Commit ebd09577 authored by Daniel Latypov's avatar Daniel Latypov Committed by Shuah Khan
Browse files

lib/test: convert lib/test_list_sort.c to use KUnit 

Functionally, this just means that the test output will be slightly
changed and it'll now depend on CONFIG_KUNIT=y/m.

It'll still run at boot time and can still be built as a loadable
module.

There was a pre-existing patch to convert this test that I found later,
here [1]. Compared to [1], this patch doesn't rename files and uses
KUnit features more heavily (i.e. does more than converting pr_err()
calls to KUNIT_FAIL()).

What this conversion gives us:
* a shorter test thanks to KUnit's macros
* a way to run this a bit more easily via kunit.py (and
CONFIG_KUNIT_ALL_TESTS=y) [2]
* a structured way of reporting pass/fail
* uses kunit-managed allocations to avoid the risk of memory leaks
* more descriptive error messages:
  * i.e. it prints out which fields are invalid, what the expected
  values are, etc.

What this conversion does not do:
* change the name of the file (and thus the name of the module)
* change the name of the config option

Leaving these as-is for now to minimize the impact to people wanting to
run this test. IMO, that concern trumps following KUnit's style guide
for both names, at least for now.

[1] https://lore.kernel.org/linux-kselftest/20201015014616.309000-1-vitor@massaru.org/


[2] Can be run via
$ ./tools/testing/kunit/kunit.py run --kunitconfig /dev/stdin <<EOF
CONFIG_KUNIT=y
CONFIG_TEST_LIST_SORT=y
EOF

[16:55:56] Configuring KUnit Kernel ...
[16:55:56] Building KUnit Kernel ...
[16:56:29] Starting KUnit Kernel ...
[16:56:32] ============================================================
[16:56:32] ======== [PASSED] list_sort ========
[16:56:32] [PASSED] list_sort_test
[16:56:32] ============================================================
[16:56:32] Testing complete. 1 tests run. 0 failed. 0 crashed.
[16:56:32] Elapsed time: 35.668s total, 0.001s configuring, 32.725s building, 0.000s running

Note: the build time is as after a `make mrproper`.

Signed-off-by: default avatarDaniel Latypov <dlatypov@google.com>
Tested-by: default avatarDavid Gow <davidgow@google.com>
Acked-by: default avatarBrendan Higgins <brendanhiggins@google.com>
Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
parent 7122debb

lib/Kconfig.debug

+3 −2
Original line number Diff line number Diff line
@@ -2047,8 +2047,9 @@ config LKDTM 
	Documentation/fault-injection/provoke-crashes.rst



config TEST_LIST_SORT

	tristate "Linked list sorting test"

	depends on DEBUG_KERNEL || m

	tristate "Linked list sorting test" if !KUNIT_ALL_TESTS

	depends on KUNIT

	default KUNIT_ALL_TESTS

	help

	  Enable this to turn on 'list_sort()' function test. This test is

	  executed only once during system boot (so affects only boot time),

lib/test_list_sort.c

+51 −78
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

#define pr_fmt(fmt) "list_sort_test: " fmt

#include <kunit/test.h>



#include <linux/kernel.h>

#include <linux/list_sort.h>
@@ -23,68 +23,52 @@ struct debug_el { 
	struct list_head list;

	unsigned int poison2;

	int value;

	unsigned serial;

	unsigned int serial;

};



/* Array, containing pointers to all elements in the test list */

static struct debug_el **elts __initdata;



static int __init check(struct debug_el *ela, struct debug_el *elb)

static void check(struct kunit *test, struct debug_el *ela, struct debug_el *elb)

{

	if (ela->serial >= TEST_LIST_LEN) {

		pr_err("error: incorrect serial %d\n", ela->serial);

		return -EINVAL;

	}

	if (elb->serial >= TEST_LIST_LEN) {

		pr_err("error: incorrect serial %d\n", elb->serial);

		return -EINVAL;

	}

	if (elts[ela->serial] != ela || elts[elb->serial] != elb) {

		pr_err("error: phantom element\n");

		return -EINVAL;

	}

	if (ela->poison1 != TEST_POISON1 || ela->poison2 != TEST_POISON2) {

		pr_err("error: bad poison: %#x/%#x\n",

			ela->poison1, ela->poison2);

		return -EINVAL;

	}

	if (elb->poison1 != TEST_POISON1 || elb->poison2 != TEST_POISON2) {

		pr_err("error: bad poison: %#x/%#x\n",

			elb->poison1, elb->poison2);

		return -EINVAL;

	}

	return 0;

	struct debug_el **elts = test->priv;



	KUNIT_EXPECT_LT_MSG(test, ela->serial, (unsigned int)TEST_LIST_LEN, "incorrect serial");

