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 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 } 35 EXPORT_SYMBOL(__list_add_valid); 36 37 bool __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 } 59 EXPORT_SYMBOL(__list_del_entry_valid); 60