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|
#!/usr/bin/perl
# Perl script to ease the use of gdb with valgrind.
#
# Invoke as: vdb.pl <command to run>
#
# This also adds some commands to the usual gdb/valgrind
# stuff.
#
# xb:
#
# xb expression
# or:
# xb expression_addr expression_length
#
# This does what you'd hope:
#
# mon xb <expression_addr> <expression_length>
#
# but it copes with expressions for the address and length
# rather than insisting on raw numbers.
#
# xs:
#
# xs expression
#
# This does what you'd hope:
#
# mon xb <expression> <strlen(expression)>
#
# would do.
#
# xv:
#
# xv expression
#
# This does what you'd hope:
#
# mon xb &<expression> sizeof(<expression>)
#
# would do.
use strict;
use warnings;
use IPC::Open3;
use IO::Select;
# Store the args
my @args = @ARGV;
# Wrap ourselves for line editing
if (!exists $ENV{'VDB_WRAPPED'}) {
`which rlwrap`;
if ($? != 0) {
print "rlwrap not available - no command line editing.\n";
print "Consider: sudo apt-get install rlwrap\n";
} else {
$ENV{'VDB_WRAPPED'}=1;
unshift(@args, "rlwrap", $0);
exec(@args);
}
}
# Global variables
my $gdbkilled = 0;
sub killgdb() {
if ($gdbkilled) {
return;
}
print GDBSTDIN " \nkill\ny\nquit\n";
$gdbkilled = 1;
}
# Make the invocation args for valgrind
my @vgargs = (
"valgrind",
"--track-origins=yes",
"--vgdb=yes",
"--vgdb-error=0" );
push(@vgargs, @args);
# Make the invocation args for gdb
my @gdbargs = (
"gdb",
$args[0]);
# Fork the subprocesses
my $vgpid = open3(0, \*VGSTDOUT, 0, @vgargs);
my $gdbpid = open3(\*GDBSTDIN, \*GDBSTDOUT, 0, @gdbargs);
# Cope with Ctrl-C
sub my_sigint_handler() {
print "Caught a SIGINT...\n";
if ($gdbkilled) {
kill 9, $vgpid;
kill 9, $gdbpid;
exit(1);
}
killgdb();
}
$SIG{'INT'} = \&my_sigint_handler;
my $sel = new IO::Select();
$sel->add(*VGSTDOUT);
$sel->add(*GDBSTDOUT);
$sel->add(*STDIN);
*STDOUT->autoflush();
my $rate_limit = 0;
sub print_lines($)
{
my $buf=shift;
while (1) {
my $loc = index($buf, "\n");
if ($loc < 0) {
last;
}
my $line = substr($buf, 0, $loc+1);
print "$line";
$rate_limit++;
if ($rate_limit >= 24) {
sleep(1);
$rate_limit = 0;
}
$buf = substr($buf, $loc+1);
}
return $buf;
}
# We scan the output of VG to look for the magic runes
# State 0 = still waiting for magic runes
# 1 = runes have been captured.
my $vg_scan_state = 0;
# We scan the output from GDB to look for responses to commands we have given it.
# State 0 = Normal output - just parrot it out.
# 1 = Waiting for the result of a print address
# 2 = Waiting for the result of a print length
my $gdb_scan_state = 0;
my $vgpartial = '';
my $gdbpartial = '';
my $inpartial = '';
my $last2print = 0; # 0 = VG, 1 = GDB
my $xb_addr;
my $xb_len;
sub go_command($) {
my $command = shift;
chomp $command;
if (!defined $command) {
# When valgrind hits EOF, exit.
killgdb();
waitpid($vgpid,0);
waitpid($gdbpid,0);
exit(0);
} elsif ($command =~ m/^\s*xb\s+(\S+)\s*$/) {
my $one = $1;
if ($one =~ m/0x[a-fA-F0-9]*/) {
$xb_addr="$one";
$xb_len="8";
print GDBSTDIN "mon xb $xb_addr $xb_len\n";
} else {
# We need to figure out the value of xb_addr;
if ($one =~ m/^\&(.+)/) {
$xb_len="sizeof($1)";
} else {
$xb_len="sizeof(*$one)";
}
print GDBSTDIN "print $one\n";
$gdb_scan_state=1; # Next thing we get back will be the address
}
} elsif ($command =~ m/^\s*xv\s+(\S+)\s*$/) {
my $one = $1;
# We need to figure out the value of xb_addr;
$xb_len="sizeof($one)";
print GDBSTDIN "print &$one\n";
$gdb_scan_state=1; # Next thing we get back will be the address
} elsif ($command =~ m/^\s*xb\s+(\S+)\s+(\S+)\s*$/) {
my $one = $1;
my $two = $2;
if ($one =~ m/0x[a-fA-F0-9]*/) {
$xb_addr="$one";
if ($two =~ m/^\d+$/) {
$xb_len="$two";
print GDBSTDIN "mon xb $xb_addr $xb_len\n";
} else {
print GDBSTDIN "print $two\n";
$gdb_scan_state=2; # Next thing we get back will be the length
}
} else {
# We need to figure out the value of xb_addr;
$xb_len="$two";
print GDBSTDIN "print $one\n";
$gdb_scan_state=1; # Next thing we get back will be the address
}
} elsif ($command =~ m/^\s*xs\s+(\S+)\s*$/) {
my $one = $1;
if ($one =~ m/0x[a-fA-F0-9]*/) {
$xb_addr="$one";
print GDBSTDIN "print strlen($one)\n";
$gdb_scan_state=2; # Next thing we get back will be the length
} else {
# We need to figure out the value of xb_addr;
$xb_len="strlen($one)";
print GDBSTDIN "print $one\n";
$gdb_scan_state=1; # Next thing we get back will be the address
}
} else {
print GDBSTDIN "$command\n";
}
}
while (my @ready = $sel->can_read())
