ksplice.pl.in

   1 #!/usr/bin/perl
   2
   3 # Copyright (C) 2008  Anders Kaseorg <andersk@mit.edu>,
   4 #                     Jeffrey Brian Arnold <jbarnold@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 use File::Copy;
  25 use Digest::MD5;
  26
  27 sub empty_diff {
  28         my ($out) = @_;
  29         my ($obj) = $out =~ /^(.*)\.KSPLICE$/ or die;
  30         unlink "$obj.KSPLICE_primary" if (-e "$obj.KSPLICE_primary");
  31         unlink "$obj.KSPLICE_helper" if (-e "$obj.KSPLICE_helper");
  32         open OUT, '>', "$out.tmp";
  33         close OUT;
  34         rename "$out.tmp", $out;
  35 }
  36
  37 sub do_snap {
  38         my ($out) = @_;
  39         my ($obj) = $out =~ /^(.*)\.KSPLICE$/ or die;
  40         die if (!-e $obj);
  41         unlink "$obj.KSPLICE_pre" if (-e "$obj.KSPLICE_pre");
  42         empty_diff($out);
  43 }
  44
  45 sub do_diff {
  46         my ($out) = @_;
  47         my ($obj) = $out =~ /^(.*)\.KSPLICE$/ or die;
  48         my $obj_old = "$obj.KSPLICE_pre";
  49         return do_snap($out) if (!-e $obj_old);
  50         die if (!-e $obj);
  51         if (system('cmp', '-s', '--', $obj_old, $obj) == 0) {
  52                 unlink $obj_old;
  53                 return empty_diff($out);
  54         }
  55
  56         my ($bits, $sections, $entrysyms) = split("\n", runsuc("objdiff", $obj_old, $obj));
  57         die if ($bits ne '32' && $bits ne '64');
  58         return empty_diff($out) if ($sections eq '' && $entrysyms eq '');
  59
  60         copy($obj, "$obj.KSPLICE_primary");
  61         copy($obj_old, "$obj.KSPLICE_helper");
  62
  63         open OBJ, '<', $obj or die;
  64         open OBJ_OLD, '<', $obj_old or die;
  65         my $tag = Digest::MD5->new->addfile(*OBJ)->addfile(*OBJ_OLD)->hexdigest;
  66         close OBJ;
  67         close OBJ_OLD;
  68
  69         my $relocs_primary = runsuc("objmanip", "$obj.KSPLICE_primary", "keep-primary", "____${tag}", "_post", split(/\s/, $sections));
  70         runsuc("objmanip", "$obj.KSPLICE_primary", "globalize", "____${tag}_post");
  71
  72         my $relocs_helper = runsuc("objmanip", "$obj.KSPLICE_helper", "keep-helper", "____${tag}", "_pre");
  73         runsuc("objmanip", "$obj.KSPLICE_helper", "globalize", "____${tag}_pre");
  74
  75         my $patchlist = "";
  76         foreach my $sym (split(/\s/, $entrysyms)) {
  77                 $patchlist .= "${sym}____${tag}_pre ${sym}____${tag}_post\n";
  78         }
  79
  80         open OUT, '>', "$out.tmp";
  81         print OUT "$bits\n$patchlist\n$relocs_primary\n$relocs_helper\n";
  82         close OUT;
  83         rename "$out.tmp", $out;
  84 }
  85
  86 sub do_combine {
  87         my ($out, @ins) = @_;
  88         my @objs;
  89         my ($outbits, $patchlist, $relocs_primary, $relocs_helper) = (undef, '', '', '');
  90         foreach my $in (@ins) {
  91                 next if (!-s $in);
  92                 my ($obj) = $in =~ /^(.*)\.KSPLICE$/ or die;
  93                 push @objs, $obj;
  94
  95                 open IN, '<', $in;
  96
  97                 chomp(my $bits = <IN>);
  98                 die if (defined $outbits && $outbits ne $bits);
  99                 $outbits = $bits;
 100
 101                 $patchlist .= $_ while (($_ = <IN>) ne "\n");
 102                 $relocs_primary .= $_ while (($_ = <IN>) ne "\n");
 103                 $relocs_helper .= $_ while (($_ = <IN>) ne "\n");
 104
 105                 close IN;
 106         }
 107
 108         return empty_diff($out) unless (defined $outbits);
 109
 110         my ($obj) = $out =~ /^(.*)\.KSPLICE$/ or die;
 111         if (@objs == 1) {
 112                 copy "$objs[0].KSPLICE_primary", "$obj.KSPLICE_primary";
 113                 copy "$objs[0].KSPLICE_helper", "$obj.KSPLICE_helper";
 114         } else {
 115                 system("ld", "-r", "-o",
 116                        map { "$_.KSPLICE_primary" } ($obj, @objs));
 117                 system("ld", "-r", "-o",
 118                        map { "$_.KSPLICE_helper" } ($obj, @objs));
 119         }
 120
 121         open OUT, '>', "$out.tmp";
 122         print OUT "$outbits\n$patchlist\n$relocs_primary\n$relocs_helper\n";
 123         close OUT;
 124         rename "$out.tmp", $out;
 125 }
 126
 127 my %handlers = (
 128         'snap' => \&do_snap,
 129         'diff' => \&do_diff,
 130         'combine' => \&do_combine,
 131 );
 132
 133 my ($cmd, @args) = @ARGV;
 134 if (exists $handlers{$cmd}) {
 135         my $handler = $handlers{$cmd};
 136         &$handler(@args);
 137 } else {
 138         print "Usage: ksplice.pl ", join('|', keys %handlers), " ...\n";
 139 };