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         next if (basename($_) =~ m/^(?:vmlinux|vmlinux\.o|\.tmp_vmlinux[0-9]+|\.tmp_kallsyms[0-9]+.o)\.KSPLICE_pre$/);
 207         copy_debug($_);
 208         copy_debug($1) if (m/^(.*)\.KSPLICE_pre(?:src)$/);
 209 }
 210
 211 my @modulepaths = ();
 212 my @modules = ();
 213 foreach(glob("$kmodsrc/*.mod.KSPLICE")) {
 214         open MOD, '<', $_;
 215         chomp(my $mod = <MOD>);
 216         close MOD;
 217         push @modulepaths, "$mod.ko" if (basename($mod) ne "vmlinux");
 218         push @modules, basename($mod);
 219 }
 220
 221 if(!@modules) {
 222         revert_orig() if(defined($diffext));
 223         print STDERR "No changes detected.\n";
 224         exit(66);
 225 }
 226
 227 if ($build_modules) {
 228         mkdir("$tmpdir/modules");
 229         runval(@make_ksplice, "KSPLICE_MODE=modinst", "MODLIB=$tmpdir/modules", "modules=@modulepaths");
 230 }
 231
 232 revert_orig() if(defined($diffext));
 233
 234 runval(@make_kmodsrc, "modules", "KSPLICE_MODULES=@modules");
 235
 236 chdir($tmpdir);
 237 mkdir($ksplice);
 238 move($patchfile, $ksplice);
 239 if ($description) {
 240         write_file("$ksplice/description", "$description\n");
 241 }
 242 write_file("$ksplice/api-version", "KSPLICE_API_VERSION\n");
 243 write_file("$ksplice/timestamp", time() . "\n");
 244 runval_outfile("$ksplice/utsname", "/usr/local/libexec/ksplice-kernel-utsname", "$kmodsrc/offsets.o");
 245 open(CONTENTS, ">", "$ksplice/contents");
 246 foreach my $mod (@modules) {
 247         (my $target = $mod) =~ s/-/_/g;
 248         my $mid = "${kid}_$target";
 249         my $module = "ksplice-$mid";
 250         rename("$kmodsrc/$module.ko", "$ksplice/$module.ko");
 251         print CONTENTS "primary $target ksplice_$mid $module.ko\n";
 252         rename("$kmodsrc/$module-helper.ko", "$ksplice/$module-helper.ko");
 253         print CONTENTS "helper $target ksplice_$mid $module-helper.ko\n";
 254 }
 255 if ($standalone) {
 256         rename("$kmodsrc/ksplice-$kid.ko", "$ksplice/ksplice-$kid.ko");
 257         print CONTENTS "core ksplice_$kid ksplice-$kid.ko\n";
 258 }
 259 if ($build_modules) {
 260         foreach my $mod (@modulepaths) {
 261                 (my $target = basename($mod)) =~ s/-/_/g;
 262                 print CONTENTS "target $target $mod\n";
 263         }
 264 }
 265
 266 mkdir("$ksplice/debug");
 267 rename("objects", "$ksplice/debug/objects");
 268 rename("modules", "$ksplice/modules") if ($build_modules);
 269 rename("$kmodsrc", "$ksplice/debug/kmodsrc");
 270
 271 close(CONTENTS);
 272 runval("tar", "czf", "$ksplice.tar.gz", "--", $ksplice);
 273 copy("$ksplice.tar.gz", "$origdir/$ksplice.tar.gz");
 274 print "Ksplice update tarball written to $ksplice.tar.gz\n";
 275 exit(0);
 276
 277 =head1 NAME
 278
 279 ksplice-create - Create a set of kernel modules for a rebootless kernel update
 280
 281 =head1 SYNOPSIS
 282
 283 B<ksplice-create> [B<--config=>I<ORIG_CONFIG>] B<--patch=>I<PATCH_FILE> I<KERNEL_SOURCE>
 284
 285 B<ksplice-create> [B<--config=>I<ORIG_CONFIG>] B<--diffext=>I<EXTENSION> I<KERNEL_SOURCE>
 286
 287 B<ksplice-create> [B<--config=>I<ORIG_CONFIG>] B<--prebuild> I<KERNEL_SOURCE>
 288
 289 =head1 DESCRIPTION
 290
 291 B<ksplice-create> creates a set of Ksplice kernel modules that, when loaded,
 292 will apply a user-specified source code patch to the running binary kernel.
 293
 294 Before you use B<ksplice-create> on a patch, you should confirm that the
 295 desired source code change does not make any semantic changes to kernel data
 296 structures--that is, changes that would require existing instances of kernel
 297 data structures to be transformed (e.g., a patch that adds a field to a global
 298 data structure would require the existing data structures to change).  If you
 299 use Ksplice on a patch that changes data structure semantics, Ksplice will not
 300 detect the problem and you could experience kernel problems as a result.
