xref: /openbmc/linux/lib/test_list_sort.c (revision e2c75e76)
1 #define pr_fmt(fmt) "list_sort_test: " fmt
2 
3 #include <linux/kernel.h>
4 #include <linux/list_sort.h>
5 #include <linux/list.h>
6 #include <linux/module.h>
7 #include <linux/printk.h>
8 #include <linux/slab.h>
9 #include <linux/random.h>
10 
11 /*
12  * The pattern of set bits in the list length determines which cases
13  * are hit in list_sort().
14  */
15 #define TEST_LIST_LEN (512+128+2) /* not including head */
16 
17 #define TEST_POISON1 0xDEADBEEF
18 #define TEST_POISON2 0xA324354C
19 
20 struct debug_el {
21 	unsigned int poison1;
22 	struct list_head list;
23 	unsigned int poison2;
24 	int value;
25 	unsigned serial;
26 };
27 
28 /* Array, containing pointers to all elements in the test list */
29 static struct debug_el **elts __initdata;
30 
31 static int __init check(struct debug_el *ela, struct debug_el *elb)
32 {
33 	if (ela->serial >= TEST_LIST_LEN) {
34 		pr_err("error: incorrect serial %d\n", ela->serial);
35 		return -EINVAL;
36 	}
37 	if (elb->serial >= TEST_LIST_LEN) {
38 		pr_err("error: incorrect serial %d\n", elb->serial);
39 		return -EINVAL;
40 	}
41 	if (elts[ela->serial] != ela || elts[elb->serial] != elb) {
42 		pr_err("error: phantom element\n");
43 		return -EINVAL;
44 	}
45 	if (ela->poison1 != TEST_POISON1 || ela->poison2 != TEST_POISON2) {
46 		pr_err("error: bad poison: %#x/%#x\n",
47 			ela->poison1, ela->poison2);
48 		return -EINVAL;
49 	}
50 	if (elb->poison1 != TEST_POISON1 || elb->poison2 != TEST_POISON2) {
51 		pr_err("error: bad poison: %#x/%#x\n",
52 			elb->poison1, elb->poison2);
53 		return -EINVAL;
54 	}
55 	return 0;
56 }
57 
58 static int __init cmp(void *priv, struct list_head *a, struct list_head *b)
59 {
60 	struct debug_el *ela, *elb;
61 
62 	ela = container_of(a, struct debug_el, list);
63 	elb = container_of(b, struct debug_el, list);
64 
65 	check(ela, elb);
66 	return ela->value - elb->value;
67 }
68 
69 static int __init list_sort_test(void)
70 {
71 	int i, count = 1, err = -ENOMEM;
72 	struct debug_el *el;
73 	struct list_head *cur;
74 	LIST_HEAD(head);
75 
76 	pr_debug("start testing list_sort()\n");
77 
78 	elts = kcalloc(TEST_LIST_LEN, sizeof(*elts), GFP_KERNEL);
79 	if (!elts)
80 		return err;
81 
82 	for (i = 0; i < TEST_LIST_LEN; i++) {
83 		el = kmalloc(sizeof(*el), GFP_KERNEL);
84 		if (!el)
85 			goto exit;
86 
87 		 /* force some equivalencies */
88 		el->value = prandom_u32() % (TEST_LIST_LEN / 3);
89 		el->serial = i;
90 		el->poison1 = TEST_POISON1;
91 		el->poison2 = TEST_POISON2;
92 		elts[i] = el;
93 		list_add_tail(&el->list, &head);
94 	}
95 
96 	list_sort(NULL, &head, cmp);
97 
98 	err = -EINVAL;
99 	for (cur = head.next; cur->next != &head; cur = cur->next) {
100 		struct debug_el *el1;
101 		int cmp_result;
102 
103 		if (cur->next->prev != cur) {
104 			pr_err("error: list is corrupted\n");
105 			goto exit;
106 		}
107 
108 		cmp_result = cmp(NULL, cur, cur->next);
109 		if (cmp_result > 0) {
110 			pr_err("error: list is not sorted\n");
111 			goto exit;
112 		}
113 
114 		el = container_of(cur, struct debug_el, list);
115 		el1 = container_of(cur->next, struct debug_el, list);
116 		if (cmp_result == 0 && el->serial >= el1->serial) {
117 			pr_err("error: order of equivalent elements not "
118 				"preserved\n");
119 			goto exit;
120 		}
121 
122 		if (check(el, el1)) {
123 			pr_err("error: element check failed\n");
124 			goto exit;
125 		}
126 		count++;
127 	}
128 	if (head.prev != cur) {
129 		pr_err("error: list is corrupted\n");
130 		goto exit;
131 	}
132 
133 
134 	if (count != TEST_LIST_LEN) {
135 		pr_err("error: bad list length %d", count);
136 		goto exit;
137 	}
138 
139 	err = 0;
140 exit:
141 	for (i = 0; i < TEST_LIST_LEN; i++)
142 		kfree(elts[i]);
143 	kfree(elts);
144 	return err;
145 }
146 module_init(list_sort_test);
147 MODULE_LICENSE("GPL");
148