test.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Base unit test (KUnit) API.
 *
 * Copyright (C) 2019, Google LLC.
 * Author: Brendan Higgins <brendanhiggins@google.com>
 */

#include <kunit/test.h>
#include <linux/kernel.h>

static void kunit_set_failure(struct kunit *test)
{
	WRITE_ONCE(test->success, false);
}

static int kunit_vprintk_emit(int level, const char *fmt, va_list args)
{
	return vprintk_emit(0, level, NULL, 0, fmt, args);
}

static int kunit_printk_emit(int level, const char *fmt, ...)
{
	va_list args;
	int ret;

	va_start(args, fmt);
	ret = kunit_vprintk_emit(level, fmt, args);
	va_end(args);

	return ret;
}

static void kunit_vprintk(const struct kunit *test,
			  const char *level,
			  struct va_format *vaf)
{
	kunit_printk_emit(level[1] - '0', "\t# %s: %pV", test->name, vaf);
}

static void kunit_print_tap_version(void)
{
	static bool kunit_has_printed_tap_version;

	if (!kunit_has_printed_tap_version) {
		kunit_printk_emit(LOGLEVEL_INFO, "TAP version 14\n");
		kunit_has_printed_tap_version = true;
	}
}

static size_t kunit_test_cases_len(struct kunit_case *test_cases)
{
	struct kunit_case *test_case;
	size_t len = 0;

	for (test_case = test_cases; test_case->run_case; test_case++)
		len++;

	return len;
}

static void kunit_print_subtest_start(struct kunit_suite *suite)
{
	kunit_print_tap_version();
	kunit_printk_emit(LOGLEVEL_INFO, "\t# Subtest: %s\n", suite->name);
	kunit_printk_emit(LOGLEVEL_INFO,
			  "\t1..%zd\n",
			  kunit_test_cases_len(suite->test_cases));
}

static void kunit_print_ok_not_ok(bool should_indent,
				  bool is_ok,
				  size_t test_number,
				  const char *description)
{
	const char *indent, *ok_not_ok;

	if (should_indent)
		indent = "\t";
	else
		indent = "";

	if (is_ok)
		ok_not_ok = "ok";
	else
		ok_not_ok = "not ok";

	kunit_printk_emit(LOGLEVEL_INFO,
			  "%s%s %zd - %s\n",
			  indent, ok_not_ok, test_number, description);
}

static bool kunit_suite_has_succeeded(struct kunit_suite *suite)
{
	const struct kunit_case *test_case;

	for (test_case = suite->test_cases; test_case->run_case; test_case++)
		if (!test_case->success)
			return false;

	return true;
}

static void kunit_print_subtest_end(struct kunit_suite *suite)
{
	static size_t kunit_suite_counter = 1;

	kunit_print_ok_not_ok(false,
			      kunit_suite_has_succeeded(suite),
			      kunit_suite_counter++,
			      suite->name);
}

static void kunit_print_test_case_ok_not_ok(struct kunit_case *test_case,
					    size_t test_number)
{
	kunit_print_ok_not_ok(true,
			      test_case->success,
			      test_number,
			      test_case->name);
}

static void kunit_print_string_stream(struct kunit *test,
				      struct string_stream *stream)
{
	struct string_stream_fragment *fragment;
	char *buf;

	buf = string_stream_get_string(stream);
	if (!buf) {
		kunit_err(test,
			  "Could not allocate buffer, dumping stream:\n");
		list_for_each_entry(fragment, &stream->fragments, node) {
			kunit_err(test, fragment->fragment);
		}
		kunit_err(test, "\n");
	} else {
		kunit_err(test, buf);
		kunit_kfree(test, buf);
	}
}

static void kunit_fail(struct kunit *test, struct kunit_assert *assert)
{
	struct string_stream *stream;

	kunit_set_failure(test);

	stream = alloc_string_stream(test, GFP_KERNEL);
	if (!stream) {
		WARN(true,
		     "Could not allocate stream to print failed assertion in %s:%d\n",
		     assert->file,
		     assert->line);
		return;
	}

	assert->format(assert, stream);

	kunit_print_string_stream(test, stream);

	WARN_ON(string_stream_destroy(stream));
}

void kunit_do_assertion(struct kunit *test,
			struct kunit_assert *assert,
			bool pass,
			const char *fmt, ...)
{
	va_list args;

	if (pass)
		return;

	va_start(args, fmt);

	assert->message.fmt = fmt;
	assert->message.va = &args;

	kunit_fail(test, assert);

	va_end(args);
}

void kunit_init_test(struct kunit *test, const char *name)
{
	spin_lock_init(&test->lock);
	INIT_LIST_HEAD(&test->resources);
	test->name = name;
	test->success = true;
}

