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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#!/usr/bin/perl -w
2#
3# reference_init.pl (C) Keith Owens 2002 <kaos@ocs.com.au>
4#
5# List references to vmlinux init sections from non-init sections.
6
7# Unfortunately I had to exclude references from read only data to .init
8# sections, almost all of these are false positives, they are created by
9# gcc. The downside of excluding rodata is that there really are some
10# user references from rodata to init code, e.g. drivers/video/vgacon.c
11#
12# const struct consw vga_con = {
13# con_startup: vgacon_startup,
14#
15# where vgacon_startup is __init. If you want to wade through the false
16# positives, take out the check for rodata.
17
18use strict;
19die($0 . " takes no arguments\n") if($#ARGV >= 0);
20
21my %object;
22my $object;
23my $line;
24my $ignore;
25
26$| = 1;
27
28printf("Finding objects, ");
29open(OBJDUMP_LIST, "find . -name '*.o' | xargs objdump -h |") || die "getting objdump list failed";
30while (defined($line = <OBJDUMP_LIST>)) {
31 chomp($line);
32 if ($line =~ /:\s+file format/) {
33 ($object = $line) =~ s/:.*//;
34 $object{$object}->{'module'} = 0;
35 $object{$object}->{'size'} = 0;
36 $object{$object}->{'off'} = 0;
37 }
38 if ($line =~ /^\s*\d+\s+\.modinfo\s+/) {
39 $object{$object}->{'module'} = 1;
40 }
41 if ($line =~ /^\s*\d+\s+\.comment\s+/) {
42 ($object{$object}->{'size'}, $object{$object}->{'off'}) = (split(' ', $line))[2,5];
43 }
44}
45close(OBJDUMP_LIST);
46printf("%d objects, ", scalar keys(%object));
47$ignore = 0;
48foreach $object (keys(%object)) {
49 if ($object{$object}->{'module'}) {
50 ++$ignore;
51 delete($object{$object});
52 }
53}
54printf("ignoring %d module(s)\n", $ignore);
55
56# Ignore conglomerate objects, they have been built from multiple objects and we
57# only care about the individual objects. If an object has more than one GCC:
58# string in the comment section then it is conglomerate. This does not filter
59# out conglomerates that consist of exactly one object, can't be helped.
60
61printf("Finding conglomerates, ");
62$ignore = 0;
63foreach $object (keys(%object)) {
64 if (exists($object{$object}->{'off'})) {
65 my ($off, $size, $comment, $l);
66 $off = hex($object{$object}->{'off'});
67 $size = hex($object{$object}->{'size'});
68 open(OBJECT, "<$object") || die "cannot read $object";
69 seek(OBJECT, $off, 0) || die "seek to $off in $object failed";
70 $l = read(OBJECT, $comment, $size);
71 die "read $size bytes from $object .comment failed" if ($l != $size);
72 close(OBJECT);
73 if ($comment =~ /GCC\:.*GCC\:/m || $object =~ /built-in\.o/) {
74 ++$ignore;
75 delete($object{$object});
76 }
77 }
78}
79printf("ignoring %d conglomerate(s)\n", $ignore);
80
81printf("Scanning objects\n");
82foreach $object (sort(keys(%object))) {
83 my $from;
84 open(OBJDUMP, "objdump -r $object|") || die "cannot objdump -r $object";
85 while (defined($line = <OBJDUMP>)) {
86 chomp($line);
87 if ($line =~ /RELOCATION RECORDS FOR /) {
88 ($from = $line) =~ s/.*\[([^]]*).*/$1/;
89 }
90 if (($line =~ /\.init$/ || $line =~ /\.init\./) &&
91 ($from !~ /\.init$/ &&
92 $from !~ /\.init\./ &&
93 $from !~ /\.stab$/ &&
94 $from !~ /\.rodata$/ &&
95 $from !~ /\.text\.lock$/ &&
96 $from !~ /\.pci_fixup_header$/ &&
97 $from !~ /\.pci_fixup_final$/ &&
98 $from !~ /\.pdr$/ &&
99 $from !~ /\__param$/ &&
100 $from !~ /\.altinstructions/ &&
Sam Ravnborg53e88e02005-07-14 20:14:42 +0000101 $from !~ /\.eh_frame/ &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 $from !~ /\.debug_/)) {
103 printf("Error: %s %s refers to %s\n", $object, $from, $line);
104 }
105 }
106 close(OBJDUMP);
107}
108printf("Done\n");