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);

 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 implementations for
 6 * DEBUG_LIST.
 7 */
 8
 9#include <linux/module.h>
10#include <linux/list.h>
 
 
 
11
12/*
13 * Insert a new entry between two known consecutive entries.
14 *
15 * This is only for internal list manipulation where we know
16 * the prev/next entries already!
17 */
18
19void __list_add(struct list_head *new,
20			      struct list_head *prev,
21			      struct list_head *next)
22{
23	WARN(next->prev != prev,
24		"list_add corruption. next->prev should be "
25		"prev (%p), but was %p. (next=%p).\n",
26		prev, next->prev, next);
27	WARN(prev->next != next,
28		"list_add corruption. prev->next should be "
29		"next (%p), but was %p. (prev=%p).\n",
30		next, prev->next, prev);
31	next->prev = new;
32	new->next = next;
33	new->prev = prev;
34	prev->next = new;
35}
36EXPORT_SYMBOL(__list_add);
37
38void __list_del_entry(struct list_head *entry)
39{
40	struct list_head *prev, *next;
41
42	prev = entry->prev;
43	next = entry->next;
44
45	if (WARN(next == LIST_POISON1,
46		"list_del corruption, %p->next is LIST_POISON1 (%p)\n",
47		entry, LIST_POISON1) ||
48	    WARN(prev == LIST_POISON2,
49		"list_del corruption, %p->prev is LIST_POISON2 (%p)\n",
50		entry, LIST_POISON2) ||
51	    WARN(prev->next != entry,
52		"list_del corruption. prev->next should be %p, "
53		"but was %p\n", entry, prev->next) ||
54	    WARN(next->prev != entry,
55		"list_del corruption. next->prev should be %p, "
56		"but was %p\n", entry, next->prev))
57		return;
58
59	__list_del(prev, next);
60}
61EXPORT_SYMBOL(__list_del_entry);
62
63/**
64 * list_del - deletes entry from list.
65 * @entry: the element to delete from the list.
66 * Note: list_empty on entry does not return true after this, the entry is
67 * in an undefined state.
68 */
69void list_del(struct list_head *entry)
70{
71	__list_del_entry(entry);
72	entry->next = LIST_POISON1;
73	entry->prev = LIST_POISON2;
74}
75EXPORT_SYMBOL(list_del);