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
 20struct 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 */
 29static struct debug_el **elts __initdata;
 30
 31static 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
 58static 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
 69static 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;
140exit:
141	for (i = 0; i < TEST_LIST_LEN; i++)
142		kfree(elts[i]);
143	kfree(elts);
144	return err;
145}
146module_init(list_sort_test);
147MODULE_LICENSE("GPL");