arch/powerpc/relocs_check.pl

   1 #!/usr/bin/perl
   2
   3 # Copyright © 2009 IBM Corporation
   4
   5 # This program is free software; you can redistribute it and/or
   6 # modify it under the terms of the GNU General Public License
   7 # as published by the Free Software Foundation; either version
   8 # 2 of the License, or (at your option) any later version.
   9
  10 # This script checks the relocations of a vmlinux for "suspicious"
  11 # relocations.
  12
  13 use strict;
  14 use warnings;
  15
  16 if ($#ARGV != 1) {
  17         die "$0 [path to objdump] [path to vmlinux]\n";
  18 }
  19
  20 # Have Kbuild supply the path to objdump so we handle cross compilation.
  21 my $objdump = shift;
  22 my $vmlinux = shift;
  23 my $bad_relocs_count = 0;
  24 my $bad_relocs = "";
  25 my $old_binutils = 0;
  26
  27 open(FD, "$objdump -R $vmlinux|") or die;
  28 while (<FD>) {
  29         study $_;
  30
  31         # Only look at relocation lines.
  32         next if (!/\s+R_/);
  33
  34         # These relocations are okay
  35         # On PPC64:
  36         #       R_PPC64_RELATIVE, R_PPC64_NONE, R_PPC64_ADDR64
  37         # On PPC:
  38         #       R_PPC_RELATIVE, R_PPC_ADDR16_HI,
  39         #       R_PPC_ADDR16_HA,R_PPC_ADDR16_LO,
  40         #       R_PPC_NONE
  41
  42         next if (/\bR_PPC64_RELATIVE\b/ or /\bR_PPC64_NONE\b/ or
  43                  /\bR_PPC64_ADDR64\s+mach_/);
  44         next if (/\bR_PPC_ADDR16_LO\b/ or /\bR_PPC_ADDR16_HI\b/ or
  45                  /\bR_PPC_ADDR16_HA\b/ or /\bR_PPC_RELATIVE\b/ or
  46                  /\bR_PPC_NONE\b/);
  47
  48         # If we see this type of relocation it's an idication that
  49         # we /may/ be using an old version of binutils.
  50         if (/R_PPC64_UADDR64/) {
  51                 $old_binutils++;
  52         }
  53
  54         $bad_relocs_count++;
  55         $bad_relocs .= $_;
  56 }
  57
  58 if ($bad_relocs_count) {
  59         print "WARNING: $bad_relocs_count bad relocations\n";
  60         print $bad_relocs;
  61 }
  62
  63 if ($old_binutils) {
  64         print "WARNING: You need at least binutils >= 2.19 to build a ".
  65               "CONFIG_RELOCATABLE kernel\n";
  66 }