Re: [PATCH] leaking_addresses: add support for 32-bit kernel addresses

kaiwan.billimoria
2017-12-04T10:20:48Z

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;

return $default_offset;
}
--
2.14.3

Thanks,
Kaiwan.

> thanks,
> Tobin.