lib/test_list_sort.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <kunit/test.h>
   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 int serial;
  27 };
  28
  29 static void check(struct kunit *test, struct debug_el *ela, struct debug_el *elb)
  30 {
  31         struct debug_el **elts = test->priv;
  32
  33         KUNIT_EXPECT_LT_MSG(test, ela->serial, (unsigned int)TEST_LIST_LEN, "incorrect serial");
  34         KUNIT_EXPECT_LT_MSG(test, elb->serial, (unsigned int)TEST_LIST_LEN, "incorrect serial");
  35
  36         KUNIT_EXPECT_PTR_EQ_MSG(test, elts[ela->serial], ela, "phantom element");
  37         KUNIT_EXPECT_PTR_EQ_MSG(test, elts[elb->serial], elb, "phantom element");
  38
  39         KUNIT_EXPECT_EQ_MSG(test, ela->poison1, TEST_POISON1, "bad poison");
  40         KUNIT_EXPECT_EQ_MSG(test, ela->poison2, TEST_POISON2, "bad poison");
  41
  42         KUNIT_EXPECT_EQ_MSG(test, elb->poison1, TEST_POISON1, "bad poison");
  43         KUNIT_EXPECT_EQ_MSG(test, elb->poison2, TEST_POISON2, "bad poison");
  44 }
  45
  46 /* `priv` is the test pointer so check() can fail the test if the list is invalid. */
  47 static int cmp(void *priv, const struct list_head *a, const struct list_head *b)
  48 {
  49         struct debug_el *ela, *elb;
  50
  51         ela = container_of(a, struct debug_el, list);
  52         elb = container_of(b, struct debug_el, list);
  53
  54         check(priv, ela, elb);
  55         return ela->value - elb->value;
  56 }
  57
  58 static void list_sort_test(struct kunit *test)
  59 {
  60         int i, count = 1;
  61         struct debug_el *el, **elts;
  62         struct list_head *cur;
  63         LIST_HEAD(head);
  64
  65         elts = kunit_kcalloc(test, TEST_LIST_LEN, sizeof(*elts), GFP_KERNEL);
  66         KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elts);
  67         test->priv = elts;
  68
  69         for (i = 0; i < TEST_LIST_LEN; i++) {
  70                 el = kunit_kmalloc(test, sizeof(*el), GFP_KERNEL);
  71                 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, el);
  72
  73                  /* force some equivalencies */
  74                 el->value = get_random_u32_below(TEST_LIST_LEN / 3);
  75                 el->serial = i;
  76                 el->poison1 = TEST_POISON1;
  77                 el->poison2 = TEST_POISON2;
  78                 elts[i] = el;
  79                 list_add_tail(&el->list, &head);
  80         }
  81
  82         list_sort(test, &head, cmp);
  83
  84         for (cur = head.next; cur->next != &head; cur = cur->next) {
  85                 struct debug_el *el1;
  86                 int cmp_result;
  87
  88                 KUNIT_ASSERT_PTR_EQ_MSG(test, cur->next->prev, cur,
  89                                         "list is corrupted");
  90
  91                 cmp_result = cmp(test, cur, cur->next);
  92                 KUNIT_ASSERT_LE_MSG(test, cmp_result, 0, "list is not sorted");
  93
  94                 el = container_of(cur, struct debug_el, list);
  95                 el1 = container_of(cur->next, struct debug_el, list);
  96                 if (cmp_result == 0) {
  97                         KUNIT_ASSERT_LE_MSG(test, el->serial, el1->serial,
  98                                             "order of equivalent elements not preserved");
  99                 }
 100
 101                 check(test, el, el1);
 102                 count++;
 103         }
 104         KUNIT_EXPECT_PTR_EQ_MSG(test, head.prev, cur, "list is corrupted");
 105
 106         KUNIT_EXPECT_EQ_MSG(test, count, TEST_LIST_LEN,
 107                             "list length changed after sorting!");
 108 }
 109
 110 static struct kunit_case list_sort_cases[] = {
 111         KUNIT_CASE(list_sort_test),
 112         {}
 113 };
 114
 115 static struct kunit_suite list_sort_suite = {
 116         .name = "list_sort",
 117         .test_cases = list_sort_cases,
 118 };
 119
 120 kunit_test_suites(&list_sort_suite);
 121
 122 MODULE_LICENSE("GPL");