projects/linux·blob v4.14-rc2 · refs

158 lines · 3.7 KiB

1#!/usr/bin/env perl
2#
3use warnings;
4use strict;
5use Math::BigInt;
6use Fcntl "SEEK_SET";
7
8die "Format: $0 [-s <systemmap-file>] <vmlinux-file> <keyring-file>\n"
9 if ($#ARGV != 1 && $#ARGV != 3 ||
10 $#ARGV == 3 && $ARGV[0] ne "-s");
11
12my $sysmap = "";
13if ($#ARGV == 3) {
14 shift;
15 $sysmap = $ARGV[0];
16 shift;
17}
18
19my $vmlinux = $ARGV[0];
20my $keyring = $ARGV[1];
21
22#
23# Parse the vmlinux section table
24#
25open FD, "objdump -h $vmlinux |" || die $vmlinux;
26my @lines = <FD>;
27close(FD) || die $vmlinux;
28
29my @sections = ();
30
31foreach my $line (@lines) {
32 chomp($line);
33 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]+)/
34 ) {
35 my $seg = $1;
36 my $name = $2;
37 my $len = Math::BigInt->new("0x" . $3);
38 my $vma = Math::BigInt->new("0x" . $4);
39 my $lma = Math::BigInt->new("0x" . $5);
40 my $foff = Math::BigInt->new("0x" . $6);
41 my $align = 2 ** $7;
42
43 push @sections, { name => $name,
44 vma => $vma,
45 len => $len,
46 foff => $foff };
47 }
48}
49
50print "Have $#sections sections\n";
51
52#
53# Try and parse the vmlinux symbol table. If the vmlinux file has been created
54# from a vmlinuz file with extract-vmlinux then the symbol table will be empty.
55#
56open FD, "nm $vmlinux 2>/dev/null |" || die $vmlinux;
57@lines = <FD>;
58close(FD) || die $vmlinux;
59
60my %symbols = ();
61my $nr_symbols = 0;
62
63sub parse_symbols(@) {
64 foreach my $line (@_) {
65 chomp($line);
66 if ($line =~ /([0-9a-f]+)\s([a-zA-Z])\s(\S+)/
67 ) {
68 my $addr = "0x" . $1;
69 my $type = $2;
70 my $name = $3;
71
72 $symbols{$name} = $addr;
73 $nr_symbols++;
74 }
75 }
76}
77parse_symbols(@lines);
78
79if ($nr_symbols == 0 && $sysmap ne "") {
80 print "No symbols in vmlinux, trying $sysmap\n";
81
82 open FD, "<$sysmap" || die $sysmap;
83 @lines = <FD>;
84 close(FD) || die $sysmap;
85 parse_symbols(@lines);
86}
87
88die "No symbols available\n"
89 if ($nr_symbols == 0);
90
91print "Have $nr_symbols symbols\n";
92
93die "Can't find system certificate list"
94 unless (exists($symbols{"__cert_list_start"}) &&
95 exists($symbols{"system_certificate_list_size"}));
96
97my $start = Math::BigInt->new($symbols{"__cert_list_start"});
98my $end;
99my $size;
100my $size_sym = Math::BigInt->new($symbols{"system_certificate_list_size"});
101
102open FD, "<$vmlinux" || die $vmlinux;
103binmode(FD);
104
105my $s = undef;
106foreach my $sec (@sections) {
107 my $s_name = $sec->{name};
108 my $s_vma = $sec->{vma};
109 my $s_len = $sec->{len};
110 my $s_foff = $sec->{foff};
111 my $s_vend = $s_vma + $s_len;
112
113 next unless ($start >= $s_vma);
114 next if ($start >= $s_vend);
115
116 die "Certificate list size was not found on the same section\n"
117 if ($size_sym < $s_vma || $size_sym > $s_vend);
118
119 die "Cert object in multiple sections: ", $s_name, " and ", $s->{name}, "\n"
120 if ($s);
121
122 my $size_off = $size_sym -$s_vma + $s_foff;
123 my $packed;
124 die $vmlinux if (!defined(sysseek(FD, $size_off, SEEK_SET)));
125 sysread(FD, $packed, 8);
126 $size = unpack 'L!', $packed;
127 $end = $start + $size;
128
129 printf "Have %u bytes of certs at VMA 0x%x\n", $size, $start;
130
131 die "Cert object partially overflows section $s_name\n"
132 if ($end > $s_vend);
133
134 $s = $sec;
135}
136
137die "Cert object not inside a section\n"
138 unless ($s);
139
140print "Certificate list in section ", $s->{name}, "\n";
141
142my $foff = $start - $s->{vma} + $s->{foff};
143
144printf "Certificate list at file offset 0x%x\n", $foff;
145
146die $vmlinux if (!defined(sysseek(FD, $foff, SEEK_SET)));
147my $buf = "";
148my $len = sysread(FD, $buf, $size);
149die "$vmlinux" if (!defined($len));
150die "Short read on $vmlinux\n" if ($len != $size);
151close(FD) || die $vmlinux;
152
153open FD, ">$keyring" || die $keyring;
154binmode(FD);
155$len = syswrite(FD, $buf, $size);
156die "$keyring" if (!defined($len));
157die "Short write on $keyring\n" if ($len != $size);
158close(FD) || die $keyring;