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 WARN(next->prev != prev, 24 "list_add corruption. next->prev should be " 25 "prev (%p), but was %p. (next=%p).\n", 26 prev, next->prev, next); 27 WARN(prev->next != next, 28 "list_add corruption. prev->next should be " 29 "next (%p), but was %p. (prev=%p).\n", 30 next, prev->next, prev); 31 next->prev = new; 32 new->next = next; 33 new->prev = prev; 34 prev->next = new; 35 } 36 EXPORT_SYMBOL(__list_add); 37 38 void __list_del_entry(struct list_head *entry) 39 { 40 struct list_head *prev, *next; 41 42 prev = entry->prev; 43 next = entry->next; 44 45 if (WARN(next == LIST_POISON1, 46 "list_del corruption, %p->next is LIST_POISON1 (%p)\n", 47 entry, LIST_POISON1) || 48 WARN(prev == LIST_POISON2, 49 "list_del corruption, %p->prev is LIST_POISON2 (%p)\n", 50 entry, LIST_POISON2) || 51 WARN(prev->next != entry, 52 "list_del corruption. prev->next should be %p, " 53 "but was %p\n", entry, prev->next) || 54 WARN(next->prev != entry, 55 "list_del corruption. next->prev should be %p, " 56 "but was %p\n", entry, next->prev)) 57 return; 58 59 __list_del(prev, next); 60 } 61 EXPORT_SYMBOL(__list_del_entry); 62 63 /** 64 * list_del - deletes entry from list. 65 * @entry: the element to delete from the list. 66 * Note: list_empty on entry does not return true after this, the entry is 67 * in an undefined state. 68 */ 69 void list_del(struct list_head *entry) 70 { 71 __list_del_entry(entry); 72 entry->next = LIST_POISON1; 73 entry->prev = LIST_POISON2; 74 } 75 EXPORT_SYMBOL(list_del); 76