block: use after free bug in __blkdev_get

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / scripts / markup_oops.pl

#!/usr/bin/perl

use File::Basename;
use Math::BigInt;

# Copyright 2008, Intel Corporation
#
# This file is part of the Linux kernel
#
# This program file is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; version 2 of the License.
#
# Authors:
#       Arjan van de Ven <arjan@linux.intel.com>


my $vmlinux_name = $ARGV[0];
if (!defined($vmlinux_name)) {
        my $kerver = `uname -r`;
        chomp($kerver);
        $vmlinux_name = "/lib/modules/$kerver/build/vmlinux";
        print "No vmlinux specified, assuming $vmlinux_name\n";
}
my $filename = $vmlinux_name;
#
# Step 1: Parse the oops to find the EIP value
#

my $target = "0";
my $function;
my $module = "";
my $func_offset = 0;
my $vmaoffset = 0;

my %regs;


sub parse_x86_regs
{
        my ($line) = @_;
        if ($line =~ /EAX: ([0-9a-f]+) EBX: ([0-9a-f]+) ECX: ([0-9a-f]+) EDX: ([0-9a-f]+)/) {
                $regs{"%eax"} = $1;
                $regs{"%ebx"} = $2;
                $regs{"%ecx"} = $3;
                $regs{"%edx"} = $4;
        }
        if ($line =~ /ESI: ([0-9a-f]+) EDI: ([0-9a-f]+) EBP: ([0-9a-f]+) ESP: ([0-9a-f]+)/) {
                $regs{"%esi"} = $1;
                $regs{"%edi"} = $2;
                $regs{"%esp"} = $4;
        }
        if ($line =~ /RAX: ([0-9a-f]+) RBX: ([0-9a-f]+) RCX: ([0-9a-f]+)/) {
                $regs{"%eax"} = $1;
                $regs{"%ebx"} = $2;
                $regs{"%ecx"} = $3;
        }
        if ($line =~ /RDX: ([0-9a-f]+) RSI: ([0-9a-f]+) RDI: ([0-9a-f]+)/) {
                $regs{"%edx"} = $1;
                $regs{"%esi"} = $2;
                $regs{"%edi"} = $3;
        }
        if ($line =~ /RBP: ([0-9a-f]+) R08: ([0-9a-f]+) R09: ([0-9a-f]+)/) {
                $regs{"%r08"} = $2;
                $regs{"%r09"} = $3;
        }
        if ($line =~ /R10: ([0-9a-f]+) R11: ([0-9a-f]+) R12: ([0-9a-f]+)/) {
                $regs{"%r10"} = $1;
                $regs{"%r11"} = $2;
                $regs{"%r12"} = $3;
        }
        if ($line =~ /R13: ([0-9a-f]+) R14: ([0-9a-f]+) R15: ([0-9a-f]+)/) {
                $regs{"%r13"} = $1;
                $regs{"%r14"} = $2;
                $regs{"%r15"} = $3;
        }
}

sub reg_name
{
        my ($reg) = @_;
        $reg =~ s/r(.)x/e\1x/;
        $reg =~ s/r(.)i/e\1i/;
        $reg =~ s/r(.)p/e\1p/;
        return $reg;
}

sub process_x86_regs
{
        my ($line, $cntr) = @_;
        my $str = "";
        if (length($line) < 40) {
                return ""; # not an asm istruction
        }

        # find the arguments to the instruction
        if ($line =~ /([0-9a-zA-Z\,\%\(\)\-\+]+)$/) {
                $lastword = $1;
        } else {
                return "";
        }

        # we need to find the registers that get clobbered,
        # since their value is no longer relevant for previous
        # instructions in the stream.

        $clobber = $lastword;
        # first, remove all memory operands, they're read only
        $clobber =~ s/\([a-z0-9\%\,]+\)//g;
        # then, remove everything before the comma, thats the read part
        $clobber =~ s/.*\,//g;

        # if this is the instruction that faulted, we haven't actually done
        # the write yet... nothing is clobbered.
        if ($cntr == 0) {
                $clobber = "";
        }

        foreach $reg (keys(%regs)) {
                my $clobberprime = reg_name($clobber);
                my $lastwordprime = reg_name($lastword);
                my $val = $regs{$reg};
                if ($val =~ /^[0]+$/) {
                        $val = "0";
                } else {
                        $val =~ s/^0*//;
                }

                # first check if we're clobbering this register; if we do
                # we print it with a =>, and then delete its value
                if ($clobber =~ /$reg/ || $clobberprime =~ /$reg/) {
                        if (length($val) > 0) {
                                $str = $str . " $reg => $val ";
                        }
                        $regs{$reg} = "";
                        $val = "";
                }
                # now check if we're reading this register
                if ($lastword =~ /$reg/ || $lastwordprime =~ /$reg/) {
                        if (length($val) > 0) {
                                $str = $str . " $reg = $val ";
                        }
                }
        }
        return $str;
}

# parse the oops
while (<STDIN>) {
        my $line = $_;
        if ($line =~ /EIP: 0060:\[\<([a-z0-9]+)\>\]/) {
                $target = $1;
        }
        if ($line =~ /RIP: 0010:\[\<([a-z0-9]+)\>\]/) {
                $target = $1;
        }
        if ($line =~ /EIP is at ([a-zA-Z0-9\_]+)\+(0x[0-9a-f]+)\/0x[a-f0-9]/) {
                $function = $1;
                $func_offset = $2;
        }
        if ($line =~ /RIP: 0010:\[\<[0-9a-f]+\>\]  \[\<[0-9a-f]+\>\] ([a-zA-Z0-9\_]+)\+(0x[0-9a-f]+)\/0x[a-f0-9]/) {
                $function = $1;
                $func_offset = $2;
        }

