tools/trace-malloc/TraceMalloc.pm@ac0c01689b40 (annotated)
tools/trace-malloc/TraceMalloc.pm
Thu, 15 Jan 2015 15:59:08 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 15 Jan 2015 15:59:08 +0100
- branch
- TOR_BUG_9701
- changeset 10
- ac0c01689b40
- permissions
- -rw-r--r--
Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
| michael@0 | 1 | # This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 2 | # License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 3 | # file, You can obtain one at http://mozilla.org/MPL/2.0/. |
| michael@0 | 4 | package TraceMalloc; |
| michael@0 | 5 | |
| michael@0 | 6 | use strict; |
| michael@0 | 7 | |
| michael@0 | 8 | # Read in the type inference file and construct a network that we can |
| michael@0 | 9 | # use to match stack prefixes to types. |
| michael@0 | 10 | sub init_type_inference($) { |
| michael@0 | 11 | my ($file) = @_; |
| michael@0 | 12 | |
| michael@0 | 13 | $::Fingerprints = { }; |
| michael@0 | 14 | |
| michael@0 | 15 | open(TYPES, "<$file") || die "unable to open $::opt_types, $!"; |
| michael@0 | 16 | |
| michael@0 | 17 | TYPE: while (<TYPES>) { |
| michael@0 | 18 | next TYPE unless /<(.*)>/; |
| michael@0 | 19 | my $type = $1; |
| michael@0 | 20 | |
| michael@0 | 21 | my $link = \%::Fingerprints; |
| michael@0 | 22 | |
| michael@0 | 23 | FRAME: while (<TYPES>) { |
| michael@0 | 24 | chomp; |
| michael@0 | 25 | last FRAME if /^$/; |
| michael@0 | 26 | |
| michael@0 | 27 | my $next = $link->{$_}; |
| michael@0 | 28 | if (! $next) { |
| michael@0 | 29 | $next = $link->{$_} = {}; |
| michael@0 | 30 | } |
| michael@0 | 31 | $link = $next; |
| michael@0 | 32 | } |
| michael@0 | 33 | |
| michael@0 | 34 | $link->{'#type#'} = $type; |
| michael@0 | 35 | |
| michael@0 | 36 | last TYPE if eof; |
| michael@0 | 37 | } |
| michael@0 | 38 | } |
| michael@0 | 39 | |
| michael@0 | 40 | # Infer the type, trying to find the most specific type possible. |
| michael@0 | 41 | sub infer_type($) { |
| michael@0 | 42 | my ($stack) = @_; |
| michael@0 | 43 | |
| michael@0 | 44 | my $link = \%::Fingerprints; |
| michael@0 | 45 | my $last; |
| michael@0 | 46 | my $type = 'void*'; |
| michael@0 | 47 | FRAME: foreach my $frame (@$stack) { |
| michael@0 | 48 | last FRAME unless $link; |
| michael@0 | 49 | |
| michael@0 | 50 | $frame =~ s/\[.*\]$//; # ignore exact addresses, as they'll drift |
| michael@0 | 51 | |
| michael@0 | 52 | $last = $link; |
| michael@0 | 53 | |
| michael@0 | 54 | # |
| michael@0 | 55 | # Remember this type, but keep going. We use the longest match |
| michael@0 | 56 | # we find, but substacks of longer matches will also match. |
| michael@0 | 57 | # |
| michael@0 | 58 | if ($last->{'#type#'}) { |
| michael@0 | 59 | $type = $last->{'#type#'}; |
| michael@0 | 60 | } |
| michael@0 | 61 | |
| michael@0 | 62 | $link = $link->{$frame}; |
| michael@0 | 63 | |
| michael@0 | 64 | if (! $link) { |
| michael@0 | 65 | CHILD: foreach my $child (keys %$last) { |
| michael@0 | 66 | next CHILD unless $child =~ /^~/; |
| michael@0 | 67 | |
| michael@0 | 68 | $child =~ s/^~//; |
| michael@0 | 69 | |
| michael@0 | 70 | if ($frame =~ $child) { |
| michael@0 | 71 | $link = $last->{'~' . $child}; |
