Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751278AbdLZCTE (ORCPT ); Mon, 25 Dec 2017 21:19:04 -0500 Received: from mail-pl0-f67.google.com ([209.85.160.67]:38299 "EHLO mail-pl0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750810AbdLZCTC (ORCPT ); Mon, 25 Dec 2017 21:19:02 -0500 X-Google-Smtp-Source: ACJfBotUJrlKTOXnT8n8uBqv/nqtTC38SuXoGXNPiq+YEK6hez+j2M2rkgquUUbJBhxVRjt1MrAEeg== Date: Tue, 26 Dec 2017 07:48:55 +0530 From: Kaiwan N Billimoria To: "Tobin C. Harding" Cc: linux-kernel@vger.kernel.org, "kernel-hardening@lists.openwall.com" Subject: Re: [PATCH] leaking_addresses: add generic 32-bit support Message-ID: <20171226074855.43205509@gmail.com> In-Reply-To: <20171218055746.GC4627@eros> References: <1513569287.8041.8.camel@gmail.com> <20171218055746.GC4627@eros> Organization: kaiwanTECH X-Mailer: Claws Mail 3.15.1-dirty (GTK+ 2.24.31; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 23564 Lines: 805 The script attempts to detect the architecture it's running upon; as of now, we explicitly support x86_64, PPC64 and x86_32. If it's one of them, we proceed "normally". If we fail to detect the arch, we fallback to 64-bit scanning, unless the user has passed either of these option switches: "--opt-32bit" and/or "--page-offset-32bit=". If so, we switch to scanning for leaked addresses based on the value of PAGE_OFFSET (via an auto-detected or fallback mechanism). As of now, we have code (or "rules") to detect special cases for x86_64 and PPC64 (in the get_address_re sub). Also, we now have also builtin "stubs", for lack of a better term, where additional rules for other 64-bit arch's can be plugged into the code, in future, as applicable. Signed-off-by: Kaiwan N Billimoria --- scripts/leaking_addresses.pl | 190 +++++++++++++++++++++++++++++++++++-------- 1 file changed, 156 insertions(+), 34 deletions(-) This patch is based on Tobin's suggestions and my replies to them (see prev email in this thread). diff --git a/scripts/leaking_addresses.pl b/scripts/leaking_addresses.pl index a29e13e577a7..b0807b3a3c7c 100755 --- a/scripts/leaking_addresses.pl +++ b/scripts/leaking_addresses.pl @@ -1,10 +1,10 @@ #!/usr/bin/env perl # # (c) 2017 Tobin C. Harding - +# (c) 2017 Kaiwan N Billimoria # Licensed under the terms of the GNU GPL License version 2 # -# leaking_addresses.pl: Scan 64 bit kernel for potential leaking addresses. +# leaking_addresses.pl: Scan kernel for potential leaking addresses. # - Scans dmesg output. # - Walks directory tree and parses each file (for each directory in @DIRS). # @@ -32,11 +32,6 @@ my @DIRS = ('/proc', '/sys'); # Timer for parsing each file, in seconds. my $TIMEOUT = 10; -# Script can only grep for kernel addresses on the following architectures. If -# your architecture is not listed here and has a grep'able kernel address please -# consider submitting a patch. -my @SUPPORTED_ARCHITECTURES = ('x86_64', 'ppc64'); - # Command line options. my $help = 0; my $debug = 0; @@ -48,7 +43,9 @@ my $suppress_dmesg = 0; # Don't show dmesg in output. my $squash_by_path = 0; # Summary report grouped by absolute path. my $squash_by_filename = 0; # Summary report grouped by filename. -my $kernel_config_file = ""; # Kernel configuration file. +my $opt_32_bit = 0; # Detect (only) 32-bit kernel leaking addresses. +my $page_offset_32bit = 0; # 32-bit: value of CONFIG_PAGE_OFFSET. +my $kernel_config_file = ""; # Kernel configuration file. # Do not parse these files (absolute path). my @skip_parse_files_abs = ('/proc/kmsg', @@ -104,10 +101,12 @@ Options: --squash-by-path Show one result per unique path. --squash-by-filename Show one result per unique