blob: 8227ca10a4942b688aacd3ef64e3f8ad7ec9b33e
1 | #!/usr/bin/perl -w |
2 | # |
3 | use strict; |
4 | use Math::BigInt; |
5 | use Fcntl "SEEK_SET"; |
6 | |
7 | die "Format: $0 [-s <systemmap-file>] <vmlinux-file> <keyring-file>\n" |
8 | if ($#ARGV != 1 && $#ARGV != 3 || |
9 | $#ARGV == 3 && $ARGV[0] ne "-s"); |
10 | |
11 | my $sysmap = ""; |
12 | if ($#ARGV == 3) { |
13 | shift; |
14 | $sysmap = $ARGV[0]; |
15 | shift; |
16 | } |
17 | |
18 | my $vmlinux = $ARGV[0]; |
19 | my $keyring = $ARGV[1]; |
20 | |
21 | # |
22 | # Parse the vmlinux section table |
23 | # |
24 | open FD, "objdump -h $vmlinux |" || die $vmlinux; |
25 | my @lines = <FD>; |
26 | close(FD) || die $vmlinux; |
27 | |
28 | my @sections = (); |
29 | |
30 | foreach 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 | |
49 | print "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 | # |
55 | open FD, "nm $vmlinux 2>/dev/null |" || die $vmlinux; |
56 | @lines = <FD>; |
57 | close(FD) || die $vmlinux; |
58 | |
59 | my %symbols = (); |
60 | my $nr_symbols = 0; |
61 | |
62 | sub 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 | $nr_symbols++; |
73 | } |
74 | } |
75 | } |
76 | parse_symbols(@lines); |
77 | |
78 | if ($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 $sysmap; |
84 | parse_symbols(@lines); |
85 | } |
86 | |
87 | die "No symbols available\n" |
88 | if ($nr_symbols == 0); |
89 | |
90 | print "Have $nr_symbols symbols\n"; |
91 | |
92 | die "Can't find system certificate list" |
93 | unless (exists($symbols{"__cert_list_start"}) && |
94 | exists($symbols{"system_certificate_list_size"})); |
95 | |
96 | my $start = Math::BigInt->new($symbols{"__cert_list_start"}); |
97 | my $end; |
98 | my $size; |
99 | my $size_sym = Math::BigInt->new($symbols{"system_certificate_list_size"}); |
100 | |
101 | open FD, "<$vmlinux" || die $vmlinux; |
102 | binmode(FD); |
103 | |
104 | my $s = undef; |
105 | foreach my $sec (@sections) { |
106 | my $s_name = $sec->{name}; |
107 | my $s_vma = $sec->{vma}; |
108 | my $s_len = $sec->{len}; |
109 | my $s_foff = $sec->{foff}; |
110 | my $s_vend = $s_vma + $s_len; |
111 | |
112 | next unless ($start >= $s_vma); |
113 | next if ($start >= $s_vend); |
114 | |
115 | die "Certificate list size was not found on the same section\n" |
116 | if ($size_sym < $s_vma || $size_sym > $s_vend); |
117 | |
118 | die "Cert object in multiple sections: ", $s_name, " and ", $s->{name}, "\n" |
119 | if ($s); |
120 | |
121 | my $size_off = $size_sym -$s_vma + $s_foff; |
122 | my $packed; |
123 | die $vmlinux if (!defined(sysseek(FD, $size_off, SEEK_SET))); |
124 | sysread(FD, $packed, 8); |
125 | $size = unpack 'L!', $packed; |
126 | $end = $start + $size; |
127 | |
128 | printf "Have %u bytes of certs at VMA 0x%x\n", $size, $start; |
129 | |
130 | die "Cert object partially overflows section $s_name\n" |
131 | if ($end > $s_vend); |
132 | |
133 | $s = $sec; |
134 | } |
135 | |
136 | die "Cert object not inside a section\n" |
137 | unless ($s); |
138 | |
139 | print "Certificate list in section ", $s->{name}, "\n"; |
140 | |
141 | my $foff = $start - $s->{vma} + $s->{foff}; |
142 | |
143 | printf "Certificate list at file offset 0x%x\n", $foff; |
144 | |
145 | die $vmlinux if (!defined(sysseek(FD, $foff, SEEK_SET))); |
146 | my $buf = ""; |
147 | my $len = sysread(FD, $buf, $size); |
148 | die "$vmlinux" if (!defined($len)); |
149 | die "Short read on $vmlinux\n" if ($len != $size); |
150 | close(FD) || die $vmlinux; |
151 | |
152 | open FD, ">$keyring" || die $keyring; |
153 | binmode(FD); |
154 | $len = syswrite(FD, $buf, $size); |
155 | die "$keyring" if (!defined($len)); |
156 | die "Short write on $keyring\n" if ($len != $size); |
157 | close(FD) || die $keyring; |
158 |