ksplice-apply.in

   1 #!/usr/bin/perl
   2
   3 # Copyright (C) 2007-2008  Jeff 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 $debug;
  26 my $debugon = 0;
  27 my $partial = 0;
  28 GetOptions(@common_options,
  29         "partial" => \$partial,
  30         "debug" => \$debugon,
  31         "debugfile=s" => \$debug) or pod2usage(1);
  32
  33 pod2usage(1) if($help || scalar(@ARGV) != 1);
  34
  35 my $file = abs_path($ARGV[0]);
  36 $debugon = 1 if(defined $debug);
  37 $debug = abs_path($debug) if (defined $debug);
  38
  39 my $tmpdir = tempdir('ksplice-tmp-XXXXXX', TMPDIR => 1, CLEANUP => 1);
  40 chdir($tmpdir);
  41 my $ksplice = unpack_update($file);
  42 chdir($ksplice);
  43
  44 die "No contents file in $file\n" if (!-e "contents");
  45 open(CONTENTS, '<', "contents");
  46 my $core;
  47 while (<CONTENTS>) {
  48         my @line = split(' ', $_);
  49         if ($line[0] eq 'core') {
  50                 die "Multiple core modules in $file!" if (defined $core);
  51                 $core = {
  52                         module => $line[1],
  53                         file => $line[2],
  54                 };
  55         }
  56 }
  57 close(CONTENTS);
  58
  59 my $nounload = runstr("lsmod") =~ m/- $/m;
  60
  61 (my $kid = $ksplice) =~s|ksplice[-_]([^-_]+)|$1|;
  62 my $update = "ksplice_$kid";
  63 if(update_loaded($kid)) {
  64         my $stage = get_stage($kid);
  65         if ($stage eq "applied") {
  66                 print STDERR "Ksplice update $kid already applied.\n";
  67                 exit(0);
  68         }
  69         die "Reversed Ksplice module $update already loaded!" if ($stage eq "reversed");
  70 }
  71
  72 runstr_err(qw(modprobe -q ksplice)) eq "" || die;
  73 if (defined $core) {
  74         die "Could not find Ksplice core module $core->{file}\n" if (!-e $core->{file});
  75         if (runstr("lsmod") =~ m/^\Q$core->{module}\E\s+/) {
  76                 die "Ksplice core module $core already loaded.";
  77         }
  78         if (!load_module($core->{file}, "debug=$debugon")) {
  79                 die "Error loading Ksplice core module $core->{module} for update $kid";
  80         }
  81 }
  82
  83 my @helpers = ();
  84 foreach my $helper (glob('ksplice-*-helper.ko')) {
  85         (my $primary = $helper) =~ s/\-helper\.ko$/.ko/;
  86         die unless(-e $primary && -e $helper);
  87         (my $target = $primary) =~ s/^ksplice-[^_]+_(.*)\.ko/$1/;
  88         if ($target ne 'vmlinux' && runstr("lsmod") !~ m/^${target}\s/m) {
  89                 if (!$partial) {
  90                         cleanup_modules();
  91                         print_error("target_not_loaded");
  92                         die "Module $target to be patched not loaded";
  93                 }
  94         }
  95         push @helpers, $helper;
  96 }
  97 foreach my $helper (@helpers) {
  98         (my $primary = $helper) =~ s/\-helper\.ko$/.ko/;
  99         if(!load_module($primary)) {
 100                 die "Error loading primary module $primary";
 101         }
 102         if(!load_module($helper)) {
 103                 my $debugfile = get_debug_output("init_$kid", $debug);
 104                 print STDERR "Error loading helper module $helper\n";
 105                 (my $module = $primary) =~ s/-/_/g;
 106                 $module =~ s/\.ko//;
 107                 cleanup_modules();
 108                 if($debugon && defined $debugfile) {
 109                         print("Debugging output saved to $debugfile\n");
 110                 }
 111                 die;
 112         }
 113 }
 114
 115 set_debug_level($kid, $debugon);
 116 set_partial($kid, $partial);
 117 set_stage($kid, "applied");
 118 my $stage = get_stage($kid);
 119 if($stage ne 'applied') {
 120         my $debugfile = get_debug_output($kid, $debug);
 121         my $abort_cause = get_abort_cause($kid);
 122         my $conflicts = get_conflicts($kid);
 123         cleanup_modules();
 124         print STDERR "Error applying Ksplice update $kid:\n";
 125         print_error($abort_cause);
 126         if ($abort_cause eq 'code_busy') {
 127                 print $conflicts;
 128         }
 129         if ($debugon && defined $debugfile) {
 130                 print("Debugging output saved to $debugfile\n");
 131         }
 132         die;
 133 }
 134 mkpath("/var/run/ksplice/updates/$kid");
 135 copy("patch", "/var/run/ksplice/updates/$kid/patch") if (-e "patch");
 136 copy("description", "/var/run/ksplice/updates/$kid/description") if (-e "description");
 137 if (!$nounload) {
 138         foreach my $helper (@helpers) {
 139                 $helper =~ s/-/_/g;
 140                 $helper =~ s/\.ko$//;
 141                 (my $primary = $helper) =~ s/_helper$//;
 142                 runval('rmmod', $helper);
 143                 runval('rmmod', $primary) if ($partial && refcount($primary) == 0);
 144         }
 145 }
 146 print "Done!\n";
 147 exit(0);
 148
 149 my @modules_loaded = qw();
 150
 151 sub load_module {
 152         my ($module, @params) = @_;
 153         if (runval_raw("insmod", $module, @params) != 0) {
 154                 child_error();
 155                 return 0;
 156         }
 157         $module =~ s/\.ko//;
 158         $module =~ s/-/_/g;
 159         push @modules_loaded, $module;
 160         return 1;
 161 }
 162
 163 sub refcount {
 164         my ($module) = @_;
 165         foreach(split(/\n/, runstr("lsmod"))) {
 166                 if (m/^(\S+)\s+[0-9]+\s+([0-9])+\s/) {
 167                         return $2 if ($1 eq $module);
 168                 }
 169         }
 170         return -1;
 171 }
 172
 173 sub cleanup_modules {
 174         foreach my $module (reverse(@modules_loaded)) {
 175                 runval("rmmod", $module) if(!$nounload);
 176         }
 177 }
 178
 179 sub print_error {
 180         my ($error) = @_;
 181         my %errors = (
 182                 "no_match" => <<'END',
 183 Ksplice has aborted the upgrade because Ksplice has been unable to match the
 184 object code produced by your current compiler and assembler against the running
 185 kernel's object code.  If you provided the exact kernel source to the running
 186 kernel, then it appears that your current compiler and/or assembler are
 187 behaving differently from the compiler and assembler used to build the running
 188 kernel.  If possible, please use the exact compiler and assembler that were
 189 used to build the running kernel.  If you are using exactly the same compiler
 190 and assembler, consider reporting a bug to PACKAGE_BUGREPORT.
