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Subject[PATCH v1] scripts: leaking_addresses.pl: add support for 32-bit kernel addresses
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The current leaking_addresses.pl script only supports showing "leaked"
64-bit kernel virtual addresses. This patch adds support for showing
"leaked" 32-bit kernel virtual addresses.

The way it currently works- once it detects we're running on an i'x'86 platform
(where x=3|4|5|6), it takes this arch into account for checking: the essential
rationale:
virt-addr >= PAGE_OFFSET => it's a kernel virtual address.

Note-
1. It's a work in progress; some pending TODOs:
- support for ARM-32
- programatically query and set the PAGE_OFFSET based on arch (it's currently
hard-coded)

2. Minor edit:
the '--raw', '--suppress-dmesg', '--squash-by-path' and
'--squash-by-filename' option switches are only meaningful
when the '----input-raw=' option is used. So, indent the 'Help' screen lines
to reflect the fact.


Feedback welcome..


Signed-off-by: Kaiwan N Billimoria <kaiwan.billimoria@gmail.com>
---
diff --git a/scripts/leaking_addresses.pl b/scripts/leaking_addresses.pl
index bc5788000018..e139de445ad1 100755
--- a/scripts/leaking_addresses.pl
+++ b/scripts/leaking_addresses.pl
@@ -12,7 +12,10 @@
#
# You may like to set kptr_restrict=2 before running script
# (see Documentation/sysctl/kernel.txt).
-
+#
+# 32-bit kernel address support : Kaiwan N Billimoria
+# <kaiwan.billimoria@gmail.com>
+#
use warnings;
use strict;
use POSIX;
@@ -35,7 +38,7 @@ 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;
@@ -48,6 +51,9 @@ 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 $bit_size = 64; # Check 64-bit kernel addresses by default
+my $PAGE_OFFSET_32BIT = 0xc0000000;
+
# Do not parse these files (absolute path).
my @skip_parse_files_abs = ('/proc/kmsg',
'/proc/kcore',
@@ -97,10 +103,10 @@ Options:

-o, --output-raw=<file> Save results for future processing.
-i, --input-raw=<file> 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.
+ --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.

@@ -177,7 +183,7 @@ 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
@@ -185,6 +191,7 @@ sub is_x86_64
my $archname = $Config{archname};

if ($archname =~ m/x86_64/) {
+ $bit_size=64;
return 1;
}
return 0;
@@ -195,6 +202,19 @@ sub is_ppc64
my $archname = $Config{archname};

if ($archname =~ m/powerpc/ and $archname =~ m/64/) {
+ $bit_size=64;
+ return 1;
+ }
+ return 0;
+}
+
+# 32-bit x86: is_i'x'86_32() ; where x is [3 or 4 or 5 or 6]
+sub is_ix86_32
+{
+ my $archname = $Config{archname};
+
+ if ($archname =~ m/i[3456]86-linux/) {
+ $bit_size=32;
return 1;
}
return 0;
@@ -215,6 +235,15 @@ sub is_false_positive
$match =~ '\bf{10}601000\b') {
return 1;
}
+ } elsif ($bit_size == 32) {
+ my $addr32 = eval hex($match);
+ if ($addr32 < $PAGE_OFFSET_32BIT ) {
+ return 1;
+ }
+ if ($match =~ '\b(0x)?(f|F){8}\b') {
+ return 1;
+ }
}

return 0;
@@ -243,6 +272,8 @@ sub may_leak_address
$address_re = '\b(0x)?ffff[[:xdigit:]]{12}\b';
} elsif (is_ppc64()) {
$address_re = '\b(0x)?[89abcdef]00[[:xdigit:]]{13}\b';
+ } elsif (is_ix86_32()) {
+ $address_re = '\b(0x)?[[:xdigit:]]{8}\b';
}

while (/($address_re)/g) {
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