[PATCH 14/14] Re-enable and clean up "check_config()" in headers_check.pl

Palmer Dabbelt
2015-11-10T01:33:41Z

I recently got bit by a CONFIG_ in userspace bug. This has apparently
happened before, but the check got disabled for triggering too much.
In order to reduce false positives, I added some hueristics to avoid
detecting comments.

Since these tests all pass, I've now re-enabled them.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Reviewed-by: Andrew Waterman <waterman@eecs.berkeley.edu>
Reviewed-by: Albert Ou <aou@eecs.berkeley.edu>
---
scripts/headers_check.pl | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/scripts/headers_check.pl b/scripts/headers_check.pl
index 62320f9..1634b51 100755
--- a/scripts/headers_check.pl
+++ b/scripts/headers_check.pl
@@ -27,6 +27,7 @@ my $ret = 0;
my $line;
my $lineno = 0;
my $filename;
+my $check_config_in_multiline_comment = 0;

foreach my $file (@files) {
$filename = $file;
@@ -40,7 +41,7 @@ foreach my $file (@files) {
&check_asm_types();
&check_sizetypes();
&check_declarations();
- # Dropped for now. Too much noise &check_config();
+ &check_config();
}
close $fh;
}
@@ -78,7 +79,21 @@ sub check_declarations

sub check_config
{
- if ($line =~ m/[^a-zA-Z0-9_]+CONFIG_([a-zA-Z0-9_]+)[^a-zA-Z0-9_]/) {
+ my $nocomments = $line;
+ $nocomments =~ s/\/\*.*\*\///; # Remove ANSI-style comments (/* to */)
+ $nocomments =~ s/\/\/.*//; # Remove C99-style comments (// to EOL)
+
+ # Check to see if we're within a multiline comment, and if so
+ # just remove the whole line. I tried matching on '^ * ', but
+ # there's one header that doesn't prepend multi-line comments
+ # with * so that won't work.
+ if ($nocomments =~ m/\/\*/) { $check_config_in_multiline_comment = 1; }
+ if ($nocomments =~ m/\*\//) { $check_config_in_multiline_comment = 0; }
+ if ($check_config_in_multiline_comment == 1) { $nocomments = "" }
+
+ # Check to see if there is something that looks like CONFIG_
+ # inside a userspace-accessible header file and if so, print that out.
+ if ($nocomments =~ m/[^a-zA-Z0-9_]+CONFIG_([a-zA-Z0-9_]+)[^a-zA-Z0-9_]/) {
printf STDERR "$filename:$lineno: leaks CONFIG_$1 to userspace where it is not valid\n";
}
}
--
2.4.10