 191 END
 192                 "code_busy" => <<'END',
 193 Ksplice has aborted the upgrade because it appears that the code that you are
 194 trying to patch is continuously in use by the system.  More specifically,
 195 Ksplice has been unable to find a moment when one or more of the to-be-patched
 196 functions is not on a thread's kernel stack.
 197 END
 198                 "bad_system_map" => <<'END',
 199 Ksplice has aborted the upgrade because it appears that the System.map file
 200 provided to ksplice-create does not match the running kernel.
 201 END
 202                 "failed_to_find" => <<'END',
 203 Ksplice has aborted the upgrade because it was unable to resolve some of the
 204 symbols used in the update.
 205 END
 206                 "already_reversed" => <<'END',
 207 The Ksplice update that you are attempting to apply has already been applied
 208 and reversed.  You need to unload the Ksplice modules associated with this
 209 update before you can apply this update again.
 210 END
 211                 "missing_export" => <<'END',
 212 Ksplice has aborted the upgrade because the symbols exported by the kernel
 213 did not match Ksplice's expectations.
 214 END
 215                 "unexpected_running_task" => <<'END',
 216 Ksplice has aborted the upgrade because of an unexpected failure during the
 217 kernel stack check.  Please consider reporting a bug to PACKAGE_BUGREPORT.
 218 END
 219                 "target_not_loaded" => <<'END',
 220 Ksplice has aborted the upgrade because one of the modules to be
 221 patched by the update was not loaded.  If you want to apply this
 222 update only to those modules that are loaded, then you should use the
 223 --partial option.
 224 END
 225                 "out_of_memory" => <<'END',
 226 Ksplice has aborted the upgrade because the kernel ran out of memory.
 227 END
 228                 "call_failed" => <<'END',
 229 Ksplice has aborted the upgrade at the request of a one of the
 230 pre-application hooks that were included as part of this Ksplice
 231 update.  This is likely the result of a bug in the patch used to
 232 generate this update.
 233 END
 234                 "unexpected" => <<'END',
 235 Ksplice has aborted because of an unexpected error.
 236 Please consider reporting a bug to PACKAGE_BUGREPORT.
 237 END
 238                 "UNKNOWN" => <<'END',
 239 The Ksplice kernel component has returned an error code that this version of
 240 ksplice-apply does not understand.
 241 END
 242                 "ok" => <<'END',
 243 Ksplice has aborted the upgrade for unknown reasons.
 244 Please consider reporting a bug to PACKAGE_BUGREPORT.
 245 END
 246         );
 247         $error = "UNKNOWN" if (!exists $errors{$error});
 248         print STDERR "\n$errors{$error}\n";
 249 }
 250
 251 =head1 NAME
 252
 253 ksplice-apply - Apply an on-disk Ksplice update to the running kernel
 254
 255 =head1 SYNOPSIS
 256
 257 B<ksplice-apply> I<UPDATE_TARBALL>
 258
 259 =head1 DESCRIPTION
 260
 261 B<ksplice-apply> takes as input a Ksplice update tarball, as generated by
 262 L<ksplice-create(8)>, and it applies the update to the running binary kernel.
 263
 264 The update tarball used with B<ksplice-apply> must have been generated for the
 265 running kernel's version.
 266
 267 =head1 OPTIONS
 268
 269 =over 8
 270
 271 =item B<--debug>
 272
 273 Applies the update with debugging output enabled.  Recommended only for
 274 debugging.
 275
 276 =item B<--debugfile=>I<filename>
 277
 278 Sets the location where debugging output should be saved.  Implies --debug.
 279
 280 =item B<--partial>
 281
 282 Applies the update only to those modules which are loaded.  Any
 283 modules patched by the update that are not loaded are ignored (without
 284 this option, Ksplice aborts if any modules patched by the update are
 285 not loaded).
 286
 287 =back
 288
 289 =head1 SEE ALSO
 290
 291 L<ksplice-create(8)>, L<ksplice-view(8)>, L<ksplice-undo(8)>
 292
 293 =head1 BUGS
 294
 295 Please report bugs to <PACKAGE_BUGREPORT>.
 296
 297 =head1 COPYRIGHT
 298
 299 Copyright (C) 2007-2008  Jeff Arnold <jbarnold@mit.edu>
 300
 301 Copyright (C) 2008  Anders Kaseorg <andersk@mit.edu>,
 302                     Tim Abbott <tabbott@mit.edu>
 303
 304 This is free software and documentation.  You can redistribute and/or modify it
 305 under the terms of the GNU General Public License, version 2.
 306
 307 =cut