Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753917AbdLDMhn (ORCPT ); Mon, 4 Dec 2017 07:37:43 -0500 Received: from mail-qt0-f195.google.com ([209.85.216.195]:34646 "EHLO mail-qt0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752316AbdLDMhl (ORCPT ); Mon, 4 Dec 2017 07:37:41 -0500 X-Google-Smtp-Source: AGs4zMZSDWk87pvLYGhIHYIwAgA/8MbnfWvRTr+4oUqDy4VB/g4k10lXbgadxt6MtuhRfbJzXEQwt9TFjoa4sSKMB+M= MIME-Version: 1.0 In-Reply-To: <1512382841.17323.11.camel@gmail.com> References: <20171129101640.GC6217@eros> <20171129204812.GE6217@eros> <1512133747.17323.3.camel@gmail.com> <20171204001106.GB27780@eros> <1512362481.17323.9.camel@gmail.com> <20171204045522.GE27780@eros> <20171204082111.GB21565@eros> <1512382841.17323.11.camel@gmail.com> From: Alexander Kapshuk Date: Mon, 4 Dec 2017 14:37:00 +0200 Message-ID: Subject: Re: [PATCH] leaking_addresses: add support for 32-bit kernel addresses To: Kaiwan Billimoria Cc: "Tobin C. Harding" , linux-kernel , kernel-hardening@lists.openwall.com Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3182 Lines: 90 On Mon, Dec 4, 2017 at 12:20 PM, wrote: > On Mon, 2017-12-04 at 19:21 +1100, Tobin C. Harding wrote: >> On Mon, Dec 04, 2017 at 10:51:53AM +0530, Kaiwan N Billimoria wrote: >> > > --- >> > diff --git a/scripts/leaking_addresses.pl b/scripts/leaking_addresses.pl >> > index 9906dcf8b807..260b52e456f1 100755 >> > --- a/scripts/leaking_addresses.pl >> > +++ b/scripts/leaking_addresses.pl >> > @@ -266,7 +266,7 @@ sub is_false_positive >> > sub is_false_positive_ix86_32 >> > { >> > my ($match) = @_; >> > - state $page_offset = eval get_page_offset(); # only gets called once >> > + state $page_offset = hex get_page_offset(); # only gets called once >> >> I don't think this is valid ;) I meant use hex() to convert the string >> to an int so it doesn't throw the warning (inside get_page_offset()). > > Yup, got it, thanks :-p > Combined patch below: > > > --- > scripts/leaking_addresses.pl | 13 ++++++------- > 1 file changed, 6 insertions(+), 7 deletions(-) > > diff --git a/scripts/leaking_addresses.pl b/scripts/leaking_addresses.pl > index 9906dcf8b807..a595a2c66b12 100755 > --- a/scripts/leaking_addresses.pl > +++ b/scripts/leaking_addresses.pl > @@ -266,8 +266,7 @@ sub is_false_positive > sub is_false_positive_ix86_32 > { > my ($match) = @_; > - state $page_offset = eval get_page_offset(); # only gets called once > - > + state $page_offset = get_page_offset(); # only gets called once > if ($match =~ '\b(0x)?(f|F){8}\b') { > return 1; > } > @@ -283,7 +282,7 @@ sub is_false_positive_ix86_32 > sub get_page_offset > { > my $page_offset; > - my $default_offset = "0xc0000000"; > + my $default_offset = hex("0xc0000000"); > my @config_files; > > # Allow --page-offset-32bit to override. > @@ -306,23 +305,23 @@ sub get_page_offset > } else { > $page_offset = parse_kernel_config_file($tmp_file); > if ($page_offset ne "") { > - return $page_offset; > + return hex($page_offset); > } > } > system("rm -f $tmp_file"); > } > > foreach my $config_file (@config_files) { > - $config_file =~ s/\R*//g; > + chomp $config_file; > $page_offset = parse_kernel_config_file($config_file); > if ($page_offset ne "") { > - return $page_offset; > + return hex($page_offset); > } > } > > printf STDERR "\nFailed to parse kernel config files\n"; > printf STDERR "*** NOTE ***\n"; > - printf STDERR "Falling back to PAGE_OFFSET = %s\n\n", $default_offset; > + printf STDERR "Falling back to PAGE_OFFSET = 0x%x\n\n", $default_offset; Better use the '#' flag with the 'x' conversion specifier: perl -e 'my $default_offset = hex("0xc0000000");printf "%#x\n", $default_offset' 0xc0000000 > > return $default_offset; > } > -- > 2.14.3 > > Thanks, > Kaiwan. > >> thanks, >> Tobin.