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_sizetypes();
 43		&check_declarations();
 44		# Dropped for now. Too much noise &check_config();
 45	}
 46	close $fh;
 47}
 48exit $ret;
 49
 50sub check_include
 51{
 52	if ($line =~ m/^\s*#\s*include\s+<((asm|linux).*)>/) {
 53		my $inc = $1;
 54		my $found;
 55		$found = stat($dir . "/" . $inc);
 56		if (!$found) {
 57			printf STDERR "$filename:$lineno: included file '$inc' is not exported\n";
 58			$ret = 1;
 59		}
 60	}
 61}
 62
 63sub check_declarations
 64{
 65	# soundcard.h is what it is
 66	if ($line =~ m/^void seqbuf_dump\(void\);/) {
 67		return;
 68	}
 69	# drm headers are being C++ friendly
 70	if ($line =~ m/^extern "C"/) {
 71		return;
 72	}
 73	if ($line =~ m/^(\s*extern|unsigned|char|short|int|long|void)\b/) {
 74		printf STDERR "$filename:$lineno: " .
 75			      "userspace cannot reference function or " .
 76			      "variable defined in the kernel\n";
 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:$lineno: " .
101		"include of <linux/types.h> is preferred over <asm/types.h>\n"
102		# Warn until headers are all fixed
103		#$ret = 1;
104	}
105}
106
107my $linux_types;
108my %import_stack = ();
109sub check_include_typesh
110{
111	my $path = $_[0];
112	my $import_path;
113
114	my $fh;
115	my @file_paths = ($path, $dir . "/" .  $path, dirname($filename) . "/" . $path);
116	for my $possible ( @file_paths ) {
117	    if (not $import_stack{$possible} and open($fh, '<', $possible)) {
118		$import_path = $possible;
119		$import_stack{$import_path} = 1;
120		last;
121	    }
122	}
123	if (eof $fh) {
124	    return;
125	}
126
127	my $line;
128	while ($line = <$fh>) {
129		if ($line =~ m/^\s*#\s*include\s+<linux\/types.h>/) {
130			$linux_types = 1;
131			last;
132		}
133		if (my $included = ($line =~ /^\s*#\s*include\s+[<"](\S+)[>"]/)[0]) {
134			check_include_typesh($included);
135		}
136	}
137	close $fh;
138	delete $import_stack{$import_path};
139}
140
141sub check_sizetypes
142{
143	if ($filename =~ /types.h|int-l64.h|int-ll64.h/o) {
144		return;
145	}
146	if ($lineno == 1) {
147		$linux_types = 0;
148	} elsif ($linux_types >= 1) {
149		return;
150	}
151	if ($line =~ m/^\s*#\s*include\s+<linux\/types.h>/) {
152		$linux_types = 1;
153		return;
154	}
155	if (my $included = ($line =~ /^\s*#\s*include\s+[<"](\S+)[>"]/)[0]) {
156		check_include_typesh($included);
157	}
158	if ($line =~ m/__[us](8|16|32|64)\b/) {
159		printf STDERR "$filename:$lineno: " .
160		              "found __[us]{8,16,32,64} type " .
161		              "without #include <linux/types.h>\n";
162		$linux_types = 2;
163		# Warn until headers are all fixed
164		#$ret = 1;
165	}
166}