	KUNIT_EXPECT_LT_MSG(test, elb->serial, (unsigned int)TEST_LIST_LEN, "incorrect serial");



	KUNIT_EXPECT_PTR_EQ_MSG(test, elts[ela->serial], ela, "phantom element");

	KUNIT_EXPECT_PTR_EQ_MSG(test, elts[elb->serial], elb, "phantom element");



	KUNIT_EXPECT_EQ_MSG(test, ela->poison1, TEST_POISON1, "bad poison");

	KUNIT_EXPECT_EQ_MSG(test, ela->poison2, TEST_POISON2, "bad poison");



	KUNIT_EXPECT_EQ_MSG(test, elb->poison1, TEST_POISON1, "bad poison");

	KUNIT_EXPECT_EQ_MSG(test, elb->poison2, TEST_POISON2, "bad poison");

}



static int __init cmp(void *priv, const struct list_head *a,

		      const struct list_head *b)

/* `priv` is the test pointer so check() can fail the test if the list is invalid. */

static int cmp(void *priv, const struct list_head *a, const struct list_head *b)

{

	struct debug_el *ela, *elb;



	ela = container_of(a, struct debug_el, list);

	elb = container_of(b, struct debug_el, list);



	check(ela, elb);

	check(priv, ela, elb);

	return ela->value - elb->value;

}



static int __init list_sort_test(void)

static void list_sort_test(struct kunit *test)

{

	int i, count = 1, err = -ENOMEM;

	struct debug_el *el;

	int i, count = 1;

	struct debug_el *el, **elts;

	struct list_head *cur;

	LIST_HEAD(head);



	pr_debug("start testing list_sort()\n");



	elts = kcalloc(TEST_LIST_LEN, sizeof(*elts), GFP_KERNEL);

	if (!elts)

		return err;

	elts = kunit_kcalloc(test, TEST_LIST_LEN, sizeof(*elts), GFP_KERNEL);

	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elts);

	test->priv = elts;



	for (i = 0; i < TEST_LIST_LEN; i++) {

		el = kmalloc(sizeof(*el), GFP_KERNEL);

		if (!el)

			goto exit;

		el = kunit_kmalloc(test, sizeof(*el), GFP_KERNEL);

		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, el);



		 /* force some equivalencies */

		el->value = prandom_u32() % (TEST_LIST_LEN / 3);
@@ -95,55 +79,44 @@ static int __init list_sort_test(void) 
		list_add_tail(&el->list, &head);

	}



	list_sort(NULL, &head, cmp);

	list_sort(test, &head, cmp);



	err = -EINVAL;

	for (cur = head.next; cur->next != &head; cur = cur->next) {

		struct debug_el *el1;

		int cmp_result;



		if (cur->next->prev != cur) {

			pr_err("error: list is corrupted\n");

			goto exit;

		}

		KUNIT_ASSERT_PTR_EQ_MSG(test, cur->next->prev, cur,

					"list is corrupted");



		cmp_result = cmp(NULL, cur, cur->next);

		if (cmp_result > 0) {

			pr_err("error: list is not sorted\n");

			goto exit;

		}

		cmp_result = cmp(test, cur, cur->next);

		KUNIT_ASSERT_LE_MSG(test, cmp_result, 0, "list is not sorted");



		el = container_of(cur, struct debug_el, list);

		el1 = container_of(cur->next, struct debug_el, list);

		if (cmp_result == 0 && el->serial >= el1->serial) {

			pr_err("error: order of equivalent elements not "

				"preserved\n");

			goto exit;

		if (cmp_result == 0) {

			KUNIT_ASSERT_LE_MSG(test, el->serial, el1->serial,

					    "order of equivalent elements not preserved");

		}



		if (check(el, el1)) {

			pr_err("error: element check failed\n");

			goto exit;

		}

		check(test, el, el1);

		count++;

	}

	if (head.prev != cur) {

		pr_err("error: list is corrupted\n");

		goto exit;

	KUNIT_EXPECT_PTR_EQ_MSG(test, head.prev, cur, "list is corrupted");



	KUNIT_EXPECT_EQ_MSG(test, count, TEST_LIST_LEN,

			    "list length changed after sorting!");

}



static struct kunit_case list_sort_cases[] = {

	KUNIT_CASE(list_sort_test),

	{}

};



	if (count != TEST_LIST_LEN) {

		pr_err("error: bad list length %d", count);

		goto exit;

	}

static struct kunit_suite list_sort_suite = {

	.name = "list_sort",

	.test_cases = list_sort_cases,

};



kunit_test_suites(&list_sort_suite);



	err = 0;

exit:

	for (i = 0; i < TEST_LIST_LEN; i++)

		kfree(elts[i]);

	kfree(elts);

	return err;

}

module_init(list_sort_test);

MODULE_LICENSE("GPL");