From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752028AbdK1VKJ (ORCPT ); Tue, 28 Nov 2017 16:10:09 -0500 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:44019 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751239AbdK1VKI (ORCPT ); Tue, 28 Nov 2017 16:10:08 -0500 X-ME-Sender: Date: Wed, 29 Nov 2017 08:10:03 +1100 From: "Tobin C. Harding" To: Alexander Kapshuk Cc: kaiwan.billimoria@gmail.com, linux-kernel , kernel-hardening@lists.openwall.com Subject: Re: [PATCH] leaking_addresses: add support for 32-bit kernel addresses Message-ID: <20171128211003.GY17858@eros> References: <1511850724-2381-1-git-send-email-me@tobin.cc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Mailer: Mutt 1.5.24 (2015-08-30) User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 28, 2017 at 03:16:24PM +0200, Alexander Kapshuk wrote: > On Tue, Nov 28, 2017 at 8:32 AM, Tobin C. Harding wrote: > > Currently, leaking_addresses.pl only supports scanning 64 bit > > architectures. This is due to how the regular expressions are formed. We > > can do better than this. 32 architectures can be supported if we take > > into consideration the kernel virtual address split. > > > > Add support for ix86 32 bit architectures. > > - Add command line option for page offset. > > - Add command line option for kernel configuration file. > > - Parse kernel config file for page offset (CONFIG_PAGE_OFFSET). > > - Use page offset when checking for kernel virtual addresses. > > > > Signed-off-by: Kaiwan N Billimoria > > Signed-off-by: Tobin C. Harding > > --- > > > > As discussed this is a patch based on Kaiwan's previous patch. This > > patch represents co development by Kaiwan and Tobin. > > > > Applies on top of commit 4fbd8d194f06 (Linux 4.15-rc1) > > > > thanks, > > Tobin. > > > > scripts/leaking_addresses.pl | 168 +++++++++++++++++++++++++++++++++++++------ > > 1 file changed, 148 insertions(+), 20 deletions(-) > > > > diff --git a/scripts/leaking_addresses.pl b/scripts/leaking_addresses.pl > > index bc5788000018..f03f2f140e0a 100755 > > --- a/scripts/leaking_addresses.pl > > +++ b/scripts/leaking_addresses.pl > > @@ -1,9 +1,11 @@ > > #!/usr/bin/env perl > > # > > # (c) 2017 Tobin C. Harding > > +# (c) 2017 Kaiwan N Billimoria (ix86 stuff) > > +# > > # 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 the kernel for potential leaking addresses. > > # - Scans dmesg output. > > # - Walks directory tree and parses each file (for each directory in @DIRS). > > # > > @@ -22,6 +24,7 @@ use Cwd 'abs_path'; > > use Term::ANSIColor qw(:constants); > > use Getopt::Long qw(:config no_auto_abbrev); > > use Config; > > +use feature 'state'; > > > > my $P = $0; > > my $V = '0.01'; > > @@ -35,18 +38,19 @@ 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; > > my $debug = 0; > > -my $raw = 0; > > -my $output_raw = ""; # Write raw results to file. > > -my $input_raw = ""; # Read raw results from file instead of scanning. > > - > > +my $raw = 0; # Show raw output. > > +my $output_raw = ""; # Write raw results to file. > > +my $input_raw = ""; # Read raw results from file instead of scanning. > > 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 $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', > > @@ -95,14 +99,16 @@ 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. > > - -d, --debug Display debugging output. > > - -h, --help, --version 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. > > + --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. > > > > Examples: > > > > @@ -115,7 +121,10 @@ Examples: > > # View summary report. > > $0 --input-raw scan.out --squash-by-filename > > > > -Scans the running (64 bit) kernel for potential leaking addresses. > > + # Scan kernel on a 32-bit system with a 2GB:2GB virtual address split. > > + $0 --page-offset-32bit=0x80000000 > > + > > +Scans the running kernel for potential leaking addresses. > > > > EOM > > exit($exitcode); > > @@ -131,6 +140,8 @@ GetOptions( > > 'squash-by-path' => \$squash_by_path, > > 'squash-by-filename' => \$squash_by_filename, > > 'raw' => \$raw, > > + 'page-offset-32bit=o' => \$page_offset_32bit, > > + 'kernel-config-file=s' => \$kernel_config_file, > > ) or help(1); > > > > help(0) if ($help); > > @@ -146,7 +157,9 @@ if (!$input_raw and ($squash_by_path or $squash_by_filename)) { > > exit(128); > > } > > > > -if (!is_supported_architecture()) { > > +if (is_supported_architecture()) { > > + show_detected_architecture() if $debug; > > +} else { > > printf "\nScript does not support your architecture, sorry.\n"; > > printf "\nCurrently we support: \n\n"; > > foreach(@SUPPORTED_ARCHITECTURES) { > > @@ -177,7 +190,7 @@ sub dprint > > > > sub is_supported_architecture > > { > > - return (is_x86_64() or is_ppc64()); > > + return (is_x86_64() or is_ppc64() or is_ix86_32()); > > } > > > > sub is_x86_64 > > @@ -200,10 +213,40 @@ sub is_ppc64 > > return 0; > > } > > > > +sub is_ix86_32 > > +{ > > + my $archname = $Config{archname}; > > + > > + if ($archname =~ m/i[3456]86-linux/) { > > + return 1; > > + } > > + return 0; > > +} > > + > > +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"; > > + } else { > > + printf "failed to detect architecture\n" > > + } > > +} > > + > > sub is_false_positive > > { > > my ($match) = @_; > > > > + if (is_ix86_32()) { > > + return is_false_positive_ix86_32($match); > > + } > > + > > + # 64 bit architectures > > + > > if ($match =~ '\b(0x)?(f|F){16}\b' or > > $match =~ '\b(0x)?0{16}\b') { > > return 1; > > @@ -220,6 +263,87 @@ sub is_false_positive > > return 0; > > } > > > > +sub is_false_positive_ix86_32 > > +{ > > + my ($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); > > + if ($addr32 < $page_offset) { > > + return 1; > > + } > > + > > + return 0; > > +} > > + > > > > > +sub get_page_offset > > +{ > > + my $page_offset; > > + my $default_offset = "0xc0000000"; > > + my @config_files; > > + > > + # Allow --page-offset-32bit to over ride. > > + if ($page_offset_32bit != 0) { > > + return $page_offset_32bit; > > + } > > + > > + # Allow --kernel-config-file to over ride. > > + if ($kernel_config_file != "") { > > + @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"; > > + } else { > > + $page_offset = parse_kernel_config_file($tmp_file); > > + if ($page_offset ne "") { > > + return $page_offset; > > + } > > + } > > + system("rm -f $tmp_file"); > > + } > > + > > + foreach my $config_file (@config_files) { > > + $page_offset = parse_kernel_config($config_file); > > + if ($page_offset ne "") { > > + return $page_offset; > > + } > > + } > > + > > + printf STDERR "Failed to parse kernel config files\n"; > > + printf STDERR "Falling back to %s\n", $default_offset; > > + return $default_offset; > > +} > > + > > +sub parse_kernel_config_file > > +{ > > + my ($file) = @_; > > + my $config = 'CONFIG_PAGE_OFFSET'; > > + my $val = ""; > > + > > + open(my $fh, "<", $file) or return ""; > > + while (my $line = <$fh> ) { > > + if ($line =~ /^$config/) { > > + my ($str, $val) = split /=/, $line; > > + chomp($val); > > + last; > > + } > > + } > > + > > + close $fh; > > + return $val; > > +} > > + > > + > > Get_page_offset attempts to build a list of config files, which are > then passed into the parsing function for further processing. > This splits up the code to do with the config files between > get_page_offset() and parse_kernel_config_file(). > May I suggest putting the kernel config file processing code into the > parse_kernel_config_file() instead, and let the parsing function > handle the config files and either return the page_offset or an empty > string. > > See below for the proposed implementation. Nice, this is much better! Thanks. > Apologies for the absence of indentation. Re-posting with indentation, comments in line. > Disclaimer: I did not test-run the code being proposed. I also did not test my comments ;) > sub get_page_offset > { > my $default_offset = "0xc0000000"; > my $page_offset; > > # Allow --page-offset-32bit to over ride. > if ($page_offset_32bit != 0) { > return $page_offset_32bit; > } > > $page_offset = parse_kernel_config_file(); > if ($page_offset ne "") { > return $page_offset > } > > printf STDERR "Failed to parse kernel config files\n"; > printf STDERR "Falling back to %s\n", $default_offset; > > return $default_offset; > } > > sub parse_kernel_config_file > { > my @config_files; > my $config = 'CONFIG_PAGE_OFFSET'; > > # Allow --kernel-config-file to over ride. > if ($kernel_config_file != "") { > @config_files = ($kernel_config_file); > } else { > my $config_file = '/boot/config-' . `uname -r`; > @config_files = ($config_file, '/boot/config'); > } > > if (-R "/proc/config.gz") { perhaps my $tmpkconf = '/tmp/tmpkconf'; > if (system("gunzip < /proc/config.gz > /tmp/tmpkconf") == 0) { > push @config_files, "/tmp/tmpkconf"; > } > } Won't there only ever be a single config file? So if /proc/config.gz is readable we could do @config_files = ($tmpkconf) > foreach my $config_file (@config_files) { > open(my $fh, "<", $config_file) or return ""; open(my $fh, "<", $config_file) or next; > while (my $line = <$fh> ) { > if ($line =~ /^$config/) { > my ($config_name, $page_offset) = split /=/, $line; > chomp($page_offset); > last; > } > } > } > system("rm -f $tmp_file"); > close $fh; > > return $page_offset; > } thanks, Tobin. From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 29 Nov 2017 08:10:03 +1100 From: "Tobin C. Harding" Message-ID: <20171128211003.GY17858@eros> References: <1511850724-2381-1-git-send-email-me@tobin.cc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: [kernel-hardening] Re: [PATCH] leaking_addresses: add support for 32-bit kernel addresses To: Alexander Kapshuk Cc: kaiwan.billimoria@gmail.com, linux-kernel , kernel-hardening@lists.openwall.com List-ID: On Tue, Nov 28, 2017 at 03:16:24PM +0200, Alexander Kapshuk wrote: > On Tue, Nov 28, 2017 at 8:32 AM, Tobin C. Harding wrote: > > Currently, leaking_addresses.pl only supports scanning 64 bit > > architectures. This is due to how the regular expressions are formed. We > > can do better than this. 32 architectures can be supported if we take > > into consideration the kernel virtual address split. > > > > Add support for ix86 32 bit architectures. > > - Add command line option for page offset. > > - Add command line option for kernel configuration file. > > - Parse kernel config file for page offset (CONFIG_PAGE_OFFSET). > > - Use page offset when checking for kernel virtual addresses. > > > > Signed-off-by: Kaiwan N Billimoria > > Signed-off-by: Tobin C. Harding > > --- > > > > As discussed this is a patch based on Kaiwan's previous patch. This > > patch represents co development by Kaiwan and Tobin. > > > > Applies on top of commit 4fbd8d194f06 (Linux 4.15-rc1) > > > > thanks, > > Tobin. > > > > scripts/leaking_addresses.pl | 168 +++++++++++++++++++++++++++++++++++++------ > > 1 file changed, 148 insertions(+), 20 deletions(-) > > > > diff --git a/scripts/leaking_addresses.pl b/scripts/leaking_addresses.pl > > index bc5788000018..f03f2f140e0a 100755 > > --- a/scripts/leaking_addresses.pl > > +++ b/scripts/leaking_addresses.pl > > @@ -1,9 +1,11 @@ > > #!