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 #include <linux/kernel.h> 12 13 /* 14 * Insert a new entry between two known consecutive entries. 15 * 16 * This is only for internal list manipulation where we know 17 * the prev/next entries already! 18 */ 19 20 void __list_add(struct list_head *new, 21 struct list_head *prev, 22 struct list_head *next) 23 { 24 WARN(next->prev != prev, 25 "list_add corruption. next->prev should be " 26 "prev (%p), but was %p. (next=%p).\n", 27 prev, next->prev, next); 28 WARN(prev->next != next, 29 "list_add corruption. prev->next should be " 30 "next (%p), but was %p. (prev=%p).\n", 31 next, prev->next, prev); 32 next->prev = new; 33 new->next = next; 34 new->prev = prev; 35 prev->next = new; 36 } 37 EXPORT_SYMBOL(__list_add); 38 39 void __list_del_entry(struct list_head *entry) 40 { 41 struct list_head *prev, *next; 42 43 prev = entry->prev; 44 next = entry->next; 45 46 if (WARN(next == LIST_POISON1, 47 "list_del corruption, %p->next is LIST_POISON1 (%p)\n", 48 entry, LIST_POISON1) || 49 WARN(prev == LIST_POISON2, 50 "list_del corruption, %p->prev is LIST_POISON2 (%p)\n", 51 entry, LIST_POISON2) || 52 WARN(prev->next != entry, 53 "list_del corruption. prev->next should be %p, " 54 "but was %p\n", entry, prev->next) || 55 WARN(next->prev != entry, 56 "list_del corruption. next->prev should be %p, " 57 "but was %p\n", entry, next->prev)) 58 return; 59 60 __list_del(prev, next); 61 } 62 EXPORT_SYMBOL(__list_del_entry); 63 64 /** 65 * list_del - deletes entry from list. 66 * @entry: the element to delete from the list. 67 * Note: list_empty on entry does not return true after this, the entry is 68 * in an undefined state. 69 */ 70 void list_del(struct list_head *entry) 71 { 72 __list_del_entry(entry); 73 entry->next = LIST_POISON1; 74 entry->prev = LIST_POISON2; 75 } 76 EXPORT_SYMBOL(list_del); 77