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 19 void __list_add(struct list_head *new, 20 struct list_head *prev, 21 struct list_head *next) 22 { 23 if (unlikely(next->prev != prev)) { 24 printk(KERN_ERR "list_add corruption. next->prev should be " 25 "prev (%p), but was %p. (next=%p).\n", 26 prev, next->prev, next); 27 BUG(); 28 } 29 if (unlikely(prev->next != next)) { 30 printk(KERN_ERR "list_add corruption. prev->next should be " 31 "next (%p), but was %p. (prev=%p).\n", 32 next, prev->next, prev); 33 BUG(); 34 } 35 next->prev = new; 36 new->next = next; 37 new->prev = prev; 38 prev->next = new; 39 } 40 EXPORT_SYMBOL(__list_add); 41 42 /** 43 * list_del - deletes entry from list. 44 * @entry: the element to delete from the list. 45 * Note: list_empty on entry does not return true after this, the entry is 46 * in an undefined state. 47 */ 48 void list_del(struct list_head *entry) 49 { 50 if (unlikely(entry->prev->next != entry)) { 51 printk(KERN_ERR "list_del corruption. prev->next should be %p, " 52 "but was %p\n", entry, entry->prev->next); 53 BUG(); 54 } 55 if (unlikely(entry->next->prev != entry)) { 56 printk(KERN_ERR "list_del corruption. next->prev should be %p, " 57 "but was %p\n", entry, entry->next->prev); 58 BUG(); 59 } 60 __list_del(entry->prev, entry->next); 61 entry->next = LIST_POISON1; 62 entry->prev = LIST_POISON2; 63 } 64 EXPORT_SYMBOL(list_del); 65