/usr/bin/env perl > > # > > # (c) 2017 Tobin C. Harding > > +# (c) 2017 Kaiwan N Billimoria (ix86 stuff) > > +# > > # 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 the kernel for potential leaking addresses. > > # - Scans dmesg output. > > # - Walks directory tree and parses each file (for each directory in @DIRS). > > # > > @@ -22,6 +24,7 @@ use Cwd 'abs_path'; > > use Term::ANSIColor qw(:constants); > > use Getopt::Long qw(:config no_auto_abbrev); > > use Config; > > +use feature 'state'; > > > > my $P = $0; > > my $V = '0.01'; > > @@ -35,18 +38,19 @@ 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; > > my $debug = 0; > > -my $raw = 0; > > -my $output_raw = ""; # Write raw results to file. > > -my $input_raw = ""; # Read raw results from file instead of scanning. > > - > > +my $raw = 0; # Show raw output. > > +my $output_raw = ""; # Write raw results to file. > > +my $input_raw = ""; # Read raw results from file instead of scanning. > > 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 $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', > > @@ -95,14 +99,16 @@ 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. > > - -d, --debug Display debugging output. > > - -h, --help, --version 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. > > + --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. > > > > Examples: > > > > @@ -115,7 +121,10 @@ Examples: > > # View summary report. > > $0 --input-raw scan.out --squash-by-filename > > > > -Scans the running (64 bit) kernel for potential leaking addresses. > > + # Scan kernel on a 32-bit system with a 2GB:2GB virtual address split. > > + $0 --page-offset-32bit=0x80000000 > > + > > +Scans the running kernel for potential leaking addresses. > > > > EOM > > exit($exitcode); > > @@ -131,6 +140,8 @@ GetOptions( > > 'squash-by-path' => \$squash_by_path, > > 'squash-by-filename' => \$squash_by_filename, > > 'raw' => \$raw, > > + 'page-offset-32bit=o' => \$page_offset_32bit, > > + 'kernel-config-file=s' => \$kernel_config_file, > > ) or help(1); > > > > help(0) if ($help); > > @@ -146,7 +157,9 @@ if (!$input_raw and ($squash_by_path or $squash_by_filename)) { > > exit(128); > > } > > > > -if (!is_supported_architecture()) { > > +if (is_supported_architecture()) { > > + show_detected_architecture() if $debug; > > +} else { > > printf "\nScript does not support your architecture, sorry.\n"; > > printf "\nCurrently we support: \n\n"; > > foreach(@SUPPORTED_ARCHITECTURES) { > > @@ -177,7 +190,7 @@ sub dprint > > > > sub is_supported_architecture > > { > > - return (is_x86_64() or is_ppc64()); > > + return (is_x86_64() or is_ppc64() or is_ix86_32()); > > } > > > > sub is_x86_64 > > @@ -200,10 +213,40 @@ sub is_ppc64 > > return 0; > > } > > > > +sub is_ix86_32 > > +{ > > + my $archname = $Config{archname}; > > + > > + if ($archname =~ m/i[3456]86-linux/) { > > + return 1; > > + } > > + return 0; > > +} > > + > > +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"; > > + } else { > > + printf "failed to detect architecture\n" > > + } > > +} > > + > > sub is_false_positive > > { > > my ($match) = @_; > > > > + if (is_ix86_32()) { > > + return is_false_positive_ix86_32($match); > > + } > > + > > + # 64 bit architectures > > + > > if ($match =~ '\b(0x)?