filename. --kernel-config-file= Kernel configuration file (e.g /boot/config) + --opt-32bit Detect (only) 32-bit kernel leaking addresses. + --page-offset-32bit= PAGE_OFFSET value (for 32-bit kernels). -d, --debug Display debugging output. - -h, --help, --versionq Display this help and exit. + -h, --help, --version Display this help and exit. -Scans the running (64 bit) kernel for potential leaking addresses. +Scans the running kernel for potential leaking addresses. EOM exit($exitcode); @@ -123,7 +122,9 @@ GetOptions( 'squash-by-path' => \$squash_by_path, 'squash-by-filename' => \$squash_by_filename, 'raw' => \$raw, - 'kernel-config-file=s' => \$kernel_config_file, + 'opt-32bit' => \$opt_32_bit, + 'page-offset-32bit=o' => \$page_offset_32bit, + 'kernel-config-file=s' => \$kernel_config_file, ) or help(1); help(0) if ($help); @@ -139,16 +140,15 @@ if (!$input_raw and ($squash_by_path or $squash_by_filename)) { exit(128); } -if (!is_supported_architecture()) { - printf "\nScript does not support your architecture, sorry.\n"; - printf "\nCurrently we support: \n\n"; - foreach(@SUPPORTED_ARCHITECTURES) { - printf "\t%s\n", $_; - } +show_detected_architecture() if $debug; - my $archname = $Config{archname}; - printf "\n\$ perl -MConfig -e \'print \"\$Config{archname}\\n\"\'\n"; - printf "%s\n", $archname; +if (!is_known_architecture()) { + printf STDERR "\nFATAL: Script does not recognize your architecture\n"; + + my $arch = `uname -m`; + chomp $arch; + printf "\n\$ uname -m\n"; + printf "%s\n", $arch; exit(129); } @@ -168,21 +168,45 @@ sub dprint printf(STDERR @_) if $debug; } -sub is_supported_architecture +sub is_known_architecture { - return (is_x86_64() or is_ppc64()); + return (is_64bit() or is_32bit()); } -sub is_x86_64 +sub is_32bit { - my $archname = $Config{archname}; + # 32-bit actual case + if (is_ix86_32()) { + return 1; + } - if ($archname =~ m/x86_64/) { + # 32-bit "forced" case (for any arch other than IA-32) + if ($opt_32_bit or $page_offset_32bit) { return 1; } return 0; } +sub is_64bit +{ + return (is_x86_64() or is_ppc64() or is_arm64() or is_mips64()); +} + +sub is_x86_64 +{ + is_arch("x86_64"); +} + +sub is_arm64 +{ + is_arch("aarch64"); +} + +sub is_mips64 +{ + is_arch("mips64"); +} + sub is_ppc64 { my $archname = $Config{archname}; @@ -193,6 +217,47 @@ sub is_ppc64 return 0; } +sub is_ix86_32 +{ + my $arch = `uname -m`; + + chomp $arch; + if ($arch =~ m/i[3456]86/) { + return 1; + } + return 0; +} + +sub is_arch +{ + my ($desc) = @_; + my $arch = `uname -m`; + + chomp $arch; + if ($arch eq $desc) { + return 1; + } + return 0; +} + +sub show_detected_architecture +{ + printf "Detected architecture: "; + if (is_32bit()) { + printf "32 bit\n"; + } elsif (is_x86_64()) { + printf "x86_64\n"; + } elsif (is_ppc64()) { + printf "PPC64\n"; + } elsif (is_arm64()) { + printf "ARM64\n"; + } elsif (is_mips64()) { + printf "MIPS64\n"; + } else { + printf "failed to detect architecture\n" + } +} + # gets config option value from kernel config file sub get_kernel_config_option { @@ -212,7 +277,6 @@ sub get_kernel_config_option } else { @config_files = ($tmp_file); } - } else { my $file = '/boot/config-' . `uname -r`; chomp $file; @@ -220,7 +284,6 @@ sub get_kernel_config_option } foreach my $file (@config_files) { - dprint("parsing config file: %s\n", $file); $value = option_from_file($option, $file); if ($value ne "") { last; @@ -258,6 +321,14 @@ sub is_false_positive { my ($match) = @_; + # 32 bit architectures, actual or forced + + if (is_32bit()) { + return is_false_positive_32bit($match); + } + + # 64 bit architectures + if ($match =~ '\b(0x)?