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	CHECK_DATA_CORRUPTION(next->prev != prev,
24		"list_add corruption. next->prev should be prev (%p), but was %p. (next=%p).\n",
25		prev, next->prev, next);
26	CHECK_DATA_CORRUPTION(prev->next != next,
27		"list_add corruption. prev->next should be next (%p), but was %p. (prev=%p).\n",
28		next, prev->next, prev);
29	CHECK_DATA_CORRUPTION(new == prev || new == next,
30		"list_add double add: new=%p, prev=%p, next=%p.\n",
31		new, prev, next);
 
 
 
 
 
32
33	return true;
34}
35EXPORT_SYMBOL(__list_add_valid);
36
37bool __list_del_entry_valid(struct list_head *entry)
 
38{
39	struct list_head *prev, *next;
40
41	prev = entry->prev;
42	next = entry->next;
43
44	CHECK_DATA_CORRUPTION(next == LIST_POISON1,
45		"list_del corruption, %p->next is LIST_POISON1 (%p)\n",
46		entry, LIST_POISON1);
47	CHECK_DATA_CORRUPTION(prev == LIST_POISON2,
48		"list_del corruption, %p->prev is LIST_POISON2 (%p)\n",
49		entry, LIST_POISON2);
50	CHECK_DATA_CORRUPTION(prev->next != entry,
51		"list_del corruption. prev->next should be %p, but was %p\n",
52		entry, prev->next);
53	CHECK_DATA_CORRUPTION(next->prev != entry,
54		"list_del corruption. next->prev should be %p, but was %p\n",
55		entry, next->prev);
56	return true;
 
 
 
 
57
 
58}
59EXPORT_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 validation and error reporting for
 6 * LIST_HARDENED and DEBUG_LIST.
 7 */
 8
 9#include <linux/export.h>
10#include <linux/list.h>
11#include <linux/bug.h>
12#include <linux/kernel.h>
13#include <linux/rculist.h>
14
15/*
16 * Check that the data structures for the list manipulations are reasonably
17 * valid. Failures here indicate memory corruption (and possibly an exploit
18 * attempt).
19 */
20
21__list_valid_slowpath
22bool __list_add_valid_or_report(struct list_head *new, struct list_head *prev,
23				struct list_head *next)
24{
25	if (CHECK_DATA_CORRUPTION(prev == NULL,
26			"list_add corruption. prev is NULL.\n") ||
27	    CHECK_DATA_CORRUPTION(next == NULL,
28			"list_add corruption. next is NULL.\n") ||
29	    CHECK_DATA_CORRUPTION(next->prev != prev,
30			"list_add corruption. next->prev should be prev (%px), but was %px. (next=%px).\n",
31			prev, next->prev, next) ||
32	    CHECK_DATA_CORRUPTION(prev->next != next,
33			"list_add corruption. prev->next should be next (%px), but was %px. (prev=%px).\n",
34			next, prev->next, prev) ||
35	    CHECK_DATA_CORRUPTION(new == prev || new == next,
36			"list_add double add: new=%px, prev=%px, next=%px.\n",
37			new, prev, next))
38		return false;
39
40	return true;
41}
42EXPORT_SYMBOL(__list_add_valid_or_report);
43
44__list_valid_slowpath
45bool __list_del_entry_valid_or_report(struct list_head *entry)
46{
47	struct list_head *prev, *next;
48
49	prev = entry->prev;
50	next = entry->next;
51
52	if (CHECK_DATA_CORRUPTION(next == NULL,
53			"list_del corruption, %px->next is NULL\n", entry) ||
54	    CHECK_DATA_CORRUPTION(prev == NULL,
55			"list_del corruption, %px->prev is NULL\n", entry) ||
56	    CHECK_DATA_CORRUPTION(next == LIST_POISON1,
57			"list_del corruption, %px->next is LIST_POISON1 (%px)\n",
58			entry, LIST_POISON1) ||
59	    CHECK_DATA_CORRUPTION(prev == LIST_POISON2,
60			"list_del corruption, %px->prev is LIST_POISON2 (%px)\n",
61			entry, LIST_POISON2) ||
62	    CHECK_DATA_CORRUPTION(prev->next != entry,
63			"list_del corruption. prev->next should be %px, but was %px. (prev=%px)\n",
64			entry, prev->next, prev) ||
65	    CHECK_DATA_CORRUPTION(next->prev != entry,
66			"list_del corruption. next->prev should be %px, but was %px. (next=%px)\n",
67			entry, next->prev, next))
68		return false;
69
70	return true;
71}
72EXPORT_SYMBOL(__list_del_entry_valid_or_report);