(f|F){16}\b' or > > $match =~ '\b(0x)?0{16}\b') { > > return 1; > > @@ -220,6 +263,87 @@ sub is_false_positive > > return 0; > > } > > > > +sub is_false_positive_ix86_32 > > +{ > > + my ($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); > > + if ($addr32 < $page_offset) { > > + return 1; > > + } > > + > > + return 0; > > +} > > + > > > > > +sub get_page_offset > > +{ > > + my $page_offset; > > + my $default_offset = "0xc0000000"; > > + my @config_files; > > + > > + # Allow --page-offset-32bit to over ride. > > + if ($page_offset_32bit != 0) { > > + return $page_offset_32bit; > > + } > > + > > + # Allow --kernel-config-file to over ride. > > + if ($kernel_config_file != "") { > > + @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"; > > + } else { > > + $page_offset = parse_kernel_config_file($tmp_file); > > + if ($page_offset ne "") { > > + return $page_offset; > > + } > > + } > > + system("rm -f $tmp_file"); > > + } > > + > > + foreach my $config_file (@config_files) { > > + $page_offset = parse_kernel_config($config_file); > > + if ($page_offset ne "") { > > + return $page_offset; > > + } > > + } > > + > > + printf STDERR "Failed to parse kernel config files\n"; > > + printf STDERR "Falling back to %s\n", $default_offset; > > + return $default_offset; > > +} > > + > > +sub parse_kernel_config_file > > +{ > > + my ($file) = @_; > > + my $config = 'CONFIG_PAGE_OFFSET'; > > + my $val = ""; > > + > > + open(my $fh, "<", $file) or return ""; > > + while (my $line = <$fh> ) { > > + if ($line =~ /^$config/) { > > + my ($str, $val) = split /=/, $line; > > + chomp($val); > > + last; > > + } > > + } > > + > > + close $fh; > > + return $val; > > +} > > + > > + > > Get_page_offset attempts to build a list of config files, which are > then passed into the parsing function for further processing. > This splits up the code to do with the config files between > get_page_offset() and parse_kernel_config_file(). > May I suggest putting the kernel config file processing code into the > parse_kernel_config_file() instead, and let the parsing function > handle the config files and either return the page_offset or an empty > string. > > See below for the proposed implementation. Nice, this is much better! Thanks. > Apologies for the absence of indentation. Re-posting with indentation, comments in line. > Disclaimer: I did not test-run the code being proposed. I also did not test my comments ;) > sub get_page_offset > { > my $default_offset = "0xc0000000"; > my $page_offset; > > # Allow --page-offset-32bit to over ride. > if ($page_offset_32bit != 0) { > return $page_offset_32bit; > } > > $page_offset = parse_kernel_config_file(); > if ($page_offset ne "") { > return $page_offset > } > > printf STDERR "Failed to parse kernel config files\n"; > printf STDERR "Falling back to %s\n", $default_offset; > > return $default_offset; > } > > sub parse_kernel_config_file > { > my @config_files; > my $config = 'CONFIG_PAGE_OFFSET'; > > # Allow --kernel-config-file to over ride. > if ($kernel_config_file != "") { > @config_files = ($kernel_config_file); > } else { > my $config_file = '/boot/config-' . `uname -r`; > @config_files = ($config_file, '/boot/config'); > } > > if (-R "/proc/config.gz") { perhaps my $tmpkconf = '/tmp/tmpkconf'; > if (system("gunzip < /proc/config.gz > /tmp/tmpkconf") == 0) { > push @config_files, "/tmp/tmpkconf"; > } > } Won't there only ever be a single config file? So if /proc/config.gz is readable we could do @config_files = ($tmpkconf) > foreach my $config_file (@config_files) { > open(my $fh, "<", $config_file) or return ""; open(my $fh, "<", $config_file) or next; > while (my $line = <$fh> ) { > if ($line =~ /^$config/) { > my ($config_name, $page_offset) = split /=/, $line; > chomp($page_offset); > last; > } > } > } > system("rm -f $tmp_file"); > close $fh; > > return $page_offset; > } thanks, Tobin.