(f|F){16}\b' or $match =~ '\b(0x)?0{16}\b') { return 1; @@ -281,6 +352,58 @@ sub is_in_vsyscall_memory_region return ($hex >= $region_min and $hex <= $region_max); } +sub is_false_positive_32bit +{ + my ($match) = @_; + state $page_offset = get_page_offset(); # only gets called once + + if ($match =~ '\b(0x)?(f|F){8}\b') { + return 1; + } + + my $addr32 = hex($match); + if ($addr32 < $page_offset) { + return 1; + } + + return 0; +} + +sub get_page_offset +{ + my $page_offset; + my $default_offset = hex("0xc0000000"); + my @config_files; + + # Allow --page-offset-32bit to override. + if ($page_offset_32bit != 0) { + return $page_offset_32bit; + } + + $page_offset = get_kernel_config_option('CONFIG_PAGE_OFFSET'); + return $default_offset; +} + +sub parse_kernel_config_file +{ + my ($file) = @_; + my $config = 'CONFIG_PAGE_OFFSET'; + my $str = ""; + my $val = ""; + + open(my $fh, "<", $file) or return ""; + while (my $line = <$fh> ) { + if ($line =~ /^$config/) { + ($str, $val) = split /=/, $line; + chomp($val); + last; + } + } + + close $fh; + return $val; +} + # True if argument potentially contains a kernel address. sub may_leak_address { @@ -300,8 +423,6 @@ sub may_leak_address } $address_re = get_address_re(); - dprint("Kernel address regular expression: %s\n", $address_re); - while (/($address_re)/g) { if (!is_false_positive($1)) { return 1; @@ -313,16 +434,17 @@ sub may_leak_address sub get_address_re { - my $re; + my $re = ""; if (is_x86_64()) { $re = get_x86_64_re(); } elsif (is_ppc64()) { $re = '\b(0x)?[89abcdef]00[[:xdigit:]]{13}\b'; - } - - if ($re eq "") { - print STDERR "$0: failed to build kernel address regular expression\n"; + ### + # Any special cases for other arch's go below this line + ### + } else { # nothing? then we assume it's a generic 32-bit + $re = '\b(0x)?[[:xdigit:]]{8}\b'; } return $re; -- 2.14.3 Thanks, Kaiwan. On Mon, 18 Dec 2017 16:57:46 +1100 "Tobin C. Harding" wrote: > On Mon, Dec 18, 2017 at 09:24:47AM +0530, kaiwan.billimoria@gmail.com > wrote: > > The script attempts to detect the architecture it's running upon; > > as of now, we explicitly support x86_64, PPC64 and x86_32. > > If it's one of them, we proceed "normally". If we fail to detect > > the arch, we fallback to 64-bit scanning, unless the user has > > passed either of these option switches: "--32-bit" and/or > > "--page-offset-32bit=". > > > > If so, we switch to scanning for leaked addresses based on the > > value of PAGE_OFFSET (via an auto-detected or fallback mechanism). > > > > As of now, we have code (or "rules") to detect special cases for > > x86_64 and ppc64 (in the get_address_re sub). Also, we now have > > also builtin "stubs", for lack of a better term, where additional > > rules for other 64-bit arch's can be plugged in, in future, as > > applicable. > > > > Signed-off-by: Kaiwan N Billimoria > > --- > > > > This is a patch based on Tobin's latest tree, 'leaks' branch. > > Applies on top of commit 6c3942594657 (leaking_addresses: add > > support for 5 page table levels (origin/leaks)) > > That commit is not the tip of the branch. leaks branch is currently at > > commit 266891c62bf0 (leaking_addresses: add support for 5 page table > levels) > > > > > Thanks, > > Kaiwan. > > > > scripts/leaking_addresses.pl | 213 > > +++++++++++++++++++++++++++++++++++++------ 1 file changed, 184 > > insertions(+), 29 deletions(-) > > > > diff --git a/scripts/leaking_addresses.pl > > b/scripts/leaking_addresses.pl index a29e13e577a7..a667f243c95b > > 100755 --- a/scripts/leaking_addresses.pl > > +++ b/scripts/leaking_addresses.pl > > @@ -1,10 +1,10 @@ > > #!