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 20 bool __list_add_valid(struct list_head *new, struct list_head *prev, 21 struct list_head *next) 22 { 23 if (CHECK_DATA_CORRUPTION(prev == NULL, 24 "list_add corruption. prev is NULL.\n") || 25 CHECK_DATA_CORRUPTION(next == NULL, 26 "list_add corruption. next is NULL.\n") || 27 CHECK_DATA_CORRUPTION(next->prev != prev, 28 "list_add corruption. next->prev should be prev (%px), but was %px. (next=%px).\n", 29 prev, next->prev, next) || 30 CHECK_DATA_CORRUPTION(prev->next != next, 31 "list_add corruption. prev->next should be next (%px), but was %px. (prev=%px).\n", 32 next, prev->next, prev) || 33 CHECK_DATA_CORRUPTION(new == prev || new == next, 34 "list_add double add: new=%px, prev=%px, next=%px.\n", 35 new, prev, next)) 36 return false; 37 38 return true; 39 } 40 EXPORT_SYMBOL(__list_add_valid); 41 42 bool __list_del_entry_valid(struct list_head *entry) 43 { 44 struct list_head *prev, *next; 45 46 prev = entry->prev; 47 next = entry->next; 48 49 if (CHECK_DATA_CORRUPTION(next == NULL, 50 "list_del corruption, %px->next is NULL\n", entry) || 51 CHECK_DATA_CORRUPTION(prev == NULL, 52 "list_del corruption, %px->prev is NULL\n", entry) || 53 CHECK_DATA_CORRUPTION(next == LIST_POISON1, 54 "list_del corruption, %px->next is LIST_POISON1 (%px)\n", 55 entry, LIST_POISON1) || 56 CHECK_DATA_CORRUPTION(prev == LIST_POISON2, 57 "list_del corruption, %px->prev is LIST_POISON2 (%px)\n", 58 entry, LIST_POISON2) || 59 CHECK_DATA_CORRUPTION(prev->next != entry, 60 "list_del corruption. prev->next should be %px, but was %px. (prev=%px)\n", 61 entry, prev->next, prev) || 62 CHECK_DATA_CORRUPTION(next->prev != entry, 63 "list_del corruption. next->prev should be %px, but was %px. (next=%px)\n", 64 entry, next->prev, next)) 65 return false; 66 67 return true; 68 69 } 70 EXPORT_SYMBOL(__list_del_entry_valid); 71