v4.19.13 snapshot.
diff --git a/scripts/headers_check.pl b/scripts/headers_check.pl
new file mode 100755
index 0000000..b6aec5e
--- /dev/null
+++ b/scripts/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;
+ }
+}