/usr/bin/env perl > > # > > # (c) 2017 Tobin C. Harding > > - > > +# (c) 2017 Kaiwan N Billimoria > > # Licensed under the terms of the GNU GPL License version 2 > > # > > -# leaking_addresses.pl: Scan 64 bit kernel for potential leaking > > addresses. +# leaking_addresses.pl: Scan kernel for potential > > leaking addresses. # - Scans dmesg output. > > # - Walks directory tree and parses each file (for each directory > > in @DIRS). # > > @@ -35,7 +35,7 @@ my $TIMEOUT = 10; > > # Script can only grep for kernel addresses on the following > > architectures. If # your architecture is not listed here and has a > > grep'able kernel address please # consider submitting a patch. > > -my @SUPPORTED_ARCHITECTURES = ('x86_64', 'ppc64'); > > +my @SUPPORTED_ARCHITECTURES = ('x86_64', 'ppc64', 'i[3456]86'); > > > > # Command line options. > > my $help = 0; > > @@ -48,7 +48,9 @@ my $suppress_dmesg = 0; # Don't > > show dmesg in output. my $squash_by_path = 0; # > > Summary report grouped by absolute path. my $squash_by_filename = > > 0; # Summary report grouped by filename. > > -my $kernel_config_file = ""; # Kernel configuration file. > > +my $opt_32_bit = 0; # Detect 32-bit kernel leaking > > addresses. +my $page_offset_32bit = 0; # 32-bit: value of > > CONFIG_PAGE_OFFSET. +my $kernel_config_file = ""; # Kernel > > configuration file. > > # Do not parse these files (absolute path). > > my @skip_parse_files_abs = ('/proc/kmsg', > > @@ -97,17 +99,19 @@ Version: $V > > > > Options: > > > > - -o, --output-raw= Save results for future > > processing. > > - -i, --input-raw= Read results from file > > instead of scanning. > > - --raw Show raw results (default). > > - --suppress-dmesg Do not show dmesg results. > > - --squash-by-path Show one result per unique > > path. > > - --squash-by-filename Show one result per unique > > filename. > > - --kernel-config-file= Kernel configuration file > > (e.g /boot/config) > > - -d, --debug Display debugging output. > > - -h, --help, --versionq Display this help and exit. > > + -o, --output-raw= Save results for future > > processing. > > + -i, --input-raw= Read results from file > > instead of scanning. > > + --raw Show raw results > > (default). > > + --suppress-dmesg Do not show dmesg > > results. > > + --squash-by-path Show one result per > > unique path. > > + --squash-by-filename Show one result per > > unique filename. > > + --32-bit Detect 32-bit kernel > > leaking addresses. > > + --page-offset-32bit= PAGE_OFFSET value (for > > 32-bit kernels). > > + --kernel-config-file= Kernel configuration file > > (e.g /boot/config). > > + -d, --debug Display debugging output. > > + -h, --help, --version Display this help and > > exit. > > We don't need this, it's already indented. > > > -Scans the running (64 bit) kernel for potential leaking addresses. > > +Scans the running kernel for potential leaking addresses. > > > > EOM > > exit($exitcode); > > @@ -123,7 +127,9 @@ GetOptions( > > 'squash-by-path' => \$squash_by_path, > > 'squash-by-filename' => \$squash_by_filename, > > 'raw' => \$raw, > > - 'kernel-config-file=s' => \$kernel_config_file, > > + '32-bit' => \$opt_32_bit, > > + 'page-offset-32bit=o' => \$page_offset_32bit, > > + 'kernel-config-file=s' => \$kernel_config_file, > > Perhaps > > $opt_32bit so as to be consistent. > > > ) or help(1); > > > > help(0) if ($help); > > @@ -139,11 +145,16 @@ if (!$input_raw and ($squash_by_path or > > $squash_by_filename)) { exit(128); > > } > > > > -if (!is_supported_architecture()) { > > - printf "\nScript does not support your architecture, > > sorry.