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@massar... [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: Daniel Latypov dlatypov@google.com --- lib/Kconfig.debug | 5 +- lib/test_list_sort.c | 128 +++++++++++++++++-------------------------- 2 files changed, 54 insertions(+), 79 deletions(-)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 417c3d3e521b..09a0cc8a55cc 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1999,8 +1999,9 @@ 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), diff --git a/lib/test_list_sort.c b/lib/test_list_sort.c index 1f017d3b610e..ccfd98dbf57c 100644 --- a/lib/test_list_sort.c +++ b/lib/test_list_sort.c @@ -1,5 +1,5 @@ // 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> @@ -23,67 +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, struct list_head *a, 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, struct list_head *a, 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); @@ -94,55 +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!"); +}

- if (count != TEST_LIST_LEN) { - pr_err("error: bad list length %d", count); - goto exit; - } +static struct kunit_case list_sort_cases[] = { + KUNIT_CASE(list_sort_test), + {} +}; + +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");