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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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use File::Basename;use Math::BigInt;use Getopt::Long;
# Copyright 2008, Intel Corporation## This file is part of the Linux kernel## Authors:# Arjan van de Ven <arjan@linux.intel.com>
my $cross_compile = "";my $vmlinux_name = "";my $modulefile = "";
# Get optionsGetopt::Long::GetOptions( 'cross-compile|c=s' => \$cross_compile, 'module|m=s' => \$modulefile, 'help|h' => \&usage,) || usage ();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;
# 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 oopswhile (<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 ($target eq "0") { print "No oops found!\n"; usage();}
# if it's a module, we need to find the .ko file and calculate a load offsetif ($module ne "") { if ($modulefile eq "") { $modulefile = `modinfo -F filename $module`; chomp($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, $cross_compile."objdump -dS $filename |") || die "Cannot start objdump"; while (<FILE>) { if ($_ =~ /^([0-9a-f]+) \<$function\>\:/) { my $fu = $1; $vmaoffset = Math::BigInt->from_hex("0x$target") - Math::BigInt->from_hex("0x$fu") - Math::BigInt->from_hex("0x$func_offset"); } } close(FILE);}
my $counter = 0;my $state = 0;my $center = -1;my @lines;my @reglines;
sub InRange { my ($address, $target) = @_; my $ad = "0x".$address; my $ta = "0x".$target; my $delta = Math::BigInt->from_hex($ad) - Math::BigInt->from_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, $cross_compile."objdump -dS --adjust-vma=$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)) { $state = 1; } } } if ($state == 1) { 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 == -1) { 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;}
sub usage { print <<EOT;Usage: dmesg | perl $0 [OPTION] [VMLINUX]
OPTION: -c, --cross-compile CROSS_COMPILE Specify the prefix used for toolchain. -m, --module MODULE_DIRNAME Specify the module filename. -h, --help Help.EOT exit;}