1#!/usr/bin/perl -w
2#
3use strict;
4use Math::BigInt;
5use Fcntl "SEEK_SET";
6
7die "Format: $0 [-s <systemmap-file>] <vmlinux-file> <keyring-file>\n"
8    if ($#ARGV != 1 && $#ARGV != 3 ||
9	$#ARGV == 3 && $ARGV[0] ne "-s");
10
11my $sysmap = "";
12if ($#ARGV == 3) {
13    shift;
14    $sysmap = $ARGV[0];
15    shift;
16}
17
18my $vmlinux = $ARGV[0];
19my $keyring = $ARGV[1];
20
21#
22# Parse the vmlinux section table
23#
24open FD, "objdump -h $vmlinux |" || die $vmlinux;
25my @lines = <FD>;
26close(FD) || die $vmlinux;
27
28my @sections = ();
29
30foreach my $line (@lines) {
31    chomp($line);
32    if ($line =~ /\s*([0-9]+)\s+(\S+)\s+([0-9a-f]+)\s+([0-9a-f]+)\s+([0-9a-f]+)\s+([0-9a-f]+)\s+2[*][*]([0-9]+)/
33	) {
34	my $seg  = $1;
35	my $name = $2;
36	my $len  = Math::BigInt->new("0x" . $3);
37	my $vma  = Math::BigInt->new("0x" . $4);
38	my $lma  = Math::BigInt->new("0x" . $5);
39	my $foff = Math::BigInt->new("0x" . $6);
40	my $align = 2 ** $7;
41
42	push @sections, { name => $name,
43			  vma => $vma,
44			  len => $len,
45			  foff => $foff };
46    }
47}
48
49print "Have $#sections sections\n";
50
51#
52# Try and parse the vmlinux symbol table.  If the vmlinux file has been created
53# from a vmlinuz file with extract-vmlinux then the symbol table will be empty.
54#
55open FD, "nm $vmlinux 2>/dev/null |" || die $vmlinux;
56@lines = <FD>;
57close(FD) || die $vmlinux;
58
59my %symbols = ();
60my $nr_symbols = 0;
61
62sub parse_symbols(@) {
63    foreach my $line (@_) {
64	chomp($line);
65	if ($line =~ /([0-9a-f]+)\s([a-zA-Z])\s(\S+)/
66	    ) {
67	    my $addr = "0x" . $1;
68	    my $type = $2;
69	    my $name = $3;
70
71	    $symbols{$name} = $addr;
72	    $nr_symbols++;
73	}
74    }
75}
76parse_symbols(@lines);
77
78if ($nr_symbols == 0 && $sysmap ne "") {
79    print "No symbols in vmlinux, trying $sysmap\n";
80
81    open FD, "<$sysmap" || die $sysmap;
82    @lines = <FD>;
83    close(FD) || die $sysmap;
84    parse_symbols(@lines);
85}
86
87die "No symbols available\n"
88    if ($nr_symbols == 0);
89
90print "Have $nr_symbols symbols\n";
91
92die "Can't find system certificate list"
93    unless (exists($symbols{"__cert_list_start"}) &&
94	    exists($symbols{"__cert_list_end"}));
95
96my $start = Math::BigInt->new($symbols{"__cert_list_start"});
97my $end = Math::BigInt->new($symbols{"__cert_list_end"});
98my $size = $end - $start;
99
100printf "Have %u bytes of certs at VMA 0x%x\n", $size, $start;
101
102my $s = undef;
103foreach my $sec (@sections) {
104    my $s_name = $sec->{name};
105    my $s_vma = $sec->{vma};
106    my $s_len = $sec->{len};
107    my $s_foff = $sec->{foff};
108    my $s_vend = $s_vma + $s_len;
109
110    next unless ($start >= $s_vma);
111    next if ($start >= $s_vend);
112
113    die "Cert object partially overflows section $s_name\n"
114	if ($end > $s_vend);
115
116    die "Cert object in multiple sections: ", $s_name, " and ", $s->{name}, "\n"
117	if ($s);
118    $s = $sec;
119}
120
121die "Cert object not inside a section\n"
122    unless ($s);
123
124print "Certificate list in section ", $s->{name}, "\n";
125
126my $foff = $start - $s->{vma} + $s->{foff};
127
128printf "Certificate list at file offset 0x%x\n", $foff;
129
130open FD, "<$vmlinux" || die $vmlinux;
131binmode(FD);
132die $vmlinux if (!defined(sysseek(FD, $foff, SEEK_SET)));
133my $buf = "";
134my $len = sysread(FD, $buf, $size);
135die "$vmlinux" if (!defined($len));
136die "Short read on $vmlinux\n" if ($len != $size);
137close(FD) || die $vmlinux;
138
139open FD, ">$keyring" || die $keyring;
140binmode(FD);
141$len = syswrite(FD, $buf, $size);
142die "$keyring" if (!defined($len));
143die "Short write on $keyring\n" if ($len != $size);
144close(FD) || die $keyring;
145