
 331 as possible.  If the current compiler and linker are too different from the
 332 original compiler and linker, B<ksplice-apply> will abort when applying the
 333 update.
 334
 335 B<ksplice-create> outputs a L<tar(1)> file, compressed with L<gzip(1)>,
 336 containing the desired Ksplice update modules.  This tarball will be created in
 337 the current directory, and it can be manipulated using the other Ksplice
 338 utilities, such as B<ksplice-apply>.
 339
 340 The first time that B<ksplice-create> is invoked on a I<KERNEL_SOURCE>
 341 directory, it must build that kernel from scratch, which is much slower than
 342 the rest of the update-creation process.  B<--prebuild> can be used to perform
 343 this initial kernel build without providing a source code patch.
 344
 345 In order to patch a function that has previously been patched by Ksplice, the
 346 user needs to ensure that the I<KERNEL_SOURCE> directory provided to Ksplice
 347 contains the source for the currently running kernel, including any patches
 348 that have previously been applied by Ksplice.
 349
 350 =head1 OPTIONS
 351
 352 =over 8
 353
 354 =item B<-v>, B<--verbose>
 355
 356 Causes B<ksplice-create> to print debugging messages about its progress.  Using
 357 multiple -v options increases the verbosity.  The maximum is 2.
 358
 359 =item B<-j> I<JOBS>, B<--jobs=>I<JOBS>
 360
 361 Specifies the number of jobs to run simultaneously while performing kernel
 362 builds.  B<ksplice-create> also honors the environment variable
 363 CONCURRENCY_LEVEL.
 364
 365 =item B<--patch-opt=>I<OPTIONS>
 366
 367 Can be used to pass options to L<patch(1)>.  If this option is NOT specified, then
 368 B<-p1> is passed to B<patch>.  If this option is specified, then only the
 369 specified options will be passed to B<patch>.  This option can be repeated in
 370 order to pass multiple options to B<patch>.  This option is ignored when the
 371 to-be-applied source code patch is specified using B<--diffext>.
 372
 373 =item B<--id=>I<ID>
 374
 375 Specifies the unique value that will be used as the identifier of the
 376 Ksplice update.  This identifier will, for example, appear in the name
 377 of the update tarball.  By default, a random 8-character ID will be
 378 generated.
 379
 380 =back
 381
 382 =head1 SEE ALSO
 383
 384 L<ksplice-apply(8)>, L<ksplice-view(8)>, L<ksplice-undo(8)>
 385
 386 =head1 BUGS
 387
 388 Please report bugs to <PACKAGE_BUGREPORT>.
 389
 390 =head1 COPYRIGHT
 391
 392 Copyright (C) 2007-2008  Jeffrey Brian Arnold <jbarnold@mit.edu>
 393
 394 Copyright (C) 2008  Anders Kaseorg <andersk@mit.edu>,
 395                     Tim Abbott <tabbott@mit.edu>
 396
 397 This is free software and documentation.  You can redistribute and/or modify it
 398 under the terms of the GNU General Public License, version 2.
 399
 400 =cut