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 |
22 | bool __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 | } |
42 | EXPORT_SYMBOL(__list_add_valid_or_report); |
43 | |
44 | __list_valid_slowpath |
45 | bool __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 | } |
72 | EXPORT_SYMBOL(__list_del_entry_valid_or_report); |
73 | |