xref: /linux/usr/include/headers_check.pl (revision 0be3ff0c) 
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 arch [files...]
7# dir:   dir to look for included files
8# arch:  architecture
9# files: list of files to check
10#
11# The script reads the supplied files line by line and:
12#
13# 1) for each include statement it checks if the
14#    included file actually exists.
15#    Only include files located in asm* and linux* are checked.
16#    The rest are assumed to be system include files.
17#
18# 2) It is checked that prototypes does not use "extern"
19#
20# 3) Check for leaked CONFIG_ symbols
21
22use warnings;
23use strict;
24use File::Basename;
25
26my ($dir, $arch, @files) = @ARGV;
27
28my $ret = 0;
29my $line;
30my $lineno = 0;
31my $filename;
32
33foreach my $file (@files) {
34	$filename = $file;
35
36	open(my $fh, '<', $filename)
37		or die "$filename: $!\n";
38	$lineno = 0;
39	while ($line = <$fh>) {
40		$lineno++;
41		&check_include();
42		&check_asm_types();
43		&check_sizetypes();
44		&check_declarations();
45		# Dropped for now. Too much noise &check_config();
46	}
47	close $fh;
48}
49exit $ret;
50
51sub check_include
52{
53	if ($line =~ m/^\s*#\s*include\s+<((asm|linux).*)>/) {
54		my $inc = $1;
55		my $found;
56		$found = stat($dir . "/" . $inc);
57		if (!$found) {
58			$inc =~ s#asm/#asm-$arch/#;
59			$found = stat($dir . "/" . $inc);
60		}
61		if (!$found) {
62			printf STDERR "$filename:$lineno: included file '$inc' is not exported\n";
63			$ret = 1;
64		}
65	}
66}
67
68sub check_declarations
69{
70	# soundcard.h is what it is
71	if ($line =~ m/^void seqbuf_dump\(void\);/) {
72		return;
73	}
74	# drm headers are being C++ friendly
75	if ($line =~ m/^extern "C"/) {
76		return;
77	}
78	if ($line =~ m/^(\s*extern|unsigned|char|short|int|long|void)\b/) {
79		printf STDERR "$filename:$lineno: " .
80			      "userspace cannot reference function or " .
81			      "variable defined in the kernel\n";
82	}
83}
84
85sub check_config
86{
87	if ($line =~ m/[^a-zA-Z0-9_]+CONFIG_([a-zA-Z0-9_]+)[^a-zA-Z0-9_]/) {
88		printf STDERR "$filename:$lineno: leaks CONFIG_$1 to userspace where it is not valid\n";
89	}
90}
91
92my $linux_asm_types;
93sub check_asm_types
94{
95	if ($filename =~ /types.h|int-l64.h|int-ll64.h/o) {
96		return;
97	}
98	if ($lineno == 1) {
99		$linux_asm_types = 0;
100	} elsif ($linux_asm_types >= 1) {
101		return;
102	}
103	if ($line =~ m/^\s*#\s*include\s+<asm\/types.h>/) {
104		$linux_asm_types = 1;
105		printf STDERR "$filename:$lineno: " .
106		"include of <linux/types.h> is preferred over <asm/types.h>\n"
107		# Warn until headers are all fixed
108		#$ret = 1;
109	}
110}
111
112my $linux_types;
113my %import_stack = ();
114sub check_include_typesh
115{
116	my $path = $_[0];
117	my $import_path;
118
119	my $fh;
120	my @file_paths = ($path, $dir . "/" .  $path, dirname($filename) . "/" . $path);
121	for my $possible ( @file_paths ) {
122	    if (not $import_stack{$possible} and open($fh, '<', $possible)) {
123		$import_path = $possible;
124		$import_stack{$import_path} = 1;
125		last;
126	    }
127	}
128	if (eof $fh) {
129	    return;
130	}
131
132	my $line;
133	while ($line = <$fh>) {
134		if ($line =~ m/^\s*#\s*include\s+<linux\/types.h>/) {
135			$linux_types = 1;
136			last;
137		}
138		if (my $included = ($line =~ /^\s*#\s*include\s+[<"](\S+)[>"]/)[0]) {
139			check_include_typesh($included);
140		}
141	}
142	close $fh;
143	delete $import_stack{$import_path};
144}
145
146sub check_sizetypes
147{
148	if ($filename =~ /types.h|int-l64.h|int-ll64.h/o) {
149		return;
150	}
151	if ($lineno == 1) {
152		$linux_types = 0;
153	} elsif ($linux_types >= 1) {
154		return;
155	}
156	if ($line =~ m/^\s*#\s*include\s+<linux\/types.h>/) {
157		$linux_types = 1;
158		return;
159	}
160	if (my $included = ($line =~ /^\s*#\s*include\s+[<"](\S+)[>"]/)[0]) {
161		check_include_typesh($included);
162	}
163	if ($line =~ m/__[us](8|16|32|64)\b/) {
164		printf STDERR "$filename:$lineno: " .
165		              "found __[us]{8,16,32,64} type " .
166		              "without #include <linux/types.h>\n";
167		$linux_types = 2;
168		# Warn until headers are all fixed
169		#$ret = 1;
170	}
171}
172