#!/usr/bin/perl -w # # reference_init.pl (C) Keith Owens 2002 <kaos@ocs.com.au> # # List references to vmlinux init sections from non-init sections. # Unfortunately I had to exclude references from read only data to .init # sections, almost all of these are false positives, they are created by # gcc. The downside of excluding rodata is that there really are some # user references from rodata to init code, e.g. drivers/video/vgacon.c # # const struct consw vga_con = { # con_startup: vgacon_startup, # # where vgacon_startup is __init. If you want to wade through the false # positives, take out the check for rodata. use strict; die($0 . " takes no arguments\n") if($#ARGV >= 0); my %object; my $object; my $line; my $ignore; $| = 1; printf("Finding objects, "); open(OBJDUMP_LIST, "find . -name '*.o' | xargs objdump -h |") || die "getting objdump list failed"; while (defined($line = <OBJDUMP_LIST>)) { chomp($line); if ($line =~ /:\s+file format/) { ($object = $line) =~ s/:.*//; $object{$object}->{'module'} = 0; $object{$object}->{'size'} = 0; $object{$object}->{'off'} = 0; } if ($line =~ /^\s*\d+\s+\.modinfo\s+/) { $object{$object}->{'module'} = 1; } if ($line =~ /^\s*\d+\s+\.comment\s+/) { ($object{$object}->{'size'}, $object{$object}->{'off'}) = (split(' ', $line))[2,5]; } } close(OBJDUMP_LIST); printf("%d objects, ", scalar keys(%object)); $ignore = 0; foreach $object (keys(%object)) { if ($object{$object}->{'module'}) { ++$ignore; delete($object{$object}); } } printf("ignoring %d module(s)\n", $ignore); # Ignore conglomerate objects, they have been built from multiple objects and we # only care about the individual objects. If an object has more than one GCC: # string in the comment section then it is conglomerate. This does not filter # out conglomerates that consist of exactly one object, can't be helped. printf("Finding conglomerates, "); $ignore = 0; foreach $object (keys(%object)) { if (exists($object{$object}->{'off'})) { my ($off, $size, $comment, $l); $off = hex($object{$object}->{'off'}); $size = hex($object{$object}->{'size'}); open(OBJECT, "<$object") || die "cannot read $object"; seek(OBJECT, $off, 0) || die "seek to $off in $object failed"; $l = read(OBJECT, $comment, $size); die "read $size bytes from $object .comment failed" if ($l != $size); close(OBJECT); if ($comment =~ /GCC\:.*GCC\:/m || $object =~ /built-in\.o/) { ++$ignore; delete($object{$object}); } } } printf("ignoring %d conglomerate(s)\n", $ignore); printf("Scanning objects\n"); foreach $object (sort(keys(%object))) { my $from; open(OBJDUMP, "objdump -r $object|") || die "cannot objdump -r $object"; while (defined($line = <OBJDUMP>)) { chomp($line); if ($line =~ /RELOCATION RECORDS FOR /) { ($from = $line) =~ s/.*\[([^]]*).*/$1/; } if (($line =~ /\.init$/ || $line =~ /\.init\./) && ($from !~ /\.init$/ && $from !~ /\.init\./ && $from !~ /\.stab$/ && $from !~ /\.rodata$/ && $from !~ /\.text\.lock$/ && $from !~ /\.pci_fixup_header$/ && $from !~ /\.pci_fixup_final$/ && $from !~ /\.pdr$/ && $from !~ /\__param$/ && $from !~ /\.altinstructions/ && $from !~ /\.eh_frame/ && $from !~ /\.debug_/)) { printf("Error: %s %s refers to %s\n", $object, $from, $line); } } close(OBJDUMP); } printf("Done\n");