{
for my $fh (@ready) {
# If valgrind says anything, just print it.
if ($fh eq *VGSTDOUT) {
my $vgbuf= '';
if (sysread(VGSTDOUT, $vgbuf, 64*1024, length($vgbuf)) == 0) {
# When valgrind hits EOF, exit.
killgdb();
waitpid($vgpid,0);
waitpid($gdbpid,0);
exit(0);
}
if ($vg_scan_state == 0) {
$vgbuf =~ m/(target remote \| .+ \-\-pid\=\d+)\s*/;
if ($1) {
print GDBSTDIN "$1\n";
$vg_scan_state = 1;
}
}
# It definitely read something, so print it.
if ($last2print == 1) { # Last to print was GDB
if ($gdbpartial ne "") { # We need a newline
print "\n";
}
# Better reprint any partial line we had
print "$vgpartial";
}
$vgpartial = print_lines($vgbuf);
print "$vgpartial";
$last2print = 0; # VG
}
# Don't say anything to or from gdb until after we've got the magic words from valgrind
if ($vg_scan_state != 0) {
if ($fh eq *STDIN) {
my $inbuf=$inpartial;
if (sysread(STDIN, $inbuf, 64*1024, length($inbuf)) == 0) {
# When gdb hits EOF start to kill stuff.
killgdb();
}
while (1) {
my $loc = index($inbuf, "\n");
if ($loc < 0) {
last;
}
my $line = substr($inbuf, 0, $loc+1);
go_command($line);
$inbuf = substr($inbuf, $loc+1);
}
$inpartial = $inbuf;
}
# Anything gdb says, should be parotted out.
if ($fh eq *GDBSTDOUT) {
my $gdbbuf='';
if (sysread(GDBSTDOUT, $gdbbuf, 64*1024, length($gdbbuf)) == 0) {
# When gdb hits EOF start to kill stuff.
killgdb();
}
while ($gdbbuf ne "") {
if ($gdb_scan_state == 0) {
# It definitely read something, so print it.
if ($last2print == 0) { # Last to print was VG
if ($vgpartial ne "") { # We need a newline
print "\n";
}
# Better reprint any partial line we had
print "$gdbpartial";
}
$gdbpartial = print_lines($gdbbuf);
$gdbbuf="";
print "$gdbpartial";
$last2print = 1; # GDB
} elsif ($gdb_scan_state == 1) {
$gdbpartial .= $gdbbuf;
$gdbbuf = "";
while (1) {
my $loc = index($gdbpartial, "\n");
if ($loc < 0) {
last;
}
my $line = substr($gdbpartial, 0, $loc+1);
$gdbpartial = substr($gdbpartial, $loc+1);
if ($line =~ m/\$\d+ =.*(0x[a-zA-Z0-9]+)/) {
$xb_addr=$1;
print GDBSTDIN "print $xb_len\n";
$gdb_scan_state = 2; # Now we look for the length
last;
}
if ($line =~ m/(.*\n)/) {
$gdbpartial =~ s/(.*\n)//;
print "$1";
$gdbbuf = $gdbpartial;
$gdbpartial = "";
$gdb_scan_state = 0; # Error
last;
}
}
} elsif ($gdb_scan_state == 2) {
$gdbpartial .= $gdbbuf;
$gdbbuf = "";
while (1) {
my $loc = index($gdbpartial, "\n");
if ($loc < 0) {
last;
}
my $line = substr($gdbpartial, 0, $loc+1);
$gdbpartial = substr($gdbpartial, $loc+1);
if ($line =~ m/\$\d+ = (\d+)/) {
$xb_len=$1;
$gdb_scan_state = 0;
print GDBSTDIN "mon xb $xb_addr $xb_len\n";
last;
}
if ($line =~ m/(.*\n)/) {
$gdbpartial =~ s/(.*\n)//;
print "$1";
$gdbbuf = $gdbpartial;
$gdbpartial = "";
$gdb_scan_state = 0; # Error
last;
}
}
}
}
}
}
}
}
|
