xref: /linux/lib/test_list_sort.c (revision 2fe05e1139a555ae91f00a812cb9520e7d3022ab)
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 		pr_err("error: cannot allocate memory\n");
81 		return err;
82 	}
83 
84 	for (i = 0; i < TEST_LIST_LEN; i++) {
85 		el = kmalloc(sizeof(*el), GFP_KERNEL);
86 		if (!el) {
87 			pr_err("error: cannot allocate memory\n");
88 			goto exit;
89 		}
90 		 /* force some equivalencies */
91 		el->value = prandom_u32() % (TEST_LIST_LEN / 3);
92 		el->serial = i;
93 		el->poison1 = TEST_POISON1;
94 		el->poison2 = TEST_POISON2;
95 		elts[i] = el;
96 		list_add_tail(&el->list, &head);
97 	}
98 
99 	list_sort(NULL, &head, cmp);
100 
101 	err = -EINVAL;
102 	for (cur = head.next; cur->next != &head; cur = cur->next) {
103 		struct debug_el *el1;
104 		int cmp_result;
105 
106 		if (cur->next->prev != cur) {
107 			pr_err("error: list is corrupted\n");
108 			goto exit;
109 		}
110 
111 		cmp_result = cmp(NULL, cur, cur->next);
112 		if (cmp_result > 0) {
113 			pr_err("error: list is not sorted\n");
114 			goto exit;
115 		}
116 
117 		el = container_of(cur, struct debug_el, list);
118 		el1 = container_of(cur->next, struct debug_el, list);
119 		if (cmp_result == 0 && el->serial >= el1->serial) {
120 			pr_err("error: order of equivalent elements not "
121 				"preserved\n");
122 			goto exit;
123 		}
124 
125 		if (check(el, el1)) {
126 			pr_err("error: element check failed\n");
127 			goto exit;
128 		}
129 		count++;
130 	}
131 	if (head.prev != cur) {
132 		pr_err("error: list is corrupted\n");
133 		goto exit;
134 	}
135 
136 
137 	if (count != TEST_LIST_LEN) {
138 		pr_err("error: bad list length %d", count);
139 		goto exit;
140 	}
141 
142 	err = 0;
143 exit:
144 	for (i = 0; i < TEST_LIST_LEN; i++)
145 		kfree(elts[i]);
146 	kfree(elts);
147 	return err;
148 }
149 module_init(list_sort_test);
150 MODULE_LICENSE("GPL");
151