[PATCH v3 1/2 RESEND] selftests: Introduce script to validate required dependencies

[Siddharth Menon <simeddon@gmail.com>]

This patch adds a script to validate that the current kernel configuration
satisfies the requirements for selftests by comparing the current
kernel configs against the required selftest configs.

The script also runs kselftest_deps.sh to check for any missing libraries
required by the selftest.

A config mismatch exits with error value 1 while matching configs or
missing config files exit with value 0. In order to silence missing
dependency output, set the environment variable SILENCE=1.

The code for extracting the current kernel configs is adapted from
scripts/kconfig/streamline_config.pl.

Suggested-by: Petr Mladek <pmladek@suse.com>
Suggested-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Siddharth Menon <simeddon@gmail.com>
---
 v1->v2:
 - check selftest/config directly rather than a separate set in the test
   makefile
 v2->v3:
 - Integrate kselftest_deps.sh to check for missing libraries (I have not
   set it to skip the tests here, as it sometimes throws outputs such as
   missing $(LIB) or $(MNL_LDLIBS))
 - Replaced spaces with tabs, removed trailing spaces and other minor
   formatting changes
 - Introduced flag to silence the missing dependencies debug statements
 - Rename script to a more meaningful name
 
 .../testing/selftests/check_kselftest_deps.pl | 170 ++++++++++++++++++
 1 file changed, 170 insertions(+)
 create mode 100755 tools/testing/selftests/check_kselftest_deps.pl

diff --git a/tools/testing/selftests/check_kselftest_deps.pl b/tools/testing/selftests/check_kselftest_deps.pl
new file mode 100755
index 000000000000..ef1a5fe8c321
--- /dev/null
+++ b/tools/testing/selftests/check_kselftest_deps.pl
@@ -0,0 +1,170 @@
+#!/usr/bin/env perl
+# SPDX-License-Identifier: GPL-2.0
+use warnings;
+use strict;
+use Getopt::Long;
+use File::Spec;
+use File::Basename;
+
+# set the environment variable SILENCE to silence
+# debug output.
+
+# Check if required arguments are provided
+die "Usage: $0 <selftest_path> <compiler>\n" unless @ARGV >= 2;
+
+my $test_path = $ARGV[0];
+my $cc = join(' ', @ARGV[1..$#ARGV]);
+my $script_dir = dirname(__FILE__);
+
+my $silenceprint;
+$silenceprint = 1 if (defined($ENV{SILENCE}));
+
+sub dprint {
+	return if ($silenceprint);
+	print STDERR @_;
+}
+
+my $uname = `uname -r`;
+chomp $uname;
+
+my @searchconfigs = (
+	{
+		"file" => ".config",
+		"exec" => "cat",
+	},
+	{
+		"file" => "/proc/config.gz",
+		"exec" => "zcat",
+	},
+	{
+		"file" => "/boot/config-$uname",
+		"exec" => "cat",
+	},
+	{
+		"file" => "/boot/vmlinuz-$uname",
+		"exec" => "scripts/extract-ikconfig",
+		"test" => "scripts/extract-ikconfig",
+	},
+	{
+		"file" => "vmlinux",
+		"exec" => "scripts/extract-ikconfig",
+		"test" => "scripts/extract-ikconfig",
+	},
+	{
+		"file" => "/lib/modules/$uname/kernel/kernel/configs.ko",
+		"exec" => "scripts/extract-ikconfig",
+		"test" => "scripts/extract-ikconfig",
+	},
+	{
+		"file" => "/lib/modules/$uname/build/.config",
+		"exec" => "cat",
+	},
+	{
+		"file" => "kernel/configs.ko",
+		"exec" => "scripts/extract-ikconfig",
+		"test" => "scripts/extract-ikconfig",
+	},
+	{
+		"file" => "kernel/configs.o",
+		"exec" => "scripts/extract-ikconfig",
+		"test" => "scripts/extract-ikconfig",
+	},
+);
+
+sub read_config {
+	foreach my $conf (@searchconfigs) {
+		my $file = $conf->{"file"};
+
+		next unless -f $file;
+
+	if (defined $conf->{"test"}) {
+		`$conf->{"test"} $file 2>/dev/null`;
+		next if $?;
+	}
+
+	my $exec = $conf->{"exec"};
+
+	# dprint "Kernel config: '$file'\n";
+
+	open(my $infile, '-|', "$exec $file") or die "Failed to run $exec $file";
+	my @config_content = <$infile>;
+	close $infile;
+
+	return @config_content;
+	}
+
+	dprint "Unable to find kernel config file, skipping check\n";
+	exit 0;
+}
+
+sub check_libs {
+	my $command = "cd $script_dir && ./kselftest_deps.sh \"$cc\" $test_path";
+	my $lib_test = `$command 2>&1`;
+	my $exit_code = $? >> 8;
+
+	if ($exit_code != 0) {
+		die "Error: Failed to run kselftest_deps.sh with exit code $exit_code\n";
+	}
+
+	return $lib_test;
+}
+
+# Check for missing libraries
+my $lib_test = check_libs();
+my $fail_libs;
+
+if ($lib_test =~
+/(--------------------------------------------------------\s
+*Missing libraries system.*?
+--------------------------------------------------------)/s) {
+	$fail_libs = $1;
+}
+
+dprint("$fail_libs\n") if $fail_libs;
+
+# Read and parse kernel config
+my @config_file = read_config();
+my %kern_configs;
+foreach my $line (@config_file) {
+	chomp $line;
+	next if $line =~ /^\s*$/ || $line =~ /^#/;
+
+	if ($line =~ /^(CONFIG_\w+)=(.+)$/) {
+	$kern_configs{$1} = $2;
+	}
+}
+
+# Read and parse test config
+my %test_configs;
+open(my $fh, '<', "$test_path/config") or exit 0;
+
+while (my $line = <$fh>) {
+	chomp $line;
+	next if $line =~ /^\s*$/ || $line =~ /^#/;
+
+	if ($line =~ /^(CONFIG_\w+)=(.+)$/) {
+		$test_configs{$1} = $2;
+	}
+}
+close $fh;
+
+# Compare selftest configs with kernel configs
+my $all_match = 1;
+my @missing_or_mismatched;
+
+foreach my $key (keys %test_configs) {
+	if (!exists $kern_configs{$key} || $kern_configs{$key} ne $test_configs{$key}) {
+		push @missing_or_mismatched, "Required: $key=$test_configs{$key}";
+		$all_match = 0;
+	}
+}
+
+if ($all_match && !$fail_libs) {
+	exit 0;
+} else {
+	dprint("--------------------------------------------------------\n") unless $fail_libs;
+	dprint("$_\n") for @missing_or_mismatched;
+	dprint("--------------------------------------------------------\n") if @missing_or_mismatched;
+
+	exit 1;
+}
-- 
2.48.1