1// SPDX-License-Identifier: GPL-2.0-only
  2#include <kunit/test.h>
  3
  4#include <linux/kernel.h>
  5#include <linux/list_sort.h>
  6#include <linux/list.h>
  7#include <linux/module.h>
  8#include <linux/printk.h>
  9#include <linux/slab.h>
 10#include <linux/random.h>
 11
 12/*
 13 * The pattern of set bits in the list length determines which cases
 14 * are hit in list_sort().
 15 */
 16#define TEST_LIST_LEN (512+128+2) /* not including head */
 17
 18#define TEST_POISON1 0xDEADBEEF
 19#define TEST_POISON2 0xA324354C
 20
 21struct debug_el {
 22	unsigned int poison1;
 23	struct list_head list;
 24	unsigned int poison2;
 25	int value;
 26	unsigned int serial;
 27};
 28
 29static void check(struct kunit *test, struct debug_el *ela, struct debug_el *elb)
 30{
 31	struct debug_el **elts = test->priv;
 32
 33	KUNIT_EXPECT_LT_MSG(test, ela->serial, (unsigned int)TEST_LIST_LEN, "incorrect serial");
 34	KUNIT_EXPECT_LT_MSG(test, elb->serial, (unsigned int)TEST_LIST_LEN, "incorrect serial");
 35
 36	KUNIT_EXPECT_PTR_EQ_MSG(test, elts[ela->serial], ela, "phantom element");
 37	KUNIT_EXPECT_PTR_EQ_MSG(test, elts[elb->serial], elb, "phantom element");
 38
 39	KUNIT_EXPECT_EQ_MSG(test, ela->poison1, TEST_POISON1, "bad poison");
 40	KUNIT_EXPECT_EQ_MSG(test, ela->poison2, TEST_POISON2, "bad poison");
 41
 42	KUNIT_EXPECT_EQ_MSG(test, elb->poison1, TEST_POISON1, "bad poison");
 43	KUNIT_EXPECT_EQ_MSG(test, elb->poison2, TEST_POISON2, "bad poison");
 44}
 45
 46/* `priv` is the test pointer so check() can fail the test if the list is invalid. */
 47static int cmp(void *priv, const struct list_head *a, const struct list_head *b)
 48{
 49	struct debug_el *ela, *elb;
 50
 51	ela = container_of(a, struct debug_el, list);
 52	elb = container_of(b, struct debug_el, list);
 53
 54	check(priv, ela, elb);
 55	return ela->value - elb->value;
 56}
 57
 58static void list_sort_test(struct kunit *test)
 59{
 60	int i, count = 1;
 61	struct debug_el *el, **elts;
 62	struct list_head *cur;
 63	LIST_HEAD(head);
 64
 65	elts = kunit_kcalloc(test, TEST_LIST_LEN, sizeof(*elts), GFP_KERNEL);
 66	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elts);
 67	test->priv = elts;
 68
 69	for (i = 0; i < TEST_LIST_LEN; i++) {
 70		el = kunit_kmalloc(test, sizeof(*el), GFP_KERNEL);
 71		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, el);
 72
 73		 /* force some equivalencies */
 74		el->value = prandom_u32() % (TEST_LIST_LEN / 3);
 75		el->serial = i;
 76		el->poison1 = TEST_POISON1;
 77		el->poison2 = TEST_POISON2;
 78		elts[i] = el;
 79		list_add_tail(&el->list, &head);
 80	}
 81
 82	list_sort(test, &head, cmp);
 83
 84	for (cur = head.next; cur->next != &head; cur = cur->next) {
 85		struct debug_el *el1;
 86		int cmp_result;
 87
 88		KUNIT_ASSERT_PTR_EQ_MSG(test, cur->next->prev, cur,
 89					"list is corrupted");
 90
 91		cmp_result = cmp(test, cur, cur->next);
 92		KUNIT_ASSERT_LE_MSG(test, cmp_result, 0, "list is not sorted");
 93
 94		el = container_of(cur, struct debug_el, list);
 95		el1 = container_of(cur->next, struct debug_el, list);
 96		if (cmp_result == 0) {
 97			KUNIT_ASSERT_LE_MSG(test, el->serial, el1->serial,
 98					    "order of equivalent elements not preserved");
 99		}
100
101		check(test, el, el1);
102		count++;
103	}
104	KUNIT_EXPECT_PTR_EQ_MSG(test, head.prev, cur, "list is corrupted");
105
106	KUNIT_EXPECT_EQ_MSG(test, count, TEST_LIST_LEN,
107			    "list length changed after sorting!");
108}
109
110static struct kunit_case list_sort_cases[] = {
111	KUNIT_CASE(list_sort_test),
112	{}
113};
114
115static struct kunit_suite list_sort_suite = {
116	.name = "list_sort",
117	.test_cases = list_sort_cases,
118};
119
120kunit_test_suites(&list_sort_suite);
121
122MODULE_LICENSE("GPL");