headers_check.pl

  1#!/usr/bin/env perl
  2# SPDX-License-Identifier: GPL-2.0
  3#
  4# headers_check.pl execute a number of trivial consistency checks
  5#
  6# Usage: headers_check.pl dir [files...]
  7# dir:   dir to look for included files
  8# files: list of files to check
  9#
 10# The script reads the supplied files line by line and:
 11#
 12# 1) for each include statement it checks if the
 13#    included file actually exists.
 14#    Only include files located in asm* and linux* are checked.
 15#    The rest are assumed to be system include files.
 16#
 17# 2) It is checked that prototypes does not use "extern"
 18#
 19# 3) Check for leaked CONFIG_ symbols
 20
 21use warnings;
 22use strict;
 23use File::Basename;
 24
 25my ($dir, @files) = @ARGV;
 26
 27my $ret = 0;
 28my $line;
 29my $lineno = 0;
 30my $filename;
 31
 32foreach my $file (@files) {
 33	$filename = $file;
 34
 35	open(my $fh, '<', $filename)
 36		or die "$filename: $!\n";
 37	$lineno = 0;
 38	while ($line = <$fh>) {
 39		$lineno++;
 40		&check_include();
 41		&check_asm_types();
 42		&check_declarations();
 43		# Dropped for now. Too much noise &check_config();
 44	}
 45	close $fh;
 46}
 47exit $ret;
 48
 49sub check_include
 50{
 51	if ($line =~ m/^\s*#\s*include\s+<((asm|linux).*)>/) {
 52		my $inc = $1;
 53		my $found;
 54		$found = stat($dir . "/" . $inc);
 55		if (!$found) {
 56			printf STDERR "$filename:$lineno: included file '$inc' is not exported\n";
 57			$ret = 1;
 58		}
 59	}
 60}
 61
 62sub check_declarations
 63{
 64	# soundcard.h is what it is
 65	if ($line =~ m/^void seqbuf_dump\(void\);/) {
 66		return;
 67	}
 68	# drm headers are being C++ friendly
 69	if ($line =~ m/^extern "C"/) {
 70		return;
 71	}
 72	if ($line =~ m/^(\s*extern|unsigned|char|short|int|long|void)\b/) {
 73		printf STDERR "$filename:$lineno: " .
 74			      "userspace cannot reference function or " .
 75			      "variable defined in the kernel\n";
 76		$ret = 1;
 77	}
 78}
 79
 80sub check_config
 81{
 82	if ($line =~ m/[^a-zA-Z0-9_]+CONFIG_([a-zA-Z0-9_]+)[^a-zA-Z0-9_]/) {
 83		printf STDERR "$filename:$lineno: leaks CONFIG_$1 to userspace where it is not valid\n";
 84	}
 85}
 86
 87my $linux_asm_types;
 88sub check_asm_types
 89{
 90	if ($filename =~ /types.h|int-l64.h|int-ll64.h/o) {
 91		return;
 92	}
 93	if ($lineno == 1) {
 94		$linux_asm_types = 0;
 95	} elsif ($linux_asm_types >= 1) {
 96		return;
 97	}
 98	if ($line =~ m/^\s*#\s*include\s+<asm\/types.h>/) {
 99		$linux_asm_types = 1;
100		printf STDERR "$filename:$lineno: " .
101		"include of <linux/types.h> is preferred over <asm/types.h>\n";
102		$ret = 1;
103	}
104}