projects/linux·blob v4.7-rc7 · refs

157 lines · 3.7 KiB

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{"system_certificate_list_size"}));
95
96my $start = Math::BigInt->new($symbols{"__cert_list_start"});
97my $end;
98my $size;
99my $size_sym = Math::BigInt->new($symbols{"system_certificate_list_size"});
100
101open FD, "<$vmlinux" || die $vmlinux;
102binmode(FD);
103
104my $s = undef;
105foreach 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 = $sec;
134}
135
136die "Cert object not inside a section\n"
137 unless ($s);
138
139print "Certificate list in section ", $s->{name}, "\n";
140
141my $foff = $start - $s->{vma} + $s->{foff};
142
143printf "Certificate list at file offset 0x%x\n", $foff;
144
145die $vmlinux if (!defined(sysseek(FD, $foff, SEEK_SET)));
146my $buf = "";
147my $len = sysread(FD, $buf, $size);
148die "$vmlinux" if (!defined($len));
149die "Short read on $vmlinux\n" if ($len != $size);
150close(FD) || die $vmlinux;
151
152open FD, ">$keyring" || die $keyring;
153binmode(FD);
154$len = syswrite(FD, $buf, $size);
155die "$keyring" if (!defined($len));
156die "Short write on $keyring\n" if ($len != $size);
157close(FD) || die $keyring;