xref: /linux/lib/test_list_sort.c (revision ee057c8c194b9283f4137b253b70e292693a39f0)
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 
21 struct debug_el {
22 	unsigned int poison1;
23 	struct list_head list;
24 	unsigned int poison2;
25 	int value;
26 	unsigned int serial;
27 };
28 
29 static 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. */
47 static 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 
58 static 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 = get_random_u32_below(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 
110 static struct kunit_case list_sort_cases[] = {
111 	KUNIT_CASE(list_sort_test),
112 	{}
113 };
114 
115 static struct kunit_suite list_sort_suite = {
116 	.name = "list_sort",
117 	.test_cases = list_sort_cases,
118 };
119 
120 kunit_test_suites(&list_sort_suite);
121 
122 MODULE_DESCRIPTION("list_sort() KUnit test suite");
123 MODULE_LICENSE("GPL");
124