1 // SPDX-License-Identifier: GPL-2.0-only
2 #define pr_fmt(fmt) "list_sort_test: " fmt
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 serial;
27 };
28
29 /* Array, containing pointers to all elements in the test list */
30 static struct debug_el **elts __initdata;
31
check(struct debug_el * ela,struct debug_el * elb)32 static int __init check(struct debug_el *ela, struct debug_el *elb)
33 {
34 if (ela->serial >= TEST_LIST_LEN) {
35 pr_err("error: incorrect serial %d\n", ela->serial);
36 return -EINVAL;
37 }
38 if (elb->serial >= TEST_LIST_LEN) {
39 pr_err("error: incorrect serial %d\n", elb->serial);
40 return -EINVAL;
41 }
42 if (elts[ela->serial] != ela || elts[elb->serial] != elb) {
43 pr_err("error: phantom element\n");
44 return -EINVAL;
45 }
46 if (ela->poison1 != TEST_POISON1 || ela->poison2 != TEST_POISON2) {
47 pr_err("error: bad poison: %#x/%#x\n",
48 ela->poison1, ela->poison2);
49 return -EINVAL;
50 }
51 if (elb->poison1 != TEST_POISON1 || elb->poison2 != TEST_POISON2) {
52 pr_err("error: bad poison: %#x/%#x\n",
53 elb->poison1, elb->poison2);
54 return -EINVAL;
55 }
56 return 0;
57 }
58
cmp(void * priv,struct list_head * a,struct list_head * b)59 static int __init cmp(void *priv, struct list_head *a, struct list_head *b)
60 {
61 struct debug_el *ela, *elb;
62
63 ela = container_of(a, struct debug_el, list);
64 elb = container_of(b, struct debug_el, list);
65
66 check(ela, elb);
67 return ela->value - elb->value;
68 }
69
list_sort_test(void)70 static int __init list_sort_test(void)
71 {
72 int i, count = 1, err = -ENOMEM;
73 struct debug_el *el;
74 struct list_head *cur;
75 LIST_HEAD(head);
76
77 pr_debug("start testing list_sort()\n");
78
79 elts = kcalloc(TEST_LIST_LEN, sizeof(*elts), GFP_KERNEL);
80 if (!elts)
81 return err;
82
83 for (i = 0; i < TEST_LIST_LEN; i++) {
84 el = kmalloc(sizeof(*el), GFP_KERNEL);
85 if (!el)
86 goto exit;
87
88 /* force some equivalencies */
89 el->value = prandom_u32() % (TEST_LIST_LEN / 3);
90 el->serial = i;
91 el->poison1 = TEST_POISON1;
92 el->poison2 = TEST_POISON2;
93 elts[i] = el;
94 list_add_tail(&el->list, &head);
95 }
96
97 list_sort(NULL, &head, cmp);
98
99 err = -EINVAL;
100 for (cur = head.next; cur->next != &head; cur = cur->next) {
101 struct debug_el *el1;
102 int cmp_result;
103
104 if (cur->next->prev != cur) {
105 pr_err("error: list is corrupted\n");
106 goto exit;
107 }
108
109 cmp_result = cmp(NULL, cur, cur->next);
110 if (cmp_result > 0) {
111 pr_err("error: list is not sorted\n");
112 goto exit;
113 }
114
115 el = container_of(cur, struct debug_el, list);
116 el1 = container_of(cur->next, struct debug_el, list);
117 if (cmp_result == 0 && el->serial >= el1->serial) {
118 pr_err("error: order of equivalent elements not "
119 "preserved\n");
120 goto exit;
121 }
122
123 if (check(el, el1)) {
124 pr_err("error: element check failed\n");
125 goto exit;
126 }
127 count++;
128 }
129 if (head.prev != cur) {
130 pr_err("error: list is corrupted\n");
131 goto exit;
132 }
133
134
135 if (count != TEST_LIST_LEN) {
136 pr_err("error: bad list length %d", count);
137 goto exit;
138 }
139
140 err = 0;
141 exit:
142 for (i = 0; i < TEST_LIST_LEN; i++)
143 kfree(elts[i]);
144 kfree(elts);
145 return err;
146 }
147 module_init(list_sort_test);
148 MODULE_LICENSE("GPL");
149