        # check if it's a module
        if ($line =~ /EIP is at ([a-zA-Z0-9\_]+)\+(0x[0-9a-f]+)\/0x[a-f0-9]+\W\[([a-zA-Z0-9\_\-]+)\]/) {
                $module = $3;
        }
        if ($line =~ /RIP: 0010:\[\<[0-9a-f]+\>\]  \[\<[0-9a-f]+\>\] ([a-zA-Z0-9\_]+)\+(0x[0-9a-f]+)\/0x[a-f0-9]+\W\[([a-zA-Z0-9\_\-]+)\]/) {
                $module = $3;
        }
        parse_x86_regs($line);
}

my $decodestart = Math::BigInt->from_hex("0x$target") - Math::BigInt->from_hex("0x$func_offset");
my $decodestop = Math::BigInt->from_hex("0x$target") + 8192;
if ($target eq "0") {
        print "No oops found!\n";
        print "Usage: \n";
        print "    dmesg | perl scripts/markup_oops.pl vmlinux\n";
        exit;
}

# if it's a module, we need to find the .ko file and calculate a load offset
if ($module ne "") {
        my $modulefile = `modinfo $module | grep '^filename:' | awk '{ print \$2 }'`;
        chomp($modulefile);
        $filename = $modulefile;
        if ($filename eq "") {
                print "Module .ko file for $module not found. Aborting\n";
                exit;
        }
        # ok so we found the module, now we need to calculate the vma offset
        open(FILE, "objdump -dS $filename |") || die "Cannot start objdump";
        while (<FILE>) {
                if ($_ =~ /^([0-9a-f]+) \<$function\>\:/) {
                        my $fu = $1;
                        $vmaoffset = hex($target) - hex($fu) - hex($func_offset);
                }
        }
        close(FILE);
}

my $counter = 0;
my $state   = 0;
my $center  = 0;
my @lines;
my @reglines;

sub InRange {
        my ($address, $target) = @_;
        my $ad = "0x".$address;
        my $ta = "0x".$target;
        my $delta = hex($ad) - hex($ta);

        if (($delta > -4096) && ($delta < 4096)) {
                return 1;
        }
        return 0;
}



# first, parse the input into the lines array, but to keep size down,
# we only do this for 4Kb around the sweet spot

open(FILE, "objdump -dS --adjust-vma=$vmaoffset --start-address=$decodestart --stop-address=$decodestop $filename |") || die "Cannot start objdump";

while (<FILE>) {
        my $line = $_;
        chomp($line);
        if ($state == 0) {
                if ($line =~ /^([a-f0-9]+)\:/) {
                        if (InRange($1, $target)) {
                                $state = 1;
                        }
                }
        } else {
                if ($line =~ /^([a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9]+)\:/) {
                        my $val = $1;
                        if (!InRange($val, $target)) {
                                last;
                        }
                        if ($val eq $target) {
                                $center = $counter;
                        }
                }
                $lines[$counter] = $line;

                $counter = $counter + 1;
        }
}

close(FILE);

if ($counter == 0) {
        print "No matching code found \n";
        exit;
}

if ($center == 0) {
        print "No matching code found \n";
        exit;
}

my $start;
my $finish;
my $codelines = 0;
my $binarylines = 0;
# now we go up and down in the array to find how much we want to print

$start = $center;

while ($start > 1) {
        $start = $start - 1;
        my $line = $lines[$start];
        if ($line =~ /^([a-f0-9]+)\:/) {
                $binarylines = $binarylines + 1;
        } else {
                $codelines = $codelines + 1;
        }
        if ($codelines > 10) {
                last;
        }
        if ($binarylines > 20) {
                last;
        }
}


$finish = $center;
$codelines = 0;
$binarylines = 0;
while ($finish < $counter) {
        $finish = $finish + 1;
        my $line = $lines[$finish];
        if ($line =~ /^([a-f0-9]+)\:/) {
                $binarylines = $binarylines + 1;
        } else {
                $codelines = $codelines + 1;
        }
        if ($codelines > 10) {
                last;
        }
        if ($binarylines > 20) {
                last;
        }
}


my $i;


# start annotating the registers in the asm.
# this goes from the oopsing point back, so that the annotator
# can track (opportunistically) which registers got written and
# whos value no longer is relevant.

$i = $center;
while ($i >= $start) {
        $reglines[$i] = process_x86_regs($lines[$i], $center - $i);
        $i = $i - 1;
}

$i = $start;
while ($i < $finish) {
        my $line;
        if ($i == $center) {
                $line =  "*$lines[$i] ";
        } else {
                $line =  " $lines[$i] ";
        }
        print $line;
        if (defined($reglines[$i]) && length($reglines[$i]) > 0) {
                my $c = 60 - length($line);
                while ($c > 0) { print " "; $c = $c - 1; };
                print "| $reglines[$i]";
        }
        if ($i == $center) {
                print "<--- faulting instruction";
        }
        print "\n";
        $i = $i +1;
}