 301
 302 The to-be-applied source code patch can be specified by providing a L<patch(1)>
 303 file (B<--patch=>I<PATCH_FILE>) or by providing a file extension
 304 (B<--diffext=>I<EXTENSION>).
 305
 306 If a file extension is specified, then the desired source code patch will be
 307 determined by comparing all of the files in the I<KERNEL_SOURCE> directory tree
 308 whose names end with the extra extension I<EXTENSION> against the corresponding
 309 files without the extra extension.  Only the new files containing the extra
 310 extension in their filenames should be modified.
 311
 312 Here is an example of using a file extension to specify a patch:
 313
 314  $ cp KERNEL_SOURCE/kernel/sys.c KERNEL_SOURCE/kernel/sys.c.prctl_fixed
 315  [edit sys.c.prctl_fixed to include the desired changes]
 316  $ ksplice-create --diffext=.prctl_fixed KERNEL_SOURCE
 317
 318 KERNEL_SOURCE must be a directory containing the to-be-updated kernel's
 319 original source code.  If your Linux distribution applies patches to the Linux
 320 kernel during the kernel build process, then those patches must be applied to
 321 the I<KERNEL_SOURCE> directory before invoking B<ksplice-create> on that
 322 directory.  B<ksplice-create> will not modify the source code in the
 323 I<KERNEL_SOURCE> directory tree, but it will perform a kernel build in that
 324 directory tree.
 325
 326 I<ORIG_CONFIG> can be used to specify the directory containing the
 327 to-be-updated kernel's original F<.config> file and original F<System.map> file
 328 (the files should have exactly those names).  I<ORIG_CONFIG> defaults to
 329 I<KERNEL_SOURCE>B</ksplice>.
 330
 331 The default L<gcc(1)> compiler and L<as(1)> assembler on the system should be as
 332 close to the compiler and assembler originally used to build the running kernel
 333 as possible.  If the current compiler and linker are too different from the
 334 original compiler and linker, B<ksplice-apply> will abort when applying the
 335 update.
 336
 337 B<ksplice-create> outputs a L<tar(1)> file, compressed with L<gzip(1)>,
 338 containing the desired Ksplice update modules.  This tarball will be created in
 339 the current directory, and it can be manipulated using the other Ksplice
 340 utilities, such as B<ksplice-apply>.
 341
 342 The first time that B<ksplice-create> is invoked on a I<KERNEL_SOURCE>
 343 directory, it must build that kernel from scratch, which is much slower than
 344 the rest of the update-creation process.  B<--prebuild> can be used to perform
 345 this initial kernel build without providing a source code patch.
 346
 347 In order to patch a function that has previously been patched by Ksplice, the
 348 user needs to ensure that the I<KERNEL_SOURCE> directory provided to Ksplice
 349 contains the source for the currently running kernel, including any patches
 350 that have previously been applied by Ksplice.
 351
 352 =head1 OPTIONS
 353
 354 =over 8
 355
 356 =item B<-v>, B<--verbose>
 357
 358 Causes B<ksplice-create> to print debugging messages about its progress.  Using
 359 multiple -v options increases the verbosity.  The maximum is 2.
 360
 361 =item B<-j> I<JOBS>, B<--jobs=>I<JOBS>
 362
 363 Specifies the number of jobs to run simultaneously while performing kernel
 364 builds.  B<ksplice-create> also honors the environment variable
 365 CONCURRENCY_LEVEL.
 366
 367 =item B<--patch-opt=>I<OPTIONS>
 368
 369 Can be used to pass options to L<patch(1)>.  If this option is NOT specified, then
 370 B<-p1> is passed to B<patch>.  If this option is specified, then only the
 371 specified options will be passed to B<patch>.  This option can be repeated in
 372 order to pass multiple options to B<patch>.  This option is ignored when the
 373 to-be-applied source code patch is specified using B<--diffext>.
 374
 375 =item B<--id=>I<ID>
 376
 377 Specifies the unique value that will be used as the identifier of the
 378 Ksplice update.  This identifier will, for example, appear in the name
 379 of the update tarball.  By default, a random 8-character ID will be
 380 generated.
 381
 382 =back
 383
 384 =head1 SEE ALSO
 385
 386 L<ksplice-apply(8)>, L<ksplice-view(8)>, L<ksplice-undo(8)>
 387
 388 =head1 BUGS
 389
 390 Please report bugs to <PACKAGE_BUGREPORT>.
 391
 392 =head1 COPYRIGHT
 393
 394 Copyright (C) 2007-2008  Jeffrey Brian Arnold <jbarnold@mit.edu>
 395
 396 Copyright (C) 2008  Anders Kaseorg <andersk@mit.edu>,
 397                     Tim Abbott <tabbott@mit.edu>
 398
 399 This is free software and documentation.  You can redistribute and/or modify it
 400 under the terms of the GNU General Public License, version 2.
 401
 402 =cut