leaking_addresses: cache architecture name

Currently we are repeatedly calling `uname -m`.  This is causing the
script to take a long time to run (more than 10 seconds to parse
/proc/kallsyms).  We can use Perl state variables to cache the result of
the first call to `uname -m`.  With this change in place the script
scans the whole kernel in under a minute.

Cache machine architecture in state variable.

Signed-off-by: Tobin C. Harding <me@tobin.cc>

diff --git a/scripts/leaking_addresses.pl b/scripts/leaking_addresses.pl
index 2ad6e7fb669840b05c5af2c5dac10e2e8baf62b4..6e5bc57caeaaf09373a479f2eaf3032e19ec61e2 100755 (executable)
--- a/scripts/leaking_addresses.pl
+++ b/scripts/leaking_addresses.pl
@@ -175,7 +175,7 @@ sub is_32bit
 
 sub is_ix86_32
 {
-       my $arch = `uname -m`;
+       state $arch = `uname -m`;
 
        chomp $arch;
        if ($arch =~ m/i[3456]86/) {
@@ -198,12 +198,14 @@ sub is_arch
 
 sub is_x86_64
 {
-       return is_arch('x86_64');
+       state $is = is_arch('x86_64');
+       return $is;
 }
 
 sub is_ppc64
 {
-       return is_arch('ppc64');
+       state $is = is_arch('ppc64');
+       return $is;
 }
 
 # Gets config option value from kernel config file.