kbuild: move headers_check.pl to usr/include/

This script is only used by usr/include/Makefile. Make it local to
the directory.

Update the comment in include/uapi/linux/soundcard.h because
'make headers_check' is no longer functional.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

2 files changed, 175 insertions, 2 deletions

diff --git a/usr/include/Makefile b/usr/include/Makefile
index 1c2ae1368079..94403806ea56 100644
--- a/usr/include/Makefile
+++ b/usr/include/Makefile
@@ -99,10 +99,12 @@ quiet_cmd_hdrtest = HDRTEST $<
       cmd_hdrtest = \
 		$(CC) $(c_flags) -S -o /dev/null -x c /dev/null \
 			$(if $(filter-out $(no-header-test), $*.h), -include $< -include $<); \
-		$(PERL) $(srctree)/scripts/headers_check.pl $(obj) $(SRCARCH) $<; \
+		$(PERL) $(srctree)/$(src)/headers_check.pl $(obj) $(SRCARCH) $<; \
 		touch $@
 
 $(obj)/%.hdrtest: $(obj)/%.h FORCE
 	$(call if_changed_dep,hdrtest)
 
-clean-files += $(filter-out Makefile, $(notdir $(wildcard $(obj)/*)))
+# Since GNU Make 4.3, $(patsubst $(obj)/%/,%,$(wildcard $(obj)/*/)) works.
+# To support older Make versions, use a somewhat tedious way.
+clean-files += $(filter-out Makefile headers_check.pl, $(notdir $(wildcard $(obj)/*)))
diff --git a/usr/include/headers_check.pl b/usr/include/headers_check.pl
new file mode 100755
index 000000000000..b6aec5e4365f
--- /dev/null
+++ b/usr/include/headers_check.pl
@@ -0,0 +1,171 @@
+#!/usr/bin/env perl
+# SPDX-License-Identifier: GPL-2.0
+#
+# headers_check.pl execute a number of trivial consistency checks
+#
+# Usage: headers_check.pl dir arch [files...]
+# dir:   dir to look for included files
+# arch:  architecture
+# files: list of files to check
+#
+# The script reads the supplied files line by line and:
+#
+# 1) for each include statement it checks if the
+#    included file actually exists.
+#    Only include files located in asm* and linux* are checked.
+#    The rest are assumed to be system include files.
+#
+# 2) It is checked that prototypes does not use "extern"
+#
+# 3) Check for leaked CONFIG_ symbols
+
+use warnings;
+use strict;
+use File::Basename;
+
+my ($dir, $arch, @files) = @ARGV;
+
+my $ret = 0;
+my $line;
+my $lineno = 0;
+my $filename;
+
+foreach my $file (@files) {
+	$filename = $file;
+
+	open(my $fh, '<', $filename)
+		or die "$filename: $!\n";
+	$lineno = 0;
+	while ($line = <$fh>) {
+		$lineno++;
+		&check_include();
+		&check_asm_types();
+		&check_sizetypes();
+		&check_declarations();
+		# Dropped for now. Too much noise &check_config();
+	}
+	close $fh;
+}
+exit $ret;
+
+sub check_include
+{
+	if ($line =~ m/^\s*#\s*include\s+<((asm|linux).*)>/) {
+		my $inc = $1;
+		my $found;
+		$found = stat($dir . "/" . $inc);
+		if (!$found) {
+			$inc =~ s#asm/#asm-$arch/#;
+			$found = stat($dir . "/" . $inc);
+		}
+		if (!$found) {
+			printf STDERR "$filename:$lineno: included file '$inc' is not exported\n";
+			$ret = 1;
+		}
+	}
+}
+
+sub check_declarations
+{
+	# soundcard.h is what it is
+	if ($line =~ m/^void seqbuf_dump\(void\);/) {
+		return;
+	}
+	# drm headers are being C++ friendly
+	if ($line =~ m/^extern "C"/) {
+		return;
+	}
+	if ($line =~ m/^(\s*extern|unsigned|char|short|int|long|void)\b/) {
+		printf STDERR "$filename:$lineno: " .
+			      "userspace cannot reference function or " .
+			      "variable defined in the kernel\n";
+	}
+}
+
+sub check_config
+{
+	if ($line =~ m/[^a-zA-Z0-9_]+CONFIG_([a-zA-Z0-9_]+)[^a-zA-Z0-9_]/) {
+		printf STDERR "$filename:$lineno: leaks CONFIG_$1 to userspace where it is not valid\n";
+	}
+}
+
+my $linux_asm_types;
+sub check_asm_types
+{
+	if ($filename =~ /types.h|int-l64.h|int-ll64.h/o) {
+		return;
+	}
+	if ($lineno == 1) {
+		$linux_asm_types = 0;
+	} elsif ($linux_asm_types >= 1) {
+		return;
+	}
+	if ($line =~ m/^\s*#\s*include\s+<asm\/types.h>/) {
+		$linux_asm_types = 1;
+		printf STDERR "$filename:$lineno: " .
+		"include of <linux/types.h> is preferred over <asm/types.h>\n"
+		# Warn until headers are all fixed
+		#$ret = 1;
+	}
+}
+
+my $linux_types;
+my %import_stack = ();
+sub check_include_typesh
+{
+	my $path = $_[0];
+	my $import_path;
+
+	my $fh;
+	my @file_paths = ($path, $dir . "/" .  $path, dirname($filename) . "/" . $path);
+	for my $possible ( @file_paths ) {
+	    if (not $import_stack{$possible} and open($fh, '<', $possible)) {
+		$import_path = $possible;
+		$import_stack{$import_path} = 1;
+		last;
+	    }
+	}
+	if (eof $fh) {
+	    return;
+	}
+
+	my $line;
+	while ($line = <$fh>) {
+		if ($line =~ m/^\s*#\s*include\s+<linux\/types.h>/) {
+			$linux_types = 1;
+			last;
+		}
+		if (my $included = ($line =~ /^\s*#\s*include\s+[<"](\S+)[>"]/)[0]) {
+			check_include_typesh($included);
+		}
+	}
+	close $fh;
+	delete $import_stack{$import_path};
+}
+
+sub check_sizetypes
+{
+	if ($filename =~ /types.h|int-l64.h|int-ll64.h/o) {
+		return;
+	}
+	if ($lineno == 1) {
+		$linux_types = 0;
+	} elsif ($linux_types >= 1) {
+		return;
+	}
+	if ($line =~ m/^\s*#\s*include\s+<linux\/types.h>/) {
+		$linux_types = 1;
+		return;
+	}
+	if (my $included = ($line =~ /^\s*#\s*include\s+[<"](\S+)[>"]/)[0]) {
+		check_include_typesh($included);
+	}
+	if ($line =~ m/__[us](8|16|32|64)\b/) {
+		printf STDERR "$filename:$lineno: " .
+		              "found __[us]{8,16,32,64} type " .
+		              "without #include <linux/types.h>\n";
+		$linux_types = 2;
+		# Warn until headers are all fixed
+		#$ret = 1;
+	}
+}