1/*
2 * Copyright 2006, Red Hat, Inc., Dave Jones
3 * Released under the General Public License (GPL).
4 *
5 * This file contains the linked list validation for DEBUG_LIST.
6 */
7
8#include <linux/export.h>
9#include <linux/list.h>
10#include <linux/bug.h>
11#include <linux/kernel.h>
12#include <linux/rculist.h>
13
14/*
15 * Check that the data structures for the list manipulations are reasonably
16 * valid. Failures here indicate memory corruption (and possibly an exploit
17 * attempt).
18 */
19
20bool __list_add_valid(struct list_head *new, struct list_head *prev,
21 struct list_head *next)
22{
23 if (CHECK_DATA_CORRUPTION(next->prev != prev,
24 "list_add corruption. next->prev should be prev (%px), but was %px. (next=%px).\n",
25 prev, next->prev, next) ||
26 CHECK_DATA_CORRUPTION(prev->next != next,
27 "list_add corruption. prev->next should be next (%px), but was %px. (prev=%px).\n",
28 next, prev->next, prev) ||
29 CHECK_DATA_CORRUPTION(new == prev || new == next,
30 "list_add double add: new=%px, prev=%px, next=%px.\n",
31 new, prev, next))
32 return false;
33
34 return true;
35}
36EXPORT_SYMBOL(__list_add_valid);
37
38bool __list_del_entry_valid(struct list_head *entry)
39{
40 struct list_head *prev, *next;
41
42 prev = entry->prev;
43 next = entry->next;
44
45 if (CHECK_DATA_CORRUPTION(next == LIST_POISON1,
46 "list_del corruption, %px->next is LIST_POISON1 (%px)\n",
47 entry, LIST_POISON1) ||
48 CHECK_DATA_CORRUPTION(prev == LIST_POISON2,
49 "list_del corruption, %px->prev is LIST_POISON2 (%px)\n",
50 entry, LIST_POISON2) ||
51 CHECK_DATA_CORRUPTION(prev->next != entry,
52 "list_del corruption. prev->next should be %px, but was %px\n",
53 entry, prev->next) ||
54 CHECK_DATA_CORRUPTION(next->prev != entry,
55 "list_del corruption. next->prev should be %px, but was %px\n",
56 entry, next->prev))
57 return false;
58
59 return true;
60
61}
62EXPORT_SYMBOL(__list_del_entry_valid);
63