| michael@0 | 72 | last CHILD; |
| michael@0 | 73 | } |
| michael@0 | 74 | } |
| michael@0 | 75 | } |
| michael@0 | 76 | } |
| michael@0 | 77 | |
| michael@0 | 78 | return $type; |
| michael@0 | 79 | } |
| michael@0 | 80 | |
| michael@0 | 81 | |
| michael@0 | 82 | #---------------------------------------------------------------------- |
| michael@0 | 83 | # |
| michael@0 | 84 | # Read in the output a trace malloc's dump. |
| michael@0 | 85 | # |
| michael@0 | 86 | sub read { |
| michael@0 | 87 | my ($callback, $noslop) = @_; |
| michael@0 | 88 | |
| michael@0 | 89 | OBJECT: while (<>) { |
| michael@0 | 90 | # e.g., 0x0832FBD0 <void*> (80) |
| michael@0 | 91 | next OBJECT unless /^0x(\S+) <(.*)> \((\d+)\)/; |
| michael@0 | 92 | my ($addr, $type, $size) = (hex $1, $2, $3); |
| michael@0 | 93 | |
| michael@0 | 94 | my $object = { 'type' => $type, 'size' => $size }; |
| michael@0 | 95 | |
| michael@0 | 96 | # Record the object's slots |
| michael@0 | 97 | my @slots; |
| michael@0 | 98 | |
| michael@0 | 99 | SLOT: while (<>) { |
| michael@0 | 100 | # e.g., 0x00000000 |
| michael@0 | 101 | last SLOT unless /^\t0x(\S+)/; |
| michael@0 | 102 | my $value = hex $1; |
| michael@0 | 103 | |
| michael@0 | 104 | # Ignore low bits, unless they've specified --noslop |
| michael@0 | 105 | $value &= ~0x7 unless $noslop; |
| michael@0 | 106 | |
| michael@0 | 107 | $slots[$#slots + 1] = $value; |
| michael@0 | 108 | } |
| michael@0 | 109 | |
| michael@0 | 110 | $object->{'slots'} = \@slots; |
| michael@0 | 111 | |
| michael@0 | 112 | # Record the stack by which the object was allocated |
| michael@0 | 113 | my @stack; |
| michael@0 | 114 | |
| michael@0 | 115 | while (/^(.*)\[(.*) \+0x(\S+)\]$/) { |
| michael@0 | 116 | # e.g., _dl_debug_message[/lib/ld-linux.so.2 +0x0000B858] |
| michael@0 | 117 | my ($func, $lib, $off) = ($1, $2, hex $3); |
| michael@0 | 118 | |
| michael@0 | 119 | chomp; |
| michael@0 | 120 | $stack[$#stack + 1] = $_; |
| michael@0 | 121 | |
| michael@0 | 122 | $_ = <>; |
| michael@0 | 123 | } |
| michael@0 | 124 | |
| michael@0 | 125 | $object->{'stack'} = \@stack; |
| michael@0 | 126 | |
| michael@0 | 127 | $object->{'type'} = infer_type(\@stack) |
| michael@0 | 128 | if $object->{'type'} eq 'void*'; |
| michael@0 | 129 | |
| michael@0 | 130 | &$callback($object) if $callback; |
| michael@0 | 131 | |
| michael@0 | 132 | # Gotta check EOF explicitly... |
| michael@0 | 133 | last OBJECT if eof; |
| michael@0 | 134 | } |
| michael@0 | 135 | } |
| michael@0 | 136 | |
| michael@0 | 137 | 1; |
| michael@0 | 138 | __END__ |
| michael@0 | 139 | |
| michael@0 | 140 | =head1 NAME |
| michael@0 | 141 | |
| michael@0 | 142 | TraceMalloc - Perl routines to deal with output from ``trace malloc'' |
| michael@0 | 143 | and the Boehm GC |
| michael@0 | 144 | |
| michael@0 | 145 | =head1 SYNOPSIS |
| michael@0 | 146 | |
| michael@0 | 147 | use TraceMalloc; |
| michael@0 | 148 | |
| michael@0 | 149 | TraceMalloc::init_type_inference("types.dat"); |
| michael@0 | 150 | TraceMalloc::read(0); |
| michael@0 | 151 | |
| michael@0 | 152 | =head1 DESCRIPTION |
| michael@0 | 153 | |
| michael@0 | 154 | =head1 EXAMPLES |
| michael@0 | 155 | |
| michael@0 | 156 | =cut |