\n"; > > - printf "\nCurrently we support: \n\n"; > > - foreach(@SUPPORTED_ARCHITECTURES) { > > - printf "\t%s\n", $_; > > +show_detected_architecture() if $debug; > > + > > +if (!is_known_architecture()) { > > + printf STDERR "\n*** WARNING! Script does not recognize > > your architecture ***\n"; > > + if ($opt_32_bit or $page_offset_32bit) { > > + printf STDERR "Scanning for 32-bit leaking kernel > > addresses\n\n"; > > + } else { > > + printf STDERR "Scanning for 64-bit leaking kernel > > addresses\n"; > > + printf STDERR "If you\'d rather scan for 32-bit > > addresses, use the "; > > + printf STDERR "--32-bit (and --page-offset-32bit=) > > option switch(es).\n\n"; } > > > > my $archname = $Config{archname}; > > @@ -168,9 +179,14 @@ sub dprint > > printf(STDERR @_) if $debug; > > } > > > > -sub is_supported_architecture > > +sub is_known_architecture > > +{ > > + return (is_64bit() or is_ix86_32()); > > +} > > + > > +sub is_64bit > > { > > - return (is_x86_64() or is_ppc64()); > > + return (is_x86_64() or is_ppc64() or is_arm64() or > > is_mips64()); } > > Perhaps we could have > > sub is_32bit > { > if ($opt_32bit or $page_offset_32bit) { > return 1; > } > > if (is_ix86_32()) { > return 1; > } > return 0; > } > > > > > sub is_x86_64 > > @@ -193,6 +209,50 @@ sub is_ppc64 > > return 0; > > } > > > > +sub is_arm64 > > +{ > > + if (`uname -m` eq "aarch64") { > > + return 1; > > + } > > + return 0; > > +} > > + > > +sub is_mips64 > > +{ > > + if (`uname -m` eq "mips64") { > > + return 1; > > + } > > + return 0; > > +} > > + > > +sub is_ix86_32 > > +{ > > + my $archname = $Config{archname}; > > + > > + if ($archname =~ m/i[3456]86-linux/) { > > + return 1; > > + } > > + return 0; > > +} > > Why do we use $Config{archname} here and `uname -m` above? Can we use > just one of them? If so we could have a helper function > > sub is_arch() > { > my ($desc) = @_; > > if (`uname -m` eq $desc) { > return 1; > } > return 0; > } > > and > > is_mips64 { is_arch("mips64"); } > ... > > > +sub show_detected_architecture > > +{ > > + printf "Detected architecture: "; > > + if (is_ix86_32()) { > > + printf "32 bit x86\n"; > > + } elsif (is_x86_64()) { > > + printf "x86_64\n"; > > + } elsif (is_ppc64()) { > > + printf "ppc64\n"; > > We probably should use capitals for PPC64 since ARM and MIPS get > capitals. > > > + } elsif (is_arm64()) { > > + printf "ARM64\n"; > > + } elsif (is_mips64()) { > > + printf "MIPS64\n"; > > + } else { > > + printf "failed to detect architecture\n" > > + } > > +} > > + > > # gets config option value from kernel config file > > sub get_kernel_config_option > > { > > @@ -220,7 +280,8 @@ sub get_kernel_config_option > > } > > > > foreach my $file (@config_files) { > > - dprint("parsing config file: %s\n", $file); > > + printf("file: %s\n", $file) if $debug; > > We should actually just remove this debugging line all together, it > will be overly verbose and not that useful (see below). > > > $value = option_from_file($option, $file); > > if ($value ne "") { > > last; > > @@ -258,6 +319,14 @@ sub is_false_positive > > { > > my ($match) = @_; > > > > + # 32 bit architectures, actual or forced > > + > > + if (!is_64bit() and ($opt_32_bit or $page_offset_32bit)) { > > + return is_false_positive_32bit($match); > > + } > > and now we could have just > > if (is_32_bit()) { > ... > > > + > > + # 64 bit architectures > > + > > if ($match =~ '\b(0x)?(f|F){16}\b' or > > $match =~ '\b(0x)?0{16}\b') { > > return 1; > > @@ -281,6 +350,91 @@ sub is_in_vsyscall_memory_region > > return ($hex >= $region_min and $hex <= $region_max); > > } > > > > +sub is_false_positive_32bit > > +{ > > + my ($match) = @_; > > + state $page_offset = get_page_offset(); # only gets called > > once + > > + if ($match =~ '\b(0x)?