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157 lines
3.3 KiB
Perl
157 lines
3.3 KiB
Perl
# This Source Code Form is subject to the terms of the Mozilla Public
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# License, v. 2.0. If a copy of the MPL was not distributed with this
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# file, You can obtain one at http://mozilla.org/MPL/2.0/.
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package TraceMalloc;
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use strict;
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# Read in the type inference file and construct a network that we can
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# use to match stack prefixes to types.
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sub init_type_inference($) {
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my ($file) = @_;
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$::Fingerprints = { };
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open(TYPES, "<$file") || die "unable to open $::opt_types, $!";
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TYPE: while (<TYPES>) {
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next TYPE unless /<(.*)>/;
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my $type = $1;
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my $link = \%::Fingerprints;
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FRAME: while (<TYPES>) {
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chomp;
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last FRAME if /^$/;
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my $next = $link->{$_};
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if (! $next) {
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$next = $link->{$_} = {};
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}
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$link = $next;
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}
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$link->{'#type#'} = $type;
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last TYPE if eof;
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}
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}
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# Infer the type, trying to find the most specific type possible.
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sub infer_type($) {
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my ($stack) = @_;
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my $link = \%::Fingerprints;
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my $last;
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my $type = 'void*';
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FRAME: foreach my $frame (@$stack) {
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last FRAME unless $link;
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$frame =~ s/\[.*\]$//; # ignore exact addresses, as they'll drift
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$last = $link;
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#
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# Remember this type, but keep going. We use the longest match
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# we find, but substacks of longer matches will also match.
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#
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if ($last->{'#type#'}) {
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$type = $last->{'#type#'};
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}
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$link = $link->{$frame};
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if (! $link) {
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CHILD: foreach my $child (keys %$last) {
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next CHILD unless $child =~ /^~/;
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$child =~ s/^~//;
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if ($frame =~ $child) {
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$link = $last->{'~' . $child};
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last CHILD;
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}
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}
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}
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}
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return $type;
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}
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#----------------------------------------------------------------------
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#
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# Read in the output a trace malloc's dump.
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#
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sub read {
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my ($callback, $noslop) = @_;
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OBJECT: while (<>) {
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# e.g., 0x0832FBD0 <void*> (80)
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next OBJECT unless /^0x(\S+) <(.*)> \((\d+)\)/;
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my ($addr, $type, $size) = (hex $1, $2, $3);
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my $object = { 'type' => $type, 'size' => $size };
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# Record the object's slots
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my @slots;
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SLOT: while (<>) {
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# e.g., 0x00000000
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last SLOT unless /^\t0x(\S+)/;
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my $value = hex $1;
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# Ignore low bits, unless they've specified --noslop
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$value &= ~0x7 unless $noslop;
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$slots[$#slots + 1] = $value;
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}
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$object->{'slots'} = \@slots;
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# Record the stack by which the object was allocated
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my @stack;
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while (/^(.*)\[(.*) \+0x(\S+)\]$/) {
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# e.g., _dl_debug_message[/lib/ld-linux.so.2 +0x0000B858]
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my ($func, $lib, $off) = ($1, $2, hex $3);
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chomp;
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$stack[$#stack + 1] = $_;
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$_ = <>;
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}
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$object->{'stack'} = \@stack;
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$object->{'type'} = infer_type(\@stack)
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if $object->{'type'} eq 'void*';
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&$callback($object) if $callback;
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# Gotta check EOF explicitly...
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last OBJECT if eof;
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}
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}
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1;
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__END__
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=head1 NAME
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TraceMalloc - Perl routines to deal with output from ``trace malloc''
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and the Boehm GC
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=head1 SYNOPSIS
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use TraceMalloc;
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TraceMalloc::init_type_inference("types.dat");
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TraceMalloc::read(0);
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=head1 DESCRIPTION
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=head1 EXAMPLES
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=cut
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