LXR linux/lib/test_list

   1// SPDX-License-Identifier: GPL-2.0-only
   2#define pr_fmt(fmt) "list_sort_test: " fmt
   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
  21struct debug_el {
  22        unsigned int poison1;
  23        struct list_head list;
  24        unsigned int poison2;
  25        int value;
  26        unsigned serial;
  27};
  28
  29/* Array, containing pointers to all elements in the test list */
  30static struct debug_el **elts __initdata;
  31
  32static int __init check(struct debug_el *ela, struct debug_el *elb)
  33{
  34        if (ela->serial >= TEST_LIST_LEN) {
  35                pr_err("error: incorrect serial %d\n", ela->serial);
  36                return -EINVAL;
  37        }
  38        if (elb->serial >= TEST_LIST_LEN) {
  39                pr_err("error: incorrect serial %d\n", elb->serial);
  40                return -EINVAL;
  41        }
  42        if (elts[ela->serial] != ela || elts[elb->serial] != elb) {
  43                pr_err("error: phantom element\n");
  44                return -EINVAL;
  45        }
  46        if (ela->poison1 != TEST_POISON1 || ela->poison2 != TEST_POISON2) {
  47                pr_err("error: bad poison: %#x/%#x\n",
  48                        ela->poison1, ela->poison2);
  49                return -EINVAL;
  50        }
  51        if (elb->poison1 != TEST_POISON1 || elb->poison2 != TEST_POISON2) {
  52                pr_err("error: bad poison: %#x/%#x\n",
  53                        elb->poison1, elb->poison2);
  54                return -EINVAL;
  55        }
  56        return 0;
  57}
  58
  59static int __init cmp(void *priv, struct list_head *a, struct list_head *b)
  60{
  61        struct debug_el *ela, *elb;
  62
  63        ela = container_of(a, struct debug_el, list);
  64        elb = container_of(b, struct debug_el, list);
  65
  66        check(ela, elb);
  67        return ela->value - elb->value;
  68}
  69
  70static int __init list_sort_test(void)
  71{
  72        int i, count = 1, err = -ENOMEM;
  73        struct debug_el *el;
  74        struct list_head *cur;
  75        LIST_HEAD(head);
  76
  77        pr_debug("start testing list_sort()\n");
  78
  79        elts = kcalloc(TEST_LIST_LEN, sizeof(*elts), GFP_KERNEL);
  80        if (!elts)
  81                return err;
  82
  83        for (i = 0; i < TEST_LIST_LEN; i++) {
  84                el = kmalloc(sizeof(*el), GFP_KERNEL);
  85                if (!el)
  86                        goto exit;
  87
  88                 /* force some equivalencies */
  89                el->value = prandom_u32() % (TEST_LIST_LEN / 3);
  90                el->serial = i;
  91                el->poison1 = TEST_POISON1;
  92                el->poison2 = TEST_POISON2;
  93                elts[i] = el;
  94                list_add_tail(&el->list, &head);
  95        }
  96
  97        list_sort(NULL, &head, cmp);
  98
  99        err = -EINVAL;
 100        for (cur = head.next; cur->next != &head; cur = cur->next) {
 101                struct debug_el *el1;
 102                int cmp_result;
 103
 104                if (cur->next->prev != cur) {
 105                        pr_err("error: list is corrupted\n");
 106                        goto exit;
 107                }
 108
 109                cmp_result = cmp(NULL, cur, cur->next);
 110                if (cmp_result > 0) {
 111                        pr_err("error: list is not sorted\n");
 112                        goto exit;
 113                }
 114
 115                el = container_of(cur, struct debug_el, list);
 116                el1 = container_of(cur->next, struct debug_el, list);
 117                if (cmp_result == 0 && el->serial >= el1->serial) {
 118                        pr_err("error: order of equivalent elements not "
 119                                "preserved\n");
 120                        goto exit;
 121                }
 122
 123                if (check(el, el1)) {
 124                        pr_err("error: element check failed\n");
 125                        goto exit;
 126                }
 127                count++;
 128        }
 129        if (head.prev != cur) {
 130                pr_err("error: list is corrupted\n");
 131                goto exit;
 132        }
 133
 134
 135        if (count != TEST_LIST_LEN) {
 136                pr_err("error: bad list length %d", count);
 137                goto exit;
 138        }
 139
 140        err = 0;
 141exit:
 142        for (i = 0; i < TEST_LIST_LEN; i++)
 143                kfree(elts[i]);
 144        kfree(elts);
 145        return err;
 146}
 147module_init(list_sort_test);
 148MODULE_LICENSE("GPL");
 149