(f|F){8}\b') { > > + return 1; > > + } > > + > > + my $addr32 = eval hex($match); > > Remember we don't like 'eval' :) Just make sure your code does not > generate warnings in the first place. > > > + if ($addr32 < $page_offset) { > > + return 1; > > + } > > + > > + return 0; > > +} > > + > > +sub get_page_offset > > +{ > > + my $page_offset; > > + my $default_offset = hex("0xc0000000"); > > + my @config_files; > > + > > + # Allow --page-offset-32bit to override. > > + if ($page_offset_32bit != 0) { > > + return $page_offset_32bit; > > + } > > We don't need the rest of this function since we now have > > get_kernel_config_option('CONFIG_PAGE_OFFSET'); > > And using this for CONFIG_PAGE_OFFSET after we have done so for > CONFIG_PGTABLE_LEVELS is why I suggest above removing debugging line. > > > + > > + # Allow --kernel-config-file to override. > > + if ($kernel_config_file ne "") { > > + @config_files = ($kernel_config_file); > > + } else { > > + my $config_file = '/boot/config-' . `uname -r`; > > + @config_files = ($config_file, '/boot/config'); > > + } > > + > > + if (-R "/proc/config.gz") { > > + my $tmp_file = "/tmp/tmpkconf"; > > + if (system("gunzip < /proc/config.gz > $tmp_file")) > > { > > + dprint " parse_kernel_config: > > system(gunzip...) failed\n"; > > + system("rm -f $tmp_file 2>/dev/null"); > > + } else { > > + $page_offset = > > parse_kernel_config_file($tmp_file); > > + system("rm -f $tmp_file"); > > + if ($page_offset ne "") { > > + return hex($page_offset); > > + } > > + } > > + } > > + > > + foreach my $config_file (@config_files) { > > + chomp $config_file; > > + $page_offset = > > parse_kernel_config_file($config_file); > > + if ($page_offset ne "") { > > + return hex($page_offset); > > + } > > + } > > + > > + printf STDERR "\nFailed to parse kernel config files\n"; > > + printf STDERR "*** NOTE ***\n"; > > + printf STDERR "Falling back to PAGE_OFFSET = %#x\n\n", > > $default_offset; + > > + return $default_offset; > > +} > > + > > +sub parse_kernel_config_file > > +{ > > + my ($file) = @_; > > + my $config = 'CONFIG_PAGE_OFFSET'; > > + my $str = ""; > > + my $val = ""; > > + > > + open(my $fh, "<", $file) or return ""; > > + while (my $line = <$fh> ) { > > + if ($line =~ /^$config/) { > > + ($str, $val) = split /=/, $line; > > + chomp($val); > > + last; > > + } > > + } > > + > > + close $fh; > > + return $val; > > +} > > + > > # True if argument potentially contains a kernel address. > > sub may_leak_address > > { > > @@ -300,7 +454,7 @@ sub may_leak_address > > } > > > > $address_re = get_address_re(); > > - dprint("Kernel address regular expression: %s\n", > > $address_re); +# dprint("Kernel address regular expression: > > %s\n", $address_re); > > Just remove this line altogether (I assume it annoyed you while > debugging). > > > while (/($address_re)/g) { > > if (!is_false_positive($1)) { > > @@ -313,16 +467,17 @@ sub may_leak_address > > > > sub get_address_re > > { > > - my $re; > > + my $re = ""; > > > > if (is_x86_64()) { > > $re = get_x86_64_re(); > > } elsif (is_ppc64()) { > > $re = '\b(0x)?[89abcdef]00[[:xdigit:]]{13}\b'; > > } elsif (is_32bit()) > $re = '\b(0x)?[[:xdigit:]]{8}\b'; > > - } > > - > > - if ($re eq "") { > > - print STDERR "$0: failed to build kernel address > > regular expression\n"; > > And then we can leave this as is. > > > + ### > > + # Any special cases for other arch's go below this line > > + ### > > + } else { # nothing? then we assume it's a generic 32-bit > > + $re = '\b(0x)?[[:xdigit:]]{8}\b'; > > } > > > > return $re; > > -- > > 2.14.3 > > thanks, > Tobin.