/*
 * Performs all logic to run a test case.
 */
static void kunit_run_case(struct kunit_suite *suite,
			   struct kunit_case *test_case)
{
	struct kunit test;

	kunit_init_test(&test, test_case->name);

	if (suite->init) {
		int ret;

		ret = suite->init(&test);
		if (ret) {
			kunit_err(&test, "failed to initialize: %d\n", ret);
			kunit_set_failure(&test);
			test_case->success = test.success;
			return;
		}
	}

	test_case->run_case(&test);

	if (suite->exit)
		suite->exit(&test);

	kunit_cleanup(&test);

	test_case->success = test.success;
}

int kunit_run_tests(struct kunit_suite *suite)
{
	struct kunit_case *test_case;
	size_t test_case_count = 1;

	kunit_print_subtest_start(suite);

	for (test_case = suite->test_cases; test_case->run_case; test_case++) {
		kunit_run_case(suite, test_case);
		kunit_print_test_case_ok_not_ok(test_case, test_case_count++);
	}

	kunit_print_subtest_end(suite);

	return 0;
}

struct kunit_resource *kunit_alloc_and_get_resource(struct kunit *test,
						    kunit_resource_init_t init,
						    kunit_resource_free_t free,
						    gfp_t internal_gfp,
						    void *context)
{
	struct kunit_resource *res;
	int ret;

	res = kzalloc(sizeof(*res), internal_gfp);
	if (!res)
		return NULL;

	ret = init(res, context);
	if (ret)
		return NULL;

	res->free = free;
	spin_lock(&test->lock);
	list_add_tail(&res->node, &test->resources);
	spin_unlock(&test->lock);

	return res;
}

static void kunit_resource_free(struct kunit *test, struct kunit_resource *res)
{
	res->free(res);
	kfree(res);
}

static struct kunit_resource *kunit_resource_find(struct kunit *test,
						  kunit_resource_match_t match,
						  kunit_resource_free_t free,
						  void *match_data)
{
	struct kunit_resource *resource;

	lockdep_assert_held(&test->lock);

	list_for_each_entry_reverse(resource, &test->resources, node) {
		if (resource->free != free)
			continue;
		if (match(test, resource->allocation, match_data))
			return resource;
	}

	return NULL;
}

static struct kunit_resource *kunit_resource_remove(
		struct kunit *test,
		kunit_resource_match_t match,
		kunit_resource_free_t free,
		void *match_data)
{
	struct kunit_resource *resource;

	spin_lock(&test->lock);
	resource = kunit_resource_find(test, match, free, match_data);
	if (resource)
		list_del(&resource->node);
	spin_unlock(&test->lock);

	return resource;
}

int kunit_resource_destroy(struct kunit *test,
			   kunit_resource_match_t match,
			   kunit_resource_free_t free,
			   void *match_data)
{
	struct kunit_resource *resource;

	resource = kunit_resource_remove(test, match, free, match_data);

	if (!resource)
		return -ENOENT;

	kunit_resource_free(test, resource);
	return 0;
}

struct kunit_kmalloc_params {
	size_t size;
	gfp_t gfp;
};

static int kunit_kmalloc_init(struct kunit_resource *res, void *context)
{
	struct kunit_kmalloc_params *params = context;

	res->allocation = kmalloc(params->size, params->gfp);
	if (!res->allocation)
		return -ENOMEM;

	return 0;
}

static void kunit_kmalloc_free(struct kunit_resource *res)
{
	kfree(res->allocation);
}

void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp)
{
	struct kunit_kmalloc_params params = {
		.size = size,
		.gfp = gfp
	};

	return kunit_alloc_resource(test,
				    kunit_kmalloc_init,
				    kunit_kmalloc_free,
				    gfp,
				    &params);
}

void kunit_kfree(struct kunit *test, const void *ptr)
{
	int rc;

	rc = kunit_resource_destroy(test,
				    kunit_resource_instance_match,
				    kunit_kmalloc_free,
				    (void *)ptr);

	WARN_ON(rc);
}

void kunit_cleanup(struct kunit *test)
{
	struct kunit_resource *resource;

	/*
	 * test->resources is a stack - each allocation must be freed in the
	 * reverse order from which it was added since one resource may depend
	 * on another for its entire lifetime.
	 * Also, we cannot use the normal list_for_each constructs, even the
	 * safe ones because *arbitrary* nodes may be deleted when
	 * kunit_resource_free is called; the list_for_each_safe variants only
	 * protect against the current node being deleted, not the next.
	 */
	while (true) {
		spin_lock(&test->lock);
		if (list_empty(&test->resources)) {
			spin_unlock(&test->lock);
			break;
		}
		resource = list_last_entry(&test->resources,
					   struct kunit_resource,
					   node);
		list_del(&resource->node);
		spin_unlock(&test->lock);

		kunit_resource_free(test, resource);
	}
}

void kunit_printk(const char *level,
		  const struct kunit *test,
		  const char *fmt, ...)
{
	struct va_format vaf;
	va_list args;

	va_start(args, fmt);

	vaf.fmt = fmt;
	vaf.va = &args;

	kunit_vprintk(test, level, &vaf);

	va_end(args);
}