the-tree/lib/test_list_sort.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 #include <kunit/test.h>
0003
0004 #include <linux/kernel.h>
0005 #include <linux/list_sort.h>
0006 #include <linux/list.h>
0007 #include <linux/module.h>
0008 #include <linux/printk.h>
0009 #include <linux/slab.h>
0010 #include <linux/random.h>
0011
0012 /*
0013  * The pattern of set bits in the list length determines which cases
0014  * are hit in list_sort().
0015  */
0016 #define TEST_LIST_LEN (512+128+2) /* not including head */
0017
0018 #define TEST_POISON1 0xDEADBEEF
0019 #define TEST_POISON2 0xA324354C
0020
0021 struct debug_el {
0022     unsigned int poison1;
0023     struct list_head list;
0024     unsigned int poison2;
0025     int value;
0026     unsigned int serial;
0027 };
0028
0029 static void check(struct kunit *test, struct debug_el *ela, struct debug_el *elb)
0030 {
0031     struct debug_el **elts = test->priv;
0032
0033     KUNIT_EXPECT_LT_MSG(test, ela->serial, (unsigned int)TEST_LIST_LEN, "incorrect serial");
0034     KUNIT_EXPECT_LT_MSG(test, elb->serial, (unsigned int)TEST_LIST_LEN, "incorrect serial");
0035
0036     KUNIT_EXPECT_PTR_EQ_MSG(test, elts[ela->serial], ela, "phantom element");
0037     KUNIT_EXPECT_PTR_EQ_MSG(test, elts[elb->serial], elb, "phantom element");
0038
0039     KUNIT_EXPECT_EQ_MSG(test, ela->poison1, TEST_POISON1, "bad poison");
0040     KUNIT_EXPECT_EQ_MSG(test, ela->poison2, TEST_POISON2, "bad poison");
0041
0042     KUNIT_EXPECT_EQ_MSG(test, elb->poison1, TEST_POISON1, "bad poison");
0043     KUNIT_EXPECT_EQ_MSG(test, elb->poison2, TEST_POISON2, "bad poison");
0044 }
0045
0046 /* `priv` is the test pointer so check() can fail the test if the list is invalid. */
0047 static int cmp(void *priv, const struct list_head *a, const struct list_head *b)
0048 {
0049     struct debug_el *ela, *elb;
0050
0051     ela = container_of(a, struct debug_el, list);
0052     elb = container_of(b, struct debug_el, list);
0053
0054     check(priv, ela, elb);
0055     return ela->value - elb->value;
0056 }
0057
0058 static void list_sort_test(struct kunit *test)
0059 {
0060     int i, count = 1;
0061     struct debug_el *el, **elts;
0062     struct list_head *cur;
0063     LIST_HEAD(head);
0064
0065     elts = kunit_kcalloc(test, TEST_LIST_LEN, sizeof(*elts), GFP_KERNEL);
0066     KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elts);
0067     test->priv = elts;
0068
0069     for (i = 0; i < TEST_LIST_LEN; i++) {
0070         el = kunit_kmalloc(test, sizeof(*el), GFP_KERNEL);
0071         KUNIT_ASSERT_NOT_ERR_OR_NULL(test, el);
0072
0073          /* force some equivalencies */
0074         el->value = prandom_u32() % (TEST_LIST_LEN / 3);
0075         el->serial = i;
0076         el->poison1 = TEST_POISON1;
0077         el->poison2 = TEST_POISON2;
0078         elts[i] = el;
0079         list_add_tail(&el->list, &head);
0080     }
0081
0082     list_sort(test, &head, cmp);
0083
0084     for (cur = head.next; cur->next != &head; cur = cur->next) {
0085         struct debug_el *el1;
0086         int cmp_result;
0087
0088         KUNIT_ASSERT_PTR_EQ_MSG(test, cur->next->prev, cur,
0089                     "list is corrupted");
0090
0091         cmp_result = cmp(test, cur, cur->next);
0092         KUNIT_ASSERT_LE_MSG(test, cmp_result, 0, "list is not sorted");
0093
0094         el = container_of(cur, struct debug_el, list);
0095         el1 = container_of(cur->next, struct debug_el, list);
0096         if (cmp_result == 0) {
0097             KUNIT_ASSERT_LE_MSG(test, el->serial, el1->serial,
0098                         "order of equivalent elements not preserved");
0099         }
0100
0101         check(test, el, el1);
0102         count++;
0103     }
0104     KUNIT_EXPECT_PTR_EQ_MSG(test, head.prev, cur, "list is corrupted");
0105
0106     KUNIT_EXPECT_EQ_MSG(test, count, TEST_LIST_LEN,
0107                 "list length changed after sorting!");
0108 }
0109
0110 static struct kunit_case list_sort_cases[] = {
0111     KUNIT_CASE(list_sort_test),
0112     {}
0113 };
0114
0115 static struct kunit_suite list_sort_suite = {
0116     .name = "list_sort",
0117     .test_cases = list_sort_cases,
0118 };
0119
0120 kunit_test_suites(&list_sort_suite);
0121
0122 MODULE_LICENSE("GPL");