lib/uuid: add a test module

It appears that somehow I missed a test of the latest UUID rework which
landed in the kernel.  Present a small test module to avoid such cases
in the future.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/Kconfig.debug

@@ -1841,6 +1841,9 @@ config TEST_BITMAP
 
 	  If unsure, say N.
 
+config TEST_UUID
+	tristate "Test functions located in the uuid module at runtime"
+
 config TEST_RHASHTABLE
 	tristate "Perform selftest on resizable hash table"
 	default n

lib/Makefile

@@ -58,6 +58,7 @@ obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o
 obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o
 obj-$(CONFIG_TEST_PRINTF) += test_printf.o
 obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o
+obj-$(CONFIG_TEST_UUID) += test_uuid.o
 
 ifeq ($(CONFIG_DEBUG_KOBJECT),y)
 CFLAGS_kobject.o += -DDEBUG

lib/test_uuid.c

@@ -0,0 +1,133 @@
+/*
+ * Test cases for lib/uuid.c module.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/uuid.h>
+
+struct test_uuid_data {
+	const char *uuid;
+	uuid_le le;
+	uuid_be be;
+};
+
+static const struct test_uuid_data test_uuid_test_data[] = {
+	{
+		.uuid = "c33f4995-3701-450e-9fbf-206a2e98e576",
+		.le = UUID_LE(0xc33f4995, 0x3701, 0x450e, 0x9f, 0xbf, 0x20, 0x6a, 0x2e, 0x98, 0xe5, 0x76),
+		.be = UUID_BE(0xc33f4995, 0x3701, 0x450e, 0x9f, 0xbf, 0x20, 0x6a, 0x2e, 0x98, 0xe5, 0x76),
+	},
+	{
+		.uuid = "64b4371c-77c1-48f9-8221-29f054fc023b",
+		.le = UUID_LE(0x64b4371c, 0x77c1, 0x48f9, 0x82, 0x21, 0x29, 0xf0, 0x54, 0xfc, 0x02, 0x3b),
+		.be = UUID_BE(0x64b4371c, 0x77c1, 0x48f9, 0x82, 0x21, 0x29, 0xf0, 0x54, 0xfc, 0x02, 0x3b),
+	},
+	{
+		.uuid = "0cb4ddff-a545-4401-9d06-688af53e7f84",
+		.le = UUID_LE(0x0cb4ddff, 0xa545, 0x4401, 0x9d, 0x06, 0x68, 0x8a, 0xf5, 0x3e, 0x7f, 0x84),
+		.be = UUID_BE(0x0cb4ddff, 0xa545, 0x4401, 0x9d, 0x06, 0x68, 0x8a, 0xf5, 0x3e, 0x7f, 0x84),
+	},
+};
+
+static const char * const test_uuid_wrong_data[] = {
+	"c33f4995-3701-450e-9fbf206a2e98e576 ",	/* no hyphen(s) */
+	"64b4371c-77c1-48f9-8221-29f054XX023b",	/* invalid character(s) */
+	"0cb4ddff-a545-4401-9d06-688af53e",	/* not enough data */
+};
+
+static unsigned total_tests __initdata;
+static unsigned failed_tests __initdata;
+
+static void __init test_uuid_failed(const char *prefix, bool wrong, bool be,
+				    const char *data, const char *actual)
+{
+	pr_err("%s test #%u %s %s data: '%s'\n",
+	       prefix,
+	       total_tests,
+	       wrong ? "passed on wrong" : "failed on",
+	       be ? "BE" : "LE",
+	       data);
+	if (actual && *actual)
+		pr_err("%s test #%u actual data: '%s'\n",
+		       prefix,
+		       total_tests,
+		       actual);
+	failed_tests++;
+}
+
+static void __init test_uuid_test(const struct test_uuid_data *data)
+{
+	uuid_le le;
+	uuid_be be;
+	char buf[48];
+
+	/* LE */
+	total_tests++;
+	if (uuid_le_to_bin(data->uuid, &le))
+		test_uuid_failed("conversion", false, false, data->uuid, NULL);
+
+	total_tests++;
+	if (uuid_le_cmp(data->le, le)) {
+		sprintf(buf, "%pUl", &le);
+		test_uuid_failed("cmp", false, false, data->uuid, buf);
+	}
+
+	/* BE */
+	total_tests++;
+	if (uuid_be_to_bin(data->uuid, &be))
+		test_uuid_failed("conversion", false, true, data->uuid, NULL);
+
+	total_tests++;
+	if (uuid_be_cmp(data->be, be)) {
+		sprintf(buf, "%pUb", &be);
+		test_uuid_failed("cmp", false, true, data->uuid, buf);
+	}
+}
+
+static void __init test_uuid_wrong(const char *data)
+{
+	uuid_le le;
+	uuid_be be;
+
+	/* LE */
+	total_tests++;
+	if (!uuid_le_to_bin(data, &le))
+		test_uuid_failed("negative", true, false, data, NULL);
+
+	/* BE */
+	total_tests++;
+	if (!uuid_be_to_bin(data, &be))
+		test_uuid_failed("negative", true, true, data, NULL);
+}
+
+static int __init test_uuid_init(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(test_uuid_test_data); i++)
+		test_uuid_test(&test_uuid_test_data[i]);
+
+	for (i = 0; i < ARRAY_SIZE(test_uuid_wrong_data); i++)
+		test_uuid_wrong(test_uuid_wrong_data[i]);
+
+	if (failed_tests == 0)
+		pr_info("all %u tests passed\n", total_tests);
+	else
+		pr_err("failed %u out of %u tests\n", failed_tests, total_tests);
+
+	return failed_tests ? -EINVAL : 0;
+}
+module_init(test_uuid_init);
+
+static void __exit test_uuid_exit(void)
+{
+	/* do nothing */
+}
+module_exit(test_uuid_exit);
+
+MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
+MODULE_LICENSE("Dual BSD/GPL");